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Archive for the ‘Population Health Management, Nutrition and Phytochemistry’ Category


Decline in Sperm Count – Epigenetics, Well-being and the Significance for Population Evolution and Demography

 

Dr. Marc Feldman, Expert Opinion on the significance of Sperm Count Decline on the Future of Population Evolution and Demography

Dr. Sudipta Saha, Effects of Sperm Quality and Quantity on Human Reproduction

Dr. Aviva Lev-Ari, Psycho-Social Effects of Poverty, Unemployment and Epigenetics on Male Well-being, Physiological Conditions affecting Sperm Quality and Quantity

 

Recent studies concluded via rigorous and comprehensive analysis found that Sperm Count (SC) declined 52.4% between 1973 and 2011 among unselected men from western countries, with no evidence of a ‘leveling off’ in recent years. Declining mean SC implies that an increasing proportion of men have sperm counts below any given threshold for sub-fertility or infertility. The high proportion of men from western countries with concentration below 40 million/ml is particularly concerning given the evidence that SC below this threshold is associated with a decreased monthly probability of conception.

1.Temporal trends in sperm count: a systematic review and meta-regression analysis 

Hagai Levine, Niels Jørgensen, Anderson Martino‐Andrade, Jaime Mendiola, Dan Weksler-Derri, Irina Mindlis, Rachel Pinotti, Shanna H SwanHuman Reproduction Update, July 25, 2017, doi:10.1093/humupd/dmx022.

Link: https://academic.oup.com/humupd/article-lookup/doi/10.1093/humupd/dmx022.

2. Sperm Counts Are Declining Among Western Men – Interview with Dr. Hagai Levine

https://news.afhu.org/news/sperm-counts-are-declining-among-western-men?utm_source=Master+List&utm_campaign=dca529d919-EMAIL_CAMPAIGN_2017_07_27&utm_medium=email&utm_term=0_343e19a421-dca529d919-92801633

3. Trends in Sperm Count – Biological Reproduction Observations

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

4. Long, mysterious strips of RNA contribute to low sperm count – Long non-coding RNAs can be added to the group of possible non-structural effects, possibly epigenetic, that might regulate sperm counts.

http://casemed.case.edu/cwrumed360/news-releases/release.cfm?news_id=689

https://scienmag.com/long-mysterious-strips-of-rna-contribute-to-low-sperm-count/

Dynamic expression of long non-coding RNAs reveals their potential roles in spermatogenesis and fertility

Published: 29 July 2017
Thus, we postulated that some lncRNAs may also impact mammalian spermatogenesis and fertility. In this study, we identified a dynamic expression pattern of lncRNAs during murine spermatogenesis. Importantly, we identified a subset of lncRNAs and very few mRNAs that appear to escape meiotic sex chromosome inactivation (MSCI), an epigenetic process that leads to the silencing of the X- and Y-chromosomes at the pachytene stage of meiosis. Further, some of these lncRNAs and mRNAs show strong testis expression pattern suggesting that they may play key roles in spermatogenesis. Lastly, we generated a mouse knock out of one X-linked lncRNA, Tslrn1 (testis-specific long non-coding RNA 1), and found that males carrying a Tslrn1 deletion displayed normal fertility but a significant reduction in spermatozoa. Our findings demonstrate that dysregulation of specific mammalian lncRNAs is a novel mechanism of low sperm count or infertility, thus potentially providing new biomarkers and therapeutic strategies.

This article presents two perspectives on the potential effects of Sperm Count decline.

One Perspective identifies Epigenetics and male well-being conditions

  1. as a potential explanation to the Sperm Count decline, and
  2. as evidence for decline in White male longevity in certain geographies in the US since the mid 80s.

The other Perspective, evaluates if Sperm Count Decline would have or would not have a significant long term effects on Population Evolution and Demography.

The Voice of Prof. Marc Feldman, Stanford University – Long term significance of Sperm Count Decline on Population Evolution and Demography

Poor sperm count appears to be associated with such demographic statistics as life expectancy (1), infertility (2), and morbidity (3,4). The meta-analysis by Levine et al. (5) focuses on the change in sperm count of men from North America, Europe, Australia, and New Zealand, and shows a more than 50% decline between 1973 and 2011. Although there is no analysis of potential environmental or lifestyle factors that could contribute to the estimated decline in sperm count, Levine et al. speculate that this decline could be a signal for other negative changes in men’s health.

Because this study focuses mainly on Western men, this remarkable decline in sperm count is difficult to associate with any change in actual fertility, that is, number of children born per woman. The total fertility rate in Europe, especially Italy, Spain, and Germany, has slowly declined, but age at first marriage has increased at the same time, and this increase may be more due to economic factors than physiological changes.

Included in Levine et al.’s analysis was a set of data from “Other” countries from South America, Asia, and Africa. Sperm count in men from these countries did not show significant trends, which is interesting because there have been strong fertility declines in Asia and Africa over the same period, with corresponding increases in life expectancy (once HIV is accounted for).

What can we say about the evolutionary consequences for humans of this decrease? The answer depends on the minimal number of sperm/ml/year that would be required to maintain fertility (per woman) at replacement level, say 2.1 children, over a woman’s lifetime. Given the smaller number of ova produced per woman, a change in the ovulation statistics of women would be likely to play a larger role in the total fertility rate than the number of sperm/ejaculate/man. In other words, sperm count alone, absent other effects on mortality during male reproductive years, is unlikely to tell us much about human evolution.

Further, the major declines in fertility over the 38-year period covered by Levine et al. occurred in China, India, and Japan. Chinese fertility has declined to less than 1.5 children per woman, and in Japan it has also been well below 1.5 for some time. These declines have been due to national policies and economic changes, and are therefore unlikely to signal genetic changes that would have evolutionary ramifications. It is more likely that cultural changes will continue to be the main drivers of fertility change.

The fastest growing human populations are in the Muslim world, where fertility control is not nearly as widely practiced as in the West or Asia. If this pattern were to continue for a few more generations, the cultural evolutionary impact would swamp any effects of potentially declining sperm count.

On the other hand, if the decline in sperm count were to be discovered to be associated with genetic and/or epigenetic phenotypic effects on fetuses, newborns, or pre-reproductive humans, for example, due to stress or obesity, then there would be cause to worry about long-term evolutionary problems. As Levine et al. remark, “decline in sperm count might be considered as a ‘canary in the coal mine’ for male health across the lifespan”. But to date, there is little evidence that the evolutionary trajectory of humans constitutes such a “coal mine”.

References

  1. Jensen TK, Jacobsen R, Christensen K, Nielsen NC, Bostofte E. 2009. Good semen quality and life expectancy: a cohort study of 43,277 men. Am J Epidemiol 170: 559-565.
  2. Eisenberg ML, Li S, Behr B, Cullen MR, Galusha D, Lamb DJ, Lipshultz LI. 2014. Semen quality, infertility and mortality in the USA. Hum Reprod 29: 1567-1574.
  3. Eisenberg ML, Li S, Cullen MR, Baker LC. 2016. Increased risk of incident chronic medical conditions in infertile men: analysis of United States claims data. Fertil Steril 105: 629-636.
  4. Latif T, Kold Jensen T, Mehlsen J, Holmboe SA, Brinth L, Pors K, Skouby SO, Jorgensen N, Lindahl-Jacobsen R. Semen quality is a predictor of subsequent morbidity. A Danish cohort study of 4,712 men with long-term follow-up. Am J Epidemiol. Doi: 10.1093/aje/kwx067. (Epub ahead of print]
  5. Levine H, Jorgensen N, Martino-Andrade A, Mendiola J, Weksler-Derri D, Mindlis I, Pinotti R, Swan SH. 2017. Temporal trends in sperm count: a systematic review and meta-regression analysis. Hum Reprod Update pp. 1-14. Doi: 10.1093/humupd/dmx022.

SOURCE

From: Marcus W Feldman <mfeldman@stanford.edu>

Date: Monday, July 31, 2017 at 8:10 PM

To: Aviva Lev-Ari <aviva.lev-ari@comcast.net>

Subject: Fwd: text of sperm count essay

Psycho-Social Effects of Poverty, Unemployment and Epigenetics on Male Well-being, Physiological Conditions as POTENTIAL effects on Sperm Quality and Quantity and Evidence of its effects on Male Longevity

The Voice of Carol GrahamSergio Pinto, and John Juneau II , Monday, July 24, 2017, Report from the Brookings Institute

  1. The IMPACT of Well-being, Stress induced by Worry, Pain, Perception of Hope related to Employment and Lack of employment on deterioration of Physiological Conditions as evidence by Decrease Longevity

  2. Epigenetics and Environmental Factors

The geography of desperation in America

Carol GrahamSergio Pinto, and John Juneau II Monday, July 24, 2017, Report from the Brookings Institute

In recent work based on our well-being metrics in the Gallup polls and on the mortality data from the Centers for Disease Control and Prevention, we find a robust association between lack of hope (and high levels of worry) among poor whites and the premature mortality rates, both at the individual and metropolitan statistical area (MSA) levels. Yet we also find important differences across places. Places come with different economic structures and identities, community traits, physical environments and much more. In the maps below, we provide a visual picture of the differences in in hope for the future, worry, and pain across race-income cohorts across U.S. states. We attempted to isolate the specific role of place, controlling for economic, socio-demographic, and other variables.

One surprise is the low level of optimism and high level of worry in the minority dense and generally “blue” state of California, and high levels of pain and worry in the equally minority dense and “blue” states of New York and Massachusetts. High levels of income inequality in these states may explain these patterns, as may the nature of jobs that poor minorities hold.

We cannot answer many questions at this point. What is it about the state of Washington, for example, that is so bad for minorities across the board? Why is Florida so much better for poor whites than it is for poor minorities? Why is Nevada “good” for poor white optimism but terrible for worry for the same group? One potential issue—which will enter into our future analysis—is racial segregation across places. We hope that the differences that we have found will provoke future exploration. Readers of this piece may have some contributions of their own as they click through the various maps, and we welcome their input. Better understanding the role of place in the “crisis” of despair facing our country is essential to finding viable solutions, as economic explanations, while important, alone are not enough.

https://www.brookings.edu/research/the-geography-of-desperation-in-america/?utm_medium=social&utm_source=facebook&utm_campaign=global

 

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Blood Pressure Lowering

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Data analysis and publication of landmark NIH blood pressure study confirm that lower blood pressure target can reduce cardiovascular disease, deaths

http://www.nih.gov/news-events/news-releases/data-analysis-publication-landmark-nih-blood-pressure-study-confirm-lower-blood-pressure-target-can-reduce-cardiovascular-disease-deaths

 

NIH-supported researchers are reporting more details on a landmark study that announced preliminary findings in September showing a lower blood pressure target can save lives and reduce the risk of cardiovascular disease in a group of non-diabetic adults 50 years and older with high blood pressure. Results of the Systolic Blood Pressure Intervention Trial (SPRINT) appear in the current online issue of the New England Journal of Medicine and were discussed today at the American Heart Association 2015 Scientific Sessions in Orlando.

The study confirms that, in adults 50 years and older with high blood pressure, targeting a systolic blood pressure of less than 120 millimeters of mercury (mm Hg) reduced rates of cardiovascular events, such as heart attack and heart failure, as well as stroke, by 25 percent. Additionally, this target reduced the risk of death by 27 percent—as compared to a target systolic pressure of 140 mm Hg.

“SPRINT is part of a proud legacy of NIH-funded clinical trials that will change clinical practice and save lives for decades to come. These results reinforce the compelling public health importance of enhancing the awareness, treatment and control of hypertension in this country and around the world,” said Gary H. Gibbons, M.D., director of the National Heart, Lung, and Blood Institute (NHLBI), the primary sponsor of SPRINT.

The SPRINT study, which began in the fall of 2009, included more than 9,300 participants age 50 and older, recruited from about 100 medical centers and clinical practices throughout the United States and Puerto Rico. About 36 percent of participants were women, 58 percent were white, 30 percent were African-American, and 11 percent were Hispanic. The SPRINT study did not include patients with diabetes, prior stroke, or polycystic kidney disease, as other NIH trials were studying those particular populations. Approximately 28 percent were 75 or older and 28 percent had chronic kidney disease. The study tested a strategy of using blood pressure medications to achieve the targeted goals of less than 120 mm Hg (intensive treatment group) versus 140 mm Hg (standard treatment group). The NIH stopped the blood pressure intervention in August—a year earlier than planned—after it became apparent that this more intensive intervention was beneficial.

“When the benefits of the stronger intervention became apparent in SPRINT, we made a commitment to rapid public health communication and peer-reviewed publication of the study results,” Dr. Gibbons said. “We are pleased to present the details of the study’s potentially lifesaving findings at this time.”

In their report, investigators provided detailed data showing that both cardiovascular deaths and overall deaths were lower in the intensive treatment group.

Certain types of serious consequences were more common in the intensive group, including low blood pressure, fainting, electrolyte abnormalities, and acute kidney damage. However, other serious adverse events associated with lower blood pressure, such as slow heart rate and falls with injuries, did not increase in the intensive group. In patients with chronic kidney disease, there was no difference in the rate of serious decline in kidney function between the two blood pressure goal groups.

“The benefits of more intensive blood pressure lowering exceeded the potential for harm, regardless of gender or race/ethnicity,” said study co-author Paul Whelton, M.D., of Tulane University School of Public Health and Tropical Medicine in New Orleans, Louisiana. He is chair of the SPRINT Steering Committee.

In addition to its primary cardiovascular outcome, the study continues to examine kidney disease, cognitive function, and dementia among the SPRINT participants; however, these results are not yet available as additional information will be collected and analyzed over the next year.

“Although the study provides strong evidence that a lower blood pressure target saves lives, patients and their health care providers may want to wait to see how guideline groups incorporate this study and other scientific reports into any future hypertension guidelines. In the meantime, patients should talk to their health care providers to determine whether this lower goal is best for their individual care,” said study co-author Lawrence Fine, M.D., Chief, Clinical Applications and Prevention Branch at NHLBI.

“It’s also important to remember that healthy lifestyle changes can make a difference in controlling high blood pressure,” Dr. Fine added. He emphasized the importance of following a healthy diet, being physically active, maintaining a healthy weight, as well as learning to check your blood pressure.

In addition to primary sponsorship by the NHLBI, SPRINT is co-sponsored by the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute of Neurological Disorders and Stroke, and the National Institute on Aging.

Part of the National Institutes of Health, the National Heart, Lung, and Blood Institute (NHLBI) plans, conducts, and supports research related to the causes, prevention, diagnosis, and treatment of heart, blood vessel, lung, and blood diseases; and sleep disorders. The Institute also administers national health education campaigns on women and heart disease, healthy weight for children, and other topics. NHLBI press releases and other materials are available online at http://www.nhlbi.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

NIH…Turning Discovery Into Health®

Landmark NIH study shows intensive blood pressure management may save lives

Embargoed for Release:

September 11, 2015, 10:30 AM EDT

Lower blood pressure target greatly reduces cardiovascular complications and deaths in older adults

More intensive management of high blood pressure, below a commonly recommended blood pressure target, significantly reduces rates of cardiovascular disease, and lowers risk of death in a group of adults 50 years and older with high blood pressure. This is according to the initial results of a landmark clinical trial sponsored by the National Institutes of Health called the Systolic Blood Pressure Intervention Trial (SPRINT). The intervention in this trial, which carefully adjusts the amount or type of blood pressure medication to achieve a target systolicpressure of 120 millimeters of mercury (mm Hg), reduced rates of cardiovascular events, such as heart attack and heart failure, as well as stroke, by almost a third and the risk of death by almost a quarter, as compared to the target systolic pressure of 140 mm Hg.

“This study provides potentially lifesaving information that will be useful to health care providers as they consider the best treatment options for some of their patients, particularly those over the age of 50,” said Gary H. Gibbons, M.D., director of the National Heart, Lung, and Blood Institute (NHLBI), the primary sponsor of SPRINT. “We are delighted to have achieved this important milestone in the study in advance of the expected closure date for the SPRINT trial and look forward to quickly communicating the results to help inform patient care and the future development of evidence-based clinical guidelines.”

High blood pressure, or hypertension, is a leading risk factor for heart disease, stroke, kidney failure, and other health problems. An estimated 1 in 3 people in the United States has high blood pressure.

The SPRINT study evaluates the benefits of maintaining a new target for systolic blood pressure, the top number in a blood pressure reading, among a group of patients 50 years and older at increased risk for heart disease or who have kidney disease. A systolic pressure of 120 mm Hg, maintained by this more intensive blood pressure intervention, could ultimately help save lives among adults age 50 and older who have a combination of high blood pressure and at least one additional risk factor for heart disease, the investigators say.

The SPRINT study, which began in the fall of 2009, includes more than 9,300 participants age 50 and older, recruited from about 100 medical centers and clinical practices throughout the United States and Puerto Rico. It is the largest study of its kind to date to examine how maintaining systolic blood pressure at a lower than currently recommended level will impact cardiovascular and kidney diseases. NIH stopped the blood pressure intervention earlier than originally planned in order to quickly disseminate the significant preliminary results.

The study population was diverse and included women, racial/ethnic minorities, and the elderly.  The investigators point out that the SPRINT study did not include patients with diabetes, prior stroke, or polycystic kidney disease, as other research included those populations.

When SPRINT was designed, the well-established clinical guidelines recommended a systolic blood pressure of less than 140 mm Hg for healthy adults and 130 mm Hg for adults with kidney disease or diabetes. Investigators designed SPRINT to determine the potential benefits of achieving systolic blood pressure of less than 120 mm Hg for hypertensive adults 50 years and older who are at risk for developing heart disease or kidney disease.

Between 2010 and 2013, the SPRINT investigators randomly divided the study participants into two groups that differed according to targeted levels of blood pressure control. The standard group received blood pressure medications to achieve a target of less than 140 mm Hg. They received an average of two different blood pressure medications. The intensive treatment group received medications to achieve a target of less than 120 mm Hg and received an average of three medications.

“Our results provide important evidence that treating blood pressure to a lower goal in older or high-risk patients can be beneficial and yield better health results overall,” said Lawrence Fine, M.D., chief, Clinical Applications and Prevention Branch at NHLBI. “But patients should talk to their doctor to determine whether this lower goal is best for their individual care.”

The study is also examining kidney disease, cognitive function, and dementia among the patients; however, those results are still under analysis and are not yet available as additional information will be collected over the next year.  The primary results of the trial will be published within the next few months.

In addition to primary sponsorship by the NHLBI, SPRINT is co-sponsored by the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute of Neurological Disorders and Stroke, and the National Institute on Aging.

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The good, the bad and the ugly of sulfur and volcanic activity

Larry H Bernstein, MD, FCAP, Curator

LPBI

 

Climate change deniers have promulgated much ignorance about the planet and our life on earth.  Nevertheless, I shall deal with geophysical and geochemical issues and indirectly, climate change in this portion of the discussion.  The good, the bad, and the ugly has everything to due with the elements and to life on earth.  This is the case, regardless of claims propagated by the tobacco and the carbon fuels interests.  I shall proceed as I have done in the previous discussions.

Is a Lack of Water to Blame for the Conflict in Syria?

A 2006 drought pushed Syrian farmers to migrate to urban centers, setting the stage for massive uprisings

By Joshua Hammer

SMITHSONIAN MAGAZINE

http://www.smithsonianmag.com/innovation/is-a-lack-of-water-to-blame-for-the-conflict-in-syria-72513729

 

An Iraqi girl stands on former marshland, drained in the 1990s because of politically motivated water policies. (Essam Al-Sudani / AFP / Getty Images)
http://thumbs.media.smithsonianmag.com//filer/Scare-Tactics-Iraqi-girl-631.jpg__800x600_q85_crop.jpg

The world’s earliest documented water war happened 4,500 years ago, when the armies of Lagash and Umma, city-states near the junction of the Tigris and Euphrates rivers, battled with spears and chariots after Umma’s king drained an irrigation canal leading from the Tigris. “Enannatum, ruler of Lagash, went into battle,” reads an account carved into an ancient stone cylinder, and “left behind 60 soldiers [dead] on the bank of the canal.”

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Water loss documented by the Gravity Recovery and Climate Experiment (GRACE), a pair of satellites operated by NASA and Germany’s aerospace center, suggests water-related conflict could be brewing on the riverbank again. GRACE measured groundwater usage between 2003 and 2009 and found that the Tigris-Euphrates Basin—comprising Turkey, Syria, Iraq and western Iran—is losing water faster than any other place in the world except northern India . During those six years, 117 million acre-feet of stored freshwater vanished from the region as a result of dwindling rainfall and poor water management policies. That’s equal to all the water in the Dead Sea. GRACE’s director, Jay Famiglietti, a hydrologist at the University of California, Irvine, calls the data “alarming.”

While the scientists captured dropping water levels, political experts have observed rising tensions. In Iraq, the absence of a strong government since 2003, drought and shrinking aquifers have led to a recent spate of assassinations of irrigation department officials and clashes between rural clans. Some experts say that these local feuds could escalate into full-scale armed conflicts .

In Syria, a devastating drought beginning in 2006 forced many farmers to abandon their fields and migrate to urban centers. There’s some evidence that the migration fueled the civil war there, in which 80,000 people have died. “You had a lot of angry, unemployed men helping to trigger a revolution,” says Aaron Wolf, a water management expert at Oregon State University, who frequently visits the Middle East.

Tensions between nations are also high. Since 1975, Turkey’s dam and hydro­power construction has cut water flow to Iraq by 80 percent and to Syria by 40 percent. Syria and Iraq have accused Turkey of hoarding water.

Hydrologists say that the countries need to find alternatives to sucking the aquifers dry—perhaps recycling wastewater or introducing desalination—and develop equitable ways of sharing their rivers. “Water doesn’t know political boundaries. People have to get together and work,” Famiglietti says. One example lies nearby, in an area not known for cross-border cooperation. Israeli and Jordanian officials met last year for the first time in two decades to discuss rehabilitating the nearly dry Jordan River, and Israel has agreed to release freshwater down the river.

“It could be a model” for the Tigris-Euphrates region, says Gidon Bromberg, a co-director of Friends of the Earth Middle East, who helped get the countries together. Wolf, too, remains optimistic, noting that stress can encourage compromise.

History might suggest a way: The world’s first international water treaty, a cuneiform tablet now hanging in the Louvre, ended the war between Lagash and Umma.

 

http://static.guim.co.uk/ni/1404220722088/Iraq_water_dams.svg

“Rebel forces are targeting water installations to cut off supplies to the largely Shia south of Iraq,” says Matthew Machowski, a Middle East security researcher at the UK houses of parliament and Queen Mary University of London.

“It is already being used as an instrument of war by all sides. One could claim that controlling water resources in Iraq is even more important than controlling the oil refineries, especially in summer. Control of the water supply is fundamentally important. Cut it off and you create great sanitation and health crises,” he said

Isis now controls the Samarra barrage west of Baghdad on the River Tigris and areas around the giant Mosul Dam, higher up on the same river. Because much of Kurdistan depends on the dam, it is strongly defended by Kurdish peshmerga forces and is unlikely to fall without a fierce fight, says Machowski.

Iraqi troops were rushed to defend the massive 8km-long Haditha Dam and its hydroelectrical works on the Euphrates to stop it falling into the hands of Isis forces. Were the dam to fall, say analysts, Isis would control much of Iraq’s electricity and the rebels might fatally tighten their grip on Baghdad.

Isis fighters in Fallujah captured the smaller Nuaimiyah Dam on the Euphrates and deliberately diverted its water to “drown” government forces in the surrounding area. Millions of people in the cities of Karbala, Najaf, Babylon and Nasiriyah had their water cut off but the town of Abu Ghraib was catastrophically flooded along with farms and villages over 200 square miles. According to the UN, around 12,000 families lost their homes.

Earlier, Kurdish forces reportedly diverted water supplies from the Mosul Dam. Equally, Turkey has been accused of reducing flows to the giant Lake Assad, Syria’s largest body of fresh water, to cut off supplies to Aleppo, and Isis forces have reportedly targeted water supplies in the refugee camps set up for internally displaced people.

Iraqis fled from Mosul after Isis cut off power and water and only returned when they were restored, says Machowski. “When they restored water supplies to Mosul, the Sunnis saw it as liberation. Control of water resources in the Mosul area is one reason why people returned,” said Machowski.

Both Isis forces and President Assad’s army are said to have used water tactics to control the city of Aleppo. The Tishrin Dam on the Euphrates, 60 miles east of the city, was captured by Isis in November 2012.

“The deliberate targeting of water supply networks … is now a daily occurrence in the conflict. The water pumping station in Al-Khafsah, Aleppo, stopped working on 10 May, cutting off water supply to half of the city.

https://i.guim.co.uk/img/static/sys-images/Guardian/Pix/pictures/2014/7/2/1404300629581/

A satellite view showing the two main rivers running from Turkey through Syria and Iraq. Credits: MODIS/NASA

The Euphrates River, the Middle East’s second longest river, and the Tigris, have historically been at the centre of conflict. In the 1980s, Saddam Hussein drained 90% of the vast Mesopotamian marshes that were fed by the two rivers to punish the Shias who rose up against his regime. Since 1975, Turkey’s dam and hydropower constructions on the two rivers have cut water flow to Iraq by 80% and to Syria by 40%. Both Syria and Iraq have accused Turkey of hoarding water and threatening their water supply.

http://www.irinnews.org/photo/

The Barada River, shown here in Damascus, is the only notable river flowing entirely within Syrian territory. The city’s water supplies are under huge strain

DAMASCUS, 25 March 2010 (IRIN) – Poor planning and management, wasteful irrigation systems, intensive wheat and cotton farming and a rapidly growing population are straining water resources in Syria in a year which has seen unprecedented internal displacement as a result of drought in eastern and northeastern parts of the country.

In 2007 Syria consumed 19.2 billion cubic metres of water – 3.5 billion more than the amount of water replenished naturally, with the deficit coming from groundwater and reservoirs, according to the Ministry of Irrigation.

Agriculture accounts for almost 90 percent of the country’s water consumption, according to government and private sector.

Agricultural policies encourage water-hungry wheat and cotton cultivation, and inefficient irrigation methods mean much water is wasted.

 

South Asia is a desperately water-insecure region, and India’s shortages are part of a wider continental crisis. According to a recent report authored by UN climate scientists, coastal areas in Asia will be among the worst affected by climate change. Hundreds of millions of people across East, Southeast and South Asia, the report concluded, will be affected by flooding, droughts, famine, increases in the costs of food and energy, and rising sea levels.

Groundwater serves as a vital buffer against the volatility of monsoon rains, and India’s falling water table therefore threatens catastrophe. 60 percent of north India’s irrigated agriculture is dependent on ground water, as is 85 percent of the region’s drinking water. The World Bank predicts that India only has 20 years before its aquifers will reach “critical condition” – when demand for water will outstrip supply – an eventuality that will devastate the region’s food security, economic growth and livelihoods.

Analysts fear that growing competition for rapidly dwindling natural resources will trigger inter-state or intra-state conflict. China and India continue to draw on water sources that supply the wider region, and a particularly concerning flashpoint is the Indus River Valley basin that spans India and Pakistan. The river’s waters are vital to the economies of areas on both sides of the border and a long-standing treaty, agreed by Pakistan and India in 1960, governs rights of access. But during the “dry season,” between October and March, water levels fall to less than half of those seen during the remainder of the year. The fear is that cooperation over access to the Indus River will fray as shortages become more desperate.

http://cdn1.pri.org/sites/default/files/styles/story_main/public/story/images/IMG_5937.jpeg

Farm worker heading for the paddy fields at Gubinder Singh’s farm

The Indo-Gangetic Basin, which lies at the foothills of the Himalayas, is one of the areas in the world facing a huge water crisis.  The Basin spans from Pakistan, across Northern India into Bangladesh. Apart from runoff from mountainous streams and glaciers, it also holds one of the largest underground bodies of water in the world. But it’s also in one of the most populous regions of the world, with more than a billion people living on the subcontinent.  Still, parts of the region are well-resourced when it comes to water supplies – like the Indian state of Punjab, which has three rivers running through it and a network of canals in some parts.

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NASA Satellites Unlock Secret to Northern India’s Vanishing Water

08.12.09

 

NASA Hydrologist Matt Rodell discusses vanishing groundwater in India. Credit:NASA
› Watch Video

http://www.nasa.gov/multimedia/nasatv/index.html

 

soil moisture belt

soil moisture belt

 

Groundwater resides beneath the soil surface in permeable rock, clay and sand as illustrated in this conceptual image. Many aquifers extend hundreds of feet underground and in some instances have filled with water over the course of thousands of years. Credit: NASA
http://www.nasa.gov/images/content/378067main_water_table%20illus_226.jpg

groundwater withdrawals as a percentage of groundwater recharge

groundwater withdrawals as a percentage of groundwater recharge

 

 

The map, showing groundwater withdrawals as a percentage of groundwater recharge, is based on state-level estimates of annual withdrawals and recharge reported by India’s Ministry of Water Resources. The three states included in this study are labeled. Credit:NASA/Matt Rodell

http://www.nasa.gov/images/content/378381main_MattRodell_vid_226.jpg

The averaging function (spatial weighting) used to estimate terrestrial water storage changes from GRACE data is mapped. Warmer colors indicate greater sensitivity to terrestrial water storage changes. Credit: NASA/Matt Rodell

http://www.nasa.gov/images/content/378067main_water_table%20illus_226.jpg

Beneath northern India’s irrigated fields of wheat, rice, and barley … beneath its densely populated cities of Jaiphur and New Delhi, the groundwater has been disappearing. Halfway around the world, hydrologists, including Matt Rodell of NASA, have been hunting for it.

Where is northern India’s underground water supply going? According to Rodell and colleagues, it is being pumped and consumed by human activities — principally to irrigate cropland — faster than the aquifers can be replenished by natural processes. They based their conclusions — published in the August 20 issue of Nature — on observations from NASA’s Gravity Recovery and Climate Experiment (GRACE).

“If measures are not taken to ensure sustainable groundwater usage, consequences for the 114 million residents of the region may include a collapse of agricultural output and severe shortages of potable water,” said Rodell, who is based at NASA’s Goddard Space Flight Center in Greenbelt, Md.

 

https://www.quora.com/Why-are-there-no-earthquakes-or-volcanos-in-the-Himalayas

The Himalayas are representative of a modern and active mountain-building event, called anorogeny in geologic parlance. Both the Himalayas and the Cascade Range are the result of plate-to-plate collision in the Theory of Plate Tectonics.
The difference between the Himalayas and the Cascade Range volcanoes is based on density of the lithospheric plates. Yes. The Cascade Range is caused by subduction of more dense ocean crust into and underneath lighter, lower density continental crust. As the oceanic plate dives deeper and deeper, the ocean crust warms, melts, and rises upward through the overriding continental crust “inland” from the plate collision boundary. As that molten rock punches through the continental crust, a curvilinear series of volcanoes, generally parallel to the plate collision boundary, begins to form.

Cascade Range Subduction

Cascade Range Subduction

 

Cascade Range Subduction from J. Wiley & Sons – 2010
In the case of the Cascade Range, the name of this type of volcanic formation is unique in process, as well as geochemistry, and has been referred to as an Andesitic-type after the Andes Mountains. Regardless, the Cascade Range is comprised of intermediate igneous rocks, with a fairly high silica content. High silica makes for high siliceous acid. That creates “sticky” igneous extrusions that often have quite dramatic eruptions [May 1980 Mt. St. Helens eruption].

 

Igneous Rock Classification

Igneous Rock Classification

Igneous Rock Classification Chart – Public Domain

The Himalayas are also a plate-to-plate collision tectonic boundary. In this case, the Indian Plate [of the Indian Subcontinent] is colliding head-on with the Eurasian Plate. Both plates are comprised of continental lithospheric crust, so there is no appreciable distinction in density. Both have a density of approximately 2.7 g/cm³. This as opposed to ocean crust with a mean density of 3.3 g/cm³. The plates try to compete in the plate-to-plate collision but the equal densities of the two plates cannot push one under the other very deep like that in a subduction zone.  The result is large-scale thickening of the continental crust in the region at and surrounding the collision boundary. Other processes occurring in the Himalayas region associated with the orogeny are metamorphism, thrust [compression] faulting, and plateau uplift.

Depiction of Himalayan Collision

Depiction of Himalayan Collision

Generalized Depiction of Himalayan Collision from FHSU – 2010
A perfect analogy is two trucks of the same make and model colliding head-on. The Himalayan Orogeny is the oft mentioned “crumple zone”. Metal does not deform in a brittle sense like competent rock does, so don’t confuse that too much.

With all that being said, there are tremendous temperatures attained at a continental plate-to-plate collision boundary. However, the crust is simply too thick, and too “squashed together” to allow anything to squeeze up and break through to the surface as volcanic eruptions.
References:

FHSU,  2010.  Image of Himalayan Collision.  Fort Hays State University.  Hays, Kansas.  2010.
Wiley & Sons, J.,  2010.  Image of Cascade Range Subduction Zone.  J. Wiley & Sons.  Hoboken, New Jersey.  2010.

 

Mt. Everest was formed (is forming) by two tectonic plates colliding–the Indo-Australian Plate and the Eurasian plate.

Sometimes, when two tectonic plates collide, volcanoes form (such as the Juan de Fuca plate and the North American Plate forming the Cascades). However, this has to do with one plate–in this case the Juan de Fuca Plate sliding or subducting beneath another–the North American Plate. This happens because the oceanic plate (the Juan de Fuca Plate) is more dense than than the continental plate (the NA Plate). For reasons I won’t get into here, magma forms between the two plates as one subducts beneath the other and volcanoes are formed.

Mt. Everest is formed by two continental plates colliding. Continental plates are generally too buoyant to subduct beneath each other. While some subduction occurred during this collision, most of what happened was crustal shortening. Think about what happens when you have a rug on a wood floor and push two ends toward each other. It buckles and folds up in itself. This is a simplified version of what happened in the Himalaya.

Because little to no subduction is occurring, no magma is forming and Mt. Everest will not become a volcano.

The Himalayas were created by two continental plates colliding. What happens when two masses of rocks with some similarities, like in density, collide? Both of them rise. There is a lot of heat produced. However, there isn’t enough heat to melt rocks completely. For there to be a volcano, there has to be a source of molten rock.

This material can occur if the two masses of rocks have vastly different densities. In this case, the heavier mass will slide above the other. The mass on the bottom will melt. This molten rock material will rise and create a volcano. or two or more. This, however can not happen in the HImalayas. The two masses in action are the Indian Plate and the Eurasian Plate, which have similar rock density.

 

Volcanic Eruptions and the Role of Sulfur Dioxide in Climate Change

In March and April of this year, a series of severe volcanic eruptions shook Alaska’s Mount Redoubt.1  To date, the largest of the eruptions produced an ash plume that reached 50,000 feet above sea level and released a significant amount of sulfur dioxide (CAS Registry Number® 7446-09-5) into the earth’s atmosphere.  According to the Alaska Volcano Observatory, “The main concerns for human health in volcanic haze consist of ash, sulfur dioxide gas (SO2), and sulfuric acid droplets (H2SO4), which forms when volcanic SO2 oxidizes in the atmosphere.”1

While there is obvious reason for alarm among local populations, sulfur dioxide from the Mount Redoubt eruption could also have more widespread impacts, particularly on the climate.  According to a 1997 article published in the Journal of Geology, “The mechanism by which large eruptions affect climate is generally accepted: injection of sulfur into the stratosphere and conversion to sulfate aerosol, which in turn reduces the solar energy reaching the earth’s surface.”2

In the years following a volcanic eruption, sulfate aerosol that remains in the atmosphere is thought to cause surface cooling by reflecting the sun’s energy back into space.  In fact, sulfate aerosol from the massive eruption of Indonesia’s Mount Tambora in 1815 is blamed, at least in part, for the “year without a summer” reported in Europe and North America in 1816:

  • “Daily temperatures (especially the daily minimums) were in many cases abnormally low from late spring through early fall; frequent northwest winds brought snow and frost to northern New England and Canada, and heavy rains fell in western Europe.  Many crops failed to ripen, and the poor harvests led to famine, disease, and social distress…”3

Supporting this claim, sulfate aerosol-related climate changes were also reported after the 1991 eruption of Mount Pinatubo in the Philippines.4  An article published inScience in 2002 summarizes a decade’s worth of research on Pinatubo’s effects on the global climate, highlighting impacts far more widespread and complex than previously thought:

You can use SciFinder® or STN® to search the CAS databases for additional information about sulfur dioxide from volcanic eruptions.  If your organization is enabled to use the web version of SciFinder, you can click the links in this article to directly access details of the substances and references.

 

Volcanic ash vs sulfur aerosols

The primary role of volcanic sulfur aerosols in causing short-term changes in the world’s climate following some eruptions, instead of volcanic ash, was hypothesized by scientists in the early 1980’s. They based their hypothesis on the effects of several explosive eruptions in Indonesia and the world’s largest historical effusive eruption in Iceland.

Scientists studied three historical explosive eruptions of different sizes in Indonesia–Tambora (1815), Krakatau (1883), and Agung (1963). They noted that decreases in surface temperatures after the eruptions were of similar magnitude (0.18-1.3 °C). The amount of material injected into the stratosphere, however, differed greatly. By comparing the estimated amount of ash vs. sulfur injected into the stratosphere by each eruption, it was suggested that the longer residence time of sulfate aerosols, not the ash particles which fall out within a few months of an eruption, was the paramount controlling factor (Rampino and Self, 1982).

In contrast to these explosive eruptions, one of the most severe volcano-related climate effects in historical times was associated with a largely nonexplosive eruption that produced very little ash–the 1783 eruption of Laki crater-row in Iceland. The eruption lasted 8-9 months and extruded about 12.3 km3 of basaltic lava over an area of 565 km2. A bluish haze of sulfur aerosols all over Iceland destroyed most summer crops in the country; the crop failure led to the loss of 75% of all livestock and the deaths of 24% of the population (H. Sigurdsson, 1982). The bluish haze drifted east across Europe during the 1783-1784 winter, which was unusually severe.

Clearly, these examples suggested that the explosivity of an eruption and the amount of ash injected into the stratosphere are not the main factors in causing a change in Earth’s climate. Instead, scientists concluded that it must be the amount of sulfur in the erupting magma.

The eruption of El Chichon, Mexico, in 1982 conclusively demonstrated this idea was correct. The explosive eruption injected at least 8 Mt of sulfur aerosols into the atmosphere, and it was followed by a measureable cooling of parts of the Earth’s surface and a warming of the upper atmosphere. A similar-sized eruption at Mount St. Helens in 1980, however, injected only about 1 Mt of sulfur aerosols into the stratosphere. The eruption of Mount St. Helens injected much less sulfur into the atmosphere–it did not result in a noticeable cooling of the Earth’s surface. The newly launched TOMS satellite (in 1978) made it possible to measure these differences in the eruption clouds. Such direct measurements of the eruption clouds combined with surface temperatures make it possible to study the corrleation between volcanic sulfur aerosols (instead of ash) and temporary changes in the world’s climate after some volcanic eruptions.

 

Hazards Of Volcanic Ash

A multitude of dangerous particals and gases, such as aerosols, are carried in volcanic ash. Some of these include;

  • Carbon dioxide
  • Sulfates (sulfur dioxide)
  • Hydrochloric acid
  • Hydroflouric acid

These each have different but serious effects on human health if exposed, which will be discussed later.

In addition, volcanic ash can cause reduced visibility, and it is recommended that precautions are taken when driving.

Sources: Where Does It Come From?

Figure 1

volcanoes found all over the Earth, particularly at plate boundaries

volcanoes found all over the Earth, particularly at plate boundaries

There are volcanoes found all over the Earth, particularly at plate boundaries (see figure 1). This is due to the collision of plates, which causes uplift in the overlying crust. This uplift results in the formation of mountainous landforms; melting of the crust due to frictional heating is what creates magma, which can erupt out of these mountains when pressure gets too high.

Some of the most notable volcanic eruptions are:

  • the 1783 eruption of Mt. Laki in Iceland
    • released clouds of poisonous flourine and sulfur dioxide which killed off about 50% of the livestock population
    • that summer in Great Britain was known as “sand-summer” due to ash carried over the Atlantic
    • poisonous clouds spread over Europe, and a buildup of aerosols caused a cooling effect in the entire Northern Hemisphere
  • the 1815 eruption of Mt. Tambora in Indonesia
    • gas releases caused the Stratosphere to change drastically
    • noxious ash and poisoned rain clouds killed off vegetation
  • the 1902 eruption of Mt. Pelee in Martinique
    • spewed toxic clouds traveling at speeds of 600mph
    • largest eruption in the 20th century

For further information on volcanoes around the world, visit http://www.mapsofworld.com/major-volcanoes.htm.

http://www.chm.bris.ac.uk/webprojects2003/silvester/Page6Famous.htm

 

  • EEA-33 emissions of sulphur oxides (SOX) have decreased by 74% between 1990 and 2011. In 2011, the most significant sectoral source of SOX emissions was ‘Energy production and distribution’ (58% of total emissions), followed by emissions occurring from ‘Energy use in industry’ (20%) and in the ‘Commercial, institutional and households’ (15%) sector.
  • The reduction in emissions since 1990 has been achieved as a result of a combination of measures, including fuel-switching in energy-related sectors away from high-sulphur solid and liquid fuels to low-sulphur fuels such as natural gas, the fitting of flue gas desulphurisation abatement technology in industrial facilities and the impact of European Union directives relating to the sulphur content of certain liquid fuels.
  • All of the EU-28 Member States have reduced their national SOX emissions below the level of the 2010 emission ceilings set in the National Emission Ceilings Directive (NECD)[1]. Emissions in 2011 for the three EEA countries having emission ceilings set under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland) were also below the level of their respective 2010 ceilings.
  • Environmental context: Typically, sulphur dioxide is emitted when fuels or other materials containing sulphur are combusted or oxidised. It is a pollutant that contributes to acid deposition, which, in turn, can lead to changes in soil and water quality. The subsequent impacts of acid deposition can be significant, including adverse effects on aquatic ecosystems in rivers and lakes and damage to forests, crops and other vegetation. SO2 emissions also aggravate asthma conditions and can reduce lung function and inflame the respiratory tract. They also contribute, as a secondary particulate pollutant, to the formation of particulate matter in the atmosphere, an important air pollutant in terms of its adverse impact on human health. Furthermore, the formation of sulphate particles in the atmosphere following the release of SO2 results in reflection of solar radiation, which leads to net cooling of the atmosphere.
faults  sn-seafloor

faults sn-seafloor

 

Glacier - Helheim

Glacier – Helheim

 

Making North America

Making North America

 

so2-global-1986

so2-global-1986

 

What caused the Nepal earthquake

What caused the Nepal earthquake

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Announcing Four e-Books from BioMed e-Series: Series B,C,D,E: Genomics, Cancer, Metabolomics, Physiology & Therapeutics

Editor-in-Chief: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/biomed-e-books/

 

onepage series BCDE covers

 

About Larry H Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2014/10/16/editorial-publication-of-articles-in-e-books-by-leaders-in-pharmaceutical-business-intelligence-contributions-of-larry-h-bernstein-md-fcap/

About Stephen J Williams, PhD

https://pharmaceuticalintelligence.com/contributors-biographies/senior-editors/stephen-j-williams-phd-pharmacology-bsc-toxicology-expert-author-writer/

About Aviva Lev-Ari, PhD, RN, BioMed e-Series, Editor-in-Chief

https://pharmaceuticalintelligence.com/founder/editorial-publication-of-articles-in-e-books-by-leaders-in-pharmaceutical-business-intelligence/

About Tilda Barliya, PhD

https://pharmaceuticalintelligence.com/contributors-biographies/senior-editors/tilda-barliya-phd-expert-author-writer-research-category-owner-nanotechnology-for-drug-delivery/

About Ritu Saxena, PhD

https://pharmaceuticalintelligence.com/contributors-biographies/experts-authors-writers-eaws/ritu-saxena/

Read Full Post »


Stress and Anxiety

Writer and Curator: Larry H Bernstein, MD, FCAP

 

Introduction

This article follows immediately after two on diet and obesity and diet and exercise. The hypothalamus has been discussed in some detail, although There is more that needs to be said about glutamate receptors, which is a topic in itself. However, this material fits in place quite well.  There is a considerable amount of obesity, and exercise is limited by time and commitment.  The shrinking middle class and the working poor, and the unemployed poor as well, have a struggle to make ends meet, and with the divorce rates that we are seeing, it is stressful for a single mother to carry on a complete life as mother and caregiver, and it is not unusual to see one or both couples in a household, regardless of sex, to hold two jobs.  Students enter colleges for higher education and leave with significant debts.  Graduates with advanced degrees may have to compete with a crowd of qualified applicants for an academic position, or even for a job in technology.  In addition, there is an increase in stress related disorders in the   pre-school, elementary and middle school population.  We no longer have to read the front pages to learn that a violent act has been carried out somewhere, in some neighborhood in our great nation that has experienced a great civil war, two world wars, the Mc Carthy hearings, the Cold War, and Vietnam, and the Iraq War, all of which was accompanied by migrations, immigration, and outsourcing of jobs.  The following is another look at how we are adjusting.

 

Effectiveness of a meditation-based stress management program as an adjunct to pharmacotherapy in patients with anxiety disorder

Sang Hyuk Lee, Seung Chan Ahn, Yu Jin Lee, Tae Kyu Choi, et al.
J Psychosomatic Research 62 (2007) 189–195
http://dx.doi.org:/10.1016/j.jpsychores.2006.09.009

Objective: The objective of this study was to examine the effectiveness of a meditation-based stress management program in patients with anxiety disorder.
Methods: Patients with anxiety disorder were randomly assigned to an 8-week clinical trial of either a meditation-based stress management program or an anxiety disorder education program. The Hamilton Anxiety Rating Scale (HAM-A), the Hamilton Depression Rating Scale (HAM-D), the State–Trait Anxiety Inventory (STAI), the Beck Depression Inventory, and the Symptom Checklist- 90 — Revised (SCL-90-R) were used to measure outcome at 0, 2, 4, and 8 weeks of the program. Results: Compared to the education group, the meditation-based stress management group showed significant improvement in scores on all anxiety scales (HAM-A, P=.001; STAI state, P=.001; STAI trait, P=.001; anxiety subscale of SCL-90-R,P=.001) and in the SCL-90-R hostility subscale (P=.01). Findings on depression measures were inconsistent, with no significant improvement shown by subjects in the meditation-based stress management group compared to those in the education group. The meditation-based stress management group did not show significant improvement in somatization, obsessive–compulsive symptoms, and interpersonal sensitivity scores, or in the SCL-90-R phobic anxiety subscale compared to the education group. Conclusions: A meditation-based stress management program can be effective in relieving anxiety symptoms in patients with anxiety disorder. However, well-designed, randomized, and controlled trials are needed to scientifically prove the worth of this intervention prior to treatment.

 

Evidence and Potential Mechanisms for Mindfulness Practices and Energy Psychology for Obesity and Binge-Eating Disorder

Renee Sojcher, Susan Gould Fogerite, and Adam Perlman
Explore 2012; 8(5):271-276
http://dx.doi.org/10.1016/j.explore.2012.06.003

Obesity is a growing epidemic. Chronic stress produces endocrine and immune factors that are contributors to obesity’s etiology. These biochemical alsocan affect appetite and eating behaviors that can lead to binge-eating disorder. The inadequacies of standard care and the problem of patient noncompliance have inspired a search for alternative treatments. Proposals in the literature have called for combination therapies involving behavioral or new biological therapies. This manuscript suggests that mindbody interventions would be ideal for such combinations. Two mind body modalities, energy psychology and mindfulness meditation, are reviewed for their potential in treating weight loss, stress, and behavior modification related to binge-eating disorder.

Whereas mindfulness meditation and practices show more compelling evidence, energy psychology, in the infancy stages of elucidation, exhibits initially promising outcomes but requires further evidence-based trials. “Diets Don’t Work” has been a mantra repeated over and over in the media. In fact, in a 2006 study in which investigators compared several popular diets comprising either high carbohydrates, high protein, or high fat, they found a rapid regression of compliance after six months, to the extent that it did not matter which diet had initially been more effective. In another study, authors examined a combination of diet and exercise compared with diet alone and observed that 50% of their subjects in both groups regained the weight that they lost after one year, despite their having lost more weight with the combination therapy. Despite the failure of diet alone in most studies, strategies incorporating both diet and exercise can be effective: a Cochrane review on exercise for overweight or obesity concluded that exercise had a positive effect on body weight and cardiovascular risk factors and that this effect was enhanced by a combination of exercise with dietary interventions.

The authors of a more recent study found that the benefits of exercise in inducing weight loss may come through psychological pathways rather than through actual energy expenditure. These factors include self-regulation and self-efficacy, which may mediate the relationship between exercise and weight change. Psychological interventions, particularly behavioral therapy and CBT, have been shown to be effective, especially when combined with diet and exercise. However, these interventions are costly and require extensive clinical contact for long durations to achieve efficacy. The authors of a recent randomized controlled trial (RCT) with a three-year follow-up period looked at a new form of CBT that addresses patients’ overeating and low level of activity, as well as factors that impede weight maintenance, and found that this form of therapy did not result in improved weight maintenance. These authors concluded that CBT is not sufficiently effective in helping patients maintain their weight loss in the long term. Although 20% of people will not change their eating behaviors under stress, most do; approximately 40% will increase and 40% will decrease their eating.

The emotional eaters, who tend to increase food intake, are more likely to crave high-fat/sweet and rewarding comfort foods. The basis for this behavior is becoming understood to entail brain pathways that involve learning and memory of reward and pleasure. Habit formation and decreased cognitive control are also involved. These habits form the basis of BED. Binge eating occurs when a person eats larger amounts of food than normal in a short amount of time. It therefore involves a loss of control and is often precipitated by a range of negative emotions, such as anxiety, depression, anger, and loneliness. Overweight subjects may or may not be characterized as binge eaters.

The stress response, also known as the “fight or flight response,” involves the interaction of the autonomic nervous system, which includes the sympathetic and the parasympathetic nervous systems, the hypothalamic pituitary adrenal axis and endocrine secretion. Together, these systems comprise neuro-endocrine pathways that collaborate to maintain the body’s regulation of homeostasis. This mechanism is very effective when stress is acute, but in the case of chronic stress, the effect can be injurious to one’s physiological state. Over time, chronic exposure to stress hormones contributes to“ allostatic load.” The stress hormones released by the body, mostly cortisol, can alter the body’s fuel metabolism, especially by adipose tissue, leading to an increase in upper-body obesity. Furthermore, hormones such as leptin, ghrelin, and neuropeptide Y can affect appetite and cause changes in fat mass storage. This results in the linking of stress and obesity.

Given the limited success of conventional approaches and the new information about the psychological and physiological mechanisms underlying obesity, we propose that a specific sub-group of mind-body therapies, including energy psychology and mindfulness-based approaches, could add an important new dimension to the integrative treatment of eating disorders. Energy psychology refers to a family of therapies that are used for treating physical disorders and psychological symptoms, which includes Thought Field Therapy, Emotional Freedom Techniques (EFT), Eye Movement Desensitization and Reprocessing, and Tapas Acupressure Technique (TAT). These therapies incorporate concepts originating from non-Western healing and spiritual systems, including acupuncture, acupressure, yoga, meditation, and qigong, and they combine physical activity with mental activation on the basis of the premise that the body is composed of electrical signals or energy fields. Energy psychology has been quite controversial among psychotherapists and has been the subject of much heated debate in the literature. Nonetheless, the clinical application of these practices is growing and is beginning to be investigated for efficacy. Mindfulness-Based Eating Awareness Training (ie,MB-EAT) involves the cultivation of mindfulness, mindful eating, emotional balance, and self-acceptance.

A pilot trial of a six-week group curriculum for providing mindfulness training to obese individuals, called Mindful Eating and Living (ie,MEAL), showed significant increases in measures of mindfulness and cognitive restraint around eating and significant decreases in weight, eating disinhibition, bingeeating, depression, perceived stress, physical symptoms, negative affect ,and C-reactive protein. In a recent systematic review of eight studies, authors examined a variety of mindfulness techniques in treating eating disorders, including anorexia, bulimia, and BED. Because trial quality varied and sample sizes were small, the researchers concluded that mindfulness may be effective in treating eating disorders but that further research was needed. The authors noted, however, that all of the articles that met the study’s criterion reported positive outcomes for the mindfulness intervention. Two additional studies recently addressed the treatment of obesity with a combination of mindfulness strategies and ACT. Lillis et al. conducted a RCT on 87 subjects who had all completed at least a six-month weight loss program. Using a wait list control against treatment of the experimental group through a one-day workshop, the authors found that, compared with the control group, the experimental group showed greater improvements in obesity-related stigma, quality of life, psychological distress, and reduction of body mass in a three-month follow-up. Alberts et al. conducted an RCT on 19 participants in a 10-week dietary group treatment that examined the effect of mindfulness plus ACT on food cravings. Experimental subjects underwent an additional seven-week, manual-based mindfulness/acceptance training. The control group received information on healthy food choices. The experimental group showed significantly lower food cravings, a lower preoccupation with food in four subscales, less loss of control, and better positive outcome expectancy, as compared with the control group. There was no significant effect observed for emotional craving. The authors of both of these studies conclude that mindfulness strategies combined with acceptance are effective in reducing the behaviors that lead many obese patients to overeat. With regards to stress, mindfulness can reduce psychological factors that have been shown to contribute to obesity.

In a recent well conducted systematic review, Mars and Abbey examined 22 studies with conditions ranging from participants with Axis I disorders, various diagnosed medical disorders, and healthy subjects. Axis I disorders include a range of psychopathologies such as childhood developmental and adjustment abnormalities, adult anxiety, and mood, sleep, and sexual disorders. Subjects with BED are known to have greater comorbidity forAxis I disorders. The authors report that five studies examining Axis I disorders showed statistically significant results for an eight-week, two hours per week MBCT program in reducing psychological stress, recurring bouts of depression, and pain. They conclude that, despite some methodological difficulties in the trials, mindfulness therapy may have a positive impact on reducing stress and depression. Despite increasing public awareness of obesity’s detrimental effects on health, the conventional approaches to managing this condition have not been effective. The recommended standard care for overweight and obesity, namely diet and exercise, are for the most part ineffective in the long term. Behavioral therapy and CBT may have some effect but are costly and difficult to implement. Issues with bariatric surgery and pharmacological therapies attributable to cost and the potential for harm, as well as lack of long-term efficacy, have limited their utility.

The effectiveness of a stress coping program based on mindfulness meditation on the stress, anxiety, and depression experienced by nursing students in Korea

Yune Sik Kang, So Young Choi, Eunjung Ryu
Nurse Education Today 29 (2009) 538–543
http://dx.doi.org:/10.1016/j.nedt.2008.12.003

This study examined the effectiveness of a stress coping program based on mindfulness meditation on the stress, anxiety, and depression experienced by nursing students in Korea. A nonequivalent, control group, pre-posttest design was used. A convenience sample of 41 nursing students were randomly assigned to experimental (n=21) and control groups (n=20). Stress was measured with the PWI-SF(5-point) developed by Chang. Anxiety was measured with Spieberger’s state anxiety y inventory. Depression was measured with the Beck depression inventory. The experimental group attended 90-min sessions for eight weeks. No intervention was administered to the control group. Nine participants were excluded from the analysis because they did not complete the study due to personal circumstances, resulting in16 participants in each group for the final analysis. Results for the two groups showed

(1) a significant difference in stress scores (F=6.145,p=0.020),

(2) a significant difference in anxiety scores (F=6.985,p=0.013), and

(3) no significant difference in depression scores (t=1.986,p=0.056).

A stress coping program based on mindfulness meditation was an effective intervention for nursing students to decrease their stress and anxiety, and could be used to manage stress in student nurses. In the future, long-term studies should be pursued to standardize and detail the program, with particular emphasis on studies to confirm the effects of the program in patients with diseases, such as cancer.

 

 

Meditation and Anxiety Reduction: A Literature Review

M. M. Delmonte Clin
Psychol Rev 1985; 5: 91-102
Meditation is increasingly being practiced as a therapeutic technique. The effects of practice on psychometrically assessed anxiety levels has been extensively researched. Prospective meditators tend to report above average anxiety. In general, high anxiety levels predict a subsequent low frequency of practice. However, the evidence suggests that those who practice regularly tend to show significant decreases in anxiety. Meditation does not appear to be more effective than comparative interventions in reducing anxiety. There is evidence to suggest that hypnotizability and expectancy may both play a role in reported anxiety decrease. Certain individuals with a capacity to engage in autonomous self-absorbed relaxation, may benefit most from meditation.

 

Meta-analysis on the effectiveness of mindfulness-based stress reduction therapy on mental health of adults with a chronic disease: What should the reader not make of it?

Ernst Bohlmeijer, Rilana Prenger, ErikTaal
Letters to the Editor/J Psychosom Res 69 (2010) 613–615
http://dx.doi.org:/10.1016/j.jpsychores.2010.09.005

In a letter to the editor, Nyklíček et al. discuss the study of Bohlmeijer et al. [1]on the meta-analysis on the effectiveness of mindfulness-based stress reduction (MBSR) therapy on mental health of adults with a chronic disease. They claim that the effects of MBSR are underestimated in this meta-analysis due to the inclusion of a study using an active education support group as control group and to the omission of some subscales for which larger effect sizes have been found. We do not agree that the study using an active education support group as a control group should not have been included in the meta-analysis. It is a common procedure to include studies with various types of control groups, e.g., waiting-list, placebo, minimal interventions, or evidence-based treatment. Normally, subgroup analyses can be conducted, contrasting studies that use differen ttypes of control groups. As seven studies used a waiting-list control condition and only one study used an education support group, this subgroup comparison was not useful. However, when we conducted a meta-analysis of the seven RCTs using a waiting-list control group an overall effect size of 0.30 instead of 0.26 was found. In addition, it is often found in meta-analyses that the largest effect sizes are reported in studies that use waiting-list control groups, e.g. ,Refs.[2,3]. The fact that almost all studies included in our meta-analysis in fact used waiting-list control groups makes it unlikely that the effects of MBSR were underestimated. As to the second claim by Nyklíček e tal.that some outcomes were selectively omitted from the meta-analysis, we can state that the subscales of the POMS were included in the meta-analysis.The program that was used in our study, Comprehensive Meta-Analysis, combined the scales that measure the same outcome, e.g., anxiety in one study. So the larger effects sizes for the subscales of the POMS were included in the meta-analysis. Lastly, Nyklíčeketal. State that ‘decentering’ is not an exclusive process of MBCT but is a central feature of MBSR as well. MBCT was specifically developed for people with recurrent depression and on the basis of a thorough analysis of the role of specific cognitions in people with recurrent depression. In ouropinion, this may explain the large effect sizes that have been found in randomized controlled trials, e.g., [4]. In general, other studies have shown that integrating MBSR in behavioral therapy is a very promising strategy for enhancing the efficacy of treatments of psychological  distress[5,6]. However, more studies with different target groups are needed to answer the question as to which mindfulness-based intervention is most effective for which target group in which setting. Overall, in response to the letter to the editor by Nyklíček et al. we cannot corroborate their claim that the effects of MBSR were underestimated and have to stand with our conclusion that, on the basis of current RCTs, MBSR has small leffects on depression and anxiety in people with chronic medical diseases.

[1] BohlmeijerET, PrengerR, TaalE, CuijpersP.
The effects of mindfulness-based stress reduction therapy on the mental health of adults with a chronic medical disease: A meta-analysis.
JPsychosom Res 2010; 68:539–44.

[2]Powers MB, Zum Vörde Sive Vörding MB, Emmelkamp PMG.
Acceptance and commitment therapy: A meta-analytic review.
Psychoth Psychosom 2009; 78:73–80.

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Diet and Exercise

Writer and Curator: Larry H. Bernstein, MD, FCAP 

 

Introduction

In the last several decades there has been a transformation in the diet of Americans, and much debate about obesity, type 2 diabetes mellitus, hyperlipidemia, and the transformation of medical practice to a greater emphasis on preventive medicine. This occurs at a time that the Western countries are experiencing a large portion of the obesity epidemic, which actually diverts attention from a larger share of malnutrition in parts of Africa, Asia, and to a greater extent in India. This does not mean that obesity or malnutrition is exclusively in any parts of the world. But there is a factor at play that involves social factors, poverty, education, cognition, anxiety, and eating behaviors, food preferences and food balance, and activities of daily living. The epidemic of obesity also involves the development of serious long term health problems, such as, type 2 diabetes mellitus, sarcopenia, fracture risk, pulmonary disease, sleep apnea in particular, and cardiovascular and stroke risk. Nevertheless, this generation of Western society is also experiencing a longer life span than its predecessors. In this article I shall explore the published work on diet and exercise.

 

‘‘Go4Life’’ exercise counseling, accelerometer feedback, and activity levels in older people

Warren G. Thompson, CL Kuhle, GA Koepp, SK McCrady-Spitzer, JA Levine
Archives of Gerontology and Geriatrics 58 (2014) 314–319
http://dx.doi.org/10.1016/j.archger.2014.01.004

Older people are more sedentary than other age groups. We sought to determine if providing an accelerometer with feedback about activity and counseling older subjects using Go4Life educational material would increase activity levels. Participants were recruited from independent living areas within assisted living facilities and the general public in the Rochester, MN area. 49 persons aged 65–95(79.5 + 7.0 years) who were ambulatory but sedentary and overweight participated in this randomized controlled crossover trial for one year. After a baseline period of 2 weeks, group 1 received an accelerometer and counseling using Go4Life educational material (www.Go4Life.nia.nih.gov) for 24 weeks and accelerometer alone for the next 24 weeks. Group 2 had no intervention for the first 24 weeks and then received an accelerometer and Go4Life based counseling for 24 weeks. There were no significant baseline differences between the two groups. The intervention was not associated with a significant change inactivity, body weight, % body fat, or blood parameters (p > 0.05). Older (80–93) subjects were less active than younger (65–79) subjects (p = 0.003). Over the course of the 48 week study, an increase in activity level was associated with a decline in % body fat (p = 0.008). Increasing activity levels benefits older patients. However, providing an accelerometer and a Go4Life based exercise counseling program did not result in a 15% improvement in activity levels in this elderly population. Alternate approaches to exercise counseling may be needed in elderly people of this age range.

It is generally recommended that older adults be moderately or vigorously active for 150 min each week. A systematic review demonstrated that only 20–60% of older people are achieving this goal. These studies determined adherence to physical activity recommendations by questionnaire. Using NHANES data, it has been demonstrated that older people meet activity recommendations 62% of the time using a self-report questionnaire compared to 9.6% of the time when measured by accelerometry. Thus, objective measures suggest that older people are falling even more short of the goal than previously thought. Most studies have measured moderate and vigorous activity. However, light activity or NEAT (non-exercise activity thermogenesis) also has an important effect on health. For example, increased energy expenditure was associated with lower mortality in community-dwelling older adults. More than half of the extra energy expenditure in the high energy expenditure group came from non-exercise (light) activity. In addition to reduced total mortality, increased light and moderate activity has been associated with better cognitive function, reduced fracture rate (Gregg et al., 1998), less cardiovascular disease, and weight loss in older people. A meta-analysis of middle-aged and older adults has demonstrated greater all-cause mortality with increased sitting time. Thus, any strategy which can increase activity (whether light or more vigorous) has the potential to save lives and improve quality of life for older adults. A variety of devices have been used to measure physical activity.

A tri-axial accelerometer measures movement in three dimensions. Studies comparing tri-axial accelerometers with uniaxial accelerometers and pedometers demonstrate that only certain tri-axial accelerometers provide a reliable assessment of energy expenditure. This is usually due to failure to detect light activity. Since light activity accounts for a substantial portion of older people’s energy expenditure, measuring activity with a questionnaire or measuring steps with a pedometer do not provide an accurate reflection of activity in older people.

A recent review concluded that there is only weak evidence that physical activity can be improved. Since increasing both light and moderate activity benefit older people, studies demonstrating that physical activity can be improved are urgently needed. Since accelerometry is the best way to accurately assess light activity, we performed a study to determine if an activity counseling program and using an accelerometer which gives feedback on physical activity, can result in an increase in light and moderate activity in older people. We also sought to determine whether counseling and accelerometer feedback would result in weight loss, change in % body fat, glucose, hemoglobin A1c, insulin, and fasting lipid profile.

The main results of the study are both the experimental and control group lost weight (about 1 kg) at 6months (p = 0.04 and 0.02, respectively). The experimental group was less active at 6 months but not significantly while the control group was significantly less active at 6 months (p = 0.006) than at baseline. The experimental group had a modest decline in cholesterol (p = 0.03) and an improvement in Get Up & go time (p = 0.03) while the control group had a slight improvement in HgbA1c (p = 0.01). However, the main finding of the study was that there were no differences between the two groups on any of these variables. Thus, providing this group of older participants with an accelerometer and Go4Life based counseling resulted in no increase in physical activity, weight loss or change in glucose, lipids, blood pressure, or body fat. There were no differences within either group or between groups from 6 to 12 months on any of the variables (data not shown). While age was correlated with baseline activity, it did not affect activity change indicating that younger participants did not respond to the program better than older participants. Performance on the Get Up and Go test and season of the year did not influence the change in activity. There were no differences in physical activity levels at 3 or 9 months.

There was a significant correlation (r = -0.38, p = 0.006) between change in activity and change in body fat over the course of the study. Those subjects (whether in the experimental or control group) who increased their activity over the course of the year were likely to have a decline in % body fat over the year while those whose activity declined were likely to have increased %body fat. There was no correlation between change in activity and any of the other parameters including weight and waist circumference (data not shown).

Older adults are the fastest growing segment of the population in the US, but few meet the minimum recommended 30 min of moderate activity on 5 days or more per week (Centers for Disease Control and Prevention, 2002). Our study found that within the geriatric population, activity declines as people age. We saw a 2.4% decline per year cross-sectionally. This finding agrees with a recent cohort study (Bachman et al., 2014). In that study, the annual decline accelerated with increasing age. Thus, there is a need to increase activity particularly in the oldest age groups. The United States Preventive Services Task Force concluded that the evidence that counseling improves physical activity is weak (Moyer and US Preventive Services Task Force, 2012). The American Heart Association reached similar conclusions (Artinian et al., 2010). Thus, new ways of counseling older patients to counter the natural decline in activity with age are urgently needed.

Applying health behavior theory to multiple behavior change: Considerations and approaches

Seth M. Noar, Melissa Chabot, Rick S. Zimmerman
Preventive Medicine 46 (2008) 275–280
http://dx.doi.org:/10.1016/j.ypmed.2007.08.001

Background.There has been a dearth of theorizing in the area of multiple behavior change. The purpose of the current article was to examine how health behavior theory might be applied to the growing research terrain of multiple behavior change. Methods. Three approaches to applying health behavior theory to multiple behavior change are advanced, including searching the literature for potential examples of such applications. Results. These three approaches to multiple behavior change include

(1) a behavior change principles approach;

(2) a global health/behavioral category approach, and

(3) a multiple behavioral approach.

Each approach is discussed and explicated and examples from this emerging literature are provided. Conclusions. Further study in this area has the potential to broaden our understanding of multiple behaviors and multiple behavior change. Implications for additional theory-testing and application of theory to interventions are discussed.

Many of the leading causes of death in the United States are behavior-related and thus preventable. While a number of health behaviors are a concern individually, increasingly the impact of multiple behavioral risks is being appreciated. As newer initiatives funded by the National Institutes of Health and Robert Wood Johnson Foundation begin to stimulate research in this important area, a critical question emerges: How can we understand multiple health behavior change from a theoretical standpoint? While multiple behavior change interventions are beginning to be developed and evaluated, to date there have been few efforts to garner a theory-based understanding of the process of multiple health behavior change. Given that so little theoretical work currently exists in this area, our main purpose is to advance the conversation on how health behavior theory can help us to achieve a greater understanding of multiple behavior change. The approaches discussed have implications for both theory-testing as well as intervention design.

A critical question that must be asked, is whether there is a common set of principles of health behavior change that transcend individual health behaviors. This is an area where much data already exists, as health behavior theories have been tested across numerous health behaviors.The integration of findings from studies across diverse behavioral areas, is not what it could be. Godin and Kok (1996) reviewed studies of the TPB applied to numerous health-related behaviors. Across seven categories of health behaviors, they found TPB components to offer similar prediction of intention but inconsistent prediction of behavior.They concluded that the nature of differing health behaviors may require additional constructs to be added to the TPB, such as actual (versus perceived) behavioral control. Prochaska et al. (1994) examined decisional balance across stages of change for 12 health-related behaviors. Similar patterns were found across nearly all of these health behaviors, with the “pros” of changing generally increasing across the stages, the “cons” decreasing, and a pro/con crossover occurring in the contemplation or preparation stages of change. Prochaska et al. (1994) concluded that clear commonalties exist across these differing health behaviors which were examined in differing samples. Finally, Rosen (2000) examined change processes from the TTM across six behavioral categories, examining whether the trajectory of change processes is similar or different across stages of change in those health areas. He found that for smoking cessation, cognitive change processes were used more in earlier stages of change than behavioral processes, while for physical activity and dietary change, both categories of change processes increased together.

A second approach is the following: Rather than applying theoretical concepts to specific behaviors, such concepts might be applied at the general or global level. A general orientation toward health may not lead directly to specific health behaviors, but it may increase the chances of particular health-related attitudes, which may in turn lead to specific health behaviors. In fact, although Ajzen and Timko (1986) found general health attitudes to be poor predictors of behavior, such attitudes were significantly related to specific health attitudes and perceived behavioral control over specific behaviors. It is likely that when we consider multiple behaviors that we may discover an entire network of health attitudes and beliefs that are interrelated. In fact, studies of single behaviors essentially take those behaviors out of the multi-attitude and multi-behavioral context in which they are embedded. For instance, although attitudes toward walking may be a better predictor of walking behavior than attitudes toward physical activity, walking behavior is part of a larger “physical activity” behavioral category. While predicting that particular behavior may be best served by the specific measure, the larger category is both relevant and of interest. Thus, it may be that there are higher order constructs to be understood here.

A third approach is a multiple behavioral approach, or one which focuses on the linkages among health behaviors. It shares some similarities to the approach just described. Here the focus is more strictly on how particular  interventions were superior to comparison groups for 21 of 41 (51%) studies (3 physical activity, 7 diet, 11 weight loss/physical activity and diet). Twenty-four studies had indeterminate results, and in four studies the comparison conditions outperformed eHealth interventions. Conclusions: Published studies of eHealth interventions for physical activity and dietary behavior change are in their infancy. Results indicated mixed findings related to the effectiveness of eHealth interventions. Interventions that feature interactive technologies need to be refined and more rigorously evaluated to fully determine their potential as tools to facilitate health behavior change.

 

A prospective evaluation of the Transtheoretical Model of Change applied to exercise in young people 

Patrick Callaghan, Elizabeth Khalil, Ioannis Morres
Intl J Nursing Studies 47 (2010) 3–12
http://dx.doi.org:/10.1016/j.ijnurstu.2009.06.013

Objectives:To investigate the utility of the Transtheoretical Model of Change in predicting exercise in young people. Design: A prospective study: assessments were done at baseline and follow-up 6 months later. Method: Using stratified random sampling 1055 Chinese high school pupils living in Hong Kong, 533 of who were followed up at 6 months, completed measures of stage of change (SCQ), self-efficacy (SEQ), perceptions of the pros and cons of exercising (DBQ) and processes of change (PCQ). Data were analyzed using one-way ANOVA, repeated measures ANOVA and independent sample t tests.
Results:The utility of the TTM to predict exercise in this population is not strong; increases in self-efficacy and decisional balance discriminated between those remaining active at baseline and follow-up, but not in changing from an inactive (e.g.,Precontemplation or Contemplation) to an active state (e.g.,Maintenance) as one would anticipate given the staging algorithm of the TTM.
Conclusion:The TTM is a modest predictor of future stage of change for exercise in young Chinese people. Where there is evidence that TTM variables may shape movement over time, self-efficacy, pros and behavioral processes of change appear to be the strongest predictors

 

A retrospective study on changes in residents’ physical activities, social interactions, and neighborhood cohesion after moving to a walkable community

Xuemei Zhu,Chia-Yuan Yu, Chanam Lee, Zhipeng Lu, George Mann
Preventive Medicine 69 (2014) S93–S97
http://dx.doi.org/10.1016/j.ypmed.2014.08.013

Objective. This study is to examine changes in residents’ physical activities, social interactions, andneighbor-hood cohesion after they moved to a walkable community in Austin, Texas.
Methods. Retrospective surveys (N=449) were administered in 2013–2014 to collect pre-and post-move data about the outcome variables and relevant personal, social, and physical environmental factors. Walkability of each resident’s pre-move community was measured using the Walk Score. T tests were used to examine the pre–post move differences in the outcomes in the whole sample and across subgroups with different physical activity levels, neighborhood conditions, and neighborhood preferences before the move. Results. After the move, total physical activity increased significantly in the whole sample and all subgroups except those who were previously sufficiently active; lived in communities with high walkability, social interactions, or neighborhood cohesion; or had moderate preference for walkable neighborhoods. Walking in the community increased in the whole sample and all subgroups except those who were previously sufficiently active, moved from high-walkability communities, or had little to no preference for walkable neighborhoods. Social interactions and neighborhood cohesion increased significantly after the move in the whole sample and all subgroups.
Conclusion.This study explored potential health benefits of a walkable community in promoting physically and socially active lifestyles, especially for populations at higher risk of obesity. The initial result is promising, suggesting the need for more work to further examine the relationships between health and community design using pre–post assessments.

 

Application of the transtheoretical model to identify psychological constructs influencing exercise behavior: A questionnaire survey

Young-Ho Kim
Intl J Nursing Studies 44 (2007) 936–944
http://dx.doi.org:/10.1016/j.ijnurstu.2006.03.008

Background: Current research on exercise behavior has largely been attempted to identify the relationship between psychological attributes and the initiation or adherence of exercise behavior based on psychological theories. A limited data are available on the psychological predictors of exercise behavior in public health. Objectives: The present study examined the theorized association of TTM of behavior change constructs by stage of change for exercise behavior. Methods: A total of 228 college students selected from 2 universities in Seoul were surveyed. Four Korean-version questionnaires were used to identify the stage of exercise behavior and psychological attributes of adolescents. Data were analyzed by frequency analysis, MANOVA, correlation analysis, and discriminant function analysis.
Results: Multivariate F-test indicated that behavioral and cognitive processes of change, exercise efficacy, and pros differentiated participants across the stages of exercise behavior. Furthermore, exercise behavior was significantly correlated with the TTM constructs, and that overall classification accuracy across the stages of change was 61.0%. Conclusions:The present study supports the internal and external validity of the Transtheoretical Model for explaining exercise behavior. As this study highlights, dissemination must increase awareness but also influences perceptions regarding theoretically based and practically important exercise strategies for public health professionals.

 

 

Does more education lead to better health habits? Evidence from the school reforms in Australia?

Jinhu Li, Nattavudh Powdthavee
Social Science & Medicine 127 (2015) 83-91
http://dx.doi.org/10.1016/j.socscimed.2014.07.021

The current study provides new empirical evidence on the causal effect of education on health-related behaviors by exploiting historical changes in the compulsory schooling laws in Australia. Since World War II, Australian states increased the minimum school leaving age from 14 to 15 in different years. Using differences in the laws regarding minimum school leaving age across different cohorts and across different states as a source of exogenous variation in education, we show that more education improves people’s diets and their tendency to engage in more regular exercise and drinking moderately, but not necessarily their tendency to avoid smoking and to engage in more preventive health checks. The improvements in health behaviors are also reflected in the estimated positive effect of education on some health outcomes. Our results are robust to alternative measures of education and different estimation methods.

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Diet and Diabetes

Writer and Curator: Larry H Bernstein, MD, FCAP 

 

Bile acid signaling in lipid metabolism: Metabolomic and lipidomic analysis of lipid and bile acid markers linked to anti-obesity and anti-diabetes in mice

Yunpeng Qi, Changtao Jiang, Jie Cheng, Kristopher W. Krausz, et al.

Biochimica et Biophysica Acta 1851 (2015) 19–29

http://dx.doi.org/10.1016/j.bbalip.2014.04.008

Bile acid synthesis is the major pathway for catabolism of cholesterol. Cholesterol 7α-hydroxylase (CYP7A1) is the rate-limiting enzyme in the bile acid biosynthetic pathway in the liver and plays an important role in regulating lipid, glucose and energy metabolism. Transgenic mice overexpressing CYP7A1 (CYP7A1-tg mice) were resistant to high fat diet (HFD)-induced obesity, fatty liver, and diabetes. However the mechanism of resistance to HFD-induced obesity of CYP7A1-tg mice has not been determined. In this study, metabolomic and lipidomic profiles of CYP7A1-tg mice were analyzed to explore the metabolic alterations in CYP7A1-tg mice that govern the protection against obesity and insulin resistance by using ultra-performance liquid chromatography-coupled with electrospray ionization quadrupole time-of-flight mass spectrometry combined with multivariate analyses. Lipidomics analysis identified seven lipid markers including lysophosphatidylcholines, phosphatidylcholines, sphingomyelins and ceramides that were significantly decreased in serum of HFD-fed CYP7A1-tgmice.Metabolomics analysis identified 13metabolites in bile acid synthesis including taurochenodeoxy-cholic acid, taurodeoxycholic acid, tauroursodeoxycholic acid, taurocholic acid, and tauro-β-muricholic acid (T-β-MCA) that differed between CYP7A1-tg and wild-type mice. Notably, T-β-MCA, an antagonist of the farnesoid X receptor (FXR) was significantly increased in intestine of CYP7A1-tg mice. This study suggests that reducing 12α-hydroxylated bile acids and increasing intestinal T-β-MCA may reduce high fat diet-induced increase of phospholipids, sphingomyelins and ceramides, and ameliorate diabetes and obesity. This article is part of a Special Issue entitled Linking transcription to physiology in lipidomics.

Bile acid synthesis is the major pathway for catabolism of cholesterol to bile acids. In the liver, cholesterol 7α-hydroxylase (CYP7A1) is the first and rate-limiting enzyme of the bile acid biosynthetic pathway producing two primary bile acids, cholic acid (CA, 3α, 7α, 12α-OH) and chenodeoxycholic acid (CDCA, 3α, 7α-OH) in humans. Sterol-12α hydroxylase (CYP8B1) catalyzes the synthesis of CA. In mice, CDCA is converted to α-muricholic acid (α-MCA: 3α, 6β, 7α-OH) and β-muricholic acid (β-MCA: 3α, 6β, 7β-OH). Bile acids are conjugated to taurine or glycine, secreted into the bile and stored in the gallbladder. After a meal, bile acids are released into the gastrointestinal tract. In the intestine, conjugated bile acids are first de-conjugated and then 7α-dehydroxylase activity in the gut flora converts CA to deoxycholic acid (DCA: 3α, 12α), and CDCA to lithocholic acid (LCA: 3α), two major secondary bile acids in humans.

In humans, most bile acids are glycine or taurine-conjugated and CA, CDCA and DCA are the most abundant bile acids. In mice, most bile acids are taurine-conjugated and CA and α- and β-MCAs are the most abundant bile acids. Bile acids facilitate absorption of dietary fats, steroids, and lipid soluble vitamins into enterocytes and are transported via portal circulation to the liver for metabolism and distribution to other tissues and organs. About 95% of bile acids are reabsorbed in the ileum and transported to the liver to inhibit CYP7A1 and bile acid synthesis. Enterohepatic circulation of bile acids provides a negative feedback mechanism to maintain bile acid homeostasis. Alteration of bile acid synthesis, secretion and transport causes cholestatic liver diseases, gallstone diseases, fatty liver disease, diabetes and obesity.

 Bile acid synthesis

 

Bile acid synthesis. In the classic bile acid synthesis pathway, cholesterol is converted to cholic acid (CA, 3α, 7α, 12α) and chenodeoxycholic acid (CDCA, 3α, 7α). CYP7A1 is the rate-limiting enzyme and CYP8B1 catalyzes the synthesis of CA. In mouse liver, CDCA is converted to α-muricholic acid (α-MCA, 3α, 6β, 7α) and β-MCA (3α, 6β, 7β). Most bile acids in mice are taurine (T)-conjugated and secreted into bile. In the intestine, gut bacteria de-conjugate bile acids and then remove the 7α-hydroxyl group from CA and CDCA to form secondary bile acids deoxycholic acid (DCA, 3α, 12α) and lithocholic acid (LCA, 3α), respectively. T-α-MCA and T-β-MCA are converted to T-hyodeoxycholic acid (THDCA, 3α, 6α), T-ursodeoxycholic acid (TUDCA, 3α, 7β), T-hyocholic acid (THCA, 3α, 6α, 7α) and T-murideoxycholic acid (TMDCA, 3α, 6β). These secondary bile acids are reabsorbed and circulated to liver to contribute to the bile acid pool. Secondary bile acids ω-MCA (3α, 6α, 7β) and LCA are excreted into feces.

Two FXR-dependent mechanisms are known to inhibit bile acid synthesis.  In the liver bile acid-activated FXR induces a negative receptor small heterodimer partner (SHP) to inhibit trans-activation activity of hepatic nuclear factor 4α(HNF4α) and liver receptor homologue-1 (LRH-1) that bind to the bile acid response element in the CYP7A1 and CYP8B1 gene promoters (Fig. 2, Pathway 1). In the intestine, bile acids activate FXR to induce fibroblast growth factor (mouse FGF15, or human FGF19), which activates hepatic FGF receptor 4 (FGFR4) and cJun N-terminal kinase 1/2 (JNK1/2) and extracellular-regulated kinase (ERK1/2) signaling of mitogen-activated protein kinase (MAPK) pathways to inhibit trans-activation of CYP7A1/CYP8B1 gene by HNF4α (Pathway 2). Several FXR-independent cell-signaling pathways have been reported and are shown as Pathway 3 (Fig. 2). Conjugated bile acids are known to activate several protein kinase Cs (PKC) and growth factor receptors, epidermal growth factor receptor (EGFR), and insulin receptor (IR) signaling to inhibit CYP7A1/CYP8B1 and bile acid synthesis via activating the ERK1/2, p38 and JNK1/2 pathways.

 

Bile acid signaling pathways. Bile acids activate FXR, TGR5 and cell signaling pathways to inhibit CYP7A1 and CYP8B1 gene transcription.

1) Hepatic FXR/SHP pathway: bile acid activated-FXR induces SHP, which inhibits HNF4α and LRH-1 trans-activation of CYP7A1 and CYP8B1 gene transcription in hepatocytes. Bile acid response element binds HNF4α and LRH-1.

2) Intestinal FXR/FGF19/FGFR4 pathway: in the intestine, FXR induces FGF15 (mouse)/FGF19 (human), which is secreted into portal circulation to activate FGF receptor 4 (FGFR4) in hepatocytes. FGFR4 signaling stimulates JNK1/2 and ERK1/2 pathways of MAPK signaling to inhibit CYP7A1 gene transcription by phosphorylation and inhibition of HNF4α binding activity.

3) FXR-independent signaling pathways: Conjugated bile acids activate PKCs,which activate the MAPK pathways to inhibit CYP7A1. Bile acids also activate insulin receptor (IR) signaling IRS/PI3K/PDK1/AKT, possibly via activation of epidermal growth factor receptor (EGFR) signaling, MAPKs (MEK, MEKK), to inhibit CYP7A1 gene transcription. The secondary bile acid TLCA activates TGR5 signaling in Kupffer cells. TGR5 signaling may regulate CYP7A1 by an unknown mechanism. TCA activates sphingosine-1-phosphate (S1P) receptor 2 (S1PR2), which may activate AKT and ERK1/2 to inhibit CYP7A1. S1P kinase 1 (Sphk1) phosphorylates sphingosine (Sph) to S-1-P, which activates S1PR2. On the other hand, nuclear SphK2 interacts with and inhibits histone deacetylase (HDAC1/2) and may induce CYP7A1. The role of S1P, SphK2, and S1PR2 signaling in regulation of bile acid synthesis is not known.

 

When challenged with an HFD, CYP7A1-tg mice had lower body fat mass and higher lean mass compared to wild-type mice. As a platform for comprehensive and quantitative description of the set of lipid species, lipidomics was used to investigate the mechanism of this phenotype. By use of an unsupervised PCA model with the cumulative R2X 0.677 for serum and 0.593 for liver, CYP7A1-tg and wild-type mice were clearly separated based on the scores plot (Supplementary Fig. S2), indicating that these two groups have distinct lipidomic profiles. Supervised PLS-DA models were then established to maximize the difference of metabolic profiles between CYP7A1-tg and wild-type groups as well as to facilitate the screening of lipid marker metabolites (Fig. 3).

PLS-DA analysis of CYP7A1-tg and wild-type (WT)mice challenged with HFD. Based on the score plots, distinct lipidomic profiles of male CYP7A1-tg and wild-type groups were shown for serum (A) and liver samples (B). Based on the loading plots (C for serum and D for liver) the most significant ions that led to the separation between CYP7A1-tg and wild-type groups were obtained and identified as follows: 1. LPC16:0; 2. LPC18:0; 3. LPC18:1; 4. LPC 18:2; 5. PC16:0-20:4; 6. PC16:0-22:6; 7. SM16:0. (not shown)

Fig. 5. OPLS-DA highlighted thirteen markers in bile acid pathway that contribute significantly to the clustering of CYP7A1-tg and wild-type (WT) mice. Ileum bile acids are shown. (not shown)

(A) In the score plot, female CYP7A1-tg andWTmicewere well separated;

(B) using a statistically significant thresholds of variable confidence approximately 0.75 in the S-plot, a number of ions were screened out as potential markers, which were later identified as 13 bile acid metabolites, including α-MCA, TCA, CDCA, and TCDCA etc.

Our recent study of CYP7A1-tg mice revealed that increased CYP7A1 expression and enlarged bile acid pool resulted in significant improvement of lipid homeostasis and resistance to high-fed diet-induced hepatic steatosis, insulin resistance, and obesity in CYP7A1-tg mice. In this study, metabolomics and lipidomics were employed to characterize the metabolic profiles of CYP7A1-tg mice and to provide new insights into the critical role of bile acids in regulation of lipid metabolism and metabolic diseases. Lipidomics analysis of serum lipid profiles of high fat diet-fed CYP7A1-tg identified 7 lipidomic markers that were reduced in CYP7A1-tg mice compared to wild type mice. Metabolomics analysis identified 13 bile acid metabolites that were altered in CYP7A1-tg mice. In CYP7A1-tg mice, TCA and TDCA were reduced, whereas T-β-MCA was increased in the intestine compared to that of wild type mice. The decrease of serum LPC, PC, SM and CER, and 12α-hydroxylated bile acids, and increase of T-β-MCA may contribute to the resistance to diet-induced obesity and diabetes in CYP7A1-tg mice (Fig. 8).

The present metabolomics and lipidomics analysis revealed that even upon challenging with HFD, CYP7A1-tg mice had reduced lipid levels including LPC, PC, SM and CER. Metabolomics studies of human steatotic liver tissues and HFD-fed mice showed that serum and liver LPC and PC and other lipids levels were increased compared with non-steatotic livers, suggesting altered lipid metabolism contributes to non-alcoholic fatty liver disease (NAFLD). In HFD-fed CYP7A1-tg mice, reduced serum PC, LPC, SM and CER levels suggest a role for bile acids in maintaining phospholipid homeostasis to prevent NAFLD. SMs are important membrane phospholipids that interact with cholesterol in membrane rafts and regulate cholesterol distribution and homeostasis. A role for SM and CER in the pathogenesis of insulin resistance, diabetes and obesity and development of atherosclerosis has been reported. CER has a wide range of biological functions in cellular signaling such as activating protein kinase C and c-Jun N-terminal kinase (JNK), induction of β-cell apoptosis and insulin resistance. CER increases reactive oxidizing species and activates the NF-κB pathway, which induces proinflammatory cytokines, diabetes and insulin resistance. CER is synthesized from serine and palmitoyl-CoA or hydrolysis of SM by acid sphingomyelinase (ASM). HFD is known to increase CER and SM in liver. The present observation of decreased SM and CER levels in HFD-fed CYP7A1-tg mice indicated that bile acids might reduce HFD-induced increase of SM and CER. DCA activates an ASM to convert SM to CER, and Asm−/− hepatocytes are resistant to DCA induction of CER and activation of the JNK pathway [65]. In CYP7A1-tg mice, enlarged bile acid pool inhibits CYP8B1 and reduces CA and DCA levels. Thus, decreasing DCA may reduce ASM activity and SM and CER levels, and contribute to reducing inflammation and improving insulin sensitivity in CYP7A1-tg mice. It has been reported recently that in diabetic patients, serum 12α-hydroxylated bile acids are increased and correlated to insulin resistance [66].

Fig. 8. Mechanisms of anti-diabetic and anti-obesity function of bile acids in CYP7A1-tg mice. In CYP7A1-tg mice, overexpressing CYP7A1 increases bile acid pool size and reduces cholic acid by inhibiting CYP8B1. Lipidomics analysis revealed decreased serum LPC, PC, SM and CER. These lipidomic markers are increased in hepatic steatosis and NAFLD. Bile acids may reduce LPC, PC, SM and CER levels and protect against high fat diet-induced insulin resistance and obesity in CYP7A1-tgmice. Metabolomics analysis showed decreased intestinal TCA and TDCA and increased intestinal T-β-MCA in CYP7A1-tgmice.High fat diets are known to increase CA synthesis and intestinal inflammation. It is proposed that decreasing CA and  DCA synthesis may increase intestinal T-β-MCA,which antagonizes FXR signaling to increase bile acid synthesis and prevent high fat diet-induced insulin resistance and obesity. (not shown)

In conclusion,metabolomics and lipidomicswere employed to characterize the metabolic profiles of CYP7A1-tg mice, aiming to provide new insights into the mechanism of bile acid signaling in regulation of lipid metabolism and maintain lipid homeostasis. A number of lipid and bile acid markers were unveiled in this study. Decreasing of lipid markers, especially SM and CER may explain the improved insulin sensitivity and obesity in CYP7A1-tg mice. Furthermore, this study uncovered that enlarged bile acid pool size and altered bile acid composition may reduce de-conjugation by gut microbiota and increase tauroconjugated muricholic acids, which partially inhibit intestinal FXR signaling without affecting hepatic FXR signaling. This study is significant in applying metabolomics for diagnosis of lipid biomarkers for fatty liver diseases, obesity and diabetes. Increasing CYP7A1 activity and bile acid synthesis coupled to decreasing CYP8B1 and 12α-hydroxylated bile acids may be a therapeutic strategy for treating diabetes and obesity.

 

Bile acids are nutrient signaling hormones

Huiping Zhou, Phillip B. Hylemon
Steroids 86 (2014) 62–68
http://dx.doi.org/10.1016/j.steroids.2014.04.016

Bile salts play crucial roles in allowing the gastrointestinal system to digest, transport and metabolize nutrients. They function as nutrient signaling hormones by activating specific nuclear receptors (FXR, PXR, Vitamin D) and G-protein coupled receptors [TGR5, sphingosine-1 phosphate receptor 2 (S1PR2), muscarinic receptors]. Bile acids and insulin appear to collaborate in regulating the metabolism of nutrients in the liver. They both activate the AKT and ERK1/2 signaling pathways. Bile acid induction of the FXR-a target gene, small heterodimer partner (SHP), is highly dependent on the activation PKCf, a branch of the insulin signaling pathway. SHP is an important regulator of glucose and lipid metabolism in the liver. One might hypothesize that chronic low grade inflammation which is associated with insulin resistance, may inhibit bile acid signaling and disrupt lipid metabolism. The disruption of these signaling pathways may increase the risk of fatty liver and non-alcoholic fatty liver disease (NAFLD). Finally, conjugated bile acids appear to promote cholangiocarcinoma growth via the activation of S1PR2.

 

In the past, bile salts were considered to be just detergent molecules that were required for the solubilization of cholesterol in the gall bladder, promoting the digestion of dietary lipids and stimulating the absorption of lipids, cholesterol and fat-soluble vitamins in the intestines. Bile salts were also known to stimulate bile flow, promote cholesterol secretion from the liver, and have antibacterial properties. However, in 1999, three independent laboratories reported that bile acids were natural ligands for the farnesoid X receptor (FXR-α) . The recognition that bile acids activated specific nuclear receptors started a renaissance in the field of bile acid research. Since 1999, bile acids have been reported to activate other nuclear receptors (pregnane X receptor, vitamin D receptor), G protein coupled receptors [TGR5, sphingosine-1-phosphate receptor 2 (S1PR2), muscarinic receptor 2 (M2)] and cell signaling pathways (JNK1/2, AKT, and ERK1/2). Deoxycholic acid (DCA), a secondary bile acid, has also been reported to activate the epidermal growth factor receptor (EGFR). It is now clear that bile acids function as hormones or nutrient signaling molecules that help to regulate glucose, lipid, lipoprotein, and energy metabolism as well as inflammatory responses.

Bile acids are synthesized from cholesterol in liver hepatocytes, conjugated to either glycine or taurine and actively secreted via ABC transporters on the canalicular membrane into biliary bile. Conjugated bile acids are often referred to as bile salts. Bile acid synthesis represents a major output pathway of cholesterol from the body. Bile acids are actively secreted from hepatocytes via the bile salt export protein (BSEP, ABCB11) along with phospholipids by ABCB4 and cholesterol by ABCG5/ABCG8 in a fairly constant ratio under normal conditions. Bile acids are detergent molecules and form mixed micelles with cholesterol and phospholipids, which help to keep cholesterol in solution in the gall bladder. Eating stimulates the gall bladder to contract, emptying its contents into the small intestines. Bile salts are crucial for the solubilization and absorption of cholesterol and lipids as well as lipid soluble vitamins (A, D, E, and K). They activate pancreatic enzymes and form mixed micelles with lipids in the small intestines, promoting their absorption. Bile acids are efficiently recovered from the intestines, primarily the ileum, by the apical sodium dependent transporter (ASBT). Bile acids are secreted from ileocytes, on the basolateral side, by the organic solute OSTα/OSTβ transporter. Secondary bile acids, formed by 7α-dehydroxylation of primary bile acids by anaerobic gut bacteria, can be passively absorbed from the large bowel or secreted in the feces. Absorbed bile acids return to the liver via the portal blood where they are actively transported into hepatocytes primarily via the sodium taurocholate cotransporting polypeptide (NTCP, SLC10A1). Bile acids are again actively secreted from the hepatocytes into the bile, stimulating bile flow and the secretion of cholesterol and phospholipids. Bile acids undergo enterohepatic circulation several times each day (Fig. 1). During their enterohepatic circulation approximately 500–600 mg/day are lost via fecal excretion and must be replaced by new bile acid synthesis in the liver. The bile acid pool size is tightly regulated as excess bile acids can be highly toxic to mammalian cells.

Enterohepatic circulation of bile acids

 

Enterohepatic circulation of bile acids. Bile acids are synthesized and conjugated mainly to glycine or taurine in hepatocytes. Bile acids travel to the gall bladder for storage during the fasting state. During digestion, bile acids travel to the duodenum via the common bile duct. 95% of the bile acids delivered to the duodenum are absorbed back into blood within the ileum and circulate back to the liver through the portal vein. 5% of bile acids are lost in feces.

There are two pathways of bile acid synthesis in the liver, the neutral pathway and the acidic pathway (Fig. 2). The neutral pathway is believed to be the major pathway of bile acid synthesis in humans under normal physiological conditions. The neutral pathway is initiated by cholesterol 7α-hydroxylase (CYP7A1), which is the rate-limiting step in this biochemical pathway. CYP7A1 is a cytochrome P450 monooxygenase, and the gene encoding this enzyme is highly regulated by a feed-back repressive mechanism involving the FXR-dependent induction of fibroblast growth factor 15/19 (FGF15/19) by bile acids in the intestines. FGF15/19 binds to the fibroblast growth factor receptor 4 (FGFR4)/β-Klotho complex in hepatocytes activating both the JNK1/2 and ERK1/2 signaling cascades. Activation of the JNK1/2 pathway has been reported to down-regulate CYP7A1 mRNA in hepatocytes. FGFR4 and β-Klotho mice have increased levels of CYP7A1 and upregulated bile acid synthesis. Moreover, treatment of FXR mice with a specific FXR agonist failed to repress CYP7A1 in the liver. These results support an important role of FGF15, synthesized in the intestines by activation of FXR, in the regulation of CYP7A1 and bile acid synthesis in the liver. CYP7A1 has also been reported to be down-regulated by glucagon and pro-inflammatory cytokines and up-regulated by glucose and insulin during the postprandial period.

Fig. 2. (not shown) Biosynthetic pathways of bile acids. Two major pathways are involved in bile acid synthesis. The neutral (or classic) pathway is controlled by cholesterol 7α-hydroxylase (CYP7A1) in the endoplasmic reticulum. The acidic (or alternative) pathway is controlled by sterol 27-hydroxylase (CYP27A1) in mitochondria. The sterol 12α-hydroxylase (CYP8B1) is required to synthesis of cholic acid (CA). The oxysterol 7α-hydroxylase (CYP7B1) is involved in the formation of chenodeoxycholic acid (CDCA) in acidic pathway. The neutral pathway is also able to form CDCA by CYP27A1.

The neutral pathway of bile acid synthesis produces both cholic acid (CA) and chenodeoxycholic acid (CDCA) (Fig. 2). The ratio of CA and CDCA is primarily determined by the activity of sterol 12α-hydroxylase (CYP8B1). The gene encoding CYP8B1 is also highly regulated by bile acids. Bile acids induce the gene encoding small heterodimer partner (SHP) in the liver via activation of the farnesoid X receptor (FXR-α). SHP is an orphan nuclear receptor without a DNA binding domain. It interacts with several transcription factors, including hepatocyte nuclear factor 4 (HNF4α) and liver-related homolog-1 (LRH-1), and acts as a dominant negative protein to inhibit transcription. In this regard, a liver specific knockout of LRH-1 completely abolished the expression of CYP8B1, but had little effect on CYP7A1. These results suggest that the interaction of SHP with LRH-1, caused by bile acids, may be the key regulator of hepatic CYP8B1 and the ratio of CA/CDCA. The acidic or alternative pathway of bile acid synthesis is initiated in the inner membrane of mitochondria by sterol 27-hydroxylase (CYP27A1). This enzyme also has low sterol 25-hydroxylase activity. CYP27A1 is capable of further oxidizing the 27-hydroxy group to a carboxylic acid. Unlike, CYP7A1, CYP27A1 is widely expressed in various tissues in the body where it may produce regulatory oxysterols. Even though CYP27A1 is the initial enzyme in the acidic pathway of bile acid synthesis, it may not be the rate limiting step. The inner mitochondrial membrane is very low in cholesterol content. Hence, cholesterol transport into the mitochondria appears to be the rate limiting step.

The acidic pathway of bile acid synthesis is now being viewed as an important pathway for generating regulatory oxysterols. For example, 25-hydroxy-cholesterol and 27-hydroxycholesterol are natural ligands for the liver X receptor (LXR), which is involved in regulating cholesterol and lipid metabolism. Moreover, recent studies report that 25-hydroxycholesterol, formed by CYP27A1, can be converted into 5-cholesten-3β-25-diol-3-sulfate in the liver. The sulfated 25-hydroxycholesterol is a regulator of inflammatory responses, lipid metabolism and cell proliferation, and is located in the liver. Recent evidence suggests that sulfated 25-hydroxycholesterol is a ligand for peroxisome proliferator-activated receptor gamma (PPARc), which is a major regulator of inflammation and lipid metabolism. The 7α-hydroxylation of oxysterols is catalyzed by oxysterol 7α-hydroxylase (CYP7B1). This biotransformation allows some of these oxysterols to be converted to bile acids. Finally, oxysterols generated in extrahepatic tissues can be transported to the liver and metabolized into bile acids.

Bile acids can activate several different nuclear receptors (FXR, PXR and Vitamin D) and GPCRs (TGR5, S1PR2, and [M2] Muscarinic receptor). The ability of different bile acids to activate FXR-α occurs in the following order CDCA > LCA = DCA > CA; for the pregnane X receptor (PXR) LCA > DCA > CA and the vitamin D receptor, 3-oxo-LCA > LCA > DCA > CA. LCA is the best activator of PXR and the vitamin D receptor which correlates with the hydrophobicity and toxicity of this bile acid toward mammalian cells. Activation of PXR and the vitamin D receptor induces genes encoding enzymes which metabolize LCA into a more hydrophilic and less toxic metabolite. These nuclear receptors appear to function in the protection of cells from hydrophobic bile acids. In contrast, FXR-α appears to play a much more extensive role in the body by regulating bile acid synthesis, transport, and enterohepatic circulation. Moreover, FXR-α also participates in the regulation of glucose, lipoprotein and lipid metabolism in the liver as well as a suppressor of inflammation in the liver and intestines.

TGR5, also referred to as membrane-type bile acid receptor (MBAR), was the first GPCR to be reported to be activated by bile acids in the order LCA > DCA > CDCA > CA. TGR5 is a Gas type receptor which activates adenyl cyclase activity increasing the rate of the synthesis of c-AMP. TGR5 is widely expressed in human tissues, including: intestinal neuroendocrine cells, gall bladder, spleen, brown adipose tissue, macrophages and cholangiocytes, but not hepatocytes. TGR5 may play a role in various physiological processes in the body. TGR5 appears to be important in regulating energy metabolism. It has been postulated that bile acids may activate TGR5 in brown adipose tissue, activating type 2-iodothyroxine deiodinase and leading to increased levels of thyroid hormone and stimulation of energy metabolism. Moreover, TGR5 has been reported to promote the release of glucagon-like peptide-1 release from neuroendocrine cells, which increases insulin release in the pancreas. These results suggest that TGR5 may play a role in glucose homeostasis in the body. TGR5 is a potential target for drug development for treating type 2 diabetes and other metabolic disorders.

Interrelationship between sphingosine 1-phosphate receptor 2 and the insulin signaling pathway

 

Interrelationship between sphingosine 1-phosphate receptor 2 and the insulin signaling pathway in regulating hepatic nutrient metabolism. S1PR2, sphingosine 1-phosphate receptor 2; Src, Src Kinase; EGFR, epidermal growth factor receptor; PPARa, peroxisome proliferator-activated receptor alpha; NTCP, Na+/taurocholate cotransporting polypeptide; BSEP, bile salt export pump; PC, phosphotidylcholine; PECK, phosphoenolpyruvate carboxykinase; G6Pase, glucose-6-phosphatase; PDK1, phosphoinositide-dependent protein kinase 1; AKT, protein kinase B; SREBP, sterol regulatory element-binding protein; PKCf, protein kinase C zeta; FXR, farnesoid X receptor; SHP, small heterodimeric partner; MDR3, phospholipid transporter (ABCB4); GSK3b, glycogen synthase kinase 3 beta.

 

Both unconjugated and conjugated bile acids activate the insulin signaling (AKT) and ERK1/2 pathways in hepatocytes. Interesting, insulin and bile acids both activated glycogen synthase activity to a similar extent in primary rat hepatocytes. Moreover, the addition of both insulin and bile acids to the culture medium resulted in an additive effect on activation of glycogen synthase activity in primary hepatocytes. Infusion of taurocholate (TCA) into the chronic bile fistula rat rapidly activated the AKT and ERK1/2 signaling pathway and glycogen synthase activity. In addition, there was a rapid down-regulation of the gluconeogenic genes, PEP carboxykinase (PEPCK) and glucose-6-phophatase (G-6-Pase) and a marked up-regulation of SHP mRNA in these sample livers. These results suggest that TCA functions much like insulin to regulate hepatic glucose metabolism both in vitro and in vivo.

It has been reported that PKCζ phosphorylates FXR-α and may allow for its activation of target gene expression. In contrast, phosphorylation of FXR-α by AMPK inhibits the ability of FXR to induce target genes. PKCζ has been reported to be important for the translocation of the bile acid transporters NTCP (SLC10A1) and BSEP (ABC B11) to the basolateral and canalicular membranes, respectively. Finally, it has been recently reported that PKCζ phosphorylates SHP allowing both to translocate to the nucleus and down-regulate genes via epigenetic mechanisms. In total, these results all suggest that the insulin signaling pathway is an important regulator of FXR-α activation and bile acid signaling in the liver.

The activation of the insulin signaling pathway and FXR-α appear to collaborate in the coordinate regulation of glucose, bile acid and lipid metabolism in the liver. SHP, an FXR target gene, is an important pleotropic regulator of multiple metabolic pathways in the liver (Fig. 3). The S1PR2 appears to be an important regulator of hepatic lipid metabolism as S1PR2 mice rapidly (2 weeks) develop overt fatty livers on a high fat diet as compared to wild type mice (unpublished data). It is well established that inflammation and the synthesis of inflammatory cytokines i.e. TNFα inhibit insulin signaling by activation of the JNK1/2 signaling pathway, which phosphorylates insulin receptor substrate 1. Inflammation is believed to be an important factor in the development of type 2 diabetes and fatty liver disease. A Western diet is correlated with low grade chronic inflammation and insulin resistance. Inhibition of the insulin signaling pathway may decrease the ability of bile acids to activate FXR-α, induce SHP and other FXR target genes, leading to an increased risk of fatty liver and non-alcoholic fatty liver disease (NAFLD).

There appears to be extensive interplay between bile salts and insulin signaling in the regulation of nutrient metabolism in both the intestines and liver. Bile salts play a key role in the solubilization and absorption of nutrients from the intestines. The absorption of nutrients stimulates the secretion of insulin from the pancreas. Moreover, bile acids may also stimulate the secretion of insulin by activating TGR5 in intestinal neuroendocrine cells resulting in the secretion of glucagon-like peptide-1. In the liver, bile salts and insulin both activate the AKT and ERK1/2 signaling pathways which yields a stronger signal than either alone. The activation of PKCζ, a branch of the insulin signaling pathway, is required for the optimal induction of FXR target genes and the regulation of the cellular location of bile acid transporters

 

Fruit and vegetable consumption and risk of type 2 diabetes mellitus: A dose-response meta-analysis of prospective cohort studies

  1. Wu, D. Zhang, X. Jiang, W. Jiang
    Nutrition, Metabolism & Cardiovascular Diseases (2015) 25, 140-147
    http://dx.doi.org/10.1016/j.numecd.2014.10.004

Background and aims: We conducted a dose-response meta-analysis to summarize the evidence from prospective cohort studies regarding the association of fruit and vegetable consumption with risk of type 2 diabetes mellitus (T2DM). Methods and results: Pertinent studies were identified by searching Embase and PubMed through June 2014. Study-specific results were pooled using a random-effect model. The dose-response relationship was assessed by the restricted cubic spline model and the multivariate random-effect meta-regression. We standardized all data using a standard portion size of 106 g. The Relative Risk (95% confidence interval) [RR (95% CI)] of T2DM was 0.99 (0.98-1.00) for every 1 serving/day increment in fruit and vegetable (FV) (P < 0.18), 0.98 (0.95-1.01) for vegetable (P < 0.12), and 0.99 (0.97-1.00) for fruit (P < 0.05). The RR (95%CI) of T2DM was 0.99 (0.97-1.01), 0.98 (0.96-1.01), 0.97 (0.93-1.01), 0.96 (0.92-1.01), 0.96 (0.91-1.01) and 0.96 (0.91-1.01) for 1, 2, 3, 4, 5 and 6 servings/day of FV (P for non-linearity < 0.44). The T2DM risk was 0.96 (0.95-0.99), 0.94 (0.90-0.98), 0.94 (0.89-0.98), 0.96 (0.91-1.01), 0.98 (0.92-1.05) and 1.00 (0.93-1.08) for 1, 2, 3, 4, 5 and 6 servings/day of vegetable (P for non-linearity < 0.01). The T2DM risk was 0.95 (0.93-0.97), 0.91 (0.89-0.94), 0.88 (0.85-0.92), 0.92 (0.88-0.96) and 0.96 (0.92-1.01) for 0.5, 1, 2, 3 and 4 servings/day of fruit (P for non-linearity < 0.01). Conclusions: Two-three servings/day of vegetable and 2 servings/day of fruit conferred a lower risk of T2DM than other levels of vegetable and fruit consumption, respectively.

dose-response analysis between total fruit and vegetable consumption and risk of type 2 diabetes mellitus

 

The dose-response analysis between total fruit and vegetable consumption and risk of type 2 diabetes mellitus. The solid line and the long dash line represent the estimated relative risk and its 95% confidence interval.

 

Healthy behaviours and 10-year incidence of diabetes: A population cohort study

G.H. Long , I. Johansson , O. Rolandsson , …, E. Fhärm, L.Weinehall, et al.
Preventive Medicine 71 (2015) 121–127
http://dx.doi.org/10.1016/j.ypmed.2014.12.013

Objective. To examine the association between meeting behavioral goals and diabetes incidence over 10 years in a large, representative Swedish population. Methods. Population-based prospective cohort study of 32,120 individuals aged 35 to 55 years participating in a health promotion intervention in Västerbotten County, Sweden (1990 to 2013). Participants underwent an oral glucose tolerance test, clinical measures, and completed diet and activity questionnaires. Poisson regression quantified the association between achieving six behavioral goals at baseline – body mass index (BMI) < 25 kg/m2, moderate physical activity, non-smoker, fat intake  < 30% of energy, fibre intake ≥15 g/4184 kJ and alcohol intake ≤ 20 g/day – and diabetes incidence over 10 years. Results. Median interquartile range (IQR) follow-up time was 9.9 (0.3) years; 2211 individuals (7%) developed diabetes. Only 4.4% of participants met all 6 goals (n = 1245) and compared to these individuals, participants meeting 0/1 goals had a 3.74 times higher diabetes incidence (95% confidence interval (CI) = 2.50 to 5.59), adjusting for sex, age, calendar period, education, family history of diabetes, history of myocardial infarction and long-term illness. If everyone achieved at least four behavioral goals, 14.1% (95% CI: 11.7 to 16.5%) of incident diabetes cases might be avoided. Conclusion. Interventions promoting the achievement of behavioral goals in the general population could significantly reduce diabetes incidence.

 

Long term nutritional intake and the risk for non-alcoholic fatty liver disease (NAFLD): A population based study

Shira Zelber-Sagi, Dorit Nitzan-Kaluski, Rebecca Goldsmith, et al.
Journal of Hepatology 47 (2007) 711–717
http://dx.doi.org:/10.1016/j.jhep.2007.06.020

Background/Aims: Weight loss is considered therapeutic for patients with NAFLD. However, there is no epidemiological evidence that dietary habits are associated with NAFLD. Dietary patterns associated with primary NAFLD were investigated. Methods: A cross-sectional study of a sub-sample (n = 375) of the Israeli National Health and Nutrition Survey. Exclusion criteria were any known etiology for secondary NAFLD. Participants underwent an abdominal ultrasound, biochemical tests, dietary and anthropometric evaluations. A semi-quantitative food-frequency questionnaire was administered. Results: After exclusion, 349 volunteers (52.7% male, mean age 50.7 ± 10.4, 30.9% primary NAFLD) were included. The NAFLD group consumed almost twice the amount of soft drinks (P = 0.03) and 27% more meat (P < 0.001). In contrast, the NAFLD group consumed somewhat less fish rich in omega-3 (P = 0.056). Adjusting for age, gender, BMI and total calories, intake of soft drinks and meat was significantly associated with an increased risk for NAFLD (OR = 1.45, 1.13–1.85 95% CI and OR = 1.37, 1.04–1.83 95% CI, respectively). Conclusions: NAFLD patients have a higher intake of soft drinks and meat and a tendency towards a lower intake of fish rich in omega-3. Moreover, a higher intake of soft drinks and meat is associated with an increased risk of NAFLD, independently of age, gender, BMI and total calories.

 

The association between types of eating behavior and dispositional mindfulness in adults with diabetes. Results from Diabetes MILES. The Netherlands

Sanne R. Tak, Christel Hendrieckx, Giesje Nefs, Ivan Nyklícek, et al.
Appetite 87 (2015) 288–295
http://dx.doi.org/10.1016/j.appet.2015.01.006

Although healthy food choices are important in the management of diabetes, making dietary adaptations is often challenging. Previous research has shown that people with type 2 diabetes are less likely to benefit from dietary advice if they tend to eat in response to emotions or external cues. Since high levels of dispositional mindfulness have been associated with greater awareness of healthy dietary practices in students and in the general population, it is relevant to study the association between dispositional mindfulness and eating behavior in people with type 1 or 2 diabetes. We analyzed data from Diabetes MILES – The Netherlands, a national observational survey in which 634 adults with type 1 or 2 diabetes completed the Dutch Eating Behavior Questionnaire (to assess restrained, external and emotional eating behavior) and the Five Facet Mindfulness Questionnaire-Short Form (to assess dispositional mindfulness), in addition to other psychosocial measures. After controlling for potential confounders, including  demographics, clinical variables and emotional distress, hierarchical linear regression analyses showed that higher levels of dispositional mindfulness were associated with eating behaviors that were more restrained (β = 0.10) and less external (β = −0.11) and emotional (β = −0.20). The mindfulness subscale ‘acting with awareness’ was the strongest predictor of both external and emotional eating behavior, whereas for emotional eating, ‘describing’ and ‘being non-judgmental’ were also predictive. These findings suggest that there is an association between dispositional mindfulness and eating behavior in adults with type 1 or 2 diabetes. Since mindfulness interventions increase levels of dispositional mindfulness, future studies could examine if these interventions are also effective in helping people with diabetes to reduce emotional or external eating behavior, and to improve the quality of their diet.

 

Soft drink consumption is associated with fatty liver disease independent of metabolic syndrome

Ali Abid, Ola Taha, William Nseir, Raymond Farah, Maria Grosovski, Nimer Assy
Journal of Hepatology 51 (2009) 918–924
http://dx.doi.org:/10.1016/j.jhep.2009.05.033

Background/Aims: The independent role of soft drink consumption in non-alcoholic fatty liver disease (NAFLD) patients remains unclear. We aimed to assess the association between consumption of soft drinks and fatty liver in patients with or without metabolic syndrome. Methods: We recruited 31 patients (age: 43 ± 12 years) with NAFLD and risk factors for metabolic syndrome, 29 patients with NAFLD and without risk factors for metabolic syndrome, and 30 gender- and age-matched individuals without NAFLD. The degree of fatty infiltration was measured by ultrasound. Data on physical activity and intake of food and soft drinks were collected during two 7-day periods over 6 months using a food questionnaire. Insulin resistance, inflammation, and oxidant–antioxidant markers were measured.
Results: We found that 80% of patients with NAFLD had excessive intake of  soft drink beverages (>500 cm3/day) compared to 17% of healthy controls (p < 0.001). The NAFLD group consumed five times more carbohydrates from soft drinks compared to healthy controls (40% vs. 8%, p < 0.001). Seven percent of patients consumed one soft drink per day, 55% consumed two or three soft drinks per day, and 38% consumed more than four soft drinks per day for most days and for the 6-month period. The most common soft drinks were Coca-Cola (regular: 32%; diet: 21%) followed by fruit juices (47%). Patients with NAFLD with metabolic syndrome had similar malonyldialdehyde, paraoxonase, and C-reactive protein (CRP) levels but higher homeostasis model assessment (HOMA) and higher ferritin than NAFLD patients without metabolic syndrome (HOMA: 8.3 ± 8 vs. 3.7 ± 3.7 mg/dL, p < 0.001; ferritin: 186 ± 192 vs. 87 ± 84 mg/dL, p < 0.01). Logistic regression analysis showed that soft drink consumption is a strong predictor of fatty liver (odds ratio: 2.0; p < 0.04) independent of metabolic syndrome and CRP level. Conclusions: NAFLD patients display higher soft drink consumption independent of metabolic syndrome diagnosis. These findings might optimize NAFLD risk stratification.

 

Dietary predictors of arterial stiffness in a cohort with type 1 and type 2 diabetes

K.S. Petersen, J.B. Keogh, P.J. Meikle, M.L. Garg, P.M. Clifton
Atherosclerosis 238 (2015) 175-181
http://dx.doi.org/10.1016/j.atherosclerosis.2014.12.012

Objective: To determine the dietary predictors of central blood pressure, augmentation index and pulse wave velocity (PWV) in subjects with type 1 and type 2 diabetes. Methods: Participants were diagnosed with type 1 or type 2 diabetes and had PWV and/or pulse wave analysis performed. Dietary intake was measured using the Dietary Questionnaire for Epidemiological Studies Version 2 Food Frequency Questionnaire. Serum lipid species and carotenoids were measured, using liquid chromatography electrospray ionization- tandem mass spectrometry and high performance liquid chromatography, as biomarkers  of dairy and vegetable intake, respectively. Associations were determined using linear regression adjusted for potential confounders. Results: PWV (n = 95) was inversely associated with reduced fat dairy intake (β = -0.01; 95% CI -0.02, -0.01; p = 0 < 0.05) in particular yoghurt consumption (β = 0.04; 95% CI -0.09, -0.01; p = 0 < 0.05) after multivariate adjustment. Total vegetable consumption was negatively associated with PWV in the whole cohort after full adjustment (β =0.04; 95% CI -0.07, -0.01; p < 0.05). Individual lipid species, particularly those containing 14:0, 15:0, 16:0, 17:0 and 17:1 fatty acids, known to be of ruminant origin, in lysophosphatidylcholine, cholesterol ester, diacylglycerol, phosphatidylcholine, sphingomyelin and triacylglycerol classes were positively associated with intake of full fat dairy, after adjustment for multiple comparisons. However, there was no association between serum lipid species and PWV. There were no dietary predictors of central blood pressure or augmentation index after multivariate adjustment. Conclusion: In this cohort of subjects with diabetes reduced fat dairy intake and vegetable consumption were inversely associated with PWV. The lack of a relationship between serum lipid species and PWV suggests that the fatty acid composition of dairy may not explain the beneficial effect.

In this cohort with type 1 and type 2 diabetes there was an inverse association between reduced fat dairy intake, in particular yoghurt consumption, and PWV, which persisted after multivariate adjustment. Serum lipid species, known to be of ruminant origin, were positively associated with full fat dairy consumption; however there was no association between these lipid species and PWV. In addition, higher vegetable intake was also associated with lower PWV. There were no dietary predictors of central blood pressure or augmentation index identified in this cohort.

In this study there was no relationship between augmentation index and PWV, which has been previously reported. Augmentation index is not a direct measure of arterial stiffness and is influenced by the timing and magnitude of the wave reflection. In contrast, PWV is a robust measure of arterial stiffness as it is determined by measuring the velocity of the waveform between the carotid and femoral arteries. Previously, it has been shown that in a population with diabetes PWV was elevated compared with healthy controls, however augmentation index was not different. Lacy et al.  concluded that augmentation index is not a reliable measure of arterial stiffness in people with diabetes. This may explain why we did not see an association between augmentation index and dietary intake, despite seeing correlations with PWV.

 

Curcumin ameliorates diabetic nephropathy by inhibiting the activation of the SphK1-S1P signaling pathway

Juan Huang, Kaipeng Huang, Tian Lan, Xi Xie, .., Peiqing Liu, Heqing Huang
Molecular and Cellular Endocrinology 365 (2013) 231–240
http://dx.doi.org/10.1016/j.mce.2012.10.024

Curcumin, a major polyphenol from the golden spice Curcuma longa commonly known as turmeric, has been recently discovered to have renoprotective effects on diabetic nephropathy (DN). However, the mechanisms underlying these effects remain unclear. We previously demonstrated that the sphingosine kinase 1-sphingosine 1-phosphate (SphK1-S1P) signaling pathway plays a pivotal role in the pathogenesis of DN. This study aims to investigate whether the renoprotective effects of curcumin on DN are associated with its inhibitory effects on the SphK1-S1P signaling pathway. Our results demonstrated that the expression and activity of SphK1 and the production of S1P were significantly down-regulated by curcumin in diabetic rat kidneys and glomerular mesangial cells (GMCs) exposed to high glucose (HG). Simultaneously, SphK1-S1P-mediated fibronectin (FN) and transforming growth factor-beta 1 (TGF-b1) overproduction were inhibited. In addition, curcumin dose dependently reduced SphK1 expression and activity in GMCs transfected with SphKWT and significantly suppressed the increase in SphK1-mediated FN levels. Furthermore, curcumin inhibited the DNA-binding activity of activator protein 1 (AP-1), and c-Jun small interference RNA (c-Jun-siRNA) reversed the HG-induced up-regulation of SphK1. These findings suggested that down-regulation of the SphK1-S1P pathway is probably a novel mechanism by which curcumin improves the progression of DN. Inhibiting AP-1 activation is one of the therapeutic targets of curcumin to modulate the SphK1-S1P signaling pathway, thereby preventing diabetic renal fibrosis.

The creation of the STZ-induced DN model relies on the level and continuous cycle of high blood glucose in vivo. Long-term hyperglycemia induces significant structural changes in the kidney, including glomerular hypertrophy, GBM thickening, and later glomerulosclerosis and tubulointerstitial fibrosis, leading to microalbuminuria and elevated Cr levels. These effects usually occur at around 8–12 weeks after diabetes formation. In the current study, the experimental diabetic model was induced by a single intraperitoneal injection of STZ (60 mg/kg). When the experiment was terminated at 12 weeks, FBG, KW/BW, BUN, Cr, and UP 24 h were significantly increased and body weight was remarkably decreased in the STZ-induced diabetic rats compared with those in the normal control group. Furthermore, PAS staining of the kidneys revealed the induction of glomerular hypertrophy, mesangial matrix expansion, and increased regional adhesion of the glomerular tuft to the Bowman’s capsule in the diabetic rats. This finding indicated the emergence of the diabetic renal injury model characterized by renal hypertrophy, glomerulus damage, and renal dysfunction. As the limited water solubility of curcumin, various methods such as heat treatment, mild alkali and sodium carboxymethyl cellulose are used to increase the solubility of curcumin before administration. Based on our previous study, we employed 1% sodium carboxymethyl cellulose as the vehicle to solubilize curcumin. Compared with the diabetic group, curcumin treatment slightly reduced FBG level and significantly decreased KW/BW, BUN, Cr, and UP 24 h. Moreover, curcumin remarkably improved glomerular pathological changes in the diabetic kidneys. Consistent with previous studies, the current results demonstrated that curcumin prominently ameliorated renal function and renal parenchymal alterations in the diabetic renal injury model. Previous studies revealed that the amelioration of renal dysfunction in diabetes by curcumin was partly related to its function in inhibiting inflammatory injury. Based on these findings, the current experiment further explored whether the renoprotective effects of curcumin are associated with the regulation of the SphK1-S1P signaling pathway.

S1P is a polar sphingolipid metabolite acting as an extracellular mediator and an intracellular second messenger. Ample evidence proves that S1P participates in cell growth, proliferation, migration, adhesion, molecule expression, and angiogenesis. The formation of S1P is catalyzed by SphK1. Recently, the SphK1-S1P signaling pathway has gained considerable attention because of its potential involvement in the progression of DN. Hyperglycemia, AGE, and oxidative stress can activate SphK1 and can increase the intracellular level of S1P. Geoffroy et al. (2004) reported that the treatment of cells with low AGE concentration increases SphK activity and S1P production, thereby and S1P content were significantly increased simultaneously with the up-regulated expression of FN and TGF-β1 (mRNA and protein) in the diabetic rat kidneys. These findings indicated the activation of the SphK1-S1P signaling pathway and the appearance of pathological alterations, including ECM accumulation. After curcumin treatment for 12 weeks, elevations of the said indexes were significantly inhibited. HG remarkably activated the SphK1-S1P signaling pathway and increased FN and TGF-β1 expressions in GMCs. Curcumin dramatically suppressed the SphK1-S1P pathway as well as FN and TGF-β1 levels in a dose-dependent manner. Overall, these results indicated that curcumin ameliorated the pathogenic progression of DN by inhibiting the activation of the SphK1-S1P signaling pathway, resulting in the down-regulation of TGF-β1 and the subsequent reduction of ECM accumulation.

SphK1 expression is mediated by a novel AP-1 element located within the first intron of the human SphK1 gene. AP-1 sites are also found in rat SphK1 promoter from NCBI. Numerous studies indicated that curcumin can inhibit the activity of AP-1 and is widely used as an AP-1 inhibitor. Therefore, further elucidating the link between the inhibition of the SphK1-S1P signaling pathway by curcumin and the suppression of AP-1 activity is important. The data showed that treatment with c-Jun-siRNA significantly down-regulated the basal levels of SphK1 expression. Thus, inhibiting AP-1 activity is one of the therapeutic targets of curcumin in modulating the SphK1-S1P signaling pathway, thereby inhibiting diabetic renal fibrosis.

In summary, curcumin inhibited SphK1 expression and activity, reduced S1P content, and effectively inhibited increased FN and TGF-β1 expressions mediated by the SphK1-S1P signaling pathway. Moreover, the inhibitory effect of curcumin on SphK1-S1P was independent of its hypoglycemic and anti-oxidant roles and might be closely related to the inhibition of AP-1 activity. Our findings suggested that the SphK1-S1P pathway might be a novel mechanism by which curcumin attenuates renal fibrosis and ameliorates DN. In addition, the present study provides further experimental evidence for the clinical application and new drug exploration of curcumin.

 

Antidiabetic Activity of Hydroalcoholic Extracts of Nardostachys jatamansi in Alloxan-induced Diabetic Rats

  1. A. Aleem, B. Syed Asad, Tasneem Mohammed, et al.
    British Journal of Medicine & Medical Research 4(28): 4665-4673, 2014

A review of literature indicates that diabetes mellitus was fairly well known and well conceived as an entity in India with complications like angiopathy, retinopathy, nephropathy, and causing neurological disorders. The antidiabetic study was carried out to estimate the anti-hyperglycemic potential of Nardostachys Jatamansi rhizome’s hydroalcoholic extracts in alloxan induced diabetic rats over a period of two weeks. The hydroalcoholic extract HAE1 at a dose (500mg/kg) exhibited significant antihyperglycemic activity than extract HAE2 at a dose (500mg/kg) in diabetic rats. The hydroalcoholic extracts showed improvement in different parameters associated with diabetes, like body weight, lipid profile and biochemical parameters. Extracts also showed improvement in regeneration of β-cells of pancreas in diabetic rats. Histopath-ological studies strengthen the healing of pancreas by hydroalcoholic extracts (HAE1& HAE2) of Nardostachys Jatamansi, as a probable mechanism of their antidiabetic activity.
Metabolic syndrome and serum carotenoids : findings of a cross-sectional study in Queensland, Australia

Coyne, T, Ibiebele, T,… McClintock, C and Shaw, J
Brit J Nutrition: Int J Nutr Sci 2009; 102(11). pp. 1668-1677
Several components of the metabolic syndrome, particularly diabetes and cardiovascular disease, are known to be oxidative stress-related conditions and there is research to suggest that antioxidant nutrients may play a protective role in these conditions. Carotenoids are compounds derived primarily from plants and several have been shown to be potent antioxidant nutrients. The aim of this study was to examine the associations between metabolic syndrome status and major serum carotenoids in adult Australians. Data on the presence of the metabolic syndrome, based on International Diabetes Federation criteria, were collected from 1523 adults aged 25 years and over in six randomly selected urban centers in Queensland, Australia, using a cross sectional study design. Weight, height, BMI, waist circumference, blood  pressure, fasting and 2-hour blood glucose and  lipids were determined, as well as five serum carotenoids. Mean serum alpha-carotene, beta-carotene and the sum of the five carotenoid concentrations were significantly lower (p<0.05) in persons with the metabolic syndrome (after adjusting for age, sex, education, BMI status, alcohol intake, smoking, physical activity status and vitamin/mineral use) than persons without the syndrome. Alpha, beta and total carotenoids also decreased significantly (p<0.05) with increased number of components of the metabolic syndrome, after adjusting for these confounders. These differences were significant among former smokers and non-smokers, but not in current smokers. Low concentrations of serum alpha-carotene, beta carotene and the sum of five carotenoids appear to be associated with metabolic syndrome status. Additional research, particularly longitudinal studies, may help to determine if these associations are causally related to the metabolic syndrome, or are a result of the pathologies of the syndrome.

Although there is no universal definition of the metabolic syndrome, it is generally described as a constellation of pathologies or anthropometric conditions, which include central obesity, glucose intolerance, lipid abnormalities, and hypertension. It is, however, universally accepted that the presence of the metabolic syndrome is associated with increased risk of type 2 diabetes and cardiovascular disease. The prevalence of the metabolic syndrome in developed countries varies widely depending upon definitions used and age ranges included, but is estimated to be 24% among adults 20 years and over in the US. Given the impending worldwide epidemic of obesity, diabetes and cardiovascular disease, strategies aimed at greater understanding of the pathology of the syndrome, as well as strategies aimed at preventing or treating persons with the syndrome are urgently required.

Few studies have investigated associations of antioxidant nutrients and the metabolic syndrome. Ford and colleagues reported lower levels of several carotenoids and vitamins C and E among those with metabolic syndrome present compared with those without the syndrome in the Third National Health and Nutrition Examination Survey. Sugiura et al.  suggested that several carotenoids may exert a protective effect against the development of the metabolic syndrome, especially among current smokers. Confirming these findings in another population may add strength to these associations.

Our study showed significantly lower concentrations of β-carotene, α-carotene and the sum of the five carotenoids among those with the metabolic syndrome present compared to those without. We also found decreasing concentrations of all the carotenoids tested as the number of the metabolic syndrome components increased. These findings are consistent with data reported by Ford et al. from the third 262 National Health and Nutrition Examination Survey (NHANES III). In the NHANES III study, significantly lower concentrations of all the carotenoids, except lycopene, were found among persons with the metabolic syndrome compared with those without, after adjusting for  confounding factors similar to those in our study.

 

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