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Effect of Dietary Magnesium Intake on Insulin Resistance

Reporter: Larry H. Bernstein, MD, FCAP

Dietary Magnesium Intake Improves Insulin Resistance among Non-Diabetic Individuals with Metabolic Syndrome Participating in a Dietary Trial

J Wang^1,2,†, G Persuitte³,†, BC Olendzki², NM Wedick², …, and Yunsheng Ma 2,*
1 Department of Preventive Medicine, Medical School of Yangzhou University, Yangzhou 225001, China
2 Division of Preventive and Behavioral Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
3 Division of Biostatistics and Health Services Research, Department of Quantitative Health Science, University of Massachusetts Medical School, Worcester, MA 01655, USA †

Nutrients 27 Sep 2013; 5(10):3910-3919; http://dx.doi.org/10.3390/nu5103910

Many cross-sectional studies show

1. an inverse association between dietary magnesium and insulin resistance, but
2. few longitudinal studies examine the ability to meet the Recommended Dietary Allowance (RDA)

• for magnesium intake through food and
• its effect on insulin resistance among participants with metabolic syndrome (MetS).

The dietary intervention study examined this question in 234 individuals with MetS. Magnesium intake was assessed using 24-h dietary recalls at baseline, 6, and 12 months.

1. Fasting glucose and insulin levels were collected at each time point; and
2. insulin resistance was estimated by the homeostasis model assessment (HOMA-IR).

The relation between magnesium intake and HOMA-IR was assessed using linear mixed models adjusted for covariates.

• Baseline magnesium intake was 287 ± 93 mg/day (mean ± standard deviation), and
• HOMA-IR, fasting glucose and fasting insulin were 3.7 ± 3.5, 99 ± 13 mg/dL, and 15 ± 13 μU/mL, respectively.

At baseline, 6-, and 12-months, 23.5%, 30.4%, and 27.7% met the RDA for magnesium. After multivariate adjustment,

• magnesium intake was inversely associated with metabolic biomarkers of insulin resistance (P < 0.01).

Further, the likelihood of elevated HOMA-IR (>3.6) over time was 71% lower [odds ratio (OR): 0.29; 95% confidence interval (CI): 0.12, 0.72] in participants

• in the highest quartile of magnesium intake than those in the lowest quartile.

For individuals meeting the RDA for magnesium,

• the multivariate-adjusted OR for high HOMA-IR over time was 0.37 (95% CI: 0.18, 0.77).

These findings indicate that dietary magnesium intake is inadequate among non-diabetic individuals with MetS and suggest that

• increasing dietary magnesium to meet the RDA has a protective effect on insulin resistance.

Keywords: magnesium; insulin resistance; metabolic syndrome; epidemiology

Cite This Article

Wang J, Persuitte G, Olendzki BC, Wedick NM, Zhang Z, Merriam PA, Fang H, Carmody J, Olendzki G-F, Ma Y. Dietary Magnesium Intake Improves Insulin Resistance among Non-Diabetic Individuals with Metabolic Syndrome Participating in a Dietary Trial. Nutrients. 2013; 5(10):3910-3919.