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Posts Tagged ‘hypogonadism’


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

Hypopituitarism is a partial or complete insufficiency of pituitary hormone secretion that may be derived from pituitary or hypothalamic disease. Onset can be at any time of life. Intrinsic pituitary disease, or any process that disrupts the pituitary stalk or damages the hypothalamus, may produce pituitary hormone deficiency. The clinical presentation of hypopituitarism widely varies, depending on patient age and on the specific hormone deficiencies, which may occur singly or in various combinations. As a general rule, diagnosis of a single pituitary hormone deficiency requires evaluating the other hormone axes.

Etiology

Hypopituitarism has multiple possible etiologies either from congenital or acquired mechanisms. The common endpoint is disrupted synthesis or release of 1 or more pituitary hormones, resulting in clinical manifestations of hypopituitarism. Genetic causes of hypopituitarism are relatively rare. However, research since the late 20th century has brought considerable advances in the understanding of the various genetic causes of congenital hypopituitarism. Inheritance patterns may be autosomal recessive, autosomal dominant, or X-linked recessive. The phenotype and severity of clinical findings in congenital hypopituitarism are determined by the specific genetic mutation. Causes of hypopituitarism can be divided into categories of congenital and acquired causes.

Congenital causes of hypopituitarism include the following:

  • Perinatal insults (eg, traumatic delivery, birth asphyxia)
  • Interrupted pituitary stalk
  • Absent or ectopic neurohypophysis
  • Pallister-Hall syndrome

Multiple Pituitary Hormone Deficiency is rare in childhood, with a possible incidence of fewer than 3 cases per million people per year. The most common pituitary hormone deficiency, growth hormone deficiency (GHD), is much more frequent; a US study reported a prevalence of 1 case in 3480 children.A 2001 population study in adults in Spain estimated the annual incidence of hypopituitarism at 4.2 cases per 100,000 population. Because hypopituitarism has congenital and acquired forms, the disease can occur in neonates, infants, children, adolescents, and adults.

Prognosis

With appropriate treatment, the overall prognosis in hypopituitarism is very good. Sequels from episodes of severe hypoglycemia, hypernatremia, or adrenal crises are among potential complications. Long-term complications include short stature, osteoporosis, increased cardiovascular morbidity/mortality, and infertility. Previous findings of increased cardiovascular morbidity and decreased life expectancy in adults with hypopituitarism were thought to be largely secondary to untreated GHD.

Mortality/morbidity

Morbidity and mortality statistics generally cannot be viewed in isolation but must instead be related to the underlying cause of hypopituitarism. For example, morbidity and mortality are minimal in the context of idiopathic GHD compared with hypopituitarism caused by craniopharyngioma. Recognition of pituitary insufficiency and appropriate hormone replacement (including stress doses of hydrocortisone, when indicated) are essential for the avoidance of unnecessary morbidity and mortality. Clinical manifestations of isolated or multiple deficiencies in pituitary hormones (anterior and/or posterior) can result in significant sequelae that include any of the following:

  • Hypoglycemia – Can cause convulsions; persistent, severe hypoglycemia can cause permanent CNS injury.
  • Adrenal crisis – Can occur during periods of significant stress, from ACTH or CRH deficiency; symptoms include profound hypotension, severe shock, and death.
  • Short stature – Can have significant psychosocial consequences.
  • Hypogonadism and impaired fertility – From gonadotropin deficiency
  • Osteoporosis – Results in increased fracture risk

GHD is believed to be an important contributing factor to morbidity and mortality associated with hypopituitarism. In a 2008 study, childhood onset GHD was associated with an increased hazard ratio for morbidity of greater than 3.0 for males and females. Causes of morbidity and mortality are multifactorial and relate to the specific cause of hypopituitarism, as well as to the degree of pituitary hormone deficiency.

Source References:

http://tbccn.org/CCJRoot/v9n3/pdf/212.pdf

http://emedicine.medscape.com/article/922410-overview

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