Effects of Anorexia Nervosa on the Endocrine System.

Anorexia nervosa (AN) is characterized by severe undernutrition associated with alterations in multiple endocrine axes, which are primarily adaptive to the state of caloric deprivation. Hormonal changes include growth hormone (GH) resistance with low insulin like growth factor-1 (IGF-1) levels, hypothalamic hypogonadism, relative hypercortisolemia and changes in appetite regulating hormones, including leptin, ghrelin, and peptide YY. These alterations contribute to abnormalities in bone metabolism leading to low bone mass, impaired bone microarchitecture, and increased risk for fracture, and may also negatively impact cognition, emotions and mood. The best strategy to improve all biologic outcomes is weight and menstrual recovery. Physiological estrogen replacement improves bone accrual rates and measures of trait anxiety in adolescents with AN. Other therapies including testosterone and IGF-1 replacement, and use of DHEA with oral estrogen-progesterone combination pills, bisphosphonates and teriparatide have also been studied to improve bone outcomes.