Anorexia nervosa and bulimia nervosa

Anorexia nervosa (AN) and bulimia nervosa (BN) are eating disorders characterized by pathological alterations in food intake. These disorders are more common among young females, although they can also affect males and older females. Rigid restriction of food intake, which can alternate with loss of control in the drive to eat, is the most striking behavioral change seen in patients with AN and BN, respectively. Some of the endocrine changes and clinical outcomes of patients with eating disorders are a mechanism to save energy and promote survival. Hypogonadism is the most striking endocrine change in patients with eating disorders, with amenorrhea as the main manifestation. Other endocrine alterations may include low T3 syndrome, hypercortisolism, loss of bone mineral density, and changes in the somatotropic axis and the glucose homeostasis. Hypoleptinemia, caused by food restriction and by the decrease of adipose tissue mass, seems to be the mediator of these endocrine changes. However, other adipocytokines and hormones involved in the regulation of food intake may also play a role in the development of the endocrine outcomes.