Altered hypothalamic-pituitary-ovarian axis function in young female athletes: implications and recommendations for management.

Young women have become increasingly active in athletics during the 20th century. Those involved in sports that emphasize lean body type are at high risk for the development of menstrual dysfunction, including amenorrhea. This is mediated by an alteration in function of the hypothalamic-pituitary-ovarian (HPO) axis, with loss of normal secretion of luteinizing hormone, and subsequent lack of estrogen production. Disruption of the HPO axis appears to be dependent on the body's recognition of an energy imbalance, which may be due to a lack of compensatory caloric intake in the face of significant energy expenditure. Other pituitary hormones, such as triiodothyronine, growth hormone, and insulin-like growth factor-1 may also be affected. These metabolic changes have an impact on bone mineralization during a critical period in the development of bone mass. Recognition by physicians of the so-called 'female athlete triad', consisting of disordered eating, amenorrhea, and osteoporosis, may allow therapeutic intervention. Diagnosis of eating disorders and decreased bone mineral density can have significant impact on the health of the young athlete. Treatment is aimed at restoring normal menstrual function by increasing caloric intake to balance the increased energy demands of athletic participation. Concurrent treatment of the hypoestrogenemic state using estrogen replacement is controversial, but may aid in alleviating further loss of bone mass.