ALTERED ADRENAL-STEROID METABOLISM UNDERLYING HYPERCORTISOLISM IN FEMALE ENDURANCE ATHLETES

Objective: To explore possible changes in adrenal steroid metabolism a nd androgenic-anabolic status in female endurance athletes as a mechan ism for their hypercortisolism. Design: Adrenal steroids and androgeni c-anabolic factors were studied during basal conditions and in respons e to ACTH stimulation related to menstrual status. Setting: Department of Obstetrics and Gynecology, Karolinska Hospital, Stockholm, Sweden. Participants: Thirteen female elite middle to long distance runners ( six eumenorrheic, seven oligoamenorrheic) and seven regularly menstrua ting controls. Interventions: Blood samples were collected before and after an injection of 250 mu g TV synthetic ACTH 1-24. Body weight, he ight, and body fat were measured. Main Outcome Measures: Basal serum c oncentrations of cortisol, androstenedione (A), DHEA, DHEAS, 17 alpha- hydroxyprogesterone (17-OHP), T, steroid-binding proteins, and insulin -like growth factor I and ACTH-induced response (area under the curve) of cortisol, DHEA, and 17-OHP. Results: Oligoamenorrheic athletes had higher basal cortisol and A concentrations compared with healthy cont rols, whereas basal levels of DHEA and DHEAS were normal. Important fi ndings in the oligoamenorrheic athletes were a significantly lower rat io between the ACTH-induced increments of DHEA and 17-OHP and an incre ased ratio between basal A and DHEAS. Insulin-like growth factor I was correlated negatively to sex hormone-binding globulin and to the amou nt of body fat in the combined material. Conclusions: The results indi cate a redistribution of adrenal steroid metabolism in favor of glucoc orticoid production in female endurance athletes. We suggest that hype rcortisolism in female endurance athletes is a physiological adaptatio n to maintain adequate blood glucose levels during a condition of ener gy deficiency.