High serum cortisol levels in exercise-associated amenorrhea.

Abstract

To determine whether basal cortisol levels are elevated in exercise-associated amenorrhea. Survey, with hormone levels measured weekly for 1 month and patients followed clinically for 6 months. Volunteers were recruited through media advertisements and fliers. Ninety-two women were enrolled; 71 (77%) completed the study. Subjects were grouped by menstrual and activity histories reported by a self-administered questionnaire. After 6 months, final groups were assigned: amenorrheic athletes, 19; eumenorrheic athletes, 35; a transition group of amenorrheic athletes who had resumed menses after entering the study, 7; and normal cyclic nonathletes, 10. Four weekly resting blood samples (0800 to 1000 hours) were obtained and measured for cortisol, estradiol, progesterone, and prolactin levels. Lumbar bone mineral density was measured by dual-photon densitometry. Mean (+/- SE) cortisol levels were higher in amenorrheic athletes (585 +/- 33 nmol/L) than in eumenorrheic athletes (411 +/- 14 nmol/L), transition athletes (378 +/- 33 nmol/L), or nonathletic women (397 +/- 30 nmol/L) (P less than 0.01). Of nine women with abnormally high cortisol levels (greater than 579 nmol/L), eight were amenorrheic athletes, and one was a eumenorrheic athlete. Bone mineral density was lower in amenorrheic athletes than in the other three groups (P less than 0.01). Increased glucocorticoid levels may be an etiologic factor in exercise-associated amenorrhea. High cortisol levels could also contribute to decreased bone density. The failure of amenorrheic athletes with hypercortisolemia to regain menses within 6 months suggests that they are at risk for a prolonged acyclic state.