Objective: To evaluate endocrine mechanisms underlying oligomenorrhea or amenorrhea in female athletes.
Design: Cross-sectional study.
Setting: Women's health clinical research unit at a university hospital.
Patient(s): Age- and BMI-matched groups of athletes active in endurance sports with and without menstrual disturbances and regularly cycling sedentary controls.
Intervention(s): Groups were compared with respect to endocrine status, body composition, and physical performance.
Main outcome measure(s): Identification of a subgroup of oligomenorrheic or amenorrheic athletes with increased androgen levels and anabolic body composition.
Result(s): A subgroup of 8 of 25 athletes with menstrual disturbances had significantly higher serum levels of free and total testosterone, androstenedione, LH-FSH ratio, and lower SHBG levels than did all other groups. Other oligomenorrheic or amenorrheic athletes had normal values comparable to those in regularly menstruating athletes and controls. The hyperandrogenic subgroup showed a more anabolic body composition, with higher total bone mineral density and upper-lower fat mass ratio than did oligomenorrheic or amenorrheic athletes with normal androgen levels. The hyperandrogenic subgroup had the highest VO2 max and the highest performance values in general.
Conclusion(s): Menstrual disturbances in female athletes are often explained as a consequence of hypothalamic inhibition and caloric deficiency. We suggest that essential hyperandrogenism is an alternative mechanism underlying oligomenorrhea or amenorrhea in some female athletes and may imply an advantage for physical performance.