OBJECTIVE: To evaluate the effects of estrogen deficiency and exercise on body composition and leptin in young women.
DESIGN: Cross-sectional clinical study.
SETTING: Volunteers in an academic research environment.
PATIENT(S): Three age- and body mass index-matched groups: normal-weight women with exercise-associated amenorrhea, regularly menstruating exercising control women, and regularly menstruating normally active control women.
INTERVENTION(S): Collection of blood samples and measurement of body fat and regional fat distribution by dual-energy x-ray absorptiometry.
MAIN OUTCOME MEASURE(S): Central fat accumulation (i.e., ratio of trunk to extremity fat) and serum concentrations of E(2) and leptin.
RESULT(S): In both regularly menstruating control groups, but not in the amenorrheic women, there was a negative correlation between the serum E(2) concentrations and the trunk-to-extremity fat ratio (r = -0.4), independent of age, exercise, body fat, and serum T concentrations. In all women, E(2) concentrations were positively and exercise inversely correlated to leptin concentrations, independent of body fat.
CONCLUSION(S): Estradiol level is inversely associated with central fat accumulation only in women with regular menstrual cycles. In all young premenopausal subjects, estrogen secretion influences leptin concentrations independently of body fat.