Resumption of menses in anorexia nervosa.

OBJECTIVE: To determine factors associated with resumption of menses (ROM) in adolescents with anorexia nervosa.

DESIGN: Cohort study with 2-year follow-up.

SETTING: Tertiary care referral center.

PATIENTS: Consecutive sample of 100 adolescent girls with anorexia nervosa.

INTERVENTIONS: Body weight, percent body fat, and luteinizing hormone, follicle-stimulating hormone, and estradiol levels were measured at baseline and every 3 months until ROM (defined as 2 or more consecutive spontaneous menstrual cycles). Treatment consisted of a combination of medical, nutritional, and psychiatric intervention aimed at weight gain and resolution of psychological conflicts.

MAIN OUTCOME MEASURES: Body weight, body composition, and hormonal status at ROM.

RESULTS: Menses resumed at a mean (+/-SD) of 9.4 +/- 8.2 months after patients were initially seen and required a weight of 2.05 kg more than the weight at which menses were lost. Mean (+/-SD) percent of standard body weight at ROM was 91.6% +/- 9.1%, and 86% of patients resumed menses within 6 months of achieving this weight. At 1-year follow-up, 47 (68%) of 69 patients had resumed menses and 22 (32%) remained amenorrheic. No significant differences were seen in body weight, body mass index, or percent body fat at follow-up in those who resumed menses by 1 year compared with those who had not. Subjects who remained amenorrheic at 1 year had lower levels of luteinizing hormone (P < .001) and follicle-stimulating hormone (P < .05) at baseline and lower levels of luteinizing hormone (P < .01) and estradiol (P < .001) at follow-up. At follow-up, a serum estradiol level of more than 110 pmol/L (30 pg/mL) was associated with ROM (relative risk, 4.6; 95% confidence interval, 1.9-11.2).

CONCLUSIONS: A weight approximately 90% of standard body weight was the average weight at which ROM occurred and is a reasonable treatment goal weight, because 86% of patients who achieved this goal resumed menses within 6 months. Resumption of menses required restoration of hypothalamic-pituitary-ovarian function, which did not depend on the amount of body fat. Serum estradiol levels at follow-up best assess ROM.