Disturbances of the menstrual cycle in bulimia nervosa.

Blood was obtained three times a week throughout one menstrual cycle or during a 6-week period from 15 patients with bulimia nervosa and from 10 healthy age-matched controls. Of the patients, three had amenorrhoea, eight had oligomenorrhoea and four had regular cycles. Normal follicular development, as judged from continuously low oestradiol (E2) values (less than 120 pg/ml or less than 440 pmol/l), did not occur in seven patients. Compared to patients with increasing E2 values (greater than 120 pg/ml), these seven had a significantly lower body weight. Among the eight patients showing follicular development (E2 greater than 120 pg/ml), four reported regular cycles, but only three developed normal plasma progesterone (P4) values during the luteal phase (P4 greater than 3 ng/ml or greater than 9.5 nmol/l). The luteal phase was of normal length in only one bulimic patient.