Gonadotropin response to LH-RH in anorexia nervosa and bulimia

Serum LH and FSH levels before and after stimulation with LH-RH were measured in 9 patients with bulimia, 7 with a restricting subtype and 6 with a bulimic subtype of anorexia nervosa. All patients with anorexia nervosa and 5 (56%) patients with bulimia showed amenorrhea for at least 5 months, while 4 (44%) of the bulimic patients showed oligomenorrhea. Mean basal levels of LH and FSH were low in patients with restricting and bulimic anorexia nervosa, but were normal in patients with bulimia. The response of LH and FSH to LH-RH was impaired in approximately half of the patients with the two subtypes of anorexia nervosa, whereas it was normal in all but one patient with bulimia. These results suggest that bulimic patients with amenorrhea or oligomenorrhea have hypothalamic dysfunctions, which do not appear to be due solely to low weight or to metabolic changes resulting from binge eating, vomiting or purgative use.