Effect of peripheral sex steroid metabolism on pituitary gonadotropin reserve of women with hypothalamic amenorrhea.

Women with hypothalamic amenorrhea without evidence of pituitary tumor were studied to ascertain (1) whether affected patients have altered pituitary sensitivities and reserves to a constant gonadotropin-releasing hormone (GnRH) infusion and (2) whether altered sex steroid metabolism contributed to altered pituitary synthesis or secretion of gonadotropin. Women with hypothalamic amenorrhea displayed abnormal gonadotropin reserves without altered pituitary sensitivity to GnRH. Those altered reserves may have reflected, abnormally low estradiol levels, which directly or indirectly affected, pituitary gonadotropin synthesis. However, sex steroid metabolism or normally cycling and amenorrheic women were not significantly different. The ovaries of both groups of patients were equally reactive to stimulation with endogenous gonadotropin, as reflected by circulating estradiol levels attained at the end of the GnRH infusion.