Normalization of androgen and sex hormone-binding globulin levels after treatment of hyperprolactinemia.

Abstract

Twenty-eight women with amenorrhea, galactorrhea and hyperprolactinemia without hirsutism were studied before and after bromocriptine therapy for 2 months. Compared to 15 euprolactinemic controls, hyperprolactinemic women had elevated levels of dehydroepiandrosterone sulfate and androstenedione and lower levels of total testosterone (T), and androst-5-ene-3 beta, 17 beta-diol (Adiol), and 17 beta-estradiol (P less than 0.05). Unbound T and unbound Adiol were significantly elevated, while sex hormone-binding globulin binding capacity was decreased (P less than 0.05) and corticosteroid-binding globulin binding capacity was normal. After treatment with bromocriptine, dehydroepiandrosterone sulfate and androstenedione decreased to control levels, as did unbound Adiol, while 17 beta-estradiol and sex hormone-binding globulin binding capacity levels increased significantly (P less than 0.05). Five hyperprolactinemic women underwent ACTH stimulation tests before and after treatment, and the results were compared to those of seven controls. Steroid ratios in response to ACTH suggested normal 3 beta ol-dehydrogenase-isomerase, 17-20-desmolase and 17 beta-hydroxysteroid dehydrogenase enzymatic activities in hyperprolactinemia. Basal steroid ratios of T to 5 alpha-androstane-17 beta-01-3-one) (DHT) and of unbound T to unbound dihydrotestosterone were elevated (P less than 0.05), suggesting reduced 5 alpha-reductase activity in hyperprolactinemia which is normalized after treatment. Hirsutism was not present in these patients with hyperprolactinemia despite elevated levels of unbound T and Adiol, and may be explained by reduced 5 alpha-reductase activity. Our data suggest that the increased levels of androgens in these patients result from the hyperprolactinemia.