Effects of estradiol valerate on growth hormone and prolactin response to growth hormone-releasing hormone stimulation in pre- and postmenopausal women

Abstract

We investigated the relationship between the growth hormone arid prolactin response to stimulation of growth hormone-releasing hormone (GHRH) and changes in body weight in pre- and postmenopausal women before and after 4 and 20 weeks of oral hormone replacement therapy (HRT). Ten postmenopausal women (with levels of follicle-stimulating hormone (FSH) of > 30 mIU/ml) were compared to ten premenopausal women suffering from post-pill amenorrhea (FSH < 10 mIU/ml). Both patient groups reported anamnestic body weight increases in the course of the former use of sex hormones. Additionally, ten postmenopausal women without anamnestic weight changes were studied. A significant reduction in the growth hormone response to GHRH was observed during the first month of HRT in women gaining weight, which was restored to pre-therapeutic levels after 6 months of HRT. A small but statistically significant increase in insulin-like growth factor (IGF)-I levels occurred in the course of HRT in all patients studied. These changes in growth hormone stimulation testing and IGF-I levels were accompanied by distinct changes in body weight. No reduction in the GHRH response was observed in those patients who did not gain body weight. Although GHRH stimulation induces a significant rise of prolactin concentrations in all patients before therapy, no influence on prolactin levels could be demonstrated during HRT.