GROWTH-HORMONE IN POSTMENOPAUSAL WOMEN AFTER LONG-TERM ORAL ESTROGEN REPLACEMENT THERAPY

Studies of estrogen effects on growth hormone (GH) and its pulsatile r elease in postmenopausal women have typically utilized estrogen replac ement therapy (ERT) of relatively short duration (days to weeks). The purpose of this study was to compare GH measures from healthy postmeno pausal women who were on oral ERT for 3 years or more (n = 24; mean ER T duration = 16.1 years) with women not on ERT (NERT; n = 40). Blood s amples were drawn remotely every 20 min for 24 h and then analyzed for mean 24-h GH, mean GR during sleep, and mean 24-h insulin-like growth factor-I (IGF-I). GH peak analyses were also performed. Mean 24-h GH and GH during sleep were significantly higher and IGF-I was significan tly lower in ERT women compared with NERT women. In addition, use of l ong-term ERT was associated with more GH peaks relative to women not o n ERT; hut no change in GH peak amplitude or area. GH was not related to age in either group. GH was strongly and negatively correlated with measures of adiposity in NERT women hut not in ERT women. in conclusi on, long-term oral ERT is associated with increased circulating GH and decreased IGF-I levels, even after many gears of treatment.