Estrogen treatment and estrogen suppression: Metabolic effects in adolescence

The metabolic consequences of reaching full reproductive maturity in humans involve not only growth hormone (GN) and insulin-like growth factor-I, but also the collaborative interaction of the gonadal sex steroids, Estrogen i s critical for completing linear growth, It also inhibits bone resorption, decreases plasma lipid levels and serves as an antiatherosclerotic agent, O ur studies show that, in low doses, estrogen increases GH production, incre ases calcium absorption and decreases bone turnover; however, unlike testos terone, estrogen has no effects as a protein-anabolic agent, at least at th e whole body level, Studies of selective estrogen suppression, achieved usi ng a potent aromatase inhibitor, show that estrogen is the main regulator o f the gonadotropin axis, In boys, selective aromatase blockade may have a r ole in delaying epiphyseal fusion. Large placebo-controlled trials will be required to study this effect further.