Prevention and treatment of osteoporosis: does the future belong to hormone replacement therapy?

Estrogen replacement therapy (ERT) after menopause prevents the development of osteoporosis and reduces the risk of fracture. Other potential benefits are cardioprotection--probably related to the effects of estrogen on lipid profile and fibrinogen levels--and a delay in the onset of Alzheimer's disease and perhaps amelioration of the disease. ERT, however, increases the risk of endometriosis and endometrial cancer unless given with a progestin for at least 10 days per menstrual cycle. It also results in a small but real increase in breast cancer. Alendronate, a bisphosphonate, is the first serious competitor of conjugated equine estrogen for the treatment of osteoporosis. Nearing FDA approval are so-called designer estrogens (e.g., raloxifene), which may selectively prevent osteoporosis with little or no effects on endometrial and breast tissue.