What is known about the effects of postmenopausal hormones on bone health?
Postmenopausal osteoporosis is characterized by decreased bone mass, deterioration of bone tissue, and increased bone fragility, making bone fractures of great concern. Low levels of estrogen are a risk factor for osteoporosis in women. Estrogen alone and estrogen combined with progestin have been shown to protect against osteoporosis. Definitive data from a recent large clinical trial support the ability of estrogen with progestin to prevent fractures at the hip, vertebrae, and other sites (106). However, some studies have shown that the beneficial effects of short-term therapy are not permanent; short-term use (three to five years) of estrogen to relieve symptoms of menopause did very little to prevent fractures from osteoporosis in women when they reached ages 75 to 80 years old (95, 98). Women who take estrogen to maintain bone density must continue taking estrogen because its beneficial effects on bone health disappear after hormone use is discontinued.
