When estrogen therapy is discontinued, bone mass declines at a rate comparable to the immediate postmenopausal period. There is no evidence that estrogen replacement therapy restores bone mass to premenopausal levels. At skeletal maturity there are sex and race differences in both the total amount of bone present and its density, in favor of men and blacks. Thus, women are at higher risk than men because they start with less bone mass and, for several years following natural or induced menopause, the rate of bone mass decline is accelerated. White and Asian women are at higher risk than black women.
Early menopause is one of the strongest predictors for the development of osteoporosis.
The mainstays of prevention and management of osteoporosis are estrogen, an adequate lifetime calcium intake, and exercise. Therefore, when not contraindicated, calcium supplementation may be helpful. Weight-bearing exercise and nutrition may be important adjuncts to the prevention and management of osteoporosis. Immobilization and prolonged bed rest produce rapid bone loss, while weight-bearing exercise has been shown both to reduce bone loss and to increase bone mass. The optimal type and amount of physical activity that would prevent osteoporosis have not been established, however in two studies, an hour of walking and running exercise twice or three times weekly significantly increased lumbar spine bone mass.