Age, estrogen, and bone density.

Osteoporosis in hypogonadal women contributes to considerable morbidity, mortality, and health care expense in our country each year. Estrogen deficiency accelerates and increases the incidence of this problem, and estrogen replacement therapy can substantially retard, and may in fact forestall, abnormally rapid loss of bone mineral mass in aging women. Moreover, estrogen therapy probably substantially decreases the incidence of disabling fractures in elderly women. These potential benefits of estrogen therapy in women at high risk to develop osteoporosis probably outweigh the risks of such a regimen, especially when a progestin is added for the last several days of each estrogen cycle. Optimal diet and suitably vigorous physical activity are advisable for all women as they enter the postmenopausal phase of their lives. Calcium supplementation, estrogen replacement therapy, or both are recommended when the patient is at high risk to develop osteoporosis.