The aging skeleton.

The importance of bone loss with aging increases year by year. When Bismarck set the age of retirement at 65, it did not cost Prussia much because few lived to receive pensions. At the turn of the century, only 4.1 per cent of our population was 65 or older. But the present change in demography, called "The Graying of America," means that we now have 13 per cent of the population 65 or older: 35 million people, 20 million women and 15 million men. For the women who are now passing through menopause or who have had oophorectomies, the predictable deformities caused by fractures of the vertebrae, wrists, and hips will make up the single largest cause of hospitalization unless prophylaxis against postmenopausal bone loss is instituted. The best established prophylaxis is now low-dose estrogen-gestagen replacement therapy. Very promising is the combination of very-low-dose estrogen and high-dose oral calcium supplements (Fig. 17). For women who cannot or will not take estrogens, certain progestational agents offer equal protection to bone, though, of course, these agents do not protect against atrophy of the other target organs, most notably the vaginal mucosa.