A five-year follow-up study of bone mass in older people

Bone mass was estimated in a simple random sample of older people from Edinburgh (215 men and 272 women aged 62-90 years), by measuring metacarpal cortical thickness and by measuring the optical density of the radius compared with that of a metal wedge on an X-ray. Information was also collected about diet, energy expenditure and anthropometric variables. The two bone mass estimations were moderately correlated (0-47 in men, 0-53 in women). Both showed decrease as age increased. Estimates of bone mass increased as body size or activity increased, but were unrelated to dietary intakes of calcium or vitamin D. Five years later the cortical thickness was remeasured in 111 men and 141 women. Loss of bone was not uniform, and some subjects actually showed a gain. The mean loss was 0-27 mm (SD 0-41) in men and 0-28 (SD 0-40) in women. This loss was unrelated to body size or to intake of calcium and vitamin D.