PROGRESSIVE LOSS OF BONE IN THE FEMORAL-NECK IN ELDERLY PEOPLE - LONGITUDINAL FINDINGS FROM THE DUBBO OSTEOPOROSIS EPIDEMIOLOGY STUDY

Objectives-To determine prospectively the rates of change in bone mine ral density in elderly people and to examine the relation between life style and demographic factors and these rates of change. Design-Longit udinal population based study. Setting-Dubbo, New South Wales, Austral ia. Subjects-Representative sample (n = 769) of residents aged greater than or equal to 60 on 1 January 1989. Main outcome measure-Rates of change in bone mineral density measured prospectively (mean scan inter val 2.5 years) at the femoral neck and lumbar spine by dual energy x r ay absorptiometry. Results-Summary rates of loss in the femoral neck w ere 0.96% per year (95% confidence interval 0.64% to 1.28%) in women a nd 0.82% per year (0.52% to 1.12%) in men. Importantly, rates of loss at the femoral neck (both percentage and absolute) increased in both s exes with advancing age. No significant loss was evident in either sex at the lumbar spine, probably because of coexistent osteoarthritis. L ifestyle factors had only modest effects on rates of loss at either si te. Conclusions-These data show that bone density of the femoral neck declines at an increasing rate in elderly people, and as this site is predictive of fracture suggest that treatment to minimise bone loss ma y be important even in very elderly people.