BONE MASS AND SUBSEQUENT RISK OF HIP FRACTURE

We examined prospectively the associations of bone density and bone di mensions with risk of hip fracture using data from the first National Health and Nutrition Examination Survey and its three follow-up studie s. A cohort of 1,489 white women age 45 years or older who received de tailed medical examinations in the baseline survey in 1971-1975 were s ubsequently contacted in 1982-1984, 1986, and 1987. Bone density and h and bone dimensions at several sites were measured at baseline. Fifty incident hip fractures were identified during the follow-up studies. U sing Cox regression analyses, we found a relative risk of 11 for women with bane density below the 5th percentile, compared with those above the 75th percentile (95% confidence interval = 2.2-58). Women with sm aller external bone dimensions also faced increased risk of hip fractu re (relative risk = 4.6 for dimensions below the 5th percentile us abo ve the 75th percentile; 95% confidence interval = 1.5-14). On the othe r hand, internal bone dimensions were not associated materially with h ip fracture.