Bone mineral density and mortality in women and men: the NHANES I epidemiologic follow-up study.

Abstract

We sought to assess the long-term association of bone mineral density with total, cardiovascular, and non-cardiovascular mortality. The First National Health and Nutrition Examination Survey data were obtained from a nationally representative sample of non-institutionalized civilians. A cohort aged 45 through 74 years at baseline (1971-1975) was observed through 1992. Subjects were followed for a maximum of 22 years. Included in the analyses were 3501 white and black subjects. Death certificates were used to identify a total of 1530 deaths. Results were evaluated to determine the relative risk for death per 1 SD lower bone mineral density, after controlling for age at baseline, smoking status, alcohol consumption, history of diabetes, history of heart disease, education, body mass index, recreational physical activity, and blood pressure medication. Bone mineral density showed a significant inverse relationship to mortality in white men and blacks, but did not reach significance in white women. Based on 1 SD lower bone mineral density, the relative risk for white men was 1.16 (95% confidence interval (CI), 1.07-1.26, p<.01), while for white women the relative risk was 1.10 (95% CI, 0.99-1.23, p=.07), and in blacks the relative risk was 1.22 (95% CI, 1.05-1.42, p<.01). Bone mineral density was also associated with non-cardiovascular mortality in all three race-gender groups. An association between bone mineral density and cardiovascular mortality was found only in white men. Bone mineral density is a significant predictor of death from all causes (white men, blacks), cardiovascular (white men only) and other causes combined, in whites and blacks.