Low bone mineral density and mortality in men and women: the Third National Health and Nutrition Examination Survey linked mortality file.

Purpose: The aim of this study is to determine the association of bone mineral density and mortality over a median follow-up of 9 years.
Methods: The baseline data used are from the Third National Health and Nutrition Examination Survey (NHANES III), a nationally representative sample of non-institutionalized civilians. A cohort of 5,769 non-Hispanic whites, non-Hispanic blacks, and Mexican Americans aged 50 years and older at baseline (1988-1994) was followed through 2000 for overall mortality using the restricted-use NHANES III Linked Mortality File (1,741 deaths). Total proximal femoral bone mineral density was measured by dual-energy x-ray absorptiometry and categorized into quartiles. Cox proportional hazards models were used to estimate the relative risk of death after adjusting for multiple risk factors.
Results: Compared with subjects in the highest quartile of bone mineral density, those in the lowest quartile had greater risk of death (relative risk, 1.53; 95% confidence interval: 1.08-2.18; P=0.02). There was no significant interaction of bone mineral density with race or ethnicity.
Conclusion: Low bone mineral density was associated with increased risk of death.