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.