Coagulation and activation of inflammatory pathways in the development of functional decline and mortality in the elderly

PURPOSE: This study was performed to determine the effects of markers of inflammation (interleukin 6) and coagulation (D-dimer) on mortality and functional status in older persons. METHODS: Subjects were selected for the Duke Established Populations for Epidemiologic Studies of the Elderly. In 1992, 2569 subjects (age >71 years) were interviewed, of whom 1,723 had interleukin-6 and D-dimer measurements. Values of interleukin 6 and D-dimer were categorized into quartiles. Outcomes were mortality (through 5 years) and functional status (through 4 years). Relative risks were estimated with proportional hazards models that adjusted for potential confounders. RESULTS: The relative risk of mortality was 1.28 (95% confidence interval CI]: 0.98 to 1.69; P = 0.06) for those with only interleukin-6 levels in the highest quartile, 1.53 (95% CI: 1.18 to 1.97; P = 0.001) for subjects with only D-dimer levels in the highest quartile, and 2.00 (95% CI: 1.53 to 2.62; P = 0.0001) for those with levels of both in the highest quartile, as compared with those who were not in either of the highest quartiles. Those with high interleukin-6 and high D-dimer levels had the greatest declines in all measures of function. CONCLUSION: Activation of the coagulation and inflammatory pathways is associated with mortality and decline in function, and may be part of the explanation for the development of a frailty phenotype in the elderly.