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 1723 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.