Relations of established aging biomarkers (IL-6, D-dimer, s-VCAM) to glomerular filtration rate and mortality in community-dwelling elderly adults.

BACKGROUND

Biomarkers improving risk prediction for elderly populations with chronic kidney disease (CKD), an independent predictor of mortality, could be particularly useful. We previously observed that interleukin-6 (IL-6), D-dimer and soluble vascular adhesion molecule (s-VCAM) were independent biomarkers of mortality in elderly individuals. Therefore, we investigated whether these established biomarkers were independently associated with both estimated glomerular filtration rate (eGFR) and mortality.

METHODS

The Established Populations for Epidemiologic Studies of the Elderly (EPESE) is a longitudinal cohort of community-dwelling elderly individuals. We investigated the association among eGFR, the biomarkers (IL-6, D-dimer and s-VCAM) and 4-year all-cause mortality using restricted cubic splines within Cox proportional hazards models.

RESULTS

Among 1907 participants in EPESE, 1342 had available creatinine and biomarker measures. Incidence of all-cause mortality was 21.6%. eGFR was associated with all-cause mortality (P < 0.01); individuals at the lowest (<30 mL/min/1.73 m) levels had the highest mortality rates. D-dimer and s-VCAM were associated (P < 0.01) with mortality, and after adjustment for IL-6, D-dimer and s-VCAM, the mortality risk varied by eGFR level.

CONCLUSIONS

In community-dwelling elderly individuals, we observed an association among eGFR, 4-year mortality and IL-6, D-dimer and s-VCAM. eGFR was independently associated with mortality, and the relation between eGFR and mortality was modified by IL-6, D-dimer and s-VCAM, which was most notable in individuals with severely reduced eGFR. These findings suggest that IL-6, D-dimer and s-VCAM may be useful biomarkers for improving risk prediction, but further studies are needed examining the role of these biomarkers in elderly individuals with CKD.