Background: Growth differentiation factor 15 (GDF-15) is emerging as a powerful risk indicator in both cardiovascular disease patients and community-dwelling individuals. We investigated GDF-15 concentrations and their changes over 5 years in elderly individuals from the community, together with the underlying conditions and prognostic implications of these measurements.
Methods: We analyzed GDF-15 concentrations using a sandwich immunoassay in participants from the PIVUS (Prospective Investigation of the Vasculature in Uppsala Seniors) study. Measurements were performed at both 70 (n = 1004) and 75 (n = 813) years of age. Median follow-up was 8.0 years.
Results: Over time, GDF-15 concentrations increased by 11.0% (P < 0.001). These changes were related to male sex, hypertension, diabetes, heart failure, renal function, and concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP). Significant relationships also emerged between changes in GDF-15 and changes in concentrations of NT-proBNP and C-reactive protein (CRP) and renal function between ages 70 and 75. The R(2) value of the model including all covariates was 0.20. GDF-15 concentrations independently predicted all-cause mortality [hazard ratio 4.0 (95% CI 2.7-6.0)] with results obtained at ages 70 and 75 as updated covariates. Baseline GDF-15 concentrations improved prognostic discrimination and reclassification [C statistic 0.06 (P = 0.006); integrated discrimination improvement = 0.030 (P = 0.004); category-free net reclassification improvement = 0.281 (P = 0.006)]. The change in GDF-15 concentrations over time independently predicted even all-cause mortality occurring after age 75 [hazard ratio 3.6 (95% CI 2.2-6.0)].
Conclusions: GDF-15 concentrations and their changes over time are powerful predictors of mortality in elderly community-dwelling individuals. GDF-15 concentrations increase with aging, and these changes are explained only partially by cardiovascular risk factors, indicators of neurohumoral activation and inflammation, and renal function. Thus GDF-15 reflects both cardiovascular and other biological processes closely related to longevity.