Association Between Serum GDF15 Concentration and Total Mortality in Community-Dwelling Japanese Older Populations: The Involvement of Renal Dysfunction

Abstract

Abstract Background Serum growth differentiation factor 15 (GDF15) is associated with age-related adverse outcomes. However, renal function has not been thoroughly evaluated in studies addressing the association between GDF15 and mortality. We aimed to clarify whether GDF15 is associated with total mortality after carefully controlling renal function markers. Methods We divided 1 801 community-dwelling Japanese older adults into quartiles according to their serum GDF15 concentrations. The correlation of GDF15 with renal function and inflammation markers was assessed by calculating Spearman correlation coefficients. Cumulative survival rates of the quartiles were estimated. In a Cox regression analysis adjusted for confounders, the association between GDF15 and mortality was evaluated. The discriminative capacity of GDF15 for the prediction of mortality was assessed with receiver-operating characteristic analysis. Results GDF15 was correlated with cystatin C (r = 0.394), β2-microglobulin (r = 0.382), C-reactive protein (r = 0.124), and interleukin-6 (r = 0.166). The highest GDF15 quartile showed poor survival compared to the others. Older adults with higher GDF15 were associated with an increased mortality risk, independent of demographics and clinically relevant variables (hazard ratio [95% confidence interval]: 1.98 [1.09–3.59]). This significant association disappeared when additionally adjusted for cystatin C (1.65 [0.89–3.05]) or β2-microglobulin (1.69 [0.91–3.12]). The ability to predict mortality was approximately comparable between GDF15 (area under the curve: 0.667), cystatin C (0.691), and β2-microglobulin (0.715). Conclusions Serum GDF15 is associated with total mortality in older Japanese after adjustment for major confounders. The increased mortality risk in older adults with higher GDF15 may be partly attributed to decreased renal function.