In the subset of patients with eGFR < 45 mL/min/1.73 m2 and known CKD reported in their medical history (18 patients, 10 of whom died), we found a linear and positive association between GDF-15 and mortality risk in the univariate Cox regression [HR 1.13 (1.01–1.27, 95% CI) for every 1 ng/mL increase in GDF-15 level], although the small sample size and low number of events did not allow us to investigate this association in multivariate models. This evidence concerns the gene GDF15 and chronic kidney disease.