A one standard deviation increase in DNAm GDF15 and plasma GDF15 was associated with a 16% [HR: 1.16; 95% CI: 1.07–1.27, p = 0.0004] and 27% [HR: 1.27; 95% CI: 1.16–1.39, p = 2.5E07] increase in dementia risk, respectively, after age and sex adjustment. The gene discussed is GDF15; the disease is dementia.