GDF15 and acute kidney injury: After excluding subjects with AKI prior to CKD, the adjusted HR was 2.32 (95% CI, 1.25 ~ 4.30; p for trend < 0.01), and 1.33 (95% CI, 1.10 ~ 1.60) for Q4 versus Q1 and per 1 SD increase of GDF-15, respectively (data not shown).