Metabolic acidosis is associated with acute kidney injury in
A retrospective cohort study using electronic health records enrolled 2 cohorts of patients with CKD Stages G3-G5: 1) 136 067 patients in the US Electronic Medical Record (EMR) based cohort; and 2) 34 957 patients in the Manitoba Claims-based cohort. The primary exposure was metabolic acidosis (serum bicarbonate between 12 and <22 mEq/L). The primary outcome was the development of AKI. In both cohorts, metabolic acidosis was associated with AKI: HR 1.57 (95% CI 1.52 – 1.61) in the US EMR cohort and HR 1.65 (95% CI 1.58 – 1.73) in the Manitoba Claims cohort. The association was consistent when serum bicarbonate was treated as a continuous variable and in multiple subgroups and sensitivity analyses including those adjusting for albuminuria. Metabolic acidosis is associated with a higher risk of AKI in patients with CKD. AKI should be considered as an outcome in studies of treatments for patients with metabolic acidosis.