Fig. 1From: Metformin use and early lactate levels in critically ill patients according to chronic and acute renal impairmentLactate levels for metformin users and nonusers according to estimated glomerular filtration rate and acute kidney injury stage. Mean lactate trajectories over time with 95% confidence interval for metformin users and nonusers were fitted by a mixed-effect model with individual-level random intercept and slope. Time after ICU admission was modeled as natural cubic spline with knot location at − 1 h, + 4 h, and + 12 h surrounding intensive care unit admission. a Total population. Subsequently, analyses were stratified according to b chronic kidney disease stage based on mean estimated glomerular filtration rate (eGFR) 1 year before ICU admission or c acute kidney injury (AKI) stage within 24 h of ICU admissionBack to article page