“…The problem of precocity, although desired, is poorly applied in clinical studies, perhaps due to the difficulty of segmenting serial samples, in addition to the need for intervention with potential renal injury with pre and post collections. In a study evaluating one hundred eleven hospitalized patients with CKD undergoing radiographic contrast procedures, the authors did not find differences in PENK or baseline Scr during the period before contrast, but the PENK delta increased in patients with AKI after use of the PENK contrast on Day 1 (198 pmol/l vs. 121 pmol/l, P < 0.01) [ 26 ]. However, the study by Shan et al [ 27 ], including 92 patients undergoing cardiac surgery, corroborates our findings, and preoperative PENK was an independent predictor of AKI (OR 23.8 (95% CI 2–270), P = 0.011).…”