Post-operative serum uric acid and acute kidney injury

We hypothesized that post-operative serum uric acid (SUA) may be associated with acute kidney injury (AKI). In this prospective, observational study, the relationships between SUA, urine neutrophil gelatinase-associated lipocalin (uNGAL) and interleukin-18 (uIL-18), serum monocyte chemoattractant protein-1 (sMCP-1) and tumor necrosis factor-alpha (sTNF-alpha), and incidence of AKI were determined. SUA were divided into tertiles and their association with AKI investigated. A total of 100 cardiac surgery patients were included for analyses. The 1st, 2nd, and 3rd SUA tertiles were associated with 15.1%, 11.7%, and 54.5% incidence of AKI, respectively. The 3rd SUA tertile, compared to the referent 1st tertile, was associated with an eightfold (OR 8.38, CI95% 2.13-33.05, p=0.002) increased risk for AKI. Patients with AKI on post-operative day 1 (n=11) were then excluded for the purpose of determining the predictive value of SUA to diagnose AKI on postoperative day 2 and during hospital stay. In comparison to the referent 1st tertile, the 3rd tertile SUA was associated with an eightfold increased risk for AKI on post-operative day 2 (adjusted OR 7.94, CI95% 1.50-42.08, P=.015) and a five-fold increased risk for AKI during hospital stay (OR 4.83, CI95% 1.21-19.20, P=.025), respectively. SUA (Area Under Curve, AUC 0.77 (CI95% 0.66-0.88, P