Serum Protein Thiol Levels in Patients with Hospital-Acquired Acute Kidney Injury

Background/Aims: This study aimed to examine antioxidants in patients with acute kidney injury (AKI) and determine whether serum protein thiol levels are associated with all-cause 90-day mortality in patients with hospital-acquired AKI. Methods: According to the RIFLE criteria, 160 patients with hospital-acquired AKI were enrolled in our prospective cohort study. As controls, 72 critically ill patients without AKI and 72 age and sex-matched healthy subjects were also recruited. Serum protein thiol levels were analyzed in relation to all-cause mortality of patients with AKI. Results: Serum protein thiol levels in AKI patients were lower than those in healthy people (p=0.010). Protein thiol levels showed a weak but significant positive correlation with serum albumin levels. The 90-day overall mortality rate was higher in AKI patients with high serum protein thiol levels than in those with low levels (p=0.032 by log rank test). In multivariate analysis (Cox regression), serum protein thiol levels (p=0.031) were independently associated with 90-day overall mortality after adjustment for age, sex, sepsis, and the Acute Physiology and Chronic Health Evaluation II score. Conclusions: Patients with hospital-acquired AKI have remarkably low serum protein thiol levels. Elevated protein thiol levels are associated with 90-day overall mortality in hospital-acquired AKI.