Serum uric acid and mortality risk among hemodialysis patients

Abstract Introduction While high serum uric acid (SUA) has been consistently associated with an increased risk of death in the general population and in persons with non-dialysis CKD, studies in patients undergoing dialysis are conflicting. It has been postulated that low SUA simply reflects poor nutritional status in dialysis patients. We here characterize the association between SUA and the risk of death in a large dialysis cohort and explore effect modification by underlying nutritional status as reflected by body composition. Methods In this retrospective cohort study, we included 16 057 hemodialysis (HD) patients treated during 2007-2016 in NephroCare centers as recorded in the European Clinical Database (EuCliD). The association between SUA, all-cause and cardiovascular (CV)-related mortality was evaluated with competing risk models and characterized with splines. Effect-modification was explored by lean tissue index (LTI) and fat tissue index (FTI). Results During a mean of 1.8 years of follow-up, 2 791 (17.4%) patients died. We found a multivariable-adjusted U-shaped pattern between SUA and all-cause mortality. Patients with SUA levels of 6.5 mg/dl (387 μmol/l) were at lowest risk of death (sHR: 0.94 [0.91; 0.96]). The form of association was not meaningfully affected by underlying LTI and FTI. Conclusions We found a U-shaped pattern between SUA levels and all-cause mortality among HD patients that was independent of the patients’ body composition.