Circulating renalase predicts all-cause mortality and renal outcomes in patients with advanced chronic kidney disease

Background/Aims Patients with chronic kidney disease (CKD) have been found to show markedly increased rates of end-stage renal disease, major adverse cardiovascular and cerebrovascular events (MACCEs), and mortality. Therefore, new biomarkers are required for the early detection of such clinical outcomes in patients with CKD. We aimed to determine whether the level of circulating renalase was associated with CKD progression, MACCEs, and all-cause mortality, using data from a prospective randomized controlled study, Kremezin STudy Against Renal disease progression in Korea (K-STAR; NCT 00860431). Methods A retrospective analysis of the K-STAR data was performed including 383 patients with CKD (mean age, 56.4 years; male/female, 252/131). We measured circulating renalase levels and examined the effects of these levels on clinical outcomes. Results The mean level of serum renalase was 75.8 ± 34.8 μg/mL. In the multivariable analysis, lower hemoglobin levels, higher serum creatinine levels, and diabetes mellitus were significantly associated with a higher renalase levels. Over the course of a mean follow-up period of 56 months, 25 deaths and 61 MACCEs occurred. Among 322 patients in whom these outcomes were assessed, 137 adverse renal outcomes occurred after a mean follow-up period of 27.8 months. Each 10-μg/mL increase in serum renalase was associated with significantly greater hazards of all-cause mortality and adverse renal outcomes (hazard ratio [HR] = 1.112, p = 0.049; HR = 1.052, p = 0.045). However, serum renalase level was not associated with the rate of MACCEs in patients with CKD. Conclusions Our results indicated that circulating renalase might be a predictor of mortality and adverse renal outcomes in patients with CKD.