Impact of red blood cell distribution width-albumin ratio on prognosis of patients with CKD

The red blood cell distribution width-albumin ratio (RAR) is a prognostic factor for adverse outcomes in various populations. However, whether RAR is associated with renal outcomes remains unclear. Therefore, we aimed to investigate the impact of RAR on the prognosis in patients with chronic kidney disease (CKD). We conducted a retrospective cohort study using 997 CKD patients who were enrolled in the Fukushima Cohort Study. Patients were categorized into tertiles (T1-3) according to the baseline RAR. The associations of RAR with end-stage kidney disease (ESKD) were assessed using Kaplan-Meier curves and multivariable cox regression analyses. Receiver operating characteristic (ROC) curves were performed to test whether significant differences were present between red cell distribution width (RDW) and RAR. The median age was 66, 57% were men, the median eGFR was 47.8 ml/min/1.73 m(2), and the median value of RAR was 3.5. The higher RAR group showed an increased risk for ESKD in the Kaplan-Meier curve analysis. Compared to the lowest RAR group, higher RAR groups had a higher risk of ESKD (hazard ratio [HR] 1.37, 95% CI 0.68-2.78 and 2.92, 95% CI 1.44-5.94) for T2 and T3 groups, respectively. ROC curve analysis proved that the discriminating ability of RAR for ESKD was superior to RDW. A higher RAR value was associated with worse renal outcomes in patients with CKD. RAR could be a convenient and useful prognostic marker for renal prognosis.