Association of red blood cell distribution width/albumin ratio with renal prognosis among patients with type 2 diabetes mellitus: A retrospective cohort study

ABSTRACT Introduction The red blood cell distribution width/albumin ratio (RAR) has been reported to be a prognostic marker for adverse clinical outcomes. However, there is limited data on the relationship between RAR and renal function in patients with type 2 diabetes mellitus (T2DM). This study aimed to investigate the effect of RAR on renal prognosis in patients with T2DM. Research Design and Methods This retrospective cohort study included 907 patients with T2DM enrolled in the Fukushima Cohort Study, divided into two groups (high and low RAR) according to their baseline RAR. The association between RAR and renal events was assessed using Kaplan–Meier curves and multivariate Cox regression analyses. Receiver operating characteristic (ROC) curve analyses, as well as the net reclassification index (NRI) and integrated discrimination improvement (IDI), examined the differences between RAR and red blood cell distribution width (RDW) alone. Results The high RAR group showed an increased risk of renal events in the Kaplan–Meier curve analysis. Compared with the low RAR group, the high RAR group showed an increased risk of renal events (adjusted hazard ratio [HR]: 3.40, 95% confidence interval: 1.76–6.57). RAR exhibited a significantly higher area under the curve (AUC), NRI, and IDI for renal events than RDW. Conclusion We observed an association between high RAR and worse renal outcomes in patients with T2DM. RAR assessment may have potential utility as a predictive tool for renal prognosis.