Association between red cell distribution width/serum albumin ratio and diabetic kidney disease

Previous studies have shown that the red cell distribution width (RDW)/serum albumin ratio (RA) is an integrative and new inflammatory marker. RA is associated with clinical outcomes in a variety of diseases, but the clinical value of RDW/RA in the assessment of diabetic kidney disease (DKD) has not been elucidated. We examined the link between diabetic RA and DKD while controlling for a wide variety of possible confounders.

Retrospective cohort analysis of the National Health and Nutrition Examination Survey (NHANES: 2009-2018) database from the Second Affiliated Hospital and Yuying Children's Hospital and the Wenzhou Medical University (WMU) database was conducted. Multivariate logistic regression analysis was used to assess the association between RA and DKD.

Overall, 4513 diabetic patients from the NHANES database (n = 2839) and the WMU (n = 1412) were included in this study; 974 patients were diagnosed with DKD in NHANES and 462 in WMU. In the NHANES cohort, diabetes mellitus (DM) patients with higher RA level had a higher risk of DKD (odds ratio = 1.461, 95% confidence interval: 1.250-1.707, p < 0.00001). After adjusting for confounders and propensity score-matched (PSM) analysis, both shown RA levels were independently linked to DKD (p_Adjust = 0.00994, p_PSM = 0.02889). Similar results were also observed in the WMU cohort (p < 0.00001).

The study observes that the RA was an independent predictor of DKD in DM patients. The RA, a biomarker that is cost-effective and easy-to-access, may have potential for risk stratification of DKD.