A NEWLY PUBLISHED analysis of US population data suggests that the red cell distribution width-to-albumin ratio (RAR), a haematological marker reflecting inflammation and nutritional status, is significantly associated with diabetic kidney disease (DKD) among adults with diabetes. The findings highlight the potential role of this simple laboratory index in early risk stratification for DKD.
Researchers analysed data from the National Health and Nutrition Examination Survey (NHANES) collected between 2005 and 2020, including 7,191 adults with diagnosed diabetes. DKD was defined using standard measures of estimated glomerular filtration rate and albuminuria. Participants were categorised into quartiles based on RAR levels, and weighted multivariable logistic regression models were used to explore associations with DKD prevalence.
Diabetic Kidney Disease Prevalence Rises with RAR
The study found that RAR levels were significantly higher in individuals with DKD compared with those without the condition. Notably, the prevalence of DKD increased progressively across RAR quartiles, rising from 25.2% in the lowest quartile to 43.3% in the highest. In unadjusted analyses, each one-unit increase in RAR was associated with a 76% higher likelihood of DKD. After adjusting for demographic factors, comorbidities, and relevant clinical variables, participants in the highest RAR quartile had more than double the odds of DKD compared with those in the lowest quartile.
Restricted cubic spline modelling suggested a largely linear relationship between RAR and DKD risk, with no significant evidence of non-linearity after adjustment. Subgroup analyses demonstrated that the association was broadly consistent across age groups, smoking status, and comorbidity profiles. However, significant interactions were observed for sex and body mass index, with stronger associations seen in males and individuals with higher BMI.
Next Steps for Diabetic Kidney Disease Risk Prediction
The authors propose that the observed relationship may reflect the combined influence of chronic inflammation, oxidative stress, and poor nutritional status, key mechanisms implicated in the progression of diabetic kidney disease. As both red cell distribution width and serum albumin are routinely measured in clinical practice, RAR represents a cost-effective and easily accessible biomarker.
While the cross-sectional design precludes causal inference, the findings support further investigation of RAR as a screening and risk-stratification tool in diabetic populations. Prospective studies are now needed to determine whether RAR can predict incident DKD and guide earlier intervention strategies.
Reference
Zou S et al. Association between red cell distribution width-to-albumin ratio and risk of diabetic kidney disease: a cross-sectional NHANES study. BMC Urol. 2025; 10.1186/s12894-025-02009-w
