Association of uric acid-to-albumin ratio with diabetic kidney disease: A cross-sectional study.

This study investigates the association between a novel inflammatory marker, the uric acid-to-albumin ratio (UAR), and diabetic kidney disease (DKD). We used multivariable logistic regression models to evaluate the independent associations of UAR with DKD, albuminuria, and reduced estimated glomerular filtration rate (eGFR). We further examined the associations of these renal outcomes with other inflammatory markers, including the Systemic Inflammatory Response Index and Systemic Immune-Inflammation Index (SII), and evaluated the diagnostic performance of these markers using receiver operating characteristic curve analysis. A total of 3984 participants from the National Health and Nutrition Examination Survey (NHANES) 2011-2020 were included, of whom 37.20% had DKD, 31.60% had albuminuria, and 19.80% had reduced eGFR. Spearman correlation analysis showed that UAR was positively correlated with both albumin-to-creatinine ratio and DKD (P < .01) but negatively correlated with eGFR (P < .05). In multivariable logistic regression analyses, each standard deviation increase in UAR was independently associated with higher odds of DKD (odds ratio [OR], 2.257; 95% CI: 1.654-3.080; P < .001), albuminuria (OR, 2.097; 95% CI: 1.541-2.852; P < .001), and reduced eGFR (OR, 6.210; 95% CI: 4.024-9.584; P < .001). Receiver operating characteristic curve analysis further showed that UAR had greater discriminative performance for DKD, albuminuria, and reduced eGFR than uric acid, albumin, Systemic Inflammatory Response Index, and SII. For DKD, UAR yielded an optimal cutoff of 1.609, with a sensitivity of 40.7%, specificity of 79.4%, and area under the curve (AUC) of 0.623. For albuminuria, the optimal UAR cutoff was 1.6282, with a sensitivity of 35.3%, specificity of 78.2%, and AUC of 0.571. For reduced eGFR, the optimal UAR cutoff was 1.5375, with a sensitivity of 62.0%, specificity of 73.7%, and AUC of 0.733. UAR was significantly associated with DKD, albuminuria, and reduced eGFR in T2DM, with the strongest association observed for reduced eGFR. These findings indicate that UAR may serve as a potential marker of renal abnormalities. However, given the cross-sectional design and potential bidirectional relationship between UAR components and renal function, these associations should not be interpreted as evidence of causality or future risk prediction. Prospective studies are needed to establish the temporal relationship between UAR and DKD and clarify causal mechanisms.