Non-insulin-dependent insulin resistance surrogate indexes for predicting chronic kidney disease in diabetic individuals: a prospective cohort study

BACKGROUND: Insulin resistance (IR) constitutes a significant pathological mechanism in chronic kidney disease (CKD) progression among individuals with diabetes. This study investigated the association between six non-insulin-dependent IR surrogate indexes and CKD risk in diabetic patients and evaluated their predictive performance. MATERIALS AND METHODS: Using data from the China Health and Retirement Longitudinal Study (CHARLS), multivariate Cox regression and nonlinear relationship analysis were employed to assess the association between non-insulin-dependent IR surrogate markers and CKD risk in diabetic population. Additionally, we assessed the predictive ability of each IR index by calculating the area under the curve (AUC), continuous net reclassification improvement (cNRI), and integrated discrimination improvement (IDI). RESULTS: In total, 3,403 eligible participants were enrolled. Multivariate Cox analysis and Kaplan-Meier survival analysis demonstrated that CKD risk in the diabetic population increased with elevated of all IR indexes except eGDR. After adjusting for multiple confounders, estimated glucose disposal rate (eGDR) as a continuous variable revealed an inverse association with CKD risk [HR (95% CI): 0.914 (0.876, 0.954)]. Similarly, the highest eGDR quartile (Q4) maintained a significant protective association with CKD [HR (95% CI): 0.644 (0.488, 0.849] when analyzed by quartiles. All indexes demonstrated modest predictive performance, with eGDR showed the highest AUC, cNRI, and IDI. CONCLUSIONS: All IR surrogate indexes demonstrated significant associations with CKD risk in diabetic populations. The eGDR showed relatively better performance for CKD risk assessment, although the overall discriminative ability of all markers was modest in this population.