Abstract
AIM: To investigate the association between changes in estimated Glucose Disposal Rate (eGDR) and Composite Kidney Outcome (CKO) among middle-aged and older adults. METHODS: This study examined data from 4,007 individuals in the China Health and Retirement Longitudinal Study (CHARLS). The eGDR was estimated based on waist circumference, HbA1c, and hypertension status. Participants were stratified by cumulative eGDR quartiles and change patterns. The primary outcome was CKO, which included Chronic Kidney Disease (CKD) and rapid kidney function decline (RKFD). Logistic regression and restricted cubic spline (RCS) models were employed to assess the relationship between eGDR changes and outcomes, while receiver operating characteristic (ROC) curves evaluated the predictive performance of eGDR. Additionally, the Weighted Quantile Sum (WQS) regression model was used to quantify the contributions of eGDR components. RESULTS: Cumulative eGDR exhibited a linear and inverse relationship with the risk of CKO (OR = 0.96 (0.94 ~ 0.99), P for nonlinear = 0.214), and the greatest cumulative eGDR group (Q4) had a 53% lower risk of CKO than the reference group (OR = 0.47 (0.28 ~ 0.79), P = 0.004). The predictive performance of cumulative eGDR surpassed both baseline eGDR and traditional insulin resistance indices. HbA1c and hypertension were the most influential components in the model. CONCLUSION: Long-term declines in eGDR were significantly associated with an increased risk of CKO. Cumulative eGDR showed enhanced predictive value, underscoring its promise as a biomarker for early CKD risk assessment.