Stage-specific associations of nutrition-related surrogate insulin resistance indices across the chronic kidney disease continuum: evidence from a Chinese cohort.

Introduction: Comparative longitudinal evidence on how different surrogate insulin resistance (IR) indices relate to chronic kidney disease (CKD) onset and subsequent renal deterioration remains limited. This study aimed to evaluate the associations of surrogate IR indices with CKD incidence, progression, and outcomes. Methods: This retrospective cohort study included participants from the Dalian Health Management Cohort, in which 12 surrogate IR indices were calculated. The primary outcome was incident CKD, while secondary outcomes included rapid kidney function decline (RKFD) and adverse renal outcomes. Kaplan-Meier analysis compared the CKD incidence across quartiles. Associations between surrogate IR indices and renal outcomes were evaluated using Cox proportional hazards and logistic regression models. Dose-response relationships were assessed using restricted cubic splines, and predictive performance was evaluated using time-dependent receiver operating characteristic curves and associated metrics. Results: Among 48,304 participants, 1,092 incident CKD cases (2.26%) were identified over a median follow-up of 4.74 years. Kaplan-Meier curves showed increasing CKD risk across the IR quartiles. Quartile-based analyses showed progressively higher incident CKD risk with increasing levels of the evaluated surrogate IR indices (all Conclusion: Surrogate IR indices were higher in groups with poorer renal outcomes. Indices emphasizing visceral adiposity-related components showed relatively stronger associations with incident CKD, whereas indices incorporating glucose-lipid metabolic and overall adiposity components showed relatively stronger associations with later renal deterioration. TyG-WC may serve as a simple marker for early risk identification and stratification.