Association between Chinese visceral adiposity index (CVAI) and CKM stage progression in middle-aged and elderly Chinese adults

Cardio-kidney-metabolic (CKM) syndrome progression from early stages (0–3) to stage 4 is a critical clinical threshold with irreversible organ damage, but population-specific associated factors for Chinese adults remain understudied. Traditional adiposity measures lack specificity for visceral adiposity, a key driver of CKM. The Chinese Visceral Adiposity Index (CVAI) is a validated population-specific surrogate for visceral adiposity, and its association with CKM progression is unexplored. A secondary analysis of the prospective China Health and Retirement Longitudinal Study (CHARLS) cohort was conducted, including 3,857 participants with baseline CKM stages 0–3 (2011) and 4-year prospective follow-up (2015). Participants were stratified by CVAI tertiles. Cox proportional hazards regression models were used to assess the risk of CKM stage 4 progression, with stratified analyses for effect modifiers and restricted cubic spline curve fitting for dose–response relationships. Variance Inflation Factor was used to avoid multicollinearity in covariate selection.Comprehensive pre-specified sensitivity analyses were performed to validate the robustness of the core findings. High CVAI (highest tertile, 119.9–261.5) was independently associated with 33% higher CKM progression risk (adjusted HR = 1.33, 95% CI 1.02–1.75, P = 0.038). No statistically significant overall linear or non-linear dose–response relationship was observed between continuous CVAI and CKM progression ( P overall = 0.159, P non-linearity = 0.19). Diabetic patients with high CVAI had a nearly threefold higher progression risk (HR = 3.08, 95% CI 1.28–7.43), with a marginally significant synergistic effect. Sensitivity analyses consistently confirmed the robustness of the association between high CVAI and elevated CKM progression risk. CVAI is a population-specific associated factor of CKM progression in Chinese middle-aged and elderly adults, with high value for identifying high-risk subgroups (especially diabetic patients). It can be integrated into clinical practice to guide targeted visceral fat reduction interventions and improve CKM outcomes.