Validation of the Triglyceride-Glucose Index as a Predictor of Coronary Artery Calcification Progression in Nondiabetic Adults with Mild Renal Insufficiency

Background: Patients with chronic kidney disease (CKD) are at increased risk for cardiovascular disease (CVD). Coronary artery calcification (CAC) serves as a marker of subclinical atherosclerosis and a predictor of future cardiovascular events. This study aimed to evaluate the association between the triglyceride-glucose (TyG) index and CAC progression in non-diabetic individuals with mild renal insufficiency (mRI), defined as an estimated glomerular filtration rate (eGFR) of 60–90 mL/min/1.73m2 using the CKD-EPI equation. Methods: This retrospective longitudinal study included adults with mRI who underwent at least two cardiac CT scans between 2006 and 2016 (derivation cohort, n = 844) and between 2017 and 2024 (validation cohort, n = 236). The TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2], and CAC progression was defined as an increase in CAC score on follow-up. Logistic regression models were used to evaluate the association between the TyG index and CAC progression, and the predictive performance was assessed using the area under the ROC curve (AUC). Results: In the derivation cohort, the TyG index was significantly associated with CAC progression (AUC = 0.600). The optimal cutoff value for TyG index was 8.662, which stratified participants with higher CAC risk. In multivariable logistic regression adjusted for age, BMI, blood pressure, waist-to-hip ratio, and sex, TyG index remained an independent predictor of CAC progression (OR = 1.34 per unit increase; P = 0.004). In quartile analysis, the highest TyG quartile (Q4) showed significantly increased odds of CAC progression compared to the lowest quartile (Q1) (OR = 1.62; 95% CI: 1.04–2.55; P = 0.035). The validation cohort confirmed the model’s discriminative ability with an AUC of 0.665. Conclusion: Among non-diabetic adults with mild renal insufficiency, a higher TyG index is independently associated with CAC progression. A TyG index of ≥8.662 may be a useful threshold to identify individuals at increased cardiovascular risk.