Association between the triglyceride-glucose-body mass index and the risk of early vascular aging in young and middle-aged Chinese adults: a cross-sectional study

Abstract Background Early vascular aging (EVA) reflects accelerated arterial aging and is increasingly recognized as an important precursor of cardiovascular disease (CVD). Insulin resistance (IR) has been implicated in the pathogenesis of vascular aging. The triglyceride–glucose–body mass index (TyG-BMI), a surrogate marker of IR, has demonstrated predictive value for several cardiometabolic disorders. However, evidence regarding its association with EVA remains limited. Methods This cross-sectional study enrolled 1,272 Chinese adults aged 30 ~ 59 years who completed brachial–ankle pulse wave velocity (baPWV) measurement. EVA was defined as a baPWV value above the 90th percentile in the corresponding 10-year age group. Multivariable logistic regression models were applied to assess the association between TyG-BMI and EVA. Restricted cubic spline (RCS) analysis was conducted to explore the potential nonlinear relationship. Additional analyses further examined the associations of TyG-BMI with baPWV and Framingham risk score (FRS)-derived indicators. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive ability of TyG-BMI for EVA. Results After full adjustment, each 10-unit increase in TyG-BMI was associated with a 14.9% increased risk of EVA (odds ratio [OR] 1.149, 95% confidence interval [CI] 1.083~1.231). RCS analysis revealed a nonlinear association between TyG-BMI and EVA, with a turning point at a TyG-BMI value of 210.98. TyG-BMI also showed a nonlinear association with baPWV and FRS-derived indicators (predicted vascular age, age gap, and predicted 10-year CVD risk). In the fully adjusted model incorporating TyG-BMI, the area under the curve (AUC) for identifying EVA was 0.8533. Conclusions This cross-sectional study demonstrated that TyG-BMI was independently and nonlinearly associated with EVA among young and middle-aged Chinese adults. The observed turning point suggests a potential reference point for this association. These findings suggest that TyG-BMI may serve as a simple, readily accessible indicator for assessing EVA risk in this population, pending external validation.