AIM To investigate the relationship between triglyceride-glucose index (TyG) and carotid artery structure and elastic function in the general adult population.

METHODS A cross-sectional study was conducted on clinical ultrasound data of healthy volunteers who underwent annual physical examinations at Tangdu Hospital from June 2021 to December 2021. A total of 594 volunteers were included. Volunteers were divided into three groups based on the interquartile range of TyG index levels: (4.24 ± 0.10) for T1 group, (4.45 ± 0.06) for T2 group, and (4.71 ± 0.11) is T3 group. Estimate the relationship between TyG index, carotid intima media thickness (CIMT), and pulse wave velocity (PWV) using a multiple linear model. Using mediation analysis to examine the mediating roles of Body Mass Index (BMI), blood pressure, blood glucose, and lipid indicators in the association between TyG index and CIMT and PWV.

RESULTS As the TyG index level increases, the various data of the survey subjects change gradually by group. The proportion of smoking in T1, T2, and T3 groups increases gradually and there is a statistical difference. Adjacent and cross group comparisons are all P<0.05; Age, proportion of females, BMI, total cholesterol, low-density lipoprotein cholesterol, triglycerides, fasting blood glucose, alcohol consumption, CIMT and PWV gradually increased, while high-density lipoprotein cholesterol gradually decreased. Adjacent and cross group comparisons were all P<0.01. Multiple linear regression analysis found that after adjusting for covariates, for every 1 unit increase in the TyG index, the CIMT increased by 0.54 μm (95% CI: 0.13～0.64; P<0.01), PWV increased by 0.28 m/s (95% CI: 0.20～ 0.37; P<0.01). The mediation effect analysis found that SBP has a positive impact on PWV indirectly mediated, with a mediation effect accounting for 18.2%.

CONCLUSION TyG index is an independent risk factor for CIMT and PWV in the normal adult population. TyG index is positively associated with PWV in an indirect manner mediated by SBP.