Association between the triglyceride–glucose index and subclinical atherosclerosis in asymptomatic adults: a large cross-sectional study of a health check-up population

Background This study aimed to investigate the association between the triglyceride–glucose (TyG) index and subclinical atherosclerosis (SA), hypothesizing that higher TyG levels are associated with increased odds of SA and may exhibit a non-linear dose–response relationship. Methods We conducted a cross-sectional study of 13,473 asymptomatic adults undergoing health examinations. SA was assessed by carotid ultrasonography. TyG was calculated from fasting triglyceride and glucose levels. Logistic regression and restricted cubic spline (RCS) models were used to evaluated the associations between TyG and SA. Results Higher TyG levels were associated with increased odds of SA in a dose–response pattern. In fully adjusted models, each 1-unit increase in TyG was associated with 20% higher odds of SA (OR 1.20, 95% CI 1.10–1.30). Participants in the highest tertile had increased odds compared with the lowest tertile (OR 1.38, 95% CI 1.22–1.56; P trend <0.001). RCS analysis suggested a significant non-linear association ( P non−linearity = 0.034), with an exploratory model-derived inflection point around 8.07. The association remained consistent in normoglycemic individuals (OR = 1.21; 95% CI: 1.02–1.44). Conclusions In this large asymptomatic population, the TyG index showed a robust positive association with SA. These findings extend existing evidence by providing preliminary insights into the dose–response relationship, although the non-linear pattern should be interpreted with caution and requires further validation.