[Association of triglyceride-glucose index and cardiovascular disease in a community-based Chinese cohort].

Objective: To investigate the association between the triglyceride-glucose (TyG) index and the incidence and mortality of cardiovascular disease (CVD) in a large population-based cohort.

Methods: Participants aged 40-79 years without a history of CVD at baseline were drawn from the CHinese Electronic health Records Research in Yinzhou (CHERRY) study between January 1, 2010, and May 31, 2020. The TyG index was calculated using baseline triglyceride and fasting blood glucose. Cox proportional hazards models were used to assess the association between the TyG index and the composite outcome of CVD (incidence and mortality), adjusting for age, gender, education, region, smoking status, body mass index, systolic blood pressure, and total cholesterol. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated. Nonlinear associations between the TyG index and CVD were further evaluated using restricted cubic splines, and subgroup analyses by gender and age were conducted to explore potential differences.

Results: A total of 226 406 individuals were included, with a mean age of (55.0±9.7) years at baseline, 46.8% of whom were men, and a median TyG index of 8.68. Over a median follow-up of 7.99 years, 9 815 (4.34%) participants experienced CVD incidence or mortality. After adjusting for age, gender, education, region, smoking status, body mass index, systolic blood pressure and total cholesterol, the risk of CVD increased with higher TyG index levels (P < 0.001). The risk in the highest TyG quartile (TyG>9.10) was 42% higher than in the lowest quartile (TyG≤8.32) (HR=1.42, 95%CI: 1.34-1.51). Individuals under 60 years had a higher HR for CVD compared with those aged 60 years and above (HR: 1.71 vs. 1.27, P < 0.05). Restricted cubic spline analysis revealed a reverse L-shaped association between the TyG index and CVD risk in the overall population (P < 0.001 for nonlinear trend), with risk increasing after the TyG index exceeded 8.67. However, the threshold varied by gender, with a lower threshold in women (8.51) than in men (8.67).

Conclusion: A significant nonlinear relationship was revealed between the TyG index and CVD risk, with a threshold effect. The risk of CVD increased once the TyG index surpassed a certain threshold, with a lower threshold in women than in men. These findings suggest that cardiovascular risk prediction and interventions based on the TyG index should be gender-stratified, and early intervention for individuals under 60 years old might have important public health implications.