The mediating role of the triglyceride-glucose index in the association between lifestyle risk score and hypertension

BACKGROUND: Although an unhealthy lifestyle is an established risk factor for hypertension, the underlying association through this effect is not fully delineated. This study aimed to examine the potential mediating role of the TyG index in the association between lifestyle and hypertension. METHODS: A cross-sectional study was analyzed among 8,201 residents of Jilin Province. A lifestyle risk score was derived from five lifestyle factors. The TyG index was calculated using fasting blood glucose and triglyceride levels. Hypertension was defined by the guidelines of the WHO and blood pressure measurements. The associations were examined using logistic regression and mediation analyses, with sensitivity and subgroup analyses employed to test the robustness. RESULTS: The study included 8,201 participants (37.8% with hypertension). Each 1-point increase in lifestyle risk score raised hypertension odds (OR 1.25, 95% CI 1.20-1.31). Mediation analysis showed TyG accounted for 39.8% of the association. All sensitivity analyses demonstrated robustness of the findings. Subgroup analysis revealed that the mediating association was statistically significant across all demographic groups, with significant effect modification by age for the TyG-hypertension association (P = 0.0007). CONCLUSIONS: The TyG index plays a significant mediating role in the association between lifestyle and hypertension (significant for all age and gender subgroups). Notably, age significantly modifies the TyG-hypertension association, suggesting that the link between insulin resistance and hypertension may be stronger in adults aged ≤ 60 years. This finding implies that interventions targeting insulin resistance could have differential effects on hypertension prevention across age groups.