Association between the cumulative average triglyceride glucose-BMI and hypertension incidence among the middle-aged and older population: a prospective nationwide cohort study in China

Objective: This study aimed to prospectively examine the association between triglyceride glucose-BMI (TyG-BMI) and hypertension incidence in a middle-aged and older Chinese population. Methods: We conducted a prospective analysis of 3614 participants without baseline hypertension from the China Health and Retirement Longitudinal Study (CHARLS). Cumulative average TyG-BMI was calculated from measurements taken in 2011 (Wave 1) and 2015 (Wave 3). Incident hypertension was defined as new physician diagnosis, antihypertensive medication use, or measured blood pressure at least 140/90 mmHg during follow-up. Multivariable Cox models and restricted cubic splines were used to assess the association. Sensitivity analyses, including propensity score matching, and subgroup analyses were performed. Results: During a mean follow-up of 60 months, 737 participants developed incident hypertension. The cumulative incidence increased steadily across quartiles of cumulative average TyG-BMI. In the fully adjusted Cox model, participants in the highest quartile had a significantly higher risk of hypertension compared with those in the lowest quartile [adjusted hazard ratio 2.095, 95% confidence interval (95% CI) 1.641–2.674; P for trend <0.001]. When analysed as a continuous variable, each 1-SD increment in cumulative average TyG-BMI was associated with a 30.6% higher hypertension risk (adjusted hazard ratio 1.306, 95% CI 1.198–1.425; P < 0.001). Restricted cubic spline analyses demonstrated a significant positive linear association without evidence of nonlinearity ( P for nonlinearity = 0.112). The association remained robust across subgroup analyses and sensitivity analyses, including exclusion of early incident cases and propensity score matching. Conclusion: Higher cumulative average TyG-BMI exposure is independently and linearly associated with increased hypertension risk in middle-aged and older Chinese adults. As a simple integrative indicator, cumulative TyG-BMI shows significant potential for risk stratification and early hypertension prevention in primary care.