Association of triglyceride–glucose index and its 6-year change with risk of hypertension: A prospective cohort study

Background and aim We aimed to investigate the association of triglyceride–glucose (TyG) index and its dynamic change with risk of hypertension in rural Chinese and, further, to explore whether the TyG index mediates the obesity-related hypertension. Methods and results A prospective cohort study, including 10,309 subjects without hypertension at baseline, was conducted in 2007–2008 and followed up in 2013–2014. TyG index was calculated as Ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. Logistic regression model was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). Mediation analysis was performed to examine the contribution of the TyG index to the association of obesity-hypertension incidence. During a median follow-up of 6 years, 2073 subjects developed hypertension. In multivariate logistic model adjusted for age, sex, alcohol drinking, smoking, physical activity and education, monthly income, family history of hypertension, TC, and HDL-C, the risk of hypertension was 1.14 (1.07–1.22) for per-SD increase in TyG. After additional controlling for obesity, this association was nonsignificant (1.06, 0.99–1.13) and (1.05, 0.99–1.13) for BMI and WC, respectively. Increasing trends were found for hypertension incidence as the TyG change increased, with or without adjustment for obesity (all Ptrend < 0.05). With per-SD increment in TyG change, the risks of hypertension incidence were 1.14 (1.07–1.22) for absolute TyG change, and 1.15 (1.08–1.22) for relative TyG change in multivariate logistic model; the results were significant after further adjustment for BMI or WC, respectively. The TyG index partially mediated the obesity-incident hypertension association: 6.84% for BMI and 6.68% for WC, respectively. Conclusions Elevated TyG index and its dynamic change were positively associated with risk of incident hypertension in rural Chinese population, and the TyG index may play a partially mediating role in obesity-related incident hypertension.