Association of changes and cumulative measures of triglyceride-glucose index-body mass index with hypertension risk: a prospective cohort study

Background: To investigate the relationships of the dynamic changes in triglyceride glucose index-body mass index (TyG‑BMI) and cumulative TyG-BMI with the risk of hypertension among middle-aged and elderly Chinese.

Methods: Data were used from the China Health and Retirement Longitudinal Study (CHARLS). Participants who participated in the baseline study (2011-2012) and in subsequent surveys (2015-2018) were included in this study. The primary exposures were changes in TyG-BMI and cumulative TyG-BMI from 2012 to 2015. Changes in TyG-BMI were categorized using k-means clustering methods, while cumulative TyG-BMI was categorized into quartiles. Cox proportional hazards regression models were performed to examine the association between changes in TyG-BMI and cumulative TyG-BMI with the incidence of hypertension. Linear regression analyzes were performed to examine the association between changes in TyG-BMI and cumulative TyG-BMI with cumulative systolic blood pressure (SBP) and cumulative diastolic blood pressure (DBP).

Results: Of a total of 2,561 participants aged 56.93 ± 8.08 years old at baseline, 253 individuals (9.9%) developed hypertension during the 7-year follow-up period. The hazard ratios (HR) and 95% confidence interval (CI) for hypertension were 1.50 (1.10-2.03) for class 2 (persistently medium class) and 2.35 (1.61-3.42) for class 3 (persistently high class), compared to class 1 (persistently low class). Additionally, class 2 showed increases of 7.70 mmHg (95% CI: 5.18-10.21) in cumulative SBP and 6.53 mmHg (95% CI: 4.68-8.38) in cumulative DBP, while class 3 exhibited increases of 14.10 mmHg (95% CI: 10.56-17.64) in cumulative SBP and 12.64 mmHg (95% CI: 10.03-15.25) in cumulative DBP, compared with class 1. Regarding cumulative TyG-BMI, the HR for hypertension were 1.75 (95% CI: 1.18-2.59) for quartile 3 and 2.15 (95% CI: 1.43-3.23) for quartile 4, compared with quartile 1. In quartile 2, cumulative SBP increased by 3.99 mmHg (95% CI: 0.88-7.11) and cumulative DBP by 2.74 mmHg (95% CI: 0.45-5.02). Quartile 3 showed increases of 8.32 mmHg (95% CI: 5.09-11.54) in cumulative SBP and 7.13 mmHg (95% CI: 4.76-9.49) in cumulative DBP. Quartile 4 exhibited the highest increases, with cumulative SBP rising by 13.15 mmHg (95% CI: 9.70-16.60) and cumulative DBP by 12.20 mmHg (95% CI: 9.67-14.74). Furthermore, a linear relationship was observed between cumulative TyG-BMI and the risk of hypertension.

Conclusions: Changes in TyG-BMI and cumulative TyG-BMI were associated with an increased risk of hypertension, as well as higher cumulative SBP and DBP in Chinese middle-aged and elderly population.