The threshold association of triglyceride glucose-waist height ratio with hypertension: a cross-sectional analysis from the China health and retirement longitudinal study

Hypertension remains a leading modifiable risk factor for cardiovascular morbidity and mortality, underscoring the need for robust predictive biomarkers. The triglyceride-glucose waist-to-height ratio (TyG-WHtR) has emerged as a novel composite biomarker of metabolic dysregulation, yet its critical threshold for hypertension association remains undetermined. Clarifying this threshold is essential for optimizing risk stratification in clinical practice. This cross-sectional analysis utilized data from the China Health and Retirement Longitudinal Study (CHARLS). Hypertension was defined per WHO criteria as systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥ 90 mmHg, or active antihypertensive treatment. Threshold regression analysis was employed to investigate the nonlinear relationship between TyG-WHtR and hypertension, adjusted for age and gender. Two-stage threshold effects were identified at TyG-WHtR = 3.05 (likelihood ratio test P < 0.001). Logistic regression models with segmented estimation were applied to identify inflection points, complemented by a likelihood ratio test to validate threshold significance. Participants below this threshold demonstrated no elevated hypertension risk (OR: 0.67, 95% CI: 0.29–1.54, P = 0.343). Conversely, values ≥ 3.05 were associated with a 2.22-fold increased hypertension risk (95% CI: 2.07–2.38, P < 0.001). The likelihood ratio test confirmed significant threshold behavior (Δdeviance = 18.6, P < 0.001), supporting 3.05 as the optimal discriminatory cut-off. Sensitivity analyses showed consistent results across age and gender subgroups. TyG-WHtR exhibits a clinically meaningful threshold association at 3.05 with hypertension, with superior risk discrimination above this value. This threshold-driven association suggests TyG-WHtR’s potential as a cost-effective risk stratification tool in primary prevention. This threshold-driven association suggests TyG-WHtR’s potential as a cost-effective risk stratification tool in primary prevention, though its predictive utility requires validation in prospective cohorts. Future prospective studies should validate its predictive utility across diverse populations.