Association between hemoglobin A1c to HDL cholesterol ratio and hypertension in middle-aged and older Chinese adults: a cross-sectional study

INTRODUCTION: The hemoglobin A1c to high-density lipoprotein cholesterol ratio (HHR) is a novel composite index reflecting both chronic glycemic exposure and lipid metabolism. However, its association with hypertension remains unclear. This study aimed to investigate the independent association between HHR and hypertension prevalence in middle-aged and older Chinese adults. METHODS: This cross-sectional study analyzed data from the 2011 and 2015 biomarker waves of the China Health and Retirement Longitudinal Study (CHARLS). Among 25,873 initially identified participants, 11,797 were ultimately included after applying the inclusion and exclusion criteria. Multivariable logistic regression and restricted cubic spline analyses were conducted to assess the association between HHR and hypertension prevalence, adjusting for sociodemographic, lifestyle, and metabolic confounding factors. RESULTS: HHR was positively associated with hypertension. In the fully adjusted model, each 0.1-unit increase in HHR was associated with higher odds of hypertension (OR = 1.02, 95% CI: 1.01-1.04). Participants in the high HHR group had significantly higher odds of hypertension than those in the low HHR group (OR = 1.38, 95% CI: 1.24-1.54). Restricted cubic spline analysis showed a significant nonlinear association between HHR and hypertension. CONCLUSION: Elevated HHR was associated with hypertension in a nonlinear pattern among middle-aged and older Chinese adults. Given the cross-sectional design, these findings should be interpreted as evidence of association rather than prediction or causality. Further prospective studies are warranted to determine whether HHR provides incremental value for hypertension risk assessment.