Exploring the nonlinear association between cardiometabolic index and hypertension in U.S. Adults: an NHANES-based study.

Abstract

Background: Hypertension is a prevalent chronic disease affecting over 1.2 billion people worldwide, representing a major modifiable risk factor for cardiovascular diseases. The Waist-to-Height Ratio (WHtR) and Triglyceride to High-Density Lipoprotein Cholesterol (TG/HDL-C) ratio are established metabolic indicators linked to the risk of cardiovascular and metabolic diseases. Recently, a Cardiometabolic Index (CMI), combining WHtR and TG/HDL-C ratios, has been proposed to provide a comprehensive assessment of metabolic health. This study investigates the association between CMI and hypertension using data from the National Health and Nutrition Examination Survey (NHANES).

Methods: The study utilized NHANES data from nine cycles spanning 2001 to 2018, encompassing 20,049 participants aged over 20. Exclusions were made for individuals with incomplete CMI or hypertension data, and pregnant women. CMI was calculated by multiplying the WHtR by the TG/HDL-C ratio. Hypertension was defined according to American Heart Association guidelines. The relationship between CMI and hypertension was evaluated using multivariate logistic regression analyses, with additional subgroup analyses conducted based on demographic factors. Nonlinear relationships were analyzed using smoothing curve fitting techniques.

Results: The study identified a significant positive correlation between CMI and hypertension risk, with an increase of one unit in CMI associated with a 9% heightened risk of hypertension (OR: 1.09, 95% CI: 1.05, 1.13). The association remained significant across various demographic subgroups. A nonlinear relationship was observed, with a critical CMI threshold of 2.64. Below this threshold, higher CMI values were associated with a progressively higher prevalence of hypertension, whereas beyond this threshold, further increases in CMI did not significantly correlate with an elevated risk of hypertension.

Conclusion: The study demonstrates that CMI is significantly associated with hypertension risk and may serve as a valuable tool for early screening and risk assessment, particularly in identifying individuals at higher risk before reaching the critical CMI threshold. These results underscore the importance of addressing metabolic health in the prevention and management of hypertension. Future research should focus on longitudinal studies to establish causality, explore the clinical utility of CMI in hypertension screening, and examine its applicability in diverse populations.