AIMS

This study aims to ascertain whether abdominal fat accumulation evaluated by waist circumference increases the risk of hypertension using the nationwide population.

METHODS

We enrolled 47,037 participants from the China Health and Nutrition Survey (CHNS), China Health and Retirement Longitudinal Study (CHARLS), and National Health, and Nutrition Examination Survey (NHANES). The adjusted logistic regression model was used to examine the relationship between waist circumference and prevalent hypertension. 9445 participants without baseline hypertension from the CHNS and CHARLS were followed up to investigate the association between waist circumference and onset hypertension. The association was evaluated using a Cox regression model and restricted cubic spline. Furthermore, Mendelian randomization was employed to explore causal inferences.

RESULTS

In the baseline survey, waist circumference demonstrated a notable correlation with hypertension, presenting an odds ratio (with 95% confidence intervals) of 1.34 (1.28 ~ 1.40). After a mean follow-up of 3.8 years for participants without baseline hypertension, 2,592 (27.5%) developed hypertension. In the pooled analysis, the Cox regression showed that every 10 cm increase in waist circumference was associated with 20% (95% CI: 13% ~ 27%) elevated risk of new-onset hypertension. Restricted cubic splines indicated a pronounced linear dose-response relationship. A subgroup analysis affirmed the persisting association between waist circumference and hypertension onset even in those with normal BMI. The Mendelian randomization method revealed a significant causative association between waist circumference and hypertension.

CONCLUSION

Elevated waist circumference stands as an independent risk factor for hypertension, even in those with normal BMI. Our results provide evidence supporting the routine measure for waist circumference.