Association of Body Mass Index and Waist Circumference with Hypertension in Older Adults

Abstract

Background: The relationship between obesity and prevalent hypertension in older adults has predominantly been estimated using categorical measures of body mass index (BMI) and waist circumference (WC), masking the shape of the dose-response relationship. We aimed to examine the precise relationship of BMI, WC with hypertension, and to assess the appropriate level of BMI and WC for hypertension. Methods: We examined data for 126,123 individuals in Xinzheng city aged ≥60 years from a population based study from January to December 2019. Logistic regression and restricted cubic spline models were applied to assess the relationship and the appropriate level of BMI and WC for hypertension. An additive interaction analysis was used to test synergistic effects between a higher BMI and WC for hypertension. Results: The full-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) of an increase of 1 kg/m2 in BMI and 1 cm in WC for hypertension were 1.084 (1.080-1.087) and 1.025 (1.024-1.027), respectively. Multivariable adjusted restricted cubic spline analyses showed the nonlinear relationships of BMI and WC with hypertension in both men and women (all P<0.001). The risk of hypertension increased steeply with increasing BMI from ≥25 kg/m2 and WC ≥ 88 cm or 86 cm for males and females, respectively. And we observed a significant additive interaction between a higher BMI and WC such that the prevalence of hypertension was significantly enhanced. Conclusion: These findings suggest increased hypertension prevalence in the elderly population with increased BMI and WC. BMI ≤ 25 kg/m2 and WC ≤ 88 cm or 86 cm for males and females may be the best suggestion with regard to primary prevention of hypertension in older adults.