Relationship Between Body Mass Index and the Risk of Hypertension in Elderly Patients With Dyslipidemia

Abstract OBJECTIVE To investigate the relationship between body mass index (BMI) and the risk of hypertension in elderly patients with dyslipidemia. METHODS Dyslipidemia patients aged 60 years and above were selected from Tianjin surveillance points of China Chronic Disease Surveillance (2019–2023). The data of gender, age, height, blood pressure, BMI, disease history, and other indicators were collected through a cross-sectional survey. The chi-square test and multivariate logistic regression were used to analyze the influencing factors of hypertension. Restricted cubic spline curves were drawn to quantify the association between BMI and hypertension and identify the key nodes. RESULTS A total of 25,229 patients aged 60 years and over with dyslipidemia were included in this study. The average age was (66.8 ± 3.62) years old, and the prevalence of hypertension was 55.9% (14,109/25,229). Multivariate logistic regression analysis showed that after adjusting for gender, age, smoking, drinking, and leisure time exercise, for every 1 kg/m2 increase in BMI, the risk of hypertension in elderly patients with dyslipidemia increased by 12% (odds ratio [OR] = 1.12, 95% confidence interval [CI]: 1.11–1.13, P < 0.001). The risk of hypertension was 56% higher in the overweight group (OR = 1.56, 95% CI: 1.47–1.65, P < 0.001), and 2.56 times higher in the obese group (OR = 2.56, 95% CI: 2.37–2.76, P < 0.001) than that in normal and low body mass group. The risk of hypertension in the obese group was 2.77 times (95% CI: 2.40–3.21, P < 0.001) and 2.66 times (95% CI: 2.35–3.00, P < 0.001) higher than that in the normal and underweight groups, respectively, in subjects with low high-density lipoprotein cholesterol and high total cholesterol. Restricted cubic spline analysis showed that after adjusting for confounding factors, the relationship between BMI and the risk of hypertension in elderly patients with dyslipidemia showed an approximately S-shaped relationship (non-linear test P < 0.001). When BMI <24 kg/m2, the risk of hypertension did not change significantly with BMI (OR = 0.99, 95% CI: 0.95–1.04, P = 0.857); when BMI was 24–29 kg/m2, the risk of hypertension increased with the increase of BMI (OR = 1.11, 95% CI: 1.06–1.16, P < 0.001), while when BMI >29 kg/m2, the risk of hypertension did not change significantly with BMI (OR = 1.02, 95% CI: 0.99–1.05, P = 0.133). CONCLUSIONS BMI and the risk of hypertension in elderly patients with dyslipidemia is “S” type distribution, when BMI is between 24 and 29 kg/m2, the risk of hypertension increases with BMI, when BMI is below or above the threshold, the risk of hypertension did not change significantly with BMI.