Body mass index and stroke incidence at age 40 years in the Chinese population: an observational study

Objectives: To identify the interaction of stroke-related lifestyle behaviors and clinical indicators, overweight/obesity in stroke risk. Methods This study was a large population-based study using multistage stratified random cluster sampling to investigate 3835 permanent residents aged over 40 in Fuyang, Anhui Province from June to November 2021. Baseline information was collected for all subjects. Non-parametric test and Chi-square test analysis were used to examine the relationship between these indicators and stroke, and then the interaction between BMI and stroke and the optimal cut-off value of BMI was determined by constructing multi-model multiple logistic regression. Results Among 3835 subjects, 2379 (62.03%) were female. The overall prevalence of stroke patients in the study population was 3.10%, and the proportion of obese/overweight patients was 57.50%, with statistical significance between the two groups (χ2=-2.629, p < 0.05). Multivariate logistic regression analysis showed that age (OR = 0.968, p = 0.000), dyslipidemia (OR = 0.653, p = 0.043), hypertension (OR = 0.381, p = 0.000) and BMI were independent risk factors for stroke. The three models showed a positive correlation between BMI and stroke. BMI=24.38 was the best cutoff for stroke occurrence, and the area under the ROC curve was 0.768 (95% CI: 0.713 to 0.824). The sensitivity was 85.3.0% and the specificity was 52.1%. Conclusion Obesity is an independent risk factor for ischemic stroke. When BMI≥24kg/m2, BMI and other risk factors work together to increase the risk of stroke. Epidemiological studies of stroke and its risk factors can help develop strategies to prevent stroke.