Supplementary Material for: Association between A Body Shape Index and the Prevalence of Stroke: A Cross-Sectional Study

Background: This investigation utilized cross-sectional NHANES data to explore the relationship between the A Body Shape Index (ABSI) and stroke, with a focus on age differences.
Methods: A total of 40,213 participants from four NHANES cycles (2003–2018) were included in the analysis. Stroke status was determined via self-report, and ABSI was calculated using waist circumference, height, and weight measurements. To investigate the relationship between ABSI and stroke risk, we employed multivariate logistic regression models adjusted for potential confounders and used restricted cubic spline analysis to explore non-linear associations. Additionally, subgroup analyses were conducted based on gender, age, race, and BMI.
Results: Elevated ABSI was linked to a higher stroke risk (OR = 1.19, 95% CI: 1.07-1.87, p = 0.002). When divided into quartiles, participants in the highest quartile (Q4) had a notably increased stroke risk compared to those in the lowest (Q1) (OR = 1.33, 95% CI: 1.05-1.76, p = 0.005). Subgroup analyses revealed this association was especially pronounced across different genders, races, and in individuals aged 40-59 (OR = 1.38, 95% CI: 1.00-1.72, p = 0.04) and 60+ (OR = 1.48, 95% CI: 1.01-1.61, p = 0.004). Additionally, restricted cubic spline analysis showed a non-linear rise in stroke risk when ABSI exceeded 0.08.
Conclusions: Higher ABSI is linked to greater stroke risk, especially in the highest quartile and among individuals aged 40 and over, with a non-linear risk increase when ABSI exceeds 0.08.