ABSTRACT NUMBER: ESOC2026A1119 THE ASSOCIATION BETWEEN BMI, METABOLIC HEALTH, AND STROKE RISK. A PROSPECTIVE COHORT STUDY WITH TIME-UPDATED COVARIATES

Abstract Background and aims The global prevalence of overweight and obesity is rising, yet the independent contribution of adiposity to stroke risk remains debated, particularly among metabolically healthy individuals. Methods We analyzed 132,045 participants from the Northern Sweden Health and Disease Study with repeated health examinations (1985-2022). Stroke events were identified via national registers. Body mass index (BMI) was modeled as continuous (splines) and categorical (WHO definitions). Cox models with time-updated covariates estimated hazard ratios (HRs), and machine learning (XGBoost-AFT) assessed complex relationships. Results Over a median 20.2-year follow-up (2.67 million person-years), 7,493 strokes occurred. In fully adjusted models, overweight (HR: 1.14; 95% CI: 1.08-1.20) and obesity (HR: 1.36; 95% CI: 1.27-1.45) independently increased stroke risk versus normal weight. Poor metabolic health was also strongly associated (HR: 1.51; 95% CI: 1.42-1.62) with increased stroke risk. Combined obesity and poor metabolic health conferred the highest risk (HR: 1.79; 95% CI: 1.67-1.93). Age modified the association between higher BMI and stroke risk (p-interaction = 0.007), with stronger associations at younger ages. Machine learning confirmed the BMI-stroke risk pattern. Conclusions Overweight and obesity are independent stroke risk factors, even among metabolically healthy individuals. Prevention strategies should address excess weight alongside metabolic risk, particularly in younger adults. Conflict of interest Marie Eriksson: nothing to disclose. Oskar Hultstrand: nothing to disclose. Anton Jernberg: nothing to disclose. Eva-Lotta Glader: nothing to disclose. David Darehed: nothing to disclose.