Association between Body Mass Index and Mortality From Aortic Aneurysm and Dissection: A Prospective Cohort Study

BACKGROUND AND OBJECTIVES: The association between obesity and aortic diseases remains uncertain. We investigated the relationship between body mass index (BMI) and mortality from aortic aneurysm and dissection. METHODS: This population-based prospective cohort study used National Health Insurance Service health examination data from 15,146,946 Korean adults aged ≥18 years who underwent health screening between 2003 and 2006, with follow-up for mortality from aortic aneurysm and dissection through national death registry linkage until 2018. Multivariable Cox proportional hazards models estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Over a median follow-up of 14.3 years, 4,299 deaths from aortic disease were identified. A J-shaped association was observed between BMI and aortic disease mortality. Underweight (BMI <18.5 kg/m²: HR, 1.23; 95% CI, 1.04-1.45; p=0.013) and higher BMI categories, including upper-normal, overweight, and obese groups (e.g., BMI ≥35 kg/m²: HR, 3.40; 95% CI, 2.10-5.49; p<0.001), were associated with increased mortality compared with BMI 21-22.9 kg/m². The association was more pronounced in younger individuals. The excess risk associated with underweight was more prominent in women, whereas the association with higher BMI was steeper in men. CONCLUSIONS: In this large nationwide general population cohort, BMI showed a J-shaped association with mortality from aortic aneurysm and dissection. Further studies are needed to determine whether maintaining BMI within a healthy range is associated with lower risk of mortality from aortic aneurysm and dissection.