The association between CT-assessed sarcopenic overweight, obesity and rupture abdominal aortic aneurysm: a cross-sectional analysis

Objective To investigate the associations of sarcopenic overweight and obesity with ruptured abdominal aortic aneurysm (rAAA). Methods This cross-sectional study retrospectively enrolled 244 patients with abdominal aortic aneurysm (AAA) between January 2022 and December 2024 (mean age: 71.09 ± 10.59 years, mean BMI: 23.39 ± 3.40 kg/m 2 , men: 80.74%). Baseline clinical characteristics, computed tomography (CT) parameters, and laboratory results were collected. Sarcopenia was diagnosed using CT measured skeletal muscle index (SMI) measured at the third lumbar vertebral level (L3). Overweight and obesity were defined according to the World Health Organization (WHO) Asia-Pacific criteria (overweight: BMI ≥ 23 kg/m 2 ; obesity: BMI ≥ 25 kg/m 2 ). Patients were stratified into two group: non-ruptured AAA group ( n = 191) and ruptured AAA group ( n = 53). The associations of sarcopenia, overweight, obesity, and their interaction with rAAA were examined using two-factor logistic regression models. Results Neither sarcopenia nor overweight alone showed a significant independent association with rAAA. Obesity was significantly associated with rAAA (odds ratio OR 2.15, 95% confidence interval CI 1.13 ~ 4.08, p = 0.020). In the two-factor logistic regression model, the interaction between sarcopenia and overweight was significantly associated with rAAA (OR = 3.86; 95% CI: 1.30 ~ 11.45; p = 0.015). A similar interaction was observed for sarcopenia and obesity (OR = 4.91; 95% CI: 1.57 ~ 15.34; p = 0.006). Conclusion Sarcopenic overweight and obesity were independently associated with rAAA. The coexistence of low muscle mass and excess adiposity, rather than either condition alone, was associated with higher odds of rupture. Integrating CT-derived skeletal muscle assessment with BMI may help identify patients with higher odds of rupture.