Body mass index and the risk of abdominal aortic aneurysm presence and postoperative mortality: a systematic review and dose-response meta-analysis

Background: The clinical data regarding the relationships between BMI and abdominal aortic aneurysm (AAA) are inconsistent, especially for the obese and overweight patients. The aims of this study were to determine whether obesity is associated with the presence of AAA and to investigate the quantitative relationship between BMI and the risk of AAA presence and postoperative mortality. Materials and methods: PubMed, Web of Science, and Embase databases were used to search for pertinent studies updated to December 2023. The pooled relative risk (RR) with 95% CI was estimated by conventional meta-analysis based on random effects model. Dose-response meta-analyses using robust-error meta-regression (REMR) model were conducted to quantify the associations between BMI and AAA outcome variables. Subgroup analysis, sensitivity analysis, and publication bias analysis were performed according to the characteristics of participants. Results: Eighteen studies were included in our study. The meta-analysis showed a higher prevalence of AAA with a RR of 1.07 in patients with obesity. The dose-response meta-analysis revealed a nonlinear relationship between BMI and the risk of AAA presence. A 'U' shape curve reflecting the correlation between BMI and the risk of postoperative mortality in AAA patients was also uncovered, suggesting the 'safest' BMI interval (28.55, 31.05) with the minimal RR. Conclusions: Obesity is positively but nonlinearly correlated with the increased risk of AAA presence. BMI is related to AAA postoperative mortality in a 'U' shaped curve, with the lowest RR observed among patients suffering from overweight and obesity. These findings offer a preventive strategy for AAA morbidity and provide guidance for improving the prognosis in patients undergone AAA surgical repair.