Association of metformin use with abdominal aortic aneurysm: A systematic review and meta-analysis

Background: Abdominal aortic aneurysm (AAA) is a cardiovascular disease characterized by a high mortality rate when ruptured. Some studies suggest a potential inverse correlation between AAA and diabetes patients, especially those undergoing metformin treatment. However, this relationship remains unclear. This paper offers a systematic review and meta-analysis with the objective of clarifying the influence of metformin on AAA. Methods: A search for relevant articles was performed across multiple databases including PubMed, ScienceDirect, Cochrane and Scopus. The focus was on studies that examined the comparative effects of metformin and non-metformin treatments on AAA patients. Data from appropriate studies were consolidated to estimate the effects. Our study encompassed 11 articles, comprising 13 cohorts that compared metformin (n = 32,250) with a control group (n = 116,339). Results: The random effects meta-analysis revealed that metformin was associated with a slower growth rate (weighted mean difference (WMD) −0.86 mm; 95% CI: −1.21 to −0.52; p < 0.01; I²: 81.4%) and fewer AAA-related events (OR: 0.54; 95% CI: 0.34 to 0.86; p = 0.01; I²: 60.9%). The findings suggest that metformin may be linked to a reduced risk of aortic aneurysm. A meta-regression analysis indicated that the association between metformin and AAA growth was significantly influenced by male gender (p = 0.027), but not by age (p = 0.801), hypertension (p = 0.256), DM (p = 0.689), smoking history (p = 0.786), use of lipid-lowering agents (p = 0.715), or baseline diameter (p = 0.291). Conclusion: These results hint at a potential role for metformin in limiting annual AAA growth, AAA-related events, and the risk of AAA.