- Pending prospective clinical trial confirmation, metformin may be a therapeutic option for limiting progression of early abdominal aortic aneurysm (AAA) disease.
Why this matters
- AAA rupture risk increases with increasing aortic diameter.
- No available medication minimizes progressive diameter enlargement or prevents eventual rupture.
- Participants were 13,843 patients with asymptomatic AAA disease and diabetes in the Veterans Affairs Health Care System, 2003-2013, with 58,833 radiographic records, of whom 39.7% were prescribed metformin.
- A subcohort of 7462 patients with baseline AAA diameter 3.5-4.9 cm had 33,418 radiographic studies.
- Funding: NIH.
- Mean imaging follow-up interval was 4.2 years.
- Average baseline AAA diameter was 38.0 mm.
- After adjustment for comorbidities, metformin decreased yearly AAA growth rate by 0.23 mm/year in 1 model analysis and by 0.20 mm/year in another (both P<.001>
- In subcohort with starting AAA size 35-49 mm and adjusted for comorbidities, metformin decreased yearly AAA growth rate by 0.27 and 0.21 mm/year in the 2 analyses, respectively (both P<.001>
- 99% of participants were men.
- Heterogeneity in diameter reporting.
- Inability to stratify AAA results by lab values or diabetes duration.
- Assumption of no change in metformin prescriptions or other clinical parameters.
- Insulin prescription status not evaluated.