• Research type

    Research Study

  • Full title

    The Metformin Aneurysm Trial (MAT) An investigator initiated and conducted, multicentre, international, double-blinded, placebo-controlled, parallel-group, randomised controlled trial to determine the effect of metformin on abdominal aortic aneurysm (AAA) associated events, including AAA repair and AAA mortality (due to aneurysm rupture).



  • Contact name

    Matt Bown

  • Contact email

  • Sponsor organisation

    James Cook University

  • Research summary

    Abdominal Aortic Aneurysm (AAA) is a common problem in older adults, affecting approximately 5% of men and 1% of women over the age of 60. Over time, there is a risk that the AAA increases in size to the point where it requires surgical intervention, or it can rupture, which is life threatening and requires emergency surgery. Other than surgery, there is currently no known effective treatment to treat AAA’s.

    Recent studies suggest that a drug called metformin might prevent AAA growth, which ultimately reduces the need to have surgery, or of the aneurysm eventually rupturing. Metformin is commonly used in the treatment of type 2 diabetes, but it has also been shown to be safe and well tolerated in people who do not have diabetes.

    The UK and other countries, are working with a research team in Australia who have funded and designed the Metformin Aneurysm Trial (MAT). The aim of this study is to find out whether or not metformin can help people with AAA and whether taking metformin will benefit patients with AAA’s by preventing them from needing surgical intervention and reducing the risk of rupture.

    Patients who are held on local NHS screening registries, who have an aneurysm measuring between 35mm-49mm, will be invited to take part. Patients will be randomised to take metformin or a placebo medication for an average of 3.5 years and up to 5 years. They will receive a telephone review every 3 months and will be seen face-to-face every year by a member of the research team from the hospital.

  • REC name

    East of England - Cambridgeshire and Hertfordshire Research Ethics Committee

  • REC reference


  • Date of REC Opinion

    31 Oct 2023

  • REC opinion

    Further Information Favourable Opinion