Led by Professor Chim Lang, head of the Division of Molecular and Clinical Medicine, the scientists found that metformin could be repurposed as a treatment for heart diseases in people who did not have type 2 diabetes.
The group's study, titled the MET-REMODEL Trial, was published in the European Heart Journal, and showed that metformin reduced the thickening of the muscle wall in the heart's left pumping chamber, a change known as left ventricular hypertrophy.
LVH is known to be a serious risk factor for heart attack, stroke and heart failure. It does not advertise its presence and people only know they have it when they suffer a heart attack or a stroke.
"The study involved treating pre-diabetic people with coronary artery disease with metformin or a placebo over a period of 12 months to see how the drug affected the heart muscle wall, using state-of-the-art MRI technology.
"The major causes of LVH are high blood pressure, obesity and insulin resistance, which are also thought to be key contributors of coronary artery disease. The dangerous thickening of the left ventricle was reduced by twice as much in those taking metformin compared to the placebo.
"We also found that metformin reduced blood pressure, oxidative stress and lost body weight — an average of 3.6kg, compared to no changes in the placebo group. If the findings from this study are substantiated in a larger-scale study, metformin could offer hope for millions of patients across the globe."
Lead author and principal investigator of the trial, Mohapradeep Mohan, said LVH was normally treated with blood pressure medication but this was not particularly effective as it could also be present in patients whose blood pressure was under control.
"In this context, we need non-blood pressure medication and we had good reason to suppose that metformin should help to reduce thickening of heart muscle wall," he said. The trial was funded by the British Heart Foundation.