Metformin protects the hearts of people with Type 1 diabetes, according to the results of the MERIT clinical trial. Metformin is an inexpensive drug that’s often used for Type 2 diabetes to lower blood sugar levels by reducing glucose production in the liver. It is not regularly given to people with Type 1 diabetes, though it can lower insulin requirements in Type 1 diabetes.
According to the Newcastle University Press Office, the MERIT trial has revealed metformin can promote a person’s ability to repair their own damaged blood vessels by decreasing the presence of microRNAs (miRs) which increases the growth of blood vessels – in addition to improving glucose levels.
In an open label, case-controlled study, the treatment group consisted of 23 people, aged between 19 and 65, with Type 1 diabetes who were free of cardiovascular disease. They were treated with metformin for 8 weeks.
Patients in the treatment group were matched with a standard group of nine Type 1 diabetic patients taking standard insulin. Additionally, there were 23 participants in the “healthy” control group without diabetes.
At the start of the study, the anti-angiogenic microRNAs, miR-222, miR-195, and miR-21a were detected to be higher in Type 1 diabetic patients compared to the control group. However, metformin treatment successfully reduced the levels of miR-222, miR-195, and miR-21a.
Moreover, as the levels of miR-222 lowered, there was a corresponding decrease in the amount of circulating endothelial cells, which indicates an improvement in vascular repair.
Dr Jolanta Weaver, Senior Lecturer in Diabetes Medicine at Newcastle University and Honorary Consultant Diabetologist at Queen Elizabeth Hospital, Gateshead, led the clinical trial at the Gateshead hospital and is lead author of the work published in the International Journal of Molecular Sciences. She said: “This is an exciting development as understanding this underlying mechanism opens up the possibility of new forms of treatment which will lower the chances of patients with Type 1 diabetes developing heart disease.
Dr Weaver adds: “These results confirm that as well as improving a patient’s blood sugar control, metformin is working to protect the heart.”