. It is not generally used for treating Type 1 diabetes, but the present clinical trial has indicated that
The researchers at Newcastle University have discovered the underlying mechanism involved.
The present study found that metformin not only controlled blood sugar levels, but also helped repair damaged blood vessels by lowering microRNA (miR) levels in the vicinity, in order to stimulate the growth of blood vessels. These miRs are very small RNA (ribonucleic acid) molecules that regulate gene expression in cells. The anti-angiogenic miRNA molecules that were used in the study included miR-222, miR-195, and miR-21a.
The present study is based upon a previous study by the same group, which showed that metformin
could improve vascular stem cells, thereby slowing the development of heart disease.
Dr. Jolanta Weaver, Senior Lecturer at the Institute of Cellular Medicine, Newcastle University and Honorary Consultant Diabetologist at the Queen Elizabeth Hospital, Gateshead, Newcastle upon Tyne, UK, led the clinical trial and is the senior author of the study, said: "As the outcomes of heart disease are worse in diabetic patients compared to people who don't have diabetes, there is a need to identify additional treatment options."
Clinical Trial Design
This clinical trial, dubbed as the MERIT Study, is the first study to evaluate the efficacy of metformin in preventing heart disease
in Type 1 diabetic patients. This was an open-label, case-controlled study, which consisted of the following groups:
- Group 1: The first group (intervention group) included 23 Type 1 diabetic patients, 19-65 years of age, who did not have any signs of heart disease. This group was treated with metformin for 2 months.
- Group 2: The second group consisted of 9 age and sex-matched Type 1 diabetic patients who were on insulin therapy.
- Group 3: The third group consisted of 23 healthy volunteers who did not have Type 1 diabetes.
Clinical Trial Findings
- The levels of the microRNAs miR-222, miR-195 and miR-21a were initially found to be higher in the Type 1 diabetes group than in the control group.
- Treatment with metformin reduced the levels of miR-222, miR-195 and miR-21a significantly.
- The fall in the levels of miR-222 was accompanied by a decrease in the levels of circulating endothelial cells.
- The above observation is indicative of the improvement in the vascular repair process.
Dr. Weaver said: "These results confirm that as well as improving a patient's blood sugar control, metformin is working to protect the heart."
She adds: "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."
The research team's future goals will focus on the development of therapeutic strategies by targeting miRs in order to modulate their function. Reference :
- Anti-Angiogenic miR-222, miR-195, and miR-21a Plasma Levels in T1DM Are Improved by Metformin Therapy, Thus Elucidating Its Cardioprotective Effect: The MERIT Study - (https://doi.org/10.3390/ijms19103242)