“In this research we found that there was a considerable reduction in deaths and heart problems when this cheap and common drug was used in conjunction with insulin,” said lead author Craig Currie, professor at Cardiff University in Britain.
Increased dosage of insulin has been previously known to raise the risk of cancer, heart attacks and mortality.
But the findings have shown that metformin can attenuate the risks associated with insulin.
However, according to researchers, there was no difference in the risk of cancer between people treated with insulin as a single therapy or in combination with metformin.
The retrospective research, published in the journal PLOS ONE, looked at people with Type 2 diabetes who were treated with insulin with or without metformin from the year 2000 onwards.
12,020 people were identified from a general practice data source, and the research team tracked them for three-and-a-half years on average, from the time they were first prescribed insulin.
“While this research indicates the potential of using these treatments together, further studies are needed to determine the risks and benefits of insulin in Type 2 diabetes and the possible benefits associated with the administration of metformin alongside insulin,” Currie concluded.