According to a study published in BMJ, the combination of insulin and metformin may not benefit individuals with type 2 diabetes. Although the combination results in less weight gain, improved blood glucose control and less need for insulin, the researchers state that further research is required in order to provide solid evidence regarding the benefits and harms, as well as the risks of premature death.

The study was conducted by researchers from the Copenhagen Trial Unit, Steno Hospital and the Copenhagen University Hospital.

At present, guidelines recommend metformin, an oral blood glucose reducing medication, for type 2 diabetics starting insulin treatment.

The researchers examined 2,217 individuals aged 18+ with type 2 diabetes.

Among the trials examined, the team found insufficient reports of important patient outcomes, such as total mortality and death from heart disease.

According to 20 trials, levels of HbA1c (a measure of average blood glucose levels over time) were reduced when insulin and metformin was taken together. Furthermore, the researchers found that the combination of drugs considerably reduced weight gain and body mass index (BMI) by an average of 1.6 kg.

The researchers state that additional studies are required in order to research the long term benefits and harms of the combination, as it increases the risk of severe hypoglycaemic attack.

In this week’s BMJ podcast, Trish Groves, the deputy editor of BMJ, talks to lead author Bianca Hemmingsen about how this study was able to draw on more data than prior studies, and how the researchers examined major complications and mortality instead of surrogate outcomes, such as blood sugar levels and weight.

In addition, Dr. Hemmingsen highlights the insufficient evidence for determining if the combination or insulin alone is best for people with type 2 diabetes and how further research is urgently required.

Click here to listen to BMJ Group podcast, covering the study