A new Cochrane Review has concluded that metformin could reduce or delay the risk of type 2 diabetes mellitus (T2DM) in at-risk individuals, when compared with placebo or diet.
Researchers reviewed evidence from 20 randomised controlled trials, which included 6,774 participants, to assess the effects of metformin for the prevention or delay of T2DM in people at an increased risk for the condition. The comparator group consisted of diet and exercise, intensive diet and exercise or another glucose‐lowering drug.
The researchers identified moderate evidence that metformin, when compared with placebo or diet and exercise, reduced or delayed the risk of T2DM in people with impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG). The authors noted that following diet and exercise or a non‐metformin anti-diabetic drug, 281 per 1,000 participants developed T2DM compared with 141 per 1,000 participants after metformin therapy.
When compared to intensive diet and exercise, metformin did not reduce or delay the risk of T2DM, while the combination of metformin and intensive diet and exercise compared to intensive diet and exercise only neither showed an advantage or disadvantage regarding the development of T2DM.
The authors pointed out that all trials had an unclear or high risk of bias.