What role for metformin in type 1 diabetes?

Abstract

Tight glycaemic control is key to reducing the risk of cardiovascular and microvascular complications in people with type 1 diabetes. Standard treatment involves optimising insulin therapy to achieve an HbA level of 48mmol/mol (6.5%) or lower. Although not licensed for use in type 1 diabetes, metformin is included in some clinical guidelines as adjuvant therapy for people with type 1 diabetes who are overweight and wish to improve glycaemic control while minimising the dose of insulin. The REMOVAL study is the largest trial to date that has investigated the longer-term effects of metformin in people with type 1 diabetes. Here, we consider the role of metformin in individuals with type 1 diabetes in light of these results and other study findings.

Metformin: Is it a drug for all reasons and diseases?

“…The conclusion of a report in the BMJ's Drug and Therapeutics Bulletin in 2018 (dtb.bmj.com): "Although metformin might limit weight gain and improve lipid levels to a minor extent, this is accompanied by an increased risk of adverse gastro-intestinal effects and biochemical vitamin B12 deficiency. Given such uncertainty over the longterm benefits, we believe that metformin has a very limited role in the management of people with type 1 diabetes" [199].…”

The Impact of Metformin in Pediatric Type-1 Diabetes Mellitus in Addition to Insulin Therapy; Literature Review

“…Regarding metformin safety profile, the most commonly reported side effect is gastrointestinal events, such as abdominal pain, anorexia, diarrhea, nausea, taste disturbance, and vomiting [14,[20][21]. Rare side effects, such as erythema, lactic acidosis, pruritis, and urticaria, were reported [20]. Kidney function should be assessed before and after starting treatment [20].…”

“…Rare side effects, such as erythema, lactic acidosis, pruritis, and urticaria, were reported [20]. Kidney function should be assessed before and after starting treatment [20]. Metformin should be used cautiously in patients with renal insufficiency, and a lower maximum daily dose is recommended for people with a glomerular filtration rate (GFR) of 30-59mL/min [20].…”

“…The most severe adverse effect is lactic acidosis, which carries a mortality rate of approximately 50% between 1960 and 2000, but it has decreased to approximately 25% [21]. Metformin is contraindicated if GFR below 30mL/min and in acute kidney injury secondary to acute conditions, such as dehydration and severe infection [20].…”

Mesa 1: Diabetes mellitus tipo 1 y enfermedad cardiovascular

“…-Metformina: su uso no ha demostrado en DM1 que reduzca las complicaciones crónicas ni la mortalidad. Sólo se evidenció reducción de la dosis diaria total de insulina y del perfil lipídico, aunque tampoco se sostuvo su efecto en el tiempo 85 .…”