A Novel Attribute of Insulin Secretion via Incretin Axis by Metformin

Metformin, a diabetes drug, has been used to control hyperglycemia in patients with type 2 diabetes for more than 50 years. Metformin exerts its antidiabetic activity by counteracting insulin resistance to hepatic glucose production and/or increasing the insulin-stimulated glucose uptake in muscle and fat. In addition to controlling blood glucose levels, it has also been shown to reduce the long-term complications of diabetes, including micro- and macrovascular diseases (1). Metformin has also been reported to reduce the incidence of type 2 diabetes in high-risk individuals with impaired glucose tolerance (2). Although lactic acidosis has been reported in patients treated with metformin, the drug is considered as the safest hypoglycemic agent to date. In contrast to treatment with other oral drugs and insulin, metformin monotherapy is not associated with the risk of hypoglycemia, nor does it cause weight gain (3). Moreover, recent studies have shown that metformin reduces the risks of developing solid organ cancer (4) and osteoporosis (5). Thus, the drug has been recently recognized as the first-line oral agent for the treatment of type 2 diabetes, particularly in overweight patients.