What is the first-line treatment for diabetes mellitus?

Metformin is regarded as the first-line treatment for type 2 diabetes mellitus due to its proven efficacy in reducing blood glucose levels, its favorable safety profile, and other beneficial effects on cardiometabolic health. It works primarily by decreasing hepatic glucose production, reducing intestinal absorption of glucose, and improving insulin sensitivity in peripheral tissues.

In addition to its glucose-lowering properties, metformin is associated with weight stabilization or modest weight loss, making it particularly advantageous for overweight individuals with diabetes. Furthermore, it has been demonstrated to have cardiovascular benefits, which is increasingly important given the high rates of cardiovascular disease in patients with diabetes.

The guidelines from various diabetes associations recommend metformin as the initial pharmacological therapy after lifestyle modifications such as diet and exercise for most patients with type 2 diabetes. This recommendation is based on extensive clinical trial data supporting its use and long-term safety.