Which antidiabetic medication helps improve insulin sensitivity?

Metformin is known for its effectiveness in improving insulin sensitivity, which is a key factor in managing type 2 diabetes. It primarily works by decreasing hepatic glucose production and enhancing tissue sensitivity to insulin. By improving how the body's cells respond to insulin, Metformin helps lower blood glucose levels without causing an increase in insulin secretion from the pancreas.

In contrast, the other medications listed function differently. Insulin directly replaces or supplements the insulin that the body is unable to produce, rather than improving sensitivity. Sitagliptin, a DPP-4 inhibitor, works by increasing incretin levels to enhance insulin secretion and decrease glucagon levels, but it does not primarily act on insulin sensitivity. Glipizide is a sulfonylurea that stimulates insulin secretion from the pancreas to lower blood glucose levels but does not directly improve insulin sensitivity. Thus, Metformin stands out for its unique role in enhancing insulin action.