INS and Hyperinsulinemia: However, activation of adenosine-monophosphate activated protein kinase (AMPK) by metformin was proposedto be responsible for the markedlyreducedglucose-stimulatedinsulinrelease fromprimarypancreatic islets [32] andβ-celllines[33].Thus, contradictory to our results, another study showed significant decrease in plasma insulin level after treatment with metformin [34]; this can be attributed to the different diet used to induce diabetes where hypercaloric diet was used leading to hyperinsulinemia in the diabetic rats.