Fatty Acids Mediate the Acute Extrahepatic Effects of Insulin on Hepatic Glucose Production in Humans

We have shown previously in humans that insulin partly suppresses hepatic glucose production (HGP) by an extrahepatic (indirect) mechanism. In the present study, we investigated the role of free fatty acids (FFAs) in mediating the extrahepatic effects of insulin in humans and determined the extent to which insulin can regulate HGP by a non–FFA-mediated effect. Sixteen healthy men received an intravenous tolbutamide infusion for 3 h, and...