Incretin action maintains insulin secretion, but not hepatic insulin action, in people with impaired fasting glucose.
Perreault L, Man CD, Hunerdosse DM, Cobelli C, Bergman BC. Incretin action maintains insulin secretion, but not hepatic insulin action, in people with impaired fasting glucose. Diabetes Res Clin Pract. 2010 Oct; 90(1):87-94.