Incretin Effect in People With Impaired Fasting Glucose

Regulation of endogenous glucose production (EGP) and insulin secretion are major actions of glucagon-like peptide-1 (GLP-1). Determining whether alterations in GLP-1 may contribute to abnormal EGP and insulin secretion in people with impaired fasting glucose (IFG) was the objective of the current study. The investigators hypothesized that defects in GLP-1 may explain the inappropriate basal EGP and diminished insulin secretion in IFG, and, furthermore, that by increasing circulating GLP-1 levels (using a new medicine called "sitagliptin") the investigators could reverse these defects.