Altered expression of glucagon-like peptide-1 and dipeptidyl peptidase IV in patients with HCV-related glucose intolerance

Background and Aim: The pathogenesis of hepatitis C virus (HCV)‐associated glucose intolerance remains unclear. Glucagon‐like peptide‐1 (GLP‐1), a gut hormone, synthesizes hepatic glycogen and is inactivated by dipeptidyl peptidase IV (DPPIV). The aims of this study were to investigate the alterations in the expression of GLP‐1 and DPPIV in HCV‐associated glucose intolerance. Methods: We enrolled patients with HCV‐ or hepatitis B virus (HBV)‐related liver disease (n = 94 and 37, respectively), patients with inflammatory bowel disease (IBD; n = 14) as disease controls, and healthy controls (n = 48). The serum or tissue GLP‐1 and DPPIV expression levels were determined by enzyme immunoassay, immunoblotting, or immunostaining. The hepatic glycogen content was assayed by periodic acid–Schiff staining. Results: The serum GLP‐1 levels were significantly decreased in the HCV group (4.9 ± 0.3 ng/mL) than those in the controls (7.5 ± 0.6 ng/mL), the HBV group (7.0 ± 0.5 ng/mL), or the IBD group (10.8 ± 1.0 ng/mL, P