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