Simultaneous analyses of carbohydrate-mediated serum GLP-1 and GLP-2 and duodenal receptor expression in children with and without celiac disease

Background: Variability in glucagon-like peptide (GLP)-1 and GLP-2 plasma concentrations has been suggested in Celiac disease (CD), with inconclusive results. We assessed the association between serum levels of GLP-1 and GLP-2 and their duodenal receptor expression in children with and without CD. Methods: This was a two-part, cross-sectional and prospective cohort study. Group assignment, performed after duodenal samples for mRNA expression of GLP-1 receptor (GLP1R) and GLP-2 receptor (GLP2R), were taken during esophagogastroduodenoscopy. The control group consisted of patients with normal endoscopy and negative serology. The CD group consisted of patients with positive serology and endoscopy suggestive of CD. All had an oral glucose-tolerance test (OGTT). CD patients underwent a second OGTT after 6 months of a gluten-free diet (GFD). Results: The CD group included 12 patients; 7 males with mean age 9.2 ± 2.5 years. The control group included 10 patients; 5 males with mean age 12 ± 4 years, (p = 0.14). No differences were detected in basal or peak levels of GLP-1 or GLP-2 between control, naïve CD (before GFD) and treated CD (after GFD) groups. Expression of GLP1R and GLP2R mRNA was similar. Significant positive correlations between glucose and C-peptide secretion (r = 0.9, p < 0.01) and GLP-1 and GLP-2 (r = 0.8, p = 0.01) were detected in the control group. Significant negative correlations were found in the naïve CD group between GLP2R expression and glucose secretion (r = −0.68, p = 0.015) and GLP1R expression and serum GLP-1 (r = −0.7, p = 0.016). Conclusions: Although no significant differences were detected in secretion patterns or gut receptor expression of GLP-1 and GLP-2 in healthy versus CD pediatric patients, the detected discrepancy between the ligand levels and their tissue receptors requires additional study.