Evaluation of plasma GLP-1 concentrations in the newly diagnosed type 1 diabetic children

Objective: This study was designed to find out whether there is any difference in the concentrations of plasma GLP-1, an insulinotropic hormone secreted from the intestine, in response to oral food intake between newly diagnosed Type 1 diabetic children and healthy controls to incur any role of this peptide in the pathogenesis of Type 1 DM.Materials and Methods: The study population consisted of 25 Type 1 diabetic and 22 age, sex, height, weight, BMI, and pubertal status matched healthy controls. Immediately after sampling for blood glucose, HbA1c, C-peptide, and GLP-1 the subjects were administered a standard oral glucose tolerance test. Another sampling was performed for plasma glucose, C-peptide and GLP-1 levels at 30 minutes.Results: As expected blood glucose, HbA1c, and serum C-peptide levels were significanty higher in the diabetes group. Plasma GLP-1 levels both pre and 30 min after OGTT were not different between groups. Also, there were no differences in pre and post OGTT plasma GLP-1 levels within each group. Plazma GLP-1 levels were not correlated with endogenous insulin secretion, as indicated by serum C-peptide levels, in either group.Conclusions: In this first GLP-1 study in type 1 diabetic children immediately after diagnosis, the results do not suggest a role for GLP-1 in the pancreatic insulin response to oral glucose intake. Follow up studies especially at honeymoon period may provide different results.Key words:Type 1 diabetes mellitus, glucagon-like peptide 1, C-peptide, blood glucose, pancreatic beta cells.