Reduced levels of active GLP-1 in patients with cystic fibrosis with and without diabetes mellitus

AbstractGlucagon like peptide 1 (GLP-1) is an incretin hormone released as a bioactive peptide from intestinal L-cells in response to eating. It acts on target cells and exerts several functions as stimulating insulin and inhibiting glucagon. It is quickly deactivated by the serine protease dipeptidyl peptidase IV (DPP-IV) as an important regulatory mechanism. GLP-1 analogues are used as antidiabetic drugs in patients with type 2 diabetes.We served patients with cystic fibrosis (CF, n=29), cystic fibrosis related diabetes (CFRD, n=19) and healthy controls (n=18) a standardized breakfast (23g protein, 25g fat and 76g carbohydrates) after an overnight fasting. Blood samples were collected before meal as well as 15, 30, 45 and 60min after the meal in tubes prefilled with a DPP-IV inhibitor. The aim of the study was to compare levels of GLP-1 in patients with CF, CFRD and in healthy controls.We found that active GLP-1 was significantly decreased in patients with CF and CFRD compared to in healthy controls (p