title: Reduced levels of active GLP-1 in patients with cystic fibrosis with and without diabetes mellitus.
abstract: Glucagon 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 (23 g protein, 25 g fat and 76 g carbohydrates) after an overnight fasting. Blood samples were collected before meal as well as 15, 30, 45 and 60 min 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<0.01). However, levels in patients with CFRD tended to be lower but were not significantly lower than in patients with CF without diabetes (p=0.06). Total GLP-1 did not differ between the groups, which points to that the inactive form of GLP-1 is more pronounced in CF patients. The endogenous insulin production (measured by C-peptide) was significantly lower in patients with CFRD as expected. However, levels in non-diabetic CF patients did not differ from the controls. We suggest that the decreased levels of GLP-1 could affect the progression toward CFRD and that more studies need to be performed in order to evaluate a possible treatment with GLP-1 analogues in CF-patients.
authors.affiliation: Department of Clinical Sciences, Biomedical Center, Lund University, Sweden. Magnus.Hillman@med.lu.se
authors.forename: Magnus
authors.initials: M
authors.lastname: Hillman
authors.forename: Leif
authors.initials: L
authors.lastname: Eriksson
authors.forename: Lena
authors.initials: L
authors.lastname: Mared
authors.forename: Karin
authors.initials: K
authors.lastname: Helgesson
authors.forename: Mona
authors.initials: M
authors.lastname: Landin-Olsson
mesh_terms: D000328:Adult; D002096:C-Peptide / Q000032:analysis; D015897:Comorbidity; D003550:Cystic Fibrosis / Q000097:blood* / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000453:epidemiology*; D018450:Disease Progression; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D055815:Young Adult
chemical_list: D002096:C-Peptide; D052216:Glucagon-Like Peptide 1