title: Effects of aerobic exercise with or without metformin on plasma incretins in type 2 diabetes.
abstract: OBJECTIVE
  Despite positive effects of incretins on insulin secretion, little is known about the effect of exercise on these hormones. Metformin can affect incretin concentrations and is prescribed to a large proportion of people with diabetes. We, therefore, examined the effects of aerobic exercise and/or metformin on incretin hormones.
  
  
  METHODS
  Ten participants with type 2 diabetes were recruited for this randomized crossover study. Metformin or placebo was given for 28 days, followed by the alternate treatment for 28 days. On the last 2 days of each condition, participants were assessed during a non-exercise day and a subsequent exercise day. Aerobic exercise took place in the morning and blood samples were taken in the subsequent hours (before and after lunch).
  
  
  RESULTS
  Aerobic exercise did not increase total plasma glucagon-like peptide-1 (GLP-1) or glucose-dependent insulinotropic polypeptide (GIP) in the pre- or post-lunch periods (all p>0.1). GLP-1 was higher in the pre-lunch (p=0.016) and post-lunch (p=0.018) periods of the metformin conditions compared with the placebo. Total plasma GIP was higher in the pre-lunch period (p=0.05), but not in the post-lunch period (p=0.95), with metformin compared with placebo.
  
  
  CONCLUSIONS
  In contrast to our hypothesis, aerobic exercise did not acutely increase total GLP-1 and GIP levels in patients with type 2 diabetes. Metformin, independent of exercise, significantly increased total plasma GLP-1 and GIP concentrations in these patients.
authors: Faculty of Physical Education and Recreation, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada.
authors: Saeed Reza Toghi
authors: SR
authors: Eshghi
authors: Gordon J
authors: GJ
authors: Bell
authors: Normand G
authors: NG
authors: Boulé
mesh_terms: D003131:Combined Modality Therapy; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy; D005081:Exercise Therapy; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000097:blood*; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged
chemical_list: D007004:Hypoglycemic Agents; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D008687:Metformin
keywords: glucagon-like peptide-1; glucose-dependent insulinotropic polypeptide; l'activité physique; le glucagon-like peptide-1; metformin; metformine; physical activity; polypeptide insulinotrope glucose-dépendante