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.
RCT Entities:
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: Timothy D Heden; Nathan C Winn; Andrea Mari; Frank W Booth; R Scott Rector; John P Thyfault; Jill A Kanaley Journal: J Appl Physiol (1985) Date: 2014-12-24
Authors: Saeed Reza Eshghi; Kevin Fletcher; Étienne Myette-Côté; Cody Durrer; Raniah Q Gabr; Jonathan P Little; Peter Senior; Craig Steinback; Margie H Davenport; Gordon J Bell; Dion R Brocks; Normand G Boulé Journal: Front Endocrinol (Lausanne) Date: 2017-07-11 Impact factor: 5.555