Physical Training and the Incretin Effect (EXINT2)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01698502
Recruitment Status : Completed
First Posted : October 3, 2012
Results First Posted : April 24, 2014
Last Update Posted : April 24, 2014
Information provided by (Responsible Party):
Michael Taulo Lund, University of Copenhagen

Brief Summary:

It is well known that continuous physical exercise leads to a number of changes in the body. Maximal oxygen uptake; the heart's pumping ability and muscle mass and strength increases. Also the metabolism adapts: The ability to oxidize fat increase and the insulin sensitivity in primarily in muscle, but also in the liver increase.

Also endocrine glands adapts according to the level of physical activity. It is known that in healthy, younger people the insulin secretion from the pancreas after administration of sugar consumed orally or given directly into a vein, is significantly lower in trained individuals compared with untrained. This change does, however, not only apply to glucose, as also stimulation by the amino acid arginine, shows the same pattern.

It seems plausible that the endocrine glands/cells adapts to the level of physical training, but this has not yet been investigated.

The gastrointestinal tract is the birthplace of a variety of hormones. One group of these is called incretin hormones. They stimulate the glucose dependant insulin secretion in the pancreas and affect hunger/satiety. Whether the incretin production and thus their concentration in the blood is regulated by physical training is unknown.

Obese and patients with type 2 diabetes, has, in contrast to well-trained, decreased insulin sensitivity. As a consequence their (type 2 diabetics, at least early in their disease course) meal stimulated insulin release is greater than in healthy, normal weight individuals. This in spite of the fact that the incretin effect is reduced in obese people and patients with type 2 diabetes compared to healthy, normal weight.

Whether physical training affects both the secretion of incretins and the incretin effect has not yet been studied.

The purpose of this study is to investigate whether incretin hormones in physical well-trained young men have a changed effect on insulin secretion from the pancreas compared to untrained young men. A difference may indicate that the body's endocrine glands adapts to training mode.

The investigators hypothesis is that incretin hormones have a decreased effect on the glucose dependant insulin release in physically trained persons and thus results in a lower insulin release at any given plasma glucose level.

Condition or disease

Study Type : Observational
Actual Enrollment : 21 participants
Observational Model: Case-Crossover
Time Perspective: Cross-Sectional
Official Title: Does Physical Training Effect the Incretin Effect
Study Start Date : August 2012
Actual Primary Completion Date : February 2013
Actual Study Completion Date : June 2013

Healthy, Endurance trained (Maximal oxygen uptake (VO2max), ml*min-1*kg-1>60), 20-30 year, BMI: 18,5-25kg/m2, males.
Healthy, sedentary (Maximal oxygen uptake (VO2max), ml*min-1*kg-1<50), 20-30 year, BMI: 18,5-25kg/m2, males.

Primary Outcome Measures :
  1. Incretin Effect (the % of Insulin Secreted Due to the Release of the Intestinal Hormones Glucagon Like Peptide-1 (GLP-1 and Glucose-dependent Insulinotropic Peptide (GIP)) [ Time Frame: Test day 1 and 2 within 7 days. ]
    The Incretin effect (the % of insulin secreted due to the release of the intestinal hormones GLP-1 and GIP) is calculated as the difference between the insulin concentration during a 3 hour oral glucose tolerance test (OGTT) (day 1) compared to a 3 hour isoglycemic intravenous glucose infusion (IIGI) (day 2) that has similar glucose excursions.

Secondary Outcome Measures :
  1. The Total Glucose-dependent Insulinotropic Peptide (GIP) Response Measured as Area Under the GIP Curve (AUC GIP). [ Time Frame: Test day 1 and 2 within 7 days. ]
    Comparison of the total release of GIP during the 3 hour OGTT and IIGI.

Biospecimen Retention:   Samples Without DNA
Human plasma samples.

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 30 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Danish University Students from University of Copenhagen,

Inclusion Criteria:

  • Sedentary: 50>Maximal oxygen uptake (VO2max), ml*min-1*kg-1 OR endurance trained VO2max, ml*min-1*kg-1>60
  • 20-30 years
  • BMI: 18,5-25kg/m2
  • Caucasian
  • Healthy

Exclusion Criteria:

  • Any kind of medication or diabetes in the family (parents, siblings),
  • Non-caucasian

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01698502

University of Copenhagen, Faculty of Health Sciences
Copenhagen, North, Denmark, 2200
Sponsors and Collaborators
University of Copenhagen
Study Chair: Flemming Dela, Prof. MD University of Copenhagen, Dep. of Biomedical Sciences, Center of healthy Ageing, XLAB


Responsible Party: Michael Taulo Lund, MD. PhD. Student, University of Copenhagen Identifier: NCT01698502     History of Changes
Other Study ID Numbers: EXINT2_FD
First Posted: October 3, 2012    Key Record Dates
Results First Posted: April 24, 2014
Last Update Posted: April 24, 2014
Last Verified: March 2014

Keywords provided by Michael Taulo Lund, University of Copenhagen:
Glucagon like peptide
glucose dependent insulinotropic peptide
Gut hormone

Additional relevant MeSH terms:
Gastric Inhibitory Polypeptide
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs
Gastrointestinal Agents