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Completed

NCT Number: NCT01765894

Influence of Moderate Exercise on Blood Glucose in Type 2 Diabetics and Healthy Controls

Project description

Research project title:

Influence of moderate exercise on blood glucose in type 2 diabetics and healthy controls.

Project description and objective

Obesity is so widespread in Denmark that 47% of the population is classed as overweight (BMI>=25) and around 13% of the population is classed as obese (BMI>=30).

The strong correlation between obesity and type 2 diabetes (at least 2/3 of type 2 diabetics are overweight) has led to many studies which look at different forms of exercise for this group, because weight loss may improve the diabetes and even defer the onset of the disorder and in doing so lower complications and increase long term survival.

For people who do not have type 2 diabetes, the work-induced increased sympathetic activity will lead to suppressed insulin secretion and increased glucagon secretion. This increases the endogenous glucose production from the liver and thus maintains a normal concentration of blood sugar in a physical training situation where the demand for glucose has increased.

The theory behind the project is that the mechanisms that help to increase glucose production in the liver during physical activity are weaker in type 2 diabetics, which can cause hypoglycaemia during and after physical exercise. In other words, we want to study the liver's sensitivity to stimulus from physical work by patients with type 2 diabetes and in relevant healthy control subjects.

Previous studies have indicated that this type of mechanism is not intact in type 2 diabetics; because the level of insulin does not fall as expected during or after physical training. However, there are no existing studies that measure the liver's glucose secretion using stable isotopes during prolonged moderate physical work. Measuring this will help to clarify our understanding of glucose homeostasis in type 2 diabetics.

This study is very relevant, because it may be expected that the preferred form of physical exercise of an overweight type 2 diabetic can be of moderate intensity and previous studies also show that this form of physical exercise delivers health gains in terms of an improvement in insulin sensitivity and a reduction in the level of insulin.

The objective of this study is to determine if the level of blood glucose stays constant before, during and after physical training and to examine the liver's ability to secret glucose accordingly.

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Key information

Conditions

Type 2 Diabetes and Exercise Behavior Diabetes Mellitus Diabetes Mellitus, Type 2 Endocrine System Diseases Glucose Metabolism Disorders Metabolic Diseases Motor Activity Nutritional and Metabolic Diseases

Age range

30 year–60 year

Sex eligibility

Male

Study type

Observational

Primary location

XLab, Center for Healthy Aging, Department of Biomedical Sciences, University of Copenhagen

Copenhagen, 2200, Denmark

About this study

Design

A group of 20 people with type 2 diabetes and 10 control subjects are twice invited to the laboratory, respectively.

The type 2 diabetes group consist of 10 individuals being treated with metformin and 10 individuals who are not being treated with Metformin. The latter group may be diet-treated diabetics or diabetics who have stopped taking their oral antidiabetic agent for 72 hours before the day of the experiment.

On the first visit, the following is carried out:

  • DXA scan, blood pressure measurement, determination of ECG and VO2-max on a cycleergometer
  • Blood sample
  • Questionnaire about everyday physical activity (I-PAQ)

On the second visit, the following is carried out:

  • 3 days of carbohydrate loading prior to this day.(By diet recommendations).
  • Insertion of arterial cannula, blood sample extraction.
  • Insertion of venus cannula. Insertion of stable glucose isotopes over a period of 4.5 hours: 2,5 hours of relaxation in bed followed by 45 minutes of cycling on an exercise bicycle (during continued isotope infusion) at 60% of maximum heart rate reserve, which was measured on test day 1. Followed by relaxation with continued blood sampling and isotope infusion, one hour after cycling ceased.

Inclusion criteria

  • Age between 30 and 60 years old,
  • Maximum oxygen consumption between 20 and 50 ml/kg/minute,
  • BMI between 25 and 35 kg/m2,
  • Normal ECG,
  • Must have a stable weight throughout the last three months and have a normal balanced diet,
  • Can cycle for 45 minutes

Exclusion criteria

  • For patients with type 2 diabetes: insulin treatment,
  • ECG that indicates cardiovascular disease,
  • Illness or medicine that may affect the results,
  • On-going weight loss diet

DXA scan

Minimal radiation - The scan lasts from six to 10 minutes and the total radiation dose with measuring is below 0.01 mSv (millisievert). This is approximately equivalent to the natural daily background exposure.

Cycling test

Prior to this test, an ECG is carried out and the person is quizzed about his/her state of health. Regarding all experiments, there is quick access to doctors in the laboratory. The laboratory is equipped with a defibrillator.

Infusion with stable glucose isotopes

Stable glucose isotopes occur naturally in the body, though in much smaller amounts. They are not radioactive and require no special precautions.

Blood sampling

An arterial cannula is inserted, from which blood samples are subsequently taken. A sample is immediately analysed (ABL analyser) for glucose and lactate concentrations and blood gases, Hgb and Hct.

Other blood samples are processed on a centrifuge and the plasma is frozen at - 80 °C until it will be analysed.

The plasma is analysed to determine concentrations of:

Insulin, glucagon, cortisol, growth hormone (GH), adrenocorticotrophic hormone (ACTH),C-peptide, catecholamines , alanin, concentration of ketone, cholesterol free fatty acids,glycerol, glucose isotope (Ra) content before, during and after the cycling.

The biological material (in the form of plasma) will be stored in a freezer. When the experiment is completed, the material will be analysed in our laboratories. When all of the analysis has been carried out, any excess materials will be destroyed. All materials will be stored anonymously.

Ethical considerations

At all times, the study will be carried out in accordance with the latest of Helsinki and current Danish legislation.

Among other things, this includes voluntary participation and that test subjects can withdraw their consent at any time and without having to provide any explanation.

The study protocol and the written patient information will be submitted to the Research Ethics Committee of the Capital Region of Denmark and the Danish Data Protection Agency will be informed. Patient inclusion cannot begin until a written approval has been received from both of these institutions. Both positive and, negative and inconclusive results must be published.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age between 30 and 60 years old
  • Maximum oxygen consumption between 20 and 50 ml/kg/minute
  • BMI between 25 and 35 kg/m2
  • Normal ECG
  • Must have a stable weight throughout the last three months and have a normal balanced diet
  • Can cycle for 45 minutes

Exclusion criteria

  • For patients with type 2 diabetes: insulin treatment
  • ECG that indicates cardiovascular disease
  • Illness or medicine that may affect the results
  • On-going weight loss diet

Treatment and study plan

45 minutes of moderate exercise at the fasted state. Before test day 2: 3 days of carbohydrate loading.

Other

Other names: exercise performed at 60% of heart rate reserve.

Primary outcomes

  1. Glucose homeostasis in controls, type 2 diabetics without medication and type 2 diabetics in metformin treatment.

    Time frame: Observational study. Glucose homeostasis is tested one day only (in our Lab). Samples are taken 2,5 hours before, during and untill 1 hour after 45 minutes of exercise. Samples are taken every 5 minutes.

    Glucose, hormones, substrates, metabolites and glucose-isotopes as mentioned in the protocol.

    These end points will be measured on test day 2 only. Hormones and metabolites will be measured as AUC and total concentrations.

Secondary outcomes

  1. MAP during moderate exercise

    Time frame: 45 min of moderate exercise (test day 2).

    MAP is continuously measured during exercise for 45 mins. (At 60% heart rate reserve)

  2. vo2max

    Time frame: one measurement each subject (test day 1)

    Is measured in all subjects prior to test day 2

  3. DXA-values

    Time frame: one measurement each subject (test day 1)

    DXA (fat%, lean body mass, BMD)is measured prior to test day 2

  4. IL-6 and incretins

    Time frame: Observational study. Each test subject is tested for IL-6 and incretins one day only (in our Lab), where blood samples are taken continously during the test day every 5 minutes before, during and after exercise (test day 2).

    Effect of exercise on IL-6 and incretins. Described as AUC and total concentrations.

Sponsors and collaborators

Lead sponsor

University of Copenhagen

Other

Collaborators

  • Department of Biomedical Sciences
  • XLab, Center of Healthy Aging

Registry information

Official study title

Influence of Moderate Exercise on Blood Glucose in Type 2 Diabetics and Healthy Controls.

Acronym: DIEGO

Important dates

Study start
2012
Primary completion
2013
Study completion
2013
First posted
Jan 10, 2013
Registry last updated
Feb 24, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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