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HealthyBV-GTNCT02612597

The Effect of Blood Volume Changes on the Glucose Tolerance

A study testing Bedrest and Exercise Training in people with Healthy and Overweight, run by Carsten Lundby at 1 site in Switzerland.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial summary

In this study the investigators would like to elaborate on the mechanisms that lead to a higher insulin sensitivity after exercise training and a lower insulin sensitivity after bedrest. Read more about this study

Who is it for?
Ages 18 to 50 years, men onlyHealthy volunteers can take part
Conditions the study is for
Healthy, Overweight
What is being tested?
Bedrest and Exercise Training
Could I receive a placebo?
No, everyone receives an active treatment
How many people
20 participants
Where
1 siteSwitzerland
Study dates
Jan 2015to Apr 2016
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 50 years
  • Men only
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Informed consent as documented by signature
  • Age: 18-35
  • healthy (no chronic diseases)
  • BMI: 19-25
  • maximal oxygen uptake: 35-50 ml O2/min/kg
  • Informed consent as documented by signature
Show all 11Show fewer
  • Age: 35-50
  • BMI: 30-40
  • Fat%: 30-40 %
  • maximal oxygen uptake: 20-35 ml O2/min/kg
  • HbA1c: 5.5 - 7.0 %

Who cannot join

  • chronic diseases
  • any health problems that do not allow the subjects to participate in the measurements (i.e. heart defect)
  • History of familiar history (1st grade relatives) of venous thrombic-embolism or renal insufficiency
  • Blood donation in the last month
  • Any medication with known influence on blood volume, glucose metabolism and body weight
  • Stay above 2500 m for more than 1 day
Show all 13Show fewer
  • Known allergies against Fragmin or Heparin
  • Training:
  • Chronic diseases
  • Any health problems that do not allow the subjects to participate in the measurements (i.e. heart defect)
  • Blood donation in the last month
  • Any medication with known influence on blood volume, glucose metabolism and body weight
  • Stay above 2500 m for more than 1 day

Trial locations and contacts

1 site in 1 country.

Switzerland1 site, 1 recruiting
  • Institute of Physiology, University of Zurich

    Zurich, Canton of Zurich, 8057

    Carsten Lundby, Prof. Dr., +41 44 635 50 52 ext. +41, carsten.lundby@access.uzh.ch

    Recruiting

Other trials in Switzerland

About this study

Official title: The Effect of Blood Volume Changes After Bed Rest and Aerobic Exercise Training on the Glucose Tolerance

In this study the investigators would like to elaborate on the mechanisms that lead to a higher insulin sensitivity after exercise training and a lower insulin sensitivity after bedrest.

The investigators speculate that the concomitant chances in blood volume during training and bedrest might explain the changed insulin sensitivity because with a changing blood volume also the dilution space of the glucose will change.

Read more

Furthermore, the investigators would like to work on the influence of a changed capacity of skeletal muscle for glucose uptake and glycogen storage on the glucose sensitivity.

Therefore, A) a bed rest study with healthy untrained subjects and B) a training study with obese pre-diabetic patients will be conducted.

Read the detailed description

While there is little doubt that physical inactivity leads to reduced insulin sensitivity and in contrast hereto that physical activity improves insulin sensitivity the underlying mechanisms are still to a large extend unknown. With this study the investigators wish to test two independent hypotheses that may explain the observed changes:

The first hypothesis is that part of the explanation for the known increase in circulating levels of glucose in response to an oral glucose tolerance test (indicating reduced insulin sensitivity) following bed rest is due to a concomitantly reduced blood volume and thereby dilution space.

In addition the investigators also speculate that the reduced glucose response to an oral glucose tolerance test (indicating improved insulin sensitivity) after a training period is related to the exercise induced increase in blood volume, and hence an increased dilution space.

Based on this, the hypothesis to be tested with these two experimental approaches (bed rest and aerobic exercise training), is that at least part of the changes observed in the glucose tolerance following bed rest and aerobic exercise training are related to concomitantly occurring changes in blood volume.

The second hypothesis to be tested is that another important contributor to the changes in circulating glucose levels following an oral glucose tolerance test after bed rest and physical training are related to diminished or improved capacity for skeletal muscle glucose uptake and glycogen storage, respectively. The rationale here fore are that exercise training increases skeletal muscle glycogen content and storage capacity in healthy and type 2 diabetic patients, respectively, and that bed rest does the opposite.

To test this hypothesis two different intervention studies will be conducted. Study 1 is a bed rest study with healthy untrained subjects and study 2 is a training study with obese "pre-diabetic patients".

Conditions
Healthy, Overweight
Being tested
Bedrest, Exercise Training
Keywords
before and after bedrest, healthy untrained, before and after exercise training
Medical subject headings
Overweight

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT02612597
Study groupRoleWhat they receive
BedrestExperimental4 days of bedrest
Receives: Other: Bedrest
Exercise TrainingExperimental6 weeks of aerobic endurance exercise training with 4 supervised sessions per week at an average intensity of 65 % of maximal heart rate
Receives: Other: Exercise Training

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in blood volume

    Measured: Baseline and 4 days

  2. Change in glucose tolerance

    Measured: Baseline and 4 days

  3. Change in blood volume

    Measured: Baseline and 6 weeks

  4. Change in glucose tolerance

    Measured: Baseline and 6 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Nov 2015 (estimated)
  2. Study startJan 2015
  3. Primary completionApr 2016 (estimated)
  4. Study completionApr 2016 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Non-randomised
Intervention model
Single group
Masking
None (open label)
Enrolment
20 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02612597
Sponsor's protocol ID
KEK-ZH-Nr. 2015-0453
Acronym
BV-GT
Status last verified
Nov 2015
First submitted
13 Nov 2015
Last updated
24 Nov 2015
Results posted
No

Questions about this trial

What is this clinical trial studying?

A study testing Bedrest and Exercise Training in people with Healthy and Overweight, run by Carsten Lundby at 1 site in Switzerland.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 11 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: status not confirmed, as of the sponsor's last update on 24 Nov 2015. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

Contact Carsten Lundby, Prof. Dr. (+41 44 635 50 52 ext. +41, carsten.lundby@access.uzh.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in blood volume (time frame: Baseline and 4 days). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Nov 2015.

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