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Ectopic LipidsNCT01467193

The Effect of Dietary Fat Load and Physical Exercise on the Flexibility and Partitioning of Ectopic Lipids.

An observational study of Ectopic Lipids and Insulin Sensitivity, run by Insel Gruppe AG, University Hospital Bern at 1 site in Switzerland.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study aims at assessing the effect of standardized dietary fat load and short-term aerobic exercise on systemic lipolysis, flexibility and partitioning of ectopic fat stores (intramyocellular = IMCL, intrahepatocellular = IHCL, intramyocardial lipids = IMCaL) in relation to FFA in endurance trained athletes and… Read more about this study

Who is it for?
Ages 18 to 80 yearsHealthy volunteers can take part
What is being tested?
Fat diet and 2h standardized aerobic exercise
How many people
30 participants
Where
1 siteSwitzerland
Study dates
Aug 2011to May 2014
Phase
Observational
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 80 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Athletes:Endurance trained athletes: minimal >50 mlO2/KG body weight GH-deficient adult patients: NO GH-replacement therapy during the last 6 months Sedentary controls: age, BMI, Gender and waist matched (to the growth hormone deficient patients) healthy control subjects

Who may be able to join

  • Male and female patients >18 years old
  • Capable to exercise for 120 minutes on a treadmill
  • Willingness to participate in the study and to give written consent.
  • Normal ECG during ergometry
  • Specific for Athletes: VO2max> 50 ml/kg/min
  • Specific for GHD patients: no GH substitution in the last 6 months
  • Specific for sedentary controls: Matched the GHD patients for age, gender, BMI and waist

Who cannot join

  • Abnormal liver or renal function
  • Active neoplasia
  • Severe cardiovascular disease (unstable coronary artery disease, heart failure NYHA III-IV)
  • Haemophilia
  • Inability to exercise
  • Contraindications to exposure to a 3 T magnetic field
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  • Abnormal ECG during ergometry
  • Women in childbearing age unless on a continuous contraceptive therapy or surgically sterilized
  • Depression, psychosis and other severe personality disorders
  • Pregnant women
  • Excessive alcohol consumption (>60g/d) or drug abuse

Trial locations and contacts

1 site in 1 country.

Switzerland1 site
  • Department of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Bern

    Bern, 3010

Other trials in Switzerland

About this study

This study aims at assessing the effect of standardized dietary fat load and short-term aerobic exercise on systemic lipolysis, flexibility and partitioning of ectopic fat stores (intramyocellular = IMCL, intrahepatocellular = IHCL, intramyocardial lipids = IMCaL) in relation to FFA in endurance trained athletes and hypopituitary patients compared to sedentary healthy control subjects.

Exercise is a powerful stimulation for growth hormone (GH) secretion in health. A standardised exercise test can, therefore, be discriminative for the diagnosis of GH-deficiency in adults. This will be assessed.

Read more

Hypothesis (ectopic fat stores)

  1. Ectopic fats stores are flexible fuel stores and are influenced by diet and physical activity.FFA availability may play an important regulatory role.
  2. There is a tissue specific partitioning of triglycerides and/or FFA among non-adipose organs after fat load and physical exercise
  3. The flexibility of ectopic fat stores is related to insulin sensitivity
  4. Lipolytic and anti-lipolytic hormones are critical for regulating FFA availability (at rest or during exercise) and therefore also for the regulation of ectopic fat stores.
  5. GH is a lipolytica hormone. Lack of GH in adulthood is related to decreased FFA availability thereby influencing ectopic lipid stores Hypothesis diagnosis of GHD
  6. A short intensive physical exercise shows a good discriminative power to diagnose GHD.
Read the detailed description

Background

Obesity, in particular visceral obesity, is associated with impaired insulin action on target tissues (insulin resistance or metabolic syndrome) that, in turn, is related to an increased risk for cardiovascular mortality and morbidity. Pathophysiological mechanism remains unclear. Interventions in patients with impaired glucose tolerance/impaired fasting glucose have consistently demonstrated that by increasing physical activity and reducing calorie intake the risk to convert to frank type 2 diabetes is decreased, even more efficiently than by early medical therapy with metformin.

Physically inactive and overweight subjects do not only store the excess of fat in the intra-abdominal or subcutaneous department but also in non-adipose tissue (="ectopic" tissues), such also skeletal muscle, liver and myocardium, also called intramyocellular lipids (IMCL), intrahepatocellular lipids (IHCL) and intramyocardial lipids (IMCaL).This ectopic lipid accumulation occurs either by increased free fatty acids (FFA) uptake, increase synthesis in the involved tissues or reduced FFA oxidation.

The relative contribution of these factors to ectopic lipid accumulation varies in different physiological conditions (i.e. physical exercise, fasting, postprandial condition) and in different tissues. In addition, it may be influenced by hormones that regulate lipid metabolism. There is increasing evidence that ectopic fat and its intermediate metabolites interfere with insulin signalling, thereby contributing to the impaired insulin action on target tissues such as liver and skeletal muscle. It has been well showed that high fat oxydation capacity allows to keep a lower lipolytic activity and therefore low levels of lipolyse degradation products. Strong evidence is accumulating that these intermediates interact with insulin signalling finally resulting in insulin resistance.

There is still scarce data about the behaviour of ectopic fat stores in the presence of positive(nutritional fat excess) or negative energy balance (physical activity) and the role of hormones in regulating these fat depots.

Additionally,we have previously shown that GH values obtained during a 2h standardized aerobic exercise of moderate intensity revealed a high diagnostic accuracy in predicting severe GHD in adult individuals. Whether a shorter exercise on higher intensity may lead to comparable results has to be assessed.

Objective

The study aims to comprehensively assess the flexibility and partitioning of ectopic fat deposition and to define the role of relevant hormones (especially GH and insulin) in relation to the availability of FFAs as well as their role in the process of ectopic fat deposition and consumption. Another objective is to investigate the role of a standardized fat load and aerobic exercise on IMCaL.

Methods

Using the two-step hyperinsulinaemic-euglycaemic clamp technique hepatic and peripheral insulin sensitivity is assessed.

Lipid depots (skeletal muscle and liver) are repeatedly measured by MR-spectroscopy, subcutaneous and visceral fat mass by whole body MR-imaging.

Exercise capacity ist measured on a bicycle (incl. spiroergometry). Counterregulatory hormones, glucose and free fatty acids are measured during a 2h physical exercise at 50-60 VO2max.

Blood samples to evaluate GH will be taken immediately before and after the Vo2 max-test, as well as 15, 30 and 45minutes after the end of the exercise test.

Being tested
Fat diet, 2h standardized aerobic exercise
Medical subject headings
Insulin Resistance, Dwarfism, Pituitary

What participants receive

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

  • Fat dietDietary supplement

    Instructions for a high fat diet will be given at the end of visit 2. This consists of the usual food intake with a supplementary fat intake of 0.75g fat/kg BW, administered as 3 additional snacks. These snacks will be distributed in pre-packed bags. A food diary will be kept. All arms will receive this diet during the 3 days preceding the clamp.

  • 2h standardized aerobic exerciseOther

    Aerobic (50-60% of Vo2 max) standardized exercise on a bicycle during 2 hours

Study groups in NCT01467193
Study groupRoleWhat they receive
1Endurance trained athletes: minimal >50 mlO2/KG body weight
2Sedentary healthy control subjects: age, BMI, Gender and waist matched (to the growth hormone deficient patients)
3GHD patients without a GH substitution therapy in the last 6 months
Receives: Dietary Supplement: Fat diet; Other: 2h standardized aerobic exercise

What is being measured

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

  1. Flexibility of IMCaL, IMCL and IHCL (fat load and exercise)

    Measured: Year 1 to 4

Secondary outcomes (3)
  1. Determination of visceral fat mass by MRI

    Measured: Year 1 to 4

  2. Determination of peripheral and hepatic insulin sensitivity by two step hyperinsulinemic euglycemic clamp

    Measured: Year 1 to 3

  3. maximal exercise capacity

    Measured: Year 1 to 3

Timeline

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

  1. First posted8 Nov 2011 (estimated)
  2. Study startAug 2011
  3. Primary completionMay 2014
  4. Study completionMay 2014

Resources

More details

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

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
30 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01467193
Sponsor's protocol ID
234/10
Status last verified
Oct 2018
First submitted
3 Nov 2011
Last updated
9 Oct 2018
Results posted
No
Data monitoring committee
No

Publications

  • Zueger T, Alleman S, Christ ER, Stettler C. Exercise-induced GH secretion in the assessment of GH deficiency in adult individuals. Eur J Endocrinol. 2011 Nov;165(5):723-8. doi: 10.1530/EJE-11-0539. Epub 2011 Aug 19.

    PubMed 21856788
  • Loher H, Jenni S, Bucher J, Krusi M, Kreis R, Boesch C, Christ E. Impaired repletion of intramyocellular lipids in patients with growth hormone deficiency after a bout of aerobic exercise. Growth Horm IGF Res. 2018 Oct-Dec;42-43:32-39. doi: 10.1016/j.ghir.2018.08.001. Epub 2018 Aug 17.

    PubMed 30153529

Questions about this trial

What is this clinical trial studying?

An observational study of Ectopic Lipids and Insulin Sensitivity, run by Insel Gruppe AG, University Hospital Bern 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 7 inclusion and 11 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: finished, as of the sponsor's last update on 9 Oct 2018. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Flexibility of IMCaL, IMCL and IHCL (fat load and exercise) (time frame: Year 1 to 4). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01467193, which also lists 2 linked publications.

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 9 Oct 2018.

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