The Effect of Dietary Fat Load and Physical Exercise on the Flexibility and Partitioning of Ectopic Lipids.
Recruitment status was: Recruiting
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.
Hypothesis (ectopic fat stores)
- Ectopic fats stores are flexible fuel stores and are influenced by diet and physical activity.FFA availability may play an important regulatory role.
- There is a tissue specific partitioning of triglycerides and/or FFA among non-adipose organs after fat load and physical exercise
- The flexibility of ectopic fat stores is related to insulin sensitivity
- 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.
- 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
- A short intensive physical exercise shows a good discriminative power to diagnose GHD.
Growth Hormone Deficiency
Dietary Supplement: Fat diet
Other: 2h standardized aerobic exercise
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||The Effect of Dietary Fat Load and Physical Exercise on the Flexibility and Partitioning of Ectopic Lipids.|
- Flexibility of IMCaL, IMCL and IHCL (fat load and exercise) [ Time Frame: Year 1 to 4 ] [ Designated as safety issue: No ]
- Determination of visceral fat mass by MRI [ Time Frame: Year 1 to 4 ] [ Designated as safety issue: No ]
- Determination of peripheral and hepatic insulin sensitivity by two step hyperinsulinemic euglycemic clamp [ Time Frame: Year 1 to 3 ] [ Designated as safety issue: No ]
- maximal exercise capacity [ Time Frame: Year 1 to 3 ] [ Designated as safety issue: No ]
|Study Start Date:||August 2011|
|Estimated Study Completion Date:||May 2015|
|Estimated Primary Completion Date:||May 2015 (Final data collection date for primary outcome measure)|
Endurance trained athletes: minimal >50 mlO2/KG body weight
Sedentary healthy control subjects: age, BMI, Gender and waist matched (to the growth hormone deficient patients)
GHD patients without a GH substitution therapy in the last 6 months
Dietary Supplement: Fat diet
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.Other: 2h standardized aerobic exercise
Aerobic (50-60% of Vo2 max) standardized exercise on a bicycle during 2 hours
Show Detailed Description
Please refer to this study by its ClinicalTrials.gov identifier: NCT01467193
|Department of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Bern|
|Berne, Switzerland, 3010|
|Principal Investigator:||Emanuel Christ, Prof. Dr med. MD, PhD||Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Bern|