Effects of Exercise on Fructose Metabolism

Study Overview
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Brief Summary
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A high fructose diet increases fasting and post-prandial triglyceride (TG) concentrations in sedentary healthy human subjects.These effects may be secondary to fructose-induced hepatic de novo lipogenesis. Recent evidence indicate that exercise can prevent fructose induced dyslipidemia.This study will evaluate how exercise effects the metabolic fate of oral fructose 1a) when exercise is performed before fructose ingestion 1b) when exercise is performed after fructose ingestion Metabolic effects of exercise will be assessed in healthy male subjects by measuring fructose oxidation (13CO2 production), fructose conversion into glucose (13C glucose concentrations in blood) and hepatic fructose conversion into lipid (13C palmitate-very low density lipoprotein (VLDL) concentrations in blood) after ingestion of 13C-labelled fructose meals how fructose and protein modulate muscle glycogen and intramyocellular lipid repletion after exercise Healthy male subjects will be fed various fructose, glucose, lipid and whey protein meals after a glycogen/intramyocellular lipid depleting exercise. The effects of meals' composition will be assessed after 24 hours by measuring intramyocellular lipids and glycogen using proton-magnetic resonance spectroscopy (MRS).

Official Title
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Effects of Exercise on Fructose Metabolism

Conditions
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Healthy Subjects

Intervention / Treatment
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* Other: exercise
* Dietary Supplement: fructose
* Dietary Supplement: glucose


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: males 18-40 years old 19 kg/m2>BMI>25kg/m2 moderate to high usual physical activity non-smokers Exclusion Criteria: family history of diabetes mellitus ECG anomaly any medication participation to blood spending or other clinical study in the 3 months before the beginning of this study consumption of drugs consumption of more than 50g alcool/week family history of food intolerance

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Study1a<br>exercice performed 90 min before 13C fructose meal ingestion | Other: exercise<br>* cycling at 100W during 60 min<br>|
| Experimental: study 1b<br>exercise performed 90 min after 13C fructose meal ingestion | Other: exercise<br>* cycling at 100W during 60 min<br>|
| No Intervention: study 1c<br>no exercise | |
| Experimental: study 2a<br>meals containing fructose, cream and whey proteins over 24 hours after a glycogen/intramyocellular lipid depleting exercise | Dietary Supplement: fructose<br>* isocaloric nutrition with fructose, cream and whey protein during the 24 hour following a glycogen/intramyocellular lipid depleting exercise<br>|
| Active Comparator: study 2b<br>meals containing glucose, cream and whey proteins over 24 hours after a glycogen/intramyocellular lipid depleting exercise | Dietary Supplement: glucose<br>* isocaloric nutrition with glucose, cream and whey protein during the 24 hour following a glycogen/intramyocellular lipid depleting exercise<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma triglyceride | measurement of total and VLDL-TG concentrations in study 1 | measurements in fasting conditions and every hour from 7:00 am to 4:00 pm (up to 9 hours) | 
| intramyocellular lipids | Measurement by 1H-MRS in muscle vastus lateralis in study 2 | after glycogen/intramyocellular lipid depleting exercise and after 24 hour controlled feeding post exercise | 
| Fructose conversion into lipids | Estimated from 13C palmitate-VLDL concentration | measured from 7:00 am to 4:00 pm in study 1 (up to 9 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fructose conversion into glucose | measurements obtained from plasma 13C glucose concentrations and whole body glucose production measured by 6,6 d2 glucose in study 1) | measured between 7:00 am and 4:oo pm (up to 9 hours) | 
| intramyocellular glycogen concentrations | Measured by 1H-MRS in muscle vastus lateralis in study 2 | after glycogen/intramyocellular lipid depleting exercise and after 24 hour controlled feeding post exercise | 
| fructose oxidation | Calculated from breath 13CO2 production | measured from 7:00 am to 4:00 pm in study 1 (up to 9 hours) | 
| exogenous lipid oxidation | Lipids ingested will be labeled with 13C-triolein, and exogenous lipid oxidation will be measured from breath 13CO2 production | measured from 7:00 am to 4:00 pm in study 2 (up to 9 hours) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gluconeogenesis, de novo lipogenesis, intramyocellular lipids, muscle glycogen, fructose