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Effects of Fructose/Glucose-rich Diet on Brown Fat in Healthy Subjects (GB7)

Not Applicable
Completed
Conditions
Type2 Diabetes
Interventions
Dietary Supplement: Diet
Other: cold exposure
Radiation: 18FDG
Radiation: 11C-acetate
Radiation: [3-3H]-glucose
Other: [U-13C]-palmitate
Other: 2H-Glycerol
Device: MRI/MRS
Device: Electromyogram (EMG)
Device: DXA
Device: Indirect calorimetry
Registration Number
NCT03188835
Lead Sponsor
Université de Sherbrooke
Brief Summary

Activating brown and beige adipose tissue (herein described as BAT) has been recently recognized as a potential means to increase energy expenditure and lower blood glucose, however, BAT activity appears to be reduced with obesity, aging or Type 2 Diabetes (T2D). BAT has the unique capability to burn large amounts of sugar and fat and effectively dissipate this energy as heat due to the expression of uncoupling protein 1 (UCP1) which is controlled by a thermogenic gene program of transcription factors, co-activators and protein kinases. Thus, enhancing the thermogenic gene program may be beneficial for treating obesity and T2D. Despite the importance of BAT in regulating metabolism our understanding of the factors which suppress its metabolic activity with obesity, aging and T2D are largely unknown. Recently, it was shown that peripheral serotonin, which is regulated by the tryptophan hydroxylase 1 (Tph1), is a negative regulator of BAT metabolic activity. In addition to serotonin, other studies have indicated that pro-inflammatory stimuli may also inhibit BAT metabolic activity. These data suggest that reduced activation of BAT may be due to increases in peripheral serotonin and inflammation. Importantly, the gut microbiome has recently been recognized as an important regulator of serotonin and inflammatory pathways suggesting the observed effects of the microbiome on obesity, T2D may be mediated in part through reductions in BAT activity.

One mechanism by which the environment may impact BAT activity and the thermogenic gene program over the last 3 decades involves changes in our food supply as result of changes in agricultural production (chlorpyrifos, glyphosphate) and the addition of food additives (fructose). These agents have been reported to alter inflammation, serotonin metabolism and the gut microbiome indicating a potential bimodal (direct and indirect via the microbiome) mechanism by which they may alter the thermogenic gene program and contribute to chronic metabolic disease. Thus, our overarching hypothesis is that environmental agents and additives related to food production may contribute to the reduced metabolic activity of BAT. The objective is to identify and characterize how food production agents and additives reduce the metabolic activity of BAT.

Detailed Description

Each subject will follow 3 metabolic studies (A, B and C), each lasting 7.5h which includes a 3h acute cold exposure.

These studies will be almost identical: same perfusion of tracers, same number of Positron Emission Tomography (PET) acquisitions and same number of Magnetic Resonance Imaging (MRI) associated with Magnetic Resonance Spectroscopy (MRS) acquisitions .

The difference will be in the diet ingested by the subjects two weeks before each metabolic study: during protocol A, the subjects will follow an isocaloric diet; during protocol B, the subjects will follow the same isocaloric diet supplemented with a daily beverage containing +25% of energy intake from fructose; and during protocol C, the subjects will follow the same isocaloric diet supplemented with a daily beverage containing +25% of energy intake from glucose.

Stool samples will be collected for each metabolic study for microbiome flora and metabolites.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
15
Inclusion Criteria
  • Healthy subjects: subjects with normal glucose tolerance determined according to an oral glucose tolerance test and with a BMI < 27 kg/m2 without first degree of familial history of type 2 diabetes (parents, siblings).
Exclusion Criteria
  1. Plasma triglycerides > 5.0 mmol/L at fasting;
  2. More than 2 alcohol consumption per day;
  3. More than 1 cigarette per day;
  4. History of total cholesterol level > 7 mmol/L, of cardiovascular disease, hypertensive crisis;
  5. Treatment with fibrates, thiazolidinedione, insulin, beta-blockers or other drugs with effects on insulin resistance or lipid metabolism (exception for anti-hypertensive drugs, statins or metformin);
  6. Presence of a non-controlled thyroid disease, renal or hepatic disease, history of pancreatitis, bleeding diatheses, cardiovascular disease or any other serious medical conditions;
  7. History of serious gastrointestinal disorders (malabsorption, peptic ulcer, gastroesophageal reflux having required a surgery, etc.);
  8. Presence of a pacemaker;
  9. Have undergone of PET study or CT scan in the past year;
  10. Chronic administration of any medication;

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Fructose diet[3-3H]-glucoseTwo weeks of hypercaloric diet supplemented with fructose
Isocaloric Diet11C-acetateTwo weeks of isocaloric diet
Isocaloric Diet[3-3H]-glucoseTwo weeks of isocaloric diet
Fructose diet11C-acetateTwo weeks of hypercaloric diet supplemented with fructose
Glucose diet[3-3H]-glucoseTwo weeks of hypercaloric diet supplemented with glucose
Glucose dietDXATwo weeks of hypercaloric diet supplemented with glucose
Fructose dietDietTwo weeks of hypercaloric diet supplemented with fructose
Isocaloric Diet18FDGTwo weeks of isocaloric diet
Isocaloric DietDXATwo weeks of isocaloric diet
Fructose dietElectromyogram (EMG)Two weeks of hypercaloric diet supplemented with fructose
Fructose dietDXATwo weeks of hypercaloric diet supplemented with fructose
Glucose diet11C-acetateTwo weeks of hypercaloric diet supplemented with glucose
Isocaloric Dietcold exposureTwo weeks of isocaloric diet
Fructose diet[U-13C]-palmitateTwo weeks of hypercaloric diet supplemented with fructose
Isocaloric Diet[U-13C]-palmitateTwo weeks of isocaloric diet
Isocaloric Diet2H-GlycerolTwo weeks of isocaloric diet
Isocaloric DietMRI/MRSTwo weeks of isocaloric diet
Isocaloric DietElectromyogram (EMG)Two weeks of isocaloric diet
Isocaloric DietIndirect calorimetryTwo weeks of isocaloric diet
Fructose diet18FDGTwo weeks of hypercaloric diet supplemented with fructose
Glucose diet2H-GlycerolTwo weeks of hypercaloric diet supplemented with glucose
Fructose dietcold exposureTwo weeks of hypercaloric diet supplemented with fructose
Fructose dietIndirect calorimetryTwo weeks of hypercaloric diet supplemented with fructose
Glucose dietIndirect calorimetryTwo weeks of hypercaloric diet supplemented with glucose
Glucose dietcold exposureTwo weeks of hypercaloric diet supplemented with glucose
Fructose diet2H-GlycerolTwo weeks of hypercaloric diet supplemented with fructose
Fructose dietMRI/MRSTwo weeks of hypercaloric diet supplemented with fructose
Glucose dietDietTwo weeks of hypercaloric diet supplemented with glucose
Glucose diet18FDGTwo weeks of hypercaloric diet supplemented with glucose
Glucose diet[U-13C]-palmitateTwo weeks of hypercaloric diet supplemented with glucose
Glucose dietMRI/MRSTwo weeks of hypercaloric diet supplemented with glucose
Glucose dietElectromyogram (EMG)Two weeks of hypercaloric diet supplemented with glucose
Primary Outcome Measures
NameTimeMethod
BAT triglyceride content4 months

will be determined by radiodensity or MRS

Microbiome metabolites4 months

assessed from stool samples

Microbiome flora4 months

assessed from stool samples

BAT oxidative metabolism4 months

will be determined using i.v. injection of 11C-acetate during dynamic PET/CT scanning

Secondary Outcome Measures
NameTimeMethod
Whole-body glucose partitioning4 months

will be assessed using i.v. injection of 18FDG with static PET/CT scanning

BAT blood flow4 months

will be determined using i.v. injection of 11C-acetate during dynamic PET/CT scanning

BAT volume of metabolic activity4 months

will be determined using a total body CT (16 mA) followed by a PET acquisition

metabolites appearance rate12 months

will be determined by perfusion of stable isotope tracers

energy metabolism (whole body production)4 months

by indirect calorimetry

BAT net glucose uptake4 months

will be assessed using i.v. injection of 18FDG with sequential dynamic PET/CT scanning.

hormonal responses12 months

analysed by colorimetric and Elisa tests

Trial Locations

Locations (1)

Centre de recherche du CHUS

🇨🇦

Sherbrooke, Quebec, Canada

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