Obesity
Conditions
Keywords
Bariatric surgery, Persistant organic pollutants, Type 2 diabetes
Brief summary
Published data suggest that inflammation and fibrosis of adipose tissue could be factors favoring the development of insulin resistance in obese individuals and that a decrease in the activity of the AMP-activity kinase protein (AMPK) could lead to these dysfunctions. However, very few data are available in humans. There is also growing interest in persistent organic pollutants (POPs) as a cardiometabolic and type 2 diabetes (T2D) risk factor. There is some evidence to suggest that POPs directly contribute to lipid metabolism dysfunction and insulin resistance. Additionally, POPs are stocked in adipose tissue. The accumulation of POPs in adipose tissue therefore limits their bioavailability to other organs, thus reducing their systemic toxicity. It has been observed that a large amplitude weight loss leads to a significant increase in POPs in the blood. The goal of this project is to identify adipose tissue factors/dysfunctions that contribute to insulin resistance and type 2 diabetes associated with obesity in humans and thus raise avenues for screening and treatment of these metabolic complications. More specifically, the objectives are: * To study the relationship between AMPK, fibrosis and inflammation of adipose tissue and their role in the development of insulin resistance and T2D associated with obesity; * To examine the relationship between POPs and the cardiometabolic profile.
Interventions
PROCEDUREBariatric surgery
Sleeve gastrectomy
OTHERBlood sampling
Blood samples will be collected to measure glucose, insulin, albumin, uric acid, HbA1c, lipids, hepatic enzymes, TSH, hs-CRP, complete blood cell counts and persistant organic pollutants
OTHERBlood pressure
Systolic and diastolic blood pressure will be measured.
Body weight, height and waist circumference will be measured.
OTHERBody composition
Body composition will be evaluated by dual-energy X-ray absorptiometry.
OTHERResting metabolic rate
Resting metabolic rate will be measured by indirect calorimetry.
OTHERFood intake
Food intake, energy intake and food quality will be evaluated using the food frequence questionnaire.
PROCEDUREAdipose tissue biopsy
A sample of 3-5g of adipose tissue will be collected under local anesthesia by needle aspiration in the periumbilical region.
Sponsors
Institut de Recherches Cliniques de Montreal
Study design
Observational model
OTHER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Awaiting bariatric surgery 2. BMI ≥ 35 kg/m2 without cardiometabolic complications or ≥ 30 kg/m2 if presence of type 2 diabetes or hypertension 3. ≥ 18 years old 4. Non smoker 5. Sedentary (less than 3 hours of regular physical activity per week)
Exclusion criteria
1. Type 1 diabetes 2. Acute event in the last 3 months (myocardial infarction, cerebrovascular hemorrhage or transient cerebral ischemia, unstable angina, peripheral vascular disease, revascularization or angioplasty, recent hospitalization for more than 4 days) 3. Infection in the last month (fever, antibiotics treatment) 4. Cancer in the last 3 years 5. Chronic inflammatory disease 6. Pharmacologic treatment (any medication affecting glucose metabolism (except those for diabetes), hypotensive medication unless stable dose for at least 1 month, lipid-lowering medication unless stable dose for at least 1 month) 7. Uncontrolled disease of pituitary or thyroid gland 8. Bleeding disorders 9. Alcohol or drug abuses 10. Claustrophobia
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Adipose tissue fibrosis using qRT-PCR, immunoblotting, histochemistry and immunohistochemistry | Before bariatric surgery |
Secondary
| Measure | Time frame |
|---|---|
| Calory intake | Before bariatric surgery |
| Food quality using the Food Frequency Questionnaire | Before bariatric surgery |
| Persistant organic pollutants measured by high-resolution chromatography combined with high-resolution mass spectrometry | Before bariatric surgery |
| AMP-activated protein kinase | Before bariatric surgery |
| Inflammation in adipose tissue using qRT-PCR, immunoblotting and immunohistochemistry | Before bariatric surgery |
Countries
Canada
Outcome results
None listed