Gastric Bypass and Peripheral Activity of the Endocannabinoid System
Condition: Obesity
MeSH terms: Obesity
Study type: Observational

Summary: 
      The aim of the study is to precise the effect of a large amount of weight loss induced by
      gastric bypass on the endocannabinoid system (plasma and adipose tissue) of morbidly obese
      patients and to determine the influence of a gastric bypass surgery compared to a lifestyle
      intervention with equivalent weight loss on the endocannabinoid system
    

Detailed description: 
      Dysregulation of the endocannabinoid system has been associated with the development of
      obesity, metabolic and cardiovascular disorders in both animals and humans.

      Obese patients, especially those with abdominal obesity, have significantly higher levels of
      endocannabinoids. No influence of moderate (5%) body weight loss (induced either by diet
      intervention or sibutramine) on the peripheral activity of the endocannabinoid system gastric
      bypass (GB) surgery is the most efficient treatment of obesity Hormonal pathways may
      participate to the weight reducing effect of the procedure.The endocannabinoid system is
      present in the gastrointestinal tract.

      In animals, sustained weight loss after GB is characterized by reduction of endocannabinoids
      levels.

      The endocannabinoid levels will be studied (baseline and after stimulation) in:

        -  Normal-weight subjects

        -  Obese subjects before and after gastric bypass surgery

        -  Obese subjects before and after a lifestyle intervention
    

Intervention name(s): Evaluation of the endocannabinoid system; Biopsy of visceral and peripheral adipose tissue; Evaluation of metabolic parameters; Evolution of behavioral parameters; Dietician consultation; Psychologist consultation
Intervention type(s): Biological; Procedure; Biological; Behavioral; Behavioral; Behavioral
Intervention description(s): The evaluation of the endocannabinoid system consist in the determination of plasma concentration of the 2 main endocannabinoids (2AG and AEA) before (5 blood samples) and after (5 blood samples) after consumption of a calibrated food. As a comparator, ghrelin will be measured at the same time.; The endocannabinoids will be also determined in adipose tissue. Biopsy of visceral and peripheral adipose tissue will be done during surgery and peripheral adipose tissue will be done 6 months after surgery.; The evaluation of the metabolic status consist in evaluation of body composition (DEXA), determination of visceral adiposity (CT scan) and measurement of plasma lipids, glucose, insulin, leptin, adiponectin.; The behavioral evaluation will de done with different questionnaires: ORWELL 97, HAD scale, Three Factor Eating Questionnaire, Beck Depression inventory, Questionnaire of personality TCI.; The evaluation of the metabolic status will also be seen by a dietician.; The behavioural evaluation will de done with a psychologist consultation
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        2 groups : from primary care clinic

          -  obese patients with gastric bypass

          -  obese patients with lifestyle intervention 1 group : volunteer
      
Biospecimen description: 
      Biopsy of visceral and peripheral adipose tissue will be done during surgery and peripheral
      adipose tissue will be done 6 months after surgery
    
Keywords: morbid obesity; bariatric surgery; lifestyle intervention; endocannabinoids system