Predictors of Weight Loss and Metabolic Health After Bariatric Surgery

Study Overview
=================
Brief Summary
-----------------
In this prospective study the investigators aim to identify preoperative predictors of improvement of metabolic health and weight loss after bariatric surgery focusing on inflammation, insulin sensitivity (in a subgroup of patients), glucoregulatory determinants, psychological traits, feeding behavior characteristics and cardiorespiratory fitness

Detailed Description
-----------------
Obesity is the result of a complex interplay between genetic and epigenetic predisposition, environment, physical activity, nutrition and psychology. It is a debilitating disorder and a risk factor for the development of metabolic disorders such as dyslipidaemia, hypertension and hyperglycaemia as well as certain cancers. Bariatric surgery has proven to be the most effective treatment for morbid obesity with established long-term results of weight loss, remission of comorbid conditions and the improvement of Quality of Life (QoL). However, variability in these results after bariatric surgery is well known. Identifying preoperative predictors of postoperative weight loss and metabolic health is of clinical priority. Predictors could help further improve the efficacy of care for obesity by tailoring treatment to the individual, based on their predicted response and therefore optimize outcome after bariatric surgery.

Official Title
-----------------
Preoperative Predictors of Weight Loss and Improved Metabolic Health After Bariatric Surgery

Conditions
-----------------
Obesity, Morbid, Insulin Sensitivity, Bariatric Surgery Candidate, Feeding Behavior

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Ability to provide informed consent Patient is ≥ 18 and ≤ 75 years old BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with obesity related comorbidity Scheduled for primary bariatric procedure: Roux-en-Y gastric bypass (RYGB) or Sleeve Gastrectomy (SG) Stable weight 3 months prior to inclusion weight (<10% change in body weight for 3 months prior to assessments) In order to be eligible to participate in the subgroup of this study, we will use the following inclusion criteria: Ability to provide informed consent Patient is ≥ 18 and ≤ 75 years old BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with obesity related comorbidity Patients scheduled for RYGB Patients who are insulin resistant (impaired fasting glucose (> 5.6 mmol/L) or fasting insulin > 74 pmol/L) Postmenopausal women (to prevent bias due to the effect of sex hormones on insulin sensitivity) Exclusion Criteria: Any actual medical condition except for obesity related health issues or well treated hypothyroidism Pregnancy anticipated in the first two years following surgery A potential subject who meet the following criteria will be excluded from participation in the subgroup of this study: Coagulation disorders and/or use anticoagulants Use of any medication except for statins, antihypertensives (except for Angiotensine converting enzyme (ACE)- or angiotensin receptor blockers) and thyroid hormone Diabetes mellitus type 2

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Predictors of improvement in metabolic health - insulin sensitivity | HOMA-IR | Baseline up to 5 years after surgery | 
| Predictors of improvement in metabolic health - level of glucose control | HbA1C (mmol/mol) | Baseline up to 5 years after surgery | 
| Predictors of improvement in metabolic health - glucose | Fasting glucose (mmol/L) | Baseline up to 5 years after surgery | 
| Predictors of improvement in metabolic health - insulin | Insulin (pmol/L) | Baseline up to 5 years after surgery | 
| Predictors of improvement in metabolic health - lipid profile | Lipids (mmol/L) | Baseline up to 5 years after surgery | 
| Predictors of improvement in metabolic health - biomarker inflammation | CRP (mg/L) | Baseline up to 5 years after surgery | 
| Predictors of improvement in metabolic health | Genetic variants using GWAS analysis | Baseline up to 5 years after surgery | 
| Predictors of weight loss | Genetic variants using GWAS analysis | Baseline up to 5 years after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Psychological factors - depression | Patient-Reported Outcomes Measurement Information System Depression (PROMIS-D: validated questionnaire for bariatric surgery. PROMIS-D: range in score from 8 to 40, higher scores indicating greater severity of depression | Baseline up to 5 years after surgery | 
| Psychological factors - anxiety | Patient-Reported Outcomes Measurement Information System Anxiety (PROMIS-A): validated questionnaire for bariatric surgery. PROMIS-A: range in score from 7 to 35, higher scores indicating greater severity of anxiety. | Baseline up to 5 years after surgery | 
| Psychological factors - impulsivity | Measurements of impulsiveness Barret Impulsiveness Scale (BIS): validated questionnaire to assess level of impulsivity BIS-11: The total scores can range from 30 to 120. Higher scores on the BIS reflect higher levels of impulsiveness. | Baseline up to 5 years after surgery | 
| Psychological factors - impulsivity | Measurements of impulsiveness Iowa Gambling Task: validated task to study impulsive behaviour Iowa gambling task: The net score is calculated by subtracting the number of disadvantageous selections from the advantageous selections. A positive net score indicates better performance | Baseline up to 5 years after surgery | 
| Predictors of weight loss - food addiction | Food addiction scale (YFAS 2.0): validated questionnaire to assess food addiction. YFAS 2.0 includes two scoring methods, a continuous symptom count and a diagnosis of food addiction. Continious symptom count ranges from zero to eleven, Diagnosis of food addiction: no food addiction (0-1 symptoms), a mild food addicition (2-3 symptoms), a moderate food addiction (4-5 symptoms), or a severe food addiction (>6 symptoms). | Baseline up to 5 years after surgery | 
| Predictors of weight loss - eating behaviour | Dutch Eating Behaviour Questionnaire (DEBQ): validated questionnaire to assess eating behaviour. DEBQ consists of 33 items.Items on the DEBQ range from 1 (never) to 5 (very often), with higher scores indicating greater endorsement of the eating behavior. | Baseline up to 5 years after surgery | 
| Predictors of weight loss - Quality of Life | Selfesteem scale of Impact of Weight on Quality of Life - lite (IWQOL-lite): validated questionnaire after weight loss interventions. The self-esteem scale consists of 7 items. Each item is rated on a 5-point scale. Higher scores represent better quality of life. | Baseline up to 5 years after surgery | 
| Predictors of weight loss - Quality of Life | OBESI-Q (Obesity): validated questionnaire for reporting Health Related Quality of Life. Outcome is expressed on a 100 point scale, a higher score is higher quality of life, with the exception of item Excess skin. | Baseline up to 5 years after surgery | 
| Predictors of weight loss - Quality of Life | EuroQuality of Life (EQ-5D): validated questionnaire for reporting Quality of Life after bariatric surgery. Each item is rated on a 5-point scale. Higher scores represent lower reported quality of life. | Baseline up to 5 years after surgery | 
| Predictors of weight loss - Impulsivity | Measurements of impulsiveness Barret Impulsiveness Scale (BIS): validated questionnaire to assess level of impulsivity BIS-11: The total scores can range from 30 to 120. Higher scores on the BIS reflect higher levels of impulsiveness. | Baseline up to 5 years after surgery | 
| Predictors of weight loss - Impulsivity | Measurements of impulsiveness Iowa Gambling Task: validated task to study impulsive behaviour Iowa gambling task: The net score is calculated by subtracting the number of disadvantageous selections from the advantageous selections. A positive net score indicates better performance | Baseline up to 5 years after surgery | 
| Predictors of weight loss - Physical activity | Short Questionnaire to Assess Health Enhancing Physical Activity (SQUASH): validated questionnaire to assess physical activity. The SQUASH measures the frequency, duration and intensity of 5 different physical activities: commuting (traveling to and from work/study), housekeeping , activities at work, leisure time, and sports. A higher score = more time spend on physical activities. | Baseline up to 5 years after surgery | 
| Sexual dimorphism in weight loss | Males versus females regarding weight loss (kg) and percentage of total weight loss | Baseline up to 5 years after surgery | 
| Sexual dimorphism in restoration of metabolic health - insulin sensitivity | Males versus females regarding insulin sensitivity (HOMA-IR) and measurements of glucose and insuline | Baseline up to 5 years after surgery | 
| Sexual dimorphism in restoration of metabolic health - improvement of diabetes | Males versus females regarding HbA1c values and diabetic drug use | Baseline up to 5 years after surgery | 
| Sexual dimorphism in restoration of metabolic health - lipid | Males versus females regarding lipids (mmol/L) and lipid-lowering agents use | Baseline up to 5 years after surgery | 
| Sexual dimorphism in restoration of metabolic health - hypertension | Males versus females regarding blood pressure (mmHg) and anithypertensive medication use | Baseline up to 5 years after surgery | 
| Peripheral insulin sensitivity | In a subset of 40 patients insulin sensitivity will be assessed using hyperinsulinemic euglycemic clamps, and adipose tissue and skeletal muscle biopsies will be taken to assess insulin signalling (expression of mRNA and phosphorylated proteins) | Before and 3 and 18 months after bariatric surgery | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Obesity, Bariatric Surgery, Metabolic health, Weight loss, Predictors