Comparison of Weight Loss Induced by Bariatric Surgery vs Conventional Treatment
- Conditions
- Obesity
- Interventions
- Behavioral: Lifestyle ChangesOther: Adjustment of oral antidiabetics/insulin therapyProcedure: Laparoscopic Roux-en-Y gastric bypassProcedure: Laparoscopic sleeve gastrectomy
- Registration Number
- NCT01572090
- Lead Sponsor
- Clinica Universidad de Navarra, Universidad de Navarra
- Brief Summary
Patients with overweight or obesity are in need to loose weight and represent a particularly challenging medical condition. Undoubtedly, any intervention achieving a negative energy balance over an extended time period will result in weight loss. Although several treatment modalities are available, currently the most extended approaches are lifestyle changes, pharmacotherapy, and bariatric surgery. Given the limited approved anti-obesity drugs, the main therapeutic strategies involve either conventional treatment or bariatric surgery. Conventional weight-reduction programs pursue a safe weight loss rate of 0,5-1,0 kg per week. The main modifiable factors affecting energy balance are dietary energy intake and energy expended through physical activity. In spite of the difficulty in achieving relevant and sustained weight loss via the conventional approach, some patients are successful in reducing weight and obesity-associated complications. Bariatric surgery has proved to be the most effective long-term treatment for weight loss and comorbidity improvement. While some of the surgery-induced benefits are directly dependent on adipose tissue reduction, others are due to specific gastrointestinal changes that take place early on and before any significant effects on body weight are observed. The present study contemplates the determination and comparison of the anthropometric and metabolic changes produced by the conventional and surgery-induced treatment modalities. Particular emphasis will be placed on the potential differential effects between conventional and surgical weight loss on body composition changes, circulating adipokines and gastrointestinal hormones together with their subsequent impact on cardiometabolic risk factors.
- Detailed Description
In spite of the recognition of obesity as a serious public health problem due to its well-known increased risk for the development of type 2 diabetes hypertension, coronary heart disease, sleep-breathing disorders, and certain forms of cancer, among others, it is proving extraordinarily difficult to halt this pandemia. Strictly speaking obesity does not refer to an excess weight or weight to height ratio. In fact, the World Health Organization defines obesity as a state of increased adipose tissue of sufficient magnitude to produce adverse health consequences. Thus, in order to better define the effects and benefits of weight loss it is important to address the impact on body fat changes. Given the limited approved anti-obesity drugs, the main therapeutic strategies involve either conventional treatment or bariatric surgery. The main modifiable factors affecting energy balance are dietary energy intake and energy expended through physical activity. In spite of the difficulty in achieving relevant and sustained weight loss via the conventional approach, some patients are successful in reducing weight and obesity-associated complications. Bariatric surgery has proved to be the most effective long-term treatment for weight loss and comorbidity improvement. While some of the surgery-induced benefits are directly dependent on adipose tissue reduction, others are due to specific gastrointestinal changes that take place early on and before any significant effects on body weight are observed. Noteworthy, currently available bariatric procedures differ on their impact on these aspects. The present study contemplates the determination and comparison of the anthropometric and metabolic changes produced by the conventional and surgery-induced treatment modalities. Particular emphasis will be placed on the potential differential effects between conventional and surgical weight loss on energy intake, energy expenditure, body composition changes, circulating adipokines and gastrointestinal hormones together with their subsequent impact on cardiometabolic risk factors. The conventional weight-reduction program (CONV) will pursue a safe weight loss rate of 0,5-1,0 kg per week. The surgery-induced weight loss will be achieved by two of the most frequently used bariatric operations, the sleeve gastrectomy \[SG (which implies a restrictive component)\] and the Roux-en-Y gastric bypass \[RYGB (which combines a restrictive and a malabsorptive component)\].
The purpose of the study is to determine the effect of three weight loss procedures that differ on their manipulation of the anatomical and functional characteristics of the gastrointestinal tract. While in the conventional treatment the gastrointestinal system remains intact, in the SG only the stomach is manipulated as opposed to the RYGB, where both the stomach and the small intestine are operated on. Since bariatric surgery is well known to induce partial or total remission of type 2 diabetes mellitus, the effects of the three different weight loss procedures will be assessed separately in obese normoglycemic and obese type 2 diabetic individuals.
Recruitment & Eligibility
- Status
- UNKNOWN
- Sex
- All
- Target Recruitment
- 600
- Age between 21 and 65 years.
- Obesity as defined by World Health Organization criteria.
- For bariatric surgery patients: qualified for obesity surgery by the -Multidisciplinary Obesity Team of the Clinica Universidad de Navarra
- For type 2 diabetic patients: T2D diagnosis confirmed by either fasting plasma glucose ≥126 mg/dL on two separate occasions, or fasting plasma glucose ≥126 mg/dL and plasma glucose ≥140 mg/dL 2 h after OGTT, or treatment with anti-diabetic medication in accordance with good clinical practice with and well-documented information on diagnosis, history, treatment(s) and HbA1c data.
- No major organ disease unrelated to excess body weight.
- Mentally able to understand the study and willingness to participate in the study.
- Pregnancy/lactation
- Poor overall general health
- Drug and/or alcohol addiction
- Prior bariatric or gastrointestinal surgery
- Active gastric or intestinal tract disease
- Thyroid disease
- Type 1 diabetes mellitus
- Portal hypertension and/or cirrhosis
- Malignancies
- History of eating disorders or major psychiatric illness
- Unable to communicate with study staff
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Laparoscopic Sleeve gastrectomy: SG-T2D Laparoscopic sleeve gastrectomy The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) type 2 diabetic (T2D) patients with proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice undergoing a sleeve gastrectomy (SG). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery as well for adjustment of antidiabetic medication. Adjustment of oral antidiabetics/insulin therapy consisting in continuation, adjustment or discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice. Conventional weight loss: CONV-T2D Adjustment of oral antidiabetics/insulin therapy Obese type 2 diabetic (T2D) patients evidenced by a body fat \>35% in women and ≥ 25% in men and proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice. Conventional weight loss will be achieved by "Lifestyle changes" including advice on increasing physical activity and prescription of a hypocaloric diet providing a daily energy deficit of 500-1000 kcal/d as calculated from the determination of the resting energy expenditure through indirect calorimetry (Vmax29, SensorMedics Corporation, Yorba Linda, CA) and multiplication by the physical activity level factor to obtain the individual's total energy expenditure. Regular visits with the dietitian will be scheduled as in the surgical groups. Conventional weight loss: CONV-NG Lifestyle Changes Obese normoglycemic (NG) patients evidenced by a body fat ≥ 35% in women and ≥ 25% in men and a 2-h oral glucose tolerance test. Conventional weight loss will be achieved by "Lifestyle changes" including advice on increasing physical activity and prescription of a hypocaloric diet providing a daily energy deficit of 500-1000 kcal/d as calculated from the determination of the resting energy expenditure through indirect calorimetry (Vmax29, SensorMedics Corporation, Yorba Linda, CA) and multiplication by the physical activity level factor to obtain the individual's total energy expenditure. Regular visits with the dietitian will be scheduled as in the surgical groups. Conventional weight loss: CONV-T2D Lifestyle Changes Obese type 2 diabetic (T2D) patients evidenced by a body fat \>35% in women and ≥ 25% in men and proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice. Conventional weight loss will be achieved by "Lifestyle changes" including advice on increasing physical activity and prescription of a hypocaloric diet providing a daily energy deficit of 500-1000 kcal/d as calculated from the determination of the resting energy expenditure through indirect calorimetry (Vmax29, SensorMedics Corporation, Yorba Linda, CA) and multiplication by the physical activity level factor to obtain the individual's total energy expenditure. Regular visits with the dietitian will be scheduled as in the surgical groups. Laparoscopic Sleeve gastrectomy: SG-T2D Adjustment of oral antidiabetics/insulin therapy The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) type 2 diabetic (T2D) patients with proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice undergoing a sleeve gastrectomy (SG). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery as well for adjustment of antidiabetic medication. Adjustment of oral antidiabetics/insulin therapy consisting in continuation, adjustment or discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice. Laparoscopic Sleeve gastrectomy: SG-T2D Lifestyle Changes The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) type 2 diabetic (T2D) patients with proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice undergoing a sleeve gastrectomy (SG). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery as well for adjustment of antidiabetic medication. Adjustment of oral antidiabetics/insulin therapy consisting in continuation, adjustment or discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice. Laparoscopic R-Y gastric bypss: RYGB-T2D Adjustment of oral antidiabetics/insulin therapy The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) type 2 diabetic (T2D) patients with proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice undergoing laparoscopic Roux-en-Y gastric bypass (RYGB). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery as well for adjustment of antidiabetic medication. Adjustment of oral antidiabetics/insulin therapy consisting in continuation, adjustment or discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice. Laparoscopic Sleeve gastrectomy: SG-NG Lifestyle Changes The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) normoglycemic (NG) patients (evidenced by a 2-h OGTT) undergoing a sleeve gastrectomy (SG). The Sleeve gastrectomy SG-NG involves the removal of the mayor curvature of the stomach. Via a laparoscopic approach. In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery. Laparoscopic Sleeve gastrectomy: SG-NG Laparoscopic sleeve gastrectomy The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) normoglycemic (NG) patients (evidenced by a 2-h OGTT) undergoing a sleeve gastrectomy (SG). The Sleeve gastrectomy SG-NG involves the removal of the mayor curvature of the stomach. Via a laparoscopic approach. In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery. Laparoscopic R-Y gastric bypass: RYGB-NG Lifestyle Changes The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) normoglycemic (NG) patients (evidenced by a 2-h OGTT) undergoing laparoscopic Roux-en-Y gastric bypass (RYGB). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery. Laparoscopic R-Y gastric bypass: RYGB-NG Laparoscopic Roux-en-Y gastric bypass The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) normoglycemic (NG) patients (evidenced by a 2-h OGTT) undergoing laparoscopic Roux-en-Y gastric bypass (RYGB). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery. Laparoscopic R-Y gastric bypss: RYGB-T2D Laparoscopic Roux-en-Y gastric bypass The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) type 2 diabetic (T2D) patients with proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice undergoing laparoscopic Roux-en-Y gastric bypass (RYGB). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery as well for adjustment of antidiabetic medication. Adjustment of oral antidiabetics/insulin therapy consisting in continuation, adjustment or discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice. Laparoscopic R-Y gastric bypss: RYGB-T2D Lifestyle Changes The intervention in this arm comprises obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) type 2 diabetic (T2D) patients with proven documentation of T2D diagnosis, history and treatment in accordance with good clinical practice undergoing laparoscopic Roux-en-Y gastric bypass (RYGB). In addition to the surgery, patients will have regular follow-up with a dietitian and endocrinologist for appropriate counselling on lifestyle changes (diet, physical activity and vitamin/mineral supplementation counselling) following bariatric surgery as well for adjustment of antidiabetic medication. Adjustment of oral antidiabetics/insulin therapy consisting in continuation, adjustment or discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice.
- Primary Outcome Measures
Name Time Method Change in body fat Baseline, 1, 6, 12, and 24 months Body fat will be assessed by air-displacement plethysmography (Bod-Pod) over the duration of the intervention.
- Secondary Outcome Measures
Name Time Method Change in glycemic control Baseline, 1, 6, 12 and 24 months Measurement of fasting plasma glucose, insulin and HbA1c concentrations over the duration of the intervention.
Change in gastrointestinal hormones Baseline, 1, 6, 12 and 24 months Measurement of fasting ghrelin, PYY, GLP-1, GIP, PP, amylin and oxyntomodulin over the duration of the intervention.
Change in gustatory threshold Baseline, 1, 6, 12 and 24 months Determination of the gustatory threshold levels by the whole-mouth chemical test procedure and tongue electrogustometry over the duration of the intervention.
Change in BMI Baseline, 1, 6, 12 and 24 months Measurement of weight and height over the duration of the intervention to calculate the BMI.
Change in energy balance Baseline, 1, 6, 12 and 24 months Energy intake will be assessed by food dietary, 24-h recall, FFQ and energy expenditure will be determined by indirect calorimetry, physical activity questionnaires and accelerometry over the duration of the intervention.
Change in cardiovascular risk factors Baseline, 1, 6, 12 and 24 months Measurement of circulating total cholesterol, LDL-cholesterol, HDL-cholesterol, fibrinogen, C-reactive protein, homocysteine, von Willebrand factor and adipokines over the duration of the intervention.
Trial Locations
- Locations (1)
Clinica Universidad de Navarra
🇪🇸Pamplona, Spain