Comparison of Weight Loss Induced by Bariatric Surgery vs Conventional Treatment

This study is enrolling participants by invitation only.
Sponsor:
Collaborators:
Instituto de Salud Carlos III
Fondo de Investigacion Sanitaria
Information provided by (Responsible Party):
Gema Frühbeck Martínez, Instituto Cientifico y Tecnologico de Navarra, Universidad de Navarra
ClinicalTrials.gov Identifier:
NCT01572090
First received: March 28, 2012
Last updated: April 3, 2012
Last verified: April 2012
  Purpose

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.


Condition Intervention
Obesity
Behavioral: Lifestyle Changes
Other: Adjustment of oral antidiabetics/insulin therapy
Procedure: Laparoscopic sleeve gastrectomy
Procedure: Laparoscopic Roux-en-Y gastric bypass

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Comparison of Weight Loss Induced by Bariatric Surgery vs Conventional Treatment on Body Composition, Adipokines, Gastro-intestinal Hormones and Cardiometabolic Risk Factors

Resource links provided by NLM:


Further study details as provided by Clinica Universidad de Navarra, Universidad de Navarra:

Primary Outcome Measures:
  • Change in body fat [ Time Frame: Baseline, 1, 6, 12, and 24 months ] [ Designated as safety issue: No ]
    Body fat will be assessed by air-displacement plethysmography (Bod-Pod) over the duration of the intervention.


Secondary Outcome Measures:
  • Change in energy balance [ Time Frame: Baseline, 1, 6, 12 and 24 months ] [ Designated as safety issue: No ]
    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 glycemic control [ Time Frame: Baseline, 1, 6, 12 and 24 months ] [ Designated as safety issue: No ]
    Measurement of fasting plasma glucose, insulin and HbA1c concentrations over the duration of the intervention.

  • Change in cardiovascular risk factors [ Time Frame: Baseline, 1, 6, 12 and 24 months ] [ Designated as safety issue: No ]
    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.

  • Change in gastrointestinal hormones [ Time Frame: Baseline, 1, 6, 12 and 24 months ] [ Designated as safety issue: No ]
    Measurement of fasting ghrelin, PYY, GLP-1, GIP, PP, amylin and oxyntomodulin over the duration of the intervention.

  • Change in gustatory threshold [ Time Frame: Baseline, 1, 6, 12 and 24 months ] [ Designated as safety issue: No ]
    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 [ Time Frame: Baseline, 1, 6, 12 and 24 months ] [ Designated as safety issue: No ]
    Measurement of weight and height over the duration of the intervention to calculate the BMI.


Estimated Enrollment: 600
Study Start Date: January 2006
Estimated Study Completion Date: December 2015
Estimated Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Conventional weight loss: CONV-NG
Obese normoglycemic (NG) patients evidenced by a body fat ≥ 35% in women and ≥ 25% in men and a 2-h oral glucose tolerance test.
Behavioral: Lifestyle Changes

Hypocaloric diet providing a 1000 kcal/d deficit from total energy expenditure assessed by indirect calorimetry and physical activity determination.

Dietetic and physical activity counselling with a dietitian.

Other Name: Conventional weight loss
Active Comparator: Conventional weight loss: CONV-T2D
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.
Behavioral: Lifestyle Changes

Hypocaloric diet providing a 1000 kcal/d deficit from total energy expenditure assessed by indirect calorimetry and physical activity determination.

Dietetic and physical activity counselling with a dietitian.

Other Name: Conventional weight loss
Other: Adjustment of oral antidiabetics/insulin therapy
Continuation-discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice.
Other Name: Pharmacological treatment adjustment
Active Comparator: Sleeve gastrectomy: SG-NG
This group will be comprised of 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).
Procedure: Laparoscopic sleeve gastrectomy
Laparoscopic sleeve gastrectomy. Dietetic and physical activity counselling with a dietitian.
Other Name: Restrictive bariatric surgery
Active Comparator: Sleeve gastrectomy: SG-T2D
This group will be comprised of 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).
Other: Adjustment of oral antidiabetics/insulin therapy
Continuation-discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice.
Other Name: Pharmacological treatment adjustment
Procedure: Laparoscopic sleeve gastrectomy
Laparoscopic sleeve gastrectomy. Dietetic and physical activity counselling with a dietitian.
Other Name: Restrictive bariatric surgery
Active Comparator: Roux-en-Y gastric bypass: RYGB-NG
This group will be comprised of obese (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities) normoglycemic (NG) patients (evidenced by a 2-h OGTT) undergoing a Roux-en-Y gastric bypass (RYGB).
Procedure: Laparoscopic Roux-en-Y gastric bypass
Laparoscopic Roux-en-Y gastric bypass. Dietetic and physical activity counselling with a dietitian.
Other Name: Mixed (restrictive & malabsorptive) bariatric surgery
Active Comparator: Roux-en-Y gastric bypass: RYGB-T2D
This group will be comprised of 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 Roux-en-Y gastric bypass (RYGB).
Other: Adjustment of oral antidiabetics/insulin therapy
Continuation-discontinuation of medical antidiabetic therapy if needed in accordance with good clinical practice.
Other Name: Pharmacological treatment adjustment
Procedure: Laparoscopic Roux-en-Y gastric bypass
Laparoscopic Roux-en-Y gastric bypass. Dietetic and physical activity counselling with a dietitian.
Other Name: Mixed (restrictive & malabsorptive) bariatric surgery

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.

  Eligibility

Ages Eligible for Study:   21 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • 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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01572090

Locations
Spain
Clinica Universidad de Navarra
Pamplona, Spain
Sponsors and Collaborators
Clinica Universidad de Navarra, Universidad de Navarra
Instituto de Salud Carlos III
Fondo de Investigacion Sanitaria
Investigators
Principal Investigator: Gema Frühbeck, MD, PhD Clinica Universidad de Navarra
  More Information

No publications provided

Responsible Party: Gema Frühbeck Martínez, MD, PhD, Instituto Cientifico y Tecnologico de Navarra, Universidad de Navarra
ClinicalTrials.gov Identifier: NCT01572090     History of Changes
Other Study ID Numbers: OBECUN-WL-01
Study First Received: March 28, 2012
Last Updated: April 3, 2012
Health Authority: Spain: Ministry of Health

Keywords provided by Clinica Universidad de Navarra, Universidad de Navarra:
Body mass index
Body fat
Obesity
Bariatric surgery
Conventional dietary treatment
Diabetes Mellitus, Type 2
Cardiometabolic risk factors
Inflammation
Adipokines
Gastrointestinal hormones
Comorbidity improvement
Energy intake
Energy expenditure
Physical activity

Additional relevant MeSH terms:
Obesity
Weight Loss
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Body Weight Changes
Hypoglycemic Agents
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on September 22, 2014