Surgical Removal of Visceral Fat Tissue (Omentectomy) Associated to Bariatric Surgery: Effects on Insulin Sensitivity

This study has been completed.
Sponsor:
Collaborator:
Fundação de Amparo à Pesquisa do Estado de São Paulo
Information provided by (Responsible Party):
Marcelo Miranda de Oliveira Lima, MD, PhD, University of Campinas, Brazil
ClinicalTrials.gov Identifier:
NCT00545805
First received: October 16, 2007
Last updated: February 17, 2013
Last verified: February 2013
  Purpose

The intraabdominal fat is associated with insulin resistance, a condition that is in the basis of diabetes, metabolic syndrome and some cardiovascular diseases. It is not clear whether it is the origin of it or a surrogate marker only. We intend to compare the effects of bariatric surgery with versus without omentectomy in morbidly obese people intended to go through bariatric surgery, accessing insulin sensitivity by metabolic tests.

If the visceral fat is causative of insulin resistance, its surgical removal (omentectomy) might lead to improvement of insulin action, as seen in animal studies and in one study with morbidly obese human volunteers.


Condition Intervention Phase
Insulin Resistance
Obesity
Metabolic Syndrome X
Procedure: Roux-en-Y Gastric Bypass plus total omentectomy
Procedure: Roux-en-Y Gastric Bypass
Phase 2
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Effects of the Surgical Removal of Visceral Fat Tissue (Omentectomy) on Insulin Sensitivity in Grade III Obese Volunteers Subjected to Bariatric Surgery

Resource links provided by NLM:


Further study details as provided by University of Campinas, Brazil:

Primary Outcome Measures:
  • Increase of insulin sensitivity as measured by euglycemic-hyperinsulinemic clamp. [ Time Frame: one month, six months and one year. ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • increase of insulin secretion as measured by intravenous glucose tolerance test [ Time Frame: one month, six months, one year ] [ Designated as safety issue: No ]
  • regression of carotid intima-media thickness [ Time Frame: one month, six months, one year ] [ Designated as safety issue: No ]
  • Improvement of the insulin cell signalling in the subcutaneous adipose tissue. [ Time Frame: one month, six months ] [ Designated as safety issue: No ]
  • increase of adipocytokines linked to greater insulin sensitivity and decrease of others linked to insulin resistance [ Time Frame: one month, six months, one year ] [ Designated as safety issue: No ]

Enrollment: 20
Study Start Date: October 2005
Study Completion Date: June 2009
Primary Completion Date: June 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: OM group Procedure: Roux-en-Y Gastric Bypass plus total omentectomy
Roux-en-Y Gastric Bypass plus total omentectomy
Active Comparator: CT group
Control group
Procedure: Roux-en-Y Gastric Bypass
Roux-en-Y Gastric Bypass without omentectomy

Detailed Description:

In order to verify a potential additional benefit of omentectomy combined to Roux-en-Y silastic ring gastric bypass, insulin sensitivity will be studied by the gold-standard test, euglycemic-hyperinsulinemic clamp, since early postoperative follow-up (before significant weight variation), compared to a control group of bariatric surgery (same technique) alone. The variables will be analyzed in the post surgical evolution for correlation to metabolic changes: adiposity-related hormones and cytokines; lipid profile and other cardiovascular risk factors; molecular expression of biopsied subcutaneous adipocytes in vitro; anthropometrics; ultrasonography of abdominal subcutaneous and intra-abdominal fat depots and carotid intima-media thickness (preclinical atherosclerosis evaluation).

  Eligibility

Ages Eligible for Study:   18 Years to 50 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Age between 21 and 50 years.
  • Female sex.
  • BMI between 40 and 50kg/m2.
  • Metabolic syndrome (NCEP/ATP III criteria).

Exclusion Criteria:

  • Weight variation >5% within 3 months prior to preoperative tests.
  • Use of antidiabetic medications within 3 months prior to preoperative tests.
  • HbA1c >8%.
  • Use of systemic corticosteroids for longer than 1 week within 3 months prior to preoperative tests.
  • Hepatic cirrhosis, renal failure or any clinical condition (other than obesity) recognized as impairing insulin sensitivity.
  • Present Smoking.
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00545805

Locations
Brazil
LIMED (Laboratory of Investigation of Metabolism and Diabetes)/GASTROCENTRO/Univeristy of Campinas (UNICAMP)
Campinas, SP, Brazil
Sponsors and Collaborators
University of Campinas, Brazil
Fundação de Amparo à Pesquisa do Estado de São Paulo
Investigators
Principal Investigator: Marcelo MO Lima, MD University of Campinas (UNICAMP)
Principal Investigator: Bruno Geloneze, PhD University of Campinas (UNICAMP)
Principal Investigator: José Carlos Pareja, PhD University of Campinas (UNICAMP)
  More Information

Publications:
Responsible Party: Marcelo Miranda de Oliveira Lima, MD, PhD, University of Campinas, Brazil
ClinicalTrials.gov Identifier: NCT00545805     History of Changes
Other Study ID Numbers: LIMED0001, FAPESP 05/58627-2
Study First Received: October 16, 2007
Last Updated: February 17, 2013
Health Authority: Brazil: National Committee of Ethics in Research

Keywords provided by University of Campinas, Brazil:
Insulin resistance
Metabolic syndrome X
Obesity
Intra-Abdominal Fat
Omentum
Bariatric surgery
Glucose Clamp Technique
Intravenous Glucose Tolerance Test
Adiponectin
Cytokines

Additional relevant MeSH terms:
Metabolic Syndrome X
Insulin Resistance
Obesity
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Insulin
Hypoglycemic Agents
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on August 21, 2014