Surgical Removal of Visceral Fat Tissue (Omentectomy) Associated to Bariatric Surgery: Effects on Insulin Sensitivity
Study Details
Study Description
Brief Summary
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 or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Phase 2/Phase 3 |
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).
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| 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
|
Outcome Measures
Primary Outcome Measures
- Increase of insulin sensitivity as measured by euglycemic-hyperinsulinemic clamp. [one month, six months and one year.]
Secondary Outcome Measures
- increase of insulin secretion as measured by intravenous glucose tolerance test [one month, six months, one year]
- regression of carotid intima-media thickness [one month, six months, one year]
- Improvement of the insulin cell signalling in the subcutaneous adipose tissue. [one month, six months]
- increase of adipocytokines linked to greater insulin sensitivity and decrease of others linked to insulin resistance [one month, six months, one year]
Eligibility Criteria
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:
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Weight variation >5% within 3 months prior to preoperative tests.
-
Use of antidiabetic medications within 3 months prior to preoperative tests.
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HbA1c >8%.
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Use of systemic corticosteroids for longer than 1 week within 3 months prior to preoperative tests.
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Hepatic cirrhosis, renal failure or any clinical condition (other than obesity) recognized as impairing insulin sensitivity.
-
Present Smoking.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | 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)
Study Documents (Full-Text)
None provided.More Information
Publications
- Barzilai N, She L, Liu BQ, Vuguin P, Cohen P, Wang J, Rossetti L. Surgical removal of visceral fat reverses hepatic insulin resistance. Diabetes. 1999 Jan;48(1):94-8.
- Gabriely I, Ma XH, Yang XM, Atzmon G, Rajala MW, Berg AH, Scherer P, Rossetti L, Barzilai N. Removal of visceral fat prevents insulin resistance and glucose intolerance of aging: an adipokine-mediated process? Diabetes. 2002 Oct;51(10):2951-8.
- Pitombo C, Araújo EP, De Souza CT, Pareja JC, Geloneze B, Velloso LA. Amelioration of diet-induced diabetes mellitus by removal of visceral fat. J Endocrinol. 2006 Dec;191(3):699-706.
- Thörne A, Lönnqvist F, Apelman J, Hellers G, Arner P. A pilot study of long-term effects of a novel obesity treatment: omentectomy in connection with adjustable gastric banding. Int J Obes Relat Metab Disord. 2002 Feb;26(2):193-9.
- LIMED0001
- FAPESP 05/58627-2