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

Obesity Clinical Trial

Official title:

Effects of the Surgical Removal of Visceral Fat Tissue (Omentectomy) on Insulin Sensitivity in Grade III Obese Volunteers Subjected to Bariatric Surgery

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00545805
• Other study ID #: LIMED0001
• Secondary ID: FAPESP 05/58627-
• Status: Completed
• Phase: Phase 2/Phase 3
• First received: October 16, 2007
• Last updated: February 17, 2013
• Start date: October 2005
• Est. completion date: June 2009

Study information

• Verified date: February 2013
• Source: University of Campinas, Brazil
• Contact: n/a
• Is FDA regulated: No
• Health authority: Brazil: National Committee of Ethics in Research
• Study type: Interventional

Clinical Trial 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.

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).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: June 2009
• Est. primary completion date: June 2009
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years to 50 Years

Eligibility

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.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Insulin Resistance
• Metabolic Syndrome X
• Obesity

Intervention

Procedure:
• Roux-en-Y Gastric Bypass plus total omentectomy
Roux-en-Y Gastric Bypass plus total omentectomy
• Roux-en-Y Gastric Bypass
Roux-en-Y Gastric Bypass without omentectomy

Locations

Country	Name	City	State
Brazil	LIMED (Laboratory of Investigation of Metabolism and Diabetes)/GASTROCENTRO/Univeristy of Campinas (UNICAMP)	Campinas	SP

Sponsors (2)

Lead Sponsor	Collaborator
University of Campinas, Brazil	Fundação de Amparo à Pesquisa do Estado de São Paulo

Country where clinical trial is conducted

Brazil, 

References & Publications (6)

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. — View Citation

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. — View Citation

Lima MM, Pareja JC, Alegre SM, Geloneze SR, Kahn SE, Astiarraga BD, Chaim ÉA, Baracat J, Geloneze B. Visceral fat resection in humans: effect on insulin sensitivity, beta-cell function, adipokines, and inflammatory markers. Obesity (Silver Spring). 2013 M — View Citation

Lima MM, Pareja JC, Alegre SM, Geloneze SR, Kahn SE, Astiarraga BD, Chaim EA, Geloneze B. Acute effect of roux-en-y gastric bypass on whole-body insulin sensitivity: a study with the euglycemic-hyperinsulinemic clamp. J Clin Endocrinol Metab. 2010 Aug;95( — View Citation

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. — View Citation

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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Increase of insulin sensitivity as measured by euglycemic-hyperinsulinemic clamp.		one month, six months and one year.	No
Secondary	increase of insulin secretion as measured by intravenous glucose tolerance test		one month, six months, one year	No
Secondary	regression of carotid intima-media thickness		one month, six months, one year	No
Secondary	Improvement of the insulin cell signalling in the subcutaneous adipose tissue.		one month, six months	No
Secondary	increase of adipocytokines linked to greater insulin sensitivity and decrease of others linked to insulin resistance		one month, six months, one year	No