Changes in Insulin Sensitivity After Weight Loss

Completed

• Conditions: Type 2 Diabetes Mellitus; Obesity; Insulin Resistance
• Interventions: Procedure: Gastric bypass; Procedure: Gastric banding; Procedure: Sleeve gastrectomy; Behavioral: Very low calorie diet

• Registration Number: NCT00627484
• Lead Sponsor: Columbia University

Brief Summary

This study is designed to compare the changes in insulin sensitivity as well as gastrointestinal hormone levels in diabetic and non-diabetic obese individuals who are undergoing weight loss procedures. The main hypothesis of this study is that weight loss induced by gastric bypass will induce a greater improvement in insulin sensitivity compared with gastric banding or low calorie diet. Subjects will be studied before and after weight loss. Studies consist of intravenous glucose tolerance test, body composition analysis, meal test, and energy expenditure.

Detailed Description

Patients who are scheduled for gastric bypass (GBP), sleeve gastrectomy (SG), or simple caloric restriction with gastric banding (BND) or a very low calorie diet (VLCD) will be examined at baseline weight, and when 6-10% total body weight has been lost. We will measure insulin sensitivity with an intravenous glucose tolerance test, and fasting levels of hormones that regulate food intake and insulin sensitivity, such as ghrelin, peptide YY (PYY), glucagon-like peptide 1 (GLP1) and leptin. Fat mass and skeletal muscle mass will be measured by dual photon absorptiometry (DXA). We will also measure the hormonal and thermic response to food with a liquid test meal and energy expenditure by indirect calorimetry. This measures how many calories are burned at rest and the in response to food. Subjects with diabetes will continue to be studied with the same protocol on an annual basis out to 5 years in order to determine the rate of remission of diabetes and the durability of this effect as subjects tend to regain some body weight over time.

Subjects with diabetes will also be followed every three months for the first year after the initial weight loss for HbA1c and fasting glucose levels. The results of this study may lead to new understanding about changes in insulin sensitivity, body composition and hormonal profile, as well as changes in energy expenditure with weight loss after bariatric surgery or with simple caloric restriction. With this greater understanding, new treatments for obesity and diabetes, that do not require surgery, may be developed.

Study Timeline

• Study Start: 2005-03-01
• Study First Submitted: 2008-02-28
• Study First Submitted QC: 2008-02-28
• Study First Posted: 2008-03-03
• Primary Completion: 2018-06-17
• Study Completion: 2018-06-17
• Status Verified: 2019-09
• Last Update Submitted: 2019-09-18
• Last Update Posted: 2019-09-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 119

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Group 3: GBP diabetic	Gastric bypass	Diabetic subjects scheduled to receive gastric bypass
Group 1: GBP non-diabetic	Gastric bypass	Non-diabetic subjects scheduled to receive gastric bypass
Group 2: BND non-diabetic	Gastric banding	Non-diabetic subjects scheduled to receive gastric banding
Group 5: SG diabetic	Sleeve gastrectomy	Diabetic subjects scheduled to receive sleeve gastrectomy
Group 4: VLCD diabetic	Very low calorie diet	Diabetic subjects scheduled to receive very low calorie diet

Primary Outcome Measures

Name	Time	Method
Change in Insulin Sensitivity	2-8 weeks	Measured by frequently sampled intravenous glucose tolerance test (FSIVGTT)

Secondary Outcome Measures

Name	Time	Method
Change in Body Composition	2-8 weeks	Measured by dual energy x-ray absorptiometry (DXA)
Change in Resting Energy Expenditure	Up to 4 hrs post-meal	Measured by indirect calorimetry using a Hood Calorimeter

Trial Locations

Locations (1)

Columbia University Medical Center; 🇺🇸 New York, New York, United States