RYGB and the Gastric Adipose Axis

Study Overview
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Brief Summary
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The purpose of this study is to determine if interruption in gastric-adipose tissue axis signaling contributes to early improvements in oxidative stress, insulin sensitivity, and inflammation, and to determine if interruption of the stomach in RYGB results in reduction of plasma acylated ghrelin (AG) and in an altered acylated ghrelin:unacylated ghrelin (AG:UAG) ratio which may contribute to decreased oxidative stress and improved insulin sensitivity.

Official Title
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RYGB Improves Metabolism by Interrupting the Gastric Adipose Tissue Axis

Conditions
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Obesity

Intervention / Treatment
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* Drug: human ghrelin
* Other: very low calorie diet
* Procedure: Hyperinsulinemic/Euglycemic Clamp


Participation Criteria
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Eligibility Criteria
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PROTOCOL I Inclusion Criteria: Age 18-65 years BMI ≥ 35 kg/m^2 Scheduled for bariatric surgery Considering bariatric surgery Waiting for insurance approval for bariatric surgery Currently not considering bariatric surgery, but otherwise eligible Enrollment in medical weight loss program Exclusion Criteria: Smoking >7 cigarettes per day Precious malabsorptive or restrictive intestinal surgery Pregnant or breastfeeding Recent history of neoplasia (5<years ago) Malabsorptive syndromes Inflammatory intestinal disease Established organ disfunction Allergy to acetaminophen

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: RYGB<br>Roux-en-Y gastric bypass surgery (RYGB) subjects to undergo hyperinsulinemic-euglycemic clamp with human ghrelin infusion pre-operatively and post-operatively. | Drug: human ghrelin<br>* 0.5-1 pmol/kg.min of human ghrelin administered by IV two times<br>Procedure: Hyperinsulinemic/Euglycemic Clamp<br>* Insulin and glucose infusions to measure glucose kinetics.<br>|
| Experimental: VSG<br>Vertical sleeve gastrectomy (VSG) subjects to undergo hyperinsulinemic-euglycemic clamp pre-operatively and post-operatively. | Procedure: Hyperinsulinemic/Euglycemic Clamp<br>* Insulin and glucose infusions to measure glucose kinetics.<br>|
| Experimental: Low Calorie Diet<br>Subjects will receive very low calorie diet prescribed for RYGB patients and undergo hyperinsulinemic-euglycemic before and after diet. | Other: very low calorie diet<br>* standard very low calorie diet that is prescribed for all RYGB patients after their operation<br>Procedure: Hyperinsulinemic/Euglycemic Clamp<br>* Insulin and glucose infusions to measure glucose kinetics.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in glucose disposal rate | Glucose disposal rate is a sensitive laboratory procedure for determining how your body uses sugar (called insulin sensitivity). | baseline and 1 week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Bariatric surgery, Nashville, Tennessee