Diabetes and Gastric By- Pass

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the mechanisms leading to rapid postoperative improvement in diabetes following Gastric By-Pass surgery for obesity.We will evaluate and compare the changes in glucose level, beta-cell function, and insulin resistance induced by a week of very low calorie liquid diet and those induced by a week of matched very -low calorie liquid diet occuring in the context of routine postoperative care following RYGB.

Detailed Description
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Volunteers planned to undergo RYGB will be studied during two-9 days periods of identical and controlled diet and activity, separated by a 4-10-week washout period. Study Period #1: This first study period is 9 days/nights long and requires you to be closely supervised at our Clinical and Translational Research Center (CTRC). During this time you will receive the same diet and are expected to have the same activity level you will be prescribed in the immediate post-operative period. Wash-out period: During this study period you are expected to return to your usual diet and exercise level. Study Period #2: This last study period is also 9 days/nights long, includes the EXACT same diet you have received during the first study period, and in addition you will undergo the planned gastric by-pass surgery. Procedures during the research: Mixed Meal Challenge test will be done four times during the entire study: days 1 and 9 for each study period. This test allows the investigators to evaluate how much insulin your body is producing and how well this insulin is processed. Measurement of resting energy expenditure will be done four times during the entire study. This test tell us how much energy your body is burning up in a resting state.

Official Title
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Unraveling the Mechanisms of Rapid Improvement in Diabetes Following Gastric By-Pass Surgery

Conditions
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Type 2 Diabetes

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: volunteers that are planned to undergo RYGB(Roux-en-Y By pass) and have type 2 diabetes diagnosed within the prior 10 years. Exclusion Criteria: abnormal renal function significant anemia difficult venous access treatment with incretin mimetics or DPP IV inhibitors in the prior 3 months recent change in use of any pharmacologic agent with potential effect on either beta-cell function or insulin resistance. pregnancy non -English speakers

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Response in Glucose AUC at Baseline vs. Following Gastric Bypass Surgery | Changes in the glucose Area Under the Curve (AUC) calculated as the difference between the initial evaluation (test 1, assessed at day 1) and the next evaluation (test 2, assessed at day 9) of study period 1. Subjects then underwent gastric bypass surgery approximately 4-10 weeks later. In study period 2 following surgery, changes in the glucose AUC was again calculated as the difference between the initial evaluation (test 3, assessed at day 1 following surgery) and the next evaluation (test 4, assessed at day 9 following surgery). Change in AUC in study period 1 was compared to change in AUC in study period 2. Blood samples were collected at 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 150, 180, 210, 240, 300, and 360 minutes after the ingestion of 240 mL of chocolate Boost Plus Nestle. Total AUC was computed using the trapezoidal rule. | 4-12 weeks | 
| Response in Insulin AUC at Baseline vs Following Gastric Bypass Surgery | Changes in the Insulin Area Under the Curve (AUC) calculated as the difference between the initial evaluation (test 1, assessed at day 1) and the next evaluation (test 2, assessed at day 9) of study period 1. Subjects then underwent gastric bypass surgery approximately 4-10 weeks later. In study period 2 following surgery, changes in the insulin AUC was again calculated as the difference between the initial evaluation (test 3, assessed at day 1 following surgery) and the next evaluation (test 4, assessed at day 9 following surgery). Change in AUC in study period 1 was compared to change in AUC in study period 2. Blood samples were collected at 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 150, 180, 210, 240, 300, and 360 minutes after the ingestion of 240 mL of chocolate Boost Plus Nestle. Total AUC was computed using the trapezoidal rule. | 4-12 weeks | 
| Response in Glucagon AUC at Baseline vs. Following Gastric Bypass | Changes in the glucagon Area Under the Curve (AUC) calculated as the difference between the initial evaluation (test 1, assessed at day 1) and the next evaluation (test 2, assessed at day 9) of study period 1. Subjects then underwent gastric bypass surgery approximately 4-10 weeks later. In study period 2 following surgery, changes in the glucagon AUC was again calculated as the difference between the initial evaluation (test 3, assessed at day 1 following surgery) and the next evaluation (test 4, assessed at day 9 following surgery). Change in AUC in study period 1 was compared to change in AUC in study period 2. Blood samples were collected at 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 150, 180, 210, 240, 300, and 360 minutes after the ingestion of 240 mL of chocolate Boost Plus Nestle. Total AUC was computed using the trapezoidal rule. | 4-12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Type 2 diabetes, Bariatric surgery, Obesity, Weight loss