The Impact of Bariatric Surgery on Adipocyte Metabolism

Study Overview
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Brief Summary
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The purpose of this study is to understand how daily rhythms of behavior affect the expression of genes in fat cells, and how these daily cycles affect the way fat cells respond to insulin (a hormone that controls blood sugar levels) before and after bariatric surgery.

Detailed Description
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Bariatric surgery as a means of weight loss has become increasingly popular over the last 10-15 years. In addition to promoting weight loss, bariatric surgery has become increasingly recognized for use in the management of diabetes. Recent studies have indicated that bariatric surgery can result in a marked improvement in insulin sensitivity before long term weight loss is attained. The goal of this project is to delineate the changes in the insulin responsiveness of subcutaneous adipocytes obtained by needle biopsy 2 weeks prior to surgery vs. 12 weeks after bariatric surgery, which could account for improvements in overall insulin sensitivity seen before any long-term sustained weight loss has occurred. The investigators will also examine gene expression in adipocytes (fat cells).

Official Title
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The Impact of Bariatric Surgery on Adipocyte Metabolism

Conditions
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Metabolic Syndrome, Obesity

Intervention / Treatment
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* Behavioral: Circadian Clock Alignment
* Behavioral: Circadian Clock Control


Participation Criteria
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Eligibility Criteria
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Obese Subjects Inclusion Criteria: 18-55 years old Female BMI greater than 40 kg/m2 Scheduled for bariatric surgery at the Center for the Surgical Treatment of Obesity at the University of Chicago Signed informed consent Exclusion Criteria: Male Diagnosed with a systemic illnesses, including heart, renal, liver, or malignant disease Uncontrolled hypertension (blood pressure greater than 140 mmHg systolic and 90 mmHg diastolic without medication) use of beta blockers hemoglobin less than 11.5g/dL known allergy to lidocaine pregnancy lactation Subjects will not have undergone surgery, donated a unit of blood, or participated in another clinical study within the last 4 weeks prior to consent. Post-menopausal Non-Obese Subjects Inclusion Criteria: 18-55 years old Female BMI less than 30 kg/m2 Signed informed consent Exclusion Criteria: Male Diagnosed with a systemic illnesses, including heart, renal, liver, or malignant disease Uncontrolled hypertension (blood pressure greater than 140 mmHg systolic and 90 mmHg diastolic without medication) use of beta blockers hemoglobin less than 11.5g/dL known allergy to lidocaine pregnancy lactation Subjects will not have undergone surgery, donated a unit of blood, or participated in another clinical study within the last 4 weeks prior to consent. Post-menopausal

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Circadian Clock Alignment - High BMI<br>Subjects will come to the Sleep Lab three nights before their bariatric surgery procedure for an intervention that will align their central circadian clock. The intervention includes eating meals and snacks at fixed times and having lights off at a specific time at night and lights on at a specific time in the morning. | Behavioral: Circadian Clock Alignment<br>* Use timed lights and meals to align the circadian clock<br>|
| Active Comparator: Circadian Clock Control - High BMI<br>Subjects will not come to the Sleep Lab and will live normally at home with no changes to their meal, sleep or wake times. | Behavioral: Circadian Clock Control<br>* No circadian clock alignment<br>|
| Active Comparator: Circadian Clock Control - Low BMI<br>Subjects will not come to the Sleep Lab and will live normally at home with no changes to their meal, sleep or wake times. | Behavioral: Circadian Clock Control<br>* No circadian clock alignment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in insulin sensitivity | Insulin sensitivity will be measured as the by the phosphorylation level of Akt in adipocytes (fat cells) at baseline and 12 weeks post bariatric surgery | 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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insulin, adipocyte, gene expression