Endocrinological and Neuronal Aspects of Bariatric Surgery

Study Overview
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Brief Summary
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The overall aim of the proposed project is to investigate the contribution of changes in neuronal food processing, hypothalamic reactivity and hormonal factors to weight loss after bariatric surgery.

Official Title
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Changes in Endocrinological and Central Neuronal Satiety Regulation Following Bariatric Surgery

Conditions
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Bariatric Surgery, Obesity

Intervention / Treatment
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* Procedure: bariatric surgery
* Dietary Supplement: conservative diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: planning to undergo bariatric surgery planning to take part in a conservative diet Exclusion Criteria: inability to undergo fMRI psychiatric disorders metabolic disorders

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| bariatric surgery participants<br>participants with obesity planning to undergo bariatric surgery | Procedure: bariatric surgery<br>* bariatric surgery<br>|
| conservative diet participants<br>participants with obesity planning to controlled conservative behavioral weight loss program | Dietary Supplement: conservative diet<br>* conservative diet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Functional magnetic resonance imaging following intravenous glucose infusion. | Change in responsivity of the hypothalamus (extracted as percent signal change) as the core region of homeostatic control will be assessed after an intravenous glucose infusion (by calculating the area under the curve of hypothalamic responsivity) before and after bariatric surgery or dietary intervention. | 2 weeks before surgery or start of dietary intervention and 2 weeks after surgery or start of dietary intervention. | 
| Experimental functional magnetic resonance imaging task (gustatory stimulation). | Neuronal gustatory processing of food stimuli will be assessed (ingestion of sweet liquids using a gustometer) using a general linear model (comparing brain activation during ingestion of sweet liquids with brain activation during the ingestion of water) and within as well as between groups analyses. Changes in neural gustatory processing of food stimuli will be assessed before and after bariatric surgery or dietary intervention. | 2 weeks before surgery or start of dietary intervention and 2 weeks after surgery or start of dietary intervention. | 
| Assessment of glucose-induced changes in peripheral ghrelin using blood samples. | Blood is collected to measure the concentration of peripheral ghrelin as an indicator of hormonal satiety signaling. Blood samples are collected at the beginning and end of each experimental session to assess the influence of intravenuous infusion of glucose on ghrelin signaling. Blood samples will be analysed using using commercially available kits (enzyme-linked immunosorbent assay). | 15 minutes before and 15 minutes after functional magnetic resonance imaging | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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fMRI, hormonal satiety signaling, hypothalamus, weight loss