Autonomic Nervous System Function Following Bariatric Surgery

Study Overview
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Brief Summary
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In the proposed study, the investigators will explore three specific aims. First, the investigators will examine cross-sectionally the association of obesity on sympathetic, parasympathetic, and sympathetic/ parasympathetic nerve fiber balance. In addition, the investigators will determine the relationship of the ANS and osteocalcin. Osteocalcin will be measured before and after a mixed meal tolerance test. In the second specific aim, the investigators will prospectively follow-up these individuals (n=30) following bariatric surgery. The effect of weight loss on measures of the ANS and osteocalcin will be examined 6 months following surgery with participants serving as their own control, pre- and post-surgical intervention. Thirdly, the investigators will address whether the effect of weight loss on the ANS and osteocalcin differ between those who had a history of diabetes at baseline versus those with no history of diabetes.

Official Title
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Autonomic Nervous System Function and Novel Determinants of Glucose Homeostasis Following Bariatric Surgery

Conditions
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Bariatric Surgery

Intervention / Treatment
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* Other: Observational study - there is no intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Individuals aged 18 - 60 years old. Individuals with a BMI > 35 kg/m2. Patients that have enrolled in a program to undergo weight loss by Roux-en-Y gastric bypass and having passed the pre-operative clearance program. Individuals with diabetes who are currently being treated with diet, exercise, and/or oral medications will be included. Exclusion Criteria: Patients that have had previous gastric surgery, including but not limited to pancreobiliary diversion, vertical banded gastroplasty, and jejunoileostomy. Individuals with known coronary artery disease (e.g., post-MI), atrial fibrillation,frequent atrial arrhythmias, frequent ventricular arrhythmias, a pacemaker, or myocardial ischemia. Individuals taking the following medications that may affect the autonomic nervous system: anti- tuberculosis drugs, nitrofurantoin, metronidazole, chloramphenicol,perhexiline maleate, amiodarone, clofibrate, tricyclic antidepressants, phenytoin,methotrexate, barbiturates, neuroleptic drugs, antiparkinsonism drugs, fluoxetine, and nitrated drugs.

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

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No treatment<br>Observing individuals pre and post bariatric surgery | Other: Observational study - there is no intervention<br>* Observational study - there is no intervention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine the association of obesity on sympathetic, parasympathetic, and sympathetic/parasympathetic nerve fiber balance and to determine the relationship of the ANS and osteocalcin. |  | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine the effect of weight loss on measures of the ANS and determinants of insulin sensitivity (e.g., osteocalcin) 6 months following surgery with participants serving as their own control, pre- and post-surgical intervention. |  | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Autonomic nervous system, Bariatric surgery, Observational study for individuals having bariatric surgery