Bariatric Surgery for Morbid Obesity

Study Overview
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Brief Summary
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Despite progress in understanding the pathophysiology of obesity, current strategies for its medical management remain largely ineffective. Most efforts have focused on reducing caloric intake or increasing energy expenditure, either through behavior modification (e.g. dieting, regular exercise) alone, or augmented by pharmacologic efforts to decrease appetite, inhibit fat absorption, or alter metabolism. Bariatric surgery remains the only proven long term treatment of morbid obesity. Super morbidly obese (SMO: Body Mass Index (BMI) > 50) and super super morbidly obese (SSMO: BMI > 60) patients lose considerable weight, but stabilize at Body Mass Indexes (BMIs) that are still obese or even morbidly obese after risking considerable morbidity and/or mortality. Among commonly performed bariatric surgeries, a laparoscopic two-stage procedure, in which an initial restrictive procedure is followed after a weight loss of  100 lbs by a more complex procedure that creates malabsorption, is gaining interest. Initial studies have demonstrated very good long-term weight loss with minimal morbidity, and no operative mortality in these high risk patients. Availability of biospecimens obtained at each stage of this protocol will allow participating scientists a unique opportunity to test in human tissues hypotheses developed in animals. Studies proposed under this application focus on fatty acids and overall fat disposition in fat depots (adipose tissue) of your body, and the role of adipose tissue hormones and inflammatory processes in obesity and its associated health related issues.

Detailed Description
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Despite rapidly growing interest in the pathogenesis of the obesity epidemic, the pathophysiology of obesity remain poorly understood. While studies in animals have yielded many insights, it has become clear that human obesity differs in important ways from that in rodents. Bariatric surgery offers better outcomes, but in the highest grades of obesity (BMI>50) remains a high risk undertaking with >5% operative mortality being reported when commonly performed bariatric surgical approaches are employed. By contrast, laparoscopic two-stage approach has resulted in excellent weight loss, minimal morbidity, and <1% mortality. Availability of blood samples and biopsies of omental and subcutaneous fat from each of the paired bariatric procedures in this protocol will provide a unique opportunity to study key issues in human obesity. This study tests the broad hypothesis that there are significant and as yet unrecognized differences between the pathobiology of obesity in man and rodents, the identification of which may lead to new therapeutic targets. Accordingly, to facilitate comparisons with aspects of obesity we have already investigated in animal models, we will 1. seek fat depot specific differences in Long Chain Fatty Acid (LCFA) disposition, macrophage infiltration and adipokine production in obesity and after surgery-induced weight loss in man, and correlate them with the presence/severity of the metabolic syndrome (MetSyn); and 2., quantify the relative significance and response to weight loss of different mechanisms contributing to hepatic steatosis and the elevated triglycerides (TG) and reduced High-Density Lipoprotein (HDL) typical of obesity and MetSyn.

Official Title
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Bariatric Surgery for Morbid Obesity: Clinical and Pathophysiologic Consequences

Conditions
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Obesity, Morbid Obesity

Intervention / Treatment
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* Procedure: Initial Surgery
* Procedure: Second Bariatric Surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients 18 - 75 years of age Scheduled to have two stage bariatric surgery BMI > 50 Exclusion Criteria: Younger than 18 or older than 75 years of age Underlying cardiac disease or other medical condition that increases the risk of their surgical procedure Pregnancy Sufficiently diminished mental capacity so as to be unable to give informed consent.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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 |
| --- | --- |
| Non-Obese (NO)<br>Patients with a BMI < 29.9 scheduled for clinically indicated laparoscopic abdominal surgery. | Procedure: Initial Surgery<br>* NO patients had initial abdominal laparoscopic surgery at study entry, during which research fat biopsies were obtained, completing their participation. MO patients had initial laparoscopic bariatric surgery (gastric bypass, adjustable gastric band, or sleeve gastrectomy) and fat biopsies at entry, completing their participation. All 30 SMO patients had initial laparoscopic bariatric surgery (sleeve gastrectomy) & fat biopsies. The first 10 to lose 100 lbs but who needed further surgery to reach optimal weight and who consented to further surgery underwent a 2nd laparoscopic bariatric surgery (either a biliopancreatic diversion with duodenal switch or a Roux-en-Y gastric bypass) and biopsies. The interval between surgeries averaged 15 mos. and the weight loss 55 kg. 30 SMO patients were initially enrolled to insure that 10 would complete 2 surgeries. When 10 had had their 2nd operation, the study was considered complete, and the remaining 20 SMO participants were so notified.<br>* Other names: The first 10 SMO patients to meet defined requirements had a second Abdominal Laparoscopic Bariatric Surgery. Details below.;|
| Morbidly Obese (MO)<br>Patients with a BMI > 40.0 scheduled for clinically indicated laparoscopic abdominal surgery. | Procedure: Initial Surgery<br>* NO patients had initial abdominal laparoscopic surgery at study entry, during which research fat biopsies were obtained, completing their participation. MO patients had initial laparoscopic bariatric surgery (gastric bypass, adjustable gastric band, or sleeve gastrectomy) and fat biopsies at entry, completing their participation. All 30 SMO patients had initial laparoscopic bariatric surgery (sleeve gastrectomy) & fat biopsies. The first 10 to lose 100 lbs but who needed further surgery to reach optimal weight and who consented to further surgery underwent a 2nd laparoscopic bariatric surgery (either a biliopancreatic diversion with duodenal switch or a Roux-en-Y gastric bypass) and biopsies. The interval between surgeries averaged 15 mos. and the weight loss 55 kg. 30 SMO patients were initially enrolled to insure that 10 would complete 2 surgeries. When 10 had had their 2nd operation, the study was considered complete, and the remaining 20 SMO participants were so notified.<br>* Other names: The first 10 SMO patients to meet defined requirements had a second Abdominal Laparoscopic Bariatric Surgery. Details below.;|
| Super-morbidly Obese (SMO)<br>Patients with a BMI > 50.0 scheduled for clinically indicated laparoscopic abdominal surgery. 10 subjects of the original 30 subjects enrolled into this group received a second bariatric procedure. The remaining 20 subjects of the original 30 subjects did not continue on to the second phase (second bariatric surgery) of the study. | Procedure: Initial Surgery<br>* NO patients had initial abdominal laparoscopic surgery at study entry, during which research fat biopsies were obtained, completing their participation. MO patients had initial laparoscopic bariatric surgery (gastric bypass, adjustable gastric band, or sleeve gastrectomy) and fat biopsies at entry, completing their participation. All 30 SMO patients had initial laparoscopic bariatric surgery (sleeve gastrectomy) & fat biopsies. The first 10 to lose 100 lbs but who needed further surgery to reach optimal weight and who consented to further surgery underwent a 2nd laparoscopic bariatric surgery (either a biliopancreatic diversion with duodenal switch or a Roux-en-Y gastric bypass) and biopsies. The interval between surgeries averaged 15 mos. and the weight loss 55 kg. 30 SMO patients were initially enrolled to insure that 10 would complete 2 surgeries. When 10 had had their 2nd operation, the study was considered complete, and the remaining 20 SMO participants were so notified.<br>* Other names: The first 10 SMO patients to meet defined requirements had a second Abdominal Laparoscopic Bariatric Surgery. Details below.;Procedure: Second Bariatric Surgery<br>* A second bariatric procedure was performed on only 10 of the original 30 Super-morbidly Obese (SMO) subjects.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Size of Adipocytes | The mean diameters of omental adipocytes were measured | 4 years | 
| Maximum Reaction Velocity (Vmax) for Facilitated LCFA Uptake | The Vmax for facilitated Long Chain Fatty Acids (LCFA) uptake by omental adipocytes was measured. | 4 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum Reaction Velocity (Vmax) for Fatty Acid Uptake Relative to Adipocyte Cell Surface Area | Fatty acid uptake was expressed relative to adipocyte cell surface area [Vmax'(pmol/sec/µm^2) = Vmax/(cell surface area) X 10^8]. | 4 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, morbid obesity, bariatric surgery