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Bariatric Surgery for Morbid Obesity

Bariatric Surgery for Morbid Obesity: Clinical and Pathophysiologic Consequences

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT00675558
Enrollment
50
Registered
2008-05-09
Start date
2006-11-30
Completion date
2012-03-31
Last updated
2013-07-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obesity, Morbid Obesity

Keywords

Obesity, morbid obesity, bariatric surgery

Brief summary

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

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.

Interventions

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.

PROCEDURESecond Bariatric Surgery

A second bariatric procedure was performed on only 10 of the original 30 Super-morbidly Obese (SMO) subjects.

Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
CollaboratorNIH
Columbia University
Lead SponsorOTHER

Study design

Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Size of Adipocytes4 yearsThe mean diameters of omental adipocytes were measured
Maximum Reaction Velocity (Vmax) for Facilitated LCFA Uptake4 yearsThe Vmax for facilitated Long Chain Fatty Acids (LCFA) uptake by omental adipocytes was measured.

Secondary

MeasureTime frameDescription
Maximum Reaction Velocity (Vmax) for Fatty Acid Uptake Relative to Adipocyte Cell Surface Area4 yearsFatty acid uptake was expressed relative to adipocyte cell surface area \[Vmax'(pmol/sec/µm\^2) = Vmax/(cell surface area) X 10\^8\].

Countries

United States

Participant flow

Recruitment details

Patients referred to several Divisions of the Department of Surgery at New York Presbyterian Hospital.

Participants by arm

ArmCount
Non-Obese (NO)
Non obese patients. Patients with a BMI \< 29.9 scheduled for clinically indicated laparoscopic abdominal surgery.
10
Morbidly Obese (MO)
Patients with a BMI \> 40.0 scheduled for clinically indicated laparoscopic abdominal surgery.
10
Super-morbidly Obese (SMO)
Patients with a BMI \> 50.0 scheduled for clinically indicated laparoscopic abdominal surgery.
30
Total50

Baseline characteristics

CharacteristicNon-Obese (NO)Morbidly Obese (MO)Super-morbidly Obese (SMO)Total
Age, Categorical
<=18 years
0 Participants
0
0 Participants
0
0 Participants
0
0 Participants
0
Age, Categorical
>=65 years
0 Participants
0
0 Participants
0
0 Participants
0
0 Participants
0
Age, Categorical
Between 18 and 65 years
10 Participants
0
10 Participants
0
30 Participants
0
50 Participants
0
Sex: Female, Male
Female
5 Participants5 Participants16 Participants26 Participants
Sex: Female, Male
Male
5 Participants5 Participants14 Participants24 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
— / —— / —— / —
other
Total, other adverse events
0 / 00 / 00 / 0
serious
Total, serious adverse events
0 / 00 / 00 / 0

Outcome results

Primary

Maximum Reaction Velocity (Vmax) for Facilitated LCFA Uptake

The Vmax for facilitated Long Chain Fatty Acids (LCFA) uptake by omental adipocytes was measured.

Time frame: 4 years

ArmMeasureValue (MEAN)Dispersion
Non-Obese (NO)Maximum Reaction Velocity (Vmax) for Facilitated LCFA Uptake8.3 pmol/secStandard Deviation 1.8
Morbidly Obese (MO)Maximum Reaction Velocity (Vmax) for Facilitated LCFA Uptake20.9 pmol/secStandard Deviation 4.1
Super-morbidly Obese (SMO)Maximum Reaction Velocity (Vmax) for Facilitated LCFA Uptake68.7 pmol/secStandard Deviation 9.45
Primary

Size of Adipocytes

The mean diameters of omental adipocytes were measured

Time frame: 4 years

ArmMeasureValue (MEAN)Dispersion
Non-Obese (NO)Size of Adipocytes73.4 µmStandard Deviation 16.1
Morbidly Obese (MO)Size of Adipocytes99.0 µmStandard Deviation 24
Super-morbidly Obese (SMO)Size of Adipocytes103.0 µmStandard Deviation 14.2
Secondary

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 \[Vmax'(pmol/sec/µm\^2) = Vmax/(cell surface area) X 10\^8\].

Time frame: 4 years

ArmMeasureValue (MEAN)Dispersion
Non-Obese (NO)Maximum Reaction Velocity (Vmax) for Fatty Acid Uptake Relative to Adipocyte Cell Surface Area0.88 pmol/sec/μm^2Standard Deviation 0.39
Morbidly Obese (MO)Maximum Reaction Velocity (Vmax) for Fatty Acid Uptake Relative to Adipocyte Cell Surface Area1.24 pmol/sec/μm^2Standard Deviation 0.36
Super-morbidly Obese (SMO)Maximum Reaction Velocity (Vmax) for Fatty Acid Uptake Relative to Adipocyte Cell Surface Area3.21 pmol/sec/μm^2Standard Deviation 1.89

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026