Changes in Body Composition Following Bariatric Surgery

November 19, 2018 updated by: Peter Nau

Roux-en-y Gastric Bypass Versus Sleeve Gastrectomy - Analysis of the Disparate Effects on Body Composition and Associated Comorbidity Resolution

Obesity is an important public health issue worldwide. In the United States, the percentage of overweight and obese adults increased from 47 and 15%, respectively, to 69 and 36% in the last 40 years. Medically supervised attempts at weight loss are fraught with failures and recidivism. Surgical approaches to this important issue are both durable and effective. The gold standard approach to the surgical treatment of obesity and the attendant medical comorbidities is the laparoscopic roux-en-y gastric bypass (RYGB) and the laparoscopic sleeve gastrectomy (LSG). The mechanisms by which these two operations work and the associated side effects are not completely understood. It is established that the RYGB induces changes in both the fatty tissue mass (FTM) and lean body mass (LBM) post-operatively. This is associated with decreases in bone mineral density, basal metabolic rate, and potentially the ability to maintain weight loss. There is only incomplete information on the influence that the LSG has on body composition. This study proposes an evaluation of the changes in body composition that occurs following these two disparate operations. Using serial measurements by the BodPod and collecting information on the patients' dietary intake, exercise habits and comorbidity resolution, this study will help to better define the influence that the LSG has on body composition. It is hypothesized that the addition of a malabsorptive component will result in increased speed weight loss and overall weight loss which will have a negative impact in the preservation of lean tissue mass for the patient. This information can then be used by bariatric surgeons to better cater the surgical procedure and post-operative plan to the patient's body make up and medical comorbidities.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Procedures

  • All patients will undergo a bariatric surgery. The decision to undergo weight loss surgery and the operation chosen will both occur independent of and prior to enrollment in the study. The University of Iowa is a Bariatric Center of Excellence with three active, board-certified bariatric surgeons.
  • Serial BodPod examinations will be performed on each patient. The BodPod is a commercially available device produced by Cosmed. It uses whole-body densitometry to determine body composition. To do this, it takes small changes in the volume of air in the BodPod chamber and records the associated changes in pressure. The pressure change typically goes unnoticed and is equivalent to the change in pressure while moving from the first floor to the second floor in an elevator. The entire process takes approximately five minutes with two minutes spent within the machine. The computer will then use mathematical formulas to calculate various body composition values.
  • Laboratory analysis - There is a battery of labs that are ordered in both the pre-operative and post-operative time frame. These labs are ordered independent of the patient's participation in the study. These labs are ordered to assist in the management of the patient's medical comorbidities and to assess for adequate nutritional intake. These labs will also be recorded in the research database to assist in quantifying the degree of resolution of medical comorbidities.
  • Queries on nutritional intake and exercise will be made at each post-operative appointment. The intake of protein is an important variable and may influence maintenance of lean tissue mass. Exercise is an important component of the post-bariatric weight loss program. This also will influence the changes in lean tissue mass.

Study Type

Observational

Enrollment (Actual)

136

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Iowa
      • Iowa City, Iowa, United States, 52242
        • University of Iowa Hospitals and Clinics

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The population consists of individuals who meet the NIH consensus statement for the surgical treatment of obesity. These individuals will have a BMI greater than 35 kg/m2 and a medical comorbidity or 40 kg/m2. These subjects will have voluntarily initiated a consultation for bariatric surgery and completed the pre-bariatric surgery weight management program. After failing this program, the patients will undergo surgical consultation for bariatric surgery. It is only after this consultation that the subjects will be approached for enrollement in the study.

Description

Inclusion Criteria:

  • Individuals will have a BMI greater than 35 kg/m2 and a medical comorbidity or 40 kg/m2
  • Individuals must have voluntarily initiated a surgical consultation for weight loss surgery
  • Individuals must have completed a medical supervised weight loss program

Exclusion Criteria:

  • Failure to adequately complete the pre-screening and educational program necessary to proceed with bariatric surgery
  • Those who are or become pregnant
  • Individuals with severe claustrophobia.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Bariatric Surgery - Gastric Bypass
This population will undergo a laparoscopic roux-en-y gastric bypass
Patients enrolled will undergo either a laparoscopic Roux-en-y Gastric Bypass or laparoscopic Sleeve Gastrectomy. The determination of which operation performed will be made independent of patients' enrollment in the study.
Bariatric Surgery - Sleeve Gastrectomy
This group will undergo a laparoscopic sleeve gastrectomy
Patients enrolled will undergo either a laparoscopic Roux-en-y Gastric Bypass or laparoscopic Sleeve Gastrectomy. The determination of which operation performed will be made independent of patients' enrollment in the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Body Composition
Time Frame: Pre-op, 6 months and 12 months post-op
Using the BodPod machine produced by Cosmed, changes in lean tissue mass and fatty tissue mass following either the laparoscopic roux-en-y gastric bypass or the laparoscopic sleeve gastrectomy will be assessed.
Pre-op, 6 months and 12 months post-op

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Comorbidity resolution
Time Frame: pre-op, 6 months post-op, 12 months post-op
Assess for correlations between the changes in body composition and the resolution of medical comorbidities when comparing the LSG and RYGB. This will be done using changes in medication regimen and changes in physical findings and laboratory values such as blood pressure and HbA1c.
pre-op, 6 months post-op, 12 months post-op
Protein intake and lean tissue mass
Time Frame: Pre-op, 6 months post-op, 12 months post-op
Assess for correlation between the preservation of lean tissue mass and daily protein intake and whether the type of operation (roux-en-y gastric bypass and sleeve gastrectomy) plays a role.
Pre-op, 6 months post-op, 12 months post-op
Exercise and lean tissue mass preservation
Time Frame: Pre-op, 6 months post-op, 12 months post-op
Test for a correlation between the changes in body composition and the amount of physical activity the patient takes part in and whether this is influenced by the type of procedure the patient had (roux-en-y gastric bypass versus sleeve gastrectomy).
Pre-op, 6 months post-op, 12 months post-op

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Peter N Nau, MD, MS, University of Iowa

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

May 1, 2014

Primary Completion (Actual)

October 1, 2018

Study Completion (Actual)

October 1, 2018

Study Registration Dates

First Submitted

May 22, 2014

First Submitted That Met QC Criteria

May 22, 2014

First Posted (Estimate)

May 28, 2014

Study Record Updates

Last Update Posted (Actual)

November 20, 2018

Last Update Submitted That Met QC Criteria

November 19, 2018

Last Verified

November 1, 2018

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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