Comparison of Body Composition Changes With Weight Loss Interventions

NCT07115069 | Recruiting DMC FDA Drug

• 2 other identifiers: 251035U16066
• Study Type: observational
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This study is being done to compare the effects of a newer class of weight loss medications to weight loss surgery on the body's muscle, metabolism, and side effects over time. People with severe obesity often lose weight using either medications like GLP-1 receptor agonists (such as semaglutide or tirzepatide) or by having bariatric surgery, such as gastric bypass. While both approaches can lead to weight loss, they may affect the body in different ways. The investigators are inviting adult patients who are planning to either start one of these weight loss medications or undergo gastric bypass surgery to join this study. Participants will be asked to complete four body composition scans (called DXA scans) over the course of a year-at the beginning of the study and again at 3, 6, and 12 months. These scans will help us measure changes in fat and muscle. Participants will also complete surveys and provide information on side effects, such as nausea or fatigue, that may affect their eating or activity levels. The investigators' goal is to better understand how different weight loss treatments impact not just weight, but also muscle mass, energy levels, and side effects. This information may help doctors and patients choose the most appropriate treatment in the future.

Conditions

Obesity

Keywords

obesity; GLP-1 receptor agonist; gastric bypass surgery; bariatric surgery; incretin; glucagon like peptide 1 receptor agonist; robotic surgery

Outcome Measures

Primary Outcomes (4)

• Skeletal Muscle Loss

  loss of skeletal muscle (reported as appendicular lean body mass (LBM) on DXA) as a percent total body mass loss from baseline to 6 months as determined by DXA

  6 months

• Skeletal Muscle Loss

  loss of skeletal muscle (reported as appendicular lean body mass (LBM) on DXA) as a percent total body mass loss from baseline to 12 months as determined by DXA

  12 months

• Patient Assessment of Upper Gastrointestinal Disorders Symptoms Questionnaire

  Median Patient Assessment of Upper Gastrointestinal Disorders Symptoms Questionnaire (PAGI-SYM score). Scores are on a 6 point Likert scale 0 (none/absent) to 5 (very severe) symptoms.

  6 months

• Patient Assessment of Upper Gastrointestinal Disorders Symptoms Questionnaire

  Median Patient Assessment of Upper Gastrointestinal Disorders Symptoms Questionnaire (PAGI-SYM score). Scores are on a 6 point Likert scale 0 (none/absent) to 5 (very severe) symptoms.

  12 months

Secondary Outcomes (6)

• Incidence of 10% weight loss

  6 months

• Incidence of 10% weight loss

  12 months

• Incidence of 15% weight loss

  6 months

• Incidence of 15% weight loss

  12 months

• Grip Strength

  3, 6, and 12 months

Study Arms (3)

GLP-1 Receptor Agonists Arm

Patient recieving Glucagon Like Peptide 1 Receptor Agonists (GLP1RA) or incretin polyagonists.

Drug: GLP-1 receptor agonist

Gastric Bypass surgery (laparoscopic)

Patients undergoing gastric bypass laparoscopically

Procedure: Gastric Bypass Surgery (laparoscopic)

Gastric Bypass surgery (robotic)

Patients undergoing Gastric Bypass surgery robotically

Procedure: Gastric Bypass Surgery (robotic)

Interventions

GLP-1 receptor agonist DRUG

Any FDA-approved GLP-1 receptor agonist

Also known as: semaglutide, tirzepatide

GLP-1 Receptor Agonists Arm

Gastric Bypass Surgery (laparoscopic) PROCEDURE

Patients undergo laparoscopic gastric bypass with a roux limb between 75 - 150 cm and biliopancreatic limb between 50 - 150 cm as determined by the primary surgeon.

Also known as: RNYGB

Gastric Bypass surgery (laparoscopic)

Gastric Bypass Surgery (robotic) PROCEDURE

Patients undergo robotic gastric bypass with a roux limb between 75 - 150 cm and biliopancreatic limb between 50 - 150 cm as determined by the primary surgeon.

Also known as: RNYGB

Gastric Bypass surgery (robotic)

Eligibility Criteria

• Age: 21 Years - 65 Years
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Participants seeking medical or surgical weight loss for class III obesity

You may qualify if:

• BMI ≥35 and ≤60
• Primary weight loss surgery (gastric bypass), or
• Medical weight loss with GLP1RAs (Semaglutide or Tirzepatide)

You may not qualify if:

• Revisional gastric bypass (e.g. sleeve to bypass),
• \<3 months of continuous use of GLP1RA,
• Type 1 Diabetes,
• Myocardial Infarction,
• Unstable Angina or Heart Failure,
• Stroke
• Solid organ transplantation,
• Systemic glucocorticoid prior 28 days,
• Uncontrolled Hypertension, (Systolic \> 150, Diastolic \> 90)
• Untreated Hyperthyroidism
• Chronic Kidney Disease (EGFR \< 60).

Sponsors & Collaborators

• Vanderbilt University Medical Center: lead

Study Sites (1)

Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States

RECRUITING

MeSH Terms

Conditions

Obesity

Interventions

semaglutide; Tirzepatide; Laparoscopy; Robotics

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptide Receptors; Receptors, G-Protein-Coupled; Receptors, Cell Surface; Membrane Proteins; Proteins; Amino Acids, Peptides, and Proteins; Receptors, Gastrointestinal Hormone; Receptors, Peptide; Endoscopy; Diagnostic Techniques, Surgical; Diagnostic Techniques and Procedures; Diagnosis; Minimally Invasive Surgical Procedures; Surgical Procedures, Operative; Automation; Technology; Technology, Industry, and Agriculture

Study Officials

• Jason M Samuels, MD

  Vanderbilt University Medical Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Jason M Samuels, MD

CONTACT

2142891373; jason.m.samuels@vumc.org

Jason Samuels

CONTACT

2142891373; jason.m.samuels@vumc.org

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: July 25, 2025
• First Posted: August 11, 2025
• Study Start: August 9, 2025
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): January 1, 2027
• Last Updated: October 21, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE
• Time Frame: At least 5 years after study end

Locations

US (1)