Changes in Fat and Muscle Tissue Function and Their Impact on Metabolic Health After Bariatric Surgery

NCT07035483 | Active Not Recruiting

• 1 other identifier: 2024552
• Study Type: observational
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective, single-center observational cohort study aims to explore the relationship between skeletal muscle quality, fat distribution, and metabolic health in Chinese patients with obesity, and to evaluate how bariatric surgery influences these parameters. A total of 120 participants will be enrolled, including 60 patients undergoing bariatric surgery and 60 age- and sex-matched healthy controls. The study involves cross-sectional comparisons of ectopic fat and muscle composition, as well as longitudinal follow-up of surgical patients at multiple time points up to 5 years postoperatively. MRI will be used to quantify regional fat and muscle composition, while metabolic parameters, inflammatory markers, and gut microbiota profiles will also be assessed. Primary outcomes include skeletal muscle mass and fat infiltration, visceral and subcutaneous fat volumes, and changes in insulin resistance. This study seeks to clarify the mechanisms by which bariatric surgery improves metabolic function and to identify early changes in muscle-fat composition that may predict long-term metabolic outcomes.

Conditions

Obesity and Obesity-related Medical Conditions; Sarcopenic Obesity; Adipose Tissue, Abdominal

Keywords

Obesity; Ectopic Fat Deposition; Sarcopenic Obesity; Bariatric Surgery; Metabolic Syndrome

Outcome Measures

Primary Outcomes (2)

• Change in Skeletal Muscle Fat Infiltration and Quality (measured by MRI)

  Quantitative evaluation of intramuscular fat content using MRI-derived proton density fat fraction (PDFF) and muscle attenuation indices in the thigh and paraspinal muscles. Muscle quality will be assessed by MRI signal intensity and texture features to detect early changes in muscle composition post-surgery.

  Baseline, 3 months, 12 months, annually up to 5 years

• Change in Visceral and Subcutaneous Fat Volume (measured by MRI)

  MRI-based measurement of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), liver fat percentage (LFP), and pancreatic fat percentage (PFP) to track region-specific fat redistribution after bariatric surgery.

  Baseline, 3 months, 12 months, annually up to 5 years

Secondary Outcomes (10)

• Change in fasting glucose

  Baseline, 3 months, 12 months, annually up to 5 years

• Change in HbA1c

  Baseline, 3 months, 12 months, annually up to 5 years

• Change in triglycerides

  Baseline, 3 months, 12 months, annually up to 5 years

• Change in LDL-C

  Baseline, 3 months, 12 months, annually up to 5 years

• Change in HDL-C

  Baseline, 3 months, 12 months, annually up to 5 years

Interventions

bariatric surgery PROCEDURE

This is a prospective observational study evaluating the metabolic and tissue-level effects of bariatric surgery in obese individuals. The intervention includes either laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (RYGB), performed according to standard clinical guidelines. No experimental procedures are added beyond routine care. Skeletal muscle quality and visceral fat distribution are assessed using MRI and clinical biomarkers at multiple postoperative time points (baseline, 3 months, 12 months, and annually up to 5 years). A healthy control group undergoes baseline evaluation only, without surgical intervention.

Eligibility Criteria

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

Study Population

This study will enroll adult participants aged 18 to 65 years, including two groups: (1) obese patients undergoing bariatric surgery (either sleeve gastrectomy or Roux-en-Y gastric bypass), and (2) healthy individuals with normal BMI (18.0-24.0 kg/m²) and no metabolic comorbidities. The surgical group consists of patients eligible for metabolic surgery based on national clinical guidelines. The healthy control group is matched by age and sex and will undergo only baseline assessments. All participants must be able to provide informed consent and comply with study procedures. The study population is recruited from Xiangya Third Hospital, Central South University.

You may qualify if:

• Aged 18 to 65 years (inclusive)
• Meets clinical criteria for sleeve gastrectomy or Roux-en-Y gastric bypass surgery
• Willing and able to comply with study procedures and follow-up visits Capable of understanding and signing the informed consent form
• Aged 18 to 65 years (inclusive)
• Body mass index (BMI) between 18.0 and 24.0 kg/m²
• No history of metabolic disorders (e.g., hypertension, type 2 diabetes, fatty liver disease, or dyslipidemia)
• No history of gastrointestinal surgery
• Able to undergo MRI and willing to provide baseline clinical data and biological samples
• Able to understand and sign informed consent

You may not qualify if:

• Type 1 diabetes mellitus or latent autoimmune diabetes in adults (LADA)
• History of pancreatitis, gastrointestinal or pancreatic surgery
• Severe complications of type 2 diabetes or major organ dysfunction that may affect surgical safety
• Active alcohol or drug dependence, severe psychiatric illness, cognitive impairment, or suicidal ideation
• Pregnant or breastfeeding women, or women planning pregnancy during the follow-up period
• Contraindications to MRI examination, including:
• Cardiac pacemaker Artificial heart valves Ferromagnetic vascular clips Metallic foreign bodies in the eye
• ∙Considered unsuitable for the study by investigators based on risk-benefit assessment

Sponsors & Collaborators

• Shaihong Zhu: lead

Study Sites (1)

Xiangya Third Hospital, Central South University

Changsha, Hunan, 410013, China

Location

MeSH Terms

Conditions

Obesity; Metabolic Syndrome

Interventions

Bariatric Surgery

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Insulin Resistance; Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases

Intervention Hierarchy (Ancestors)

Bariatrics; Obesity Management; Therapeutics; Surgical Procedures, Operative

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Chief of Metabolic and Bariatric Surgery, Xiangya Third Hospital, Central South University

Study Record Dates

• First Submitted: June 8, 2025
• First Posted: June 25, 2025
• Study Start: January 18, 2025
• Primary Completion: December 31, 2025
• Study Completion (Estimated): December 31, 2029
• Last Updated: June 25, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: Beginning 6 months after publication of primary results; available for up to 3 years.
• Access Criteria: Requests must be accompanied by a research proposal and data use agreement. Access will be granted to researchers whose proposed use of the data has been approved by the study team.

Locations

CN (1)