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

Active, not recruiting

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

• Registration Number: NCT07035483
• Lead Sponsor: Shaihong Zhu

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2025-01-18
• Status Verified: 2025-06
• Study First Submitted: 2025-06-08
• Study First Submitted QC: 2025-06-15
• Last Update Submitted: 2025-06-15
• Study First Posted: 2025-06-25
• Last Update Posted: 2025-06-25
• Primary Completion: 2025-12-31
• Study Completion: 2029-12-31

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 120

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Change in Skeletal Muscle Fat Infiltration and Quality (measured by MRI)	Baseline, 3 months, 12 months, annually up to 5 years	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.
Change in Visceral and Subcutaneous Fat Volume (measured by MRI)	Baseline, 3 months, 12 months, annually up to 5 years	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.

Secondary Outcome Measures

Name	Time	Method
Change in HbA1c	Baseline, 3 months, 12 months, annually up to 5 years	HbA1c to evaluate metabolic improvement after surgery.
Change in triglycerides	Baseline, 3 months, 12 months, annually up to 5 years	Triglycerides to evaluate metabolic improvement after surgery.
Change in LDL-C	Baseline, 3 months, 12 months, annually up to 5 years	LDL-C to evaluate metabolic improvement after surgery.
Change in HDL-C	Baseline, 3 months, 12 months, annually up to 5 years	HDL-C to evaluate metabolic improvement after surgery.
Change in total cholesterol	Baseline, 3 months, 12 months, annually up to 5 years	total cholesterol to evaluate metabolic improvement after surgery.
Change in insulin resistance	Baseline, 3 months, 12 months, annually up to 5 years	HOMA-IR to evaluate metabolic improvement after surgery.
Change in body mass index	Baseline, 3 months, 12 months annually up to 5 years	Body mass index (BMI), calculated as weight in kilograms divided by height in meters squared (kg/m²), will be measured at baseline and follow-up visits to assess changes in overall adiposity after bariatric surgery. BMI will be used as a general anthropometric indicator of weight loss efficacy over time.
Change in waist circumference	Baseline, 3 months, 12 months annually up to 5 years	Waist circumference will be measured in centimeters using a standardized tape measure at the midpoint between the lowest rib and the iliac crest. This anthropometric indicator will be used to evaluate central (abdominal) fat reduction following bariatric surgery. Measurements will be taken at baseline and at follow-up time points to assess longitudinal changes.
Change in hip circumference	Baseline, 3 months, 12 months annually up to 5 years	Hip circumference will be measured in centimeters at the widest portion of the buttocks using a standardized measuring tape. This anthropometric measure will help assess changes in fat distribution following bariatric surgery. Measurements will be recorded at baseline and follow-up visits to monitor longitudinal changes in body composition.
Change in fasting glucose	Baseline, 3 months, 12 months, annually up to 5 years	Fasting glucose to evaluate metabolic improvement after surgery.

Trial Locations

Locations (1)

Xiangya Third Hospital, Central South University; 🇨🇳 Changsha, Hunan, China