Muscle Ultrasound for Sarcopenia Assessment in Kidney Transplant Recipients (KT-SARC)

A Prospective Observational Study of Multimodal Muscle Ultrasound for Sarcopenia Assessment in Kidney Transplant Recipients

This is a single-center prospective observational study designed to evaluate the effectiveness of multimodal muscle ultrasound for the assessment of sarcopenia in kidney transplant recipients. Adult patients undergoing kidney transplantation will undergo both muscle ultrasound and bioelectrical impedance analysis (BIA) at predefined time points before and after transplantation.

The primary objective is to evaluate the diagnostic performance of muscle ultrasound for sarcopenia assessment, including its correlation and agreement with BIA-derived skeletal muscle index (BIA-SMI), as well as its diagnostic accuracy. Secondary objectives include describing the longitudinal changes in sarcopenia prevalence and muscle-related parameters from the pre-transplant period to 1 year after transplantation.

The study aims to provide evidence for a convenient, noninvasive, radiation-free, and reliable method for sarcopenia assessment in kidney transplant recipients.

Study Overview

• Status: Not yet recruiting
• Conditions: Sarcopenia; Kidney Transplantation; Muscle Wasting
• Intervention / Treatment: Diagnostic test: Muscle Ultrasound

Detailed Description

Sarcopenia is highly prevalent among patients with end-stage renal disease and is associated with poor clinical outcomes. Although kidney transplantation may improve overall health status, perioperative stress, immunosuppressive therapy, and postoperative metabolic changes may influence muscle mass and function. Reliable assessment of sarcopenia in kidney transplant recipients remains clinically important.

Current methods for sarcopenia assessment include computed tomography (CT), dual-energy X-ray absorptiometry (DXA), and bioelectrical impedance analysis (BIA). However, CT and DXA are limited by radiation exposure, cost, and accessibility, while BIA may be affected by changes in hydration status, especially in transplant recipients. Muscle ultrasound is a portable, radiation-free, and bedside-available imaging modality that may provide a practical alternative for muscle assessment.

This prospective observational study will enroll adult kidney transplant recipients at Sichuan Provincial People's Hospital. Participants will undergo multimodal muscle ultrasound and BIA examinations at predefined perioperative time points. Ultrasound parameters will include muscle thickness, cross-sectional area, and echogenicity.

The primary study objective is to evaluate the diagnostic performance of muscle ultrasound for sarcopenia assessment using BIA-derived skeletal muscle index (BIA-SMI) as the reference standard. Correlation analysis, intraclass correlation coefficients, Bland-Altman analysis, and receiver operating characteristic (ROC) curve analysis will be performed to evaluate agreement and diagnostic accuracy.

Secondary objectives include evaluating longitudinal changes in muscle-related parameters and sarcopenia prevalence from the pre-transplant period to 1 year after kidney transplantation. Linear mixed-effects models or generalized estimating equations will be used to analyze temporal trends.

This study aims to establish muscle ultrasound as a practical and reliable tool for sarcopenia assessment in kidney transplant recipients and to improve understanding of perioperative muscle changes after transplantation.

• Study Type: Observational
• Enrollment (Estimated): 140

Contacts and Locations

• Study Contact: Name: Yifu Hou, MD, PhD; Phone Number: +86-18980732072; Email: houyifu0726@foxmail.com

Study Locations

• China
  • Sichuan
    • Chengdu, Sichuan, China, 610072
      • Sichuan Provincial People's Hospital
      • Contact: Yifu Hou, MD, PhD; Phone Number: +86-18980732072; Email: houyifu0726@foxmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult kidney transplant recipients undergoing perioperative sarcopenia assessment at Sichuan Provincial People's Hospital.

Description

Inclusion Criteria:

• Adult patients aged 18 years or older
• Patients scheduled to undergo kidney transplantation
• Ability to undergo muscle ultrasound and bioelectrical impedance analysis (BIA)
• Ability to provide written informed consent

Exclusion Criteria:

• Patients with severe limb deformity or conditions preventing muscle ultrasound assessment
• Patients with implanted electronic devices contraindicating BIA assessment
• Inability to complete study assessments

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Kidney Transplant Recipients; Adult kidney transplant recipients undergoing prospective assessment of sarcopenia using multimodal muscle ultrasound and bioelectrical impedance analysis (BIA).	Diagnostic test: Muscle Ultrasound; Multimodal muscle ultrasound assessment performed for evaluation of sarcopenia in kidney transplant recipients.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area under the receiver operating characteristic (ROC) curve of muscle ultrasound for detecting sarcopenia using BIA-derived skeletal muscle index (BIA-SMI) as the reference standard.	Diagnostic performance of multimodal muscle ultrasound for sarcopenia assessment using BIA-derived skeletal muscle index (BIA-SMI) as the reference standard, including receiver operating characteristic (ROC) curve analysis and area under the curve (AUC).	From baseline to 1 year after kidney transplantation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Muscle Thickness Measured by Ultrasound	Longitudinal changes in muscle thickness measured by ultrasound from baseline to 1 year after kidney transplantation.	From baseline to 1 year after kidney transplantation
Change in Muscle Cross-Sectional Area Measured by Ultrasound	Longitudinal changes in muscle cross-sectional area measured by ultrasound from baseline to 1 year after kidney transplantation.	From baseline to 1 year after kidney transplantation
Change in Muscle Echogenicity Measured by Ultrasound	Longitudinal changes in muscle echogenicity measured by ultrasound from baseline to 1 year after kidney transplantation.	From baseline to 1 year after kidney transplantation

Collaborators and Investigators

• Sponsor: Sichuan Provincial People's Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): May 30, 2026
• Primary Completion (Estimated): August 30, 2027
• Study Completion (Estimated): January 30, 2028

Study Registration Dates

• First Submitted: May 11, 2026
• First Submitted That Met QC Criteria: May 19, 2026
• First Posted (Actual): May 26, 2026

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 19, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Frailty; Muscle Mass; Bioelectrical Impedance Analysis; Kidney Transplant Recipient; Prospective Cohort; Muscle Ultrasound; BIA-SMI
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Pathologic Processes; Pathological Conditions, Anatomical; Atrophy; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Frailty; Sarcopenia; Muscular Atrophy
• Other Study ID Numbers: 2026-304

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be publicly available due to institutional policy and participant privacy considerations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No