Muscle Endurance in Children With Cystic Fibrosis

January 5, 2026 updated by: Betül Çınar, Bezmialem Vakif University

Do Children With Cystic Fibrosis Differ in Muscle Endurance? A Comparative Study

Cystic fibrosis (CF) is a genetic disorder affecting exocrine glands, leading to thick, viscous secretions that damage organs such as the lungs, pancreas, and reproductive system. Respiratory failure from CF lung disease is a major cause of morbidity and mortality, with chronic inflammation and infections disrupting mucociliary clearance. This results in declining respiratory functions, muscle strength, physical inactivity, and quality of life. While some studies compare respiratory and lower extremity muscle endurance in children with CF, none have evaluated core muscle endurance. This study aims to compare respiratory muscle strength, endurance, and muscle endurance in the core and lower extremities between children with CF and healthy peers.

Study Overview

Detailed Description

Cystic fibrosis (CF) is an autosomal recessive genetic disease characterized by the involvement of exocrine glands, resulting from a disorder in the synthesis or function of the Cystic Fibrosis Transmembrane Regulator (CFTR) protein. The CFTR protein is responsible for ion and water transport in the cell epithelium. Dysfunction of this protein causes the secretion produced to be deficient in water. Viscous secretion, which is difficult to remove from its environment, causes permanent damage to many organs and systems such as the lungs, pancreas, hepatobiliary system and reproductive system. Respiratory failure due to CF lung disease is the most important cause of morbidity and mortality. The basic mechanism in the pathophysiology of CF lung disease is chronic inflammation and recurrent infections that occur as a result of the disruption of mucociliary clearance by sticky secretions. This vicious cycle causes obstruction in the airways and leads to progressive losses in respiratory functions. The decrease in respiratory functions; loss of muscle strength, reduced functional capacity, physical inactivity and reduced quality of life. There are limited studies in the literature comparing the respiratory muscle strength, respiratory muscle endurance and lower extremity muscle endurance of children with CF with their healthy peers. However, there is no study evaluating the core muscle endurance of children with CF. This study aims to compare the respiratory muscle strength, respiratory muscle endurance, core muscle endurance and lower extremity muscle endurance in children with CF and their healthy peers.

Study Type

Observational

Enrollment (Actual)

48

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

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

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Children diagnosed with cystic fibrosis and age matched healthy volunteers who do not have any diagnosed chronic diseases

Description

Inclusion Criteria for Children with Cystic Fibrosis

  • Being between the ages of 6-18,
  • Being diagnosed with Cystic Fibrosis according to the American Cystic Fibrosis Association consensus guideline,
  • Having a forced expiratory volume in one second (FEV1) above 40% of the predicted value

Exclusion Criteria for Children with Cystic Fibrosis

  • Not being able to cooperate with the assessment methods performed in the study
  • Having an orthopedic, neurological, vestibular, etc. problem that may negatively affect the assessment methods performed in the study
  • Having a history of exacerbation in the last month
  • Having an organ transplantation history
  • Using systemic corticosteroids

Inclusion Criteria for Healthy Children

- Being between the ages of 6-18

Exclusion Criteria for Healthy Children

  • Not being able to cooperate with the assessment methods performed in the study
  • Having an orthopedic, neurological, vestibular, etc. problem that may negatively affect the assessment methods performed in the study
  • Having had a respiratory tract infection in the last month

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
Children with cystic fibrosis
Children diagnosed cystic fibrosis
Endurance of the flexor, extensor and lateral trunk muscles will be assessed using the McGill Trunk Endurance Tests.
Inspiratory and expiratory muscle strength will be made with a portable, electronic intra-oral pressure measuring device.
Respiratory muscle endurance testing will be measured using an inspiratory muscle training device at increasing threshold load.
Peripheral muscle endurance will be assessed by performing 30 and 60 second sit-to-stand tests.
Healthy children
Age-matched healthy volunteers
Endurance of the flexor, extensor and lateral trunk muscles will be assessed using the McGill Trunk Endurance Tests.
Inspiratory and expiratory muscle strength will be made with a portable, electronic intra-oral pressure measuring device.
Respiratory muscle endurance testing will be measured using an inspiratory muscle training device at increasing threshold load.
Peripheral muscle endurance will be assessed by performing 30 and 60 second sit-to-stand tests.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Core muscles endurance
Time Frame: Baseline
Endurance of the flexor, extensor and lateral trunk muscles will be assessed using the McGill Trunk Endurance Tests.
Baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Respiratory Muscle Strength
Time Frame: Baseline
Inspiratory and expiratory muscle strength will be made with a portable, electronic intra-oral pressure measuring device.
Baseline
Respiratory muscle endurance
Time Frame: Baseline
Respiratory muscle endurance testing will be measured using an inspiratory muscle training device at increasing threshold load.
Baseline
Peripheral muscle endurance
Time Frame: Baseline
Peripheral muscle endurance will be assessed by performing 30 and 60 second sit-to-stand tests.
Baseline

Collaborators and Investigators

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

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 (Actual)

February 5, 2025

Primary Completion (Actual)

November 3, 2025

Study Completion (Actual)

December 29, 2025

Study Registration Dates

First Submitted

February 3, 2025

First Submitted That Met QC Criteria

February 3, 2025

First Posted (Actual)

February 6, 2025

Study Record Updates

Last Update Posted (Actual)

January 6, 2026

Last Update Submitted That Met QC Criteria

January 5, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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