An observational study in Cystic Fibrosis (CF) and Primary Ciliary Dyskinesia (PCD), sponsored by Gazi University. Completed at 1 site in Turkey (Türkiye). Open to participants aged 6 Years to 18 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-03.
Sponsored by Gazi University · Observational
Cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) are genetic diseases characterized by chronic respiratory tract infections. In both diseases, impaired mucociliary clearance, recurrent respiratory infections, and persistent inflammation lead to progressive deterioration in respiratory function. This condition limits patients' activities of daily living, leading to physical inactivity and exercise intolerance. Functional exercise capacity in patients with CF and PCD is reduced due to increased respiratory load, musculoskeletal involvement, and nutritional deficiencies. In exercise tests involving the upper and lower extremities, both patient groups exhibited significantly lower performance compared to healthy individuals. Muscle oxygenation is particularly reduced in patients with cystic fibrosis and is associated with inadequate oxygen delivery to peripheral muscles, mitochondrial dysfunction, and increased muscle fatigue. Although studies on muscle oxygenation in PCD patients are limited, it is thought to be affected by similar pathophysiological mechanisms. Respiratory muscle strength is weakened in both patient groups due to chronic cough, hyperinflation, and increased respiratory effort. This is particularly evident in a significant decrease in inspiratory and expiratory muscle strength. The number of studies in the literature evaluating muscle oxygenation, respiratory muscle strength, and physical activity levels in patients with CF and PCD is limited. There are no studies comparing muscle oxygenation between patients with CF and PCD.
In patients with cystic fibrosis (CF) and primary ciliary dyskinesia (PCD), lower extremity exercise capacity, skeletal muscle function, respiratory muscle strength, and physical activity levels are limited by various pathophysiological mechanisms. In CF patients, lower extremity exercise capacity is significantly reduced due to ventilation limitation, respiratory muscle fatigue, and mitochondrial dysfunction. Early fatigue findings such as delayed oxygen uptake and lactate accumulation have been reported in lower extremity-specific exercise tests. In PCD patients, respiratory workload increases due to ventilation-perfusion mismatch and impaired mucociliary clearance, which can limit muscle oxygen utilization during exercise. Recent studies have shown that PCD patients have lower resting muscle oxygen saturation compared to healthy individuals, but these values are relatively maintained during exercise. In CF, respiratory muscle strength is weakened, particularly at the diaphragm and intercostal muscles, leading to a decrease in ventilatory reserve during exercise. Similarly, submaximal respiratory muscle fatigue and decreased inspiratory muscle strength have been reported in patients with PCD. Regarding physical activity levels, daily activity levels in both patient groups are significantly lower than in healthy peers, and this has been associated with disease progression, muscle dysfunction, and exercise intolerance. Objectively measured studies in children and adolescents with CF have reported that they fall below the recommended daily activity level, and this inadequacy negatively impacts muscle function over time. A similar tendency toward physical inactivity is also found in PCD patients, and this is considered directly related to exercise capacity. The number of studies in the literature evaluating muscle oxygenation, respiratory muscle strength, and physical activity levels in patients with CF and PCD is limited. There are no studies comparing muscle oxygenation in patients with CF and PCD. The aim of our study was to compare functional exercise capacity, muscle oxygenation, respiratory muscle strength, and physical activity in children with CF, PCD, and healthy children.
1,581 studies on the registry are indexed under Cystic Fibrosis; 190 are open to participants now.
This study's enrollment of 88 is close to the median of 85 across 482 observational studies indexed under Cystic Fibrosis.
Browse Cystic Fibrosis studies →Gazi University is the lead sponsor of 531 studies on the registry; 99 are open to participants now.
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Thirty-one patients with CF, 27 patients with PSD were included in the study. There are 30 healthy data.
Cystic fibrosis patients;
Primary ciliary dyskinesia patients;
Healthy controls;
Exclusion Criteria:
Patients;
Healthy controls;
Demographic information (age, gender, education level), physical characteristics (weight, height, BMI (Body Mass Index)), medical history (past and present history, family history, diagnosis, disease duration, smoking and environmental exposure, exacerbation status within the last year, number of hospital admissions and hospitalizations, medications used, parental consanguinity, socioeconomic status, number of siblings diagnosed with primary ciliary dyskinesia (PCD) or, cystic fibrosis (CF) body weight, height, and BMI Z scores were recorded. Pulmonary function, respiratory muscle strength and endurance, functional exercise capacity, muscle oxygenation, and physical activity level were assessed for all individuals.
Demographic information (age, gender, education level), physical characteristics (weight, height, BMI (Body Mass Index)), medical history (past and present history, family history, diagnosis, disease duration, smoking and environmental exposure, exacerbation status within the last year, number of hospital admissions and hospitalizations, medications used, parental consanguinity, socioeconomic status, number of siblings diagnosed with primary ciliary dyskinesia (PCD) or, cystic fibrosis (CF) body weight, height, and BMI Z scores were recorded. Pulmonary function, respiratory muscle strength and endurance, functional exercise capacity, muscle oxygenation, and physical activity level were assessed for all individuals.
Demographic information (age, gender, education level), physical characteristics (weight, height, BMI (Body Mass Index)), body weight, height, and BMI Z scores were recorded. Pulmonary function, respiratory muscle strength and endurance, functional exercise capacity, muscle oxygenation, and physical activity level were assessed for all individuals.
Functional Exercise Capacity
The six minute walk test (six-MWT) was used to assess functional exercise capacity. The six-MWT was administered according to the criteria of the American Thoracic Society and the European Respiratory Society. Heart rate at rest, after the test, and at the first minute of recovery were assessed using a heart rate monitor (Polar FTI00, China), blood pressure using a sphygmomanometer (Erka Perfect Aneroid, Germany), oxygen saturation using a portable pulse oximeter (Nonin Onyx Vantage 9590, Minnesota, USA), and respiratory frequency (counting the number of breaths taken per minute). The severity of dyspnea and body and leg fatigue was determined using the modified Borg Scale. The six-MWT was repeated twice. Walking distance was expressed in meters and as a percentage of the predicted value. The best walking distance result was selected for analysis. The percentage of the predicted walking distance values was calculated using the reference equation of Gibbons et al.
Time frame: First Day
Muscle oxygenation (Resting muscle oxygen saturation (SmO2rest))
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the six-MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (Minimum muscle oxygen saturation (SmO2min))
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (Maximum muscle oxygen saturation (SmO2max))
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (ΔSmO2)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (SmO2averaged-min)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (SmO2averaged -max)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (ΔSmO2averaged)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (SmO2recovery)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (SmO2recovery-averaged)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (Resting total hemoglobin level (THbrest))
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded
Time frame: First Day
Muscle oxygenation (Minumum total hemoglobin level (THbmin))
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6PBRT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (Maximum total hemoglobin level (Thbmax))
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (ΔTHb)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT, the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Muscle oxygenation (THbrecovery)
Muscle oxygenation was assessed using the Moxy monitor device (Moxy, Fortiori Design LLC, Minnesota, ABD). During the 6MWT the device was placed on the quadriceps muscle of the dominant leg, and measurements were recorded.
Time frame: First Day
Heart rate
Heart rate at rest, after the test, and at the first minute of recovery were assessed using a heart rate monitor (Polar FTI00, China).
Time frame: First day
Blood pressure
Blood pressure at rest, after the test, and at the first minute of recovery were assessed using a sphygmomanometer (Erka Perfect Aneroid).
Time frame: First day
Oxygen saturation
Oxygen saturation at rest, after the test, and at the first minute of recovery were assessed using a portable pulse oximeter (Nonin Onyx Vantage 9590, Minnesota, USA).
Time frame: First day
Breathing frequency
Breathing frequency at rest, after the test, and at the first minute of recovery were assessed using a counting the number of breaths taken per minute.
Time frame: First day
Dyspnea
The severity of dyspnea was determined using the modified Borg Scale.
Time frame: First day
Body and leg fatigue
The severity of body and leg fatigue was determined using the modified Borg Scale.
Time frame: First day
Pulmonary function (Forced vital capacity (FVC))
Pulmonary function was assesed with the spirometry. Dynamic lung volume measurements were made according to ATS and ERS criteria. With the device, forced vital capacity (FVC) was assessed.
Time frame: First Day
Pulmonary function (Forced expiratory volume in the first second (FEV1))
Pulmonary function was assessed with the spirometry. Dynamic lung volume measurements were made according to ATS and ERS criteria. With the device, forced expiratory volume in the first second (FEV1) was assessed.
Time frame: First Day
Pulmonary function (FEV1 / FVC)
Pulmonary function was assessed with the spirometry. Dynamic lung volume measurements were made according to ATS and ERS criteria. With the device, FEV1 / FVC was assessed.
Time frame: First Day
Pulmonary function (Flow rate 25-75% of forced expiratory volume (FEF 25-75%))
Pulmonary function was assessed with the spirometry. Dynamic lung volume measurements were made according to ATS and ERS criteria. With the device, flow rate 25-75% of forced expiratory volume (FEF 25-75%) was assessed.
Time frame: First Day
Pulmonary function (Peak flow rate (PEF))
Pulmonary function was assessed with the spirometry. Dynamic lung volume measurements were made according to ATS and ERS criteria. With the device, peak flow rate (PEF) was assessed.
Time frame: First Day
Respiratory Muscle Strength
Maximal inspiratory (MIP) and maximal expiratory (MEP) pressures expressing respiratory muscle strength were measured using a portable mouth pressure measuring device according to American Thoracic Society and European Respiratory Society criteria
Time frame: Second Day
Respiratory Muscle Endurance
Incremental threshold loading test
Time frame: Second Day
Physical Activity Level (Total energy expenditure)
Physical activity will be evaluated with the Multi sensor activity monitor (SenseWear®, Inc Pittsburgh, ABD). The patient will wear the multisensor physical activity monitor over the triceps muscle of the non-dominant arm for 4 continuous days. The patient will be informed about removing the device while taking a bath. Total energy expenditure (joule / day) will be measured with the multi-sensor physical activity monitor. The parameters measured over two days will be averaged and analyzed with the "SenseWear® 7.0 Software" program.
Time frame: Second Day
Physical activity (Active energy expenditure (joule / day))
Physical activity will be evaluated with the Multi sensor activity monitor (SenseWear®, Inc Pittsburgh, ABD). The patient will wear the multisensor physical activity monitor over the triceps muscle of the non-dominant arm for 4 continuous days. The patient will be informed about removing the device while taking a bath. Active energy expenditure (joule / day) will be measured with the multi-sensor physical activity monitor. The parameters measured over two days will be averaged and analyzed with the "SenseWear® 7.0 Software" program.
Time frame: Second Day
Physical activity (Physical activity time (min / day))
Physical activity will be evaluated with the Multi sensor activity monitor (SenseWear®, Inc Pittsburgh, ABD). The patient will wear the multisensor physical activity monitor over the triceps muscle of the non-dominant arm for 4 continuous days. The patient will be informed about removing the device while taking a bath. Physical activity time (min / day)will be measured with the multi-sensor physical activity monitor. The parameters measured over two days will be averaged and analyzed with the "SenseWear® 7.0 Software" program.
Time frame: Second day
Physical activity (Average metabolic equivalent (MET / day))
Physical activity will be evaluated with the Multi sensor activity monitor (SenseWear®, Inc Pittsburgh, ABD). The patient will wear the multisensor physical activity monitor over the triceps muscle of the non-dominant arm for 4 continuous days. The patient will be informed about removing the device while taking a bath. Average metabolic equivalent (MET / day) will be measured with the multi-sensor physical activity monitor. The parameters measured over two days will be averaged and analyzed with the "SenseWear® 7.0 Software" program.
Time frame: Second Day
Physical activity (Number of steps (steps / day))
Physical activity will be evaluated with the Multi sensor activity monitor (SenseWear®, Inc Pittsburgh, ABD). The patient will wear the multisensor physical activity monitor over the triceps muscle of the non-dominant arm for 4 continuous days. The patient will be informed about removing the device while taking a bath. Number of steps (steps / day) will be measured with the multi-sensor physical activity monitor. The parameters measured over two days will be averaged and analyzed with the "SenseWear® 7.0 Software" program.
Time frame: Second Day
Physical activity (Time spent lying down (min / day) days))
Physical activity will be evaluated with the Multi sensor activity monitor (SenseWear®, Inc Pittsburgh, ABD). The patient will wear the multisensor physical activity monitor over the triceps muscle of the non-dominant arm for 4 continuous days. The patient will be informed about removing the device while taking a bath. Time spent lying down (min / day) days) will be measured with the multi-sensor physical activity monitor. The parameters measured over two days will be averaged and analyzed with the "SenseWear® 7.0 Software" program.
Time frame: Second Day
Physical activity (Sleep time (min / day))
Physical activity will be evaluated with the Multi sensor activity monitor (SenseWear®, Inc Pittsburgh, ABD). The patient will wear the multisensor physical activity monitor over the triceps muscle of the non-dominant arm for 4 continuous days. The patient will be informed about removing the device while taking a bath. Sleep time (min / day) will be measured with the multi-sensor physical activity monitor. The parameters measured over two days will be averaged and analyzed with the "SenseWear® 7.0 Software" program.
Time frame: Second Day
Plan to share: No
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