Balance Impairment, Muscle Oxygenation, and Functional Exercise Capacity in Patients With Primary Ciliary Dyskinesia

BACKGROUND AND OBJECTIVES: Extrapulmonary effects are observed in patients with primary ciliary dyskinesia (PCD), however, few studies have examined these manifestations, particularly regarding balance and muscle oxygenation during exercise. This study aimed to compare balance, functional exercise capacity, muscle oxygenation, respiratory and peripheral muscle strength, and inspiratory muscle endurance in patients with PCD and healthy peers. METHODS: Twenty-seven patients with PCD and 26 healthy peers were included. Balance (Biodex Balance System and Y Balance Test), exercise capacity (6-min walk test [6MWT]), muscle oxygenation (Moxy device), respiratory muscle strength (maximal inspiratory [MIP] and maximal expiratory [MEP]), inspiratory muscle endurance (incremental threshold loading test), and muscle strength (quadriceps femoris) were evaluated. RESULTS: ) during the 6MWT was higher in patients with PCD (p < 0.05). MIP, MEP, inspiratory muscle endurance, postural stability indices, and other parameters of the Y balance test were similar between groups (p > 0.05). DISCUSSION: In patients with PCD, dynamic balance, functional exercise capacity, and lower extremity muscle strength are impaired, whereas respiratory muscle strength and static balance are preserved. Inspiratory muscle endurance was similarly decreased in both groups. A greater decrease in muscle oxygen saturation was observed during submaximal lower extremity activity in the patients. These findings indicate that, beyond traditional respiratory evaluations, balance and muscle oxygenation should be assessed in patients with PCD, and early assessment may guide rehabilitation strategies and future clinical research. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04895150.