Impacts of Comprehensive Respiratory Exercise Program on Pulmonary Function, Tongue Strength, Endurance, and Stiffness in Patients with Obstructive Sleep Apnea

This study investigates the effects of a comprehensive respiratory exercise program on tongue muscle strength, endurance, stiffness, lung function, and RMS in OSA patients. 

Newly diagnosed OSA patients were randomly allocated into the comprehensive respiratory exercise program or control group. The intervention group engaged in oropharyngeal exercises, respiratory muscle training, aerobic training, and sleep education for three months. The control group received only sleep education. Polysomnography, tongue muscle strength, endurance, stiffness, lung function, and RMS were assessed before and after the interventions. The analysis of the group-by-time effect in this study was conducted using Generalized Estimating Equations. 

Twenty-two participants were recruited, with 11 individuals assigned to each group. No significant differences were found in age, body mass index, and Apnea-Hypopnea Index (AHI), except neck and waist circumferences, which were significantly greater in the intervention group at baseline. Tongue muscle parameters showed significant improvements, with increases in various tongue strength and endurance measures, with a group-by-time effect found (p0.001), highlighting the efficacy of the intervention program. Moreover, ultrasound shear wave elastography revealed a significant decrease in the stiffness of the genioglossus muscle (β = 0.58, p 0.001), and a notable reduction in geniohyoid muscle stiffness (β = 15.00, p 0.001). Additionally, the intervention group showed improvement in maximal voluntary ventilation (MVV) (β = 15.27 (p0.002), while maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) improved by 39.92 cmh₂o (p0.001) and 41.79 cmh₂o (p0.001), respectively. No significant group-by-time effect was found in the Apnea-Hypopnea Index, Forced Expiratory Volume in 1 second, and Forced Vital Capacity. 

After three months of a comprehensive Respiratory Exercise Program, the intervention group demonstrated significant improvements in tongue muscle strength and endurance, and a notable decrease in genioglossus and geniohyoid stiffness compared to the control group. Additionally, significant enhancements were observed in respiratory measures including MVV, MIP, and MEP.

This research demonstrated notable enhancements in tongue muscle strength, endurance, and reduced stiffness of the genioglossus and geniohyoid muscle, advocating the integration of oropharyngeal exercises, respiratory muscle training, and aerobic exercise into standard physiotherapy for OSA patients. Improvements in MVV, MIP, and MEP further justify the inclusion of respiratory exercise programs in comprehensive OSA care, particularly for patients with significant respiratory deficiencies. Such findings support the development of specialized programs tailored to OSA patients, aimed at enhancing lung function and tongue dynamics, enhancing overall treatment efficacy.