RESUMO
BACKGROUND: The effects of expiratory muscle strength training (EMST) with different intensity on stages of sleep were not examined in patients with obstructive sleep apnea syndrome (OSAS). OBJECTIVES: The aim of this study was to compare the effects of high- and low-intensity EMST (H-EMST and L-EMST) on disease severity, sleep stages, disease-related symptoms, daytime sleepiness, fatigue severity, and sleep quality in adult patients with severe OSAS using non-invasive mechanical ventilation (NIMV). METHODS: Thirty-one clinically stable patients with severe OSAS were included in this prospective, randomized controlled, double-blinded study. These were randomly divided into two groups. The H-EMST group underwent training at 60% of maximum expiratory pressure (MEP) and the L-EMST group at 30% of MEP, seven days a week for eight weeks. Apnea hypopnea index (AHI), sleep stages, and respiratory sleep parameters were recorded using polysomnographic sleep analysis. RESULTS: AHI decreased by 34.57% and 20.20% in the H-EMST and L-EMST groups, respectively. A statistically significant improvement in disease severity classifications distributions was observed in the H-EMST group after training (p = 0.016). A greater number of symptoms improved in the H-EMST. The effects of training on respiratory muscle strength, daytime sleepiness, fatigue perception, and sleep quality levels were comparable between the two groups (p>0.05). CONCLUSIONS: H-EMST training is more effective in reducing disease severity and disease-related symptoms than L-EMST. Further studies are warranted for evaluating the long-term effects of EMST with larger sample sizes in OSAS.
