The role of continuous positive airway pressure in achieving asthma control in patients with severe asthma and concurrent obstructive sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) frequently coexists with severe asthma, complicating disease management and clinical outcomes. Continuous positive airway pressure (CPAP) has been reported to improve asthma control. However, available evidence remains inconsistent. We aimed to evaluate the effectiveness of CPAP in achieving asthma control among patients with severe asthma and coexisting OSA. METHODS: This prospective cohort study included 47 participants with severe asthma. Participants underwent polysomnography and were stratified into three groups: (1) severe asthma without OSA (control), (2) severe asthma with OSA who declined CPAP therapy (off-therapy), and (3) severe asthma with OSA who accepted CPAP therapy (on-therapy). Asthma control was assessed monthly for 3 months using the Asthma Control Test (ACT), the Global Initiative for Asthma (GINA) control criteria, and the rate of asthma exacerbations. RESULTS: OSA was diagnosed in 53.1% of participants. We observed no significant between-group difference in the change of ACT scores over time ( P = 0.09). The proportion of participants with well-controlled asthma did not differ over time across the study groups based on either ACT or GINA criteria ( P > 0.05). However, the reduction in asthma exacerbation rate differed significantly between groups, with a 93% reduction in the on-therapy group compared with 23% in the off-therapy group ( P < 0.01). CONCLUSION: OSA was highly prevalent among patients with severe asthma. Although 3 months of CPAP therapy did not improve overall asthma control, it was associated with a marked reduction in asthma exacerbation rates, supporting its potential role in reducing disease burden in patients with severe asthma and coexisting OSA. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (Identifier: NCT05470153) on July 22, 2022.