Long-term CPAP treatment improves asthma control in patients with asthma and obstructive sleep apnoea

Both asthma and obstructive sleep apnoea cause sleep disturbance, daytime sleepiness and diminished quality of life. Continuous positive airway pressure (CPAP) is efficient in reducing symptoms related to sleep apnoea. Here we report the impact of long-term use of CPAP on asthma symptoms. A survey questionnaire was distributed to all of our obstructive sleep apnoea patients with CPAP therapy in 2013. We used the Finnish version of the Asthma Control Test (TM) (ACT) and a visual analogue scale (0 = no symptoms, 100 = severe asthma symptoms). Asthma was defined as self-reported physician-diagnosed disease and a special reimbursement for asthma medication by the Social Insurance Institution. We sent 2577 questionnaires and received 1586 answers (61 %). One hundred ninety-seven patients were asthmatics with a prevalence of asthma among CPAP users of 13 %. We studied 152 patients (58 females) whose CPAP therapy was initiated after starting asthma medication. Their mean (SD) age was 62 (10) years, duration of CPAP 5.7 (4.7) years and their CPAP daily use was 6.3 (2.4) h. Self-reported asthma severity decreased significantly from 48.3 (29.6) to 33.1 (27.4) (p < 0.001), and ACT score increased significantly from 15.35 (5.3) to 19.8 (4.6) (p < 0.001) without a significant change in the body mass index (BMI). The percentage of patients using rescue medication daily reduced from 36 to 8 % with CPAP (P < 0.001). We noticed a significant decrease in asthma symptoms with long-term use of CPAP in patients with both asthma and obstructive sleep apnoea.