CPAP treatment falls short of improving asthma control in patients with concomitant OSAS
Continuous positive airway pressure (CPAP) treatment offers little benefit to asthmatic patients with obstructive sleep apnoea syndrome (OSAS), with a recent study showing that the intervention does not improve asthma control.
On the other hand, CPAP may attenuate daytime sleepiness, as well as enhance asthma-related quality of life and vitality.
A total of 122 patients with nocturnal asthma symptoms despite treatment with at least moderate‐dose inhaled corticosteroid and long‐acting bronchodilators underwent a home sleep study using a portable diagnostic system. Forty-one patients (33.6 percent) were found to have significant OSAS (apnoea–hypopnoea index [AHI] ≥10/h), among whom 37 were randomized to receive either CPAP (n=17) or conservative treatment (n=20) for 3 months.
Relative to those who did not have the sleep apnoea, OSAS patients had higher body mass index (mean, 27.4 vs 25.1 kg/m2; p=0.016), bigger neck circumference (mean, 36.6 vs 34.8 cm; p=0.006) and lower minimum SaO2 (mean, 80.7 vs 87.2 percent; p<0.001).
CPAP treatment did not produce a significant change in Asthma Control Test score compared with conservative treatment (mean, 3.2 vs 2.4; p=0.568) at month 3. However, CPAP-treated patients showed notable improvements in Epworth Sleepiness Scale (mean, −3.0 vs 0.5; p=0.014), Asthma Quality of Life Questionnaire (mean, 0.6 vs 0.02; p=0.022) and SF‐36 questionnaire vitality domain (mean, 14.7 vs 0.3; p=0.012) scores.
Characterized by repetitive episodes of upper airway obstruction, OSAS has been reported to be highly prevalent in asthmatic populations. The sleep apnoea causes intermittent hypoxia, sleep fragmentation, impaired cognitive function and poor health status. [Thorax 2004;59:618-622; J Thorac Dis 2017;9:1945-1958]