LAUSR

Background: Unrecognized obstructive sleep apnea syndrome (OSAS) may lead to poor asthma control despite optimal therapy. We aimed to assess asthma control, airway responsiveness, daytime sleepiness and health status at baseline and at 3 months after continuouos positive airway pressure (CPAP) treatment among asthma patients with nocturnal symptoms and OSAS. Methods: Patients with nocturnal asthma symptoms despite receiving at least moderate dose inhaled corticosteroid and long acting bronchodilators underwent a limited sleep study using “Embletta” portable diagnostic system (Medcare, Iceland). Patients with significant OSAS (apnea hypopnea index (AHI) ≥10/hr) were randomized to receive either CPAP or conventional treatment for 3 months. Assessments included asthma control test (ACT) score, and asthma related quality of life (AQLQ). Results: [mean (SD) unless stated otherwise]: Total 41 patients were found to have AHI ≥10/hour. Using intention-to-treat analysis among 37 patients with AHI ≥10/hour [CPAP group (n=17) vs control group (n= 20)), there was no significant difference in the change of ACT score [CPAP 3.2(2.7) vs control 2.4(5.7), p=0.066) but CPAP group had lower Epworth Sleepiness Score (-3.0(4.5) vs 0.5(3.8), p=0.014) and better AQLQ (0.6(0.8) vs 0.02(0.7), p=0.022) after 3 months. CPAP usage was 5.0(2.1) hrs/d at 1 month and 5.2 (1.8) hrs/d at 3 months. Conclusions: CPAP therapy for 3 months in OSAS patients with nocturnal asthma despite treatment with at least moderate dose inhaled corticosteroid and long acting bronchodilators did not improve asthma control but alleviated daytime sleepiness and improved asthma related quality of life.