Impact of obstructive sleep apnea and sleep parameters on level of asthma control

Background and Objective: Several studies support high prevalence of obstructive sleep apnea (OSA) symptoms in patients with asthma. Our objective was to evaluate the relationship between OSA severity and level of asthma control if any and analyze sleep parameters in patients having different levels of asthma control. Methods: A cross-sectional study among asthma patients having symptoms of sleep-related breathing disorders. Eligible patients were assessed clinically and with sleep questionnaire including asthma control followed by level 1 Polysomnography. Results: Among 53 patients of asthma (mean age 48.16 years), OSA was present in 84.21% of uncontrolled asthma, 35% in partially controlled asthma, and 7.14% in well-controlled asthma. Uncontrolled asthma patients were associated with higher apnea/hypopnea index (AHI) (30.8±17.6 vs. 3.7±1.2; p-value < 0.0001), more time spent in non rapid eye movement (NREM) 1 stage (18.5±11.9% vs. 13.0±11.2% of total sleep time), higher nocturnal desaturation episodes (152.5±13 vs. 22.1±16.7; p-value < 0.001), and severe OSA in supine position (AHI 33.1±17.7 vs. 9.2±9.7; p-value < 0.001) compared with well-controlled asthma. Conclusion: There seems a strong relationship between desaturation events and higher AHI with poor level of asthma control, especially during supine position. OSA must be suspected in patients with uncontrolled asthma. An early detection and treatment of OSA may improve the level of asthma control as well as quality of life in such patients.