Association Between Sleep Characteristics and Asthma Control in Middle-Aged and Older Adults: A Prospective Cohort Study

BACKGROUND: Nocturnal asthma symptoms are a well-known feature of sleep disturbance. However, there are few reports on the association between sleep-related characteristics and asthma exacerbation. The aim of the current prospective observational study was to explore the factors while sleeping associated with future asthma exacerbation. MATERIALS AND METHODS: At baseline, adult asthmatics underwent home sleep monitoring by a Watch-PAT instrument and then they were prospectively followed-up for the occurrence of exacerbations. The number of asthma exacerbation was observed over a period of one year, and multivariable analyses of the factors associated with asthma exacerbation were performed. RESULTS: A total of 62 asthmatic subjects were enrolled (mean age 62.1 years), 59 of whom were finally included in the prospective observational study. Obstructive sleep apnea (defined by an apnea-hypopnea index based on peripheral arterial tone more than 5 times/hour) were observed in 81% of the subjects. During the one-year monitoring period, 14 of the 59 subjects (24%) used occasional systemic corticosteroids for their exacerbation asthma (worsened group) while the other 45 subjects did not experience asthma exacerbation (stable group). A comparison of the baseline clinical characteristics and sleep-related data between the two groups, mean forced expiratory volume one second percent (FEV(1)/FVC), mean baseline Asthma Control Test (ACT) score, median pAHI value, and median oxygen desaturation index value were significantly lower in the worsened group than those in the stable group. Additionally, mean prevalence of the left lateral decubitus (LLD) position in sleep monitoring were significantly higher in the worsened group than that in the stable group. Among the independent variables, baseline asthma severity, ACT score, and the LLD position showed significant associations with asthma exacerbation. DISCUSSION/CONCLUSION: The present study identified that sleeping in the LLD position was also associated with asthma exacerbation.