The relationships among sleep efficiency, pulmonary functions, and quality of life in patients with asthma

Sleep disturbance is commonly observed in patients with asthma, especially in those with poorly controlled asthma. Evaluating sleep quality to achieve good control of asthma is important since nocturnal asthmatic symptoms such as cough, wheezing, and chest tightness may disturb sleep. Actigraphy is an objective, ambulatory monitoring method for tracking a patient's sleep and wake activities and for assessing sleep quality, as reflected by total sleep time, sleep efficiency, duration of awakening after sleep onset (WASO), and sleep onset latency.

Fifty patients with asthma were enrolled in this study. Sleep quality was assessed employing wristwatch-type actigraphy (Actiwatch 2). The level of asthma control was assessed by the Asthma Control Questionnaire (ACQ), and asthma-related quality of life was assessed by the Asthma Quality of Life Questionnaire (AQLQ). The parameters for sleep quality were compared using ACQ scores, AQLQ scores, and pulmonary function test results.

The total sleep time was 387.2 minutes, WASO was 55.8 minutes, sleep efficiency was 87.01%, sleep onset latency was 8.17 minutes, and the average ACQ was 0.36. Neither sleep efficiency nor WASO correlated with respiratory functions, ACQ scores, or AQLQ scores.

Sleep-related parameters assessed by actigraphy in well-controlled asthma do not correlate with pulmonary functions, the asthma control level, or daytime quality of life. Sleep quality should be evaluated independently when asthma is well-controlled.