Apnea-related sleep fragmentation and poor vigilance in children with well-controlled asthma

Abstract

It has been reported that sleep problems and neurocognitive deficit in asthmatic children is prevalent. However, systematic studies on these problems in stable asthma using polysomnography have rarely been performed. We therefore investigated sleep and neurocognitive functioning in children with well-controlled asthma. Forty-three children with well-controlled, stable asthma and 31 controls (age range: 6-9years) were enrolled in the study. Subjects were questioned for daytime sleepiness using the Paediatric Daytime Sleepiness Scale. Complete overnight polysomnography and neurocognitive function tests were performed on all subjects. Children with stable asthma had lower pulmonary function in comparison to their age-matched controls. Asthmatic children had a higher apnea-hypopnea index (P<0.001) and apnea-hypopnea-related arousal index (P<0.001) as compared with non-asthmatics. Deep sleep was decreased in asthmatics (P=0.001). In the vigilance test, the mean number of correct answers was lower (P=0.005) and the mean reaction time was slower (P=0.002) in asthmatic children. A hierarchical multiple linear regression showed that deep sleep and apnea-hypopnea-related arousal index were significant predictors of vigilance. The data suggest that the prevalence of paediatric sleep-disordered breathing and sleep fragmentation could be very high among children with well-controlled asthma. Moreover, vigilance, the ability to maintain attention and alertness, was worse in stable asthmatic children when compared with healthy controls. Sleep-disordered breathing should be checked even in stable asthmatic children as they are at risk for developing neurobehavioural deterioration associated with frequent arousals during sleep. Furthermore, early treatment for asthma may be required in order to prevent airway remodelling that could cause sleep problems.