Children with frequent asthma symptoms reported feeling more sleepy during the day than their healthier counterparts, a new study has found.
Treating the symptoms, however, may help the children feel more rested, the data suggest.
"We only found that children who experienced frequent symptoms experienced more sleepiness, whereas children with infrequent asthma symptoms did not report more sleepiness than healthy children. This suggests that effective treatment of asthma might result in an improvement of sleepiness," said Annette van Maanen, who led the research at the University of Amsterdam in the Netherlands.
How the study was done
As reported online in the European Respiratory Journal, van Maanen and her team studied 2 529 11-year-old subjects in the Prevention and Incidence of Asthma and Mite Allergy birth cohort study. In that group, 317 children had asthma symptoms, which broke down into 97 with frequent symptoms and 220 with infrequent symptoms.
Multivariate analysis found a significantly higher rate of daytime sleepiness among the 97 kids with frequent symptoms. Of those, 34.4% reported experiencing daytime sleepiness or tiredness at least once a week, compared to 22.2% of the children with infrequent symptoms, and 21.9% of the healthy children.
The data were self-reported, with parents reporting on their children's asthma symptoms and the children themselves reporting on the quality of their nightly sleep and on their daytime sleepiness.
Struggle to pay attention
Interestingly, the asthmatic children in the study did not appear to sleep less or more poorly than the others. That may raise questions about the cause of the daytime sleepiness, but researchers attribute the apparent discrepancy to inaccuracies inherent in reporting on the quality of one's own sleep.
"Bad sleep quality concerns problems with sleep onset, sleeping through the night and feeling not rested after sleep. So, children with frequent asthma symptoms may report positively on one or more of these aspects, e.g. having few nocturnal awakenings, but taken together, their sleep duration and sleep quality may be unsatisfactory and so induce sleepiness and tiredness during the day," says van Maanen.
An earlier study cited in van Maanen's paper did find associations between asthma and sleep quality in children.
"The differences in the methodology adopted could possibly explain the variation in findings," said Dr Ashok Shah from the University of Delhi in India, who led that earlier study, which was published in 2006 in the Asian Pacific Journal of Allergy and Immunology.
Dr Shah, who is president of the Indian College of Allergy, Asthma and Applied Immunology, said, "The current study is a community based study which appears to be retrospective and based on recollection. In our study, both parents actively participated and maintained sleep and peak expiratory flow diaries."
Echoing van Maaken, Dr Shah points out that her paper questions the power of the survey to detect nocturnal awakenings.
Still, van Maaken says, "We would (advise) physicians to pay attention to sleepiness in children who have frequent asthma symptoms as this can have negative consequences for their daytime functioning."
(Reuters Health, September 2012)
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