Sleep-disordered breathing is associated with asthma severity in children.

Objective: To examine the relationships among obesity, sleep-disordered breathing (SDB, defined as intermittent nocturnal hypoxia and habitual snoring), and asthma severity in children. We hypothesized that obesity and SDB are associated with severe asthma at a 1- year follow-up.

Study Design: Children aged 4-18 years were recruited sequentially from a specialty asthma clinic and underwent physiological, anthropometric, and biochemical assessment at enrollment. Asthma severity was determined after 1 year of follow-up and guideline-based treatment, using a composite measure of level of controller medication, symptom burden, and health care utilization. Multivariate logistic regression was used to examine adjusted associations of SDB and obesity with asthma severity at 12-month follow-up.

Results: Among 108 subjects (mean age, 9.1±3.4 years; 45.4% African-American; 67.6% male), obesity and SDB were common, affecting 42.6% and 29.6% of subjects, respectively. After adjusting for obesity, race, and sex, children with SDB had a 3.62-fold increased odds of having severe asthma at follow-up (95% CI, 1.26-10.40). Obesity was not associated with asthma severity.

Conclusion: SDB is a modifiable risk factor for severe asthma after 1 year of specialty asthma care. Further studies are needed to determine whether treating SDB improves asthma morbidity.