Shared and unique individual risk factors and clinical biomarkers in children with allergic rhinitis and obstructive sleep apnea syndrome.

Introduction: Rhinitis and obstructive sleep apnea syndrome (OSAS) are different diseases, but have some similar risk factors.

Objective: The aims of this study were to compare the risk factors and clinical biomarkers for rhinitis and OSAS in children.

Methods: We examined 3917 children (age 4-13 years) who were enrolled in a cross-sectional study conducted in Seongnam, Korea. Their parents completed the Pediatric Sleep Questionnaire (PSQ) for evaluation of OSAS and the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire for evaluation of rhinitis. Clinical biomarkers, including total eosinophil count and neutrophil-lymphocyte ratio (NLR), were measured in a subset of these children.

Results: OSAS and rhinitis had prevalences of 4.0% and 43.5%, respectively. Body mass index (P < 0.001) and prematurity (P = 0.016) were significantly associated with OSAS, but not with rhinitis. Higher parental education and income increased the risk for rhinitis, but decreased the risk for OSAS. Having more siblings and birth by Cesarean delivery decreased the risk for rhinitis, but living in a new household increased the risk for rhinitis. A short distance of the residence to a main road during pregnancy significantly increased the risk of OSAS. Males, increased exposure to mould, and firstborns had increased risk of OSAS and rhinitis. The NLR was higher in OSAS patients than in those with allergic rhinitis (P = 0.001).

Conclusion: OSAS and rhinitis shared some risk factors, whereas other factors had inverse association with the two disorders. These results imply that different strategies might be used for prevention of rhinitis and OSAS.