Association between asthma and sleep-disordered breathing in elementary school children in Japan.

Objective: The aim of this study was to investigate the associations of snoring and sleep-disordered breathing (SDB) with asthma in a large community-based survey of school children, with a focus on sex- and age-specific differences.

Methods: We conducted a cross-sectional survey using a standard questionnaire among nearly 20,000 elementary school children in Matsuyama City, Japan. The questionnaire included inquiries on asthma diagnosis, snoring, and demographic variables. The question regarding the presence of asthma (yes/no) was answered by parents. The associations of snoring frequency, snoring loudness, and SDB with the prevalence of asthma were analyzed using multivariable logistic regression analysis. SDB was determined by higher scores of the Japanese version of the Severity Hierarchy Score (J-SHS) for pediatric obstructive sleep apnea screening.

Results: The multivariable-adjusted odds ratios (95 % confidence intervals) for asthma according to snoring frequency were 1.34 (1.14-1.58) and 1.40 (1.16-1.70) for boys and girls, respectively. The odds ratios for asthma according to snoring loudness were 1.43 (1.21-1.68) and 1.50 (1.23-1.83), respectively. The association between asthma and SDB was observed only in girls in grades 4-6, as the odds ratio was 3.60 (1.99-6.52) for high J-SHS scores.

Conclusion: Asthma was significantly associated with frequency and loudness of snoring in children. Furthermore, an association between asthma and SDB based on J-SHS was observed in girls in grades 4-6.