The prevalence of symptoms of sleep-disordered breathing in Brazilian schoolchildren Prevalência de sintomas de distúrbios respiratórios do sono em escolares brasileiros

Objective: To identify the prevalence of symptoms of sleep-disordered breathing among children of low socioeconomic status in the South of Brazil. Methods: This was a cross-sectional study, carried out in the city of Uruguaiana, RS, in which a specific questionnaire about symptoms of sleep-disordered breathing was completed by the parents of a sample of schoolchildren aged 9 to 14 years, enrolled on the International Study of Asthma and Allergies in Childhood (ISAAC). Results: From the total of 1,011 eligible schoolchildren, 998 questionnaires were completed. The parents of 27.6% of the children reported habitual snoring, while 0.8% reported apnea, 15.5% described daytime mouth breathing and 7.8% complained of excessive daytime sleepiness. Children with excessive daytime sleepiness were at greater risk of habitual snoring (OR = 2.7; 95%CI 1.4-5.4), apnea (OR = 9.9; 95%CI 1.2-51), mouth breathing (OR = 13.1; 95%CI 6.2-27.4) and learning difficulties (OR = 9.9; 95%CI 1.9-51.0). Rhinitis, maternal smoking and positive allergy skin test results were significantly associated with habitual snoring and daytime mouth breathing. Conclusions: There is an elevated prevalence of symptoms of sleep-disordered breathing among children from 9 to 14 in the city of Uruguaiana. The prevalence of habitual snoring was almost twice that described in this age group in other populations. Children with excessive daytime sleepiness appear to have almost 10 times the risk of learning difficulties.