Prevalence and factors associated with snoring in 3-year olds: early links with behavioral adjustment.

OBJECTIVE: Identify the prevalence of sleep disordered breathing (SDB) symptoms in a community sample of New Zealand 3-year olds. To examine sleep, demographic, health, environmental, familial, perinatal, and behavioral adjustment factors associated with habitual snoring.
METHODS: A cross sectional study, in which parents of 823 children aged 3 years 0 months to 3 years 12 months (M:F=1:0.9) were recruited from the community. Participants completed questionnaires designed to assess information relevant to their children's sleep, with a particular focus on snoring.
RESULTS: Parents reported snoring at least once a week in 36.9% of children, and habitual snoring (more than four nights per week) in 11.3% of children. Univariate analysis showed habitual snoring was more common amongst Māori (indigenous New Zealanders) (P=0.04) and males (P=0.05), and that habitual snorers came from more socio-economically deprived neighborhoods (P<0.01). Several other SDB-related symptoms were significantly associated with habitual snoring: mouth breathing, sweating profusely, waking during the night, sleeping with neck extended, constant runny nose, and suffering from tonsillitis. Mouth breathing was the most strongly associated. Multivariate analyzes revealed a strong positive relationship between snoring and some health and familial factors, as well as parent reported child irritability (OR=2.83; 95% CI 1.4-5.6) and hyperactivity (OR=1.6; 95% CI 1.0-2.7).
CONCLUSIONS: The prevalence of habitual snoring amongst New Zealand pre-schoolers is similar to that reported elsewhere. Factors associated with habitual snoring include male gender, Māori ethnicity, and poorer deprivation neighborhood, as well as a variety of other environmental and health factors. The data provide evidence that habitual snoring associated with irritable and hyperactive behavior is evident in children as young as three.