Children who snore are more likely to have behavioural problems than other children their age, according to a new study.

Canadian and US researchers found in a birth cohort of children followed to the age of three that 35% of persistent snorers were at risk of disorders including hyperactivity, inattention and depression compared to 12% of transient snorers and 10% of non-snorers.

“Our findings… highlight the importance of routine screening for snoring,” the authors wrote.

“It is important to ask specifically about snoring, because parents’ responses to more general sleep questions may not reflect this hallmark symptom of sleep-disordered breathing.”

The 249 children in the study were classified into three groups: 9% were dubbed persistent snorers as they snored at least twice a week at age two and at age three; 23% were transient snorers who snored at least twice a week either at age two or at age three, and 68% were non-snorers.

The children’s parents were surveyed about their children’s behaviour and a trained research associate assessed the development of the child’s cognitive and motor development.

“As predicted, children who were persistent snorers had significantly higher behaviour problem scores at age three than those who never snored or who were transient snorers,” the authors wrote.

“The findings from this study suggest that sleep-disordered breathing in young children is associated with behavioural problems, potentially because of the cumulative effects of sleep-disordered breathing on early childhood learning and on the development of neurologic systems that underlie attention and behaviour regulation.”

Most of the snoring group consisted of African American children and while the researchers have suggested that craniofacial features may be a predictor of snoring, they believe that low socioeconomic status was a more “robust risk factor” for snoring than race.

Breastfed children were also less likely to snore, the study showed. Previously research has suggested the act of breastfeeding promotes the development of a healthy upper airway structure and that breast milk provides immunologic protection against infections that promote sleep-disordered breathing.

The authors suggest that breastfeeding beyond five months may result in incremental protection against sleep-disordered breathing.

Pediatrics 2012; online August 13

As first appeared in Medical Observer