Infants who snore so loudly that they wake themselves have lower scores on standardized mental development tests, a study shows. The study also hints that exposure to secondhand cigarette smoke may contribute to the deleterious effects of infant snoring.

The link between sleep-disordered breathing and cognitive functioning in preschool and school-aged children “now has been established clearly,” Drs. Hawley E. Montgomery-Downs, of West Virginia University, Morgantown, and David Gozal of the University of Louisville in Kentucky charge in their report in Pediatrics.

“This study and others clearly support the need for identification and evaluation of the youngest children with recognizable risk factors for sleep disordered breathing,” the authors conclude.

“This may pose a formidable challenge when we consider that the symptoms of sleep disordered breathing, such as snoring, are less frequently the presenting complaint in such children when compared with associated comorbidities, such as recurrent upper respiratory tract infections and delays in growth and development.”

In their study, the researchers assessed the potential association between snoring and decrements in developmental performance among 35 healthy infants who were an average of 8.2 months of age. The possible contribution of exposure to cigarette smoke was also examined.

Respiratory arousal was significantly negatively correlated with mental development and snoring-associated arousals accounted exclusively for this association.

Thirty-three percent of the infants were from a home in which at least one parent smoked. Infants from smoking households were more likely to snore and significantly more likely to have respiratory-related arousals. However, no significant differences in mental development scores were seen between infants from smoking or non-smoking households.

SOURCE: Pediatrics March 2006.