Children who persistently snore during their early childhood may be more likely to have behavioral problems such as aggression and hyperactivity, according to a new study.
Researchers studied 249 mother-child pairs and found the children who snored at both age 2 and age 3 were nearly 3.5 times more likely to have signs of behavioral issues when compared with those who did not snore at these ages, or who only snored during one of those years. Among the kids who snored at both ages, 35 percent showed signs of behavioral problems, while 10 percent in nonsnorers, and 12 percent in kids who only snored for one year, showed such signs.
The findings show the importance of getting good sleep, the researchers said.
"We know that if you take away naps for preschoolers, and then give them challenging tasks, they're grumpier," said lead study author Dean Beebe, director of the neuropsychology program at Cincinnati Children's Hospital Medical Center.
The researchers tracked the children starting during their mothers' pregnancies until they were 3 years old, conducting phone interviews with mothers every few months to get a sense of their children's sleeping patterns and other activities. The researchers also met with the children every year to assess levels of behavioral problems in a face-to-face setting.
The finding is in line with previous work showing an association between snoring and behavioral issues, particularly when the snoring is persistent.
The problems with snoring
A person snores when they are having difficulty breathing during sleep. This difficulty could be the result of anything from a cold or allergies to enlarged adenoid glands; in each case, snoring causes problems by disrupting sleep, restricting oxygen and requiring more effort to breathe.
"It's not like in the cartoons, where snoring is what signifies sleep," Beebe said.
In the short term, as in the case of a cold, this is not problematic, but consistent snoring over months or years affects a child's mood and brain.
Children who don't get enough good sleep will not be as easygoing as other kids, and will be more likely to have behavior problems due to this grumpiness, Beebe said. Adults will come to expect grumpiness from the child, and may treat him or her differently.
From a neurological standpoint, lack of proper sleep inhibits the development of pathways between neurons in the brain, Beebe said.
"We're talking about a brain that is constantly remodeling through early childhood, with connections being strengthened and weakened," he said.
Fixing the underlying cause of snoring can help to reverse these effects, but because parents don't realize the problems with snoring, it often goes untreated.
"Bad sleep, to most parents, is the stuff that disrupts the parents' sleep," Beebe said.
Breast-feeding and socioeconomic status
The researchers found that children were more likely to snore if they weren't breast-fed as babies, or if they were from a lower socioeconomic class.
Children of lower socioeconomic status face a number of risk factors, from worse air quality to poor nutrition that may make it harder for them to sleep soundly, Beebe said.
Breast-feeding, which is more challenging for an infant than drinking from a bottle, may remodel the airway to reduce snoring. Additionally, breast milk increases a child's immunity, and spending less time being sick may also mean less snoring.
Additionally, the bonding that occurs between a mother and child during breast-feeding could also serve to alleviate behavioral problems, said Karen Bonuck, professor of family and social medicine at New York's Albert Einstein College of Medicine, who was not involved in the study.
Overall, the new study was impressive in size and methods, particularly because the researchers assessed children's behavioral issues in person, Bonuck said.
The results show that snoring is not normal in childhood, Bonuck said, citing another recent study that found that nearly half of parents considered snoring a sign of healthy sleep.
"Don't dismiss snoring as benign," she said.