(dailyRx News) Baby snores might sound cute, but the problems they might cause later are not. Children with troubles breathing during sleep are at a much higher risk of later behavior problems.
In a long-term study of over 11,000 children, researchers found a strong link between children's sleep-breathing problems, such as snoring or sleep apnea, and later behavioral problems - even if the sleep-breathing problems eventually went away.
Karen Bonuck, Ph.D., professor of family and social medicine and of obstetrics and gynecology and women's health at Albert Einstein College of Medicine, led this study, the largest one to look at the long-term impact of sleep breathing problems in children.
The study began with 13,467 babies enrolled in the Avon Longitudinal Study of Parents and Children in the U.K.
The children were tracked for six years, and parents were asked to fill out questionnaires when their children were 6 months, 18 months, 2.5 years, 3.5 years, nearly 5 years old and nearly 6 years old.
Children who were multiples (twins or triplets) or who had chronic health conditions were excluded from the study. Of the total, 9,140 remained in the study at age 4, and 8,098 remained at age 7.
Any type of breathing problems during sleep was included in the study, including snoring, sleep apnea and mouth-breathing, or any combination of these.
The behavioral issues the researchers looked for included hyperactivity or inattention, peer problems, emotional problems (anxiety or depression), aggressive or limit-pushing conduct problems, and pro-social behavior like helpfulness and sharing.
Bonuck's team found that children who had any sleep-disordered breathing symptom had 40 percent more behavioral problems when they were 4 years old and 60 percent more problems at age 7 - and these percentages were on the low end of the spectrum.
"We found that children with sleep-disordered breathing were from 40 to 100 percent more likely to develop neurobehavioral problems by age 7, compared with children without breathing problems," said Bonuck. "The biggest increase was in hyperactivity, but we saw significant increases across all five behavioral measures."
Among children in the "worst case" group - whose symptoms reached their peak at 2.5 years and then lessened - later behavioral issues at age 7 included problems such as hyperactivity, poor conduct or peer difficulties.
Even among children whose sleep-breathing difficulties were worst before 18 months and then disappeared on their own, there was a 40 to 50 percent greater likelihood they would have behavioral problems when they were 7 years old.
"This is the strongest evidence to date that snoring, mouth breathing, and apnea [abnormally long pauses in breathing during sleep] can have serious behavioral and social-emotional consequences for children," Bonuck said.
Because past studies have not been as comprehensive and long-running as this one, researchers were less able to establish a causation link between the sleep-breathing problems and the later behavioral problems. While this study still does not establish that the sleep breathing problems cause the poor behavior, they establish a much stronger link between the two.
"Previous studies suggesting a possible connection between sleep disordered breathing symptoms and subsequent behavioral problems weren't definitive," said Dr. Ronald Chervin, a co-author and a professor of sleep medicine and neurology at the University of Michigan.
"But this study shows clearly that SDB symptoms do precede behavioral problems and strongly suggests that SDB symptoms are causing those problems," Chervin said.
Dr. William Kohler, M.D., director of the Florida Sleep Institute and director of Pediatric Sleep Services at Florida Hospital Tampa, was not associated with this study but also pointed out its significance in confirming what previous research has hinted at.
"There were indications in the past that sleep disordered breathing would lead to behavioral and cognitive problems," he said, "but this study, since it's such a large number of children involved, further substantiates the fact that sleep disordered breathing is associated with significant behavioral and cognitive dysfunction."
Both the questionnaires used to assess children's breathing problems during sleep and their behavioral issues are commonly used measures that have shown high levels of accuracy in previous research.
The researchers took into account 15 other factors that might have accounted for behavioral problems, including socioeconomic status and family factors, child characteristics (gender, race, weight), and characteristics of the mother (age, smoking or alcohol use, breastfeeding, etc.).
Several explanations were offered as possible reasons that the sleep-disordered breathing may be associated with later behavioral problems, such as the possibility that the sleep breathing problems interrupted the children's bodies from "resetting" during sleep or that they interfered with various chemical systems.
The researchers also considered the possibility that the problems were related to lower oxygen levels and higher carbon dioxide levels in the front part of the brain, which is responsible for complex thinking, personality, decision making and social behavior.
Other studies have shown that factors interfering with this part of the brain can prevent children from being able to suppress certain inappropriate behavior, regulate their emotions, plan ahead, or pay attention and organize.
Breathing problems during sleep have already been associated with behavioral and neurological problems with children in past research, but most studies have only followed children for one or two years and studied a single symptom, such as apnea or snoring (but not both).
Bonuck said the most important take-away from this study is that both pediatricians and parents should be more vigilant about potential breathing problems children may experience during sleep.
"Although snoring and apnea are relatively common in children, pediatricians and family physicians do not routinely check for sleep-disordered breathing," Bonuck said. "Physicians need to specifically ask parents whether their children are experiencing one or more of the symptoms—snoring, mouth breathing or apnea—of sleep disordered breathing."
She said parents should not hesitate to talk to their doctors if they see these symptoms.
"If they suspect that their child is showing symptoms of sleep disordered breathing, they should ask their pediatrician or family physician if their child needs to be evaluated by an otolaryngologist (ear, nose and throat physician) or sleep specialist," she said.
There are a range of possible treatments for children who experience breathing problems while sleeping. For those with apnea, CPAP therapy (continuous positive-air pressure) can be administered with machines that begin at about $180 and up, but which are generally covered by most insurance plans.
Those whose breathing problems are associated with oversized tonsils may be treated surgically, and children whose problems result from being overweight or obese can address the problem with weight loss.
The study appeared online ahead of print in March in the journal Pediatrics. It was funded by the National Heart, Lung and Blood Institute and the National Institutes of Health. The authors indicated no conflicts of interest.