(CINCINNATI) -- Aside from being a nocturnal annoyance, a new study confirms snoring in young kids can have implications for their behavior later on.
Previous research has shown that poor sleep quality in children, including snoring, is linked to hyperactivity. However, little is known about "how much" snoring is too much, and whether the behavioral effects last over time.
The link between snoring and effects on behavior may be related to hypoxia, or decreased oxygen delivery to the brain. Snoring may be a sign that not enough air is going through a person's airway -- a situation many doctors believe occurs frequently with sleep-disruptive breathing disorders. Less oxygen delivery to the brain can mean inflammation, and even changes in the brain tissue itself.
"Many preschool children snore for brief periods, [for example] when they have a cold," says Dean Beebe, a neuropsychologist at Cincinnati Children's Hospital Medical Center. "But loud snoring that lasts for months or years is abnormal and may signal a sleep-related breathing problem that could affect a child's behaviors during the day."
Beebe and colleagues explored these issues in a new study published Monday in the journal Pediatrics. Their goal was to focus on younger children and "follow kids over time to get a sense of what happens when snoring persists," he says.
Researchers looked at 249 mother/child pairs at 2 and 3 years of age and asked parents how frequently they heard "loud snoring" coming from their child's bedroom. Children were characterized as "non-snorers" if they snored less than once per week, "transient snorers" if they snored more than two times per week at age 2 or age 3, or "persistent snorers" if they snored more than two times per week both at age 2 and at age 3.
The same children were also assessed for behavioral problems -- including hyperactivity, aggression, depression and inattention -- based on a validated questionnaire known as the Behavior Assessment System for Children.
The results of this study demonstrated that the persistent snorers had significantly worse overall behavioral functioning at age 3, specifically in the areas of hyperactivity, depression and attention, compared to the transient snorers and the non-snorers. In fact, 35 percent of persistent snorers were found to be at risk for behavioral problems.
Pediatric sleep specialists say they are enthused by the findings.
"In my opinion, this study is very important," states Dr. Frisca Yan-Go, a neurologist from UCLA, "because it gives data to support clinicians in emphasizing that habitual snoring is not normal at any age."
Yan-Go explains that if a sleep-related breathing disorder disrupts a child's sleep, "[It] definitely will affect the child's daytime function, including behavior, learning and development."
Sleep experts say parents who have kids who snore loudly and persistently should inform their pediatricians as soon as they can.
Copyright 2012 ABC News Radio