June 4 -- WEDNESDAY, June 3 (HealthDay News) -- Children with chubby bellies are more likely to have sleep-disordered breathing, a condition that's associated with behavioral problems, hyperactivity and difficulty staying awake at school, new research shows.
In the study, researchers examined 700 children between the ages of 5 and 12 randomly chosen from 18 public elementary schools in Pennsylvania. Each child had a physical exam and was monitored for nine hours at a sleep laboratory using polysomnography, which measures brain electrical activity, heart activity, airflow, respiration and oxygen saturation during sleep.
About 25 percent of children had mild sleep-disordered breathing and 1.2 percent had moderate sleep-disordered breathing, defined as five or more breathing pauses per hour. More than 15 percent had primary snoring, the researchers found.
Those with sleep-disordered breathing tended to have a larger body-mass index and a higher waist circumference relative to their peers. Unlike in adults, a large neck circumference was not a predictor of sleep-disordered breathing in children, the study authors note in their report in the June issue of SLEEP.
Until recently, enlarged tonsils or adenoids were believed to cause most sleep-disordered breathing in children, but the study found no link between tonsil size and disordered breathing, according to a news release from the American Academy of Sleep Medicine (AASM).
Instead, obesity may be playing the greater role, said study author Edward O. Bixler, of Penn State University College of Medicine.
"Risk factors for sleep-disordered breathing in children are complex and include metabolic, inflammatory and anatomic factors," Bixler said in the news release. "Because sleep-disordered breathing in children is not just the outcome of anatomical abnormalities, treatment strategies should consider alternative options, such as weight loss and correction of nasal problems."
Sleep-disordered breathing can range from mild to severe, according to information from the AASM. Mild cases might be marked by persistent snoring due to nasal anatomic features such as chronic sinusitis, rhinitis and nasal drain. Severe cases may include obstructive sleep apnea, a potentially dangerous condition in which breathing repeatedly starts and stops throughout the night. Each pause typically lasts from 10 to 20 seconds and can occur 20 to 30 times per hour.
While children tend to have milder forms of sleep-disordered breathing than adults, they can suffer from obstructive sleep apnea.
Older children were more likely to have moderately disordered breathing. Two percent of children between the ages of 9 and 12 years had moderate sleep-disordered breathing, compared with only 0.2 percent of children between 5 and 8, the news release notes.
Obstructive sleep apnea occurs when soft tissue in the back of the throat collapses and blocks the airway during sleep. In children, loud snoring, obvious pauses in breathing and gasping for breath are warning signs. Parents often notice that the child seems to be working hard to breathe during sleep, according to the AASM.
Find out more about obstructive sleep apnea and sleep breathing disorders in children at the American Academy of Sleep Medicine.
SOURCE: American Academy of Sleep Medicine, news release, June 1, 2009