Dec. 15 (HealthDay News) -- Among teenagers, being overweight or obese increases the risk of obstructive sleep apnea, but the same does not appear to be true for younger children, Australian researchers have found.
In sleep tests conducted on 234 white children, aged 2 to 18, who were referred for evaluation of snoring and possible obstructive sleep apnea, the researchers found that among those aged 12 and older the risk of obstructive sleep apnea increased 3.5-fold with each standard-deviation increase in body-mass index (BMI) score. But, increasing BMI did not significantly increase the risk of obstructive sleep apnea in younger children.
The increased risk of obstructive sleep apnea in overweight and obese teens may be linked to developmental changes, such as anatomic changes and reductions in upper airway tone, the study authors noted in the Dec. 15 issue of the Journal of Clinical Sleep Medicine.
"These results were a little surprising to us initially, as obesity is generally considered to increase the risk of sleep apnea amongst all children. Previous results have been inconsistent, however, and appear to be confounded by using mixed ethnic populations and different ages of children," principal investigator Mark Kohler, research fellow at the Children's Research Center at the University of Adelaide, said in a news release from the American Academy of Sleep Medicine.
He and his colleagues said developmental changes in the association between obesity and obstructive sleep apnea may occur at different ages in children of other races and ethnicities. They noted that black American children appear to be at higher risk for obstructive sleep apnea independent of obesity and they may begin puberty earlier than white children.
Tonsil size may be another factor that interacts with obesity to affect the risk of obstructive sleep apnea, they added.
SOURCE: American Academy of Sleep Medicine, news release, Dec. 15, 2009