Brain oxygen levels and blood pressure may play a role in the complex relationship between sleep-disordered breathing (SDB) and cognitive problems in children.

About two-thirds of children with SDB (snoring or obstructive sleep apnea) have some degree of cognitive deficit, but it's been difficult to match the severity of cognitive deficit to the severity of the SDB. This suggests that other factors may be involved or that the correct factors weren't being measured, according to background information in an American Thoracic Society news release about the study.
For this study, which included children aged 7 to 13, the researchers used infrared spectroscopy to determine whether a new factor -- the degree to which the brain's blood remains oxygenated during sleep -- could explain variability in cognitive dysfunction better than SDB severity. The children's blood pressure was also measured. The results showed that children with snoring had lower regional cerebral oxygen concentration than healthy children. However, children with sleep apnea (usually considered a more severe type of SDB) had higher regional cerebral oxygen concentration than children with just snoring.

"By taking into account the role of blood pressure in regulating the amount of oxygen concentration in the brain, we might have a better understanding of the relationship between sleep-disordered breathing and cognitive deficit," said Amin, who added that this research may prove important in future prevention and treatment efforts. The study was published in the first issue for November of theAmerican Journal of Respiratory and Critical Care Medicine.

Source: American Thoracic Society, news release, Oct. 7, 2008