Sleep Apnea Confirmed Common in Children with Down Syndrome
Parents of children with Down syndrome weak to identify signs of sleep apnea
Monday, May 08, 2006
Children with Down syndrome are known to have a greater risk for obstructive sleep apnea. A new study by researchers at Cincinnati Children's Hospital Medical Center shows that few parents of children with Down syndrome are in tune with whether their child has obstructive sleep apnea.
The study appears in the April 17 issue of the Journal of the American Medical Association.
Obstructive sleep apnea syndrome is defined by sleep abnormalities that consist of complete and partial upper airway obstruction during sleep, a reduction in the amount of air entering the lungs with an abnormally high level of carbon dioxide in the blood, and oxygen loss.
Although obstructive sleep apnea is seen in only 0.7 to 2 percent of all children, a previous study based on 53 children and adults with Down syndrome between the ages of four weeks and 51 years old (an average of seven years old), found an incidence of sleep abnormalities as high as 100 percent in some cases. With this very high incidence in children, Sally R. Shott, MD, a pediatric otolaryngologist at Cincinnati Children's and principal investigator of the JAMA study, questioned whether all children with Down syndrome should be objectively evaluated for sleep abnormalities, obstructive sleep apnea, and at what age this evaluation should be done.
"Our results point to the need for objective testing for the presence of obstructive sleep apnea in children as young as three to four years old. Because there is a high incidence of sleep disorders in children with Down syndrome, clinical sleep studies are recommended even if the parents report no sleep problems in their child," Dr. Shott said.
Dr. Shott and her colleagues investigated the incidence of obstructive sleep apnea in 65 children with Down syndrome who were followed in a longitudinal, five-year study from the ages of two to five years old. The children in the study underwent a polysomnogram, or sleep study, between three and four years old. Researchers also examined the ability of parents to identify sleep abnormalities in their child.
They found that in general, parents of children with Down syndrome significantly underestimated the severity of their child's sleep disturbances. Overall, 69 percent of parents reported no sleep problems. Yet, 57 percent of children expressed abnormal sleep patterns. In the children with abnormal sleep study results, only 23 percent correctly predicted a problem. In a previous study, only 32 percent of parents suspected their child had obstructive sleep apnea, despite a 100 percent incidence of abnormal studies.
There is concern that an excessive number of arousals may lead to fragmented sleep and sleep deprivation. Excessive sleep arousals and sleep fragmentation have been linked to symptoms usually associated with sleep deprivation such as daytime sleepiness, lack of energy and lack of initiative.
Increased arousals have been associated with decreased neurocognitive abilities and lower results on IQ testing. It has been suggested that the increased arousal rate seen in children with Down syndrome may affect their daytime function and could exacerbate learning or behavior disorders. In children with Down syndrome, behavior and learning disabilities associated with sleep loss tend to be overlooked and assumed to be associated with the limited intellectual abilities associated with Down syndrome.
Because children with Down syndrome have an increased risk of sleep abnormalities, in 2001 the American Academy of Pediatrics recommend that primary care physicians question parents about possible sleep disorders when the children are five years old and older. However, no recommendations are made for specific testing. This study recommends objective testing by polysomnography, or sleep study, in all children with Down syndrome.
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