Sleep apnea is a common condition in adults, and it can also occur in children. What factors cause sleep apnea to occur in children? There are various contributions that can lead to a narrowing or instability of the upper airway, which can cause the pauses in breathing characteristic of sleep apnea. As sleep apnea can have serious consequences in children including impacts on growth, intelligence, and behavior, it is important to identify correctable causes.
When sleep is disrupted in young children, especially those who have yet to finish growing, there can be significant consequences. Growth hormone is secreted during the night during specific sleep stages.
Deep, non-REM sleep that occurs early in the night seems especially important for its secretion. This sleep predominates in the first third of the night. If this sleep is disrupted, growth may not occur normally. Children who are affected may begin to fall off their growth curve: for example, if a child was in the 50th percentile by height and weight in early development, the affected child may fall into the 10th percentile over time.
As an example of the impacts of sleep disorders on normal growth, it is known that sleep apnea in children can have profound effects on growth. These children have periodic obstructions in their upper airway that can cause snoring or pauses in their breathing. The body awakens itself into lighter sleep to open the airway and resume normal breathing. As such, deeper sleep may become fragmented and growth hormone secretion may be compromised.
Sleep apnea in a child occurs when the muscles of the upper airway relax enough to temporarily reduce or obstruct airflow. This can occur repeatedly over the course of a night and result in disrupted sleep as the brain attempts to awaken the body and resume normal breathing. Both events can be associated with a drop in blood oxygen levels.
In children, sleep apnea is diagnosed when at least one apnea event occurs per hour of sleep as observed during a diagnostic sleep study. (For adults, more than five events per hour indicate apnea.)
Surprising signs of sleep apnea in children include mouth breathing, bedwetting, sleepwalking, restlessness, and sweating during sleep. There are also several potential consequences for a child's mental and physical health associated with sleep apnea.
Approximately 1% to 3% of preschool-aged children have sleep apnea.2 Apnea in children tends to peak between ages 2 and 6. Due to the course of normal growth during this period of time a child's tonsils and adenoids tend to be proportionately larger than their airway. This crowding makes the airway more easily obstruction.
The risk of sleep apnea also is higher in adolescents who are severely overweight or obese. Children of any age who have asthma or allergies also are more prone to developing sleep apnea.
Sleep apnea may increase sleep fragmentation, meaning that rather than experiencing the normal periods associated with each sleep stage, a child with apnea moves more frequently between deep and lighter stages of sleep. Research suggests that the long-term effects of sleep apnea in children include cognitive, behavioral, and psychosocial problems as well as growth delays and impacts on cardiovascular health.
Children with untreated sleep apnea may perform poorly on standardized tests of mental development. In a school-based study in India, children with sleep apnea were found to perform significantly less well in academic subjects than their peers. Other potential problems with intellectual development include lower scores on learning and memory metrics and on some types of intelligence quotient (IQ) tests. Children with the most severe apnea appear to also experience the most significant challenges to cognitive development.