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.
Unlike in adults—who become sleepy and sedate with sleep deprivation—children tend to become hyperactive. This may cause difficulties with attention and social behavior and may also contribute to anxiety and depression. Hyperactivity resulting from sleep apnea in children sometimes is misdiagnosed as Attention Deficit and Hyperactivity Disorder (ADHD).
An English study in the Journal of Thoracic Disease also showed that children with untreated apnea were more likely to exhibit poor social and communication skills and have difficulty regulating their behaviors. These traits are often experienced by caregivers as uncooperativeness or emotional volatility.
When sleep apnea continues over a long period in childhood, increasing markers of inflammation can also be found. Inflammation, in turn, can lead to a cascade of negative health outcomes such as compromised organ function.
A child who is not getting enough restorative sleep at night could show signs of excessive sleepiness during the day. Babies and children need different amounts of sleep based on their age and stage, but if you notice your child napping longer or more frequently than usual or seeming tired when he or she is normally energetic, apnea could be the cause.
Sleep-disordered breathing in children is associated with negative effects on growth. Children with apnea may lose ground among their peers, or slow along their previous growth path, resulting in an inability to meet their full growth potential. This may be caused by frequent awakening from deep, slow-wave sleep which in turn could disrupt normal hormonal secretion, including growth hormones. In extreme circumstances, a child with apnea whose growth falls far below healthy levels may be diagnosed with failure to thrive.