AAP Issues a Wake-up Call on Teen Sleep
For the first time, the American Academy of Pediatrics (AAP) has issued a policy statement on school start times, urging middle schools and high schools to begin classes no earlier than 8:30 am, in order to address an epidemic of sleep insufficiency among adolescents and teens.
"The American Academy of Pediatrics strongly supports the efforts of school districts to optimize sleep in students and urges high schools and middle schools to aim for start times that allow students the opportunity to achieve optimal levels of sleep (8.5 to 9.5 hours) and to improve physical (eg, reduced obesity risk) and mental (eg, lower rates of depression) health, safety (eg, drowsy driving crashes), academic performance, and quality of life," the policy statement notes.
The group cites statistics from a National Sleep Foundation poll showing that as many as 59% of 6th- through 8th-graders and 87% of high school students in the United States get less than the recommended amount of sleep on school nights and that the average amount of school-night sleep obtained by high school seniors is fewer than 7 hours.
The same survey found that as many as 71% of parents believed that their adolescent was obtaining sufficient sleep.
"This mismatch indicates a significant lack of awareness among adults regarding the extent of adolescent sleep loss," the AAP notes.
Lifestyle factors ranging from staying up late playing video games to taking on heavier academic challenges contribute to the failure to get enough regular sleep. However, a big part of the problem is simply biological, according to Judith Owens, MD, FAAP, director of sleep medicine at the Children's National Health System and lead author of the policy statement, which was published in the September issue of Pediatrics.
Circadian Rhythm Changes
"There are changes in circadian rhythms that occur in conjunction with puberty that simply make it very difficult for adolescents to go to sleep before 11 at night," Dr. Owens told Medscape Medical News.
Changes in adolescence cause delays in the timing of nocturnal melatonin secretion, thereby slowing a youth's 'sleep drive,' in which the pressure to fall asleep is more gradual, she added.
Research has detailed the potential fallout when school schedules are not adjusted to correspond with the biological changes.
Various studies have shown that for adolescents, even a 30-minute earlier school start time is associated with shorter sleep duration, increased sleepiness, and problems with concentration, behavior, and absenteeism compared with later start times.
Meanwhile, the benefits of later start times have been documented. One key study (Carskadon MA, et al. Sleep. 1998;21:871-881) showed that delaying school start times for middle school students resulted in more total sleep on school nights and less daytime sleepiness, and important academic improvements were also evident, including reduced tardiness, improved academic performance, and improvements on computerized attention tasks.
Despite the evidence, as many as 43% of public high schools in the United States currently have a start time of earlier than 8:00 am, according to US Department of Education statistics.
Dr. Owens explained that at many schools, the problem is the result of an adherence to long-held, tiered transportation systems in which a first round of busses picks up the oldest students first, and earliest, and the youngest students are picked up last, and latest.
"The problem with that scenario is that it is pretty much the exact opposite of what we should do from a biological standpoint," Dr. Owens said. "Typically, younger kids are actually ready to go to school much earlier than the adolescents."
The effects of insufficient sleep on mental health have been shown to extend well beyond school performance, with potential consequences in mood, affect regulation, memory, attention, and behavior control.
The effects have also been shown to be potentially long-lasting, with sleep deprivation in teen years linked to diabetes and cardiovascular disease in later years.
"There's even the suggestion that chronic sleep loss may be linked to the development of Alzheimer's disease and other neurodegenerative diseases," Dr. Owens said.
An increased risk for obesity has been commonly linked to insufficient sleep, and the latest research, published last week in the Journal of Pediatrics, in fact shows a longitudinal association between adolescent sleep duration and the onset of obesity in young adulthood in both males in females.
Previous studies have shown the association to primarily involve boys. The new study, which looked at more than 10,000 American teens from a mean age of 16 years through young adulthood in the National Longitudinal Study of Adolescent Health, did also show only an association in boys in a cross-sectional analysis; however, a longitudinal analysis showed the association with both males and females (risk ratio 1.2; 95% confidence interval, 1.0 - 1.6])
The higher risk was seen among individuals who reported getting fewer than 6 hours of sleep per night, compared with those who got more than 8 hours.
Importantly, the study found that nearly one fifth of 16-year-olds fell into the less than 6 hours of sleep per night category.
According to lead author Shakira Suglia, ScD, the specific mechanisms behind the association are not clear, but the numerous adverse effects of sleep deprivation could play a role.
"It's plausible that fatigue from lack of sleep reduces overall physical activity," Dr. Suglia told Medscape Medical News.
"Lack of sleep may also make it harder to make healthy dietary choices, but unfortunately, we could not examine the role of diet in this study," said Dr. Suglia, assistant professor, Department of Epidemiology, Columbia University Mailman School of Public Health, New York City.
"There is also the potential that lack of sleep affects a number of hormones, particularly growth hormones and hormones that affect appetite and satiety."
Although unable to comment on the specifics of the AAP recommendations, Dr. Suglia noted that mounting evidence shows a multitude of short-term and long-term of benefits from receiving adequate sleep in adolescence.
"I can say that ensuring that adolescents get more than 8 hours of sleep per night will help with multiple benefits not only in their current day-to-day lives but also as adults."
In its statement, the AAP underscored the fact that, despite the potentially important benefits of later school start times in helping teens get adequate sleep, the measure is likely only one piece of the puzzle, and efforts should address the various other factors that contribute to sleep loss.
"It should also be emphasized that delaying school start times alone is less likely to have a significant effect without concomitant attention to other contributing and potentially remediable factors, such as excessive demands on students' time because of homework, extracurricular activities, after-school employment, social networking, and electronic media use," the AAP wrote.
Dr. Owens added that the policy statement should serve as wake-up call of sorts that teen sleep issues have important implications.
"What the policy statement does is bring sleep as a health issue to the forefront and really frames the issue of sleep not just as a luxury but as an absolute health imperative," she said.
"And it should be noted that all of the things that go into making sleep an important priority in the family, even to the extent of limiting after-school activities or employment, have to be part of the package."
The authors and Dr. Suglia report no relevant financial relationships.
Pediatrics. 2014;134:642–649. Full text