*The following is excerpted from an online article posted on HealthDay.
Singapore's teens are the world's best on an international test of academic performance, but they pay for it with their sleep.
Most get well below the recommended eight to 10 hours of shut-eye on school nights. But a new study finds that delaying the morning school bell would help.
Studies in Western nations have found that later school start times improve students' sleep and well-being. But the impact in East Asian countries, where students are under strong pressure to excel, has been less clear, the researchers explained.
The new study included 375 students at an all-girl's high school in Singapore that moved its start time from 7:30 a.m. to 8:15 a.m.
In Singapore, school typically begins around 7:30 a.m. (That's an hour earlier than recommended by the American Academy of Pediatrics, the American Medical Association and the American Academy of Sleep Medicine.) On average, teens in Singapore average 6.5 hours of sleep a night on school nights.
At a follow-up one month after the later school start was introduced, teens were spending an extra 23 minutes in bed on school nights. The percentage who said they slept at least 8 hours a night rose from just under 7 percent to 16 percent, the researchers found.
After nine months, total sleep time had increased by about 10 minutes a night, the findings showed.
At both follow-ups, the teens reported less daytime sleepiness, greater alertness, as well as fewer depressive symptoms and mood problems.
"Starting school later in East Asia is feasible and can have sustained benefits," said lead researcher Michael Chee. He is a professor in the neuroscience and behavioral disorders program at Duke-NUS Medical School in Singapore.
The study was published April 10 in Sleep, the international journal for sleep and circadian science.