October 9, 2012
Researchers studied 4,100 teenagers and found that the one-third with the poorest sleep quality were more likely to be overweight or have unhealthy eating habits or cholesterol. Those teenagers who do not get enough sleep are more likely to be affected by conditions that impact heart health.
Poor sleep problems included issues falling asleep and staying asleep, bedtime “restlessness,” and bad dreams. The findings of the study, according to researcher Dr. Brian McCrindle at the Hospital for Sick Children in Toronto, Canada, do not prove that the sleep problems are to blame. In an interview he stated:
"It's hard to get at the causal pathway.”
Sleep problems are often linked to a number of poor life style habits. People who did not get enough sleep tend to exercise less, spend more time watching television, and eat a unhealthy diet than those who get enough sleep. The study found that this was true in sleep-deprived teens. Even when the research did add in poor lifestyle habits, poor sleep was still linked to a potential for heart disease. This would indicate that it is possible that disturbed sleep may also play a role. Researchers say that even if the link between them is indirect with daytime drowsiness keeping kids from being active, it is still important for kids to get enough sleep.
"When people think about cardiovascular risk, sleep doesn't usually come up," McCrindle said. "These findings give some more evidence that sleep is one of the things people should think about."
The study was published in the Canadian Medical Association Journal. It included 4,100 Ontario teens who were asked to answer questions about their sleep patterns. All of the participants in the study were healthy, but the one-third of those teens with the worst sleep scores showed signs of possible heart trouble later in life. 48 percent of those teens were either overweight or showed elevated blood pressure or high levels of “bad” cholesterol. In comparison with 39 percent of those who were more well-rested.
Researchers looked at other factors such as teen’s diet, exercise and television habits. Findings showed that one-third of teens that had the worst sleep quality were 43 percent more likely to show risk factors for heart disease than those who had better quality of sleep. Teens do not show signs of poor heart health yet, but that could change later on.
"These risk factors tend to track into adulthood," McCrindle said. "And they tend to get worse."
Other studies in adults have linked poor sleep habits to heart disease and diabetes. Researchers still are not sure of the exact reason, but one theory is that not getting enough sleep could negatively affect hormones, specifically those that regulate metabolism and appetite. Another reason may be that those who are awake into the late night/early morning hours are more likely to snack.
"I think the importance of sleep hygiene cannot be overemphasized," said Dr. Indra Narang, the lead researcher on the study.
"In general, we recommend that teenagers get 8 to 9 hours of sleep each night," Narang said.
But in reality, she noted, studies suggest that half of teenagers get fewer than 7 hours of sleep on weeknights.
Weekends tell a different story, when most teens take advantage of being able to sleep in. Narang noted, this will not make up for poor sleep and late nights during the week.
"You don't repay your sleep debt by sleeping in on the weekends," she said.
Both Narang and McCrindle said parents should help to encourage their teens to keep a consistent sleep schedule and remove “stimulants” such as TVs, computers and cell phones from their bedrooms.
Adapted from NBCNews.com "Teens' poor sleep tied to heart risk factors." Amy Norton/ Reuters/ October 2, 2012