Telling adolescents to get enough sleep can sometimes be a tall order, but a new study in The Journal of Pediatrics reminds us just how important a good night's sleep can be. It suggests obese youths who do not get adequate sleep may increase their risk for developing diabetes, heart disease and stroke.
The researchers, from the University of Michigan Health System and Baylor University, say the combination of inadequate sleep and obesity has been linked to raised risks of cardiovascular diseases in adults and younger children.
But this link has been unclear in adolescents, a group notorious for lack of sleep and whose obesity and overweight proportion totals 30% in the US.
According to the Centers for Disease Control and Prevention (CDC), adolescent obesity has quadrupled over the past 30 years. The percentage of youths between the ages of 12 and 19 who were obese increased from 5% in 1980 to almost 21% in 2012.
The CDC note that obese adolescents are more likely to have prediabetes, joint problems, sleep apnea and poor self-esteem. Over the long term, they are more likely to be obese adults, putting them at risk for heart disease, stroke, cancer and osteoarthritis.
Armed with this knowledge, the researchers from this latest study - led by Heidi IglayReger, supervisor of the Physical Activity Laboratory at the Michigan Metabolomics and Obesity Center - studied 37 obese youths between the ages of 11 and 17.
Low sleep levels are a 'significant cardiometabolic risk factor'
The team measured the adolescents' risk factors for type 2 diabetes and cardiovascular disease, which included fasting cholesterol, blood sugar, waist circumference, body mass index (BMI) and blood pressure. They used this data to create a continuous cardiometabolic risk score.
Overweight adolescents who do not get adequate sleep have higher cardiometabolic risks, the study shows.
Wearing a physical monitor 24 hours a day for a full 7 days, the adolescents' physical activity and sleep patterns were then monitored.
Of the participants, the researchers found that one third met the minimum physical activity recommendation, which was 60 minutes per day.
Although most participants slept 7 hours each night, waking up at least once on average, just over 13% of them met the minimum sleep recommendation, at 8.5 hours per night.
After controlling for factors like BMI and physical activity, which could impact cardiometabolic risk, the team found that low sleep levels were still a significant factor for cardiometabolic risk in the adolescents.
Though the researchers say their findings cannot conclude that lack of sleep actually causes cardiometabolic disease or that obesity causes sleep disturbances, Heidi IglayReger says:
"However, the strong association between sleep duration and cardiometabolic risk score independent of the effects of body composition and physical activity suggest a potential influence of sleep duration on cardiometabolic health in obese adolescents."
Further studies needed
The researchers also add that their data show sleep assessment could be a useful tool in identifying adolescents who are at risk, though further studies are needed.
Heidi IglayReger talked to Medical News Today about their plans for further study. She said they plan to create a "study arm" in which getting optimal sleep is the primary goal for all participants.
"We will track sleep objectively with the same accelerometers utilized within this publication and will stratify primary outcome variables by sleep group," she explained. This will allow the team to determine whether sleep-based interventions improve cardiometabolic profile.
"We will further consider the actual amount and quality of sleep obtained overall," IglayReger said. "For instance, do adolescents in the sleep group actually sleep more?"
"We know that for a lot of reasons adolescents do not get enough sleep. We hope that by helping obese adolescents and their families make lifestyle changes, such as obtaining optimal sleep, we can improve cardiometabolic health."
The team concludes their study by noting that their findings show how even among obese youths already at risk for cardiometabolic disease, decreased sleep duration was linked to increased cardiometabolic risk.
Medical News Today recently reported on a study that suggested bedroom TVs are linked to childhood obesity.