Kids who stay up all night playing video games, reading comic books, or being on social media must be told to sleep early, especially if they are obese.
A new study, led by Heidi IglayReger, supervisor of the Physical Activity Laboratory at the Michigan Metabolomics and Obesity Center, part of the University of Michigan Health System, has found that teens who get less than 8.5 hours of sleep a day puts them at risk for cardiometabolic diseases like heart disease and diabetes.
The researchers studied the physical activity levels, sleeping habits, and overall health of 37 obese Americans aged between 11 and 17. The researchers measured for type 2 diabetes and cardiovascular disease risk, which included factors like body mass index (BMI), waist circumference, and blood sugar levels. The participants were also fitted with a physical activity monitor which they wore for 24 hours a day for a week. The monitor measures typical patterns of sleep and physical activity.
The researchers have found that only one-thirds of the 37 participants were physically active for at least 60 minutes a day, the minimum recommendation for physical activity. Most of them slept for 7 hours every night, waking up at least once. However, only about 13 percent met the minimum sleep requirements of 8.5 hours a day for their age group.
The study, published in The Journal of Pediatrics, stated that sleep assessments may be useful in identifying teens who are at risk for heart disease and diabetes, as too little sleep was associated with an increased risk of these two conditions.
"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," said IglayReger.
Scientists and doctors have proven that there is a direct link between lack of sleep and the incidence of diabetes and heart disease in children and adults, but this link has not yet been established in the case of adolescents, who are known for lack of sleep. In the US, the obesity and overweight proportion of adolescents totals 30 percent.
The Centers for Disease Control and Prevention (CDC) has said that over the past three decades, obesity rates have quadrupled. Obese youths aged 12 to 19 comprised only 5 percent of the obese population in 1980. In 2012, that number has risen to 21 percent.
"Obese youth are more likely to have risk factors for cardiovascular disease, such as high cholesterol or high blood pressure. In a population-based sample of 5- to 17-year-olds, 70% of obese youth had at least one risk factor for cardiovascular disease," said the CDC.