Lack of sleep in obese teens predicts heart disease risk

Low levels of sleep -- fewer than 8 1/2 hours -- is a significant predictor of cardiometabolic risk in obese teens, U.S. researchers say. Lead author Heidi IglayReger, supervisor of the Physical Activity Laboratory at the Michigan Metabolomics and Obesity Center, part of the University of Michigan Health System, and colleagues at Baylor University studied 37 obese adolescents, ages 11 to 17. The researchers measured for type 2 diabetes and cardiovascular disease risk factors such as fasting cholesterol, blood sugar, waist circumference, body mass index and blood pressure. The teens were fitted with a physical activity monitor, which they worn 24-hours a day for seven days to measure typical patterns of physical activity and sleep. One-third of the study participants met the minimum recommendation of being physically active at least 60 minutes a day, while most participants slept approximately 7 hours each night -- usually waking up at least once. Only five of the participants met the minimal recommended 8 1/2 hours of sleep per night. The study, published in The Journal of Pediatrics, found even after controlling for factors that might impact cardiometabolic risk, such as BMI and physical activity, low levels of sleep remained a significant predictor of cardiometabolic risk in obese teens. The study could not determine whether lack of sleep caused cardiometabolic disease or if obesity, or other factors caused sleep disturbances, IglayReger said.