Obese adolescents not getting enough sleep?

Cincinnati, OH, March 6, 2014 -- Lack of sleep and obesity have been associated with an increased risk of cardiovascular and metabolic diseases in adults and young children. However, the association is not as clear in adolescents, an age group that is known to lack adequate sleep and have an overweight and obesity prevalence rate of 30% in the US. In a new study scheduled for publication in The Journal of Pediatrics, researchers found that cardiometabolic risk in obese adolescents may be predicted by typical sleep patterns.

Heidi B. IglayReger, PhD, and colleagues from the University of Michigan and Baylor University studied 37 obese adolescents (11-17 years of age). Metabolic syndrome characteristics (fasting cholesterol and blood sugar, waist circumference, body mass index [BMI], and blood pressure) were measured to create a continuous cardiometabolic risk score. The adolescents were fitted with a physical activity monitor, which was worn 24 hours a day for seven days, to measure typical patterns of physical activity and sleep.

One-third of the participants met the minimum recommendation of being physically active at least 60 minutes a day. Most participants slept approximately seven hours each night, usually waking up at least once. Only five of the participants met the minimal recommended 8.5 hours of sleep per night. Even after controlling for factors that may impact cardiometabolic risk, like BMI and physical activity, low levels of sleep remained a significant predictor of cardiometabolic risk in obese teens. This shows that even among those already considered to be at risk for cardiometabolic disease, in this case obese teens' decreased sleep duration was predictive of increased cardiometabolic risk.

This study cannot determine whether lack of sleep causes cardiometabolic disease or if obesity itself causes sleep disturbances. However, according to Dr. IglayReger, "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." These data provide evidence that objective sleep assessment may be a useful screening tool to identify at-risk adolescents. Future studies are needed to determine if improving sleep duration would decrease the risk of developing cardiometabolic diseases.