Grant: Project Grant

Humans have a built-in circadian rhythm (body clock) that repeats every 24-hrs. It tells our bodies when we should be awake or asleep and it stays on time by using information from the environment around us, like light, regularly timed meals, and activity. The body clock controls the rhythms of most functions including body temperature, heart rate, blood pressure, and hormone release. Sometimes the timing of these bodily functions gets disrupted and out of sync with the rhythm of the body clock, which is called circadian misalignment (e.g., bed/wake times shifts later). Teenagers experience many changes in the timing of their sleep. Teens commonly go to bed later and sleep in on the weekends. Our 24hr society promotes this later sleep delay. Using gadgets late at night, staying up late on weekends, and having inconsistent routines across the week can contribute to this shift toward later sleep timing. Shifts in sleep times often happen during puberty. Girls start going to bed later before boys, which coincides with their earlier puberty onset than boys. In fact, compared to adults, teenagers have a body clock slightly longer than 24 hours. Our project tracks the evolution of the circadian timing system changes across puberty. We will investigate if circadian misalignment might be a culprit in child obesity and cardiometabolic health. Wearable gadgets will be worn by teens to monitor their sleep, activity, temperature, heart rate, and blood pressure. The information we learn from this project will help parents, schools, and policy makers develop better prevention programs to improve childhood health. We also help science make technology smarter so wearable gadgets can give more accurate information about bodily rhythms.