Do you wake up early for work on weekdays? Then we're afraid researchers from the University of Pittsburgh have some bad news for you: You should be waking up early on weekends, too. UPI reports that a study published in the Journal of Clinical Endocrinology & Metabolism found changes in sleep patterns throughout the week can increase people's risk of heart disease, diabetes, and more. The study is the first to show a link between "social jetlag"—the difference between someone's natural sleep patterns and the sleep schedule imposed on them by work and other responsibilities—and negative health effects in otherwise healthy people, according to a press release from the Endocrine Society.
Of the 447 people studied by researchers, 85% went to sleep later and woke up later on their days off, reports the New York Times. Those with the biggest shifts in sleep schedule had worse cholesterol, a higher BMI, a larger waist circumference, and more, results that held even when taking physical activity and diet into account. "Our findings suggest that a misalignment of sleep timing is associated with metabolic risk factors that predispose to diabetes and ... cardiovascular disease," the study states. Researchers say people need to be better informed about their workplace choices. "If future studies replicate what we found here, then we may need to consider as a society how modern work and social obligations are affecting our sleep and health," one researcher concludes. (On the flip side, a late bedtime might be making you fat.)