Out-of-sync days throw heart and metabolism out of whack

Study shows sleep/wake cycle is more important than number of hours slept

Sleeping during the day and staying awake at night can lead to heart and metabolic problems, even after just a few days of the out-of-sync schedule, a new study reports. The results, published online March 2 in Proceedings of the National Academy of Sciences, may help explain the high rates of heart disease, diabetes and obesity among people who work the graveyard shift.