Skipping sleep 'hardens arteries'

People who scrimp on sleep are more likely to develop hardening of their arteries. Calcified arteries were found in nearly a third of people who slept fewer than five hours a night. This dropped to around one in 10 for those who slept an extra hour, the Journal of the American Medical Association study of 495 adults found. In the study, the volunteers underwent two CT scans, designed to assess the build-up of calcium in the heart's arteries, five years apart. They also filled out sleep questionnaires, kept a sleep diary and wore a wrist monitor for six nights that measured movement to give an estimate of how long they were actually lying still and asleep. At the first scan, none of the volunteers had any calcification in their arteries but five years later 61 of them did. This calcification appeared to be linked with lack of sleep. The risk was lowest for those who regularly had more than seven hours sleep each night.