A good night's sleep may be just what your arteries need. So finds a new five-year study in which middle-aged people who had an extra hour of sleep each night were less likely to have artery-stiffening calcium deposits. Lauderdale and her colleagues have been following a group of young adults for years, studying their heart arteries from a number of angles. The latest report linked the sleeping habits of 495 participants, ages 35 to 47, with the incidence of artery calcification, measured by CT scans. Calcium deposits can make the coronary arteries less flexible and ultimately lead to heart disease....