Regularly getting less than six hours' sleep a night may raise the risk of stroke in middle age.

Scientists in the US studied 5,666 people aged 45 and older who had no history of stroke and were of normal weight. Over three years they found that those who habitually slept for less than six hours were significantly more likely to suffer a stroke. This had a greater effect than risk factors such as obesity, researchers from the University of Alabama told the Sleep 2012 meeting in Boston.