Too Much or Too Little Sleep Increases Risk of Mortality

Sleep anything but seven to eight hours a night and you may greatly increase your risk of death, shows a Finnish study of 21,268 twins published in yesterday's issue of the journal SLEEP.

Based on questionnaires completed between 1975 and 1981, these subjects were classified by how long and how well they slept and whether they used hypnotics or tranquilizers. Results showed that short sleepers, those who slept seven hours or less per night, had an increased risk of mortality of 26 percent for males and 21 percent for women. Similar results were found for sleeping more than eight hours, however, with respective increases of 24 and 17 percent. Meanwhile frequent use of hypnotics/tranquilizers increased risk of mortality by 31 percent in men and 39 percent in women.

Previous studies have noted the connection between sleep disturbances, deficits and excesses and increased mortality. Moral of the story? See a doctor if you have trouble sleeping between seven and eight hours a night, but be wary about taking sleep aids regularly.

Read more: Too much sleep 'could cut life span'