Amount of nightly sleep that confers the lowest heart risk, according to a new study. People getting less than 6 hours a night were twice as likely to have a stroke or heart attack and 1.6 times more likely to have congestive heart failure than those who slept more. People who slept too much — more than 8 hours a night — were also more likely to have chest pain and coronary artery disease. Lack of sleep has been linked to diabetes and high stress hormones, blood pressure, heart rate and inflammatory markers, which are all bad for the heart. The ill effects of too much sleep are harder to suss, but oversleepers may be more likely to be depressed and exercise less, which increases heart risks. [via ABC News]
