Sleeping too much or too little could increase the risks of major cardiovascular events and mortality, suggests new research published in the European Heart Journal.
The study investigated the association between estimated total daily sleep duration and daytime nap duration with mortality and major cardiovascular events among 116,632 adults from 21 countries from the Prospective Urban Rural Epidemiology (PURE) study.
It found that sleeping six hours or less a day and longer than eight hours a day was linked with an increased risk of cardiovascular events and mortality (HR 1.09; 95% CI 0.99-1.20). An estimated sleep duration of six to eight hours per day was associated with the lowest risk of deaths and major cardiovascular events.
Compared to people who slept for the recommended time, those who slept eight to nine hours a day had a 5 per cent increased risk of the composite outcome. People sleeping between nine and 10 hours a day had an increased risk of 17 per cent and those sleeping more than 10 hours a day had a 41 per cent increased risk (P<.0001>
Daytime napping was associated with increased risks of major cardiovascular events and deaths only in those with more than six hours of nighttime sleep.