Is there a sleep duration sweet spot to decrease your risk of heart attacks? According to researchers from the University of Colorado: Boulder, there is! The research team—consisting of researchers from CU Boulder, Massachusetts General Hospital, and the University of Manchester—aimed to discover associations between sleep duration and myocardial infarction while accounting for genetic risk and other factors impacting sleep duration.
The study was published this week in the Journal of the American College of Cardiology. In a press release from CU Boulder regarding the study lead author and assistant professor of Integrative Psychology Celine Vetter stated that “This provides some of the strongest proof yet that sleep duration is a key factor when it comes to heart health, and this holds true for everyone.”
Researchers analyzed self-reported data from more than 461,000 UK Biobank participants (who were not suffering from relevant heart conditions) aged 40 to 69, as well as their genetic information. They followed the study participants over seven years. “Short sleep duration” was classified as less than six hours, while “long sleep duration” was considered more than nine hours of sleep.
Their results showed six to nine hours of sleep nightly reduced heart attack risk by 18% for those study participants genetically predisposed to heart disease. Those not genetically predisposed to heart disease had a 20% higher risk of myocardial infarction if they slept less than six hours and a 34% higher risk if they slept more than nine hours.
As study participants fell farther away from the six to nine-hour sleep range, their risk of heart attack increased even more. Those who slept only five hours per night had a 52% increased risk of myocardial infarction and those whole slept 10 hours a night doubled their risk.
Sleep duration can be impacted by numerous factors. However, this study accounted for a total of 30 factors including body composition, physical activity, socioeconomic status, and mental health. This study did not attempt to understand why sleep duration impacts heart attack risk, but researchers are hopeful that this information alone will help increase awareness about the importance of sleep and heart-health.