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Sleep Health

Sleeping More or Less than This Many Hours a Night May Lead to Serious Health Issues


For many of us, the fall season ushers in work, stress, and a lack of sleep. You may be too busy keeping up with your family’s schedule to get a full night’s rest. On the weekends, you might try to catch up by getting more than eight hours. However, now’s the time to change those habits as best you can. New research suggests that your long-term health will benefit from six to eight hours of sleep every night. Those benefits include a lower risk for heart disease, depression, diabetes, and high blood pressure. Better yet, high-quality sleep may increase how long you live.

The study published in the Nature and Science of Sleep Journal is unique because it doesn’t rely on self-reported data from participants. Instead, researchers used accelerometry and primary care data from over 84,404 patients in the U.K. Accelerometry is a form of research that uses accelerometers, or devices that measure movement during sleep.  

A Closer Look at the Sleep Study 

The researchers received the data for the study from the UK Biobank, which is a large database of in-depth genetic and health information from volunteers in the U.K. From 2006 to 2010, the Biobank recruited participants between 40 and 69 years old. From 2013 to 2015, many of those recruited participants agreed to provide sleep data to the Biobank by wearing wrist accelerometers for seven consecutive days on their dominant wrist. 

At the same time, the researchers collected the participants’ primary care information. That included disease diagnoses, prescriptions, lab tests, and vaccination records. The team also recorded hospital visits.  

Based on the data they had, the researchers divided the participants into five groups: those who got fewer than five hours of sleep per night, five to six hours per night, six to seven, seven to eight, and eight to nine hours. In addition, they measured sleep fragmentation, or repetitive, short interruptions of sleep.  

About 56 percent of the participants were female and 44 percent were male. They also classified 69 percent of the patients as having an optimal sleep pattern, which meant that 31 percent of them had less optimal sleep. 

A Lack of Sleep and Too Much Sleep Are Both Bad for Health 

Interestingly, the researchers noticed the extreme ends of sleep duration were linked to a higher risk of many diseases. For instance, the risk of hypertension skyrocketed in participants who got fewer than five hours of sleep. But it also increased in participants who got over eight hours of sleep. The same was true for coronary heart disease and other arterial diseases.  

There was a greater risk for mood disorders such as depression in those who got fewer than five hours of sleep and more than eight hours of sleep. That risk was about equal for both groups of sleepers. In addition, the risk of diabetes increased in participants who got fewer than five hours of sleep. Unlike the other diseases mentioned, diabetes risk didn’t significantly increase in those who got over eight hours.  

As a result, six to eight hours of uninterrupted sleep seemed to be the ideal amount for long-term health. Previous research supports this theory. Another study published in the European Society of Cardiology, for example, found that the sweet spot is between six and eight hours. This duration reduced the risk of dying from coronary artery disease or stroke.  

So, before you hit the pillow, set your alarm six to eight hours ahead! It may take a few weeks to figure out where your exact sweet spot lies (is it at six hours, seven, or eight?) If you struggle to stay asleep for even six hours, try not to take naps after 3 p.m. and stay clear of alcohol and caffeine starting around the same time. Get yourself sleepy with a little soothing music and a dark, quiet room. Hopefully, you’ll start snoozing in no time.  

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