Sleeping Longer Than 9 Hours Or Long Naps During The Day Increases Risk Of Strokes
Source: Thailand Medical News Dec 15, 2019 4 years, 11 months, 1 week, 2 days, 4 hours, 13 minutes ago
Individuals who take long naps during the day or
sleep nine or more hours at night may have an increased risk of
stroke, according to a study published in
Neurology, the medical journal of the American Academy of Neurology.
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Also, individuals who took a regular
midday nap lasting more than 90 minutes were 25 percent more likely to later have a
stroke than people who took a regular
nap lasting from one to 30 minutes. People who took no
naps or took
naps lasting from 31 minutes to one hour were no more likely to have a
stroke than people who took
naps lasting from one to 30 minutes.
Dr Xiaomin Zhang, MD, Ph.D., of Huazhong University of Science and Technology in Wuhan, Chin and study author told
Thailand Medical News, "More research is needed to understand how taking
long naps and
sleeping longer hours at night may be tied to an increased risk of
stroke, but previous studies have shown that long nappers and sleepers have unfavorable changes in their cholesterol levels and increased waist circumferences, both of which are risk factors for
stroke. In addition, long
napping and
sleeping may suggest an overall inactive lifestyle, which is also related to increased risk of
stroke."
The research involved 31,750 people in China with an average age of 62. The people did not have any history of
stroke or other major health problems at the start of the study. They were followed for an average of six years. During that time, there were 1,557
stroke cases.
All research participants were asked questions about their
sleep and
napping habits. Midday napping is common in China, Zhang said. Eight percent of the people took
naps lasting more than 90 minutes. And 24 percent said they slept nine or more hours per night.
The research found that people who
sleep nine or more hours per night are 23 percent more likely to later have a
stroke than people who
sleep seven to less than eight hours per night. People who
sleep less than seven hours per night or between eight and less than nine hours per night were no more likely to have a
stroke than those who slept from seven to less than eight hours per night.
The study findings were all adjusted for other factors that could affect the risk of
stroke. These include high blood pressure, diabetes and smoking.
Individuals who were both long
nappers and long
sleepers were 85 percent more likely to later have a
stroke than people who were moderate
sleepers and
nappers.
The medical r
esearchers also asked people about how well they slept. People who said their
sleep quality was poor were 29 percent more likely to later have a
stroke than people who said their
sleep quality was good.
About 1 percent of cases per person-years of the long
nappers later had a
stroke, compared to 0.7 percent of cases per person-years of the moderate
nappers. The numbers were the same for the long and moderate sleepers, with 1 percent of cases per person-years compared to 0.7 percent of cases per person-years having a
stroke.
Dr Zhang added, "These results highlight the importance of moderate
napping and
sleeping duration and maintaining good
sleep quality, especially in middle-age and older adults.”
Dr Zhang noted that the study does not prove cause and effect between long n
apping and
sleeping and
stroke. It only shows an association. Limitations of the study include that information on
sleep and
napping was taken from questionnaires, not from recording people's actual
sleep and information was not collected on
sleep disorders such as snoring and
sleep apnea. Also, the study involved older, healthy Chinese adults, so the results may not apply to other groups.
Source Reference: Zhou L, et al "Sleep duration, midday napping, and sleep quality and incident stroke: The Dongfeng-Tongji cohort" Neurology 2019; DOI:10.1212/WNL.0000000000008739. 
