Long Naps, Long Nighttime Sleeping May Be Risk Factors for Stroke

By Dorothy L. Tengler, via Multibriefs

Every 40 seconds someone has a stroke; every four minutes, someone dies from stroke. Although stroke risk increases with age, strokes can — and do — occur at any age. In 2009, 34% of those hospitalized for stroke were younger than 65 years of age.

Every year, about 795,000 people in the United States have a stroke. About 610,000 of these are first strokes; 185,000 are recurrent strokes. Medical conditions, lifestyle factors, ethnicity, and family history all play a part in the risk for stroke.

Hypertension, high cholesterol, smoking, obesity, and diabetes are the leading causes of stroke and, in fact, 1 in 3 adults in the United States has at least one of these conditions or habits. Some risk factors such as hormones and pregnancy are specific to women.

A new study suggests another risk of stroke is too much sleep, including long daytime naps or longer than nine hours at night. People who took a regular midday nap lasting more than 90 minutes were 25% 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.

The study involved 31,750 people in China, with an average age of 62 years. Inclusion criteria specified that participants did not have any history of stroke or other major health problems at study start.

They were followed for about six years. During that time, 1,557 stroke cases were reported.The participants were asked questions about their sleep and napping habits. According to the study, 8% of the people took naps lasting more than 90 minutes. And 24% said they slept nine or more hours per night.

People who were both long nappers and long sleepers were 85% more likely to later have a stroke than people who were moderate sleepers and nappers. People who said their sleep quality was poor were 29% more likely to later have a stroke than people who said their sleep quality was good.

Of the long nappers, 1% of cases per person-years later had a stroke, compared to 0.7% of cases per person-years of the moderate nappers. The numbers were the same for the long and moderate sleepers — with 1% of cases per person-years compared to 0.7% of cases per person-years having a stroke.

According to Xiaomin Zhang, MD, Ph.D., of Huazhong University of Science and Technology in Wuhan, China, further research would help explain how taking long naps and sleeping longer hours at night may be tied to an increased risk of stroke. However, 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, indicating that an inactive lifestyle may be at play.

Dorothy L. Tengler, MA, is a freelance medical writer/communication specialist with nearly 20 years of experience in the pharmaceutical and medical communication industries. She has developed educational and medical marketing materials, including monographs, slide kits, health articles, primary and review manuscripts, and pharmaceutical sales training materials.