睡眠不足增加脑中风的风险

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睡眠不足增加脑中风的风险

中风，现代医学称为急性脑血管病或脑血管意外，是多种原因引起的一种严重危害人类健康的常见病，特别多见于中老年人，有不少中风病人往往出现过睡眠呼吸暂停综合症。一项新的研究表明，有30％的成年人经常晚上睡不到6小时，他们患中风的风险是睡眠充足人的4倍。

据《今日美国报》报导，这一为期3年的研究共调查了5,666名成年人，研究发现，每天睡眠少于6小时人的中风风险是睡眠7到8小时人的4倍。这一结论对于那些身体质量指数（BMI）在正常范围、低睡眠呼吸暂停风险的人群一样适用。

本研究的第一作者、伯明罕（Birmingham）阿拉巴马大学（University of Alabama）研究员鲁维特（Megan Ruiter）表示，即便对于没有超重、没有中风其他易患因素的那些人，他们睡眠不足也一样易得中风。

鲁维特说：“人们都知道健康饮食、适当的运动对预防中风的重要性，但大多数人都不太知道睡眠不足对中风的影响。睡眠真的是非常的重要，睡眠不足整个人就笼罩在紧张的压力状态下。”

此前研究已表明，持续的睡眠不足中度增加心血管病的风险，如心脏病发作等。波士顿布莱根妇女医院（Brigham and Women's Hospital）的心脏病学家潘德（Reena Pande）说，这次研究的重点是那些体重正常、没有中风其他风险的人群。他说：“睡眠不足会在心血管系统中会产生许多有害的变化，这点非常清楚。”

健康专家建议，每天的睡眠时间应有7到9小时。但来自全国睡眠基金会（National Sleep Foundation）的资料表明，每天晚上睡眠8小时或8小时以上的人从2001年的38％降至现在的28％。5月份政府的一项研究发现，30％的在职人员每天只睡6小时甚至更少。

报导说，中风仍然是美国的第4大死亡原因，当脑部血供受限或不足时易发生中风。吸烟、体重超重和缺乏运动是中风的主要危险因素。

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Too Little Sleep Tied to Stroke Risk

Getting fewer than six hours a night may affect cardiovascular system, study says
URL of this page: http://www.nlm.nih.gov/medlineplus/news/fullstory_126126.html(*this news item will not be available after 09/09/2012)

Monday, June 11, 2012
Related MedlinePlus Pages

Sleep Disorders [http://www.nlm.nih.gov/medlineplus/sleepdisorders.html]  
Stroke [http://www.nlm.nih.gov/medlineplus/stroke.html]  
MONDAY, June 11 (HealthDay News) -- Middle-aged and older people who regularly sleep less than six hours a night may be significantly raising their risk of stroke, a new study suggests.

As much as a fourfold increased risk was seen among normal-weight people who didn't suffer from sleep apnea but got fewer than six hours of sleep each night, the researchers found. Both obesity and sleep apnea are known risk factors for stroke.

"Sleep is important," said lead researcher Megan Ruiter, a postdoctoral fellow at the University of Alabama at Birmingham's School of Medicine. "There is evidence that insufficient sleep ... increases all sorts of abnormal responses in the body."

Lack of sleep increases inflammation and causes increases in blood pressure and the release of certain hormones, all creating a greater stress response that can increase the risk for stroke, Ruiter said.

The results of the study were scheduled to be presented Monday at the annual meeting of the Associated Professional Sleep Societies in Boston. The data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

For the study, Ruiter's group collected data on more than 5,600 people who took part in a larger study on geographical and racial differences in stroke.

Over three years of follow-up, the researchers found that sleeping fewer than six hours a night was associated with an increased risk of stroke in normal-weight people beyond that related to other risk factors.

They didn't find any association between stroke and short sleep among overweight and obese people.

Although the study found an association between shorter sleep and stroke, it did not prove a cause-and-effect relationship.

Dr. Michael Frankel, director of vascular neurology at Emory University and director of the Marcus Stroke & Neuroscience Center at Grady Hospital, both in Atlanta, commented that "although difficult to define why this may be occurring, one can speculate about a possible mechanism linked to changes in cortisol levels, an important stress hormone that may be in higher levels in people who have shortened sleep."

Elevated levels of this hormone may trigger dysfunction of the cells that line and protect people's blood vessels and set in motion the cascade of events that leads to stroke, he explained.

This finding may explain why people without traditional vascular risk factors such as obesity, hypertension and diabetes occasionally have a stroke, he added.

"We know that in about a third of patients with ischemic stroke, doctors are unable to define a cause," Frankel said. "Reduction in sleep may be contributing in some of these patients."

"For those of us who chronically work long hours, we may need to listen closely to these findings and adjust our lifestyle to reduce our risk of stroke," he added.

Controlling blood pressure; eating a low-calorie, balanced diet; exercising; not smoking; not drinking heavily; having regular checkups; and closely following doctors' advice remain critical for vascular health, Frankel said.

"But attention to proper sleep may be equally important," he added.

Another expert, Dr. Keith Siller, medical director of the NYU Comprehensive Stroke Care Center in New York City, agreed that sleep is an important factor.

"I see this as part of a general message that along with exercise and a proper diet, a good night's sleep should be included in a healthy lifestyle," he said.

SOURCES: Megan Ruiter, Ph.D., postdoctoral fellow, University of Alabama at Birmingham School of Medicine; Michael Frankel, M.D., professor and director, vascular neurology, Emory University, and director, Marcus Stroke & Neuroscience Center, Grady Hospital, Atlanta; Keith Siller, M.D., medical director, NYU Comprehensive Stroke Care Center, New York City; June 11, 2012, presentation, Associated Professional Sleep Societies annual meeting, Boston