Diseases
Dozing off daytime signals higher risk of stroke
By Ben Wasserman
Feb 22, 2008 - 10:30:31 AM

FRIDAY FEB 22, 2008 (Foodconsumer.org) -- Excessive daytime sleepiness is not a good sign.  Dozing off at work or during the daytime may suggest you have a higher risk of stroke, heart attack and other cardiovascular disease, according to a new US study.

The study reported at the American Stroke Association's International Stroke Conference 2008 showed the stroke risk was two to four folds higher in those with moderate dozing compared to those who did not experience dozing-off.

Dosing is defined as unemotionally falling asleep.

For the study, Bernadette Boden-Albala, Ph.D., lead author of the study, at Columbia University's College of Physicians and Surgeons in New York City and colleagues followed 2,153 men and women at an average age of 73 for two years.

The risk of stroke was 2.6 times higher among those who reported "some dozing" and 4.5 greater among those with "significant dozing" compared to than those reported "no dozing".
 
Boden-Albala said the findings suggest daytime dozing "may be an important and novel stroke risk factor" and physicians need to further evaluate their patients for their risk of stroke if they doze off often.

Still, the researchers do not know whether the dozing off was caused by sleep deprivation or nighttime apnea.  The latter was early found associated with an increased risk of stroke.

The current study involved a population with an average age of 73 comprised of 60 percent Hispanic, 20 percent black and 18 percent white.  All participants of whom 64 percent were women had not suffered a stroke when entering the study.

Starting in 2004, Boden-Albala and team collected daytime dozing data annually for two years using the Epworth Sleepiness Scale, which asks people to rate their frequency of dozing off during specific situations such as watching TV, sitting and talking to others, sitting quietly after a lunch without alcohol and stopping in traffic while driving.

Then, they classified participants into three groups based on the Epworth data as "no dozing" (44%), "some dozing" (47%) and "significant dozing" (9%).

During the follow-up, the researchers identified 40 strokes and 127 vascular events (defined as heart attack or stroke death caused by vascular problem).

After other risk factors such as age, race-ethnicity, sex, education, blood pressure, diabetes, obesity and physical activity were considered, the greater risk of stroke was observed in the "some dozing" and "significant dozing" groups compared to "no dozing" group.

Also, the risk of heart attack or vascular death was greater, 1.6 percent among the moderate dozers and 2.6 percent higher among the significant dozers. The results were similar for both sexes and all ethnicities.

"Given what’s known now, it's worth assessing patients for sleep problems,” Boden-Albala said.

"And the initial assessment can be something as simple as the Epworth scale. If patients are moderately or significantly dozing, physicians need to think about sending them for further evaluation."