For Your Heart's Sake, Dream of a Nap
Blood pressure drops with the simple anticipation of a midday siesta

(HealthDay News) -- Planning to take a nap may be even better for the heart than actually taking one.

Researchers found that a person's blood pressure doesn't drop much during a nap, but systolic blood pressure -- that's the top number in a reading -- drops an average of 5 points when people simply think about an afternoon snooze.

Still, the researchers say it's probably too soon to recommend a midday siesta to improve heart health.

"The increase in blood pressure after waking from a daytime nap might be just as important as the pre-sleep reduction," one of the study's authors, Greg Atkinson from the Research Institute of Sport and Exercise Science at Liverpool John Moores University in England, told HealthDay .

"Any extrapolation of the study results to the benefits of napping is a bridge too far," Atkinson added.

Heart disease remains the leading cause of death for American adults, accounting for 29 percent of all deaths, according to the U.S. Centers for Disease Control and Prevention. Each year, nearly 700,000 people in the United States die from heart disease, the CDC reports. About half of those deaths occur before emergency services or transportation to a hospital arrives.

High blood pressure is one of the most significant risk factors for heart disease, and more than 30 percent of American adults have high blood pressure, according to the CDC.

Previous research, involving a large Greek population, found that people who napped a half-hour or more at least three times a week were 37 percent less likely to die from heart disease -- findings that prompted Atkinson's study.

He and the other researchers recruited nine healthy adults -- one woman and eight men, none of them regular nappers. For three nights, the participants got just four hours of sleep a night. The following days, they went to the sleep lab. The first afternoon was spent resting in bed, though they weren't allowed to sleep. The next day, they were asked to stand for an hour. On the final day, they were allowed to nap for an hour.

During the time spent in bed waiting to fall asleep, the researchers found that systolic blood pressure dropped by 4.7 mm Hg and diastolic fell by 3.6 mm Hg. But during the nap, there was no significant change in blood pressure, Atkinson said.

Dr. Gregg C. Fonarow, a professor of cardiology at the University of California , Los Angeles , told HealthDay that "individuals interested in lowering their cardiovascular risk should focus on maintaining healthy blood pressure, healthy lipid [cholesterol] levels and healthy weight, and exercise and don't smoke."

As for napping? "Whether napping will offer additional benefits to what is tried and true is unknown," Fonarow said.

Atkinson said the researchers plan further study of the effects of midday napping.

On the Web

To learn more about preventing heart disease, visit the American Heart Association.

SOURCES: HealthDay News ; Greg Atkinson, Ph.D., physiologist, Research Institute of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, England; Gregg C. Fonarow, M.D., professor of cardiology, University of California, Los Angeles; October 2007, Journal of Applied Physiology ; U.S. Centers for Disease Control and Prevention (www.cdc.gov)
Author: Serena Gordon
Publication Date: Nov. 30, 2008
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