Long Hours Up High Blood Pressure Risk

(WebMD)  The more hours you work, the greater your risk of high blood pressure.

That finding comes from a 2001 telephone survey of more than 24,000 California workers analyzed by Haiou Yang, PhD; Dean Baker, MD, MPH; and colleagues at the University of California, Irvine.

Compared with people who work 11 to 39 hours a week, those who work 40 hours are 14% more likely to report having high blood pressure. Those who work 41 to 50 hours a week report 17% more high blood pressure. And those who work 51 or more hours are 29% more likely to have this heart disease risk factor.

About a third of people with high blood pressure don't know it. So it's likely the study, based on self-reporting, underestimates the risk of working long hours.

"American workers now work longer hours than workers in any other industrial country in the world -- including Japan," Baker said, in a news release.

American "Karoshi?"

In Japan, there's a word for this: "Karoshi," meaning "sudden death from overwork." High blood pressure, Baker and colleagues note, contributes to this phenomenon.

Many factors affect a person's blood pressure -- including job type. Compared with professionals, for example, clerical workers have a 23% higher risk of high blood pressure -- and unskilled workers have a 50% higher risk.

But even when the researchers controlled for other factors, the link between hours worked and high blood pressure remained.

That, the researchers suggest, is because working longer hours leaves a person less time to recover from the effects of hard work. Longer hours may mean more drinking, smoking, and fast food, and too little exercise - things all linked to high blood pressure and heart disease.

And, they suggest, long hours mean more exposure to "noxious psychosocial factors" on the job. These things -- being underpaid for your work, for example -- are hard on the heart.

Baker suggests people make their doctors aware of what kind of work they do and how long they spend doing it. Some may need counseling about how to control job factors that affect their blood pressure.

Yang, Baker, and colleagues also suggest that government intervention may be needed in the U.S.

"Nearly every country has some type of regulation regarding limiting working time for adults except the United States," they observe.

The researchers report their findings in the October issue of the journal Hypertension.

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SOURCES: Yang, H. Hypertension, October 2006; vol 48, online rapid access edition. News release, American Heart Association.

By Daniel DeNoon
Reviewed by Louise Chang, M.D