May 9, 2006 -- A fight with your boss may get your blood pumping for a little while, but a new study suggests that the much-publicized effects of job on may be full of hot air.
The review of 48 studies on job stress and blood pressure showed that most studies actually found no relationship between job stress and blood pressure; researchers say those that did find a relationship were weak and inconsistent.
"For example, researchers would sometimes find no overall effect of job stress on blood pressure, but would then report a relationship limited to a small subgroup of the study population," says researcher Samuel Mann, professor of clinical medicine at Weill Medical College of Cornell University, in a news release. "The trouble was that if any specific subgroup was particularly susceptible, you'd expect to see that subgroup crop up across studies. None did."
Crunching the Numbers
In the study, researchers analyzed information from 48 studies on job stress and blood pressure published in English-language journals from 1982 to 2004. The studies included more than 100,000 people.
Of the 48 studies included, 20 found a relationship between job stress and blood pressure, but 28 didn't.
In addition, researchers say only about half of the studies (26) looked at the relationship between job stress and blood pressure over time using ambulatory blood pressure measurements. Those measurements are considered more accurate because they measure blood pressure in a person's natural environment and many measurements are taken over an extended time period.
Of the 26 studies using ambulatory measurements, just 10 showed a positive relationship between job stress and systolic blood pressure (the upper number in a blood pressure measurement). Systolic blood pressure is considered a more reliable indicator ofrisk than diastolic blood pressure (the bottom number).
Mann says two of the studies failed to mention the effects of job stress on systolic blood pressure at all and only mentioned diastolic blood pressure readings.
Although Mann says there is no question that clashes with co-workers can raise blood pressure over the short term, this review shows that the corollary that recurring stress at work leads to sustained high blood pressure has yet to be demonstrated.