"It's been a cherished notion that chronic stress in this case, job stress contributes to hypertension," said Dr. Samuel Mann, a hypertension specialist at New York Presbyterian Hospital and Weill Cornell Medical Center in New York City. "It's time to set the record straight, however."
Mann reviewed dozens of studies on the subject, and his findings are published in the May issue of Current Hypertension Reviews.
Mann concludes that the evidence on workplace stress having a lasting effect on blood pressure is weak and inconsistent. He points out that the misconception could have life-altering effects when doctors advise patients "to quit or change jobs to help them avoid hypertension."
After having looked over a study published in 2003 that found no effect of job strain on hypertensions, Dr Mann, in his review, analyzed data from 48 studies on job stress and blood pressure from 1982 to 2004 and found that most studies actually found no relationship between job stress and blood pressure.
"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," he said.
Other flaws Mann says he found in past studies include:
- Focusing on a weak relationship between blood pressure and one measure of job stress, instead of all job stress combined.
- Focusing solely on how job strain affected diastolic blood pressure (bottom number), despite the fact that it didn't affect the systolic pressure (top number).
- Many of the potential remedies for chronic stress were ineffective in lowering blood pressure levels, suggesting that job stress wasn't causing hypertension in the first place.
According to Mann, the idea that job strain is a contributor to high blood pressure persists among researchers, clinicians and the general public because stress does elevate blood pressure in the moment. But he concludes that there has been a lack of hard evidence to prove it, despite decades of research that aimed to do just that.
Mann, however, is quick to note that clashes with co-workers or supervisors can boost blood pressure in the short-term.
"Reliable studies have shown that ongoing difficulties at work can contribute to coronary artery disease," he said. "That appears to be true, but blood pressure does not seem to be the link between the two."