People who regularly feel stressed out by their jobs may have a higher risk of developing asthma than those with a more-relaxed work atmosphere, a new study suggests.

High on-the-job stress has been linked to a number of health consequences, including heightened risks of heart disease, diabetes and depression.

The new findings, published in the journal Allergy, are the first to show an association between work stress and later asthma risk, according to the researchers.

The investigators found that among more than 5,100 adults they followed for nearly a decade, those who reported high job stress at the outset were twice as likely as those with low levels of work stress to develop asthma.

The odds of any study participant being newly diagnosed with asthma were low, however. Among those with high job stress, 2.4 percent developed asthma during the study period, compared with 1.3 percent of men and women who reported little on-the-job stress.

The findings do not prove that work stress, itself, is the reason for the relatively higher asthma rate.

But the findings build on other evidence that chronic stress may contribute to asthma development in some people, write Dr. Adrian Loerbroks and colleagues at Heidelberg University in Germany.

Other studies, they note, have linked distressing life events and stress-related personality traits, for example, to heightened asthma risk.

For their study, Loerbroks and his colleagues used data from 5,114 adults, aged 40 to 65 years, who completed questionnaires on their health, lifestyle and jobs, and then were followed for 8.5 years.

Work stress was measured by a questionnaire that asked participants to rate how much strain they felt at work, and how often, at the end of the workday, they thought about work or felt exhausted or unable to cope with their job demands.

Overall, participants with high scores on the work-stress measure tended to have higher asthma rates at the outset. Moreover, among men and women who were asthma-free, those with high job stress were twice as likely to develop the lung condition over the follow-up period.

That higher risk was seen even with a number of other variables taken into account, including body weight, exercise habits, smoking, and family history of asthma.

It is not fully clear why work stress, itself, might affect asthma risk in some people.

Less-healthy lifestyle did not appear to account for the relationship, the researchers note, so it’s possible that there are direct effects of chronic stress on the hormonal and immune systems that contribute to asthma development - by, for example, making the airways more prone to inflammation in response to an environmental trigger.

The researchers point out, however, that even if work stress does raise asthma risk in some people, the absolute risk to any one worker would be small - given that only 2 percent of all study participants developed asthma over 8.5 years.

And from a public-health standpoint, the researchers write, curbing on-the-job stress would prevent only a small number of asthma cases.

SOURCE:

Allergy, online April 27, 2010.