NEW YORK – Even without classic risk factors for type 2 diabetes, people
with high-stress, low-control jobs were over 60 percent more likely to
develop the disease than unstressed workers
in a new German study.The findings add to substantial evidence that job strain represents a serious health risk on its own, researchers say.
“What
we first suspected was that job strain might be related to lifestyle
variables - that people who are under high job strain would smoke or
maybe eat unhealthy food more, but this was not the case,” said lead
study author Karl-Heinz Ladwig, of the Technical University in Munich.
“For me this was the most exciting thing, to find out that these things might not responsible for this unique effect,” he said.
Past
research dating back decades has established that jobs with a
combination of high demands and low control over how the work is done
offer a formula for high worker stress.
That particular kind of
job strain has long been linked to heart disease and death. The
underlying cause is generally thought to be a mixture of physical
wear-and-tear from the chronic stress itself and unhealthy coping
behaviors like smoking, drinking and overeating.
A few studies in
more recent years have connected this form of worker stress to
diabetes, although sometimes the effect was seen only in women or was
largely linked to coping behaviors.
To explore the connection further, Ladwig’s team followed more than 5,000 men and women in Germany for over 12 years.
None
of the participants had diabetes at the beginning of the study, when
each answered a well-established questionnaire to measure job strain. It
included 11 questions, some of which focused on job demands, such as
having to work fast, hard, under time pressure or with conflicting
demands, or having excessive amounts of work.
Other questions
were meant to assess the person’s level of job control, including their
level of responsibility and competence for the job and ability to make
decisions in their current position.
Based on the answers, participants were subdivided into groups: low job strain, high job strain, passive and active.
Participants
with demanding jobs who had control over how their work got done, or
those with undemanding jobs, were considered to have “low job strain.”
Those with high job demands and low control over their work were
considered to have “high job strain.”
Apart from job demands,
people in jobs that afforded some control were considered “active” and
those without control were categorized as “passive.”
Almost 300
cases of type 2 diabetes developed during the follow-up period, and the
largest proportion of these, almost 7 percent, came from the high
job-strain group, the study team reports in the journal Psychosomatic
Medicine.
The passive or active categories contributed the next
largest number of cases, followed by the low job strain group, with 4
percent.
The researchers calculated that the high job strain
participants had a 63 percent higher chance of developing diabetes than
the low job strain group.
The results held after the team
accounted for age, sex, family history of diabetes and weight. The
difference did shrink somewhat when researchers factored in
socioeconomic status and physical intensity of work, but remained
significant.
In general, the participants with high job strain
were more often female, physically inactive, smoked and had low
education levels. But none of these variables made a difference in the
diabetes risk based on job strain.
That suggests the stress
itself is causing the effect, Ladwig and his team speculate, and the
likely culprit is the stress hormone cortisol, which can alter the way
the body regulates blood sugar.
“The rising prevalence of type 2
diabetes is a worldwide concern and this study is investigating the role
of job strain in this growing epidemic,” said Mikaela von Bonsdorff, a
gerontology researcher at the University of Jyväskylä in Finland, who
was not involved in the study.
The American Diabetes Association says that by 2050, one in every three Americans will have diabetes
Von
Bonsdorff cautions that although the authors found high job strain
might increase the risk of type 2 diabetes, it is evident that other
factors such as, socioeconomic position and unhealthy living habits may
be playing a role.
Loretta Platts, a researcher at Kings College
London who also was not involved in the study, said, “It is also
possible that the real influence of stressful work on type 2 diabetes
might be even larger than is suggested by the results found in this
study.”
“The investigators could only measure work stress at one
time-point, and it is likely to be the cumulative impact of work stress
over individuals’ whole working lives which may affect their chances of
developing type 2 diabetes, not necessarily stress happening at any
specific time-point,” she said.
“People are very engaged in their job situation and they have no distance from it and I think that we should get into a balanced life situation where working is one part which is important but not the only important thing in the world,” said Ladwig. — Reuters
