Researchers have substantially defined the specific characteristics of stressful occupations and have examined whether they promote the risk of coronary heart disease (CHD), which is the progressive and often fatal hardening of the blood vessels that surround the heart.
Specifically, the question of whether high job strain can be used to predict job stress-related CHD is worth asking in this era of constant communication and information flow.
What constitutes high job strain?
Although many subjective and environmental factors can determine the level of strain in any one individual, the accepted common-sense definition is circumstances of high demand and correspondingly few opportunities to control outcomes.
In other words, the most psychogenic strain would appear to be the feeling of not being in control of one’s situation, but instead of being at the mercy of marketplace vagaries, office politics, erratic directives, difficult bosses, and the like. Thus, high job demand/low control have been theorized to promote heart disease and to reduce life spans.
Is the theory supported by research?
A 1980 study of occupational stress and CHD in women had suggested that circumstances at work and family demands and the amount of control the individual has over these situations can affect the probability of CHD. The job demand/control hypothesis had also been invoked in a 1981 study to explain cardiovascular disease and mortality among Swedish workers.
Recent studies however show conflicting findings, which have made the relation between job strain and CHD more controversial.
In 2003, the effect of high job strain on the 10-year incidence of CHD and total mortality was examined in men and women participating in the Framingham Offspring Study; 3,039 participants, 1,711 men and 1,328 women, aged 18-77 years, were examined between 1984 and 1987 and followed for 10 years. Measures of job strain, occupational characteristics, and risk factors for CHD were collected. The authors found that high job strain was not associated with mortality or incident CHD in either men or women over the follow-up period. Contrary to expectation, women with active job strain (high demands/high control) had a 2.8-fold increased risk of CHD compared with women with high job strain (high demands/low control). For men, higher education, personal income, and occupational prestige were related to decreased risk of total mortality and CHD. These findings do not appear to support the theory that high job strain is a significant risk factor for CHD or death in men or women.
What do we know for sure about CHD risk factors?
The Framingham Heart Study, a major epidemiologic study of heart disease conducted by the National Institutes of Health that began in 1948, has continued to examine this issue. Over the years, careful monitoring of the Framingham Study population has led to the identification of the major cardiovascular disease risk factors. They are high blood pressure, high blood cholesterol, smoking, obesity, diabetes, and physical inactivity, as well as the effects of related factors such as blood triglyceride and HDL cholesterol levels, age, gender, and psychosocial issues. In the latter category, job strain is also included.