Job strain and the prevalence and outcome of coronary artery disease.

BACKGROUND

It has been hypothesized that jobs that have both high psychological demands and low decision latitude ("job strain") can lead to coronary disease. The objective of this study was to test whether job strain was correlated with the presence of coronary disease at angiography or with long-term outcome in patients with angiographic coronary disease.

METHODS AND RESULTS

Employed patients under the age of 65 years undergoing diagnostic coronary angiography completed a self-administered questionnaire about their job duties and work environment. Job strain was measured by the method of Karasek. Patients were separated into three groups, based on extent of coronary disease: significant disease (> or = 75% stenosis), insignificant disease (> 0% but < 75% stenosis), and normal coronary arteries. Statistical analyses were performed using logistic regression and the Cox proportional hazards model. The 1489 patients enrolled had a median age of 52 years; 76% were male and 88% were white. By design, all patients were employed, 60% in white-collar jobs and only 16% in jobs requiring heavy labor. Traditional cardiac risk factors were most prevalent in the 922 patients with significant coronary artery disease, at intermediate levels in the 204 patients with insignificant disease, and least prevalent in the 363 patients with normal coronary arteries (all P < .01). Job strain was actually more common in patients with normal coronary arteries (35%) than in patients with insignificant (26%) or significant disease (25%, P < .002). In a multivariate analysis, job strain was not significantly correlated with the presence of coronary disease. Job strain was not correlated with angina frequency at the time of angiography. Job strain was not a predictor of cardiac events (cardiac death or nonfatal myocardial infarction) during follow-up.

CONCLUSIONS

Job strain was not correlated with the prevalence or severity of coronary artery disease in a cohort of patients undergoing coronary angiography. The outcome of patients with angiographically defined coronary disease was not affected by the level of job strain as measured by the method of Karasek.