While some analytic studies have sug gested that individuals in occupations representing higher compared with lower socioeconomic status have a de creased risk of coronary heart disease, it is unclear whether occupation itself has an etiologic role in the development of coronary heart disease or whether differences in as yet un controlled coronary risk factors may account for these dif ferences in risk.
White collar vs blue-collar occupation and risk of coronary heart disease was evaluated among 230 male patients hospitalized for a first myocardial infarction and 222 control subjects of the same age, sex, and neigh borhood of residence. Information on coronary risk factors was obtained from home interviews, and blood specimens were drawn to test lipid and lipoprotein levels. Usual occu pation was dichotomized into white-collar and blue-collar occupation according to the Edwards' classification.
The relative risk of myocardial infarction of white-collar compared with blue-collar workers was 0.74 (95% confidence interval, 0.46 to 1.19) after controlling for age, cigarette smoking, family history of premature myocar dial infarction, history of treatment for high blood pressure, body mass index, history of diabetes, alcohol consumption, type A personality, leisure-time physical activity, total calo ries, and percentage of calories consumed as saturated fat. However, there was no residual association after control for high-density lipoprotein cholesterol yielding a relative risk of 0.98 (95% confidence interval, 0.59 to 1.63).
These results suggest that white-collar oc cupation per se does not appear to protect from coronary heart disease. Any apparent protective effect on myocardial infarction that has been previously observed in white-collar compared with blue-collar workers may be attributable to differences in high-density lipoprotein cholesterol levels.(Arch Intern Med. 1992;152:2253-2257)