Work hours, job strain, and occupation with endothelial function: the Multi-Ethnic Study of Atherosclerosis (MESA).
Objectives: To investigate associations of work hours, job control, job demands, job strain, and occupational category with endothelial function, a predictor of cardiovascular disease (CVD). Method: Currently employed participants free of CVD (n = 1499; 55.5% men; 62% non-white) of the Multi-Ethnic Study of Atherosclerosis provided information on work hours, job decision latitude, and job demands. Responses to current occupation were coded using the Census 2000 Occupational Codes; codes were collapsed to provide four occupational categories. Brachial artery flow-mediated dilation (FMD), a validated measure of endothelial function, was obtained using high-resolution ultrasound. Mean values of FMD, expressed as percent change in brachial artery diameter, were examined across categories of work hours (<40, 40, 41.49, .50) and the other exposures using ANOVA/ANCOVA. Results: Occupational category was significantly associated with FMD overall, with Blue-collar workers showing the lowest mean values after adjustment for age, gender, race/ethnicity, education, waist circumference, total and HDL cholesterol, body mass index, systolic and diastolic blood pressure, physical activity, smoking status, and pack-years of smoking: Management/Professional = 4.96 +/- 0.22%; Sales/Office = 5.06 +/- 0.27%; Services = 4.70 +/- 0.29%; Blue-collar workers = 4.18 +/- 0.27% (adjusted p = 0.001). There was evidence of effect modification between occupational category and FMD by gender (p = 0.031) such that in stratified analyses, significant associations were observed among women (adjusted p = 0.002) but not men (adjusted p = 0.098). None of the other work exposures were significantly associated with FMD. Conclusions: Blue-collar workers had decreased endothelial function compared to other workers; potential reasons should be examined in future studies. Decreased endothelial function may reflect a biological mechanism explaining occupational differences in CVD.
Humans; Men; Cardiovascular-disease; Sociological-factors; Analytical-processes; Ultrasound; Women; Workers; Work-environment; Behavior; Body-weight; Occupations; Job-stress; Age-groups; Racial-factors; Education; Blood-pressure; Physical-fitness; Physiological-factors; Smoking; Demographic-characteristics; Surveillance-programs; Statistical-analysis