Associations of work hours, job strain, and occupation with endothelial function: the Multi-Ethnic Study of Atherosclerosis (MESA).

OBJECTIVE: To investigate associations of work hours, job control, job demands, job strain, and occupational category with brachial artery flow-mediated dilation (FMD) in 1499 Multi-Ethnic Study of Atherosclerosis participants.

METHODS: Flow-mediated dilation was obtained using high-resolution ultrasound. Mean values of FMD were examined across categories of occupation, work hours, and the other exposures using regression analyses.

RESULTS: Occupational category was significantly associated with FMD overall, with blue-collar workers showing the lowest mean values-management/professional = 4.97 ± 0.22%; sales/office = 5.19 ± 0.28%; services = 4.73 ± 0.29%; and blue-collar workers = 4.01 ± 0.26% (adjusted P < 0.001). There was evidence of effect modification by sex (interaction P = 0.031)-significant associations were observed among women (adjusted P = 0.002) and nearly significant results among men (adjusted P = 0.087). Other exposures were not significantly associated with FMD.

CONCLUSIONS: Differences in endothelial function may account for some of the variation in cardiovascular disease across occupational groups.