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 flowmediated dilation (FMD) in 1499 Multi-Ethnic Study of Atherosclerosis participants.

Methods: Flow-mediated dilation was obtained using highresolution 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.