Standing at work and progression of carotid atherosclerosis

Objectives The association between the amount of standing at work and the p rogression of carotid intima media thickness (IMT) was studied among 584 ac tive working men participating in the Kuopio Ischemic Heart Disease Risk Fa ctor Study. Methods Ultrasound measurements of atherosclerotic changes in the carotid a rteries were performed at the beginning of the study and after 4 years. Ana lyses of changes in IMT included adjustments for risk factors and stratific ation by base-line levels of atherosclerosis and prevalent ischemic heart d isease (IHD). Results significant relationships were found between the amount of standing at work and atherosclerotic progression. After adjustment for the heavines s of the work, psychosocial job factors, income, and biological and behavio ral risk factors, the mean change in maximum IMT for those standing not at all, a little, a lot, and very much was 0.24, 0.25, 0.28, and 0.33 mm, resp ectively. For men with IHD the respective changes were 0.08, 0.15, 0.37, an d 0.75 mm - a 9-fold difference between the no-exposure and high-exposure g roup. For the men with carotid stenosis, the respective difference was 3-fo ld. Conclusions These findings provide the first empirical support in a populat ion study for the role of hemodynamic factors in the progression of atheros clerosis induced by long-term standing. Men with carotid stenosis or IHD ap pear especially vulnerable to the adverse effects associated with standing at work. Reducing the duration of standing at work should be considered bot h in the occupational rehabilitation of such patients and in the primary pr evention of atherosclerosis.