Purpose: The preventive use of noninvasive measurement of carotid intima media thickness and plaque visualization (CIMT+P) is in the Netherlands a relatively new method to detect subclinical atherosclerosis of employees. The aim of the use of CIMT+P is to archive endurable lifestyle modification in employees without cardiovascular disease.

Methods: In one and the same Dutch company (a Steel Mill) we did CIMT+P measurements in 2008, 2009 and 2011 to follow the progression of atherosclerosis of the employees. With motivational interviewing and health advice by a dedicated occupational health physician we have been stimulating the employees to modify their lifestyle (quit smoking, eat a healthy life style, increase exercise, relaxation techniques in addition to treat hypertension). With a longitudinal analysis we investigate the effects of our intervention using both CIMT and plaque formation images as end-points and as additional substitute modifiers

Results: The mean thickness of the common carotid arteries right and left in 169 cases average age 49 years range 39-64 y. were combined plaque formation was measured in the bulb when these were present. A distinction was made between soft plaques and calcified plaques.

The results were the following: 2008 2009 2011

Mean value of CIMT (mm) was 0.7104 0.7023 0.7001

Number of cases with soft plaques 26 13 11

Number of cases with all plaques 46 43 36

Conclusions: CIMT+P can be used as a preventive method for lifestyle modification in healthy Dutch employees. In a longitudinal follow up of 3 years a stabilization or even regression of subclinical atherosclerosis can be archived as an effect of lifestyle modification. It is noteworthy that cases that were smoking and quit smoking were the ones were the soft plaque disappeared or calcified. Hypertension treatment was another significant risk factor that correlated well with plaque formation whereas LDL-cholesterol control and a HDL-c increase was significant correlated to the change on the average CIMT. Motivational interviewing may have played an important role.