Evaluation of coronary heart disease risk model by carotid ultrasonography in the occupational setting--intima-media thickness and coronary heart disease risk

Abstract

Recently, because of an increase in aged workers with high risk health conditions in Japan, it is becoming necessary to have a preventive control system for work-related diseases, such as coronary heart disease. We have already built a system by applying the prediction model of Framingham's risk equation for management after an annual check-up since 1999. At that time, we considered the relationship between CHD risk and intimamedia thickness (IMT) as an index of actual atherosclerosis. Correlation coefficients among max IMT, CHD risk and the several health factors in the corporate annual health check-up were obtained by Spearman's method. Significant associations with max IMT were only for CHD risk and systolic blood pressure. Correlation coefficients were 0.30 and 0.21 for CHD risk and systolic blood pressure, respectively. Furthermore, when we divided findings into those for the atherosclerotic and non-atherosclerotic groups defined by a max IMT over 1.1 mm or less, the difference between the two groups in CHD risks was investigated by t-test. The CHD risk for the atherosclerotic group was revealed to be significantly higher than that for the non-atherosclerotic group, with the means +/- SD in the two groups being 21.4 +/- 9.4% and 17.0 +/- 7.7%, respectively. CHD risk was therefore concluded to be important for the objective index of atherosclerosis from the viewpoint of high-risk-strategy in the worksite.