Strategy for primary prevention of coronary heart disease based on results of health check-up

Abstract

To investigate one of the strategies for effective primary prevention of coronary heart disease (CHD) in employees, the future morbidity of CHD was predicted from the results of an annual health check-up. The decrease in morbidity by measures against coronary risk factors was estimated with simulations. By a CHD risk prediction algorithm based on the Framingham Study, the 10-yr incidence of CHD was predicted in 6,444 male employees of a manufacturing company according to the results of a health check-up in 1998: age, total cholesterol (TC), HDL-cholesterol (HDL-C), blood pressure (BP), diabetes mellitus, and smoking habit. The decrease in CHD incidence obtained by a decrease in TC, increase in HDL-C, decrease in BP, control of diabetes mellitus, or quitting the smoking habit was estimated with simulations by means of the algorithm. The mean +/- SD in 6,444 employees was 45 +/- 11 yr for age; 121 +/- 16 and 79 +/- 10 mmHg for systolic and diastolic BP, respectively; 193 +/- 34, 53 +/- 13, and 98 +/- 18 mg/dl for TC, HDL-C, and fasting blood sugar, respectively; 4.80 +/- 0.58% for HbA1c; and 44% for the frequency of the smoking habit. Among 6,444 males, 455 (7.1%) were predicted to suffer from CHD for 10 yr ahead. If TC was decreased to less than 200 mg/dl in all 2,614 males (N) with TC > or = 200 mg/dl, the decrease (D) in the predicted number of employees with CHD was 64; namely, a reduction of TC to less than 200 mg/dl in 41 males (N/D) with TC > or = 200 mg/dl was estimated to decrease the number of CHD patients by one. Similarly, the D and N/D were 38 and 35 for reduction in BP to less than 140/90 mmHg; 20 and 17 for control of diabetes mellitus; and 90 and 32 for quitting the smoking habit, respectively. A measure against diabetes mellitus was the most effective in respect of N/D, but the predicted total reduction was small (D = 20). On the other hand, a measure against the smoking habit was estimated to have a relatively small N/D as well as the largest D. In 5,386 employees with at least one of the risk factors of TC > or = 200 mg/dl, HDL-C < 45 mg/dl, BP > or = 130/85 mmHg, diabetes mellitus, and the smoking habit, the normalization of all risk factors was estimated to decrease by 230 CHD patients (D = 230, N/D = 23). These results suggest that the strategy for effective primary prevention of CHD in employees of a company should include at first, quitting the smoking habit supported by total prohibition of smoking within company facilities, followed by measures against hyperlipidemia, hypertension and diabetes mellitus.