Prevalence and magnitude of classical risk factors for Coronary Heart Disease in a cohort of 4400 Chinese steelworkers over 13.5 years follow-up

BACKGROUND: The incidence and mortality of cardiovascular disease among Orientals are very different than among Caucasians. This study addresses the prevalence and magnitude of classic cardiovascular disease risk factors associated with coronary heart disease (CHD) in an Oriental cohort of at-risk men (blood pressure, total cholesterol, Body Mass Index [BMI] and smoking), compared to Caucasian populations. We also address which blood pressure index (SBP, DBP, mean arterial pressure [MAP] and pulse pressure [PP]) is the best predictor of CHD. METHODS AND RESULTS: A cohort of 5092 male steelworkers (18-74 years old) recruited between 1974-1980 was followed up for an average of 13.5 years. The prevalence of risk factors was lower in Orientals than in Caucasians, except for smoking. The relative risks (RRs) of CHD associated with classic risk factors in this Oriental population were similar to Caucasians, except for blood pressure. The RRs of CHD associated with both SBP and DBP in this Oriental group were higher than in Caucasians; RR of CHD was approximately 3 for each 40 mmHg rise of SBP versus approximately 2 in Caucasians. SBP was the single best predictor for CHD, followed by MAP, and DBP. The population attributable risk (PAR%) for hypertension (140/90 mmHg) was 42.4. CONCLUSION: Our results would indicate that the lower incidence of CHD in Orientals is at least partly due to the lower prevalence of hypertension, hypercholesterolemia, and obesity. The magnitude of the risk associated with these factors is similar to that in Caucasians, except perhaps for a greater risk associated with hypertension. The most predictive BP index for CHD is SBP. These results are based on indirect comparisons only and should be studied further in prospective multi-ethnic cohorts.