Accelerating Epidemic of Heart Disease in Rural China
Robert Detrano MD， PhD
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Approximately， 800 million persons or one of every eighth human beings on earth lives in the Chinese countryside. This region of the world has great variability in terms of economic development but a large part is still impoverished and lacking in many basic services such as health care.  The prevalence of hypertension among adults in rural China varies from 8 to 40 % (1-3) and is growing (1，3).  The percentage of rural Chinese hypertensives that are undergoing treatment is known to be as low as 27% and to vary greatly between geographic areas.  The percentage of rural Chinese whose hypertension is controlled is as low as 1.4% (1).  Hyperlipidemia， diabetes prevalence and obesity are also increasing while smoking prevalence remains high and relatively constant.  Not only are risk factor prevalences rapidly increasing in rural areas， many rural residents spend significant time in nearby cities where they adapt atherogenic lifestyles and presumably increased cardiovascular risk. 

 We estimate that by the middle of the present century there will be over five million deaths per year from cardiovascular causes in rural China.  The health care infrastructure for primary and preventive cardiovascular care is improving but is still inadequate to address this growing epidemic.   The extent and severity of the epidemic requires excellent epidemiologic studies using modern technology for a full evaluation.  Only when compete and accurate knowledge is obtained can appropriate public health measures be implemented.

We， at the China California Heart Watch， propose application of high technology but relatively inexpensive methods and the use of limited sample sizes to adequately address this accelerating epidemic.

Western research has shown that echo-cardiographicly determined left ventricular mass is a powerful predictor of future congestive heart failure and cardiac death.  Portable echo-cardiographic devices are now available that can be taken to rural villages in order to study the prevalence and predictors of increased left ventricular mass in untreated hypertensives.  We are presently engaged in such a study using a sample size of only 400 persons in western rural China (4). 

Multiple epidemiological studies have shown the prevalence of coronary heart disease to be much higher in the northern rural areas than in southern rural areas of China (5-6).  The large geographical difference in the prevalence of vascular disease in China has not been explained using traditional risk factors.  Unknown environmental or genetic factors may explain these differences. This problem lends itself well to study using coronary computed tomography for calcification.  We have recently completed a small preliminary study (sample size of only 150 persons and cost under