International collaborative study of cardiovascular disease in Asia: design, rationale, and preliminary results

The overall objective of the International Collaborative Study of Cardiovascular Disease in Asia (InterASIA) was to estimate the prevalence and distribution of cardiovascular disease risk factors, including hypertension, hypercholesterolemia, diabetes, obesity, cigarette smoking, and physical inactivity, in the general population of both China and Thailand.

A multistage cluster sampling method was used to select a nationally representative sample of 15,838 adults, aged 35-74 years, in China, and 5,350 similarly aged adults in Thailand. Data on medical history, cigarette smoking, alcohol consumption, diet, physical activity, and awareness and control of risk factors for cardiovascular disease, were collected. Blood pressure, body weight and height, and hip and waist circumferences, were measured using standard methods. Fasting blood specimens were collected to measure levels of total cholesterol, high-density lipoprotein cholesterol, triglycerides, glucose, and creatinine. All data were carefully collected by specially trained, experienced observers using standardized methods and a stringent level of quality control. The prevalence of self-reported cardiovascular disease in Chinese adults aged 35-74 years was 3.3% in men and 3.6% in women (representing 8,147,000 male and 8,270,000 female cases nationally). The prevalence of self-reported cardiovascular disease in Thai adults was 1.5% in men and 1.7% in women (representing 184,000 male and 226,000 female cases).

The InterASIA study provides important information on the current prevalence and control of both cardiovascular disease and its risk factors in the region. These findings will be useful for developing national strategies to reduce the large, and increasing, burden of cardiovascular disease in China and Thailand.