Epidemiology
The ageing of the population is the major force driving the epidemic of chronic diseases. In 2000, 7% of the Chinese population were aged 65 years or older, and more than 400 million Chinese adults are now aged 20–39 years. If current trends continue, by 2040 the group aged 65 years and older will have increased to almost 20% of the population. The ageing of the population alone is predicted to produce a 200% increase in deaths from cardiovascular disease in China between the years 2000 and 2040.
In addition to the ageing of the population, China is experiencing dramatic transformations in many social and economic conditions that will continue to increase the incidence of major chronic diseases. For example, the country has recorded spectacular economic growth since 1978 and, on average, people's standard of living is far higher than ever before in the rapidly expanding urban areas. From 1990 to 2000, the proportion of people living in urban settings in China increased from 26% to 36%, the number of cities increased to 663, and the number of towns also soared. It is expected that urbanization in China will reach 45% by 2010, and 60% by 2030, with an extra 200 million more people expected in the urban areas before 2010. This growth comes at a cost in health terms. For example, a clear relation exists between urbanization and the prevalence of diabetes in China (diabetes defined as diabetic symptoms and a random blood glucose concentration of 11.1 mmol/L or more, a fasting blood glucose of 7.0 mmol/L or more, or an abnormal result of 2-h oral glucose tolerance test).
The rapid environmental changes that follow urbanization are increasing the prevalence of the major risk factors for chronic disease. Tobacco use, unhealthy nutrition, and physical inactivity leading to obesity and hypertension are already common, and physical inactivity is increasing. The prevalence of current cigarette smoking in men (smoked in the past 30 days) was 57% in 2002, but had fallen from 63% in 1996; less than 3% of women are current smokers. This favorable trend must be continued, because lung cancer death rates are calculated to have more than doubled in men between 1991 and 1995, and are increasing at 2–5% per year in urban and rural working men aged 15–54 years. The decrease in smoking is the only encouraging risk factor trend, and is consistent with the plateau of tobacco consumption over this same period in the face of a rising adult population, as has occurred in other countries where tobacco taxes have been raised sharply. In 1999 the first Global Youth Tobacco Survey in China showed that 22% of students aged 13–15 years had ever tried to smoke; the current smoking rate was only 5%.
China's first comprehensive survey in the fields of nutrition and health was done in 2002. 71,971 households were chosen from 132 counties of 31 provinces, autonomous regions, and the municipalities, using the Central Government household census, and 243,479 people were included in the survey. The prevalence of hypertension (blood pressure 140/90 or higher) in people aged 18 years or older was 19%—a 30% increase since 1991. The prevalence of adult overweight (23%) and obesity (7%) had increased by 39% and 97%, respectively, over a 10-year period.
Of particular note is the rapidly developing epidemic of obesity in Chinese children. The overall prevalence rates of overweight plus obesity in 2000 among students in six sites (Beijing, Tianjin, and Shanghai cities and Hebei, Liaoning, and Shandong provinces) increased from 1–2% in 1985 to 25% for boys aged 7–9 years, 25% for boys aged 10–12 years, 17% for girls aged 7–9 years, and 14% for girls aged 10–12 years. In 2002, prevalence rates in children aged 7–17 years varied from 13% overweight and 8% obese in a range of big cities to 2% overweight and less than 1% obese in a range of rural sites.
Read more about this topic: Chronic Disease In China