Major causes of death during the past 25 years in China

Life expectancy in China doubled from 35 to 71 years between 1949 and 2001. China's human development index has been rising steadily, and it ranked 85th among countries with an index of 0.755 in 2003. According to China's human development report, the national Gini coefficient for income distribution rose to 0.45 in 2002 from 0.30 in 1982.1 However, disparities in health indicators between urban and rural areas are widening. Life expectancy is 75.2 years for urban residents and 69.6 for rural residents. The human development index is 0.816 in urban areas and 0.685 in rural areas. Rural areas have only 2.4 medical personnel per 1000 residents, compared with 5.2 per 1000 residents in urban areas.1 Historically, infant mortality and death from infectious diseases have been the major causes of death in developing countries, including China. In 1957, respiratory diseases, acute infectious diseases, and tuberculosis were the leading causes of death, accounting for 16.9%, 7.9%, and 7.5% of the total deaths, respectively. In the same period, diseases of heart, cerebrovascular disease, and malignant neoplasms were the fifth, sixth, and seventh leading causes of death, accounting for 6.6%, 5.5%, and 5.2% of total deaths, respectively.2 Up to 1975, cerebrovascular diseases (21.6%), heart diseases (19.5%), malignant neoplasms (18.8%) were the top three causes of death, followed by respiratory diseases (10.8%), digestive diseases (4.9%), and pulmonary tuberculosis (3.4%).3 China's gross domestic product (GDP) has grown at the extraordinary annual rate of 8 percent during the past 25 years, and its economy is now among the world's largest and most rapidly expanding. As a result of China's rapid but asymmetric economic growth, health gaps are widening between urban and rural areas and poor and rich population groups. China's rapid economic growth and the consequent improvement in living conditions, nutrition, and health care have resulted in decreased mortality of perinatal diseases and increased life expectancy. Nonetheless, with the serious health threats brought on by the increasing prevalence of chronic diseases and an aging population, weaknesses in China's health system are hampering the achievement of improved health in the country. During the past 25 years, the five leading causes of death were malignant neoplasms, cerebrovascular diseases, diseases of heart, respiratory diseases, injury and poisoning in both urban and rural residents (Fig).Fig.: Mortality for the five leading causes of death from 1982 through 2006 in China. Mortality data of urban population are presented in panel A and mortality data of rural population in panel B. Data are from the Chinese Ministry of Health.In urban population, the number one cause of death still was cerebrovascular diseases in 1982, which was replaced by diseases of heart from 1983 to 1986. Death rates due to diseases of heart have been dropping more rapidly than death rates due to both malignant neoplasms and cerebrovascular diseases during the past two decades. Since 1987 cancer has become the number one cause of death for urban people. Respiratory diseases used to be the forth leading cause in the past 25 years, which escalated to as high as diseases of heart since 1987. Injury and poisoning were always the fifth leading cause of deaths for urban residents during the past 25 years. In rural population, death rate due to diseases of heart was listed in the first place between 1982 and 1986, which declined by half from 1987 and was the fourth one in 2006. During the same period, respiratory diseases were the fourth cause of death in the one-fifth of the last 25 years, which increased by double and became the top cause of death and lasted for 15 years, and decreased dramatically in the recent 5 years. In 1980s, 1990s and early this century, death rates due to malignant neoplasms and cerebrovascular diseases were similar, and were much lower than those in urban residents. It should be noted that death rate due to malignant neoplasms increased gradually in the last five years and became the number one cause of death in 2006. In 2006, the order of five leading causes was the same in urban and rural residents, which was malignant neoplasms, cerebrovascular diseases, diseases of heart, respiratory diseases, and injury and poisoning, respectively. The above five leading causes of death accounted for approximately 80% of all deaths. As shown in the table, the other main diseases could be listed in the first ten causes of death were endocrine and metabolic diseases, digestive diseases, genitourinary diseases, neurologic diseases, mental disorders, perinatal diseases, tuberculosis, or non-tuberculosis infectious diseases. Endocrine and metabolic diseases became one of the top ten causes of death since 1987 in urban residents, but the situation was not the same until 1997 in rural population. Tuberculosis and non-tuberculosis infectious diseases were excluded from the top ten death causes in urban residents since 1992, and these infectious diseases were still the main causes of death till 2004 in rural areas. Death rates due to neurologic diseases and mental disorders were also a major problem since 1994 in urban residents, and 12 years later appeared so in rural residents. Cigarette smoking is a major preventable risk factor for death in China. If cigarette smoking was eliminated, it could be estimated that the total mortality could be reduced by 10.0% among men and by 3.5% among women in China.4 China will have the world's highest number of lung cancer patients, i.e., 1 million a year, by 2025 if smoking and pollution are not effectively curbed, as experts have warned, suggested by the World Health Organization figures. According to the National Tumor Prevention and Cure Research Office Affiliated to the Ministry of Health, the country had 120 000 new lung cancer patients during the past five years. Lung cancer killed more people than any other disease, i.e., one out of every four, sources said.5 Smoking is likely to have a particularly devastating effect on China, where the annual death toll from smoking-related diseases already exceeds 1 million —2.5 times that in the United States— and is expected to double by 2025 if smoking rates are not reduced. In 2005, cigarette sales generated US$32.5 billion in taxes and profits in China, approximately 7.6% of the government's total revenue.6 The number of smokers in China has reached about 350 million, the highest in the world. And about 100 000 of the 1 million Chinese who die due to smoking-related diseases each year are passive smokers, says a national tobacco control report released on May 29, 2007 by the Ministry of Health of China. As many as 540 million Chinese are exposed to second-hand smoke, of which 180 million are under the age of 15 years, says a national tobacco control report released on May 29, 2007 by the Ministry of Health of China. Women and children are most vulnerable to second-hand smoke with the smoking rate among men reaching 57%. What's worse, a whopping 90% of the women are exposed to second-hand smoke at home.7 It has been estimated that tobacco-related diseases may kill a third of middle-aged men by 2030 in China, where smoking habits resemble those of America in the 1950s.8 The deteriorating state of the environment is also contributing to the rising rate of cancer in China. Epidemiological investigations have found that the prevalence of lung cancer in industrial and polluted regions is higher than in non-industrial regions. “Occurrence of lung cancer is closely related to motor vehicle exhausts,” SUN Yan, a cancer expert and academician of the Chinese Academy of Engineering, told the China Daily.5 Pollution caused by indoor furnishings can also be a factor; and experts advise people not to choose material containing harmful chemicals for indoor furnishings. Hypertension is the most common risk factor for cardiovascular and cerebrovascular diseases worldwide. Hypertension is the leading preventable risk factor for death among adult Chinese; total mortality was 48% higher among hypertension patients than among people who did not have hypertension. Furthermore, the prevention and control of hypertension could reduce the total mortality by 11.7%.4 The number of Chinese suffering from high blood pressure has increased 31% over the past decade to 160 million, according to statistics from the Ministry of Health of China.9 Between 1993 and 2003, the prevalence of cardiovascular disease increased from 31.4% to 50.0%; diabetes increased from 1.9% to 5.6%. During 1990-2003, although total mortality rate decreased, overall the mortality rate and contribution to total death of obesity-related chronic disease increased, in particular, in rural areas. Mortality rate of cardiovascular disease increased from 128 to 145 and its contribution to total death, 27% to 32%, in rural areas; the figures decreased slightly in urban areas.10 China was once considered to have one of the leanest populations, but it is fast catching up with the West in terms of the prevalence of overweight and obesity; disturbingly, this transition has occurred within a remarkably short time.11 With the increase in overweight and obesity, obesity-, and diet-related chronic diseases also increased over the past decade and became a more important preventable cause of death.10 China now is facing the challenge of a rapidly aging population. The proportion of people aged over 65 years reached 6.9% in 2000 and is predicted to be as high as 22.7% in 2050.12 The ageing problem exists in many countries other than China, but most developed countries have an annual GDP of between US$ 5000 and US$ 10 000 for each of its citizens. In contrast, China only had an annual GDP of US$ 1700 per capita last year, it will experience an aging population before it becomes affluent. Making things worse for China is that the country has not yet established a pension plan and health care system covering all of its citizens. 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.13 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 2010.14 This growth comes at a cost in health terms. For example, a clear relation exists between urbanization and the prevalence of diabetes in China.15 Facing unsustainable health-care costs and a rapidly aging population, Chinese government must reposition the health-care system to tackle future threats, while combating newly entrenched inequalities and satisfying the heightened expectations of an increasingly prosperous population. Efforts for final eradication of smoking must start among young people, as it is better not to let them develop this bad habit than to encourage them quit when they have already become addicted. These measures should include public campaigns to instill an awareness in children that smoking damages not only the health of those who smoke but also passive smokers. Stopping selling cigarettes to children not only means denying their access to cigarettes, but also instills in them the notion that it is bad for them to smoke. Since Chinese people are getting heavier and less healthy, it is necessary to translate the science of healthy eating, combining exercise into a practical pattern of food choices that meets nutritional needs, promotes health and minimizes the risk of nutrition-related chronic diseases.