Cardio-cerebrovascular disease and cancer will remain the top two killers in China in the years 2026-2030, with their proportionate distributions continuing to increase for both sexes, according to researchers who undertook a large study conducted over 42 years in Shanghai -- China's largest city -- into causes of death.
The study, published in CMAJ (Canadian Medical Association Journal), also says that diabetes will become the third most common cause of death as an indirect consequence of the proportion of deaths from respiratory diseases continuing to decrease over time. Diabetes will likely be the third most common cause of death in women and the fourth most common cause of death in men.
The study looked at data on deaths among inhabitants of Yangpu, a district in Shanghai, to see how political and socioeconomic developments affect health. The study period included several key events in Chinese history, including the rise of polluting industries (1949 to the 1980s), the Great Chinese Famine (1959 to 1961), the Cultural Revolution (1966 to 1976) and economic reforms (1979 to present). For example, birth cohorts exposed to the Great Chinese Famine in early life had increased mortality from several chronic diseases in later life.
All causes of death were classified into three groups according to the World Health Organization Global Health Estimates standard classification of diseases: (1) communicable, maternal, perinatal and nutritional conditions [group-1 causes], (2) chronic noncommunicable diseases [group-2 causes] and (3) injuries [group-3 causes].
Group-1 causes, group-2 causes and group-3 causes accounted for 3.80%, 86.50% and 5.56% of all-cause mortality, respectively, for the years 1974 to 2015.
The trends in age-standardised mortality reflect the effect of public health efforts and the nature of life-threatening diseases. Deaths from group-1 causes decreased after 1988, corresponding to the actions taken by the municipal government to greatly enhance public health infrastructure to control infectious disease, after the outbreak of hepatitis A in January 1988.
Similarly, improvements in air quality and medical services from the 1980s onward may account for the reduction in deaths from respiratory diseases such as COPD, as smoking and air pollution are well-established risk factors for COPD.
However, it is difficult to reduce the burden of group-2 causes. Age-standardised mortality from cancer started to decrease from 1991, possibly because polluting industries were removed from urban Shanghai after the 1980s.
The risks of death from chronic diseases in those born after 1940 declined, but the risks of death from cancer and diabetes increased in those born after 1949, indicating that the exposure of their risk factors kept increasing. High intake of red and processed meat, tobacco smoking, overweight or obesity, physical inactivity, low intake of vegetables, and alcohol consumption increase the risk of cancer.
The research teams says that socioeconomic events in the past should be taken into consideration when designing strategies for the prevention and control of diseases, especially noncommunicable diseases.