Impact of Individual and Combined Lifestyle Factors on Mortality in China: A Cohort Study

Although numerous studies have suggested that lifestyle-related factors are associated with chronic diseases and preventable deaths, limited evidence is available for the Chinese population.

This study established a prospective cohort of >360,000 residents on the basis of the Yinzhou Health Information System in China during 2004-2017 and calculated the combined effects of lifestyle-related factors, including BMI, smoking, alcohol consumption, and physical activity, using a points system. A Cox regression model estimated the combined effects of lifestyle-related factors on total mortality, and a competing risk model estimated the combined effects on cancer and cardiovascular disease mortality. All data analyses were conducted in 2018‒2019.

During 3,755,879 person-years of follow-up, 11,791 deaths were identified, including 4,983 from cancer and 3,143 from cardiovascular disease. Having a standard BMI, never smoking, never drinking, and engaging in physical activity more than 4 times per week had protective effects on total mortality. Overall, the risk of total and cause-specific mortality increased with the increment of risk score. Compared with subjects in the lowest quartile, the risk of total and cause-specific mortality peaked among individuals in the fourth quartile (total mortality: hazard ratio=1.87, 95% CI=1.77, 1.98; cancer mortality: hazard ratio=2.05, 95% CI=1.87, 2.25; cardiovascular disease mortality: hazard ratio=1.51, 95% CI=1.35, 1.68). Sensitivity analyses excluding individuals with follow-up <3 years did not materially change the results.

The combined effects of lifestyle-related factors, including BMI, smoking, alcohol drinking, and physical activity, are associated with total, cancer, and cardiovascular disease mortality among the Chinese population.