Associations of Diabetes and Prediabetes With Mortality and Life Expectancy in China: A National Study

OBJECTIVE To investigate the excess mortality and life-years lost associated with diabetes and prediabetes in China. RESEARCH DESIGN AND METHODS This national cohort study enrolled 135,405 participants aged 18 years or older from the general population in China. Cox proportional hazards regression models were used to estimate adjusted mortality rate ratio (RR). The life table method was used to estimate life expectancy. RESULTS Among the 135,405 participants, 10.5% had diabetes and 36.2% had prediabetes in 2013. During a median follow-up of 6 years, 5517 deaths were recorded, including 1428 and 2300 deaths among people with diabetes and prediabetes, respectively. Diabetes and prediabetes were significantly associated with increased risk of all-cause (diabetes: RR, 1.61 [95% CI 1.49, 1.73]; prediabetes: RR, 1.08 [95% CI 1.01, 1.15]), and cardiovascular disease (diabetes: RR, 1.59 [95% CI 1.41, 1.78]; prediabetes: RR, 1.10 [95% CI 1.00, 1.21]) mortality. Additionally, diabetes was significantly associated with increased risks of death resulting from cancer, respiratory disease, liver disease, and diabetic ketoacidosis or coma. Compared with participants with normoglycemia, life expectancy of those with diabetes and prediabetes was shorter, on average, by 4.2 and 0.7 years at age 40 years, respectively. The magnitude of the associations of diabetes and prediabetes with all-cause and cardiovascular disease mortality varied by age and residence. CONCLUSIONS In this national study, diabetes and prediabetes were significantly associated with reduced life expectancy and increased all-cause and cause-specific mortality risks. The disparities in excess mortality associated with diabetes and prediabetes between different ages and residences have implications for diabetes and prediabetes prevention and treatment programs.