Diabetes and Cause-Specific Mortality in a Prospective Cohort of One Million U.S. Adults

OBJECTIVE: Diabetes is a major predictor of death from heart disease and stroke; its impact on nonvascular mortality, including specific cancers, is less understood. We examined the association of diabetes with cause-specific mortality, including deaths from specific cancers. RESEARCH DESIGN AND METHODS: A prospective cohort of 1,053,831 U.S. adults, without cancer at baseline, enrolled in the Cancer Prevention Study-II in 1982 and was followed for mortality until December 2008. At baseline, participants completed a self-administered questionnaire that included information on diabetes, smoking, physical activity, height, and weight. Multivariable-adjusted relative risks (RRs) (95% CI) were estimated using Cox proportional hazards regression. RESULTS: During 26 years of follow-up, 243,051 men and 222,109 women died. In multivariable models that controlled for age, BMI, and other variables, diabetes was associated with higher risk of all-cause mortality (women RR 1.90 95% CI 1.87-1.93; men 1.73 1.70-1.75). Among women, diabetes was associated with higher risk of death from cancers of the liver (1.40 1.05-1.86), pancreas (1.31 1.14-1.51), endometrium (1.33 1.08-1.65), colon (1.18 1.04-1.33), and breast (1.16 1.03-1.29). Among men, diabetes was associated with risk of death from cancers of the breast (4.20 2.20-8.04), liver (2.26 1.89-2.70), oral cavity and pharynx (1.44 1.07-1.94), pancreas (1.40 1.23-1.59), bladder (1.22 1.01-1.47), colon (1.15 1.03-1.29), and (inversely) prostate (0.88 0.79-0.97). Diabetes was also associated with higher risks of death involving the circulatory system, respiratory system, digestive system, genitourinary system, and external causes/accidental deaths. CONCLUSIONS: Diabetes is associated with higher risk of death for many diseases, including several specific forms of cancer.