Diagnosed diabetes and premature death among middle-aged Japanese: results from a large-scale population-based cohort study in Japan (JPHC study)

OBJECTIVE: To examine the association between diabetes and premature death for Japanese general people. DESIGN: Prospective cohort study. SETTING: The Japan Public Health Center-based prospective study (JPHC study), data collected between 1990 and 2010. POPULATION: A total of 46 017 men and 53 567 women, aged 40–69 years at the beginning of baseline survey. MAIN OUTCOME MEASURES: Overall and cause specific mortality. Cox proportional hazards models were used to calculate the HRs of all cause and cause specific mortality associated with diabetes. RESULTS: The median follow-up period was 17.8 years. During the follow-up period, 8223 men and 4640 women have died. Diabetes was associated with increased risk of death (856 men and 345 women; HR 1.60, (95% CI 1.49 to 1.71) for men and 1.98 (95% CI 1.77 to 2.21) for women). As for the cause of death, diabetes was associated with increased risk of death by circulatory diseases (HR 1.76 (95% CI 1.53 to 2.02) for men and 2.49 (95% CI 2.06 to 3.01) for women) while its association with the risk of cancer death was moderate (HR 1.25 (95% CI 1.11 to 1.42) for men and 1.04 (95% CI 0.82 to 1.32) for women). Diabetes was also associated with increased risk of death for ‘non-cancer, non-circulatory system disease’ (HR 1.91 (95% CI 1.71 to 2.14) for men and 2.67 (95% CI 2.25 to 3.17) for women). CONCLUSIONS: Diabetes was associated with increased risk of death, especially the risk of death by circulatory diseases.