Mortality of Japanese diabetics in a seven-year follow-up study

To clarify the prognosis of Japanese diabetics, 143 patients with IDDM, 3394 with NIDDM and 384 with IGT who had visited the Diabetes Center of the Tokyo Women's Medical College from 1976 through 1980 were followed up during 3-7 years. The follow-up rates of the patients with IDDM, NIDDM and IGT were 100.0%, 99.6% and 99.7%, respectively. The mortality rates per 1000 person-years among the patients with IDDM, NIDDM and IGT were 8.73%, 25.24 and 13.72, respectively. On the other hand, the ratios of observed number of deaths among diabetics to expected number of deaths among a sex- and age-matched general population were 3.39 in IDDM, 1.55 in NIDDM and 1.03 in IGT. The leading cause of death in IDDM was acute cardiac failure and in both NIDDM and IGT, malignant neoplasms. In NIDDM, a statistically significant excess of deaths from diabetes mellitus itself, ischemic heart disease and malignant neoplasms was observed compared with the general population. This is the first report concerning mortality and causes of death among Japanese diabetics separately for IDDM, NIDDM and IGT.