Mortality from Coronary Heart Disease and Cerebrovascular Disease and Associated Risk Factors in Patients with Type 2 Diabetes Mellitus : A 15-year Follow-up Study in Osaka

An analysis was made of factors related to death from coronary heart disease (CHD) and cerebrovascular disease (CVD) in diabetic patients. The study included 1, 939 patients (the mean age at entry was 52.8±11.1 years), 1, 200 males and 739 females, with type 2 diabetes mellitus. These patients entered the study between 1960 and 1979 and were followed until the end of 1993. The mean observation perrrriod was 14.9±6.6 years. At the end of the follow-up, 1, 000 patients (51.6%) were alive, 880 (45.4%) had died and 59 (3.0%) had been lost to follow-up. Among the deceased patients, 111 had died of CHD and 128 of CVD. The relationship of risk factors to death from CHD or CVD was analyzed in terms of the mortality rate per 1, 000 person-year and odds ratios (relative risks), as well as multiple logistic regression method. In our univariate analysis, we found that deaths from CHD were related to fasting plasma glucose level, blood pressure, ischemic ECG changes, serum cholesterol level, retinopathy, proteinuria and therapeutic regimen. Deaths from CVD were related to hypertension, proteinuria and therapeutic regimen. However, in subsequent multiple logistic analysis, only systolic blood pressure, ischemic changes in electrocardiogram (ECG) findings, serum cholesterol level and retinopathy remained significant with respect to mortality from CHD, while hypertension and fasting plasma glucose level were significant with respect to CVD, in addition to age. We found a much lower mortality from CHD, even in our diabetic subjects, than has been found in Western countries. Moreover, there seemed to be a substantial difference in terms of risk factors between mortality from CHD and from CVD.