[A nested case-control study of risk factors for circulatory disease--correlation of initial medical examination findings with mortality and their progression].

Risk factors for cerebrovascular disease (CVD) and heart disease (HD) were studied prospectively in 2112 men and women, aged 30-59, initially without history of either disease, living in the Nishi-izu district of Shizuoka Prefecture. Baseline medical examinations were performed in 1964-1966 and subjects were followed until 1985. There were 93 CVD cases and 64 HD cases identified by death certificate during the follow-up period. Using a nested case-control design, risk variables at the last medical examination before death of the 157 cases (93 CVD cases and 64 HD cases) were compared to examination results of 314 controls (survivors) matched for gender, age (+/- 2 years), and residential district. Using the same design, the progression of risk variables over the 5 +/- 1 years prior to the last examination was followed to identify factors associated with circulatory disease. From conditional logistic regression analysis using findings at the last health examination, significant risk variables for CVD were found to be high blood pressure and abnormality in electrocardiogram (ECG), while risk variables for HD were hypertensive or arteriosclerotic changes in ocular fundus, and ECG abnormalities. From the same multivariate analysis using the progression of findings, the most significant risk variable for either CVD or HD was abnormalities in ECG. The present study suggests that in addition to cross-sectional findings on a given occasion, following the progression of findings through serial health examinations yields useful information for management of the health of residents.