[A case-control study on the risk factors of sudden death. An analysis of 44 cases in a company by health care records].

A case-control study was conducted on sudden deaths in a company having about 40,000 workers to determine the risk factors of sudden death. Sudden death was defined as internal death within 24 hours from the onset of the event. Two controls whose sex and age were matched with a case were selected from the employees of the company. The risk factors studied were age, sex, obesity, blood pressure, serum glucose, total cholesterol, triglyceride, uric acid, urinary, protein, urinary sugar, electrocardiographic (ECG) findings, diabetes mellitus, smoking history and drinking history. These data were collected from the latest health care record including health examinations performed annually in the company. t test, U test and Fisher's test were applied to each of the variables. Multiple logistic regression analysis and canonical discriminant analysis were applied, using mean systolic blood pressure for 5 years, body mass index (BMI), abnormal Q wave on ECG, and serum glucose as explanatory variables. From 1984 to 1990 44 sudden death cases composed of 42 males and two females were identified. The age-specific mortality rate increased exponentially with age with a peak at the sixth decade. The most frequent cause of sudden death was heart disease (77%) followed by cerebrovascular disease (18%). Statistical analysis showed that significant risk factors were high blood pressure, low BMI, diabetes mellitus, and ST-T change on ECG.