[A case-control study of life styles associated with myocardial infarction].

Preclinical events, especially life styles associated with myocardial infarction (MI), were evaluated in a case-control study. A total of 56 male cases were studied along with matched (1:2) controls. Cases were diagnosed at the Department of Cardiovascular Medicine, Hokkaido University School of Medicine and its related hospitals. Cases were matched to two controls each according to sex, age (+/- 3 year) and residence in central Hokkaido. Preclinical life events (diet, alcohol and smoking, working environment, health behaviors, social life etc.) were inquired in a one-to-one personal structurized interview. In order to evaluate univariate effects and the combined effects of the major multivariate variables, unconditional logistic model was used. The 14 independent variables revealing significant associations with MI were screened in the four areas of lifestyles, 1) diet: more consumption of rice-based non-fat sweets, less consumption of vegetable salads, irregular meal times, 2) alcohol and smoking: non-drinker as well as excessive drinker of alcohol, more than 30 cigarettes per day, 3) working environment, social association and personality: more than 10 hours work per day, feelings not shared with family about work, difficulty in reorientation during concentration, being easily moved to tears and 4) health-promotion, leisure and life style: not eager to watch TV programs on health, not eager to read health articles in newspaper, irregular sleep times, not watching TV in leisure time. Combined odds ratios were calculated in a multivariate logistic analysis, which disclosed phenomenal elevation of the risks in those having more lifestyle factors associated with MI.