[Impact of the relationship between smoking and stressogenic behavior (type A behavior) and their cumulative effect on development of myocardial infarction and mortality (25-year follow-up data)].

The aim of the present study was to determine the significance of risk areas of stressogenic behavior (type A) and smoking for development of myocardial infarction and death within various time periods from the first health screening; as well as to evaluate the impact of the cumulative effect of these two factors upon the development of myocardial infarction and death. Behavioral activity (type A behavior) was assessed using short D. Jenkins questionnaire, and four factors (competitiveness, impatience, job stress, and responsibility), which were obtained via factor analysis of the 61-item D. Jenkins questionnaire. Risk areas of these variables were calculated by purposeful segmentation method. Smoking pattern was attributed to either dissonant or consonant by answers to a specially constructed question. The subjects were 1806 middle-aged men, participants of Kaunas-Rotterdam Intervention Study, who had undergone behavioral assessment, and were free from myocardial infarction at entry. Myocardial infarction and deaths were registered since the beginning of the study in 1972-1974 until January 1, 1997 (within that period myocardial infarction was diagnosed to 243 men, and 638 men died from various causes). The results showed that consonant smoking precipitates the onset of myocardial infarction, while the same effect of dissonant smoking reveals itself after a longer time period. Likelihood to die from various causes within 25 years did not depend upon a particular pattern of smoking, and was the greatest among the heaviest smokers. Consonant smoking, as detected during the first health screening, increases mortality rate within subsequent 16 years, while this effect among dissonant smokers manifests itself after the 16-year period. The relationship of overall type A behavior disposition with myocardial infarction was found within the first 16 years from the first screening, while that of competitiveness and myocardial infarction could be detected earlier (within the first 8 years). Cumulative effect of type A behavior and smoking patterns upon myocardial infarction and deaths was ambiguous; i. e. competitiveness was not related to smoking, while myocardial infarction precipitating impact of type A behavior was more prominent among smokers. Smoking was more related to mortality rates; therefore mortality-related effect of responsibility factor was greater among non-smokers.