1979 Volume 16 Issue 5 Pages 439-448
Epidemiological studies of myocardial infarction (MI) in recent years have directed attention to several coronary risk factors usually associated with high incidence. Several risk factors already reported included in cigarette smoking, obesity, hypertension, diabetes mellitus and hyperlipemia. The purpose of this report was to analyse the role of risk factors, and their sex and age differences by comparing retrospectively clinical data between the MI group and the control group.
The material consisted of 660 cases with MI (538 males and 122 females) and 18117 normal cases (14524 males and 3593 females). They were subdivided into the following three groups: the younger age group (29-40 year age group), the middle age group (50-60 year age group) and the older age group (70-80 year age group). Risk factor analyzed were cigarette smoking, obesity, hypertension, diabetes mellitus and hyperlipemia.
The frequency of cigarette smoking, hypertension, diabetes mellitus and hypercholesterolemia was significantly higher in the MI group than in the control group in both males and females. This data indicated that such risk factors were more important on the development of MI. The frequency of overweight (weight experience 20% or more above their ideal weight) showed no significant differences between the MI group and the control group.
The frequency of elevated serum triglycerides was significantly higher in the MI group than in the control group only in males below the age of 50. Obesity and elevated serum triglycerides were thought not to be important risk factors. Both were thought to be indirected risk factors, because obesity could induced to hypertension and hypercholesterolemia, and there were many hyperlipemia of such a type that both cholesterol and triglycerides elevated in the MI group.
As to sex difference of risk factors, the degree of the significant difference in the number of diabetes mellitus, hypercholesterolemia between the MI group and the control group were larger in males than in females. This data indicated that these risk factors have less important roles in females, and the result may suggest that endocrine factors related to the menopause such estrogen have an influence on the development of MI. As to age difference of risk factors, comparing with the control group, the number of people who had risk factors analyzed in this study were more in the younger age group than in the older age group in both sexes. This data would indicated that risk factors have a more important role in the younger age group.
