Life-style related factors and idiopathic dilated cardiomyopathy--a case-control study using pooled controls.

A case-control study was conducted to investigate how basic habits of life including dietary habit, physical activity, cigarette smoking, and drinking, are involved in the development of idiopathic dilated cardiomyopathy (DCM). Collection of cases was entrusted to the clinical research group of DCM, and national pooled controls established by sex and age category by the epidemiological research group of intractable diseases were used to ensure representativeness of the controls. Fifty-eight cases of DCM which developed in and after January 1991 were collected, and 5,912 controls matched with the cases by residential area, sex, and age were selected. Analysis of the results of the study showed that items in the questionnaire suggestive of viral infection, such as "susceptibility to common cold" and "susceptibility to diarrhea", items concerning dietary habit, including "taking no breakfast", "ingestion of salty food", and "ingestion of fatty food", and such items as "cigarette smoking" and "lack of sleep" tended to be observed in the case group at significantly higher frequencies. Since viral infection has been suspected as a causative factor of DCM, further research of this area is thought to be of particular importance for determining the etiology of DCM.