RESUMO
While the mortality rate of cerebral hemorrhage of Okinawa Prefecture is the lowest in Japan, the presence of a high incidence rate for cerebral hemorrhage has been pointed out in Hirara-city, Okinawa Prefecture. In order to develop an effective counter-measure, a case-control study of risk factors for cerebral hemorrhage was performed. Cases were 62 residents in Hirara city aged 40-69 years who had experienced cerebral hemorrhage between April 1987 through March 1992. From the 62 cases interviewed, responses were obtained from 49 cases. Controls were 147 residents without a history of stroke who were matched to cases individually by sex and age (control/case ratio = 3). From the 49 cases, 28 cases who had participated in residential mass health examinations before experiencing the cerebral hemorrhage, were matched individually sex and age with different randomly selected controls (control/case ratio = 10). From conditional logistic regression analysis of the interview survey data, history of hypertension, interruption of hypertension therapy, family history of stroke, long working hours, overwork and difficulty of taking a day-off each week were strongly related to increased risk of cerebral hemorrhage. Smoking, preference for salty taste and habitual drinking, also, elevated risk slightly. From analysis of the residential mass health examination data, high blood pressure was found to be strongly associated with cerebral hemorrhage, while serum cholesterol was inversely related.
