Trends in cerebrovascular mortality and in its risk factors in Finland during the last 20 years.

At the beginning of the 1970s, the mortality rates from cerebrovascular disease in Finland were among the highest in the world. In addition, the levels of the main known risk factors for cardiovascular disease, such as high blood pressure, elevated serum cholesterol level and cigarette smoking, were by international comparisons very high. Within Finland, higher mortality from both stroke and ischemic heart disease was observed in the eastern part of the country, where the levels of the risk factors mentioned were higher than in the western regions. Official mortality statistics show that deaths from stroke in Finland declined steeply in the 1970s, and continued to decline, although at a slower pace, during the 1980s. Furthermore, the decline in stroke mortality was greater in eastern Finland than in the western part of the country, such that the gap observed between east and west Finland in stroke mortality has now almost disappeared. These findings are supported by the trends observed from the North Karelia stroke register and from the FINMONICA stroke register. A cohort study has demonstrated that high blood pressure, high blood cholesterol level and cigarette smoking are risk factors for fatal stroke in the male population of eastern Finland. In women, only high blood pressure was found to be a risk factor for fatal stroke, while for cigarette smoking and high blood cholesterol levels the risk, though increased, was not statistically significant. A national strategy has been developed to control and reduce the main cardiovascular risk factors in Finland. The North Karelia project, started in Finland in 1972, was the first program of its type aimed at the reduction of risk factors in a whole population. Arterial blood pressure and total blood cholesterol levels have decreased significantly during the last 20 years in both men and women. The prevalence of cigarette smoking has been reduced only in men. The changes in risk factors that have occurred parallel the changes in stroke mortality, suggesting that the selected strategy--to reduce risk factor levels on a population-wide basis--has been effective in reducing stroke mortality in Finland.