SALT INTAKE AND STROKE - A POSSIBLE DIRECT EFFECT

We have performed an ecological analysis of the relationship between r egional mortality from cerebrovascular disease in western Europe and r egional data on urinary sodium excretion, systolic blood pressure and relevant confounding variables. We have used published WHO cerebrovasc ular disease mortality rates and data provided by the INTERSALT study. Inter-relationships between these variables were investigated by line ar regression analysis, with the regression coefficients, weighted for population size. On univariate analysis a significant linear relation ship was observed between regional stroke mortality and median 24 hour urinary sodium excretion (coef. = 0.01, t = 3.28, P = 0.008), body ma ss index (coef. = 0.24, t = 3.21, P = 0.009) and alcohol intake (mls/w eek, coef. = 1.54, t = 3.99, P = 0.003). The relationship between stro ke mortality and systolic blood pressure, though positive, was weaker than that between stroke mortality and sodium excretion and was not si gnificant in this data. The stroke mortality sodium excretion relation ship was independent of BMI on multivariate analysis. These data are c onsistent with the hypothesis that a high intake of salt may increase the risk of stroke, independent of effects on blood pressure.