Arterial blood pressure and urinary electrolytes.

The relationship between blood pressure levels and urinary sodium and potassium concentrations were examined by sex and race in a random population sample of 1939 residents, aged 34-57. They were selected from three cities of the United States which had reported marked differences in morbidity and mortality due to stroke. We found that high blood pressure was associated with higher urinary sodium/potassium ratio and lower urinary potassium concentration. Part of this relationship might be due to obesity. Blacks had higher blood pressure than whites and they also had higher sodium and lower potassium concentrations in the urine. In addition, black women were much heavier than white women. Blood pressure was lower among individuals with higher education. Both obesity and urinary Na/K ratio were inversely related to the level of education among white women.