Urinary sodium and potassium profile of blacks and whites in relation to education in two different geographic urban areas.

The high Na/low K environment of modern society is involved in the genesis of hypertension and stroke. There is prior evidence of racial, geographic and education differences in Na and K intake and blood pressure. The baseline data in the Treatment of Mild Hypertension Study (TOMHS) was used to examine urinary Na and K excretion profiles by race, geographic area and education. The study cohort consisted of adult blacks (B) and whites (W) from the Birmingham, AL (B=40, W=153) and Chicago, IL (B=114, W=128) areas. Level of education was categorized as < college graduate and ≥ college graduate. Participants with education ≥ college graduate were B=22% and W=38%. Age/gender-adjusted means follow: The urinary Na:K ratio was significantly higher in both blacks and whites in Birmingham than in Chicago. This was due to lower excretion of K. The highest Na:K ratio was observed in blacks in Birmingham with low education, although urinary Na excretion was high in blacks with low education in both cities. No such differences were seen in whites. Although not population-based, these findings suggest that potassium intake among mild hypertensives is related to geographic area in blacks and whites, and sodium intake is related to education in blacks.