Inverse relationship between diastolic blood pressure and urinary excretion of potassium in girls aged 8 to 9 years--a preliminary communication.

In order to investigate the association of urinary excretion of sodium and potassium with blood pressure, 72 prepubertal healthy children between 8 and 9 years were investigated in a cross sectional study. We determined anthropometric data, diastolic (DBP), and systolic blood pressure (SBP) and urinary excretion of sodium and potassium in 24-hour urine samples. No relationship was found between urinary sodium or potassium excretion and systolic or diastolic blood pressure, neither with regard to simple, nor multiple regression analysis. However, on simple linear and multiple regression analysis a significant inverse association between the excretion of potassium and diastolic blood pressure (r = -0.53; p less than 0.01 and r = -0.60; p less than 0.001) was observed in girls. From our data we conclude that in normal weight, healthy children urinary excretions of sodium and potassium are not associated with systolic blood pressure. However, a high 24-hour urinary excretion of potassium might be associated with lower diastolic blood pressure in prepubertal girls.