The utility of renin profiling in childhood hypertension.

Criteria to categorize children as having hypertension associated with high, low or normal PRA as determined by the technique of renin sodium indexing; or with PRA responsiveness which was normal, suppressed or excessive after acute volume depletion induced by a loop diuretic were established in 30 normotensive adolescents. Four hour upright PRA corrected for daily sodium excretion was elevated in 16% of 43 and 84% of 25 children with essential and renal related hypertension. Low PRA was found in 5 of 43 and 0 of 25 children. In 36 children with essential hypertension evaluated after acute volume depletion, 4 and 5 had hyper- and hypo- responsive PRA compared to the 30 normotensive children. The application of these two approaches enables the renin angiotensin system to be systematically categorized in hypertensive children.