Renin-stimulating test in children.

: Plasma renin activity (PRA) was measured after various stimuli to evaluate a renin-stimulating test and to screen suppressed PRA in 60 children with labile hypertension aged 10 to 14 years. There was a significant difference between supine PRA and that after both standing (for 15 or 60 minutes) or frusemide administration (P less than 0.001, respectively); however, there was no statistical difference between the PRA while standing or after frusemide. Children who gripped a hand dynamometer for three minutes did not show any change in PRA. Standing upright for 15 minutes or supine rest for 90 minutes after the administration of frusemide i.v. are easily applicable to children and seem the most appropriate renin-stimulating test in childhood. No subjects showed suppressed PRA in this study.