Plasma concentration and urinary excretion of arginine vasopressin in children with moderately impaired renal function.

Plasma concentration and urinary excretion of arginine vasopressin (AVP) were measured in 20 children and adolescents with normal or moderately impaired renal function. Plasma AVP was higher in children with an inulin clearance less than 60 ml/min X 1.73 m2, whereas plasma osmolality did not differ in all children. Urinary excretion and urinary clearance of AVP (UCAVP) decreased in relation to impairment of renal function, and a strong negative correlation was found between plasma AVP and log UCAVP. Reduced urinary excretion of AVP may contribute to elevated plasma AVP in children with impaired renal function.