REFERENCE VALUES OF UREA, CREATININE, AND CREATININE CLEARANCE IN CHILDREN AND ADOLESCENTS

We have studied 2,030 children and adolescents between 3 and 18 years of age (578 girls and 622 boys). We obtained reference values of creat inine, urea and urea/creatinine serum ratio in all of them, and creati nine clearance (Cl(cr)) in 1,200. We found an increase in serum creati nine levels with age in both sexes, with an uncharging serum urea leve l that results in a decrease of serum urea/creatinine ratio. The Cl(cr ) increase with age, but not with sex. We suggest the use of the formu la: FG = K.L/Pcr to determinate renal function; it was derived from co mparison with Cl(cr) in 10 h. urine collections.