Uric acid excretion in normal children.

Standard values were established for urinary excretion and clearance of uric acid in 95 normal, nonhospitalized children. We found that urinary uric acid excretion and serum uric values increase throughout childhood; that in early childhood, fractional excretion and clearance of uric acid are higher than adult norms; and that despite an increasing filtered load of uric acid, there is a progressive decrease in fractional excretion and clearance of uric acid with advancing age. Some tubular maturational change, either decreasing secretion or increasing reabsorption, must account for the progressive decline in fractional excretion and clearance of uric acid.