Validity of corrections for creatinine excretion and creatinine clearance.

Corrections of values for creatinine excretion and creatinine clearance on the basis of body weight reduce the population variation, i.e., narrow the reference range. The range is not further narrowed, however, by correcting for calculated surface area or calculated lean body mass. Corrections of creatinine clearance for body weight and calculated lean body mass remove the sex difference seen in the uncorrected clearances, but creatinine clearance corrected for surface area, although not significantly different between the sexes, give appreciably different reference ranges. These conclusions apply to individuals healthy in terms of body composition.