[Significance of clearance values in advanced renal insufficiency (author's transl)].

Under physiological conditions there is satisfactory agreement between the clearance values of endogenous creatinine and inulin in humans. In chronic renal insufficiency the endogenous creatinine clearance cannot be considered as an index for glomerular filtrate because of considerable individual variations. In spite of this limitation endogenous creatinine clearance proves to be a sensitive test for hospital and general practice to estimate the loss of renal function in chronic progressive renal diseases if the loss of function has not yet led to an increase of the serum creatinine concentration.