[Significance of the determination of serum and urinary creatinine for the clinical use, dispensatory care and screening of patients with kidney diseases].

In the early recognition, control of course and therapy of patients with chronic renal diseases the proof of disturbances of the renal functions has a particular value. Here the determination of creatinine in the serum and in the urine increasingly gains significance, since an automatisation stood the test. The creatinine values may be used as orientation values for the clearance method in the dispensary or in the screening as well as in the sense of reference values for other substances normally contained in the urine. In patients with chronic renal diseases a shift of the daily variation of the renal function according to the development of a nycturia is to be observed still before the formation of an isosthenuria. In female test persons the excretion of creatinine is on an average lower than in male ones. This may be based on the differently developed muscle masses. When creatinine is used as reference value for other substances the dependence on age and sex must be taken into consideration in the case that the substance concerned does not reveal the same age- and sex-specific course of behaviour.