[Urea clearance and measurement of glomerular filtration in patients with chronic renal insufficiency].

In 31 patients with chronic renal insufficiency (CHRI) the authors investigated the relationship between insulin or polyfructosan S (CPFS) clearance, urea clearance (Curea) and creatinine clearance (Ccr). The mean clearance values of these substances were as follows: CPFS: 0.198 (+/- 0.091) ml/s, Curea: 0.183 (+/- 0.086) ml/s, Ccr: 0.315 (+/- 0.169) ml/s. Between the values of Curea and CPFS, similarly as between values of Ccr and CPFS, a significant linear relationship was revealed, however, the regression line indicating the relationship between Curea and CPFS was closer to the identity line than the relationship between Ccr and CPFS. The results suggest that in patients with CHRI (where CPFS less than 0.4 ml/s) Curea is close to the value of glomerular filtration.