The aim of our study was a re-analysis of data obtained from a prospective long-term rando mized multicentric study designed to evaluate the effect of concomitant administration of a low-protein diet (LPD) with essential amino acid (AA) ketoanalogs on proteinuria and aminoaciduria in patients in chronic renal insufficiency (CRI). The study was designed to monitor, over a 3-year period, a total of 70 patients randomized into group I (35 patients) receiving LPD (0.6 g protein/kg/day), with AA ketoanalogs (100 mg/kg/day) and group II (35 patients, control group) given only LPD. Examinations performed at the start and at 6-month intervals demonstrated a significant decrease in proteinuria (p < 0.01) and branched-chain aminoaciduria (p < 0.01) in group I associated with improved protein metabolism parameters. At the same time, slower CRI progression was observed as assessed using inulin clearance (p < 0.01). Besides a modified haemodynamic effect associated with a significant rise in urinary NOx (p < 0.02), changes in amino acid tubular transport were also seen. AA ketoanalog adminis- tration combined with LPD had a beneficial effect on the examined metabolic parameters and, through its glomerulo-tubular action, it also had an effect on the long-term progression of CRI.

        Key words: ketoanalogs, proteinuria, aminoaciduria, renal insufficiency.