The aim of our study was to assess the metabolic effect and renal excretion of amino acids following the administration of their keto-analogs to patients with chronic renal insufficiency (CRI). A prospective study was started in 18 CRI patients in stable metabolic conditions who were on a low-protein diet supplemented by oral keto-amino acids (100 mg/kg/d) for a period of 3 months. Examinations performed at baseline and at the end of the follow-up period revealed a significant increase in the serum levels of branched-chain amino acids (leucine, isoleucine, and valine) while the renal excretion fraction declined. Keto-amino acid administration had no effect on the glomerular filtration rate as the clearance of polyfructosan (inulin) but, also, that of endogenous creatinine and urea remained unaltered. Significant decreases in the levels of urea and the rate of its excretion in urine, proteinuria, and a rise in albumin levels were also noted.

        Key words: keto-analogs, branched-chain amino acids, renal clearance, fractional excretion.