The effect of a high protein intake on renal function of patients with chronic renal insufficiency.

In 30 patients with chronic renal disease, glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured after 4 weeks of protein restriction and subsequently after adhering to a high protein intake for the same period. Twenty-four patients adhered to their advised diets according to the 24-hour urea excretion. These 24 patients showed a significant increase in GFR, ERPF and proteinuria (n = 15) during a high protein intake, even if their renal function was markedly impaired. It is concluded that although in patients with markedly impaired renal function a meat meal or an infusion of amino acids does not change renal function anymore, prolonged high protein intake is accompanied by an increase in GFR, poorly dependent on GFR after prolonged protein restriction.