Dietary protein restriction and preservation of kidney function in chronic kidney disease.

Dietary protein augmentation elicits an increase in single nephron glomerular filtration rate (GFR) and increased transglomerular pressure. This is similar to the hemodynamic response to reduction in renal mass. Among patients and experimental animals with proteinuric renal disease, these changes also cause an increase in glomerular permselectivity, which in experimental animals accelerates loss of renal function. A meta-analysis of a group of prospective randomized trials including over 2,000 patients found a significant effect on reducing dietary protein decreasing the risk of end-stage renal disease or death (defined as renal death). This differs somewhat in the outcomes of clinical trials using intermediate outcomes, such as the Modification of Diet in Renal Disease study that used change in GFR in part because of the initial hemodynamic effect of reduction in GFR mediated by dietary protein restriction.