Eating a low-protein diet supplemented with ketoanalogues postpones the need for dialysis in patients with chronic kidney disease, according to a study conducted by a team of researchers from Bucharest, Romania. The study, “Ketoanalogue-Supplemented Vegetarian Very Low–Protein Diet and CKD Progression,” was published in the Journal of the American Society of Nephrology (JASN).

Low-protein diets have been one of the cornerstones in the management of chronic kidney disease (CKD) for more than five decades. Apart from mitigating the accumulation of nitrogenous wastes and metabolic disturbances, both of which are characteristic of advanced stages of CKD, such diets also reduce the quantities of sulfates, phosphates, potassium, and sodium ingested, thus leading to a more favorable metabolic profile and possibly improved disease progression.

Adding ketoanalogues, nitrogen-free analogues of essential amino acids, to very low-protein diets for patients with chronic kidney disease (CKD) may significantly delay dialysis initiation. But the extent of improvement and effect of ketoanalogue supplementation has not been clear.

To address this issue, researchers conducted a prospective randomized controlled trial to assess the safety and effectiveness of a vegetarian diet low in protein supplemented with ketoanalogues to reduce CKD progression.

A total of 207 CKD patients were randomly assigned to a low-protein diet supplemented with ketoanalogues (0.3 g/kg vegetable proteins and ketoanalogues per day), or simply a low-protein diet (0.6 g/kg per day) for a period of 15 months.

Five CKD patients with stage 4 or higher kidney function needed to follow the ketoanalogue-supplemented diet to avoid a more than 50 percent reduction in kidney function, or, in one patient, the need to undergo dialysis.

Overall, the favorable effects of the vegetarian low protein diet supplemented with ketoanalogues appeared to stem from its capacity to correct metabolic complications of advanced stages of CKD, rather than its effects on kidney function.

Compliance to diet was good, with no changes in nutritional parameters and no adverse reactions.

“The results draw attention to the role of dietary interventions, particularly of a ketoanalogue-supplemented vegetarian protein-restricted diet, as effective, safe, and feasible in selected pre-dialysis patients with CKD,” Dr. Garneata said in a news release. “This type of nutritional intervention could be used in compliant patients with advanced disease and with good nutritional status to postpone dialysis initiation.”