MO579: The Long-Term Efficacy and Safety of Low-Protein Diets in Non-Diabetic Patients with Advanced CKD: Focus on Elderly
Authors: Garneata Liliana , Mocanu Carmen-Antonia , Mircescu Gabriel 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Current data suggest the benefits of protein restriction in the management of advanced chronic kidney disease (CKD), improving metabolic abnormalities, optimizing blood pressure control and allowing to postpone kidney replacement therapy (KRT). However, feasibility, safety and even the long-term benefits of low protein diets (LPDs) are questioned, especially in elderly.
This study aimed to compare the long-term efficacy and safety of two types of LPDs in elderly non-diabetic patients with advanced CKD.

METHOD
Long-term follow-up (FU) data from a prospective randomized controlled single-center trial (RCT) on 207 CKD stage 4 + non-diabetic patients are presented. The RCT compared the effects of vegetarian very low protein diet supplemented with keoanalogues of essential amino acids (sVLPD, vegetable proteins 0.3 g/kg-day plus, Ketosteril®, Bad Homburg, Germany, 1 tb/5 kg bw-day) with conventional LPD (mixed proteins 0.6g/kg-day) for 15 months (Garneata L et al. JASN. 2016; doi:10.1681/ASN.2 015 040 369). The composite endpoint was the need of KRT or the patients’ death. The census point was either the occurrence of primary endpoint or 31 July 2018.
We are presenting a sub-analysis focusing on elderly patients (&gt;65 years old). Safety was assessed throughout the study by anthropometric measures, Subjective Global Assessment (SGA), serum levels of albumin (SAlb) and C-reactive protein (CRP). Davies Comorbidity score was also registered during the follow-up.

RESULTS
Two hundred patients who ended the RCT were enrolled in the FU. All of them voluntarily continued the prescribed intervention. Data analysis showed sVLPD to be superior to LPD on long-term with respect to the primary endpoint, preserving the nutritional status (published data).
Of the 200 subjects, 36 (18%) were elderly, 15 on LPD and 21 on sVLPD.
At 31 July 2018, more than 10 years after the end of RCT, 70% of the elderly patients were alive with no statistically significant difference between groups (81 versus 43.3%, P = 0.08 in sVLPD and LPD, respectively).
The median follow-up was significantly higher in the sVLPD group: 116 (106–123) versus 97 (49–115) months.
The need for KRT during FU was significantly lower in patients on sVLPD: 43 versus 100%. The time until KRT was similar between groups: 32 (7–54) versus 35 (6–131) months, sVLPD and LPD, respectively.
There were no significant differences between sVLPD and LPD at the end of FU (EOFU) in the nutritional status assessed by SGA and SAlb [4.41 (4.14–4.56) versus 4.31 (3.90–4.35) g/dL]. At the EOFU, CRP was significantly lower in the sVLPD group: 7 (4–9) versus 10.5 (7–16) mg/L. Davies Comorbidity Score increased during the FU in both groups, with no difference: 3 (1–3) versus 3 (3–5), sVLPD and LPD, respectively. Kaplan–Meier analysis showed better survival rates in the sVLPD group, both for the patient (10-year survival 78 versus 53% in sVLPD and LPD, respectively) and for kidney (10-year survival 82 versus 20% in sVLPD and LPD, respectively). Cox regression analysis of data showed SGA A and the sVLPD to be associated with better patients’ survival, while only sVLPD was associated with better kidneys’ survival.

CONCLUSION
Both types of protein-restricted diets proved feasible and safe on long-term in elderly. Vegetarian very low protein diet supplemented with ketoanalogues was associated with better patients and kidneys survival as compared with low protein diet in elderly non-diabetic patients.