Low-protein diet for conservative management of chronic kidney disease: a systematic review and meta-analysis of controlled trials.
Study Goal
The researchers aimed to determine whether a low-protein diet could safely and effectively manage chronic kidney disease (CKD) by delaying dialysis initiation and slowing CKD progression without causing protein-energy wasting or cachexia.
Results Summary
The study found that low-protein diets (<0.8 g/kg/day) were associated with improved serum bicarbonate and phosphorus levels, reduced azotemia, slower progression to end-stage renal disease, and a trend toward lower all-cause mortality. Very-low-protein diets (<0.4 g/kg/day) showed greater kidney function preservation and further reduced progression to end-stage renal disease, with no increased risk of malnutrition or protein-energy wasting.
Population
Patients with non-dialysis-dependent chronic kidney disease (CKD).
Effective Dosage
<0.8 g/kg/day (low-protein diet), <0.4 g/kg/day (very-low-protein diet).
Duration
Not specified in the abstract.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
low-protein diet (protein intake <0.8 g/kg/day) | increase | serum bicarbonate levels | patients with CKD | - | were associated with higher | #1 |
low-protein diet (protein intake <0.8 g/kg/day) | decrease | phosphorus levels | patients with CKD | - | were associated with lower | #2 |
low-protein diet (protein intake <0.8 g/kg/day) | decrease | azotemia | patients with CKD | - | were associated with lower | #3 |
low-protein diet (protein intake <0.8 g/kg/day) | decrease | rates of progression to end-stage renal disease | patients with CKD | - | were associated with lower | #4 |
low-protein diet (protein intake <0.8 g/kg/day) | decrease | rates of all-cause death | patients with CKD | - | a trend towards lower | #5 |
very-low-protein diets (protein intake <0.4 g/kg/day) | increase | kidney function | patients with CKD | - | were associated with greater preservation of | #6 |
very-low-protein diets (protein intake <0.4 g/kg/day) | decrease | progression to end-stage renal disease | patients with CKD | - | reduction in the rate of | #7 |
low-protein diet | no change | safety and adherence | patients with CKD | - | was not inferior to a normal protein diet | #8 |
low-protein diet | no change | malnutrition or protein-energy wasting | patients with CKD | - | there was no difference in the rate of | #9 |
BACKGROUND: Recent data pose the question whether conservative management of chronic kidney disease (CKD) by means of a low-protein diet can be a safe and effective means to avoid or defer transition to dialysis therapy without causing protein-energy wasting or cachexia. We aimed to systematically review and meta-analyse the controlled clinical trials with adequate participants in each trial, providing rigorous contemporary evidence of the impact of a low-protein diet in the management of uraemia and its complications in patients with CKD. METHODS: We searched MEDLINE (PubMed) and other sources for controlled trials on CKD to compare clinical management of CKD patients under various levels of dietary protein intake or to compare restricted protein intake with other interventions. Studies with similar patients, interventions, and outcomes were included in the meta-analyses. RESULTS: We identified 16 controlled trials of low-protein diet in CKD that met the stringent qualification criteria including having 30 or more participants. Compared with diets with protein intake of >0.8 g/kg/day, diets with restricted protein intake (<0.8 g/kg/day) were associated with higher serum bicarbonate levels, lower phosphorus levels, lower azotemia, lower rates of progression to end-stage renal disease, and a trend towards lower rates of all-cause death. In addition, very-low-protein diets (protein intake <0.4 g/kg/day) were associated with greater preservation of kidney function and reduction in the rate of progression to end-stage renal disease. Safety and adherence to a low-protein diet was not inferior to a normal protein diet, and there was no difference in the rate of malnutrition or protein-energy wasting. CONCLUSIONS: In this pooled analysis of moderate-size controlled trials, a low-protein diet appears to enhance the conservative management of non-dialysis-dependent CKD and may be considered as a potential option for CKD patients who wish to avoid or defer dialysis initiation and to slow down the progression of CKD, while the risk of protein-energy wasting and cachexia remains minimal.