Effect of diet protein restriction on progression of chronic kidney disease: A systematic review and meta-analysis

Abstract

BackgroundDietary protein restriction has long been thought to play an important role in the progression of chronic kidney disease (CKD); however, the effect of dietary protein on the rate of decline in kidney function remains controversial.ObjectiveWe undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the influence of protein restriction on chronic kidney disease.MethodOvid MEDLINE (from 1946 to March 5, 2016), EMBASE (from 1966 to March 5, 2016), and the Cochrane Library (Inception to March 5, 2016) were searched to identify RCTs comparing different levels of protein intake for at least 24 weeks in adult patients with CKD. The outcomes included kidney failure events, the rate of change in estimated glomerular filtration rate (eGFR) per year, all cause death events, and changes in proteinuria, serum phosphorus concentration, serum albumin, and body mass index (BMI).ResultsNineteen trials with 2492 subjects were analyzed. A low protein diet reduced the risk of kidney failure (odds ratio (OR) = 0.59, 95% CI: 0.41 to 0.85) and end-stage renal disease (ESRD) (OR = 0.64, 95% CI: 0.43 to 0.96), but did not produce a clear beneficial effect for all cause death events (OR = 1.17, 95% CI: 0.67 to 2.06). The change in the mean difference (MD) for the rate of decline in the eGFR was significant (MD: −1.85, P = 0.001), and for proteinuria (MD: −0.44, P = 0.02). A low protein diet also reduced the serum phosphorus concentration (MD: −0.37, 95% CI: −0.5 to −0.24) and BMI (MD: −0.61, 95% CI: −1.05 to −0.17). However the change in albumin presented no significant difference between two groups (MD: 0.23, 95% CI: −0.51 to 0.97).ConclusionsBased on the findings of our meta-analysis, protein-restricted diet may reduce the rate of decline in renal function and the risk of kidney failure for CKD populations, but did not produce a clear beneficial effect for all cause death events. Besides However, the optimal level of protein intake in different participants is left unanswered, and the nutritional status should be regarded with caution.

Long-Term Effects of Ketoanalogues on Mortality and Renal Outcomes in Advanced Chronic Kidney Disease Patients Receiving a Low-Protein Diet

“…A low-protein diet (LPD) has been found to delay chronic kidney disease (CKD) progression in studies on animal and carefully selected patients with CKD [1][2][3][4]. In the systematic review and meta-analysis of randomized controlled trials, a protein-restricted diet may reduce kidney function deterioration rate and renal failure risk of patients with CKD, but did not produce a positive effect on all-cause death events [5]. However, considering non-diabetic patients with CKD 4 and 5, a recent systematic review and meta-analysis of randomized controlled trials showed that compared with a normal-protein diet, an LPD may make little difference in the rate of decreasing renal function in non-diabetic patients with CKD 4 and 5 who progress to renal replacement therapy, but a very low protein diet (VLPD) probably decrease the number of non-diabetic patients with CKD 4 and 5, who progress to renal replacement therapy [6].…”

Salt, but not protein intake, is associated with accelerated disease progression in autosomal dominant polycystic kidney disease

“…2 The role of dietary protein restriction in slowing progression of CKD is more controversial, although several meta-analyses indicate a beneficial, albeit small effect. 3,4 In autosomal dominant polycystic kidney disease (ADPKD) specifically, there are only scarce data on the renal effects of salt and protein intake.…”

Effect of low‐protein intake on all‐cause mortality in subjects with an estimated glomerular filtration rate higher than 60 mL/min/1.73 m2with or without albuminuria

“…In a randomised trial 22 conducted in patients who had an eGFR less than 30 mL/min/1.73 m 2 , a ketoanalogue‐supplemented vegetarian diet with protein intake of 0.3 g/kg/day was associated with a prolonged dialysis‐free survival, compared with a protein intake of 0.6 g/kg/day. However, in a meta‐analysis 19 of 19 trials with 2492 subjects who had either a low eGFR or albuminuria, a low‐protein diet reduced the risk of ESRD (odds ratio 0.64, 95% CI 0.43‐0.96), but did not lower all‐cause mortality (odds ratio 1.17, 95% CI 0.67‐2.06). In another meta‐analysis 28 that included 17 studies with a total of 2996 subjects who had stages 3‐5 CKD, a protein intake of 0.5‐0.6 g/kg/day was not significantly associated with a lower risk of mortality (risk ratios 0.77, 95% CI 0.51‐1.18), compared with a protein intake of ≥0.8 g/kg/day.…”

“…In a randomised trial 22 conducted in 207 patients with an estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m 2 , the authors reported that a ketoanalogue‐supplemented vegetarian diet with a protein intake of 0.3 g/kg/day led to a prolonged dialysis‐free survival, compared with a protein intake of 0.6 g/kg/day. Nevertheless, mortality risk was not reduced with a low‐protein diet (odds ratio 1.17, 95% CI 0.67‐2.06) in meta‐analysis 19 of 19 trials with 2492 subjects who had either a low eGFR or albuminuria. In contrast, a protein intake of 0.28 g/kg/day appeared to increase mortality risk (hazard ratios, HRs 1.92, 95% CI 1.15‐3.20) 23 compared with a protein intake of 0.58 g/kg/day in patients with CKD.…”

“…In addition to pharmacologic treatment for controlling risk factors, 9,10 guidelines recommend nutritional management for patients with CKD 11,12 to improve outcomes. Protein intake restriction to less than 0.8 g/kg/day for patients with CKD 12‐14 has been suggested in light of the evidence that a low‐protein intake was associated with preservation of renal function 15‐19 . In the Modification of Diet in Renal Disease study 15 conducted in patients with non‐diabetic CKD, assignment to a low‐protein diet appeared to slow the decline in renal function 15,16 .…”