Effect of Nonsupplemented Low-Protein Diet on the Initiation of Renal Replacement Therapy in Stage 4 and 5 Chronic Kidney Disease: A Retrospective Multicenter Cohort Study in Japan.

OBJECTIVE: In subjects with chronic kidney disease (CKD), the effect of low-protein diet (LPD) is expected to alleviate uremic symptoms. However, whether LPD is effective in preventing loss of kidney function is controversial. The aim of this study was to evaluate the association between LPD and renal outcomes. METHODS: We conducted a multicenter cohort study of 325 patients who suffered CKD stage 4 and 5 with eGFR ≥10 mL/min/1.73 m,2 between January 2008 and December 2014. The primary diseases of the patients were chronic glomerulonephritis (47.7%), nephrosclerosis (16.9%), diabetic nephropathy (26.2%), and others (9.2%). The patients were divided into four groups, based on the mean protein intake (PI)/day, group 1 (n = 76): PI < 0.5 g/kg ideal body weight/day, group 2 (n = 56): 0.5 ≤ PI < 0.6 g/kg/day, group 3 (n = 110): 0.6 ≤ PI < 0.8 g/kg/day, group 4 (n = 83): PI ≥ 0.8 g/kg/day. Dietary supplementation with essential amino acids and ketoanalogues was not used. The outcome measure was occurrence of renal replacement therapy (RRT) (hemodialysis, peritoneal dialysis, renal transplantation (excluding preemptive transplantation)) and all-cause mortality until December 2018. Cox regression models were used to examine whether LPD was associated with the risk of outcomes. RESULTS: During a mean follow-up of 4.1 ± 2.2 years. Thirty-three patients (10.2%) died of all causes, 163 patients (50.2%) needed to start RRT, and 6 patients (1.8%) received a renal transplant. LPD therapy of 0.5 g/kg/day or less was significantly related to a lower risk of RRT and all-cause mortality [Hazard ratio = 0.656; 95% confidence interval, 0.438 to 0.984, P = .042]. CONCLUSIONS: These results suggest that non-supplemented LPD therapy of 0.5 g/kg/day or less may prolong the initiation of RRT in stage 4 and 5 CKD patients.

Effect of nonsupplemented low-protein diet on very late stage CRF.

BACKGROUND: There are few reports of the effect of a low-protein diet on very late-stage chronic renal failure (CRF), eg, serum creatinine level greater than 10 mg/dL (884 micromol/L). In this retrospective study, we examined the effects of a very low-protein diet in patients with very late-stage CRF. METHODS: A very low-protein diet (0.25 to 0.54 g/kg body weight/d [0.39 +/- 0.01g/kg body weight/d]) without supplementation of essential amino acids or keto analogues was administered to 76 patients with very late-stage CRF who had serum creatinine levels greater than 10 mg/dL (884 micromol/L). Twenty-one patients with the same serum creatinine level and protein intake of 0.55 to 1.2 g/kg body weight/d (0.68 +/- 0.03 g/kg body weight/d) were observed in lieu of controls. RESULTS: Blood urea nitrogen was significantly suppressed to 43.1 +/- 1.9 g/dL (15.4 +/- 0.7 mmol/L) in the low-protein group compared with 111.2 +/- 7.0 mg/dL (39.7 +/- 2.5 mmol/L; P < 0.001) in the control group. The rate of decline in glomerular filtration rate (creatinine clearance) was 36-fold slower with the low-protein diet (-7.1 +/- 1.0 versus -0.2 +/- 0.4 mL/mon, respectively; P < 0.001). Nutritional state in the low-protein group exceeded that of the control group. Consequently, the renal survival rate improved significantly (P < 0.0001). All patients in the control group were initiated on dialysis treatment within 6 months from a serum creatinine level of 10 mg/dL (884 micromol/L). Conversely, 58% of the low-protein group are still on predialysis treatment. CONCLUSION: A severe low-protein diet is effective not only in preventing deterioration in renal function, but also in maintaining nutritional state despite no supplementation of essential amino acids or keto analogues, even as serum creatinine level is more than 10 mg/dL (884 micromol/L).