Na Jiang

Better preservation of residual renal function in peritoneal dialysis patients treated with a low-protein diet supplemented with keto acids: a prospective, randomized trial

BACKGROUND While a low-protein diet may preserve residual renal function (RRF) in chronic kidney disease (CKD) patients before the start of dialysis, a high-protein intake is usually recommended in dialysis patients to prevent protein-energy wasting. Keto acids, which were often recommended to pre-dialysis CKD patients treated with a low-protein diet, had also been reported to be associated with both RRF and nutrition maintenance. We conducted a randomized trial to test whether a low-protein diet with or without keto acids would be safe and associated with a preserved RRF during peritoneal dialysis (PD). METHODS To assess the safety of low protein, we first conducted a nitrogen balance study in 34 incident PD patients randomized to receive in-centre diets containing 1.2, 0.9 or 0.6 g of protein/kg ideal body weight (IBW)/day for 10 days. Second, 60 stable PD patients [RRF 4.04 +/- 2.30 ml/ min/1.73 m(2), urine output 1226 +/- 449 ml/day, aged 53.6 +/- 12.8 years, PD duration 8.8 (1.5-17.8) months] were randomized to receive either a low- (LP: 0.6-0.8 g/kg IBW/day), keto acid-supplemented low- (sLP: 0.6-0.8 g/kg IBW/day with 0.12 g/kg IBW/day of keto acids) or high-protein (HP: 1.0-1.2 g/kg IBW/day) diet. The groups were followed for 1 year and RRF as well as nutritional status was evaluated serially. RESULTS A neutral or positive nitrogen balance was achieved in all three groups. RRF remained stable in group sLP (3.84 +/- 2.17 to 3.39 +/- 3.23 ml/min/1.73 m(2), P = ns) while it decreased in group LP (4.02 +/- 2.49 to 2.29 +/- 1.72 ml/min/1.73 m(2), P < 0.05) and HP (4.25 +/- 2.34 to 2.55 +/- 2.29 ml/min/1.73 m(2), P < 0.05). There was no change from baseline on nutritional status in any of the groups during follow-up. CONCLUSIONS A diet containing 0.6-0.8 g of protein/kg IBW/day is safe and, when combined with keto acids, is associated with an improved preservation of RRF in relatively new PD patients without significant malnutrition or inflammation.

Initiation of Glucose-Based Peritoneal Dialysis Is Associated with Increased Prevalence of Metabolic Syndrome in Non-Diabetic Patients with End-Stage Renal Disease

Background: Glucose-based peritoneal dialysis (PD) is the original PD form. However, glucose uptake from the peritoneal cavity may contribute to dysmetabolism. Methods: We retrospectively assessed metabolic syndrome (MS) and its components in 195 non-diabetic incident PD patients at baseline and after 34.3 (20.5–60.0) months of PD. MS was defined according to the Adult Treatment Panel III criteria. Results: While 22.1% of the patients met MS criteria at baseline, 69.2% (p < 0.01) exhibited MS during PD. MS burden increased significantly after PD (p < 0.01). The disorder BMI and lipids, and MS components number, correlated with peritoneal glucose exposure and PD duration (p < 0.05). In Cox analysis, age, BMI, triglyceride, C-reactive protein (CRP) and glucose exposure were all independently associated with MS development. Conclusions: PD commencement in end-stage renal disease patients was associated with an increased MS prevalence. High glucose exposure and long PD duration were associated with MS existence, along with old age, high BMI, triglyceride and CRP.

Design and challenges of the Randomized Evaluation of Normal versus Augmented Level Replacement Therapy (RENAL) Trial: high-dose versus standard-dose hemofiltration in acute renal failure

Background/Aims: The optimal dose of renal replacement therapy (RRT) in acute renal failure (ARF) is uncertain. Methods: The Randomized Evaluation of Normal versus Augmented Level Replacement Therapy Trial tests the hypothesis that higher dose continuous veno-venous hemodiafiltration (CVVHDF) at an effluent rate of 40 ml/kg/h will increase survival compared to CVVHDF at 25 ml/kg/h of effluent dose. Results: This trial is currently randomizing critically ill patients in 35 intensive care units in Australia and New Zealand with a planned sample size of 1,500 patients. This trial will be the largest trial ever conducted on acute blood purification in critically ill patients. Conclusion: A trial of this magnitude and with demanding technical requirements poses design difficulties and challenges in the logistics, conduct, data collection, data analysis and monitoring. Our report will assist in the development of future trials of blood purification in intensive care. This study was registered with ClinicalTrials.gov (NCT00221013).

Interleukin-6 trans-signaling induces VEGF synthesis partly via Janus kinases-STAT3 pathway in human mesothelial cells.

Interleukin‐6 (IL‐6) is a vital inflammatory factor in the peritoneal cavity of peritoneal dialysis (PD) patients. Because intraperitoneal inflammation is closely associated with angiogenesis, we sought to explore the effect of IL‐6 on vascular endothelial growth factor (VEGF) synthesis and its transduction pathway in mesothelial cells.

Interleukin-6 trans-signalling induces vascular endothelial growth factor synthesis partly via Janus kinases-STAT3 pathway in human mesothelial cells

Interleukin‐6 (IL‐6) is a vital inflammatory factor in the peritoneal cavity of peritoneal dialysis (PD) patients. Because intraperitoneal inflammation is closely associated with angiogenesis, we sought to explore the effect of IL‐6 on vascular endothelial growth factor (VEGF) synthesis and its transduction pathway in mesothelial cells.

High Peritoneal Glucose Exposure Is Associated with Increased Incidence of Relapsing and Recurrent Bacterial Peritonitis in Patients Undergoing Peritoneal Dialysis.

Aim: We investigated the association of peritoneal glucose exposure and dialysis exchange number with peritonitis outcome in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Methods: The first episodes of bacterial peritonitis were retrospectively analyzed in 187 CAPD patients. Peritoneal glucose exposure was calculated based on PD prescription at the onset of peritonitis. Results: Patients with peritoneal glucose exposure ≤140 g/day showed a higher and complete cure rate of peritonitis (66 vs. 51.7%, p = 0.047), lower occurrence of relapsing/recurrent peritonitis (10.0 vs. 21.8%, p = 0.026) and catheter removal (14.0 vs. 26.4%, p = 0.033). Patients who exchanged more than three times every day demonstrated marginally higher catheter removal rate (24.1 vs. 13.0%, p = 0.085). Logistic analysis indicated that peritoneal glucose exposure >140 g/day was an independent predictor for relapsing/recurrent peritonitis (RR: 1.959, p = 0.042). Conclusion: High peritoneal glucose exposure is associated with increased incidence of relapsing/recurrent peritonitis in CAPD patients.

Low-Protein Diet Supplemented with Keto Acids Is Associated with Suppression of Small-Solute Peritoneal Transport Rate in Peritoneal Dialysis Patients

Objective. We investigate whether low-protein diet would show benefits in suppressing peritoneal transport rate in peritoneal dialysis (PD) patients. Methods. This is a supplemented analysis of our previously published trial, which randomized 60 PD patients to receive low- (LP: dietary protein intake of 0.6–0.8 g/kg/d), keto-acid-supplemented low- (sLP: 0.6–0.8 g/kg/d with 0.12 g/kg/d of keto acids), or high- (HP: 1.0–1.2 g/kg/d) protein diet and lasted for one year. In this study, the variations of peritoneal transport rate were assessed. Results. While baseline D/Pcr (dialysate-to-plasma concentration ratio for creatinine at 4 hour) and D/D0glu (dialysate glucose at 4 hour to baseline dialysate glucose concentration ratio) were similar, D/Pcr in group sLP was lower, and D/D0glu was higher than those in the other two groups (P < 0.05) at 12th month. D/D0glu increased (P < 0.05), and D/Pcr tended to decrease, (P = 0.071) in group sLP. Conclusions. Low-protein diet with keto acids may benefit PD patients by maintaining peritoneum at a lower transport rate.

Improved plasma amino acids pattern following 12 months of supplemented low-protein diet in peritoneal dialysis patients

Background: Decreased plasma essential amino acid (EAA) levels, increased nonessential amino acid (NEAA) levels, and low EAA to NEAA ratio (E/NEAA) are common in peritoneal dialysis (PD) patients and may impact uremic complications. In the present study, we investigate the impact of keto acids–supplemented low–protein (sLP) diet on plasma amino acids (AAs) patterns in stable PD patients. Methods: This is a supplemental analysis of a previously published prospective and randomized trial. Thirty-nine PD patients selected from the original population were divided to receive either low (LP: 0.6–0.8 g/kg ideal body weight [IBW]/d, n = 13), keto acids–supplemented low- (sLP: 0.6–0.8 g/kg IBW/d + 0.12 g/kg IBW/d of keto acids, n = 12), or high- (HP: 1.0–1.2 g/kg IBW/d, n = 14) protein diets and followed for 1 year. Plasma AA patterns were assessed at baseline and 12 months using high-performance liquid chromatography. Results: Whereas there were no significant differences between the three groups at baseline, following 12 months, the E/NEAA had increased significantly in group sLP (0.58 ± 0.16 to 0.83 ± 0.20, p < 0.05), but was not different in either LP (0.62 ± 0.20 to 0.72 ± 0.13, p = ns) or HP (0.66 ± 0.14 to 0.74 ± 0.12, p = ns) group. This change in E/NEAA in group sLP was due to a significant decrease in NEAA concomitantly with maintained EAA levels, whereas in the other two groups, neither EAA nor NEAA changed significantly. Conclusions: A low-protein diet supplemented with keto acids significantly improved the pattern of plasma AA in prevalent PD patients.

Improving diet recipe and cooking methods attenuates hyperphosphatemia in patients undergoing peritoneal dialysis

BACKGROUND AND AIMS Hyperphosphatemia is an independent predictor for cardiovascular and all-cause mortality in patients undergoing peritoneal dialysis (PD). The study aimed to investigate the effect of dietary intervention on reducing serum phosphate concentration in hyperphosphatemic PD patients. METHODS AND RESULTS In this single-center clinical trial, 97 prevalent PD patients with serum phosphate concentration ≥ 1.6 mmol/l were allocated to the intervention (n = 48) or control (n = 49) group and followed up for 1 year. In addition to phosphate binder (calcium carbonate) therapy, patients in the intervention group were intensively educated to reduce phosphate-rich food intake and improve cooking methods. While stable in the control group (1.97 ± 0.20 to 1.94 ± 0.35 mmol/l, p > 0.05), the serum phosphate concentration decreased significantly in the intervention group (1.98 ± 0.28 to 1.65 ± 0.33 mmol/l, p = 0.015) concurrently with the drop in dietary phosphate intake (13.03 ± 3.39 to 10.82 ± 3.00 mg/kg ideal body weight/day, p = 0.001). Moreover, after 6 months of intervention, fewer patients needed to use calcium carbonate (from 64.6% to 41.5%, p = 0.029) and the medicine dose reduced significantly (from 2.25 (0, 3.94) to 0 (0, 1.50) g/day, p < 0.001). CONCLUSIONS Our data indicated that intensive dietary intervention of reducing phosphate-rich food intake and improving cooking methods attenuated hyperphosphatemia in PD patients. It suggests that regular assessment of dietary phosphate intake and modification of diet recipe and cooking methods are essential for hyperphosphatemia treatment in PD patients in addition to phosphate binder therapy.