The impact of a nutritional intervention based on egg white for phosphorus control in hemodialyis patients

Effect of Egg-White Protein Alone or Combined With Niacin on Nutritional Status, and Phosphorus Control in Maintenance Hemodialysis Patients: A Randomized Controlled Trial

OBJECTIVE

Niacin is reported to decrease phosphorus concentration in maintenance hemodialysis (MHD) patients. Egg white is one of the main substitutable proteins in MHD patients due to its low phosphorus content. Therefore, we aimed to evaluate the effects of combined egg white and niacin supplementation on dialysis patients' serum phosphorus and nutritional biomarkers.

DESIGN AND METHODS

In this randomized controlled clinical trial, 98 patients on MHD were randomly allocated to four groups for 8 weeks: 24 g egg white (n = 25), 600 g niacin daily (n = 24), egg white combined with niacin (n = 24), and control (n = 24). Calcium, phosphorus, fibroblast growth factor-23, and other nutritional markers were assessed.

RESULTS

There was a significant difference among the groups only in phosphorus at the end of the trial, which was significantly lower in the niacin group (4.38 + 0.812 mg/dL) than in both the egg white (5.07 + 0.49 mg/dL) and egg white with niacin supplementation (5.41 + 0.662 mg/dL) groups. In this regard, albumin increased in egg white and egg white with niacin supplementation, while albumin did not change significantly in the niacin group. Urea reduction ratio and Kt/V rose only in the egg-white group, while aspartate aminotransferase increased only in the niacin and control groups.

CONCLUSION

Niacin decreases serum phosphorus concentration more than egg-white protein or a combined intervention. Egg white protein supplementation has beneficial effects on some nutritional statuses other than phosphorus control without the side effects of niacin.

Assessment of Dietary Phosphorus Intake and Implementation of Parental Phosphate Education in Pediatric Chronic Kidney Disease

Introduction

Management of dietary phosphorus intake is a challenge in children with chronic kidney disease and is governed by regional food sources and culinary practices. The aim of this study was to evaluate dietary intake of phosphorus in these children and assess the utility of parental phosphate education for control of hyperphosphatemia.

Methods

This prospective study included children aged 2-18 years with CKD stages 2-5D. Phosphorus intake was assessed by 24-hour dietary recall, analyzed using food processor software, and interpreted based on dietary reference intake (DRI) and suggested dietary intake (SDI). Parents of those with hyperphosphatemia were subjected to a structured phosphate education, and serum phosphate was monitored every 2 months for 6 months.

Results

Seventy children were recruited (mean age 9.4 ± 3.4 years, CKD5/5D: 51% (n = 36)) with median duration of CKD being 3.8 (IQR2,6) years. In the overall cohort, 50% (35/70) had phosphorus intake exceeding DRI with no significant difference between groups [CKD 5/5D,52.7% (n = 19) vs CKD2-4 47% (n = 16), P = 0.63]. Mean daily phosphorus intake was comparable between children with and without hyperphosphatemia [908 ± 279 mg vs 814 ± 302 mg, P = 0.1]. Based on DRI, 44% of children with normal serum phosphate and 58% with hyperphosphatemia had increased dietary intake of phosphorus (P = 0.15). Based on SDI, 26% with normal serum phosphate and 94% with hyperphosphatemia had increased dietary phosphorus intake (P < 0.001). Hyperphosphatemia was observed in 51% (CKD 2-4); 33% CKD5-5D 66%, P = 0.6). Among 29 children completing 6 months of follow up, there was a significant reduction in mean serum phosphate levels (P = 0.001) which was independent of age, stage of CKD or intake of phosphate binders. At end of the study, hyperphosphatemia persisted in 34%.

Conclusion

Compared to DRI, dietary assessment of phosphorus intake based on SDI was significantly associated with hyperphosphatemia in children with CKD 2-5D. In the majority, repeated parental structured phosphate education over 6 months was useful in managing hyperphosphatemia.

The effect of egg white diet on phosphorus control in dialysis patients

INTRODUCTION

Nutritional interventions have been envisaged to improve hyperphosphatemia and malnutrition, two important risk factors associated with mortality in dialysis patients. We evaluated the effects of egg white consumption on serum phosphate and malnutrition in dialysis patients.

METHODS

In an open-label, per protocol clinical trial, conducted in Kerman dialysis centers, 150 hemodialysis patients aged ≥18 years with serum phosphorus ≥5.5 mg/dl were included in the study. All participants limited their intake of foods containing phosphorus for 4 weeks, and then they were divided into a control and an intervention group. The control group continued their ordinary diet and the participants in the intervention group consumed a Telavang egg white pack (containing six egg whites, 96 calories, 24 g protein) as a substitute for meat products 3 days a week for 8 weeks. Finally, changes in serum albumin, phosphorus, calcium, PTH, and cholesterol were measured.

FINDINGS

At the baseline, there were no significant differences in the laboratory variables between the two groups. After 8 weeks, serum cholesterol (124.3 ± 38.1, vs. 135.8 ± 28.8, p = 0.003) and phosphorus levels (4.5 ± 1.03, vs. 6.7 ± 1.5, p = 0.001) were significantly lower in the intervention group compared with the control group. Also, serum albumin (4.5 ± 0.07 vs. 3.7 ± 0.4, p = 0.001) was significantly higher in the intervention group. Moreover, phosphorus, PTH, and cholesterol levels in the intervention group were significantly lower than their baseline values (p = 0.001).

CONCLUSION

The results showed that the egg white could be a useful source of protein for dialysis patients, as it simultaneously reduces serum phosphorus and cholesterol, and increases serum albumin.

The Effect of Non-Pharmacological and Pharmacological Interventions on Measures Associated with Sarcopenia in End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis provides a synthesis of the available evidence for the effects of interventions on outcome measures associated with sarcopenia in end-stage kidney disease (ESKD). Thirteen databases were searched, supplemented with internet and hand searching. Randomised controlled trials of non-pharmacological or pharmacological interventions in adults with ESKD were eligible. Trials were restricted to those which had reported measures of sarcopenia. Primary outcome measures were hand grip strength and sit-to-stand tests. Sixty-four trials were eligible (with nineteen being included in meta-analyses). Synthesised data indicated that intradialytic exercise increased hand grip strength (standardised mean difference, 0.58; 0.24 to 0.91; p = 0.0007; I2 = 40%), and sit-to-stand (STS) 60 score (mean difference, 3.74 repetitions; 2.35 to 5.14; p < 0.001; I2 = 0%). Intradialytic exercise alone, and protein supplementation alone, resulted in no statistically significant change in STS5 (−0.78 s; −1.86 to 0.30; p = 0.16; I2 = 0%), and STS30 (MD, 0.97 repetitions; −0.16 to 2.10; p = 0.09; I2 = 0%) performance, respectively. For secondary outcomes, L-carnitine and nandrolone-decanoate resulted in significant increases in muscle quantity in the dialysis population. Intradialytic exercise modifies measures of sarcopenia in the haemodialysis population; however, the majority of trials were low in quality. There is limited evidence for efficacious interventions in the peritoneal dialysis and transplant recipient populations.

Dietary casein, egg albumin, and branched-chain amino acids attenuate phosphate-induced renal tubulointerstitial injury in rats

Dietary phosphate intake is closely correlated with protein intake. However, the effects of the latter on phosphate-induced organ injuries remain uncertain. Herein, we investigated the effects of low (10.8%), moderate (23.0%), and high (35.2%) dietary casein and egg albumin administration on phosphate-induced organ injuries in rats. The moderate and high casein levels suppressed renal tubulointerstitial fibrosis and maintained mitochondrial integrity in the kidney. The serum creatinine levels were suppressed only in the high casein group. Phosphate-induced muscle weakness was also ameliorated by high dietary casein. The urinary and fecal phosphate levels in the early experiment stage showed that dietary casein did not affect phosphate absorption from the intestine. High dietary egg albumin showed similar kidney protective effects, while the egg albumin effects on muscle weakness were only marginally significant. As the plasma branched-chain amino acid levels were elevated in casein- and egg albumin-fed rats, we analyzed their effects. Dietary supplementation of 10% branched-chain amino acids suppressed phosphate-induced kidney injury and muscle weakness. Although dietary protein restriction is recommended in cases of chronic kidney disease, our findings indicate that the dietary casein, egg albumin, and branched-chain amino acid effects might be reconsidered in the era of a phosphate-enriched diet.