Protein intake during hemodialysis maintains a positive whole body protein balance in chronic hemodialysis patients

Deleterious effects of intradialytic meals' suppression during the COVID pandemic

BACKGROUND&AIMS

Patients with end-stage renal failure on chronic hemodialysis present an important risk of malnutrition, which is associated with a significant risk of morbidity and mortality. Meals during the dialysis session are important for maintaining the nutritional status of dialysis patients but represent a risk for intradialytic hypotension. During the COVID-19 pandemic, several dialysis centers stopped providing meals during the dialysis session as a protective measure. The aim of this retrospective, multicentric cross-over study was to study the evolution of the nutritional parameters of a cohort of hemodialysis patients for 12 months before, during and after the suspension of meals during dialysis due to the COVID-19 pandemics.

METHODS

We registered the evolution of dry weight, C Reactive Protein (CRP), serum Potassium and Phosphate before the dialysis session, serum albumin and prealbumin levels as well as normalized Protein Catabolic Ratio (nPCR).

RESULTS

We studied 168 hemodialysis patients (113M, 55F, mean age at inclusion:68.45 ± 0.45 years). The results ares shown as mean values (±SEM). The supression of the intradialytic meals led to significant reduction of the patients' dry weight (in Kg) from 78.66 ± 0.72 to 76.50 ± 0.49, p = 0.013, serum albumin (in g/l) (from 40.72 ± 0.16 to 39.25 ± 0.12, p < 0.001) and prealbumin levels (in g/l) (from 33.82 ± 0.31 to 32.73 ± 0.22, p = 0.004) as well as the nPCR values (from 1.08 ± 0.08 to 1.05 ± 0.11, p = 0.021). Serum CRP as well as predialytic Potassium and Phosphate levels did not change significantly. The reinstitution of the intradialytic meals led to a complete correction of the studied nutritional parameters with Body weight values evolving from 76.50 ± 0.49 to 78.28 ± 1.01, p = 0.025, serum albumin from 39.25 ± 0.12 to 40.53 ± 1.04, p < 0.001, serum prealbumin levels from 32.73 ± 0.22 to 33.95 ± 0.64, p = 0.001 an nPCR from 1.05 ± 0.11 to 1.08 ± 0.08, p = 0.021.

CONCLUSION

In conclusion, the suppression of intradialytic meals during the COVID-19 pandemic had deleterious effects on the nutritional parameters of patients on chronic hemodialysis.

Branched-chain ketoacid co-ingestion with protein lowers amino acid oxidation during hemodialysis: A randomized controlled cross-over trial

BACKGROUND & AIMS

Hemodialysis removes amino acids from the circulation, thereby stimulating muscle proteolysis. Protein ingestion during hemodialysis can compensate for amino acid removal but may also increase uremic toxin production. Branched-chain ketoacid (BCKA) co-ingestion may provide an additional anabolic stimulus without adding to uremic toxin accumulation. In the present study we assessed the impact of BCKA co-ingestion with protein on forearm amino acid balance and amino acid oxidation during hemodialysis.

METHODS

Nine patients (age: 73 ± 10 y) on chronic hemodialysis participated in this crossover trial. During two 4-h hemodialysis sessions, patients ingested 18 g protein with (PRO + BCKA) or without (PRO) 9 g BCKAs in a randomized order. Test beverages were labeled with L-[ring-¹³C₆]-phenylalanine and provided throughout the last 3 h of hemodialysis as 18 equal sips consumed with 10-min intervals. Arterial and venous plasma as well as breath samples were collected frequently throughout hemodialysis.

RESULTS

Arterial plasma total amino acid (TAA) concentrations during PRO and PRO + BCKA treatments were significantly lower after 1 h of hemodialysis (2.6 ± 0.3 and 2.6 ± 0.3 mmol/L, respectively) when compared to pre-hemodialysis concentrations (4.2 ± 1.0 and 4.0 ± 0.5 mmol/L, respectively; time effect: P < 0.001). Arterial plasma TAA concentrations increased throughout test beverage ingestion (time effect: P = 0.027) without differences between treatments (time∗treatment: P = 0.62). Forearm arteriovenous TAA balance during test beverage ingestion did not differ between timepoints (time effect: P = 0.31) or treatments (time∗treatment: P = 0.34). Whole-body phenylalanine oxidation was 33 ± 16% lower during PRO + BCKA when compared to PRO treatments (P < 0.001).

CONCLUSIONS

BCKA co-ingestion with protein during hemodialysis does not improve forearm net protein balance but lowers amino acid oxidation.

The Effects of Two Kinds of Dietary Interventions on Serum Metabolic Profiles in Haemodialysis Patients

The goal of this study was to evaluate the effects of two kinds of 24-week dietary interventions in haemodialysis patients, a traditional nutritional intervention without a meal before dialysis (HG1) and implementation of a nutritional intervention with a meal served just before dialysis (HG2), in terms of analysing the differences in the serum metabolic profiles and finding biomarkers of dietary efficacy. These studies were performed in two homogenous groups of patients (n = 35 in both groups). Among the metabolites with the highest statistical significance between HG1 and HG2 after the end of the study, 21 substances were putatively annotated, which had potential significance in both of the most relevant metabolic pathways and those related to diet. After the 24 weeks of the dietary intervention, the main differences between the metabolomic profiles in the HG2 vs. HG1 groups were related to the higher signal intensities from amino acid metabolites: indole-3-carboxaldehyde, 5-(hydroxymethyl-2-furoyl)glycine, homocitrulline, 4-(glutamylamino)butanoate, tryptophol, gamma-glutamylthreonine, and isovalerylglycine. These metabolites are intermediates in the metabolic pathways of the necessary amino acids (Trp, Tyr, Phe, Leu, Ile, Val, Liz, and amino acids of the urea cycle) and are also diet-related intermediates (4-guanidinobutanoic acid, indole-3-carboxyaldehyde, homocitrulline, and isovalerylglycine).

Effects of the Malnutrition-Eat Additional Meal (MEAM) Diet on the Serum Levels of Albumin and C-Reactive Protein in Hemodialysis Patients

The main objective of this project was to evaluate the efficiency of two kinds of nutritional intervention implemented in hemodialysis patients for 24 weeks (traditional nutritional intervention without a meal served before dialysis for group HG1, and nutritional intervention involving a meal served before dialysis for group HG2), and their impact on nutritional status and serum concentrations of C-reactive protein (CRP). Nutritional status and serum biochemical parameters were analyzed in the control group (CG, n = 70) and in two homogeneous groups of patients, HG1 (n = 35) and HG2 (n = 35). There was an interesting trend in both groups of patients connected with increased intake, mainly of energy and protein. In HG1, the greatest increase in energy intake was observed on Sundays, and in HG2 on the days with dialysis. In HG2, after 24 weeks of the nutritional intervention, an increase in serum albumin (p = 0.0157) and a decrease in CRP concentration (p = 0.0306) were observed, whereas in HG1 there was a decrease in serum albumin concentration (p = 0.0043) with no significant change in CRP concentration. The nutritional intervention applied, called the Malnutrition-Eat Additional Meal (MEAM) diet with an easily digestible meal served before dialysis, was aimed at improving the patients' nutritional status and the obtained results indicate the need not only for substantial reeducation of hemodialysis patients in the area of their diet, but also for undertaking further research and discussions on the possibility of ensuring adequate meals for hemodialysis patients before the dialysis procedure.

Intradialytic parenteral nutrition for patients on hemodialysis: when, how and to whom?

Hemodialysis is associated with high morbidity and mortality rates as well as low quality of life. Altered nutritional status and protein-energy wasting are important indicators of these risks. Maintaining optimal nutritional status in patients with hemodialysis is a critical but sometimes overlooked aspect of care. Nutritional support strategies usually begin with dietary counseling and oral nutritional supplements. Patients may not comply with this advice or oral nutritional supplements, however , or compliance may be affected by other complications of progressive chronic kidney disease. Intradialytic parenteral nutrition (IDPN) may be a possibility in these cases, but lack of knowledge on practical aspects of IDPN delivery are seldom discussed and may represent a barrier. In this review, we, as a consensus panel of clinicians experienced with IDPN, survey existing literature and summarize our views on when to use IDPN, which patients may be best suited for IDPN, and how to effectively deliver and monitor this strategy for nutritional support.

Assessing Global Kidney Nutrition Care

BACKGROUND AND OBJECTIVES

Nutrition intervention is an essential component of kidney disease management. This study aimed to understand current global availability and capacity of kidney nutrition care services, interdisciplinary communication, and availability of oral nutrition supplements.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The International Society of Renal Nutrition and Metabolism (ISRNM), working in partnership with the International Society of Nephrology (ISN) Global Kidney Health Atlas Committee, developed this Global Kidney Nutrition Care Atlas. An electronic survey was administered among key kidney care stakeholders through 182 ISN-affiliated countries between July and September 2018.

RESULTS

Overall, 160 of 182 countries (88%) responded, of which 155 countries (97%) answered the survey items related to kidney nutrition care. Only 48% of the 155 countries have dietitians/renal dietitians to provide this specialized service. Dietary counseling, provided by a person trained in nutrition, was generally not available in 65% of low-/lower middle-income countries and "never" available in 23% of low-income countries. Forty-one percent of the countries did not provide formal assessment of nutrition status for kidney nutrition care. The availability of oral nutrition supplements varied globally and, mostly, were not freely available in low-/lower middle-income countries for both inpatient and outpatient settings. Dietitians and nephrologists only communicated "sometimes" on kidney nutrition care in ≥60% of countries globally.

CONCLUSIONS

This survey reveals significant gaps in global kidney nutrition care service capacity, availability, cost coverage, and deficiencies in interdisciplinary communication on kidney nutrition care delivery, especially in lower-income countries.

Amino acid removal during hemodialysis can be compensated for by protein ingestion and is not compromised by intradialytic exercise: a randomized controlled crossover trial

BACKGROUND

Patients with end-stage renal disease (ESRD) undergoing hemodialysis experience a rapid decline in skeletal muscle mass and strength. Hemodialysis removes amino acids (AAs) from the circulation, thereby lowering plasma AA concentrations and stimulating proteolysis.

OBJECTIVES

In the present study, we evaluate the impact of intradialytic protein ingestion at rest and following exercise on AA removal and plasma AA availability in patients with ESRD.

METHODS

Ten patients (age: 65 ± 16 y, male/female: 8/2, BMI: 24.2 ± 4.8 kg/m2, serum albumin: 3.4 ± 0.3 g/dL) with ESRD undergoing hemodialysis participated in this randomized controlled crossover trial. During 4 hemodialysis sessions, patients were assigned to ingest 40 g protein or a placebo 60 min after initiation, both at rest (PRO and PLA, respectively) and following exercise (PRO + EX and PLA + EX, respectively). Spent dialysate and blood samples were collected every 30 min throughout hemodialysis to assess AA removal and plasma AA availability.

RESULTS

Plasma AA concentrations declined by 26.1 ± 4.5% within 30 min after hemodialysis initiation during all interventions (P < 0.001, η2p > 0.79). Protein ingestion, but not intradialytic exercise, increased AA removal throughout hemodialysis (9.8 ± 2.0, 10.2 ± 1.6, 16.7 ± 2.2, and 17.3 ± 2.3 g during PLA, PLA + EX, PRO, and PRO + EX interventions, respectively; protein effect P < 0.001, η2p = 0.97; exercise effect P = 0.32, η2p = 0.11). Protein ingestion increased plasma AA concentrations until the end of hemodialysis, whereas placebo ingestion resulted in decreased plasma AA concentrations (time effect P < 0.001, η2p > 0.84). Plasma AA availability (incremental AUC) was greater during PRO and PRO + EX interventions (49 ± 87 and 70 ± 34 mmol/L/240 min, respectively) compared with PLA and PLA + EX interventions (-227 ± 54 and -208 ± 68 mmol/L/240 min, respectively; protein effect P < 0.001, η2p = 0.98; exercise effect P = 0.21, η2p = 0.16).

CONCLUSIONS

Protein ingestion during hemodialysis compensates for AA removal and increases plasma AA availability both at rest and during recovery from intradialytic exercise. Intradialytic exercise does not compromise AA removal or reduce plasma AA availability during hemodialysis in a postabsorptive or postprandial state.

Meal timing and frequency implications in the development and prognosis of chronic kidney disease

Patients with chronic kidney disease (CKD) have a higher risk of death than the general population, the main cause being cardiovascular disease (CVD). Nutrition plays a key role in the prevention and treatment of CVD and kidney diseases. Currently, new evidence reinforces the importance of specific foods and general dietary patterns rather than isolated nutrients for cardiovascular risk. In addition, dietary patterns and healthy eating habits seem extremely relevant in decreasing risk factors. Epidemiologic and clinical intervention studies have suggested that late-night dinner and skipping breakfast are associated with an increased risk of obesity, insulin resistance, and CVD. In CKD, despite important changes in nutritional counseling in recent decades, less attention has been paid to meal timing and frequency. Therefore, the purpose of this review is to discuss the evidence of meal timing and frequency in CKD development and prognosis, presented under three main topics: risk of developing CKD, importance of dietary habits, and implications of fasting.

Impact of First Wave COVID-19 Crisis on Dialysis Parameters of COVID-Free Hemodialysis Patients: A NephoCare France Longitudinal Retrospective Cohort Study

Background

Chronic hemodialysis (HD) patients are at high risk of severe COVID-19 with a high risk of death. The organization of dialysis units to treat chronic HD patients with COVID-19 is demanding to prevent virus transmission both in COVID-free patients and the staff. These constraints may have an impact on the dialysis delivery to COVID-free HD patients. We report our experience in French NephroCare (NC) centers.

Methods

We report retrospectively dialysis and nutritional indicators among COVID-free prevalent chronic HD patients' cohort treated in French NC units from February 2020 to April 2020. The COVID-free HD patients were split into 2 subgroups for the analysis, Paris region and other regions because the incidence of COVID-19 was different according to the French regions.

Results

The Paris region was the most impacted by COVID-19 with 73% of all the contaminations that occurred in French NC units (n = 118). The dialysis frequency was not reduced all over the NC regions. 2,110 COVID-free HD patients were split into 2 subgroups including Paris region (748 patients) and other regions (1,362 patients). The weekly treatment time decreased significantly in Paris region from February to April (723–696 min [p < 0.00001]) but remained stable in the other regions. The processed blood volume, KT/V, and convective volume declined significantly in the Paris region subgroup but not in other regions. The 3-month weight loss significantly increased in the whole group of patients whatever the region from 0.0 to 0.2% between February 2020 and April 2020 (p < 0.00001). Ultrafiltration rate (UFR) and the normalized proteic catabolic rate remained stable all along the period. The stepwise regression analysis identified February serum albumin level and April UFR as negatively associated with 3-month weight loss.

Conclusion

HD delivery to COVID-free HD patients was negatively impacted in the Paris region because of the strong constraints on units' organization related to the treatment of COVID-19+ HD patients and with a higher proportion of limited care/self-care units with less staff resources. The 3-month weight loss increase may be related to the suppression of intradialytic snack that impacted mostly the more malnourished patients or patients with lower interdialytic weight gain. These consequences of the COVID-19 crisis on COVID-free HD patients must be recognized and corrected to prevent further deleterious effects on patients' outcomes.

Evolution of body composition and wasting indicators by time of day of haemodialysis

BACKGROUND

It has been a long-standing clinical concern that haemodialysis (HD) patients on afternoon shifts (ASs) are more prone to protein-energy wasting (PEW) than those on morning shifts (MSs), as their dialysis scheme and post-dialysis symptoms may interfere with meal intake. We evaluated the effect of time of day of HD on the evolution of body composition changes and PEW surrogates.

METHODS

We conducted a retrospective study among 9.963 incident HD patients treated in NephroCare centres (2011-16); data were routinely collected in the European Clinical Database. The course of multi-frequency bioimpedance determined lean and fat tissue indices (LTI and FTI) between patients in MSs/ASs over 2 years were compared with linear mixed models. Secondary PEW indicators were body mass index, albumin, creatinine index and normalized protein catabolic rate. Models included fixed (age, sex, vascular access and diabetes mellitus) and random effects (country and patient).

RESULTS

Mean baseline LTI and FTI were comparable between MSs (LTI: 12.5 ± 2.9 kg/m2 and FTI: 13.7 ± 6.0 kg/m2) and ASs (LTI: 12.4 ± 2.9 kg/m2 and FTI: 13.2 ± 6.1 kg/m2). During follow-up, LTI decreased and FTI increased similarly, with a mean absolute change (baseline to 24 months) of -0.3 kg/m2 for LTI and +1.0 kg/m2 for FTI. The course of these malnutrition indicators did not differ between dialysis shifts (P for interaction ≥0.10). We also did not observe differences between groups for secondary PEW indicators.

CONCLUSIONS

This study suggests that a dialysis shift in the morning or in the afternoon does not impact the long-term nutritional status of HD patients. Regardless of time of day of HD, patients progressively lose muscle mass and increase body fat.

Anabolic Resistance of Muscle Protein Turnover Comes in Various Shapes and Sizes

Anabolic resistance is defined by a blunted stimulation of muscle protein synthesis rates (MPS) to common anabolic stimuli in skeletal muscle tissue such as dietary protein and exercise. Generally, MPS is the target of most exercise and feeding interventions as muscle protein breakdown rates seem to be less responsive to these stimuli. Ultimately, the blunted responsiveness of MPS to dietary protein and exercise underpins the loss of the amount and quality of skeletal muscle mass leading to decrements in physical performance in these populations. The increase of both habitual physical activity (including structured exercise that targets general fitness characteristics) and protein dense food ingestion are frontline strategies utilized to support muscle mass, performance, and health. In this paper, we discuss anabolic resistance as a common denominator underpinning muscle mass loss with aging, obesity, and other disease states. Namely, we discuss the fact that anabolic resistance exists as a dimmer switch, capable of varying from higher to lower levels of resistance, to the main anabolic stimuli of feeding and exercise depending on the population. Moreover, we review the evidence on whether increased physical activity and targeted exercise can be leveraged to restore the sensitivity of skeletal muscle tissue to dietary amino acids regardless of the population.

Protein and energy intake: Comparison of two food services in patients during hemodialysis treatment

OBJECTIVES

Radboud University Medical Center introduced a new food service (NFS) to the hemodialysis (HD) department, which contains several small protein-rich foods and adheres to the Dutch dietary HD guidelines. The objectives were to investigate whether the NFS improves protein and energy intake compared with the old food service (OFS), the number of symptomatic hypotensive events (SHEs), and patient satisfaction.

METHODS

This was a prospective cohort (pilot) study of 25 adult patients with HD at the Radboud University Medical Center between August 2018 and February 2019. Differences in protein and energy intake over time by repeated measurements of the OFS and NFS were evaluated by linear mixed models with adjustments for confounders. SHEs, defined as a systolic drop >20 mmHg between two blood pressure measurements and 1) temporary or permanent stop ultrafiltration, 2) nausea, or 3) dizziness were collected. Patient satisfaction was determined by means of a self-developed questionnaire.

RESULTS

Protein and energy intake for the OFS and NFS differed significantly. Mean ± standard deviation for protein intake was 26 ± 11 g and 31 ± 13 g, respectively, and for energy intake 603 ± 218 kcal and 724 ± 244 kcal, respectively. No increase in SHEs occurred between the food services (2 SHEs at OFS vs 1 SHE at NFS). OFS patient satisfaction was graded 6.7 ± 2.3 and NFS was graded 7.3 ± 1.7.

CONCLUSIONS

NFS resulted in increased protein and energy intake and patient satisfaction, but no increase in SHEs was observed.

Can an intradialytic snack model compensate the catabolic impact of hemodialysis?

BACKGROUND AND AIMS

Hemodialysis (HD) has a catabolic effect caused by alterations in protein metabolism, increase in resting energy expenditure (REE) and protein needs due to inflammation, HD circuit blood and heat losses, protein losses to dialysate and HD filter membrane biocompatibility. We aim to determine, as a proof of concept, whether a standardized intradialytic snack model is adequate to compensate the catabolic impact of HD.

METHODS

Cross sectional analysis of patients' chosen intradialytic intake according to a snack model, at the day of blood sample collection of three different months. As targets for the compensation of the catabolic impact of HD, we considered 316.8kCal (1.32 (±0.18) kcal/min - 240' of HD) for the estimated increase in REE and at least 7 g of protein losses/HD treatment.

RESULTS

A total of 448 meals were analyzed, with 383 given during daytime shifts. No intolerances were registered. The mean nutritional profile of the daytime shifts intakes was 378.8 (±151.4) kcal, 13.5 (±7.2) g of protein, 676 (±334) mg of sodium (Na), 361.0 (±240.3) mg of potassium (K) and 249.3 (±143.0) mg of phosphates (P). We found that 68% of the meals provided an intake ≥316.8kCal and 82% a protein intake ≥ 7 g, with a significant association found between treatment shift and energy (p < 0.028), protein (p < 0.028), lipids (p < 0.004), Na (p < 0.004), K (p < 0.009) and P (p < 0.039) intakes.

CONCLUSIONS

We found that this intradialytic snack model meets the target for the treatment-related increases in protein and energy needs. Although sodium intake was found to be high, potassium and phosphate intake was considered adequate.

Chronic Kidney Disease and Nutrition Support

Individuals with chronic kidney disease (CKD), particularly those undergoing maintenance dialysis, are prone to protein-energy wasting (PEW), the latter of which can be ameliorated with different methods of nutrition support. Dietary counseling guided by dietitians is the key for preventing and managing PEW in CKD. If dietary counseling per se fails to meet the recommended energy and protein requirements, the addition of oral nutrition supplements (ONSs) would be necessary. When these initial measures cannot attain the recommended energy and protein requirements, nutrition support, including enteral tube feeding or parenteral nutrition (PN), should be considered as a viable option to improve nutrition status. Partial PN, comprising intraperitoneal PN (IPPN) and intradialytic PN (IDPN) therapies, may be attempted as supplemental nutrition support in patients with PEW requiring peritoneal dialysis and hemodialysis, respectively. Despite the debatable effectiveness of IPPN for patients undergoing peritoneal dialysis, it remains a feasible means in these patients. The indications for IPPN in patients undergoing peritoneal dialysis include inadequate dietary intake of energy and protein, and barriers of oral intake and other forms of enteral supplementation such as issues with suitability, tolerance, and compliance. Nonetheless, in the case of spontaneous dietary consumption of energy and protein meeting the difference between the IDPN provision and the nutrition targets, the use of IDPN is rational. In patients with PEW and malfunctioning gastrointestinal tract, as well as those whose enteral intake (with or without partial PN) is below the recommended nutrient requirements, total PN becomes a relevant nutrition intervention.

How to Overcome Anabolic Resistance in Dialysis-Treated Patients?

A current hypothesis is that dialysis-treated patients are "anabolic resistant" i. e., their muscle protein synthesis (MPS) response to anabolic stimuli is blunted, an effect which leads to muscle wasting and poor physical performance in aging and in several chronic diseases. The importance of maintaining muscle mass and MPS is often neglected in dialysis-treated patients; better than to describe mechanisms leading to energy-protein wasting, the aim of this narrative review is to suggest possible strategies to overcome anabolic resistance in this patient's category. Food intake, in particular dietary protein, and physical activity, are the two major anabolic stimuli. Unfortunately, dialysis patients are often aged and have a sedentary behavior, all conditions which per se may induce a state of "anabolic resistance." In addition, patients on dialysis are exposed to amino acid or protein deprivation during the dialysis sessions. Unfortunately, the optimal amount and formula of protein/amino acid composition in supplements to maximixe MPS is still unknown in dialysis patients. In young healthy subjects, 20 g whey protein maximally stimulate MPS. However, recent observations suggest that dialysis patients need greater amounts of proteins than healthy subjects to maximally stimulate MPS. Since unneccesary amounts of amino acids could stimulate ureagenesis, toxins and acid production, it is urgent to obtain information on the optimal dose of proteins or amino acids/ketoacids to maximize MPS in this patients' population. In the meantime, the issue of maintaining muscle mass and function in dialysis-treated CKD patients needs not to be overlooked by the kidney community.

End-Stage Renal Disease Patients Lose a Substantial Amount of Amino Acids during Hemodialysis

BACKGROUND

Poor nutritional status is frequently observed in end-stage renal disease patients and associated with adverse clinical outcomes and increased mortality. Loss of amino acids (AAs) during hemodialysis (HD) may contribute to protein malnutrition in these patients.

OBJECTIVE

We aimed to assess the extent of AA loss during HD in end-stage renal disease patients consuming their habitual diet.

METHODS

Ten anuric chronic HD patients (mean ± SD age: 67.9 ± 19.3 y, BMI: 23.2 ± 3.5 kg/m2), undergoing HD 3 times per week, were selected to participate in this study. Spent dialysate was collected continuously and plasma samples were obtained directly before and after a single HD session in each participant. AA profiles in spent dialysate and in pre-HD and post-HD plasma were measured through ultra-performance liquid chromatography to determine AA concentrations and, as such, net loss of AAs. In addition, dietary intake before and throughout HD was assessed using a 24-h food recall questionnaire during HD. Paired-sample t tests were conducted to compare pre-HD and post-HD plasma AA concentrations.

RESULTS

During an HD session, 11.95 ± 0.69 g AAs were lost via the dialysate, of which 8.26 ± 0.46 g were nonessential AAs, 3.69 ± 0.31 g were essential AAs, and 1.64 ± 0.17 g were branched-chain AAs. As a consequence, plasma total and essential AA concentrations declined significantly from 2.88 ± 0.15 and 0.80 ± 0.05 mmol/L to 2.27 ± 0.11 and 0.66 ± 0.05 mmol/L, respectively (P < 0.05). AA profiles of pre-HD plasma and spent dialysate were similar. Moreover, AA concentrations in pre-HD plasma and spent dialysate were strongly correlated (Spearman's ρ = 0.92, P < 0.001).

CONCLUSIONS

During a single HD session, ∼12 g AAs are lost into the dialysate, causing a significant decline in plasma AA concentrations. AA loss during HD can contribute substantially to protein malnutrition in end-stage renal disease patients. This study was registered at the Netherlands Trial Registry (NTR7101).

Dietary Protein and Physical Activity Interventions to Support Muscle Maintenance in End-Stage Renal Disease Patients on Hemodialysis

End-stage renal disease patients have insufficient renal clearance capacity left to adequately excrete metabolic waste products. Hemodialysis (HD) is often employed to partially replace renal clearance in these patients. However, skeletal muscle mass and strength start to decline at an accelerated rate after initiation of chronic HD therapy. An essential anabolic stimulus to allow muscle maintenance is dietary protein ingestion. Chronic HD patients generally fail to achieve recommended protein intake levels, in particular on dialysis days. Besides a low protein intake on dialysis days, the protein equivalent of a meal is extracted from the circulation during HD. Apart from protein ingestion, physical activity is essential to allow muscle maintenance. Unfortunately, most chronic HD patients have a sedentary lifestyle. Yet, physical activity and nutritional interventions to support muscle maintenance are generally not implemented in routine patient care. To support muscle maintenance in chronic HD patients, quantity and timing of protein intake should be optimized, in particular throughout dialysis days. Furthermore, implementing physical activity either during or between HD sessions may improve the muscle protein synthetic response to protein ingestion. A well-orchestrated combination of physical activity and nutritional interventions will be instrumental to preserve muscle mass in chronic HD patients.

Results from the randomized controlled IHOPE trial suggest no effects of oral protein supplementation and exercise training on physical function in hemodialysis patients

Few long-term studies have assessed whether changes in both diet and exercise can improve the health and quality of life (QOL) of hemodialysis (HD) patients. Here we examined whether 12 months of intradialytic protein supplementation and endurance exercise improves physical function, risk of cardiovascular disease (CVD), and QOL in HD patients in a randomized controlled trial (RCT). A total of 138 HD patients (average age 58 years) were assigned for 12 months to control, intradialytic protein, or protein plus exercise groups. The protein and protein plus exercise groups consumed an oral protein supplement (30 grams of whey) three days/week during dialysis. The protein plus exercise group cycled for 30-45 minutes during dialysis treatment. The primary outcome was change in physical function at 12 months, assessed by a shuttle walk test. Secondary outcomes included arterial stiffness, blood pressure, body composition, muscle strength, markers of nutritional status, and QOL. Assessments were conducted at baseline, 6 and 12 months. In total, 101 patients completed the intervention. There were no significant differences between groups in shuttle walk test performance from baseline to 12 months. There were trends for improvements in some secondary measures of physical function and strength in the protein and protein plus exercise groups at six or 12 months, but these did not reach statistical significance. Thus, our trial did not demonstrate significant improvements in markers of physical function, risk of CVD or QOL after one year of intradialytic oral OPS and aerobic exercise training. More comprehensive lifestyle management may be needed to uncover robust improvements in the health and QOL of HD patients.

Oral nutritional supplements and 30-day readmission rate in hypoalbuminemic maintenance hemodialysis patients

INTRODUCTION

Hemodialysis (HD) patients are hospitalized nearly twice yearly, and 35% of these patients are rehospitalized within 30-days postdischarge. We hypothesized that monitored oral nutritional supplementation (ONS) during HD treatment may decrease readmissions.

METHODS

A cohort of maintenance HD patients, treated at a large dialysis organization, who were hospitalized with a postdischarge albumin of ≤3.5 g/dL, without documented ONS use 90 days prior to the index hospitalization were identified. Individuals who received monitored intradialytic ONS postdischarge were compared to those without receipt of ONS. The outcome of interest was 30-day hospital readmissions. Logistic regression was used to assess the association between ONS receipt and 30-day readmission events, with adjustment for case-mix and laboratory variables.

FINDINGS

Of 5479 eligible patients, ONS was prescribed to 1420 individuals. Mean age was 64.6 ± 14.1 (SD) years; median dialysis vintage was 3.9 years. There were 274 (19%) readmissions among ONS recipients vs. 1571 (38.7%) among controls during the 30-day follow-up period. Individuals who did not receive ONS had increased odds of readmission [OR 2.26 (95% CI 1.02, 2.53)] in 30 days, as compared to those who did receive ONS postdischarge. In sensitivity analyses using a propensity score matched cohort, the odds ratio of readmissions within 30 days postdischarge was 1.71 (95% CI: 1.42, 2.07) for individuals who did not receive ONS as compared to those who received ONS.

DISCUSSION

Consumption of ONS during HD sessions is associated with reduced hospital readmission rates among in-center maintenance HD with severe hypoalbuminemia at 30 days post-hospital discharge.

Inadequate dietary energy intake associates with higher prevalence of metabolic syndrome in different groups of hemodialysis patients: a clinical observational study in multiple dialysis centers

BACKGROUND

Metabolic syndrome (MetS) has been established as a risk for cardiovascular diseases and mortality in hemodialysis patients. Energy intake (EI) is an important nutritional therapy for preventing MetS. We examined the association of self-reported dietary EI with metabolic abnormalities and MetS among hemodialysis patients.

METHODS

A cross-sectional study design was carried out from September 2013 to April 2017 in seven hemodialysis centers. Data were collected from 228 hemodialysis patients with acceptable EI report, 20 years old and above, underwent three hemodialysis sessions a week for at least past 3 months. Dietary EI was evaluated by a three-day dietary record, and confirmed by 24-h dietary recall. Body compositions were measured by bioelectrical impedance analysis. Biochemical data were analyzed using standard laboratory tests. The cut-off values of daily EI were 30 kcal/kg, and 35 kcal/kg for age ≥ 60 years and < 60 years, respectively. MetS was defined by the American Association of Clinical Endocrinologists (AACE-MetS), and Harmonizing Metabolic Syndrome (HMetS). Logistic regression models were utilized for examining the association between EI and MetS. Age, gender, physical activity, hemodialysis vintage, Charlson comorbidity index, high sensitive C-reactive protein, and interdialytic weight gains were adjusted in the multivariate analysis.

RESULTS

The prevalence of inadequate EI, AACE-MetS, and HMetS were 60.5%, 63.2%, and 53.9%, respectively. Inadequate EI was related to higher proportion of metabolic abnormalities and MetS (p <  0.05). Results of the multivariate analysis shows that inadequate EI was significantly linked with higher prevalence of impaired fasting glucose (OR = 2.42, p <  0.01), overweight/obese (OR = 6.70, p <  0.001), elevated waist circumference (OR = 8.17, p <  0.001), AACE-MetS (OR = 2.26, p <  0.01), and HMetS (OR = 3.52, p <  0.01). In subgroup anslysis, inadequate EI strongly associated with AACE-MetS in groups of non-hypertension (OR = 4.09, p = 0.004), and non-cardiovascular diseases (OR = 2.59, p = 0.012), and with HMetS in all sub-groups of hypertension (OR = 2.59~ 5.33, p <  0.05), diabetic group (OR = 8.33, p = 0.003), and non-cardiovascular diseases (OR = 3.79, p <  0.001).

CONCLUSIONS

Inadequate EI and MetS prevalence was high. Energy intake strongly determined MetS in different groups of hemodialysis patients.

Dysregulated Handling of Dietary Protein and Muscle Protein Synthesis After Mixed-Meal Ingestion in Maintenance Hemodialysis Patients

Introduction

Skeletal muscle loss is common in patients with renal failure who receive maintenance hemodialysis (MHD) therapy. Regular ingestion of protein-rich meals are recommended to help offset muscle protein loss in MHD patients, but little is known about the anabolic potential of this strategy.

Methods

Eight MHD patients (age: 56 ± 5 years; body mass index [BMI]: 32 ± 2 kg/m²) and 8 nonuremic control subjects (age: 50 ± 2 years: BMI: 31 ± 1 kg/m²) received primed continuous L-[ring-²H₅]phenylalanine and L-[1-¹³C]leucine infusions with blood and muscle biopsy sampling on a nondialysis day. Participants consumed a mixed meal (546 kcal; 20-g protein, 59-g carbohydrates, 26-g fat) with protein provided as L-[5,5,5-²H₃]leucine-labeled eggs.

Results

Circulating dietary amino acid availability was reduced in MHD patients (41 ± 5%) versus control subjects (61 ± 4%; P = 0.03). Basal muscle caspase-3 protein content was elevated (P = 0.03) and large neutral amino acid transporter 1 (LAT1) protein content was reduced (P = 0.02) in MHD patients versus control subjects. Basal muscle protein synthesis (MPS) was ∼2-fold higher in MHD patients (0.030 ± 0.005%/h) versus control subjects (0.014 ± 0.003%/h) (P = 0.01). Meal ingestion failed to increase MPS in MHD patients (absolute change from basal: 0.0003 ± 0.007%/h), but stimulated MPS in control subjects (0.009 ± 0.002%/h; P = 0.004).

Conclusions

MHD patients demonstrated muscle anabolic resistance to meal ingestion. This blunted postprandial MPS response in MHD patients might be related to high basal MPS, which results in a stimulatory ceiling effect and/or reduced plasma dietary amino acid availability after mixed-meal ingestion.

Pilot Study of the Effects of High-Protein Meals During Hemodialysis on Intradialytic Hypotension in Patients Undergoing Maintenance Hemodialysis

OBJECTIVE

Patients undergoing hemodialysis (HD) have high protein and energy requirements, and protein-energy wasting is common and associated with poor outcomes. Eating during dialysis may improve nutritional status by counteracting the catabolic effects of HD treatment; but eating during HD may be discouraged because of concerns of postprandial hypotension. However, little data are available to support this practice. In this study, we hypothesized that high-protein meals during HD do not lead to symptomatic intradialytic hypotension events.

DESIGN

A 9-week, nonrandomized, parallel-arm study.

SETTING

A single in-center HD clinic.

SUBJECTS

Eighteen patients undergoing HD from 2 shifts completed the study. Patients were aged 62 ± 16 years with dialysis vintage of 3.4 ± 2.6 years.

INTERVENTION

Patients in the intervention group (n = 9) undergoing HD received meals of ∼30 g protein and ∼1/3 daily recommended intakes of sodium, potassium, phosphorus, and fluid during dialysis for 25 consecutive HD sessions. The control group (n = 9) completed all aspects of the study including a visit by study personnel but were not given meals. The 25 consecutive sessions before the start of the intervention/control phase were used as a baseline comparison for each patient.

MAIN OUTCOME MEASURE

Symptomatic hypotension event frequency.

RESULTS

In the intervention arm, there were 19 symptomatic hypotension events in 5 patients prestudy and 18 events in 6 patients during the study. In the control arm, there were 16 events in 7 patients prestudy and 13 events in 7 patients during the study. Change in the frequency of symptomatic hypotension events from prestudy to during study was not different between groups (P = .71). There was no effect of meals on nutritional status, but patients reported positive attitudes toward receiving meals during dialysis.

CONCLUSION

High-protein meals during HD did not increase symptomatic hypotension events. Larger, longer term studies are needed to confirm these results and evaluate whether high-protein meals on dialysis benefit nutritional status and clinical outcomes.

The cut-off values of dietary energy intake for determining metabolic syndrome in hemodialysis patients: A clinical cross-sectional study

Dietary energy intake strongly linked to dialysis outcomes. We aimed to explore the optimal cut-off point of energy intake (EI) for identification of metabolic syndrome (MetS) in hemodialysis patients. The cross-sectional data of 243 hemodialysis patients from multi-dialysis centers in Taiwan was used. The dietary intake was assessed by using the three-day dietary questionnaire, and a 24-hour dietary recall, clinical and biochemical data were also evaluated. The MetS was diagnosed by the Harmonized Metabolic Syndrome criteria. The receiver operating characteristic (ROC) curve was to depict the optimal cut-off value of EI for the diagnosis of MetS. The logistic regression was also used to explore the association between inadequate EI and MetS. The optimal cut-off points of EI for identifying the MetS were 26.7 kcal/kg/day for patients aged less than 60 years, or with non-diabetes, and 26.2 kcal/kg/day for patients aged 60 years and above, or with diabetes, respectively. The likelihood of the MetS increased with lower percentiles of energy intake in hemodialysis patients. In the multivariate analysis, the inadequate dietary energy intake strongly determined 3.24 folds of the MetS. The assessment of dietary EI can help healthcare providers detecting patients who are at risk of metabolic syndrome.

Effects of Oral Nutritional Supplements on Mortality, Missed Dialysis Treatments, and Nutritional Markers in Hemodialysis Patients

OBJECTIVE

Protein-energy wasting is common in end-stage renal disease patients undergoing dialysis and is strongly associated with mortality and adverse outcomes. Intradialytic oral nutritional supplements (ONS) reduce risk of mortality in these patients. Large studies characterizing the impact of ONS on other outcomes are lacking. We assessed the associations between administration of ONS and clinical and nutritional outcomes.

DESIGN

Retrospective evaluation of a pilot program providing ONS to patients at a large dialysis organization in the United States. The pilot program provided ONS to in-center hemodialysis patients with serum albumin ≤3.5 g/dL at 408 facilities.

SUBJECTS

ONS patients were compared to matched controls with serum albumin ≤3.5 g/dL, identified from facilities not participating in the ONS program (n = 3,374 per group).

INTERVENTION

Receipt of ONS.

MAIN OUTCOME MEASURES

Death, missed dialysis treatments, hospitalizations, serum albumin, normalized protein catabolic rate, and postdialysis body weight were abstracted from large dialysis organization electronic medical records.

RESULTS

There was a 69% reduction in deaths (hazard ratio = 0.31; 95% confidence interval = 0.25-0.39), and 33% fewer missed dialysis treatments (incidence rate ratio = 0.77; 95% confidence interval = 0.73-0.82) among ONS patients compared to controls (P < .001 for both). The effects of ONS on nutritional indices were mixed: serum albumin was lower, whereas normalized protein catabolic rate values, a surrogate for dietary protein intake, and postdialysis body weights were higher for ONS patients compared to controls during follow-up.

CONCLUSIONS

Our evaluation confirmed the beneficial effects of ONS in reducing mortality and improving some indices of nutritional status for hypoalbuminemic hemodialysis patients. We also report the novel finding that ONS can reduce the number of missed dialysis treatments. These results support the use of intradialytic ONS as an effective intervention to improve the outcomes in hemodialysis patients with low serum albumin.

Effect of an intradialytic protein-rich meal intake in nutritional and body composition parameters on hemodialysis patients

BACKGROUND AND AIMS

Protein intake is a key point to maintain an adequate nutritional status in hemodialysis (HD) patients. There are some studies that confirm the positive influence of intradialytic oral nutritional supplementation in several nutritional parameters in HD patients. The aim of this study was to evaluate the effect of an intradialytic protein rich meal in nutritional and body composition parameters on HD patients.

METHODS

This was a 6-months single center non-randomized study with 99 patients in HD from one Nephrocare dialysis unit in Portugal. Patients in the intervention group (IG) presented one albumin value ≤ 3.8 g/dL in the two measurements prior to the beginning of the study. The IG ate a protein rich meal during each treatment. The control group (CG) continued to eat their usual snack brought from home. Albumin, nPCR, potassium, phosphorus, C-reactive protein (CRP), dry weight and body composition were measured at baseline and at the end of the study.

RESULTS

Patient's mean age was 69.9 ± 12.9 years and HD vintage, 60.0 ± 50.5 months. Both groups were similar at the start of the study, except in albumin (p = 0.019). After the intervention, protein intake increased in the IG (p = 0.001). Albumin decreased in both groups but this difference was higher and only statistically significant in the CG (p = 0.039). Regarding body composition, in the CG, the fat tissue index (FTI) (p = 0.022) and the lean tissue index (LTI) (p = 0.003) diminished after the 6 months of the follow-up. However, in the IG the LTI value also reduced (p = 0.008) but FTI increased (p = <0.001) at the end of the study. There were no statistically significant differences on dry weight, potassium, phosphorus, and CRP.

CONCLUSION

Apart from the effect on protein intake, the importance of this study relies on the positive changes in regard to patient's body composition obtained after 6 months of an intradialytic intake of a protein rich meal during the HD treatment. This type of intervention can contribute to ameliorate patient's nutritional status without a negative effect on other parameters.

Nutritional Status in Nocturnal Hemodialysis Patients - A Systematic Review with Meta-Analysis

Background

Hemodialysis patients experience an elevated risk of malnutrition associated with increased morbidity and mortality. Nocturnal hemodialysis (NHD) results in more effective removal of waste products and fluids. Therefore, diet and fluid restrictions are less restricted in NHD patients. However, it is ambiguous whether transition from conventional hemodialysis (CHD) to NHD leads to improved intake and nutritional status. We studied the effect of NHD on protein intake, laboratory indices of nutritional status, and body composition.

Study design

Systematic review with meta-analysis.

Population

NHD patients.

Search strategy

Systematic literature search from databases, Medline, Cinahl, EMBASE and The Cochrane Library, to identify studies reporting on nutritional status post-transition from CHD to NHD.

Intervention

Transition from CHD to NHD.

Outcomes

Albumin, normalized protein catabolic rate (nPCR), dry body weight (DBW), body mass index (BMI), phase angle, protein intake, and energy intake.

Results

Systematic literature search revealed 13 studies comprising 282 patients that made the transition from CHD to NHD. Meta-analysis included nine studies in 229 patients. In control group controlled studies (n = 4), serum albumin increased significantly from baseline to 4–6 months in NHD patients compared with patients that remained on CHD (mean difference 1.3 g/l, 95% CI 0.02; 2.58, p = 0.05). In baseline controlled studies, from baseline to 4–6 months of NHD treatment, significant increases were ascertained in serum albumin (mean difference (MD) 1.63 g/l, 95% CI 0.73–2.53, p<0.001); nPCR (MD 0.16 g/kg/day; 95% CI 0.04–0.29, p = 0.01); protein intake (MD 18.9 g, 95% CI 9.7–28.2, p<0.001); and energy intake (MD 183.2 kcal, 95% CI 16.8–349.7, p = 0.03). Homogeneity was rejected only for nPCR (baseline versus 4–6 months). DBW, BMI, and phase angle did not significantly change. Similar results were obtained for comparison between baseline and 8–12 months of NHD treatment.

Limitations

Most studies had moderate sample sizes; some had incomplete dietary records and relatively brief follow-up period. Studies markedly differed with regard to study design.

Conclusions

NHD is associated with significantly higher protein and energy intake as well as increases in serum albumin and nPCR. However, the data on body composition are inconclusive.

In-Center Nutrition Practices of Clinics within a Large Hemodialysis Provider in the United States

BACKGROUND AND OBJECTIVES

Eating during hemodialysis treatment remains a controversial topic. It is perceived that more restrictive practices in the United States contribute to poorer nutritional status and elevated mortality compared with some other parts of the world. However, in-center food practices in the United States have not been previously described.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In 2011, we conducted a survey of clinic practices and clinician (dietitian, facility administrator, and medical director) opinions related to in-center food consumption within a large dialysis organization. After the initial survey, we provided clinicians with educational materials about eating during treatment. In 2014, we performed a follow-up survey. Differences in practices and opinions were analyzed using chi-squared tests and logistic regression.

RESULTS

In 2011, 343 of 1199 clinics (28.6%) did not allow eating during treatment, 222 clinics (18.2%) did not allow drinking during treatment, and 19 clinics (1.6%) did not allow eating at the facility before or after treatment. In 2014, the proportion of clinics that did not allow eating during treatment had declined to 22.6% (321 of 1422 clinics), a significant shift in practice (P<0.001). Among the 178 (6.8%) clinics that self-reported that eating was "more allowed" in 2014, the main reason for this shift was an increased focus on nutritional status. Among clinicians, a higher percentage encouraged eating during treatment (53.1% versus 37.4%; P<0.05), and facility administrators and medical directors were less concerned about the seven reasons commonly cited for restricting eating during treatment in 2014 compared with 2011 (P<0.05 for all).

CONCLUSIONS

We found that 28.6% and 22.6% of hemodialysis clinics within the United States restricted eating during treatment in 2011 and 2014, respectively, a rate more than double that found in an international cohort on which we previously published. However, practices and clinician opinions are shifting toward allowing patients to eat. Additional research is warranted to understand the effect that these practices have on patient outcomes and outline best practices.

Intradialytic protein supplementation reduces inflammation and improves physical function in maintenance hemodialysis patients

OBJECTIVE

Protein malnutrition is both a cause and consequence of inflammation and related comorbidities for maintenance hemodialysis (MHD) patients. This study sought to determine if oral supplementation with soy or whey protein during dialysis treatment reduces inflammation and improves physical function and body composition in MHD patients.

DESIGN

The design used in the study was randomized controlled trial, and the setting used was hemodialysis clinics in Champaign and Chicago, Illinois.

SUBJECTS

Patients who received treatment ≥3 days/week, were ages ≥30 years did not have congestive heart failure or chronic obstructive pulmonary disease, and were receiving dialysis treatment for ≥3 months were eligible for inclusion.

INTERVENTION

Patients were randomized to oral supplementation with a whey protein, soy protein, or placebo beverage. Patients (WHEY, n = 11; SOY, n = 12; CON, n = 15) consumed their assigned beverage before every dialysis session for 6 months.

MAIN OUTCOME MEASURES

Body composition was measured by dual-energy x-ray absorptiometry, physical function by gait speed and shuttle walk test, and markers of inflammation (C-reactive protein and interleukin 6) using commercially available enzyme-linked immunosorbent assay kits before and after the 6-month intervention. Dietary intake was assessed by 24-hour dietary recalls.

RESULTS

Six months of whey or soy supplementation significantly reduced predialysis interleukin 6 levels (P < .05 for both), whereas there was a trend for a reduction in C-reactive protein when both protein groups were combined (P = .062). Gait speed and shuttle walk test performance also significantly improved in the protein groups (P < .05 for both). No changes in body composition were observed. However, alkaline phosphatase, a marker of bone turnover, was significantly reduced in the protein groups.

CONCLUSIONS

Intradialytic protein supplementation during a 6-month intervention reduced inflammation and improved physical function and represents an affordable intervention to improve the health of MHD patients.

Impaired postprandial response of the insulin-like growth factor system in maintenance haemodialysis

OBJECTIVE

Patients on maintenance haemodialysis (HD) have reduced circulating free and bioactive insulin-like growth factor I (IGF-I) due to increased IGF-binding proteins (IGFBPs). This study investigated the postprandial response of the IGF system in HD patients compared with matched healthy subjects.

DESIGN AND PATIENTS

In a crossover study, twelve nondiabetic HD patients were assigned in a random order to three 10-h study days: (1) a non-HD day with one meal served at baseline (NHDM1), (2) an HD day with one meal served during HD (HDM1) and (3) an HD day with two meals served during and after HD, respectively (HDM2). Twelve healthy controls conducted session 1.

RESULTS

After the baseline meal, insulin concentrations changed similarly in HD patients and controls, whereas hyperglycaemia was more prolonged in HD patients (P < 0·001). Postprandial IGFBP-1 showed greater reductions from baseline in controls (-76% [-81; -70%], mean [95% confidence intervals], P < 0·001) than in patients on non-HD days (-45% [-57; -30%], P < 0·001). In the latter group, the response was even more attenuated during HD (-22% [-38; -1%] and -24% [-40; -4%], P ≤ 0·041). After the second meal on HDM2 days, IGFBP-1 further decreased (-50% [-61; -37%], P < 0·001), whereas IGFBP-1 returned to baseline levels on the other study days. Consistently, at the end of the study days, bioactive IGF-I was significantly above baseline only on HDM2 days (+22% [+5; +43%], P = 0·012).

CONCLUSIONS

HD patients were unable to suppress IGFBP-1 to the same extent as healthy controls, which may increase the risk of protein-energy wasting in maintenance HD. A second meal after HD, however, effectively suppressed IGFBP-1 and increased bioactive IGF-I.

Nutrition: Intradialytic oral nutrition--the ultimate conviction

Protein-energy wasting occurs frequently during maintenance dialysis. Known aetiologies include a loss of nutrients during the haemodialysis procedure and anorexia. Providing energy and protein during dialysis improves metabolism; however, the benefits of long-term support are debated. Weiner and colleagues report convincing data with an intradialytic oral nutritional intervention using protein supplements.

Prevention and treatment of protein energy wasting in chronic kidney disease patients: a consensus statement by the International Society of Renal Nutrition and Metabolism

Protein energy wasting (PEW) is common in patients with chronic kidney disease (CKD) and is associated with adverse clinical outcomes, especially in individuals receiving maintenance dialysis therapy. A multitude of factors can affect the nutritional and metabolic status of CKD patients requiring a combination of therapeutic maneuvers to prevent or reverse protein and energy depletion. These include optimizing dietary nutrient intake, appropriate treatment of metabolic disturbances such as metabolic acidosis, systemic inflammation, and hormonal deficiencies, and prescribing optimized dialytic regimens. In patients where oral dietary intake from regular meals cannot maintain adequate nutritional status, nutritional supplementation, administered orally, enterally, or parenterally, is shown to be effective in replenishing protein and energy stores. In clinical practice, the advantages of oral nutritional supplements include proven efficacy, safety, and compliance. Anabolic strategies such as anabolic steroids, growth hormone, and exercise, in combination with nutritional supplementation or alone, have been shown to improve protein stores and represent potential additional approaches for the treatment of PEW. Appetite stimulants, anti-inflammatory interventions, and newer anabolic agents are emerging as novel therapies. While numerous epidemiological data suggest that an improvement in biomarkers of nutritional status is associated with improved survival, there are no large randomized clinical trials that have tested the effectiveness of nutritional interventions on mortality and morbidity.

Effect of hyperinsulinemia during hemodialysis on the insulin-like growth factor system and inflammatory biomarkers: a randomized open-label crossover study

Background

A marked reduction in serum levels of bioactive insulin-like growth factor-I (IGF-I) has been observed in fasting hemodialysis (HD) patients during a 4-h HD session. The aim of the present study was to investigate the beneficial effect of hyperinsulinemia during HD on bioactive IGF-I and inflammatory biomarkers.

Methods

In a randomized cross-over study, 11 non-diabetic HD patients received a standardised HD session with either: 1) no treatment, 2) glucose infusion (10% glucose, 2.5 mL/kg/h), or 3) glucose-insulin infusion (10% glucose added 30 IU NovoRapid® per litre, 2.5 mL/kg/h). Each experiment consisted of three periods: pre-HD (−120 to 0 min), HD (0 to 240 min), and post-HD (240 to 360 min). A meal was served at baseline (−120 min); infusions were administered from baseline to 240 min. The primary outcome was change in bioactive IGF-I during the experiment. Secondary outcomes were changes in high-sensitivity C-reactive protein, interleukin-1β, interleukin-6, and tumor necrosis factor α. Comparisons were performed using mixed-model analysis of variance for repeated measures.

Results

From baseline to the end of study, no significant differences were observed in the changes in either serum bioactive IGF-I or total IGF-I between study days. Overall, serum bioactive IGF-I levels rose above baseline at 120 to 300 min with a maximum increase of 20% at 120 min (95% confidence interval (CI), 9 to 31%; p < 0.001), whereas total IGF-I levels rose above baseline at 180 to 300 min with a maximum increase of 5% at 240 min (95% CI, 2 to 9%; p = 0.004). A significant difference was observed in the changes in serum IGF-binding protein-1 (IGFBP-1) between study days (p = 0.008), but differences were only significant in the post-HD period. From baseline to the end of HD, no significant difference was observed in the changes in serum IGFBP-1 levels between study days, and in this time period overall serum IGFBP-1 levels were below baseline at all time points with a maximum decrease of 51% at 180 min (95% CI, 45 to 57%; p < 0.001). None of the investigated inflammatory biomarkers showed any differences in the changes over time between study days.

Conclusions

Postprandial insulin secretion stimulated the IGF-system during HD with no further effect of adding glucose or glucose-insulin infusion. Hyperinsulinemia during HD had no effect on biomarkers of inflammation.

Trial registration

ClinicalTrials.gov registry: NCT01209403

Outcomes associated with intradialytic oral nutritional supplements in patients undergoing maintenance hemodialysis: a quality improvement report

BACKGROUND

Insufficient clinical data exist to determine whether provision of oral nutritional supplements during dialysis can improve survival in hypoalbuminemic maintenance hemodialysis patients.

STUDY DESIGN

Retrospective matched-cohort study.

SETTING & PARTICIPANTS

All oral nutritional supplement program-eligible in-center maintenance hemodialysis patients with albumin level ≤3.5 g/dL in quarter 4 of 2009 without oral nutritional supplements in the prior 90 days at Fresenius Medical Care, North America facilities.

QUALITY IMPROVEMENT PLAN

Monitored intradialytic oral nutritional supplements were provided to eligible maintenance hemodialysis patients upon physician order, to continue for a year or until serum albumin level was ≥4.0 g/dL.

OUTCOME

Mortality (including deaths and withdrawals), followed up until December 31, 2010.

MEASUREMENTS

Both an intention-to-treat (ITT) and an as-treated analysis was performed using a 1:1 geographic region and propensity score-matched study population (using case-mix, laboratory test, access type, 30-day prior hospitalization, and incident patient status) comparing patients treated with intradialytic oral nutritional supplements with usual-care patients. Cox models were constructed, unadjusted and adjusted for facility standardized mortality ratio and case-mix and laboratory variables.

RESULTS

The ITT and as-treated analyses both showed lower mortality in the oral nutritional supplement group. The conservative ITT models with 5,227 matched pairs had 40% of controls subsequently receiving oral nutritional supplements after January 1, 2010 (because many physicians delayed participation), with comparative death rates of 30.1% versus 30.4%. The corresponding as-treated (excluding crossovers) death rates for 4,289 matched pairs were 30.9% versus 37.3%. The unadjusted ITT mortality HR for oral nutritional supplement use was 0.95 (95% CI, 0.88-1.01), and the adjusted HR was 0.91 (95% CI, 0.85-0.98); the corresponding as-treated HRs were 0.71 (95% CI, 0.66-0.76) and 0.66 (95% CI, 0.61-0.71) before and after adjustment, respectively.

LIMITATIONS

Limited capture of oral nutritional supplement intake outside the facility and potential residual confounding from unmeasured variables, such as dietary intake.

CONCLUSIONS

Maintenance hemodialysis patients with albumin levels ≤3.5 g/dL who received monitored intradialytic oral nutritional supplements showed survival significantly better than similar matched patient controls, with the as-treated analysis highlighting the potentially large effect of this strategy in clinical practice.

Diets and enteral supplements for improving outcomes in chronic kidney disease

Protein-energy wasting (PEW), which is manifested by low serum levels of albumin or prealbumin, sarcopenia and weight loss, is one of the strongest predictors of mortality in patients with chronic kidney disease (CKD). Although PEW might be engendered by non-nutritional conditions, such as inflammation or other comorbidities, the question of causality does not refute the effectiveness of dietary interventions and nutritional support in improving outcomes in patients with CKD. The literature indicates that PEW can be mitigated or corrected with an appropriate diet and enteral nutritional support that targets dietary protein intake. In-center meals or oral supplements provided during dialysis therapy are feasible and inexpensive interventions that might improve survival and quality of life in patients with CKD. Dietary requirements and enteral nutritional support must also be considered in patients with CKD and diabetes mellitus, in patients undergoing peritoneal dialysis, renal transplant recipients, and in children with CKD. Adjunctive pharmacological therapies, such as appetite stimulants, anabolic hormones, and antioxidative or anti-inflammatory agents, might augment dietary interventions. Intraperitoneal or intradialytic parenteral nutrition should be considered for patients with PEW whenever enteral interventions are not possible or are ineffective. Controlled trials are needed to better assess the effectiveness of in-center meals and oral supplements.

Energy balance in advanced chronic kidney disease and end-stage renal disease

Energy intake, resting energy expenditure, and energy expended for physical activity (EEPA) are components of energy balance that may be disrupted by a number of disorders and clinical conditions commonly present in advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD). Energy intake of patients with CKD has been consistently lower than the recommended intake in multiple reports. On the other hand, while reduced energy intake due to anorexia may be applicable for ESRD patients with overt protein-energy wasting, it is potentially unrealistic for overweight or obese subjects who are able to maintain their body weight. Studies on resting energy expenditure have provided mixed results, most likely as a consequence of differences in the population characteristics, clinical conditions, and stage of the disease. Finally, although there is lack of specific studies on EEPA, there is evidence that ESRD patients, particularly those undergoing hemodialysis are in general less active than sedentary healthy individuals. These observations may raise questions regarding the accuracy of dietary reports and the uncertainties related to the energy requirements, optimal dietary energy intake, and recommendations for physical activity in these patients.

The effect of resistance exercise to augment long-term benefits of intradialytic oral nutritional supplementation in chronic hemodialysis patients

BACKGROUND

Resistance exercise combined with intradialytic oral nutrition (IDON) supplementation improves net protein balance in the acute setting in chronic hemodialysis patients. We hypothesized that combination of long-term resistance exercise and IDON would improve markers of muscle mass and strength further compared with IDON alone.

METHODS

Thirty-two participants (21 male; mean age, 43 ± 13 years) on chronic hemodialysis were randomly assigned to IDON plus resistance exercise (NS + EX), or IDON (NS) alone for 6 months. IDON consisted of a lactose-free formula consisting of protein, carbohydrate, and fat. Three sets of 12 repetitions of leg-press were completed before each dialysis session in the NS + EX arm. Primary outcome measurement was lean body mass. Muscle strength and other nutritional parameters were measured as secondary outcomes.

RESULTS

Of 32 participants, 22 completed the 6-month intervention. There were no statistically significant differences between the study interventions with respect to changes in lean body mass and body weight, when comparing NS + EX to NS. There were also no statistically significant differences in any of the secondary outcomes measured in the study. Body weight (80.3 ± 16.6 kg, 81.1 ± 17.5 kg, and 80.9 ± 18.2 kg at baseline, month 3, and month 6, respectively; P = .02) and 1-repetition maximum (468 ± 148 lb, 535 ± 144 lb, and 552 ± 142 lb, respectively; P = .001) increased statistically significantly during the study for all patients combined.

CONCLUSION

This study did not show further benefits of additional resistance exercise on long-term somatic protein accretion above and beyond nutritional supplementation alone. When both treatments groups were combined, body weight and muscle strength improved during the study.