Protein-energy wasting syndrome in advanced chronic kidney disease: prevalence and specific clinical characteristics

Multicenter Study to Validate a Hospitalization Risk Assessment Tool in Hemodialysis Patients

Introduction Protein-energy wasting is a prevalent condition in patients with chronic kidney disease. Our goal was to validate the risk assessment tool (Hashmi's tool) in multiple centers, developed in 2018, as it was easily applicable and cost-effective. Methods The following variables were scored as 0, 1, 2, or 3 as per severity: body mass index, HD vintage in years, functional capacity, serum albumin, serum ferritin, and the number of co-morbid conditions (diabetes mellitus, hypertension, ischemic heart disease, and cerebrovascular disease). This scoring system was applied to maintenance hemodialysis patients in six different centers. The patient's record was evaluated for two years. Patients were divided into low-risk (score <6) and high-risk (score ≥6). We compared the two groups using the chi-square test for the difference in hospitalization and mortality. Results A total of 868 patients' records were analyzed, and the maximum score was 13 with the application of Hashmi's tool. Four hundred twenty-nine patients were in the low-risk group, and 439 patients fell into the high-risk group. Four hundred sixty-seven patients were male, and 401 were females; 84% had hypertension, and 54% had diabetes mellitus. In the high-risk group, we identified more females. Patients' likelihood of being in the high-risk group was higher if they had diabetes mellitus, hypertension, or ischemic heart disease. Hospitalization due to vascular or non-vascular etiologies was more common in the high-risk group (p=0.036 and p<0.001, respectively). A total of 123 patients died during the study period, 92 from the high-risk group as compared to 31 from the low-risk group. This was three times higher and statistically significant (p<0.001). Conclusion Using a simple and cost-effective tool, we have identified malnourished patients who are at risk of hospitalization and mortality. This study has validated the previous work at a single center, which has now been reflected in six dialysis units across Saudi Arabia.

New approaches in the nutritional treatment of advanced chronic kidney disease

INTRODUCTION

Patients with advanced chronic kidney disease (ACKD) have a high prevalence of malnutrition. The dietary restrictions that we usually apply in terms of macro and micronutrients force our patients to follow dietary guidelines that deviate from healthy patterns.

OBJETIVES

To determine if a personalized nutritional intervention program, minimizing the usual restrictions would be justified in case it improved the evolution of kidney disease compared to standard treatment.

SECUNDARY OBJETIVES

To determine changes in nutrient intakes and in anthropometric and biochemical parameters, as well as quantify episodes of hyperkalemia.

MATERIAL AND METHODS

A single-center, randomized and controlled educational intervention clinical trial was conduct in patients from the ERCA outpatients clinic at the Complejo Hospitalario Universitario de Albacete. 75 patients were included, assigning 35 to a Control group and 40 to the Intervention group with 1-year follow-up. The nutritional status was determined using anthropometric data, body composition by Bioimpedance, blood and urine biochemical parameters and a 24-h recall questionnaire. The nutritional intervention was carried out in three different ways: individual, collective and telephone recall.

RESULTS

At the beginning of the study, the BMI showed a situation of weight excess with a mean of 28.83 kg/m² (5.4) in men and 26.96 kg/m² (4.09) in women. 70% of our patients had overweight. The abdominal circumference was 105.3 cm (10.2) and 92.3 cm (13.7) for men and women respectively without significant changes throughout the study. The percentage of fat mass (FM) was high in both groups for men and women throughout the study. We did not find biochemical parameters of malnutrition and only significant differences were observed in glomerular filtration rate (GFR), which increased in the intervention group. No patient presented any episodes of hyperkalemia during the study. The energy intake in both groups showed an inadequate distribution of macronutrients with a poor intake of carbohydrates (CH) that was supplemented with an excess of fat. In the case of micronutrients, we did observe an increase in potassium and fiber intakes with a decrease in sodium and phosphorus in the intervention group.

CONCLUSIONS

Malnutrition is not exclusively an intake defficit and encompasses both the problems derived from a deficit and an excess of nutrients intake. Un to 70% of our patients showed weight excess and a fat mass higher than desirable. The implementation of an individualized nutritional education program, including a vegetables and fiber rich diet, less atherogenic, not only did not cause electrolyte alterations but also slowed the progression of kidney disease.

Severity of protein-energy wasting and obesity are independently related with poor quality of life in peritoneal dialysis patients

Protein-energy wasting (PEW) and poor health-related quality of life (HRQoL) are independently associated with morbi-mortality in continuous ambulatory peritoneal dialysis (CAPD). PEW may reduce HRQoL; however, we hypothesized HRQoL is affected differentially by PEW degrees or by individual criteria of nutritional status. AIM: To evaluate HRQoL according to PEW severity and nutritional status indicators in CAPD. This is a cross-sectional study in 151 patients. Subjective global assessment (SGA) was employed, and nutritional status classified as normal, mild-moderate PEW, and severe PEW. HRQoL was evaluated using Kidney Disease Quality of Life Short Form™, including physical (PCS), mental (MCS) and kidney disease (KDCS) components, and their subscales. Dietary intake, anthropometric and biochemical variables were measured. Forty-six percent of patients were well-nourished, 44% had mild-moderate PEW, and 10% severe PEW. Compared with well-nourished patients, those with mild-moderate (p=0.06) and severe (p=0.005) PEW had lower HRQoL score [68 (52-75), 55 (45-72), 46 (43-58), respectively]. PCS, MCS, and KDCS and their subscales had lower values as PEW was more severe. Patients with obesity and hypoalbuminemia had significantly lower HRQoL overall and component scores than their counterparts. Dietary intake was not associated with quality of life. In multivariate analysis obesity, PEW (by SGA), hypoalbuminemia, and low educational level predicted poor HRQoL (χ² 58.2, p<0.0001). As conclusion, PEW severity was related with worse HRQoL, either as overall score or in every component or subscale in CAPD patients. Poor HRQoL was predicted independently by PEW severity and obesity; additional predictors were hypoalbuminemia and low education.

Consensus on the standard terminology used in the nutrition care of adult patients with chronic kidney disease

This nutrition consensus document is the first to coordinate the efforts of three professional organizations - the Brazilian Association of Nutrition (Asbran), the Brazilian Society of Nephrology (SBN), and the Brazilian Society of Parenteral and Enteral Nutrition (Braspen/SBNPE) - to select terminology and international standardized tools used in nutrition care. Its purpose is to improve the training delivered to nutritionists working with adult patients with chronic kidney disease (CKD). Eleven questions were developed concerning patient screening, care, and nutrition outcome management. The recommendations set out in this document were developed based on international guidelines and papers published in electronic databases such as PubMed, EMBASE(tm), CINHAL, Web of Science, and Cochrane. From a list of internationally standardized terms, twenty nutritionists selected the ones they deemed relevant in clinical practice involving outpatients with CKD. The content validity index (CVI) was calculated with 80% agreement in the answers. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework was used to assess the strength of evidence and recommendations. A total of 107 terms related to Nutrition Assessment and Reassessment, 28 to Diagnosis, nine to Intervention, and 94 to Monitoring and Evaluation were selected. The list of selected terms and identified tools will be used in the development of training programs and the implementation of standardized nutrition terminology for nutritionists working with patients with chronic kidney disease in Brazil.

New approaches in the nutritional treatment of advanced chronic kidney disease

INTRODUCTION

Patients with advanced chronic kidney disease (ACKD) have a high prevalence of malnutrition. The dietary restrictions that we usually apply in terms of macro and micronutrients force our patients to follow dietary guidelines that deviate from healthy patterns.

OBJECTIVES

To determine if a personalized nutritional intervention program, minimizing the usual restrictions would be justified in case it improved the evolution of kidney disease compared to standard treatment.

SECONDARY OBJECTIVES

To determine changes in nutrient intakes and in anthropometric and biochemical parameters, as well as quantify episodes of hyperkalemia.

MATERIAL AND METHODS

A single-center, randomized and controlled educational intervention clinical trial was conduct in patients from the ERCA outpatients clinic at the Complejo Hospitalario Universitario de Albacete. 75 patients were included, assigning 35 to a Control group and 40 to the Intervention group with 1-year follow-up. The nutritional status was determined using anthropometric data, body composition by Bioimpedance, blood and urine biochemical parameters and a 24-h recall questionnaire. The nutritional intervention was carried out in three different ways: individual, collective and telephone recall.

RESULTS

At the beginning of the study, the BMI showed a situation of weight excess with a mean of 28.83 kg/m2 (5.4) in men and 26.96 kg/m2 (4.09) in women. 70% of our patients had overweight. The abdominal circumference was 105.3 cm (10.2) and 92.3 cm (13.7) for men and women respectively without significant changes throughout the study. The percentage of fat mass (FM) was high in both groups for men and women throughout the study. We did not find biochemical parameters of malnutrition and only significant differences were observed in glomerular filtration rate (GFR), which increased in the intervention group. No patient presented any episodes of hyperkalemia during the study. The energy intake in both groups showed an inadequate distribution of macronutrients with a poor intake of carbohydrates (CH) that was supplemented with an excess of fat. In the case of micronutrients, we did observe an increase in potassium and fiber intakes with a decrease in sodium and phosphorus in the intervention group.

CONCLUSIONS

Malnutrition is not exclusively an intake deficit and encompasses both the problems derived from a deficit and an excess of nutrients intake. Un to 70% of our patients showed weight excess and a fat mass higher than desirable. The implementation of an individualized nutritional education program, including a vegetables and fiber rich diet, less atherogenic, not only did not cause electrolyte alterations but also slowed the progression of kidney disease.

Severity of protein-energy wasting and obesity are independently related with poor quality of life in peritoneal dialysis patients

Protein-energy wasting (PEW) and poor health-related quality of life (HRQoL) are independently associated with morbi-mortality in continuous ambulatory peritoneal dialysis (CAPD). PEW may reduce HRQoL; however, we hypothesized HRQoL is affected differentially by PEW degrees or by individual criteria of nutritional status. AIM: To evaluate HRQoL according to PEW severity and nutritional status indicators in CAPD. This is a cross-sectional study in 151 patients. Subjective global assessment (SGA) was employed, and nutritional status classified as normal, mild-moderate PEW, and severe PEW. HRQoL was evaluated using Kidney Disease Quality of Life Short Form™, including physical (PCS), mental (MCS) and kidney disease (KDCS) components, and their subscales. Dietary intake, anthropometric and biochemical variables were measured. Forty-six percent of patients were well-nourished, 44% had mild-moderate PEW, and 10% severe PEW. Compared with well-nourished patients, those with mild-moderate (p=0.06) and severe (p=0.005) PEW had lower HRQoL score [68 (52-75), 55 (45-72), 46 (43-58), respectively]. PCS, MCS, and KDCS and their subscales had lower values as PEW was more severe. Patients with obesity and hypoalbuminemia had significantly lower HRQoL overall and component scores than their counterparts. Dietary intake was not associated with quality of life. In multivariate analysis obesity, PEW (by SGA), hypoalbuminemia, and low educational level predicted poor HRQoL (χ2 58.2, p<0.0001). As conclusion, PEW severity was related with worse HRQoL, either as overall score or in every component or subscale in CAPD patients. Poor HRQoL was predicted independently by PEW severity and obesity; additional predictors were hypoalbuminemia and low education.

Significance of Adipose Tissue Maintenance in Patients Undergoing Hemodialysis

In the general population, obesity is known to be associated with adverse outcomes, including mortality. In contrast, high body mass index (BMI) may provide a survival advantage for hemodialysis patients, which is known as the obesity paradox. Although BMI is the most commonly used measure for the assessment of obesity, it does not distinguish between fat and lean mass. Fat mass is considered to serve as an energy reserve against a catabolic condition, while the capacity to survive starvation is also thought to be dependent on its amount. Thus, fat mass is used as a nutritional marker. For example, improvement of nutritional status by nutritional intervention or initiation of hemodialysis is associated with an increase in fat mass. Several studies have shown that higher levels of fat mass were associated with better survival in hemodialysis patients. Based on body distribution, fat mass is classified into subcutaneous and visceral fat. Visceral fat is metabolically more active and associated with metabolic abnormalities and inflammation, and it is thus considered to be a risk factor for cardiovascular disease and mortality. On the other hand, subcutaneous fat has not been consistently linked to adverse phenomena and may reflect nutritional status as a type of energy storage. Visceral and subcutaneous adipose tissues have different metabolic and inflammatory characteristics and may have opposing influences on various outcomes, including mortality. Results showing an association between increased subcutaneous fat and better survival, along with other conditions, such as cancer or cirrhosis, in hemodialysis patients have been reported. This evidence suggests that fat mass distribution (i.e., visceral fat and subcutaneous fat) plays a more important role for these beneficial effects in hemodialysis patients.

Effect of parathyroidectomy on bone tissue biomarkers and body composition in patients with chronic kidney disease and secondary hyperparathyroidism

BACKGROUND/OBJECTIVE

Loss of renal function may induce secondary hyperparathyroidism (s-HPT), which triggers several complications leading to an extreme decline in quality of life and increased mortality in affected patients. We evaluated whether parathyroidectomy (PTx), as surgical treatment for s-HPT, modifies body composition, and hormones involved in the protein-energy metabolism of affected patients.

SUBJECTS/METHODS

Overall, 30 s-HPT patients were evaluated at two times, before PTx (pre PTx) and 6 months after PTx (post PTx). Patients were evaluated by biochemistry analysis, anthropometry, electrical bioimpedance (BIA), food intake diary, handgrip strength, and modified global subjective nutritional assessment (SGA).

RESULTS

After PTx, patients showed decreased serum levels of total and ionic calcium, as well as decreased alkaline phosphatase and PTH, and increased 25 (OH) vitamin D. These results demonstrate that PTx was efficient to correct part of the mineral disorder. We also observed an increase in caloric intake, body weight, body mass index (BMI), phase angle, handgrip strength, SGA score, and a decreasing in the percentage of weight loss. The osteocalcin concentration of both carboxylated (cOC) and undercarboxylated form was diminished post PTx. The cOC correlated with bone metabolism markers and SGA score.

CONCLUSIONS

PTx modified body composition improving nutritional status and preventing the progression of weight loss with increased of energy intake, BMI, handgrip strength, phase angle of BIA, and SGA score. The present study also suggests an association of cOC with bone markers and SGA score. Further studies are needed to better clarify these associations with larger sample size.

Extended-Hours Hemodialysis without Dietary Restrictions Is Associated with Lower Risk for Developing of Dialysis-Related Amyloidosis

Dialysis-related amyloidosis (DRA) is characterized by the deposition of amyloid consisting of beta2-microglobulin in the musculoskeletal system, causing carpal tunnel syndrome, destructive spondyloarthropathy, and/or bone cysts. Increased cystic radiolucency of the bones and tendon thickening due to inflammation are common findings in DRA. We have developed a new dialysis method, extended-hours hemodialysis without dietary restrictions for the aim of improving both hypertension and malnutrition. We retrospectively evaluated the clinical effects of dialysis time on the risk for developing of DRA. The study subjects were all of the 30 patients who had received this treatment for more than 11 years. They were divided into two groups according to the weekly dialysis hours: 15 patients ≥ 16.5 hours/week (L-group) and 15 patients ≤ 15.5 hours/week (S-group). Plain x-ray imaging and ultrasonography were used to assess cystic radiolucency of the bones and thickness/diameter of the soft tissues. The proportion of the carpal bone cystic radiolucency was lower in the L-group. The severity of median nerve compression at the wrist was significantly less in the L-group (right hand: p = 0.0082, left hand: p = 0.0137). Multivariate regression analysis showed that dialysis time was a predictor of median nerve compression (β = -0.559, p = 0.005). In conclusion, extended-hours hemodialysis without dietary restrictions contributes to lower the risk for developing of DRA at the wrist. We therefore propose that extended-hours hemodialysis without dietary restrictions is a preferred method which maintains the patients' quality of life compared with the conventional hemodialysis method.

Association among kidney function, frailty, and oral function in patients with chronic kidney disease: a cross-sectional study

Background

Chronic kidney disease (CKD) involves many factors that can cause frailty and oral hypofunction. We aimed to investigate the prevalence of frailty and oral hypofunction and to examine the associations among kidney function, frailty, and oral function in adults with CKD in Japan.

Methods

This cross-sectional study was conducted at two institutions. The participants included 109 patients with CKD stages 3–5 who visited outpatient clinics or were admitted for inpatient treatment. Frailty was evaluated using the Japanese version of the Cardiovascular Health Study frailty criteria. Oral function was evaluated by assessing oral motor skills [oral diadochokinesis (ODK) rate], masticatory ability, and the repetitive saliva swallowing test. The estimated glomerular filtration rate (eGFR) was used to indicate kidney function. We examined the associations among kidney function, frailty, and oral function using binomial logistic regression analysis.

Results

In total, 31 participants (28.4%) were classified as being frail. Univariate analysis showed that age, body mass index, eGFR, and haemoglobin level were significantly associated with frailty. ODK and swallowing function were significantly associated with frailty. Multivariate analysis revealed that frailty was significantly associated with eGFR [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.92–1.00, p = 0.048] and ODK rate (OR 0.68, CI 0.47–0.98, p = 0.038). However, no significant association was found between CKD severity and masticatory or swallowing function.

Conclusion

We found a high prevalence of frailty in patients with CKD and a significant association between frailty and oral motor skills, affecting the swallowing function of patients with nondialysis CKD. The high prevalence of frailty among patients with CKD suggests that routine assessment of frailty is necessary to prevent the development of severe complications. In addition, oral and kidney function should be carefully evaluated, and oral health education and interventions should be performed for patients with CKD.

Differences and Effects of Metabolic Fate of Individual Amino Acid Loss in High-Efficiency Hemodialysis and Hemodiafiltration

OBJECTIVE

The objective of the study was to quantify the loss and arterial blood concentration of the three main classes of amino acids (AAs)-nonessential amino acids (NEAAs), essential amino acids (EAAs), and branched-chain amino acids-as resulting from high-efficiency hemodialysis (HED) and hemodiafiltration (HDF). We moreover aimed to identify the different fates and metabolic effects manifested in patients undergoing hemodialysis and the consequences on body composition and influence of nutritional decline into protein energy wasting.

DESIGN AND METHODS

Identical dialysis monitors, membranes, and dialysate/infusate were used to ensure consistency. Ten patients were recruited and randomized to receive treatment with on-line modern HED and HDF. Arterial plasma concentrations of individual AAs were compared in healthy volunteers and patients undergoing hemodialysis, and AA levels outflowing from the dialyzer were evaluated. Baseline AA plasma levels of patients undergoing hemodialysis were compared with findings obtained 1 year later.

RESULTS

A severe loss of AA with HED/HDF was confirmed: a marked loss of total AAs (5 g/session) was detected, corresponding to more than 65% of all AAs. With regard to individual AAs, glutamine displayed a consistent increase (+150%), whereas all other AAs decreased after 12 months of HD/HDF. Only a few AAs, such as proline, cysteine, and histidine maintained normal levels. The most severe metabolic consequences may result from losses of EAAs such as valine, leucine, and histidine and from NEAAs including proline, cysteine, and glutamic acid eliciting the onset of hypercatabolism threatening muscle mass loss.

CONCLUSION

Dialysis losses, together with the effect of chronic uremia, resulted in a reduction of fundamental EAAs and NEAAs, which progressively led our patients after 12 months to a deterioration of lean mass toward sarcopenia. Therefore, the reintroduction of a correctly balanced AA supplementation in patients undergoing HD to prevent or halt decline of hypercatabolism into cachexia is recommended.

[So doctor, what could I eat then?]

Introduction

Introduction: the strict dietary recommendations we impose on patients with advanced chronic kidney disease (ACKD) have negative impact on quality of life. Objective: determine whether such restrictions are justified and if an educational program can improve health-related quality of life (HRQL) parameters. Methods: we carried out an educational intervention, single center, randomized, controlled clinical trial on ACKD outpatients in Albacete. Seventy-five patients were included, 35 in the control group and 40 in the intervention group. Nutritional assessment was based on the Subjetive Global Assessment (SGA) and body mass index (BMI). We used the SF-36 health questionnaire to measure HRQL. In the intervention group we carried out individual, collective and telephone nutritional interventions, adapting diet advice and restrictions in a personalized way. Results: malnutrition measured by Subjective Global Assessment (SGA) in the control group was 20%; meanwhile, in the intervention group it was 29.3% and it improved at the end of the study, but not significantly. BMI showed overweight with a mean of 28.83 kg/m² (DE: 5.4) and 26.96 kg/m² (DE: 4.09), respectively, and did not change throughout the study. The nutritional intervention improved the score in all the subscales except for body pain score. Besides, mental and physical components also improved their scores in the intervention group and worsened them in the control group (p < 0.001). Conclusions: quality of life can be improved in ACKD patients applying an educational nutrition program.

Kidney cachexia or protein-energy wasting in chronic kidney disease: facts and numbers

BACKGROUND

Weight loss and homeostatic disturbances of both energy and protein balances are characteristics of several illnesses including cancer, heart failure, and chronic kidney disease (CKD). Different definitions have been used to describe this deleterious process. The term protein-energy wasting (PEW) has been proposed for CKD patients by the International Society of Renal Nutrition and Metabolism.

METHODS

We searched the publication in Medline from February 2008 to September 2018 using PEW or cachexia in their title.

RESULTS

Since its inception, the term PEW has been exceptionally successful, highlighted by 327 original publications referenced in PubMed over 10 years. Using this classification, several studies have confirmed that PEW is among the strongest predictors of mortality in CKD patients [hazard ratio of 3.03; confidence interval of 1.69-5.26 in 1068 haemodialysis patients and 1.40 (1.04-1.89) in 1487 non-dialysed patients across PEW stages 0 to 4]. Based on this classification, prevalence of PEW is 28% to 54% among 16 434 adults undergoing maintenance dialysis. PEW prevalence increases when renal function declines, that is, from <2% in CKD stages 1-2 to 11-54% in CKD stages 3-5. A more general definition of cachexia for all chronic diseases proposed by the Society on Sarcopenia, Cachexia and Wasting Disorders was also published concurrently. In the CKD area, we found 180 publications using 'cachexia' underlining that some confusion or overlap may exist. The definitions of PEW and cachexia are somewhat similar, and the main difference is that a loss of body weight >5% is a mandatory criterion for cachexia but supportive for PEW.

CONCLUSIONS

The recent understanding of cachexia physiopathology during CKD progression suggests that PEW and cachexia are closely related and that PEW corresponds the initial state of a continuous process that leads to cachexia, implicating the same metabolic pathways as in other chronic diseases. Despite the success of the definition of PEW, using a more uniform term such as 'kidney disease cachexia' could be more helpful to design future research through collaborative groups of researchers with focus on cachexia.

Differences in Amino Acid Loss Between High-Efficiency Hemodialysis and Postdilution and Predilution Hemodiafiltration Using High Convection Volume Exchange-A New Metabolic Scenario? A Pilot Study

OBJECTIVE

The objective of the study was to quantify the loss of total amino acids (TAAs), nonessential amino acids, essential amino acids, and branched chain amino acids (BCAAs) produced by high-efficiency hemodialysis (HEHD), postdilution hemodiafiltration (HDFpost), and predilution hemodiafiltration (HDFpre) using high ultrafiltration volumes; and to define the specific AA losses registered in HEHD, HDFpost, and HDFpre; to identify a potential metabolic and nutritional decline into protein energy wasting; to compare AA analysis of arterial blood samples taken from healthy controls and patients with end-stage renal disease undergoing hemodialysis.

DESIGN AND METHODS

Identical dialysis monitors, membranes, and dialysate/infusate were used to homogenize extracorporeal body influence. Ten patients were recruited and randomized to receive treatment with HEHD, HDFpost, and HDFpre it was used on-line dialytic water methodologies (OL); patients' AA arterial concentrations were measured at the start and on completion of dialysis; TAA from the dialyzer filter was calculated, and baseline levels were subsequently compared with findings obtained 1 year later. Finally, the results obtained were compared with the data from a study of 8 healthy volunteers conducted using bioimpedance analysis and laboratory blood tests to assess nutritional status.

RESULTS

A higher convective dose results in a higher weekly loss of TAA, nonessential AAs, essential AAs, and BCAAs (HEHD: 15.7 g; HDFpost-OL: 16.1 g; HDFpre-OL: 16.3 g, P < .01). After 12 months, the same hemodialys patients showed a reduced body and water intracellular mass and reduced phase angle. Arterial concentrations of TAAs and BCAAs were lower than those detected in healthy subjects (P < .01).

CONCLUSION

The study shows that the AA losses in dialytic liquid are greater after high exchange volume HDF techniques, especially HDFpre. The AA losses are not metabolically compensated, so these increase the derangements of predialytic arterial plasma AA levels. Both AA losses and arterial AA perturbations further worsened body composition already after 12 months of additional dialysis.

Influence of dietary protein intake on body composition in chronic kidney disease patients in stages 3-5: A cross-sectional study

INTRODUCTION

A controlled protein intake has shown beneficial effects to preserve renal function and nutritional status in chronic kidney disease (CKD) patients. This study aimed to analyze usual dietary protein intake and its potential contribution to body composition in CKD patients in stages 3-5.

METHOD

Cross-sectional study in 134 CKD patients in stages 3-5 (mean e-GFR: 19.4±8.7ml/min/1.73m²; males 68.7% and primary CKD etiology was diabetes mellitus, 35.8%). Demographic, clinical and nutritional parameters were evaluated. Normalized protein nitrogen appearance (nPNA), was used as a surrogate marker of dietary protein intake. The sample was classified into three nPNA groups (G_n): G₁: <0.8g/kg/day; G₂: 0.8-1g/kg/day and, G₃: ≥1g/kg/day. Assessment of nutritional status using the malnutrition-inflammation score (MIS), anthropometric measures and laboratory parameters. Analysis of body composition and hydration status by bioelectrical impedance analysis (BIVA-101-RJL system). Statistical analysis by SPSS v.20.

RESULTS

Overall mean nPNA values were 0.91±0.23g of protein/kg BW/day and only 32.1% had a dietary protein intake <0.8g of protein/kg BW/day. Most of the CKD patients (65.5%) were in stages 4 or 5. Prevalence of protein-energy-wasting (PEW) syndrome measured by MIS was 15%. By analyzing differences between nPNA groups, body weight (BW), BMI and triceps-skinfold (TSF) thickness were significantly higher in the group with nPNA ≥1g/kg BW/day (G₃), whereas a significant inverse relationship was found with the percentages of body cell mass (BCM%), fat-free mass (FFM%), muscle mass (MM%) and phase angle (PA) in the group with the lowest nPNA (G₁). Analysis of gender among subjects showed significant differences with BW, FFM%, TSF and mid-arm muscle circumference (MAMC%). Linear regression analysis showed that resistance, BCM%, MM%, and serum albumin were significant predictors of nPNA as a surrogate marker of daily protein intake (R=0.51; R²=0.29; R² adjusted=0.23; p<0.001).

CONCLUSION

Controlled protein intake is one of the cornerstones of treatment in CKD patients. A low protein intake in patients with CKD stages 3 and 4-5 was associated with loss of muscle mass in the advanced-CKD unit. The loss of muscle mass appears as an early indicator of nutritional comprised. Factors such, elderly age and loss of eGFR, showed lower protein intake and were associated with muscle loss, especially in women. Further longitudinal studies are required to evaluate the contribution of different protein intakes to uremic symptoms, nutritional status, body composition and CKD progression.

Nutritional therapy in autosomal dominant polycystic kidney disease

CKD-related nutritional therapy (NT) is a crucial cornerstone of CKD patients' treatment, but the role of NT has not been clearly investigated in autosomal dominant polycystic kidney disease (ADPKD). Several clinical studies have focused on new pharmacological approaches to delay cystic disease progression, but there are no data on dietary interventions in ADPKD patients. The aim of this paper is to analyze the evidence from the literature on the impact of five nutritional aspects (water, sodium, phosphorus, protein intake, and net acid load) in CKD-related ADPKD extrapolating-where information is unavailable-from what occurs in CKD non-ADPKD patients Sodium intake restriction could be useful in decreasing the growth rate of cysts. Although further evidence is needed, restriction of phosphorus and protein intake restriction represent cornerstones of the dietary support of renal non-ADPKD patients and common sense can guide their use. It could be also helpful to limit animal protein, increasing fruit and vegetables intake together with a full correction of metabolic acidosis. Finally, fluid intake may be recommended in the early stages of the disease, although it is not to be prescribed in the presence of moderate to severe reduction of renal function.