Nutritional treatment of advanced CKD: twenty consensus statements

Ketogenic diets in chronic kidney disease patients: a review for skeptics by skeptics

Over the last few decades, there has been growing interest in the use of ketogenic diets, mainly as a weight loss strategy. Obesity and diabetes are major risk factors for kidney disease, and obese patients with chronic kidney disease (CKD) are potential candidates for weight reducing diets, among them ketogenic diets. Of further relevance to nephrology, a limited number of recent studies suggests a favorable effect of ketogenic diets in patients affected by autosomal dominant polycystic kidney disease (ADPKD). However, concerns remain about safety in patients with CKD, particularly in the long term and in those with poor residual kidney function. The confusion surrounding the definition of ketogenic diets adds to these concerns. The aim of this review is to summarize information on the main types of ketogenic diets used in daily practice and to discuss the options for their implementation in CKD patients, limiting ultra-processed or industrial preparations.Although further studies are needed to identify the profile of CKD patients who may benefit from the implementation of ketogenic diets to treat obesity or slow the progression of ADPKD, and to assess short- and long-term safety and adherence, the available data appear promising. This critical review is intended to stimulate further research.

Sustainability and role of plant-based diets in chronic kidney disease prevention and treatment

Chronic kidney disease (CKD) affects 10% of the world's population (namely, 800 million of people) and an increase in CKD prevalence has been observed over the years. This phenomenon in developed countries is related to the spread of chronic degenerative non-communicable diseases (CDNCDs), such as diabetes mellitus, arterial hypertension, obesity, etc., while in low-income to middle-income countries, the CKD prevalence is attributable not only to CDNCDs, but also to infection conditions (like HIV, hepatitis, etc.). Another important difference lies in the age of onset of CKD, which is about 20 years lower in developing countries compared to developed ones. Therefore, CKD is becoming a public health problem, requiring preventive and treatment strategies to counteract its spread and to slow its progression. Moreover, the healthcare costs for the CKD management increase as the disease progresses. In this regard, the approach to prevent and reduce the CKD progression involves pharmacological and nutritional treatments (like Mediterranean Diet, MedRen diet, Flexitarian Diet, Vegetarian Diet and Plant-dominant Low Protein Diet) in order to improve the patients' quality of life and, at the same time, promote the environmental sustainability. Recent studies have highlighted the benefits of these diets not only for individuals, but also for environment. In particular, plant-based diets have increasingly gained an important role in the prevention and management of chronic diseases, including CKD. In fact, recent scientific studies have highlighted how a greater adherence to predominantly plant-based diets, is associated with a lower risk in developing CKD and also in slowing its progression. With regard to environmental sustainability, it is known how our food choices influence the climate crisis, since the food sector contributes for the 25% to the greenhouse gas emissions. Therefore, to reduce the consumption of animal proteins and to replace them with plant-based proteins are key strategies for sustainability and health, also supported by the European policies. In this context, food industries are starting to increase the offer of plant-based products that have similar characteristics, both sensorial and nutritional, to those of animal origin. This innovation, in fact, presents difficulties due to the perception of taste and the organoleptic appearance of these products. An additional challenge concerns the resistance of the traditional food industry and the lack of awareness of the consumer. The paradigm shift is dictated by the obtained benefits for health and for environment. Life cycle assessment studies have compared the land footprint, carbon footprint and blue water footprint of plant-based products with those of animal origin and pointed out the lower environmental impact of the former. In conclusion, the adoption of sustainable food models will slow down the spread of CDNCDs, such as CKD, positively impacting both on human health and on planet, significantly reducing the costs and resources of the National Health Systems, since they absorb up to 70%-80% of the healthcare costs.

Dietary Needs, Barriers, and Facilitators Among Patients on Hemodialysis and Their Caregivers: The GoodRENal Project in Spain

OBJECTIVE

Dietary restrictions are common in patients undergoing hemodialysis (HD). These restrictions result in a complex diet that becomes difficult for patients to understand and to follow. Therefore, we aimed to identify dietary needs, barriers, and facilitators that influence the adherence to dietary recommendations as perceived by patients on HD and their caregivers.

METHODS

Seventy-two Spanish patients on HD and 57 caregivers participated in this explorative study by replying a questionnaire consisting of 20 and 10 questions respectively. The responses were assessed using a Likert scale varying from 1 to 5 (strongly agree, agree, neither disagree or disagree, disagree, strongly disagree, respectively) to evaluate the perception of patients and caregivers regarding dietary needs, barriers, and facilitators to adhere to the recommended diet. For analysis purposes, the responses were grouped in 3 categories (agree, neither agree or disagree, disagree).

RESULTS

Seventy percent of the patients agreed that knowing the food sources of potassium, protein and phosphate was a need for them to know to be able to adhere to the dietary recommendations. Moreover, patients stated that not being able to eat what they liked, and feeling thirsty, were important barriers. For caregivers, the support of a renal dietitian was mentioned as an important facilitator to assist those they cared for to adhere to the diet.

CONCLUSIONS

Knowing food sources of potassium, phosphate, and protein, exploring foods patients like to eat and adjusting fluid intake to avoid feeling thirsty were identified as important by the patients. These findings can be used to develop strategies and educational material to improve the dietary adherence in patients undergoing HD. Moreover, the presence of a renal dietitian was identified as an important resource by the caregivers.

The Effects of a Food Supplement, Based on Co-Micronized Palmitoylethanolamide (PEA)-Rutin and Hydroxytyrosol, in Metabolic Syndrome Patients: Preliminary Results

BACKGROUND

Metabolic syndrome (MetS) patients have impaired hypothalamic regulatory functions involved in food intake and energy expenditure and suffer from a state of meta-inflammation. Pre-clinical studies demonstrated that ultramicronized palmitoylethanolamide (PEA) acts both on the adipose tissue and the central nervous system, while hydroxytyrosol (HTyr) counteracts several types of dysmetabolism.

OBJECTIVES

The aim of our randomized crossover double-blind placebo-controlled pilot study was to evaluate the potential effects of a food supplement (FS) containing a co-micronized formulation of PEA and rutin along with HTyr, combined with a tailored calorie-controlled Mediterranean diet, in patients with MetS.

METHODS

Nineteen patients were enrolled and block-randomized to an eight-week MD together with the FS or placebo. After a two-week washout period, the treatments were reversed. Data on laboratory parameters and those detected by capillary sampling, anthropometry, body composition analysis, ultrasound examination, blood pressure monitoring, the 36-Item Short-Form Health Survey questionnaire, handgrip strength test, and physical performance tests were collected at each time point (protocol code R.S. 262.22, registered on 20 December 2022).

RESULTS

At the end of the study, patients supplemented with the FS showed a significant reduction in body weight, body mass index, fat mass, and inflammation biomarkers (CRP and ESR), compared to placebo-supplemented patients. In contrast, the fat-free mass, phase angle, and body cell mass were increased in FS compared to placebo patients.

CONCLUSIONS

Although preliminary, the results of our clinical study suggest that co-micronized PEA-rutin and HTyr may be of help against adiposopathy in patients with MetS.

Association of plant and animal protein intake with sleep quality and quality of life in hemodialysis patients: a multicenter cross-sectional study

Background

The current study aimed to evaluate the association between the intake of plant-based protein, animal-based protein, total protein, and the ratio of plant to animal protein with sleep quality and quality of life in patients undergoing hemodialysis.

Methods

In this cross-sectional study, 479 adult patients undergoing dialysis for a minimum of 3 months were included. The dietary intake was calculated using information from a validated 168-item semi-quantitative food frequency questionnaire. Quality of life (QOL) was assessed using the Kidney Disease Quality of Life Short Form (KDQOL-SF 1.3). and the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality.

Results

In this study, the mean age of the participants was 58.18 years (± 14.25 years), with the majority being male (58.2%). After adjusting for potential confounders, significant positive associations were observed between total protein intake (β = 0.12, p = 0.03) and quality of life (QOL). Conversely, there were significant negative associations between the ratio of plant to animal protein intake (β = -0.94, p < 0.01) and QOL. Furthermore, significant negative associations were found between total protein intake (β = -0.02, p < 0.05) and animal protein intake (β = -0.19, p < 0.05) with poor sleep quality. Additionally, there were significant positive associations between the ratio of plant to animal protein intake (β = 0.188, p < 0.05) and poor sleep quality.

Conclusion

Increased consumption of animal protein is associated with improved sleep quality and Quality of Life (QOL) in patients undergoing hemodialysis (HD). Further research, especially prospective studies, is required to confirm these associations.

Effects of Diet and Supplements on Parameters of Oxidative Stress, Inflammation, and Antioxidant Mechanisms in Patients with Chronic Renal Failure Undergoing Hemodialysis

The prevalence of chronic kidney disease (CKD) worldwide increases as the population ages. The progression of the disease increases the risk of complications and death and leads to end-stage renal failure, requiring renal replacement therapy. Despite the positive effect of hemodialysis (HD), patients are at risk of developing malnutrition, inflammation, oxidative stress, or cardiovascular disease, which worsens quality of life and can lead to organ dysfunction. The occurrence of the mentioned disorders depends largely on the diet, so changes in diet composition are an important part of the treatment of kidney disease. This study aimed to evaluate the effects of a balanced diet on some parameters of oxidative stress, immune response, and nutritional status in patients. This study included 57 HD patients (19 women and 38 men). In all of them, nutritional status and diet were initially determined, and then, they were divided into six groups, which received different diets and supplements. Serum levels of albumin, total protein, MDA, and the cytokines Il-1, IL-6, IL-8, TNF-α, and IL-10 were determined, and the activity of the enzymes such as CAT, SOD, and GSH-Px were determined in erythrocytes by spectrophotometry. Based on the results of BMI, albumin, and total protein, it can be concluded that a well-balanced diet can reduce weight loss. This study shows that a well-balanced diet can reduce the secretion of pro-inflammatory cytokines, and ensure the normal activity of antioxidative enzymes in the blood of HD patients.

Effects of additional physical exercise on the nutritional status and disease progression during the low-protein diet in Chronic Kidney Disease Patients: a systematic review and meta-analysis

Low-protein diet (LPD) is the core of dietary and nutritional therapy for non-dialysis chronic kidney disease (CKD) patients. In addition, physical exercise could prevent and treat various illnesses and chronic diseases. The objective of the study was to search for and appraise evidence on the effect of additional physical exercise on patients' nutritional status and indicators of disease progression when compared with the LPD alone. PubMed Central, Embase, Cochrane, and Web of Knowledge for randomized controlled trials (published between January 1, 1956 and May 17, 2023) were searched. A total of 8698 identified studies, 9 were eligible and were included in our analysis (N = 250 participants). Compared with the LPD alone, additional physical exercise reduced serum creatinine by a mean of -0.21 mg/dL (95% CI -0.39 to -0.03) in CKD patients. Similarly, blood pressure decreased after physical exercise, with systolic blood pressure decreasing by -7.05 mm Hg (95% CI -13.13 to -0.96) and diastolic blood pressure decreasing by -5.31 mm Hg (95% CI -7.99 to -2.62). Subgroup analyses revealed that resistance exercise (RE) was effective in decreasing estimated glomerular filtration rate (eGFR) of -1.71 mL/min per 1.73 m² (95% CI -3.29 to -0.14). In addition, the VO2peak increasing by 2.41 mL/kg/min (95% CI 0.13 to 4.70) when physical exercise was continued for 24 weeks. The above results suggest that the LPD with additional physical exercise care is more beneficial for patients with CKD.

Exercise, Dialysis, and Environment: A Narrative Review in an Ecological Perspective

BACKGROUND

Patient empowerment and environmental sustainability may contribute to creating efficient and resilient healthcare models. Chronic kidney diseases call for a sustainable approach aimed at improving physical function and mental health of patients and possibly contributing to the slowing down of the evolution toward the end stage of renal disease (ESRD) with a reduction of the environmental and economic impact.

SUMMARY

Multidisciplinary interventions should be implemented particularly, at the final stages when patients are exposed to sedentariness, reduced health-related quality of life (HR-QoL), high cardiovascular morbidity and mortality, and the healthcare services to high costs, and participation in environmental pollution. Ecological strategies based on specific nutritional approaches, exercise, and environment should be designed and tested. In particular, the introduction to physical exercise represents a useful replacement therapy to counteract the hazards derived from the sedentary behavior of ESRD patients, with low physical function associated with poor clinical outcomes. A more active and healthy lifestyle, particularly in the natural environment, could impact HR-QoL, mental and physical well-being but also on socialization, with lower anxiety and fatigue stress levels. Otherwise, combining sustainable exercise models into the patient's daily routine can be enhanced by the biophilic design called to reproduce a natural environment in the dialysis center. Finally, the involvement of the personnel and the health professionals in properly managing the exercise interventions and the related factors (location, modality, dose, intensity, and duration) might improve the patients' participation. In particular, ecological programs should be broadly inclusive and aimed to target the lowest performing populations through minimal feasible doses of exercise.

KEY MESSAGES

Moving toward an ecological framework of lifestyle change in the very advanced stages of kidney disease, the potential synergies between environment, diet, and exercise may improve the physical and mental health of the patients and reduce the impact of dialysis.

A study of the low-protein diet in delaying the course of chronic kidney disease

A low-protein diet (LPD) has become an important way to delay the progression of chronic kidney disease (CKD) and to delay the need for dialysis. A review of the literature reveals the low-protein diet's influence on the course of chronic kidney disease. An artificial low-protein food, wheat starch, for example, can not only increase the high-quality protein intake ratio, but can ensure adequate energy intake on a low-protein diet while meeting the nutritional needs of the body, effectively reducing the burden on the damaged kidneys. The purpose of this review is to provide a reference for the clinical implementation of diet and nutrition therapy in patients with chronic kidney disease.

Soilless cultivation systems to produce tailored microgreens for specific nutritional needs

BACKGROUND

The awareness of the importance of following dietary recommendations that meet specific biological requirements related to an individual's health status has significantly increased interest in personalized nutrition. The aim of this research was to test agronomic protocols based on soilless cultivation for providing consumers with new dietary sources of iodine (I), as well as alternative vegetable products to limit dietary potassium (K) intake; proposed cultivation techniques were evaluated according to their suitability to obtain such products without compromising agronomic performance.

RESULTS

Two independent experiments, focused on I and K respectively, were conducted in a commercial greenhouse specializing in soilless production. Four different species were cultivated using three distinct concentrations of I (0, 1.5 and 3 mg L-1 ) and K (0, 60 and 120 mg L-1 ). Microgreens grown in I-rich nutrient solution accumulate more I, and the increase is dose-dependent. Compared to unbiofortified microgreens, the treatments with 1.5 and 3 mg L-1 of I resulted in 4.5 and 14 times higher I levels, respectively. Swiss chard has the highest levels of K (14 096 mg kg-1 of FW), followed by rocket, pea and radish. In radish, rocket and Swiss chard, a total reduction of K content in the nutrient solution (0 mg L-1 ) resulted in an average reduction of 45% in K content.

CONCLUSION

It is possible to produce I-biofortified microgreens to address I deficiency, and K-reduced microgreens for chronic kidney disease-affected people. Species selection is crucial to customize nutritional profiles according to specific dietary requirements due to substantial mineral content variations across different species. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of Dietary Intervention on Nutritional Status in Elderly Individuals with Chronic Kidney Disease

The prevalence of chronic kidney disease (CKD) is rising, especially in elderly individuals. The overlap between CKD and aging is associated with body composition modification, metabolic abnormalities, and malnutrition. Renal care guidelines suggest treating CKD patient with a low-protein diet according to the renal disease stage. On the other hand, geriatric care guidelines underline the need for a higher protein intake to prevent malnutrition. The challenge remains of how to reconcile a low dietary protein intake with insuring a favorable nutritional status in geriatric CKD populations. Therefore, this study aims to evaluate the effect of a low-protein adequate energy intake (LPAE) diet on nutritional risk and nutritional status among elderly CKD (stage 3-5) patients and then to assess its impact on CKD metabolic abnormalities. To this purpose, 42 subjects [age ≥ 65, CKD stage 3-5 in conservative therapy, and Geriatric Nutritional Risk Index (GNRI) ≥ 98] were recruited and the LPAE diet was prescribed. At baseline and after 6 months of the LPAE diet, the following data were collected: age, sex, biochemical parameters, anthropometric measurements, body composition, and the GNRI. According to their dietary compliance, the subjects were divided into groups: compliant and non-compliant. For the compliant group, the results obtained show no increased malnutrition risk incidence but, rather, an improvement in body composition and metabolic parameters, suggesting that the LPAE diet can provide a safe tool in geriatric CKD patients.

Association between the prognostic nutritional index (PNI) and all-cause mortality in patients with chronic kidney disease

BACKGROUND

Nutrition and immunity play an important role in many chronic diseases. The prognostic nutritional index (PNI) has been proposed as a comprehensive indicator of an individual's immune and nutritional status. However, there is a lack of evidence regarding the association between the PNI and mortality in patients with chronic kidney disease (CKD).

METHODS

We used National Health and Nutrition Examination Survey (NHANES) data from 2001-2014 for participants with CKD. Mortality data were obtained from the National Death Index and matched to NHANES participants. Cox proportional hazards models were used to estimate hazard ratios for all-cause mortality.Results: The patients were 72.5 ± 9.8 years old, and 47.57% were male. The median follow-up was 58 months, and the mortality rate in patients with CKD was 30.27%. A higher PNI protected against all-cause mortality in patients with CKD, with an adjusted hazard ratio (aHR) of 0.98 (95% confidence interval (CI): 0.97-0.99). After grouping according to PNI quartiles, statistically significant between-group differences were observed in survival probabilities. The aHR for the lowest PNI quartile compared to the highest PNI quartile was 1.64 (95% CI: 1.26-2.14). Sensitivity analysis further supported this association. Restricted cubic spline analysis revealed an L-shaped association between the PNI and all-cause mortality in patients with CKD, with a critical value of 50.5.

CONCLUSIONS

The PNI is a protective factor in patients with CKD, with an L-shaped decrease in all-cause mortality with an increasing PNI.

Prevalence, associated factors and clinical implications of medication literacy linked to frailty in hemodialysis patients in China: a cross-sectional study

BACKGROUND

Maintenance hemodialysis (MHD) patients have complex medication regimens that require a high level of skill to interpret medication information. However, there is currently a lack of research evaluating the ability to read and understand medication labels in Chinese MHD patients. In addition, the relationship between frailty and medication literacy among MHD patients remains unclear. Therefore, this study aims to assess the potential factors affecting medication literacy in MHD patients and to explore the relationship between frailty and medication literacy.

METHODS

This cross-sectional study was conducted using convenience sampling in West China Hospital of Sichuan University, China. Using a general questionnaire, we collected demographic, clinical and laboratory data. Medication literacy was assessed by the Chinese Medication Literacy Scale, and frailty was assessed by the FRAIL Scale. Univariate analyses examined potential factors associated with medication literacy. An ordered logistic regression was used to analyze the relationships between medication literacy and these factors. Spearman's correlation was used to assess the association between medication literacy and frailty.

RESULTS

A total of 290 MHD patients were included in the analysis. Inadequate, marginal, and adequate medication literacy was found in 56 (19.3%), 153 (52.8%), and 81 (27.9%) patients, respectively. Ordered logistic regression revealed factors associated with inadequate medication literacy: age (OR = 0.281, 95% CI = 0.139-0.565, p < 0.001 for < 65 years); education (OR = 8.612, 95% CI = 3.524-21.046, p < 0.001 for ≤ primary school education; OR = 3.405, 95% CI = 1.683-6.887, p = 0.001 for junior high school education); presence of caregiver medication assistance (OR = 2.302, 95% CI = 1.173-4.516, p = 0.015); frailty (OR = 0.440, 95% CI = 0.216-0.893, p = 0.023 for frail patients); and high β2-microglobulin (β2-MG) (OR = 1.010, 95% CI = 1.002-1.019, p = 0.012). Spearman's analysis showed that medication literacy was negatively correlated with frailty in MHD patients (R=-0.189, p = 0.001).

CONCLUSIONS

Medication literacy levels in MHD patients needed improvement and were associated with certain patient characteristics, including age, education level, presence of caregiver support, β2-microglobulin levels, and risk of frailty. This study identified subgroups of MHD patients, such as those who were older, had lower education, had caregiver assistance, had high β2-microglobulin levels, or were frail, to have inadequate medication literacy. These findings underscore the need for routine screening and targeted interventions to improve medication literacy in this population.

AI-Powered Renal Diet Support: Performance of ChatGPT, Bard AI, and Bing Chat

Patients with chronic kidney disease (CKD) necessitate specialized renal diets to prevent complications such as hyperkalemia and hyperphosphatemia. A comprehensive assessment of food components is pivotal, yet burdensome for healthcare providers. With evolving artificial intelligence (AI) technology, models such as ChatGPT, Bard AI, and Bing Chat can be instrumental in educating patients and assisting professionals. To gauge the efficacy of different AI models in discerning potassium and phosphorus content in foods, four AI models-ChatGPT 3.5, ChatGPT 4, Bard AI, and Bing Chat-were evaluated. A total of 240 food items, curated from the Mayo Clinic Renal Diet Handbook for CKD patients, were input into each model. These items were characterized by their potassium (149 items) and phosphorus (91 items) content. Each model was tasked to categorize the items into high or low potassium and high phosphorus content. The results were juxtaposed with the Mayo Clinic Renal Diet Handbook's recommendations. The concordance between repeated sessions was also evaluated to assess model consistency. Among the models tested, ChatGPT 4 displayed superior performance in identifying potassium content, correctly classifying 81% of the foods. It accurately discerned 60% of low potassium and 99% of high potassium foods. In comparison, ChatGPT 3.5 exhibited a 66% accuracy rate. Bard AI and Bing Chat models had an accuracy rate of 79% and 81%, respectively. Regarding phosphorus content, Bard AI stood out with a flawless 100% accuracy rate. ChatGPT 3.5 and Bing Chat recognized 85% and 89% of the high phosphorus foods correctly, while ChatGPT 4 registered a 77% accuracy rate. Emerging AI models manifest a diverse range of accuracy in discerning potassium and phosphorus content in foods suitable for CKD patients. ChatGPT 4, in particular, showed a marked improvement over its predecessor, especially in detecting potassium content. The Bard AI model exhibited exceptional precision for phosphorus identification. This study underscores the potential of AI models as efficient tools in renal dietary planning, though refinements are warranted for optimal utility.

The Role of Plant-Based Diets in Preventing and Mitigating Chronic Kidney Disease: More Light than Shadows

Chronic kidney disease (CKD) is a non-communicable disease that affects >10% of the general population worldwide; the number of patients affected by CKD is increasing due in part to the rise in risk factors such as obesity, hypertension, and diabetes mellitus. As many studies show, diet can be an important tool for preventing and mitigating the onset of non-communicable diseases. Plant-based diets (PBDs) are those that emphasize the consumption of plant foods and may or may not include small or moderate amounts of animal foods. Recently, these diets have received increasing interest because they have been associated with favourable effects on health and also appear to protect against the development and progression of CKD. PBDs, which are associated with protein restrictions, seem to offer adjunctive advantages in patients with chronic kidney disease, as compared to conventional low-protein diets that include animal proteins. The principal aims of this review are to provide a comprehensive overview of the existing literature regarding the role of plant-based diets and low-protein, plant-based diets in the context of chronic kidney disease. Moreover, we try to clarify the definition of plant-based diets, and then we analyse possible concerns about the use of PBDs in patients with chronic kidney disease (nutritional deficiency and hyperkalaemia risk). Finally, we offer some strategies to increase the nutritional value of plant-based low-protein diets. In the Materials and Methods section, many studies about plant-based diets and low-protein plant-based diets (e.g., the very-low-protein diet and vegan low-protein diet, LPD) in chronic kidney disease were considered. In the Results and Conclusion section, current data, most from observational studies, agree upon the protective effect of plant-based diets on kidney function. Moreover, in patients with advanced CKD, low-protein plant-based options, especially a very-low-protein diet supplemented with heteroanalogues (VLPDs), compared to a conventional LPD appear to offer adjunctive advances in terms of delaying dialysis and mitigating metabolic disturbances. However, further studies are necessary to better investigate the possible metabolic and cardiovascular advantages of plant-based LPDs versus conventional LPDs.

The association between plant and animal protein intake and quality of life in patients undergoing hemodialysis

Background

Hemodialysis (HD) patients often experience a significant reduction in quality of life (QOL). The source of dietary protein intake may influence the renal function and complications of HD patients. The present study assessed the relationship between plant and animal protein intake and QOL in HD patients.

Methods

264 adult patients under dialysis for at least three months were included in this cross-sectional study. Dietary intakes were collected using a valid and reliable 168-item semi-quantitative food frequency questionnaire (FFQ) over the past year. Total, animal, and plant proteins were calculated for each patient. To evaluate QOL, Kidney Disease Quality of Life Short Form (KDQOL-SF 1/3) was used. Anthropometric measures were assessed according to standard protocols.

Results

In this study, the average age of participants was 58.62 ± 15.26 years old; most (73.5%) were men. The mean of total, plant, and animal proteins intake were 66.40 ± 34.29 g/d, 34.60 ± 18.24 g/d, and 31.80 ± 22.21 g/d. Furthermore, the mean score of QOL was 59.29 ± 18.68. After adjustment for potential confounders, a significant positive association was found between total dietary protein intake and QOL (β = 0.12; p = 0.03). Moreover, there was a significant association between plant-based protein intake and QOL (β = 0.26; p < 0.001). However, the association between animal protein intake and QOL was insignificant (β = 0.03; p = 0.60).

Conclusion

Higher total and plant proteins intake were associated with better QOL in HD patients. Further studies, particularly prospective ones, are needed to corroborate these associations.

Supplemented Very Low Protein Diet (sVLPD) in Patients with Advanced Chronic Renal Failure: Clinical and Economic Benefits

The supplemented very low-protein diet (sVLPD) has proven effective in slowing the progression of stage 5 chronic renal failure and postponing the start of the dialysis treatment. However, sVLPD could expose the patient to the risk of malnutrition. This diet is also difficult to implement due to the required intake of large number of keto-analogue/amino acid tablets. In our Center, the Department of Nephrology and Dialysis of Azienda Sanitaria Territoriale n 1, Pesaro-Urbino, of Italy, respecting the guidelines of normal clinical practice, we prescribed sVLPD (0.3 g/prot/day) supplemented with only essential amino acids without the use of ketoanalogues in stage 5 patients and verified its efficacy, safety and clinical and economic effects. Over the 24 months period of observation the progression of chronic kidney disease (CKD) slowed down (mean eGFR 11.6 ± 3.3 vs. 9.3 ± 2.7 mL/min/1.73 m2, p < 0.001) and the start of the dialysis treatment (adjusted HR = 0.361, CI 0.200-0.650, p = 0.001) was delayed without evidence of malnutrition, in compliant vs. non-compliant patients. This led to a substantial cost reduction for the National Health System. This non-interventional longitudinal observational study is part of standard clinical practice and suggests that VLPD supplemented with essential amino acids could be extensively used to reduce the incidence of dialysis treatments, with a favorable economic impact on the NHS.

Hyperkalemia in CKD: an overview of available therapeutic strategies

Hyperkalemia (HK) is a life-threatening condition that often occurs in patients with chronic kidney disease (CKD). High serum potassium (sKsK) is responsible for a higher risk of end-stage renal disease, arrhythmias and mortality. This risk increases in patients that discontinue cardio-nephroprotective renin-angiotensin-aldosterone system inhibitor (RAASi) therapy after developing HK. Hence, the management of HK deserves the attention of the clinician in order to optimize the therapeutic strategies of chronic treatment of HK in the CKD patient. The adoption in clinical practice of the new hypokalaemic agents patiromer and sodium zirconium cyclosilicate (SZC) for the prevention and chronic treatment of HK could allow patients, suffering from heart failure and chronic renal failure, to continue to benefit from RAASi therapy. We have updated a narrative review of the clear variables, correct definition, epidemiology, pathogenesis, etiology and classifications for HK among non-dialysis CKD (ND CKD) patients. Furthermore, by describing the prognostic impact on mortality and on the progression of renal damage, we want to outline the strategies currently available for the control of potassium (K+) plasma levels.

Nutritional Strategies to Prevent Muscle Loss and Sarcopenia in Chronic Kidney Disease: What Do We Currently Know?

Loss of muscle mass is an extremely frequent complication in patients with chronic kidney disease (CKD). The etiology of muscle loss in CKD is multifactorial and may depend on kidney disease itself, dialysis, the typical chronic low-grade inflammation present in patients with chronic kidney disease, but also metabolic acidosis, insulin resistance, vitamin D deficiency, hormonal imbalances, amino acid loss during dialysis, and reduced dietary intake. All these conditions together increase protein degradation, decrease protein synthesis, and lead to negative protein balance. Aging further exacerbates sarcopenia in CKD patients. Nutritional therapy, such as protein restriction, aims to manage uremic toxins and slow down the progression of CKD. Low-protein diets (LPDs) and very low-protein diets (VLPDs) supplemented with amino acids or ketoacids are commonly prescribed. Energy intake is crucial, with a higher intake associated with maintaining a neutral or positive nitrogen balance. Adequate nutritional and dietary support are fundamental in preventing nutritional inadequacies and, consequently, muscle wasting, which can occur in CKD patients. This review explores the causes of muscle loss in CKD and how it can be influenced by nutritional strategies aimed at improving muscle mass and muscle strength.

Astragaloside IV Blunts Epithelial-Mesenchymal Transition and G2/M Arrest to Alleviate Renal Fibrosis via Regulating ALDH2-Mediated Autophagy

Previous studies show that astragaloside IV (ASIV) has anti-renal fibrosis effects. However, its mechanism remains elusive. In this study, we investigated the anti-fibrosis mechanisms of ASIV on chronic kidney disease (CKD) in vivo and in vitro. A CKD model was induced in rats with adenine (200 mg/kg/d, i.g.), and an in vitro renal fibrosis model was induced in human kidney-2 (HK-2) cells treated with TGF-β1. We revealed that ASIV significantly alleviated renal fibrosis by suppressing the expressions of epithelial-mesenchymal transition (EMT)-related proteins, including fibronectin, vimentin, and alpha-smooth muscle actin (α-SMA), and G2/M arrest-related proteins, including phosphorylated p53 (p-p53), p21, phosphorylated histone H3 (p-H3), and Ki67 in both of the in vivo and in vitro models. Transcriptomic analysis and subsequent validation showed that ASIV rescued ALDH2 expression and inhibited AKT/mTOR-mediated autophagy. Furthermore, in ALDH2-knockdown HK-2 cells, ASIV failed to inhibit AKT/mTOR-mediated autophagy and could not blunt EMT and G2/M arrest. In addition, we further demonstrated that rapamycin, an autophagy inducer, reversed the treatment of ASIV by promoting autophagy in TGF-β1-treated HK-2 cells. A dual-luciferase report assay indicated that ASIV enhanced the transcriptional activity of the ALDH2 promoter. In addition, a further molecular docking analysis showed the potential interaction of ALDH2 and ASIV. Collectively, our data indicate that ALDH2-mediated autophagy may be a novel target in treating renal fibrosis in CKD models, and ASIV may be an effective targeted drug for ALDH2, which illuminate a new insight into the treatment of renal fibrosis and provide new evidence of pharmacology to elucidate the anti-fibrosis mechanism of ASIV in treating renal fibrosis.

Advanced glycosylation end products as metabolic predictors of systemic pro-inflammatory and prooxidant status in patients with end-stage renal disease

Controlling systemic proinflammatory and prooxidant effectors is essential for mitigating cardiovascular risk and mortality in patients with end-stage renal disease (ESRD). However, monitoring these processes is still challenging due to the high uncertainty about their determinants and predictors. Thus, we investigated the relationship between advanced glycosylation end products (AGE), proinflammatory and prooxidant effectors in ESRD patients undergoing hemodialysis (HD). In addition to nutritional profile and dialysis efficiency, AGE, cytokines, chemokines, C-reactive protein (CRP), total (TAC) and non-protein (npAC) antioxidant capacity, lipid and protein oxidation were analyzed in blood samples from 43 HD patients. AGE, CRP, cytokines, chemokines, protein carbonyl (PCn), and malondialdehyde (MDA) were upregulated, while TAC and npAC were down-regulated in HD patients compared to heath subjects. Dialysis efficiency, TAC and npAC were reduced, while leucocytes counting, pre- and post-HD urea, TNF, IL-6, IL-10, CCL-2, MIP-1β, PCn, and MDA were increased in patients with higher AGE accumulation compared to those with lower AGE levels. Serum levels of CRP, protein carbonyl, malondialdehyde, and all cytokines and chemokines analyzed were correlated with AGE circulating levels for patients with higher AGE accumulation. AGE was inversely correlated with IL-10, TAC and npAC in patients with higher AGE accumulation. AGE exhibited predictive value (determination coefficient) to explain CRP, cytokines, chemokines, PCN, MDA, TAC and npAC variability in patients with higher AGE levels. Taken together, our findings provide evidence that AGE accumulation is associated with important proinflammatory and prooxidant effectors in patients with ESRD undergoing hemodialysis. Thus, AGE monitoring may be relevant to predict systemic inflammatory stress and the balance between oxidant and antioxidant status in these patients.

Mediterranean Dietary Pattern Adjusted for CKD Patients: The MedRen Diet

A number of studies in the general population showed that healthy dietary patterns, such as the Mediterranean Diet, can improve or prevent the development of several chronic diseases and are associated with a significant reduction in all-cause and cardiovascular mortality. The Mediterranean diet may also have favorable effects for the prevention of chronic kidney disease (CKD), but no evidence of renoprotection exists in CKD patients. The Mediterranean Renal (MedRen) diet is an adaptation of the Mediterranean diet recommendations comprising a quantitative reduction in the RDA values of protein, salt and phosphate intake for the general population. Hence, MedRen supplies 0.8 g/Kg of protein, 6 g of salt and less than 800 mg of phosphate daily. Obviously, there is a preference for products of plant origin, which contain more alkali, fibers, unsaturated fatty acids than animal-based food. The MedRen diet can be implemented easily in mild-to-moderate stages of CKD with good results, both in terms of adherence to prescriptions and metabolic compensation. In our opinion, it should be the first step of CKD stage 3 nutritional management. This paper describes the features and reports our experience in the implementation of the MedRen diet as an early nutritional approach to CKD.

Plant or Animal-Based or PLADO Diets: Which Should Chronic Kidney Disease Patients Choose?

Nutrition therapy is the cornerstone treatment for chronic kidney disease (CKD). Although much attention has been given to dietary protein intake in CKD patients, many findings now demonstrate that the type of dietary protein intake may be more critical for CKD patients. In protein bioavailability and malnutrition prevention, many physicians recommend that CKD patients adhere to a low protein diet and restrict their plant foods, such as vegetables, fruits, and soybeans. However, nephrologists should not ignore the potential benefits of plant foods for CKD patients. It is not advisable to restrict the intake of plant foods in the later stage of CKD simply to prevent the development of hyperkalemia and malnutrition. This article highlights the benefits and possible problems of a plant-dominant low protein diet (PLADO) diet, defined as an LPD with dietary protein intake of 0.6-0.8 g/kg/day with at least 50% plant-based source for CKD patients. We hope to provide new opinions for clinical work and CKD patients.

Diagnosis, Prevalence and Significance of Obesity in a Cohort of CKD Patients

BACKGROUND

data regarding the association between obesity and morbidity/mortality in patients with chronic kidney disease (CKD) are uncertain and sometimes contradictory. The aims of our study were to determine the associations among different measures of obesity and adiposity, and the risk of all-cause mortality or dialysis entry in stage 3-5 CKD patients.

MATERIALS

this observational cohort study included 178 CKD patients followed for a median of 71 months. Biochemistry, anthropometric measures such as body mass index (BMI), waist-to-hip ratio, mid-arm muscle circumference (MAMC) and body composition by bioimpedance analysis were evaluated.

RESULTS

we found a weak agreement between BMI and other measures of adiposity. In multivariable regression analysis, all measures of obesity such as BMI, waist circumference and waist-to-height ratio were not associated with dialysis entry and/or mortality. Instead, MAMC was associated with dialysis entry HR 0.82 [95% CI: 0.75-0.89] and high FM% with mortality HR 2.08 [95% CI: 1.04-4.18].

CONCLUSIONS

in our CKD population, lower MAMC was predictive of dialysis commencing, while a higher percentage of fatty mass was a predictor of mortality. Instead, obesity, as defined by BMI, is not associated with dialysis commencing or all-cause mortality.

Comorbidity and nutritional status in adult with advanced chronic kidney disease influence the decision-making choice of renal replacement therapy modality: A retrospective 5-year study

Background

Nutritional and inflammation status are significant predictors of morbidity and mortality risk in advanced chronic kidney disease (ACKD). To date, there are a limited number of clinical studies on the influence of nutritional status in ACKD stages 4-5 on the choice of renal replacement therapy (RRT) modality.

Aim

This study aimed to examine relationships between comorbidity and nutritional and inflammatory status and the decision-making on the choice of RRT modalities in adults with ACKD.

Methods

A retrospective cross-sectional study was conducted on 211 patients with ACKD with stages 4-5 from 2016 to 2021. Comorbidity was assessed using the Charlson comorbidity index (CCI) according to severity (CCI: ≤ 3 and >3 points). Clinical and nutritional assessment was carried out by prognosis nutritional index (PNI), laboratory parameters [serum s-albumin, s-prealbumin, and C-reactive protein (s-CRP)], and anthropometric measurements. The initial decision-making of the different RRT modalities [(in-center, home-based hemodialysis (HD), and peritoneal dialysis (PD)] as well as the informed therapeutic options (conservative treatment of CKD or pre-dialysis living donor transplantation) were recorded. The sample was classified according to gender, time on follow-up in the ACKD unit (≤ 6 and >6 months), and the initial decision-making of RRT (in-center and home-RRT). Univariate and multivariate regression analyses were carried out for evaluating the independent predictors of home-based RRT.

Results

Of the 211 patients with ACKD, 47.4% (n = 100) were in stage 5 CKD, mainly elderly men (65.4%). DM was the main etiology of CKD (22.7%) together with hypertension (96.6%) as a CV risk factor. Higher CCI scores were significantly found in men, and severe comorbidity with a CCI score > 3 points was 99.1%. The mean time of follow-up time in the ACKD unit was 9.6 ± 12.8 months. A significantly higher CCI was found in those patients with a follow-up time > 6 months, as well as higher mean values of eGFR, s-albumin, s-prealbumin, s-transferrin, and hemoglobin, and lower s-CRP than those with a follow-up <6 months (all, at least p < 0.05). The mean PNI score was 38.9 ± 5.5 points, and a PNI score ≤ 39 points was found in 36.5%. S-albumin level > 3.8 g/dl was found in 71.1% (n = 150), and values of s-CRP ≤ 1 mg/dl were 82.9% (n = 175). PEW prevalence was 15.2%. The initial choice of RRT modality was higher in in-center HD (n = 119 patients; 56.4%) than in home-based RRT (n = 81; 40.5%). Patients who chose home-based RRT had significantly lower CCI scores and higher mean values of s-albumin, s-prealbumin, s-transferrin, hemoglobin, and eGFR and lower s-CRP than those who chose in-center RRT (p < 0.001). Logistic regression demonstrated that s-albumin (OR: 0.147) and a follow-up time in the ACKD unit >6 months (OR: 0.440) were significantly associated with the likelihood of decision-making to choose a home-based RRT modality (all, at least p < 0.05).

Conclusion

Regular monitoring and follow-up of sociodemographic factors, comorbidity, and nutritional and inflammatory status in a multidisciplinary ACKD unit significantly influenced decision-making on the choice of RRT modality and outcome in patients with non-dialysis ACKD.

Diet Management of Patients with Chronic Kidney Disease in Bariatric Surgery

Morbid obesity is considered a civilization disease of the 21st century. Not only does obesity increase mortality, but it is also the most important cause of the shortening life expectancy in the modern world. Obesity is associated with many metabolic abnormalities: dyslipidemia, hyperglycemia, cardiovascular diseases, and others. An increasing number of patients diagnosed with chronic kidney disease (CKD) are obese. Numerous additional disorders associated with impaired kidney function make it difficult to conduct slimming therapy and may also be associated with a greater number of complications than in people with normal kidney function. Currently available treatments for obesity include lifestyle modification, pharmacotherapy, and bariatric surgery (BS). There are no precise recommendations on how to reduce excess body weight in patients with CKD treated conservatively, undergoing chronic dialysis, or after kidney transplantation. The aim of this study was to analyze studies on the bariatric treatment of obesity in this group of people, as well as to compare the recommendations typical for bariatrics and CKD.

Rehabilitation Nutrition in Patients with Chronic Kidney Disease and Cachexia

Rehabilitation nutrition is a proposed intervention strategy to improve nutritional status and physical function. However, rehabilitation nutrition in patients with cachexia and protein-energy wasting (PEW), which are the main nutrition-related problems in patients with chronic kidney disease (CKD), has not been fully clarified. Therefore, this review aimed to summarize the current evidence and interventions related to rehabilitation nutrition for cachexia and PEW in patients with CKD. CKD is a serious condition worldwide, with a significant impact on patient prognosis. In addition, CKD is easily complicated by nutrition-related problems such as cachexia and PEW owing to disease background- and treatment-related factors, which can further worsen the prognosis. Although nutritional management and exercise therapy are reportedly effective for cachexia and PEW, the effectiveness of combined nutrition and exercise interventions is less clear. In the future, rehabilitation nutrition addressing the nutritional problems associated with CKD will become more widespread as more scientific evidence accumulates. In clinical practice, early intervention in patients with CKD involving both nutrition and exercise after appropriate assessment may be necessary to improve patient outcomes.

Obesity-Related Chronic Kidney Disease: Principal Mechanisms and New Approaches in Nutritional Management

Obesity is the epidemic of our era and its incidence is supposed to increase by more than 30% by 2030. It is commonly defined as a chronic and metabolic disease with an excessive accumulation of body fat in relation to fat-free mass, both in terms of quantity and distribution at specific points on the body. The effects of obesity have an important impact on different clinical areas, particularly endocrinology, cardiology, and nephrology. Indeed, increased rates of obesity have been associated with increased risk of cardiovascular disease (CVD), cancer, type 2 diabetes (T2D), dyslipidemia, hypertension, renal diseases, and neurocognitive impairment. Obesity-related chronic kidney disease (CKD) has been ascribed to intrarenal fat accumulation along the proximal tubule, glomeruli, renal sinus, and around the kidney capsule, and to hemodynamic changes with hyperfiltration, albuminuria, and impaired glomerular filtration rate. In addition, hypertension, dyslipidemia, and diabetes, which arise as a consequence of overweight, contribute to amplifying renal dysfunction in both the native and transplanted kidney. Overall, several mechanisms are closely related to the onset and progression of CKD in the general population, including changes in renal hemodynamics, neurohumoral pathways, renal adiposity, local and systemic inflammation, dysbiosis of microbiota, insulin resistance, and fibrotic process. Unfortunately, there are no clinical practice guidelines for the management of patients with obesity-related CKD. Therefore, dietary management is based on the clinical practice guidelines for the nutritional care of adults with CKD, developed and published by the National Kidney Foundation, Kidney Disease Outcome Quality Initiative and common recommendations for the healthy population. Optimal nutritional management of these patients should follow the guidelines of the Mediterranean diet, which is known to be associated with a lower incidence of CVD and beneficial effects on chronic diseases such as diabetes, obesity, and cognitive health. Mediterranean-style diets are often unsuccessful in promoting efficient weight loss, especially in patients with altered glucose metabolism. For this purpose, this review also discusses the use of non-classical weight loss approaches in CKD, including intermittent fasting and ketogenic diet to contrast the onset and progression of obesity-related CKD.

The Effect of Dietary Intervention on Autosomal-Dominant Polycystic Kidney Disease (ADPKD) Patients on Tolvaptan and Their Quality of Life

Background and objective

Autosomal-dominant polycystic kidney disease (ADPKD) is the most common inherited renal disorder; it affects people of all ethnic groups and is found in up to 10% of patients with end-stage renal disease (ESRD). Dietary intervention is important in people with renal disease, and it has been linked to greater estimated glomerular filtration rate (eGFR) preservation. Tolvaptan, an orally-active nonpeptide, selective arginine vasopressin (AVP) V2R antagonist, was recently licensed in numerous countries for the treatment of ADPKD. The aim of this study was to assess the role of dietary intervention in decreasing the osmotic load on the urine volume and its impact on the quality of life (QOL) of patients with ADPKD on tolvaptan.

Methods

This prospective cohort study was carried out at a Hamilton nephrology genetics clinic. ADPKD patients on well-tolerated doses of tolvaptan for three months were included in the study. Gitelman and Bartter Symptom Health-related QOL questionnaire was used among the study participants.

Results

Our study consisted of nine adult patients with ADPKD who were on a stable dose of tolvaptan therapy. Patients had laboratory values for urine volume, sodium (Na), and urea. No significant difference was found between pre- and post-diet intervention values in 24-hour urine volume (5.9 vs. 5.49 L/d; p=0.423), urine Na (p=0.174), and 24-hour urine urea (p=0.404).

Conclusion

Dietary intervention in ADPKD patients on tolvaptan therapy can play a vital role in improving their QOL. Further research including interventional studies and clinical trials with larger sample sizes is needed to gain deeper insight into the subject.

Does Mediterranean Adequacy Index Correlate with Cardiovascular Events in Patients with Advanced Chronic Kidney Disease? An Exploratory Study

The Mediterranean Diet (MD) is a healthy dietary pattern, demonstrated to reduce the risk of cancer, diabetes, cardiovascular and neurodegenerative diseases, and early death. The Mediterranean Adequacy Index (MAI) is used to measure adherence to the MD in perspective studies in the general population and correlates with cardiovascular events. The aim of this study was to calculate the MAI among patients with advanced chronic kidney disease (CKD) and correlate it with traditional uremic, microbiota-derived, and proatherogenic toxins as well as nutritional status, quality of life, and cardiovascular events. A total of 60 adult patients with advanced CKD were enrolled and their MAI was calculated. According to the median value, patients were divided into lower (l-MAI, <1.80) and higher (h-MAI, ≥1.80) MAI groups. Biochemical parameters, microbiota-derived and proatherogenic toxins (p-Cresyl sulphate, Indoxyl-sulphate, and Lipoprotein-associated phospholipase A2), nutritional status, quality of life, and cardiovascular events that occurred in the previous three years were recorded. The mean value of the MAI was 2.78 ± 2.86. The MAI was significantly higher in foreigners (median (IQR) 6.38 (8.98) vs. 1.74 (1.67), p < 0.001) and diabetic patients. The l-MAI and h-MAI groups had similar routinary blood, p-Cresyl-sulphate, Indoxyl-sulphate, and Lp-PLA2 as well as nutritional status and quality of life parameters. The MAI was not associated with previous cardiovascular events and did not correlate with cardiovascular events in CKD patients. New and nephro-tailored indexes are warranted to evaluate nutritional therapy in CKD patients.

Probiotics-Supplemented Low-Protein Diet for Microbiota Modulation in Patients with Advanced Chronic Kidney Disease (ProLowCKD): Results from a Placebo-Controlled Randomized Trial

The probiotics-supplemented low-protein diet in chronic kidney disease (ProLowCKD) was a single-centre, double-blind, placebo-controlled, randomised trial that was conducted to investigate whether the association between a low protein diet (LPD) and a new formulation of probiotics (Bifidobacterium longum and Lactobacillus reuteri) was effective at reducing traditional uremic, microbiota-derived, and proatherogenic toxins in sixty patients affected by advanced CKD. After 2 months of a LPD-a reduction in blood urea nitrogen (52 ± 17 vs. 46 ± 15 mg/dL, p = 0.003), total cholesterol (185 ± 41 vs. 171 ± 34 mg/dL, p = 0.001), and triglycerides (194 ± 148 vs. 161 ± 70 mg/dL, p = 0.03) was observed; 57 subjects were then randomized to receive probiotics or a placebo for the subsequent 3 months. A total of 27 patients in the placebo group showed increased serum values of total cholesterol (169 ± 36 vs. 185 ± 40 mg/dL, p = 0.01), LDL cholesterol (169 ± 36 vs. 185 ± 40 mg/dL, p = 0.02), lipoprotein-associated phospholipase A2 (155.4 ± 39.3 vs. 167.5 ± 51.4 nmol/mL/min, p = 0.006), and indoxyl-sulphate (30.1 ± 17.6 vs. 34.5 ± 20.2 μM, p = 0.026), while the 24 subjects in the probiotics group showed a trend in the reduction of microbiota toxins. A reduction of antihypertensive and diuretic medications was possible in the probiotics group. This study shows that associating probiotics to LPD may have an additional beneficial effect on the control and modulation of microbiota-derived and proatherogenic toxins in CKD patients.

Unraveling the Metabolic Hallmarks for the Optimization of Protein Intake in Pre-Dialysis Chronic Kidney Disease Patients

The daily amount and quality of protein that should be administered by enteral nutrition in pre-dialysis chronic kidney disease (CKD) patients is a widely studied but still controversial issue. This is due to a compromise between the protein necessary to maintain muscular proteostasis avoiding sarcopenia, and the minimal amount required to prevent uremia and the accumulation of nitrogenous toxic substances in blood because of the renal function limitations. This review underlines some intracellular and extracellular features that should be considered to reconcile those two opposite factors. On one hand, the physiological conditions and usual side effects associated with CKD, mTOR and other proteins and nutrients involved in the regulation of protein synthesis in the muscular tissue are discussed. On the other hand, the main digestive features of the most common proteins used for enteral nutrition formulation (i.e., whey, casein and soy protein) are highlighted, due to the importance of supplying key amino acids to serum and tissues to maintain their concentration above the anabolic threshold needed for active protein synthesis, thereby minimizing the catabolic pathways leading to urea formation.

Possible Benefits of a Low Protein Diet in Older Patients With CKD at Risk of Malnutrition: A Pilot Randomized Controlled Trial

BACKGROUND

Current guidelines do not clarify whether older patients with advanced chronic kidney disease (CKD) may benefit of low protein (LP) diet if they are at risk of malnutrition. We compared the effects of normocalorie/normoprotein (NP) and normocalorie/LP diet on nutritional status and metabolic complications related to the progression of kidney damage in these patients.

METHODS

This pilot study had an open-label randomized-controlled design (ClinicalTrials.gov Id: NCT05015647). Thirty-five patients were treated for 6 months with two different diets (LP = 17) and (NP = 18). Malnutrition was assessed by the Malnutrition Inflammation Score and International Society of Renal Nutrition and Metabolism criteria. Renal function was assessed by creatinine and cystatin-C-based estimated glomerular filtration rate (eGFR).

RESULTS

At the end of the study, Malnutrition Inflammation Score was improved in both LP and NP groups (respectively: 3 ± 3 vs. 6 ± 1.5, p = 0.020 and 3 ± 2.5 vs. 6 ± 2, p = 0.012), prevalence of protein energy wasting syndrome decreased only in LP. LP group had higher eGFRcys-C (17 ± 6 vs. 12 ± 4 ml/min/1.73 m2; p < 0.05), lower serum urea (105 ± 65 vs. 138 ± 30 mg/dl; p < 0.05) and lower parathormone (68 ± 10 vs. 99 ± 61 ng/L; p < 0.05) than NP. Serum and urinary phosphorous did not change while fibroblast growth factor 23 (FGF23)-intact and FGF23 c-terminal increased in both groups [FGF23-intact in LP: 70 (48; 98) vs. 126 (90; 410) pg/ml, p < 0.01 and in NP: 86 (57; 194) vs. 143 (119; 186) pg/ml, p < 0.01; FGF23 c-terminal in LP: 77 (30.3; 112) vs. 111 (63; 384) RU/ml, p < 0.01 and in NP: 142 (56.6; 175) vs. 157 (76.7; 281) RU/ml, p < 0.01].

CONCLUSIONS

LP diet has a favorable impact on nutritional status as much as NP diet with possible greater benefits on the progression of kidney disease and some of its metabolic complications.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT05015647, identifier: NCT05015647.

Compliance, Adherence and Concordance Differently Predict the Improvement of Uremic and Microbial Toxins in Chronic Kidney Disease on Low Protein Diet

Background. In medicine, “compliance” indicates that the patient complies with the prescriber’s recommendations, “adherence” means that “the patient matches the recommendations” and “concordance” means “therapeutic alliance” between patient and clinician. While a low protein diet (LPD) is a cornerstone treatment of chronic kidney disease (CKD), monitoring the actual performance of LPD is a challenge. Patients. Fifty-seven advanced CKD adult patients were enrolled and LPD prescribed. Compliance was evaluated through the normalized protein catabolic rate (nPCR), adherence by the dietitian by means of a 24-h dietary recall and concordance by the nephrologist during consultations. Traditional parameters as well as total p-Cresyl Sulphate (t-PCS), total Indoxyl Sulphate (t-IS) and Lipoprotein-associated phspholipase A₂ (Lp-PLA₂) were compared between adherent/not adherent and concordant/not concordant subjects at enrolment and after two months. Results. nPCR, blood urea nitrogen, cholesterol and triglycerides significantly decreased in all patients. t-PCS and t-IS decreased among adherent subjects. Lp-PLA₂, t-PCS, free-PCS and t-IS decreased among concordant subjects, while these increased in non-concordant ones. Conclusion. This study demonstrates that LPD may improve the control of traditional uremic toxins and atherogenic toxins in “adherent” and “concordant” patients. A comprehensive and multidisciplinary approach is needed to evaluate the compliance/adherence/concordance to LPD for optimizing nutritional interventions.

Curcumin Supplementation (Meriva®) Modulates Inflammation, Lipid Peroxidation and Gut Microbiota Composition in Chronic Kidney Disease

Chronic kidney disease (CKD) subjects suffer from high risk of cardiovascular mortality, and any intervention preventing the progression of CKD may have an enormous impact on public health. In the last decade, there has been growing awareness that the gut microbiota (GM) can play a pivotal role in controlling the pathogenesis of systemic inflammatory state and CKD progression. To ameliorate the quality of life in CKD subjects, the use of dietary supplements has increased over time. Among those, curcumin has demonstrated significant in vitro anti-inflammatory properties. In this pilot study, 24 CKD patients and 20 healthy volunteers were recruited. CKD patients followed nutritional counselling and were supplemented with curcumin (Meriva^®) for six months. Different parameters were evaluated at baseline and after 3-6 months: uremic toxins, metagenomic of GM, and nutritional, inflammatory, and oxidative status. Curcumin significantly reduced plasma pro-inflammatory mediators (CCL-2, IFN-γ, and IL-4) and lipid peroxidation. Regarding GM, after 6 months of curcumin supplementation, Escherichia-Shigella was significantly lower, while Lachnoclostridium was significant higher. Notably, at family level, Lactobacillaceae spp. were found significantly higher in the last 3 months of supplementation. No adverse events were observed in the supplemented group, confirming the good safety profile of curcumin phytosome after long-term administration.

Relative validity and reproducibility of food frequency questionnaire for individuals on hemodialysis (NUGE-HD study)

INTRODUCTION

Adequate assessment of food intake is essential to establish the magnitude and direction of the relationship of food, nutrients, and bioactive compounds with clinical outcomes of individuals in hemodialysis. We evaluated the relative validity and reproducibility of a specific food frequency questionnaire for individuals on hemodialysis (FFQ-HD).

METHODS

Eighty-two participants (57.3% male, 57.5 ± 14.4 years) from the open cohort Nutrition and Genetics in Hemodialysis Outcomes participated in this study. The relative validity of the FFQ-HD was assessed using the mean of two 24-h food recall (24hR) adjusted for within-subject variability as a reference method. We also performed Pearson correlations, and agreement between tertile, kappa statistics, and Bland-Altman scatter plots were validated. Reproducibility was assessed after 1 year using intraclass correlation coefficient (ICC).

FINDINGS

Daily energy intake was not different between FFQ-HD and 24hR (mean difference of 50.1 kcal). Intake of protein, linolenic acid, fiber, phosphorus, potassium, sodium, calcium, and sugar showed a moderate correlation (r between 0.4 and 0.5) among instruments, while mean correlation coefficient was r = 0.38 to food group intake. Bland-Altman plots showed good agreement for micronutrients, phosphorus, sodium, and potassium and for the groups "flour, bread, and pasta" and "processed, canned meat, salts, and seasonings". The reproducibility of FFQ-HD for nutrients and food groups was satisfactory, reaching a maximum ICC of 0.72 and 0.59, respectively.

DISCUSSION

The FFQ-HD showed moderate validity and reproducibility for calories, nutrients, and food groups of clinical and nutritional interest for HD subjects so that it can be a useful tool in epidemiological studies in this population.

Higher dietary fibre intake is associated with lower CVD mortality risk among maintenance haemodialysis patients: a multicentre prospective cohort study

High fibre intake is associated with reduced mortality risk in both general and chronic kidney disease populations. However, in dialysis patients, such data are limited. Therefore, the association between dietary fibre intake (DFI) and the risk of all-cause and CVD mortality was examined in this study. A total of 1044 maintenance haemodialysis (MHD) patients from eight outpatient dialysis centres in China were included in this study. Data on DFI were collected using 24-h dietary recalls for 3 d in a week and were normalised to actual dry weight. The study outcomes included all-cause and CVD mortality. Over a median of 46 months of follow-up, 354 deaths were recorded, of which 210 (59 %) were due to CVD. On assessing DFI as tertiles, the CVD mortality risk was significantly lower in patients in tertiles 2-3 (≥0·13 g/kg per d; hazard ratio (HR) 0·71; 95 % CI 0·51, 0·97) compared with those in tertile 1 (<0·13 g/kg per d). A similar but non-significant trend was found for the association between DFI (tertiles 2-3 v. tertile 1; HR 0·83; 95 % CI 0·64, 1·07) and all-cause mortality. In summary, higher DFI was associated with lower CVD mortality risk among Chinese MHD patients. This study emphasises the significance of DFI in MHD patients and provides information that is critical for the improvement of dietary guidelines for dialysis patients.

Are Food Additives a Really Problematic Hidden Source of Potassium for Chronic Kidney Disease Patients?

Dietary treatment in chronic kidney disease (CKD) recommends limiting the consumption of foods rich in potassium to reduce risk of hyperkalemia. Currently, the increased supply of processed foods on the market could be a new "hidden" source of potassium for these patients, which is causing concern among health professionals who treat them. The aim of this study was to check which EU authorized food additives contain potassium, its conditions of use and classified them according to their risk for CKD patients. In addition, the frequency of appearance of potassium additives in processed foods in a European sample through the analysis of 715 products labeling from France, Germany, and Spain were evaluated. Results showed 41 potassium-containing additives allowed in the European Union, but only 16 were identified, being the most frequent: E202; E252, E340, E450, E452, E508, and E950. The 37.6% of the processed products analyzed contained at least one potassium additive. The food categories that showed the greatest presence of additives were breaded products, meat derivatives, non-alcoholic beverage, ready-to-eat products, and cereal derivatives. Potassium additives are widely distributed in processed foods and therefore pose a risk of hidden sources of potassium in CKD dietary management. These results could be really useful for developing educational tools for CKD patients.

Supplemented Low-Protein Diet May Delay the Need for Preemptive Kidney Transplantation: A Nationwide Population-Based Cohort Study

BACKGROUND

Although several studies suggest the benefit of a low-protein diet supplemented with amino acids and keto acids (sLPD) in delaying the initiation of hemodialysis, evidence on whether these nutritional approaches could delay the timing of preemptive transplantation is lacking.

METHODS

Retrospective nationwide cohort study, from Taiwan's National Health Insurance Research Database. Patients having undergone a first preemptive kidney transplantation between 2001 and 2017 were identified and divided into two groups according to the presence of sLPD treatment or not. The primary outcome was the time between the diagnosis of advanced CKD and transplantation. Secondary outcomes were post-transplantation adverse events.

RESULTS

A total of 245 patients who received their first preemptive kidney transplantation were identified from the nationwide database; 63 of them had been on an sLPD prior to transplantation (sLPD group). The duration between the day of advanced CKD diagnosis and the day of transplantation was significantly longer in the sLPD group compared with the non-sLPD group (median duration: 345 vs. 220 days, p = 0.001). The risk of post-transplantation adverse events did not differ between the two groups.

CONCLUSIONS

Within the limits of its observational, retrospective design, this is the first study to suggest that nutritional management with sLPDs can safely delay the timing of preemptive kidney transplantation.

Rice Endosperm Protein Improves the Anti-Inflammatory Effects of High-Density Lipoprotein and Produces Lower Atherosclerotic Lesion Accelerated by the Renal Mass Reduction than Casein in a Mouse Model

Chronic kidney disease (CKD) impairs the anti-inflammatory effects of high-density lipoprotein (HDL) and increases cardiovascular mortality. Though the potential role of dietary interventions to manage HDL is well studied, the clinical trials aimed to increase HDL levels have failed to reduce cardiovascular risk, rendering HDL function to be explored as a more relevant clinical parameter. This study investigates the effects of rice endosperm protein (REP), a plant-based protein, on the anti-inflammatory properties of HDL and renal injury-driven atherosclerosis in comparison with casein, an animal protein.

Ten-week-old apolipoprotein E-deficient hyperlipidemic mice underwent uninephrectomy. The mice (n = 6 each) were pair-fed a normal casein-based diet or a REP-based diet (both with 20.0% protein content) for seven weeks. Atherosclerotic lesions were detected by en face Sudan IV staining of the aorta.

The number and sizes of the atherosclerotic lesions were significantly lower in the REP-based diet-fed group than the casein-based diet-fed group (p = 0.038). However, the REP-based diet neither elicited an ameliorative effect on kidney function or histology nor impacted the cholesterol profiles. Furthermore, HDL from the REP-based diet-fed mice significantly suppressed the inflammatory cytokine response of human umbilical vein endothelial cells than that from the casein-based diet-fed mice (MCP-1, p = 0.010; IL-6, p = 0.011; IL-1β, p = 0.028).

The REP-based diet has a higher potential to lessen the atherosclerotic lesions accelerated by renal mass reduction than a casein-based diet, which could be associated with the anti-inflammatory effects of HDL.

Ten-year experience of an outpatient clinic for CKD-5 patients with multidisciplinary team and educational support

PURPOSE

To analyze the results of an outpatient clinic with a multidisciplinary team and educational support for patients with late-stage CKD (lsCKD), to check its possible effect on their outcomes.

METHODS

Longitudinal cohort study on patients followed up in the MaReA (Malattia Renale Avanzata = CKD5) outpatient clinic at ASST Spedali Civili of Brescia from 2005 to 2015 for at least six months. Trajectory of renal function over time has been evaluated only in those patients with at least four estimations of eGFR before referring to MaReA.

RESULTS

Seven hundred and six patients were enrolled, their mean age was 72 ± 14 years, 59% were males. At the end of the study, 147 (21%) were still on MaReA, 240 (34%) on dialysis, 92 (13%) on very low-protein diet (VLPDs), 13 (2%) on pre-hemodialysis clinic, 23 (3%) improved renal function, 10 (1%) transplanted, 62 (9%) transferred/lost to follow-up, and 119 (17%) died. Optimal dialysis start (defined as start with definitive dialysis access, as an out-patient and without lsCKD complications) occurred in 180/240 (75%) patients. The results showed a slower eGFR decrease during MaReA follow-up compared to previous renal follow-up: - 2.0 vs. - 4.0 mL/min/1.73 m² BSA/year (p < 0.05), corresponding to a median delay of 17.7 months in dialysis start in reference to our policy in starting dialysis. The patient cumulative survival was 75% after 24 months and 25% after 70.

LIMITATIONS

(1) lack of a control group, (2) one-center-study, (3) about all patients were Caucasians.

CONCLUSION

The follow-up of lsCKD patients on MaReA is associated with an optimal and delayed initiation of dialysis.

Nutritional Approaches for the Management of Metabolic Acidosis in Chronic Kidney Disease

Metabolic acidosis is a severe complication of chronic kidney disease (CKD) which is associated with nefarious impairments such as bone demineralization, muscle wasting, and hormonal alterations, for example, insulin resistance. Whilst it is possible to control this condition with alkali treatment, consisting in the oral administration of sodium citrate or sodium bicarbonate, this type of intervention is not free from side effects. On the contrary, opting for the implementation of a targeted dietetic-nutritional treatment for the control of CKD metabolic acidosis also comes with a range of additional benefits such as lipid profile control, increased vitamins, and antioxidants intake. In our review, we evaluated the main dietary-nutritional regimens useful to counteract metabolic acidosis, such as the Mediterranean diet, the alkaline diet, the low-protein diet, and the vegan low-protein diet, analyzing the potentialities and limits of every dietary-nutritional treatment. Literature data suggest that the Mediterranean and alkaline diets represent a valid nutritional approach in the prevention and correction of metabolic acidosis in CKD early stages, while the low-protein diet and the vegan low-protein diet are more effective in CKD advanced stages. In conclusion, we propose that tailored nutritional approaches should represent a valid therapeutic alternative to counteract metabolic acidosis.

Management of Kidney Failure in Patients with Diabetes Mellitus: What Are the Best Options?

Diabetic kidney disease (DKD) is the most frequent cause of kidney failure (KF). There are large variations in the incidence rates of kidney replacement therapy (KRT). Late referral to nephrology services has been associated with an increased risk of adverse outcomes. In many countries, when patients reach severely reduced glomerular filtration rate (GFR), they are managed by multidisciplinary teams led by nephrologists. In these clinics, efforts will continue to halt chronic kidney disease (CKD) progression and to prevent cardiovascular mortality and morbidity. In patients with diabetes and severely reduced GFR and KF, treating hyperglycemia is a challenge, since some drugs are contraindicated and most of them require dose adjustments. Even more, a decision-making process will help in deciding whether the patient would prefer comprehensive conservative care or KRT. On many occasions, this decision will be conditioned by diabetes mellitus itself. Effective education should cover the necessary information for the patient and family to answer these questions: 1. Should I go for KRT or not? 2. If the answer is KRT, dialysis and/or transplantation? 3. Dialysis at home or in center? 4. If dialysis at home, peritoneal dialysis or home hemodialysis? 5. If transplantation is desired, discuss the options of whether the donation would be from a living or deceased donor. This review addresses the determinant factors with an impact on DKD, aiming to shed light on the specific needs that arise in the management and recommendations on how to achieve a comprehensive approach to the diabetic patient with chronic kidney disease.

Nutritional status, hyperkalaemia and attainment of energy/protein intake targets in haemodialysis patients following plant-based diets: a longitudinal cohort study

Background

Patients undergoing haemodialysis (HD) are often discouraged from eating fruits and vegetables because of fears of hyperkalaemia and undernutrition, yet evidence to support these claims is scarce. We here explore the association between adherence to a healthy plant-based diet with serum potassium, surrogates of nutritional status and attainment of energy/protein intake targets in HD patients.

Methods

We performed an observational single-centre study of stable patients undergoing HD with repeated dietary assessment every 3 months. Patients were provided with personalized nutritional counselling according to current guidelines. The diet was evaluated by 3-day food records and characterized by a healthy plant-based diet score (HPDS), which scores positively the intake of plant foods and negatively animal foods and sugar. The malnutrition inflammation score (MIS) and serum potassium were also assessed at each visit. We used mixed-effects models to evaluate the association of the HPDS with markers of nutritional status, serum potassium levels and attainment of energy/protein intake targets.

Results

After applying inclusion and exclusion criteria, a total of 150 patients contributing to 470 trimestral observations were included. Their mean age was 42 years [standard deviation (SD) 18] and 59% were women. In multivariable models, a higher HPDS was not associated with serum potassium levels or odds of hyperkalaemia {potassium >5.5 mEq/L; odds ratio [OR] 1.00 [95% confidence interval (CI) 0.94–1.07] per HPDS unit higher}. Patients with a higher HPDS did not differ in terms of energy intake [OR for consuming <30 kcal/kg day 1.05 (95% CI 0.97–1.13)] but were at risk of low protein intake [OR for consuming <1.1 g of protein/kg/day 1.11 (95% CI 1.04–1.19)]. A higher HPDS was associated with a lower MIS, indicating better nutritional status.

Conclusions

In patients undergoing HD, adherence to a healthy plant-based diet was not associated with serum potassium, hyperkalaemia or differences in energy intake. Although these patients were less likely to reach daily protein intake targets, they appeared to associate with better nutritional status over time.

Protection of Residual Renal Function and Nutritional Treatment: First Step Strategy for Reduction of Uremic Toxins in End-Stage Kidney Disease Patients

The retention of uremic toxins and their pathological effects occurs in the advanced phases of chronic kidney disease (CKD), mainly in stage 5, when the implementation of conventional thrice-weekly hemodialysis is the prevalent and life-saving treatment. However, the start of hemodialysis is associated with both an acceleration of the loss of residual kidney function (RKF) and the shift to an increased intake of proteins, which are precursors of uremic toxins. In this phase, hemodialysis treatment is the only way to remove toxins from the body, but it can be largely inefficient in the case of high molecular weight and/or protein-bound molecules. Instead, even very low levels of RKF are crucial for uremic toxins excretion, which in most cases are protein-derived waste products generated by the intestinal microbiota. Protection of RKF can be obtained even in patients with end-stage kidney disease (ESKD) by a gradual and soft shift to kidney replacement therapy (KRT), for example by combining a once-a-week hemodialysis program with a low or very low-protein diet on the extra-dialysis days. This approach could represent a tailored strategy aimed at limiting the retention of both inorganic and organic toxins. In this paper, we discuss the combination of upstream (i.e., reduced production) and downstream (i.e., increased removal) strategies to reduce the concentration of uremic toxins in patients with ESKD during the transition phase from pure conservative management to full hemodialysis treatment.

Ketoanalogs' Effects on Intestinal Microbiota Modulation and Uremic Toxins Serum Levels in Chronic Kidney Disease (Medika2 Study)

Nutritional therapy (NT) is a therapeutic option in the conservative treatment of chronic kidney disease (CKD) patients to delay the start of dialysis. The aim of this study was to evaluate the specific effect of ketoanalogs (KA)-supplemented diets for gut microbiota modulation. In a previous study we observed that the Mediterranean diet (MD) and a KA-supplemented very-low-protein diet (VLPD) modulated beneficially gut microbiota, reducing indoxyl- and p-cresyl-sulfate (IS, PCS) serum levels, and ameliorating the intestinal permeability in CKD patients. In the current study, we added a third diet regimen consisting of KA-supplemented MD. Forty-three patients with CKD grades 3B–4 continuing the crossover clinical trial were assigned to six months of KA-supplemented MD (MD + KA). Compared to MD, KA-supplementation in MD + KA determined (i) a decrease of Clostridiaceae, Methanobacteriaceae, Prevotellaceae, and Lactobacillaceae while Bacteroidaceae and Lachnospiraceae increased; (ii) a reduction of total and free IS and PCS compared to a free diet (FD)—more than the MD, but not as effectively as the VLPD. These results further clarify the driving role of urea levels in regulating gut integrity status and demonstrating that the reduction of azotemia produced by KA-supplemented VLPD was more effective than KA-supplemented MD in gut microbiota modulation mainly due to the effect of the drastic reduction of protein intake rather than the effect of KA.

Dietary intake in adults on hemodialysis compared with guideline recommendations

Background

Clinical practice guidelines of dietary management are designed to promote a balanced diet and maintain health in patients undergoing haemodialysis but they may not reflect patients’ preferences. We aimed to investigate the consistency between the dietary intake of patients on maintenance haemodialysis and guideline recommendations.

Methods

Cross-sectional analysis of the DIET-HD study, which included 6,906 adults undergoing haemodialysis in 10 European countries. Dietary intake was determined using the Global Allergy and Asthma European Network (GA²LEN) Food Frequency Questionnaire (FFQ), and compared with the European Best Practice Guidelines. Consistency with guidelines was defined as achieving the minimum daily recommended intake for energy (≥ 30 kcal/kg) and protein (≥ 1.1 g/kg), and not exceeding the maximum recommended daily intake for phosphate (≤ 1000 mg), potassium (≤ 2730 mg), sodium (≤ 2300 mg) and calcium (≤ 800 mg).

Results

Overall, patients’ dietary intakes of phosphate and potassium were infrequently consistent with guidelines (consistent in 25% and 25% of patients, respectively). Almost half of the patients reported that energy (45%) and calcium intake (53%) was consistent with the guidelines, while the recommended intake of sodium and protein was consistent in 85% and 67% of patients, respectively. Results were similar across all participating countries. Intake was consistent with all six guideline recommendations in only 1% of patients.

Conclusion

Patients on maintenance haemodialysis usually have a dietary intake which is inconsistent with current recommendations, especially for phosphate and potassium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-020-00962-3.

AGREEing on Nutritional Management of Patients with CKD-A Quality Appraisal of the Available Guidelines

Chronic kidney disease (CKD) is an important public health issue with increasing prevalence worldwide. Several clinical practice guidelines have been recently published regarding the nutritional management of CKD patients. The purpose of the present study is to evaluate the quality of the published guidelines and provide recommendation for future updates. PubMed, Scopus and Google Scholar were searched for relevant guidelines and 11 clinical practice guidelines were finally included. Guidelines developed by the American Society for Parenteral and Enteral nutrition (ASPEN), the Dietitians Association of Australia (DAA), the German Society for Nutritional Medicine (DGEM), the European Best Practice Guidelines (EBPG), the European Dialysis and Transplantation Nurses Association-European Renal Care Association (EDTNA-ERCA), the European Society for Clinical Nutrition and Metabolism (ESPEN), the Andalusian Group for Nutrition Reflection and Investigation (GARIN) group, the National Kidney foundation-Kidney Disease Outcomes Quality Initiative (KDOQI), the Italian Society of Nephrology-Association of Dieticians-Italian Association of Hemodialysis, Dialysis and Transplant (SIN-ANDID-ANED), and the Renal Association were assessed using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool. Guidelines by KDOQI, ESPEN, and DAA were of moderate quality and the rest of them were low-quality guidelines. Our study demonstrates gaps related to the development of guidelines and therefore greater emphasis on methodological approaches is recommended. AGREE II tool can be useful to improve quality of guidelines.