A Delphi consensus panel on nutritional therapy in chronic kidney disease

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.

Nutritional Treatment as a Synergic Intervention to Pharmacological Therapy in CKD Patients

Nutritional and pharmacological therapies represent the basis for non-dialysis management of CKD patients. Both kinds of treatments have specific and unchangeable features and, in certain cases, they also have a synergic action. For instance, dietary sodium restriction enhances the anti-proteinuric and anti-hypertensive effects of RAAS inhibitors, low protein intake reduces insulin resistance and enhances responsiveness to epoetin therapy, and phosphate restriction cooperates with phosphate binders to reduce the net phosphate intake and its consequences on mineral metabolism. It can also be speculated that a reduction in either protein or salt intake can potentially amplify the anti-proteinuric and reno-protective effects of SGLT2 inhibitors. Therefore, the synergic use of nutritional therapy and medications optimizes CKD treatment. Quality of care management is improved and becomes more effective when compared to either treatment alone, with lower costs and fewer risks of unwanted side effects. This narrative review summarizes the established evidence of the synergistic action carried out by the combination of nutritional and pharmacological treatments, underlying how they are not alternative but complementary in CKD patient care.

An international Delphi consensus statement on metabolic dysfunction-associated fatty liver disease and risk of chronic kidney disease

BACKGROUND

With the rising global prevalence of fatty liver disease related to metabolic dysfunction, the association of this common liver condition with chronic kidney disease (CKD) has become increasingly evident. In 2020, the more inclusive term metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed to replace the term non-alcoholic fatty liver disease (NAFLD). The observed association between MAFLD and CKD and our understanding that CKD can be a consequence of underlying metabolic dysfunction support the notion that individuals with MAFLD are at higher risk of having and developing CKD compared with those without MAFLD. However, to date, there is no appropriate guidance on CKD in individuals with MAFLD. Furthermore, there has been little attention paid to the link between MAFLD and CKD in the Nephrology community.

METHODS AND RESULTS

Using a Delphi-based approach, a multidisciplinary panel of 50 international experts from 26 countries reached a consensus on some of the open research questions regarding the link between MAFLD and CKD.

CONCLUSIONS

This Delphi-based consensus statement provided guidance on the epidemiology, mechanisms, management and treatment of MAFLD and CKD, as well as the relationship between the severity of MAFLD and risk of CKD, which establish a framework for the early prevention and management of these two common and interconnected diseases.

Delphi case: Sharing of clinical experiences for improvement in the treatment of chronic venous disease

Chronic venous disease (CVD) is a common condition with major health consequences that is associated with poor long-term prognosis, significant socioeconomic impact, disabling symptoms, and reduced quality of life. To provide a novel evidence-based approach in the management of CVD, a consensus process (“Delphi Case”) following a first Delphi Consensus was conceived. With a real-life fashion analysis, a steering committee formed by 3 expert leaders on chronic venous disease drove a panel of 77 expert Italian angiologists/vascular surgeons along a collegial discussion, integrating data coming from the guidelines recommendations of different Vascular Scientific Societies with the consensus agreement statements gathered from the first Delphi Consensus, and with data coming from the discussion of few statements in which there was disagreement. From July 15 to October 16, 2020, demographic, anamnestic, objective, and therapeutic data coming from a total of 2,275 patients were collected by the experts panel using a predefined case report form. The results of this second consensus provided a real-life picture of CVD management in the Italian population and clearly showed that a tailored therapeutic approach together with an appropriate lifestyle (e.g., diet, physical activity, weight loss) must be considered as the milestones for the CVD-related signs and symptoms clinical improvement in daily clinical practice. An evaluation of the adherence and of the efficacy of the prescribed pharmacological and compressive treatment in a medium-long term follow-up of the study population has been planned as the last step of this course and will be object of a future final publication.

Second-line administration of thrombopoietin receptor agonists in immune thrombocytopenia: Italian Delphi-based consensus recommendations

Introduction:

In patients with primary immune thrombocytopenia (ITP), a short course of steroids is routinely given as first-line therapy. However, the response is often transient and additional therapy is usually needed. Thrombopoietin receptor agonists (TPO-RAs) are frequently used as second-line therapy, although there is little clinical guidance on the timing of their administration and on tapering/discontinuation of the drug. To provide clinical recommendations, we used the Delphi technique to obtain consensus for statements regarding administration and on tapering/discontinuation of second-line TPO-RAs among a group of Italian clinicians with expertise in management of ITP.

Methods:

The Delphi process was used to obtain agreement on five statements regarding initiation and on tapering/discontinuation of second-line TPO-RAs. Agreement was considered when 75% of participants approved the statement. Eleven experts participated in the voting.

Results:

Full consensus was reached for three of the five statements. The experts held that an early switch from corticosteroids to a TPO-RA has the dual advantage of sparing patients from corticosteroid abuse and improve long-term clinical outcomes. All felt that dose reduction of TPO-RAs can be considered in patients with a stable response and platelet count >100 × 10⁹/L that is maintained for at least 6 months in the absence of concomitant treatments, although there was less agreement in patients with a platelet count >50 × 10⁹/L. Near consensus was reached regarding the statement that early treatment with a TPO-RA is associated with an increase in clinically significant partial or complete response. The experts also agreed that optimization of tapering and discontinuation of TPO-RA therapy in selected patients can improve the quality of life.

Conclusion:

The present consensus can help to provide guidance on use of TPO-RAs in daily practice in patients with ITP.

Plain language summary

Second-line administration of thrombopoietin receptor agonists in immune thrombocytopenia

Low Protein Diets and Plant-Based Low Protein Diets: Do They Meet Protein Requirements of Patients with Chronic Kidney Disease?

A low protein diet (LPD) has historically been used to delay uremic symptoms and decrease nitrogen (N)-derived catabolic products in patients with chronic kidney disease (CKD). In recent years it has become evident that nutritional intervention is a necessary approach to prevent wasting and reduce CKD complications and disease progression. While a 0.6 g/kg, high biological value protein-based LPD has been used for years, recent observational studies suggest that plant-derived LPDs are a better approach to nutritional treatment of CKD. However, plant proteins are less anabolic than animal proteins and amino acids contained in plant proteins may be in part oxidized; thus, they may not completely be used for protein synthesis. In this review, we evaluate the role of LPDs and plant-based LPDs on maintaining skeletal muscle mass in patients with CKD and examine different nutritional approaches for improving the anabolic properties of plant proteins when used in protein-restricted diets.

Effects of Intensive Individualized Nutrition Counseling on Nutritional Status and Kidney Function in Patients With Stage 3 and 4 Chronic Kidney Disease

OBJECTIVE

Although dietary modification is a critical component of chronic kidney disease (CKD) management, compliance with dietary recommendations is often suboptimal. This prospective intervention study was conducted to evaluate the effects and adherence of intensive, individualized nutrition counseling in CKD patients from a single nation Asian ethnic group.

METHODS

Patients with Stages 3 and 4 CKD were recruited from a tertiary hospital outpatient clinic in Korea. The intensive group received 3 monthly sessions of individualized intensive nutrition counseling. The control group received a one-time group program. The intensive group was compared with the control group at 3 months.

RESULTS

A total of 59 patients were enrolled, and 42 (71.2%) completed the study (23/32 of the intensive group; 19/27 of the control group). The mean age of the patients was 64.7 ± 12.5 years, and 81% were male. The most common nutritional diagnosis was an excessive intake of sodium (Na, 97.6%), followed by potassium (K, 78.6%), protein (52.4%), and phosphorus (P, 31.0%). After 3 months of nutrition counseling, K and P intakes decreased significantly in both the intensive group (K, 2,760.9 ± 677.4 vs. 1,500.7 ± 398.5 mg/d, P < .001; P, 1,010.5 ± 247.4 vs. 631.3 ± 178.1 mg/d, P < .001) and the control group (K, 2,090.8 ± 765.3 vs. 1,703.9 ± 490.0 mg/d, P = .036; P, 807.2 ± 163.8 vs. 679.1 ± 175.9 mg/d, P = .044). Meanwhile, protein (68.3 ± 21.8 vs. 45.4 ± 10.1 g/d, P = .001), Na (4,009.8 ± 1,418.2 vs. 2,224.6 ± 759.8 mg/d, P < .001), and energy intakes (1,857.1 ± 411.5 vs. 1,273.7 ± 231.5 kcal, P < .001) decreased in the intensive group, but were comparable in the control group. Notably, BMI decreased (BMI, 25.4 ± 2.5 vs. 24.9 ± 2.9 kg/m2, P = .014) while eGFR (43.1 ± 11.8 vs. 48.9 ± 13.7 mL/min/1.73m2, P = .002) improved significantly in the intensive group only.

CONCLUSION

Intensive individualized nutrition counseling results in better adherence to dietary recommendations and improvement in kidney function in CKD patients.

Geriatric nutritional risk index is associated with mortality in peritoneal dialysis patients

BACKGROUND

Malnutrition is one of the most common complications among dialysis patients. The Geriatric Nutritional Risk Index (GNRI) is rarely used in dialysis patients, especially peritoneal dialysis (PD).

AIM

To use the GNRI to evaluate the initial nutritional state of PD patients and to examine the association between the GNRI and mortality in chronic PD patients.

METHODS

We retrospectively examined the medical records at our centre to identify all adults (≥18 years) who had undergone PD for over 3 months before recruitment from January 2005 to December 2017. The correlation between the GNRI and mortality was examined by Kaplan-Meier and Cox proportional hazards analyses.

RESULTS

A total of 1804 patients was enrolled in the study. Significant correlations were noted between the initial GNRI and Charlson index, uric acid, blood calcium, potassium, triglycerides, low-density lipoprotein cholesterol, haemoglobin and so on. Multivariate Cox proportional hazards analyses demonstrated that the GNRI was associated with all-cause mortality (hazard ratio = 0.96, P < 0.001, 95% confidence interval: 0.95-0.98) after adjustment. Compared with the lowest GNRI group, all-cause mortality decreased significantly for each level of GNRI after adjusting for various influencing factors, and the mortality risk of the highest GNRI grade decreased by 66%. The Kaplan-Meier analysis survival rate was significantly different among the four groups in terms of all-cause mortality and cardiovascular and cerebrovascular mortality (log-rank test, P < 0.05).

CONCLUSIONS

These results demonstrated that the GNRI is significantly associated with mortality and can be a simple, clinically useful marker for the assessment of nutritional status in PD patients.

Refining diagnosis and management of chronic venous disease: Outcomes of a modified Delphi consensus process

Chronic venous disease (CVD) is a common condition with major health consequences that is associated with poor long-term prognosis, significant socioeconomic impact, disabling symptoms and reduced quality of life. To provide practical guidance for diagnosis and management of CVD, a Delphi panel of 5 experts in steering committee and 28 angiologists/vascular surgeons met with the major aim of providing a supplement for established national and international guidelines. A total of 24 statements were voted upon in two rounds, of which consensus was reached on 22 statements, indicating a high level of overall agreement. Consensus was reached on 7 of 8 statements relative to diagnosis (CEAP classification, diagnostic tools, QoL assessment, diagnostic imaging) and on 15 of 16 statements on management (conservative treatments, compressive therapy, pharmacological therapy, surgical treatment). The results of the consensus reached are discussed herein from which it is clear that diagnostic and management approaches utilising personalised therapies tailored to the individual patient should be favoured. While it is clear that additional studies are needed on many aspects of diagnosis and management of CVD, the present Delphi survey provides some key recommendations for clinicians treating CVD that may be useful in daily practice.

Chronic hyperkalemia in non-dialysis CKD: controversial issues in nephrology practice

Chronic hyperkalemia is a major complication of chronic kidney disease (CKD) that occurs frequently, heralds poor prognosis, and necessitates careful management by the nephrologist. Current strategies aimed at prevention and treatment of hyperkalemia are still suboptimal, as evidenced by the relatively high prevalence of hyperkalemia in patients under stable nephrology care, and even in the ideal setting of randomized trials where best treatment and monitoring are mandatory. The aim of this review was to identify and discuss a range of unresolved issues related to the management of chronic hyperkalemia in non-dialysis CKD. The following topics of clinical interest were addressed: diagnosis, relationship with main comorbidities of CKD, therapy with inhibitors of the renin-angiotensin-aldosterone system, efficacy of current dietary and pharmacological treatment, and the potential role of the new generation of potassium binders. Opinion-based answers are provided for each of these controversial issues.

Nutritional treatment of advanced CKD: twenty consensus statements

The Italian nephrology has a long tradition and experience in the field of dietetic-nutritional therapy (DNT), which is an important component in the conservative management of the patient suffering from a chronic kidney disease, which precedes and integrates the pharmacological therapies. The objectives of DNT include the maintenance of an optimal nutritional status, the prevention and/or correction of signs, symptoms and complications of chronic renal failure and, possibly, the delay in starting of dialysis. The DNT includes modulation of protein intake, adequacy of caloric intake, control of sodium and potassium intake, and reduction of phosphorus intake. For all dietary-nutritional therapies, and in particular those aimed at the patient with chronic renal failure, the problem of patient adherence to the dietetic-nutritional scheme is a key element for the success and safety of the DNT and it can be favored by an interdisciplinary and multi-professional approach of information, education, dietary prescription and follow-up. This consensus document, which defines twenty essential points of the nutritional approach to patients with advanced chronic renal failure, has been written, discussed and shared by the Italian nephrologists together with representatives of dietitians (ANDID) and patients (ANED).

Safety and effectiveness of low-protein diet supplemented with ketoacids in diabetic patients with chronic kidney disease

BACKGROUND

The impact of the low-protein diet on nutrition in CKD diabetics is uncertain.

METHODS

The metabolic and nutritional effects of a low-protein (0.5-0.6 g/kg/d), normal-high energy (30-35 kcal/kg/d) diet supplemented with ketoacids (LPD-KA) were prospectively evaluated in CKD patients with (DM) and without (non-DM) diabetes mellitus.

RESULTS

197 patients on CKD stages 3-5 were enrolled. DM (n = 81) and non-DM (n = 116) were comparable for gender (Male 58 vs 55%), age (66 ± 9 vs 63 ± 18 years), renal function (eGFR 23 ± 13 vs 24 ± 13 mL/min). After 6-month, serum urea (DM: 131 ± 58 to 105 ± 49 mg/dl, p < 0.05; non-DM: 115 ± 52 to 88 ± 36, p < 0.05) and phosphate (DM: 4.5 ± 1.3 to 4.1 ± 1.2 mg/dl, p = 0.06; non-DM: 4.3 ± 1.0 to 3.7 ± 0.8, p < 0.05) declined. Fasting glucose decreased in DM (126 ± 52 to 103 ± 29 mg/dl, p < 0.05) without insulin dose increase. These effects were preserved after 3-year. Serum albumin did not change after 6 months (DM: 3.7 ± 0.6 to 3.8 ± 0.4 mg/dl; non-DM: 4.0 ± 0.6 to 4.0 ± 0.4) and in the long-term. Body weight (BW) declined after the diet start (DM: 68.9 ± 14.3 to 65.1 ± 12.1 kg, p < 0.05; non-DM: 66.6 ± 15.1 to 64.1 ± 15.1, p < 0.05) and was stable at 6 months and 3 years. Muscle strength at baseline was reduced in all patients and remained stable during the diet period. Changes of nutritional markers during the study were similar among groups and diabetes was not associated to any nutritional change at the multivariate analysis. As attain wasting, lower BMI (< 23 kg/m²) and albumin (< 3.8 g/dl) levels were present in 1/3 patients at start and along 3 years, cholesterol never dropped below the lower threshold (< 100 mg/dl) and poorer FM (< 10%) was less than 10% during the study in both groups.

CONCLUSIONS

In diabetic CKD patients a low-protein diet supplemented with ketoacids improves uremia and diabetes, causes sudden decline of body weight which remains stable over time and has not a negative effect on wasting and muscle mass and fitness. In diabetic CKD patients the LPD-KA is safe and the nutritional impact is the same as in non-diabetics CKD.

Assessment of physical performance and body composition in male renal transplant patients

BACKGROUND

Renal transplant (RTX) recipients seem to experience a better quality of life compared to dialysis patients. However, the factors responsible for this positive effect are not completely defined. Conceivably, a change in the physical performance of these patients could play a role.

METHODS

To assess this, we measured: (1) waist circumference, fat mass and appendicular fat-free mass (aFFM) by dual-energy X-ray densitometry, (2) physical performance with the Short Physical Performance Battery, and (3) muscle strength with the handgrip test, in 59 male RTX, 11 chronic kidney disease in conservative treatment (CKD) and 10 peritoneal dialysis (PD) patients.

RESULTS

Surprisingly, anthropometric characteristics and body composition were similar among the three groups. However, despite a low aFFM, muscle strength was higher in stable RTX recipients > 5 years after transplantation than in dialyzed patients. Instead, CKD (wait-listed for RTX) had similar muscle strength to RTX patients. Waist circumference in RTX recipients showed a redistribution of body fat with increased central adipose tissue allocation compared to PD. At linear regression analysis, age, weight, height, aFFM, hemoglobin and transplant age were independent predictors of handgrip strength, explaining about 37% of the variance. Age and transplant age accounted for 18 and 12% of variance, respectively.

CONCLUSIONS

Our study demonstrates, for the first time, that clinically stable RTX recipients have greater muscle strength than dialyzed patients and suggests that the handgrip test could be an effective and easy-to-perform tool to assess changes in physical performance in this large patient population.

Very low-protein diet to postpone renal failure: Pathophysiology and clinical applications in chronic kidney disease

The uremic syndrome is a metabolic disorder characterized by the impairment of renal handling of several solutes, the resulting accumulation of toxic products and the activation of some adaptive but detrimental mechanisms which all together contribute to the progression of renal damage. In moderate to advanced renal failure, the dietary manipulation of nutrients improves metabolic abnormalities and may contribute to delay the time of dialysis initiation. This commentary focuses on the physiopathological rationale and the clinical application of the very low-protein diet supplemented with ketoanalogs for the management of chronic kidney disease.

Microbiota metabolites: Pivotal players of cardiovascular damage in chronic kidney disease

In chronic kidney disease (CKD), cardiovascular (CV) damage is present in parallel which leads to an increased risk of CV disease. Both traditional and non-traditional risk factors contribute to CV damage in CKD. The systemic role of the microbiota as a central player in the pathophysiology of many organs is progressively emerging in the literature: the microbiota is indeed involved in a complex, bi-directional network between many organs, including the kidney and heart connection, although many of these relationships still need to be elucidated through in-depth mechanistic studies. The aim of this review is to provide evidence that microbiota metabolites influence non-traditional risk factors, such as inflammation and endothelial dysfunction in CKD-associated CV damage. Here, we report our current understanding and hypotheses on the gut-kidney and gut-heart axes and provide details on the potential mechanisms mediated by microbial metabolites. More specifically, we summarize some novel hypotheses linking the microbiota to blood pressure regulation and hypertension. We also emphasise the idea that the nutritional management of CKD should be redesigned and include the new findings from research on the intrinsic plasticity of the microbiota and its metabolites in response to food intake. The need is felt to integrate the classical salt and protein restriction approach for CKD patients with foods that enhance intestinal wellness. Finally, we discuss the new perspectives, especially the importance of taking care of the microbiota in order to prevent the risk of developing CKD and hypertension, as well as the still not tested but very promising CKD innovative treatments, such as postbiotic supplementation and bacteriotherapy. This interesting area of research offers potential complementary approaches to the management of CKD and CV damage assuming that the causal mechanisms underlying the gut-kidney and gut-heart axes are clarified. This will pave the way to the design of new personalized therapies targeting gut microbiota.

Diet and enteral nutrition in patients with chronic kidney disease not on dialysis: a review focusing on fat, fiber and protein intake

The clinical data available on dietary requirements of patients with chronic kidney disease (CKD) not on dialysis are limited and largely inconclusive in terms of the renal, cardiovascular and nutritional outcomes achievable through dietary modifications. Restriction of protein intake during the early stages of CKD may in fact slow its progression, but at the same time this approach may also lead to protein-energy wasting, if energy intake is not adequate and properly monitored. Unfortunately, compliance to dietary recommendations is traditionally low in this patient population. A switch from saturated to mono- and polyunsaturated fats is generally recognized as advantageous for cardiac health; however, the benefits in term of renal function are largely unknown. Similarly, the association between dietary fiber intake and kidney disease is largely unknown. In fact, while there is evidence on the positive health effects of dietary fibers in the general population, nutritional guidelines for CKD lack formal recommendations concerning fiber intake. This paper reviews data and evidence from clinical trials and meta-analyses on renal and cardiovascular outcomes related to modifications in protein, fat and fiber intake. Suggestions for maintaining nutritional status through patient-oriented dietary patterns and enteral supplementation in CKD patients on conservative therapy are also presented.