The International Society of Renal Nutrition and Metabolism Commentary on the National Kidney Foundation and Academy of Nutrition and Dietetics KDOQI Clinical Practice Guideline for Nutrition in Chronic Kidney Disease

Abstract

The Academy of Nutrition and Dietetics and the National Kidney Foundation collaborated to provide an update to the Clinical Practice Guidelines (CPG) for nutrition in chronic kidney disease (CKD). These guidelines provide a valuable update to many aspects of the nutrition care process. They include changes in the recommendations for nutrition screening and assessment, macronutrients, and targets for electrolytes and minerals. The International Society of Renal Nutrition and Metabolism assembled a special review panel of experts and evaluated these recommendations prior to public review. As one of the highlights of the CPG, the recommended dietary protein intake range for patients with diabetic kidney disease is 0.6-0.8 g/kg/day, whereas for CKD patients without diabetes it is 0.55-0.6 g/kg/day. The International Society of Renal Nutrition and Metabolism endorses the CPG with the suggestion that clinicians may consider a more streamlined target of 0.6-0.8 g/kg/day, regardless of CKD etiology, while striving to achieve intakes closer to 0.6 g/kg/day. For implementation of these guidelines, it will be important that all stakeholders work to detect kidney disease early to ensure effective primary and secondary prevention. Once identified, patients should be referred to registered dietitians or the region-specific equivalent, for individualized medical nutrition therapy to slow the progression of CKD. As we turn our attention to the new CPG, we as the renal nutrition community should come together to strengthen the evidence base by standardizing outcomes, increasing collaboration, and funding well-designed observational studies and randomized controlled trials with nutritional and dietary interventions in patients with CKD. The Academy of Nutrition and Dietetics and the National Kidney Foundation collaborated to provide an update to the Clinical Practice Guidelines (CPG) for nutrition in chronic kidney disease (CKD). These guidelines provide a valuable update to many aspects of the nutrition care process. They include changes in the recommendations for nutrition screening and assessment, macronutrients, and targets for electrolytes and minerals. The International Society of Renal Nutrition and Metabolism assembled a special review panel of experts and evaluated these recommendations prior to public review. As one of the highlights of the CPG, the recommended dietary protein intake range for patients with diabetic kidney disease is 0.6-0.8 g/kg/day, whereas for CKD patients without diabetes it is 0.55-0.6 g/kg/day. The International Society of Renal Nutrition and Metabolism endorses the CPG with the suggestion that clinicians may consider a more streamlined target of 0.6-0.8 g/kg/day, regardless of CKD etiology, while striving to achieve intakes closer to 0.6 g/kg/day. For implementation of these guidelines, it will be important that all stakeholders work to detect kidney disease early to ensure effective primary and secondary prevention. Once identified, patients should be referred to registered dietitians or the region-specific equivalent, for individualized medical nutrition therapy to slow the progression of CKD. As we turn our attention to the new CPG, we as the renal nutrition community should come together to strengthen the evidence base by standardizing outcomes, increasing collaboration, and funding well-designed observational studies and randomized controlled trials with nutritional and dietary interventions in patients with CKD. Diet is fundamental to nearly every aspect of care in patients with chronic kidney disease (CKD). In the early stages of CKD, dietary interventions can slow CKD progression and onset of symptoms, while in later stages it may delay the need for kidney replacement therapy.1Kalantar-Zadeh K. Fouque D. Nutritional management of chronic kidney disease.N Engl J Med. 2017; 377: 1765-1776Crossref PubMed Scopus (229) Google Scholar Medical nutrition therapy also plays an important role in preventing and treating protein-energy wasting, electrolyte imbalances, and bone and mineral abnormalities. However, dietary regimens for kidney diseases are also among the most restrictive of any chronic disease.2Kalantar-Zadeh K. Tortorici A.R. Chen J.L. et al.Dietary restrictions in dialysis patients: is there anything left to eat?.Semin Dial. 2015; 28: 159-168Crossref PubMed Scopus (95) Google Scholar The National Kidney Foundation and the Academy of Nutrition and Dietetics have provided an update to the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) Clinical Practice Guidelines for Nutrition in Chronic Kidney Disease.3Ikizler T.A. Burrowes J.D. Byham-Gray L.D. et al.KDOQI Nutrition in CKD Guideline Work Group. KDOQI clinical practice guideline for nutrition in CKD: 2020 update.Am J Kidney Dis. 2020; 76: S1-S107Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar While the update process did not directly involve the International Society of Renal Nutrition and Metabolism (ISRNM), the largest international nutritional organization for patients with kidney disease, many ISRNM members played important roles in the guideline development. The ISRNM also assembled a special review panel of 15 international experts (see Appendix S1) who evaluated these recommendations prior to public review. Later, remaining members of the ISRNM Council and renal nutrition leaders reviewed and critically analyzed the updated guidelines. Members also considered the meaning of the nutrition guidelines and how the field moves forward toward the future of renal nutrition. Clinicians will notice a number of changes from the previous version of the guidelines.4Clinical practice guidelines for nutrition in chronic renal failure. K/DOQI, National Kidney Foundation.Am J Kidney Dis. 2000; 35: S1-S140Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar The first step in the nutrition care process is nutrition assessment. The new guidelines suggest that it is reasonable to screen patients with CKD stages 3-5D for nutrition status biannually and provide direction for when a registered dietitian or international equivalent should conduct a detailed nutrition assessment. Another welcomed change is the emphasis on global or composite scores, as opposed to single biomarkers (i.e., albumin, prealbumin, and normalized protein catabolic rate), to indicate nutritional status. While there is strong evidence for single measures (e.g., albumin) as predictors of hospitalization and mortality,5Brown-Tortorici A.R. Naderi N. Tang Y. et al.Serum albumin is incrementally associated with increased mortality across varying levels of kidney function.Nutrition. 2020; 79-80: 110818Crossref PubMed Scopus (2) Google Scholar some have been widely utilized as a marker of overall nutritional status, particularly in patients undergoing dialysis. The new emphasis on composite scores may lead to a move away from such single biomarker measurements as isolated metrics of nutritional status. Many clinicians will welcome the new recommendations for minerals and electrolytes. In the past, clinicians may have felt obligated to restrict sodium, potassium, and phosphorus in all patients with CKD. Owing to the limited overlap in foods high in these minerals, such eating patterns are difficult to follow and may contribute to reduced overall dietary intake.2Kalantar-Zadeh K. Tortorici A.R. Chen J.L. et al.Dietary restrictions in dialysis patients: is there anything left to eat?.Semin Dial. 2015; 28: 159-168Crossref PubMed Scopus (95) Google Scholar,6Biruete A. Jeong J.H. Barnes J.L. Wilund K.R. Modified nutritional recommendations to improve dietary patterns and outcomes in hemodialysis patients.J Ren Nutr. 2017; 27: 62-70Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar These restrictions also led to reduced intakes of foods traditionally considered healthy, such as fruits, vegetables, whole grains, legumes, and nuts.6Biruete A. Jeong J.H. Barnes J.L. Wilund K.R. Modified nutritional recommendations to improve dietary patterns and outcomes in hemodialysis patients.J Ren Nutr. 2017; 27: 62-70Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar The new guidelines allow dietitians to work with patients to adjust dietary intake to maintain serum levels of these minerals and electrolytes. This will allow patients to expand their diet to include more of these heart-healthy foods and implement a more individualized approach. There are also important changes that will influence protein, energy, and delivery of macronutrients. The most noticeable difference is in the recommendations for low-protein diets (Table 1). The new guidelines make distinctions between predialysis patients with and without diabetes and provide specific ranges of protein for each. For clinically stable patients with stage 3-5 CKD and without diabetes, the new recommendations specify a range of 0.55-0.60 g/kg/day or a very low–protein diet of 0.28-0.43 g/kg/day supplemented with keto-acid analogs. This latter recommendation may be difficult in some geographic locations due to the continued unavailability of keto-acid analogs or lack of dietitians with hands-on training and experience in this area. Unlike patients without diabetes, which received a 1A recommendation, there was a lack of high-quality data for which to make a recommendation for patients with diabetic kidney disease. However, based on the opinion of experts, a slightly higher range of 0.6-0.8 g/kg/day is recommended.Table 1Ranges of dietary protein intake vis-à-vis relevant kidney disease conditions in the context of the KDOQI CPG in Kidney Disease 2020Dietary Protein Intake RangeDaily Grams of Protein Intake per kg Body Weight (g/kg/day)∗KDOQI CPG in Kidney Disease 2020 states it may be reasonable for a Registered Dietitian or Physician to use clinical judgment in determining the method to assess body weight.CommentProtein-free diet<0.25 g/kg/dayGenerally not recommended for any person including CKD patients.Very low–protein diet0.25-0.55 g/kg/dayUsually supplemented with essential amino acids or their ketoacids or hydroxy-acids. KDOQI CPG recommends 0.28 to 0.43 g/kg/day with additional keto acid/amino acid analogs to meet protein requirements (0.55 to 0.60 g/kg body weight/day) for metabolically stable CKD patients without diabetes.Low-protein diet for nondiabetic CKD†Recommended by the KDOQI Clinical Practice Guidelines in Kidney Disease.0.55-0.6Recommended by KDOQI CPG for CKD patients without diabetes.Low-protein diet (for DKD†Recommended by the KDOQI Clinical Practice Guidelines in Kidney Disease.)0.6-0.8 g/kg/dayMore consistently recommended for advanced CKD (eGFR<45 ml/min/1.73m2 or substantial proteinuria), usually no supplementation is needed as long as the regimen contains at least 50% high biologic value proteins. This range is recommended by KDOQI CPG for CKD patients with diabetes.Moderately low-protein intake0.8-1.0 g/kg/dayRecommended range for adults without CKD but at high risk of CKD including those with a solitary kidney (following nephrectomy), diabetes mellitus, hypertension, and polycystic kidneys.Moderate protein intake1.0-1.2 g/kg/dayRecommended by KDOQI CPG for metabolically stable patients on maintenance HD or PD.Moderately high-protein diet1.2-1.5 g/kg/dayReported protein intake of average United States adult without CKD.High- to very high–protein diet>1.5 g/kg/dayCan be used over limited period of time for acute conditions such as hypercatabolic AKI, high-grade burns, and PEW.AKI, acute kidney injury; CKD, chronic kidney disease; CPG, clinical practice guideline; DKD, diabetic kidney disease; DPI, dietary protein intake; eGFR, estimated glomerular filtration rate; HD, hemodialysis; KDOQI, Kidney Disease Outcomes Quality Initiative; PD, peritoneal dialysis; PEW, protein-energy wasting.Adapted from Supplementary-Appendix Table S3 by Kalantar-Zadeh and Fouque.1Kalantar-Zadeh K. Fouque D. Nutritional management of chronic kidney disease.N Engl J Med. 2017; 377: 1765-1776Crossref PubMed Scopus (229) Google Scholar∗ KDOQI CPG in Kidney Disease 2020 states it may be reasonable for a Registered Dietitian or Physician to use clinical judgment in determining the method to assess body weight.† Recommended by the KDOQI Clinical Practice Guidelines in Kidney Disease. Open table in a new tab AKI, acute kidney injury; CKD, chronic kidney disease; CPG, clinical practice guideline; DKD, diabetic kidney disease; DPI, dietary protein intake; eGFR, estimated glomerular filtration rate; HD, hemodialysis; KDOQI, Kidney Disease Outcomes Quality Initiative; PD, peritoneal dialysis; PEW, protein-energy wasting. Adapted from Supplementary-Appendix Table S3 by Kalantar-Zadeh and Fouque.1Kalantar-Zadeh K. Fouque D. Nutritional management of chronic kidney disease.N Engl J Med. 2017; 377: 1765-1776Crossref PubMed Scopus (229) Google Scholar There is some concern that multiple targets for protein intake among patients with CKD may create confusion and present challenges for implementation. Kidney hyperfiltration caused by high dietary protein intake and resultant protein degradation products is thought to be a contributing factor to kidney function decline.1Kalantar-Zadeh K. Fouque D. Nutritional management of chronic kidney disease.N Engl J Med. 2017; 377: 1765-1776Crossref PubMed Scopus (229) Google Scholar,7Jhee J.H. Kee Y.K. Park S. et al.High-protein diet with renal hyperfiltration is associated with rapid decline rate of renal function: a community-based prospective cohort study.Nephrol Dial Transpl. 2020; 35: 98-106PubMed Google Scholar Despite the slightly higher protein target for diabetic kidney disease as opposed to nondiabetic CKD, there is evidence that patients with diabetes may experience greater hyperfiltration following protein consumption.8Tuttle K.R. Bruton J.L. Perusek M.C. Lancaster J.L. Kopp D.T. DeFronzo R.A. Effect of strict glycemic control on renal hemodynamic response to amino acids and renal enlargement in insulin-dependent diabetes mellitus.N Engl J Med. 1991; 324: 1626-1632Crossref PubMed Scopus (136) Google Scholar Furthermore, the lower dietary protein targets may be challenging to achieve. For example, in the low-protein trials considered in the guidelines actual dietary protein intake was generally above 0.6 g/kg/day despite a prescribed target of 0.55-0.6 g/kg.9Locatelli F. Alberti D. Graziani G. Buccianti G. Redaelli B. Giangrande A. Prospective, randomised, multicentre trial of effect of protein restriction on progression of chronic renal insufficiency. Northern Italian Cooperative Study Group.Lancet. 1991; 337: 1299-1304Abstract PubMed Scopus (209) Google Scholar, 10Hansen H.P. Tauber-Lassen E. Jensen B.R. Parving H.H. Effect of dietary protein restriction on prognosis in patients with diabetic nephropathy.Kidney Int. 2002; 62: 220-228Abstract Full Text Full Text PDF PubMed Scopus (230) Google Scholar, 11Cianciaruso B. Pota A. Bellizzi V. et al.Effect of a low- versus moderate-protein diet on progression of CKD: follow-up of a randomized controlled trial.Am J Kidney Dis. 2009; 54: 1052-1061Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar, 12Sanchez C. Aranda P. Planells E. et al.Influence of low-protein dietetic foods consumption on quality of life and levels of B vitamins and homocysteine in patients with chronic renal failure.Nutr Hosp. 2010; 25: 238-244PubMed Google Scholar, 13Jesudason D.R. Pedersen E. Clifton P.M. Weight-loss diets in people with type 2 diabetes and renal disease: a randomized controlled trial of the effect of different dietary protein amounts.Am J Clin Nutr. 2013; 98: 494-501Crossref PubMed Scopus (53) Google Scholar, 14Meloni C. Morosetti M. Suraci C. et al.Severe dietary protein restriction in overt diabetic nephropathy: benefits or risks?.J Ren Nutr. 2002; 12: 96-101Abstract Full Text Full Text PDF PubMed Google Scholar Therefore, it may be reasonable for clinicians to aim for the lower-end of a streamlined target of 0.6-0.8 g/kg/day, regardless of CKD etiology. Clinical judgment, patient preference, and adherence will be important in the application and practical implementation of these updated protein recommendations. The new renal nutrition guidelines also do not make recommendations related to the type of protein utilized in low-protein diets. This is likely the result of the reliance on randomized controlled trials. While these provide strong evidence that can limit the risk of bias, in the absence of randomized trials it may be reasonable for clinicians to consider observational data. There are a number of observational studies,15Joshi S. Shah S. Kalantar-Zadeh K. Adequacy of plant-based proteins in chronic kidney disease.J Ren Nutr. 2019; 29: 112-117Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar,16Joshi S. Hashmi S. Shah S. Kalantar-Zadeh K. Plant-based diets for prevention and management of chronic kidney disease.Curr Opin Nephrol Hypertens. 2020; 29: 16-21Crossref PubMed Scopus (15) Google Scholar including a number that have been published after the guidelines evidence review,17Sussman E.J. Singh B. Clegg D. Palmer B.F. Kalantar-Zadeh K. Let them eat healthy: can emerging potassium binders help overcome dietary potassium restrictions in chronic kidney disease?.J Ren Nutr. 2020; Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar, 18Kim H. Caulfield L.E. Garcia-Larsen V. Steffen L.M. Coresh J. Rebholz C.M. Plant-based diets are associated with a lower risk of incident cardiovascular disease, cardiovascular disease mortality, and all-cause mortality in a general population of middle-aged adults.J Am Heart Assoc. 2019; 8: e012865Crossref PubMed Scopus (99) Google Scholar, 19Kim H. Caulfield L.E. Garcia-Larsen V. et al.Plant-based diets and incident CKD and kidney function.Clin J Am Soc Nephrol. 2019; 14: 682-691Crossref PubMed Scopus (60) Google Scholar, 20Liu H.W. Tsai W.H. Liu J.S. Kuo K.L. Association of vegetarian diet with chronic kidney disease.Nutrients. 2019; 11: 279Crossref Scopus (16) Google Scholar, 21Bach K.E. Kelly J.T. Palmer S.C. Khalesi S. Strippoli G.F.M. Campbell K.L. Healthy dietary patterns and incidence of CKD: a meta-analysis of cohort studies.Clin J Am Soc Nephrol. 2019; 14: PubMed Scopus Google Scholar that generally plant-based protein or eating Therefore, based on observational data and such as and it may be reasonable for nutrition to suggest plant-based proteins with of patient and these changes the ISRNM endorses the updated nutrition guidelines for patients with CKD. The implementation of these guidelines will from across the kidney Many patients to be that have reduced kidney The early of CKD is an important first step to the dietary changes that may slow progression and kidney failure. to the Kidney 2020 these are important to ensure effective primary and secondary prevention of K. to kidney disease and Nephrol. 2020; PubMed Scopus (36) Google G. et for prevention to and to Int. 2020; Full Text Full Text PDF PubMed Scopus Google Scholar Many including the National Kidney Foundation have to expand Furthermore, the Kidney Disease and can also expand these with the of in in kidney J. et Kidney Disease and a for increasing in Am Soc Nephrol. 25: PubMed Scopus Google Scholar Once patients are as CKD, it is important that are referred to registered dietitians or an international H. 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S. global to increasing and in kidney the International Society of Renal Nutrition and Metabolism Renal Ren Nutr. 2019; 29: Full Text Full Text PDF PubMed Scopus Google Scholar many important international that will improve evidence related to and in patients with kidney disease. International such as will be important to the of renal nutrition the ISRNM many important and published that the and of protein-energy T.A. H. et and of protein in chronic kidney disease patients: a by the International Society of Renal Nutrition and Int. 2013; Full Text Full Text PDF PubMed Scopus Google Scholar, D. Kalantar-Zadeh K. J. et and for protein-energy in acute and chronic kidney Int. Full Text Full Text PDF PubMed Scopus Google Scholar, D. Burrowes J.D. et hemodialysis from the International Society of Renal Nutrition and Ren Nutr. 28: Full Text Full Text PDF PubMed Scopus Google Scholar, F. 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