Protein energy wasting (PEW) is common in patients with chronic kidney disease and is associated with adverse clinical outcomes, especially in individuals receiving maintenance dialysis therapy. A significant number of factors affect nutritional and metabolic status in dialysis patients leading to a multiple of adverse consequences (see Figure 1).1 These factors include, but are not limited to, inadequate dietary protein and calorie intake relative to the increased needs; catabolic effects of kidney replacement therapies and a multitude of concurrent metabolic and hormonal derangements such as systemic inflammation; metabolic acidosis, insulin resistance, hypogonadism and resistance to growth hormone.
Current status: Based on available data, it is estimated that up to 60% of maintenance dialysis patients could be at risk of or are suffering from protein-energy wasting. The occurrence of PEW is higher in dialysis patients who also have diabetes and/or cardiovascular disease — a preponderance of patients. Accordingly, a number of measures are routinely employed to identify, prevent or treat PEW in these patients. These include encouragement of increased dietary protein and calorie intake (> 1.2 g/kg of ideal body weight/day and >30 kcal/kg of ideal body weight/day, respectively), provision of optimal dialysis dose (Kt/V > 1.2), and management of co-morbidities. Unfortunately, these efforts are insufficient to circumvent the high prevalence of PEW in this patient population. Recent evidence indicates that oral nutritional supplementation leads to an anabolic state in the short and long term and is associated with better hospitalization and death rates.
Barriers: A number of factors can lead to inadequate management of nutritional and metabolic complications of end-stage renal disease. These include, but are not limited to 1) the complexity of the uremic state and presence of multiple co-morbidities exacerbating PEW (i.e. diabetes, heart failure, atherosclerosis, etc.); 2) focusing dietitians’ time on only a reactive approach to nutritional deficiencies and with, perhaps, over-emphasis on management of mineral bone disorders; 3) restrictions related to feeding during dialysis; 4) lack of reimbursement associated with nutritional supplementation; 5) inability to employ novel dialytic strategies that could be beneficial to nutritional and metabolic state; 6) a misunderstanding of the OIG limitations on intra-dialytic supplementation; and 7) a lack of proactive identification and intervention of patients at risk for loss of nutritional competence.
Recommendations: Prevention and treatment of PEW of CKD should involve an integrated approach to limit and prevent protein and energy depletion, in addition to therapies that will avoid further losses and replenish already wasted stores (see Figure 2).2 In addition to aforementioned routine preventive measures, additional nutritional supplementation administered orally, enterally or parenterally, should be provided to patients where spontaneous oral dietary intake from regular meals cannot maintain adequate nutritional status. Controlled provision and allowance of in-center meals should be encouraged to counteract the catabolic effects of hemodialysis. In clinical practice, the advantages of in-center meals or oral nutritional supplements include proven efficacy, safety and compliance, especially when provided during dialysis. For patients in whom additional nutritional supplementation is ineffective, further strategies such as anabolic steroids and exercise, in combination with nutritional supplementation or alone, may improve protein stores and represent potential additional approaches for the treatment of PEW. Appetite stimulants, anti-inflammatory interventions and newer anabolic agents are emerging as novel therapies. It is also recommended that renal dietitians 1) be directed to intensify their time teaching dialysis patients about nutritional aspects of kidney disease and identifying those at highest risk for loss of nutritional competence; and 2) be expected to pursue continuous education, supported by the providers, on the implementation of a variety of nutritional interventions. Although payment for these services is unlikely, it is recommended. Adequate treatment of this disorder will be essential in integrated care models.
Research recommendations: While numerous epidemiological data suggest that an improvement in biomarkers of nutritional status is associated with improved survival, there are no large randomized clinical trials that have tested the effectiveness of nutritional interventions on mortality and morbidity. Pragmatic clinical trials, in collaboration with the federal funding agencies and dialysis organizations, are highly recommended for testing the efficacy of large-scale implementation of nutritional interventions in maintenance dialysis patients. Until such studies are completed, it is appropriate to provide intradialytic meals or oral nutritional supplements as well as intensive dietary counseling to dialysis patients to improve longevity and quality of life in this high-risk patient population.
1. Carrero, J. J., Stenvinkel, P., Cuppari, L., Ikizler, T. A., Kalantar-Zadeh, K., Kaysen, G., Mitch, W. E., Price, S. R., Wanner, C., Wang, A. Y., ter Wee, P., and Franch, H. A. (2013) Etiology of the protein-energy wasting syndrome in chronic kidney disease: a consensus statement from the International Society of Renal Nutrition and Metabolism (ISRNM), J Ren Nutr 23, 77-90.
2. Ikizler, T.A., Cano, N. J., Franch, H., Fouque, D., Himmelfarb, J., Kalantar-Zadeh, K., Kuhlmann, M. K., Stenvinkel, P., Terwee, P., Teta, D., Wang, A. Y., and Wanner, C. (2013) Prevention and treatment of protein energy wasting in chronic kidney disease patients: a consensus statement by the International Society of Renal Nutrition and Metabolism, Kidney Int.
This report has been endorsed by the following:
Allen Nissenson, CMO DaVita Healthcare Partners Inc.
Doug Johnson, CMO Dialysis ClinicInc.
Tom Parker, CMO Renal Ventures Management LLC
Stan Lindenfeld, CMO U.S. Renal Care
J.G. Bhat, CMO Atlantic Dialysis Management Services LLC
Peter DeOreo, CMO Centers for Dialysis Care
Frank Maddux, CMO Fresenius Medical Care North America
Jonathan Lorch, CMO Rogosin Institute
John Sadler, CMO Independent Dialysis Foundation Inc.
Brigitte Schiller, CMO Satellite Healthcare Inc.
Richard Cronin, National Medical Director, American Renal Associates Inc.
Vincent Dennis, Senior Medical Advisor, Innovative Dialysis Systems Inc.
Alp Ikizler, Chair, Medical Advisory Board, DSI Renal Inc. / Vanderbilt University
Suhail Ahmed, CMO, Northwest Kidney Centers