Introduction

Abstract

Malnutrition continues to afflict a large proportion of patients with chronic kidney disease and particularly those with end-stage renal failure who are undergoing maintenance hemodialysis (MHD) or chronic peritoneal dialysis (CPD). Although the prevalence of malnutrition varies among different studies, probably an accurate estimate of the reported prevalence of this condition in maintenance dialysis (MD) patients is about 40%.1Fouque D. Nutritional requirements in maintenance hemodialysis.Adv Ren Replace Ther. 2003; 10: 183-193Google Scholar, 2Mehrotra R. Kopple J.D. Protein and energy nutrition among adult patients treated with chronic peritoneal dialysis.Adv Ren Replace Ther. 2003; 10: 194-212Google Scholar, 3Kalantar-Zadeh K. Stenvinkel P. Pillon L. et al.Inflammation and nutrition in renal insufficiency.Adv Ren Replace Ther. 2003; 10: 155-169Google Scholar In this regard, it should be noted that MD patients are not only at high risk for developing protein-energy malnutrition, but they are also at increased risk for malnutrition of certain minerals (eg, calcium, zinc, iron) and vitamins (especially for vitamins D, C, B6 and folate). The associations between evidence for malnutrition and high morbidity and mortality that have been repeatedly observed2Mehrotra R. Kopple J.D. Protein and energy nutrition among adult patients treated with chronic peritoneal dialysis.Adv Ren Replace Ther. 2003; 10: 194-212Google Scholar, 4Kalantar-Zadeh K. Ikizler T.A. Block G. et al.Malnutrition-inflammation complex syndrome in dialysis patients Causes and consequences.Am J Kidney Dis. 2003; 42: 864-881Google Scholar underscore the clinical importance of this condition. There are clearly many causes of malnutrition in individuals with chronic kidney disease, including patients who are undergoing MD. In recent years, there has been much interest and emphasis on the potential contributions of inflammation and oxidant and carbonyl stress to the pathogenesis of malnutrition in these patients.2Mehrotra R. Kopple J.D. Protein and energy nutrition among adult patients treated with chronic peritoneal dialysis.Adv Ren Replace Ther. 2003; 10: 194-212Google Scholar, 4Kalantar-Zadeh K. Ikizler T.A. Block G. et al.Malnutrition-inflammation complex syndrome in dialysis patients Causes and consequences.Am J Kidney Dis. 2003; 42: 864-881Google Scholar, 5Stenvinkel P. Heimbürger O. Paultre F. et al.Strong associations between malnutrition, inflammation and atherosclerosis in chronic renal failure.Kidney Int. 1999; 55: 1899-1911Google Scholar, 6Witko-Sarsat V. Friedlander M. Nguyen-Khoa T. et al.Advanced oxidation protein products as novel mediators of inflammation and monocyte activation in chronic renal failure.J Immunol. 1998; 161: 2524-2532Google Scholar, 7Miyata T. van Ypersele de Strihou C. Kurokawa K. et al.Alterations in non-enzymatic biochemistry in uremia Origin and significance of “carbonyl stress” in long-term uremic complications.Kidney Int. 1999; 55: 389-399Google Scholar Inflammation may induce protein-energy malnutrition by at least 2 mechanisms: the generation and release of proteins, proinflammatory cytokines, and oxidants that may induce protein degradation and/or suppress protein synthesis and the release of anorexigens that may suppress appetite and hence lead to inadequate dietary nutrient intake. Moreover, evidence suggests that oxidant and probably carbonyl stress may predispose to inflammation.2Mehrotra R. Kopple J.D. Protein and energy nutrition among adult patients treated with chronic peritoneal dialysis.Adv Ren Replace Ther. 2003; 10: 194-212Google Scholar, 5Stenvinkel P. Heimbürger O. Paultre F. et al.Strong associations between malnutrition, inflammation and atherosclerosis in chronic renal failure.Kidney Int. 1999; 55: 1899-1911Google Scholar, 6Witko-Sarsat V. Friedlander M. Nguyen-Khoa T. et al.Advanced oxidation protein products as novel mediators of inflammation and monocyte activation in chronic renal failure.J Immunol. 1998; 161: 2524-2532Google Scholar, 7Miyata T. van Ypersele de Strihou C. Kurokawa K. et al.Alterations in non-enzymatic biochemistry in uremia Origin and significance of “carbonyl stress” in long-term uremic complications.Kidney Int. 1999; 55: 389-399Google Scholar This issue of Advances in Renal Replacement Therapy provides a timely review of these issues with a particular focus on patients with end-stage renal disease who are undergoing MHD or CPD. The topics include, with regard to renal failure patients, the causes of malnutrition; methods of assessing nutritional status; inflammation and the interrelationships between malnutrition and inflammation; the association between measures of nutritional and inflammatory status and morbidity and mortality; and treatment of and dietary requirements for energy, protein, vitamins, minerals, and trace elements for individuals undergoing MHD or CPD. In addition, some of the complexities and challenges of and potential solutions to the dilemma of malnutrition and providing nutritional therapy to individuals who are living in developing countries are discussed. Because people in developing countries comprise a large proportion of the world’s population and because even in more affluent countries there are substantial subpopulations that live in poverty, this latter article, authored by Georgi Abraham, MD, and his associates,8Abraham G. Varsha Mathew M. et al.Malnutrition and nutritional therapy of chronic kidney disease in developing countries The Asian perspective.Adv Ren Replace Ther. 2003; 10: 213-221Google Scholar may be of particular interest and relevance. It is hoped that these reviews will be informative and stimulating to the reader and may lead to both improved patient care and more research in this field.