Interaction between protein-energy wasting and geriatric nutritional risk index in elderly patients on dialysis.

Proteineenergy malnutrition has been proposed to be a cause of refractory anemia that accompanies the malnutritioneinflammation complex (or cachexia) syndrome in dialysis patients. Malnutritioneinflammation complex syndrome and the obesity paradox are also the main etiology for “reverse epidemiology” of cardiovascular risk factors and outcomes in dialysis patients. However, in some dialysis patients, protein-energy wasting (PEW) is not related to inadequate nutrient intake. The 2013 International Society of Renal Nutrition and Metabolism meeting report notes that PEW is responsible for loss of protein mass and fuel reserve, and that PEW is a nonspecific inflammatory process. The term kidney disease wasting emphasizes the strong association between kidney diseases and PEW. However, kidney disease wasting does not provide any insight into the different causes of PEW in kidney disease. Moreover, the lack of association between kidney disease (acute kidney injury and chronic kidney disease) and PEW may be found between young (pancreatitis) and elderly individuals (chronic obstructive pulmonary disease) with different etiologies. Therefore, the expert panel reached the conclusion that the term kidney disease wasting is not a suitable substitute for PEW. There is a wide variety of causes of PEWand frailty in elderly patients with end-stage renal disease, including genotype, phenotype, comorbid conditions, duration and severity of renal failure, psychosocial problems, and lifestyle, in addition to low anabolic (insulin, growth hormone, and insulin growth factor-1) but high catabolic hormones (parathyroid hormone and glucagon), and age-related mitochondrial dysfunction and oxidative stress. Numerous different terminologies have been used to describe the phenomena of malnutrition and inflammatory wasting coexisting in patients with kidney diseases, such as uremic malnutrition, proteineenergy malnutrition, malnutritioneinflammation atherosclerosis syndrome, and malnutritioneinflammation complex syndrome. Several inflammatory markers, such as C-reactive protein, interleukin-6, tumor necrosis factor-a, interleukin-1, and serum amyloid A, have recently been shown to be associated with concomitant malnutrition and inflammatory wasting. Geriatric Nutritional Risk Index (GNRI) was first used to evaluate malnutrition and related morbidity and mortality in