Frailty and Protein-Energy Wasting in Elderly Patients with End Stage Kidney Disease

Abstract

Older people constitute an increasingly greater proportion of patients with advanced CKD, including those patients undergoing maintenance dialysis treatment. Frailty is a biologic syndrome of decreased reserve and resistance to stressors that results from cumulative declines across multiple physiologic systems and causes vulnerability to adverse outcomes. Frailty is common in elderly CKD patients, and it may be associated with protein-energy wasting (PEW), sarcopenia, dynapenia, and other complications of CKD. Causes of frailty with or without PEW in the elderly with CKD can be classified into three categories: causes primarily caused by aging per se, advanced CKD per se, or a combination of both conditions. Frailty and PEW in elderly CKD patients are associated with impaired physical performance, disability, poorer quality of life, and reduced survival. Prevention and treatment of these conditions in the elderly CKD patients often require a multifaceted approach. Here, we examine the causes and consequences of these conditions and examine the interplay between frailty and PEW in elderly CKD patients.

Physical Performance and All-Cause Mortality in CKD

“…A number of adverse conditions have been associated epidemiologically with these impairments, including physical deconditioning, muscle atrophy, anemia, a propensity toward increased serum inflammatory markers, and lower quality of life. 4,6,7 The relative contributions of these putative causes to impaired exercise capacity and reduced physical performance are not well defined.Another poorly explored area is the clinical consequences to CKD patients who manifest these disorders. No one, to my knowledge, has previously reported whether reduced exercise capacity or physical performance associates with increased morbidity or mortality in nondialyzed CKD patients.…”

“…A number of adverse conditions have been associated epidemiologically with these impairments, including physical deconditioning, muscle atrophy, anemia, a propensity toward increased serum inflammatory markers, and lower quality of life. 4,6,7 The relative contributions of these putative causes to impaired exercise capacity and reduced physical performance are not well defined.…”

“…Further studies will be necessary to examine the causal factors that are responsible for these findings. Given the current high interest in the problem of frailty in CKD patients, 3,5,7 it can be anticipated that much new information on this question will become available in the near future.…”

Distinguishing Between Cachexia, Sarcopenia and Protein Energy Wasting in End-Stage Renal Disease Patients on Dialysis

“…These characteristics and associated pathologies are reviewed elsewhere in the literature, 5,[9][10][11] and while the diagnostic criteria share similarities they are not identical. For example, weight loss is part of the definition of both cachexia in chronic illness and PEW in renal disease, but the duration of the weight loss differs (weight loss of 5% over 6 months in cachexia as opposed to 5% over 3 months in PEW).…”

“…The evidence-based development of these terms is essential to enable health care professionals to clearly identify and differentiate between such conditions. This greater understanding of the difference and interplay between cachexia, PEW and sarcopenia in ESRD Sarcopenia of old age 9 Cachexia in chronic illness 10 Protein energy wasting in renal disease 5,11 (i) Weight Not stated, but weight gain is expected in obese sarcopenia whereas weight loss can occur otherwise Oedema-free "unintentional" weight loss of at least 5% in 12 months or less in the presence of underlying illness.…”