Physical Performance and All-Cause Mortality in CKD

Abstract

It is well documented that measures of exercise capacity and physical performance are impaired in people with ESRD who are undergoing maintenance dialysis therapy. 1-3 Several studies have also described impaired exercise capacity in CKD patients who have lesser degrees of reduced GFR, and who are not receiving chronic dialysis treatment. 4,5 The causes for impaired exercise capacity and physical performance are not entirely clear. 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. The article published by Roshanravan et al. in this issue of JASN is unique in that it is the first to address the question of whether physical performance is associated with mortality rates. 8 It examined this question in 385 patients who were not receiving chronic dialysis therapy, but had stage 2-4 CKD. Patients were recruited from two prospective cohorts: the Seattle Kidney Study and the University of Maryland Study of Chronic Kidney Disease. There were some differences in the characteristics of the patients in these two separate cohorts, but these differences would not be expected to invalidate the results of the study. 8 Physical performance was measured by usual gait speed (walking 4 m at the patient's usual pace), timed up and go test (TUAG) (time to stand from a seated position and walk around a cone placed 4 m distant), 6-minute walking distance, and handgrip strength (HGS). For some study participants, the reduction in GFR was rather modest. The inclusion criteria required the estimated GFR (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration study equation 9 to be ,90 ml/min per 1.73 m 2 . Other inclusion criteria were that the patient was not receiving chronic renal replacement treatment at the time of the physical performance assessment, did not have a stroke, was not using a wheel chair, and had completed at least one physical performance measurement. Mortality rate was monitored over a median duration of 3 years.The mean age of the participants was 61613 years, and the mean eGFR was 41619 ml/min per 1.73 m 2 . The results of this innovative study indicate that measures of physical performance of the lower extremities were at least 30% below predicted values and were strongly associated with mortality rates. Each 0.1-m/s decrement in gait speed was associated with a 26% higher risk for all-cause death (hazard ratio, 1.26; 95% confidence interval, 1.09 to 1.47). Each 1-second longer TUAG was associate...

Gait disorders in CKD patients: muscle wasting or cognitive impairment? A cross-sectional pilot study to investigate gait signatures in Stage 1–5 CKD patients

“…It is widely known that CKD severity affects the health status both for physical and cognitive performance [ 1 – 3 , 9 ] and the clinical parameters collected in this study confirms this. The relation between muscle strength and gait performance is well known [ 20 , 26 , 46 ] and decreased muscle strength may explain why people show decreased walking velocity [ 47 ].…”

“…Patients at end stage renal disease (ESRD) are known to be particularly frail [ 1 ]. Compared to the general population, they show a reduced physical performance [ 2 , 3 ], a higher fall rate [ 4 – 8 ], and higher cognitive impairment [ 9 ].…”

Physical function was related to mortality in patients with chronic kidney disease and dialysis

“…24 Thus, cardiovascular disease remains a main cause of morbidity and mortality in patients with CKD. 25 The 6-minute walk test (6MWT) is widely used to evaluate functional capacity and predict mortality in CKD populations. Specifically, impaired exercise capacity and reduced physical performance is associated with increased morbidity or mortality in nondialyzed patients with CKD.…”

“…Specifically, impaired exercise capacity and reduced physical performance is associated with increased morbidity or mortality in nondialyzed patients with CKD. 25 The 6-minute walk test (6MWT) is widely used to evaluate functional capacity and predict mortality in CKD populations. 26 Performance on the 6MWT predicts the risk for mortality, cardiovascular events, and hospitalizations in patients with CKD on dialysis.…”

A Pilot Observational Study Assessing Long-Term Changes in Clinical Parameters, Functional Capacity and Fall Risk of Patients With Chronic Renal Disease Scheduled for Hemodialysis

“…The frailty status of the HD population is broadly described in the literature (7,16,84), and recently many studies have analyzed the health status of the CKD population classified into different disease stages, and thus the relationship between CKD severity and frailty (29,(85)(86)(87)(88), slower gait speed (26), and decline in cognitive function (89) is becoming more evident. However, thus far the role of the transitional phase from predialysis to longterm dialysis in the frailty development process of patients with CKD is not well understood (32).…”