Physical Functioning In Patients With Chronic Kidney Disease

Abstract

Patients with end stage renal disease have markedly reduced levels of physical functioning (PF). Little is known of the levels of PF in patients with chronic kidney disease (CKD) prior to renal replacement therapy or how PF is related to the level of renal function as measured by glomerular filtration rate (GFR). PURPOSE To document levels of PF in patients with chronic renal insufficiency using both objective laboratory measures and performance tests. METHODS Thirty one patients with stage 3 CKD (GFR < 60 ml/min/1.73 m2) (26 males/5 females; mean age 57.1±14.9 yr) were recruited for the study. Testing included symptom limited treadmill testing with measurement of VO, 6 minute walk test (6MW), sit to stand to sit (10 cycles) (STS10), and 20 foot gait speed (GS)(comfortable and fast speed). All measures except for the 6MW were converted to % of age predicted values. RESULTS VO2peak was markedly reduced (x = 17.9±6.77 ml/kg/min) and averaged 59.4±20.2% of age predicted values. Performance measures were not as markedly reduced as a percentage of normal age-predicted values: comfortable GS: 123.7±15.3%; fast GS: 86.0±16.6%; STS10: 60.9±47.3%. The only PF measure that was correlated to GFR was fast GS (r=.37; p.=05). Although the performance tests results were not as reduced compared to age-predicted values as VO2peak there were significant correlations between VO2peak and 6MW (r=.68; p < .001), comfortable GS (r=.413; p.=02) and fast GS (r=.611; p < .001). CONCLUSION Basic functioning of normal gait speed appears to be preserved in patients with CKD, with more impairments noted in activities requiring greater energy expenditure, such as fast gait speed, sit to stand tasks and symptom-limited exercise testing. Exercise training may be warranted in this population with the goal of maintaining overall functioning.