TY - JOUR
T1 - Uremic Myopathy Limits Aerobic Capacity in Hemodialysis Patients
AU - Moore, G. E.
AU - Parsons, D. B.
AU - Stray-Gundersen, J.
AU - Painter, P. L.
AU - Brinker, K. R.
AU - Mitchell, J. H.
N1 - Funding Information:
From the Moss Heart Center, University of Texas Southwestern Medical Center, and Dallas Nephrology Associates, Dallas, TX. Received May 22, 1992; accepted in revisedform March 9, 1993. Supported by a grant from the American Heart Association, Texas Affiliate. Presented in part in abstract form at the Annual Meeting of the American College of Sports Medicine, Salt Lake City, UT,1990. * Present address: Department of Internal Medicine, Presbyterian Hospital of Dallas, Dallas, TX. Address reprint requests to Jere H. Mitchell, MD, Division of Cardiopulmonary Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75235. © 1993 by the National Kidney Foundation, Inc. 0272-6386/93/2202-0007$3.00/0
PY - 1993
Y1 - 1993
N2 - Eleven end-stage renal disease patients trained by stationary cycling during their hemodialysis treatments. After a 6-week control period, 12 weeks of training began and was increased to 30 to 60 minutes at ≥70% of peak heart rate. Baseline, pretraining and, posttraining exercise tests were performed. Workload (WL), oxygen uptake ( V˙O 2peak), cardiac output ( Q˙), heart rate (HR), and arterial oxygen content (CaO2) were measured. Stroke volume (SV), arteriovenous oxygen difference ((a-v)O2), and mixed-venous oxygen content (CvO2) were calculated. Rectus femoris biopsies were obtained pretraining and posttraining. At peak exercise, WL increased from 60 ± 4 to 70 ± 6 W (P < 0.05), V˙O 2peak showed an upward trend from 14.8 ± 0.9 to 16.8 ± 1.3 mL/kg/min (P < 0.1), and Q˙, HR, SV, CaO2, CvO2, and (a-v)O2 were unchanged. Ten of the 11 patients increased WL, but only six increased V˙O 2peak (five of 11 patients decreased V˙O 2peak). The difference between groups (P < 0.02) was attributable to (a-v)O2, which increased in those who increased V˙O 2peak (P < 0.02). There was an upward trend for succinate dehydrogenase activity (P < 0.06), and phosphofructokinase activity increased (P < 0.05). However, the rectus femoris capillary to fiber ratio, type I and II fiber areas, and fiber area variability were unchanged, and neither histomorphologic nor enzymatic activity changes were related to change in V˙O 2peak. We conclude that not all dialysis patients increase V˙O 2peak after training, but most can improve exercise capacity. Patients who improved V˙O 2peak widened their (a-v)O2 difference, increasing oxygen extraction and showing that oxygen delivery is not always the limiting factor. Thus, the limitation of V˙O 2peak in dialysis patients is a complex interaction of central and peripheral factors. Muscle therapies, such as exercise training, are needed in addition to increased oxygen delivery in rehabilitation of dialysis patients.
AB - Eleven end-stage renal disease patients trained by stationary cycling during their hemodialysis treatments. After a 6-week control period, 12 weeks of training began and was increased to 30 to 60 minutes at ≥70% of peak heart rate. Baseline, pretraining and, posttraining exercise tests were performed. Workload (WL), oxygen uptake ( V˙O 2peak), cardiac output ( Q˙), heart rate (HR), and arterial oxygen content (CaO2) were measured. Stroke volume (SV), arteriovenous oxygen difference ((a-v)O2), and mixed-venous oxygen content (CvO2) were calculated. Rectus femoris biopsies were obtained pretraining and posttraining. At peak exercise, WL increased from 60 ± 4 to 70 ± 6 W (P < 0.05), V˙O 2peak showed an upward trend from 14.8 ± 0.9 to 16.8 ± 1.3 mL/kg/min (P < 0.1), and Q˙, HR, SV, CaO2, CvO2, and (a-v)O2 were unchanged. Ten of the 11 patients increased WL, but only six increased V˙O 2peak (five of 11 patients decreased V˙O 2peak). The difference between groups (P < 0.02) was attributable to (a-v)O2, which increased in those who increased V˙O 2peak (P < 0.02). There was an upward trend for succinate dehydrogenase activity (P < 0.06), and phosphofructokinase activity increased (P < 0.05). However, the rectus femoris capillary to fiber ratio, type I and II fiber areas, and fiber area variability were unchanged, and neither histomorphologic nor enzymatic activity changes were related to change in V˙O 2peak. We conclude that not all dialysis patients increase V˙O 2peak after training, but most can improve exercise capacity. Patients who improved V˙O 2peak widened their (a-v)O2 difference, increasing oxygen extraction and showing that oxygen delivery is not always the limiting factor. Thus, the limitation of V˙O 2peak in dialysis patients is a complex interaction of central and peripheral factors. Muscle therapies, such as exercise training, are needed in addition to increased oxygen delivery in rehabilitation of dialysis patients.
KW - Dialysis
KW - exercise
KW - muscle
KW - oxygen uptake
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U2 - 10.1016/S0272-6386(12)70319-0
DO - 10.1016/S0272-6386(12)70319-0
M3 - Article
C2 - 8352254
AN - SCOPUS:0027209896
SN - 0272-6386
VL - 22
SP - 277
EP - 287
JO - American Journal of Kidney Diseases
JF - American Journal of Kidney Diseases
IS - 2
ER -