title: Low Physical Function in Maintenance Hemodialysis Patients Is Independent of Muscle Mass and Comorbidity.
abstract: OBJECTIVE
  It is unknown whether muscle wasting accounts for impaired physical function in adults on maintenance hemodialysis (MHD).
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Outpatient dialysis units and a fall clinic.
  
  
  METHODS
  One hundred eight MHD and 122 elderly nonhemodialysis (non-HD) participants.
  Mid-thigh muscle area was measured by magnetic resonance imaging.
  
  
  METHODS
  Physical function was measured by distance walked in 6 minutes.
  
  
  RESULTS
  Compared with non-HD elderly participants, MHD participants were younger (49.2 ± 15.8 vs. 75.3 ± 7.1 years; P < .001) and had higher mid-thigh muscle area (106.2 ± 26.8 vs. 96.1 ± 21.1 cm2; P = .002). However, the distance walked in 6 minutes was lower in MHD participants (322.9 ± 110.4 vs. 409.0 ± 128.3 m; P < .001). In multiple regression analysis adjusted for demographics, comorbid conditions, and mid-thigh muscle area, MHD patients walked significantly less distance (-117 m; 95% confidence interval: -177 to -56 m; P < .001) than the non-HD elderly.
  
  
  CONCLUSIONS
  Even when compared with elderly non-HD participants, younger MHD participants have poorer physical function that was not explained by muscle mass or comorbid conditions. We speculate that the uremic milieu may impair muscle function independent of muscle mass. The mechanism of impaired muscle function in uremia needs to be established in future studies.
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, Utah.
authors.forename: Robin L
authors.initials: RL
authors.lastname: Marcus
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, Utah.
authors.forename: Paul C
authors.initials: PC
authors.lastname: LaStayo
authors.affiliation: Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: T Alp
authors.initials: TA
authors.lastname: Ikizler
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Guo
authors.initials: G
authors.lastname: Wei
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Ajay
authors.initials: A
authors.lastname: Giri
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Radiology, University of Utah, Salt Lake City, Utah.
authors.forename: Glen
authors.initials: G
authors.lastname: Morrell
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, Utah.
authors.forename: Patricia
authors.initials: P
authors.lastname: Painter
authors.affiliation: Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah; Veterans Affairs Salt Lake City Healthcare System, Renal Section, Salt Lake City, Utah. Electronic address: Srinivasan.beddhu@hsc.utah.edu.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Beddhu
mesh_terms: D000368:Aged; D015897:Comorbidity; D003920:Diabetes Mellitus; D005260:Female; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000503:physiopathology / Q000628:therapy*; D008171:Lung Diseases / Q000150:complications; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000150:complications*; D006435:Renal Dialysis; D013848:Thigh; D014652:Vascular Diseases / Q000150:complications; D016138:Walking / Q000502:physiology / Q000706:statistics & numerical data*
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