title: Hemiparetic muscle atrophy and increased intramuscular fat in stroke patients.
abstract: OBJECTIVE
  To determine if skeletal muscle atrophy and greater fat deposition within the muscle are present in the hemiparetic limb of chronic (>6 mo) hemiparetic stroke patients.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Hospital-based research center.
  
  
  METHODS
  Sixty patients (47 men, 13 women; mean age +/- standard deviation, 65+/-9 y).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Patients underwent a total body scan by dual-energy x-ray absorptiometry to determine percentage of body fat, total lean mass, fat mass, and lean mass of the paretic and nonaffected legs, thighs, and arms. Thirty patients received computed tomography (CT) scans of their midthigh to determine muscle area, subcutaneous fat, and low-density lean tissue, as a measure of fat within the muscle area, of the paretic and nonaffected midthigh.
  
  
  RESULTS
  Patients were deconditioned (VO(2)peak: 1.2+/-0.3 L/min) with a percentage of body fat of 31.4%+/-9.8% and total lean mass of 51.4+/-9.1 kg. Lean mass of the paretic leg and thigh were 4% and 3% lower than the nonaffected leg (P<.001), but leg fat was not different. Arm lean mass of the paretic side was 7% lower than the nonaffected side, whereas arm fat was not different. CT studies showed that midthigh muscle area was 20% lower in the paretic limb than in the nonaffected leg (P<.001), midthigh subcutaneous fat was similar, and midthigh low-density lean tissue showed a trend to be 3% higher in the paretic leg (P=.06). The ratio of midthigh low-density lean tissue to muscle area was higher in the paretic leg (P<.001), which indicates a greater intramuscular fat relative to muscle area in the affected limb.
  
  
  CONCLUSIONS
  Our results show hemiparetic skeletal muscle atrophy and more fat within the muscle, factors that may contribute to functional disability and increased cardiovascular disease risk in chronic hemiparetic stroke patients.
authors.affiliation: Department of Medicine, Division of Gerontology, University of Maryland School of Medicine, Baltimore, MD, USA. aryan@grecc.umaryland.edu
authors.forename: Alice S
authors.initials: AS
authors.lastname: Ryan
authors.forename: C Lynne
authors.initials: CL
authors.lastname: Dobrovolny
authors.forename: Gerald V
authors.initials: GV
authors.lastname: Smith
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Silver
authors.forename: Richard F
authors.initials: RF
authors.lastname: Macko
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism*; D000368:Aged; D001823:Body Composition; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000209:etiology* / Q000378:metabolism; D010291:Paresis / Q000209:etiology / Q000378:metabolism; D020521:Stroke / Q000150:complications / Q000378:metabolism; D000071939:Stroke Rehabilitation