title: Circulating blood markers and functional impairment in peripheral arterial disease.
abstract: OBJECTIVE
  To determine whether higher levels of inflammatory blood markers, D-dimer, and homocysteine were associated with greater impairment in lower extremity functioning in persons with peripheral arterial disease (PAD).
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Three Chicago-area medical centers.
  
  
  METHODS
  Four hundred twenty-three persons with PAD (ankle-brachial index (ABI) <0.90).
  
  
  METHODS
  Lower extremity performance was assessed using the 6-minute walk and with usual- and fast-paced 4-m walking speed. Blood markers were D-dimer, C-reactive protein (CRP), interleukin-6 (IL-6), soluble vascular cellular adhesion molecule-1 (sVCAM-1), soluble intracellular adhesion molecule-1 (sICAM-1), and homocysteine. Calf muscle area was measured using computed tomography.
  
  
  RESULTS
  Adjusting for confounders, higher levels of D-dimer (P<.001), IL-6 (P<.001), sVCAM-1 (P=.006), CRP (P=.01), homocysteine (P=.004), and sICAM-1 (P=.046) were associated with poorer 6-minute walk performance. Higher levels of D-dimer (P<.001), IL-6 (P=.003), sVCAM-1 (P=.001), and homocysteine (P=.005) were associated with slower usual-paced 4-m walking speed. Higher levels of D-dimer, sVCAM-1, sICAM-1, IL-6, and homocysteine were associated with slower fast-paced walking speed. Results were attenuated after additional adjustment for calf muscle area.
  
  
  CONCLUSIONS
  Higher levels of inflammation and D-dimer were associated with poorer lower extremity performance in participants with PAD, independent of confounders including ABI.
authors.affiliation: Department of Medicine and Preventive Medicine, Feinberg School of Medicine, Northwestern University Cicago, IL, USA. mdm608@northwestern.edu
authors.forename: Mary M
authors.initials: MM
authors.lastname: McDermott
authors.forename: Kiang
authors.initials: K
authors.lastname: Liu
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Lu
authors.initials: L
authors.lastname: Tian
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: David
authors.initials: D
authors.lastname: Green
authors.forename: Jin
authors.initials: J
authors.lastname: Tan
authors.forename: Yihua
authors.initials: Y
authors.lastname: Liao
authors.forename: William H
authors.initials: WH
authors.lastname: Pearce
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Schneider
authors.forename: Kimberly
authors.initials: K
authors.lastname: McCue
authors.forename: Paul
authors.initials: P
authors.lastname: Ridker
authors.forename: Nader
authors.initials: N
authors.lastname: Rifai
authors.forename: Michael H
authors.initials: MH
authors.lastname: Criqui
mesh_terms: D000203:Activities of Daily Living / Q000145:classification*; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000097:blood / Q000175:diagnosis*; D001794:Blood Pressure; D004185:Disability Evaluation; D005080:Exercise Test; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D005500:Follow-Up Studies; D015577:Geriatric Assessment; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D007383:Intermittent Claudication / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D018836:Inflammation Mediators; C036309:fibrin fragment D; D006710:Homocysteine