title: D-dimer, inflammatory markers, and lower extremity functioning in patients with and without peripheral arterial disease.
abstract: BACKGROUND
  We determined whether higher levels of D-dimer, C-reactive protein (CRP), fibrinogen, and serum amyloid A are associated independently with functional impairment in patients with and without peripheral arterial disease (PAD).
  
  
  RESULTS
  Participants were 370 men and women with PAD (ankle brachial index <0.90) and 231 without PAD. Functional outcomes were 6-minute walk distance and 4-meter walking velocity. A summary performance score combined performance in walking speed, standing balance, and time for 5 repeated chair rises into an ordinal score ranging from 0 to 12 (12=best). Adjusting for age, sex, ankle brachial index, comorbidities, and other potential mediators and confounders, D-dimer levels were associated independently and inversely with performance on all 3 functional measures in the entire cohort and among patients with and without PAD, respectively. Adjusting for known and potential confounders, CRP levels were associated independently with 6-minute walk distance and the summary performance score among participants with PAD. No significant associations were observed between CRP and the functional measures among participants without PAD. Fibrinogen and SAA levels were not associated independently with the functional measures.
  
  
  CONCLUSIONS
  Higher D-dimer levels are associated with poorer functioning among individuals with and without PAD. Higher CRP levels were associated with poorer 6-minute walk performance and a lower summary performance score among participants with PAD but not among those without PAD. Additional study is needed to determine whether D-dimer and CRP are involved in the pathophysiology of functional impairment or whether they are simply sensitive markers of the extent of systemic atherosclerosis.
authors.affiliation: Department of Medicine, Northwestern University's Feinberg School of Medicine, Chicago, IL, USA. mdm608@northwestern.edu
authors.forename: Mary McGrae
authors.initials: MM
authors.lastname: McDermott
authors.forename: Philip
authors.initials: P
authors.lastname: Greenland
authors.forename: David
authors.initials: D
authors.lastname: Green
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Michael H
authors.initials: MH
authors.lastname: Criqui
authors.forename: Kiang
authors.initials: K
authors.lastname: Liu
authors.forename: Cheeling
authors.initials: C
authors.lastname: Chan
authors.forename: William H
authors.initials: WH
authors.lastname: Pearce
authors.forename: Lloyd
authors.initials: L
authors.lastname: Taylor
authors.forename: Paul M
authors.initials: PM
authors.lastname: Ridker
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Schneider
authors.forename: Gary
authors.initials: G
authors.lastname: Martin
authors.forename: Nader
authors.initials: N
authors.lastname: Rifai
authors.forename: Maureen
authors.initials: M
authors.lastname: Quann
authors.forename: Myriam
authors.initials: M
authors.lastname: Fornage
mesh_terms: D000368:Aged; D000842:Ankle / Q000098:blood supply / Q000503:physiopathology; D015415:Biomarkers / Q000032:analysis; D001916:Brachial Artery / Q000503:physiopathology; D002097:C-Reactive Protein / Q000032:analysis; D015331:Cohort Studies; D005080:Exercise Test; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D000685:Serum Amyloid A Protein / Q000032:analysis; D016138:Walking
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; D000685:Serum Amyloid A Protein; C036309:fibrin fragment D; D005340:Fibrinogen; D002097:C-Reactive Protein