Circulating blood markers and functional impairment in peripheral arterial disease.
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.
McDermott
Mary M
MM
Department of Medicine and Preventive Medicine, Feinberg School of Medicine, Northwestern University Cicago, IL, USA. mdm608@northwestern.edu
Liu
Kiang
K
Ferrucci
Luigi
L
Tian
Lu
L
Guralnik
Jack M
JM
Green
David
D
Tan
Jin
J
Liao
Yihua
Y
Pearce
William H
WH
Schneider
Joseph R
JR
McCue
Kimberly
K
Ridker
Paul
P
Rifai
Nader
N
Criqui
Michael H
MH
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
D005338:Fibrin Fibrinogen Degradation Products; D018836:Inflammation Mediators; C036309:fibrin fragment D; D006710:Homocysteine