Functional decline in patients with and without peripheral arterial disease: predictive value of annual changes in levels of C-reactive protein and D-dimer.
BACKGROUND
Inflammation may be a potential mechanism of aging-related functional decline. We determined whether greater annual increases in levels of high sensitivity C-reactive protein (hsCRP) and D-dimer predicted greater decline in functioning among persons with and without lower extremity peripheral arterial disease (PAD).


METHODS
We prospectively studied 296 men and women with PAD and 191 without PAD. Objective measures of functioning, hsCRP, and D-dimer were obtained at baseline and annually for 3 years (mean follow-up = 36.3 +/- 6.4 months).


RESULTS
Among PAD participants, greater annual increases in hsCRP were associated with greater annual declines in 6-minute walk performance (-2.63 ft/mg/L, p =.039) but not in other functional outcomes. Higher prior year absolute hsCRP levels were associated with greater declines in 6-minute walk (-2.93 ft/mg/L, p =.022), summary performance score (-0.038/mg/L, p =.017), and rapid paced 4-meter walk (-0.29 cm/s/mg/L, p =.026) during the subsequent year. Among participants without PAD, greater annual increases in hsCRP were associated with greater annual declines in 6-minute walk (-7.47 ft/mg/L, p =.002), usual-pace 4-meter walk (-0.33 cm/s/mg/L, p <.001), fast paced 4-meter walk (-0.56 cm/s/mg/L, p =.003), and the summary performance score (-0.029 mg/L, p <.001). There were no consistent associations between D-dimer levels and functional decline.


CONCLUSIONS
These findings suggest that inflammation may play a role in functional decline in persons with and without PAD.
McDermott
Mary M
MM
Northwestern University's Feinberg School of Medicine, Chicago, Illinois, USA. mdm608@northwestern.edu
Liu
Kiang
K
Guralnik
Jack M
JM
Ferrucci
Luigi
L
Green
David
D
Greenland
Philip
P
Tian
Lu
L
Criqui
Michael H
MH
Lo
Carol
C
Rifai
Nader
N
Ridker
Paul M
PM
Zheng
Jane
J
Pearce
William
W
D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D015331:Cohort Studies; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000097:blood* / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D011237:Predictive Value of Tests
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D002097:C-Reactive Protein