Spinal cord injury leads to increased risk for cardiovascular disease and results in greater risk of death. Sub-clinical markers of atherosclerosis have been reported in carotid arteries of spinal cord injured individuals (SCI), but the development of lower extremity peripheral arterial disease has not been investigated in this population. The purpose of this study was to determine the effect of spinal cord injury on ankle-brachial index (ABI) and intima-media thickness (IMT) of upper-body and lower-extremity arteries. We hypothesized that the aforementioned measures of lower-extremity peripheral arterial disease would be worsened in SCI compared to controls and that regular participation in endurance exercise would improve these in both groups. To test these hypotheses, ABI and IMT were determined in 105 SCI and compared to 156 able-bodied controls with groups further sub-divided into physically active and sedentary. ABIs were significantly lower in SCI versus controls (0.96 ± 0.12 vs. 1.06 ± 0.07, p < 0.001) indicating a greater burden of lower-extremity peripheral arterial disease (PAD). . Upper-body IMTs were similar for brachial and carotid arteries in controls versus SCI. Lower extremity IMTs revealed similar thicknesses for both superficial femoral and popliteal arteries, but when normalized for artery diameter, individuals with SCI had greater IMT than controls in the superficial femoral (0.094 ± 0.03 vs. 0.073 ± 0.02 mm/mm lumen diameter, p < 0.01) and popliteal (0.117 ± 0.04 vs. 0.091 ± 0.02 mm/mm lumen diameter, p < 0.01). The ABI and normalized IMT of SCI compared to controls indicate that sub-clinical measures of lower-extremity peripheral arterial disease are worsened in individuals with SCI. These findings should prompt physicians to consider using the ABI as a screening method to detect lower-extremity PAD in SCI.
- peripheral arterial disease
- spinal cord injury
- Copyright © 2011, American Journal of Physiology - Heart and Circulatory Physiology