Reduced antioxidant defense and increased oxidative stress in spinal cord injured patients.

OBJECTIVE

To determine the plasma and urine levels of antioxidants and oxidative stress biomarkers in subjects with spinal cord injury (SCI) the first year after injury.

DESIGN

Descriptive 1-year follow-up study.

SETTING

Rehabilitation and research center.

PARTICIPANTS

SCI subjects (n=37; age range, 18-70 y) consecutively enrolled within the first month after injury. A healthy, able-bodied control group (n=346) was also included.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Blood and urine levels of antioxidants and oxidative stress biomarkers were measured at inclusion and after 3 and 12 months postinjury.

RESULTS

One month after injury, the plasma antioxidants (total and oxidized glutathione and 6 different carotenoids and α-tocopherol) were reduced by 19% to 71% among the SCI subjects compared with the controls. The redox potential was reduced by 7% among the SCI subjects. The oxidative stress biomarker urinary 8-epi prostagladin F2α (PGF2α) increased to 161% in the SCI subjects compared with the controls. After 3 and 12 months, most of the antioxidant biomarkers were still significantly reduced compared with the controls, while urinary 8-epi PGF2α had increased to 208% compared with the controls.

CONCLUSIONS

The levels of antioxidants were significantly lower, while the marker of oxidative stress was higher in the SCI subjects compared with the controls. This observation demonstrates that SCI patients experience increased oxidative stress and reduced antioxidant defense the first year after injury. Our findings warrant intervention studies where SCI patients receive dietary antioxidant support as part of their rehabilitation.