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

Abstract

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.