Objective: This study compared plasma antioxidant/oxidant status and the dietary nutrient intake of patients with systemic lupus erythematosus (SLE) to those of healthy controls.
Patients and methods: The study included 97 consecutive patients with SLE and 97 age- and sex-matched healthy controls. Blood samples from 19 patients and 19 controls were subjected to analyses of plasma concentrations of alpha-tocopherol and malone dialdehyde and the activities of superoxide dismutase and glutathione peroxidase in the plasma. All patients and controls were interviewed using a semiquantitative food-frequency questionnaire.
Results: The plasma alpha-tocopherol concentration was lower in patients, but this difference was not statistically significant. Plasma superoxide dismutase and glutathione peroxidase activities were significantly lower in patients than in controls, and the plasma malone dialdehyde level was significantly higher in patients than in controls. The intake of all major dietary antioxidants, including vitamin A, beta-carotene, and vitamin C, but not retinol, was lower in patients than in controls, but this difference was significant only for vitamin A and beta-carotene.
Conclusions: These results show that plasma antioxidant status is impaired and dietary antioxidant intake is decreased in patients with SLE.