Antioxidant Status and Lipid Peroxides in Rheumatoid Arthritis

Oxygen free radicals have been implicated as mediators of tissue damage in patients with rheumatoid arthritis. The aim of our study was to assess the lipid peroxide products and antioxidant status in rheumatoid arthritis patients (RA). The study involved determination of two plasma lipid peroxide products, malondialdehyde (MDA) and conjugated dienes (CD), two plasma antioxidant vitamins (C and E ) in 91 RA patients and 26 healthy subjects. The results showed that rheumatoid patients had increased plasma CD but not MDA and decreased plasma vitamin E, when properly expressed per unit cholesterol and triglyceride. This finding suggested that RA patients had increased oxidant stress that might play a role in the tissue damage and inflammation process of this disease. SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH Vol 31 No. 2 June 2000 336 malondialdehyde (MDA), conjugated dienes (CD), vitamin E (Vit E), vitamin C (Vit C), cholesterol and triglyceride. MDA was determined by its reaction with thiobarbituric acid (TBA) to form a red MDA-TBA complex (Das et al, 1990) which was quantitated by fluorometry (Richard et al, 1991). CD was measured as relative absorbance at 233 nm wavelength (Beuge and Aust, 1978; Hunter and Mohamed, 1986). Plasma vitamins E and C were determined by a fluorometric method (Taylor et al, 1976) and a spectrophotometric method (Omaye et al, 1979) respectively while plasma cholesterol and triglyceride were quantitated with a commercial enzymatic kit. Statistical analysis All data were expressed as mean±SD. Unpaired student’s t-test was used for between-group comparisons. Differences were considered of statistical significance when the p-value was less than 0.05.