Fatty acids and antioxidant micronutrients in psoriatic arthritis

OBJECTIVE. Red blood cell (RBC) fatty acid composition and micronutrient status were investigated in patients with psoriatic arthritis (PsA), with special regard to their relationship to clinical variables. METHODS. RBC fatty acid composition, selenium status--serum selenium and RBC glutathione-peroxidase activity (GSH-Px)--plasma copper, plasma and RBC zinc, plasma vitamins A and E, and RBC thiobarbiturate reactive substances (TBARS) after H2O2 exposure as an index of susceptibility to lipoperoxidation were measured in 25 patients with PsA and in 25 sex and age matched controls. RESULTS. A significant increase in C16:0 (p < 0.01) and in total saturated fatty acids (SFA) (p < 0.05), a significant decrease in C18:2 (p < 0.05), C20:4 (p < 0.001) and omega-6 polyunsaturated fatty acids (PUFA) (p < 0.001), a lower level of serum selenium (p < 0.01) and an increased level of plasma copper (p < 0.05) were observed in patients with PsA in comparison with controls. Significant direct correlations were observed between RBC SFA and erythrocyte sedimentation rate (ESR) (r = 0.445), duration of disease (r = 0.403) and morning stiffness (r = 0.434). CONCLUSION. As in other reports for rheumatoid arthritis (RA), our results support the view that an abnormal fatty acid pattern might be a particular metabolic modification involved or associated with the pathogenesis of rheumatic diseases.