Oxidative Damage and Antioxidant Status in Diabetes Mellitus and Rheumatoid Arthritis: A Comparative Study

The present work compares and correlates antioxidant defenses and oxidative stress markers in patients with Diabetes Mellitus (DM) and in those with Rheumatoid Arthritis (RA) in order to find out if new evidences for a possible relationship between these pathologies can be found. Stress markers and antioxidant defenses were tested in blood samples from RA, Type I and Type II DM patients. Erythrocytes (RBC) showed increased susceptibility to lipid peroxidation in both DM and RA, whereas basal oxidation was higher only in RA. Both pathologies showed elevated oxidized LDL concentration and decreased RBC membrane fluidity. In DM, plasma TRAP was decreased and showed an inverse correlation RBC oxidative damage. On the other hand, TRAP was normal in RA. In both pathologies, TRAP was not correlated with oxidized LDL. We can conclude that the peroxidative damage would occur through a complex mechanism, with different factors involved in both illnesses. In this way, an association between these diseases could not be established.