Advanced glycation end products, advanced oxidation protein products, and ferric reducing ability of plasma in patients with rheumatoid arthritis: a focus on activity scores

Background Rheumatoid arthritis (RA) is a prevalent inflammatory disorder causing functional disabilities. Oxidative stress can cause inflammation and can also be induced by inflammation. Measuring oxidative stress markers could help better understand the pathophysiology of RA and may be used to define the disease severity. Material and method In this case–control study, 75 RA patients were selected among those referred to the rheumatology clinic. Patients were further categorized into two groups, with active and inactive disease according to the Disease Activity Score (DAS) 28. Forty healthy volunteered persons were selected as the control group. Blood samples were obtained, and advanced glycation end products (AGEs), advanced oxidation protein products (AOPPs), and ferric reducing ability of plasma (FRAP) were measured. The results were compared via student t-test and Chi-square. Results Mean ± SD values for AGEs, AOPP, and FRAP in cases and controls were 53.29 ± 6.82 vs. 44.43 ± 7.13 (p = 0.001), 146.08 ± 19.56 vs. 135.79 ± 14.23 (p = 0.004), and 967.13 ± 226.66 vs. 1012.87 ± 215.94 (p = 0.2), respectively. Mean ± SD values for AGEs, AOPP, and FRAP in patients with active disease and inactive disease were 53.32 ± 7.2 vs. 53.26 ± 6.48 (p = 0.9), 146.97 ± 17.56 vs. 145.06 ± 21.84 (p = 0.6), and 953.17 ± 217.09 vs. 983.09 ± 239.31 (p = 0.5), respectively. Conclusion AGEs and AOPP but not FRAP were significantly increased in RA patients compared to healthy controls. There was no significant difference between AGEs, AOPP, and FRAP in RA patients with active and inactive disease. Key points • AGEs and AOPP but not FRAP were significantly increased in RA patients compared to healthy controls. • There was no significant difference between AGEs, AOPP, and FRAP in RA patients with active and inactive disease