Is Serum Uric Acid Level Associated with Disease Activity in Rheumatoid Arthritis Patients

Background: An association between serum uric acid (UA) and disease activity in rheumatoid arthritis (RA) patients has not been well studied. We describe RA patients with high and normal UA and study its association with RA activity. Methods: Adult RA patients from the Kuwait Registry for Rheumatic Diseases (KRRD) were studied from February 2012 through March 2022. Patients with documented UA levels were included. UA of > 357 μmol/L (6mg/dL) was considered high. Statistical comparison and correlation were made using multivariate logistic regression. Results: Overall, 1054 patients with documented UA. A total of 158 patients (15%) had high UA level with a mean of 409± 44.4μmol/L. The mean age for the high UA group and low UA group were 59.3 ± 10.7 years and 54.5 ± 12.4 years, respectively ( p < 0.001). 49.4% were female in high UA group, and 62.2% were female in low UA group, respectively ( p < 0.05). Logistic analysis showed an inverse relation between DAS28 and UA, as lower DAS28 score was associated with higher UA level ( p =0.032) OR 1.39. There was a direct relation with HAQ, creatinine and UA. A higher HAQ is associated with a higher UA level ( p =0.019) OR 0.78. High creatinine level is also associated with high UA level ( p < 0.001) OR 0.24. The use of antirheumatic drugs was similar among patients with high and normal UA. Conclusion: RA patients with a higher UA had a lower disease activity despite using similar antirheumatic drugs. The reasons behind this association need to be further studied. Keywords: rheumatoid arthritis, uric acid, disease activity, DAS28, registry, KRRD, Kuwait, Middle East