Role of uric acid in predicting renal dysfunction in patients with rheumatoid arthritis

Abstract

Seraj Ahmed Khan, Sabin Tamrakar, Rosan Prasad Shah Kalawar

Objective: Recent epidemiologic studies provide evidence for hyperuricemia as a potential independent risk factor for the development of kidney disease as well as in its progression. Recent evidence supports the hypothesis that uric acid (UA) may take on a direct pathogenic role in multiple diseases, including renal disease. Previous reports have indicated that patients with rheumatoid arthritis (RA) also have considerable incidence of renal disease. Therefore, in this study, we investigate the potential association of UA with renal dysfunction in patients with RA. Methods: In this hospital-based cross-sectional study, 100 newly diagnosed cases of RA were included. Three millilitre of blood sample was collected from the patients, separated, and stored at −20°C until analysis. Serum UA (SUA) was estimated by the uricase-peroxidase method. Serum creatinine was measured by Jaffe’s method. Pearson’s correlation and Spearman’s Rho were used for the correlation. Linear regression analysis was performed to predict the outcome variable in the patients. SPSS version 18 was used for the statistical analysis of the data. Results: A total of 97 RA patients were recruited, out of which, 55 were males and 42 were females. Mean age of the patients was 48.64 ± 12.35 and body mass index (BMI) was 28.20 ± 3.41. SUA and creatinine level were 8.0 ± 1.38 mg/dl and 1.42 ± 0.81, respectively. The mean estimated glomerular filtration rate (eGFR) of the patients was 67.28 ± 28.05 ml/minutes/1.73 m2. Based on eGFR there were 23% with normal renal function, 31% had a mild renal impairment, 41% had moderate renal impairment, and 5% had severe renal impairment. Linear regression model showed age and UA was strongly associated with eGFR (β = −0.324, P = 0.004; β = −0.472, P < 0.001) and predicts the incidence of altered kidney function. Conclusion: This study shows that age and UA is an independent predictor of renal dysfunction in patients with RA.