Background: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease, common in Thailand. The prevalence of chronic kidney disease (CKD) in Thai RA patients is uncertain.

Objective: To study the prevalence and associated factors of CKD in RA patients.

Materials and Methods: A retrospective study based on medical records was conducted. Participants were RA patients who visited Ratchaburi Hospital between May 2022 and October 2022. CKD was defined according to an eGFR below 60 mL/minute/1.73 m² by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The prevalence of CKD and associated factors was determined. Logistic regression was used to analyze the data.

Results: The present study included three hundred and two patients with a mean (SD) age of 53.7 (±12.1) years. Median (IQR) RA disease duration was 60.0 (97.7) months. The prevalence of CKD was 19.2%, consisting of 13.2% at stage 3a, 4.0% at stage 3b, 2.0% at stage 4, and 0% at stage 5. The factors associated with CKD were age of 60 years or older, hypertension, dyslipidemia, age of RA onset of 60 years or older, more than three months of joint pain before disease-modifying antirheumatic drugs (DMARDs) treatment, higher erythrocyte sedimentation rate (ESR) and RA treatment without methotrexate (p<0.05). The findings from the multivariate analysis of factors associated with CKD revealed that hypertension (adjusted OR 2.84, 95% CI 1.36 to 5.90), more than three months of joint pain before DMARDs treatment (adjusted OR 56.70, 95% CI 12.64 to 254.41), higher ESR (adjusted OR 1.01, 95% CI 1.01 to 1.03), and RA treatment without methotrexate (adjusted OR 5.45, 95% CI 1.87 to 15.89) were associated with CKD after adjusting for age.

Conclusion: The prevalence of CKD in RA patients was higher than in normal population. Factors associated with CKD were hypertension, more than three months of joint pain before DMARDs use, and higher ESR and RA treatment without methotrexate. Results from the present study should be applied to the management plans for patients with RA.

Received 19 January 2024 | Revised 9 April 2024 | Accepted 11 April 2024

DOI: 10.35755/jmedassocthai.2024.5.13991