Association of Rheumatoid Arthritis with Chronic Kidney Disease

Background Rheumatoid arthritis (RA) has been linked to an increased risk of chronic kidney disease (CKD), but the predominant renal phenotype and its independence from established risk factors remain unclear. We examined the RA–CKD association in a large, population-based cohort. Methods RA and CKD were defined using ACR-EULAR and KDIGO criteria. Logistic regression models were employed with stepwise adjustment: first for cardiovascular risk (SCORE2), followed by a model including age, sex, metabolic syndrome, smoking status, NSAID use and high-sensitivity C-reactive protein (hsCRP). Interaction terms were tested to evaluate effect modification. Results Among 9,665 participants from the Paracelsus 10,000 cohort, 296 (3.1%) had RA. CKD prevalence was higher in the RA group compared to controls (11.8% vs. 6.7%, p<0.001). Albuminuria at preserved GFR was the dominant renal manifestation in RA (6.8% vs 4.2%, p=0.027). In unadjusted analyses, RA was associated with higher odds of CKD (OR 1.86, 95% CI 1.30–2.68), an association that persisted after cardiovascular risk adjustment. However, the association was attenuated and no longer statistically significant in the fully adjusted model (OR 1.43, 95% CI 0.96–2.13). A significant interaction was observed with NSAID use (p=0.042), whereby the association was largely confined to RA patients not using NSAIDs. Conclusions RA is associated with a higher prevalence of CKD, primarily driven by albuminuria at preserved kidney function. This distinct renal phenotype appears largely mediated by metabolic comorbidities rather than inflammation alone. Our findings highlight the need for systematic albuminuria screening in RA patients to enable earlier detection and intervention.