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 American College of Rheumatology/European Alliance of Associations for Rheumatology and KDIGO criteria. Logistic regression models were employed with stepwise adjustment: first for cardiovascular risk [Systematic COronary Risk Evaluation 2 (SCORE2)], followed by a model including age, sex, metabolic syndrome, smoking status, non-steroidal anti-inflammatory drug (NSAID) use and high-sensitivity C-reactive protein. Interaction terms were tested to evaluate effect modification. Results: Among 9665 participants from the Paracelsus 10,000 cohort, 296 (3.1%) had RA. CKD prevalence was higher in the RA group compared with controls (11.8% vs 6.7%, 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.