To assess the prevalence and associations of renal dysfunction in patients with rheumatoid arthritis (RA).
COMEDRA is a French nationwide cross-sectional multicenter study on comorbidities in RA. Renal function was assessed from the estimated glomerular filtration rate (eGFR), using the Modification of Diet in Renal Disease equation. RA characteristics and risk factors for renal impairment were collected. Two logistic regression models, 1 with and 1 without the Framingham Risk Score, were constructed from variables that were significantly associated with an eGFR of <60 ml/minute/1.73 m(2) or were clinically relevant.
Of the 970 recruited patients, 931 were analyzed (women 79.6%, mean age 57.8 years, disease duration 11.1 years, Disease Activity Score in 28 joints using the erythrocyte sedimentation rate [DAS28-ESR] 3.1). A total of 82 patients (8.8%) had an eGFR <60 ml/minute/1.73 m(2) and 9% had proteinuria. In univariate analysis, renal impairment was associated with age (P < 0.001), history of hypertension (P < 0.001), high systolic blood pressure (P = 0.03), and the Systematic Coronary Risk Evaluation (SCORE) equation (P = 0.002), but not with sex, disease duration, disease activity (as assessed by DAS28-ESR), nonsteroidal antiinflammatory drug use, disease severity (erosions, joint replacement), or RA medications. Multivariate analysis models showed that age (odds ratio [OR] 1.05 [95% confidence interval (95% CI) 1.03-1.09]) and hypertension (OR 2.5 [95% CI 1.5-4.3]) were associated with renal impairment. A second model showed that the SCORE equation (OR 1.33 [95% CI 1.06-1.67]) was associated with renal impairment.
Renal impairment is relatively common in RA and is associated with cardiovascular risk factors such as age, hypertension, and the SCORE equation but not with disease activity or severity.