POS0487 ASSOCIATION OF RHEUMATOID ARTHRITIS WITH MORTALITY IN A COHORT OF CHRONIC KIDNEY DISEASE PATIENTS

Rheumatoid Arthritis (RA) is associated with an increased risk of cardiovascular disease. RA is also associated with increased risk of chronic kidney disease (CKD) (1, 2), which is a known cardiovascular risk factor (3). We hypothesized that RA (compared with no RA) would be associated with increased risk of mortality among a cohort of patients with CKD.To determine the risk of mortality in RA patients with CKD.This study was conducted using participants from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) prospective Chronic Renal Insufficiency Cohort (CRIC) study. Approximately 3600 participants were enrolled from seven US clinical centers. Patients aged 21 – 74 years with mild to moderate CKD were eligible for enrollment. The primary outcome of interest was all-cause mortality. Secondary outcomes of interest included: kidney event defined as end stage renal disease (ESRD) or 50% decline in estimated glomerular filtration rate (eGFR), myocardial infarction (MI), cerebrovascular accident (CVA), heart failure and a composite cardiovascular endpoint. The association of RA mortality over time was examined using Cox multivariate proportional hazards regression, adjusting for potential covariates (age, sex, race/ethnicity, BMI, current smoker, education). The study cohort included 492 participants with self-reported RA with a mean follow up of 9.5 years. Compared to the non-RA group, RA patients tended to be older, female, Black. Hypertension, diabetes, use of prednisone was more prevalent among the RA cohort. The unadjusted hazards ratio (HR) for mortality based on RA status was 1.45 (1.26, 1.67) but this association was attenuated after adjusting for the confounding factors [aHR 1.09 (0.94, 1.27)] (Table 1). Participants with RA had a significantly higher risk for heart failure than those without RA [aHR 1.17 (1.02, 1.34)]. We did not observe a statistically significant association between RA status and other secondary outcomes.RA was not associated with higher mortality among participants with CKD. However, RA was associated with higher rates of heart failure. Further studies evaluating the mechanisms behind this association are needed. [1]Kochi M, Kohagura K, Shiohira Y, Iseki K, Ohya Y. Chronic kidney disease, inflammation, and cardiovascular disease risk in rheumatoid arthritis. J Cardiol. 2018;71(3):277-83. [2]Sumida K, Molnar MZ, Potukuchi PK, Hassan F, Thomas F, Yamagata K, et al. Treatment of rheumatoid arthritis with biologic agents lowers the risk of incident chronic kidney disease. Kidney Int. 2018;93(5):1207-16. [3]Chiu HY, Huang HL, Li CH, Chen HA, Yeh CL, Chiu SH, et al. Increased Risk of Chronic Kidney Disease in Rheumatoid Arthritis Associated with Cardiovascular Complications - A National Population-Based Cohort Study. PLoS One. 2015;10(9):e0136508. [4]Muthukumar P, Dhanapriya J, Gopalakrishnan N, Dineshkumar T, Sakthirajan R, Balasubramaniyan T. Evaluation of renal lesions and clinicopathologic correlation in rheumatoid arthritis. Saudi J Kidney Dis Transpl. 2017;28(1):44-50.Table 1.Estimated hazard ratios (HR) for various outcomes from Cox proportional hazards regression for RA statusUnadjustedModel 1Model 2HR (95% CI)HR (95% CI)HR (95% CI)Death1.45 (1.26, 1.67)1.09 (0.94, 1.27)1.13 (0.97, 1.32)MI or death1.43 (1.25, 1.63)1.09 (0.95, 1.26)1.15 (0.99, 1.33)CVA or death1.42 (1.24, 1.63)1.07 (0.92, 1.24)1.11 (0.95, 1.29)CHF or death1.54 (1.35, 1.75)1.17 (1.02, 1.34)1.22 (1.06, 1.40)Composite1.49 (1.31, 1.69)1.13 (0.99, 1.30)1.18 (1.03, 1.35)Kidney event1.09 (0.94, 1.27)0.91 (0.78, 1.07)1.01 (0.85, 1.20)Model 1 adjusted for: age, sex, race/ethnicity, BMI, current smoker, educationModel 2 adjusted for: model 1 + cardiovascular risk factors (urine albumin creatinine ratio, systolic blood pressure, estimated glomerular filtration rate)None declared