Association of rheumatoid arthritis with mortality in chronic kidney disease: a cohort study

Abstract

Background: Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD) as well as with an increased risk of chronic kidney disease (CKD), also a known cardiovascular risk factor. However, it is not known if RA is a predictor of adverse outcomes in patients with CKD. We hypothesized that among a cohort of patients with CKD, RA would be associated with an increased risk of mortality.

Materials and methods: We conducted a retrospective study of 3939 participants with CKD from the prospective Chronic Renal Insufficiency Cohort (CRIC) study. The primary outcome of interest was all-cause mortality. Secondary outcomes included CKD progression (defined as end-stage kidney disease or 50% decline in estimated glomerular filtration rate), cardiovascular endpoints, and composite of myocardial infarction, cerebrovascular accident, heart failure, or death. Multivariable Cox proportional hazards regression was utilized, adjusting for potential confounders including age, sex, race/ethnicity, body mass index, current smoker, and education.

Results: The study cohort included 83 participants with RA on a disease modifying anti-rheumatic drug (DMARD). In the adjusted analysis, CKD-RA status was significantly associated with an increased risk of death (adjusted HR, aHR, 1.73 (1.27, 2.35)) and composite outcome (aHR 1.65 (1.27-2.15)) even after adjusting for traditional risk factors. Similar statistically significant associations were observed between CKD-RA and other secondary outcomes except for CKD progression.

Conclusion: RA was associated with higher mortality among individuals with CKD but not progressive renal decline. Further studies evaluating the mechanisms behind this association are needed. Key Points • Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD) as well as with an increased risk of chronic kidney disease (CKD), also a known cardiovascular risk factor. However, it is not known if RA is an independent predictor of adverse outcomes in patients with CKD • In this study, we observed that CKD patients with RA experience higher mortality as well as an increased risk of CVD compared to patients with CKD without comorbid RA • These data provide rationale for more aggressive monitoring for CVD in patients with CKD and RA. They also underscore the need for determining which interventions can help decrease the burden of mortality in these patients.

Keywords: Chronic kidney disease; Mortality; Rheumatoid arthritis.