Association of cardiovascular disease and traditional cardiovascular risk factors with the incidence of dementia among patients with rheumatoid arthritis

Abstract

Objective: To determine the incidence of dementia in patients with rheumatoid arthritis (RA) 65 years and older, and compare the incidence of dementia in patients with RA with prevalent cardiovascular (CV) disease (CVD), CV risk factors but no prevalent CVD and neither (referent group).

Methods: We analyzed claims data from the Center for Medicare & Medicaid Services (CMS) from 2006-2014. Eligibility criteria included continuous medical and pharmacy coverage for ≥ 12 months (baseline period 2006), > 2 RA diagnoses by a rheumatologist and at least 1 medication for RA. CVD and CV risk factors were identified using codes from the Chronic Condition Data Warehouse. Incident dementia was defined by 1 inpatient or 2 outpatient claims, or one dementia specific medication. Age-adjusted incident rates were calculated within each age strata. Univariate and multivariate Cox proportional hazard models were used to calculate Hazard Ratios (HR) and 95% confidence intervals.

Results: Among 56,567 patients with RA, 11,789 (20.1%) incident cases of dementia were included in the main analysis. Age adjusted incident rates were high among all groups and increased with age. After adjustment for age, sex, comorbidities and baseline CV and RA medications, patients with CVD and CV risk factors between 65 and 74 years had an increased risk for incident dementia compared to those without CVD and without CV risk factors (HR 1.18 (95% CI 1.04-1.33) and HR 1.03 (95% CI 1.00-1.11), respectively). We observed a trend towards increased risk in patients between 75 and 84 years with CVD at baseline.

Conclusion: Patients with RA with both CVD and CV risk factors alone are at an increased risk for dementia compared to those with neither CVD nor CV risk factors; however, this risk is attenuated with increasing age. The impact of RA treatment and CV primary prevention strategies in the prevention of dementia in patients with RA warrants further studies.

Keywords: Cardiovascular disease; Cardiovascular risk factors; Dementia; Rheumatoid arthritis.

Figure 1.

Flow Diagram of the Patients Included in Study at Baseline Year 2006 RA = rheumatoid arthritis, PsA = psoriatic arthritis, AS = ankylosing spondylitis, JIA= juvenile idiopathic arthritis, FFS = fee for service, HIV = human immunodeficiency virus.

Figure 2.

Age-adjusted Incidence Rates Per 1000-person years of Dementia in Patients with RA Stratified by Age and CVD State. A. Patients between 65 and 74 years old. B. Patients between 75 and 84 years old. C. Patients 85 years old and older. CVD = cardiovascular disease, CV = cardiovascular

Figure 3.

Multivariable-Adjusted Hazard Ratios (HR)* of Incident Dementia in Patients with RA Stratified by Age and CVD State A. RA patients in age groups 65-74 and 75-84 years old. * Model 3. Adjusted for sex, race, comorbidities, statins, cardiovascular medications (beta-blockers, ACEI/ARBs, diuretics), csDMARDs, bDMARDs, opioids and ambulatory clinical encounters. CVD = cardiovascular disease, CV = cardiovascular