Cardiovascular (CV) morbidity and mortality are increased in rheumatoid arthritis (RA). Prior investigations of the association of RA with measures of carotid atherosclerosis have yielded conflicting results. We compared carotid intima-media thickness (IMT) of both the common carotid (CCA) and proximal internal carotid (bulb-ICA) arteries, and plaque prevalence, between RA and non-RA participants.
Subjects with RA were participants in a cohort study of subclinical CV disease in RA. Non-RA controls were selected from the Multi-Ethnic Study of Atherosclerosis. Both groups underwent B-mode ultrasonography of the right and left CCA and bulb-ICA. Linear regression was used to model the association of RA status with CCA and bulb-ICA-IMT, and logistic regression for the association of RA status with plaque.
We compared 195 RA patients to 198 non-RA controls. CV risk factors were similarly distributed, except for a higher prevalence of hypertension in the RA group. Mean adjusted bulb-ICA-IMT was higher in RA patients than controls (1.16 vs 1.02 mm, respectively; p < 0.001), while mean adjusted CCA-IMT did not differ significantly. After adjusting for CV risk factors, the odds of plaque were significantly increased in RA participants compared to controls (OR 2.41, 95% CI 1.26-4.61). The association of gender, age, smoking, and hypertension with bulb-ICA-IMT and plaque did not significantly differ by RA status. Interleukin 6 was strongly associated with bulb-ICA-IMT and plaque in controls but not in RA patients. In the RA group, shared epitope was associated with an increased prevalence of plaque.
Compared to controls, RA was associated with a higher prevalence and higher severity of atherosclerosis in the bulb-ICA but not the CCA. Our data suggest that future studies in RA that utilize carotid artery measurements should include assessment of the bulb-ICA.