Black Africans currently experience a distinctly low frequency of atherosclerotic cardiovascular disease. Whether this protection persists in those with rheumatoid arthritis (RA) is unknown. We compared the carotid atherosclerosis burden and its relationships with cardiovascular (CV) risk factors between Africans with RA from a developing black and developed CV population.
We performed high resolution B-mode ultrasonography and assessed CV risk factors in 243 patients with established RA, of whom 121 were black and 122 white. Data were analyzed in age, sex, and healthcare center-adjusted regression models.
The mean±SD common carotid intima-media thickness (cIMT) was 0.694±0.097 mm in black and 0.712±0.136 mm in white patients (adjusted p=0.8). Plaque prevalence was also similar in black compared to white cases (35.5% and 44.3%, respectively; adjusted OR 0.83, 95% CI 0.32-2.20, p=0.7). Interactions between population grouping and several CV risk factors were independently associated with cIMT and plaque. In stratified analysis, that is, in each population group separately, risk factors associated with cIMT or/and plaque comprised the systolic blood pressure (p=0.02), serum cholesterol/high-density lipoprotein cholesterol ratio (p=0.004), C-reactive protein concentrations (p=0.01), and the presence of extraarticular manifestations (p=0.01) in whites but, contrastingly, the Arthritis Impact Measurement Scales tension score (p=0.04) and use of nonsteroidal antiinflammatory agent (p=0.03) in black patients. The Framingham score was significantly associated with atherosclerosis only in whites (p<0.0001).
The carotid atherosclerosis burden is similar in black compared to white Africans with RA, but relationships between modifiable CV risk factors and atherosclerosis vary substantially among Africans with RA.