The count of tender rather than swollen joints correlates with aortic stiffness in patients with rheumatoid arthritis

BACKGROUND Patients with rheumatoid arthritis (RA) are at a higher cardiovascular (CV) risk in comparison to the general population. CV risk associates closely with aortic stiffness. Aim of this exploration was therefore to evaluate aortic stiffness in patients with RA and to examine its association with various RA associated parameters as well as with traditional CV risk factors. METHODS Measurements of carotid-femoral pulse wave velocity (cfPWV) were analyzed retrospectively in 38 RA patients and 25 controls. We investigated the statistical difference between cfPWV values in the two groups. Furthermore, we analyzed the associations of cfPWV with laboratory and clinical RA parameters including Disease Activity Score 28 and its components, rheumatoid factor, cyclic citrullinated peptide antibodies, antinuclear antibodies and RA duration. Finally, we explored the relationship of cfPWV with traditional CV risk factors in the RA group. RESULTS cfPWV was not significantly higher in RA patients in comparison to controls in an adjusted statistical model for confounding factors [-0.587 95 % CI (-1.38 to 0.201), p = 0.144]. Among RA patients there was a statistically significant correlation of cfPWV with age (rho = 0.544, p = 0.001) and the count of tender joints [0.051 95 % CI (0.008-0.207), p = 0.034]. Finally, C-reactive protein associated only marginally with cfPWV [0.105 95 % CI (-0.410 to 0.003), p = 0.053]. CONCLUSIONS In RA patients the number of tender, rather than swollen joints correlates with stiffness of the aorta, as measured through cfPWV. Therefore, RA associated joint pain might play a role in the development of aortic stiffness and thus increase CV risk.