Assessment of subclinical vascular disease associated with ankylosing spondylitis

Studies indicate that ankylosing spondylitis (AS), as well as rheumatoid arthritis, may be associated with accelerated atherosclerosis and vascular disease. We assessed endothelial dysfunction, carotid atherosclerosis, and aortic stiffness in AS in context with clinical and laboratory measurements.

Forty-three patients with AS and 40 matched healthy controls were studied. We assessed common carotid intima-media thickness (ccIMT), flow-mediated vasodilation (FMD), and pulse-wave velocity (PWV) in association with age, disease duration, smoking habits, body mass index, patient's assessment of pain and disease activity, Bath AS Disease Activity Index, Bath AS Functional Index (BASFI), metric measurements, erythrocyte sedimentation rate, C-reactive protein, and HLA-B27 status.

We found impaired FMD (6.85 ± 2.98% vs 8.30 ± 3.96%; p = 0.005), increased ccIMT (0.65 ± 0.15 vs 0.54 ± 0.15 mm; p = 0.01), and higher PWV (8.64 ± 2.44 vs 8.00 ± 1.46 m/s; p = 0.03) in patients with AS compared to controls, respectively. We also found that ccIMT negatively correlated with FMD (r = -0.563; p = 0.0001) and positively correlated with PWV (r = 0.374; p = 0.018). Both ccIMT and PWV correlated with disease duration (r = 0.559; p = 0.013 and r = 0.520; p = 0.022, respectively), BASFI (r = 0.691; p = 0.003 and r = 0.654; p = 0.006), decreased lumbar spine mobility (r = -0.656; p = 0.006 and r = -0.604; p = 0.013), chest expansion (r = -0.502; p = 0.047 and r = -0.613; p = 0.012), and increased wall-occiput distance (r = 0.509; p = 0.044 and r = 0.614; p = 0.011).

In this well characterized AS population, impaired FMD and increased ccIMT and PWV indicate abnormal endothelial function and increased atherosclerosis and aortic stiffness, respectively. The value of noninvasive diagnostic tools needs to be further characterized.