Assessment of carotid intima-media thickness in patients with axial Spondyloarthritis: relationship with disease serverity

Abstract

OBJECTIVE: Axial spondyloarthritis (SpA) is a chronic rheumatic disease characterised by inflammation of the spine, sacroiliac and peripheral joints, causing pain and functional disabilities. As the disease advances, syndesmophytes will form in axial joints leading to further functional loss. Carotid intima-media thickness (IMT) is widely used as a surrogate marker for subclinical atherosclerosis. It is proposed that persistent systemic inflammation in SpA is associated with early carotid atherosclerosis. The aim of this study was to evaluate the changes of carotid IMT in patients with axial SpA and their relationship with the underlying disease severity. METHODS: A total of 104 patients with axial SpA (mean age, 45.5 ± 13.3 years; 69.2% male) and 52 age- and gendermatched healthy controls were enrolled into the study. All patients underwent clinical examination, laboratory blood tests, and spine radiographs. High-resolution ultrasonography was used to measure far-wall carotid IMT at the common carotid artery. Bilateral maximum carotid IMT measurements were performed offline using semi-automated imaging processing software and the mean carotid IMT was calculated for evaluating atherosclerosis. The disease duration, erythrocyte sedimentation rate and C-reactive protein levels, Bath Ankylosing spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Functional Index (BASFI) scores were recorded. The disease severity of the axial SpA patients was assessed by modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). RESULTS: Carotid IMT was significantly increased in patients with axial SpA compared with controls (0.78 ± 0.19 mm vs 0.69 ± 0.10 mm; P < 0.001). In axial SpA patients, BASDAI (β = 0.22, P = 0.03), BASFI (β = 0.45, P < 0.001), and mSASSS (β = 0.60, P < 0.001) correlated significantly with carotid IMT. Multivariate analysis adjusting for potential confounding factors demonstrated that mSASSS was independently associated with carotid IMT (β = 0.23, 95% confidence interval, 0.00-0.01; P=0.03). In patients with mSASSS score above the median value (14.75), carotid IMT was significantly higher compared with patients below the median value (0.85 ± 0.18 mm vs 0.71 ± 0.16 mm; P < 0.001). CONCLUSION: Our study demonstrated that patients with axial SpA had early carotid atherosclerosis. mSASSS remained independently associated with carotid IMT after adjusting for the confounding factors. Importantly, the group with mSASSS score above the median value had a significantly higher carotid IMT. In conclusion, this study shows that patients with axial SpA have a tendency to develop subclinical atherosclerosis which correlates significantly with the disease severity. Whether effective disease control could prevent the development of atherosclerosis remains to be investigated.