Impaired endothelial function in patients with ankylosing spondylitis

In recent years, accelerated atherosclerosis and increased risk of cardiovascular events have been described in patients with rheumatic disease, particularly for rheumatoid arthritis and systemic lupus erythematosus. However, the link between inflammation, atherosclerosis and ankylosing spondylitis is controversial. We evaluated the degree of atherosclerosis and endothelial function of ankylosing spondylitis patients ultrasonographically.

Fifty-four patients with ankylosing spondylitis (37 +/- 11 yr, 29 males, 25 females) and 31 healthy controls (35 +/- 9 yr, 16 males, 15 females) were consecutively enrolled in the study. Serum lipids, creatinine, glucose, and acute-phase proteins were assessed. The Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) were also evaluated. Flow-mediated dilatation and endothelium-independent dilatation of the brachial artery and intima-media thickness of the common carotid artery were measured sonographically.

Left, right and averaged intima-media thickness of the common carotid artery did not show a statistically significant difference between the ankylosing spondylitis and control groups. However, flow-mediated dilatation was significantly lower in the ankylosing spondylitis patients (14.1 +/- 6.7 vs 17.6 +/- 8%; P = 0.03). Likewise, nitroglycerin-induced dilatation was lower in the patient group, but the difference was not significant (16.4 +/- 6.8 vs 19.8 +/- 10%; P = 0.07). No correlation was detected between flow-mediated dilatation and age, sex, serum lipids, CRP, ESR, smoking habits and disease activity scores. Intima-media thickness of the common carotid artery was positively correlated with age and BASMI score (r = 0.55, P = 0.00; r = 0.22, P = 0.04, respectively).

This study demonstrates impairment of endothelial function in ankylosing spondylitis.