[Endothelial dysfunction in patients with Bechterew's disease (ankylosing spondylitis)]

The aim of the study was to assess signs of endothelial dysfunction and lesion in patients with ankylosing spondylitis (AS) of different degrees of activity. Forty-four male patients aged 20 to 45 (mean age 34.2 +/- 6.6 years) with a valid diagnosis of AS and no manifest cardiovascular pathology were examined. According to the degree of disease activity, the patients were divided into two groups: group one included 19 patients with low or moderate disease activity, and group two consisted of 25 patients with a high degree of disease activity. Conventional cardiovascular risk factors were screened, and total coronary risk (TCR) and the risk of fatal cardiovascular events were determined. The functional condition of endothelium was assessed by Doppler examination of the brachial artery in re-reactive hyperemia tests (endothelium-dependent vasodilation--EDVD), and in nytroglycerine test (endothelium-independent vasodilation--EIVD). The level of circulating endothelial cells (CEC) was measured as a marker of endothelial lesion. No significant differences were observed between the groups in terms of most conventional cardiovascular risk factors, TCR, and the risk of fatal cardiovascular events. EDVD was significantly less in patients with a high AS activity vs. patients with low or moderate activity and controls. EIVD after nytroglycerine intake was significantly stronger in both groups not only by comparison with that in controls, but also by comparison with the degree of EDVD, which can also be judged as a manifestation of endothelial dysfunction. The level of CEC in high-activity patients was significantly higher than that in the low to moderate activity group and controls. Thus, patients suffering from AS display signs of endothelial dysfunction and lesion, which are most prominent in high activity of the disease and manifest by a decrease in EDVD with a simultaneous increase in EIVD and CEC level elevation. This shows that patients with high activity of AS are at a higher risk of developing cardiovascular pathology than those with a low level of disease activity and age- and sex-comparable healthy individuals.