STUDY OF VASCULAR ENDOTHELIAL DYSFUNCTION IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE

Abstract

Abstract. Currently, inflammatory bowel disease (IBD) is the most complex and not fully resolved problem in modern gastroenterology. IBD, with its two main subtypes, Crohn's disease (CD) and ulcerative colitis (UC), is a complex multifactorial pathology caused by external and internal factors, including host genetics, the immune system, environmental factors, and the gut microbiome. The possible involvement of endothelial dysfunction is also discussed. There is evidence that in diseases characterized by chronic systemic inflammation, it affects the properties of the arteries and causes both endothelial dysfunction and changes in arterial stiffness. The aim is to study the functional state of the vascular endothelium in patients with inflammatory bowel diseases. Material and methods. A total of 69 patients with IBD aged 18 to 70 years (44.0 ± 1.4 years) were examined. All patients were divided into 2 groups depending on the nosology. 1st group consisted of 45 patients with UC, among them 23 women (51.1 %) and 22 men (48.9 %), 2nd group – 24 patients with HC, of which 14 women (58.3 %) and 10 men (41.7 %). To assess endothelial function, the method for determining endothelium-dependent vasodilation of the brachial artery (BA) in a test with reactive hyperemia was used to assess the change in BA diameter (dPA), a ATL PHILIPS HDI 5000 SONOS CT ultrasound machine with a 7.5 MHz linear transducer was used. The endothelial function index was calculated as the difference between dPA after decompression and the initial value, expressed as a percentage. The content of a soluble vascular cell adhesion molecule 1 (VCAM-1) was determined in blood serum by an enzyme immunoassay using a test system («Bender MedSystems GmbH», Austria) using an enzyme immunoassay analyzer «Stat Fax 303 Plus» («Awareness Technology Inc.», USA). The number of desquamated endothelial cells in the peripheral blood was determined by the method of J. Hladovec. Results. In the study of endothelium-dependent vasodilation (EDVD) PA in a test with reactive hyperemia, dysfunctions of the vascular endothelium were found in 75.4 % of the examined patients. Changes in vascular endothelial function were found in 82.3 % of patients with UC and 62.5 % with CC, mainly due to endothelial dysfunction (ED). Significant differences were found between the indicators of the average increase in dPA in the test with reactive hyperemia with decreased endothelial function (DEF) and normal endothelial function (NEF), as well as with DEF and ED in patients with severe UC. ED was observed 5.2 times more often than NEF (c2 = 56.8; p < 0.001) and 2.6 times more often than PFE (c2 = 31.5; p < 0.001). With moderate severity of the disease, DEF and ED occurred with the same frequency and 2.2 times higher than the number of patients with NEF (c2 = 11.3; p = 0.0008), changes in endothelium-dependent vasodilation were accompanied by a significant increase in the VCAM-1 level in serum of all IBD patients, but the highest expression of VCAM-1 was observed in UC. At the same time, the concentration of VCAM-1 was inversely correlated with endothelium-dependent vasodilation of BA (r = - 0.54, p < 0.01), which is confirmed by the quantitative characteristics of the level of VCAM-1 in various states of the endothelium. The study of the content of circulating desquamated endothelial cells in the peripheral blood made it possible to establish an increase in their number by 5 times with ED – up to (15.5 ± 4.8) × 104/L (p < 0.05), 2 times with DEF – up to (5.7 ± 0.3) × 104/L (p < 0.001) versus (3.1 ± 0.4) × 104/L in the control group. An inverse correlation was found between the number of desquamated endothelial cells and endothelium-dependent BA vasodilation (r = - 0.59, p < 0.01). Conclusions. The results of a comprehensive study of the functional state of the vascular endothelium indicate that the course of IBD is accompanied by a syndrome of endothelial dysfunction (with a predominance of DE), which is characterized by a decrease in endothelium-dependent vasodilation of BA, an increase in the level of VCAM-1 and the content of circulating desquamated endothelial cells in the blood. Keywords: inflammatory bowel disease, Crohn's disease, ulcerative colitis, endothelial dysfunction.