Interrelationship of endothelial function parameters in children with bronchial asthma in exacerbation and remission

Introduction: In children with asthma, endothelial dysfunction signs are observed, and their extent depends on the severity of the disease. These changes are also present in remission. High level of soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) expression causes active adhesion of inflammatory cells and can indicate direct endothelium participation in development and supporting of chronic inflammation. Bronchial asthma (BA) is characterised by airways chronic inflammation. A special role in this inflammatory process formation is played by development of endothelial dysfunction. The aim of the study was to evaluate endothelial state in children with clinically stable and exacerbated asthma.

Material and methods: 91 children with persistent asthma were examined. Among them there were 40 patients with mild persistent (group I), 34 subjects with moderate persistent (group II) and 17 individuals with severe persistent (group III) asthma. 20 healthy children were selected as controls. The serum levels of sVCAM-1 were determined by enzyme-linked immunosorbent assay (ELISA). The ultrasound assessment of endothelium-dependent flow-mediated dilation of the brachial artery (FMD%) has been made. Ultrasonography has been used for investigation of the intima-media thickness (I-M) complex. Data analysis was performed with the Statsoft Statistica Version 8 (Tulsa, OK).

Results: The serum levels of sVCAM-1 were significantly increased in the patients with asthma exacerbation (p < 0.001) and remission (p < 0.001), compared with the controls. The index of FMD% was significantly diminished in the patients of I, II, III group with exacerbation (p < 0.001) and stayed lower in the subjects with asthma in remission (p < 0.001), compared with the controls. The thickness of I-M complex was significantly increased in the patients of I, II, III group, compared with the controls (p < 0.001). The endothelium parameter levels: sVCAM-1 (H = 56.11, p = 0.0001), FMD% (H = 43.20, p = 0.0000), the thickness of I-M complex (H = 49.37, p = 0.0000) depend on the severity of the disease. Correlations between the endothelium and pulmonary function parameters were proved (p < 0.05).

Conclusions: Endothelial dysfunction in children with asthma was determined. Dependence of severity of the disease on functional state of the vascular endothelium was proved.