Endothelial dysfunction in workers in underground mining of chrome ores
Authors: Zaitseva N. V. , Nosov A. E. , Ivashova Ju. A. , Baidina A. S. , Kostarev V. G. 
Published: December 2019

Introduction. Currently, endothelial dysfunction is considered as one of the initial stages of the pathogenesis of cardiovascular diseases. By isolating a number of biologically active compounds, the endothelium helps to maintain vascular tone and physiological rheology of the blood. Modern production of chrome ore is characterized by a variety of harmful occupational factors (chromium, dust, noise, vibration, severity and intensity of work, cooling microclimate), which can disrupt the normal functioning of the vascular endothelium and lead to the development of cardiovascular diseases.

The aim of the study was to study the features of endothelial function in workers engaged in underground mining of chrome ore in harmful working conditions.

Materials and methods. The study included 98 miners of the enterprise for the extraction of chrome ore. The comparison group (working in conditions outside the influence of the studied production factors) consisted of 75 employees-managers and specialists of administrative and managerial personnel of the enterprise, comparable in age and experience with the observation group. To assess the vasomotor function of the endothelium, a flow-dependent (endothelium-dependent) vasodilation test was performed using the D. S. Celermajer technique. Post-occlusive increase in brachial artery diameter, brachial artery sensitivity coefficient to endothelial shift change were evaluated.

Results. The endothelial function of mine workers did not differ significantly from the comparison group with work experience up to 10 years (the values of the relative increase in the diameter of the brachial artery 12.2% in the observation group and in the comparison group 12.6%, p=0.74). With experience of more than 10 years, the value of the relative increase in the diameter of the brachial artery in the observation group with experience of more than 10 years corresponded to the signs of endothelial dysfunction and amounted to 8.6%, while in the comparison group this figure was 12.4%, which corresponded to normal endothelial function (p=0.019). Endothelial function progressively deteriorated with increasing seniority in mine workers. 

Conclusions. For workers engaged in underground mining of chrome ore for more than 10 years, a reduced vasodilation reaction to reperfusion after an occlusion test and a low coefficient of sensitivity of the endothelium to shear stress are characteristic. There was no statistically significant decrease in increase in brachial artery diameter and the coefficient of sensitivity of endothelium to shear stress relative to the comparison group was selected only from persons with experience more than 10 years. The comparative analysis of the results of the evaluation of the functional activity of the endothelium in workers of the compared groups indicates that the change in the functional state of the endothelium in miners is associated not only with age, but also with working conditions. The revealed changes predispose to the development of cardiovascular pathology associated with atherosclerosis in workers of underground chrome ore mining.