RELATIVE TELOMERE LENGTH OF PERIPHERAL BLOOD LYMPHOCYTES AND STRUCTURAL AND FUNCTIONAL STATE OF THE LEFT VENTRICLE MYOCARDIUM IN CLEAN-UP WORKERS OF THE CHORNOBYL ACCIDENT WHO SUFFERED FROM STENOTIC CORONARY ATHEROSCLEROSIS

Abstract

The objective was to analyze the relative telomere length (RTL) of peripheral blood lymphocytes depending on myocardium structural and functional state in emergency workers (EW) of the Chornobyl accident who suffered from coronary arteries stenotic atherosclerosis. Materials and methods. There were examined 60 male EW who operated at the Chornobyl nuclear power plant at 1986 and 25 male non-irradiated persons (control group – CG) with coronary heart disease (CHD). Everyone EW and CG patients were almost healthy before the accident. During the period 2016–2021, they underwent a comprehensive clinical and laboratory examination, echodopplercardiographic examination and determination of RTL by fluorescent hybridization in situ using laser flow cytometry. Results. EW almost did not differ from CG according to its clinical characteristics, the presence of risk factors, indices of systolic and diastolic heart functions, as well as RTL. The analysis of variance showed that RTL was influenced by the fact of irradiation in combination with obesity (p = 0.020). At normal body weight, RTL average value in CG was significantly higher than in EW (p = 0.023). According to the results of hierarchical cluster analysis of two variables as RTL and end-diastolic volume normalized by body surface area (EDV/BSA), EW and CG patients together were divided into two subgroups. The first subgroup (1st cluster) differed from the second (2nd cluster) by significantly larger average values of left ventricle (LV) EDV and end-systolic volume (ESV) as well as EDV/BSA and ESV/BSA, LV myocardial mass (MM) and MM/BSA, reduced ejection fraction (EF). In patients of the 1st cluster telomeres were significantly shorter than in the 2nd one (10,3 ± 1.7 vs. 14.3 ± 2.0 at p = 0.000). The increase of myocardial mass and LV wall thickness caused the development of its hypertrophy. The number of people with hypertrophy LV was significantly higher among patients of the 1st cluster (91.6 vs. 67.2 %, p < 0.001) due to eccentric hypertrophy LV. Accordingly, concentric hypertrophy LV was more common among patients in the 2nd cluster (24.6 vs. 4.2 % at p < 0.01). Patients of the 1st cluster was characterized by a more severe course of heart failure. Conclusions. In patients who suffered from CHD with stenotic atherosclerosis of the coronary arteries and were exposed to radiation 30–35 years earlier, having normal body weight, there was a reduction in telomere. Hierarchical cluster analysis proved to be a good tool that allows by the value of RTL and EDV/BSA to separate the group of patients with the most severe clinical course of CHD and LV systolic dysfunction among patients with the same pathology. Key words: emergency workers of the accident at the Chornobyl NPP, radiation exposure, coronary heart disease, stenotic atherosclerosis of the coronary arteries, myocardial infarction, relative telomere length, end-diastolic volume.