Telomerase Activity, Hyperlipidemia and Features of Atherosclerotic Lesions of the Brachiocephal Arteries in Asymptomic Patients of Working Age with Subclinical Hypothyroidism
Authors:   Belarusian State Medical University, Petrova E.B. ,   Minsk, Republic of Belarus,   Republican Scientific and Practical Center "Cardiology"; Minsk, Republic of Belarus, Shishko O.N. ,   Belarusian State Medical University; Minsk, Republic of Belarus,   Minsk City Endocrinology Center; Minsk, Republic of Belarus, Оgurtsova S.E. ,   Institute of Bioorganic Chemistry; Minsk, Republic of Belarus, Popel A.N. ,   Republican Scientific and Practical Center "Cardiology"; Minsk, Republic of Belarus, Mitkovskaya N.P. ,   Belarusian State Medical University; Minsk, Republic of Belarus,   Republican Scientific and Practical Center "Cardiology"; Minsk, Republic of Belarus
Published: August 2024

Aim. To study telomerase activity, lipidemia and to assess the severity of atherosclerotic lesions of the brachiocephalic arteries in asymptomatic patients of working age with subclinical hypothyroidism. Design. A cross-sectional cohort study. Materials and methods. Data on 131 patients of working age (32 men and 99 women) with different hormonal status of the thyroid gland (thyroid) without clinical signs of chronic cerebral circulatory insufficiency were analyzed. Based on the assessment of the hormonal status of the thyroid gland, 2 groups of patients were formed: 87 with laboratory-confirmed hypertension (thyroid-stimulating hormone level > 4.0 mMU/l with normal characteristics of free fractions of thyroid hormones) and 44 patients without thyroid dysfunction. The groups formed were comparable in age, gender composition, presence and severity of hypertension, aggravated family history of early cardiovascular events, and smoking. All patients underwent ultrasound examination of the brachiocephalic arteries, determination of the lipid spectrum and telomerase concentration. The processing of the obtained data was carried out using statistical packages Excel, Statistica v. 10.0. The data obtained were interpreted as reliable, and the differences between the indicators were considered significant when the error-free prediction value was equal to or greater than 95% (p < 0.05). Results. In the group of people with hypothyroidism, the proportion of people with multivessel atherosclerotic lesion was higher (34.5% (n = 30) vs. 13.6% (n = 6) (χ2 = 6.37; p < 0.05)), one or a combination of several signs of instability of atherosclerotic plaque (41.4% (n = 36) vs. 18.2% (n = 8) (χ2 = 7.05; p < 0.01)). In patients with subclinical hypothyroidism, precerebral atherosclerosis occurs against the background of atherogenic type IIa secondary hyperlipidemia (67.8% (n = 59) vs. 34.1% (n = 6) (χ2 = 13.52; p < 0.001) in combination with insufficiency of antiatherogenic high density lipoproteins (74.7% (n = 65) vs. 45.5% (n = 20) (χ2 = 10.98; p < 0.001)), lower values of telomerase concentration in comparison with the group of people without thyroid dysfunction: (8.2 (7.4–9.5) vs. 10.8 (10.1–12.2) ng/ml (p < 0.001)). The relationship between the level of telomerase activity (r = –0.72; p < 0.05) and the presence of subclinical hypothyroidism, atherosclerotic lesions of the precerebral bed in patients (r = –0.33; p < 0.05) was established. Conclusion. In clinically healthy patients of working age with newly diagnosed, medically uncorrected subclinical hypothyroidism, the proportion of persons with ultrasound signs of multivessel atherosclerotic lesions of the brachiocephalic arteries is higher, and precerebral atherosclerosis occurs against the background of atherogenic type IIa secondary hyperlipidemia in combination with insufficiency of antiatherogenic high density lipoproteins, lower values of telomerase activity in comparison with the group of persons without thyroid dysfunction. Etiopathogenetic mechanisms of "early vascular aging", the criteria for stratification of risk groups for atherosclerosis-associated cardiovascular disease, the choice of diagnostic algorithms for visualizing preclinical stages of atherogenesis, and timely antiatherogenic tactics in asymptomatic patients with comorbid thyroid pathology require further study. Verification of a stenosing hemodynamically significant or non-hemodynamically significant atherosclerotic lesion of the coronary basin, regardless of the clinical component, is a factor of high cardiovascular risk requiring immediate correction of hyperlipidemia. Keywords: thyroid gland, hypothyroidism, hyperlipidemia, atherosclerosis, precerebral (brachiocephalic) arteries, telomerase activity, comorbid pathology.