MODERN VIEWS ON PRIMARY HYPOTHYROIDISM IN THE LIGHT OF CONCEPTION OF CARDIOVASCULAR RISK (LITERATURE REVIEW)

The article gives prevalence data for hypothyroidism and substantiates expediency of screening examination for TSH in all cardio-logical patients for the purpose of verification of thyroid diseases as a possible cause of insufficient effectiveness of hypolipidemic, antihypertensive therapy and development of approaches to treatment optimization. Thyroid pathology ranks first among all endocrinopathies in Ukraine. Practically, the whole area of Ukraine is experiencing an iodine deficiency. Hypothyroidism belongs to one of the most widespread forms of thyroid pathology and occurs in 8 % of adult population of our planet. The frequency of hypothyroidism among females is from 4 to 21 %, among males: 3-16%. In general, in the world spread of manifested hypothyroidism reached 2-3 % cases in the whole population, while subclinical hypothyroidism in females is in average 10 % independently from age, and at the age above 60 years, it increases to 20 %. During the first year, 5-15 % cases of sub-clinical hypothyroidism become a manifested form with the development of cardiovascular complications in 70-80 % cases. Surgical treat-ment of thyroid diseases (nodular goiter, diffuse toxic goiter, adenomas, and carcinomas) causes acquired hypothyroidism. A special attention is paid to influence on cardiovascular diseases of manifested hypothyroidism, as well subclinical hypothyroidism. Subclinical hypothyroidism in females of the age above 55 years with TSH level 4-10 mIU/l is an important development factor of atherosclerotic diseases and myocardial infarction, independently of cholesterol level. Thyroid hormone deficiency is accompanied usually by violation of metabolic processes with further development of changes of different severity degree in all without exception organs and systems. Exactly lesion of the cardiovascular system with an early vascular atherosclerosis, development of so-called «myxedema heart» is the most serious complication of hypothyroidism. There is an opinion that hypothyroidism causes hemodynamic disorders mainly as result of the diastolic cardiac dysfunction, and presence of cardiomyopathy can be a sole symptom hypothyroidism manifesting with, including the presence of pericardial effusion. The frequency of hypothyroidism among the common population of patients with arterial hypertension is 3-4 %, comparing to renovascular arterial hypertension, which frequency is 1 %. As by hypothyroidism, as well by arterial hypertension, heart size changes. By hypothyroidism, it is seen dilata-tion of cardiac chambers, increasing of septum аnd left ventricular posterior wall thickness, as well ventricular remodeling.