Features of the influence of subclinical hypothyroidism on the cardiovascular system

Dysfunction of the thyroid gland has serious consequences for the state of the cardiovascular system. In conditions of deficiency of thyroid hormones, the production of a number of cellular enzymes decreases, that leads to the development of dyslipidemia, insulin resistance, endothelial dysfunction, arterial hypertension, abnormalities in the blood coagulation system, oxidative stress. is a risk factor for cardiovascular disease because associated with dyslipidemia, insulin resistance, arterial hypertension, oxidative stress, endothelial dysfunction, disorders in the blood coagulation system and, thus, atherosclerosis. Subclinical hypothyroidism, as a risk factor for cardiovascular disease, does not have a specific symptomatology, it remains unrecognized for a long time, and by the time the development of manifest hypothyroidism leads to irreversible changes in the cardiovascular system. Detection of abnormalities at the phase of subclinical hypothyroidism and the timely assignment of replacement therapy will avoid an additional risk of cardiovascular pathology. The absence of a unified position in regard to subclinical hypothyroidism does not allow to adopt clear clinical recommendations. Data on the efficacy and need for levothyroxine replacement therapy are contradictory due to the absence of randomized clinical trials. This review article examines mechanisms of the influence of subclinical hypothyroidism on various types of metabolism, methods of diagnosing disorders caused by subclinical hypothyroidism and their modification under the influence of replacement therapy.