Role of thyroid gland in metabolic syndrome and in combination with chronic coronary heart disease and type 2 diabetes mellitus

Background. Metabolic syndrome (MS) is a topical issue of 21st century, a criterion for type 2 diabetes mellitus (DM) and coronary heart disease (CHD) severity. Violations of lipid, carbohydrate exchange and hormonal state, in particular the functional state of hypothalamic pituitary and thyroid systems, underlie MS. The functional state of thyroid gland in MS becomes the object of many researches. It is proved that thyroid hormones regulate secretion of insulin. The concept of hypothyroidism­induced MS is well­known. Subclinical hypothyroidism is an independent risk factor of atherosclerosis and acute coronary syndrome for the elderly women. It is important to pay a considerable attention to the study of thyroid function in comorbid pathology. The purpose of research is to study the thyroid function in MS and in combination with chronic CHD and type 2 DM, both compensated and decompensated. Materials and methods. Three hundred nineteen patients with MS combined with chronic CHD, compensated and decompensated type 2 DM were examined. Depending on a presence or absence of the combined pathology, six groups of patients with MS were formed. The first group was represented by patients with MS without complications, second group — MS and compensated type 2 DM, third group — MS and decompensated type 2 DM, fourth group — MS in combination with chronic CHD, fifth group — MS combined with chronic CHD and compensated type 2 DM, sixth group included patients with MS, chronic CHD and decompensated type 2 DM. The levels of thyroid­stimulating hormone (TSH), cortisol, free thyroxine, antithyroglobulin and thyroid peroxidase antibodies were determined to study the thyroid functional state and to confirm of its pathogenic role in this combined pathology. Results. According to the results of research, increase of TSH level was observed in patients with MS without complications, MS with chronic CHD, MS with chronic CHD and compensated type 2 DM. These changes are specific for subclinical hypothyroidism, having regard to the normal levels of free thyroxine. The level of cortisol was increased in MS without complications, with its further decrease. In MS with chronic CHD and decompensated type 2 DM, TSH was at the level in control group that indicates normalization of thyroid function, the cortisol level was increase. Conclusions. Levels of TSH and cortisol are the markers of severity of the combined pathology of MS with CHD and type 2 DM.