Additional methods of examination

Clinical blood analysis: normochromic anemia, reduction of hemoglobin values, leucopenia, relative lymphocytosis, granulocytopenia, easy thrombocytopenia.

Biochemical blood analysis: oral glucose tolerance is impaired, modest reduction in serum total and LDL cholesterol concentrations, serum triglyceride concentration is normal, hepatic lipase activity and plasma free fatty acid concentration are increased. Serum alanine and aspartate aminotransferase, bilirubin concentrations are increased.

Immunological examination: decreased of T-lymphocytes and T-lymphocytes-supressors, increased of level of immunoglobulins, antibodies to thyroglobulin; appearance of thyrostimulating immunoglobulins.

Radioimmunological examination: increased serum total and free T4 and T3 concentrations and decreased TSH concentration. Thyroid radioiodine uptake is increased in most patients.

ECG: atrial fibrillation, depresses ST-segment and inverted T-wave.

Hypothyroidism

Hypothyroidism (hypothyroid syndrome) is pathological condition which resulted from insufficient secretion the thyroid hormones by thyroid gland.

Etiology

• inherited disorder of thyroid hormones biosynthesis;

• defects of embryonic development, resulting to hypo- or aplasia of thyroid gland;

• infectious-inflammatory processes, including chronic infections (tuberculosis, syphilis), attended with the degenerative changes of gland parenchyma;

• residence in endemic region with the deficit of iodine in environment;

• Hashimoto's thyroiditis;

• jatrogenic hypothyroidism due to thyroidectomy or radioactive iodine therapy;

• outcomes of treatment the diffuse toxic goiter with antithyroide drugs; pathology of the hypotaiamo-hypophysal system, relevant with decreasing of thyrotrophin-releasing hormone.

Pathogenesis

Hypothyroidism is a result of organ-specific autoimmune process which leads to destructive lymphoid infiltration of the thyroid gland transformed in fibrosis, atrophy and decreased amount of functional cells that accompanied delayed synthesis of thyroid hormones and impairment of functional activity of gland. The deficiency of the thyroid hormones are responsible for disorders every forms of metabolism. The specific sign of hypothyroidism is accumulation in extravascular tissue hydrophilic mucopolysaccharides, hyaluronic acid and chondroitin sulfate which possessing ability to retain water in organism and development of mucous edema.

The other causes of edema are increased vascular permeability and decreased lymph flow. Hypothyroidism is accompanied by hemodynamic disorders: decreasing of the rate and force of cardiac contractility, cardiac output, increasing peripheral resistance, cerebral, cutaneous and renal blood flow are reduced with corresponding clinical appearance.

The metabolic disorders are accompanied by following features: decreased energy production); electrolyte exchange; the expressed dystrophic changes in all organs and tissues; diminished crythropoesis; the considerable changes of central and peripheral nervous system; cardiovascular system with predominance of hypokinetic type of hemodinamic, digestive systems with decreased secretory and motor functions of stomach and intestine. The pathology of hypothalamo-hypophysal region and decreased release of TSH secretion lead to depressed synthesis of thyroid hormone, which results in development of the secondary hypothyroid syndrome.