CONTENT OF CATEHOLAMINES IN THE URINE AND CORTISOL IN THE BLOOD OF PATIENTS RECEIVING SUPPRESSIVE TYROXINOTHERAPY
It is known that with thyrotoxicosis and hyperthyroidism, changes in the functioning of the sympathoadrenal system can occur, but the question of the influence of subclinical hyperthyroidism on the activity of the mediator and hormonal component of the sympathoadrenal system, as well as the activity of the cortical layer of the adrenals, is still controversial. Patients with thyroid cancer receive suppressive therapy with levothyroxine according to vital indications, so this issue is topical from the medical point of view. The aim of the study is to evaluate the catecholamine content in the urine and cortisol in the blood of patients with highly differentiated thyroid cancer depending on the degree of suppression of the thyroid-stimulating hormone and the signs of the developing cardiovascular pathology (tachycardia, high blood pressure) and the tone of the autonomic nervous system. 93 patients with a suppressed thyroid-stimulating hormone level (TTG < 0.5 mE/L) and 50 individuals of the control group were examined. It is shown that patients differ from the control group by a significant decrease in the level of normetanephrine (noradrenaline metabolite) in the urine. In patients with a predominance of the sympathetic tone of the autonomic nervous system, there was a decrease in the levels of metanephrine and dopamine in the urine, as compared with healthy individuals with a similar tone of the autonomic nervous system. In patients with thyroid-stimulating hormone supersuppression (TTG < 0.1 mE/L), there was a significant decrease in the median of the cortisol level in the blood as compared to the control. The obtained data demonstrate the presence of compensatory mechanisms of balance of the sympathoadrenal system in subclinical hyperthyroidism, as well as the threat of development of hypocorticism in supersuppression of the thyroid-stimulating hormone (TTG < 0.1 mE/L).