Peripheral blood flow in patients with graves’ disease depending on level of thyroid status compensation

Abstract

Aim. To study the features of peripheral blood flow using laser Doppler flowmetry in patients with Graves’ disease depending on level of thyroid status compensation. Methods. 45 patients with Graves’ disease were divided into three groups 15 patients each depending on level of thyroid status compensation. The first group included patients with compensated hyperthyroidism, the second - with subcompensated hyperthyroidism, the third - with decompensated hyperthyroidism. All patients received combined thyrotropic (thiamazole 15-30 mg, average dose 22.4±1.7 mg) and cardio- and vasotropic therapy (metoprolol 50-100 mg, average dose 72.1±3.3 mg, and fozinopril 10-20 mg, average dose 17.8±2.4 mg), doses were individually adjusted. Results were compared with the control group (15 healthy patients). The peripheral blood flow was evaluated using LAKK-01 («LAZMA», Russia) device. Results. The comparison of control group and patients with Graves’ disease depending on level of thyroid status compensation demonstrated substantial differences. Doppler flowmetry registered increased blood flow, square deviation, variation coefficient in patients with diffuse thyrotoxic goitre, reflecting increase of tissue blood perfusion and reduced vascular tone. The analysis of the frequency histogram showed that the increase of average blood flow amplitude in case of hyperthyroidism was initiated by increase in amplitudes of all flaxmotions characterizing metabolic processes in capillaries. The relevant correlation between registered variables of blood flow and level of thyroid status compensation was registered. The most marked changes were revealed in patients with subcompensated and decompensated hyperthyroidism. In patients with compensated hyperthyroidism, the blood flow was altered the least compared to control group. Increased impact of active blood flow modulation mechanisms due to neurogenic activity and vascular tone was revealed. At the same time, endothelial activity was decreased. Predominance of sympathetic stimuli and compensatory mechanisms intensifying were discovered. Conclusion. The changes of peripheral blood flow in patients with Graves’ disease were typical for congestive-hyperemic type of microcirculation. Intensity of blood flow alterations is defined by thyroid status compensation. However, even the complete clinical and laboratory compensation doesn’t result in total recovery of capillary blood flow compared to healthy people.