Efectul tratamentului cu levotiroxină asupra funcției și structurii cardiace la pacienții cu hipotiroidism subclinic

Abstract

Subclinical hypothyroidism affects 5-15% of the general population; however, the need of lifelong LT4 therapy is still controversial. As myocardium is a main target of thyroid hormone action, we investigated whether SHT induces cardiovascular alterations. Fifteen patients were assigned to receive LT4 therapy and were followed for 50 weeks. Ten sex and age-matched normal subjects served as controls. Doppler echocardiography was performed in all subjects. Patients had a significantly higher IVRT (94.4 ± 7 vs. 84.3 ± 8; P: 0.0002), peak A (55.6±7 vs. 48.4 ± 3.8, P: 0.02), and pre-ejection/ejection time (0.71 ± 0.03 vs. 0.58 ± 0.03, P: 0.001). LT4 treated patients showed a significant reduction of the PEP/ET ratio (P<0.0001), peak A (P<0.02). In conclusion, SHT affects both myocardial structure and contractility. These alterations may be reversed by LT4 therapy.