Impact of subclinical hypothyroidism treatment in systolic and diastolic cardiac function.

OBJECTIVE To evaluate the effects of levothyroxine (L-T4) replacement in echocardiographic parameters of middle-aged women with subclinical hypothyroidism (SH). SUBJECTS AND METHODS This was a randomized, double-blind, placebo-controlled study. Echocardiographic evaluation was carried out at baseline and one year after restoration of euthyroidism. Thirty-three women with SH were assigned to one of two groups (L-T4 or placebo). RESULTS The two groups had similar basal characteristics. There was a significant deterioration of left ventricular Tei index after one year of placebo use, which differed from the effect of L-T4 replacement (+0.086 ± 0.092 vs. -0.014 ± 0.012; p = 0.047). There was also a slight reduction in cardiac output and cardiac index with placebo use, which was not different from L-T4 effect. CONCLUSION Results suggest a positive impact of L-T4 replacement in cardiac function of middle-aged women with SH.