Thickening of the epicardial adipose tissue can be alleviated by thyroid hormone replacement therapy in patients with subclinical hypothyroidism.
BACKGROUND
Subclinical hypothyroidism (SCH) is a common disorder which has adverse cardiovascular effects. Epicardial adipose tissue (EAT), a novel marker of cardiovascular risk, is increased in SCH.


OBJECTIVE
We aimed to investigate whether L-thyroxine treatment can reverse the thickening of EAT in SCH.


METHODS
Forty-four patients with SCH and 42 euthyroid control subjects were included. EAT thickness was measured using transthoracic echocardiography at baseline and after restoration of the euthyroid status with 3 months of L-thyroxine treatment.


RESULTS
At baseline, mean EAT thickness was significantly greater in the SCH group when compared to the control group (6.3 ± 1.7 mm vs. 4.1 ± 0.9 mm, respectively, p < 0.001). There was a significant positive correlation between baseline serum thyroid stimulating hormone (TSH) level and EAT thickness in the SCH group. There was a significant reduction in mean EAT thickness in response to L-thyroxine treatment (6.3 ± 1.7 mm vs. 5.1 ± 1.4 mm, p < 0.001). The decrease in EAT thickness after L-thyroxine treatment when compared to baseline (DEAT) significantly correlated to the difference in TSH levels before and after treatment (DTSH; r = 0.323; p = 0.032).


CONCLUSIONS
Epicardial adipose tissue thickness is increased in patients with SCH. This thickening was alleviated with restoration of the euthyroid status with L-thyroxine treatment in our study population of predominantly male, relatively old subjects with greater baseline EAT thickness.
Department of Internal Medicine, Ufuk University School of Medicine, Ankara, Turkey. irmaksayin@yahoo.com.
Irmak
I
Sayin
Aycan Fahri
AF
Erkan
Berkay
B
Ekici
Utku
U
Kutuk
Ahmet
A
Corakci
Hasan Fehmi
HF
Tore
D000273:Adipose Tissue / Q000187:drug effects / Q000473:pathology*; D000328:Adult; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010496:Pericardium / Q000187:drug effects / Q000473:pathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use*
D013972:Thyrotropin; D013974:Thyroxine
L-thyroxine; epicardial adipose tissue; subclinical hypothyroidism