Evaluation of epicardial fat tissue thickness as a marker of cardiovascular risk in patients with subclinical hypothyroidism.

ABSTRACT

BACKGROUND: Epicardial fat thickness (EFT) has been evaluated as a marker of cardiovascular disease, with good correlation with classical cardiovascular risk factors in the general population. The aim of this study was to evaluate the EFT in subclinical hypothyroidism (SCH), in comparison to a group without thyroid dysfunction. METHODS: A cross-sectional study was performed with 100 participants, including 52 SCH patients and 48 individuals without any thyroid dysfunction (euthyroid group-EU). Transthoracic echocardiography (TE), thyroid hormone levels, lipid profile, and assessment of body composition by bioelectrical impedance (BIA) and anthropometry were measured in all subjects. RESULTS: The SCH and EU groups were comparable with respect to age, gender, and Framingham risk scores. Serum thyroid-stimulating hormone (TSH) was 6.7 ± 1.4 mIU/L in the SCH group and 2.0 ± 0.84 mIU/L in the control group. EFT was similar in both groups (SCH 3.5 ± 1.3 mm, EU 3.5 ± 1.1 mm, p = 0.43). EFT showed a slight trend for a positive correlation with serum TSH in the SCH group (r s = 0.263, p = 0.05). EFT correlated with the body fat percentage in the SCH group (r s = 0.350, p = 0.03) and EU group (r s = 0.033, p = 0.04). EFT in this cohort was not independently correlated to changes in TSH and Framingham risk score. CONCLUSIONS: EFT determination by TE does not seem to be a good marker of cardiovascular risk in SCH patients with serum TSH <10.0 mIU/L and no pre-existing cardiovascular morbidity.