Evaluation of epicardial fat tissue thickness in patients with Hashimoto thyroiditis

Abstract

Hypothyroidism, whether overt or subclinical, has multiple effects on the cardiovascular system. Epicardial fat tissue (EFT) is closely related to cardiovascular disorders and atherosclerosis. Our study aimed to assess EFT thickness and carotid artery intima-media thickness (CIMT) in patients with Hashimoto's thyroiditis (HT) displaying overt and subclinical hypothyroidism (SCH). The study included 33 patients with SCH and 24 patients with overt hypothyroidism (OH) with HT as well as 32 healthy controls. EFT thickness, CIMT, thyroid hormone levels and lipid parameters were measured in all subjects. Correlation analysis and linear regression analysis were performed for EFT thickness. Mean EFT thickness was 2·89±0·38, 3·53±0·92 and 4·56±1·61mm in control, SCH and OH groups, respectively (P<0·001). EFT thickness of OH patients was high compared with SCH and control subjects (P<0·01 and <0·001, respectively). CIMT of OH patients was high compared with SCH and control subjects (P<0·01 and <0·001, respectively). In addition, EFT was significantly thicker in SCH patients than in controls (P<0·05). Correlation analysis showed that EFT thickness was significantly positively correlated with CIMT, age, body mass index, systolic blood pressure, thyroid-stimulating hormone, total and LDL cholesterol and triglyceride and negatively correlated with free T4. In the regression analysis, EFT thickness retained its independent and positive association with CIMT, patient group (particularly OH) and systolic blood pressure. Epicardial fat tissue thickness may be a useful indicator of early atherosclerosis in SCH and OH patients with HT.