Thyroid dysfunction and non-alcoholic fatty liver disease

Thyroid hormones are crucial for hepatic lipid and glucose metabolism. Non-alcoholic fatty liver disease (NAFLD), a very common and potentially serious disease of modern society, shares common clinical features with hypothyroidism, such as obesity, insulin resistance and dyslipidemia. Furthermore, in certain studies, increased prevalence of hypothyroidism was observed in patients with NAFLD. However, whether there is a linear relationship between thyroid hormone levels, including values within or in proximity to the reference range and NAFLD incidence and severity remains a contradictory subject in the literature. On the other hand, attempts to treat NAFLD with thyromimetic drugs remain at an early stage. In this review, data derived from observational studies along with evidence on possible treatment with thyroid hormone analogues are presented.