Metabolic syndrome is a clustering of various metabolic parameters, which include
diabetes, low high-density lipoprotein cholesterol, elevated triglycerides, abdominal obesity, and
hypertension. It has merged as a worldwide epidemic and a major public health care concern. However,
due to the different criteria used for the assessment, the frequency of metabolic syndrome in
the general population is variable but it is more common in the older people. Metabolic syndrome is
closely linked to cardiovascular risk and increases cardiovascular outcomes and all-cause mortality.
Recent evidences showed that alterations of the thyroid function could have an impact on the
components of the metabolic syndrome, suggesting that thyroid hormones have a variety of effects
on energy homeostasis, lipid and glucose metabolism, and blood pressure.
In this review, we summarize available data on the action of thyroid hormone on the components of