Evaluation of the Pattern of Thyroid Dysfunctions in Patients With Metabolic Syndrome

The metabolic syndrome (MetS) is a clustering of multiple risk factors for atherosclerotic cardiovascular disease such as central obesity, impaired fasting glucose (IFG) or type 2 diabetes mellitus (T2DM), elevated triglyceride (TG), reduced high density lipoprotein cholesterol (HDL-C) and hypertension (HTN).This cluster of metabolic abnormalities is associated with increased risk for atherosclerotic cardiovascular disease and type 2 diabetes mellitus Despite of the controversy on its definition, it is estimated that one out of four people around the world suffers from MetS. The prevalence of MetS is increasing all over the world.

Thyroid hormones play an important role in regulating energy homeostasis, carbohydrate, lipids and protein metabolism. These hormones accelerate metabolic processes and may be associated with metabolic syndrome. Hyperthyroidism is usually associated with low cholesterol and glucose intolerance; whereas hypothyroidism is associated with high cholesterol tendency, and patients are prone to weight gain and cardiac signs like bradycardia. Thyroid functions affect the components of MetS including HDLcholesterol (HDL-C), triglycerides (TG), blood pressure and plasma glucose.

Thyroid dysfunction (TD) is defined as the altered serum thyroid stimulating hormone (TSH) level with normal or altered thyroid hormones (free triiodothyronine and free thyroxine.TD is risk factors for CardioVascular Disease mediated by the effects of thyroid hormones on lipid and glucose metabolism and blood pressure, hence on components of MetS.MetS and TD are both characterized by a cluster of common abnormalities such as abdominal obesity, hyperglycemia, HTN, reduced HDL-C, and elevated TG and recognized independent risk factors of ASCVD ..Thyroid dysfunction, prominently subclinical hypothyroidism has been observed more frequently in metabolic syndrome patients than general population .

The study on evaluation the pattern of TD in MetS population may help us to know the magnitude of overlap of these two disease entities and may highlight the importance of thyroid function tests in patients with MetS. This can lead to proper planning and adequate management strategies, resulting in significant reduction in cardiovascular morbidity and mortality due to MetS with TD. Thus, this study aims to evaluate the pattern of TD in patients with MetS and to explore the relationship between TD and components of the MetS.