Thyroid hormones (T3 and T4) synthesized by thyroid gland and play an essential role in normal body development and tissue metabolism. Iodine is an essential factor that is required for the synthesis of thyroid hormones. The secretion of thyroid hormones is
regulated by Negative feedback mechanism. After reached in blood circulation the majority of T4 and T3 bound with carrier proteins called thyroxine binding proteins (TBG) which shows higher affinity for T4. The common diseases related to thyroid hormones include Hypothyroidism, hyperthyroidism, thyroiditis, goiter, nodes, and tumors of thyroid glands (benign and malignant). Subclinical hypothyroidism also called mild thyroid failure is defined as normal thyroid hormones but mildly elevated TSH (5 – 10 uIU/ml) with no or mild sign and symptoms. The thyroid disorders are more prevalent in females than males. Hypothyroidism is associated with obesity and various studies conducted to find out the relationship between TSH and BMI observed different finding in the particular study. In the present study, a poor positive correlation between TSH and BMI was observed in the total euthyroid subjects. A poor negative association between TSH and BMI in euthyroid males and poor positive (r value – 0.21) relationship was observed in euthyroid females. In Subclinical hypothyroid patients (total, male and female), Poor negative correlation was observed between TSH and BMI. The
conclusion of this study is, as TSH increased the BMI will also increase in (mostly females) euthyroid subjects. The Inverse or poor negative correlation was observed within TSH and BMI among euthyroid males and an inverse correlation was noticed in patients with subclinical hypothyroidism.