Interlinking Between Altered Thyroid State and Development of Insulin Resistance: A Review

It has long been recognized that thyroid hormones have marked effects on glucose homeostasis. Glucose intolerance is associated with hyperthyroidism and most recently it was shown that hypothyroidism is characterized by insulin resistance (IR). The interaction between thyroid function and insulin sensitivity is an important contributor to diabetic dyslipidemia. Effect of thyroid status on insulin sensitivity is of great interest but despite various studies reveal conflicting data on this subject. Thyroid disorders, including both hypo- and hyperthyroidism, may be associated with IR due to a plethora mechanism like, increased FFA, accumulation of intramyocellular lipids (IMCLs), increase in (Tumor Necrosis Factor)TNF-α, altered peripheral glucose disposal, altered blood flow, impaired GLUT4 translocation, decreased glycogen synthesis, down regulated intracellular glucose catabolism, decreased muscle oxidative capacity and many more contributing factors.