Biochemical isthmus [nexus] between type 2 diabetes mellitus and thyroid status—an update

Both Type 1 [T1DM] and Type 2 diabetes mellitus [T2DM] share a nexus with altered thyroid status. In recent times, evidences point to the link between thyroid hormones andT2DM in particular. Several lines of evidences suggest an array of biochemical and molecular events. Gene polymorphism, disturbances in gene expression and regulation, enhanced and bizarre absorption of dietary glucose from intestine, decreased utilization of glucose by tissues and aberrations in hepatic handling of glucose with the onus on Gluconeogenesis are some of the projected mechanisms. Insulin resistance, a progressive condition is the hallmark in T2DM. Hypothyroidism as well as hyperthyroidism have been associated with insulin resistance which are synonymous with impaired glucose metabolism in T2DM. A multitude of basic, clinical and molecular studies provide an insight into thyroid comorbidity in T2DM, though there are a few instances to suggest equivocal link denoting cause-effect relationship. In biochemical pharmacology, as fortified by pharmacogenomics, modalities have now been proposed, through drug trials, to underline the utility of specifically designed thyroid hormone analogues in addressing metabolic syndrome, DM and associated cardiovascular pathology. A thorough understanding of the physiological, biochemical and molecular mechanisms would certainly open newer vistas in the perspectives of T2DM with special reference to alterations in thyroid status.