THYROID HORMONES AND GLUCOSE HOMEOSTASIS: A COMPREHENSIVE REVIEW OF THEIR INTERDEPENDENCE IN DIABETES

Abstract

Two of the most prevalent endocrine diseases in the world include thyroid dysfunction and diabetes mellitus, and growing evidence indicates that there is significant interaction between thyroid hormone regulation and glucose homeostasis. This review of the current literature (2020-2025) provides a detailed assessment of the physiological, molecular, and clinical pathways between thyroid hormones (TSH, T3, and T4) and glucose metabolism, insulin sensitivity, and diabetic progression. The review combines evidence of epidemiological research, mechanistic research, and interventional research, indicating the existence of regular links between thyroid aberrancies, particularly subclinical hypothyroidism, and inadequate glycemic regulation. Molecular analyses also indicate that thyroid hormones have an effect on the PI3K-Akt-GLUT4 pathway, hepatic gluconeogenesis, and mitochondrial activities. Even with improvements, there are still serious gaps in research, such as inconsistency in screening procedures, inadequate representation of subclinical thyroid disease, and fewer multi-center population studies. In this review, the importance of combined endocrine evaluation is highlighted, and the direction of future research is also suggested to maximize clinical management of diabetes patients with thyroid dysfunction.