Thyroid Disorders and Diabetes Mellitus: Prevalence and Assosciation

Background: Diabetes mellitus and thyroid dysfunction are closely related. Numerous studies have reported an increased prevalence of thyroid disorders in diabetic patients, especially in type 1 diabetes mellitus.

Objectives: Therefore, the purpose of this review is to discuss the numerous underlying mechanisms behind the relationship between diabetes mellitus and thyroid dysfunction in order to demonstrate that the correlation between these two prevalent conditions is unlikely to be a coincidental finding.

Review: Diabetes and Thyroid disorders are characterized by endocrine system dysfunction. Thyroid hormones influence glucose metabolism in different ways, for example, they increase absorption of glucose from the gut, increase GLUT-2 level, regulate energy balance, and cause increased lipolysis which ultimately raises glucose levels in the body. Furthermore, thyroid hormones interact with adiponectin, leptin, ghrelin, to affect glucose metabolism. Additionally, studies suggest that hyperthyroidism impairs diabetic glycemic control, whereas hypothyroidism increases the risk of hypoglycemia, further complicating diabetes management.

Conclusion: This paper emphasizes thyroid abnormalities, if left untreated, can raise the risk of several diabetes complications including retinopathy, neuropathy, and nephropathy, and can worsen diabetic symptoms. As a result, treating subclinical hypothyroidism or hypothyroidism in diabetic individuals can be advantageous. Therefore, a systematic method for early thyroid testing in diabetic patients to avoid severe complications is highly recommended.