IMPACTS OF THYROID DISORDERS ON GLYCEMIC CONTROL IN PATIENTS WITH TYPE 1 DIABETES

Abstract

Type 1 diabetes mellitus (T1DM) is an autoimmune condition characterized by insulin deficiency, often associated with other autoimmune diseases, such as thyroid disorders. These, including hypothyroidism and hyperthyroidism, affect 17-30% of T1DM patients, directly influencing glycemic control and increasing the risk of metabolic complications. This study reviews the association between thyroid disorders and glycemic control in patients with type 1 diabetes mellitus (T1DM). It is a narrative literature review that adopted inclusion and exclusion criteria, with a systematized search to enhance research relevance, using the descriptors: Type 1 Diabetes Mellitus, Thyroid Gland Diseases, Glycemic Control. A total of 12 articles were identified. The high prevalence of thyroid dysfunctions (17-30%) in T1DM patients, stemming from shared autoimmune mechanisms, significantly impacts glycemia management. Hypothyroidism increases insulin resistance and the risk of hypoglycemia, while hyperthyroidism enhances glycolysis, leading to hyperglycemia and a higher risk of diabetic ketoacidosis. Annual TSH screening is recommended to mitigate metabolic complications, with levothyroxine replacement improving insulin sensitivity in 70-80% of cases. In Brazil, where T1DM is prevalent and adequate glycemic control is achieved by less than 13% of patients, thyroid monitoring is crucial. Future studies should focus on pediatric populations and the standardization of screening protocols to optimize T1DM management.