Impact of Type 2 Diabetes Mellitus on Thyroid Function: A Clinical Investigation of Endocrine Interactions

Background: Endocrine disorders frequently manifest in clinical settings, with diabetes mellitus and thyroid dysfunction standing out as particularly prevalent conditions. These two ailments exhibit a complex relationship, each capable of influencing the other’s pathophysiology. Diabetes mellitus exerts its effects on thyroid function through hypothalamic regulation and peripheral mechanisms. Conversely, thyroid abnormalities, particularly unmanaged hyperthyroidism, can significantly disrupt insulin dynamics affecting the glycemic control. Aim: To investigate the effect of glycemic status on thyroid profile in type 2 diabetes mellitus in a hospital setting. Methodology: The investigation employed a cross-sectional, observational design, conducted in a hospital setting over period of one year. Total of 200 participants (100 cases and 100 controls) underwent assessments for Total Triiodothyronine (T3), Total Thyroxine (T4), Thyroid Stimulating Hormone (TSH), as well as fasting and postprandial plasma glucose levels. Results: The study revealed a notably higher prevalence of thyroid disorders among diabetic participants. Statistical analysis showed significantly elevated mean fasting blood sugar (p = 0.0) and mean serum TSH levels (p = 0.0027) in the diabetic group. The mean serum T4 levels (p < 0.0001) were significantly lower in diabetic individuals, notably in females. Conclusion: As glycemic control deteriorates, thyroid disorders become more prevalent, especially in women. Among the thyroid function abnormalities, subclinical hypothyroidism is the most common.