A Study of Association of Thyroid Dysfunctions in Patients with Type 2 Diabetes Mellitus

Background: Type 2 diabetes mellitus is known to be associated with other endocrine dysfunctions and thyroid is one of them. In the current study we tried to evaluate the frequency of thyroid dysfunctions in patients with type 2 diabetes mellitus and compare them with a normal control population. Methods: This cross-sectional study was carried out in the Department of Physiology and Department of General Medicine, Kakatiya Medical College, and MGM Hospital, Warangal, India. A total of 50 consecutive patients with diabetes mellitus type 2 were selected as cases, and an equal number of age- and sex-matched individuals with normoglycemia as controls. Laboratory investigations included measurements of fasting blood sugar [FBS] and HbA1c values after overnight fasting for eight hours, serum triglycerides, along with serum TSH, FT3, and FT4, which were measured by chemiluminescence immunoassay. Results: Among all cases of type 2 diabetes mellitus, eight (16%) presented thyroid disorders, with 10% in male patients and 6% in female patients. The overall frequency of thyroid disorders was found in four (8%) cases, of which two (4%) in males and two in females. The values of TSH μIU/ml and FBS mg/dl in type 2 diabetes mellitus cases were plotted and a Pearson correlation coefficient of +0.70 was calculated, indicating a positive correlation between the TSH and FBS. Along with TSH levels, the values of HbA1c were plotted in patients with type 2 diabetes mellitus and a Pearson correlation coefficient of +0.76 was calculated. Conclusion: Within the limitations of the present study, it can be concluded that the prevalence of thyroid dysfunctions is more common in patients with type 2 diabetes mellitus. Also, a continuous positive correlation of TSH with FBS and HbA1c was found. Hence, a periodic screening for their coexistence in thyroid dysfunctions among diabetic patients is advisable.