Evaluation of Thyroid Autoantibodies in Type 2 Diabetes

OBJECTIVE: Diabetes mellitus and thyroid disease are the two common endocrinopathies seen in adult population. Studies to evaluate thyroid disorders in patients with type 2 diabetes are lacking. The aim of this study was to compare prevalence of thyroid dysfunction and autoim-munity in type 2 diabetic patients with age and sex matched non-diabetic control group. MATERIAL AND METHODS: Among patients referred to Yazd Diabetes Research Center, 2797 type 2 diabetic patients were recruited. Clinical examination were carried out and samples for thyroid function test were obtained including thyroxin (T4), triiodothyronine (T3), Thyroid Stimulating Hormone (TSH), T3 Resin Uptake (T3RU), thyroid peroxidase antibodies (TPO-Ab) and thyroglobulin antibodies (TG-Ab). They were compared with 4844 non-diabetic, age and sex matched control subjects. RESULTS: Our findings showed that the levels of thyroid hormone were not significantly different from levels in non-diabetic controls (P < 0.05). Positive TPO antibody was found in 1032 type 2 diabetic patients (36.9%) versus 1802 (37.2%) in control group (P = 0.8). Positive both thyroid antibodies, TPO antibody and TG antibody were found in 314 diabetic patients; (11.2%) versus 516 (10.8%) in controls (P = 0.54). CONCLUSION: Our findings indicate that the frequency of thyroid autoimmunity is not significantly higher in type 2 diabetic patients than in non-diabetic control group.