Prevalence of Thyroid Dysfunction and Thyroid Autoimmunity in Patients with Type 1 Diabetes Mellitus attending Tertiary Care Hospital in Madurai, South India

Objectives: To assess the prevalence of thyroid dysfunction and antithyroid peroxidase (Anti TPO) positivity in patients with type 1 diabetes mellitus attending tertiary care centre in Madurai. Research Design& Methods: This was a cross sectional observational study among subjects with type 1 Diabetes mellitus attending Department of Endocrinology, Madurai Medical College, Madurai. Thyroid function tests (TFT) and antithyroid peroxidase (Anti TPO) were measured using the electro chemiluminiscence method. Results: A total of 177 patients (M: F, 92: 85) were recruited and mean age was 11.58 3.65 years (Range 2-18 years). Mean age at diagnosis and mean duration of diabetes mellitus was 9.5 3.64 and 3.56 3.1 years respectively. The prevalence of antithyroid peroxidase (Anti TPO) positivity was 29.9 % and the prevalence of overt, subclinical hypothyroidism and Graves disease were 14.6 %, 5.6 % and 1.1 % respectively. Significantly higher proportion of female has autoimmune positivity than males (71.7 % vs 28.3 %, respectively, P =0.005). Conclusion: Our study demonstrated that autoimmune hypothyroidism is highly prevalent among patients with type 1 diabetes mellitus. Screening for hypothyroidism and thyroid autoimmunity should be undertaken in all Type 1 Diabetes mellitus at diagnosis and periodic intervals.