Objective: The prevalence of thyroid dysfunction in patients with type 1 diabetes is two to threefold higher than in the general population and occurrence of thyroid dysfunction is often diagnosed late in type 1diabetic population. Our aim is to determine the natural history of thyroid dysfunction in Indian patients with type 1 diabetes. Methods: Sixty type 1 diabetic patients were recruited in the study from the diabetic clinic attached with S.P. Medical College, Bikaner. In addition to clinical assessment of all patients, determinations were made of thyroid function tests (thyroid stimulating hormone [TSH], thyroxine [T4] and triiodothyronine [T3]) and thyroid peroxidase (TPO) antibodies. Results: Out of 60 type 1 diabetic patients, a total of 8 patients had hypothyroidism and 1 patient had hyperthyroidism. 1 patient having hypothyroidism before the onset of diabetes was excluded from the study. The mean age at diagnosis was 137.5 yrs for type 1diabetes and 159.4 yrs for hypothyroidism. Hypothyroidism was more common in female 6/59 (10.2%) than in male subjects 2/59 (3.39%) and in patients with positive TPO antibodies. There was no difference in BMI, HbA1c, lipid profile, insulin level and c-peptide between patients with/without thyroid dysfunction. Conclusions: The present study indicates that each child with type 1 diabetes, apart form diabetes control, should undergo regular screening of serum TSH measurements to detect asymptomatic thyroid dysfunction, particularly those with positive TPO antibodies.
