Thyroid Autoimmunity in Patients with Type 1 Diabetes

Introduction: Although with significant geographic differences, the prevalence of thyroid autoimmunity is higher in patients with type 1 diabetes. Female sex, age, and diabetes duration have been associated with higher risk of thyroid autoimmunity. We aim to evaluate, in our population of type 1 diabetes patients, the occurrence of thyroid autoimmunity and determine differences for age and gender. Material and Methods: Retrospective study of laboratory results with clinical information on type 1 diabetes from the last 15 years in our hospital. Thyroid autoimmunity was defined by positive thyroid autoantibodies (thyroid peroxidase antibody and/or thyroglobulin antibody). Statistical analysis: IBM SPSS v. 20. Results: We analyzed data from 554 type 1 diabetes patients, however, only 263 (47.5%) patients had at least one determination of thyroid auto-antibodies and were included for the analysis. The patients had a median age of 22.0 years (IQR 13.0-34.0). Most patients were adults (60.1%; n = 158) and females (56.7%; n = 149). Thyroid autoimmunity was present in 23.2% (n = 61) and there were no statistical differences in age (p = 0.055) or gender (p = 0.310). Conclusion: Thyroid autoimmunity was present in almost one-quarter of type 1 diabetes patients, without statistical differences between gender and age. In contrast with previous studies that reported a higher prevalence in females, our study failed to demonstrate the female bias in thyroid autoimmunity occurrence.