Patients were classified as having coexistent thyroid dysfunctions based on information on autoantibodies against thyroid peroxidase (anti-TPO), thyroglobulin (anti-Tg) and thyrotropin receptor (TRAb), thyroid function (serum free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH)), thyroid volume (sonography) as well as thyroid disease treatment for individual diagnoses according to the following criteria:. Here, TPO is linked to thyroid gland disorder.