Endocrine Abstracts

The prevalence of GD (Graves–Basedow disease) in adolescents with T1DM (type 1 diabetes mellitus) is around 0.5%. Most often the diagnosis of GD in T1DM patients is made many years after the onset of T1DM. The present clinical case describes an adolescent with GD and T1DM and highlights how difficult the management of this disease can be. 17-year-old male was referred to our Department for reevaluation of Graves–Basedow disease. Patient suffered from T1DM for 14 years, with unsatisfactory metabolic control (HbA1c 9.17%). Moreover in 2009 he was diagnosed with Hashimoto’s thyroiditis (elevated thyroid antibodies), however remained euthyroid. In September 2011 patient was diagnosed with hyperthyroidism and treated with methimazole (MMI) to maintain euthyroidism. 2 months before the referral, a trial period off medication had been attempted, but the patient experienced a return of symptoms (fatigue, palpitations, and heat intolerance). Family history was significant for autoimmune thyroid disease and T1DM in his mother. On physical examination, the patient had a heart rate of 110 b.p.m., BP of 130/70 mmHg. There was no evidence of ophthalmopathy. Thyroid examination revealed enlarged thyroid gland. Laboratory funds showed recurrence of hyperthyroidism (TSH<0.004 μU/ml, fT₄ 36.76 pmol/l). After discussing both therapeutic options with parents (MMI treatment continuation or radioiodine ablation) the patient was administered I-131. Within 2 months of radioiodine therapy, hypothyroidism was achieved, and the patient started thyroid hormone replacement. Three months after definitive therapy, the patient reported improved school performance, decreased fatigue and no abnormalities in heart rhythm. Diabetes metabolic control did not alter during the treatment.