Background: Thyroid dysfunction is a known complication of transfusion-dependent β-thalassemia. However, information on its frequency and risk factors among Egyptian Children is still unclear.
Objective: We aimed to determine the frequency of functional thyroid abnormalities among young patients with β-thalassemia and compare the thyroid function status among patients with β-thalassemia major (TM) and β-thalassemia intermedia (TI).
Materials and methods: This was a cross-sectional study that included 52 β-thalassemia children [27 boys and 25 girls; 34 (65.4%) with TM and 18 (34.6%) with TI]. Their mean age was 16.0±1.91 (range: 12-18) years. Thyroid function and iron load status were assessed by measurement of free tetraiodothyronine, free triiodothyronine, thyroid stimulating hormone (TSH), and serum ferritin concentrations.
Results: Serum TSH of the studied cases ranged from 0.28 to 25 μIU/ml with a mean of 4.5±4.8 μIU/ml. None of the studied cases had overt primary hypothyroidism and the frequency of subclinical hypothyroidism was 19.2%. No risk factors for thyroid dysfunction could be identified among our cases. The thyroid profile was comparable in TM and TI patients (P>0.05) and the frequency of subclinical hypothyroidism among TM cases was 20.6% and it was comparable to the 16.7% found among TI patients (P>0.05). No correlations were found between TSH, serum ferritin, chelation therapy, and frequency of blood transfusion.
Conclusion and recommendations: Both TM and TI patients are at risk for subclinical thyroid failure regardless of their iron overload status. Early evaluation of thyroid function in β-thalassemia children and thyroid replacement therapy for subclinical hypothyroidism should be introduced in the treatment protocols.