Study of thyroid function in Egyptian children with β-thalassemia major and β-thalassemia intermedia

Abstract

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. 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). 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. 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. 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.