Assessment of Thyroid Function in Children Aged 1-13 Years with Beta-Thalassemia Major

Objective: Hypothyroidism usually appears in the second decade of life and is thought to be associated with iron overload in patients with thalassemia major. This study aimed to evaluate thyroid dysfunctions in patients with beta-thalassemia major and to see if they appear in the earlier period of life.
Methods: Thyroid function and iron load status were evaluated in 90 children with a mean age of 7.17±3.78 years with beta-thalassemia major by measuring serum free thyroxin (FT4), serum free triiodothyronine (FT3), total thyroxin (T3), serum total triiodothyronine (T4), thyroid-stimulating hormone (TSH) and ferritin levels from serum of patients admitted to the Pediatric Department, Faculty of Medicine University of Dicle between March 2005 and July 2009. A control group formed from an age-sex matched healthy children with a mean age of 6.98±3.66 years was also included. A standard thyrotropin releasing hormone test was applied to 3 patients who had high TSH levels and were classified as subclinical primer hypothyroidism. The study was designed according to the Declaration of Helsinki and informed consent was obtained from the parents of all participants.
Findings: All thyroid parameters in patients were in the normal ranges compared with the controls except three of them which had high TSH levels. Serum ferritin level (2703±1649 ng/mL) in patients was significantly higher than in controls (81.5±15.5 ng/mL).
Conclusion: The work implies that hypothyroidism could be even seen in the first decade of life in patients with beta-thalassemia major in spite of improved hematological cares.

Keywords
Beta-Thalassemia; Hypothyroidism; Iron Overload; Chelation Therapy; Spelenectomy