A study of prevalence of hypothyroidism in -thalassemia major in Ahvaz Shafa hospital

Thalassemia is a genetic disorder with autosomal recessive inheritance and due to defect in hemoglobin chain synthesis. Although living in these patients is dependent to blood transfusion, but this can produce iron overload in organs and damage to endocrine glands as pituitary and thyroid. Therefore, primary hypothyroidism is a common complication in thalassemic patients. The aim of this study was the determination of the prevalence of hypothyroidism and the consequent complications in relation to serum ferritin among patients with - thalassemia major in Shafa hospital.Subjects and Two hundred and thirty patients who received regular blood transfusions were included in this study. Data was recorded via a questionnaire. Evaluation of thyroid function was monitored by checking of TSH (thyroid stimulating hormone) and T4 (thyroxin). In patients with abnormality in thyroid function tests (TFT), SMR (sexual maturity rating) evaluation, serum ferritin, and echocardiography for ejection fraction (EF), chest x-ray, RT wrist x-ray for bone age, were checked. Then the results were compared with control group (similar in sex and age from euthyroid thalassemic patients). Sixteen patients were excluded from study. From a total 214 patients there were 53.5 % male. Age in 17.5 % was less than 8 years, 22% were between 8-14, 42 % were between 14-20, and in 18.5% was more than 20 years with median 15.6 ± 4.2. Eleven patients suffered from hypothyroidism (5.1 %) among whom 5 patients had overt hypothyroidism (elevated TSH and decreased T4) and in 6 patients had subclinical hypothyroidism (elevated TSH with normal T4). Comparison of Tanner score, height, weight percentiles, bone age in patient and control group revealed that growth retardation and poor sexual maturation is related to many factor rather than hypothyroidism. EF in 72.5% of patients was less than 60 % that in comparison with control group (P=0.20) revealed hypothyroidism can produce some negative effects on cardiac muscle and can augment toxic effect of iron overload in myocardium alone. In both groups serum ferritin was more than 2000 ng/ml with median 5100 ± 1800 versus 5700 ± 1450 (P=0.676) in meaning of there is no correlation between serum ferritin and hypothyroidism. In all patients Anti TPO was negative and all hypothyroidisms were primary. Early detection and treatment of hypothyroidism in thalassemic patient reduces cardiac dysfunction and can improve quality of life in these patients.