High prevalence of central hypothyroidism among patients with transfusion dependent thalassemia in Hospital Pulau Pinang: A cross sectional study

INTRODUCTION: Thalassemia is the most common heritable haematological disorder in Malaysia. Hypothyroidism is one of the complications of the transfusion dependent thalassemia (TDT) patients as a result of iron overload.

MATERIALS AND METHODS: All registered TDT patients attending Haematology day care, Hospital Pulau Pinang from January 2019 to January 2020 were included in the study. Hypothyroidism was defined according to TSH and FT4, or based on the history of treatment for diagnosed hypothyroidism.

RESULTS: There were 51 TDT patients, with 24 (47%) males and 27 (53%) females. Most of the patients were Malays (27, 53%) followed with Chinese (23, 45%) and Indonesian (1, 2%). Beta thalassemia major and HbE beta thalassaemia accounted for 35 (68.8%) and 14 (27.5%) TDT patients respectively, while two (3.9%) were HbH Constant Spring. Eleven (21.6%) had hypothyroidism; of which seven (63.6%) had central hypothyroidism, three (27.3%) had subclinical hypothyroidism, the remaining one (9.1%) had primary hypothyroidism. Three (27.3%) had concomitant hypogonadism, one (9.1%) had hypocortisolism and another (9.1%) had both diabetes mellitus and hypogonadism. There was no statistical relationship between the prevalence of hypothyroidism and age, serum ferritin, splenectomy history and iron chelation therapy.

CONCLUSION: High prevalence of central hypothyroidism is reported. Measurement of both TSH and FT4 is recommended as initial screening for thyroid dysfunction among patient with TDT.