Evaluation of Endocrine Complications in Beta-Thalassemia Intermedia Patients: A Cross Sectional Multi-Center Study

The diagnosis of beta thalassemia intermedia (BTI) is mainly based on the severity of clinical phenotype. It is associated with a wide range of specific complications including extramedullary hematopoiesis, leg ulcers, gallstones, hypercoagulable state, pulmonary hypertension (PHT), endocrine disorders and osteoporosis. The commonest endocrine complication in beta thalassemia major (TM) patients is hypogonadism followed by hypothyroidism and diabetes but the data on endocrine disorders in BTI patients are scarce. The aim of this study is to determine the prevalence of endocrine complications in a large series of BTI patients.

Methods: In this multi-countries cross-sectional study, all BTI patients registered at 12 thalassemic treatment centers in Iran (2 Centers), Italy (2 Centers), Greece, Turkey (2 centers), Oman, Qatar, Jordan, Cyprus and United Kingdom were enrolled during 2017. Non transfusion- dependent beta-thalassemia patients or those who received blood transfusion 3-4 times or less annually, were evaluated. Required information was collected from medical records using a designed questionnaire. Demographic data, clinical characteristics and laboratory data included age, sex, splenectomy, type of treatment (blood transfusion, iron chelation, hydroxyurea), hormonal assays, bone mineral density, calcium -phosphorous metabolism, serum ferritin, liver function tests, fetal and total hemoglobin levels,, platelet and nucleated red blood cell counts, were collected.

Results: A total of 721 BTI patients were enrolled in the survey from 9 countries. The most prevalent disease-related complications were osteoporosis (21.6%) and hypogonadism (12.6%) followed by: central hypothyroidism (8.3%), non-insulin-dependent diabetes mellitus (7.8%), primary hypothyroidism (5.5%), insulin-dependent diabetes mellitus (4.2%), hypoparathyroidism (2.2%), growth hormone deficiency (1.1%), adrenal mass (1%) and thyroid cancer (0.5%).

Conclusion: This study evaluated the largest cohort of BTI patients with endocrine disorders. Although BTI patients are non-transfusion dependent or only occasionally transfused, iron-overload due to increased intestinal iron absorption and enhanced bone marrow activity cause endocrine disorders and osteoporosis. This study demonstrate that although endocrine complications are less common in patients with BTI compared to data reported in literature in TM patients , a regular monitoring with timely diagnosis and proper management underscoring on osteoporosis and gonadal disorders are crucial to prevent endocrine complications in these patients.