Final Height and Endocrine Complications in Patients with β-Thalassemia Intermedia: Our Experience in Non-Transfused Versus Infrequently Transfused Patients and Correlations with Liver Iron Content

BACKGROUND: β-thalassemia intermedia (TI) spans a wide spectrum of severity and carries higher morbidity than previously recognized, including extramedullary hematopoiesis, leg ulcers, gallstones, thrombosis, secondary heart failure, pulmonary hypertension, skeletal deformity, growth retardation and endocrine abnormalities, such as diabetes mellitus, hypothyroidism, osteoporosis, and hypogonadism. OBJECTIVES: To evaluate the final height and the endocrine complications encountered in young adult patients with TI followed at Hematology Section, Doha (Qatar) in relation to liver iron content in non-transfused versus infrequently transfused TI patients. PATIENTS AND METHODS: This retrospective cohort study was performed on 28 young adults with TI who were randomly selected from the Hematology Clinic of the Hematology Section, National Centre for Cancer Care and Research, Hamad Medical Corporation of Doha (Qatar). Eligibility criteria for this retrospective analysis included TI patients diagnosed by complete blood count, hemoglobin electrophoresis and young adult age ( ≥ 18 years). Group 1 included nine patients who did not receive any blood transfusion, and Group 2 included 19 patients who infrequently received blood transfusions. Data recorded from charts included demographic characteristics (gender, date of birth, ethnicity), disease and treatment characteristics (e.g., transfusion frequency, history of chelation therapy, and splenectomy), auxological and pubertal data [growth percentiles and pubertal stages, and body mass index (BMI)], laboratory data and target organ complications (including endocrinopathies and liver disease). Iron overload was assessed by direct (liver iron content; LIC) and indirect methods (SF), and bone mass index (BMA) by dual-energy X-ray absorptiometry (DXA). RESULTS: Short stature [Final Height (Ht) SDS < −2] occurred in 25% of patients with no difference between the two groups of patients. Insulin growth factor 1 (IGF-1) SDS was low in 35.7 % of patients with no statistical difference among the two groups. Impaired fasting blood glucose occurred in 17.8% of patients, diabetes mellitus in 25% and hypogonadotropic hypogonadism in 10.7% of them. Morning cortisol was low in one patient. No thyroid or hypo-parathyroid abnormalities were detected in any patient. Liver iron content (LIC) > 15 mg/g dry weight and SF > 2,000 ng/mL were detected in 75% of the patients. The values resulted significantly higher in the transfused group (Group 2). High liver enzyme level (ALT) was detected in 42.8 % of patients, and the values were significantly higher in the transfused group (Group 2). Total and fetal Hb was significantly higher in group 1 versus group 2. Osteopenia was diagnosed in 14.3% of patients. Females had significantly better final height SDS, higher IGF-1 SDS, lower LIC and fasting blood glucose level compared to males. Significant correlations were found between Ht-SDS and IGF-1 SDS; LIC and SF, level; ALT and LIC, SF levels. Total and fetal Hb did not correlate significantly with Ht-SDS or IGF-1 level. CONCLUSIONS: A significant number of TI patients have high LIC, short stature and endocrine disorders. Patients who require occasional transfusions have more liver iron overload and higher hepatic dysfunction. Females appear to attain a better final adult height and have higher IGF1-SDS versus males. Our data emphasize the need for long term surveillance for identification of organ-specific risk factors and early disease manifestations. We also recommend close monitoring of endocrine and other complications, according to the international guidelines.