Background: Low bone mass is common among adolescents with transfusion-dependent -thalassemia despite adequate transfusion and iron chelation. However, there are few reports regarding bone mineral density (BMD) among adolescents with nontransfusion-dependent thalassemia (NTDT). Indeed, only BMD data in patients with nontransfusion-dependent (NTD) -thalassemia intermedia have been reported. No previous study has investigated BMD among adolescents with NTD hemoglobin (Hb) E/ -thalassemia.
Objective:To determine the prevalence of low bone mass among adolescents with NTD Hb E/ -thalassemia and factors relating to low bone mass.
Methods:We investigated BMD of lumbar spine (L2-L4; BMDLS) and total body (BMDTB), as measured by dual-energy X-ray absorptiometry, in 22 adolescents (aged 13.2-20 years) with NTD Hb E/ -thalassemia.Results: Low bone mass was found to be 18.2% and 22.7% at the lumbar spine (BMDLS Z-score adjusted for bone age and height age) and 13.6% and 9.1% at the total body (BMDTB Z-score adjusted for bone age and height age). Patients with mean Hb level <8 g/dl were more likely to have low bone mass (BMDLS and BMDTB Z-scores adjusted for bone age) compared to those with Hb level ≥ 8 g/dl. Mean Hb level correlated with BMDLS and BMDTB Z-scores adjusted for bone age.
Conclusion:We demonstrated that a low Hb level was associated with low bone mass among adolescents with NTD Hb E/ -thalassemia. A significant proportion of low bone mass among these patients highlights the importance of appropriate management, including red cell transfusion, vitamin D and calcium supplementation for improved long-term bone health.
K E Y W O R D Sadolescents, bone mineral density, Hb E/ -thalassemia, nontransfusion-dependent thalassemia (NTDT), thalassemia Abbreviations: BMD, bone mineral density; BMDLS, BMD of lumbar spine (L2-L4); BMDTB, BMD of total body; DXA, dual-energy X-ray absorptiometry; Hb, hemoglobin; LIC, liver iron concentration; LPI, labile plasma iron; NTBI, nontransferrin-bound iron; NTD, nontransfusion-dependent; NTDT, non-transfusion-dependent thalassemia; TDT, transfusion-dependent thalassemia; 25-OHD, 25-hydroxyvitamin D