Bone Abstracts

Objectives: Beta thalassemia major (BTM) is characterized by anemia and iron overload, especially in children with inadequate chelation therapy. Dual energy x-ray absorptiometry software (DXA) may misanalyse bone measurements due to iron overload/deposition in organs such as the liver. Our objective was to study difference between the anterio-posterior spine measurements of bone mineral content (BMC), area (BA) and density (BMD) in non-chelated beta thalassaemia children with and without inclusion of the liver in the DXA analysis.

Methods: We studied 50 children (2 to 18 year old, 17 girls) with BTM and their anthropometry, haemoglobin and serum ferritin concentrations.AP Spine measurements were performed using a GE iDXA (Wisconsin, MD, USA). With the use of tissue point typing feature of GE iDXA (EnCore software, version 16), analysis was carried out including and excluding the iron overloaded liver. Machine generated Z-scores of L1-L4 BMD were used for analysis.

Results: Mean age of children was 11.6±3.4 years. Mean height and weightfor age Z-scores were −1.8±1.3, −1.6±0.8. Mean Hb and ferritin were 8.2±1.7 g/dl and 1836.3±1478.7 ng/ml respectively.When the liver was included in the tissue point typing during the analysis,mean BMC, BA and BMD at L1–L4 were 19.0±7.6 g, 27.6±6.9 cm² and 0.669±0.13 g/cm² respectively. After removing the liver from the analysis, the mean BMC (19.9±7.9 g) and BMD (0.702±0.13 g/cm²) improved significantly (P<0.05), the BA remained unchanged. Mean BMD Z-score was −1.64±0.95, which significantly (P<0.05) improved to −1.36±1.0 after exclusion of the liver from the analysis.

Conclusion: In poorly chelated children with thalassaemia the inclusion ofiron overloaded liver in the tissue analysis may exaggerate the deficit in bone parameters at AP Spine. Liver should be manually excluded during analysis of the AP spine.

Disclosure: The authors declared no competing interests.