Using bone mineral apparent density for BMD adjustment in chronic diseases: Thalassemia an example

Area of Science:

• Pediatric Endocrinology
• Bone Metabolism
• Medical Imaging

Background:

• Low bone mineral density (BMD) is prevalent in major thalassemia patients.
• Dual-energy X-ray absorptiometry (DXA) poses challenges in assessing bone density in children with chronic diseases due to smaller bone size.
• Bone mineral apparent density (BMAD) offers a potential solution to account for bone size variations.

Purpose of the Study:

• To evaluate the utility of BMAD in addressing the impact of bone size on BMD measurements in children with thalassemia.
• To compare BMD and BMAD values between thalassemic children and a healthy pediatric cohort.

Main Methods:

• A cohort of 110 children (73 males, mean age 9.6 ± 4.3 years) diagnosed with thalassemia was studied.
• Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA).
• Bone mineral apparent density (BMAD) was calculated, and results were compared with those of healthy Iranian children.

Main Results:

• Thalassemic patients exhibited significantly lower femoral BMD (P=0.003) and spinal BMD (P<0.001) and BMAD (P<0.001) compared to controls.
• Femoral BMAD in thalassemic patients was not significantly different from that of healthy children.
• Spinal BMD and BMAD remained significantly lower in thalassemic patients even after adjustment for bone size.

Conclusions:

• BMAD effectively corrects for bone size, normalizing femoral BMD differences between thalassemic patients and healthy children.
• BMAD is a useful tool for interpreting femoral DXA scans in thalassemic pediatric patients.
• BMAD does not fully account for the observed differences in spinal bone density in thalassemic children, indicating persistent spinal bone loss.