Bone mineral density in children and young adults with β-thalassemia trait

Abstract

Background: Homozygous β-thalassemia is a hereditary hematological disease due to defective β-globin synthesis. Consequently, there is ineffective erythropoiesis and increased peripheral hemolysis. Increased erythropoiesis in bone marrow results in expansion of marrow cavity and reduced bone mass. Patients with heterozygous β-thalassemia or β-thalassemia trait may have mild anemia, and consequently mildly increased erythropoiesis. Whether modestly increased erythropoiesis might decrease bone mass is not well established. Objective: To evaluate bone mineral density (BMD) in children and young adults with β-thalassemia trait. Methods: Thirty-one healthy young adults aged 20-45 yr and 26 healthy children aged 8-15 yr with β-thalassemia trait were enrolled in the study. BMD was determined by dual X-ray absorptiometry (DEXA). Determinations of intact parathormone (PTH), 25-hydroxyvitamin D (25-OHD), and bone markers were performed. Results: In adults, all had z-scores of BMD more than -2 above the mean. The mean z-scores of BMD of lumbar spine, radius and femoral neck were 0.11, -0.10 and 0.41, respectively. In children, only two of 26 had z-scores of lumbar spine BMD more than -2 below the mean. The mean z-scores of BMD of total body, lumbar spine, radius and femoral neck were 0.12, -0.28, 0.30 and -0.14, respectively. All subjects had normal PTH, 25-OHD and bone markers levels. Conclusions: β-Thalassemia trait is not a contributing factor for osteopenia/osteoporosis in children and young adults.