Bone mass and metabolism in thalassemic children and adolescents treated with different iron-chelating drugs

Abstract

We evaluated bone mineral density (BMD) and bone turnover in 22 homozygous prepubertal beta-thalassemic patients treated with desferrioxamine. Ten patients underwent treatment with desferrioxamine for the whole study period, while 12 patients stopped desferrioxamine and were then treated with deferiprone (L1). Lumbar and femoral BMD and bone metabolism markers were examined at baseline and after 1 and 3 years of follow up. All patients were prepubertal at baseline and they all became pubertal over the 3 years of follow up. At baseline, the mean lumbar Z score value was −2.048 SD ± 0.75; the Z score was less than −2 SD in 13 children, within −1 and −2 SD in 6, and within 0 and −1 SD in only 3 subjects. A significant BMD increase (P ≪ 0.0001) was observed at both the lumbar (+8.466%/year) and the femoral level (average of +3.46%/year at neck and +5.83%/year at the intertrochanteric region) after 3 years, without any significant difference being shown between patients treated with desferrioxamine and those treated with L1. The mean Z score SD values increased to −1.957 ± 0.975 at 1 year (not significantly different from baseline) and to −1.864 ± 1.221 at 3 year follow up (P ≪ 0.05 vs baseline); an increase in bone turnover was also observed. These findings show that low BMD, a hallmark of beta-thalassemia, improves significantly when puberty begins; this increase involves different skeletal sites, regardless of pharmacological treatment with different iron-chelating drugs.