Napoli N, Carmina Enrico, Bucchieri Salvatore, Sferrazza C, Rini G B, Di Fede G
Dipartimento di Medicina Clinica e Delle Patologie Emergenti, Via del Vespro 143, 90127 Palermo, Italy.
Bone. 2006 Jun;38(6):888-92. doi: 10.1016/j.bone.2005.11.018. Epub 2006 Feb 7.
Adult thalassemic patients have reduced bone mass due to disturbances in several different mechanisms affecting bone turnover. To determine if vitamin D deficiency contributes to the low bone mass of adult thalassemic subjects, we studied serum 25-OH-vitamin D levels in 90 patients (age ranging between 21 and 48 years) affected with thalassemia major (TM) and 35 (age 21-56 years) with thalassemia intermedia (TI). TM patients had been receiving regular transfusions from the age of 2 years and had increased serum ferritin, glutamic oxalacetic transaminase, glutamic piruvic transaminase as well as low bone density (L1-L4 Z score -2.07 +/- 0.2). TI patients did not receive transfusions, but their ferritin levels were increased as well (520.3 +/- 138,1). 8 TM patients (10.1%) and 4 TI (11.4%) had serum 25-OH-vitamin D less than 10.4 ng/ml and were considered presenting an absolute deficiency of vitamin D. Mean 25-OH-vitamin D was significantly (P < 0.01) lower in both TM and TI patients (20.3 +/- 0.7 ng/ml and 20.9 +/- 2.3 ng/ml, respectively) than in 100 healthy control subjects of similar age (25.2 +/- 1 ng/ml). 1,25-OH-vitamin D levels were in the normal-lower levels (45.15 +/- 1.5 mg/dl), while 24 H urinary calcium was below the normal range (15.75 mg/dl). In TM patients, the 25-OH-vitamin D levels correlated negatively with age (P < 0.05) and with serum ferritin (P < 0.05). TM and TI patients with low 25-OH-vitamin D levels (<17.8 ng/ml) presented higher serum ferritin levels (P < 0.01) and higher PTH (P < 0.05) compared to those with normal vitamin D. Moreover, TM patients with low 25-OH-vitamin D levels were significantly older (P < 0.05) and had higher GPT (P < 0.05) than patients with normal vitamin D. In conclusion, calcium metabolism is frequently impaired in adult thalassemic patients. An early and effective medical treatment should be taken in consideration by the clinician in order to improve the bone health in these patients.
成年地中海贫血患者由于影响骨转换的多种不同机制紊乱，骨量减少。为了确定维生素D缺乏是否导致成年地中海贫血患者骨量低，我们研究了90例重型地中海贫血（TM）患者（年龄在21至48岁之间）和35例中间型地中海贫血（TI）患者（年龄在21至56岁之间）的血清25-羟基维生素D水平。TM患者从2岁起就接受定期输血，血清铁蛋白、谷草转氨酶、谷丙转氨酶升高，骨密度降低（L1-L4 Z评分-2.07±0.2）。TI患者未接受输血，但其铁蛋白水平也升高（520.3±138.1）。8例TM患者（10.1%）和4例TI患者（11.4%）的血清25-羟基维生素D低于10.4 ng/ml，被认为存在维生素D绝对缺乏。TM和TI患者的平均25-羟基维生素D水平（分别为20.3±0.7 ng/ml和20.9±2.3 ng/ml）均显著低于（P<0.01）100例年龄相仿的健康对照者（25.2±1 ng/ml）。1,25-二羟基维生素D水平处于正常低水平（45.15±1.5 mg/dl），而24小时尿钙低于正常范围（15.75 mg/dl）。在TM患者中，25-羟基维生素D水平与年龄（P<0.05）和血清铁蛋白（P<0.05）呈负相关。与维生素D正常的患者相比，25-羟基维生素D水平低（<17.8 ng/ml）的TM和TI患者血清铁蛋白水平更高（P<0.01），甲状旁腺激素水平更高（P<0.05）。此外，25-羟基维生素D水平低的TM患者比维生素D正常的患者年龄显著更大（P<0.05），谷丙转氨酶更高（P<0.05）。总之，成年地中海贫血患者的钙代谢经常受损。临床医生应考虑采取早期有效的医学治疗，以改善这些患者的骨骼健康。
