Quan A, Adams R, Ekmark E, Baum M
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75235-9063, USA.
Pediatrics. 1998 Sep;102(3):E34. doi: 10.1542/peds.102.3.e34.
Difficulties with ambulation in patients with myelomeningocele often lead to physical inactivity, osteoporosis, and subsequent development of pathologic fractures.
The purpose of this study was to examine bone mineral density and biochemical markers of bone metabolism in patients with myelomeningocele.
A total of 35 patients between 6 and 19 years of age with myelomeningocele (ambulatory and nonambulatory) were randomly chosen at the Texas Scottish Rite Hospital for Children. We measured bone mineral density of the distal radius in these patients using single photon absorptiometry and measured the biochemical markers of bone metabolism including parathyroid hormone, 1,25 vitamin D, osteocalcin, urinary pyridinolines/deoxypyridinolines, and urinary calcium excretion.
Bone mineral density of the distal radius in the patients with myelomeningocele was approximately 1 to 2 standard deviation units below the mean of the normal population. There were no significant differences between ambulators and nonambulators. However, bone mineral density of the 8 patients who suffered multiple fractures (19) was significantly lower than that for those remaining patients without fractures. Elevated urinary pyridinoline levels, which indicate elevated bone reabsorption, were found more frequently in both non- and limited ambulators than in full-time ambulators. Urinary calcium excretion also was greater than twofold higher in nonambulatory patients versus ambulatory patients. There were no other differences in the biochemical markers of bone metabolism (osteocalcin, parathyroid hormone, 1,25 vitamin D, and urinary deoxypyridinolines) between ambulators and nonambulators. Bone mineral density rises in normal growing children 6 to 19 years of age. When the boys and girls were considered separately, bone mineral density rises with age in boys, but not in girls.
Patients with myelomeningocele have decreased bone mineral density and are at risk of suffering pathologic bone fractures. The measurement of bone mineral density may help to identify those patients at greatest risk of suffering multiple fractures. The urinary calcium excretion of nonambulators was higher than that of ambulators and likely contributes to their decreased bone mineral density. Bone mineral density increases with age in boys, but not in girls.
脊髓脊膜膨出患者行走困难常导致身体活动不足、骨质疏松及随后病理性骨折的发生。
本研究旨在检测脊髓脊膜膨出患者的骨密度及骨代谢生化标志物。
在德克萨斯州苏格兰 rite 儿童医院随机选取 35 例 6 至 19 岁的脊髓脊膜膨出患者（能行走和不能行走的）。我们使用单光子吸收法测量这些患者桡骨远端的骨密度，并测量骨代谢生化标志物，包括甲状旁腺激素、1,25 - 维生素 D、骨钙素、尿吡啶啉/脱氧吡啶啉以及尿钙排泄量。
脊髓脊膜膨出患者桡骨远端的骨密度比正常人群均值低约 1 至 2 个标准差单位。能行走者与不能行走者之间无显著差异。然而，8 例发生多次骨折的患者（19）的骨密度显著低于其余未发生骨折的患者。尿吡啶啉水平升高表明骨吸收增加，在非行走者和行走受限者中比在完全行走者中更常见。非行走患者的尿钙排泄量也比行走患者高出两倍多。能行走者与不能行走者在骨代谢生化标志物（骨钙素、甲状旁腺激素、1,25 - 维生素 D 和尿脱氧吡啶啉）方面无其他差异。6 至 19 岁正常生长儿童的骨密度会升高。当分别考虑男孩和女孩时，男孩的骨密度随年龄增长而升高，而女孩则不然。
脊髓脊膜膨出患者骨密度降低，有发生病理性骨折的风险。骨密度测量可能有助于识别那些发生多次骨折风险最高的患者。非行走者的尿钙排泄量高于行走者，这可能是导致他们骨密度降低的原因。男孩的骨密度随年龄增长而增加，而女孩则不然。
