Shriners Hospital for Children and Department of Pediatrics, McGill University, Montréal, Québec, Canada.
J Clin Endocrinol Metab. 2013 May;98(5):E990-5. doi: 10.1210/jc.2012-4146. Epub 2013 Mar 22.
We recently found that patients with X-linked hypophosphatemic rickets (XLH) have a muscle function deficit in the lower extremities. As muscle force and bone mass are usually closely related, we hypothesized that patients with XLH could also have a bone mass deficit in the lower extremities.
The study objective was to assess the muscle-bone relationship in the lower extremities of patients with XLH.
The study was carried out in the outpatients department of a pediatric orthopedic hospital.
Thirty individuals with XLH (6 to 60 y; 9 male patients) and 30 age- and gender-matched controls participated.
Calf muscle size and density as well as tibia bone mass and geometry were assessed by peripheral quantitative computed tomography. Muscle function was evaluated as peak force in the multiple 2-legged hopping test.
Muscle force was significantly lower in XLH patients than in controls but muscle cross-sectional area did not differ (after adjustment for tibia length). External bone size, expressed as total bone cross-sectional area, was higher in the XLH group than in controls. The XLH cohort also had statistically significantly higher bone mineral content.
Patients with XLH have increased bone mass and size at the distal tibia despite muscle function deficits.
我们最近发现 X 连锁低磷血症性佝偻病（XLH）患者下肢存在肌肉功能缺陷。由于肌肉力量和骨量通常密切相关，我们假设 XLH 患者下肢也可能存在骨量不足。
本研究旨在评估 XLH 患者下肢的肌肉-骨骼关系。
该研究在一家儿科骨科医院的门诊部门进行。
30 名 XLH 患者（6 至 60 岁；9 名男性患者）和 30 名年龄和性别匹配的对照组参与者参与了研究。
通过外周定量计算机断层扫描评估小腿肌肉大小和密度以及胫骨骨量和几何形状。肌肉功能通过多次 2 腿跳跃测试中的峰值力量进行评估。
XLH 患者的肌肉力量明显低于对照组，但肌肉横截面积没有差异（调整胫骨长度后）。外部骨大小，以总骨横截面积表示，XLH 组高于对照组。XLH 组的骨矿物质含量也显著升高。
尽管存在肌肉功能缺陷，但 XLH 患者的远端胫骨骨量和大小增加。
