Ma H T, Griffith J F, Xu L, Leung P C
Department of Electronic and Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Rm 205C, C Building, HIT Campus, University Town, Xili, Nanshan, Shenzhen, China, 518055,
Osteoporos Int. 2014 Mar;25(3):999-1004. doi: 10.1007/s00198-013-2482-7. Epub 2013 Sep 13.
This study used the "functional muscle-bone unit" concept to investigate muscle-bone interaction of the lumbar spine in subjects of varying bone mineral density. It was found that unit bone mass corresponded to a relatively more muscle mass in subjects with reduced bone mineral density, indicating a relatively higher mechanical load from muscles exerted on trabecular bone.
Bone is an architecturally adaptive tissue which responds to mechanical loading. This study is proposed to use "functional muscle-bone unit" to reflect this muscle-bone interaction at spine in subjects with different bone mineral density.
The study was carried out in young normal subjects (21 females; age, 29 ± 3) and elderly subjects (155 females; age, 73 ± 3.9) with varying bone mineral density. Cross-sectional area of paravertebral muscle groups was measured in MR images to indicate the muscle mass, while the bone mineral content by dual X-ray absorptiometry was used to represent the bone mass. The functional muscle-bone unit was calculated as the ratio between the bone mass to muscle mass.
It showed that with aging, the muscle mass decreased with the bone mass losing. However, more pronounced reduction was found in bone mass than in muscle mass in the subjects with lower bone mineral density.
Muscle-bone interaction was changed in elderly, especially in those with osteoporosis. Unit bone mass corresponded to a higher muscle mass in subjects with reduced bone mineral density than those normal subjects. This may be contributory to the occurrence of nontraumatic vertebral fractures in elderly subjects with reduced bone mineral density.
本研究采用“功能性肌肉-骨骼单位”概念，调查不同骨矿物质密度受试者腰椎的肌肉-骨骼相互作用。研究发现，在骨矿物质密度降低的受试者中，单位骨量对应的肌肉量相对较多，这表明肌肉对小梁骨施加的机械负荷相对较高。
骨骼是一种具有结构适应性的组织，会对机械负荷做出反应。本研究旨在使用“功能性肌肉-骨骼单位”来反映不同骨矿物质密度受试者脊柱的这种肌肉-骨骼相互作用。
该研究在骨矿物质密度不同的年轻正常受试者（21名女性；年龄，29±3岁）和老年受试者（155名女性；年龄，73±3.9岁）中进行。在磁共振图像中测量椎旁肌肉群的横截面积以指示肌肉量，同时使用双能X线吸收法测量的骨矿物质含量来代表骨量。功能性肌肉-骨骼单位计算为骨量与肌肉量之比。
结果表明，随着年龄增长，肌肉量随骨量流失而减少。然而，在骨矿物质密度较低的受试者中，骨量的减少比肌肉量的减少更为明显。
老年人尤其是骨质疏松症患者的肌肉-骨骼相互作用发生了变化。骨矿物质密度降低的受试者比正常受试者的单位骨量对应更高的肌肉量。这可能是骨矿物质密度降低的老年受试者发生非创伤性椎体骨折的原因之一。
