Sex-specific developmental changes in muscle size and bone geometry at the femoral shaft
Sex-specific developmental changes in muscle size and bone geometry at the femoral shaft
复制标题
DOI：
10.1016/j.bone.2008.01.008
复制
发表时间：
2008-05-01
期刊：
影响因子：
4.1
通讯作者：
Woodhead, H. J.
中科院分区：
文献类型：
--
作者：
Hoegler, W.;Blimkie, C. J. R.;Woodhead, H. J.
简介：当以年轻成年人平均结果的百分比表示时，骨矿物质含量在青春期前落后于骨长度。即使这一观察结果导致儿童骨脆性的猜测，这种关系可能只是由于缩放效应时，不同的几何尺寸compared.Methods：研究人群包括145名健康受试者（6 - 25岁，94名女性）。使用磁共振成像和双能X线吸收测定法测定股骨长度、骨矿物质含量、皮质骨矿物质密度、横截面骨几何形状（骨直径;皮质厚度;总面积、皮质面积和髓面积;横截面和面积极矩;骨强度指数）和股骨近端1/3部位的肌肉面积。通过将二维、三维和四维变量分别提高到1/2、1/3和1/4的幂，对结果进行维度缩放。性别差异也进行了评估之前和之后的功能调整股骨长度和重量或肌肉大小的变量。结果如下：在青春期前的儿童中，以成人值的百分比表示的未密封结果对于具有最高维度的变量（例如，面积矩<骨矿物质含量<横截面积<股骨长度）。然而，当尺寸缩放时，即使在功能调整后，儿童的结果也代表了各自平均成人值的相似百分比。在青春期之前，在调整后的骨骼或肌肉变量中没有性别差异。青春期后，男性有更大的总骨面积和皮质骨面积，骨直径，面积矩，骨强度指数和肌肉面积比女性，无论是在绝对值以及调整股骨长度和重量。肌肉面积的性别差异最大。当相对于肌肉大小相比，年轻的成年女性获得更大的总骨和皮质骨面积比manifest.Conclusions：股骨长度，直径，质量和强度的增长出现在青春期前协调良好。青春期后的女性股骨较窄，骨强度和肌肉尺寸比男性小。然而，当考虑到肌肉的大小，女性有一个更大的股骨横截面和更多的皮质骨。这些性别差异可能是青春期发生的机械和激素效应的综合结果。(c)2008年爱思唯尔公司All rights reserved.
Introduction: When expressed as a percentage of the average result in young adults, bone mineral content lags behind bone length before puberty. Even though this observation has led to speculation about bone fragility in children, such relationships could simply be due to scaling effects when measures with different geometrical dimensions are compared.Methods: The study population comprised 145 healthy subjects (6-25 years, 94 females). Magnetic resonance imaging and dual-energy X-ray absorptiometry were used to determine femur length, bone mineral content, cortical bone mineral density, cross-sectional bone geometry (bone diameter; cortical thickness; total, cortical and medullary areas; cross-sectional and polar moments of area; bone strength index) and muscle area at the proximal one-third site of the femur. Results were dimensionally scaled by raising two-, three- and four-dimensional variables to the power of 1/2, 1/3 and 1/4, respectively. Sex-differences were also assessed before and after functionally adjusting variables for femur length and weight or muscle size. Results: In prepubertal children, unsealed results expressed as percentages of adult values were lowest for variables with the highest dimensions (e.g., moments of area < bone mineral content < cross-sectional areas < femur length). However, when dimensionally scaled, results in children represented similar percentages of the respective average adult values, even after functional adjustments. Before puberty, there was no sex-difference in adjusted bone or muscle variables. After puberty, males had greater total and cortical bone area, bone diameter, moments of area, bone strength index and muscle area than women, both in absolute terms as well as adjusted for femur length and weight. The largest sexdifference was found for muscle area. When compared relative to muscle size, young adult women attained greater total and cortical bone area than men.Conclusions: Growth in femoral length, diameter, mass and strength appears well coordinated before puberty. Postpubertal females have narrower femora, less bone strength and muscle size than mates. However, when muscle size is taken into account, females have a larger femoral bone cross-section and more cortical bone. These sex-differences likely result from a combination of mechanical and hormonal effects occurring during puberty. (c) 2008 Elsevier Inc. All rights reserved.