Proximal femur bone geometry is appropriately adapted to lean mass in overweight children and adolescents
Proximal femur bone geometry is appropriately adapted to lean mass in overweight children and adolescents
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DOI：
10.1016/j.bone.2004.12.003
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发表时间：
2005-03-01
期刊：
影响因子：
4.1
通讯作者：
Leonard, MB
中科院分区：
文献类型：
--
作者：
Petit, MA;Beck, TJ;Leonard, MB
目前尚不清楚超重儿童的骨骼是否适当地适应了增加的负荷。这项研究的目的是比较40名超重(体重指数[BMI]和GT；85%)和94名健康体重(BMI：85%)受试者的骨几何形状，年龄在4-20岁之间。采用Hip Structure Analyst软件分析股骨干(FS)和窄颈(NN)的双能X线骨密度仪(HOLOGIC QDR 2000)扫描图像。测量骨膜下宽度、皮质厚度、骨轴向强度和抗弯强度指标(骨横截面积[CSA]和截面弹性系数[Z])。多因素回归模型用于比较超重和健康体重受试者。在调整了身高、成熟度和性别后，重度超重受试者(P<；0.001)FS和NN的Z分别高出11%(95%可信区间5，19)和13%(7，20)。在NN，较高的Z是由于骨膜下宽度[4%(2，7)]和骨CSA[10%(5，16)]，而在FS，较高的骨CSA[10%(5，16)]和较厚的皮质[9%(3，15)]。当模型中加入瘦体重时，超重和健康体重受试者之间的骨变量没有差异(P>；0.22)，除了NN骨膜下宽度[3%(0，6)，P=0.04]。脂肪质量对任何模型都没有显著影响。综上所述，超重儿童股骨近端骨几何强度与瘦体重和身高相适应，但以脂肪块形式存在的较大体重对骨弯曲强度没有完全独立的影响。这些几何上的适应符合机械师的假设，即骨骼强度主要适应于肌肉力量，而不是体重所代表的静态负荷。(C)2004 Elsevier Inc.保留所有权利。
It is unclear if the bones of overweight children are appropriately adapted to increased loads. The objective of this study was to compare bone geometry in 40 overweight (body mass index [BMI] > 85th percentile) and 94 healthy weight (BMI :! 85th percentile) subjects, ages 4-20 years. Dual energy X-ray absorptiometry (Hologic QDR 2000) scans were analyzed at the femoral shaft (FS) and narrow neck (NN) by the Hip Structure Analysis program. Subperiosteal width, cortical thickness and indices of bone axial and bending strength (bone cross-sectional area [CSA] and section modulus [Z]) were measured from bone mass profiles. Multivariate regression models were used to compare overweight and healthy weight subjects. Z was 11 (95% CI 5, 19) and 13 (7, 20) percent higher at the FS and NN, respectively, ill overweight subjects (P < 0.001), adjusted for height, maturation and gender. At the NN, higher Z was due to greater subperiosteal width [4% (2, 7)] and bone CSA [10% (5, 16]) and at the FS, to higher bone CSA [10% (5, 16)] and thicker cortices [9% (3, 15)]. When lean mass was added to the models, bone variables did not differ between overweight and healthy weight subjects (P > 0.22), with the exception of NN subperiosteal width [3% (0, 6), P = 0.04]. Fat mass did not contribute significantly to any model. In summary, proximal femur bone geometric strength in overweight children was appropriately adapted to lean mass and height but greater weight in the form of fat mass did not have all independent effect on bone bending strength. These geometric adaptations are consistent with the mechanostat hypothesis that bone strength adapts primarily to muscle forces, not to static loads represented by body weight. (c) 2004 Elsevier Inc. All rights reserved.