Characterising cortical density in the mid-tibia: intra-individual variation in adolescent girls and boys
Characterising cortical density in the mid-tibia: intra-individual variation in adolescent girls and boys
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DOI：
10.1136/bjsm.2008.049528
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发表时间：
2008-08-01
影响因子：
18.4
通讯作者：
McKay, H. A.
中科院分区：
文献类型：
--
作者：
Cooper, D. M. L.;Ahamed, Y.;McKay, H. A.
背景资料：皮质骨体积密度（CoD）的个体间差异，如与性别相关的差异，是重塑率差异的产物。虽然皮质骨通常被视为均匀的组织，但重塑率在个体骨内也不同。在外周定量计算机断层扫描（pQCT）图像的分析中，这种适应水平在很大程度上被忽视了。此外，在生长的骨骼中，从未评估过CoD的这种变化。我们假设，在青少年胫骨中段的同一横截面内，CoD变化显著。我们进一步假设，由于雌激素对重塑的深刻影响，这种变化将是不同的性别。方法：受试者是183名青少年（99名女孩和84名男孩）在6年级和7年级的平均年龄为12.1岁。我们使用身高增长速度峰值时的年龄来调整性别之间的成熟差异。对每例受试者胫骨中段pQCT扫描的图像数据进行区域性评估，评估范围为围绕皮质分布的8个扇区，并与胫骨前嵴对齐。我们使用重复测量的一般线性模型来评估CoD的个体内变异，同时控制种族、成熟度、身高、体重、体力活动水平和总横截骨面积（ToA）的差异。
Background: Inter-individual differences in cortical bone volumetric density (CoD), such as those related to sex, are a product of differences in remodelling rates. While cortical bone is often treated as a uniform tissue, remodelling rates also vary within individual bones. This level of adaptation has largely been overlooked in analyses of peripheral quantitative computed tomography (pQCT) images. Further, such variation in CoD has never been assessed in growing bones. We hypothesised that CoD varied significantly within the same cross-section of the mid-tibia of adolescents. We further hypothesised that due to the profound impact of oestrogen on remodelling, this variation would be different between sexes.Methods: Subjects were 183 adolescents (99 girls and 84 boys) in grade 6 and 7 with a mean age of 12.1 years. We used age at peak height velocity to adjust for maturational differences between sexes. Image data from a mid-tibia pQCT scan of each subject were assessed regionally within eight sectors distributed about the cortex and aligned by the anterior tibial crest. We used a repeated measures general linear model to assess intra-individual variation in CoD while controlling for differences in ethnicity, maturity, height, weight, physical activity level and total cross-sectional bone area (ToA).Results: Sector based variation in CoD was significant (p