Rantalainen Timo, Weeks Benjamin K, Nogueira Rossana C, Beck Belinda R
Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia.
Griffith Health Institute, Centre for Musculoskeletal Research, School of Allied Health Sciences, Griffith University, Gold Coast, Australia.
Bone. 2015 Mar;72:101-8. doi: 10.1016/j.bone.2014.11.015. Epub 2014 Nov 26.
Growth is the opportune time to modify bone accrual. While bone adaptation is known to be dependent on local loading and consequent deformations (strain) of bone, little is known about the effects of sex, and bone-specific physical activity on location-specific cross-sectional bone geometry during growth. To provide more insight we examined bone traits at different locations around tibial cross sections, and along the tibia between individuals who vary in terms of physical activity exposure, sex, and pubertal status. Data from 304 individuals aged 5-29 years (172 males, 132 females) were examined. Peripheral quantitative computed tomography (pQCT) was applied at 4%, 14%, 38%, and 66% of tibial length. Maturity was established by estimating age at peak height velocity (APHV). Loading history was quantified with the bone-specific physical activity questionnaire (BPAQ). Comparisons, adjusted for height, weight and age were made between sex, maturity, and BPAQ tertile groups. Few to no differences were observed between sexes or BPAQ tertiles prior to APHV, whereas marked sexual dimorphism and differences between BPAQ tertiles were observed after APHV. Cross-sectional location-specific differences between BPAQ tertiles were not evident prior to APHV, whereas clear location-specificity was observed after APHV. In conclusion, the skeletal benefits of physical activity are location-specific in the tibia. The present results indicate that the peri- or post-pubertal period is likely a more favourable window of opportunity for enhancing cross-sectional bone geometry than pre-puberty. Increased loading during the peri-pubertal period may enhance the bone of both sexes.
生长是改变骨量积累的适当时机。虽然已知骨适应依赖于局部负荷以及随之而来的骨变形（应变），但关于性别和特定于骨的身体活动对生长期间特定部位横截面骨几何形状的影响却知之甚少。为了提供更多见解，我们研究了不同身体活动暴露、性别和青春期状态的个体胫骨横截面周围不同位置以及沿胫骨的骨特征。研究了304名5至29岁个体（172名男性，132名女性）的数据。在胫骨长度的4%、14%、38%和66%处应用外周定量计算机断层扫描（pQCT）。通过估计身高速度峰值年龄（APHV）来确定成熟度。用特定于骨的身体活动问卷（BPAQ）对负荷历史进行量化。对性别、成熟度和BPAQ三分位数组进行了调整身高、体重和年龄后的比较。在APHV之前，性别或BPAQ三分位数之间几乎没有观察到差异，而在APHV之后观察到明显的性别二态性和BPAQ三分位数之间的差异。在APHV之前，BPAQ三分位数之间的横截面特定位置差异不明显，而在APHV之后观察到明显的位置特异性。总之，身体活动对骨骼的益处是胫骨特定部位的。目前的结果表明，青春期前后时期可能比青春期前更有利于增加横截面骨几何形状的机会窗口。青春期前后增加负荷可能会增强两性的骨骼。
