Bouts of Vigorous Physical Activity and Bone Strength Accrual During Adolescence
Bouts of Vigorous Physical Activity and Bone Strength Accrual During Adolescence
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DOI：
10.1123/pes.2017-0043
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发表时间：
2017-11-01
影响因子：
1.8
通讯作者：
McKay, Heather A.
中科院分区：
文献类型：
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作者：
Gabel, Leigh;Macdonald, Heather M.;McKay, Heather A.
目的：我们研究了剧烈体力活动(VPA)比赛频率对青春期骨强度累积的影响，与VPA总量无关。方法：对309名青少年(99岁，13岁；126岁，13岁；84岁，18岁)每年使用腰佩式加速度计(Actgraph GT1M)测量VPA(6个代谢量当量；总体积和运动频率及持续5分钟)。我们将有限元分析应用于胫骨远端(8%部位)的高分辨率外周定量计算机断层扫描，以评估骨强度(失效载荷；F.载荷，牛顿)。我们建立了一个混合效应模型，其中成熟度偏移量(距年龄高峰时的年龄)为随机效应，性别、种族、胫骨长度、瘦体重和VPA(体积和比赛频率)为固定效应。结果：在整个青春期，VPA容量和比赛频率与F负荷呈正相关，但一旦将VPA比赛频率包括在模型中，VPA容量不能预测F负荷。在整个青春期，VPA比赛频率高四分位数的参与者(类似于每天33次比赛)的F负荷比最低四分位数的参与者(类似于每天9次比赛；P=0.012)高10%(500N)。每天增加一次VPA与增加21N的F负荷有关，与VPA的总量无关。结论：应提倡频繁的VPA，以获得最佳的骨强度。
Purpose: We examined the influence of vigorous physical activity (VPA) bout frequency on bone strength accrual across adolescence, independent of total volume of VPA. Methods: We measured VPA (6 metabolic equivalents; total volume and bout frequency < 5 min in duration) annually using waist-worn accelerometers (ActiGraph GT1M) in 309 adolescents (9-20 y at baseline: 99, < 13 y; 126, 13-18 y; 84, > 18 y) over a maximum of 4 years. We applied finite element analysis to high-resolution peripheral quantitative computed tomography scans of the distal tibia (8% site) to estimate bone strength (failure load; F. Load, Newtons). We fit a mixed effects model with maturity offset (years from age at peak height velocity) as a random effect and sex, ethnicity, tibia length, lean body mass, and VPA (volume and bout frequency) as fixed effects. Results: VPA volume and bout frequency were positively associated with F. Load across adolescence; however, VPA volume did not predict F. Load once VPA bout frequency was included in the model. Participants in the upper quartile of VPA bout frequency (similar to 33 bouts per day) had 10% (500 N) greater F. Load across adolescence compared with participants in the lowest quartile (similar to 9 bouts per day; P = .012). Each additional daily bout of VPA was associated with 21 N greater F. Load, independent of total volume of VPA. Conclusion: Frequent VPA should be promoted for optimal bone strength accrual.