Bone Adaptation in Adult Women Is Related to Loading Dose: A 12-Month Randomized Controlled Trial
Bone Adaptation in Adult Women Is Related to Loading Dose: A 12-Month Randomized Controlled Trial
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DOI：
10.1002/jbmr.3999
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发表时间：
2020-03-30
影响因子：
6.2
通讯作者：
Butler, Tiffiny A.
中科院分区：
文献类型：
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作者：
Troy, Karen L.;Mancuso, Megan E.;Butler, Tiffiny A.
尽管有强有力的证据表明，某些活动可以增加人体的骨密度和结构，但目前还不清楚是什么特定的机械因素控制了这种反应。这一点很重要，因为了解机械信号对骨骼的影响有助于更有效的骨质疏松预防方法和有效的临床试验设计。应变速率和应变幅度在多大程度上控制着人类的骨适应，从来没有进行过前瞻性的测试。在这里，我们研究了一项自愿的上肢压缩负荷任务对健康成年女性在12个月的前瞻性期间的影响。共有102名21至40岁的女性参加了两个实验之一：(I)低应变(n=21)和高应变(n=24)；或(Ii)低应变(n=21)和高应变(n=20)。对照组(n=16)不干预。使用特定于受试者的有限元模型来指定应变。载荷循环以数字方式记录下来。主要结果是QCT评估的超远端桡骨积分骨矿含量(IBMC)的变化。用高分辨率的pQCT(HRpQCT)评估中间时间点和二次预后。66名参与者完成了干预，对77名参与者的中期数据进行了分析。低应变率组和高应变率组12个月的超常IBMC(对照改变：-1.3+/-2.7%，低应变率：2.7+/-2.1%，高应变率：3.4+/-2.2%)、总IBMC和其他指标均显著增加，可能与改善的顺应性和较高的负荷剂量有关。“负荷剂量”与超长IBMC的12个月变化呈正相关，与总BMD、皮质厚度和骨小梁内侧BMD的中期变化呈正相关。获得最多骨骼的参与者平均完成了128次加载，平均应变为575mU/S。我们得出的结论是，与应变大小、速率和加载次数有关的信号有助于健康成年女性的骨适应，但只能解释骨骼变化的微小差异。(C)2020作者。《骨与矿物研究杂志》，由美国骨与矿物研究学会出版。
Although strong evidence exists that certain activities can increase bone density and structure in people, it is unclear what specific mechanical factors govern the response. This is important because understanding the effect of mechanical signals on bone could contribute to more effective osteoporosis prevention methods and efficient clinical trial design. The degree to which strain rate and magnitude govern bone adaptation in humans has never been prospectively tested. Here, we studied the effects of a voluntary upper extremity compressive loading task in healthy adult women during a 12-month prospective period. A total of 102 women age 21 to 40 years participated in one of two experiments: (i) low (n = 21) and high (n = 24) strain magnitude; or (ii) low (n = 21) and high (n = 20) strain rate. Control (n = 16) no intervention. Strains were assigned using subject-specific finite element models. Load cycles were recorded digitally. The primary outcome was change in ultradistal radius integral bone mineral content (iBMC), assessed with QCT. Interim time points and secondary outcomes were assessed with high resolution pQCT (HRpQCT) at the distal radius. Sixty-six participants completed the intervention, and interim data were analyzed for 77 participants. Likely related to improved compliance and higher received loading dose, both the low-strain rate and high-strain rate groups had significant 12-month increases to ultradistal iBMC (change in control: -1.3 +/- 2.7%, low strain rate: 2.7 +/- 2.1%, high strain rate: 3.4 +/- 2.2%), total iBMC, and other measures. "Loading dose" was positively related to 12-month change in ultradistal iBMC, and interim changes to total BMD, cortical thickness, and inner trabecular BMD. Participants who gained the most bone completed, on average, 128 loading bouts of (mean strain) 575 mu epsilon at 1878 mu epsilon/s. We conclude that signals related to strain magnitude, rate, and number of loading bouts contribute to bone adaptation in healthy adult women, but only explain a small amount of variance in bone changes. (c) 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.