TY - JOUR
T1 - Bone Adaptation in Adult Women Is Related to Loading Dose
T2 - A 12-Month Randomized Controlled Trial
AU - Troy, Karen L.
AU - Mancuso, Megan E.
AU - Johnson, Joshua E.
AU - Wu, Zheyang
AU - Schnitzer, Thomas J.
AU - Butler, Tiffiny A.
N1 - Funding Information:
KLT reports grants and personal fees from National Institutes of Health, during the conduct of the study; non‐financial support from International Society of Biomechanics, grants from Merck, Inc, personal fees from National Science Foundation, outside the submitted work; MEM reports grants from National Science Foundation (DGE‐1106756),during the conduct of the study; All other authors declare no conflicts of interest.
Funding Information:
This research was fully supported by NIAMS of the National Institutes of Health under award number R01AR063691.The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This material is also based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1106756. We thank Sabahat Ahmed for her organization and dedication as research coordinator, and Dr. Jane Marone for serving as our Independent Safety Monitor. Authors' roles: Study conceived by KLT and designed by KLT with assistance from TJS. Data collection by MEM, KLT, JEJ, and TAB. Data analysis and interpretation: MEM, KLT, JEJ, TAB, ZW, TJS. Manuscript writing: KLT and MEM. Manuscript approval: MEM, KLT, JEJ, TAB, ZW, TJS.
Funding Information:
This research was fully supported by NIAMS of the National Institutes of Health under award number R01AR063691.The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This material is also based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE‐1106756. We thank Sabahat Ahmed for her organization and dedication as research coordinator, and Dr. Jane Marone for serving as our Independent Safety Monitor.
Publisher Copyright:
© 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - 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 με at 1878 με/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.
AB - 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 με at 1878 με/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.
KW - BIOMECHANICS
KW - BONE MODELING AND REMODELING
KW - BONE QCT/μCT
KW - CLINICAL TRIALS
KW - EXERCISE
UR - http://www.scopus.com/inward/record.url?scp=85082749072&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85082749072&partnerID=8YFLogxK
U2 - 10.1002/jbmr.3999
DO - 10.1002/jbmr.3999
M3 - Article
C2 - 32154945
AN - SCOPUS:85082749072
SN - 0884-0431
VL - 35
SP - 1300
EP - 1312
JO - Journal of Bone and Mineral Research
JF - Journal of Bone and Mineral Research
IS - 7
ER -
