Maturity- and sex-related changes in tibial bone geometry, strength and bone–muscle strength indices during growth: A 20-month pQCT study

Macdonald, Heather M., Kontulainen, Saija A., MacKelvie-O'Brien, Kerry J., Petit, Moira A., Janssen, Patricia, Khan, Karim M. and McKay, Heather A. (2005) Maturity- and sex-related changes in tibial bone geometry, strength and bone–muscle strength indices during growth: A 20-month pQCT study. Bone, 36 6: 1003-1011. doi:10.1016/j.bone.2004.12.007


Author Macdonald, Heather M.
Kontulainen, Saija A.
MacKelvie-O'Brien, Kerry J.
Petit, Moira A.
Janssen, Patricia
Khan, Karim M.
McKay, Heather A.
Title Maturity- and sex-related changes in tibial bone geometry, strength and bone–muscle strength indices during growth: A 20-month pQCT study
Journal name Bone   Check publisher's open access policy
ISSN 8756-3282
Publication date 2005-06-01
Sub-type Article (original research)
DOI 10.1016/j.bone.2004.12.007
Open Access Status DOI
Volume 36
Issue 6
Start page 1003
End page 1011
Total pages 9
Place of publication New York
Publisher Elsevier Science
Language eng
Subject 1103 Clinical Sciences
Abstract During growth, bone strength is conferred through subtle adaptations in bone mass and geometry in response to muscle forces. Few studies have examined the changes in bone geometry, strength and the bone–muscle strength relationship across maturity in boys and girls. Our aims were to describe (i) 20-month changes in bone geometry and strength at the tibial midshaft across three maturity groups of boys and girls, (ii) differences in these adaptations between sexes at the same approximate level of maturity and (iii) the bone–muscle strength relationship across maturity groups of boys and girls and between sexes. We used peripheral quantitative computed tomography (pQCT, Stratec XCT-2000) to measure change in total bone cross-sectional area (ToA, mm2), cortical area (CoA, mm2), average cortical thickness (C.Th., mm), section modulus (mm3) and muscle cross-sectional area (mm2) at the tibial midshaft (50% site) in 128 EARLY-, PERI- and POST-pubertal girls (n = 69, 11.9 ± 0.6 years) and boys (n = 59, 12.0 ± 0.6 years) across 20 months. We also calculated two bone–muscle strength indices (BMSI) for compression (CoA/MCSA) and bending [strength index/MCSA; where strength index = Z / (tibial length / 2)]. EARLY boys and girls had smaller ToA at baseline than same sex PERI or POST participants. There were no sex differences in ToA or CoA at baseline; however, boys increased both parameters significantly more than girls in every maturity group (8.5–11.1%, P < 0.01). These changes in bone geometry conferred greater gains in bone strength for boys compared with girls in each maturity group (13.8–15.6%, P < 0.01). Baseline BMSIs did not differ between sexes for EARLY and PERI groups, whereas BMSIs were significantly higher for POST boys compared with POST girls (P < 0.05). BMSIs decreased for EARLY and PERI girls (−7.4–(−1.1%)) whereas the ratios remained stable for EARLY and PERI boys (−0.6–2.5%). This sex difference in BMSI change was due to a relatively greater increase in CoA among EARLY and PERI boys compared with same-maturity girls. BMSIs remained stable in POST girls and decreased in POST boys due to relatively greater gains in MCSA. This study provides novel longitudinal descriptions of the maturity- and sex-specific changes in bone geometry, strength and bone–muscle strength indices.
Keyword Peripheral quantitative computed tomography (pQCT)
Bone geometry
Bone strength
Bone–muscle strength index
Puberty
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Human Movement and Nutrition Sciences Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 45 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 52 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 10 Mar 2009, 01:23:47 EST by Ms Lynette Adams on behalf of School of Human Movement and Nutrition Sciences