Testing the Functional Model of Bone Development: Direct and Mediating Role of Muscle Strength on Bone Properties in Growing Youth
Metadata
Show full item recordEditorial
MDPI
Materia
Children Bone development Muscle strength Radial speed of sound Tibial speed of sound Bone turnover
Date
2021Referencia bibliográfica
Ludwa, I.A.; Mongeon, K.; Sanderson, M.; Gracia Marco, L.; Klentrou, P. Testing the Functional Model of Bone Development: Direct and Mediating Role of Muscle Strength on Bone Properties in Growing Youth. Int. J. Environ. Res. Public Health 2021, 18, 3154. https://doi.org/10.3390/ijerph 18063154
Sponsorship
Natural Sciences and Engineering Research Council of Canada (grant #2015–04424); Canadian Institutes for Health Research (grant #199944); Ontario Graduate Scholarship (OGS) and the Ontario Graduate Scholarship in Science and Technology (OGSST); Undergraduate Summer Research Award from the Natural Sciences and Engineering Research Council of Canada; Gracia-Marco was funded by “La Caixa” Foundation within the Junior Leader fellowship programme (ID 100010434; code LCF/BQ/PR19/11700007)Abstract
This study examines the functional model of bone development in peri-pubertal boys and
girls. Specifically, we implemented a mixed-longitudinal design and hierarchical structural models to
provide experimental evidence in support of the conceptual functional model of bone development,
postulating that the primary mechanical stimulus of bone strength development is muscle force.
To this end, we measured radial and tibial bone properties (speed of sound, SOS), isometric grip
and knee extensors strength, bone resorption (urinary NTX concentration), body mass index (BMI),
somatic maturity (years from peak height velocity) and skeletal maturity (bone age) in 180 children
aged 8–16 years. Measurements were repeated 2–4 times over a period of 3 years. The multilevel
structural equation modeling of 406 participant-session observations revealed similar results for
radial and tibial SOS. Muscle strength (i.e., grip strength for the radial and knee extension for tibial
model) and NTX have a significant direct effect on bone SOS (β = 0.29 and −0.18, respectively).
Somatic maturity had a direct impact on muscle strength (β = 0.24) and both a direct and indirect
effect on bone SOS (total effect, β = 0.30). Physical activity and BMI also had a significant direct
impact on bone properties, (β = 0.06 and −0.18, respectively), and an additional significant indirect
effect through muscle strength (β = 0.01 and 0.05, respectively) with small differences per bone
site and sex. Muscle strength fully mediated the impact of bone age (β = 0.14) while there was no
significant effect of energy intake on either muscle strength or bone SOS. In conclusion, our results
support the functional model of bone development in that muscle strength and bone metabolism
directly affect bone development while the contribution of maturity, physical activity, and other
modulators such as BMI, on bone development is additionally modulated through their effect on
muscle strength.