Journal article
Objectively measured physical activity trajectories predict adolescent bone strength: Iowa Bone Development Study
British journal of sports medicine, Vol.48(13), pp.1032-1036
07/2014
DOI: 10.1136/bjsports-2014-093574
PMCID: PMC4550443
PMID: 24837241
Abstract
Physical activity improves bone strength and reduces the risk for osteoporotic fractures. However, there are substantial gaps in our knowledge as to when, how and how much activity is optimal for bone health. In this cohort study, we examined developmental trajectories of objectively measured physical activity from childhood to adolescence to discern if moderate-and-vigorous intensity physical activity (MVPA) predicts bone strength. Starting at age 5 and continuing at 8, 11, 13, 15 and 17 years, Iowa Bone Development Study participants (n=530) wore an accelerometer for 3-5 days. At age 17, we assessed dual X-ray energy absorptiometry outcomes of mass and estimated geometry (femoral neck cross-sectional area and section modulus). We also assessed geometric properties (bone stress index and polar moment of inertia) of the tibia using peripheral computer quantitative tomography. Latent class modelling was used to construct developmental trajectories of MVPA from childhood to late adolescence. General linear models were used to examine the trajectory groups as predictors of age 17 bone outcomes. Girls and boys who accumulated the most MVPA had greater bone mass and better geometry at 17 years when compared to less active peers. The proportion of participants achieving high levels of MVPA throughout childhood was very low (<6% in girls) and by late adolescence almost all girls were inactive. Bone health benefits of physical activity are not being realised due to low levels of activity for most youth, especially in girls.
Details
- Title: Subtitle
- Objectively measured physical activity trajectories predict adolescent bone strength: Iowa Bone Development Study
- Creators
- Kathleen F Janz - Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa, USA Department of Epidemiology, The University of Iowa, Iowa City, Iowa, USAElena M Letuchy - Department of Epidemiology, The University of Iowa, Iowa City, Iowa, USATrudy L Burns - Department of Epidemiology, The University of Iowa, Iowa City, Iowa, USA Department of Pediatrics, The University of Iowa, Iowa City, Iowa, USAJulie M Eichenberger Gilmore - Department of Clinical and Translational Science, The University of Iowa, Iowa City, Iowa, USAJames C Torner - Department of Epidemiology, The University of Iowa, Iowa City, Iowa, USASteven M Levy - Department of Epidemiology, The University of Iowa, Iowa City, Iowa, USA Department of Preventive and Community Dentistry, The University of Iowa, Iowa City, Iowa, USA
- Resource Type
- Journal article
- Publication Details
- British journal of sports medicine, Vol.48(13), pp.1032-1036
- DOI
- 10.1136/bjsports-2014-093574
- PMID
- 24837241
- PMCID
- PMC4550443
- NLM abbreviation
- Br J Sports Med
- ISSN
- 1473-0480
- eISSN
- 1473-0480
- Publisher
- England
- Grant note
- M01-RR00059 / NCRR NIH HHS M01 RR000059 / NCRR NIH HHS R01 DE009551 / NIDCR NIH HHS R01-DE12101 / NIDCR NIH HHS R01-DE09551 / NIDCR NIH HHS UL1 RR024979 / NCRR NIH HHS R01 DE012101 / NIDCR NIH HHS UL1 TR000442 / NCATS NIH HHS UL1-TR000442 / NCATS NIH HHS UL1-RR024979 / NCRR NIH HHS
- Language
- English
- Date published
- 07/2014
- Academic Unit
- Preventive and Community Dentistry; Epidemiology; Surgery; Injury Prevention Research Center; Neurosurgery; Health, Sport, and Human Physiology
- Record Identifier
- 9983917669102771
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