Displaying all 3 publications

Abstract:
Sort:
  1. Fulltext Reply to The effect of vigorous physical activity and body composition on cortical bone mass in adolescence
    Tan VP, Macdonald HM, McKay HA
    J. Bone Miner. Res., 2015 Mar;30(3):585-6.
    PMID: 25381875 DOI: 10.1002/jbmr.2399
  2. Physical activity, but not sedentary time, influences bone strength in late adolescence
    Tan VP, Macdonald HM, Gabel L, McKay HA
    Arch Osteoporos, 2018 Mar 20;13(1):31.
    PMID: 29556801 DOI: 10.1007/s11657-018-0441-9
    Physical activity is essential for optimal bone strength accrual, but we know little about interactions between physical activity, sedentary time, and bone outcomes in older adolescents. Physical activity (by accelerometer and self-report) positively predicted bone strength and the distal and midshaft tibia in 15-year-old boys and girls. Lean body mass mediated the relationship between physical activity and bone strength in adolescents.

    PURPOSE: To examine the influence of physical activity (PA) and sedentary time on bone strength, structure, and density in older adolescents.

    METHODS: We used peripheral quantitative computed tomography to estimate bone strength at the distal tibia (8% site; bone strength index, BSI) and tibial midshaft (50% site; polar strength strain index, SSIp) in adolescent boys (n = 86; 15.3 ± 0.4 years) and girls (n = 106; 15.3 ± 0.4 years). Using accelerometers (GT1M, Actigraph), we measured moderate-to-vigorous PA (MVPAAccel), vigorous PA (VPAAccel), and sedentary time in addition to self-reported MVPA (MVPAPAQ-A) and impact PA (ImpactPAPAQ-A). We examined relations between PA and sedentary time and bone outcomes, adjusting for ethnicity, maturity, tibial length, and total body lean mass.

    RESULTS: At the distal tibia, MVPAAccel and VPAAccel positively predicted BSI (explained 6-7% of the variance, p 

  3. Fulltext Influence of physical activity on bone strength in children and adolescents: a systematic review and narrative synthesis
    Tan VP, Macdonald HM, Kim S, Nettlefold L, Gabel L, Ashe MC, et al.
    J. Bone Miner. Res., 2014 Oct;29(10):2161-81.
    PMID: 24737388 DOI: 10.1002/jbmr.2254
    A preponderance of evidence from systematic reviews supports the effectiveness of weight-bearing exercises on bone mass accrual, especially during the growing years. However, only one systematic review (limited to randomized controlled trials) examined the role of physical activity (PA) on bone strength. Thus, our systematic review extended the scope of the previous review by including all PA intervention and observational studies, including organized sports participation studies, with child or adolescent bone strength as the main outcome. We also sought to discern the skeletal elements (eg, mass, structure, density) that accompanied significant bone strength changes. Our electronic-database, forward, and reference searches yielded 14 intervention and 23 observational studies that met our inclusion criteria. We used the Effective Public Health Practice Project (EPHPP) tool to assess the quality of studies. Due to heterogeneity across studies, we adopted a narrative synthesis for our analysis and found that bone strength adaptations to PA were related to maturity level, sex, and study quality. Three (of five) weight-bearing PA intervention studies with a strong rating reported significantly greater gains in bone strength for the intervention group (3% to 4%) compared with only three significant (of nine) moderate intervention studies. Changes in bone structure (eg, bone cross-sectional area, cortical thickness, alone or in combination) rather than bone mass most often accompanied significant bone strength outcomes. Prepuberty and peripuberty may be the most opportune time for boys and girls to enhance bone strength through PA, although this finding is tempered by the few available studies in more mature groups. Despite the central role that muscle plays in bones' response to loading, few studies discerned the specific contribution of muscle function (or surrogates) to bone strength. Although not the focus of the current review, this seems an important consideration for future studies.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links