TY - JOUR
T1 - Bone health, activity and sedentariness at age 11–12 years
T2 - Cross-sectional Australian population-derived study
AU - Osborn, William
AU - Simm, Peter
AU - Olds, Tim
AU - Lycett, Kate
AU - Mensah, Fiona K.
AU - Muller, Josh
AU - Fraysse, Francois
AU - Ismail, Najmi
AU - Vlok, Jennifer
AU - Burgner, David
AU - Carlin, John B.
AU - Edwards, Ben
AU - Dwyer, Terence
AU - Azzopardi, Peter
AU - Ranganathan, Sarath
AU - Wake, Melissa
N1 - Funding Information:
WO and KL had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. This work has been supported to date by the National Health and Medical Research Council (NHMRC) of Australia (Project Grants 1041352 , 1109355 ), The Royal Children's Hospital Foundation (Grant 2014–241 ), Murdoch Children's Research Institute and The University of Melbourne . Research at the Murdoch Childrens Research Institute research is supported by the Victorian Government's Operational Infrastructure Program. The NHMRC supported MW (Senior Research Fellowship 1046518), KL (NHMRC Early Career Fellowship 1091124, National Heart Foundation Postdoctoral Fellowship 101239) and FM (Career Development Fellowship 1111160) in this work. MW was further supported by Cure Kids New Zealand. This paper uses unit record data from Growing Up in Australia, the Longitudinal Study of Australian Children. LSAC is conducted in partnership between the Department of Social Services (DSS), the Australian Institute of Family Studies (AIFS) and the Australian Bureau of Statistics (ABS). The findings and views reported in this paper are those of the author and should not be attributed to DSS, AIFS, the ABS or any of the funding bodies. Some study data were collected and managed using REDCap (Research Electronic Data Capture) electronic data capture tools, a secure, web-based application designed to support data capture for research studies.
PY - 2018/7
Y1 - 2018/7
N2 - Aim: To examine cross-sectional associations of children's bone health (size, density, strength) with moderate-vigorous physical activity (MVPA) and sedentary behaviour by considering: (1) duration of activity, (2) fragmentation, and (3) duration/fragmentation combined. Methods: Design: Population-based cross-sectional study. Participants: 11–12 year-olds in the Longitudinal Study of Australian Children's Child Health CheckPoint. Exposures: MVPA and sedentary behaviour (7-day accelerometry), yielding (1) daily average durations (min/day) and (2) fragmentations (the parameter alpha, representing the relationship between activity bout frequency and bout length). Outcomes: Tibial peripheral quantitative computed tomography (bone density, geometry, strength). Analysis: Multivariable regression models including activity durations and fragmentations separately and combined. Results: Of 1357 children attending the CheckPoint, 864 (64%) provided both bone and accelerometry data (mean age 11.4 years (standard deviation (SD) 0.5); 49% male). Mean daily MVPA and sedentary behaviour durations were 34.4 min/day (SD 28.3) and 667.9 min/day (SD 71.9) respectively for boys and girls combined. Each additional daily hour of MVPA was associated with small bone health benefits comprising greater periosteal and endosteal circumference (standardised effect sizes 0.25, 95% CI 0.10 to 0.40 and 0.21, 95% CI 0.03 to 0.39, respectively) and bone strength (0.26, 95% CI 0.14 to 0.38). Sedentary duration and fragmentation of either MVPA or sedentary behaviour showed little association with bone health. Conclusions: In early adolescence, MVPA duration showed associations with better bone health that, while modest, could be of population-level importance. MVPA fragmentation and sedentary behaviour duration and fragmentation seemed less important.
AB - Aim: To examine cross-sectional associations of children's bone health (size, density, strength) with moderate-vigorous physical activity (MVPA) and sedentary behaviour by considering: (1) duration of activity, (2) fragmentation, and (3) duration/fragmentation combined. Methods: Design: Population-based cross-sectional study. Participants: 11–12 year-olds in the Longitudinal Study of Australian Children's Child Health CheckPoint. Exposures: MVPA and sedentary behaviour (7-day accelerometry), yielding (1) daily average durations (min/day) and (2) fragmentations (the parameter alpha, representing the relationship between activity bout frequency and bout length). Outcomes: Tibial peripheral quantitative computed tomography (bone density, geometry, strength). Analysis: Multivariable regression models including activity durations and fragmentations separately and combined. Results: Of 1357 children attending the CheckPoint, 864 (64%) provided both bone and accelerometry data (mean age 11.4 years (standard deviation (SD) 0.5); 49% male). Mean daily MVPA and sedentary behaviour durations were 34.4 min/day (SD 28.3) and 667.9 min/day (SD 71.9) respectively for boys and girls combined. Each additional daily hour of MVPA was associated with small bone health benefits comprising greater periosteal and endosteal circumference (standardised effect sizes 0.25, 95% CI 0.10 to 0.40 and 0.21, 95% CI 0.03 to 0.39, respectively) and bone strength (0.26, 95% CI 0.14 to 0.38). Sedentary duration and fragmentation of either MVPA or sedentary behaviour showed little association with bone health. Conclusions: In early adolescence, MVPA duration showed associations with better bone health that, while modest, could be of population-level importance. MVPA fragmentation and sedentary behaviour duration and fragmentation seemed less important.
KW - Accelerometry
KW - Adolescents
KW - Bone health
KW - Physical activity
KW - Sedentary behaviour
KW - pQCT
UR - http://www.scopus.com/inward/record.url?scp=85046167389&partnerID=8YFLogxK
U2 - 10.1016/j.bone.2018.04.011
DO - 10.1016/j.bone.2018.04.011
M3 - Article
C2 - 29674127
AN - SCOPUS:85046167389
VL - 112
SP - 153
EP - 160
JO - Bone
JF - Bone
SN - 8756-3282
ER -