Success of a general school-based physical activity intervention on bone mineral content depends on pubertal stage but not on gender

Details

Serval ID
serval:BIB_979882F75114
Type
Inproceedings: an article in a conference proceedings.
Publication sub-type
Abstract (Abstract): shot summary in a article that contain essentials elements presented during a scientific conference, lecture or from a poster.
Collection
Publications
Institution
Title
Success of a general school-based physical activity intervention on bone mineral content depends on pubertal stage but not on gender
Title of the conference
IOF World Congress on Osteoporosis and 10th European Congress on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis
Author(s)
Meyer U., Kriemler S., Zahner L., Puder J.J., Rizzoli R.
Address
Florence, Italy, May 5-8, 2010
ISBN
0937-941X
Publication state
Published
Issued date
2010
Peer-reviewed
Oui
Volume
21
Series
Osteoporosis International
Pages
249
Language
english
Notes
Meeting Abstract
Abstract
Aims: We performed a randomised controlled trial in children of both gender and different pubertal stages to determine whether a school-based physical activity (PA) program during a full schoolyear influences bone mineral content (BMC) and whether there are differences in response for boys and girls before and during puberty.
Methods: Twenty-eight 1st and 5th grade classes were cluster randomised to an intervention (INT, 16 classes, n=297) and control (CON; 12 classes, n=205) group. The intervention consisted of a multi-component PA intervention including daily physical education during a full school year. Each lesson was predetermined, included about ten minutes of jumping or strength training exercises of various intensity and was the same for all children. Measurements included anthropometry (height and weight), tanner stages (by self-assessment), PA (by accelerometry) and BMC for total body, femoral neck, total hip and lumbar spine using dualenergy X-ray absorptiometry (DXA). Bone parameters were normalized for gender and tanner stage (pre- vs. puberty). Analyses were performed by a regression model adjusted for gender, baseline height, baseline weight, baseline PA, post-intervention tanner stage, baseline BMC, and cluster. Researchers were blinded to group allocation. Children in the control group did not know about the intervention arm.
Results: 217 (57%) of 380 children who initially agreed to have DXA measurements had also post-intervention DXA and PA data. Mean age of prepubertal and pubertal children at baseline was 9.0±2.1 and 11.2±0.6 years, respectively. 47/114 girls and 68/103 boys were prepubertal at the end of the intervention. Compared to CON, children in INT showed statistically significant increases in BMC of total body (adjusted z-score differences: 0.123; 95%>CI 0.035 to 0.212), femoral neck (0.155; 95%>CI 0.007 to 0.302), and lumbar spine (0.127; 95%>CI 0.026 to 0.228). Importantly, there was no gender*group, but a tanner*group interaction consistently favoring prepubertal children.
Conclusions: Our findings show that a general, but stringent school-based PA intervention can improve BMC in elementary
school children. Pubertal stage, but not gender seems to determine
bone sensitivity to physical activity loading.
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Create date
01/09/2010 12:19
Last modification date
20/08/2019 14:59
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