Link to publicationCitation for published version (APA): Cöster, M. E., Rosengren, B. E., Karlsson, C., Dencker, M., & Karlsson, M. K. (2016). Effects of an 8-year childhood physical activity intervention on musculoskeletal gains and fracture risk. Bone, 93, 139-145. AbstractBackground: Physical activity (PA) in childhood is associated with musculoskeletal benefits while the effect on fracture risk is yet to be determined. The aim of this study was to evaluate whether extension of a PA intervention leads to improvement in musculoskeletal traits with an accompanied reduced fracture risk. We hypothesized that the PA program would have beneficial effects in both sexes, but more so in girls since they tend to be less physically active than boys during this time frame. Methods:In one elementary school we increased physical education (PE) from 60 to 200 minutes per school week and followed 65 girls and 93 boys from a mean age of 7 years until a mean age of 15 years. Thirty-nine girls and 37 boys in three other schools continued with 60 minutes of PE per week during the same years and served as controls. We measured bone mineral content (BMC), areal bone mineral density (aBMD), and bone area annually with dual energy X-ray absorptiometry, and leg muscle strength with a computerized dynamometer. In 3 534 children within the same PE program (1 339 in the intervention and 2 195 in the control group) we registered incident fractures during the 8-year study period and estimated annual sex-specific fracture incidence rate ratios (IRRs).Results: Girls in the intervention group annually gained more total body less head aBMD, spine aBMD (p<0.01), femoral neck BMC (p<0.05), lumbar vertebrae size (p<0.05), and knee flexion strength (p<0.05) than girls in the control cohort. In boys we found no group differences. There was an inverse correlation between number of years with extra PE and the annual IRR of sustaining fractures in both girls (r = -0.90 (95% CI -0.98 to -0.51); p<0.001) and boys (r = -0.74 (95% CI -0.94 to -0.02); p<0.05). Conclusion:In this 8-year pediatric school-based moderate exercise intervention program there is an inverse correlation in both sexes between annual IRR and each additional year of extra PA. A sub-cohort of girls in the intervention group had greater gains in bone mass, bone size, and muscle strength, which could possibly explain the inverse correlation between years within the PA program and fracture risk, while in boys the reason for the inverse correlation remains unknown. It should be noted that differences in unreported factors such as skeletal maturity status, diet, and spare time PA could confound our inferences. That is, true causality cannot be stated.
Increased PA is associated with decreased fracture risk, probably in part due to beneficial gains in aBMD and muscle strength.
ObjectivesRecent evidence from the 7-year follow-up of the Pediatric Osteoporosis Prevention (POP) study indicates an inverse correlation between years of participation in a physical activity (PA) intervention and fracture risk in children. However, we could not see a statistically significant reduction in fracture risk, which urged for an extension of the intervention.SettingThe study was conducted in 4 neighbouring elementary schools, where 1 school functioned as intervention school.ParticipantsWe included all children who began first grade in these 4 schools between 1998 and 2012. This resulted in 1339 children in the intervention group and 2195 children in the control group, all aged 6–8 years at the state of the study.InterventionWe launched an 8-year intervention programme with 40 min of moderate PA per school day, while the controls continued with the Swedish national standard of 60 min of PA per week.Primary outcome measureWe used the regional radiographic archive to register objectively verified fractures and we estimated annual fracture incidences and incidence rate ratios (IRRs).ResultsDuring the first year after initiation of the intervention, the fracture IRR was 1.65 (1.05 to 2.08) (mean 95% CI). For each year of the study, the fracture incidence rate in the control group compared with the intervention group increased by 15.7% (5.6% to 26.8%) (mean 95% CI). After 8 years, the IRR of fractures was 52% lower in the intervention group than in the control group (IRR 0.48 (0.25 to 0.91) (mean 95% CI))].ConclusionsIntroduction of the school-based intervention programme is associated with a higher fracture risk in the intervention group during the first year followed by a gradual reduction, so that during the eighth year, the fracture risk was lower in the intervention group.Trial registration numberNCT00633828.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.