The association between childhood fractures and adolescence bone outcomes: a population-based study, the Tromsø Study, Fit Futures

• Published in: Osteoporosis International
• Main Authors: Christoffersen, Tore, Emaus, Nina, Dennison, Elaine, Furberg, Anne-Sofie, Gracia-Marco, Luis, Grimnes, Guri, Nilsen, Ole-Andreas, Vlachopoulos, Dimitris, Winther, Anne, Ahmed, Luai A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Verlag (Germany) 2017
• Subjects: VDP::Medical disciplines: 700::Health sciences: 800; VDP::Medisinske Fag: 700::Helsefag: 800; Fracture; Child; Physical activity; Bone mineral density; DXA; Tromsø
• Online Access: https://hdl.handle.net/10037/13826; https://doi.org/10.1007/s00198-017-4300-0

This is a post-peer-review, pre-copyedit version of an article published in Osteoporosis International . The final authenticated version is available online at: https://doi.org/10.1007/s00198-017-4300-0 . SUMMARY : Childhood fracture may predict persistent skeletal fragility, but it may also reflect high physical activity which is beneficial to bone development. We observe a difference in the relationship between previous fracture and bone outcome across physical activity level and sex. Further elaboration on this variation is needed. PURPOSE : Childhood fracture may be an early marker of skeletal fragility, or increased levels of physical activity (PA), which are beneficial for bone mineral accrual. This study investigated the association between a previous history of childhood fracture and adolescent bone mineral outcomes by various PA levels. METHODS : We recruited 469 girls and 492 boys aged 15-18 years to this study. We assessed PA levels by questionnaire and measured areal bone mineral density (aBMD) and bone mineral content (BMC) using dual-energy X-ray absorptiometry (DXA) at arm, femoral neck (FN), total hip (TH), and total body (TB) and calculated bone mineral apparent density (BMAD, g/cm3). Fractures from birth to time of DXA measurements were retrospectively recorded. We analyzed differences among participants with and without fractures using independent sample t test. Multiple linear regression was used to examine the association between fractures and aBMD and BMC measurements according to adolescent PA. RESULTS : Girls with and without a previous history of fracture had similar BMC, aBMD, and BMAD at all sites. In multiple regression analyses stratified by physical activity intensity (PAi), there was a significant negative association between fracture and aBMD-TH and BMC-FN yet only in girls reporting low PAi. There was a significant negative association between forearm fractures, BMAD-FN, and BMAD-arm among vigorously active boys. CONCLUSION : Our findings indicate a negative association between childhood fractures and aBMD/BMC in adolescent girls reporting low PAi. In boys, such an association appears only in vigorously active participants with a history of forearm fractures.