Bone Abstracts

Objectives: Cross-sectional studies show that exercise may have positive effects on bone outcomes in youth. However, there is no evidence from longitudinal studies, which type of sports can induce improvements in bone acquisition in adolescent athletes. Therefore, this study aimed to investigate the longitudinal differences in bone acquisition and bone metabolism between adolescent males participating in osteogenic (football) and non-osteogenic (swimming, cycling) sports compared to a control group over 1 year.

Methods: A total of 116 adolescent males aged 12–14 years at baseline (T0) were measured and followed up for 1 year (T1): 37 swimmers, 37 footballers, 29 cyclists and 14 controls not engaged in these sports more than 3 hours per week in the last three years. Bone mineral content (BMC) was measured using dual-energy x-ray absorptiometry (DXA) at the femoral neck and lumbar spine. Bone geometry estimates at the femoral neck were measured using hip structural analysis (HSA) and bone microarchitecture of the lumbar spine using trabecular bone score (TBS). Bone formation was measured using procollagen type 1 aminoterminal propeptide (P1NP), bone resorption using isomer of the Carboxi-terminal telopeptide of type 1 collagen (CTX-I) and blood markers of total calcium serum and 25 hydroxyvitamin D [25(OH)D]. Moderate to vigorous physical activity (MVPA) was measured for 7 days using accelerometers. Bone acquisition was compared after controlling for age, height, lean mass, MVPA and baseline bone outcomes.

Results: Footballers had significantly (P<0.05) higher BMC acquisition at the lumbar spine and femoral neck compared to cyclists and at the lumbar spine compared to swimmers. Footballers had significantly (P<0.05) higher acquisition in all HSA outcomes at the femoral neck compared to cyclists, and significantly (P<0.01) higher acquisition in TBS score at the lumbar spine compared to cyclists and swimmers. There were no significant differences in bone acquisition between swimmers and cyclists. At T1 footballers had significantly higher P1NP compared to swimmers and cyclists, and 25(OH)D was significantly higher in footballers and cyclists compared to controls and swimmers.

Conclusions: This longitudinal study demonstrates for first time superior changes in bone mass, geometry and metabolism in adolescent male footballers compared to swimmers and cyclists.

Funding sources: The research leading to these results has received funding from the European Union Seventh Framework Programme ([FP7/2007-2013] under grant agreement n°. PCIG13-GA-2013-618496.

Disclosure: The authors declared no competing interests