Sustained Skeletal Benefits of Adolescent Exercise

描述（由申请人提供）：将使用体操参与作为机械负荷模型，确定青少年活动对骨量、结构和强度峰值改善的程度。一项对大约60名青春期后期的女体操运动员和非体操运动员进行的为期6-10年的纵向研究将通过增加80名青春期早期的女孩（体操运动员和非体操运动员）来扩展和补充。每年对前臂、股骨近端、腰椎和全身进行双能x线吸收仪扫描，同时对前臂进行外围定量计算机断层扫描，将评估骨骼的几何形状、密度和强度。每半年对饮食、体操等身体活动、人体测量和坦纳自我阶段进行评估；肌肉力量将每年测量一次，以配合骨骼扫描。纵向和混合纵向设计将使用多层模型来检查几何和密度骨骼适应的相对贡献，并确定这些益处对骨骼成熟的持久性。这项工作将提供一个独特的纵向视角的骨骼生长和骨骼维护在成熟和体操活动的背景下。如果这种极端的机械载荷模型不能产生持久的骨骼改善，那么更广泛适用的模式不太可能带来持久的好处。增强峰值骨量和结构是预防骨质疏松症的重要策略。机械负荷似乎增加了生长过程中的骨获取，但这些益处在多大程度上得以维持尚不清楚。这项拟议的研究将详细描述青少年体操活动对骨骼的反应，并评估其对成年期的益处，为制定青少年运动处方以改善最终的骨骼健康提供基础。

DESCRIPTION (provided by applicant): The extent to which peak bone mass, structure, and strength are improved by adolescent activity will be determined, using gymnastics participation as a model of mechanical loading. A 6-10 year longitudinal study of approximately 60 late-adolescent female gymnasts and non-gymnasts will be extended and supplemented by the addition of 80 early-adolescent girls (gymnasts and non-gymnasts). Annual dual energy X-ray absorptiometry scans of the forearm, proximal femur, lumbar spine, and total body, with concurrent peripheral quantitative computed tomography scans of the forearm, will evaluate skeletal geometry, density and strength. Diet, gymnastics and other physical activity, anthropometry and Tanner self-stage will be assessed semi-annually; muscle strength will be measured annually to coincide with skeletal scans. Longitudinal and mixed longitudinal designs will use Multilevel Modeling to examine the relative contributions of geometric and densitometric skeletal adaptations and determine the persistence of those benefits to skeletal maturity. This work will provide a unique longitudinal perspective of bone growth and skeletal maintenance in the context of maturation and gymnastic activity. If this extreme model of mechanical loading does not yield persistent skeletal improvements, more widely applicable modes are unlikely to confer lasting benefits. Enhancement of peak bone mass and structure is a crucial strategy for the prevention of osteoporosis. Mechanical loading appears to increase bone acquisition during growth, yet the extent to which these benefits are maintained is unclear. The proposed study will detail skeletal responses to adolescent gymnastic activity and assess maintenance of benefits to adulthood, providing a foundation for the development of an adolescent exercise prescription to improve ultimate bone health.