Sustained Skeletal Benefits of Adolescent Exercise

描述(由申请者提供)：将使用体操参与作为机械负荷的模型来确定青少年活动对峰值骨量、结构和强度的改善程度。对大约60名青春期后期女体操运动员和非体操运动员进行为期6-10年的纵向研究，并增加80名青春期早期女孩(体操运动员和非体操运动员)作为补充。每年对前臂、股骨近端、腰椎和全身进行双能量X射线吸收扫描，同时对前臂进行外围定量计算机断层扫描，以评估骨骼的几何形状、密度和强度。饮食、体操和其他体力活动、人体测量和晒黑自我阶段将每半年进行一次评估；肌肉力量将每年进行一次测量，以与骨骼扫描相一致。纵向和混合纵向设计将使用多水平建模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，在成熟和体操活动的背景下，骨骼生长和骨骼维护。如果这种极端的机械负荷模式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保持尚不清楚。这项拟议的研究将详细说明青少年体操活动的骨骼反应，并评估成年后的益处维持，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.