Exercise and Bone Development in Young Girls

年轻女孩的运动和骨骼发育

• 批准号: 7612746
• 负责人: Scott B Going
• 金额: $ 61.98万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-11 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7612746
• 关键词: Acceleration; Address; Adolescence; Adolescent; Adult; Age; Animals; Area; Attention; Body Composition; Body Size; Bone Density; Bone Development; Bone Mineral Contents; Boxing; Child; Childhood; Conflict (Psychology); Cross-Sectional Studies; Data; Development; Diet; Disease; Dose; Dual-Energy X-Ray Absorptiometry; Environment; Environmental Risk Factor; Exercise; Fostering; Fracture; Future; Growth; Health; Humulus; Incidence; Intervention; Investigation; Length; Life; Life Style; Longevity; Maintenance; Measurement; Measures; Mechanics; Methods; Minerals; Osteoporosis; Osteoporosis prevention; Participant; Physical activity; Prevention; Public Health; Publishing; Reaction; Relative (related person); Reporting; Research Personnel; Risk; Sampling; Shapes; Site; Staging; Stimulus; Structure; Testing; Thick; Time; Weight-Bearing state; Work; Writing; Youth; base; bone; bone loss; bone mass; bone strength; clinically significant; control trial; density; design; follow-up; girls; improved; interest; intervention effect; osteogenic; pediatrician; post intervention; programs; prospective; response; skeletal; therapy design; two-dimensional

DESCRIPTION (provided by applicant): Osteoporosis, with its increased fracture risk, is a major public health concern. While the majority of past prevention efforts have targeted slowing bone loss, there is great interest in skeletal adaptations to interventions during development. Both bone mass and structural geometry are important determinants of bone strength and fracture risk. Animal studies clearly show structural adaptations to mechanical stimuli during development. Children and adolescents, more so than adults, may have the ability to modify structural geometry as well as increase bone mineral mass and density in response to increased loads, which would increase bone strength and potentially protect against fractures later in life. This proposition has not been adequately tested. Moreover, from the few available studies, there have been conflicting reports regarding relative adaptations in girls at different stages of development. Thus the optimal timing of interventions is not known. To address these issues, we propose to assess the effects of "ground-reaction (e.g., jumping, hopping, etc.) exercise on bone macro-architectural development in pre-pubescent and early pubescent girls. Bone mineral content (BMC), bone mineral density (BMD), and bone structural geometry will be measured in girls in 4th (Tanner stage 1) and 6th (Tanner stage II and III) grade at baseline, and at regular intervals thereafter, to assess the effects of two years of exercise on bone accrual and structure. Follow-up measures will be made at 1 and 2 years post intervention to assess whether intervention effects persist. Physical activity, diet, maturation, body size and body composition will also be measured to control for differences in growth, maturation, and important environmental factors that may influence bone development and the interpretation of the adaptations to the intervention. This study is unique in several ways including: i) its focus on structural changes in addition to BMC and BMD; ii) the focus on pre- and early pubescent girls to define the optimal "window of opportunity" for adaptation to occur; iii) the two-year intervention so we can examine whether benefits continue to accrue with longer duration intervention; iv) comprehensive measurement of important covariates; and v) its focus on the maintenance of adaptations over two years of follow-up after intervention. Past studies have failed to adequately control for body and bone size, which confound area) BMD from DXA, and which vary with maturation. The inclusion of pQCT vBMD and measures of structural geometry allows an appropriate interpretation of changes in BMC and BMD, and provides a prospective test of the effects of exercise on structural adaptations in developing girls which contribute to bone strength and which may have lasting benefit for lowering fracture risk. We expect this study will make a significant contribution to our understanding of bone macro-architectural adaptations to exercise and will provide critical information for the design and optimal timing of interventions designed to enhance bone development to lessen future fracture risk.

描述（由申请人提供）：骨质疏松症具有增加的骨折风险，这是一个主要的公共健康问题。尽管过去的大多数预防努力都针对减慢骨质流失，但对开发过程中干预措施的骨骼适应性兴趣引起了极大的兴趣。骨骼质量和结构几何形状都是骨强度和断裂风险的重要决定因素。动物研究清楚地表明了在发育过程中对机械刺激的结构适应。儿童和青少年比成年人更重要，可能具有改变结构几何形状，并增加骨矿物质质量和密度，以响应增加的负荷，这将增加骨骼强度并有可能预防生命后期的裂缝。该命题尚未得到充分检验。此外，从少数可用的研究中，关于不同发展阶段的女孩的相对适应性的报道相互矛盾。因此，尚不清楚干预措施的最佳时机。为了解决这些问题，我们建议评估“地面反应（例如跳跃，跳跃等）锻炼对骨头宏观构造的发展的影响。在此之后，在干预后1和2年，将在骨骼和结构上评估两年的骨骼和结构措施的影响。关于BMC和BMD之外的结构变化； ii）重点是定义适应的最佳“机会之窗”的重点； iii）两年的干预措施，因此我们可以检查持续时间较长的干预措施是否继续产生福利； iv）全面测量重要协变量； v）它的重点是在干预后两年的随访中维护适应。过去的研究未能充分控制身体和骨骼大小，这使DXA的BMD混淆，并且随成熟而变化。包括PQCT VBMD和结构几何形状的度量，可以适当解释BMC和BMD的变化，并提供了对运动对发展中女孩结构适应作用的前瞻性测试，这有助于骨骼强度，这可能会降低分裂风险。我们预计这项研究将为我们理解骨骼宏观结构的适应性做出重大贡献，并将为旨在增强骨骼发育的干预措施的设计和最佳时机提供关键信息，从而减少未来的断裂风险。