PREDICTORS OF STRESS FRACTURE IN ACTIVE ADOLESCENT FEMALES

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。自1972年颁布《教育修正案法》第九条以来，参加体育运动在青春期女性中已变得越来越普遍，该法案要求女性的校际体育活动应与她们在学生中的代表性成比例。这对青少年保健提供者来说是一个受欢迎的趋势，因为积极的生活方式对健康有显著的好处。对年轻女性来说，一个特别的好处是改善骨骼健康的潜力。青春期是年轻女性一生中获得骨量的关键时期，超过一半的成年人骨钙在青少年时期积累，女性的峰值骨密度可能在10至30岁之间达到。负重运动是骨骼重塑的主要刺激因素，增加了骨矿化，从而增加了骨密度。在青春期通过参加体育运动来最大限度地增加骨密度(BMD)，可能会在这些年轻女性的晚年预防骨质疏松症。骨质疏松症目前是导致2000多万美国妇女晚年发病和死亡的主要原因。对于导致青春期女孩应力性骨折的因素，人们知之甚少。我们认为许多危险因素与成年女性是相同的，并开发了一个发病模型来描述和解释它们之间的关系。我们假设，只有低骨密度和运动直接影响应力性骨折的风险。我们进一步假设，闭经通过对BMD产生负面影响而增加应力性骨折的风险。作为青少年健康护理提供者，我们为缺乏证据来回答这样一个问题而感到困扰：“多大的运动量是安全的？”我们特别关注闭经年轻女性参加运动的安全性。我们目前的护理标准要求通过双能x射线骨密度仪(DXA)评估

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Athletic participation has become increasingly common among adolescent females since the enactment of Title IX of the Educational Amendments Act in 1972, which required women's intercollegiate athletic offerings to be proportional to their representationin the student body. This has been a welcome trend to adolescent health care providers, as there are notable health benefits derived from an active lifestyle. A particular benefit for young women is the potential for improved skeletal health. Adolescence is the critical period in a yound woman's life for bone mass acquisition, with over half of the adult bone calcium laid down during the teenage years and a woman's peak bone density likely reached between the ages of 10 and 30 years. Weight-bearing exercise is a major stimulus for skeletal remodeling, increased bone mineralization, and thereby, increased bone density. maximizing bone mineral density (BMD) by participation in athletics during adolescence could result in the prevention of osteoporosis later in these young women's lives. Osteoporosis is currently a mojor cause of morbidity and mortality for over 20 million American women in their later years. Less is known about factors that contribute to stress fractures in adolescent girls. We hpothesize that many of the risk factors are the same as in adult women and have developed a pathogenetic model to describe and explain the relationships among them. We hypothesize that only low BMD and exercise directly influence the risk of stress fracture. We further hypothesize that amenorrhea increases the risk of stress fracture by negaively impacting on BMD. As adolescent health care providers, we are vexed by the lack of evidence upon which to answer the question, "How much exercise is safe?" We are particularly concerned about the safety of athletic participation by young women with amenorrhea. Our current standard of care calls for assessment of bone density by dual energy x-ray absorptiometry (DXA) in