OSTEOPOROSIS PREVENTION IN SEDENTARY ADOLESCENT FEMALES

描述（改编自研究者摘要）：本研究的目的 研究是实施一种新的行为计划，旨在增加 身体活动和增强骨矿化。研究的重点是 久坐不动的青少年女性，一个特别高风险的人群， 在晚年患上骨质疏松症。研究人员假设， 干预会增加身体活动，这些活动的增加 将与特定心理社会特征的变化相关， 它们会导致骨形成和骨矿物质密度的增加 超过10个月本研究的目的是：（1）测试干预措施 旨在增加女性青少年的身体活动;（2）评估 干预措施的一个组成部分，包括基于互联网的 与激励性榜样故事相联系的锻炼日记;（3）评估 特定的心理社会特征的各自作用， （4）确定是否采用和维持体力活动; 随着时间的推移，心理社会特征的积极变化与以下因素有关： 增加参与体育活动;（5）测试假设， 增加体力活动可促进骨矿化。 久坐的青少年女性将被分配到全面干预（n=100）， 改良干预组（n=100）或对照组（n=100）治疗10个月。所有 参加者每日均会接受钙质补充。骨形成将是 在基线（DEXA）、5周和5个月时进行评估。（血清和尿液测量），以及 10个月（DEXA）。社会心理特征与体育活动参与 将在所有四个时间间隔测量。

Description (adapted from the investigator's abstract): The goal of this research is to implement a novel behavioral program designed to increase physical activity and enhance bone mineralization. The study focuses on sedentary adolescent females, a population at particularly high risk for developing osteoporosis later in life. The investigators hypothesize that the intervention will increase physical activity, that these increases in activity will be associated with changes in specific psychosocial characteristics, and that they will lead to increases in bone formation and bone mineral density over 10 months. The proposed research intends to: (1) test the intervention designed to increase female adolescents' physical activity; (2) evaluate the efficacy of one component of the intervention consisting of an Internet-based exercise diary linked with motivational role model stories; (3) evaluate the respective roles of specific psychosocial characteristics that may predispose toward the adoption and maintenance of physical activity; (4) determine whether positive changes in psychosocial characteristics over time are associated with increased participation in physical activity; and (5) test the hypothesis that increased physical activity enhances bone mineralization. Sedentary adolescent females will be assigned to full intervention (n=100), modified intervention (n=100), or comparison group (n=100) for 10 months. All participants will receive daily calcium supplementation. Bone formation will be assessed at baseline (DEXA), 5 wks and 5 mo. (serum and urinary measures), and 10 mo. (DEXA). Psychosocial characteristics and physical activity participation will be measure at all four intervals.