Fluoride, Dietary, and Other Factors Related to Young Adult Bone Measures and Dental Caries

 描述(由申请人提供)：这项建议的目的是通过将我们对独特的IBDS队列的评估延长到成年早期(23岁)，以解决从青春期晚期到成年期早期的重要过渡阶段的主要问题，从而加强对正常骨骼发育及其决定因素的了解。我们将获得23岁的骨骼结果(DXA、pQCT和MDCT)；收集详细的饮食、酒精、烟草、睡眠、体力活动和身体成分数据；并模拟整个骨骼、骨小梁和皮质骨微结构的个体发育变异性。具体地说，我们建议：1)确定青春期-成人过渡期间(19岁、21岁和23岁测量)身体属性(体重、脂肪组织、瘦体重)和生活方式行为(体力活动、饮食摄入量、烟草使用和睡眠)的变化对DXA、pQCT和MDCT(19岁和23岁测量)得出的骨量、密度、几何形状和微结构测量的影响，以及2)评估5至23岁和青春期前身体属性、体力活动、饮食摄入量和其他因素的水平和模式之间的关系，根据骨量、密度、几何形状和微结构的测量，对青春期周围和青春期后的发育期进行评估，既在23岁骨发育基本完成的时候进行评估，也在5岁到23岁之间进行纵向评估。青春期后期/成年期早期是生活方式行为发生重大变化的时期，但在青春期-成人过渡期中，对于可改变和不可改变的因素对骨骼发育的影响，我们的理解仍然存在重大差距。这段时间对于确定未来骨质疏松和骨折的风险非常重要。很少有研究纵向评估从童年中期到成年早期的骨骼结果及其决定因素。爱荷华州骨发育研究(IBDS)已进入第17个年头，它正在调查身体属性、生活方式行为、饮食摄入量和其他因素对骨骼发育和微结构的影响。我们在5岁、8岁、11岁、13岁、15岁和17岁时使用双能X射线骨密度仪(DXA)和外周定量计算机断层扫描(PQCT)评估骨骼测量，收集出生以来的饮食数据，并从5岁开始通过加速计量仪和问卷评估体力活动。队列父母也可以使用类似的横断面测量。19岁的检查正在进行中(到目前为止有255例)，增加了胫骨远端的高分辨率多探测器CT扫描(MDCT)和先进的算法来评估骨骼微结构、先进的3D加速度计和更详细的生活方式问卷。对成人早期IBDS队列的持续跟踪，重点是微结构，将为许多解释因素对骨骼发育和力量以及影响最大的发育期(S)的相对重要性提供重要见解，为未来制定战略和干预措施提供坚实的基础 优化骨骼健康。

 DESCRIPTION (provided by applicant): The objective of this proposal is to enhance understanding of normal bone development and its determinants by extending our assessments of the unique IBDS cohort into early adulthood (age 23 years) to address major questions about the important transition period from late adolescence to early adulthood. We will obtain age 23 bone outcomes (DXA, pQCT, and MDCT); collect detailed dietary, alcohol, tobacco, sleep, physical activity and body composition data; and model the variability in individual development of whole bone, and trabecular and cortical bone micro-architecture. Specifically, we propose to: 1) Determine the impact of changes in physical attributes (weight, adipose tissue, lean body mass), and lifestyle behaviors (physical activity, dietary intakes, tobacco use, and sleep) during the adolescent-adult transition (measured at 19, 21 and 23 years of age) on changes in measures of bone mass, density, geometry and micro-architecture derived from DXA, pQCT, and MDCT (measured at 19 and 23 years of age), and 2) Assess the relationships between levels and patterns of physical attributes, physical activity, dietary intakes, and other factors from 5 to 23 years of age and during the pre-pubertal, peri-pubertal, and post-pubertal developmental periods on measures of bone mass, density, geometry and micro-architecture, assessed both at age 23 when bone development is largely complete, as well as longitudinally from age 5 to 23. Late adolescence/early adulthood is a period of major lifestyle behavior changes, but major gaps remain in our understanding of the effects of modifiable and non-modifiable factors on bone development during the adolescent-adult transition period. This period is important in determining future risk for osteoporosis and bone fractures. Few studies have assessed bone outcomes and their determinants longitudinally from middle childhood to early adulthood. The Iowa Bone Development Study (IBDS), in its 17th year, is investigating the effects of physical attributes, lifestyle behaviors, dietary intakes, and other factors on bone development and micro-architecture. We assessed bone measures at ages 5, 8, 11, 13, 15, and 17 years using dual-energy x-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT), collected dietary data from birth, and assessed physical activity by accelerometry and questionnaire from age 5. Analogous cross-sectional measures for cohort parents are also available. Age 19 exams are in progress (n=255 to date), with the addition of high-resolution multi-detector CT scans (MDCT) of the distal tibia and advanced algorithms to assess bone micro-architecture, advanced 3-D accelerometry, and more detailed lifestyle questionnaires. Continued follow-up of the IBDS cohort to early adulthood with emphasis on micro-architecture will provide major insights into the relative importance of the many explanatory factors on bone development and strength and the developmental period(s) of greatest impact, providing a strong foundation for future design of strategies and interventions to optimize skeletal health.