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

 描述（由申请人提供）：本提案的目的是通过将我们对独特的IBDS队列的评估扩展到成年早期（23岁），以解决有关从青春期后期到成年早期的重要过渡期的主要问题，从而增强对正常骨发育及其决定因素的理解。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;并对整个骨骼、骨小梁和皮质骨微结构的个体发育变异性进行建模。具体而言，我们建议：1）确定物理属性变化的影响（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）（在19、21和23岁时测量）对源自DXA、pQCT、和MDCT（在19岁和23岁时测量），以及2）评估5至23岁年龄段和青春期前、青春期周围和青春期后发育期期间身体属性、身体活动、饮食摄入量和其他因素的水平和模式之间的关系，测量骨质、密度、几何形状和微结构，在骨骼发育基本完成的23岁时进行评估，以及从5岁到23岁进行纵向评估。 青春期后期/成年早期是一个主要的生活方式行为变化的时期，但在我们的理解的影响，可修改和不可修改的因素对骨发育的影响，在发育-成人过渡期仍然存在重大差距。这一时期对于确定骨质疏松症和骨折的未来风险非常重要。很少有研究纵向评估从童年中期到成年早期的骨结局及其决定因素。爱荷华州骨发育研究（IBDS），在其第17个年头，正在调查的影响，身体属性，生活方式行为，饮食摄入量，和其他因素对骨发育和微结构。我们使用双能X线吸收测定法（DXA）和外周定量计算机断层扫描（pQCT）评估了5岁、8岁、11岁、13岁、15岁和17岁时的骨测量值，从出生时收集饮食数据，并从5岁起通过加速度计和问卷调查评估体力活动。也可以为队列父母提供类似的横截面测量。年龄19岁的检查正在进行中（迄今为止n=255），增加了胫骨远端的高分辨率多探测器CT扫描（MDCT）和评估骨微结构的高级算法，高级3-D加速度计和更详细的生活方式问卷。 持续随访IBDS队列至成年早期，重点关注微结构，这将为许多解释因素对骨发育和强度的相对重要性以及最大影响的发育期提供重要见解，为未来设计策略和干预措施提供坚实基础， 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.