Doctoral Dissertation Research: Life history tradeoffs affecting bone maintenance and development in women

骨骼是一种动态组织，在整个生命周期中都会发生变化。本论文的研究将结合骨转换的标记物和骨密度的测量来了解骨是如何随身体活动和生活史而变化的。该项目旨在了解两个生活方式不同的相关人群中骨密度的缓慢变化和维持骨骼更新的过程。除了雌激素和身体活动水平的数据外，co-PI还将收集月经初潮年龄、后代数量和母乳喂养持续时间等信息，这些生活史特征会随着能量供应和压力水平的变化而变化，反映出雌激素浓度的变化，并可能与骨骼特征相关。在这种比较背景下，结合过去条件和当前生活方式因素的数据将扩大我们对成年女性一生中骨骼健康的理解。该项目还将促进国际合作、学生培训和指导以及公共科学推广活动。该项目建立在生活史和人类生殖生态学的先前工作基础上，并将这些方法应用于骨骼健康分析。利用这些范式来解释生态和进化背景下的女性生殖内分泌学，本研究将骨骼作为人类女性一生中激素、能量和机械需求的产物。在多个生理系统中整合身体活动对骨骼的影响是很重要的，因为它们不是彼此独立运作的。通过比较波兰妇女与第二代和第三代波兰裔美国妇女之间的身体活动水平、当前雌激素浓度和生活史变量，本研究将检验关于生活史、身体活动以及这些变量之间雌激素介导的相互作用影响健康成年妇女骨密度和更替的假设。这项工作扩展了资源分配的生活史概念，将骨骼维护作为生长，维护和繁殖之间的权衡之一。此外，它有助于更广泛的人类学讨论关于人口过渡到久坐的工业化生活方式对健康的影响。

Bone is a dynamic tissue that changes through the lifespan. This dissertation research will combine markers of bone turnover with measures of bone density to understand how bone varies with physical activity and life history. The project seeks to understand the slow change in bone density and the processes that maintain bone turnover, in two related populations with different lifestyles. In addition to data on estrogen and physical activity levels, the co-PI will collect information on age at menarche, number of offspring, and duration of breastfeeding, which are life history traits that can vary with energy availability and stress levels, reflect changing estrogen concentrations, and may correlate with bone characteristics. Combining data on past conditions and current lifestyle factors in this comparative context will expand our understanding bone health through the lifecourse in adult women. The project will also promote international collaborations, student training and mentoring, and public science outreach activities. This project builds upon previous work in life history and human reproductive ecology and applies these approaches to analyses of bone health. Using these paradigms for interpreting female reproductive endocrinology in ecological and evolutionary contexts, this research focuses on bone as a product of the hormonal, energetic, and mechanical demands of the human female across the lifespan. Integrating the bone-related effects of physical activity across multiple physiological systems is important because they do not operate independently of one another. By comparing physical activity levels, current estrogen concentrations, and life history variables between Polish women and second and third generation Polish-American women, this research will test hypotheses about the ways in which life history, physical activity, and the estrogen-mediated interactions between these variables affect bone density and turnover in healthy adult women. This work extends the life history concept of resource allocation to include bone maintenance as one of the tradeoffs between growth, maintenance, and reproduction. Additionally, it contributes to broader anthropological discussions regarding health effects of demographic transitions to sedentary industrialized lifestyles.