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

骨骼是一种动态组织，会随着寿命的变化而变化。这项研究将结合骨转换指标和骨密度测量来了解骨骼如何随着体力活动和生活史的变化而变化。该项目试图了解在两个生活方式不同的相关人群中，骨密度的缓慢变化以及维持骨转换的过程。除了有关雌激素和体力活动水平的数据外，co-PI还将收集关于月经初潮年龄、后代数量和母乳喂养持续时间的信息，这些生命史特征可以随能量供应和压力水平而变化，反映雌激素浓度的变化，并可能与骨骼特征相关。在这种比较的背景下，结合过去状况和当前生活方式因素的数据，将扩大我们对成年女性生命周期中骨骼健康的理解。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。这个项目建立在生命史和人类生殖生态学之前的工作基础上，并将这些方法应用于骨健康分析。使用这些范式在生态和进化的背景下解释女性生殖内分泌学，这项研究侧重于骨作为人类女性一生中荷尔蒙、能量和机械需求的产物。在多个生理系统中整合与骨骼有关的身体活动的影响是很重要的，因为它们不是彼此独立运作的。通过比较波兰女性和第二代和第三代波兰裔美国女性的体力活动水平、当前的雌激素浓度和生活史变量，这项研究将检验有关生活史、体力活动以及这些变量之间的雌激素介导的相互作用如何影响健康成年女性骨密度和周转率的假设。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，它还有助于更广泛的人类学讨论，讨论人口向久坐工业化生活方式转变对健康的影响。

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.