Do Hair Cortisol and Hair Oxytocin represent the Stressful and Supportive Experiences of Preschool Children?

早期生活压力（ELS）可以破坏神经，心血管，代谢和免疫系统的发育。 系统，导致整个生命周期的身心健康状况不佳。ELS的日益流行， 学龄前儿童是一个主要的公共卫生问题，在流行病学上与青年发病率较高有关。 自杀约会暴力酗酒和吸毒个体通过释放皮质醇对急性压力做出反应; 因此，头发皮质醇浓度（HCC）可以量化儿童反复或慢性压力的暴露。 我们关于HCC的试点数据揭示了与学龄前儿童慢性压力相关的各种因素。 我们建议头发催产素浓度（HOC）作为支持性和/或社会性的总结性措施， 亲和体验本研究的具体目的是：（1）验证新的测定方法， 1200名学龄前儿童及其父母的HCC和HOC，以量化他们的累积暴露， 压力与支持性早期经验;（2）测量毛发生长率，从而确定时间 与此类暴露相关的时期及其头发成分（蛋白质、脂质、水含量），以解释和/或 校正从学龄前儿童及其父母获得的HCC和HOC值。 我们将收集1-5岁儿童（n=1200）和至少一名陪同父母的头发样本 （n=1200）。从父母那里，我们将获得他们孩子的人口统计学、发展、健康和环境 数据头发样本将使用我们的新提取方法进行处理，并使用特定的酶进行分析- HCC和HOC的联免疫吸附试验（ELISA）;这些试验将使用串联质谱法进行验证。 质谱法（LC/MS-MS）。我们将使用标准的照片技术来测量头发的生长速度 和毛发组成的直接分光光度检测。这些数据将建立参考标准 学龄前儿童的HCC和HOC及其毛发生长率将确定这些HCC发生的时间段， 或HOC值表示。 我们将研究HCC、HOC和毛发生长率与年龄、性别、种族、 种族、父母、社会经济或其他环境因素。HCC和HOC值从 同样的头发样本也将使我们能够检查催产素介导的皮质醇对ELS反应的调节。 我们有一个多学科的团队（临床医生，心理学家，社会学家，生物化学家，统计学家），设备， 成功完成拟议项目的经验和试点数据。这项研究的完成将 为健康学龄前儿童的HCC、HOC和毛发生长率提供年龄特异性参考标准。这 该项目将解决我们目前知识的根本差距，并建立一个科学框架， 调查儿童早期压力的长期身心健康后果， 心理创伤、创伤性/中毒性应激、暴力相关伤害、虐待儿童以及急性或危重 疾病-被NICHD确定为高度优先研究领域。

Early life stress (ELS) can disrupt the development of nervous, cardiovascular, metabolic, and immune systems, leading to poor physical and mental health throughout the lifespan. The rising prevalence of ELS in preschool children is a major public health concern, epidemiologically linked with higher rates of youth suicides, dating violence, drinking, and drug abuse. Individuals respond to acute stress by releasing cortisol; thus, hair cortisol concentrations (HCC) can quantify the exposures to recurrent or chronic stress in children. Our pilot data on HCC revealed various factors that are associated with chronic stress in preschool children. We propose hair oxytocin concentrations (HOC) as a summative measure of supportive and/or socially affiliative experiences. Specific aims of the proposed study are: (1) to validate novel assays for measuring HCC and HOC in 1200 preschool children and their parents, in order to quantify their cumulative exposures to stressful vs. supportive early experiences; and (2) to measure hair growth rates, thereby delineating the time periods related to such exposures and their hair composition (protein, lipid, water content) to interpret and/or adjust the HCC and HOC values obtained from the preschool children and their parents. We will collect hair samples from children ages 1-5 years (n=1200) and at least one accompanying parent (n=1200). From parents we will obtain their child's demographic, developmental, health and environmental data. Hair samples will be processed using our novel extraction methods and analyzed using specific enzyme- linked immunosorbent assays (ELISA) for HCC and HOC; these assays will be validated using tandem mass spectrometry (LC/MS-MS). We will measure hair growth rates using the standard phototrichogram technique and hair composition using direct spectrophotometric detection. These data will establish the reference norms for HCC and HOC in preschool children and their hair growth rates will identify the time periods that these HCC or HOC values represent. We will examine the natural variations in HCC, HOC, and hair growth rates in relation to age, sex, race, ethnicity, parental, socioeconomic, or other environmental factors. HCC and HOC values obtained from the same hair sample will also allow us to examine oxytocin-mediated regulation of the cortisol responses to ELS. We have a multidisciplinary team (clinician, psychologist, sociologist, biochemists, statistician), the equipment, the experience, and pilot data to successfully complete the proposed project. Completion of this research will provide age-specific reference norms for HCC, HOC, and hair growth rates in healthy preschool children. This project will address fundamental gaps in our current knowledge and establish a scientific framework to investigate long-term physical and mental health consequences of early childhood stress, following physical or psychological trauma, traumatic/toxic stress, violence-related injury, child maltreatment, and acute or critical illnesses – identified as a high-priority research area by NICHD.