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、新陈代谢和免疫的发育。 导致一生中身心健康状况不佳。ELS在中国的患病率不断上升 学龄前儿童是一个主要的公共卫生问题，从流行病学上讲，学龄前儿童与较高的青少年比例有关 自杀、约会暴力、酗酒和吸毒。个体对急性压力的反应是释放皮质醇； 因此，头发皮质醇浓度(HCC)可以量化儿童在反复或慢性压力下的暴露情况。 我们关于肝癌的初步数据揭示了与学龄前儿童慢性应激相关的各种因素。 我们建议将头发催产素浓度(HOC)作为支持性和/或社会性的终结性指标 从属体验。拟议研究的具体目标是：(1)验证用于测量的新的分析方法 对1200名学龄前儿童及其父母进行了肝癌和HOC的调查，以量化他们的累积暴露于 (2)测量毛发生长速度，从而确定时间。 与这种接触有关的时期及其头发成分(蛋白质、脂肪、水分含量)以解释和/或 调整从学龄前儿童及其家长那里获得的HC值和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)。我们将从父母那里获得他们孩子的人口统计、发育、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- 用于肝癌和HOC的链接免疫吸附分析(ELISA)；这些检测将使用串联质谱仪进行验证 光谱分析(LC/MS-MS)。我们将使用标准的照相三叉图技术测量毛发生长速度 以及使用直接分光光度检测的头发成分。这些数据将建立参考规范 对于学龄前儿童的肝癌和HOC，他们的毛发生长率将确定这些肝癌的时间段 或者特定的值代表。 我们将研究肝癌、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。HOC和HOC的值从 同样的头发样本也将允许我们检查催产素介导的皮质醇对ELS反应的调节。 我们有一支多学科的团队(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。完成这项研究将 为健康学龄前儿童的肝癌、HOC和毛发生长速度提供特定年龄的参考标准。这 该项目将解决我们目前知识中的根本差距，并建立一个科学框架来 调查儿童早期应激对身心健康的长期影响 心理创伤、创伤/中毒应激、与暴力有关的伤害、虐待儿童和急性或危重 疾病--NICHD将其确定为高度优先的研究领域。

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.