Department of Biological and Experimental Psychology, Queen Mary University of London, London, UK.
Department of Psychology, The University of Texas at Austin, Austin, TX, USA.
Mol Psychiatry. 2021 Sep;26(9):4823-4838. doi: 10.1038/s41380-020-0747-z. Epub 2020 May 4.
The progression of lifelong trajectories of socioeconomic inequalities in health and mortality begins in childhood. Dysregulation in cortisol, a stress hormone that is the primary output of the hypothalamus-pituitary-adrenal (HPA) axis, has been hypothesized to be a mechanism for how early environmental adversity compromises health. However, despite the popularity of cortisol as a biomarker for stress and adversity, little is known about whether cortisol output differs in children being raised in socioeconomically disadvantaged environments. Here, we show that there are few differences between advantaged and disadvantaged children in their cortisol output. In 8-14-year-old children from the population-based Texas Twin Project, we measured cortisol output at three different timescales: (a) diurnal fluctuation in salivary cortisol (n = 400), (b) salivary cortisol reactivity and recovery after exposure to the Trier Social Stress Test (n = 444), and (c) cortisol concentration in hair (n = 1210). These measures converged on two moderately correlated, yet distinguishable, dimensions of HPA function. We tested differences in cortisol output across nine aspects of social disadvantage at the home (e.g., family socioeconomic status), school (e.g., average levels of academic achievement), and neighborhood (e.g., concentrated poverty). Children living in neighborhoods with higher concentrated poverty had higher diurnal cortisol output, as measured in saliva; otherwise, child cortisol output was unrelated to any other aspect of social disadvantage. Overall, we find limited support for alteration in HPA axis functioning as a general mechanism for the health consequences of socioeconomic inequality in childhood.
毕生社会经济不平等对健康和死亡率轨迹的影响始于儿童期。皮质醇失调，即下丘脑-垂体-肾上腺 (HPA) 轴的主要输出物，被认为是早期环境逆境影响健康的一种机制。然而，尽管皮质醇作为压力和逆境的生物标志物很受欢迎，但对于生活在社会经济劣势环境中的儿童的皮质醇分泌是否存在差异知之甚少。在这里，我们表明，在皮质醇分泌方面，优势儿童和劣势儿童之间几乎没有差异。在基于人群的德克萨斯双胞胎项目的 8-14 岁儿童中，我们在三个不同的时间尺度上测量了皮质醇的分泌：(a)唾液皮质醇的昼夜波动（n=400），(b)暴露于特里尔社会压力测试后的唾液皮质醇反应性和恢复（n=444），和 (c)头发中的皮质醇浓度（n=1210）。这些测量结果集中在 HPA 功能的两个中等相关但可区分的维度上。我们在家庭（例如家庭社会经济地位）、学校（例如平均学业成绩）和社区（例如集中贫困）等九个方面测试了皮质醇分泌的差异。生活在集中贫困程度较高的社区的儿童唾液中的皮质醇昼夜波动较高；否则，儿童的皮质醇分泌与社会劣势的任何其他方面都没有关系。总体而言，我们发现 HPA 轴功能改变作为儿童期社会经济不平等对健康影响的一般机制的证据有限。
