社会经济地位差异与儿童慢性生理应激相关的大脑结构改变。
Socioeconomic Disparities in Chronic Physiologic Stress Are Associated With Brain Structure in Children.
机构信息
Teachers College, Columbia University, New York, New York.
University of Massachusetts, Amherst, Massachusetts.
出版信息
Biol Psychiatry. 2019 Dec 15;86(12):921-929. doi: 10.1016/j.biopsych.2019.05.024. Epub 2019 Jun 12.
BACKGROUND
Socioeconomic factors have been consistently linked with the structure of children's hippocampus and anterior cingulate cortex (ACC). Chronic stress-as indexed by hair cortisol concentration-may represent an important mechanism underlying these associations. Here, we examined associations between hair cortisol and children's hippocampal and ACC structure, including across hippocampal subfields, and whether hair cortisol mediated associations between socioeconomic background (family income-to-needs ratio, parental education) and the structure of these brain regions.
METHODS
Participants were 5- to 9-year-old children (N = 94; 61% female) from socioeconomically diverse families. Parents and children provided hair samples that were assayed for cortisol. High-resolution, T1-weighted magnetic resonance imaging scans were acquired, and FreeSurfer 6.0 was used to compute hippocampal volume and rostral and caudal ACC thickness and surface area (n = 37 with both child hair cortisol and magnetic resonance imaging data; n = 41 with both parent hair cortisol and magnetic resonance imaging data).
RESULTS
Higher hair cortisol concentration was significantly associated with smaller CA3 and dentate gyrus hippocampal subfield volumes but not with CA1 or subiculum volume. Higher hair cortisol was also associated with greater caudal ACC thickness. Hair cortisol significantly mediated associations between parental education level and CA3 and dentate gyrus volumes; lower parental education level was associated with higher hair cortisol, which in turn was associated with smaller volume in these subfields.
CONCLUSIONS
These findings point to chronic physiologic stress as a potential mechanism through which lower parental education level leads to reduced hippocampal volume. Hair cortisol concentration may be an informative biomarker leading to more effective prevention and intervention strategies aimed at childhood socioeconomic disadvantage.
背景
社会经济因素与儿童海马体和前扣带皮层（ACC）的结构一直存在关联。头发皮质醇浓度可作为慢性应激的指标，可能是这些关联的重要机制。在此，我们研究了头发皮质醇与儿童海马体和 ACC 结构之间的关联，包括海马体各亚区，以及头发皮质醇是否介导了社会经济背景（家庭收入需求比、父母教育程度）与这些大脑区域结构之间的关联。
方法
参与者为来自社会经济背景多样家庭的 5 至 9 岁儿童（N=94；61%为女性）。父母和儿童提供了头发样本，用于检测皮质醇。采集高分辨率 T1 加权磁共振成像扫描数据，并使用 FreeSurfer 6.0 计算海马体体积和前、后扣带回皮质厚度和表面积（n=37 名儿童同时提供了头发皮质醇和磁共振成像数据；n=41 名父母同时提供了头发皮质醇和磁共振成像数据）。
结果
头发皮质醇浓度越高，海马体 CA3 和齿状回亚区体积越小，但 CA1 和下托体积无显著变化。头发皮质醇浓度越高，后扣带回皮质厚度越大。头发皮质醇显著介导了父母教育程度与 CA3 和齿状回体积之间的关联；父母教育程度越低，头发皮质醇水平越高，进而导致这些亚区的体积越小。
结论
这些发现表明，慢性生理应激可能是父母教育程度较低导致海马体体积减小的潜在机制。头发皮质醇浓度可能是一个有意义的生物标志物，有助于制定更有效的预防和干预策略，以减少儿童的社会经济劣势。
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