New York University School of Global Public Health, Department of Epidemiology, 708 Broadway, New York, NY 10003, USA.
New York University School of Global Public Health, Department of Epidemiology, 708 Broadway, New York, NY 10003, USA.
Psychoneuroendocrinology. 2022 Jun;140:105730. doi: 10.1016/j.psyneuen.2022.105730. Epub 2022 Mar 21.
The chronic disease burden among African Americans has continued to rise. Although racial disparities in chronic disease risk are well documented, the role of chronic stress in risk disparities among racial and ethnic minorities is not well understood. This systematic review of studies reporting on the relationship between chronic stress, education, and/or income, and biomarkers of chronic stress (allostatic load and telomere length) longitudinally among African Americans, seeks to contribute to this knowledge gap.
To use the existing literature to both examine the strength of two objective biomarkers--telomere length and allostatic load--as measures of the overactivation of physiological stress processes in African American adults; and determine if existing studies used these two biomarkers to assess the relationship between chronic stress, income and level of educational attainment among African Americans longitudinally.
In order to identify English-language articles published prior to October 11, 2021, a comprehensive search strategy was developed using five databases: PubMed/Medline, EMBASE, Web of Science Plus, Global Health (Ovid), and PsycINFO. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was used to record progress on the comprehensive search for studies reporting on allostatic load and/or telomere length biomarkers longitudinally within all bodily fluids and chronic stress among African American adults.
In total, 7 studies met the search criteria; 902 were excluded. Thus, less than 1% of all studies reporting on biomarkers of chronic stress longitudinally included African Americans. Each of the 7 studies described the relationship between telomere length and/or allostatic load among African Americans and chronic stress, education, and/or income. Higher chronic stress levels and experiences of racial discrimination were associated with telomere shortening while lower income and higher chronic stress levels were associated with an increase in allostatic load among African Americans.
Given the limited number of studies reporting on the association between allostatic load, telomere length, and/or the relationship between both in assessing chronic stress severity longitudinally among African American populations, it is impossible to determine whether one biomarker has greater predictive value than the other. However, based on the literature included in this review, higher chronic stress levels and experiences of racial discrimination were associated with shorter telomere length, while lower income and higher chronic stress levels are associated with an increase in allostatic load among African Americans.
These data illustrate a gap in the literature on the relationship between the biomarkers of telomere length and allostatic load combined as a potential measure for chronic stress among African Americans. To our knowledge, none the current literature describes the relationship between telomere length and allostatic load longitudinally among African American adults. As the field strives to develop a "gold standard" for measuring chronic stress, the combination of these biomarkers needs to be the subject of scientific inquiry and thus, fully examined. Future longitudinal studies among African Americans are needed to better understand which biomarker, or combination of biomarkers will provide the most accurate measure of physiological stress processes.
非裔美国人的慢性病负担持续上升。尽管种族间慢性病风险存在明显差异，但慢性应激在种族和民族少数群体的风险差异中的作用尚未得到充分理解。本系统评价旨在填补这一知识空白，通过报告非裔美国人慢性应激、教育和/或收入与生物标志物（全身应激指标和端粒长度）之间的纵向关系的研究，探讨慢性应激与慢性病负担之间的关系。
利用现有文献，评估两种客观生物标志物——端粒长度和全身应激指标的强度，作为评估非裔美国成年人生理应激过程过度激活的指标；并确定现有的研究是否使用这两种生物标志物来评估慢性应激、收入和非裔美国人受教育程度之间的纵向关系。
为了确定 2021 年 10 月 11 日之前发表的英文文章，我们使用了五个数据库：PubMed/Medline、EMBASE、Web of Science Plus、全球健康（Ovid）和 PsycINFO，制定了全面的搜索策略。使用系统评价和荟萃分析的首选报告项目（PRISMA）方法记录了所有研究的全面搜索进展情况，这些研究报告了非裔美国成年人所有体液中的全身应激指标和/或端粒长度生物标志物的纵向变化。
共有 7 项研究符合搜索标准，排除了 902 项研究。因此，只有不到 1%的研究报告了慢性应激纵向生物标志物，其中包括非裔美国人。这 7 项研究都描述了端粒长度和/或全身应激指标与非裔美国人慢性应激、教育和/或收入之间的关系。较高的慢性应激水平和种族歧视经历与端粒缩短有关，而较低的收入和较高的慢性应激水平与非裔美国人的全身应激指标增加有关。
鉴于报告非裔美国人人群中全身应激指标、端粒长度和/或两者结合作为慢性应激严重程度纵向评估的生物标志物之间关联的研究数量有限，因此无法确定哪种生物标志物具有更大的预测价值。然而，根据本综述中包含的文献，较高的慢性应激水平和种族歧视经历与端粒缩短有关，而较低的收入和较高的慢性应激水平与非裔美国人全身应激指标的增加有关。
这些数据说明了在非裔美国人中，端粒长度和全身应激指标作为慢性应激潜在测量指标的文献存在差距。据我们所知，目前尚无文献描述非裔美国成年人的端粒长度和全身应激指标的纵向关系。随着该领域努力开发测量慢性应激的“黄金标准”，需要对这些生物标志物进行科学研究，以充分检验。需要对非裔美国人进行进一步的纵向研究，以更好地了解哪种生物标志物或生物标志物组合将提供对生理应激过程最准确的测量。
