Hair Cortisol as a Marker of Intergenerational Heritage of War? A Study of Veterans and Their Offspring

Hair Cortisol Research in Posttraumatic Stress Disorder - 10 Years of Insights and Open Questions. A Systematic Review

BACKGROUND

Cortisol is one of the most extensively studied biomarkers in the context of trauma/posttraumatic stress disorder (PTSD). For more than a decade, hair cortisol concentrations (HCC) have been measured in this context, leading to a two-staged dysregulation model. Specifically, an elevated secretion during/immediately after trauma exposure eventually reverts to hyposecretion with increasing time since trauma exposure has been postulated.

OBJECTIVE

The aim of our systematic review was to re-evaluate the two-staged secretion model with regard to the accumulated diagnostic, prognostic, and intervention-related evidence of HCC in lifetime trauma exposure and PTSD. Further, we provide an overview of open questions, particularly with respect to reporting standards and quality criteria.

METHOD

A systematic literature search yielded 5,046 records, of which 31 studies were included.

RESULTS

For recent/ongoing (traumatic) stress, the predictions of cortisol hypersecretion could be largely confirmed. However, for the assumed hyposecretion temporally more distal to trauma exposure, the results are more ambiguous. As most studies did not report holistic overviews of trauma history and confounding influences, this may largely be attributable to methodological limitations. Data on the prognostic and intervention-related benefits of HCC remain sparse.

CONCLUSION

Over the last decade, important insights could be gained about long-term cortisol secretion patterns following lifetime trauma exposure and PTSD. This systematic review integrates these insights into an updated secretion model for trauma/PTSD. We conclude with recommendations for improving HCC research in the context of trauma/PTSD in order to answer the remaining open questions.

Prenatal maternal stress and offspring aggressive behavior: Intergenerational and transgenerational inheritance

Even though studies have shown that prenatal maternal stress is associated with increased reactivity of the HPA axis, the association between prenatal maternal stress and fetal glucocorticoid exposure is complex and most likely dependent on unidentified and poorly understood variables including nature and timing of prenatal insults. The precise mechanisms in which prenatal maternal stress influence neuroendocrine signaling between the maternal-placental-fetal interface are still unclear. The aim of this review article is to bring comprehensive basic concepts about prenatal maternal stress and mechanisms of transmission of maternal stress to the fetus. This review covers recent studies showing associations between maternal stress and alterations in offspring aggressive behavior, as well as the possible pathways for the “transmission” of maternal stress to the fetus: (1) maternal-fetal HPA axis dysregulation; (2) intrauterine environment disruption due to variations in uterine artery flow; (3) epigenetic modifications of genes implicated in aggressive behavior. Here, we present evidence for the phenomenon of intergenerational and transgenerational transmission, to better understands the mechanism(s) of transmission from parent to offspring. We discuss studies showing associations between maternal stress and alterations in offspring taking note of neuroendocrine, brain architecture and epigenetic changes that may suggest risk for aggressive behavior. We highlight animal and human studies that focus on intergenerational transmission following exposure to stress from a biological mechanistic point of view, and maternal stress-induced epigenetic modifications that have potential to impact on aggressive behavior in later generations.

Trauma-related but not PTSD-related increases in hair cortisol concentrations in military personnel

Dysregulated hypothalamic-pituitary-adrenal (HPA) axis functioning has been associated with posttraumatic stress disorder (PTSD). The current literature is inconsistent regarding this association, possibly due to confounding influences. Hair cortisol concentrations (HCC) allow for retrospective assessment of cumulative HPA axis secretion over several weeks and are considered a trait-like marker of HPA axis activity. Three groups of active and former German Armed Forces service members, comprising PTSD patients (n = 19), healthy controls with deployment-related trauma exposure (n = 10), and non-deployed healthy controls (n = 10) provided samples for HCC analysis. We observed significantly higher HCC in the PTSD and the deployed compared to the non-deployed group. HCC was neither significantly correlated with perceived chronic stress, nor with PTSD severity within patients. The results suggest a differential impact of trauma exposure on HPA axis activity and highlight the notion of cumulative, retrospective cortisol secretion as a psychobiological indicator of trauma exposure. TRIAL REGISTRATION: Australian Clinical Trials Registry (ACTRN12616000956404).

Cross-sectional relation of long-term glucocorticoids in hair with anthropometric measurements and their possible determinants: A systematic review and meta-analysis

BACKGROUND

Long-term glucocorticoids (HairGC) measured in scalp hair have been associated with body mass index (BMI), waist circumference (WC), and waist-hip-ratio (WHR) in several cross-sectional studies. We aimed to investigate the magnitude, strength, and clinical relevance of these relations across all ages.

METHODS

We performed a systematic review and meta-analysis (PROSPERO registration CRD42020205187) searching for articles relating HairGC to measures of obesity. Main outcomes were bivariate correlation coefficients and unadjusted simple linear regression coefficients relating hair cortisol (HairF) and hair cortisone (HairE) to BMI, WC, and WHR.

RESULTS

We included k = 146 cohorts (n = 34,342 individuals). HairGC were positively related to all anthropometric measurements. The strongest correlation and largest effect size were seen for HairE-WC: pooled correlation 0.18 (95%CI 0.11-0.24; k = 7; n = 3,158; I²  = 45.7%) and pooled regression coefficient 11.0 cm increase in WC per point increase in 10-log-transformed HairE (pg/mg) on liquid-chromatography-(tandem) mass spectrometry (LC-MS) (95%CI 10.1-11.9 cm; k = 6; n = 3,102). Pooled correlation for HairF-BMI was 0.10 (95%CI 0.08-0.13; k = 122; n = 26,527; I²  = 51.2%) and pooled regression coefficient 0.049 kg/m² per point increase in 10-log-transformed HairF (pg/mg) on LC-MS (95%CI 0.045-0.054 kg/m² ; k = 26; n = 11,635).

DISCUSSION

There is a consistent positive association between HairGC and BMI, WC, and WHR, most prominently and clinically relevant for HairE-WC. These findings overall suggest an altered setpoint of the hypothalamic-pituitary-adrenal axis with increasing central adiposity.

Neuroendocrine and autonomic stress systems activity in young adults raised by mothers with mental health and substance abuse problems: A prospective cohort study

Among the well-known physiological consequences of early adverse environments is dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. A number of studies demonstrate that negative parenting and living with parents with a history of substance abuse and mental health problems may be associated with HPA axis dysregulation in children. In contrast, studies of more delayed effects in adult offspring, especially prospective, are still scarce. This study was a prospective longitudinal investigation of the association between maternal mental illnesses/substance abuse and maternal negative parenting/parental stress on one side and, on the other side, adult offspring outcomes 10 years later-specifically, we studied the activity of offspring's neuroendocrine (cortisol) and autonomic (heart rate) systems when exposed to a mild psychological stressor. Children of mothers with mental illnesses and/or substance abuse were exposed to more disadvantaged conditions (higher negative parenting and community violence). Despite this, maternal risk groups (having a mother with mental illnesses and/or substance abuse) were not associated with any of the indicators of stress systems activity. Regardless of the risk group, participants with dysregulated HPA axis activity experienced a higher level of negative parenting. Altogether, our study provides evidence that negative parenting may have long-lasting effects on stress-sensitive physiological mechanisms.