Cortisol in hair measured in young adults - a biomarker of major life stressors?

Hair Cortisol Concentrations as a Biomarker to Predict a Clinical Pregnancy Outcome after an IVF Cycle: A Pilot Feasibility Study

Our objective was to examine the feasibility of hair cortisol concentrations (HCC) as a biomarker to predict clinical pregnancy outcomes and investigate its potential associations with perceived anxiety, resilience, and depressive symptoms. A total of 43 participants were assessed using HCC, the state trait anxiety inventory (STAI), resilience scale (RS), and the depression subscale of the symptom checklist 90-R (SCL-90-R). Participants were approached at their second consultation with the reproductive endocrinologist (T1), before scheduling their IVF cycle, and then 12 weeks after (T2), at their post-transfer visit with the study coordinators, before the human chorionic gonadotropin (HCG) pregnancy test. The logistic regression model revealed that HCC at T2 predicted 46% of a positive pregnancy test [R2 = 0.46, (ß = 0.11, p < 0.05)]. Pregnant women had higher levels of resilience at T2 (M = 149.29; SD = 17.56) when compared with non-pregnant women at T2 (M = 119.96; SD = 21.71). Significant differences were found between both groups in depression at T2 (t = 3.13, p = 0.01) and resilience at T2 (t = -4.89, p = 0.01). HCC might be a promising biomarker to calculate the probability of pregnancy in women using assisted reproductive technologies (ART).

Pre-traumatic conditions can influence cortisol levels before and after a brain injury

OBJECTIVE

Satisfactory anabolic reactions, including the activation of the hypothalamic-pituitary-adrenal (HPA) axis, are essential following severe traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (SAH). Many factors may influence this activation. This study aimed to investigate whether individuals who reported chronic diseases, psychosocial afflictions, or stressful events before a severe brain injury display a different pattern regarding cortisol levels retrospectively and up to three months compared with those who did not report stressful experiences.

MATERIALS AND METHODS

Fifty-five patients aged 16-68 years who were admitted to the neurointensive care unit (NICU) were included. Hair cortisol measurements offer a unique opportunity to monitor cortisol levels retrospectively and after the trauma. Hair strands were collected as soon as possible after admission to the NICU and every month until three months after the injury/insult. The participants/relatives were asked about stressful events, psychosocial afflictions and recent and chronic diseases.

RESULTS

The group who reported chronic diseases and/or stressful events before the brain injury had more than twice as high median hair cortisol levels before the brain injury compared with those who did not report stress, but the difference was not statistically significant (P = .12). Those who reported stress before the brain injury had statistically significantly lower hair cortisol values after the brain injury and they remained until three months after the injury.

CONCLUSIONS

Stressful events and/or chronic disease before brain injury might affect mobilization of adequate stress reactions following the trauma. However, the large variability in cortisol levels in these patients does not allow firm conclusions and more studies are needed.

Cumulative cortisol exposure increases during the academic term: Links to performance-related and social-evaluative stressors

OBJECTIVE

To examine whether cumulative cortisol production changes during a period of increased demands when cortisol and stress are assessed concurrently. The study also compared stress perceptions vs. cumulative stressful events on their respective association with cortisol output. Finally, it explored whether certain types of stressful events, those involving school/job performance or social-evaluative threat, were linked to cortisol levels across multiple weeks.

METHOD

The current study assessed cumulative cortisol production via hair sample in 56 undergraduates (88 % female) during both lower stress (summer break) and higher stress (academic term) periods. During the latter, both negative events (checklist) and stress perceptions were assessed weekly, and these reports were aggregated across the 10-weeks to minimize retrospective bias.

RESULTS

Cortisol levels in hair samples were significantly higher (d = 0.84) during the academic term (M = 14.24 pg/mg, SD = 11.36) compared to summer break (M = 8.00 pg/mg, SD = 4.14), suggesting greater cumulative exposure to cortisol. Although perceived stress was not associated with cortisol levels (r_partial(53) = .10, p = 0.46), exposure to more stressful events (r_partial(53) = .27, p = 0.047), particularly events involving academic demands (r_partial(53) = .37, p = 0.006), or negative evaluation/social rejection (r_partial(53) = .27, p = 0.045), was positively associated with cumulative cortisol exposure.

CONCLUSIONS

This study demonstrates that cortisol levels in hair may be linked to cumulative exposure to stressors when measured concurrently (3 months), and that stressful events, rather than perceptions, are reflected in HPA axis activity. Real-world stressors involving performance demands and social-evaluative threat accumulate to enhance cortisol production, consistent with their acute HPA effects in the lab. Hair samples may provide a window into the past by allowing researchers to feasibly assess cortisol production before, during, and after the onset of a chronic stressor.

Preliminary Indications That First Semester Students From Academic Households Exhibit Higher Hair Cortisol Concentrations Than Their Peers From Nonacademic Households

Previous research has extensively addressed social disparity in education using certain aspects, including the stress differences between students from nonacademic families and those from academic families during the transition from secondary school to a university. However, this issue has not yet been fully understood; the current literature suggests contradictory predictions, and physiological indicators of stress have never been assessed. Therefore, we tested whether hair cortisol concentrations (HCCs) in first semester students from nonacademic families are different from those of first semester students from academic families during their first six weeks at university. We analyzed hair samples and parental educational background reports from 71 female first semester students at a university in Switzerland in two waves (n = 34 in the autumn of 2016 and n = 37 in the autumn of 2017). The HCCs were extracted from the hair using a well-established protocol. The analyses revealed higher HCCs in the students from the academic families across the two cohorts. This difference could not be attributed to different control variables (e.g., age, migration background). These preliminary findings were in line with the sociological theory that an academic parental background is associated with pressure to avoid a drop in one's social status.

The interactive association of proximal life stress and cumulative HPA axis functioning with depressive symptoms

BACKGROUND

Stress is consistently implicated in depression. Using a vulnerability-stress framework, the hypothalamic-pituitary-adrenal (HPA) axis may be one factor affecting the stress-depression association. However, the interactive influence of recent life stress and HPA axis functioning on depressive symptoms remains unclear. It is particularly important to understand the synergistic association during adolescence, as this is a developmental period associated with a high risk for depression.

METHODS

A community sample of 58 adolescents (67% female, 59% Caucasian; mean age, 15.07 years) participated. Adolescents completed a well-validated measure of depressive symptoms and a structured life events interview to assess recent life stress. Hair cortisol concentration was obtained to measure cumulative exposure to HPA axis functioning.

RESULTS

Recent life stress and cumulative HPA axis exposure measured through hair cortisol were directly associated with higher depressive symptoms. Further, cumulative HPA axis exposure moderated the relationship between recent life stress and depressive symptoms. The recent life stress-depression association occurred for adolescents who experienced average and high, but not low, levels of cumulative HPA axis exposure.

CONCLUSIONS

The current study builds on prior work and finds both a direct and interactive association of recent life stress and cumulative HPA axis functioning with depressive symptoms during adolescence. Identifying youth who experience high levels of HPA axis exposure is important to prevent the onset of depression.

Importance of methodological details in the measurement of cortisol in human hair

OBJECTIVE

The measurement of cortisol in hair became a popular and frequently used methodology in human stress research. This methodological approach, depending on the length of hair analyzed, allows to reflect cortisol secretion over prolong time periods in a retrospective fashion. There is a big variability in the experimental approaches to cortisol extraction used in individual laboratories. Moreover, there are many methodological details which are not described in most of the published papers, although they may be influential. The aim of the present study was to identify and optimize selected methodological steps of hair cortisol extraction.

METHODS

As the starting point served the methodology of Xiang et al. (2016). A hair pool was used to test the procedures. The main steps modified were pulverization, methanol extraction and centrifugation.

RESULTS

In the presented procedure, we decreased the speed and duration of the pulverization, we increased the volume of methanol and increased the time and speed of centrifugation. The results showed obtaining lower variability and higher cortisol concentrations than those we obtained by the methodology of Xiang et al. (2016), which was optimized.

CONCLUSION

The presented methodology is relatively simple and is likely to provide reliable results with low variability of cortisol concentrations measured in the same sample.

Inflammatory mediators of stress exposure and neurodevelopment in very preterm infants: Protocol for the stress neuro-immune study

AIMS

(a) Determine relationships among stress exposure, inflammation, and neurodevelopment in very preterm infants and determine the mediated effect of inflammation on the relationship between stress exposure and neurodevelopment; (b) describe cytokine trajectories following birth and determine the effect of stress exposure on these trajectories; and (c) examine relationships between stress exposure and chronic stress responses in very preterm infants.

DESIGN

Non-experimental, repeated measures.

METHODS

Very preterm infants born 28-31 weeks post menstrual age will be enrolled. Cumulative stress exposure over the first 14 days of life will be measured using the Neonatal Infant Stressor Scale. Blood will be collected weekly for the quantification of cytokines. Neurodevelopment will be assessed using the Neurobehavioral Assessment of the Preterm Infant and hair for quantification of hair cortisol will be collected at 35 weeks post menstrual age. Multiple linear regression and conditional process analysis will be used to analyse the relationships among stress exposure, inflammation and neurodevelopment. Linear mixed models will be used to determine inflammatory trajectories over time. IRB approval for the study was received May 2017, and funding from the National Institute of Nursing Research was awarded July 2017.

DISCUSSION

This study will determine the extent to which inflammation mediates the relationship between stress exposure and neurodevelopment. Interventions to attenuate inflammation in preterm infants may improve outcomes.

IMPACT

Determining the potentially modifiable mediators of stress exposure and neurodevelopment in preterm infants is critical to improving long-term outcomes.

Chronic stress and emotion: Differential effects on attentional processing and recognition memory

Previous research indicates that acute stress around the time of learning facilitates attention and memory for emotionally salient information. Despite accumulating evidence for these acute stress effects, less is known about the role of chronic stress. In the present study, we therefore tested emotional and neutral scene processing and later recognition memory in female participants using hair cortisol concentrations as a biological marker for chronic stress. Event-related potentials recorded during picture viewing indicated enhanced late positive potentials (LPPs) for emotional, relative to neutral contents. These brain potentials varied as a function of long-term hair cortisol levels: hair-cortisol levels were positively related to overall LPP amplitudes. Results from recognition memory testing one week after encoding revealed better memory for emotional relative to neutral scenes. Hair-cortisol levels, however, were related to poorer memory accuracy. Taken together, our results indicate that chronic stress enhanced attentional processing during encoding of new stimuli and impaired later recognition memory. Results are discussed with regard to putatively opposite effects of chronic stress on certain brain regions (e.g., amygdala and hippocampus).

A systematic review of studies utilizing hair glucocorticoids as a measure of stress suggests the marker is more appropriate for quantifying short-term stressors

Quantitating glucocorticoids (GCs) in hairs is a popular method for assessing chronic stress in studies of humans and animals alike. The cause-and-effect relationship between stress and elevated GC levels in hairs, sampled weeks later, is however hard to prove. This systematic review evaluated the evidence supporting hair glucocorticoids (hGCs) as a biomarker of stress. Only a relatively small number of controlled studies employing hGC analyses have been published, and the quality of the evidence is compromised by unchecked sources of bias. Subjects exposed to stress mostly demonstrate elevated levels of hGCs, and these concentrations correlate significantly with GC concentrations in serum, saliva and feces. This supports hGCs as a biomarker of stress, but the dataset provided no evidence that hGCs are a marker of stress outside of the immediate past. Only in cases where the stressor persisted at the time of hair sampling could a clear link between stress and hGCs be established.

The Impact of Parental Role Distributions, Work Participation, and Stress Factors on Family Health-Related Outcomes: Study Protocol of the Prospective Multi-Method Cohort "Dresden Study on Parenting, Work, and Mental Health" (DREAM)

The Dresden Study on Parenting, Work, and Mental Health (“DResdner Studie zu Elternschaft, Arbeit, und Mentaler Gesundheit”, DREAM) aims to prospectively investigate the relationship between parental work participation, role distribution, stress factors, and their effects on perinatal outcomes and long-term family mental and somatic health in a community sample targeting N = 4,000 individuals, i.e., 2,000 couples, expecting a child and residing in Dresden, Germany (interim sample of N = 1,410 participants, recruitment ongoing). Various questionnaires are completed at four measurement points from pregnancy to 2 years postpartum (prolongation into middle childhood planned). Applying a multi-method approach, long-term endocrinological data (analyses of hair cortisol concentrations and other endogenous hormones, “DREAM_HAIR”) and qualitative interview data (regarding gender role attitudes and distribution of domestic work, child care, and paid employment; “DREAM_TALK”) are obtained. In this study protocol, the theoretical background, methods, and preliminary results considering sociodemographic characteristics during pregnancy and birth-related factors at 8 weeks postpartum are presented. Additionally, there is a focus on our endocrinological sub-study DREAM_HAIR. In this sub-study currently comprising N = 152 participants, i.e., 88 families (recruitment ongoing), we want to gain knowledge on the transgenerational processes of stress regulation and psychopathology in the whole family by analyzing hair cortisol concentrations in both parents and children during the course from pregnancy (or after birth regarding children) to at least 2 years postpartum. By comparing data of the community sample to a clinical sample of mothers with postpartum mental disorders, their children, and their partners during the period between admission and discharge from a mother-baby unit and post-treatment (“DREAM_MBU”), the course of mothers' psychopathology, parent-infant interaction, and infant regulation disorders with special regard to long-term endocrine correlates will be examined. With previous studies neglecting the fathers or partners involved, a major advantage of DREAM is the use of a multi-method and multi-level approach by examining the whole family in a longitudinal design. Therefore, the DREAM study will contribute to a better understanding of the role of social, work, and stress factors for mental and somatic health and its long-term endocrine correlates in the natural course of becoming a family.

Long-term stress levels are synchronized in dogs and their owners

This study reveals, for the first time, an interspecific synchronization in long-term stress levels. Previously, acute stress, has been shown to be highly contagious both among humans and between individuals of other species. Here, long-term stress synchronization in dogs and their owners was investigated. We studied 58 dog-human dyads and analyzed their hair cortisol concentrations (HCC) at two separate occasions, reflecting levels during previous summer and winter months. The personality traits of both dogs and their owners were determined through owner-completed Dog Personality Questionnaire (DPQ) and human Big Five Inventory (BFI) surveys. In addition, the dogs’ activity levels were continuously monitored with a remote cloud-based activity collar for one week. Shetland sheepdogs (N = 33) and border collies (N = 25), balanced for sex, participated, and both pet dogs and actively competing dogs (agility and obedience) were included to represent different lifestyles. The results showed significant interspecies correlations in long-term stress where human HCC from both summer and winter samplings correlated strongly with dog HCC (summer: N = 57, χ² = 23.697, P < 0.001, β = 0.235; winter: N = 55, χ² = 13.796, P < 0.001, β = 0.027). Interestingly, the dogs’ activity levels did not affect HCC, nor did the amount of training sessions per week, showing that the HCC levels were not related to general physical activity. Additionally, there was a seasonal effect in HCC. However, although dogs’ personalities had little effects on their HCC, the human personality traits neuroticism, conscientiousness, and openness significantly affected dog HCC. Hence, we suggest that dogs, to a great extent, mirror the stress level of their owners.

In sickness and in health: partner's physical and mental health predicts cortisol levels in couples

Individuals in stable relationships tend to be healthier than those not in stable relationships. Despite this general positive influence of relationships on health, the mechanisms for the impact of relationship quality on health are not clear. Research has focused on many factors to explain this connection, including inter- and intra-couple dynamics of physiology and behavior. To address this issue, we examined the relationship between perceived health, depressive symptoms, and relationship quality on diurnal cortisol in 30 male/female romantic dyads (N = 60). Participants provided saliva samples on two weekdays to assess total cortisol output. Females' lower perceived physical health, lower relationship satisfaction, and higher depression scores were each related to higher cortisol output in their male partners. Males' physical health, relationship satisfaction, and depression scores were unrelated to females' cortisol output. Further, physical health, relationship satisfaction, and depression scores did not predict intra-individual cortisol levels for either sex. Measures of diurnal cortisol slope (DCS) were unrelated to psychosocial factors in males and females. Results provide further support for the interpersonal influence of partners' mental and physical health on physiological outcomes and suggest females may influence their male partners more than vice versa.

Interaction Effects of Life Events and Hair Cortisol on Perceived Stress, Anxiety, and Depressive Symptoms Among Chinese Adolescents: Testing the Differential Susceptibility and Diathesis-Stress Models

The differential susceptibility model and the diathesis-stress model on the interaction effect between the individuals’ traits and environmental factors will be conducive to understand in depth whether the psychophysiological traits are the risk factors of child development. However, there is no study focusing on the activity of the hypothalamic-pituitary-adrenal (HPA) axis. We examined whether the HPA activity serves as a physiological marker of the differential susceptibility model or the diathesis-stress model by exploring the interactive effect of life events and hair cortisol on perceived stress, anxiety, and depressive symptoms among Chinese adolescents. The participants were 324 students in senior high school. They reported their psychological states with questionnaires in their first semester after a 3-month adaptation period; 2 weeks later, they provided 1-cm hair segments closest to the scalp. We measured hair cortisol concentration as a biomarker of HPA activity using high-performance liquid chromatography–tandem mass spectrometry. There was a significant interaction effect of academic events and hair cortisol on adolescents’ perceived stress, anxiety, and depression symptoms. We also observed a significant interaction between interpersonal events and hair cortisol on adolescents’ anxiety symptoms. Looking at the region of significance, proportion of interaction index, and proportion affected index, we found that adolescents with higher cortisol levels had a tendency to experience higher perceived stress and anxiety symptoms when they had high academic events scores, but lower perceived stress and anxiety symptoms when they had lower academic events scores. By contrast, adolescents with higher cortisol levels had a greater risk of experiencing high depressive symptoms only when they had higher academic events scores. Adolescents with higher cortisol levels also tended to have lower anxiety symptoms when they had higher interpersonal events scores, but greater anxiety symptoms when they had lower interpersonal events scores. These results suggested that HPA activity might serve as a biomarker of the differential susceptibility model for perceived stress and anxiety symptoms, while for depressive symptoms, it might serve as a marker of the diathesis-stress model.

Hair cortisol and cortisone as markers of stress in Indigenous and non-Indigenous young adults

Chronic, ongoing stress can impact negatively on health and wellbeing. Indigenous Australians are at an increased risk of experiencing multiple stressors. Hair glucocorticoids have been used as a marker for chronic stress. This study aimed to assess the associations of hair cortisol and cortisone with sociodemographic (age, gender, Indigenous Identification), substance use, emotional wellbeing, and emotional stress, in a cohort at increased risk of stressful events and psychological distress. Cross-sectional data (age 21-28 years) are presented from two Australian longitudinal studies; the Aboriginal Birth Cohort (n = 253) and non-Indigenous Top End Cohort (n = 72). A third of the cohort reported psychological distress, with Indigenous participants reporting higher rates of stressful events compared to non-Indigenous (6 vs. 1; p < .001). Significantly higher levels of cortisone were seen in Indigenous women compared to non-Indigenous women (β 0.21; p = .003). A positive association with age was present in hair cortisol and cortisone in Indigenous young adults (β 0.29 and β 0.41; p < .001, respectively). No association with substance use, emotional wellbeing or emotional stress was seen. Sub-analysis in women suggested a possible curvilinear relationship between hair cortisone and the number of stressful events. In this culturally diverse cohort, hair sampling provides a noninvasive, easily conducted and generally well tolerated mechanism to measure stress markers. The association with age, even in this narrow age range, likely represents the manifold changes in circumstances (financial independence, becoming parents, increased risk of substance use and mental illness) that occur during this transitional period of life, particularly for young Indigenous women. LAY ABSTRACT Chronic stress can impact negatively on health and emotional wellbeing. A hair sample is an easy way to measure chronic stress in Indigenous and non-Indigenous young people. The markers of chronic stress, cortisol and cortisone, were different between Indigenous and non-Indigenous, men and women and increased with age in Indigenous young adults.

Innovations in biological assessments of chronic stress through hair and nail cortisol: Conceptual, developmental, and methodological issues

Much of the existing research on biological mechanisms underlying the stress experience has focused largely on moment-to-moment stress, rather than on chronic stress, an arguably more powerful predictor of long-term outcomes. Recent methodological innovations have paved the way for new lines of research on chronic stress, with promising implications for developmental researchers and for those who study health and adversity. In particular, there are increasing studies that have focused on chronic stress assessments by relying on cortisol derived from hair and nails as a biomarker for chronic stress. In this paper, we provide an overview of their use, describe how hair and nail cortisol ought to be conceptualized differently across the lifespan, how developmental factors may impact its interpretation, and the circumstances under which its use may be more methodologically sensible. The purpose of this review is to provoke further discussion and encourage careful research designs that utilize hair and nail cortisol for understanding the effects of chronic stress exposure from the early developmental period, across adverse contexts, and in association with psychological and physical health outcomes.

Hair cortisol concentrations in a Spanish sample of healthy adults

BACKGROUND

Hair cortisol concentration (HCC), as a novel promising method to retrospectively measure hypothalamic-pituitary-adrenal (HPA) axis activation, is being increasingly studied. We tested the relationships between HCC and a range of possible confounding variables in a Spanish sample of healthy adults and pregnant women.

METHODS

The number of healthy adults who participated in the study was 529, being 270 males and 259 females, with a combined mean age of 37.88 years (SD = 15.66). Additionally, a separate sample of 62 pregnant women was also recruited with a mean age of 32.95 (SD = 3.67), and in the first trimester of pregnancy. Each participant was interviewed before the study to obtain sociodemographic and lifestyle variables, and a hair sample was taken from the posterior vertex of the head, cut as close to the scalp as possible. Assuming the average growth rate of head hair is 1 cm per month, a 3-cm segment was analysed, in order to measure the cortisol concentrations from a three-month period. For the pregnant women, hair samples for each trimester of pregnancy were analysed.

RESULTS

The mean hair cortisol concentration was 127.91 (111.52) pg/mg for the general sample. The variables of age, education, employment status, use of hair dyes, use of oral contraceptives, and physical exercise had a significant relation to HCC. When adjusted for further variables, only education and physical exercise remained statistically significant. When including the use of oral contraceptives and only with respect to females, only physical exercise remains statistically significant. For the subsample of pregnant woman, the mean hair cortisol concentration was 334.51 (409.77) pg/mg for the first trimester, 302.18 (270.24) pg/mg for the second trimester, and 331.31 (295.46) pg/mg for the third trimester of pregnancy. None of the assessed confounding variables (age, body mass index, previous miscarriages, employment status, hair dyes, dependent children and physical exercise), except education level, was related to HCC.

CONCLUSIONS

In this sample of healthy Spaniards, results suggested an association between HCC and physical exercise and educational level. In pregnant women, the prevalence of HCC was higher than in non-pregnant woman, and was related to educational level. This study emphasises the need to determine the relationship between HCC and confounders such as sociodemographic and lifestyle variables in the general population and specific groups formed by individuals such as pregnant women.

Hair cortisol analysis: An update on methodological considerations and clinical applications

BACKGROUND

Hair cortisol analysis is increasingly being appreciated and applied in both research and medicine, aiding endocrinologists with diagnosis.

CONTENT

We provide an overview of hair cortisol research in general and an update on methodological considerations including the incorporation of cortisol into hair, hair growth rates, and sampling procedures, mincing vs. grinding of samples during preparation for extraction, various extraction protocols, and quantification techniques. We compare the clinical utility and application of hair cortisol with traditional methods of measurement while acknowledging the limitations of analysis including variations in hair growth parameters. We explore the value of hair cortisol in cases of Cushing syndrome (particularly Cyclical Cushing), Adrenal insufficiency (including Addison's disease), therapy monitoring, cardiovascular disease, stress, and mental illness.

SUMMARY

Hair cortisol provides a unique objective biomarker for the analysis of endogenous cortisol levels for not only clinical diagnostic purposes but also in research. The use of hair cortisol has great potential for advancing patient care.

In Individuals Following Aneurysmal Subarachnoid Haemorrhage, Hair Cortisol Concentrations Are Higher and More Strongly Associated with Psychological Functioning and Sleep Complaints than in Healthy Controls

BACKGROUND

Following an aneurysmal subarachnoid haemorrhage (aSAH), many patients report persistent deficits in psychological functioning, characterised by high levels of stress and symptoms of depression, low life satisfaction, along with poor sleep. Such deficits have been associated with altered saliva and serum cortisol levels due to a dysregulation of hypothalamic-pituitary-adrenal axis activity (HPA-AA). However, hair cortisol concentrations (HCCs) have not been assessed in this population, although this method allows a long-term insight into cortisol values. Therefore, the objective of this study was to compare HCCs in aSAH patients and healthy controls and to examine how HCCs are associated with perceived stress, psychological functioning, and sleep complaints.

METHODS

In this cross-sectional study, data on depressive symptoms, hypochondriacal beliefs, life satisfaction, and sleep complaints were gathered in 15 aSAH patients and 17 healthy controls. HCCs of the previous 3 months were assessed.

RESULTS

aSAH patients had significantly higher HCCs than healthy controls. In aSAH patients, higher HCCs were significantly associated with increased depressive symptoms, hypochondriacal beliefs, lower life satisfaction, and increased sleep complaints. Such significant associations were not found in healthy controls.

CONCLUSIONS

Our findings indicate that a dysregulation of HPA-AA is associated with some of the long-term impairments in psychological functioning and sleep in aSAH survivors. While the direction of association remained unclear, a dysregulated HPA-AA may be causally linked with the maintenance of poor psychological functioning and poor sleep. The overall findings should be considered in the planning of long-term treatment aimed at improving psychological functioning and sleep in aSAH patients.

Psychopathological sequelae of female genital mutilation and their neuroendocrinological associations

BACKGROUND

Anecdotal evidence suggests the frequently traumatic nature of female genital mutilation (FGM). At present, systematic research on the psychological sequelae of this tradition has remained limited. The study provides preliminary, high-quality psychodiagnostic data on potential psychopathological consequences of FGM, with a focus on posttraumatic stress disorder (PTSD), shutdown dissociation and other stress-related variables.

METHODS

We investigated a convenience sample of N = 167 women, supported by the women's affairs headquarters in Jijiga (capital of the Ethiopian Somali Region) and a local Ethiopian non-governmental organization. Our main outcome measures were PTSD (PSS-I) and shutdown dissociation (ShuD). We also assessed depression and anxiety (HSCL-25), major depression, substance abuse and dependence, suicidality and psychotic disorders (M.I.N.I.; sub-scales A., B., K., and L.). In addition, we collected hair samples to assess hair cortisol concentrations (HCC) as a neuroendocrinological measure.

RESULTS

The majority of women endured FGM (FGM I: 36%, FGM II/III: 52%) and, regardless of the level of the physical invasiveness, almost all women reported having felt intense fear and/or helplessness. FGM II/III, the more invasive form, was associated with a greater vulnerability to PTSD symptoms (p < .001) and shutdown dissociation (p < .001). Symptoms of depression (p < .05) and anxiety (p < .01) were also elevated. Random forest regression with conditional inference trees revealed evidence of an alteration of the cortisol levels in relation to the age when FGM was experienced (< 1 year) and the invasiveness of the procedure.

CONCLUSION

More extensive forms of FGM are associated with more severe psychopathological symptoms - particularly with an increased vulnerability to PTSD. Higher hair cortisol levels in women who experienced FGM before their first year of age or had more severe forms of FGM indicate long-term neuroendocrinological consequences of FGM and trauma in general on the stress system.

Using hair and fingernails in binary logistic regression for bio-monitoring of heavy metals/metalloid in groundwater in intensively agricultural areas, Thailand

In this study, the hair and fingernails of the local people in an intensively cultivated agricultural area in Ubon Ratchathani province, Thailand, were used as biomarkers of exposure to arsenic (As) and heavy metals. The study area has shallow acidic groundwater that is contaminated with As and heavy metals. The local people often consume this shallow groundwater; thus, they are exposed to As and heavy metals. Hair and fingernail samples were collected to characterize the differences between shallow groundwater drinking (SGWD) and tap water drinking (TWD) residents. The concentrations of As and the heavy metals Cd, Pb and Hg were significantly higher in the hair samples from the SGWD group than those from the TWD group, especially for As (0.020-0.571 vs. 0.024-0.359µg/g) and Cd (0.009-0.575 vs. 0.013-0.230µg/g). Similarly, the concentrations of As and the heavy metals in the fingernail samples collected from the SGWD group were larger than those of the TWD group, especially for As (0.039-2.440µg/g vs. 0.049-0.806µg/g). The χ² statistic and binary logistic regression were used to find the associated factors and assess the associated probabilities. The regression results show that the factors associated with the concentrations of As and the heavy metals in the hair samples were drinking water source, rate of water consumption, gender, bathing water source, education, smoking and underlying disease, whereas the factors associated with the concentrations of these species in the fingernail samples were drinking water source, gender, occupation, work hours per day, alcohol consumption, and the use of pesticides.

Hair cortisol and work stress: Importance of workload and stress model (JDCS or ERI)

Hair cortisol concentrations (HCCs) are a potential physiological indicator of work related stress. However, studies that tested the relationship between HCC and self-reported stress in a work setting show mixed findings. This may be because few studies used worker samples that experience prolonged stress. Therefore, we compared a high workload sample (n = 81) and a normal workload sample (n = 91) and studied whether HCC was related to: (i) high job demands, low control, and low social support (JDCS model), and (ii) high effort, low reward, and high overcommitment (ERI model). Results showed that self-reported stress related to HCC only in the high workload sample and only for the variables of the ERI model. We found that HCC was higher when effort was high, reward low, and overcommitment high. An implication of this study is that a certain stress threshold may need to be reached to detect a relationship between self-reported stress and physiological measures such as HCC.

Contact to Nature Benefits Health: Mixed Effectiveness of Different Mechanisms

How can urban nature contribute to the reduction of chronic stress? We twice measured the concentration of the “stress hormone” cortisol in the hair of 85 volunteer gardeners (six months apart), relating cortisol level change to (self-reported) characteristics of their recreational activities. Both time spent in nature and physical activity led to decreases in cortisol, while time spent being idle led to an increase. At high levels of present stressors, however, the relationship for time spent in nature and for idleness was reversed. Time spent with social interaction had no effect on cortisol levels. Our results indicate that physical activity is an effective means of mitigating the negative effects of chronic stress. The results regarding the time spent in nature and time spent being idle are less conclusive, suggesting the need for more research. We conclude that if chronic stress cannot be abolished by eradicating its sources, public health may take to measures to reduce it—providing urban nature being one effective possibility.

DHEAS patterning across childhood in three sub-Saharan populations: Associations with age, sex, ethnicity, and cortisol

OBJECTIVES

Hormones have many roles in human ontogeny, including the timing of life history 'switch points' across development. Limited hormonal data exist from non-Western children, leaving a significant gap in our understanding of the diversity of life history patterning. This cross-sectional study examines dehydroepiandrosterone sulfate (DHEAS) production in relation to age, sex, ethnicity, and cortisol concentrations, as well as average age of adrenarche, among Aka and Ngandu children of the Central African Republic and Sidama children of Ethiopia.

METHODS

Hair was collected from 480 children (160 per population) aged 3-18 years old. These samples were analyzed for DHEAS and cortisol concentrations using ELISAs. A generalized additive model was used to examine DHEAS patterning in relation to age, sex, cortisol, and ethnicity. The derivative of DHEAS as a function of age was used to identify average age of adrenarche in each population.

RESULTS

DHEAS patterning in these three populations is distinct from Euro-American patterns of production. In all three groups, the population-level age at adrenarche onset occurs slightly later than Euro-American averages, with both Central African populations experiencing a later onset than the Ethiopian population.

CONCLUSIONS

DHEAS patterns and age at adrenarche vary across cultures, perhaps indicating adaptive life history responses in diverse eco-cultural environments. Delayed involution of the fetal zone and DHEAS patterning may offer both cognitive protection and immune defense in high-risk, nutritionally-poor environments. Additional research in the majority world is essential to improving our understanding of the diversity of hormonal development and timing of 'switch points' in life history trajectories.

Assessment of Brain Derived Neurotrophic Factor in hair to study stress responses: A pilot investigation

To study pathogenic stress-effects in health and disease, it is paramount to define easy access parameters for non-invasive analysis of biological change in response to stress. Hair samples successfully provide this access for the study of hypothalamus-pituitary-adrenal axis (HPA) changes. In this study, we assess the hair expression and corresponding epigenetic changes of a neurotrophin essential for autonomic nervous system function and mental health: brain derived neurotrophic factor (BDNF). In three independent studies in healthy academic volunteers (study I: German students, N=36; study II, German academic population sample, N=28; study III: Mexican students, N=115), BDNF protein expression or BDNF gene (BDNF) histone acetylation was determined. Simultaneously, mental distress and distress-associated somatic complaints were assessed by self-report. In study I, we found a negative correlation between hair-BDNF protein level and hair-cortisol as well as between hair-BDNF and somatic complaints, while hair-cortisol correlated positively with mental distress. In study II, we found a negative correlation between H4 histone acetylation at the BDNF gene P4-promoter and somatic complaints. Regression analysis confirmed confounder stability of associations in both studies. In study III, we confirmed study I and found lower hair-BDNF protein level in volunteers with high somatic complaints, who also reported higher mental distress during the end of term exams. The results indicate that BDNF protein levels can be detected in clipped hair and are associated with somatic complaints and stress in life. In addition, we concluded that plucked hair can provide material for the study of epigenetic changes in stress-affected tissues. These tools can prove valuable for future studies on distress, both under experimental and field conditions.

Relationships between affiliative social behavior and hair cortisol concentrations in semi-free ranging rhesus monkeys

Sociality is a fundamental aspect of human behavior and health. One benefit of affiliative social relationships is reduced short-term levels of glucocorticoids (GCs), which are indicative of physiological stress. Less is known, however, about chronic GC production in relation to affiliative social behavior. To address this issue, we studied a semi-free ranging troop of rhesus macaques (Macaca mulatta) and collected hair samples to measure hair cortisol concentrations (HCCs), as a measure of chronic GC production, during routine biannual exams. We collected social behavior (both aggressive and affiliative) and hair samples for 32 adult female rhesus macaques over one year (Experiment 1). Our results indicated that adult females who initiated higher levels of social affiliation had significantly lower levels of HCCs. Neither the initiation nor the receipt of aggression were significantly related to HCCs in this study. In a second experiment we studied 28 mother-infant dyads for the first 90days postpartum to examine mother-infant facial interactions (i.e. mutual gazing). We analyzed HCCs during weaning approximately one year later, which is a major transitional period. We found that infants that engaged in higher levels of mutual gazing in the first 90days postpartum had significantly lower levels of HCCs during weaning. Finally, we studied 17 infant rhesus macaques (13 males) to examine whether social behavior (such as play) in the first five months of life correlated with infant HCCs over those months (Experiment 3). We found that infant males that engaged in more social play had significantly lower levels of HCCs. By relying on an animal model, our study shows that affiliative social traits are associated with lower long-term GC production. Future research should address the complex interactions between social behavior, chronic GC production, and mental and physical health.

Hair analysis reveals subtle HPA axis suppression associated with use of local corticosteroids: The Lifelines cohort study

BACKGROUND AND AIMS

Scalp hair is increasingly used to measure the long-term exposure to endogenous glucocorticoids hormones. Long-term cortisone (HairE) and cortisol (HairF) have been associated with obesity, metabolic syndrome, cardiovascular disease and psychopathology. However, little is known about the influence of the use of local corticosteroids and major stressful life events on hair glucocorticoids.

MATERIALS AND METHODS

We determined HairE and HairF using liquid chromatography - tandem mass spectrometry in 295 adult participants of the population-based Lifelines cohort study (75% females, median age 42). We collected anthropometry and fasting metabolic laboratory values, questionnaires on hair characteristics, recent use of corticosteroids, and recent major stressful life events.

RESULTS

After adjustment for covariates, hair glucocorticoids increased with age, male sex, black or brown hair color, and frequency of sweating on the scalp, and decreased with higher hair washing frequency (P<0.05). HairE was decreased in participants who used systemic corticosteroids (5.4 vs. 8.5pg/mg hair, P=0.041), and in participants who only used local agents such as inhaled, topical and nasal corticosteroids (6.8 vs. 8.5pg/mg, P=0.005). Recent life events were positively associated with HairF after adjustment for age and sex (P=0.026), but this association lost significance after adjustment for hair related characteristics (P>0.05).

CONCLUSIONS

HairE can be a useful marker to detect mild adrenal suppression due to corticosteroid use in the general population, even when only inhaled, nasal or topical corticosteroids are used, which suggests that these commonly used agents induce systemic effects.

Geometric classification of scalp hair for valid drug testing, 6 more reliable than 8 hair curl groups

INTRODUCTION

Curly hair is reported to contain higher lipid content than straight hair, which may influence incorporation of lipid soluble drugs. The use of race to describe hair curl variation (Asian, Caucasian and African) is unscientific yet common in medical literature (including reports of drug levels in hair). This study investigated the reliability of a geometric classification of hair (based on 3 measurements: the curve diameter, curl index and number of waves).

MATERIALS AND METHODS

After ethical approval and informed consent, proximal virgin (6cm) hair sampled from the vertex of scalp in 48 healthy volunteers were evaluated. Three raters each scored hairs from 48 volunteers at two occasions each for the 8 and 6-group classifications. One rater applied the 6-group classification to 80 additional volunteers in order to further confirm the reliability of this system. The Kappa statistic was used to assess intra and inter rater agreement.

RESULTS

Each rater classified 480 hairs on each occasion. No rater classified any volunteer's 10 hairs into the same group; the most frequently occurring group was used for analysis. The inter-rater agreement was poor for the 8-groups (k = 0.418) but improved for the 6-groups (k = 0.671). The intra-rater agreement also improved (k = 0.444 to 0.648 versus 0.599 to 0.836) for 6-groups; that for the one evaluator for all volunteers was good (k = 0.754).

CONCLUSIONS

Although small, this is the first study to test the reliability of a geometric classification. The 6-group method is more reliable. However, a digital classification system is likely to reduce operator error. A reliable objective classification of human hair curl is long overdue, particularly with the increasing use of hair as a testing substrate for treatment compliance in Medicine.

AN EFFECTIVE NEUROFEEDBACK TRAINING, WITH CORTISOL CORRELATES, IN A CLINICAL CASE OF ANXIETY

Background and objectives: Neurofeedback treatments have shown successful results in anxiety disorders. Thus, the effectiveness of a beta1 Neurofeedback protocol was tested in a longitudinal clinical case study. Design and methods: A participant suffering from an anxiety syndrome was treated with 10 sessions of Neurofeedback, which protocol consisted in uptraining beta1 rhythm (16-21 Hz) while downtraining theta (4-8 Hz) band. For each of the 10 sessions the state anxiety and salivary cortisol levels were measured in a pre/post design. Initial and final examinations of anxiety symptoms and sustained attention performance were taken in addition. Results: The final evaluation showed that levels of anxiety fell within normative range and sustained attention improved. A t-test for related samples disclosed a significant improvement of beta1 amplitude across sessions, without modifications in untrained bands. A significant inverse correlation between beta1 amplitude and salivary cortisol appeared, suggesting that brain activity could be considered a marker of anxiety. The validation of the beta1 Neurofeedback protocol was assessed by independence, trainability and interpretability criteria. Conclusions: We showed an effective Neurofeedback protocol on anxiety and sustained attention, the success of which could consist on the reestablishment of an optimal cortical arousal capable of inhibiting the elevated amygdalar activity. (English)

Chronic stress in the mother-infant dyad: Maternal hair cortisol, infant salivary cortisol and interactional synchrony

Stress physiology is shaped by early experience, with enduring effects on health. The relation of chronic maternal physiological stress, as indexed by hair cortisol, to infants' stress systems and to mother-infant interaction quality has not been established. We examined maternal hair and salivary cortisol, six-month-old infants' salivary cortisol, and mother-infant interaction in 121 mother-infant dyads. High maternal hair cortisol was related to higher infant average salivary cortisol concentration. Maternal hair cortisol and bedtime salivary cortisol were both uniquely related to infant bedtime salivary cortisol. Mothers with higher hair cortisol were more intrusive and had lower positive engagement synchrony with their infants. Maternal intrusiveness moderated the association of maternal hair cortisol and infant salivary cortisol, such that maternal hair and infant average salivary cortisol were related only when mothers were more intrusive. Maternal chronic physiological stress may upregulate infants' developing stress systems, particularly in the context of lower mother-infant interaction quality.

Hair and stress: A pilot study of hair and cytokine balance alteration in healthy young women under major exam stress

Mouse models show that experimental stress mimicking prolonged life-stress exposure enhances neurogenic inflammation, induces adaptive immunity cytokine-imbalance characterized by a shift to Type 1 T-helper cell cytokines and increases apoptosis of epithelial cells. This affects hair growth in otherwise healthy animals. In this study, we investigate whether a prolonged naturalistic life-stress exposure affects cytokine balance and hair parameters in healthy humans. 33 (18 exam, 15 comparison) female medical students with comparable sociobiological status were analyzed during a stressful final examination period, at three points in time (T) 12 weeks apart. T1 was before start of the learning period, T2 between the three-day written exam and an oral examination, and T3 after a 12 week rest and recovery from the stress of the examination period. Assessments included: self-reported distress and coping strategies (Perceived Stress Questionnaire [PSQ], Trier Inventory for the Assessment of Chronic Stress [TICS]), COPE), cytokines in supernatants of stimulated peripheral blood mononucleocytes (PBMCs), and trichogram (hair cycle and pigmentation analysis). Comparison between students participating in the final medical exam at T2 and non-exam students, revealed significantly higher stress perception in exam students. Time-wise comparison revealed that stress level, TH1/TH2 cytokine balance and hair parameters changed significantly from T1 to T2 in the exam group, but not the control. However, no group differences were found for cytokine balance or hair parameters at T2. The study concludes that in humans, naturalistic stress, as perceived during participation in a major medical exam, has the potential to shift the immune response to TH1 and transiently hamper hair growth, but these changes stay within a physiological range. Findings are instructive for patients suffering from hair loss in times of high stress. Replication in larger and more diverse sample populations is required, to assess suitability of trichogram analysis as biological outcome for stress studies.

Hair cortisol as a marker of hypothalamic-pituitary-adrenal Axis activity in female patients with major depressive disorder

Hair cortisol is regarded as a promising marker of hypothalamic-pituitary-adrenal axis (HPAA) activity alterations due to stress, somatic and mental health conditions. Hair cortisol was previously reported to be elevated in patients with depression, however the data related to remission and recurrent depressive episodes are different. In this study, levels of hair cortisol were assessed in female patients with major depressive disorder (MDD) and the validity of hair cortisol as a marker of HPAA activity in this condition was evaluated. Hair cortisol was measured in 1 cm hair segments of 21 female patients with MDD and 22 female age-matched controls using enzyme-immunoassay analysis. Concurrently, serum cortisol was assessed and psychological status was evaluated using 17-item Hamilton Depression Rating Scale (HAMD-17), Beck Depression Inventory (BDI) and the Spielberger state trait anxiety inventory (STAI). The levels of hair cortisol were significantly lower in the MDD group, while serum cortisol levels were significantly higher in patients, as compared with controls. A significant negative correlation was found between HAMD-17 scores and hair cortisol. Decreased hair cortisol found in female patients with MDD as compared to controls suggests downregulation of HPAA activity during the preceding month. Further studies are needed to investigate the profiles of hair cortisol at different stages of depressive disorder to establish this parameter as a handy clinical tool.

A novel method for assessing chronic cortisol concentrations in dogs using the nail as a source

Cortisol, a glucocorticoid secreted in response to stress, is used to assess adrenal function and mental health in clinical settings. Current methods assess cortisol sources that reflect short-term secretion that can vary with current stress state. Here, we present a novel method for the extraction and quantification of cortisol from the dog nail using solid phase extraction coupled to enzyme-linked immunosorbent assay. Validation experiments demonstrated accuracy (r = 0.836, P < 0.001) precision (15.1% coefficients of variation), and repeatability (14.4% coefficients of variation) with this method. Furthermore, nail cortisol concentrations were positively correlated to an established hair cortisol method (r = 0.736, P < 0.001). Nail cortisol concentrations did not differ with dog sex, breed, age, or weights; however, sample size limitations may preclude statistical significance. Nail cortisol may provide information on cortisol secretion integrated over the time corresponding to nail growth and may be useful as a tool for diagnosing stress and adrenal disorders in dogs.

Stress-related and basic determinants of hair cortisol in humans: A meta-analysis

The analysis of hair cortisol concentrations (HCC) is a relatively new strategy to measure long-term cumulative cortisol levels, which is increasingly used in psychoneuroendocrinological research. Here, we conduct a first comprehensive meta-analysis of HCC research based on aggregated data from a total of 124 (sub)samples (66 independent studies; total N=10,289). We seek to answer two central questions: (i) Which covariates and basic features of HCC need to be considered in future research? (ii) What are the main determinants of HCC in terms of chronic stress exposure and mental health? Concerning basic characteristics, our findings identify several covariates to be considered (age, sex, hair washing frequency, hair treatment, oral contraceptive use), confirm a decline of HCC from the first to the second proximal 3cm hair segment, and show positive associations between HCC and short-term salivary cortisol measures. Regarding chronic stress, we show that stress-exposed groups on a whole exhibit 22% increased HCC. This long-term cortisol hypersecretion emerges particularly when stress is still ongoing at the time of study (+43% HCC) but is not present in conditions of past/absent stress (-9% HCC, n.s.). We also report evidence for 17%-reduced HCC in anxiety disorders, such as PTSD. Interestingly, no consistent associations with mood disorders and self-reports of perceived stress, depressiveness or social support are found. However, our findings reveal positive associations of HCC with stress-related anthropometric (body mass index, waist-to-hip ratio) and hemodynamic measures (systolic blood pressure). These meta-analytic results are discussed in the light of their practical implications and important areas for future inquiry are outlined.

Cortisol levels in hair are altered in irritable bowel syndrome - A case control study in primary care

OBJECTIVE

Stress is an important component in the pathophysiology of irritable bowel syndrome (IBS). Long term Hypothalamus Pituitary Adrenal (HPA)-axis activity can be studied by measuring hair cortisol concentrations (HCC). Some previous studies have indicated a dysregulated HPA-axis in IBS patients, but cortisol levels in hair have not yet been studied. We investigated whether HCC and self-reported stress differentiate IBS patients from controls.

METHODS

In a cross-sectional study within 10 Swedish Primary Health Care Centers we compared patients in working age with active IBS to patients without GI complaints. The participants donated hair samples and completed questionnaires including a scale of self-reported perceived stress (PSS). 169 Rome III-fulfilling IBS patients and 316 non-IBS patients were available for final analyses.

RESULTS

IBS patients had significantly lower HCC, median=16.3pg/mg, IQR=26.9pg/mg, compared to non-IBS patients, median=22.8pg/mg, IQR=29.1pg/mg. There was also a difference in the distribution of HCC quintiles between the two groups, with 30.2% IBS patients and 14.2% of non-IBS patients in the lowest quintile of HCC. PSS was higher among IBS patients with a mean (SD) total score of 25.3 (8.0) compared to controls 21.4, (7.5). Quintiles of HCC and PSS stayed significantly but very weakly related to IBS (B=-0.332, Std error=0.146, p<0.005) in multivariable analyses.

CONCLUSION

This study suggests a possible suppression of the HPA-axis activity in a considerable portion of IBS patients.

Sociodemographic, lifestyle, and psychosocial determinants of hair cortisol in a South London community sample

OBJECTIVE

Hypothalamic-pituitary-adrenal (HPA) measures are crucial for research into stress and stress-related disorders. Most HPA measures fluctuate depending on diurnal rhythms and state confounders. Hair cortisol concentrations (HCC) are less susceptible to such fluctuations, but less is known about trait-like confounders. Using a community sample, we tested the relationship between HCC and a range of variables including demographic variables, hair treatment, and medication, as well as psychosocial variables, namely childhood trauma, critical life events, and depressive symptoms.

METHODS

Hair samples were collected from 144 individuals from the South East London Community Health (SELCoH) study. Childhood trauma, life events, and depressive symptoms were measured, together with age, sex, ethnicity, relationship status, educational attainment, employment status, occupational social class, hair washing frequency, hair treatments, season reflected in the hair sample, hazardous drinking, smoking, medication intake, and body mass index. Hair samples reflecting the past 3 months were collected and analysed using immunoassays. First, correlations (continuous variables) and simple linear regressions (dichotomous variables) were conducted to identify sociodemographic, hair-related, and lifestyle determinants of HCC. Next, multiple linear regressions were conducted to test the relationship between psychosocial variables and HCC when controlling for the identified confounders.

RESULTS

Age (r=-0.17, p=0.050), White British ethnicity (β=-0.19, p=0.023), heat-based treatments (β=-0.22, p=0.010), and winter season (β=-0.18, p=0.024) were associated with lower HCC, whereas summer season (β=0.24, p=0.024), painkillers (β=0.25, p=0.003), anxiolytics/antidepressants (β=0.21, p=0.014), and hormonal contraceptives (β=0.27, p=0.006) were associated with higher HCC. Controlling for these confounders, physical neglect during childhood (β=-0.17, p=0.057), war-related experiences (β=0.20, p=0.027), separation (β=0.18, p=0.054), and being the victim of a serious crime (β=-0.17, p=0.062) were linked with altered HCC.

CONCLUSION

Our findings suggest that variation in HCC occurs according to sociodemographic, hair-related, and lifestyle variables, and that certain associations between stress and altered HCC can only be revealed when accounting for these confounders.

Hair Measurements of Cortisol, DHEA, and DHEA to Cortisol Ratio as Biomarkers of Chronic Stress among People Living with HIV in China: Known-Group Validation

Background

Existing literature suggests that endocrine measures, including the steroid hormones of cortisol and Dehydroepiandrosterone (DHEA), as well as the DHEA to cortisol ratio in the human hair can be used as promising biomarkers of chronic stress among humans. However, data are limited regarding the validity of these measures as biomarkers of chronic stress among people living with HIV (PLWH), whose endocrine system or hypothalamic pituitary adrenal (HPA) axis may be affected by HIV infection and/or antiretroviral therapy (ART) medications.

Method

Using hair sample data and self-reported survey from 60 PLWH in China, we examined the validity of three endocrine measures among Chinese PLWH using a known-groups validation strategy. High-stress group (n = 30) and low-stress group (n = 30) of PLWH were recruited through individual assessment interviews by a local licensed psychologist. The endocrine measures in hair were extracted and assessed by LC-APCI-MS/MS method. Both bivariate and multivariate analyses were conducted to examine the associations between the endocrine measures and the stress level, and to investigate if the associations differ by ART status.

Results

The levels of endocrine measures among Chinese PLWH were consistent with existing studies among PLWH. Generally, this pilot study confirmed the association between endocrine measures and chronic stress. The high stress group showed higher level hair cortisol and lower DHEA to cortisol ratio. The higher stress group also reported higher scores of stressful life events, perceived stress, anxiety and depression. Hair cortisol level was positively related to anxiety; DHEA was negatively associated with stressful life events; and the DHEA to cortisol ratio was positively related to stressful life events and perceived stress. ART did not affect the associations between the endocrine measures and stress level.

Conclusions

Our findings suggest that hair cortisol and DHEA to cortisol ratio can be used as promising biomarkers of chronic stress among PLWH. Clarifying the role of steroid hormones in the psychoimmunology of PLWH may yield important implications for clinical practice and psychological intervention.

Intimate partner violence is associated with increased maternal hair cortisol in mother-child dyads

BACKGROUND

The chronic consequences of intimate partner violence (IPV) on HPA activation are a topic of debate. The current study investigated hair cortisol concentrations in female victims of IPV and their children.

METHODS

A total of 52 mother-child dyads were divided into two groups depending on exposure to IPV: IPV group (n=27 dyads) and control group (n=25 dyads). Hair cortisol concentration was measured in 1-cm-long hair strands, representing 30days of exposure before assessment. PTSD and depression symptoms were assessed in the mother and child.

RESULTS

Women reporting IPV presented with higher hair cortisol levels, depression and PTSD symptoms severity in comparison to control women. Children who witnessed IPV reported more severe PTSD symptoms, but depressive symptoms and hair cortisol were not statistically different than those in control children. Correlation analyses revealed a positive association between the number of injury events and the level of hair cortisol in children. No associations between the hair cortisol levels in mothers and those in their children were found.

CONCLUSION

Higher hair cortisol levels detected in women exposed to IPV reflected long-lasting changes in HPA axis functioning associated with chronic stress exposure. Children whose parents recurrently engage in violent conflicts with intimate partners may often feel threatened and consequently reporting more PTSD-related symptoms. Given that experiencing and witnessing violence during childhood and adolescence are predictive of intimate partner violence in adulthood, the need of early interventions is crucial.

Hair cortisol and its potential value as a physiological measure of stress response in human and non-human animals

There is considerable interest in the potential for measuring cortisol in hair as a means of quantifying stress responses in human and non-human animals. This review updates the rapid advancement in our knowledge of hair cortisol, methods for its measurement, its relationship to acute and chronic stress, and its repeatability and heritability. The advantages of measuring cortisol in hair compared with other matrices such as blood, saliva and excreta and the current theories of the mechanisms of cortisol incorporation into the fibre are described. Hair cortisol as a measure of the physiological response to stress in a variety of species is presented, including correlations with other sample matrices, the relationship between hair cortisol and psychosocial stress and the repeatability and heritability of hair cortisol concentrations. Current standards for the quantification of hair cortisol are critically reviewed in detail for the first time and gaps in technical validation of these methods highlighted. The known effects of a variety of sources of hair cortisol variation are also reviewed, including hair sampling site, sex, age and adiposity. There is currently insufficient evidence to conclude that cortisol concentration in hair accurately reflects long-term blood cortisol concentrations. Similarly, there is a lack of information surrounding the mechanisms of cortisol incorporation into the hair. This review highlights several directions for future research to more fully validate the use of hair cortisol as an indicator of chronic stress.

Association between hair cortisol concentration and perceived stress in female methamphetamine addicts

OBJECTIVE

The present study aims to explore whether hair cortisol concentration is associated with explicit stress or implicit stress in female methamphetamine addicts.

METHODS

Hair samples were collected from 51 female methamphetamine addicts from inpatient addiction treatment programs. Perceived stress was assessed by both explicit and implicit measures through the Perceived Stress Scale (PSS) and the Implicit Association Test (IAT), respectively.

RESULTS

The positive relationship between hair cortisol concentration with D-scores of the IAT reached statistically significant difference. A marginal correlation between hair cortisol concentration and scores of the PSS was observed. Additionally, linear regression analysis indicated that D-scores of the IAT are strongly predictive of hair cortisol concentration.

CONCLUSION

Hair cortisol concentration is strongly related to implicit stress but only weakly related with explicit stress.

Methodological Considerations for Hair Cortisol Measurements in Children

BACKGROUND

Hair cortisol levels are used increasingly as a measure for chronic stress in young children. We propose modifications to the current methods used for hair cortisol analysis to more accurately determine reference ranges for hair cortisol across different populations and age groups.

METHODS

The authors compared standard (finely cutting hair) versus milled methods for hair processing (n = 16), developed a 4-step extraction process for hair protein and cortisol (n = 16), and compared liquid chromatography-mass spectrometry (LC-MS) versus enzyme-linked immunosorbent assays (ELISAs) for measuring hair cortisol (n = 28). The extraction process included sequential incubations in methanol and acetone, repeated twice. Hair protein was measured through spectrophotometric ratios at 260/280 nm to indicate the hair dissolution state using a BioTek plate reader and dedicated software. Hair cortisol was measured using an ELISA assay kit. Individual (n = 13), pooled hair samples (n = 12) with high, intermediate, and low cortisol values, and the ELISA assay internal standards (n = 3) were also evaluated by LC-MS.

RESULTS

Milled and standard methods showed highly correlated hair cortisol (rs = 0.951, P < 0.0001) and protein values (rs = 0.902, P = 0.0002), although higher yields of cortisol and protein were obtained from the standard method in 13 of 16 and 14 of 16 samples, respectively (P < 0.05). Four sequential extractions yielded additional amounts of protein (36.5%, 27.5%, 30.5%, 3.1%) and cortisol (45.4%, 31.1%, 15.1%, 0.04%) from hair samples. Cortisol values measured by LC-MS and ELISA were correlated (rs = 0.737; P < 0.0001), although cortisol levels [median (interquartile range)] detected in the same samples by LC-MS [38.7 (14.4-136) ng/mL] were lower than that by ELISA [172.2 (67.9-1051) ng/mL]. LC-MS also detected cortisone, which comprised of 13.4% (3.7%-25.9%) of the steroids detected.

CONCLUSIONS

Methodological studies suggest that finely cutting hair with sequential incubations in methanol and acetone, repeated twice, extracts greater yields of cortisol than does milled hair. Based on these findings, at least 3 incubations may be required to extract most of the cortisol in human hair samples. In addition, ELISA-based assays showed greater sensitivity for measuring hair cortisol levels than LC-MS-based assays.

The Association between Hair Cortisol and Self-Reported Symptoms of Depression in Pregnant Women

Depression has been linked to an imbalance in cortisol. Until recently, cortisol has been studied by measuring concentrations at single time points in blood or saliva samples. Cortisol concentrations vary with circadian rhythm and experiences, from time point to time point. The measurement of hair cortisol concentration (HCC) is a new method of accessing mean, long-term cortisol concentrations. Recent studies show positive associations between depression and HCC, and prenatal maternal cortisol is thought to influence the developing fetus. We therefore examined the association between HCC and self-reported symptoms of depression in second trimester pregnant women. Participants were 181 women, recruited between September 2011 and October 2013 to the Little-in-Norway (LiN)-study. These women answered the Edinburgh Postnatal Depression Rating Scale (EPDS) on self-reported symptoms of depression, and one cm maternal scalp hair was collected and analyzed for cortisol concentrations. Multiple regression analyses did not show depressive symptoms as a predictor for HCC in our selection of pregnant women, while gestational age was significantly related. In conclusion, our study indicated that symptoms of depression during pregnancy did not predict HCC, but further studies of clinically depressed, pregnant women using gestational age as an adjustment variable are warranted.

Validation of an adapted procedure to collect hair for cortisol determination in adolescents

INTRODUCTION

In the last decades, cortisol has been extensively studied in association to early exposure to adversity as well as in the etiology of a number of physical and mental problems. While saliva and blood samples allow the measurement of acute changes in cortisol secretion, hair samples are thought to provide a valid retrospective measure of chronic cortisol secretion over an extended period of time. Nevertheless, the existing protocol for hair collection involves considerable financial and logistical challenges when performed in large epidemiological studies.

OBJECTIVE

This study aimed to validate an adapted collection protocol asking participants to sample their hair at home and to send it back to our laboratory by regular mail.

METHODS

Participants were 34 teenagers between 17 and 18 years of age. They participated in two hair collections: (a) at home, with the help of someone they know, and (b) in our laboratory, with a trained research assistant.

RESULTS

We noted a strong correlation between cortisol ascertained from hair collected at home and at the laboratory. No mean difference in cortisol levels could be detected between the two protocols. Moreover, we showed that a wide range of hair-related, sociodemographic, lifestyle factors that may be associated with hair cortisol levels did not affect the association between cortisol measures derived from each protocol.

CONCLUSION

Our study provides initial support that reliable measures of chronic cortisol secretion could be obtained by asking adolescents to collect a sample of their hair at home and send them to the laboratory by regular mail. This adapted protocol has considerable financial and logistical advantages in large epidemiological studies.

An integrative model linking traumatization, cortisol dysregulation and posttraumatic stress disorder: Insight from recent hair cortisol findings

Abundant evidence suggests links between trauma exposure, altered secretion of the glucocorticoid cortisol and the development/maintenance of posttraumatic stress disorder (PTSD), albeit with some inconsistency in findings. Further insight into the complex relations underlying this process may be derived from an increasing number of studies using hair cortisol analysis, a novel assessment strategy assumed to retrospectively capture long-term integrated cortisol secretion. Here, we evaluate the utility of hair cortisol analysis as a method in trauma/PTSD research and review current findings in this context. We compare hair cortisol data on the complex links between trauma, cortisol dysregulation and PTSD against the main findings obtained using traditional cortisol assessment methods. Finally, we integrate these data into a model which proposes that traumatization leads to dose and time-dependent changes in long-term cortisol output (initial post-traumatic increase, subsequent chronic attenuation) and that such dysregulation may partly mediate the link between traumatic load and the risk of PTSD development upon additional trauma exposure ("building block effect").

Cumulative stress in research animals: Telomere attrition as a biomarker in a welfare context?

Progress in improving animal welfare is currently limited by the lack of objective methods for assessing lifetime experience. I propose that telomere attrition, a cellular biomarker of biological age, provides a molecular measure of cumulative experience that could be used to assess the welfare impact of husbandry regimes and/or experimental procedures on non-human animals. I review evidence from humans that telomere attrition is accelerated by negative experiences in a cumulative and dose-dependent manner, but that this attrition can be mitigated or even reversed by positive life-style interventions. Evidence from non-human animals suggests that despite some specific differences in telomere biology, stress-induced telomere attrition is a robust phenomenon, occurring in a range of species including mice and chickens. I conclude that telomere attrition apparently integrates positive and negative experience in an accessible common currency that translates readily to novel species--the Holy Grail of a cumulative welfare indicator.

Increased Risk Taking in Relation to Chronic Stress in Adults

Chronic stress is a public health problem that affects a significant part of the population. While the physiological damage it causes is under ongoing scrutiny, its behavioral effects have been overlooked. This is one of the first studies to examine the relation between chronic stress and decision-making, using a standard lottery paradigm. We measured risk taking in the gain domain through binary choices between financially incentivized lotteries. We then measured self-reported chronic stress with the Trier Inventory for the Assessment of Chronic Stress (TICS). We additionally collected hair samples in a subsample of volunteers, in order to quantify accumulation of the stress hormone cortisol. We discovered a significant positive, though modest, correlation between self-reported chronic stress and risk taking that is stronger for women than for men. This confirms part of the findings in acute stress research that show a connection between higher stress and increased risk taking. However, unlike the biologically-based results from acute stress research, we did not identify a significant relation between hair cortisol and behavior. In line with previous literature, we found a clear gender difference in risk taking and self-reports: women generally take less risk and report slightly higher stress levels than men. We conclude that perceived chronic stress can impact behavior in risky situations.

Hair cortisol varies with season and lifestyle and relates to human interactions in German shepherd dogs

It is challenging to measure long-term endocrine stress responses in animals. We investigated whether cortisol extracted from dog hair reflected the levels of activity and stress long-term, during weeks and months. Hair samples from in total 59 German shepherds were analysed. Samples for measuring cortisol concentrations were collected at three occasions and we complemented the data with individual scores from the Canine Behavioural Assessment and Research Questionnaire (C-BARQ). Generalised linear mixed model (GLMM) results showed that hair cortisol varied with season and lifestyle: competition dogs had higher levels than companion, and professional working dogs, and levels were higher in January than in May and September. In addition, a positive correlation was found between the cortisol levels and the C-BARQ score for stranger-directed aggression (r = 0.31, P = 0.036). Interestingly, the factor “playing often with the dog” (r = −0.34, P = 0.019) and “reward with a treat/toy when the dog behaves correctly” (r = −0.37, P = 0.010) correlated negatively with cortisol levels, suggesting that positive human interactions reduce stress. In conclusion, hair cortisol is a promising method for revealing the activity of the HPA-axis over a longer period of time, and human interactions influence the cortisol level in dogs.

The lifetime experience of traumatic events is associated with hair cortisol concentrations in community-based children

Adversity early in life can disrupt the functioning of the hypothalamic-pituitary-adrenal axis (HPAA) and increase risk for negative health outcomes. Recent research suggests that cortisol in scalp hair represents a promising measure of HPAA function. However, little is known about the relationship between early exposure to traumatic events and hair cortisol concentrations (HCC) in childhood, a critical period of HPAA development. The current study measured HCC in scalp hair samples collected from 70 community-based children (14 males, mean age=9.50) participating in the Imaging Brain Development in the Childhood to Adolescence Transition Study (iCATS). Data were also collected on lifetime exposure to traumatic events and current depressive symptoms. Lifetime exposure to trauma was associated with elevated HCC; however, HCC was not associated with current depressive symptoms. Consistent with some prior work, males were found to have higher HCC than females, although results should be treated with caution due to the small number of males who took part. Our findings suggest that hair cortisol may represent a biomarker of exposure to trauma in this age group; however, further study is necessary with a particular focus on the characterization of trauma and other forms of adversity.

Hair cortisol levels, perceived stress and body mass index in women and children living in socioeconomically disadvantaged neighborhoods: the READI study

Disadvantaged communities provide adverse psychosocial exposures that have been linked to high levels of stress, and this may provide one explanatory pathway linking socioeconomic disadvantage to obesity. This study used hair cortisol analysis to quantify associations between stress and body mass index (BMI), and between hair cortisol and perceived psychological stress levels, in women and children living in socioeconomically disadvantaged neighborhoods. Participants were a volunteer sample of 70 women from the Resilience for Eating and Activity Despite Inequality study, including 30 maternal-child pairs. Women self-reported body weight, height and perceived psychological stress using the Perceived Stress Scale (PSS), and provided hair samples for themselves and their child. Children's body weight and height were measured. Following extraction, hair cortisol levels were measured using enzyme-linked immunosorbent assay. Multiple linear regression models examined associations between stress and BMI, and between hair cortisol and perceived stress levels in women and children. Women's hair cortisol levels were not associated with their BMI or PSS scores. Women's PSS scores were positively associated with their BMI (p = 0.015). Within maternal-child pairs, mothers and children's hair cortisol levels were strongly positively associated (p = 0.006). Maternal hair cortisol levels and PSS scores were unrelated to their child's zBMI. Children's hair cortisol levels were not associated with their zBMI or with their mother's PSS score. Findings suggest that cortisol-based and perceived psychological measures of stress may be distinct among women and children living in disadvantaged neighborhoods. Perceived psychological measures may be more important predictors of weight-related risk.

The relationship between cortisol, stress and psychiatric illness: New insights using hair analysis

BACKGROUND

Stress is an established important contributor to the development of mental illness and stress related disorders. The biology implicated in the homeostasis of pathological stress mechanisms is not fully established. One of the difficulties with current techniques is the limitation in capturing chronic levels of cortisol as an expression of stress levels in humans. Hair samples can be used to evaluate cortisol levels averaged over relatively long periods of time, therefore providing a more valid measure of chronic levels of this hormone. A highly replicable technique to measure long-term cortisol could prove pivotal in improving our understanding of the role of stress in psychiatric disorders.

METHODS

This review synthesises all the published studies relating hair cortisol concentration (HCC) to stress and to psychiatric disorders. It describes and summarises their findings with the aim of providing a summary picture of the current state of this line of research.

RESULTS

The strongest finding to date is the replicable increases in hair cortisol associated with stressful life events. Findings in psychiatric disorders are more sparse and inconsistent. There is some support for the presence of raised HCC in major depressive disorders, and for lowered HCC in posttraumatic stress disorder, suggesting chronic hypercortisolaemia and hypocortisolaemia respectively.

CONCLUSIONS

HCC is a promising methodology to study chronic cortisol levels with the potential to help characterise psychiatric and stress related disorders. The combination of chronic and acute cortisol measurements has the potential for more accurately determining different aspects of the stress response, and ultimately for the development of a biological marker to aid diagnosis and response to treatment.