Higher Hair Cortisol Research Articles

Black American Maternal Prenatal Choline, Offspring Gestational Age at Birth, and Developmental Predisposition to Mental Illness.

Black Americans have increased risk for schizophrenia and other mental illnesses with prenatal origins. Prenatal choline promotes infant brain development and behavioral outcomes, but choline has not been specifically assessed in Black Americans. Pregnant women (N = 183, N = 25 Black Americans) enrolled in a study of prenatal stressors and interactions with prenatal choline. Black American women had lower 16-week gestation plasma choline than Whites. Lower choline was not related to obesity, income, or metabolic genotypes. Pregnant women in rural Uganda have higher choline levels than Black American women. Black Americans' lower choline was associated with higher hair cortisol, indicative of higher stress. Lower maternal choline was associated with offsprings' lower gestational age at birth and with decreased auditory P50 inhibition, a marker of inhibitory neuron development. Behavioral development was assessed on the Infant Behavior Questionnaire-R-SF (IBQ-R) at 3 months. Lower Black American maternal gestational choline was associated with lower infant IBQ-R Orienting/Regulation, indicating decreased attention and relation to caregivers. Additional evidence for developmental effects of choline in Black Americans comes from a randomized clinical trial of gestational phosphatidylcholine supplementation versus placebo that included 15 Black Americans. Phosphatidylcholine increased gestational age at birth and newborn P50 inhibition and decreased Social Withdrawn and Attention problems at 40 months of age in Black Americans' offspring compared to placebo. Inhibitory and behavioral deficits associated with lower prenatal choline in offspring of Black American women indicate potential developmental predispositions to later mental illnesses that might be ameliorated by prenatal choline or phosphatidylcholine supplementation.

Stress Reactivity Influences the Relationship between Emotional Labor Strategies and Job Burnouts among Chinese Hospital Nurses.

Extant studies mostly focused on the buffering role of social and external organizational resources and personal mental resources. However, there is no research exploring the moderating role of personal physiological resources (e.g., stress reactivity). The present study is aimed at examining the interactive effect of emotional labor and stress reactivity on job burnout. The present study utilized cortisol content in a 1 cm hair segment as the biomarker of total stress reactivity in one month. The participants were 229 female hospital nurses randomly recruited from city hospitals, China. They self-reported their emotional labor strategies and job burnout syndromes and provided 1 cm hair segments closest to the scalp two weeks later after the survey. Hair cortisol content was determined with high-performance liquid chromatography-tandem mass spectrometry. The results revealed that hair cortisol can moderate the associations of surface acting with emotional exhaustion and personal burnout; of deep acting with emotional exhaustion, depersonalization, and personal burnout; and of expression of naturally felt emotions with professional inefficacy. In particular, nurses with high cortisol levels not only showed higher emotional exhaustion than those with low cortisol levels under high surface acting but also showed lower emotional exhaustion under low surface acting. A similar situation was true for nurses' emotional exhaustion and depersonalization in the context of deep acting. Nurses with low hair cortisol levels not only showed higher professional inefficacy than those with high hair cortisol levels under low expression of naturally felt emotions but also showed lower professional inefficacy under high expression of naturally felt emotions. Additionally, nurses with high hair cortisol levels showed lower personal burnout than those with low hair cortisol levels under low surface acting or high deep acting. In summary, the interaction pattern between stress reactivity and emotional labor was varied with the nature of emotional labor strategy and job burnout.

Hair cortisol concentrations are associated with hippocampal subregional volumes in children

The human hippocampus, a brain structure crucial for memory across the lifespan, is highly sensitive to adverse life events. Stress exposures during childhood have been linked to altered hippocampal structure and memory performance in adulthood. Animal studies suggest that these differences are in part driven by aberrant glucocorticoid secretion during development, with strongest effects on the CA3 region and the dentate gyrus (CA3-DG) of the hippocampus, alongside associated memory impairments. However, only few pediatric studies have examined glucocorticoid associations with hippocampal subfield volumes and their functional relevance. In 84 children (age range: 6–7 years), we assessed whether volumes of hippocampal subregions were related to cumulative glucocorticoid levels (hair cortisol), parenting stress, and performance on memory tasks known to engage the hippocampus. We found that higher hair cortisol levels were specifically related to lower CA3-DG volume. Parenting stress did not significantly correlate with hair cortisol, and there was no evidence to suggest that individual differences in hippocampal subregional volumes manifest in memory performance. Our results suggest that the CA3-DG may be the hippocampal region most closely associated with hair cortisol levels in childhood. Establishing causal pathways underlying this association and its relation to environmental stress and memory development necessitates longitudinal studies.

Prenatal maternal hair cortisol concentrations are related to maternal prenatal emotion dysregulation but not neurodevelopmental or birth outcomes.

Hair cortisol concentrations measured during pregnancy have emerged as a novel biomarker for prenatal stress exposure. However, associations between prenatal stress and distress, broadly defined, and hair cortisol concentrations during pregnancy are inconsistent. We examined relations among hair cortisol concentrations during the third trimester with (a) emotion dysregulation and (b) detailed measures of maternal prenatal stress. We also examined the predictive validity of maternal hair cortisol during pregnancy for adverse newborn health outcomes. Cortisol concentrations were derived from 6cm of hair during the third trimester of pregnancy. Mothers reported on their emotion dysregulation and stress at this time. A standardized newborn neurobehavioral exam was conducted shortly after birth and newborn birth weight and gestational age were assessed from medical records. All hypotheses were preregistered on the Open Science Framework (osf.io/279ng). High levels of emotion dysregulation, but not stress, were predictive of high hair cortisol concentrations. Maternal prenatal BMI mediated the relation between maternal prenatal emotion dysregulation and hair cortisol concentrations. There was no association between hair cortisol and infant birth outcomes. This research supports the notion that transdiagnostic markers of psychopathology are important correlates of hair cortisol concentrations during pregnancy.

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

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. Fifty-five patients aged 16-68years 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. 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. 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.

Higher hair cortisol is associated with reduced cerebral oxygenation in a population-based study of older adults

Higher hair cortisol is associated with reduced cerebral oxygenation in a population-based study of older adults

Socioeconomic Disparities in Chronic Physiologic Stress Are Associated With Brain Structure in Children

BackgroundSocioeconomic factors have been consistently linked with the structure of children’s hippocampus and anterior cingulate cortex (ACC). Chronic stress—as indexed by hair cortisol concentration—may represent an important mechanism underlying these associations. Here, we examined associations between hair cortisol and children’s hippocampal and ACC structure, including across hippocampal subfields, and whether hair cortisol mediated associations between socioeconomic background (family income-to-needs ratio, parental education) and the structure of these brain regions. MethodsParticipants were 5- to 9-year-old children (N = 94; 61% female) from socioeconomically diverse families. Parents and children provided hair samples that were assayed for cortisol. High-resolution, T1-weighted magnetic resonance imaging scans were acquired, and FreeSurfer 6.0 was used to compute hippocampal volume and rostral and caudal ACC thickness and surface area (n = 37 with both child hair cortisol and magnetic resonance imaging data; n = 41 with both parent hair cortisol and magnetic resonance imaging data). ResultsHigher hair cortisol concentration was significantly associated with smaller CA3 and dentate gyrus hippocampal subfield volumes but not with CA1 or subiculum volume. Higher hair cortisol was also associated with greater caudal ACC thickness. Hair cortisol significantly mediated associations between parental education level and CA3 and dentate gyrus volumes; lower parental education level was associated with higher hair cortisol, which in turn was associated with smaller volume in these subfields. ConclusionsThese findings point to chronic physiologic stress as a potential mechanism through which lower parental education level leads to reduced hippocampal volume. Hair cortisol concentration may be an informative biomarker leading to more effective prevention and intervention strategies aimed at childhood socioeconomic disadvantage.

Using Hair Cortisol to Examine the Role of Stress in Children's Health Inequalities at 3 Years

ObjectiveChildren exposed to early adversity (eg, financial hardship, family violence, parent mental health difficulties) are at greater risk of poor health outcomes. Physiological stress is one mechanism thought to explain this pathway. We investigated associations between adversity and young children's health and whether child stress (measured using hair cortisol) mediated these associations. MethodsThis was a cross-sectional study of 3-year-old children whose mothers were recruited during pregnancy, through the right@home trial, for their experience of adversity. Using total counts of 9 sociodemographic and 9 psychosocial indicators of adversity, regression models examined relationships among adversity risk counts, child hair cortisol (potential mediator), and 5 health outcomes: externalizing and internalizing problems, physical and socioemotional wellbeing, and overweight/obesity. ResultsHair cortisol data were available for 297 out of 500 (59%) participating children. When examined separately, sociodemographic adversity risk was associated with higher externalizing problems, and psychosocial adversity risk was associated with higher externalizing problems and poorer physical/socioemotional wellbeing. When examined together in a single model, psychosocial (but not sociodemographic) adversity was associated with higher externalizing problems (unstandardized mean difference [β], 0.53; P = .002) and poorer physical wellbeing (β, 1.19; P = .009); higher hair cortisol was associated with higher externalizing problems (β, 0.76; P = .02). There was no evidence that stress (hair cortisol) mediated associations between adversity and health. ConclusionsIn 3-year-old children, we found no evidence that physiological stress (hair cortisol) mediated associations between adversity risk and children's health. Hair cortisol may be limited as a single measure of stress, or physiological stress may not be a mechanism for explaining the effects of adversity on these young children's health.

Hair Cortisol in Sheltered Cows and Its Association with Other Welfare Indicators.

Simple SummaryHair cortisol concentrations are measured for the assessment of long-term stress in animals. The objective of this study was to assess the levels of stress in retired, abandoned and unproductive cows housed in traditional shelters through the measurement of their hair cortisol levels. The study further aimed to explore the association of the hair cortisol concentrations with other cow and resource-based welfare indicators. High hair cortisol levels were associated with dung lying in the sheds, low dry bulb temperature and shelters having little access to the yards. At the cow level, high hair cortisol levels were associated with injuries on the joints and body, dehydration, old age, and low body hair loss level. The study concluded that hair cortisol is an effective tool to assess stress levels in cows under field conditions.India, the country with the largest population of dairy cows in the world, has a policy of retiring abandoned and non-lactating cows in shelters, but the level of provision for their welfare in these shelters is unclear. Cows in 54 shelters across India were assessed for historic evidence of physiological stress, through determination of hair cortisol in 540 samples from 10 cows in each shelter by enzyme immunoassay. Animal-based and shelter resource-based welfare measures were recorded and correlations with the hair cortisol investigated by multivariable analysis. High hair cortisol concentrations were associated with dung in the lying area of the cowshed, a low dry bulb temperature there and little cow access to yards, as shelter-based variables. At a cow level, high hair cortisol concentrations were associated with dirty flanks, hock joint ulceration, carpal joint injuries, body lesions, dehydration, an empty rumen, old age, and low levels of body hair loss. Hair cortisol level promises to be an effective biomarker of stress in cows when conducting studies under field conditions.

Hair cortisol as a measure of the stress response to social adversity in young children.

Hair cortisol has the potential to provide insight into young children's long-term stress response to social adversity. This study investigated associations between children's exposure to adversity from pregnancy to 2years of age and their hair cortisol at 2years, using a longitudinal cohort of children enriched for adversity risk, whose mothers were recruited during pregnancy through the "right@home" trial. Exposures were 18 maternal socioeconomic and psychosocial indicators of adversity, examined as concurrent, cumulative, and longitudinal exposure from pregnancy to 2years. Hair samples were analyzed from 319/603 (53%) children participating at 2years. Multivariable regression analyses for concurrent exposure showed three indicators of adversity were associated with higher hair cortisol (housing tenure of public rental, paying board or living rent free; not living in a safe place; higher maternal stress symptoms), one with lower hair cortisol (housing problems), and 14 indicators with no evidence of association. There was no evidence of association for the cumulative adversity count. Longitudinal exposure showed "intermittent" and "persistent" high maternal stress symptoms were associated with higher hair cortisol. The small number of associations identified suggests that hair cortisol is limited as a measure of stress response to social adversity in children at 2years.

Verbal and physical client aggression – A longitudinal analysis of professional caregivers’ psychophysiological stress response and burnout

ObjectiveWe investigated the impact of verbal and physical client aggression on risk of developing high hair cortisol concentration (HCC) as an indicator of chronic stress exposure and burnout in a Swiss population of professional caregivers working in youth residential care. MethodParticipants (n = 121; 62.0% women) reported on client aggression and burnout symptoms and provided hair samples at four annual sampling points. HCC was determined in the first 1.5 cm hair segment. Sociodemographic variables, private stressors, burnout symptoms, and HCC were compared between participants reporting either ‘no aggression’, ‘verbal’ aggression, or ‘verbal + physical’ aggression. Cox proportional hazards regressions were calculated to compute hazard ratios (HR) and 95% confidence intervals (CI) for the association between client aggression and risk of high HCC or burnout over the course of three years. ResultsProfessional caregivers reporting ‘verbal + physical’ aggression had higher HCC, more cognitive burnout symptoms, and greater burden in interpersonal domains. Both ‘verbal’ and ‘verbal + physical’ aggression were positively associated with burnout risk (verbal: HR = 1.83; 95% CI = 1.27–2.65; verbal + physical: HR = 2.44, 95% CI = 1.56–3.84). ‘Verbal + physical’ aggression was positively associated with risk of high HCC (HR = 1.58; 95% CI = 1.07–2.36). ConclusionsThis longitudinal analysis suggested that psychophysiological stress response is primarily associated with combined verbal and physical aggression. The emotional wearing-down associated with verbal aggression should however not be disregarded. Our exploratory findings could have implications for youth welfare policy, clinical child psychiatry, and future research.

High hair cortisol concentrations predict worse cognitive outcome after stroke: Results from the TABASCO prospective cohort study

Background and purposeThe role of stress-related endocrine dysregulation in the development of cognitive changes following a stroke needs further elucidation. We explored this issue in a longitudinal study on stroke survivors using hair cortisol concentrations (HCC), a measure of integrated long-term cortisol levels. MethodsParticipants were consecutive cognitively intact first-ever mild-moderate ischemic stroke/transient ischemic attack (TIA) survivors from the Tel Aviv Brain Acute Stroke Cohort (TABASCO) study. They underwent 3T magnetic resonance imaging (MRI) scanning and were cognitively assessed at admission, and at 6, 12 and 24 months post-stroke. Scalp hair samples were obtained during the initial hospitalization. ResultsFull data on baseline HCC, MRI scans and 2 years neuropsychological assessments were available for 65 patients. Higher HCC were significantly associated with a larger lesion volume and with worse cognitive results 6, 12 and 24 months post-stroke on most of the neurocognitive tests. 15.4% of the participants went on to develop clinically significant cognitive decline in the follow-up period, and higher HCC at baseline were found to be a significant risk factor for this decline, after adjustment for age, gender, body mass index and APOE e4 carrier status (HR=6.553, p=0.038). ConclusionsOur findings suggest that individuals with higher HCC, which probably reflect higher long-term cortisol release, are prone to develop cognitive decline following an acute stroke or TIA.

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.

Cortisol dysregulation is associated with daily diary-reported hot flashes among midlife women.

Hot flashes are reported by 70-80% of women during the menopause transition. It has been proposed that cortisol dysregulation is involved in hot flashes, but the relationship between cortisol and hot flashes has received little empirical attention. This study examined the relationship between cortisol and daily self-reported hot flashes. For 7 days, participants used electronic diaries to report their hot flash frequency, severity and bothersomeness, along with mood and health behaviours, multiple times each day. Participants also provided hair samples for cortisol assays at baseline and morning and bedtime saliva samples for salivary cortisol collection over 3 days during the observation period. Hierarchical linear regression was used to examine the relationships between cortisol and hot flashes. Forty-four women (41% African American, 39% non-Hispanic White) who reported daily hot flashes were enrolled. Salivary cortisol, hair cortisol and the frequency, severity and bothersomeness of daily diary-reported hot flashes were measured in this study. Controlling for health and demographic variables, higher hair cortisol was associated with a higher frequency of hot flashes (β = 0·05, P = 0·01). A flatter diurnal cortisol slope was associated with greater hot flash severity (β = 0·09, P = 0·03) and bother (β = 0·10, P = 0·01). Hair cortisol was no longer significant after adjusting for depression or disturbed sleep; all other associations persisted. Cortisol dysregulation was related to more frequent, severe and bothersome daily self-reported hot flashes. These findings support a potential role of the HPA axis in the aetiology and phenomenology of these common menopause symptoms.

Splitting hair for cortisol? Associations of socio-economic status, ethnicity, hair color, gender and other child characteristics with hair cortisol and cortisone

The aim of this study was to examine associations of SES and ethnicity with hair cortisol and cortisone and to identify potential child and family characteristics that can assist in choosing covariates and potential confounders for analyses involving hair cortisol and cortisone concentrations. Hair samples were collected in 2484 6-year-old children from the Generation R Study, a prospective cohort in Rotterdam, the Netherlands. Measurements for cortisol and cortisone were used as the outcome in regression analyses. Predictors were SES, ethnicity, hair color and child characteristics such as birthweight, gestational age at birth, BMI, disease, allergy, and medication use. Lower family income, more children to be supported by this income, higher BMI and darker hair color were associated with higher hair cortisol and cortisone levels. Boys also showed higher levels. Ethnicity (Dutch and North European descent) was related to lower levels. High amounts of sun in the month of hair collection was related to higher levels of cortisone only. More recent hair washing was related to lower levels of cortisol and cortisone. Gestational age at birth, birth weight, age, medication use, hair washing frequency, educational level of the mother, marital status of the mother, disease and allergy were not associated with cortisol or cortisone levels. Our results serve as a starting point for choosing covariates and confounders in studies of substantive predictors or outcomes. Gender, BMI, income, the number of persons in a household, ethnicity, hair color and recency of hair washing are strongly suggested to take into account.

Hair cortisol and cortisol awakening response are associated with criteria of the metabolic syndrome in opposite directions.

Findings on the association between hypothalamic-pituitary-adrenal (HPA) axis activity and metabolic risk are equivocal. Different methods of measuring HPA activity might indicate adverse vs. beneficial effects of HPA activity on metabolic risk thus contributing to heterogenous findings. In this study, we aimed to determine whether (1) the salivary cortisol awakening response (CAR) as a marker of awakening-induced activation of the HPA axis and (2) hair cortisol as a marker of long-term cortisol secretion are associated with criteria of the metabolic syndrome. Therefore, we recruited 41 healthy individuals (26 women, mean age: 41.2 years) and 44 patients with major depression (28 women, 41.4 years) and assessed CAR and hair cortisol values as well as all criteria of the metabolic syndrome (abdominal obesity, blood pressure, plasma glucose, triglycerides and high-density cholesterol levels) according to the International Diabetes Federation. CAR and hair cortisol values were divided into tertiles. Across groups, participants with hair cortisol or hair cortisone in the highest tertile showed significantly more criteria of the metabolic syndrome compared to participants in the medium or low tertile (F2,64=3.37, p=.04). These results were corroborated by significant positive correlations between mean hair cortisol values with waist circumference (r=.29, p=.03), triglycerides (r=.34, p=.01) and systolic blood pressure (r=.29, p=.04) and between mean hair cortisone and triglycerides (r=.46, p<.01). In contrast, mean CAR values correlated negatively with diastolic (r=-.29, p=.03) and systolic blood pressure (r=-.32, p=.02). Our results indicate that higher hair cortisol and hair cortisone levels but lower CAR values are associated with an unfavorable metabolic and cardiovascular risk profile.

Hair Cortisol Measurement in Mitotane-Treated Adrenocortical Cancer Patients

The only approved drug for the treatment of adrenocortical cancer (ACC) is mitotane. Mitotane is adrenolytic and therefore, hydrocortisone replacement therapy is necessary. Since mitotane increases cortisol binding globulin (CBG) and induces CYP3A4 activity, high doses of hydrocortisone are thought to be required. Evaluation of hydrocortisone therapy in mitotane-treated patients has been difficult since there is no good marker to evaluate hydrocortisone therapy. Measurement of cortisol in scalp hair is a novel method that offers the opportunity to measure long-term cortisol levels. Our aim was to evaluate whether hair cortisol measurements could be useful in evaluating recent hydrocortisone treatment in mitotane-treated ACC patients. Hair cortisol levels were measured in 15 mitotane-treated ACC patients on hydrocortisone substitution and 96 healthy individuals. Cortisol levels were measured in 3 cm hair segments, corresponding to a period of 3 months. Hair cortisol levels were higher in ACC patients compared to healthy individuals (p<0.0001). Seven ACC patients (47%) had hair cortisol levels above the reference range. None of the patients had hair cortisol levels below normal. In contrast to hydrocortisone doses (β=0.03, p=0.93), hair cortisol levels were associated with BMI (β=0.53, p=0.042). There was no correlation between hair cortisol levels and hydrocortisone doses (β=0.41, p=0.13). Almost half of the ACC patients had high hair cortisol levels, suggesting long-term over-substitution of hydrocortisone in some of the patients, whereas none of the patients was under-substituted. Hair cortisol measurements might be useful in long-term monitoring hydrocortisone treatment in mitotane-treated ACC patients.

EPA-1041 – Hair cortisol analysis in patients with bipolar disorder: towards a new endophenotype?

Introduction Dysregulation of the hypothalamic-pituitary-adrenal (HPA-)axis is hypothesized to play a role in the pathogenesis of bipolar disorder (BD). Conflicting results have been reported when saliva or serum was used to measure cortisol levels. A recently developed method is to measure cortisol in scalp hair, with one cm of scalp hair representing one month. We studied whether there are differences in long-term hair cortisol levels between BD patients and healthy individuals and whether there are associations between hair cortisol, life events and disease characteristics. Methods Hair samples were collected in 100 BD patients and 195 healthy controls. Long-term cortisol levels were determined in 3 cm hair segments. Saliva samples were collected on two consecutive evenings. Documented disease characteristics were disease state, age of onset, psychiatric co-morbidity, and life events. Results Hair cortisol levels were not statistically different in BD patients compared to healthy controls (p=0.233) and were not associated with the disease state at the moment of sample collection (p=0.978). Clinical characteristics, such as age of onset ≥30 years (p=0.004) and psychiatric co-morbidity (44.87 versus 31.41 pg/mg hair; p=.021), appeared to associate with higher hair cortisol levels. Panic disorder associated with decreased cortisol levels (22.13 versus 34.67 pg/mg hair; p=0.019). The occurrence of recent negative major life events, but not of positive major life events, was associated with an increase in HCC in BD patients.

High Long-Term Cortisol Levels, Measured in Scalp Hair, Are Associated With a History of Cardiovascular Disease

Stress is associated with an increased incidence of cardiovascular disease. The impact of chronic stress on cardiovascular risk has been studied by measuring cortisol in serum and saliva, which are measurements of only 1 time point. These studies yielded inconclusive results. The measurement of cortisol in scalp hair is a novel method that provides the opportunity to measure long-term cortisol exposure. Our aim was to study whether long-term cortisol levels, measured in scalp hair, are associated with cardiovascular diseases. A group of 283 community-dwelling elderly participants were randomly selected from a large population-based cohort study (median age, 75 y; range, 65-85 y). Cortisol was measured in 3-cm hair segments, corresponding roughly with a period of 3 months. Self-reported data concerning coronary heart disease, stroke, peripheral arterial disease, diabetes mellitus, and other chronic noncardiovascular diseases were collected. Hair cortisol levels were significantly lower in women than in men (21.0 vs 26.3 pg/mg hair; P < .001). High hair cortisol levels were associated with an increased cardiovascular risk (odds ratio, 2.7; P = .01) and an increased risk of type 2 diabetes mellitus (odds ratio, 3.2; P = .04). There were no associations between hair cortisol levels and noncardiovascular diseases. Elevated long-term cortisol levels are associated with a history of cardiovascular disease. The increased cardiovascular risk we found is equivalent to the effect of traditional cardiovascular risk factors, suggesting that long-term elevated cortisol may be an important cardiovascular risk factor.

A novelty seeking phenotype is related to chronic hypothalamic-pituitary-adrenal activity reflected by hair cortisol

Reduced hypothalamic pituitary adrenal (HPA) activity is associated with greater novelty seeking in humans. Hair cortisol represents an integrated proxy measure of total cortisol production/release over an extended period of time and may be a valuable tool for tracking the HPA system. Sampling approaches (collection of blood, saliva, urine, or feces) for socially housed nonhuman primates present a number of technical challenges for collection particularly when repeated sampling is necessary. Herein we describe a relationship between cortisol levels measured in hair collected from 230 socially housed female vervet ( Chlorocebus aethiops sabaeus) monkeys and a free-choice novelty seeking phenotype. A predator-like object was placed at the periphery of the outdoor enclosures for 30 min and speed of approach (latency to approach within 1 m) and persistence of interest (number of 1 min intervals within 1 m) were scored. A composite Novelty Seeking score, combining these two measures, was calculated. The intra-class correlation coefficient (ICC = .68) for two different objects across years indicated that this score reflects a stable aspect of temperament. Hair samples were collected from each subject approximately 3–6 months following the second assessment; cortisol levels were determined from the hair. A significant inverse relationship of Novelty Seeking score with hair cortisol level (p < .01) was noted. The high hair cortisol groups had significantly lower Novelty Seeking scores than the low cortisol groups both years (p's < .05). These results suggest that low average cortisol levels promote novelty seeking, while high average levels inhibit novelty seeking behavior.