Assessing cortisol from hair samples in a large observational cohort: The Whitehall II study

Chronic stress, hair cortisol and depression: A prospective and longitudinal study of medical internship

BACKGROUND

Stress plays a causal role in depression onset, perhaps via alteration of hypothalamic-pituitary-adrenal (HPA) axis functioning. HPA axis hyperactivity has been reported in depression, though inconsistently, and the nature of this relationship remains unclear, partly because cortisol measurement over time has been challenging. Development of hair cortisol assessment, a method that captures cortisol over prolonged periods of time, creates new possibilities. In this study, hair cortisol was incorporated into a prospective and longitudinal study of medical internship, stress and symptoms of depression. This provided a rare opportunity to 1) prospectively assess hair cortisol responses to stress, and 2) examine whether stress-induced changes in hair cortisol predict depressive symptom development.

METHODS

Hair cortisol, depressive symptoms, and stress-relevant variables (work hours, sleep, perceived stress, mastery/control) were assessed in interns (n = 74; age 25-33) before and repeatedly throughout medical internship.

RESULTS

Hair cortisol sharply increased with stressor onset, decreased as internship continued, and rose again at year's end. Depressive symptoms rose significantly during internship, but were not predicted by cortisol levels. Hair cortisol also did not correlate with increased stressor demands (work hours, sleep) or stress perceptions (perceived stress, mastery/control); but these variables did predict depressive symptoms.

DISCUSSION

Hair cortisol and depressive responses increased with stress, but they were decoupled, following distinct trajectories that likely reflected different aspects of stress reactivity. While depressive symptoms correlated with stressor demands and stress perceptions, the longitudinal pattern of hair cortisol suggested that it responded to contextual features related to anticipation, novelty/familiarity, and social evaluative threat.

Determinants of hair cortisol concentration in children: A systematic review

BACKGROUND

Several factors are known contribute to hair cortisol concentration (HCC) in adults. However, there is less research on determinants of HCC in children and adolescents. HCC is a valuable tool for medical research pertaining to the hypothalamic-pituitary-adrenal (HPA) axis. This review aims to assess the extent to which established determinants of HCC in adults have been consistently reported in children (birth - 18 years) and to identify determinants of HCC specific to this age group.

METHODS

Eligible studies were identified, selected and appraised as per PRISMA-P guidelines and as detailed in our systematic review protocol, registered on PROSPERO (registration number CRD42017056220). In view of contrasting methods and measures, a meta-analysis could not be done but a qualitative synthesis was performed.

RESULTS

Thirty-six studies were included in the analysis. Higher HCC is associated with male sex and anthropometry, particularly increased body mass index and waist circumference. There is preliminary evidence to suggest that socio-economic status is inversely related to child HCC, particularly with reference to caregiver education and income. Of note, most of the studies analysing socio-economic variables were performed in relatively equal societies. Hair wash frequency and use of hair products and treatments do not affect HCC when proximal segments of hair are used. There is conflicting evidence regarding the relationship between HCC and age in children and adolescents. Further investigation is required to better delineate if and how the following are associated with HCC in children: hair colour, hair type, exposure to trauma and stressors, psychiatric illness, atopic illness, steroid use (including topical and inhaled steroids) and perinatal variables.

CONCLUSIONS

Sex and anthropometry are potential confounders and should be considered for adjustment in hair cortisol research. Hair wash frequency and use of hair products and treatments are not important confounders when proximal hair segments are used. A better understanding of HCC in children in relation to exposure to trauma and stressors is required before it can be used as a biomarker, particularly in terms of vulnerable developmental stages, definition and measurement of stress, and temporal relationship to stressors. Age, SES and other correlates also warrant further investigation.

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.

Conscientiousness, hair cortisol concentration, and health behaviour in older men and women

Conscientious is associated with greater longevity and other favourable health outcomes, but the processes underlying these links are poorly understood. Health behaviours such as physical activity and avoidance of smoking and excessive alcohol consumption may contribute, but direct associations with neuroendocrine and inflammatory processes may also be relevant. We tested the associations between conscientiousness and hair cortisol concentration in 2318 older men and women (mean age 66.2 years) from the English Longitudinal Study of Ageing. Conscientiousness was positively associated with physical activity and fruit and vegetable consumption, and negatively related to alcohol intake, sedentary behaviour, body mass index and depressive symptoms (all p<0.001). We found an inverse association between conscientiousness and hair cortisol concentration that was independent of age, sex, education and wealth (β=-0.053, p=0.012), and the relationship remained significant with additional adjustment for health behaviour and depressive symptoms (β=-0.048, p=0.025). The observation that greater conscientiousness was correlated with lower hair cortisol indicates that this trait might impact central nervous regulation of hypothalamic-pituitary-adrenocortical function, with effects that are possibly advantageous for health.

Hair cortisol levels, psychological stress and psychopathological symptoms as predictors of postpartum depression

Postpartum depression affects a huge number of women and has detrimental consequences. Knowing the factors associated with postpartum depression during pregnancy can help its prevention. Although there is evidence surrounding behavioral or psychological predictors of postpartum depression, there is a lack of evidence of biological forecasters. The aim of this study was to analyze the sociodemographic, obstetric, and psychological variables along with hair cortisol levels during the first, second, and third trimesters of pregnancy that could predict postpartum depression symptoms. A sample of 44 pregnant women was assessed during 3 trimesters of pregnancy and the postpartum period using psychological questionnaires and hair cortisol levels. Participants were divided into 2 groups: a group with postpartum depression symptoms and a group with no postpartum depression symptoms. Results showed significant positive differences between groups in the first trimester regarding the Somatization subscale of the SCL-90-R (p < .05). In the second trimester, significant differences were found in the Somatization, Depression, Anxiety, and GSI subscales (p < .05). In the third trimester significant differences between both groups were found regarding pregnancy-specific stress. We found significant positive differences between groups regarding hair cortisol levels in the first and the third trimester. Hair cortisol levels could predict 21.7% of the variance of postpartum depression symptoms. In conclusion, our study provided evidence that psychopathological symptoms, pregnancy-specific stress, and hair cortisol levels can predict postpartum depression symptoms at different time-points during pregnancy. These findings can be applied in future studies and improve maternal care in clinical settings.

Scalp hair cortisol for diagnosis of Cushing's syndrome

OBJECTIVE

Current first-line screening tests for Cushing's syndrome (CS) only measure time-point or short-term cortisol. Hair cortisol content (HCC) offers a non-invasive way to measure long-term cortisol exposure over several months of time. We aimed to evaluate HCC as a screening tool for CS.

DESIGN

Case-control study in two academic referral centers for CS.

METHODS

Between 2009 and 2016, we collected scalp hair from patients suspected of CS and healthy controls. HCC was measured using ELISA. HCC was available in 43 confirmed CS patients, 35 patients in whom the diagnosis CS was rejected during diagnostic work-up and follow-up (patient controls), and 174 healthy controls. Additionally, we created HCC timelines in two patients with ectopic CS.

RESULTS

CS patients had higher HCC than patient controls and healthy controls (geometric mean 106.9 vs 12.7 and 8.4 pg/mg respectively, P < 0.001). At a cut-off of 31.1 pg/mg, HCC could differentiate between CS patients and healthy controls with a sensitivity of 93% and a specificity of 90%. With patient controls as a reference, specificity remained the same (91%). Within CS patients, HCC correlated significantly with urinary free cortisol (r = 0.691, P < 0.001). In two ectopic CS patients, HCC timelines indicated that cortisol was increased 3 and 6 months before CS became clinically apparent.

CONCLUSIONS

Analysis of cortisol in a single scalp hair sample offers diagnostic accuracy for CS similar to currently used first-line tests, and can be used to investigate cortisol exposure in CS patients months to years back in time, enabling the estimation of disease onset.

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.

Hair dyeing, hair washing and hair cortisol concentrations among women from the healthy start study

BACKGROUND

Hair cortisol concentration (HCC) has been suggested as a promising marker for chronic stress. However, studies investigating the influence of hair dyeing and hair washing frequency on HCC have shown inconsistent results.

OBJECTIVE

To examine associations between HCC and hair dyeing status or weekly hair washing frequency among women.

METHODS

This cross-sectional study was based on data from 266 mothers participating in the Healthy Start intervention study. HCC was measured in the proximal end of the hair (1-2cm closest to the scalp) while hair dyeing status, frequency of hair washing and covariates were reported by the women. Linear regression analyses were applied to assess the associations between HCC and hair dyeing or weekly frequency of hair washing.

RESULTS

No statistically significant difference (p=0.91) in HCC was found between women who dyed hair (adjusted mean: 137pg/mg [95% CI: 122,153]) and women with natural hair color (adjusted mean: 139pg/mg [95% CI: 123,155]). Frequency of hair washing was not associated with HCC (β: -3.7 [95% CI: -9.0, 1.5; P=0.20]).

CONCLUSIONS

This study of 266 Danish women provides no evidence in support of an association between HCC and hair dyeing status or hair washing frequency.

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.