Sex differences in cortisol levels in depression: A systematic review and meta-analysis.

Higher prevalence of depression in females might be associated with sex-specific cortisol levels. Evidence exists that cortisol levels differ between healthy females and males, however a sex-specific association in depression has not been systematically assessed. Thus, the current study quantifies the existing literature on different cortisol parameters, i.e., basal cortisol, hair cortisol, cortisol awakening response (CAR), and cortisol stress reactivity comparing depressed females and males as well as sex-specific comparisons with healthy controls. Following an extensive literature research, fifty original articles were included. Depressed females had significantly higher hair cortisol, higher CAR, and lower cortisol stress reactivity compared to depressed males. In comparison with sex-matched controls, female patients had significantly higher evening basal cortisol, higher CAR and lower cortisol stress reactivity, and male patients had significantly higher general, morning and evening basal cortisol. Overall, sex as a fundamental driver of cortisol levels in depression needs to be taken into account.

Prospective associations of technostress at work, burnout symptoms, hair cortisol, and chronic low-grade inflammation.

BACKGROUND: Working conditions in the age of digitalization harbor risks for chronic stress and burnout. However, real-world investigations into biological effects of technostress, that is stress in the context of digital technology use, are sparse. This study prospectively assessed associations between technostress, general work stress, burnout symptoms, hair cortisol, and chronic low-grade inflammation. METHODS: Hospital employees (N = 238, 182 females, Mage = 28.5 years) participated in a prospective cohort study with two follow-ups six months apart (T2, T3). Participants answered standardized questionnaires on general job strain (job demand-control ratio), technostressors (work interruptions, multitasking, information overload), burnout symptoms (exhaustion, mental distance), and relevant confounders. Moreover, they provided capillary blood samples for C-reactive protein (CRP) and hair strands for hair cortisol concentration (HCC) analysis. Structural equation modelling was performed. RESULTS: The factorial structure of survey measures was confirmed. Burnout symptoms (MT2 = 2.17, MT3 = 2.33) and HCC (MT2 = 4.79, MT3 = 9.56; pg/mg) increased over time, CRP did not (MT2 = 1.15, MT3 = 1.21; mg/L). Adjusted path models showed that technostress was negatively associated with HCC (ß = -0.16, p =.003), but not with burnout and CRP. General work stress in contrast, was not significantly associated with burnout, HCC or CRP. Furthermore, there were reciprocal effects of CRP on HCC (ß = 0.28, p =.001) and of HCC on CRP (ß = -0.10, p ≤.001). Associations were robust in additional analyses including further confounders. CONCLUSION: This is the first study on prospective effects of technostress on employees' endocrine and inflammatory systems. Results suggest differential effects of technostress on the hypothalamic-pituitary-adrenocortical axis activity. Given its key role for long-term health, the findings have important implications for occupational health and safety in digitalized work environments.

Hair cortisol determinants in 11-year-old children: Environmental, social and individual factors.

INTRODUCTION: Children's exposure to chronic stress is associated with several health problems. Measuring hair cortisol concentration is particularly useful for studying chronic stress but much is unknown about hair cortisol determinants in children and adolescents, and previous research has often not considered the simultaneous exposure of multiple variables. This research is focused on investigating the relationship between environmental, social and individual factors with hair cortisol concentration in children. METHODS: The data used in this study are from the INMA prospective epidemiological cohort study. The assessment of chronic stress was made on the basis of hair samples taken at the age of 11 years in the INMA-Gipuzkoa cohort (n = 346). A metamodel summarizing the hypothesized relationships among environmental, social and individual factors and hair cortisol concentration was constructed based on previous literature. Structural Equation Modelling was performed to examine the relationships among the variables. RESULTS: In the general model higher behavioural problems were associated with higher cortisol levels and an inverse relationship between environmental noise and cortisol levels was observed, explaining 5 % of the variance in HCC. Once stratified by sex these associations were only hold in boys, while no significant effect of any of the study variables was related with cortisol levels in girls. Importantly, maternal stress was positively related to behavioural difficulties in children. Finally, higher traffic-related air pollution and lower exposure to neighborhood greenness were related to higher environmental noise. DISCUSSION: This study highlights that simultaneous exposure to different environmental, social and individual characteristics may determine the concentration of hair cortisol. More research is needed and future studies should include this complex view to better understanding of hair cortisol determinants in children.

Hair cortisol and dehydroepiandrosterone and their associations with optimism and pessimism in older people.

The cumulative negative effects of prolonged Hypothalamic-Pituitary-Adrenal axis (HPA axis) activation are associated with several age-related diseases. Some psychological traits such as optimism and pessimism have been shown to be related to both health and the stress response, although their relationship with the HPA axis is inconclusive. More stable HPA axis biomarkers, such as hair samples of cortisol (HC) and dehydroepiandrosterone (HDHEA), would help to clarify the association between these psychological traits and HPA axis functioning. The main aim of this study was to test the relationships between optimism and pessimism and chronic stress biomarkers measured in hair (HC and HDHEA). Additionally, a secondary objective was to explore sex differences in HC and HDHEA levels and their relationship with these psychological traits. We measured optimism, pessimism, and their combination (dispositional optimism) using the Life Orientation Test Revised (LOT-R) and chronic stress biomarkers (HC and HDHEA) in 119 healthy participants (46 men and 73 women) between 56 and 81 years old who belonged to a university program. Regression analyses controlling for perceived stress and BMI indicated that higher dispositional optimism was related to lower HC and HC:HDHEAratio (ß = -0.256, p = .008 and ß = -0.300, p = .002, respectively). More specifically, higher pessimism was related to higher HC (ß = 0.235; p = .012) and HC:HDHEAratio (ß = 0.240; p = .011), whereas higher optimism was associated with a lower HC:HDHEAratio(ß = -0.205; p = .031). Moderation analyses showed no sex differences. To date, this is the first study to investigate the link between these traits and HC and HDHEA in older people. Our results confirm that positive and negative expectations about the future (i.e. optimism and pessimism) may play an important role in health due to their relationship with the HPA axis. They also strengthen the idea that the negative effects of pessimism have a greater weight than the protective effects of optimism in their relationship with HPA axis regulation.

Long-term stress exposure, cortisol level and cardiovascular activity and reactivity: Observations in patients with fibromyalgia.

Previous research suggested that exposure to long-lasting or repeated laboratory stressors may lead to rearrangement of cardiovascular control, with a shift of regulation mechanisms from dominant cardiac to dominant vascular influences between the early and late response phases, respectively. This study investigated whether similar rearrangement occurs during life stress accompanying chronic disease by analyzing also associations between cortisol level and cardiovascular variables in patients with fibromyalgia (FM). In 47 women with FM and 36 healthy women (HW), cardiovascular recordings were taken during active body posture changes (sitting, lying down, and standing). Moreover, hair cortisol concentration (HCC) was obtained. During standing, which involved orthostatic challenge, FM patients showed higher total peripheral resistance (TPR) but lower stroke volume (SV), cardiac output (CO), and baroreflex sensitivity than HW. During sitting and lying down, TPR was more closely associated with blood pressure (BP) than CO in FM patients; in contrast, CO was more closely associated with BP than TPR in HW. HCC correlated positively with TPR and BP in FM patients, but negatively with TPR and BP and positively with SV and CO in HW. Results suggest that chronic disease-related stress is associated with alterations in cardiovascular regulation toward greater involvement of vascular than cardiac mechanisms in BP control. Stress-related cortisol release may contribute to the long-term rearrangement of autonomic regulation. At the behavioral level, the dominance of vascular over cardiovascular control may relate to reduced somatic mobilization during an active fight-flight response in favor of passive and behaviorally immobile coping.

Hair cortisol and self-perceived stress in adolescents with multi-system functional somatic disorders.

BACKGROUND: Long-term stress causing altered hypothalamic-pituitary-adrenal (HPA) axis dynamics with cortisol dysfunction may be involved in the pathophysiology of functional somatic disorders (FSD), but studies on adolescents with multi-system FSD are lacking. Therefore, we investigated: 1) whether hair cortisol concentration (HCC) differentiates adolescents with multi-system FSD from a) a population-based sample and b) a subgroup derived from the sample reporting a high physical symptom load, and 2) whether FSD population HCC is associated with primary symptom presentations and self-perceived stress. METHODS: We used data from a clinical sample with multi-system FSD (N = 91, age 15-19 years) and a population-based sample (N = 1,450, age 16-17 years) including a subgroup with top 10% total scores on physical symptoms (N = 147). Density plots and multiple linear regression were applied to compare HCC between groups. In the clinical sample, multiple linear regression was employed to assess the association between HCC and primary symptom clusters and self-perceived stress. RESULTS: Median HCC was lower in the clinical sample than in the population-based sample (ß = 0.80 (95%CI: 0.66, 0.97)), but not significantly different from median HCC in the derived subgroup (ß = 0.84 (95%CI: 0.66, 1.07)). In the clinical sample, HCC was not significantly associated with primary symptom clusters (F(2, 82) = 0.13, p = 0.88) or self-perceived stress (F(4, 83) = 1.18, p = 0.33). CONCLUSION: Our findings indicate that HCC is lowered in adolescents with multi-system FSD but not significantly associated with primary symptom presentations or self-perceived stress. Future studies including multiple measures of HPA axis dynamics alongside psychological measures may further elucidate the role of long-term stress in FSD. TRIAL REGISTRATION: The AHEAD study was pre-registered at ClinicalTrials.gov (NCT02346071), 26/01/2015.

Hair cortisol concentrations in pregnant women with bipolar, depressive, or schizophrenic spectrum disorders.

PURPOSE: Maternal cortisol levels in pregnancy may support the growth of or adversely affect fetal organs, including the brain. While moderate cortisol levels are essential for fetal development, excessive or prolonged elevations may have negative health consequences for both the mother and the offspring. Little is known about predictors of altered hypothalamic-pituitary-adrenal (HPA) axis activity during pregnancy. This study examined maternal hair cortisol concentration (HCC) in the 3rd trimester of pregnancy in relation to severe psychopathology. METHODS: Hair samples were collected from 69 women, 32 with a lifetime diagnosis of severe mental disorders (bipolar I or II disorder, moderate or severe depressive disorder, schizophrenic spectrum disorder), and 37 non-clinical controls. Hair samples were collected during the 3rd trimester, and liquid chromatography tandem mass spectrometry was used for cortisol assessment. Psychiatric diagnosis and current level of symptomatic functioning were assessed using the structured clinical interview from the DSM-5 and the global assessment of functioning scale. RESULTS: Women with a lifetime diagnosis of severe mental illness had significantly elevated HCC compared to controls. Poorer current symptomatic functioning was also significantly associated with elevated HCC in pregnancy. CONCLUSIONS: The implications of alterations in HCC on both maternal and infant health need further study.

Over-commitment positively predicts hair cortisol concentrations only in nurses with high need for recovery.

PURPOSE: In the contemporary workplace, enduring fatigue has become a standard for employees. This investigation assesses whether such working conditions exacerbate the depletion of employees' personal resources. The need for recovery serves as an indicator of the necessity to mitigate post-work fatigue. A high need for recovery signifies that employees must commence a new workday while already fatigued. METHODS: This research recruited two cohorts of nurses, categorized by a high need for recovery and a low need for recovery, to examine the correlation between work effort and hair cortisol concentrations in each group. RESULTS: Hair cortisol concentrations serve as a biological marker of cumulative cortisol secretion over a specific time frame, reflecting overall personal resource expenditure during this interval. Findings revealed a notable positive correlation between intrinsic work effort (over-commitment) and hair cortisol levels exclusively among nurses with a high need for recovery. CONCLUSION: These outcomes imply that active effort amidst fatigue may lead to excessive strain. This insight enriches the classic 'effort-recovery' model by illustrating how an employee' s personal volition can influence the accumulation of fatigue.

Sense of coherence, mental health, and hair cortisol concentrations among older people during the COVID -19 pandemic: a cross-sectional study.

BACKGROUND: A person's sense of coherence (SoC) is likely to affect coping when exposed to a life changing event like the COVID -19 pandemic, which impacted the older population especially hard, an age group that already suffers from a lot of mental illness. Thus, the aim of this study was to investigate the associations between SoC and mental health in older adults using both screening scales and hair cortisol concentrations (HCC). METHOD: A cross-sectional design studying a cohort of 70-80 years old, N = 260, set in Swedish primary care during the pandemic years 2021-2022. Instruments used are sense of coherence 13 (SoC-13), EQ-5D-3L, Geriatric depression scale 20 (GDS-20), Hospital anxiety and depression scale (HADS), and Perceived stress scale 10 (PSS-10). Sociodemography and factors concerning SoC, and mental health are explored. HCC are measured using radioimmunoassay. Outcome measures are factors independently associated with SoC. Linear regression models were performed with SoC as dependent variable, and priory path analyses explored whether associations with SoC were direct, or indirect via anxiety. RESULTS: SoC was significantly associated with anxiety (p < 0.001), perceived economic status (p = 0.003), belief in the future (p = 0.001), and perceived negative mental effect from the COVID -19 pandemic (p = 0.002). The latter was 96% indirectly associated with SoC (p < 0.001), whereas perceived economic status together with belief in the future was 82% directly associated with SoC (p = 0.17). HCC and sex were not significantly associated with SoC, but, noticeably, high HCC was equally distributed between women and men. Women reported significantly lower quality of life (p = 0.03), and more symptoms of anxiety (p = 0.001) and depression (p < 0.001). CONCLUSION: Anxiety, belief in the future, perceived negative effect on mental health due to the pandemic, and perceived economic status were significantly associated with SoC. Anxiety is suggested to be important in explaining the association between perceived negative mental effect from the COVID-19 pandemic and SoC. Women reported significantly poorer mental health and life quality than men.

Associations between adversity in the family of origin and hair cortisol concentration in adulthood.

The current study examined associations between parental adversities as experienced in adolescence and hair cortisol concentration (HCC) 26 years later (n = 47). Specifically, bivariate correlations and linear regressions were used to examine harsh parenting as well as parental economic pressure, emotional distress, and body mass index (BMI) when their adolescent was between 15 and 16 years old (parent average age 43). HCC was measured when the adolescent was an adult (average 42 years old), at a similar age to when their parent(s) first participated in the study. We also assessed their economic pressure, emotional distress, obesity, and perceived stress in adulthood. For results across generations, parental economic pressure experienced during adolescence was significantly related to HCC when these adolescents were adults. None of the adult economic pressure, emotional distress, BMI, and perceived stress variables were associated with their HCC. Interestingly, there were significant associations among adult perceived stress, economic pressure, emotional distress, and obesity. Thus, the association between parental economic pressure and adult HCC is independent of adult adversities. Results highlight early economic adversity as a possible childhood stressor that has implications throughout the life course.

Associations of Household and Neighborhood Contexts and Hair Cortisol Among Mexican-Origin Adolescents From Low-Income Immigrant Families.

Although neighborhood contexts serve as upstream determinants of health, it remains unclear how these contexts "get under the skin" of Mexican-origin youth, who are disproportionately concentrated in highly disadvantaged yet co-ethnic neighborhoods. The current study examines the associations between household and neighborhood socioeconomic status (SES), neighborhood racial-ethnic and immigrant composition, and hair cortisol concentration (HCC)-a physiological index of chronic stress response-among Mexican-origin adolescents from low-income immigrant families in the United States. A total of 297 (54.20% female; mage = 17.61, SD = 0.93) Mexican-origin adolescents had their hair cortisol collected, and their residential addresses were geocoded and merged with the American Community Survey. Neighborhoods with higher Hispanic-origin and foreign-born residents were associated with higher neighborhood disadvantage, whereas neighborhoods with higher non-Hispanic White and domestic-born residents were associated with higher neighborhood affluence. Mexican-origin adolescents living in neighborhoods with a higher proportion of Hispanic-origin residents showed lower levels of HCC, consistent with the role of the ethnic enclave. In contrast, adolescents living in more affluent neighborhoods showed higher levels of HCC, possibly reflecting a physiological toll. No association was found between household SES and HCC. Our findings underscore the importance of taking sociocultural contexts and person-environment fit into consideration when understanding how neighborhoods influence adolescents' stress physiology.

Differences in Physicians' Ratings of Work Stressors and Resources Associated With Digital Transformation: Cross-Sectional Study.

BACKGROUND: The emergence of the COVID-19 pandemic rapidly accelerated the need and implementation of digital innovations, especially in medicine. OBJECTIVE: To gain a better understanding of the stress associated with digital transformation in physicians, this study aims to identify working conditions that are stress relevant for physicians and differ in dependence on digital transformation. In addition, we examined the potential role of individual characteristics (ie, age, gender, and actual implementation of a digital innovation within the last 3 years) in digitalization-associated differences in these working conditions. METHODS: Cross-sectional web-based questionnaire data of 268 physicians (mean age 40.9, SD 12.3 y; n=150, 56% women) in Germany were analyzed. Physicians rated their chronic stress level and 11 relevant working conditions (ie, work stressors such as time pressure and work resources such as influence on sequence) both before and after either a fictional or real implementation of a relevant digital transformation at their workplace. In addition, a subsample of individuals (60; n=33, 55% women) submitted self-collected hair samples for cortisol analysis. RESULTS: The stress relevance of the selected working conditions was confirmed by significant correlations with self-rated chronic stress and hair cortisol levels (hair F) within the sample, all of them in the expected direction (P values between .01 and <.001). Multilevel modeling revealed significant differences associated with digital transformation in the rating of 8 (73%) out of 11 working conditions. More precisely, digital transformation was associated with potentially stress-enhancing effects in 6 working conditions (ie, influence on procedures and complexity of tasks) and stress-reducing effects in 2 other working conditions (ie, perceived workload and time pressure). Younger individuals, women, and individuals whose workplaces have implemented digital innovations tended to perceive digitalization-related differences in working conditions as rather stress-reducing. CONCLUSIONS: Our study lays the foundation for future hypothesis-based longitudinal research by identifying those working conditions that are stress relevant for physicians and prone to differ as a function of digital transformation and individual characteristics.

Maternal early life and prenatal stress in relation to birth outcomes in Argentinian mothers.

Environmental influences before and during pregnancy significantly impact offspring development. This study investigates open research questions regarding the associations between maternal early life stress (ELS), prenatal psychosocial stress, prenatal hair cortisol (HC), and birth outcomes in Argentinian women. Data on ELS, prenatal life events, HC (two samples representing first and second half of pregnancy), and birth outcomes were collected from middle-class Argentinian women (N = 69) upon delivery. Linear mixed models indicated that HC increased from the first half to the second half of pregnancy with considerable variability in the starting values and slopes between individuals. Mothers who experienced more ELS, were taller, or more educated, tended to show lower increases in HC. Older age was positively related to HC increases. Our data did not suggest an interaction between ELS and prenatal life events in relation to HC. We found that the change in HC was most likely negatively associated with birth weight. Our data are most compatible with either a weak or the absence of an association between ELS or prenatal life events and absolute values of HC. Mothers with stronger increases in hair cortisol tended to have newborns with slightly lower birth weight. Hence, ELS and birthweight may either have been related to changes in cortisol exposure during pregnancy or to factors that influence accumulation or retention of cortisol in hair.

Association between maltreatment, hair cortisol concentration, positive parent-child interaction, and psychosocial outcomes in Chinese preschool children.

Children now are facing an increasing risk of early life stress (ELS), which leads to detrimental psychosocial outcomes. Behavior studies suggested that positive parental interactions might moderate the negative impact of ELS, but the related biological alteration remains unclear. This study aims to investigate whether positive parent-child interactions moderate the association between maltreatment (as a severe form of ELS) and hair cortisol concentration (HCC), as well as between HCC and psychosocial outcomes in young children. Participants were 6-year-old Chinese children (N = 257, Mage = 6.2, 121 were male) selected by stratified cluster random sampling from a Shanghai population representative cohort. Proximal 3 cm hair strands were analyzed using liquid chromatography coupled with tandem mass spectrometry for HCC. Children's psychosocial outcome was evaluated using the parental report Strengths and Difficulties Questionnaire (SDQ). Parents also reported the frequency of positive parent-child interactions using the Chinese Parent-Child Interaction Scale (CPCIS) as well as the history of maltreatment. Multi-level logistic regression models adjusting for individual, kindergarten, and district confounders were used to evaluate the associations between maltreatment, HCC, and psychosocial outcomes. Interactions terms tested whether more frequent positive parent-child interactions moderates the association between maltreatment and HCC, as well as between HCC and psychosocial outcomes. Maltreated children exhibited higher levels of HCC (B = 1.20, 95% CI: 0.38,2.02; p = 0.004), and children with higher HCC exhibited poorer psychosocial outcomes (B = 0.34, 95% CI: 0.18,0.51; p < 0.001). Positive parent-child interactions did not have a moderating effect on the association between maltreatment and HCC, but they demonstrated a moderating effect on the association between increased HCC and psychosocial outcomes (interaction term: B = -0.42, 95% CI: -0.75,-0.10; p = 0.01). These findings provide evidence that positive parental interaction may serve as a moderator between chronic cortisol exposure and psychosocial problems. It highlights the importance of frequent parent-child interactions, especially among children under a high risk of ELS.

Perceived stress and hair cortisol levels amongst conscripts during basic military training: A repeated measures study.

The aim was to examine hair cortisol levels and self-reported stress amongst conscripts during their basic military training, and how they are related to four types of theory-derived determinants. The following prediction was made: lower levels of perceived stress and hair cortisol will be associated with: (1) higher levels of emotional stability (the individual nonmilitary aspect); (2) a lower degree of private life problems (the contextual nonmilitary aspect); (3) more positive attitudes toward the military, higher engagement in military service, and higher adaptability to military conditions (the individual-military aspect); and (4) stronger group cohesion and better leadership (the contextual-military aspect). The sample consisted of a total of 107 male Lithuanian conscripts. Assessments were made at the beginning of their basic military training, in the middle, and at the end. Established instruments were used on all self-reported scales. Hair cortisol levels were established through analyses of hair samples. Low to moderate levels of stress were found throughout the basic training period regarding perceived stress levels. Hair cortisol levels were mainly unrelated to the self-rating scales. Regarding perceived stress, the prediction was fully confirmed. The future value of the theoretical model is discussed.

Hair cortisol concentrations are associated with greater adiposity in late adolescence amongst non-Hispanic White individuals.

INTRODUCTION: Hair cortisol concentration (HCC) is a biomarker of long-term stress. Higher HCC is associated with higher adiposity in adults; however, associations are not well characterized in adolescents. OBJECTIVE: To examine cross-sectional associations of HCC with adiposity in late adolescence. METHODS: Amongst 336 non-Hispanic White participants (48.5% female, mean 17.7 years) in Project Viva, we used multivariable linear regression models, overall and sex-stratified, to estimate associations of HCC with body mass index (BMI), bioelectric impedance (BIA) percent body fat, waist circumference (WC) and dual X-ray absorptiometry-measured percent and total fat or trunk fat mass. We adjusted models for age and known predictors of adiposity. RESULTS: Median (interquartile range) HCC was 2.1 pm/mg (1.0-4.5) and mean (SD) BMI was 23.1 kg/m2 (3.9), BIA %body fat 20.2% (9.9) and WC 80.6 cm (10.9). In adjusted models, higher HCC (per doubling) was associated with higher BMI (ß = 0.19 kg/m2; 95%CI 0.00, 0.37) and BIA percent body fat (ß = 0.41%; 95%CI 0.04, 0.77). We observed no evidence of effect modification by sex. CONCLUSIONS: Higher HCC was associated with greater adiposity in late adolescence. Further research is needed to disentangle the relationship between HCC and adolescent adiposity, including the temporal direction of the relationship and sex-specific associations.

Hair cortisol levels are associated with overweight and obesity in the ELSA-Brasil cohort.

Introduction: Hair cortisol level has recently been identified as a promising marker for detecting long-term cortisol levels and a marker of hypothalamic-pituitary-adrenal cortex (HPA) axis activity. However, research on the association between obesity and an altered cortisol metabolism remains controversial. Objective: This study aimed to investigate the relationship between hair cortisol levels and overweight and obesity in participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Methods: This was a cross-sectional study involving 2,499 participants from the second follow-up (visit 3, 2017-2019) attending research centers in Rio de Janeiro and Rio Grande do Sul states. Hair samples were collected, and cortisol levels were analyzed using enzyme-linked immunosorbent assay (ELISA) kits. Cortisol levels were classified as low (< 40 pg/mg), medium (40-128 pg/mg), or high (> 128 pg/mg). The participants were classified as eutrophic, overweight, or obese according to their weight (kg) and height (m2). Odds ratios (ORs) with 95% confidence intervals (95%CI) were estimated. Results: Of the 2499 individuals, 30% had eutrophic weight, 40% were overweight, and 30% were obese. Notably, cortisol levels gradually increased with increasing body weight. Among participants with high hair cortisol levels, 41.2% were classified as overweight and 34.2% as obese. Multinomial logistic regression analysis indicated that participants with high cortisol levels were 43% (OR =1.43; 95%CI: 1.02-2.03) more likely to be overweight and 72% (OR =1.72; 95%CI:1.20-2.47) more likely to be obese than participants with low hair cortisol levels. After adjustment for all covariates, high cortisol levels remained associated with obesity (OR = 1.54; 95%CI:1.02-2.31) and overweight (OR =1.33; 95%CI:0.91-1.94). Conclusion: In the ELSA-Brazil cohort, hair stress were positively associated with overweight and obesity. These results underscore the importance of considering stress and cortisol as potential factors in obesity prevention and intervention efforts, and highlight a novel aspect of the complex relationship between stress and obesity in the Brazilian population.

Hair cortisol stability after 5-year storage: Insights from a sample of 17-year-old adolescents.

Background: Hair has become an increasingly valuable medium to investigate the association between chronic stress, stable differences in systemic cortisol secretion and later health. Assessing cortisol in hair has many advantages, notably its non-invasive and retrospective nature, the need for a single biospecimen and convenient storage until analysis. However, few studies offered empirical evidence documenting the long-term temporal stability of hair cortisol concentration (HCC) prior to analysis, especially in humans. Yet, knowing how long hair samples can be stored without compromising the accuracy of cortisol measurement is of crucial importance when planning data collection and analysis. This study examined the stability of HCC in hair samples assayed twice, five years apart. Methods: We randomly selected from a larger distribution of HCC measured in 17-year-old participants 39 hair samples to be reanalyzed five years later, under the same general conditions. Samples were assayed in duplicate using a luminescence immunoassay and compared with the original HCC using the Lin's concordance correlation coefficient (CCC), Bland-Altman plot analysis and Wilcoxon rank test. Results: Findings indicated a good concordance and temporal stability between the two samples assayed five years apart (CCC [95% confidence interval] = 0.84 [0.72-0.91]), although a small decrease in HCC was noted 5 years later (8.4% reduction, p = 0.001). Conclusion: Our study confirms that hair samples, when stored at room temperature and away from sunlight, can be assayed for at least five years without risking a loss of precision in HCC measurement.

It's all in the hair: Association between changes in hair cortisol concentrations in reaction to the COVID-19 pandemic and post-traumatic stress symptoms in children over time.

After exposure to a stressful/traumatic event, some individuals will develop post-traumatic stress symptoms (PTSS). In adults, low cortisol levels appear to be a risk factor for the development of PTSS. Indeed, both lower pre-trauma cortisol levels and low cortisol levels in the aftermath of a traumatic event have been associated with greater PTSS. In contrast, studies conducted in children showed that elevated cortisol levels shortly after trauma exposure are associated with more severe post-traumatic stress symptomatology. The few studies that have examined how pre-trauma cortisol levels predict PTSS in children have found no effect. Given that a pandemic can induce PTSS in certain individuals, we investigated whether cortisol secretion prior to and in the early stages of the COVID-19 pandemic in Quebec (Canada) predicted PTSS in children. In June 2020, we collected a hair sample from 71 children (8-15 y/o, M = 11.65; 54.93% girls) without a history of psychopathology or exposure to previous traumatic events. Hair samples allowed us to derive cumulative measures of cortisol levels for the months prior to (from mid-December 2019 to mid-March 2020) and at the beginning of the pandemic (from mid-March 2020 to mid-June 2020). PTSS were assessed every 3 months between June 2020 (T1) and March 2021 (T4). The results showed that a greater increase in hair cortisol at the beginning of the pandemic predicted less PTSS at T1, with an increase in these symptoms over time. This study highlights the utility of using hair cortisol during future chronic stressful events to better understand its association with the evolution of distress.