Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to ...index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation MAD) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges.
Abstract Maternal stress during pregnancy is associated with negative maternal/child outcomes. One potential biomarker of the maternal stress response is cortisol, a product of activity of the ...hypothalamic–pituitary–adrenal axis. This study evaluated cortisol levels in hair throughout pregnancy as a marker of total cortisol release. Cortisol levels in hair have been shown to be easily quantifiable and may be representative of total cortisol release more than single saliva or serum measures. Hair cortisol provides a simple way to monitor total cortisol release over an extended period of time. Hair cortisol levels were determined from each trimester (15, 26 and 36 weeks gestation) and 3 months postpartum. Hair cortisol levels were compared to diurnal salivary cortisol collected over 3 days (3 times/day) at 14, 18, 23, 29, and 34 weeks gestational age and 6 weeks postpartum from 21 pregnant women. Both salivary and hair cortisol levels rose during pregnancy as expected. Hair cortisol and diurnal salivary cortisol area under the curve with respect to ground (AUCg) were also correlated throughout pregnancy. Levels of cortisol in hair are a valid and useful tool to measure long-term cortisol activity. Hair cortisol avoids methodological problems associated with collection other cortisol measures such as plasma, urine, or saliva and is a reliable metric of HPA activity throughout pregnancy reflecting total cortisol release over an extended period.
Summary A growing body of research has revealed that social evaluative stressors trigger biological and psychological responses that in chronic forms have been linked to aging and disease. Recent ...research suggests that self-compassion may protect the self from typical defensive responses to evaluation. We investigated whether brief training in self-compassion moderated biopsychological responses to the Trier Social Stress Test (TSST) in women. Compared to attention (placebo) and no-training control conditions, brief self-compassion training diminished sympathetic (salivary alpha-amylase), cardiac parasympathetic, and subjective anxiety responses, though not HPA-axis (salivary cortisol) responses to the TSST. Self-compassion training also led to greater self-compassion under threat relative to the control groups. In that social stress pervades modern life, self-compassion represents a promising approach to diminishing its potentially negative psychological and biological effects.
To investigate the relationships between psychological and physiologic measures of stress, mood, and gestational age at delivery and preterm birth.
This prospective cohort study recruited healthy ...women in the early second trimester who were 18-45 years of age. Validated psychological measures of perceived stress, depressive symptoms, and anxiety were completed at 16, 22, 28, 34, and 40 weeks of gestation. Cortisol concentration was measured in maternal hair at 16, 28, and 40 weeks of gestation to approximate first-, second-, and third-trimester levels of physiologic stress. Statistical methods included: analyses of variance, t tests, χ, Pearson correlations, regression modeling, and mediation analysis as appropriate. Hair cortisol concentrations were natural log-transformed to normalize values.
Eleven (12%) of the 90 included women had a spontaneous preterm birth or preterm premature rupture of membranes. Perceived stress at 16 weeks of gestation correlated with both second-trimester cortisol concentration (r=0.28, P=.007) and earlier gestational age at delivery (r=-0.30, P<.01). Gestational age at delivery was also negatively correlated with cortisol concentration in the second trimester (r=-0.25, P=.02) and second-trimester cortisol concentration was higher in preterm- (2.7 ± 0.4 log-transformed pg/mg) compared with term- (2.0 ± 0.7 log-transformed pg/mg, P<.001) delivered women. Using mediation statistics, the association between the psychological measure, the physiologic measure, and gestational age at delivery was mainly driven by increased physiologic stress (hair cortisol concentration) in the second trimester (difference in coefficients standard error=-0.05 0.02).
Higher perceived stress in the second trimester is associated with both elevated second-trimester hair cortisol concentration and gestational age at delivery. Physiologic measure of stress in the second trimester appears most strongly associated with preterm birth. Identification and amelioration of early pregnancy stressors may attenuate physiologic stress and ultimately affect preterm birth.
Latent herpes virus reactivation has been demonstrated in astronauts during shuttle (10-16 days) and International Space Station (≥180 days) flights. Following reactivation, viruses are shed in the ...body fluids of astronauts. Typically, shedding of viral DNA is asymptomatic in astronauts regardless of mission duration; however, in some cases, live/infectious virus was recovered by tissue culture that was associated with atopic-dermatitis or skin lesions during and after spaceflight. Hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medullary (SAM) axes activation during spaceflight occurs as indicated by increased levels of stress hormones including cortisol, dehydroepiandrosterone, epinephrine, and norepinephrine. These changes, along with a decreased cell mediated immunity, contribute to the reactivation of latent herpes viruses in astronauts. Currently, 47/89 (53%) astronauts from shuttle-flights and 14/23 (61%) astronauts from ISS missions shed one or more herpes viruses in saliva/urine samples. Astronauts shed Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and herpes-simplex-1 (HSV-1) in saliva and cytomegalovirus (CMV) in urine. Larger quantities and increased frequencies for these viruses were found during spaceflight as compared to before or after flight samples and their matched healthy controls. The shedding did not abate during the longer ISS missions, but rather increased in frequency and amplitude. These findings coincided with the immune system dysregulation observed in astronauts from shuttle and ISS missions. VZV shedding increased from 41% in space shuttle to 65% in ISS missions, EBV increased 82 to 96%, and CMV increased 47 to 61%. In addition, VZV/CMV shed ≤30 days after ISS in contrast to shuttle where VZV/CMV shed up to 5 and 3 days after flight respectively. Continued shedding of infectious-virus post-flight may pose a potential risk for crew who may encounter newborn infants, sero-negative adults or any immunocompromised individuals on Earth. Therefore, developing spaceflight countermeasures to prevent viral reactivation is essential. Our spaceflight-developed technologies for saliva collection/rapid viral detection have been extended to include clinical applications including zoster patients, chicken pox, post-herpetic neuralgia, multiple sclerosis, and various neurological disorders. These protocols are employed in various clinics and hospitals including the CDC and Columbia University in New York, as well as overseas in Switzerland and Israel.
•In a sample of White, Hispanic, and African American adults, hair cortisol concentration was associated with greater metabolic syndrome severity.•Perceived stress was associated with greater hair ...cortisol concentration, but only for low-resilience participants.•Resilience moderated the indirect association of perceived stress with greater metabolic syndrome severity via elevated HCC.
Psychological resilience is considered to protect against detrimental effects of perceived stress on cardiovascular and metabolic health, but few studies have tested biological mechanisms underlying these relationships.
This study examined whether psychological resilience moderated the indirect association of perceived stress with Metabolic Syndrome (MetS) severity via hair cortisol concentration (HCC), a retrospective index of hypothalamic pituitary adrenal (HPA) axis activity.
Participants included 228 adults (73 White, 86 Hispanic, 69 African American; mean age 45.29 years; 68% females). Participants completed questionnaires assessing perceived stress (Perceived Stress Scale) and resilience (Brief Resilience Scale). The first 3 cm of scalp-near hair were analyzed for cortisol concentration using enzyme-linked immunoassay analysis. Cardiometabolic risk factors including blood glucose, lipids, blood pressure, and waist circumference were assessed, from which a sex- and race/ethnicity-specific continuous MetS severity score was calculated. A moderated mediation model was tested using path analysis.
Psychological resilience moderated the association of perceived stress with HCC (R2 change for interaction = 0.014, p = 0.043), such that the association of perceived stress and HCC decreased as resilience scores increased. Resilience also moderated the indirect association of perceived stress with MetS severity via HCC (b = -0.039, 95% CI -0.001; -0.100), such that HCC mediated the association of greater perceived stress with greater MetS severity only for individuals reporting Brief Resilience Scale scores 3 or below (range: 1.17–5.00). Psychological resilience was also associated with lower MetS severity (β = -0.227, p = 0.014) independent of perceived stress and HCC.
Findings suggest that psychological resilience may serve as both a stress buffer and as a direct determinant of cardiometabolic health. These results extend literature on psychological resilience to measures of retrospective HPA axis function and MetS severity in a diverse sample.
Prolonged stress is a potentially harmful and often undetected risk factor for chronic illness in older adults. Cortisol, one indicator of the body's hormonal responses to stress, is regulated by the ...hypothalamic-pituitary-adrenal (HPA) axis and is commonly measured in saliva, urine, or blood samples. Cortisol possesses a diurnal pattern and thus collection timing is critical. Hair cortisol is a proxy measure to the total retrospective activity of the HPA axis over the preceding months, much like hemoglobin A1c is a proxy measure of glucose control over the past 3 months. The aim of this review is to examine a novel biomarker, hair cortisol, as a practical measure of long-term retrospective cortisol activity associated with chronic stress in older adults. Hair cortisol analysis advances the science of aging by better characterizing chronic stress as a risk factor for chronic illness progression and as a biomarker of the effectiveness of stress reduction interventions.
Animal models have shown that chronic stress increases cortisol, which contributes to overeating of highly palatable food, increased abdominal fat and lower cortisol reactivity. Few studies in humans ...have simultaneously examined these trajectories. We examined premenopausal women, either mothers of children with a diagnosis of an autism spectrum disorder (n = 92) or mothers of neurotypical children (n = 91). At baseline and 2-years, we assessed hair cortisol, metabolic health, and reward-based eating. We compared groups cross-sectionally and prospectively, accounting for BMI change. Caregivers, relative to controls, had lower cumulative hair cortisol at each time point, with no decreases over time. Caregivers also had stable levels of poor metabolic functioning and greater reward-based eating across both time points, and evidenced increased abdominal fat prospectively (all ps ≤.05), independent of change in BMI. This pattern of findings suggest that individuals under chronic stress, such as caregivers, would benefit from tailored interventions focusing on better regulation of stress and eating in tandem to prevent early onset of metabolic disease, regardless of weight status.
Highlights • This is the first study to show low hair cortisol concentrations in attempters. • In our study, hair cortisol concentrations reflect levels prior to suicide attempt. • Attempters also ...show low GR-α mRNA and increased C-reactive Protein and TNF-α mRNA. • This is a distinct biological profile compared to ideators and healthy controls. • Hair cortisol was associated with GR-α mRNA, childhood abuse, and perceived stress
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