The awakening cortisol response and blood glucose levels

Revealing Structure and Localization of Steroid Regioisomers through Predictive Fragmentation Patterns in Mass Spectrometry Imaging

Identifying and mapping steroids in tissues can provide opportunities for biomarker discovery, the interrogation of disease progression, and new therapeutics. Although separation coupled to mass spectrometry (MS) has emerged as a powerful tool for studying steroids, imaging and annotating steroid isomers remains challenging. Herein, we present a new method based on the fragmentation of silver-cationized steroids in tandem MS, which produces distinctive and consistent fragmentation patterns conferring confidence in steroid annotation at the regioisomeric level without using prior derivatization, separation, or instrumental modification. In addition to predicting the structure of the steroid with isomeric specificity, the method is simple, flexible, and inexpensive, suggesting that the wider community will easily adapt to it. We demonstrate the utility of our approach by visualizing steroids and steroid isomer distributions in mouse brain tissue using silver-doped pneumatically assisted nanospray desorption electrospray ionization mass spectrometry imaging.

Glucocorticoid feedback paradox: a homage to Mary Dallman

As the end product of the hypothalamus-pituitary-adrenal (HPA) axis, the glucocorticoid hormones cortisol and corticosterone coordinate circadian activities, stress-coping, and adaptation to change. For this purpose, the hormone promotes energy metabolism and controls defense reactions in the body and brain. This life-sustaining action exerted by glucocorticoids occurs in concert with the autonomic nervous and immune systems, transmitters, growth factors/cytokines, and neuropeptides. The current contribution will focus on the glucocorticoid feedback paradox in the HPA-axis: the phenomenon that stress responsivity remains resilient if preceded by stress-induced secretion of glucocorticoid hormone, but not if this hormone is previously administered. Furthermore, in animal studies, the mixed progesterone/glucocorticoid antagonist RU486 or mifepristone switches to an apparent partial agonist upon repeated administration. To address these enigmas several interesting phenomena are highlighted. These include the conditional nature of the excitation/inhibition balance in feedback regulation, the role of glucose as a determinant of stress responsivity, and the potential of glucocorticoids in resetting the stress response system. The analysis of the feedback paradox provides also a golden opportunity to review the progress in understanding the role of glucocorticoid hormone in resilience and vulnerability during stress, the science that was burned deeply in Mary Dallman's emotions.

Carbon Electrode Sensor for the Measurement of Cortisol with Fast-Scan Cyclic Voltammetry

Cortisol is a vital steroid hormone that has been known as the "stress hormone", which is elevated during times of high stress and anxiety and has a significant impact on neurochemistry and brain health. The improved detection of cortisol is critically important as it will help further our understanding of stress during several physiological states. Several methods exist to detect cortisol; however, they suffer from low biocompatibility and spatiotemporal resolution, and they are relatively slow. In this study, we developed an assay to measure cortisol with carbon fiber microelectrodes (CFMEs) and fast-scan cyclic voltammetry (FSCV). FSCV is typically utilized to measure small molecule neurotransmitters by producing a readout cyclic voltammogram (CV) for the specific detection of biomolecules on a fast, subsecond timescale with biocompatible CFMEs. It has seen enhanced utility in measuring peptides and other larger compounds. We developed a waveform that scanned from -0.5 to -1.2 V at 400 V/s to electro-reduce cortisol at the surface of CFMEs. The sensitivity of cortisol was found to be 0.87 ± 0.055 nA/μM (n = 5) and was found to be adsorption controlled on the surface of CFMEs and stable over several hours. Cortisol was co-detected with several other biomolecules such as dopamine, and the waveform was fouling resistant to repeated injections of cortisol on the surface of the CFMEs. Furthermore, we also measured exogenously applied cortisol into simulated urine to demonstrate biocompatibility and potential use in vivo. The specific and biocompatible detection of cortisol with high spatiotemporal resolution will help further elucidate its biological significance and further understand its physiological importance and impact on brain health.

Physical Activity and Cortisol Regulation: A Meta-Analysis

Physical activity participation is associated with effective stress coping, indicated by decreases in both physiological stress reactivity and perceived stress. Quantifying the effect of physical activity on the diurnal regulation of one key physiological stress indicator, the stress hormone, cortisol, across studies may demonstrate the extent to which physical activity participation is associated with diurnal HPA axis regulation. We meta-analyzed studies examining relations between physical activity participation and indices of HPA axis regulation: the diurnal cortisol slope and the cortisol awakening response. We also examined moderators of the relation. The analysis revealed a small, non-zero negative averaged correlation between physical activity and the diurnal cortisol slope (r = -0.043, 95% CI [-0.080, -0.004]). Examination of sample sociodemographic differences, study design characteristics, cortisol measurement methods, and physical activity variables as moderators revealed few effects on the relation between physical activity and diurnal cortisol slope. We did not observe lower levels of variability in the mean cortisol awakening response at higher levels of physical activity participation, and moderator analyses showed little evidence of reductions in heterogeneity for this effect. We found some evidence of systematic publication bias. Findings suggest higher physical activity is associated with a steeper diurnal cortisol slope. However, the cortisol awakening response did not differ by physical activity level. Future studies testing the physical activity and cortisol regulation association should use standardized physical activity measures, follow guidelines for better quality cortisol sampling collection and analysis, and test relations in large-scale empirical studies to confirm the direction and causality of the effect.

Sex differences in saliva-based DNA methylation changes and environmental stressor in young African American adults

BACKGROUND

Low socioeconomic status neighborhood exposure to stress and violence may be sources of negative stimuli that poses significant health risks for children, adolescents and throughout the life course of an individual. The study aims to investigate if aberrant epigenetic DNA methylation changes may be a potential mechanism for regulating neighborhood exposures and health outcomes.

METHODS

Exposure to environmental stressors identified in 98 young African American (AA) adults aged 18-25 years old from the Washington D.C., area were used in the study. We correlated the association between stress markers; cortisol, CRP, IgG, IGA, IgM, and self-reported exposure to violence and stress, with quantitative DNA methylation changes in a panel of gene-specific loci using saliva DNA.

RESULTS

In all participants studied, the exposure to violence was significant and negatively correlated with DNA methylation of MST1R loci (p = 0.032; r = -0.971) and nominally significant with NR3C1 loci (p = 0.053; r = -0.948). In addition, we observed significant and negative correlation of DNA methylation changes of LINE1 (p = 0.044; r = -0.248); NR3C1 (p = 0.017; r = -0.186); MSTR1 (p = 0.022; r = -0.192); and DRD2 (p = 0.056; r = -0.184; albeit nominal significant correlation) with IgA expression. On the other hand, we observed a significant and position correlation of DNA methylation changes in DRD2 (p = 0.037; r = 0.184) with IgG expression. When participants were stratified by sex, we observed in AA young male adults, significant DNA methylation changes of MST1R (p< 0.05) and association with exposure to violence and IgG level. We also observed significant DNA methylation levels of DRD2 (p< 0.05) and association with IgA, IgG, and cortisol level. Furthermore, we observed significant DNA methylation changes of NR3C1 (p< 0.05) with stress, IgA, and IgG in the male participants only. On the other hand, we only observed significant and a positive association of IgG with DNA methylation levels of ESR1 (p = 0.041) in the young AA female participants.

CONCLUSION

Our preliminary observation of significant DNA methylation changes in neuronal and immune genes in saliva samples supports our recently published genome-wide DNA methylations changes in blood samples from young AA male adults indicating that saliva offers a non-invasive means for DNA methylation prediction of exposure to environmental stressors in a gender-specific manner.

The Role of Bioactive Compounds from Dietary Spices in the Management of Metabolic Syndrome: An Overview

Metabolic syndrome (MetS) is a combination of physiologically dysregulated parameters that can include elevated fasting blood glucose, high blood pressure, central obesity, increased triglyceride levels, insulin resistance, diabetes, elevated low density lipoprotein levels, and reduced high density lipoprotein levels in the blood. Effective clinical management of MetS is critical as it is strongly associated with long lasting and fatal complications in patients. Alongside standard care of lifestyle changes and medication, dietary supplements derived from herbal resources could be an alternative therapeutic strategy that is safe, efficient, culturally acceptable, and has few side effects. Of the dietary supplements, spicy foods have always been considered a great source of functional bioactive compounds. Herbal therapy is broadly used in many countries as a treatment or as a preventive measure in the management of MetS risk factors, including blood glucose, blood pressure, and blood lipid levels. Herein, an attempt is made to evaluate the recent studies in the management of MetS with herbal alternatives, and to explore the possibility of their use as therapeutic treatments or supplements.

Broad Metabolome Alterations Associated with the Intake of Oral Contraceptives Are Mediated by Cortisol in Premenopausal Women

The use of oral contraceptives (OCs) has been associated with elevated blood cortisol concentrations. However, metabolic downstream effects of OC intake are not well described. Here, we aimed to determine if the blood metabolome is associated with the use of OCs and to estimate if these associations might be statistically mediated by serum cortisol concentrations. Plasma metabolites measured with the Biocrates AbsoluteIDQ p180 Kit and serum cortisol concentrations measured by an immunoassay were determined in 391 premenopausal women (116 OC users) participating in two independent cohorts of the Study of Health in Pomerania (SHIP). After correction for multiple testing, 27 metabolites were significantly associated with OC intake in SHIP-TREND (discovery cohort), of which 25 replicated in SHIP-2. Inter alia, associated metabolites included 12 out of 38 phosphatidylcholines with diacyl residue, 7 out of 14 lysophosphatidylcholines and 5 out of 21 amino acids. The associations with phosphatidylcholines were statistically mediated by cortisol, whereas lysophosphatidylcholines showed no mediation effect. The results represent a step toward a better understanding of the metabolic consequences of OC intake. Connecting cortisol with metabolic consequences of OC intake could help to understand the mechanisms underlying adverse effects. The blood metabolome may serve as a biomarker for identifying users at high risk for developing such adverse effects.

Ambulatory Assessment of Psychological and Physiological Stress on Workdays and Free Days Among Teachers. A Preliminary Study

Objective

Teachers are affected by high levels of job stress, leading to one of the highest rates of burnout. The purpose of our pilot study was to investigate the diurnal course of teachers’ psychological and physiological stress responses [cortisol levels, alpha-amylase, heart rate (HR), and heart rate variability (HRV)]. Another aim of the project was to test the applicability of ambulatory assessment methods in daily teaching situations.

Methods

In a non-clinical sample of eight primary school teachers (mean age = 43, SD = 15.22, 6 females) in Switzerland, continuous biopsychological data on two workdays and a free day were assessed. The teachers’ HRs and HRV were measured continuously using an ambulatory ECG. Additionally, eight saliva samples were collected from the teachers repeatedly throughout the day to determine the diurnal course of salivary cortisol and alpha-amylase (sAA). Perceived stress and anger ratings were assessed simultaneously.

Results

As hypothesized, the teachers’ morning cortisol levels, perceived stress, and anger levels were significantly higher, and their overall HRV was significantly lower on workdays than on a free day. Conversely, sAA levels and HRs showed no significant differences between working and free days. Salivary markers exhibited the expected diurnal course, with decreasing cortisol and increasing sAA levels over the course of the day, while self-rated stress reached the maximum at midday during working days.

Conclusion

The results of the present explorative study show that physiological and psychological parameters differ within working and free days for teachers. A comparison between working and free days resulted in differences in morning cortisol levels, HRV as well as stress and anger levels. The ambulatory assessment method was found to be applicable in daily teaching situations.

A multichannel system integrating molecularly imprinted conductive polymers for ultrasensitive voltammetric determination of four steroid hormones in urine

This work reports on a modularized electrochemical method for the determination of the hormones cortisol, progesterone, testosterone and 17β-estradiol in urine. These hormones were employed as templates when generating molecular imprints from aniline and metanilic acid by electropolymerization on the surface of screen-printed electrodes. The electrically conductive imprint was characterized by SEM, AFM and cyclic voltammetry. A four-channel system was then established to enable simultaneous determination of the hormones by cyclic voltammetry. The detection limits for cortisol, progesterone, testosterone and 17β-estradiol are as low as 2, 2.5, 10 and 9 ag·mL^-1 (for S/N = 3). Graphical abstract A four-channel system was established to enable simultaneous determination of 4 steroid hormones by cyclic voltammetry and by using moleculalry imprinted polymers.

The Cortisol Awakening Response: Association With Training Load in Endurance Runners

The cortisol awakening response (CAR) is commonly used as a marker of psychological stress; however, it is unknown whether CAR is affected by regular physical-exercise-induced stress.

PURPOSE

To assess the relationship between training load and CAR.

METHODS

Recreational endurance athletes were recruited from local running clubs. Subjects (n = 15) completed training logs for 2 wk, with various training loads, including psychometric analysis (Recovery-Stress Questionnaire for Athletes). Subjects provided saliva samples each day immediately after waking and 30 min postwaking. Samples were analyzed for cortisol concentration via enzyme-linked immunosorbent assay and subsequently were analyzed for CAR and CAR%. Daily training load was calculated and analyzed as training impulse. Simple linear regression was used to assess the relationship between CAR and training impulse.

RESULTS

CAR (r² = .352, P = .025) and CAR% (r² = .373, P = .012) both showed a significant negative relationship with training load.

CONCLUSIONS

These results suggest that CAR is affected by regular exercise training loads in recreational athletes. It is recommended that future CAR research control for fitness level and exercise training load in physically active populations.

Salivary cortisol and cortisone responses to short-term psychological stress challenge in late adolescent and young women with different hyperandrogenic states

Hyperandrogenic disorders have been associated with psychological distress, reduced quality of life, anxiety and depression. The hypothalamic-pituitary-adrenal (HPA) axis plays a pivotal role in the adaptive response to stressor events. Salivary cortisol (SalF) and cortisone (SalE) testing have been proven to be useful in the evaluation of HPA-axis activity. This study investigated whether SalF and SalE responses to two putative stressor levels differed between the hyperandrogenic states in late adolescent and young women, thus measuring the HPA-axis adaptive response to acute stress events. We selected 161 drug-free females aged 16-19 years from a large population previously enrolled in a cross-sectional epidemiological study. Saliva was collected in the morning before and after two putative stressor events consisting in a self-filled questionnaire (weaker stressor) and in a structured interview plus physical examination by an endocrinologist (stronger stressor). SalF and SalE, as well as blood steroids, were assessed by liquid chromatography-tandem mass spectrometry. Subjects were subdivided into different groups according to the presence of: isolated menstrual irregularities (MI, oligo-amenorrhea; n = 22), isolated hirsutism (HIR, modified Ferriman-Gallwey score ≥ 8; n = 26), isolated hyperandrogenaemia (HT, testosterone >0.438 ng/mL; n = 14), and polycystic ovary syndrome (PCOS, MI with HIR and/or HT, n = 16). The remaining 83 apparently healthy subjects were used as controls. SalF and SalE significantly decreased after the weaker stressor, following the physiologic diurnal loss, in all the groups except for isolated HIR, where they remained unchanged (P = 0.091 and P = 0.118, respectively). In contrast, SalF and SalE remained unchanged after the stronger stressor in isolated MI, isolated HT and controls, whereas SalF increased significantly in isolated HIR (P = 0.011), and SalE increased significantly both in isolated HIR (P = 0.005) and in PCOS (P = 0.011) groups. SalF percentage variation in response to the stronger stressor was positively associated with systolic blood pressure in PCOS (P = 0.018), and both SalF and SalE percentage variations were positively associated with diastolic blood pressure in the isolated HIR group (P = 0.010 and P = 0.006, respectively). In addition, in the isolated HIR group, the SalF percentage variation was negatively associated with HDL cholesterol levels (P = 0.005). Finally, SalF and SalE percentage variations were positively associated with circulating androstenedione (P = 0.031 and P = 0.011, respectively) and DHEA (P = 0.020 and P = 0.003, respectively) in the isolated HIR group. In conclusion, this study demonstrates that hirsute and PCOS adolescent and young women are characterized by HPA-axis overactivity in response to stressful stimuli, as detectable by salivary glucocorticoid measurements. These data also indicate that the higher the HPA-axis activity, the higher the adrenal androgen output and the worse the metabolic profile.

Integrated metabolomic and transcriptome analyses reveal finishing forage affects metabolic pathways related to beef quality and animal welfare

Beef represents a major dietary component and source of protein in many countries. With an increasing demand for beef, the industry is currently undergoing changes towards naturally produced beef. However, the true differences between the feeding systems, especially the biochemical and nutritional aspects, are still unclear. Using transcriptome and metabolome profiles, we identified biological pathways related to the differences between grass- and grain-fed Angus steers. In the latissimus dorsi muscle, we have recognized 241 differentially expressed genes (FDR < 0.1). The metabolome examinations of muscle and blood revealed 163 and 179 altered compounds in each tissue (P < 0.05), respectively. Accordingly, alterations in glucose metabolism, divergences in free fatty acids and carnitine conjugated lipid levels, and altered β-oxidation have been observed. The anti-inflammatory n3 polyunsaturated fatty acids are enriched in grass finished beef, while higher levels of n6 PUFAs in grain finished animals may promote inflammation and oxidative stress. Furthermore, grass-fed animals produce tender beef with lower total fat and a higher omega3/omega6 ratio than grain-fed ones, which could potentially benefit consumer health. Most importantly, blood cortisol levels strongly indicate that grass-fed animals may experience less stress than the grain-fed individuals. These results will provide deeper insights into the merits and mechanisms of muscle development.

Implicit associations have a circadian rhythm

The current study shows that people's ability to inhibit implicit associations that run counter to their explicit views varies in a circadian pattern. The presence of this rhythmic variation suggests the involvement of a biological process in regulating automatic associations—specifically, with the current data, associations that form undesirable social biases. In 1998, Greenwald, McGhee, and Schwartz introduced the Implicit Association Test as a means of measuring individual differences in implicit cognition. The IAT is a powerful tool that has become widely used. Perhaps most visibly, studies employing the IAT demonstrate that people generally hold implicit biases against social groups, which often conflict with their explicitly held views. The IAT engages inhibitory processes similar to those inherent in self-control tasks. Because the latter processes are known to be resource-limited, we considered whether IAT scores might likewise be resource dependent. Analyzing IAT performance from over a million participants across all times of day, we found a clear circadian pattern in scores. This finding suggests that the IAT measures not only the strength of implicit associations, but also the effect of variations in the physiological resources available to inhibit their undesirable influences on explicit behavior.

Biochemical Effects of Xylazine, Propofol, and Ketamine in West African Dwarf Goats

Anaesthesia was induced in West African Dwarf (WAD) goats using different combinations of propofol (P), xylazine (X), and ketamine (K), and the biochemical effect of the drugs determined. Twenty male (WAD) goats were randomly assigned to five treatment groups viz. Control (C) (2.5 mL IV normal saline); group K + X (5 mg/kg IV ketamine + 0.05 mg/kg IV xylazine), group P + X (5 mg/kg IV propofol + 0.05 mg/kg IV xylazine), group P + K (propofol 5 mg/kg IV + ketamine 5 mg/kg IV), and group P + K + X (propofol 2.5 mg/kg IV + ketamine 2.5 mg/kg IV + xylazine 0.05 mg/kg IV), respectively. There was increase (P < 0.05) in blood glucose in K + X, P + X and P + K + X. The serum cortisol level increased (P < 0.05) in all groups except in P + X. ALT value increased (P < 0.05) in K + X, P + K, and P + K + X. BUN increased (P < 0.05) in K + X but decreased (P < 0.05) in P + K + X. There was no significant variation (P > 0.05) in serum creatinine. These biochemical changes were transient. P + K + X would be the best drug combinations considering the biochemical parameter measured. However, data on blood glucose, ALT, BUN, and cortisol levels in an anaesthsized goat should be interpreted with caution in order to avoid erroneous interpretation in these animals.

Individual differences in the cortisol and salivary α-amylase awakening responses in early childhood: relations to age, sex, and sleep

Recent studies have examined post-waking changes in cortisol as a marker of HPA functioning, but questions remain about the stability of this response, as well as its relation to sleep and other ANS markers. The purposes of this study were to a) examine the presence and developmental changes in the cortisol awakening response (CAR) and salivary α-amylase awakening (sAA-AR) in a toddler sample and b) determine whether and how sleep relates to these responses in this age group. We measured cortisol and sAA upon awakening (and 30 min post-waking) and sleep characteristics using actigraphy (e.g., total sleep time, sleep efficiency, number of awakenings) in toddlers (N = 47; 36% female, ages 12-24 months). Forty-six percent of toddlers demonstrated a CAR and 52% demonstrated a sAA-AR. Strength of either response did not change linearly with age. Additionally, likelihood of demonstrating the CAR and sAA-AR was unrelated to age, sex, awakening time, time between samples, and time since feeding. Higher waking cortisol levels were associated with a shorter total sleep time and an earlier awakening. No associations were observed between sleep characteristics and the sAA-AR, ps > .05. Our findings suggest that these awakening responses function independently of sleep in toddlers. Additionally, the lack of change in percentage of children showing a CAR or sAA-AR across these ages suggests that these responses are stable and not emerging reliably across the second year of life.

A day-centered approach to modeling cortisol: diurnal cortisol profiles and their associations among U.S. adults

Diurnal cortisol is a marker of HPA-axis activity that may be one of the biological mechanisms linking stressors to age-related health declines. The current study identified day-centered profiles of diurnal cortisol among 1101 adults living in the United States. Participants took part in up to four consecutive days of salivary cortisol collection, assessed at waking, 30min post-waking, before lunch, and before bedtime. Growth mixture modeling with latent time basis was used to estimate common within-day trajectories of diurnal cortisol among 2894 cortisol days. The 3-class solution provided the best model fit, showing that the majority of study days (73%) were characterized by a Normative cortisol pattern, with a robust cortisol awakening response (CAR), a steep negative diurnal slope, coupled with low awakening and bedtime levels. Relative to this profile, diurnal cortisol on the remainder of days appeared either elevated throughout the day (20% of days) or flattened (7% of days). Relative to the normative trajectory, the elevated trajectory was distinguished by a higher morning cortisol level, whereas the flattened trajectory was characterized by a high bedtime level, with weaker CAR and diurnal slope parameters. Relative to the normative profile, elevated profile membership was associated with older age and cigarette smoking. Greater likelihood of the flattened cortisol pattern was observed among participants who were older, male, smoked cigarettes, used medications that are known to affect cortisol output, and reported poorer health. The current study demonstrates the value of a day-centered growth mixture modeling approach to the study of diurnal cortisol, showing that deviations from the classic robust rhythm of diurnal cortisol are associated with older age, male sex, use of medications previously shown to affect cortisol levels, poorer health behaviors, and poorer self-reported health.

Enhanced cortisol increase upon awakening is associated with greater pain ratings but not salivary cortisol or soluble tumor necrosis factor-α receptor II responses to acute pain

OBJECTIVES

The cortisol awakening response (CAR) is related to psychosocial factors and health in potentially significant ways, suggesting that it may be a distinctive marker of hypothalamic-pituitary-adrenal axis function and dysfunction. This study sought to expand upon previous work that examined the association between CAR and ratings of laboratory-evoked acute pain stimulation. In addition to evoked pain ratings, this study also tested whether CAR was prospectively related with salivary cortisol and soluble tumor necrosis factor-α receptor II responses to acute pain stimulation.

METHODS

This study included 36 healthy, pain-free volunteers of both sexes recruited through posted study flyers. Prior to completion of laboratory pain testing, salivary cortisol samples were obtained at home over the course of a single morning according to the following time frame: upon awakening, and 15, 30, and 60 minute after awakening. After collection of saliva, study participants brought their home saliva samples to the laboratory for assay and subsequently completed acute experimental pain testing procedures.

RESULTS

Cluster analysis of CAR revealed two distinct groups with similar patterns of cortisol response to awakening; increased and flattened. Relative to flattened CAR, increased CAR was associated with greater ratings of pain intensity and unpleasantness. Salivary cortisol was significantly increased and soluble tumor necrosis factor-α receptor II significantly decreased after pain testing, but neither of these responses differed as a function of increased versus flattened CAR.

DISCUSSION

CAR may be a marker for stress sensitivity and/or the anticipation of impending stress, which could explain why the increased CAR cohort reported greater acute pain ratings.

Cortisol awakening response and nighttime salivary cortisol levels in healthy working Korean subjects

PURPOSE

Cortisol awakening response (CAR) and nighttime cortisol levels have been used as indices of adrenocortical activity. However, population-based statistical information regarding these indices has not been provided in healthy subjects. This study was carried out to provide basic statistical information regarding these indices.

MATERIALS AND METHODS

Cortisol levels were measured in saliva samples collected immediately upon awakening (0 min), 30 min after awakening and in the nighttime on two consecutive days in 133 healthy subjects.

RESULTS

We determined the mean [standard deviation (SD)], median (interquartile range) and 5th-95th percentile range for each measure and auxiliary indices for CAR, i.e., the secreted cortisol concentration within 30 min of awakening (CARscc) and absolute and relative increases in cortisol level within 30 min of awakening (CARi and CARi%, respectively). We also determined these values for auxiliary indices derived from nighttime cortisol level, i.e., the ratio of cortisol level 30 min after awakening (CA(₃₀ min)) to nighttime level (CA(₃₀ min)/NC), as well as absolute and relative decreases in cortisol levels from CA(₃₀ min) to nighttime (DCd and DCd%, respectively). We found no significant differences in cortisol level for any time point or in auxiliary indices between collection days, genders and ages.

CONCLUSION

The provided descriptive information and statistics on the CAR and nighttime cortisol level will be helpful to medical specialists and researchers involved in hypothalamus- pituitary-adrenal axis assessment.

Do neighbourhoods matter? Neighbourhood disorder and long-term trends in serum cortisol levels

BACKGROUND

Characteristics associated with low socioeconomic status neighbourhoods may put children at risk for unique chronic stressors that affect cortisol levels. This research sought to explore whether neighbourhood stressor exposure affected serum cortisol levels among children.

METHODS

A total of 148 African and European-American children with an average age of 8.28 years participated in a longitudinal study evaluating ethnic differences in body composition and disease risk. Five waves of data were included in analyses. Mixed modelling was used to explore neighbourhood stressors, which was a composite index of five items for zip code level poverty and physical disorder, and serum cortisol outcomes for the full sample, by race/ethnicity and gender. Adjustments were made for individual level correlates age, pubertal status, gender and total fat mass.

RESULTS

Neighborhood disorder was predictive of lower serum cortisol levels among African-American children (p<0.05), such that higher neighbourhood stressor exposure resulted in lower serum cortisol over time compared with individuals in socially ordered neighbourhoods. Neighbourhood disorder was marginally significant and predictive of higher serum cortisol among European-American children (p<0.10). Transition to a higher pubertal status, nested in age was also predictive of lower serum cortisol levels (p<0.01) among European-American children.

CONCLUSION

Children who are exposed to negative socioenvironmental climates over time are more likely to have altered serum cortisol levels. This may be an adaptive mechanism to cope with stress; however, disrupted cortisol levels may have negative effects on general physical and mental health.

Interindividual differences and intraindividual variability in the cortisol awakening response: an examination of age and gender

This article shows age and gender differences in the magnitude and day-to-day variability of the cortisol awakening response (CAR) using a national sample of 1,143 adults who completed the second wave of the National Study of Daily Experiences, a part of the Midlife Development in the United States survey. Participants between the ages of 33 and 84 years completed 8 consecutive nightly interviews and provided 4 saliva samples (upon waking, 30 min after waking, before lunch, and before bed) on 4 consecutive interview days. Results revealed substantial day-to-day variability in the CAR as well as significant AgexGender interactions, indicating that although no systematic age-related differences emerged for women, the magnitude and day-to-day variability of the CAR increased with age among men.

Circadian Variation in Cortisol Reactivity to an Acute Stressor

To investigate the role of the circadian pacemaker in cortisol reactivity to a cold pressor challenge, 26 diurnally subjects participated in a constant-routine protocol and were divided into two groups. Group 1 started immediately after a monitored sleep period at 09:00 h, while group 2 started 12 h later. After 2 h of adaptation, a cold pressor test was presented every 3 h. The cortisol response was assessed by means of saliva samples that were taken before and after the test. The pretest samples were considered to be base-rate measures and base-rate values as subtracted from post-test values were considered as reactivity measures. Both measures showed distinct Time-of-Day variations (respectively: F(7,168) = 16.92, p < 0.001, epsilon = 0.383; and F(7,175) = 8.01, p < 0.001, epsilon = 0.523). These findings are interpreted as evidence for the existence of an endogenous circadian periodicity underlying the sensitivity of the hypothalamus-pituitary-adrenal (HPA)-axis to acute stress.

A blunted cortisol awakening response and hippocampal atrophy in type 2 diabetes mellitus

There is emerging evidence from healthy individuals, as well as direct and indirect evidence from psychiatric and neurological patients with disease-related hippocampal atrophy, linking the cortisol awakening response (CAR) to hippocampal volume. Type 2 diabetes mellitus (T2DM) is a metabolic disease that is also accompanied by hippocampal atrophy, and therefore can serve as a model for ascertaining the relationship between CAR and hippocampal volume. We contrasted a group of 18 individuals with T2DM with 12 matched controls on MRI-based hippocampal volume and salivary diurnal cortisol profile including CAR. Individuals with T2DM had smaller hippocampal volumes and exhibited a blunting of the CAR relative to controls, while diurnal cortisol was not affected. Across all subjects, fasting insulin and hippocampal volume were associated with the CAR, independent of diagnosis. Our findings support the hypothesis that hippocampal integrity is an important predictor of the CAR.

Attenuated morning salivary cortisol concentrations in a population-based study of persons with chronic fatigue syndrome and well controls

CONTEXT

A substantial body of research on the pathophysiology of chronic fatigue syndrome (CFS) has focused on hypothalamic-pituitary-adrenal axis dysregulation. The cortisol awakening response has received particular attention as a marker of hypothalamic-pituitary-adrenal axis dysregulation.

OBJECTIVE

The objective of the current study was to evaluate morning salivary cortisol profiles in persons with CFS and well controls identified from the general population.

DESIGN AND SETTING

We conducted a case-control study at an outpatient research clinic. CASES AND OTHER PARTICIPANTS: We screened a sample of 19,381 residents of Georgia and identified those with CFS and a matched sample of well controls. Seventy-five medication-free CFS cases and 110 medication-free well controls provided complete sets of saliva samples.

MAIN OUTCOME MEASURES

We assessed free cortisol concentrations in saliva collected on a regular workday immediately upon awakening and 30 and 60 min after awakening.

RESULTS

There was a significant interaction effect, indicating different profiles of cortisol concentrations over time between groups, with the CFS group showing an attenuated morning cortisol profile. Notably, we observed a sex difference in this effect. Women with CFS exhibited significantly attenuated morning cortisol profiles compared with well women. In contrast, cortisol profiles were similar in men with CFS and male controls.

CONCLUSIONS

CFS was associated with an attenuated morning cortisol response, but the effect was limited to women. Our results suggest that a sex difference in hypocortisolism may contribute to increased risk of CFS in women.

No effects of repeated forced wakings during three consecutive nights on morning cortisol awakening responses (CAR): a preliminary study

OBJECTIVE

The cortisol awakening response (CAR) is considered a reliable measure for the acute reagibility of the hypothalamus-pituitary-adrenal (HPA) axis. Whether repeated nightly awakenings at different times during the night also stimulate the HPA-axis and whether, consequently, the CAR is altered has not been tested, so far. We aimed to investigate whether three experimentally induced awakenings during three consecutive nights would be associated with HPA-axis stimulation and an altered morning CAR.

METHODS

The study sample consisted of 13 healthy adult women who were waken up three times in each of three consecutive nights. Cortisol levels were measured immediately and 15 min after each awakening in the night and in the morning, respectively. Also, the morning CARs after three nights of undisturbed sleep were assessed.

RESULTS

A significant difference between night time cortisol responses to awakening and the morning CAR was found. While cortisol levels during the first half of the night did not rise significantly after awakening in the night, some reactivity was seen during awakenings in the very early morning hours, and pronounced awakening responses were observed in the morning before getting out of bed. Interestingly, the morning CAR after disturbed sleep did not differ from the morning CAR following undisturbed sleep.

CONCLUSION

In healthy female individuals, the morning CAR appears to be unchanged even if sleep was repeatedly interrupted by forced wakings.

Blunted cortisol response to awakening in mild to moderate depression: regulatory influences of sleep patterns and social contacts

Cortisol is elevated during severe depression. However, some studies of outpatients suggest reduced cortisol levels, either basal or poststress. More definite evidence of this phenomenon is needed, and correlates that may explain the disparate findings should be identified. Women from the community (37 depressed and 36 nondepressed) completed electronic diaries in order to help researchers assess the cortisol awakening response (CAR), sleep, and social contacts. Depressed women had a blunted CAR compared with nondepressed women. Among the nondepressed but not among depressed women, time of waking, and number of social contacts (especially positive ones) were independently associated with CAR. These psychosocial factors may contribute to a normal CAR, but their regulatory influence may become disrupted during mild to moderate clinical depression.

Neuroendocrine aspects of PTSD

This chapter discussed how neuroendocrine findings in posttraumatic stress disorder (PTSD) potentially inform hypothalamic-pituitary-adrenal (HPA) alterations in PTSD and highlight alterations relevant to the identification of targets for drug development. Most studies demonstrate alterations consistent with an enhanced negative feedback inhibition of cortisol on the pituitary, an overall hyperreactivity of other target tissues (adrenal gland, hypothalamus), or both in PTSD. However, findings of low cortisol and increased reactivity of the pituitary in PTSD are also consistent with reduced adrenal output. The observations in PTSD are part of a growing body of neuroendocrine data providing evidence of insufficient glucocorticoid signaling in stress-related neuropsychiatric disorders.

The effect of dawn simulation on the cortisol response to awakening in healthy participants

Bright light exposure after awakening has been shown to elevate cortisol levels in healthy participants. The present study examined the effect of dawn simulation (a treatment for seasonal affective disorder) on the cortisol response to awakening and mood. Twelve healthy participants were supplied with a dawn simulator (The Natural Alarm Clock, Outside In, Cambridge Ltd), a bedside light that increases in intensity prior to awakening to approximately 250 lux over 30 mins when an audible alarm sounds. A counterbalanced study was performed on 4 consecutive normal weekdays, two of which were control days (no dawn simulation) and two experimental (dawn simulation). Saliva samples were taken immediately on awakening then at 15, 30 and 45 minutes post awakening on all 4 study-days. Total cortisol production during the first 45 mins after awakening was found to be significantly higher in the experimental condition than in the control condition. Participants also reported greater arousal in the experimental condition and there was a trend for an association between increased arousal and increased cortisol secretory activity under dawn simulation. This study provides supportive evidence for the role of light and the suprachiasmatic nucleus in the awakening cortisol response.

Differences in cortisol awakening response on work days and weekends in women and men from the Whitehall II cohort

It is thought that the salivary cortisol awakening response can serve as a reliable marker of hypothalamic-pituitary-adrenocortical activity. Response magnitude might be influenced by stress, but results of studies on work-related stress have been inconclusive. Non-compliance with the sampling schedule is a potential confounding factor that has rarely been controlled. The objective of the study was to determine whether the cortisol awakening response is greater on a work day than on a weekend day, and whether responses vary with gender and socioeconomic position. Compliance was controlled by excluding participants who reported a delay of more than 10 min between waking up and taking the first saliva sample. Data were collected from 196 men and women aged 47 to 59 years drawn from the Whitehall II cohort of British civil servants, with free salivary cortisol sampled immediately after waking up and 30 min later on 2 days. Data on stress, perceived control and happiness over the remainder of the day, and on sleep quality, time of waking, and health behaviour were also obtained. The awakening response was lower in non-compliant participants than in compliant ones, so non-compliant participants were excluded from further analyses. Salivary cortisol levels on waking did not differ by gender or socioeconomic position, or between work and weekend days. However, the cortisol awakening response (defined as the difference between waking and 30 min later) was greater on work than weekend days (mean increases 10.5 and 3.7 nmol/l, P < 0.001). On the work day, women showed larger increases than men (P = 0.011), but there were no gender differences on the weekend day. Across both days, lower socioeconomic position was associated with a larger cortisol awakening response (P = 0.014). Time of waking up was not related to the cortisol awakening response on either day. Participants rated themselves as more stressed, less in control, and less happy over the remainder of the work than weekend day. These results indicate that the cortisol awakening response occurs on both work and non-work days, but that anticipation of the working day is associated with an enhanced response. Cortisol output over the early part of the day may be particularly sensitive to the influence of chronic stress and its anticipation, especially in women.

The awakening cortisol response: methodological issues and significance

The awakening cortisol response (ACR) is a discrete and distinctive part of the cortisol circadian cycle. In healthy adults salivary free cortisol concentrations increase by between 50 and 160% in the first 30 min immediately post-awakening (approximate average increase of 9 nmol/l, range 4-15 nmol/l, estimated to be equivalent to about three secretory episodes). However there are no agreed norms for the absolute concentrations of free cortisol in saliva either immediately post-awakening (range of 4.7-18.5 nmol/l) or 30 min post-awakening (range of 8.6-21.9 nmol/l). This review explores reasons for these discrepancies in normative data including confounding factors such as gender, age, awakening time, light and participant adherence. Although the physiological role of the ACR has not been clearly defined evidence is discussed that suggests it is under a distinct regulatory influence, different from the rest of the diurnal cortisol secretory cycle. Despite the difficulties associated with its measurement a range of studies have demonstrated an association between the ACR and psychosocial variables, stress and health. However it remains unclear whether positive affect and good health are consistently associated with larger or smaller awakening responses. It is early days in the search for the role and significance of the ACR. Its putative role in the regulation of physiological function across the day (e.g. the immune system) and its sensitivity to psychosocial variables make it a prime candidate as an intermediary linking mind and health.

Rise in morning saliva cortisol is associated with abdominal obesity in men: a preliminary report

An abnormal regulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with risk factors for cardiovascular disease and Type 2 diabetes mellitus. The objective of this study was to examine if morning saliva cortisols show similar associations. Twenty-eight men, all 53 yr of age, delivered during an ordinary working day saliva cortisol samples immediately upon awakening and 15 min thereafter as well as at different times during the day, including after a standardized lunch. Dexamethasone (0.5 mg) suppression of cortisol was also measured. The rise of morning cortisol values was positively associated with body mass index (r: 0.45, p=0.016), waist/hip ratio (r: 0.54, p=0.003), abdominal sagittal diameter (r: 0.54, p=0.003), glucose (r: 0.54, p=0.003), insulin (r: 0.57, p=0.002) and triglycerides (r: 0.46, p=0.014). The morning rise also correlated positively with the elevation of cortisol following lunch (r: 0.45, p=0.043) but not with other cortisol measurements or dexamethasone suppression. Elevation of cortisol immediately after awakening has previously been found to provide a simple indicator of HPA axis regulation, as suggested also by the results of this study, and an elevated rise has been reported after exposure to frequent or chronic perceived stress. The rise of cortisol immediately after awakening might be an indicator of an increased risk of developing serious, prevalent diseases via the metabolic syndrome.

Relationship between 24-hour urinary-free cortisol excretion and salivary cortisol levels sampled from awakening to bedtime in healthy subjects

The utility of repeated salivary cortisol sampling as a substitute for 24-hour urinary-free cortisol (UFC) assessment was examined. Forty-four participants completed both 24-hour collections and 6 salivary collections at wake-up, 08:00, 12:00, 16:00, 20:00 and bedtime, during the same 24-hour period. The results demonstrated that mean, maximum, and amplitude (maximum minus minimum) for salivary cortisol all correlated positively with urinary cortisol, but the associations of these variables with urinary-free cortisol excretion were relatively small. Furthermore, a single salivary sample taken at wake-up was as good an indicator of overall cortisol production as the measures derived from multiple salivary samples. An examination of subject compliance indicated that many subjects failed to collect the timed salivary collections as instructed. The authors conclude that diurnal salivary cortisol sampling versus 24-hour urinary cortisol collections are likely to provide different information about ambient hypothalamic-pituitary-adrenal productivity, and therefore these measures should not be used interchangeably. In addition, subject compliance is a serious consideration in designing studies that employ home salivary collections.

Components of the diurnal cortisol cycle in relation to upper respiratory symptoms and perceived stress

OBJECTIVE

The purpose of this study was to investigate the relationship between the diurnal pattern of salivary free cortisol to perceived stress and susceptibility to symptoms of upper respiratory illness (URI).

METHODS

Salivary free cortisol concentration was determined in 34 healthy participants (students) at eight time points, synchronized to awakening, on 2 consecutive days. Participants completed a standard questionnaire to assess perceived stress and subsequently kept a daily record of social proximity and symptoms of upper respiratory illness for 2 weeks.

RESULTS

Participants characterized by consistently larger awakening responses went on to report significantly more URI symptoms. Participants with less pronounced diurnal decline (flatter profiles) reported fewer URI symptoms. The two cortisol components were themselves related and interacted such that participants high on an interactive vector reported approximately three times more URI symptoms than other participants. The URI-associated cortisol components (dynamic changes) were not related to perceived stress, but underlying cortisol secretory activity (overall levels) in the first 45 minutes after awakening was. Dynamic components were, however, related to a social proximity measure, which in turn was related to URI symptoms. Proximity and the interactive cortisol vector together explained a substantial (28%) percentage of the variance in URI symptom reports. The cortisol vector independently and significantly explained 12% of the variation; the proximity measure independently and nonsignificantly contributed 6% of the variation.

CONCLUSIONS

URI symptoms were associated with two related dynamic components of the cortisol cycle as determined by synchronization to awakening, whereas stress was related to a measure of overall secretory activity.

Salivary hormone concentrations in mothers and fathers becoming parents are not correlated

A time- and date-matched set of saliva samples (N = 229) from nine couples first expecting, and then caring for, their first child were used to test whether hormone changes in the father could be predicted by the hormonal status of the mother. Testosterone, cortisol, and estradiol were quantified from saliva. Neither testosterone nor estradiol concentration was correlated within couples before or after the birth, although there was a positive correlation for cortisol concentration in the mother and father before the birth. As the hormone that might be influenced by chemical signals, that already played a similar role in men and women, and that had been empirically linked to paternal behavior, cortisol concentration was also compared with sex steroid concentrations. The mother's cortisol concentration was positively correlated to the father's testosterone concentration, and the mother's testosterone concentration was positively correlated with the father's cortisol concentration. However, both effects were similar in magnitude to the cortisol to cortisol correlation, and all could parsimoniously be explained by similar responses to a shared environment. Thus, this analysis rejects parallels in peripheral hormone concentrations of estradiol, testosterone, and cortisol in mothers and fathers. However, the available data were not able to test or reject hypotheses about local neuroendocrine homology, nor to control for masking effects of other hormonal demands on men and women, nor to determine the relative importance of shared environment versus mother-father signaling.

Current status of cortisol findings in post-traumatic stress disorder

This article summarizes findings of hypothalamic-pituitary-adrenal axis alterations in post-traumatic stress disorder (PTSD) and evaluates likely reasons for the lack of agreement among published studies. Sources of variance caused by methodologic and interpretative differences are highlighted, but the disparate findings are explained as illustrating a more complex neuroendocrinology of PTSD than has previously been described.

Changes in testosterone, cortisol, and estradiol levels in men becoming fathers

OBJECTIVE

To quantify longitudinally steroid hormone (testosterone, cortisol, and estradiol) concentrations in men becoming fathers for the first time ("dads").

SUBJECTS AND METHODS

Volunteer study subjects were recruited from first-trimester prenatal classes in Kingston, Ontario, in February 1999. Twenty-three dads provided saliva samples from recruitment through 3 months after the birth of their children. Fourteen men who were not fathers were recruited from the general population to serve as age-matched controls for season and time of day. Estradiol, testosterone, and cortisol levels were quantified.

RESULTS

After controlling for effects of time of day and season, dads had lower mean +/- SE testosterone (6.5+/-0.7 vs 10.0+/-0.9 ng/dL; P<.005) and cortisol (morning values, 0.30+/-0.05 vs 0.53+/-0.05 microg/dL; P<.005) concentrations, a higher proportion of samples with detectable estradiol concentrations (68% [308/454] vs 57% [87/154]; P=.01), and higher estradiol concentrations in those detectable samples (3.81+/-0.09 pg/mL [13 dads] vs 3.26+/-0.11 pg/mL [9 controls]; P<.002) than did control men. Within 10 individual dads with frequent samples before and after the birth, the percentage of samples with detectable estradiol was lower during the month before the birth than during the month after (51% vs 71%; P=.02), and cortisol concentration was increased in the week before the birth (to a mean of 0.16 microg/dL). In each of 13 dads providing frequent samples, testosterone concentration and variance were low immediately after the birth (no change from previous levels in 5, decrease after prebirth increase in 3, and decrease relative to all other times in 5).

CONCLUSIONS

In this population of Canadian volunteers attending prenatal classes, expectant fathers had lower testosterone and cortisol levels and a higher proportion of samples with detectable estradiol concentrations than control subjects. Individual patterns of testosterone variance relative to the birth and estradiol and cortisol concentrations immediately before the birth may be worthy of further investigation. The physiologic importance of these hormonal changes, if any, is not known. However, they are hormones known to influence maternal behavior.

The Cortisol Response to Normal and Nocturnal Awakening

Abstract Free cortisol as measured in saliva increases markedly following awakening. It is not clear, however, whether this is truly a stress-neuroendocrine response to awakening or a manifestation of the hypothalamic-pituitary-adrenal (HPA) circadian cycle. We investigated whether the awakening cortisol response can be generated in the middle of nocturnal sleep, when secretory activity in the HPA axis is low. In a within subject design, salivary cortisol response was measured under three different awakening conditions: (1) awakening at the normal morning awakening time; (2) awakening four hours prior to normal awakening time, and (3) awakening the following morning after interrupted sleep. The overall main effect was a linear increase in free cortisol following awakening with no significant interaction with awakening condition. Cortisol levels, as determined by area under the cortisol curve calculated with reference to zero, did differ by awakening condition. The two morning awakening conditions were comparable but values were lower for night awakening. Area under the curve change (calculated with reference to the first awakening cortisol base value), however, did not distinguish the three awakening conditions. We conclude from these data that there is a clear free cortisol response to awakening for both nocturnal and morning awakening although the absolute levels produced are lower for nocturnal awakening when basal cortisol is low. Nocturnal interruption of sleep did not affect the subsequent morning response.