Effects of hatha yoga and african dance on perceived stress,affect, and salivary cortisol

Background: Dance and yoga have been shown to produce improvements in psychological well-being.Purpose: The aim of this study was to examine some of the psychological and neuroendocrine responses to these activities.Methods: Sixty-nine healthy college students participated in one of three 90-min classes: African dance (n = 21), Hatha yoga (n = 18), or a biology lecture as a control session (n = 30). Before and after each condition participants completed the Perceived Stress Scale (PSS), completed the Positive Affect and Negative Affect Schedule, and provided a saliva sample for cortisol.Results: There were significant reductions in PSS and negative affect (ps < .0001) and Time × Treatment interactions (ps < .0001) such that African dance and Hatha yoga showed significant declines, whereas there was no significant change in biology lecture. There was no significant main effect for positive affect (p = .53), however there was a significant interaction effect (p < .001) such that positive affect increased in African dance, decreased in biology lecture, and did not change significantly in Hatha yoga. There was a significant main effect for salivary cortisol (p < .05) and a significant interaction effect (p < .0001) such that cortisol increased in African dance, decreased in Hatha yoga, and did not change in biology. Changes in cortisol were not significantly related to changes in psychological variables across treatments. There was 1 significant interaction effect (p = .04) such that change in positive affect and change in cortisol were negatively correlated in Hatha yoga but positively correlated in African dance and biology.Conclusions: Both African dance and Hatha yoga reduced perceived stress and negative affect. Cortisol increased in African dance and decreased in Hatha yoga. Therefore, even when these interventions produce similar positive psychological effects, the effects may be very different on physiological stress processes. One factor that may have particular salience is the amount of physiological arousal produced by the intervention. This research was supported by grants from the General Clinical Research Center of Oregon Health Sciences University and Reed College.     

Relationships among socioeconomic status, stress induced changes in cortisol, and blood pressure in african american males

The inverse relation between socioeconomic status (SES) and cardiovascular disease (CVD) risk has been posited to be partially due to exaggerated cardiovascular reactivity (CVR) to stress. Stress elicits hypothalamic-pituitary-adrenal axis activation (e.g., increased cortisol secretion), which may contribute to subsequent blood pressure (BP) elevation. Univariate associations among SES, cortisol secretion, and aggregated change scores to stressors (i.e., video game and forehead cold) for systolic BP (SBP) and diastolic BP (DBP) were assessed in a sample of 24 African American males (M age = 18.8, ± 2.7 years). Circadian variability of cortisol level was taken into account by partialling out collection time. Family SES was inversely related to initial cortisol level (partial r = -.46, p < .03). Neighborhood SES was inversely related to DBP reactivity (r = -.41, p < .05). The change in cortisol level during the stressor protocol was related to SBP reactivity (partial r = .44, p < .05). These results suggest that SES may be linked to CVD via BP and cortisol reactivity to stress, but prospective studies are needed to clarify whether such is the case. Preparation of this article was supported in part by Grants HL 69999 and HL 41781 from the National Institutes of Health.     

Auditory reflex thresholds elevated by stress-induced cortisol secretion

To study steroid effects on auditory perception, 24 volunteers were unexpectedly confronted with a psychological stressor. Auditory reflexes to pure tones and noise were recorded before stress exposure, up to 100 min afterwards and in a second control session. Repeated measurements of cortisol and testosterone in saliva, as well as blood pressure, heart rate, and subjective feelings confirmed the stressful nature of the test. Following stress induction the auditory reflex of the contralateral ear needed significantly higher loudness (i.e. more decibels) to be elicited than at baseline or control measures. Two lines of evidence suggest that this stress-induced change may be specifically related to glucocorticoid actions: (1) In a previous study similar elevations in auditory reflex threshold had been obtained by the administration of exogenous glucocorticoids (hydrocortisone), and (2) in the present study the overall effect of stress induction on acoustic reflex described above was mainly observed in a subgroup of subjects, who responded to the stressor with a marked rise in free cortisol.     

Severe decrements in cognition function and mood induced by sleep loss, heat, dehydration, and undernutrition during simulated combat.

BACKGROUND: Military exercises generate high levels of stress to simulate combat, providing a unique opportunity to examine cognitive and physiologic responses of normal humans to acute stress. METHODS: Cognitive and physiologic markers of stress were evaluated before, during, and after an intense training exercise conducted for 53 hours in the heat. Cognitive performance, mood, physical activity, sleep, body composition, hydration, and saliva cortisol, testosterone, and melatonin were assessed. Volunteers were 31 male U.S. Army officers from an elite unit, aged 31.6 +/- .4 years. RESULTS: Wrist activity monitors documented that soldiers slept only 3.0 +/- .3 hours during the exercise and were active throughout. Volunteers lost 4.1 +/- .2 kg (p < .001) of weight, predominately water (3.1 +/- .3 L) (p < .001). Substantial degradation in cognitive function, assessed with computerized tests, occurred. Vigilance, reaction time, attention, memory, and reasoning were impaired (p < .001). Mood, including vigor (p < .001), fatigue (p < .001), confusion (p < .001), depression (p < .001), and tension (p < .002), assessed by questionnaire, deteriorated. The highest cortisol and testosterone levels were observed before the exercise. CONCLUSIONS: This study quantifies the overwhelmingly adverse impact of multiple stressors on cognitive performance, mood, and physiologic parameters, during a continuous but brief military exercise conducted by highly motivated, well-trained officers.     

EFFECT OF MULTI-FUNCTIONAL FABRIC ON SLEEP STAGES AND GROWTH HORMONE LEVELS DURING SLEEP

Nine young girls participated in cross-over sessions, sleeping with either­ multi-functional fabric (experimental session) or cotton (control session). The relative duration of slow-wave sleep (SWS) was 1.89-fold higher in the experimental session than in the control session. The peak growth hormone (GH) secretion in the experimental session was more than 2.4-fold higher than during the control session (p &lt;. 001). The quality of sleep during the experimental session was significantly better than in the control session (p &lt;. 01). These results suggest that multi-functional fabric wear is effective in inducing deep sleep, increasing GH, and improving the quality of sleep.     

Exposure to violence and cardiovascular and neuroendocrine measures in adolescents

Background: Exposure to violence has clear, detrimental psychological consequences, but the physiological effects are less well understood.Purpose: This study examined the influence of exposure to violence on biological basal and reactivity measures in adolescents.Methods: There were 115 high school student participants. Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), HR variability (HRV), and cortisol levels were recorded during baseline and a laboratory stressor. The Exposure to Violence interview was administered and assessed two dimensions: total observed violence and total personally experienced violence. These were then divided into component parts: lifetime frequency, proximity, and severity.Results: Greater total experienced violence was associated with increased basal SBP (r = .19, p < .05) and decreased acute stress reactivity in terms of SBP (β =−.13, p = .05), HR (β =−.21, p = .00), and HRV (β = .13, p = .05). Lifetime frequency of experienced violence was associated with higher basal DBP (r = .33, p < .05), HR (r = .33, p < .05), and cortisol (r = .53, p < .00), and decreased SBP (β = −.27, p < .05) and DBP (β = −.31, p < .05) reactivity. Exposure to violence is associated with increased biological basal levels in adolescents, supporting allostatic-load research and decreased cardiovascular reactivity, supporting the inoculation effect.Conclusions: The findings illustrate that being a victim of violence has more pervasive biological consequences than witnessing violence and that the accumulation of stressful experiences has the greatest effect on biological markers. This research was supported by the Division 38 graduate student research award in Health Psychology (American Psychological Association), the Canadian Institutes for Health Research, the Michael Smith Foundation for Health Research, and theWilliam T. Grant Foundation.     

Dynamics of telomerase activity in response to acute psychological stress

Telomerase activity plays an essential role in cell survival, by lengthening telomeres and promoting cell growth and longevity. It is now possible to quantify the low levels of telomerase activity in human leukocytes. Low basal telomerase activity has been related to chronic stress in people and to chronic glucocorticoid exposure in vitro. Here we test whether leukocyte telomerase activity changes under acute psychological stress. We exposed 44 elderly women, including 22 high stress dementia caregivers and 22 matched low stress controls, to a brief laboratory psychological stressor, while examining changes in telomerase activity of peripheral blood mononuclear cells (PBMCs). At baseline, caregivers had lower telomerase activity levels than controls, but during stress telomerase activity increased similarly in both groups. Across the entire sample, subsequent telomerase activity increased by 18% one hour after the end of the stressor (p < 0.01). The increase in telomerase activity was independent of changes in numbers or percentages of monocytes, lymphocytes, and specific T cell types, although we cannot fully rule out some potential contribution from immune cell redistribution in the change in telomerase activity. Telomerase activity increases were associated with greater cortisol increases in response to the stressor. Lastly, psychological response to the tasks (greater threat perception) was also related to greater telomerase activity increases in controls. These findings uncover novel relationships of dynamic telomerase activity with exposure to an acute stressor, and with two classic aspects of the stress response – perceived psychological stress and neuroendocrine (cortisol) responses to the stressor.     

Cortisol-dependent stress effects on cell distribution in healthy individuals and individuals suffering from chronic adrenal insufficiency

Chronic adrenal insufficiency (CAI) is characterized by a lack of glucocorticoid and mineralocorticoid production due to destroyed adrenal cortex cells. However, elevated cortisol secretion is thought to be a central part in a well-orchestrated immune response to stress. This raises the question to what extent lack of cortisol in CAI affects stress-related changes in immune processes.To address this question, 28 CAI patients (20 females) and 18 healthy individuals (11 females) (age: 44.3 ± 8.4 years) were exposed to a psychosocial stress test (Trier Social Stress Test: TSST). Half the patients received a 0.03 mg/kg body weight injection of hydrocortisone (HC) post-TSST to mimic a healthy cortisol stress response. Catecholamines and immune cell composition were assessed in peripheral blood and free cortisol measured in saliva collected before and repeatedly after TSST.CAI patients showed norepinephrine (NE) stress responses similar to healthy participants, however, epinephrine (E) as well as cortisol levels were significantly lower. HC treatment post-TSST resulted in cortisol increases comparable to those observed in healthy participants (interaction effects – NE: F = 1.05, p = .41; E: F = 2.56, p = .045; cortisol: F = 13.28, p < .001). Healthy individuals showed the expected pattern of stress-related early lymphocyte increase with subsequent decrease below baseline. The opposite pattern was observed in granulocytes. While exhibiting a similar initial increase, lymphocytes kept increasing over the following 2 h in untreated patients. HC treatment buffered this effect (interaction effects – lymphocyte%: F = 7.31, p < .001; granulocyte%: F = 7.71, p < .001).Using CAI in humans as a model confirms cortisol’s central involvement in post-stress lymphocyte migration from blood into immune-relevant body compartments. As such, future studies should investigate whether psychosocial stress exposure may put CAI patients at an increased health risk due to attenuated immune responses to pathogens.     

Self-assessed parental depressive problems are associated with blunted cortisol responses to a social stress test in daughters. The TRAILS Study

Depression runs in families and is considered a stress-related disorder. Familial risk for depression may be transmitted via deregulated psychophysiological stress responses from parent to child. In this study, we examined the association between self-assessed lifetime parental depressive problems (PDP) and adolescent offspring' cortisol responses to a social stress test. Data were collected as part of the third assessment wave of TRAILS (TRacking Adolescents' Individual Lives Survey), a large prospective population study of Dutch adolescents. Data of 330 adolescents (mean age 16.04; 40.9% girls) who participated in a laboratory session, including a standardized performance-related social stress task (public speaking and mental arithmetic) were examined. Four saliva cortisol samples were collected before, during and after the social stress task which were analyzed with repeated measures Analysis of Variance. Lifetime parental depressive problems were assessed by self-reports from both biological parents. PDP was associated with daughter' cortisol responses (F(3,133)=3.90, p=.02), but no association was found in sons (F(3,193)=0.27, p=.78). Girls whose parents ever experienced depressive symptoms displayed a blunted cortisol response to the standardized social stress test, while girls whose parents never had such problems displayed the characteristic curvilinear response pattern. This effect was not mediated by offspring stress history (age 0-16). Analyses were corrected for smoking behaviour and adolescent depressed mood. The fact that PDP were measured by self-report questionnaires and did not reflect clinical DSM-IV diagnosis could be considered a limitation of the study.     

Enhanced adrenocortical responses to stress in Hypertension-Prone Men and Women

Hypertension risk may be associated with increased adreno-cortical activity, but the extent to which this enhanced activation differs between men and women at rest and in response to psychological stress is not known. This study examined gender differences in adrenocortical responses to an extended public-speaking stressor in persons at high (resting systolic blood pressure > median; n = 21)or low risk (negative parental history and = median systolic blood pressure; n = 26). Salivary cortisol levels were assessed at rest and in response to public speaking in a repeated measure design on two test sessions held on separate days. Heart rate, systolic blood pressure, and diastolic blood pressure were obtained at 3-min intervals before, during, and after the task. High-risk participants showed greater cortisol, blood pressures, and heart rate responses to the public-speaking stressor than the low-risk group (ps < .01). Men showed greater cortisol concentrations than women (p < .05), independent of hypertension risk status. Cardiovascular measures during the acute stressor predicted subsequent cortisol production, but only in the high-risk group. Results suggest that hypertension risk is associated with enhanced physiological reactivity across sympathetic and adrenocortical systems, supporting the possibility that this exaggerated reactivity may represent a marker of risk in hypertension-prone men and women. This research was supported in part by grants from the Minnesota Medical Foundation, the University of Minnesota Graduate School Grant-in-Aid program, and the Whiteside Clinical Research Institute. During this study Mustafa al’Absi was also funded by National Institute of Health Grants CA 88272 and HL 64794. We thank Clemens Kirschbaum of the University of Düsseldorf, Germany, for assistance with the salivary cortisol assay. We also thank Katie Bellmont, Todd Amunrud, and Nicolas Crost for assistance with data collection and management. We thank Carol Peterman for her editorial work on this article.     

Investigation into the cross-correlation of salivary cortisol and alpha-amylase responses to psychological stress

Stress is a multidimensional construct. To accurately represent stress physiology, multiple stress measures across multiple stress-related systems should be assessed. However, associations may be masked given that different systems underlie different time courses. Salivary cortisol and alpha-amylase (sAA) are reliable biological stress markers of the sympathetic nervous system (SNS) and the hypothalamus pituitary adrenal (HPA) axis, respectively. Studies examining the link between sAA and cortisol levels in response to stress have produced inconsistent results. Here, we investigated whether the covariance of stress-induced sAA and cortisol release is dependent on the distinct temporal dynamics of the two stress markers. A total of 50 male participants were exposed to a psychological laboratory stressor with high frequency (2-min interval) saliva sampling in two independent studies. Synchronized time series of sAA and cortisol measures before, during and after stress induction were obtained. Cross-correlation analysis was applied to test for the association of sAA and cortisol levels at various stages relative to the onset of the stressor. Positive and negative cross-correlations between lagged pairs of sAA and cortisol measures were found in both studies. The strongest correlation was found for sAA preceding cortisol release by 13.5 min (r = .27, p < .001). With a smaller effect size cortisol also significantly preceded sAA by 13.5 min (r = -.16, p < .001). We suggest that sAA and cortisol stress responses are reliably associated at various time lags throughout a stressful situation. As a possible connection site between HPA axis and SNS that may underlie sAA-cortisol associations, we discuss CRF neurons of the hypothalamus involved in sympathetic regulation.     

Slow-wave sleep and androgens: selective slow-wave sleep suppression affects testosterone and 17α-hydroxyprogesterone secretion

ObjectivesLevels of steroid hormones such as androgens and cortisol exhibit circadian variation, and their fluctuations are related to the sleep-wake cycle. Currently, the functional role of different stages of sleep in steroid hormone secretion remains unclear. The present study aims to explore the effect of slow-wave sleep (SWS) suppression on morning levels of cortisol and androgens.MethodsTwelve healthy male volunteers participated in two experimental sessions: a session with selective SWS suppression during night sleep and a session with regular night sleep (control). SWS suppression was achieved by stimulation using an acoustic tone. Salivary samples were collected in the morning immediately after awakening and again 40 min later. The samples were analysed by liquid chromatography-tandem mass spectrometry for testosterone, androstenedione (Ad), dehydroepiandrosterone (DHEA), 17α-hydroxyprogesterone (17-OHP), and cortisol.ResultsSWS suppression reduced overall SWS duration by 54.2% without significant changes in total sleep time and sleep efficiency. In the session with selective SWS suppression, the average level of morning testosterone was lower than in the control session (p = 0.017). Likewise, 17-OHP was lower in the SWS suppression condition (p = 0.011) whereas the ratio of DHEA/Ad was higher (p = 0.025). There were no significant differences between sessions in cortisol, Ad, or DHEA concentrations.ConclusionsThe effect of selective SWS suppression on morning levels of testosterone and 17-OHP points to the importance of SWS for the synthesis and secretion of androgens. These results suggest that chronic sleep problems, which lead to reduced SWS, increase the risk for the development of androgen deficiency in the long term.     

Plasma testosterone levels in patients with combat-related posttraumatic stress disorder

BACKGROUND: An abnormal level of androgens has been reported in various psychiatric disorders and the important role of androgens in the regulation of human sexuality, aggression, cognition, emotions and personality have been described. Previous studies in the area of stress and the hypothalamic-pituitary-gonadal (HPG) system in humans indicate that circulating testosterone levels are suppressed by physical and psychological stress. However, there is also evidence that plasma levels of testosterone can increase during potentially stressful events and may be elevated in combat-related posttraumatic stress disorder (CR-PTSD) in comparison with normal subjects and major depressive disorder patients. METHODS: The aim of the present study was to examine the possible involvement of the HPG system in chronic untreated CR-PTSD. To this end, we assessed the morning plasma levels of testosterone and cortisol in never-treated chronic CR-PTSD outpatients compared with normal healthy controls. RESULTS: There were no statistically significant differences between the CR-PTSD patients and healthy control subjects in morning plasma testosterone (547.8 +/- 152.2 ng/dl vs. 565.6 +/- 122.4 ng/dl; p = 0.7) and cortisol (19.0 +/- 8.5 microg/dl vs. 15.4 +/- 5.1 microg/dl; p = 0.1) levels. However, a significant correlation between plasma testosterone level and avoidance symptom scores of the Impact of Events Scale (IES) was found in the CR-PTSD patients (r = 0.43, p < 0.05). CONCLUSIONS: The findings of plasma testosterone levels comparable with normal controls in CR-PTSD patients may indicate that the previously described reduction in testosterone levels in normal subjects under stressful conditions may reflect the acute stress response of the HPG axis, in contrast to an adaptation of the HPG axis under chronic psychological stress.     

Effects of web-based cognitive behavioral stress management and health promotion interventions on neuroendocrine and inflammatory markers in men with advanced prostate cancer: A randomized controlled trial

Cognitive behavioral stress management (CBSM) improves quality of life and mitigates stress biology in patients with early-stage cancer, including men with localized prostate cancer. However, treatments for advanced prostate cancer like androgen deprivation therapy (ADT) can lead to significant symptom burden that may be further exacerbated by stress-induced inflammation and cortisol dysregulation. The aim of this study was to examine the effects of CBSM (versus an active health promotion control) on circulating inflammatory markers and cortisol in men with advanced prostate cancer. Methods: Men with stage III or IV prostate cancer (N = 192) who had undergone ADT within the last year were randomized to CBSM or health promotion. Both interventions were 10 weeks, group-based, and delivered online. Venous blood was drawn at baseline, 6 months, and 12 months to measure circulating levels of CRP, IL-6, IL-8, IL-10, and TNF-α. Saliva samples were collected at awakening, 30 min after awakening, evening, and night for two consecutive days at baseline, 6-months, and 12-months to measure diurnal cortisol slopes. Results: Mixed modeling analyses demonstrated that changes in inflammatory markers and cortisol did not differ by intervention. Men in both CBSM and health promotion showed decreases in IL-10, IL-8, and TNF-α from baseline to 6 months (β = −3.85–−5.04, p’s = 0.004–<0.001). However, these markers generally demonstrated a rebound increase from 6 to 12 months (β = 1.91–4.06, p’s = 0.06–<0.001). Men in health promotion also demonstrated a flatter diurnal cortisol slope versus men in CBSM at 6 months (β = −2.27, p = .023), but not at 12 months. There were no intervention effects on CRP, IL-6, or overall cortisol output. Conclusions: Contrary to hypotheses, CBSM did not lead to changes in the circulating inflammatory markers and cortisol relative to health promotion. CBSM may be associated with healthy diurnal cortisol rhythm because of its focus on cognitive behavioral approaches to stress management. More research is needed to understand the impact of CBSM and health promotion on biomarkers among men with advanced prostate cancer.     

Eccentric-exercise induced inflammation attenuates the vascular responses to mental stress

Mental stress has been identified as a trigger of myocardial infarction (MI), with inflammation and vascular responses to mental stress independently implicated as contributing factors. This study examined whether inflammation moderates the vascular responses to mental stress. Eighteen healthy male participants completed a stress task under two counter balanced conditions. In the exercise condition, a morning bout of eccentric exercise (12 × 5 repetitions of unilateral eccentric knee extension at 120% intensity of concentric one repetition maximum) was used to increase levels of inflammatory-responsive cytokines during an afternoon stress session scheduled 6 h later. In the control condition, participants sat and relaxed for 45 min, 6 h prior to the afternoon stress session. Forearm blood flow, calf blood flow (measured in the leg which completed the exercise task), blood pressure, heart rate and cardiac output were assessed at rest and in response to mental stress. As expected, interleukin-6 was higher (p = .02) 6 h post exercise, i.e., at the start of the stress session, as compared to the no-exercise control condition. Mental stress increased forearm blood flow, calf blood flow, blood pressure, heart rate, and cardiac output in both conditions (p’s < .001). Stress-induced calf blood flow was attenuated in the exercise condition compared to the control condition (p < .05) which was not the case for forearm blood flow. This study found that the inflammatory response to eccentric exercise attenuated the vascular responses to mental stress locally at the site of eccentric exercise-induced inflammation. The observed impairment in vascular responses to stress associated with increased levels of inflammation suggests a mechanism through which inflammation might increase the risk for MI.     

Marital-role quality and stress-related psychobiological indicators

Background: The quality of one’s marital relationship is gaining recognition as a potential stressor associated with negative health outcomes.Purpose: In this study, we estimated the relationship between marital-role quality and three psychobiological stress indicators (self-reported stress, cortisol levels, and ambulatory blood pressure).Method: Participants were 105 middle-age adults (67 men, 38 women) who had previously taken part in the Whitehall psychobiology study. Ambulatory monitoring and saliva sampling were carried out over a working day, and marital relationships were assessed with the Marital/Partner Role Quality scales.Results: We found that marital-role concerns (but not marital-role rewards) were related to all three psychobiological stress indicators; results did not vary by gender. Specifically, participants with more marital concerns reported greater stress throughout the day (p=.014), showed an attenuated cortisol increase following waking (p=.042) and a flatter cortisol slope over the day (p=.010), and had elevated ambulatory diastolic blood pressure over the middle of the workday (p=.004), with a similar trend in systolic pressure (p=.069).Conclusions: The results suggest that in addition to the carryover of work stress into domestic life that has been evident for many years, there are also influences of domestic strain on biological function over the working day and evening. Previous research suggests that a possible mechanism linking troubled marriages to health outcomes is depressed immune functioning. This study suggests a second mechanism—poorer stress-related biological response. This research was supported by the Medical Research Council.     

Increasing correlations between personality traits and cortisol stress responses obtained by data aggregation

Attempts to links personality traits and cortisol stress responses have often been inconclusive. The aim of this paper was to investigate this association by aggregating cortisol stress responses. Therefore, 20 healthy men were exposed to a task consisting of public speaking and mental arithmetics in front of an audience on five days. Six cortisol levels were measured in relation to the stressful task obtained at 10-min intervals on each day. Psychological assessment included the Questionnaire for Competence and Control (FKK) and the Giessen-Test (G-T). These questionnaires focus on assessing personality traits, i.e. locus of control and self-concept. Areas under the response curve (AUC) of the six cortisol samples were computed to obtain an index of the individual's cortisol stress response on each day. Since novelty is a random situational factor likely to mask individual differences in the stress response, the AUC cortisol stress responses of days two to five were consecutively aggregated, excluding the first day. Scales of the two questionnaires employed did not correlate with the AUC cortisol stress response of the first stress trial. The correlation pattern of the AUC cortisol measures of days two to five with the questionnaire scales was inconclusive. However, significant correlations emerged with an increasing number of cortisol stress responses aggregated. Correlations between the measure of social dominance and aggregated AUC cortisol stress responses rose from r = −.47 on day two of the experimental session to r = −.70 after aggregating days two to five. Similarly, measures of locus of control and cortisol stress responses became increasingly correlated with aggregation of several stress exposures. These data provide preliminary evidence for a relationship between questionnaire scales aiming at assessing personality traits and cortisol stress responses uncovered by repeated stress exposure and data aggregation. While novelty may mask the impact of personality on the cortisol stress response on the first exposure, differences in the ability to cope with the stressful situation may lead to different cortisol stress response patterns on subsequent stress exposures. With data aggregation, an association between the trait component of cortisol stress responses and questionnaire scales might be uncovered. For reliable investigation of correlations between personality variables and cortisol stress responses, repeated stress exposure and data aggregation is suggested.     

Effect of Sleep Extension on the Subsequent Testosterone,Cortisol and Prolactin Responses to Total Sleep Deprivation and Recovery

Total sleep deprivation (TSD) in humans is associated with altered hormonal levels, which may have clinical relevance. Less is known about the effect of an extended sleep period before TSD on these hormonal changes. Fourteen subjects participated in two experimental counterbalanced conditions (randomised cross‐over design): extended sleep (21.00–07.00 h time in bed, EXT) and habitual sleep (22.30–07.00 h time in bed, HAB). For each condition, subjects performed two consecutive phases: six nights of either EXT or HAB. These nights were followed by 3 days in the sleep laboratory with blood sampling at 07.00 and 17.00 h at baseline (B‐07.00 and B‐17.00), after 24 and 34 h of continuous awakening (24 h‐CA, 34 h‐CA) and after one night of recovery sleep (R‐07.00 and R‐17.00) to assess testosterone, cortisol, prolactin and catecholamines concentrations. At 24 h of awakening, testosterone, cortisol and prolactin concentrations were significantly lower compared to B‐07.00 and recovered basal levels after recovery sleep at R‐07.00 (P < 0.001 for all). However, no change was observed at 34 h of awakening compared to B‐17.00. No effect of sleep extension was observed on testosterone, cortisol and catecholamines concentrations at 24 and 34 h of awakening. However, prolactin concentration was significantly lower in EXT at B‐07.00 and R‐07.00 compared to HAB (P < 0.05, P < 0.001, respectively). In conclusion, 24 h of awakening inhibited gonadal and adrenal responses in healthy young subjects and this was not observed at 34 h of awakening. Six nights of sleep extension is not sufficient to limit decreased concentrations of testosterone and cortisol at 24 h of awakening but may have an impact on prolactin concentration.     

Influence of sleep deprivation and circadian misalignment on cortisol,inflammatory markers,and cytokine balance

Cortisol and inflammatory proteins are released into the blood in response to stressors and chronic elevations of blood cortisol and inflammatory proteins may contribute to ongoing disease processes and could be useful biomarkers of disease. How chronic circadian misalignment influences cortisol and inflammatory proteins, however, is largely unknown and this was the focus of the current study. Specifically, we examined the influence of weeks of chronic circadian misalignment on cortisol, stress ratings, and pro- and anti-inflammatory proteins in humans. We also compared the effects of acute total sleep deprivation and chronic circadian misalignment on cortisol levels. Healthy, drug free females and males (N = 17) aged 20–41 participated. After 3 weeks of maintaining consistent sleep–wake schedules at home, six laboratory baseline days and nights, a 40-h constant routine (CR, total sleep deprivation) to examine circadian rhythms for melatonin and cortisol, participants were scheduled to a 25-day laboratory entrainment protocol that resulted in sleep and circadian disruption for eight of the participants. A second constant routine was conducted to reassess melatonin and cortisol rhythms on days 34–35. Plasma cortisol levels were also measured during sampling windows every week and trapezoidal area under the curve (AUC) was used to estimate 24-h cortisol levels. Inflammatory proteins were assessed at baseline and near the end of the entrainment protocol. Acute total sleep deprivation significantly increased cortisol levels (p < 0.0001), whereas chronic circadian misalignment significantly reduced cortisol levels (p < 0.05). Participants who exhibited normal circadian phase relationships with the wakefulness–sleep schedule showed little change in cortisol levels. Stress ratings increased during acute sleep deprivation (p < 0.0001), whereas stress ratings remained low across weeks of study for both the misaligned and synchronized control group. Circadian misalignment significantly increased plasma tumor necrosis factor-alpha (TNF-α), interleukin 10 (IL-10) and C-reactive protein (CRP) (p < 0.05). Little change was observed for the TNF-α/IL-10 ratio during circadian misalignment, whereas the TNF-α/IL-10 ratio and CRP levels decreased in the synchronized control group across weeks of circadian entrainment. The current findings demonstrate that total sleep deprivation and chronic circadian misalignment modulate cortisol levels and that chronic circadian misalignment increases plasma concentrations of pro- and anti-inflammatory proteins.     

Intranasal insulin attenuates the hypothalamic-pituitary-adrenal axis response to psychosocial stress

Previous studies have shown that intranasally administered insulin exerts an inhibitory influence on the basal hypothalamic-pituitary-adrenal (HPA) axis activity. To date, however, it remains unclear as to whether intranasal insulin does furthermore affect HPA axis responsiveness in situations of stress. Here, we tested whether intranasally administered insulin attenuates the HPA axis response to psychosocial stress. Fifty minutes before being exposed to the Trier Social Stress Test (TSST), 26 healthy young male participants received a single intranasal dose of human insulin (40 I.U.) or placebo in a placebo controlled, double-blind between-subject design. Plasma cortisol, saliva cortisol, heart rate, and blood pressure were measured at resting baseline and in response to the TSST. Plasma cortisol (P<.001) and saliva cortisol (P<.001) increased in response to stress, as did heart rate (P<.001) and blood pressure (P<.001). Intranasal insulin did not influence plasma or saliva cortisol, heart rate, blood pressure, blood glucose, and plasma insulin levels at baseline. However, intranasal insulin diminished the saliva cortisol (two-way ANOVA; treatment by time interaction: P=.05) and plasma cortisol (two-way ANOVA; treatment by time interaction: P=.05) response to the TSST without affecting heart rate, and blood pressure stress reactivity. Our data show that a single intranasal insulin administration effectively lowers stress-induced HPA axis responsiveness. Intranasal insulin may offer a therapeutic potential to prevent hyperactivity of the HPA system.