The effect of cognitive reappraisal and early-life maternal care on neuroendocrine stress responses.

Early-life adversity (ELA) is related to profound dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, reflected in both, blunted or exaggerated cortisol stress responses in adulthood. Emotion regulation strategies such as cognitive reappraisal might contribute to this inconsistent finding. Here, we investigate an interaction of early-life maternal care (MC), where low MC represents a form of ELA, and instructed emotion regulation on cortisol responses to acute stress. Ninety-three healthy young women were assigned to a low (n = 33) or high (n = 60) MC group, based on self-reported early-life MC. In the laboratory, participants received regulation instructions, asking to cognitively reappraise (reappraisal group, n = 45) or to focus on senses (control group, n = 48) during subsequent stress exposure, induced by the Trier Social Stress Test. Salivary cortisol and subjective stress levels were measured repeatedly throughout the experiment. Multilevel model analyses confirmed a MC by emotion regulation interaction effect on cortisol trajectories, while controlling for hormonal status. Individuals with low MC in the control compared with the reappraisal group showed increased cortisol responses; individuals with high MC did not differ. These results highlight the significance of emotion regulation for HPA axis stress regulation following ELA exposure. They provide methodological and health implications, indicating emotion regulation as a promising target of treatment interventions for individuals with a history of ELA.

Estimation of antibody levels after COVID-19 vaccinations: Preliminary evidence for immune interoception.

To date, 72 % of the world's population has received at least one COVID-19 vaccination. The number of antibodies produced by some individuals is exponentially higher than in others, for various mostly unknown reasons. This variation causes great diversity in the future susceptibility to infection by the original or variants of the SARS-CoV-2 virus. The following study investigated whether individuals were able to estimate the strength of their antibody response after their COVID-19 vaccinations. 166 recently vaccinated participants provided a blood sample for determination of antibody titers. Participants were asked to estimate how many antibodies they thought they had produced, and were further asked how protected they felt from COVID-19 due to vaccination. Both self-rated antibody levels, and feelings of protection against COVID-19 were significantly related to their actual IgG spike antibody titers, after controlling for age, days since vaccination, BMI and cross vaccination. These results suggest that individuals may have a form of "immune interoception" which relates to their response to their COVID-19 vaccination.

Increased empathic distress in adults is associated with higher levels of childhood maltreatment.

While many studies investigated basic facets of empathy, less is known about the association with early life adversity (ELA). To investigate a possible association of empathy with ELA, we assessed self-reported ELA, using the Childhood Trauma Questionnaire (CTQ), the Parental Bonding Instrument (PBI) for mother and father, and empathy, using the Interpersonal Reactivity Index (IRI), in a sample of N = 228 (83% female, agemean = 30.51 ± 9.88 years, agerange = 18-60). Further, we measured willingness to donate a certain percentage of study compensation to a charity as an index of prosocial behavior. In line with our hypotheses that stated a positive association of empathy with ELA, increased levels of emotional, physical, and sexual abuse, and emotional and physical neglect were positively correlated with personal distress in response to others' suffering. Likewise, higher parental overprotection and lower parental care were related to higher personal distress. Furthermore, while participants with higher levels of ELA tended to donate more money on a merely descriptive level, only higher levels of sexual abuse were significantly related to larger donations after correction for multiple statistical tests. Other facets of the IRI (empathic concern, perspective taking and fantasy) were not related to any other ELA measure. This suggests ELA only affects levels of personal distress.

Challenges and opportunities of diagnostic markers of Alzheimer's disease based on structural magnetic resonance imaging.

OBJECTIVES: This article aimed to carry out a narrative literature review of early diagnostic markers of Alzheimer's disease (AD) based on both micro and macro levels of pathology, indicating the shortcomings of current biomarkers and proposing a novel biomarker of structural integrity that associates the hippocampus and adjacent ventricle together. This could help to reduce the influence of individual variety and improve the accuracy and validity of structural biomarker. METHODS: This review was based on presenting comprehensive background of early diagnostic markers of AD. We have compiled those markers into micro level and macro level, and discussed the advantages and disadvantages of them. Eventually the ratio of gray matter volume to ventricle volume was put forward. RESULTS: The costly methodologies and related high patient burden of "micro" biomarkers (cerebrospinal fluid biomarkers) hinder the implementation in routine clinical examination. In terms of "macro" biomarkers- hippocampal volume (HV), there is a large variation of it among population, which undermines its validity Considering the gray matter atrophies while the adjacent ventricular volume enlarges, we assume the hippocampal to ventricle ratio (HVR) is a more reliable marker than HV alone the emerging evidence showed hippocampal to ventricle ratio predicts memory functions better than HV alone in elderly sample. CONCLUSIONS: The ratio between gray matter structures and adjacent ventricular volumes counts as a promising superior diagnostic marker of early neurodegeneration.

The effects of left dorsolateral prefrontal transcranial direct current stimulation on episodic future thinking following acute psychosocial stress.

INTRODUCTION: Research on stress-related disorders and brain imaging suggests that (acute) stress might impact the capacity to mentally simulate specific episodic future events (EFT) through the effects of cortisol on brain regions supporting this cognitive function, such as the prefrontal cortices. This study aims to examine the mechanisms underlying this link, using transcranial Direct Current Stimulation (tDCS) over the left dorsolateral prefrontal cortex. METHODS: 60 healthy participants were subjected to the Montreal Imaging Stress Task (MIST), followed by either active or sham tDCS. After stimulation, the EFT task was administered. Salivary cortisol was measured throughout the protocol. RESULTS: Higher cortisol AUCi values were linked to less specific episodic future thoughts. Moreover, active tDCS enhanced EFT specificity irrespective of cortisol, especially in high trait ruminators. We did not observe an effect from active tDCS on cortisol AUCi, and equally there was no interaction effect between cortisol AUCi and stimulation condition predictive for EFT specificity. CONCLUSION: Although we did not find evidence for the effects of tDCS on the HPA-system, our data reveal a crucial link between two critical predictors of mental health for the first time, and provide a solution to help rehabilitate EFT deficits.Trial registration: Netherlands National Trial Register identifier: ntr004..

A novel stress-based intervention reduces cigarette use in non-treatment seeking smokers.

Tobacco use is the leading cause of preventable mortality worldwide. Since current smoking cessation aids show only modest efficacy, new interventions are needed. Given the evidence that stress is a potent trigger for smoking, the present randomized clinical trial tested whether stress could augment the effects of a memory updating (retrieval-extinction) intervention. Non-treatment seeking smokers (n = 76) were assigned to one of four conditions composed of either a stressful or non-stressful psychosocial challenge followed by either smoking or neutral cues. Ten minutes after this manipulation, all underwent a 60-minute extinction procedure during which they viewed smoking-related videos and images and manipulated smoking paraphernalia. Compared to participants who were not exposed to the laboratory stressor, the stressor-exposed groups exhibited greater psychophysiological responses during their intervention and greater decreases in cigarette use at two- and six-weeks follow-up independent of smoking cue exposure. Together, these findings suggest that the ability of stress to activate cigarette seeking processes can be exploited to decrease cigarette use. With replication, the stress-based intervention could become a novel strategy for decreasing cigarette use in non-treatment seeking smokers.Clinicaltrials.gov identifier: NCT04843969.

Evaluation and update of the expert consensus guidelines for the assessment of the cortisol awakening response (CAR).

The cortisol awakening response (CAR) is frequently assessed in psychobiological (stress) research. Obtaining reliable CAR data, however, requires careful attention to methodological detail. To promote best practice, expert consensus guidelines on the assessment of the CAR were published (Stalder et al., 2016, PNEC). However, it is unclear whether these highly cited guidelines have resulted in actual methodological improvements. To explore this, the PNEC editorial board invited the present authors to conduct a critical evaluation and update of current CAR methodology, which is reported here. (i) A quantitative evaluation of methodological quality of CAR research published in PNEC before and after the guidelines (2013-2015 vs. 2018-2020) was conducted. Disappointingly, results reveal little improvement in the implementation of central recommendations (especially objective time verification) in recent research. (ii) To enable an update of guidelines, evidence on recent developments in CAR assessment is reviewed, which mostly confirms the accuracy of the majority of the original guidelines. Moreover, recent technological advances, particularly regarding methods for the verification of awakening and sampling times, have emerged and may help to reduce costs in future research. (iii) To aid researchers and increase accessibility, an updated and streamlined version of the CAR consensus guidelines is presented. (iv) Finally, the response of the PNEC editorial board to the present results is described: potential authors of future CAR research to be published in PNEC will be required to submit a methodological checklist (based on the current guidelines) alongside their article. This will increase transparency and enable reviewers to readily assess the quality of the respective CAR data. Combined, it is hoped that these steps will assist researchers and reviewers in assuring higher quality CAR assessments in future research, thus yielding more reliable and reproducible results and helping to further advance this field of study.

Stress and Stress-Induced Glucocorticoids Facilitate Empathic Accuracy in Men but Have No Effects for Women.

Empathy, the ability to understand the feelings of other people, is critical for navigating our social world and maintaining social connections. Given that acute stress, and resulting increased glucocorticoids, triggers a shift in two large-scale brain networks, prioritizing salience over executive control, we predicted that acute psychosocial stress would facilitate empathic accuracy. We also investigated the moderating role of gender, given that men typically show a more robust glucocorticoid response to acute stress than women. As predicted, results from two independent experiments (N = 267 college-age participants; 2,256 observations) showed that acute psychosocial stress facilitated empathic accuracy for men, an effect related to their glucocorticoid response in the stress condition. Conversely, psychosocial stress had no effect on empathic accuracy for women, who also showed a smaller cortisol response to stress than men. Exploratory analyses further revealed that women taking oral contraceptives performed worse on the empathic-accuracy task than regularly cycling women. This research highlights the important, but complex, role of stress in cognitive empathy.

Nature-Based Relaxation Videos and Their Effect on Heart Rate Variability.

Growing evidence suggests that natural environments - whether in outdoor or indoor settings - foster psychological health and physiological relaxation, indicated by increased wellbeing, reduced stress levels, and increased parasympathetic activity. Greater insight into differential psychological aspects modulating psychophysiological responses to nature-based relaxation videos could help understand modes of action and develop personalized relaxation interventions. We investigated heart rate variability (HRV) as an indicator of autonomic regulation, specifically parasympathetic activity, in response to a 10-min video intervention in two consecutive studies as well as heart rate (HR). We hypothesized that a nature-based relaxation video elicits HRV increase and HR decrease, with response magnitude being affected by aspects of early life adversity (conceptualized as low parental care and high overprotection/constraint) and trait mindfulness. In Study 1, N = 60 participants (52% female, age mean = 23.92 ± 3.13 years, age range = 18-34 years) watched a relaxation video intervention depicting different natural scenery. We analyzed changes in HR and respiratory sinus arrhythmia (RSA) as a standard HRV measure, both based on 3-min segments from the experimental session, in multiple growth curve models. We found a decrease in HR and increase of RSA during the video intervention. Higher paternal care and lower trait mindfulness observing skills (assessed via questionnaires) were associated with higher RSA values before but not during video exposure. In Study 2, N = 90 participants (50% female, age mean = 22.63 ± 4.57 years, age range = 18-49 years) were assigned to three video conditions: natural scenery from Study 1, meditation video, or short clip from "The Lord of the Rings." Again, HR decreased, and RSA increased during video segments, yet without expected group differences across different video types. We found higher parental care and lower parental overprotection to predict higher RSA at different times during the experiment. Interestingly, lower paternal overprotection predicted overall higher RSA. These results suggest a generic relaxation effect of video interventions on autonomic regulation that we discuss in light of different theories mapping restorative effects of natural environments. Further, psychological characteristics like aspects of early life adversity and trait mindfulness could contribute to individual differences in autonomic regulation. This study contributes to a better understanding of autonomic and psychological responses to relaxation videos.

Validation of an online version of the trier social stress test in adult men and women.

The Trier Social Stress Test (TSST) is a reliable and efficient protocol to induce acute psychosocial stress in the laboratory. If circumstances do not allow in-person assessments, an online version of the TSST could create more flexible research opportunities. To date, studies have confirmed subjective and autonomic stress responses to online TSST protocols. In this preregistered study (https://osf.io/u57aj), we focused on the effect of a TSST online for adults (TSST-OA) on cortisol and alpha amylase levels, and pleasure and arousal ratings. As cortisol stress reactivity is mediated by sex, we further compared men and women. We hypothesized significant increases in cortisol, alpha amylase and arousal, and a decrease in pleasure in response to the TSST-OA. Also, we expected stronger cortisol responses in males as compared with females, as in the laboratory TSST. N = 48 adults (56% female, meanage=23.02 years, SD=3.19) participated in the study. Saliva sampling devices were sent to participants' home before testing sessions, during which the experimenter, a mixed-sex panel, and the participant joined a video call. Participants underwent the TSST-OA and overall provided five saliva samples for cortisol and alpha amylase detection. Pleasure and arousal ratings and psychometric questionnaires were also completed online. As hypothesized, the TSST-OA significantly increased cortisol, alpha amylase, and arousal levels, while it decreased pleasure. Moreover, cortisol responses were significantly stronger in males as compared to females. 64% of subjects were classified as responders (cortisol rise>1.5nmol/l). The TSST-OA successfully induced psychophysiological stress in adults. Our protocol offers new possibilities to study stress outside of the laboratory.

The social transmission of stress in animal collectives.

The stress systems are powerful mediators between the organism's systemic dynamic equilibrium and changes in its environment beyond the level of anticipated fluctuations. Over- or under-activation of the stress systems' responses can impact an animal's health, survival and reproductive success. While physiological stress responses and their influence on behaviour and performance are well understood at the individual level, it remains largely unknown whether-and how-stressed individuals can affect the stress systems of other group members, and consequently their collective behaviour. Stressed individuals could directly signal the presence of a stressor (e.g. via an alarm call or pheromones), or an acute or chronic activation of the stress systems could be perceived by others (as an indirect cue) and spread via social contagion. Such social transmission of stress responses could then amplify the effects of stressors by impacting social interactions, social dynamics and the collective performance of groups. As the neuroendocrine pathways of the stress response are highly conserved among vertebrates, transmission of physiological stress states could be more widespread among non-human animals than previously thought. We therefore suggest that identifying the extent to which stress transmission modulates animal collectives represents an important research avenue.

Probiotic Mixture Containing Lactobacillus helveticus, Bifidobacterium longum and Lactiplantibacillus plantarum Affects Brain Responses to an Arithmetic Stress Task in Healthy Subjects: A Randomised Clinical Trial and Proof-of-Concept Study.

Probiotics are suggested to impact physiological and psychological stress responses by acting on the gut-brain axis. We investigated if a probiotic product containing Bifidobacterium longum R0175, Lactobacillus helveticus R0052 and Lactiplantibacillus plantarum R1012 affected stress processing in a double-blinded, randomised, placebo-controlled, crossover proof-of-concept study (NCT03615651). Twenty-two healthy subjects (24.2 ± 3.4 years, 6 men/16 women) underwent a probiotic and placebo intervention for 4 weeks each, separated by a 4-week washout period. Subjects were examined by functional magnetic resonance imaging while performing the Montreal Imaging Stress Task (MIST) as well as an autonomic nervous system function assessment during the Stroop task. Reduced activation in regions of the lateral orbital and ventral cingulate gyri was observed after probiotic intervention compared to placebo. Significantly increased functional connectivity was found between the upper limbic region and medioventral area. Interestingly, probiotic intervention seemed to predominantly affect the initial stress response. Salivary cortisol secretion during the task was not altered. Probiotic intervention did not affect cognitive performance and autonomic nervous system function during Stroop. The probiotic intervention was able to subtly alter brain activity and functional connectivity in regions known to regulate emotion and stress responses. These findings support the potential of probiotics as a non-pharmaceutical treatment modality for stress-related disorders.

Selective effects of psychosocial stress on plan based movement selection.

Efficient movement selection is crucial in everyday activities. Whether this function is governed by our stress system is so far unknown. In the current study, data from thirty-six young male adults were analyzed. They performed rule- and plan-based movement selection tasks before (session 1) and after (session 2) a psychosocial stressor, or after a control condition without additional social stressor. Results showed that the rule-based efficiency advantage which was observed prior to the psychosocial stressor was significantly reduced afterwards in the whole sample, as well as in the stress group. Regression analyses revealed that this effect was due to a modulation of the plan-based approach. Especially variations-both increase and decrease-in the parasympathetic activity (reflected by the heart rate variability measure RMSSD) appeared to be disadvantageous for plan-based movement selection improvement. In contrast, performance in the rule-based movement selection tasks appeared to be rather invariant to external influences. The current results suggest that autonomic nervous system activity might modulate motor-cognitive performance. This modulatory capability might be selective for plan-based approaches, hence the applied strategy to movement selection could be decisive when it comes to the vulnerability of motor-cognitive processes towards psychosocial stress.

The Hippocampal-Ventral Medial Prefrontal Cortex Neurocircuitry Involvement in the Association of Daily Life Stress With Acute Perceived Stress and Cortisol Responses.

OBJECTIVE: Daily life stressors include everyday irritants, hassles, and inconveniences, such as problems in traffic and unexpected work deadlines. A growing body of research has suggested higher daily stress is associated with blunted cortisol response to acute psychosocial stressors. However, so far, the neural mechanism underlying this association has not been elucidated. The current study aimed to examine the role of stress neurocircuitry between the hippocampus and the ventral medial prefrontal cortex in this relationship. METHODS: To this end, as an index of daily stress in 44 young healthy individuals (23 females; mean [standard deviation] age = 19.07 [1.11] years), the total stressful rating score of daily life stress events that occurred in a 24-hour period was quantified. Individuals were then administered a modified version of the Montreal Imaging Stress Task while undergoing functional magnetic resonance imaging scans, and their saliva samples were collected for assessment of the stress hormone cortisol. RESULTS: Results revealed that a higher level of daily stress was associated with lower salivary cortisol secretion (r = -0.39, p = .008) and lower activation of the left hippocampus (tpeak = -5.51) in response to the Montreal Imaging Stress Task. Furthermore, a higher level of daily stress was associated with stronger functional connectivity between the left hippocampus and the ventral medial prefrontal cortex/subgenual anterior cingulate cortex (tpeak = 4.91, R2= 0.365). CONCLUSIONS: Taken together, the current study suggested a possible neurocircuitry of the hippocampus and ventral medial prefrontal cortex in the relationship between daily life stress and acute psychosocial stress.

The effects of voice content on stress reactivity: A simulation paradigm of auditory verbal hallucinations.

OBJECTIVES: Psychosis is associated with increased subjective and altered endocrine and autonomic nervous system stress-reactivity. Psychosis patients often experience auditory verbal hallucinations, with negative voice content being particularly associated with distress. The present study developed a voice-simulation paradigm and investigated the effect of simulated voices with neutral and negative content on psychophysiological stress-reactivity, and the effect of mindful voice-appraisals on stress-reactivity. METHOD: Eighty-four healthy participants completed the Montreal Imaging Stress Task with simultaneous presentation of one of three randomly allocated auditory stimuli conditions: negative voices, neutral voices or non-voice ambient sounds. Subjective stress-levels and mindful voice-appraisals were assessed using questionnaire measures, and cortisol and α-amylase levels were measured using saliva samples. RESULTS: ANOVA revealed a significant effect of condition on subjective stress-levels (p = .002), but not cortisol (p = .63) or α-amylase (p = .73). Post-hoc analyses showed that negative voices increased subjective stress-levels relative to neutral voices (p = .002) and ambient sounds (p = .01), which did not differ from each other (p = .41). Mindful voice-appraisals were associated with less distress across conditions (p = .003), although negative voices were also associated with less mindful appraisals (p < .001). CONCLUSIONS: Negative voice content, rather than voices or auditory stimuli per se, is linked to greater subjective but not physiological stress-reactivity. Mindful appraisals may partially moderate this effect. These findings highlight the importance of voice content for the impact of voice-hearing, and highlight the potential value of mindfulness training to treat voice distress in psychosis.

[Psychometric Properties of a German Translation of the Parental Bonding Instrument]. / Psychometrische Kennwerte einer deutschen Übersetzung des Parental Bonding Instrument.

Parenting behavior affects a child's development as well as the etiology and treatment of mental disorders. The Parental Bonding Instrument (PBI; Parker, Tupling & Brown, 1979) is a well-known measurement tool to retrospectively assess parenting styles. Yet, no sufficiently validated German version exists to date. Therefore, we developed an updated translation of the German PBI version (PBI-dt) and analyzed its psychometric properties in an online survey based on a sample of n=791 German-speaking participants with a focus on item and reliability characteristics, construct and criterion validity as well as factorial structure of the PBI-dt.Our results indicated good item characteristics and reliability (α=0.86-0.95). Correlations between PBI and CTQ-SF (Childhood Trauma Questionnaire Short Form) scales were in line with the literature. Significant differences in the reported parenting style were found between people with and without mental illness as well as between normal-weight and overweight people. These results indicated the presence of good construct and criterion validity. Confirmatory factor analyses indicated an acceptable model fit for all fit indices in the original 2-factor model of Parker et al. (1979) as well as in the 3-factor model with the scales CareCareCareCareCareCare, Discouragement of behavioral freedomDiscouragement of behavioral freedomDiscouragement of behavioral freedomDiscouragement of behavioral freedomDiscouragement of behavioral freedomDiscouragement of behavioral freedom and Denial of psychological autonomyDenial of psychological autonomyDenial of psychological autonomyDenial of psychological autonomyDenial of psychological autonomyDenial of psychological autonomy. A 3-factor structure provided additional information, e. g., a better differentiation between normal and overweight people. Hence, this German translation of the PBI has good psychometric properties and is a reliable measuring instrument.

Determinants and Mechanisms of the Renin-Aldosterone Stress Response.

OBJECTIVE: The renin-angiotensin-aldosterone system (RAAS) plays a relevant role in regulating blood pressure and thus maintaining cardiovascular homeostasis. Although it was recently shown that RAAS parameters are responsive to acute psychosocial stress, the psychobiological determinants of the acute stress-induced RAAS activation have not yet been investigated. In a randomized placebo-controlled design, we investigated potential psychological and physiological determinants of the RAAS response and underlying mechanisms. METHODS: Fifty-seven young healthy male participants underwent either an acute standardized psychosocial stress test or a nonstress placebo task. We measured aldosterone in plasma and saliva, as well as renin, and the stress-reactive endocrine measures adrenocorticotropic hormone (ACTH), epinephrine, and norepinephrine in plasma at rest, immediately after the task and several times up to 3 hours thereafter. Moreover, we assessed stress-reactive psychological (anticipatory cognitive stress appraisal, mood, physical discomfort) and basal demographic-physiological measures (age, body mass index, blood pressure). RESULTS: Acute psychosocial stress elicited changes in all assessed endocrine (p values ≤ .028, ηp2 values ≥ 0.07) and stress-reactive psychological measures (p values ≤ .003, ηp2 values ≥ 0.15). The basal parameter body mass index, the stress-reactive endocrine parameters ACTH and norepinephrine, and the psychological parameter anticipatory stress appraisal were identified as determinants of higher RAAS parameter reactivity to acute psychosocial stress. The association between anticipatory cognitive stress appraisal and plasma RAAS measures was fully mediated by ACTH increases (p values ≤ .044, ηp2 values ≥ 0.05). CONCLUSIONS: Cognitive stress appraisal processes seem to modulate RAAS stress reactivity. This points to potential clinical implications for psychoeducative therapeutical interventions targeting stress appraisal processes to reduce endocrine stress reactivity.

Effects of psychological, sensory, and metabolic energy prime manipulation on the acute endocrine stress response in fasted women.

The stress response supports survival through energy mobilization. Paradoxically, a low blood glucose level dampens the endocrine stress response, and sugar consumption prior to stress restores it. Thus, energy availability may play a causal role in the endocrine stress response. Yet, it has never been tested whether sweet taste or expectations towards a drink content modulate the stress response. We investigated the potential role of sweetness, energy load and expectations towards energy load of a drink consumed prior to stress in restoring stress reactivity after fasting. N = 152 women (meanage=21.53, sdage=2.61) participated in the Trier Social Stress Test for groups in the morning after an overnight fast. Prior to stress induction, participants consumed a drink containing saccharose (sugar, n = 51), an equally sweet drink containing non-caloric sweetener (sweetener, n = 46), or water (n = 56). Additionally, participants in the sugar and sweetener group (n = 97) were informed whether or not their drink contained any calories (energy prime), which was deceptive in 50% of the cases. Eight salivary cortisol (-30, -20, -10, 0, +12, +25, +35, +45 min) and three blood glucose samples (-30, 0, +25 min) were assessed throughout the experiment. The effects of the experimental manipulations on cortisol trajectories were tested using multilevel mixed models. We found that compared with water, sugar and sweetener both significantly increased cortisol stress reactivity and with comparable intensity. However, our sensitivity analysis revealed a significant effect of sugar on cortisol trajectories compared to water and to sweetener. Drink-induced changes in blood glucose concentration were not associated with increases in cortisol. The energy prime did not affect the stress response. Overall, we could replicate the boosting effect of sugar consumption in a female sample after 8 h of fasting. The specific contribution of sweet taste and metabolic hormones to this boosting effect should be tested more rigorously in sex-balanced designs in the future.

Influence of stress on physiological synchrony in a stressful versus non-stressful group setting.

Physiological synchrony (PS) is defined as the co-occurrence and interdependence of physiological activity between interaction partners. Previous research has uncovered numerous influences on the extent of PS, such as relationship type or individual characteristics. Here, we investigate the influence of acute stress on PS. We do so in a setting in which PS was not promoted, but contact between group members was explicitly minimized. We reanalyzed cortisol, alpha-amylase, and subjective stress data from 138 participants (mean age = [Formula: see text], 47.1% female) who previously underwent the Trier Social Stress Test for groups (TSST-G) or a non-stressful control task together, collected as part of a larger project by Popovic et al. (Sci Rep 10: 7845, 2020). Using a stability and influence model, an established method to test for synchrony, we tested whether individuals' cortisol and alpha-amylase concentrations could be predicted by group members' levels. We found cortisol PS in participants who were in the same group, the extent of which was stronger in the non-stressful control condition. For alpha-amylase, participants were synchronized as well; furthermore, there was an interaction between previous stress levels and PS. This suggests that while synchrony of both stress markers can occur in group settings even with spurious interaction, stressor exposure might attenuate its extent. We argue that if PS occurs in a sample where interaction was minimal, the phenomenon might be more widespread than previously thought. Furthermore, stressor exposure might influence whether a situation allows for PS. We conclude that PS should be investigated within group settings with various degrees of social interaction to further expose mechanisms of and influence on PS.

Acute Stress-Induced Blood Lipid Reactivity in Hypertensive and Normotensive Men and Prospective Associations with Future Cardiovascular Risk.

Hyperreactivity to stress may be one explanation for the increased risk of cardiovascular disease (CVD) in individuals with essential hypertension. We investigated blood lipid reactivity to the Montreal Imaging Stress Task (MIST), a psychosocial stressor, in hypertensive and normotensive men and tested for prospective associations with biological risk factors. Fifty-six otherwise healthy and medication-free hypertensive and normotensive men underwent the MIST. We repeatedly measured cortisol and blood lipid profiles (total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG)) immediately before and up to 1 h after stress. Lipid levels were corrected for stress hemoconcentration. Thirty-five participants completed follow-up assessment 2.9 ± 0.12 (SEM) years later. CVD risk was assessed by prospective changes in TC/HDL-C ratio, IL-6, D-dimer, and HbA1c from baseline to follow-up. The MIST induced significant changes in all parameters except TC (p-values ≤ 0.043). Compared with normotensives, hypertensives had higher TC/HDL-C-ratio and TG (p-values ≤ 0.049) stress responses. Blood lipid stress reactivity predicted future cardiovascular risk (p = 0.036) with increases in HbA1c (ß = 0.34, p = 0.046), IL-6 (ß = 0.31, p = 0.075), and D-dimer (ß = 0.33, p = 0.050). Our results suggest that the greater blood lipid reactivity to psychosocial stress in hypertensives, the greater their future biological CVD risk. This points to lipid stress reactivity as a potential mechanism through which stress might increase CVD risk in essential hypertension.