Salivary Alpha-Amylase as a Biomarker of Stress in Behavioral Medicine

A psychobioecological model to understand the income-food insecurity-obesity relationship

Food insecurity, defined by unpredictable access to food that may not meet a person's nutritional needs, is associated with higher BMI (kg/m2) and obesity. People with food insecurity often have less access to food, miss meals and go hungry, which can lead to psychological and metabolic changes that favor energy conservation and weight gain. We describe a conceptual model that includes psychological (food reinforcement and delay discounting) and physiological (thermic effect of food and substrate oxidation) factors to understand how resource scarcity associated with food insecurity evolves into the food insecurity-obesity paradox. We present both animal and human translational research to describe how behavioral and metabolic adaptations to resource scarcity based on behavioral ecology theory may occur for people with food insecurity. We conclude with ideas for interventions to prevent or modify the behaviors and underlying physiology that characterize the income-food insecurity-obesity relationship.

Genetic and environmental influences on alpha amylase stress reactivity and shared genetic covariation with cortisol

Salivary alpha amylase (sAA) is a common measure of stress reactivity, primarily reflecting sympathetic nervous system activity. Salivary cortisol is also a reliable, frequently used biomarker of stress and reflects the hypothalamic-pituitary-adrenal (HPA) axis response. This study examined heritability across varying metrics of sAA in response to a social evaluative stressor, the Trier Social Stress Test (TSST). The goal of this study was to estimate genetic and environmental influences on measurements of sAA stress reactivity. Moreover, we evaluated the shared genetic covariation between sAA and cortisol. Participants included twins aged 15-20 years (54% female). We measured alpha amylase and cortisol reactivity to the TSST via serial salivary cortisol samples collected pre- and post-TSST. Modest to moderate heritability estimates (11-64%) were observed across measures purported to capture alpha amylase stress reactivity (peak, area under the curve, baseline-to-peak change). Findings also indicate that sAA baseline and peak are primarily influenced by a shared genetic factor. There was no evidence of shared genetic influences between sAA and cortisol. These findings suggest the genetic control of the HPA and Sympathetic Adreno-Medullar axis are genetically independent of one another despite both playing a role in response to stressors.

Examining surgeon stress in robotic and laparoscopic surgery

Robotic surgery may decrease surgeon stress compared to laparoscopic. To evaluate intraoperative surgeon stress, we measured salivary alpha-amylase and cortisol. We hypothesized robotic elicited lower increases in surgeon salivary amylase and cortisol than laparoscopic. Surgical faculty (n = 7) performing laparoscopic and robotic operations participated. Demographics: age, years in practice, time using laparoscopic vs robotic, comfort level and enthusiasm for each. Operative data included operative time, WRVU (surgical "effort"), resident year. Saliva was collected using passive drool collection system at beginning, middle and end of each case; amylase and cortisol measured using ELISA. Standard values were created using 7-minute exercise (HIIT), collecting saliva pre- and post-workout. Linear regression and Student's t test used for statistical analysis; p values < 0.05 were significant. Ninety-four cases (56 robotic, 38 laparoscopic) were collected (April-October 2022). Standardized change in amylase was 8.4 ± 4.5 (p < 0.001). Among operations, raw maximum amylase change in laparoscopic and robotic was 23.4 ± 11.5 and 22.2 ± 13.4; raw maximum cortisol change was 44.21 ± 46.57 and 53.21 ± 50.36, respectively. Values normalized to individual surgeon HIIT response, WRVU, and operative time, showing 40% decrease in amylase in robotic: 0.095 ± 0.12, vs laparoscopic: 0.164 ± 0.16 (p < 0.02). Normalized change in cortisol was: laparoscopic 0.30 ± 0.44, robotic 0.22 ± 0.4 (p = NS). On linear regression (p < 0.001), surgeons comfortable with complex laparoscopic cases had lower change in normalized amylase (p < 0.01); comfort with complex robotic was not significant. Robotic may be less physiologically stressful, eliciting less increase in salivary amylase than laparoscopic. Comfort with complex laparoscopic decreased stress in robotic, suggesting laparoscopic experience is valuable prior to robotic.

Support from parents, teachers, and peers and the moderation of subjective and objective stress of secondary school student

During adolescence, students increasingly report suffering from stress and school burnout, which poses a risk to students' healthy development. However, social support may counteract perceived stress according to the Buffering Hypothesis and the Conservation of Resources Theory. In search of factors that would support healthy student development, studies have primarily focused on self-report data and neglected biophysiological processes. Addressing this research desideratum, this study examined whether perceived social support buffers the interplay of self-reported stress considering biophysiological markers (i.e., cortisol, alpha-amylase, oxidative stress, and telomere length). 83 secondary school students (Mage = 13.72, SD = 0.67; 48% girls) from Germany participated in a questionnaire study and biophysiological testing. Moderation analyses in R revealed that support from parents moderated the relationships between psychological stress as well as cynicism and inadequacy at school linked to alpha-amylase.

The Stress Phenotyping Framework: A multidisciplinary biobehavioral approach for assessing and therapeutically targeting maladaptive stress physiology

Although dysregulated stress biology is becoming increasingly recognized as a key driver of lifelong disparities in chronic disease, we presently have no validated biomarkers of toxic stress physiology; no biological, behavioral, or cognitive treatments specifically focused on normalizing toxic stress processes; and no agreed-upon guidelines for treating stress in the clinic or evaluating the efficacy of interventions that seek to reduce toxic stress and improve human functioning. We address these critical issues by (a) systematically describing key systems and mechanisms that are dysregulated by stress; (b) summarizing indicators, biomarkers, and instruments for assessing stress response systems; and (c) highlighting therapeutic approaches that can be used to normalize stress-related biopsychosocial functioning. We also present a novel multidisciplinary Stress Phenotyping Framework that can bring stress researchers and clinicians one step closer to realizing the goal of using precision medicine-based approaches to prevent and treat stress-associated health problems.

Exposure to prenatal stressors and infant autonomic nervous system regulation of stress

OBJECTIVES

The purpose of this study was to determine the relationship between fetal exposure to maternal prenatal stressors and infant parasympathetic (PNS) and sympathetic (SNS) nervous function at 3 timepoints across the first year of life.

BACKGROUND

Autonomic nervous system impairments may mediate associations between gestational exposure to stressors and later infant health problems. Heart rate variability (HRV) provides a sensitive index of PNS and SNS function. However, no studies have assessed longitudinal associations between prenatal stressors and infant HRV measures of both PNS and SNS over the first year of life.

METHODS

During the third trimester of pregnancy, 233 women completed measures of life stressors and depression. At 1, 6 and 12 months of age, a stressor protocol was administered while infant electrocardiographic (ECG) data were collected from a baseline through a post-stressor period. HRV measures of PNS and SNS activity (HF, LF, LF/HF ratio) were generated from ECG data. We used multilevel regression to examine the aims, adjusting for maternal depression and neonatal morbidity.

RESULTS

There were no associations between prenatal stressors and any baseline or reactivity HRV metric over the infant's first year of life. However, exposure to more stressors was associated with lower post-stressor LF HRV at both 6 (β = -.44, p = .001) and 12 (β = -.37, p = .005) months of age.

CONCLUSIONS

Findings suggest potential alterations in development of the vagally mediated baroreflex function as a result of exposure to prenatal stressors, with implications for the infants' ability to generate a resilient recovery in response to stressors.

Psychologically aggressive parenting and later aggression: Salivary alpha-amylase reactivity and sex as moderators

Psychologically aggressive parenting (PAP) exposure negatively affects children's development of aggression. Nevertheless, not all children exposed to PAP display aggressive behaviors. Sympathetic nervous system (SNS) activity may influence the impact of early adversity on aggression. This study examines whether SNS reactivity and sex moderate the link between psychologically aggressive parenting (PAP) during childhood and later aggression. Emerging adults (N = 182, mean age = 19.03 years, 53 % female) retrospectively reported on their childhood PAP and current aggression. Salivary alpha-amylase (sAA) collected from a social stress task indexed SNS reactivity to stress. Childhood PAP was associated with emerging adulthood anger, hostility, physical, and verbal aggression. Moreover, males were more likely to exhibit anger, verbal, and physical aggression and had higher levels of sAA reactivity than females. A significant three-way interaction between childhood PAP, sAA reactivity, and sex accounted for participants' current verbal aggression. The link between childhood PAP and later verbal aggression was stronger for males at higher levels of sAA reactivity. Females with higher levels of sAA reactivity displayed lower levels of verbal aggression regardless of PAP exposure. Males and females with lower levels of sAA reactivity were at elevated risk for verbal aggression regardless of PAP exposure. Moreover, we found a significant two-way interaction between PAP and sex on anger, such that higher levels of PAP exposure were associated with more anger among males, but not females. These findings highlight the importance of examining interactions between biological and environmental factors and sex in accounting for later aggression.

Physiological stress reactivity and self-harm: A meta-analysis

OBJECTIVE

Self-harm is associated with alterations in the psychobiological stress response. Specifically, the reactivity of the autonomic nervous system (ANS) and the endocrine hypothalamic-pituitary-adrenal (HPA) axis may differ in individuals who engage in self-harm. However, evidence in this regard is inconsistent.

BACKGROUND

We conducted a preregistered random-effects meta-analysis of sympathetic ANS, parasympathetic ANS, sympathetic-parasympathetic, i.e., mixed-influence ANS, and HPA axis reactivity following laboratory stress exposure in individuals who engage in self-harm and controls. Stress exposure consisted of paradigms using either social-evaluative (e.g., TSST), emotional (e.g., negatively valenced visual stimuli), or physical (e.g., cold pressor test) challenges. A total of 29 studies (self-harm: n = 954, controls: n = 1122, 74% females) were included in the analysis.

RESULTS

Regarding ANS reactivity to stress, no differences emerged between the two groups. However, parasympathetic ANS activity was lower before stress (g = -0.30, CI -0.51 to -0.09) and after stressor cessation (g = 0.54, CI -1.07 to -0.01) in the self-harm group compared to controls. Regarding HPA axis reactivity, individuals who engage in self-harm showed significantly lower cortisol responses to stress than did controls (g = -0.26, CI -0.45 to -0.08). After stressor cessation (i.e., during stress recovery), cortisol was also lower in individuals who engage in self-harm compared to controls (g = -0.26, CI -0.43 to -0.08).

CONCLUSIONS

Lower basal parasympathetic ANS activity and flattened cortisol responses indicate dysregulation of psychobiological stress systems in individuals who engage in self-harm. A better understanding of the psychobiological underpinnings of self-harm may allow for the establishment of biomarkers of risk stratification and treatment monitoring in affected individuals.

Beyond the Bottle: Exploring Health-Promoting Compounds in Wine and Wine-Related Products-Extraction, Detection, Quantification, Aroma Properties, and Terroir Effects

Health-promoting compounds in wine and wine-related products are important due to their potential benefits to human health. Through an extensive literature review, this study explores the presence of these compounds in wine and wine-related products, examining their relationship with terroir and their impact on the aromatic and flavor properties that are perceived orally: sunlight exposure, rainfall patterns, and soil composition impact grapevines' synthesis and accumulation of health-promoting compounds. Enzymes, pH, and the oral microbiome are crucial in sensory evaluation and perception of health promotion. Moreover, their analysis of health-promoting compounds in wine and wine-related products relies on considerations such as the specific target compound, selectivity, sensitivity, and the complexity of the matrix.

Comparison of self-rated pain and salivary alpha-amylase and cortisol levels during early stages of fixed orthodontic and clear aligner therapy

OBJECTIVES

To compare self-rated orthodontic pain (OP) and whole salivary alpha-amylase (αA) and cortisol levels (CL) during early stages of fixed orthodontic and clear aligner therapy (CAT).

METHODS

In groups 1 and 2, malocclusions were treated using fixed orthodontic appliances and CAT, respectively. In Group-3, individuals had normal occlusion and had never undergone orthodontic therapy. Self-rated OP was assessed using the visual-analogue-scale at baseline (T0); after 24-hours (T1) of appliance activation; and after 30 days (T2). Unstimulated whole saliva was collected and αA and CL were measured using enzyme-linked immunosorbent assay. p < .01 was considered statistically significant.

RESULTS

Twenty-four (Group-1), 24(Group-2) and 25 (Group-3) patients were included. In groups 1 and 2, participants had Class-I malocclusion with anterior-crowding in both arches. At baseline (T0) none of the participants reported pain on mastication. In groups 1 (p < .01) and 2 (p < .01), OP was higher at T1 than T2. In groups 1 and 2, αA and CL were higher at T1 (p < .01) than T0 and T2. At T1 and T2, salivary αA and CL were higher in groups 1 (p < .01) and 2 (p < .01) than Group-3. In groups 1 and 2, a significant correlation was recorded between OP and αA (p < .01) and CL (p < .01) at T1 interval.

CONCLUSION

Self-rated OP and salivary αA and CL during the early stages of fixed OT and CAT are similar. Whole salivary αA and CL and OP and are high during the first 24 hours of fixed OT and CAT activation.

Psychosocial stress-induced intestinal permeability in healthy humans: What is the evidence?

An impaired intestinal barrier function can be detrimental to the host as it may allow the translocation of luminal antigens and toxins into the subepithelial tissue and bloodstream. In turn, this may cause local and systemic immune responses and lead to the development of pathologies. In vitro and animal studies strongly suggest that psychosocial stress is one of the factors that can increase intestinal permeability via mast-cell dependent mechanisms. Remarkably, studies have not been able to yield unequivocal evidence that such relation between stress and intestinal permeability also exists in (healthy) humans. In the current Review, we discuss the mechanisms that are involved in stress-induced intestinal permeability changes and postulate factors that influence these alterations and that may explain the translational difficulties from in vitro and animal to human studies. As human research differs highly from animal research in the extent to which stress can be applied and intestinal permeability can be measured, it remains difficult to draw conclusions about the presence of a relation between stress and intestinal permeability in (healthy) humans. Future studies should bear in mind these difficulties, and more research into in vivo methods to assess intestinal permeability are warranted.

Virtual adjunctive gut-directed hypnotherapy for people with Crohn's disease: A randomized controlled pilot and feasibility trial

BACKGROUND

Gut-directed hypnotherapy appears to be a promising adjunctive treatment for people with Crohn's disease. The primary objective of this pilot trial was to evaluate feasibility and acceptability of virtually delivered hypnotherapy to determine the parameters for a future definitive trial.

METHODS

This prospective, single-site, randomized controlled pilot and feasibility trial compared a 7-week course of virtually delivered adjunctive gut-directed hypnotherapy to standard medical treatment only for adults with Crohn's disease. Primary outcomes were study feasibility and intervention acceptability. Secondary outcomes were objective disease activity and patient-reported outcomes. Assessments took place at five time-points: baseline, post-intervention, and follow-up three-, six-, and 12-months post-intervention.

KEY RESULTS

Recruitment took place between July 2020 and August 2021 at a tertiary hospital. Recruitment was initially slow and subsequently expanded to community settings. Thirty-seven participants were enrolled in the trial: 95% were retained at post-intervention and 76% at 12-months. Completion of online assessments was high (97-100% across all time-points) whilst objective data collection was low (34-44%). Most intervention participants completed all hypnotherapy sessions (88%) and reported being extremely satisfied (73%), despite 60% experiencing technical issues.

CONCLUSION & INFERENCES

Virtually delivered hypnotherapy was acceptable to participants. Certain aspects of the trial including online assessment were feasible, while recruitment and objective data collection were challenges. Undertaking a future definitive trial will require broader recruitment scope and significant funding for widespread objective data collection.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ANZCTR#1260000348954.

Can you smell my stress? Influence of stress chemosignals on empathy and emotion recognition in depressed individuals and healthy controls

Human body odors contain chemical signals that play a key role in our non-verbal communication regarding health, genetic identity, immune system, fitness, and emotional state. Studies on human chemosignaling in individuals with psychiatric diseases are scarce but indicate altered smell perception and emotion recognition in depressed individuals. In the present project, we aimed to investigate the influence of chemosensory substances in social stress sweat on emotion recognition, perspective taking, affective responsiveness as well as stress level in healthy and depressed individuals. Therefore, chemosensory stimuli (sweat samples from Trier social stress test (TSST) and friendly-TSST (fTSST)) were obtained from 39 healthy participants (19 females). In a next step, chemosensory stimuli and an odor-free blank (cotton pad) were used to stimulate another group of 40 healthy participants (20 females) and 37 individuals with depression (24 females). Those stimuli were examined regarding their influence on subjective feelings of stress, emotion perception and empathic reactions using an empathy test. Furthermore, physiological data (breathing, heart rate, skin conductance response, stress hormones) of the participants were collected during chemosensory stimulation. Depressed individuals improved their ability of perspective taking and affective responsiveness for the emotion grief when presented with stress chemosignals compared to no chemosignals. Healthy individuals remained unaffected regarding perspective taking and affective responsiveness. Both depressed and healthy individuals showed no increased stress hormone cortisol and α-amylase values during the social stress chemosignals condition, but reduced values for fTSST condition compared to no chemosignals respectively. The results imply that stress chemosignals do not trigger a stress reaction, but for depressed individuals they lead to a better emotion assessment for grief. This research contributes to a deeper understanding of the effects of social stress chemosignals on healthy and depressed individuals. Knowing the impact of human chemosignals on emotional processing is crucial for a better understanding of non-verbal human interaction.

Changes in stress pathways as a possible mechanism of aerobic exercise training on brain health: a scoping review of existing studies

Physical activity (PA) in the form of aerobic exercise (AE) preserves and improves neurocognitive function across the lifespan. However, a mechanistic understanding of the pathways by which aerobic exercise impacts brain health is still lacking, particularly with respect to stress-related pathways. One mechanistic hypothesis is that AE improves neurocognitive health in part by modifying circulating levels of stress-related hormones and signaling factors associated with the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS), as commonly measured by the biomarkers cortisol (CORT) and salivary α-amylase (sAA). Thus, this hypothesis predicts that changes in stress biomarkers, such as CORT and sAA, are possible explanatory pathways mediating the positive effects of AE on neurocognitive health. In the present review article, we provide a summary of available studies examining the possibility that exercise-induced changes to stress biomarkers could partly account for exercise-related improvements in neurocognitive health. Our review indicates that despite the intuitive appeal of this hypothesis, there is insufficient evidence available to conclude that chronic and habitual AE affects neurocognitive health by altering stress biomarker pathways. The cross-sectional nature of the majority of reviewed studies highlights the need for well-controlled studies to adequately test this hypothesis.

A preliminary investigation of salivary α-amylase as a novel biomarker of subjective response to alcohol: A brief report

Alcohol misuse represents a universal public health concern that spans multiple demographics. As such, understanding shared, biological indicators of alcohol-related risk is vital to implementing targeted prevention and intervention efforts. Self-report measures of subjective response to alcohol (SR) capture both psychological and pharmacological effects of alcohol and robustly predict patterns of alcohol use, negative consequences, and the development of alcohol use disorders. Importantly, several biological markers of alcohol's sedating effects, including cortisol, have been identified and complement subjective response assessments. However, biological markers of alcohol's stimulating effects are less understood. Studies have implicated alcohol-induced changes in heart rate as a viable marker, but heart rate measurements are susceptible to measurement error. Salivary α-amylase, a reliable indicator of sympathetic nervous system activation, represents a promising alternative biomarker of alcohol-induced stimulation. Using data from a large, placebo-controlled alcohol administration study (N = 448), the present study examined the extent to which α-amylase is a viable marker of alcohol-induced stimulation. To test this, a measurement model was estimated in which baseline and ascending limb subjective stimulation latent variables were created using two validated measures of subjective response. Ascending self-reports of stimulation and levels of α-amylase were then regressed onto beverage conditions and allowed to correlate with each other. Findings indicated that α-amylase is sensitive to acute alcohol consumption and is positively, but not statistically reliably, related to the ascending limb stimulant SR. Future studies should consider including salivary α-amylase as a noninvasive physiological indicator of alcohol's stimulating effects. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Evaluating the feasibility and exploring the efficacy of an emotion-based approach-avoidance modification training (eAAMT) in the context of perceived stress in an adult sample - protocol of a parallel randomized controlled pilot study

BACKGROUND

Stress levels and thus the risk of developing related physical and mental health conditions are rising worldwide. Dysfunctional beliefs contribute to the development of stress. Potentially, such beliefs can be modified with approach-avoidance modification trainings (AAMT). As previous research indicates that effects of AAMTs are small, there is a need for innovative ways of increasing the efficacy of these interventions. For this purpose, we aim to evaluate the feasibility of the intervention and study design and explore the efficacy of an innovative emotion-based AAMT version (eAAMT) that uses the display of emotions to move stress-inducing beliefs away from and draw stress-reducing beliefs towards oneself.

METHODS

We will conduct a parallel randomized controlled pilot study at the Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany. Individuals with elevated stress levels will be randomized to one of eight study conditions (n = 10 per condition) - one of six variants of the eAAMT, an active control intervention (swipe-based AAMT), or an inactive control condition. Participants in the intervention groups will engage in four sessions of 20-30 min (e)AAMT training on consecutive days. Participants in the inactive control condition will complete the assessments via an online tool. Non-blinded assessments will be taken directly before and after the training and 1 week after training completion. The primary outcome will be perceived stress. Secondary outcomes will be dysfunctional beliefs, symptoms of depression, emotion regulation skills, and physiological stress measures. We will compute effect sizes and conduct mixed ANOVAs to explore differences in change in outcomes between the eAAMT and control conditions.

DISCUSSION

The study will provide valuable information to improve the intervention and study design. Moreover, if shown to be effective, the approach can be used as an automated smartphone-based intervention. Future research needs to identify target groups benefitting from this intervention utilized either as stand-alone treatment or an add-on intervention that is combined with other evidence-based treatments.

TRIAL REGISTRATION

The trial has been registered in the German Clinical Trials Register (Deutsches Register Klinischer Studien; DRKS00023007 ; September 7, 2020).

Reducing Stress with Yoga: A Systematic Review Based on Multimodal Biosignals

Stress is an enormous concern in our culture because it is the root cause of many health issues. Yoga asanas and mindfulness-based practices are becoming increasingly popular for stress management; nevertheless, the biological effect of these practices on stress reactivity is still a research domain. The purpose of this review is to emphasize various biosignals that reflect stress reduction through various yoga-based practices. A comprehensive synthesis of numerous prior investigations in the existing literature was conducted. These investigations undertook a thorough examination of numerous biosignals. Various features are extracted from these signals, which are further explored to reflect the effectiveness of yoga practice in stress reduction. The multifaceted character of stress and the extensive research undertaken in this field indicate that the proposed approach would rely on multiple modalities. The notable growth of the body of literature pertaining to prospective yoga processes is deserving of attention; nonetheless, there exists a scarcity of research undertaken on these mechanisms. Hence, it is recommended that future studies adopt more stringent yoga methods and ensure the incorporation of suitable participant cohorts.

Effect of transcutaneous vagus nerve stimulation on stress-reactive neuroendocrine measures in a sample of persons with temporal lobe epilepsy

OBJECTIVE

Dysregulation of stress-reactive neuroendocrine measures, as well as subjective stress, have been found to worsen epilepsy. Transcutaneous vagus nerve stimulation (tVNS) is a relatively new treatment option for epilepsy. We were interested in its effect on the activity of the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS) as well as subjective stress and tiredness in patients with temporal lobe epilepsy (TLE).

METHODS

Twenty patients (age 44 ± 11 years, 13 women) were enrolled in the study. They were free of seizures for more than 1 year. All took part in two sessions with 4 h of stimulation (tVNS vs. sham) in a randomized order. Saliva samples and subjective stress and tiredness levels were measured at five time points each session (before and after stimulation and three time points every hour in between). Data were analyzed using repeated measures analysis of variance as well as paired t-tests.

RESULTS

There was a dampened salivary cortisol (sCort) decrease during tVNS (time × condition effect: F[2.38, 38.15]  = 6.50, P = 0.002, partial η2  = 0.29). Furthermore, we detected a dampened increase in salivary flow rate during tVNS (time × condition effect: F[3.28, 55.67]  = 2.82, P = 0.043, partial η2  = 0.14). There was neither a difference in overall sCort or salivary alpha-amylase (sAA) levels nor in subjective stress or tiredness levels between conditions. sAA levels at the last measurement point were slightly higher during tVNS (t(19)  = 2.26, P = 0.035, d = 0.51), but this effect failed to reach significance when controlled for multiple comparisons.

SIGNIFICANCE

Our results partially support that tVNS influences the regulation of stress-reactive neuroendocrine systems (namely the HPA axis and ANS) in epilepsy. More research with larger samples is needed on the difference between short-term and repeated long-term stimulation.

Immersive virtual plus-maze to examine behavior and psychophysiological-related variables in young people with problematic alcohol and cannabis consumption

Stressful events appear to be risky situations that can precipitate the consumption of drugs. One way to recreate stressful contexts, in an ecological and controlled method, is through immersive virtual reality (VR). In our study, we designed the scenario of an elevated plus-maze (EPM) using VR, which is widely used in animal models to assess unconditioned anxiety. This task allowed us to analyze the behavioral, psychophysiological (heart rate and electrodermal activity), and hormonal response (salivary cortisol and Alpha-amylase) to this stressful situation in different moments (before VR task (anticipation), at the end of the task and 10 minutes later) in young people with problematic alcohol use (AU, n = 27), alcohol combined with cannabis consumption (AU + C, n = 10), as well as in a control group (CO, n = 33). Behavioral analysis revealed that the AU group displayed fewer entries into open arms than the CO group, whereas both experimental groups spent less time at the end of the open arms, as well as lower time by look down index compared to the CO group. Moreover, our VR EPM induced different psychophysiological responses in the different moments measured. In general, electrodermal activity seemed to be a good biomarker of recovery from a stressful situation, as once the exposure to the stressful situation ended, the AU + C group took longer to recover compared to the CO group. Regarding hormonal analyses, we observed a similar response pattern in all groups suggesting that our VR task was able to activate both stress systems. The alpha-amylase to cortisol ratio, proposed as a biomarker of stress systems dysregulation, was higher in the group of young participants with alcohol abuse. Interestingly, our VR EPM was able to induce a slight alcohol craving in both experimental groups. In conclusion, our results suggest certain subtle behavioral and physiological differences that could be used to detect young individuals at risk of future severe addictions or other stress-related comorbidities. Moreover, it could help us to develop prevention strategies focused on emotional, cognitive, and psychophysiological aspects.

Music therapy for health workers to reduce stress, mental workload and anxiety: a systematic review

BACKGROUND

The physical and mental exhaustion of health care workers urgently needs to be addressed as a public health priority. Benefits of music on stress parameters have been extensively reported.

METHODS

We carried out a systematic review to examine the efficacy of music interventions on stress parameters by selecting studies conducted in genuine care stress conditions. To approach the potential benefit of music therapy (MT) versus music medicine (MM), we followed international music-based intervention guidelines.

RESULTS

Five outcomes were considered in our studies: stress, anxiety, mental workload, burnout risk and psychosomatic symptoms. Corresponding measures, including psychological, physiological questionnaires or stress biological parameters, showed significant results for the majority of them in music groups. Implications of music types, designs and limitations are discussed. Only one study compared MM and MT with an advantage for customized playlists over time.

CONCLUSIONS

In spite of heterogeneity, music interventions seem to significantly decrease stress parameters. The individual, customized supports with MT may be a crucial condition for this specific professional category. The impact of MT versus MM, the number of music sessions and the effect over time need to be explored.

The diurnal course of salivary cortisol and alpha-amylase on workdays and leisure days in teachers and the role of social isolation and neuroticism

Teachers are among the occupational groups with the highest sick leave rates due to workplace stress and burnout symptoms. A substantial body of research has suggested social isolation and neuroticism to be related to physiological stress activity. However, the relationship between such characteristics and stress experiences has rarely been studied in conjunction with physiological stress indicators in the teachers' natural settings. Thus, the present study examines salivary cortisol and α-amylase as physiological stress indicators on teachers' work and leisure days and their relationship with social isolation. Furthermore, we test whether neuroticism moderates the relationship between social isolation and salivary biomarkers. Forty-two teachers completed questionnaires assessing social isolation (Trier Inventory for the Assessment of Chronic Stress) and neuroticism (Big-Five Inventory). Participants collected eight saliva samples on three days, two workdays, and one leisure day to measure the concentration of cortisol and α-amylase as biomarkers of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS), respectively. Results showed a significantly higher Cortisol Awakening Response (CAR) and diurnal cortisol slope (DCS) on workdays than on the leisure day but no significant differences regarding measures of α-amylase. We found a significant positive relationship between social isolation and the CAR on the leisure day but no association with the α-amylase measures. Furthermore, after controlling for confounders, social isolation was unrelated to neuroticism, and the latter did not moderate between social isolation and the CAR. Our findings suggest an association between social isolation and the HPA axis, i.e., the CAR, but do not support an association with the ANS, which would be indicated by the α-amylase assessments. Finally, our findings could not support an association of neuroticism with the HPA axis and ANS.

From threat to challenge-Improving medical students' stress response and communication skills performance through the combination of stress arousal reappraisal and preparatory worked example-based learning when breaking bad news to simulated patients: study protocol for a randomized controlled trial

BACKGROUND

Breaking bad news (BBN; e.g., delivering a cancer diagnosis) is perceived as one of the most demanding communication tasks in the medical field and associated with high levels of stress. Physicians' increased stress in BBN encounters can negatively impact their communication performance, and in the long term, patient-related health outcomes. Although a growing body of literature acknowledges the stressful nature of BBN, little has been done to address this issue. Therefore, there is a need for appropriate tools to help physicians cope with their stress response, so that they can perform BBN at their best. In the present study, we implement the biopsychosocial model of challenge and threat as theoretical framework. According to this model, the balance between perceived situational demands and perceived coping resources determines whether a stressful performance situation, such as BBN, is experienced as challenge (resources > demands) or threat (resources < demands). Using two interventions, we aim to support medical students in shifting towards challenge-oriented stress responses and improved communication performance: (1) stress arousal reappraisal (SAR), which guides individuals to reinterpret their stress arousal as an adaptive and beneficial response for task performance; (2) worked examples (WE), which demonstrate how to BBN in a step-by-step manner, offering structure and promoting skill acquisition.

METHODS

In a randomized controlled trial with a 2 (SAR vs. control) x 2 (WE vs. control) between-subjects design, we will determine the effects of both interventions on stress response and BBN skills performance in N = 200 third-year medical students during a simulated BBN encounter. To identify students' stress responses, we will assess their perceived coping resources and task demands, record their cardiovascular activity, and measure salivary parameters before, during, and after BBN encounters. Three trained raters will independently score students' BBN skills performances.

DISCUSSION

Findings will provide unique insights into the psychophysiology of medical students who are tasked with BBN. Parameters can be understood more comprehensively from the challenge and threat perspective and linked to performance outcomes. If proven effective, the evaluated interventions could be incorporated into the curriculum of medical students and facilitate BBN skills acquisition.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05037318), September 8, 2021.

Does workplace telepressure get under the skin? Protocol for an ambulatory assessment study on wellbeing and health-related physiological, experiential, and behavioral concomitants of workplace telepressure

BACKGROUND

The daily working life of many employees requires the use of modern information and communication technology (ICT) devices such as computers, tablets, and smartphones. The double-edged nature of digital work environments has been increasingly highlighted. Benefits such as increased flexibility come at a personal cost. One of the potential downsides is workplace telepressure, i.e., the experience of urge and preoccupation to quickly reply to work-related messages and demands using ICT. There is initial - mainly survey-based-evidence that workplace telepressure may have negative effects on a variety of wellbeing and health outcomes.

AIMS AND HYPOTHESES

Adopting the Effort-Recovery Model and the concept of allostatic load as theoretical frameworks, the present study aims to investigate the hypothesis that workplace telepressure is significantly associated with increased "wear and tear", in the form of more psychosomatic complaints, worse sleep quality (self-reported and actigraphy-based), worse mood, and biological alterations (lower cardiac vagal tone, lower anabolic balance defined as the ratio of salivary dehydroepiandrosterone to salivary cortisol, and higher salivary alpha-amylase). Additionally, the study aims to investigate the hypothesis that connection to work defined as work-related workload and work-related perseverative cognition plays a significant role in the mediation of these relationships.

METHODS

To test our hypotheses, we will conduct an ambulatory assessment study with a convenience sample of 120 healthy workers regularly using ICTs for job communication. For one week, participants will be asked to complete electronic diaries assessing their level of workplace telepressure, psychosomatic complaints, sleep quality, mood, work-related workload, and work-related perseverative cognition. They will also continuously wear the Bittium Faros 180L ECG monitor, the wrist-worn actigraph MotionWatch 8, and perform saliva sampling five times per day.

DISCUSSION

This study will be the most comprehensive ambulatory investigation of workplace telepressure and its psychophysiological concomitants to date and constitutes an important step towards understanding how high levels of workplace telepressure may lead in the long term to secondary alterations (e.g., hypertension, chronic inflammation) and disease (e.g., heart disease). The findings of this study are also anticipated to contribute to guiding the development and implementation of interventions, programs, and policies relevant to employees' digital wellbeing.

Interactive teaching enhances students' physiological arousal during online learning

The pure transfer of face-to-face teaching to a digital learning environment can be accompanied by a significant reduction in the physiological arousal of students, which in turn can be associated with passivity during the learning process, often linked to insufficient levels of concentration and engagement in the course work. Therefore, the aim of this study was to investigate whether students' psychobiological stress responses can be enhanced in the context of anatomical online learning and how increased physiological parameters correlate with characteristics of learning experiences in a digital learning environment. Healthy first-year medical students (n = 104) experienced a regular practical course in Microscopic Anatomy either in face-to-face learning, in passive online learning or in an interaction-enhanced version of online learning. Compared to passive online learning, students engaged in the interaction-enhanced version of online learning displayed a significantly reduced Heart Rate Variability (P 0.001, partial η² = 0.381) along with a strong increase in salivary cortisol (P 0.001, partial η² = 0.179) and salivary alpha-amylase activity (P 0.001, partial η² = 0.195). These results demonstrated that the physiological arousal of students engaged in online learning can be enhanced via interactive teaching methods and pointed towards clear correlations between higher physiological responses and elementary criteria of learning experience such as engagement and attention.

Fluorometric biosensing of α-amylase using an artificial allosteric biosensor immobilized on nanostructured interface

Protein biosensors hold a promise to transform the way we collect physiological data by enabling quantification of biomarkers outside of specialized laboratory environment. However, achieving high specificity and sensitivity in homogeneous assay format remains challenging. Here we report construction of fluorescent biosensor arrays based on artificial allosteric α-amylase-activated PQQ-dependent glucose dehydrogenase (Amy-GDH). Amy-GDH was covalently immobilized on silica nanoparticles that were then arrayed on fiberglass sheets. The activity of the biosensor was monitored using a smartphone camera via emergence of bright fluorescence (λ_ex 365 nm) originating from reduced phenazine methosulfate upon glucose oxidation by Amy-GDH. We show that such biosensor arrays demonstrate an apparent K_d of 115 pM for α-amylase with a detection limit of 2 pM. Using the developed biosensor arrays, we were able to specifically and accurately quantify the concentration of α-amylase in biological fluids such as serum and saliva. We propose that the presented approach can enable construction of ultrasensitive point-of-care diagnostic arrays.

HPA-SAM co-activation among racially diverse, economically disadvantaged early adolescents: Secondary analysis with a preliminary test of a multisystem, person-centered approach

Investigating the co-activation of hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenomedullary (SAM) responses to acute stress can provide insight into how risk might become biologically embedded during early adolescence and improve understanding of what distinguishes physiological dysregulation from normative/expected physiological responses to stress. Evidence has thus far been mixed as to whether symmetric or asymmetric co-activation patterns are associated with higher exposure to chronic stress and poorer mental health outcomes during adolescence. This study expands on a prior multisystem, person-centered analysis of lower-risk, racially homogenous youth by focusing on HPA-SAM co-activation patterns in a higher-risk, racially diverse sample of early adolescents from low-income families (N = 119, Mage=11.79 years, 55.5% female, 52.7% mono-racial Black). The present study was conducted by performing secondary analysis of data from the baseline assessment of an intervention efficacy trial. Participants and caregivers completed questionnaires; youth also completed the Trier Social Stress Test-Modified (TSST-M) and provided six saliva samples. Multitrajectory modeling (MTM) of salivary cortisol and alpha-amylase levels identified four HPA-SAM co-activation profiles. In accordance with the asymmetric-risk model, youth exhibiting Low HPA-High SAM (n = 46) and High HPA-Low SAM (n = 28) profiles experienced more stressful life events, posttraumatic stress, and emotional and behavioral problems relative to Low HPA-Low SAM (n = 30) and High HPA-High SAM (n = 15) youth. Findings highlight potential differences in biological embedding of risk during early adolescence based on individuals' exposure to chronic stress and illustrate the utility of multisystem and person-centered approaches in understanding how risk might get "underneath the skin" across systems.

Planning, conducting, and analyzing a psychophysiological experiment on challenge and threat: A comprehensive tutorial

The biopsychosocial model of challenge and threat (BPS-CT) is a powerful framework linking psychological processes to reliable patterns of cardiovascular responses during motivated performance situations. Specifically, the BPS-CT poses challenge and threat as two motivational states that can emerge in response to a demanding, self-relevant task, where greater challenge arises when perceived resources are higher than demands, and greater threat arises when perceived resources are lower than demands. By identifying unique patterns of physiological responses associated with challenge and threat, respectively, the BPS-CT affords insight into subjective appraisals of resources and demands, and their determinants, during motivated performance situations. Despite its broad utility, lack of familiarity with physiological concepts and difficulty with identifying clear guidelines in the literature are barriers to wider uptake of this approach by behavioral researchers. Our goal is to remove these barriers by providing a comprehensive, step-by-step tutorial on conducting an experiment using the challenge and threat model, offering concrete recommendations for those who are new to the method, and serving as a centralized collection of resources for those looking to deepen their understanding. The tutorial spans five parts, covering theoretical introduction, lab setup, data collection, data analysis, and appendices offering additional details about data analysis and equipment. With this, we aim to make challenge and threat research, and the insights it offers, more accessible to researchers throughout the behavioral sciences.

The effect of an internet-based intervention for depression on cortisol and alpha-amylase

INTRODUCTION

Psychotherapeutic interventions for major depressive disorder (MDD) have been suggested to be associated with a normalization of biological stress system (i.e., the hypothalamic-pituitary-adrenal axis and the autonomic nervous system) dysregulation. Furthermore, pre-intervention cortisol parameters have been identified as prescriptive biological markers of treatment success. However, evidence of treatment effects on the biological stress systems is still sparse, and results are heterogeneous. The current study examined the effect of an internet-based intervention for MDD on salivary cortisol and alpha-amylase as well as hair cortisol concentrations. Moreover, the prescriptive capacity of pre-intervention cortisol and alpha-amylase concentrations on treatment response was explored.

METHODS

Thirty-eight participants suffering from mild to moderate MDD collected saliva and hair samples throughout the intervention. Biological outcome parameters were salivary cortisol and alpha-amylase (awakening response, total diurnal output, diurnal slope) and hair cortisol concentrations. Treatment response was indicated by change in depression severity and perceived chronic stress.

RESULTS

Treatment response on depression scores or chronic stress was not associated with changes in any of the cortisol or alpha-amylase parameters. Exploratory analysis indicated that non-responders showed a steeper alpha-amylase slope pre-intervention.

DISCUSSION

The results indicate that changes in depressive symptoms did not correspond to changes of the biological stress systems, contradicting the suggested normalization of dysregulated hypothalamic-pituitary-adrenal axis or autonomic nervous system activity through a psychotherapeutic intervention. However, the results point to a potential role of pre-intervention alpha-amylase slope as a prescriptive marker of treatment response for depression.

Does Modifying the Consent Process Based on the Dominant Intelligence Type Reduce Anxiety During 3rd Molar Operations?

PURPOSE

Third molar surgery is one of the most commonly performed operations, usually associated with high anxiety. The purpose of this study was to determine if patients' anxiety would reduce if consent was modified to match their dominant intelligence type (DIT).

METHODS AND MATERIALS

A singlecenter, prospective randomized clinical study was conducted in the Maxillofacial Surgery Clinic of Ordu University on patients admitted for lower third molar removal between October 2020 and June 2021. The participants were randomly assigned to a study group where consent was based on DIT or a control group where consent was obtained in the standard fashion. DIT was determined using the multiple intelligence test and was further categorized as visual/spatial, verbal/linguistic, and bodily/kinesthetic. The consent method was the primary and the type of DIT was the secondary predictor variable. The primary and secondary outcome variables were the salivary cortisol level and Modified Dental Anxiety Scale (MDAS) scores measured before and after the consent, and after the operation. Mann-Whitney U, Friedman, Pearson correlation, and χ²tests were conducted for statistical analysis.

RESULTS

Eighty patients (55 females and 25 males; mean age 23.5 ± 6.2) were included. No significant difference was observed between the study and control groups for the change in cortisol levels and MDAS scores before-after consent (-11.15 ± 62.64; -6.84 ± 32.9) (P = .389), -0.6 ± 3.46; -0.7 ± 2.49) (P = .832) and before consent-after operation (-39.80 ± 108.2; -39.72 ± 77.04) (P = .987), (-4.31 ± 5.97; -3 ± 4.34) (P = .867). The change in MDAS scores and cortisol levels was not correlated after consent (P = .587, r = 0.62) and operation (P = .406, r = 0.94).

CONCLUSION

Providing consent based on DIT is not statistically different than providing consent in the standard fashion. The role of consent strategy in managing anxiety and lack of correlation between salivary cortisol and MDAS requires further investigation.

Bioluminescent-Triple-Enzyme-Based Biosensor with Lactate Dehydrogenase for Non-Invasive Training Load Monitoring

Saliva is one of the most significant biological liquids for the development of a simple, rapid, and non-invasive biosensor for training load diagnostics. There is an opinion that enzymatic bioassays are more relevant in terms of biology. The present paper is aimed at investigating the effects of saliva samples, upon altering the lactate content, on the activity of a multi-enzyme, namely lactate dehydrogenase + NAD(P)H:FMN-oxidoreductase + luciferase (LDH + Red + Luc). Optimal enzymes and their substrate composition of the proposed multi-enzyme system were chosen. During the tests of the lactate dependence, the enzymatic bioassay showed good linearity to lactate in the range from 0.05 mM to 0.25 mM. The activity of the LDH + Red + Luc enzyme system was tested in the presence of 20 saliva samples taken from students whose lactate levels were compared by the Barker and Summerson colorimetric method. The results showed a good correlation. The proposed LDH + Red + Luc enzyme system could be a useful, competitive, and non-invasive tool for correct and rapid monitoring of lactate in saliva. This enzyme-based bioassay is easy to use, rapid, and has the potential to deliver point-of-care diagnostics in a cost-effective manner.

Exploring the Impact of α-Amylase Enzyme Activity and pH on Flavor Perception of Alcoholic Drinks

The introduction of a drink in the mouth and the action of saliva and enzymes cause the perception of basic tastes and some aromas perceived in a retro-nasal way. Thus, this study aimed to evaluate the influence of the type of alcoholic beverage (beer, wine, and brandy) on lingual lipase and α-amylase activity and in-mouth pH. It was possible to see that the pH values (drink and saliva) differed significantly from the pH values of the initial drinks. Moreover, the α-amylase activity was significantly higher when the panel members tasted a colorless brandy, namely Grappa. Red wine and wood-aged brandy also induced greater α-amylase activity than white wine and blonde beer. Additionally, tawny port wine induced greater α-amylase activity than red wine. The flavor characteristics of red wines due to skin maceration and the contact of the brandy with the wood can cause a synergistic effect between beverages considered "tastier" and the activity of human α-amylase. We can conclude that saliva-beverage chemical interactions may depend on the saliva composition but also on the chemical composition of the beverage, namely its constitution in acids, alcohol concentration, and tannin content. This work is an important contribution to the e-flavor project, the development of a sensor system capable of mimicking the human perception of flavor. Furthermore, a better understanding of saliva-drink interactions allow us to comprehend which and how salivary parameters can contribute to taste and flavor perception.

Physical body experiences questionnaire simplified for active aging (PBE-QAG): Rasch validation

PURPOSE

To validate the Physical Body Experiences Questionnaire simplified for Active aGing (PBE-QAG) with Rasch Measurement Theory. PBE-QAG measures body awareness during physical activity.

METHODS

Community-dwelling adults were recruited at the Minnesota State Fair, Highland Fest, and in the Brain Body Mind Lab (University of Minnesota). They completed demographic, clinical, and behavioral questionnaires and the PBE-QAG, which has 12 items, with scoring options ranging between 0 (totally true) and 4 (totally false). A lower total PBE-QAG score on reflects better body awareness. We validated the structural validity of PBE-QAG in community-dwelling older adults, and in community-dwelling adults (18-99 years of age). We also performed a pilot structural validity in community-dwelling adults with chronic stroke. We evaluated item and person fit, targeting, unidimensionality, person separation reliability, differential item functioning for demographic and clinical characteristics, principal component of residuals, and local item dependence.

RESULTS

We obtained unidimensionality and item fit after deleting and rescoring items in older adults (n = 133), adults (n = 530), and adults with chronic stroke (n = 36). In community-dwelling adults, 7 participants did not fit the model (1.13%). There was minimal floor (5.28%), no ceiling effect (0.00%), and no local item dependence or differential item functioning. The person mean location was -1.77±1.22 logits.

CONCLUSIONS

PBE-QAG demonstrated good item and person fit, but the targeting is off. Therefore, the current version of PBE-QAG is not recommended for use in community-dwelling adults. We encourage further validation of PBE-QAG by adding more difficult items. We also recommend evaluating the PBE-QAG in a larger group of adults with stroke.

Physiological and affective responses to green space virtual reality among pregnant women

BACKGROUND

Benefits of green spaces on stress reduction have been shown in previous studies. Most existing studies to date have focused on the general population. However, there is a lack of understanding of physiological mechanisms underlying the beneficial effects of green space among special populations, such as pregnant women.

OBJECTIVES

To examine physiological and affective responses to green space on stress recovery among pregnant women, using simulated green space exposure through virtual reality (VR).

METHODS

We recruited 63 pregnant women between 8 and 14 weeks' gestational age for a laboratory experiment. Participants were randomly assigned to view one of three, 5-min, VR videos of an urban scene with different green space levels (i.e., non-green, moderate, and high) after a laboratory stressor, the Trier Social Stress Test. Physiological stress responses were measured via changes in blood pressure, heart rate, skin conductance level, salivary alpha-amylase, and salivary cortisol. Affective response was measured using the Positive and Negative Affect Scale.

RESULTS

We found that visual exposure to a green space environment in VR was associated with both physiological and affective stress reduction among pregnant women, including lower systolic blood pressure [-4.6 mmHg, 95% confidence interval (CI): -8.8, -0.4], reduced salivary alpha-amylase concentration (-1.2 ng/ml, 95% CI: -2.2, -0.2), improved overall positive affect (score: 6.6, 95% CI: 0.3, 13.0) and decreased negative affect of anxiety (score: -2.6, 95% CI: -5.19, -0.04) compared to non-green space environment. Exposure to high green space environment in park-like setting had the strongest impacts on stress recovery.

CONCLUSION

This study demonstrated that virtual green space exposure could effectively ease stress and improve mental health and well-being during pregnancy. Even a short immersion in VR-based green space environment may bring health benefits, which has significant implications for pregnant women when access to an actual nature may not be possible.

Cortisol and α-amylase awakening response in children and adolescents with functional neurological (conversion) disorder

OBJECTIVE

Stress system dysregulation is considered to have an important role in the aetiology of paediatric functional neurological (conversion) disorder. This study examined salivary cortisol and α-amylase awakening responses in children with functional neurological disorder to determine activation patterns of the hypothalamic-pituitary-adrenal axis and sympathetic system. A healthy cortisol awakening response involves a robust increase in cortisol within 30 minutes of awakening. Alpha-amylase awakening response is variable in children.

METHODS

Cortisol and α-amylase were measured in saliva from 32 patients with functional neurological disorder (26 girls and 6 boys, aged 11.3-16.1 years) and 31 healthy controls (23 girls and 8 boys, aged 8.6-17.7 years). Saliva samples were collected using a Salivette sampling device at two time points - upon awakening and 30 minutes after awakening.

RESULTS

Patients with functional neurological disorder showed a decrease in cortisol awakening response (-4 nmol.min/L) and controls showed an increase (107 nmol.min/L), t(55) = -.4.6, p < 0.001. Within the functional neurological disorder group, 57% showed an attenuated cortisol awakening response and 43% showed an obliterated/reversed cortisol awakening response: Cortisol awakening response was negatively correlated with adverse childhood experiences, r(58) = -0.6, p = 0.002, and subjective distress (total Depression Anxiety and Stress Scales score), r(58) = -0.4, p = 0.050. In controls, cortisol awakening response showed no correlation with adverse childhood experiences and a positive correlation with subjective distress, r(56) = 0.4, p = 0.023. Total cortisol remained similar between the functional neurological disorder and control group. No significant differences were observed between the functional neurological disorder and control group in any of the α-amylase analyses.

DISCUSSION

The results suggest dysregulation of the hypothalamic-pituitary-adrenal axis in children with functional neurological disorder. Hypothalamic-pituitary-adrenal dysregulation in children with functional neurological disorder may contribute to comorbid symptoms of fatigue, sleep disturbance and subjective loss of well-being because circadian rhythms and energy metabolism are disrupted. Hypothalamic-pituitary-adrenal dysregulation - and changes in glucocorticoid (cortisol) signalling at the molecular level - may also contribute to increased vulnerability for functional neurological disorder symptoms because of epigenetically mediated changes to neural networks implicated in functional neurological disorder.

Association of total and pancreatic serum amylase enzymatic activity with insulin resistance and the glucose and insulin responses to oral starch test in Mexican children

BACKGROUND/OBJECTIVES

Little is known about the effect of serum amylase enzymatic activity on glucose metabolism. We investigated the association of serum amylase enzymatic activity with fasting plasma glucose, insulin resistance (IR), and the plasma glucose and insulin response to an oral starch test (OST) in Mexican children.

METHODS

Anthropometric data, glucose and insulin levels, and the serum enzymatic activity of total (AMYt), salivary (AMY1), and pancreatic (AMY2) amylase were analysed in 764 children (N_{normal weight}  = 427/N_obesity  = 337). After categorization into low (LA) and high (HA) AMYt, an OST with commercial white bread was performed in 39 children (N_{normal weight}  = 17/N_obesity  = 22).

RESULTS

A positive association between serum enzymatic activity of AMY2 and IR was observed in children with obesity (p = 0.018). Children with normal weight had lower plasma glucose and insulin response to OST than children with obesity (P_glucose  = 4.1 × 10^-12 ; P_insulin  = 2.1 × 10^-15 ). Compared with the LA group, children with HA showed lower plasma glucose and insulin response to OST (P_glucose  ≤ 0.040; P_insulin  ≤ 0.015).

CONCLUSION

Our results suggest that AMY2 is positively associated with IR. A high level of AMYt is related to lower glucose and insulin responses to OST in Mexican children, regardless of their weight status.

Stress effects on memory retrieval of aversive and appetitive instrumental counterconditioning in men

Extinction training creates a second inhibitory memory trace and effectively reduces conditioned responding. However, acute stress inhibits the retrieval of this extinction memory trace. It is not known whether this also applies to other forms of associative learning such as instrumental counterconditioning, where previously learned associations are reversed and paired with the opposite valence. Therefore, the current preregistered study investigates whether stress decreases the retrieval of instrumental counterconditioning memories with aversive and appetitive consequences. Fifty-two healthy men were randomly assigned to either a stress or control group and took part in a two-day instrumental learning paradigm. During a first phase, participants learned that pressing specific buttons in response to the presentation of four neutral stimuli either leads to gaining or losing money. During a second phase, two stimuli reversed their contingencies (counterconditioning). One day later, participants were exposed to acute stress or a control condition prior to the same task, which no longer included feedback about gains or losses. Stressed participants showed more approach behavior towards appetitive and less avoidance behavior towards aversive stimuli as compared to non-stressed participants. Our findings indicate that stress effects on memory retrieval differ depending on the associative learning approach in men. These differences might be related to stress effects on decision making and different motivational systems involved.

Salivary mental stress biomarkers in COVID-19 patients

BACKGROUND

During the COVID-19 pandemic, mental health disorders and level of stress show a major increase compared to before the pandemic. Coronavirus-related stress is recently the leading cause of negative impacts on global mental health. Thus, maintaining positive mental health is as important as maintaining physical health during COVID-19. The aim of this study was to analyze salivary mental stress biomarkers as cortisol, alpha-amylase, and chromogranin A in hospitalized patients with COVID-19 to compare their potential relationship with stress symptoms.

MATERIAL AND METHODS

A total of 80 adult hospitalized patients with moderate COVID-19 disease and a control group (n = 80) randomly selected were conducted as participants. Saliva cortisol (sCort), saliva alpha-amylase (sAA), and saliva and chromogranin A (sCgA) were determined by the ELISA method (Bio Vendor, USA). Symptoms of stress were measured with a stress symptom checklist (SSCL).

RESULTS

The patients group presented significantly higher levels of sCort, sAA, and sCgA compared with the control group. The correlation analysis showed a positive correlation with strong strength between sCort and sAA (r = 0.934, p < 0.01), as well as sAA with sCgA (r = 0.714, p < 0.01). A moderate positive correlation was found between sCort with sCgA (r = 0.618, p < 0.05). Based on their stress scores from the SSCL the patients were associated with high stress level (30.00%) and very high stress levels (67.5%). In terms of the controls, all the participants showed a low to moderate stress level. We found significant positive correlation between levels of stress and salivary biomarkers.

CONCLUSION

Data from our study demonstrated that salivary biomarkers are promising tools of exploring COVID-19 related stress.

Evidence for a modulating effect of transcutaneous auricular vagus nerve stimulation (taVNS) on salivary alpha-amylase as indirect noradrenergic marker: A pooled mega-analysis

BACKGROUND

Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) has received tremendous attention as a potential neuromodulator of cognitive and affective functions, which likely exerts its effects via activation of the locus coeruleus-noradrenaline (LC-NA) system. Reliable effects of taVNS on markers of LC-NA system activity, however, have not been demonstrated yet.

METHODS

The aim of the present study was to overcome previous limitations by pooling raw data from a large sample of ten taVNS studies (371 healthy participants) that collected salivary alpha-amylase (sAA) as a potential marker of central NA release.

RESULTS

While a meta-analytic approach using summary statistics did not yield any significant effects, linear mixed model analyses showed that afferent stimulation of the vagus nerve via taVNS increased sAA levels compared to sham stimulation (b = 0.16, SE = 0.05, p = 0.001). When considering potential confounders of sAA, we further replicated previous findings on the diurnal trajectory of sAA activity.

CONCLUSION(S)

Vagal activation via taVNS increases sAA release compared to sham stimulation, which likely substantiates the assumption that taVNS triggers NA release. Moreover, our results highlight the benefits of data pooling and data sharing in order to allow stronger conclusions in research.

The chronic effects of a combination of herbal extracts (Euphytose®) on psychological mood state and response to a laboratory stressor: A randomised, placebo-controlled, double blind study in healthy humans

BACKGROUND

Global lifetime prevalence of anxiety disorders has been estimated at approximately 16.6%, with subclinical prevalence likely much higher. Herbal approaches to reduce anxiety may be as effective as pharmacological treatments and are less likely to be associated with adverse side effects. The herbal species, namely, valerian, passionflower, hawthorn and ballota, have a long history of use as anxiolytics in traditional medicine, further supported by recent pre-clinical and clinical trials.

AIMS

To assess the effects of chronic (14 days) supplementation with a multi-herb extract preparation (MHEP, Euphytose^®) on psychological state and psychological and physiological stress responses during a laboratory stressor.

METHODS

In this crossover study, 31 healthy participants (aged 19-58 years) received a MHEP and placebo for 14 days with a 28-day washout. Anxiety (State-Trait Anxiety Inventory), mood and physiological measures of stress (heart rate, galvanic skin response, salivary α-amylase and cortisol levels) were measured before and after an Observed Multitasking Stressor. Cognitive performance was also assessed.

RESULTS

MHEP was associated with reduced tension-anxiety (p = 0.038), with participants showing an attenuated response to the observed multitasking psychosocial stressor following MHEP, evidenced by lower salivary α-amylase (p = 0.041) and galvanic skin response (p = 0.004).

CONCLUSIONS

The combination of herbal extracts contained within the MHEP reduced subjective anxiety in a healthy population and lowered electrodermal skin conductance and concentration of salivary α-amylase in response to a psychosocial stressor, compared to placebo. The study was registered on clinicaltrials.gov (identifier: NCT03909906).

[Latest Research Findings on Health Management Based on Saliva Testing]

Being one of the most important exocrine fluids of the human body, saliva can reflect the health status of the body. Soliva collection has various advantages--it is simple, painless, fast, and safe, and soliva can be collected multiple times a day. Therefore, it has been gradually applied in the exploration for biomarkers for disease detection, providing a basis for the monitoring of the course of diseases, medication monitoring, and efficacy evaluation. We should implement health management based on saliva testing, collect the medical data of the healthy and diseased individuals and monitor their whole life cycle health, perform clinical cohort study, aggregate the data on platforms for big data on health and medicine, manage and provide guidance for the health status of populations, pinpoint the high-risk factors for pathogenesis, and provide effective intervention, early warning, and assessment of the vital signs of individuals, thereby reinforcing health management of the whole life cycle and safeguarding people's health in an all-round way. In addition, it drives the development of the health industry and bears strategic significance for the promotion of national economic development. It is becoming a hot research topic promising great potential and impressive applicational prospects. Herein, we reviewed new techniques for clinical saliva testing and health management based on saliva testing.

Multi-trajectory analysis uncovers latent associations between psychological and physiological acute stress response patterns

Encounter with an acute stressor elicits multiple physiological and psychological response trajectories that spread at different times-scales and directions. Associating a single physiological response trajectory with a specific psychological response has remained a challenge, due to putative interactions between the different stress response pathways. Hence, multidimensional analysis of stress response trajectories may be better suited to account for response variability. To test this, 96 healthy female participants underwent a robust acute laboratory stress induction procedure while their psychological [positive and negative affect (PANAS)] and physiological [heart rate (HR), heart rate variability (HRV), saliva cortisol (CORT)] responses were recorded before, during and after stress. Combining these data using unsupervised group-based multi-trajectory modelling uncovered three latent classes that best accounted for variability across psychological and physiological stress response trajectories. These classes were labelled based on their psychological response patterns as: A prototypical response group that depict a moderate increase in negative and decrease in positive affect during stress, with both patterns recovering after stress offset (n = 55); A heightened response group that depict excessive affective responses during stress that recover after stress offset (n = 24); and a lack of recovery group that depict a moderate increase in negative and decrease in positive affect during stress, with both patterns not recovering after stress offset (n = 17). With respect to physiological acute stress trajectories, all three groups exhibited comparable increases in HR and CORT during stress that recovered after stress offset, yet only the prototypical group expressed the expected stress-induced reduction in HRV, while the other two groups exhibited blunted HRV response. Critically, focusing on a single physiological stress response trajectory, including HRV, did not account for psychological response variability and vice versa. Taken together, a multi-trajectory approach may better account for the multidimensionality of acute stress response and uncover latent associations between psychological and physiological response patterns. Compared to the other two groups, the prototypical group also exhibited significantly lower overall stress scores based on the DASS-21 scale. This, alongside the uncovered response patterns, suggest that latent psycho-physiological associations may shed light on stress response adaptivity or lack thereof.

A Review of Psychological Stress among Students and Its Assessment Using Salivary Biomarkers

Numerous psychoneuroimmune factors participate in complex bodily reactions to psychological stress, and some of them can be easily and non-invasively measured in saliva (cortisol, alpha-amylase, proinflammatory cytokines). Cortisol plays a crucial role in the stress response; thus, stressful events (academic examinations, cardiac surgery, dental procedures) are accompanied by an increase in cortisol levels. (A correlation between cortisol blood levels and salivary values has already been confirmed, particularly during stress). Academic stress is defined as everyday stress among students that has an impact on aspects of their psychological and physiological well-being. For example, exams are considered one of the most acute stressful experiences for students. The strength of the association between academic self-efficacy, psychological stress, and anxiety depends on a variety of factors: the type of academic challenge (e.g., oral exam), the presence of an audience, etc. Higher stress levels were predominantly recorded among younger students, primarily regarding their academic tasks and concerns (grades, exams, competing with peers for grades, fear of failing the academic year, etc.). The measurement of stress levels during academic stress can improve our understanding of the character and influence of stressful events in populations of students, preventing adverse reactions to long-term stress, such as a decreased immune response and increased anxiety.

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.

Real-time racial discrimination, affective states, salivary cortisol and alpha-amylase in Black adults

Perceived racial discrimination has been associated with the autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis activities-two major stress response systems. To date, most studies have used cross-sectional data that captured retrospective measures of the racial discrimination associated with current physiological stress responses. The purpose of this study was to examine the relationship between racial discrimination measured in real-time and physiological stress responses. Twelve healthy Black adults completed baseline surveys and self-collected saliva samples 4x/day for 4 days to measure cortisol and alpha amylase (AA) as a proxy of HPA and ANS systems, respectively. Real-time racial discrimination was measured using ecological momentary assessments (EMA) sent to participants 5x/day for 7 days. Multilevel models were conducted to examine the relationship between racial discrimination and stress responses. In multilevel models, the previous day's racial discrimination was significantly associated with the next day's cortisol level at wakening (β = 0.81, partial r = 0.74, p<0.01) and diurnal slope (β = -0.85, partial r = -0.73, p<0.01). Also, microaggressions were significantly associated with the diurnal cortisol slope in the same day, indicating that on the day when people reported more microaggressions than usual, a flatter diurnal slope of cortisol was observed (β = -0.50, partial r = -0.64, p<0.01). The concurrent use of salivary biomarkers and EMA was feasible methods to examine the temporal relationship between racial discrimination and physiological stress responses. The within-person approach may help us understand the concurrent or lagged effects of racial discrimination on the stress responses. Further studies are needed to confirm the observed findings with a large sample size and to improve stress related health outcomes in racial/ethnic minorities.

Real sweating in a virtual stress environment: Investigation of the stress reactivity in people with primary focal hyperhidrosis

Background

Hyperhidrosis (excessive sweating, OMIM %114110) is a complex disorder with multifactorial causes. Emotional strains and social stress increase symptoms and lead to a vicious circle. Previously, we showed significantly higher depression scores, and normal cortisol awakening responses in patients with primary focal hyperhidrosis (PFH). Stress reactivity in response to a (virtual) Trier Social Stress Test (TSST-VR) has not been studied so far. Therefore, we measured sweat secretion, salivary cortisol and alpha amylase (sAA) concentrations, and subjective stress ratings in affected and non-affected subjects in response to a TSST-VR.

Method

In this pilot study, we conducted TSST-VRs and performed general linear models with repeated measurements for salivary cortisol and sAA levels, heart rate, axillary sweat and subjective stress ratings for two groups (diagnosed PFH (n = 11), healthy controls (n = 16)).

Results

PFH patients showed significantly heightened sweat secretion over time compared to controls (p = 0.006), with highest quantities during the TSST-VR. In both groups, sweating (p < 0.001), maximum cortisol levels (p = 0.002), feelings of stress (p < 0.001), and heart rate (p < 0.001) but not sAA (p = 0.068) increased significantly in response to the TSST-VR. However, no differences were detected in subjective ratings, cortisol concentrations and heart rate between PFH patients and controls (p_all > 0.131).

Conclusion

Patients with diagnosed PFH showed stress-induced higher sweat secretion compared to healthy controls but did not differ in the stress reactivity with regard to endocrine or subjective markers. This pilot study is in need of replication to elucidate the role of the sympathetic nervous system as a potential pathway involved in the stress-induced emotional sweating of PFH patients.

Psychobiological effects of chronic ethnic discrimination in Turkish immigrants: Stress responses to standardized face-to-face discrimination in the laboratory

OBJECTIVE

Ethnic discrimination negatively affects the health of ethnic minorities. The dysregulation of psychobiological stress systems, such as the autonomic nervous system (ANS) or the hypothalamic-pituitary-adrenal (HPA) axis, might be an intermediary in this association and chronicity of ethnic discrimination may matter. We studied stress responses to a standardized discriminatory event in Turkish immigrants living in Austria.

BACKGROUND

Seventy-two male Turkish immigrants were recruited; n = 35 had experienced high levels of ethnic discrimination (high), n = 37 infrequent ethnic discrimination (low). During a two-hour laboratory appointment, they underwent a previously validated 10-minute ethnic discrimination paradigm, i.e., a simulated physician's consultation with verbal and non-verbal discriminatory cues. Perceived stress, perceived discrimination, salivary cortisol, and alpha-amylase were assessed seven times, and ANS measures (heart rate, heart rate variability, and electrodermal activity) were measured continuously. In addition, hair cortisol concentrations were determined.

RESULTS

The ethnic discrimination paradigm elicited stress responses across all outcomes in both groups. Compared to the low group, the high group reported higher levels of perceived stress and discrimination, exhibited a less steep increase in cortisol in response to the paradigm, and showed higher hair cortisol concentrations. No group differences were found regarding ANS measures.

CONCLUSIONS

The combination of high subjective stress, flattened cortisol responses, and relatively high hair cortisol concentrations may indicate a dysregulation of the HPA axis in chronic ethnic discrimination. A better understanding of the psychobiological effects of chronic ethnic discrimination is crucial given that alterations in stress response systems may, over time, lead to illness and ultimately to substantial health inequities in ethnic minorities.

The Effect of Dental Treatments in Caries Management on Stress and Salivary Protein Levels

A great burden is put on healthcare systems by dental caries and understanding patients’ treatment needs is of utmost importance. The aim of this pre−post study was to assess dental anxiety and the psychological stress induced by two different types of dental treatment (prophylaxis and cavity preparation), by combining psychometric evaluations with salivary biomarkers, in a group of 28 schoolchildren presenting in a university clinic. Pre- and post-treatment unstimulated whole saliva was collected and levels of cortisol, alpha-amylase (sAA) and total protein content were measured. The State−Trait Anxiety Inventory for Children and the Frankl Behaviour Rating Scale (FBRS) were applied. Statistical analysis was performed using the Stata/IC 16 (StataCorp) programme. All salivary parameters showed strong positive correlations between pre- and post-treatment levels. Post-treatment, salivary cortisol decreased (p = 0.008, paired t-test), sAA did not change significantly (p = 0.572, sign test), while the sAA/cortisol ratio (AOC) increased (p = 0.036, sign test). There were no correlations between state and trait anxiety levels. State anxiety scores registered significantly higher values for children with an FBRS score of 3 compared with a score of 4 (p < 0.001, unpaired t-test). The post-treatment decrease in the salivary cortisol level was higher for prophylaxis compared with the cavity preparation group (p = 0.024, t-test). These results demonstrate that sAA and cortisol levels are altered differently by psychological stress induced by two different types of dental treatment.