Academic exam stress and depressive mood are associated with reductions in exhaled nitric oxide in healthy individuals

fMRI BOLD responses to film stimuli and their association with exhaled nitric oxide in asthma and health

Little is known about central nervous system (CNS) responses to emotional stimuli in asthma. Nitric oxide in exhaled breath (FENO) is elevated in asthma due to allergic immune processes, but endogenous nitric oxide is also known to modulate CNS activity. We measured fMRI blood oxygen-dependent (BOLD) brain activation to negative (blood-injection-injury themes) and neutral films in 31 participants (15 with asthma). Regions-of-interest analysis was performed on key areas relevant to central adaptive control, threat processing, or salience networks, with dorsolateral prefrontal cortex (PFC), anterior insula, dorsal anterior cingulate cortex (dACC), amygdala, ventral striatum, ventral tegmentum, and periaqueductal gray, as well as top-down modulation of emotion, with ventrolateral and ventromedial PFC. Both groups showed less BOLD deactivation from fixation cross-baseline in the left anterior insula and bilateral ventromedial PFC for negative than neutral films, and for an additional number of areas, including the fusiform gyrus, for film versus recovery phases. Less deactivation during films followed by less recovery from deactivation was found in asthma compared to healthy controls. Changes in PCO2 did not explain these findings. FENO was positively related to BOLD activation in general, but more pronounced in healthy controls and more likely in neutral film processing. Thus, asthma is associated with altered processing of film stimuli across brain regions not limited to central adaptive control, threat processing, or salience networks. Higher levels of NO appear to facilitate CNS activity, but only in healthy controls, possibly due to allergy's masking effects on FENO.

Development of a digital biomarker and intervention for subclinical depression: study protocol for a longitudinal waitlist control study

BACKGROUND

Depression remains a global health problem, with its prevalence rising worldwide. Digital biomarkers are increasingly investigated to initiate and tailor scalable interventions targeting depression. Due to the steady influx of new cases, focusing on treatment alone will not suffice; academics and practitioners need to focus on the prevention of depression (i.e., addressing subclinical depression).

AIM

With our study, we aim to (i) develop digital biomarkers for subclinical symptoms of depression, (ii) develop digital biomarkers for severity of subclinical depression, and (iii) investigate the efficacy of a digital intervention in reducing symptoms and severity of subclinical depression.

METHOD

Participants will interact with the digital intervention BEDDA consisting of a scripted conversational agent, the slow-paced breathing training Breeze, and actionable advice for different symptoms. The intervention comprises 30 daily interactions to be completed in less than 45 days. We will collect self-reports regarding mood, agitation, anhedonia (proximal outcomes; first objective), self-reports regarding depression severity (primary distal outcome; second and third objective), anxiety severity (secondary distal outcome; second and third objective), stress (secondary distal outcome; second and third objective), voice, and breathing. A subsample of 25% of the participants will use smartwatches to record physiological data (e.g., heart-rate, heart-rate variability), which will be used in the analyses for all three objectives.

DISCUSSION

Digital voice- and breathing-based biomarkers may improve diagnosis, prevention, and care by enabling an unobtrusive and either complementary or alternative assessment to self-reports. Furthermore, our results may advance our understanding of underlying psychophysiological changes in subclinical depression. Our study also provides further evidence regarding the efficacy of standalone digital health interventions to prevent depression. Trial registration Ethics approval was provided by the Ethics Commission of ETH Zurich (EK-2022-N-31) and the study was registered in the ISRCTN registry (Reference number: ISRCTN38841716, Submission date: 20/08/2022).

Respiratory psychophysiology and COVID-19: A research agenda

After multiple waves of the COVID-19 pandemic, it has become clear that the impact of SARS-CoV-2 will carry on for years to come. Acutely infected patients show a broad range of disease severity, depending on virus variant, vaccination status, age and the presence of underlying medical and physical conditions, including obesity. Additionally, a large number of patients who have been infected with the virus present with post-COVID syndrome. In September 2020, the International Society for the Advancement of Respiratory Psychophysiology organized a virtual interest meeting on 'Respiratory research in the age of COVID-19', which aimed to discuss how research in respiratory psychophysiology could contribute to a better understanding of psychophysiological interactions in COVID-19. In the resulting current paper, we propose an interdisciplinary research agenda discussing selected research questions on acute and long-term neurobiological, physiological and psychological outcomes and mechanisms related to respiration and the airways in COVID-19, as well as research questions on comorbidity and potential treatment options, such as physical rehabilitation.

Reducing Anxiety and Social Stress in Primary Education: A Breath-Focused Heart Rate Variability Biofeedback Intervention

Primary school students suffer from high levels of anxiety and stress. Having emotional regulation abilities can help them to manage challenging emotional situations. Conscious and slow breathing is a physiological, emotional regulation strategy that is feasible for primary school students to learn. Following Polyvagal Theory and PMER Theory, this research presents the results of a breath-focused heart rate variability biofeedback intervention. The intervention aimed to reduce anxiety and physiological and social stress in primary school children. A total of 585 students (46.4% girls and 53.6% boys) from the same public school, aged between 7 and 12 years (M = 8.51; SD = 1.26), participated in this study. To assess the impact of training, a mixed design was used with two groups (Treatment and Control groups), two evaluation phases (Pretest and Post-test), and three educational cycles (first, second and third cycles). To examine heart rate variability, emWave software was used and anxiety and social stress were measured by the BASC II test. The results showed that after the intervention, the students learned to breathe consciously. Moreover, they reduced their levels of anxiety (M(SD)_pretest = 12.81(2.22) vs. M(SD)_posttest = 13.70(1.98)) and stress (M(SD)_pretest = 12.20(1.68) vs. M(SD)_posttest = 12.90(1.44)). The work also discusses the limitations and benefits of this type of intervention in primary schools.

The roles of parental absence, life skills and personality traits in mental health status among adolescents in rural China

PROBLEM

Mental health issues in adolescents are public health concerns worldwide including China. However, there is a lack of research examining the role of parental absence status, life skills, and personality traits on the mental health of adolescents in rural China.

METHOD

The purpose of this cross-sectional study was to examine the role of parental absence status, life skills, and personality traits on the mental health of adolescents in rural China. This study used self-developed demographic questionnaire, Mental Health Test (MHT), Middle School Student Life Skills Rating Scale, and Eysenck Personality Questionnaire. Binary logistic regression analyses were performed to examine the associated factors on different domains of MHT.

RESULTS

Adolescents in rural China reported high proportion of mental health disorders (MHDs), including learning anxiety, sensitiveness, self-accusation, and physical symptoms tendency. Although 75.6% experienced parental absence, this was not associated with MHT after controlling for all other variables. Better mental health was correlated with life skills including communication skills, interpersonal morality, self-efficacy, and stress coping. The instability-neuroticism personality trait was positively associated with MHDs.

DISCUSSION

Adolescents in rural China reported high positive rates of MHDs. Communication skills, interpersonal morality, self-efficacy, ability to cope with stress and Instability-neuroticism were important associated factors of MHDs.

APPLICATION TO PRACTICE

Life skills and personality are two important factors that should be considered when assessing the mental health status of adolescents and formulating interventions.

Role of amygdala in stress-induced upregulation of airway IL-1 signaling in asthma

Psychological stress, an important contributor to asthma morbidity, potentiates the immune response to allergen, but the brain mechanisms mediating this response are not fully understood. The amygdala is likely to play an important role, given its sensitivity to threat and connectivity with descending immune modulatory pathways. In this study, we recruited thirty asthmatic participants and examined glucose metabolism in the amygdala, using [F-18]fluorodeoxyglucose positron emission tomography, during a laboratory stressor. Stress hormone and airway inflammatory measurements were also acquired. Results showed that activity in the amygdala was significantly increased during the stressor, compared to a matched control task (p < .05 corrected). Moreover, the increase in amygdala activity was associated with a greater increase in sputum IL-1R1 mRNA and alpha amylase response (p < .05 corrected), which were also positively correlated (p = .01). These findings suggest that heightened amygdala reactivity may contribute to asthma morbidity via descending proinflammatory sympathetic signaling pathways.

Paeoniflorin: A neuroprotective monoterpenoid glycoside with promising anti-depressive properties

BACKGROUND

Depression, as a prevalent and debilitating psychiatric disease, severely decreases the life quality of individuals and brings heavy burdens to the whole society. Currently, some antidepressants are applied in the treatment of severe depressive symptoms, while there are still some undesirable drawbacks. Paeoniflorin is a monoterpenoid glycoside that was firstly extracted from Paeonia lactiflora Pall, a traditional Chinese herb that is widely used in the Chinese herbal formulas for treating depression.

PURPOSE

This review summarized the previous pre-clinical studies of paeoniflorin in treating depression and further discussed the potential anti-depressive mechanisms for that paeoniflorin to be further explored and utilized in the treatment of depression clinically.

METHODS

Some electronic databases, e.g., PubMed and China National Knowledge Infrastructure, were searched from inception until April 2021.

RESULTS

This review summarized the effective anti-depressive properties of paeoniflorin, which is related to its functions in the upregulation of the levels of monoaminergic neurotransmitters, inhibition of the hypothalamic-pituitary-adrenal axis hyperfunction, promotion of neuroprotection, promotion of hippocampus neurogenesis, and upregulation of brain-derived neurotrophic factor level, inhibition of inflammatory reaction, downregulation of nitric oxide level, etc. CONCLUSION: This review focused on the pre-clinical studies of paeoniflorin in depression and summarized the recent development of the anti-depressive mechanisms of paeoniflorin, which approves the role of paeoniflorin plays in anti-depression. However, more high-quality pre-clinical and clinical studies are expected to be conducted in the future.

Chronic stress experience, sleep, and physical activity: Relations with change in negative affect and acute stress response to a naturalistic stressor

OBJECTIVES

Prior research indicates that chronic stress increases allostatic load and alters individuals' affective response to stress. Recent studies have linked health-related behaviours including poor sleep and physical inactivity with elevated negative affect responses to stress. This study extends prior work to investigate chronic stress experience, sleep, and physical activity as predictors of negative affect and acute stress experience during acute, sustained naturalistic stress.

DESIGN

Students (N = 637) were assessed during an academic semester and end-of-term final exam period.

METHODS

Self-report ratings of chronic stress experience, negative affect, acute stress experience, sleep, physical activity, demographics, and health were obtained. Hierarchical multiple regression analyses examined the extent to which chronic stress experience, sleep duration and sleep quality, habitual physical activity, and their interactions, predicted changes in negative affect and acute stress experience during final exams. Health-related behaviours were also examined as mediators between chronic stress experience and changes in negative affect and acute stress experience.

RESULTS

Greater chronic stress experience and shorter exam period sleep duration, but not habitual sleep duration or physical activity, predicted greater increases in negative affect and acute stress experience. Poorer overall sleep quality was a significant predictor in these models and partially mediated the relation between chronic stress experience and negative affect and acute stress experience.

CONCLUSIONS

Findings highlight the importance of chronic stress experience and sleep in predicting individuals' affective health during naturalistic stress. Interventions that reduce chronic stress experience and improve sleep may help individuals' buffer against impairments to affective health during these episodes.

Academic self-efficacy and test anxiety in high school students: A conditional process model of academic buoyancy and peer support

Based on social cognitive theory and ecological systems theory, this study constructed a conditional process model to explore the relationship between academic self-efficacy and test anxiety as well as underlying psychological mechanisms through academic buoyancy and peer support. A sample of Chinese high school students ( N = 560) completed questionnaires assessing academic self-efficacy, academic buoyancy, peer support, and test anxiety. Structural equation modeling (SEM) revealed an indirect effect of academic self-efficacy on test anxiety through academic buoyancy. Moreover, the results of the conditional process analysis demonstrated that this indirect effect was moderated by peer support. The findings suggested that both personal positive psychological characteristics (e.g., academic buoyancy) and school environmental factors (e.g., peer support) are protective factors for test anxiety in high school students. Limitations and implications for future research are discussed.

Boosting nitric oxide in stress and respiratory infection: Potential relevance for asthma and COVID-19

Nitric oxide (NO) is a ubiquitous signaling molecule that is critical for supporting a plethora of processes in biological organisms. Among these, its role in the innate immune system as a first line of defense against pathogens has received less attention. In asthma, levels of exhaled NO have been utilized as a window into airway inflammation caused by allergic processes. However, respiratory infections count among the most important triggers of disease exacerbations. Among the multitude of factors that affect NO levels are psychological processes. In particular, longer lasting states of psychological stress and depression have been shown to attenuate NO production. The novel SARS-CoV-2 virus, which has caused a pandemic, and with that, sustained levels of psychological stress globally, also adversely affects NO signaling. We review evidence on the role of NO in respiratory infection, including COVID-19, and stress, and argue that boosting NO bioavailability may be beneficial in protection from infections, thus benefitting individuals who suffer from stress in asthma or SARS-CoV-2 infection.

Lower fractional exhaled nitric oxide levels are associated with depressive symptom in males: A population-based cross-sectional study

BACKGROUND

We examined cross-sectional associations between depression and both inflammatory markers and fractional exhaled nitric oxide (FeNO).

METHODS

This cross-sectional study is a secondary analysis of the data of the Iwaki Health Promotion Project 2016 (1,148 subjects). We analyzed the subjects' characteristics and laboratory data including plasma interleukin (IL)-6, high-sensitivity C-reactive protein (hs-CRP), and FeNO. The subjects with Center for Epidemiologic Studies Depression Scale scores ≥16 were assigned to the depression group. We performed a multivariate logistic regression analysis to determine whether inflammatory markers and FeNO were associated with depression.

RESULTS

We assessed 1,099 subjects (430 males, 669 females). The depression group was 237 subjects (21.5%) [84 males (19.5%), 153 females (22.9%)]. The non-depression group was 862 subjects (346 males and 516 females). There were no significant differences in IL-6, hs-CRP, or FeNO between both groups. However, the multivariate logistic regression analysis indicated that lower FeNO was significantly associated with depression in males after adjusting for possible confounding factors (age, BMI, comorbidities, high-sensitivity troponin T, FEV₁%, asthma, antidepressant use, smoker and alcohol drinker) (per 1 bpm increase, OR: 0.982; 95%CI: 0.967-0.998; p = 0.032).

CONCLUSION

Our findings indicate that lower FeNO may be associated with depression in males.

Simultaneous capillary electrophoresis of anions and cations in a single injection using an anion exchanger-modified capillary for determination of salivary ions in combination with statistical analyses

This paper describes the simultaneous capillary electrophoresis (CE) of anions and cations using an anion exchange-modified capillary, which was prepared by chemical coating with a cationic silylating reagent, and its application to saliva analysis. The CE method provides high-throughput (5 min for a single sample injection) analysis by generating a high-velocity electroosmotic flow at pH 3.0-3.5. The detection limits at a signal-to-noise ratio of 3 ranged from 1.2 to 18 μM for anions and 1.0 to 2.7 μM for cations. The relative standard deviations for the migration times and peak areas of analytes (n = 4) ranged from 0.05% to 0.40% and 0.94% to 4.7%, respectively. The CE system was used to analyze 11 common ions in saliva samples collected from long-distance runners and sedentary university students before and after running for a set distance or a set time. Interestingly, the SCN^- concentrations decreased in the saliva samples of all 14 athletes and 16 sedentary students after running. Furthermore, when the concentrations of the analyzed ions were compared with that of cortisol as a typical stress marker by multiple regression analysis, SCN^- and NO₃^- in saliva samples from the two subject groups strongly correlated with cortisol levels, as determined by an electrochemiluminescence immunoassay. This study improves our knowledge of both the analytical methodology for CE and statistical methods for identifying common ions that could be used as physical stress markers.

Machine Learning Analysis of Electronic Nose in a Transdiagnostic Community Sample With a Streamlined Data Collection Approach: No Links Between Volatile Organic Compounds and Psychiatric Symptoms

Non-intrusive, easy-to-use and pragmatic collection of biological processes is warranted to evaluate potential biomarkers of psychiatric symptoms. Prior work with relatively modest sample sizes suggests that under highly-controlled sampling conditions, volatile organic compounds extracted from the human breath (exhalome), often measured by an electronic nose ("e-nose"), may be related to physical and mental health. The present study utilized a streamlined data collection approach and attempted to replicate and extend prior e-nose links to mental health in a standard research setting within large transdiagnostic community dataset (N = 1207; 746 females; 18-61 years) who completed a screening visit at the Laureate Institute for Brain Research between 07/2016 and 05/2018. Factor analysis was used to obtain latent exhalome variables, and machine learning approaches were employed using these latent variables to predict three types of symptoms independent of each other (depression, anxiety, and substance use disorder) within separate training and a test sets. After adjusting for age, gender, body mass index, and smoking status, the best fitting algorithm produced by the training set accounted for nearly 0% of the test set's variance. In each case the standard error included the zero line, indicating that models were not predictive of clinical symptoms. Although some sample variance was predicted, findings did not generalize to out-of-sample data. Based on these findings, we conclude that the exhalome, as measured by the e-nose within a less-controlled environment than previously reported, is not able to provide clinically useful assessments of current depression, anxiety or substance use severity.

Nitric oxide: Antidepressant mechanisms and inflammation

Millions of individuals worldwide suffers from mood disorders, especially major depressive disorder (MDD), which has a high rate of disease burden in society. Although targeting the biogenic amines including serotonin, and norepinephrine have provided invaluable links with the pharmacological treatment of MDD over the last four decades, a growing body of evidence suggest that other biologic systems could contribute to the pathophysiology and treatment of MDD. In this chapter, we highlight the potential role of nitric oxide (NO) signaling in the pathophysiology and thereby treatment of MDD. This has been investigated over the last four decades by showing that (i) levels of NO are altered in patients with major depression; (ii) modulators of NO signaling exert antidepressant effects in patients with MDD or in the animal studies; (iii) NO signaling could be targeted by a variety of antidepressants in animal models of depression; and (iv) NO signaling can potentially modulate the inflammatory pathways that underlie the pathophysiology of MDD. These findings, which hypothesize an NO involvement in MDD, can provide a new insight into novel therapeutic approaches for patients with MDD in the future.

Perceived stress and reference ranges of hair cortisol in healthy adolescents

Background

Chronic stress during adolescence has usually been evaluated through subjective measures, leaving aside objective measures such as hair cortisol concentrations. Therefore, the aim of this study was to provide reference ranges for hair cortisol concentrations by sex and age and to study the relationship between subjective and objective measures of stress and temporal stability.

Methods

The participants were 170 adolescents aged between 12 and 14 years (mean = 12.78 years; standard deviation = 0.71 years; 52.40% girls) who completed the Perceived Stress Scale 4 and had their hair sampled.

Results

The results revealed hair cortisol concentrations ranging from 0.07 pg/mg to 9.54 pg/mg. Subjective and objective measures of stress were not related, nor was there intraindividual stability of the hair cortisol concentrations. Girls had higher hair cortisol concentrations, and there were no age differences.

Conclusions

This research provides cortisol reference values for adolescents that will allow the early detection of chronic stress. Such detection methods make it possible to prevent problems arising from stress because we can act more quickly and the treatments will be more effective. The study suggests that there is no relationship between perceived and objective stress; while perceived stress remained stable, the levels of hair cortisol were increased at 6 months. Despite the interesting findings of the study, there are some limitations: the sample was not obtained through probabilistic sampling, the age range was narrow, and some demographic, anthropomorphic and clinical factors are missing, which make the generalization of results difficult.

Beetroot juice supplementation for the prevention of cold symptoms associated with stress: A proof-of-concept study

OBJECTIVES

Psychological stress has been linked to common cold symptoms. Nitric oxide (NO) is part of the first line of epithelial defense against pathogens, and beetroot juice is a source of dietary nitrate that increases NO availability. We therefore tested whether beetroot juice protects against cold symptoms in a period of sustained acute stress.

DESIGN

Seventy-six students, 16 of these with asthma, were randomly assigned to seven daily doses of beetroot juice or no supplementation control during their final exams.

METHODS

Participants completed stress ratings, a cold symptom questionnaire, and exhaled NO measurements at a low-stress period and two periods during their final exams, with one questionnaire follow-up assessment seven days after finals.

RESULTS

Beetroot juice was associated with reduced symptoms of cold and sickness during and following finals. Those with asthma showed the greatest benefits. Higher exhaled NO was concurrently and prospectively associated with reduced symptomatology.

CONCLUSION

Beetroot juice during periods of psychological stress protects against cold symptoms. Preliminary evidence suggests particular benefits in asthma, which could translate into reduced asthma exacerbations due to respiratory infections. Clinical Trial ID: NCT03159273.

Pathologic role of nitrergic neurotransmission in mood disorders

Mood disorders are chronic, recurrent mental diseases that affect millions of individuals worldwide. Although over the past 40 years the biogenic amine models have provided meaningful links with the clinical phenomena of, and the pharmacological treatments currently employed in, mood disorders, there is still a need to examine the contribution of other systems to the neurobiology and treatment of mood disorders. This article reviews the current literature describing the potential role of nitric oxide (NO) signaling in the pathophysiology and thereby the treatment of mood disorders. The hypothesis has arisen from several observations including (i) altered NO levels in patients with mood disorders; (ii) antidepressant effects of NO signaling blockers in both clinical and pre-clinical studies; (iii) interaction between conventional antidepressants/mood stabilizers and NO signaling modulators in several biochemical and behavioral studies; (iv) biochemical and physiological evidence of interaction between monoaminergic (serotonin, noradrenaline, and dopamine) system and NO signaling; (v) interaction between neurotrophic factors and NO signaling in mood regulation and neuroprotection; and finally (vi) a crucial role for NO signaling in the inflammatory processes involved in pathophysiology of mood disorders. These accumulating lines of evidence have provided a new insight into novel approaches for the treatment of mood disorders.

Exhaled breath analysis in evaluation of psychological stress: A short literature review

Physiological stress is pervasive in today's society. Its detection is normally performed through several unobtrusive methods, driving both caregivers and patients to take measures to reduce the burden of this condition on human health. Among the methods for assessing stress, exhaled breath analysis represents a non-invasive, real-time alternative to classic laboratory tests. Therefore, a literature review was performed to assess the presence of altered parameters, related to psychological stress, in exhaled breath. Most studies in our review measured nitric oxide (NO), whose concentration was often correlated, either positively or negatively, with psychological stress, with reasonable scientific support. Other compounds (isoprene, terpene and so on) were rarely studied and with mixed evidence. Further investigations are needed to elucidate the involvement and the pathophysiological role of NO in stress, possibly including a greater number of individuals, as sample size actually represents the main limitation of the work published to date.

Associations between self-rated health, sickness behaviour and inflammatory markers in primary care patients with allergic asthma: a longitudinal study

Allergic asthma is a chronic inflammatory disorder associated with elevated levels of immunoglobulin E (IgE), serum eosinophilic cationic protein (S-ECP), plasma eosinophil-derived neurotoxin (P-EDN) and fraction of exhaled nitric oxide (FENO). Poor self-rated health and sickness behaviour has repeatedly been associated with inflammatory markers, but the nature of this relationship in chronic inflammatory disease is not known. Likewise, such findings largely rely on cross-sectional investigations. Self-rated health (How would you rate your general state of health?), sickness behaviour (mean rating of satisfaction with energy, sleep, fitness, appetite and memory), IgE, S-ECP, P-EDN, and FENO were assessed in 181 non-smoking primary care patients with asthma in a 1-year longitudinal study. Associations between repeated measurements were calculated using mixed regression models and Spearman's correlations for change scores. Poor self-rated health was associated with high levels of seasonal IgE (p = 0.05) and food IgE (p = 0.04), but not total IgE or inflammatory markers. An increase over 1 year in perennial IgE was associated with a worsening of self-rated health (ρ = 0.16, p = 0.04). Poor self-rated health was associated with more pronounced sickness behaviour (p < 0.001), and a worsening in sickness behaviour was associated with a worsening of self-rated health over time (ρ = 0.21, p = 0.007). The study corroborates the importance of sickness behaviour as a determinant of self-rated health by showing that these factors co-vary over a 1-year period in a group of patients with allergic asthma. The importance of specific IgE for perceived health in primary care patients with mild to moderate asthma needs further investigation.

Exhaled nitric oxide and vascular endothelial growth factor as predictors of cold symptoms after stress

OBJECTIVE

Prior research has demonstrated that psychosocial stress is associated with respiratory infections. Immunologic, endocrine, and cardiovascular predictors of such infections have been explored with varying success. We therefore sought to study the unexplored role of airway mucosal immunity factors, nitric oxide (NO) and vascular endothelial growth factor (VEGF). NO is secreted by airway epithelial cells as part of the first line of defense against bacteria, viruses, and fungi. VEGF is expressed by mast cells in respiratory infections and recruits immune cells to infected sites, but in excess lead to vulnerability of the airway epithelium.

METHODS

In this proof-of-concept study we measured exhaled NO, exhaled breath condensate (EBC) VEGF, salivary VEGF, and salivary cortisol in 36 students undergoing final academic examinations at three occasions: a low-stress baseline during the term, an early phase of finals, and a late phase of finals. Participants also reported on cold symptoms at these time points and approximately 5 and 10days after their last academic examination.

RESULTS

Higher baseline NO was associated with fewer cold symptoms after stress, whereas higher baseline VEGF in EBC and saliva were associated with more cold symptoms after stress. Perceived stress at baseline as well as salivary VEGF and cortisol late in the finals also contributed to the prediction of later cold symptoms.

CONCLUSION

Basal levels of NO and VEGF may inform about mucosal immunocompetence and add to preventative treatments against airway infections from periods of stress in daily life.

The relationship between examination-related academic stress, salivary antioxidant capacity and exercise patterns of final-year Saudi dental students

OBJECTIVE

To study the impact of examination stress on the total antioxidant capacity (TAC) of senior dental students and compare changes in TAC between students who exercise regularly and those who do not.

METHODS

A questionnaire designed to evaluate physical activity levels, body mass index (BMI) and academic performance was distributed to 325 senior dental students. Of the 312 who responded, a total of 70 were enrolled in the study, of whom 60 completed the study. The students were composed of a low-activity group (n = 30), who had a Goddard-Sheppard (GS) exercise score of <25, and a high-exercise group (n = 30), who had a GS score >60. Dental Environment Stress (DES) questionnaires and salivary samples were collected at the first week of the semester and at the week of the examinations. Salivary TAC was measured using a commercially available Radical Absorbance Antioxidant Assay measurement kit (Zen-Bio ORAC™, AMS Biotechnology, Abington UK). A total of 60 students completed the study.

RESULTS

A significant increase in DES values and a significant reduction in salivary TAC values were observed in the week of the examination compared to baseline scores. Although no differences were observed in the DES scores between the high-exercise and low-exercise groups, the high-exercise group showed a significantly lower reduction in examination week salivary TAC compared to their counterparts in the low-exercise group. Regression models showed a significant association between the TAC, exercise scores and DES scores in the week of the examinations.

CONCLUSION

Regular exercise may help protect students against the oxidative stress associated with academic stress.

Sensitivity of salivary hydrogen sulfide to psychological stress and its association with exhaled nitric oxide and affect

BACKGROUND

Hydrogen sulfide (H₂S) is the third gasotransmitter recently discovered after nitric oxide (NO) and carbon monoxide. Both NO and H₂S are involved in multiple physiological functions. Whereas NO has been shown to vary with psychological stress, the influence of stress on H₂S and the relationship between H₂S and NO are unknown. We therefore examined levels of salivary H₂S and NO in response to a stressful final academic exam period.

METHODS

Measurements of stress, negative affect, and fraction of exhaled NO (FE_NO), were obtained from students (N=16) and saliva was collected at three time points: low-stress period in the semester, early exam period, and late exam period. Saliva was immediately analyzed for H₂S with the fluorescent probe Sulfidefluor-4.

RESULTS

H₂S increased significantly during the early exam period and FE_NO decreased gradually towards the late exam period. H₂S, FE_NO, negative affect, and stress ratings were positively associated with each other: as stress level and negative affect increased, values of H₂S increased; in addition, as FE_NO levels decreased, H₂S also decreased. Asthma status did not modify these associations.

CONCLUSION

Sustained academic stress increases H₂S and these changes are correlated with NO and the experience of stress and negative affect. These findings motivate research with larger samples to further explore the interaction and function of H₂S and FE_NO during psychological stress.

Association of arginase I or nitric oxide-related factors with job strain in healthy workers

This study evaluated the associations between job strain and arginase I in 378 healthy Japanese factory workers by a cross-sectional study measuring nitric oxide (NO)-related parameters (arginase I, L-arginine, exhaled nitric oxide (FeNO), and NOx), clinical parameters, and job strain using a Japanese version of the Job Content Questionnaire by Karasek. Arginase I and FEV1% were negatively correlated with job strain and positively correlated with job control and social support. FeNO and hs-CRP were negatively correlated with job strain. Multiple regression analysis showed negative association of arginase I with job strain and positive association with job control and social support in females. It is concluded that serum levels of arginase I may be useful biomarkers for the diagnosis of job stress in healthy female workers, although many factors can be influencing the data.

A novel biomarker associated with distress in humans: calcium-binding protein, spermatid-specific 1 (CABS1)

Calcium-binding protein spermatid-specific 1 (CABS1) is expressed in the human submandibular gland and has an anti-inflammatory motif similar to that in submandibular rat 1 in rats. Here, we investigate CABS1 in human saliva and its association with psychological and physiological distress and inflammation in humans. Volunteers participated across three studies: 1) weekly baseline measures; 2) a psychosocial speech and mental arithmetic stressor under evaluative threat; and 3) during academic exam stress. Salivary samples were analyzed for CABS1 and cortisol. Additional measures included questionnaires of perceived stress and negative affect; exhaled nitric oxide; respiration and cardiac activity; lung function; and salivary and nasal inflammatory markers. We identified a CABS1 immunoreactive band at 27 kDa in all participants and additional molecular mass forms in some participants. One week temporal stability of the 27-kDa band was satisfactory (test-retest reliability estimate = 0.62-0.86). Acute stress increased intensity of 18, 27, and 55 kDa bands; 27-kDa increases were associated with more negative affect and lower heart rate, sympathetic activity, respiration rate, and minute ventilation. In both acute and academic stress, changes in 27 kDa were positively associated with salivary cortisol. The 27-kDa band was also positively associated with VEGF and salivary leukotriene B4 levels. Participants with low molecular weight CABS1 bands showed reduced habitual stress and negative affect in response to acute stress. CABS1 is readily detected in human saliva and is associated with psychological and physiological indicators of stress. The role of CABS1 in inflammatory processes, stress, and stress resilience requires careful study.

Mind-body interactions in the regulation of airway inflammation in asthma: A PET study of acute and chronic stress

BACKGROUND

Psychological stress has long been recognized as a contributing factor to asthma symptom expression and disease progression. Yet, the neural mechanisms that underlie this relationship have been largely unexplored in research addressing the pathophysiology and management of asthma. Studies that have examined the mechanisms of this relationship in the periphery suggest that it is the superimposition of acute stress on top of chronic stress that is of greatest concern for airway inflammation.

METHODS

We compared asthmatic individuals with high and low levels of chronic life stress in their neural and peripheral physiological responses to the Trier Social Stress Test and a matched control task. We used FDG-PET to measure neural activity during performance of the two tasks. We used both circulating and airway-specific markers of asthma-related inflammation to assess the impact of acute stress in these two groups.

RESULTS

Asthmatics under chronic stress had a larger HPA-axis response to an acute stressor, which failed to show the suppressive effects on inflammatory markers observed in those with low chronic stress. Moreover, our PET data suggest that greater activity in the anterior insula during acute stress may reflect regulation of the effect of stress on inflammation. In contrast, greater activity in the mid-insula and perigenual anterior cingulate seems to reflect greater reactivity and was associated with greater airway inflammation, a more robust alpha amylase response, and a greater stress-induced increase in proinflammatory cytokine mRNA expression in airway cells.

CONCLUSIONS

Acute stress is associated with increases in markers of airway inflammation in asthmatics under chronic stress. This relationship may be mediated by interactions between the insula and anterior cingulate cortex, that determine the salience of environmental cues, as well as descending regulatory influence of inflammatory pathways in the periphery.

Effects of academic exam stress on nasal leukotriene B4 and vascular endothelial growth factor in asthma and health

OBJECTIVE

To examine the effect of final exam stress on the concentrations of leukotriene B4 (LTB4) and vascular endothelial growth factor (VEGF) in the upper airways among healthy and asthmatic individuals.

METHOD

Nasal samples were collected from 12 individuals with asthma and 23 healthy controls early and late in a final exam period, and during a low-stress period in the semester. We determined LTB4 and VEGF concentrations using Enzyme-Linked Immunoassays.

RESULTS

Mixed effects analysis of variance models showed that asthmatic participants with allergies in contrast to healthy individuals experienced a decrease in nasal LTB4 during the final exam period as compared to mid-semester (low stress period). There were no significant changes in nasal VEGF across the observation period. Changes in nasal LTB4 and VEGF were not associated with salivary cortisol, exhaled nitric oxide, or spirometric lung function.

CONCLUSIONS

Our results suggest that nasal LTB4 concentrations change in periods of psychological stress for asthmatic individuals with allergies.

Cortisol response to acute stress in asthma: Moderation by depressive mood

Both individuals with asthma and depression show signs of a dysregulated hypothalamus-pituitary-adrenal axis. However, little is known about the cortisol response to stress in the context of co-occurring asthma and depressive mood. Thirty-nine individuals with asthma and 41 healthy controls underwent a combined speech and mental arithmetic stressor. During the course of the laboratory session, salivary cortisol was collected 5 times, with 1 sample at 0min before the stressor and 4 samples at 0, 15, 30 and 45min after the stressor. Depressive mood in the past week was assessed with the Hospital Anxiety and Depression Scale at the beginning of the session. Depressive symptoms moderated cortisol response to the acute stressor, but only among asthmatic patients. Higher depressive mood was associated with a significant increase in cortisol, whereas low depressive mood was associated with no cortisol response. In healthy participants, depressive mood had no substantial effect on cortisol response to the stressor. These findings suggest that depressive mood and chronic inflammatory diseases such as asthma can interact to augment cortisol response to stress.

Increases in exhaled nitric oxide after acute stress: association with measures of negative affect and depressive mood

BACKGROUND

Increases in fractional exhaled nitric oxide (FeNO) have been observed after acute laboratory stress, which could indicate a strengthening of immune defenses in acute stress because of the quick onset of the response and the role of nitric oxide in airway-protective functions. In addition, because sustained psychological distress and depression are known to deteriorate immune defenses systems, they may dampen the FeNO response to acute stress.

METHODS

FeNO and negative affect were measured before and after a speech and mental arithmetic stressor. We examined the association of stress-induced FeNO changes with momentary negative affect and questionnaires of perceived stress, anxious mood, and depressive mood in 39 asthma patients and 41 healthy controls.

RESULTS

FeNO increased from baseline to stress in participants with asthma (from 3.38 [0.102] to 3.46 [0.103] ln(ppb)) and controls (2.86 [0.098] to 2.92 [0.099]; F(4,141) = 3.26, p = .014), but the magnitude of the FeNO response did not differ between groups (F < 1). Only low levels of depressive mood were associated with FeNO increases after stress (most pronounced at 0 minute poststress; t(76) = 3.87, p < .001). In contrast, only higher perceived stress was associated with FeNO increases (most pronounced at 0 minute poststress; t(75) = 4.09, p < .001), and momentary negative affect was associated with higher FeNO throughout assessments (β = 0.08, t(114) = 8.27, p = .005). Associations of FeNO with psychological variables were largely unrelated to asthma status and inhaled corticosteroid use.

CONCLUSIONS

Depressive mood is associated with a reduced mobilization of airway nitric oxide in acute stress, whereas other indicators of negative affect are positively associated with overall FeNO levels and reactivity.

The role of fractional exhaled nitric oxide in asthma management

Measuring fractional exhaled nitric oxide (FeNO) is a relatively new option for assessing allergic inflammation in the lungs. Clinical management of asthma is challenging, and measuring exhaled nitric oxide can provide another type of data to assist in meeting this challenge. FeNO is easy to perform, and the equipment is not forbiddingly expensive. FeNO provides a complement to traditional measures of asthma control and can help guide diagnostic and treatment choices. This article explains what it is, how the measurements are performed, what the norms are, and its use and limitations in the management of asthma.

Social support as a predictor exhaled nitric oxide in healthy individuals across time

Psychosocial factors such as social support and depression have long been associated with health outcomes. Elevated depressive symptoms are usually associated with worse health outcomes, whereas social support has been related to improvements in health. Nitric oxide levels are an important marker of both cardiovascular health and immune function. Research suggests that exhaled nitric oxide is affected by stress, negative affect, and depression; however, the effect of social support has not been previously explored. Thus, we sought to examine the association of social support, negative affect, and depression with exhaled nitric oxide in a group of 35 healthy individuals (10 males and 25 females) with a mean age of 20.5years across five weekly assessments. Results showed that changes in social support within individuals were positively associated with levels of exhaled nitric oxide independent of other psychosocial factors. Further exploration of the health implications of this positive relationship between airway nitric oxide and social support is necessary.

Vagus Nerve Stimulation

The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality.

Taming a wandering attention: short-form mindfulness training in student cohorts

Mindfulness training (MT) is a form of mental training in which individuals engage in exercises to cultivate an attentive, present centered, and non-reactive mental mode. The present study examines the putative benefits of MT in University students for whom mind wandering can interfere with learning and academic success. We tested the hypothesis that short-form MT (7 h over 7 weeks) contextualized for the challenges and concerns of University students may reduce mind wandering and improve working memory. Performance on the sustained attention to response task (SART) and two working memory tasks (operation span, delayed-recognition with distracters) was indexed in participants assigned to a waitlist control group or the MT course. Results demonstrated MT-related benefits in SART performance. Relative to the control group, MT participants had higher task accuracy and self-reported being more “on-task” after the 7-week training period. MT did not significantly benefit the operation span task or accuracy on the delayed-recognition task. Together these results suggest that while short-form MT did not bolster working memory task performance, it may help curb mind wandering and should, therefore, be further investigated for its use in academic contexts.

Airway nitric oxide and psychological processes in asthma and health: a review

OBJECTIVE

The fraction of exhaled nitric oxide (FeNO) has been widely used as a marker of airway inflammation in asthma in recent years. However, NO serves multiple functions throughout the organism, and various influences on FeNO levels beyond inflammation have been documented. Emerging literature indicates that psychological processes are systematically linked to FeNO.

DATA SOURCES

Academic Search Complete, PubMed, PsychArticles, and PsychInfo databases.

STUDY SELECTIONS

Relevant studies were identified using keywords exhaled nitric oxide paired with psychological stress, stress psychology, emotion, major depression, anxiety, or psychopathology. Studies measuring FeNO during naturalistic observation of emotion and stress, laboratory stress and emotion-induction protocols, and correlational designs using psychological questionnaires were included.

RESULTS

Acute stress, anxiety, and negative affect have been repeatedly linked with higher FeNO levels, whereas more prolonged states of stress, in particular depression, have been associated with lower FeNO levels. The literature on FeNO is paralleled by research on NO in the cardiovascular and central nervous systems, which also shows systematic associations with psychosocial variables. Potential mechanisms of association include stimulation of NO release from different cells, including the epithelia and macrophages, through noradrenaline, interferon-γ, or vascular endothelial growth factor, changes in oxidative stress or arginase levels, or facilitation of diffusion by mechanical factors.

CONCLUSION

Psychosocial factors may need to be considered in the interpretation of longitudinal FeNO changes in monitoring and management of patients with asthma. The distinction between constitutive and inducible sources of NO will be essential for future research.