Salivary chromogranin-A as a marker of psychological stress during a cognitive test battery in humans

A Multimodal Approach to Measuring Listening Effort: A Systematic Review on the Effects of Auditory Task Demand on Physiological Measures and Their Relationship

OBJECTIVES

Listening effort involves the mental effort required to perceive an auditory stimulus, for example in noisy environments. Prolonged increased listening effort, for example due to impaired hearing ability, may increase risk of health complications. It is therefore important to identify valid and sensitive measures of listening effort. Physiological measures have been shown to be sensitive to auditory task demand manipulations and are considered to reflect changes in listening effort. Such measures include pupil dilation, alpha power, skin conductance level, and heart rate variability. The aim of the current systematic review was to provide an overview of studies to listening effort that used multiple physiological measures. The two main questions were: (1) what is the effect of changes in auditory task demand on simultaneously acquired physiological measures from various modalities? and (2) what is the relationship between the responses in these physiological measures?

DESIGN

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, relevant articles were sought in PubMed, PsycInfo, and Web of Science and by examining the references of included articles. Search iterations with different combinations of psychophysiological measures were performed in conjunction with listening effort-related search terms. Quality was assessed using the Appraisal Tool for Cross-Sectional Studies.

RESULTS

A total of 297 articles were identified from three databases, of which 27 were included. One additional article was identified from reference lists. Of the total 28 included articles, 16 included an analysis regarding the relationship between the physiological measures. The overall quality of the included studies was reasonable.

CONCLUSIONS

The included studies showed that most of the physiological measures either show no effect to auditory task demand manipulations or a consistent effect in the expected direction. For example, pupil dilation increased, pre-ejection period decreased, and skin conductance level increased with increasing auditory task demand. Most of the relationships between the responses of these physiological measures were nonsignificant or weak. The physiological measures varied in their sensitivity to auditory task demand manipulations. One of the identified knowledge gaps was that the included studies mostly used tasks with high-performance levels, resulting in an underrepresentation of the physiological changes at lower performance levels. This makes it difficult to capture how the physiological responses behave across the full psychometric curve. Our results support the Framework for Understanding Effortful Listening and the need for a multimodal approach to listening effort. We furthermore discuss focus points for future studies.

Non-invasive stress estimation in simulative endoscopy setting: literature review

One of the most common stressors is so-called "occupational stress." It is defined as the sum of physical, mental and physiological responses to work in situations where the workload or stress associated with it intensifies for an extended period of time. It is a gradual process in which individual cognitive assessments of occupational stressors generate adverse health events and may lead to burnout. Since it has become a major problem in the medical field, studying, measuring and limiting it have been set as goals for the future.

Salivary biomarkers to evaluate psychological disorders in oral lichen planus: A systematic review with meta-analysis

OBJECTIVE

To analyze the use of salivary biomarkers to identify psychological disorders (anxiety, depression, and stress) in individuals with oral lichen planus (OLP).

MATERIALS AND METHODS

The search was made in Medline/Pubmed, Scopus, Web of Science, Virtual Health Library, ProQuest, and by cross-reference. Original case-control, cross-sectional, and cohort studies, in human subjects (age ≥18 years) with clinical and histopathological diagnosis, with or without the use of psychometric scales, published until June 2021, were included. Random-effects meta-analyses, subgroup analyses, and sensitivity were performed. Publication bias was measured using the Egger test and visual inspection of the funnel plot.

RESULTS

A total of 67 articles were found, of which 12 were included in the meta-analysis. Among the different biomarkers identified, it was only possible to perform a meta-analysis for cortisol. The mean difference between salivary cortisol levels in patients with OLP compared to controls was 3.43 ng/ml (95% CI: 1.20-5.65) with I2  = 98.9%. Studies considered outliers were removed and based on sensitivity analyses, results did not change, therefore, being stable.

CONCLUSION

The studies analyzed demonstrated that cortisol was the most quantified biomarker to identify psychological disorders; however, DHEA, IgA, adiponectin, and α-amylase were also evaluated.

The Effect of the Rice Endosperm Protein Hydrolysate on the Subjective Negative Mood Status in Healthy Humans: A Randomized, Double-Blind, and Placebo-Controlled Clinical Trial

The rice endosperm protein (REP) hydrolysate containing the following rice endosperm protein derived oligopeptides QQFLPEGQSQSQK, LPEGQSQSQK, and pEQFLPEGQSQSQK (a N-terminal pyroglutamate residue-modified peptide) reportedly showed an antidepressant-like effect in an animal model. We investigated the effect of the REP hydrolysate on healthy humans who self-reported mental fatigue with subjectively low vigor. Seventy-six participants (age: 20-64 years) were randomly allocated to two groups. The influence of the REP hydrolysate on the mood state was evaluated in two studies: single intake (Study 1) and repeated intake over 4 weeks (Study 2). A salivary stress marker, Chromogranin A (CgA), was measured in Study 1. The single intake of the REP hydrolysate significantly improved the Profile of Mood Status 2nd edition for adults (POMS 2) subscale of Tension-Anxiety. Additionally, the salivary CgA concentrations were remarkably reduced after the single intake of the REP hydrolysate. Though a single intake of the REP hydrolysate did not significantly influence the other subscales and the TMD of the POMS 2 and the Euthymia Scale, both the subjective and objective results supported the possible effect of the REP hydrolysate on reducing anxiety and nervousness. No significant positive effects on the subjective mood state (Euthymia Scale and POMS 2) and sleep quality (Insomnia Severity Index) were observed in the trial setting employed for Study 2. In conclusion, a single intake of REP hydrolysate might help relax the subjective feelings of tension and anxiety. The effectiveness of repeated REP hydrolysate intake needs to be tested in a different clinical setting.

Treat more than heat-New therapeutic implications of Cimicifuga racemosa through AMPK-dependent metabolic effects

BACKGROUND

Cimicifuga racemosa extracts (CRE) have obtained a "well-established use status" in the treatment of postmenopausal (i.e., climacteric) complaints, which predominantly include vasomotor symptoms such as hot flushes and sweating, as well as nervousness, irritability, and metabolic changes. Although characteristic postmenopausal complaints are known for a very long time and the beneficial effects of CRE on climacteric symptoms are well accepted, both the pathophysiology of postmenopausal symptoms and the mechanism of action of CREs are not yet fully understood. In particular, current hypotheses suggest that changes in the α-adrenergic and serotonergic signaling pathways secondary to estrogen depletion are responsible for the development of hot flushes.

PURPOSE

Some of the symptoms associated with menopause cannot be explained by these hypotheses. Therefore, we attempted to extend our classic understanding of menopause by integrating of partly age-related metabolic impairments.

METHODS

A comprehensive literature survey was performed using the PubMed database for articles published through September 2021. The following search terms were used: (cimicifuga OR AMPK) AND (hot flush* OR hot flash* OR menopaus* OR osteoporos* OR cancer OR antioxida* OR cardiovasc*). No limits were set with respect to language, and the references cited in the articles retrieved were used to identify additional publications.

RESULTS

We found that menopause is a manifestation of the general aging process, with specific metabolic changes that aggravate menopausal symptoms, which are accelerated by estrogen depletion and associated neurotransmitter dysregulation. Cimicifuga extracts with their metabolic effects mitigate climacteric symptoms but may also modulate the aging process itself. Central to these effects are effects of CRE on the metabolic key regulator, the AMP-activated protein kinase (AMPK).

CONCLUSIONS

As an extension of this effect dimension, other off-label indications may appear attractive in the sense of repurposing of this herbal treatment.

Use of saliva stress biomarkers to estimate novice male endoscopist's stress during training in a high-end simulator

OBJECTIVE

Simulated endoscopic training can be challenging and stressful for the novice trainee. The absence of a reliable stress detection method during simulated endoscopic training makes estimating trainees' mental stress difficult to quantify. This study concomitantly measures the responses of four saliva stress biomarkers and compares them to the video score (VS) achieved by novice endoscopists in a reproducibly stressful simulation environment.

METHODS

Thirty-six male endoscopy naïve surgery residents were enrolled. After an orientation phase, a saliva specimen was collected for cortisol (sC), alpha-amylase (sAA), Chromogranin A (sCgA), and immunoglobulin A (sIgA) measurements (baseline phase, BL). Thereafter, the simulation exercise phase (E) started, practicing in the Fundamentals of Endoscopic Surgery Skills module (GI-Bronch Mentor). Immediately after, a second saliva sample for measuring the above-cited biomarkers was collected. The whole experiment was videotaped, and the VS was calculated. The percentage (E-BL)_diff of each of the four saliva biomarkers was calculated and examined for correlation to VS.

RESULTS

sCgA_diff showed the best correlation with VS, followed by sAA_diff.

CONCLUSIONS

sCgA and sAA, are saliva stress biomarkers that are easy to collect non-invasively and showed the best correlation with novice endoscopist's performance in our simulation setting, and therefore, they could be used for monitoring stress.

Differential responses of salivary cortisol, amylase, and chromogranin A to academic stress

Salivary biomarkers have been widely used to help diagnose stress, anxiety, and/or depression. This study aimed to compare the responses of three commonly investigated salivary stress biomarkers that represent the hypothalamic-pituitary-adrenal activity (cortisol; sCort) and the sympathetic activity (alpha-amylase; sAA and chromogranin A; sCgA), using academic oral presentation as a model of stress. Twenty postgraduate dental students attended the seminar class as presenter and audience. The presenters' performances were evaluated by the instructors suggesting more stress than the audience. The saliva was collected two times: before attending class and after an academic presentation (for presenters) or during the class (for audience). The pulse rates (PR) were also recorded. The results showed that the levels of all three biomarkers, as well as PR, were significantly higher in the presenter group compared with the audience group; however, the changes were most prominent with sCort and sAA (99.56 ± 12.76% for sCort, 93.48 ± 41.29% for sAA, 16.86 ± 6.42% for sCgA, and 15.06 ± 3.41% for PR). When compared between pre-post presentation, the levels of sCgA were not different, while those of sCort and sAA were significantly increased. These results suggest more sensitive reactivity to academic stress of sCort and sAA compared with sCgA and that the response of sCgA did not necessarily follow sAA pattern even though both are claimed to reflect the sympathetic activity. More studies are needed to elucidate the roles of sCgA in stress.

Biological Markers in Anxiety Disorders

Anxiety disorders are one of the most commonly reported disorders in psychiatry, causing a high medical and socio-economic burden. Recently, there has been a soaring interest in the biological basis of anxiety disorders, which is reflected in an increasing number of articles related to the topic. Due to the ambiguity of the diagnosis and a large number of underdiagnosed patients, researchers are looking for laboratory tests that could facilitate the diagnosis of anxiety disorders in clinical practice and would allow for the earliest possible implementation of appropriate treatment. Such potential biomarkers may also be useable in monitoring the efficacy of pharmacological therapy for anxiety disorders. Therefore this article reviews the literature of potential biomarkers such as components of saliva, peripheral blood, cerebrospinal fluid (CSF), and neuroimaging studies. There are promising publications in the literature that can be useful. The most valuable and promising markers of saliva are cortisol, lysozyme, and α-amylase (sAA). In the blood, in turn, we can distinguish serotonin, brain-derived serum neurotrophic factor (BDNF), cortisol, and microRNA. Structural changes in the amygdala and hippocampus are promising neuroimaging markers, while in CSF, potential markers include oxytocin and 5-Hydroxyindoleacetic acid (5-HIAA). Unfortunately, research in the field of biomarkers is hampered by insufficient knowledge about the etiopathogenesis of anxiety disorders, the significant heterogeneity of anxiety disorders, frequent comorbidities, and low specificity of biomarkers. The development of appropriate biomarker panels and their assessment using new approaches may have the prospective to overcome the above-mentioned obstacles.

Salivary Biomarkers of Stress, Anxiety and Depression

Stress, anxiety and depressive disorders are often characterized by the activation of the stress axis, which results in similar symptoms at some point in these disorders. These disorders are closely related to each other—they occur simultaneously or follow one another. The diagnosis of stress, anxiety and depression is not a perfect procedure currently—it is based on patient observation and an interview with the patient and their family. There are no laboratory tests that would dispel the doubts of the doctor making the diagnosis and allow the appropriate treatment to be implemented as soon as possible. Therefore, this study will review the components of saliva that could be helpful in the quick diagnosis of stress, anxiety and/or depression. Such potential salivary biomarkers could also be useful in monitoring the effectiveness of pharmacological treatment prescribed by a psychiatrist. The following are promising salivary biomarkers of stress, anxiety or depression: cortisol, immunoglobulin A (sIgA), lysozyme, melatonin, α-amylase (sAA), chromogranin A (CgA) and fibroblast growth factor 2 (FGF-2). To the best valuable potential salivary markers of stress, we can include cortisol, lysozyme, sAA and CgA. To differentiate depression from stress, salivary cortisol and melatonin can be helpful. Fluctuations in the concentrations of the above-mentioned substances in saliva indicate a particularly strong relationship with typical human psychological problems, such as stress, depression or anxiety.

Associations of serum chromogranin A with depressive symptoms in men with unipolar depressive disorder

OBJECTIVE

The aim of the present study was to determine the changes of serum chromogranin A (CgA) levels upon depression by investigating the relationship between serum CgA levels and the depressive symptoms assessed by 24-item Hamilton Rating Scale for Depression (HRSD-24).

METHOD

Serum CgA levels were measured by enzyme-linked immunosorbent assay in 133 male patients with major depressive disorder (MDD) and were compared with those of 47 healthy controls. Then generalized linear regression, logistic regression and restricted cubic spline models were performed to examine the association between serum CgA levels and depressive symptoms.

RESULTS

Serum CgA levels were lower in MDD patients than in controls (P < 0.001) and were inversely associated with scores on HRSD-24 in unadjusted, age, smoking, alcohol consumption, traumatic life events and family history of depression-adjusted and fully adjusted linear regression model. The fully adjusted regression coefficient with 95% confidence intervals was -0.028 (-0.045, -0.010) for serum CgA levels and HRSD-24 score. Serum CgA levels were inversely associated with depressive symptoms (HRSD ≥20) in each logistic regression model.

CONCLUSION

Serum CgA decrease was noted in male patients of MDD and may be inversely associated with depressive symptoms.

Brain-derived neurotrophic factor is related to stress and chewing in saliva and salivary glands

Chewing is one of the most important orofacial functions. During this process, food is reduced in size, while saliva moistens the food and binds it into a bolus that can be easily swallowed. Characteristics of the oral system, including the number of teeth, bite force, and salivary flow, influence the masticatory process. In addition, salivary glands produce several cell growth factors and play an important role in human health. The nerve growth factor (NGF) family consists of NGF, brain-derived neurotrophic factor (BDNF), and neurotrophins-3 to 7. BDNF is a well-studied neurotrophin involved in the neurogenesis, differentiation, and maintenance of select peripheral and central neuronal cell populations during development and adulthood. However, there has been no detailed description of the expression of neurotrophins other than NGF in the salivary gland. We previously studied the effect of immobilization stress + chewing on BDNF secretion and its receptor, tyrosine receptor kinase B, in rat submandibular glands and found increased BDNF expression in duct cells under these conditions. In this review, we describe recent advances in understanding the role of stress and chewing-related BDNF in the saliva and salivary glands.

Physiological Indicators of Attachment in Domestic Dogs (Canis familiaris) and Their Owners in the Strange Situation Test

Behaviorally, attachment is demonstrated when one individual maintains close proximity to another individual and shows distress upon separation. For 29 owner-dog dyads, we employed a modified Ainsworth's Strange Situation Test (SST) to investigate whether both members would show a physiological reaction to separation. Dogs experienced a series of separation from and reuniting events with their owners and were introduced to a stranger. Before and after the SST, saliva samples were taken from each dyad to measure stress-related analytes: cortisol (CORT) and chromogranin A (CgA). Dogs exhibited attachment behaviors toward owners as evidenced by more time spent in close proximity, more contact initiated and less time spent near the door, compared to episodes with the stranger. Dogs that initiated more contact with their owners in re-uniting episodes had lower CgA than dogs that initiated less contact, but their owners had higher CgA levels. Also during re-uniting episodes, dogs and owners spent more time near each other when owner CgA levels were low, owner CORT levels were high, and the dog had owner-reported separation anxiety. During the episodes alone with the stranger, dogs with higher CORT spent more time with the stranger. Finally, dogs' initial CgA levels were correlated with their owner's initial CORT levels, and dog final CORT levels were correlated with their owners' final CORT levels, suggesting some hormonal synchrony within the dyad. As all owner-dog dyads were assessed as securely attached, attachment style differences could not explain variation in hormonal or behavioral results. These results suggest that dogs may respond to owner hormonal state and/or behavior and demonstrate that individual differences in responses to a behavioral challenge reflect the stress physiology of both dogs and their owners.

Psychophysiological measurement of affective responses during speech perception

When people make decisions about listening, such as whether to continue attending to a particular conversation or whether to wear their hearing aids to a particular restaurant, they do so on the basis of more than just their estimated performance. Recent research has highlighted the vital role of more subjective qualities such as effort, motivation, and fatigue. Here, we argue that the importance of these factors is largely mediated by a listener's emotional response to the listening challenge, and suggest that emotional responses to communication challenges may provide a crucial link between day-to-day communication stress and long-term health. We start by introducing some basic concepts from the study of emotion and affect. We then develop a conceptual framework to guide future research on this topic through examination of a variety of autonomic and peripheral physiological responses that have been employed to investigate both cognitive and affective phenomena related to challenging communication. We conclude by suggesting the need for further investigation of the links between communication difficulties, emotional response, and long-term health, and make some recommendations intended to guide future research on affective psychophysiology in speech communication.

Effect of environmental enrichment and herbal compound supplementation on physiological stress indicators (chromogranin A, cortisol and tumour necrosis factor-α) in growing pigs

Stress response induces physiological, behavioural, immunological and biochemical changes that directly affect health and well-being. Provision of environmental enrichment and herbal compounds may reduce stress in current commercial pig husbandry systems. The aim of this study was to evaluate the effect of providing different environmental enrichment materials (EE) and a herbal compound (HC) on physiological indicators of acute and chronic stress in growing pigs (salivary cortisol and chromogranin A (CgA), hair cortisol and tumour necrosis factor-α (TNF-α)). Salivary cortisol and CgA have been reported as biomarkers basically of acute stress, whereas hair cortisol and TNF-α have been more related to chronic stress. For this purpose, eight groups of seven pigs each (14 pigs/treatment, 56 pigs in total) were used: (a) two EE groups, (b) two groups supplemented with HC, (c) two groups provided both with EE and HC and (d) two control groups. Samples of hair, saliva and blood were taken to measure cortisol (in hair and saliva), CgA (in saliva) and TNF-α (in blood) at three different times: before starting the experiment (T0), and after 1 (T1) or 2 months (T2) of providing the materials and herbal compound. No differences were found at T0 in salivary or hair cortisol, CgA or TNF-α, whilst at T2, the control group showed significant increased concentrations of CgA and hair cortisol, when compared with the rest of the treatments (P<0.001). These differences were significant at T1 only for CgA (P<0.001). Furthermore, an overall correlation was reported between hair cortisol and salivary CgA (r=0.48, P<0.001). These results support that providing enrichment material or an herbal compound may reduce stress in growing pigs. Furthermore, the results support that hair cortisol and CgA may be proper non-invasive tools to detect stress, specially associated with factors of chronic exposure.

Masticatory performance alters stress relief effect of gum chewing

PURPOSE

We evaluated the effects of gum chewing on the response to psychological stress induced by a calculation task and investigated the relationship between this response and masticatory performance.

METHODS

Nineteen healthy adult volunteers without dental problems undertook the Uchida-Kraepelin (UK) test (30 min of reiterating additions of one-digit numbers). Before and immediately after the test, saliva samples were collected from the sublingual area of the participants. Three min after the UK test, the participants were made to chew flavorless gum for 3 min, and the final saliva samples were collected 10 min after the UK test. The experiment was performed without gum chewing on a different day. Masticatory performance was evaluated using color-changing chewing gum.

RESULTS

Salivary CgA levels at immediately and 10 min after the UK test were compared with and without gum chewing condition. Two-way repeated measures analysis of variance revealed significant interaction between gum chewing condition and changes in CgA levels during post 10 min UK test period. A significant correlation was found between changes in CgA levels and masticatory performance in all participants.

CONCLUSION

Our results indicate that gum chewing may relieve stress responses; however, high masticatory performance is required to achieve this effect.

Salivary markers of inflammation in response to acute stress

There is burgeoning interest in the ability to detect inflammatory markers in response to stress within naturally occurring social contexts and/or across multiple time points per day within individuals. Salivary collection is a less invasive process than current methods of blood collection and enables intensive naturalistic methodologies, such as those involving extensive repeated measures per day over time. Yet the reliability and validity of saliva-based to blood-based inflammatory biomarkers in response to stress remains unclear. We review and synthesize the published studies that have examined salivary markers of inflammation following exposure to an acute laboratory stressor. Results from each study are reviewed by analyte (IL-1β, TNF-α, IL-6, IL-2, IL-4, IL-10, IL-12, CRP) and stress type (social-cognitive and exercise-physical), after which methodological issues and limitations are addressed. Although the literature is limited, several inflammatory markers (including IL-1β, TNF-α, and IL-6) have been reliably determined from saliva and have increased significantly in response to stress across multiple studies, with effect sizes ranging from very small to very large. Although CRP from saliva has been associated with CRP in circulating blood more consistently than other biomarkers have been associated with their counterparts in blood, evidence demonstrating it reliably responds to acute stress is absent. Although the current literature is presently too limited to allow broad assertion that inflammatory biomarkers determined from saliva are valuable for examining acute stress responses, this review suggests that specific targets may be valid and highlights specific areas of need for future research.

Biological function and clinical relevance of chromogranin A and derived peptides

Chromogranin A (CgA (CHGA)) is the major soluble protein co-stored and co-released with catecholamines and can function as a pro-hormone by giving rise to several bioactive peptides. This review summarizes the physiological functions, the pathogenic implications, and the recent use of these molecules as biomarkers in several pathological conditions. A thorough literature review of the electronic healthcare databases MEDLINE, from January 1985 to September 2013, was conducted to identify articles and studies concerned with CgA and its processing. The search strategies utilized keywords such as chromogranin A, vasostatins 1 and 2, chromofungin, chromacin, pancreastatin, catestatin, WE14, chromostatin, GE25, parastatin, and serpinin and was supplemented by the screening of references from included papers and review articles. A total of 209 English-language, peer-reviewed original articles or reviews were examined. The analysis of the retrospective literature suggested that CgA and its several bioactive fragments exert a broad spectrum of regulatory activities by influencing the endocrine, the cardiovascular, and the immune systems and by affecting the glucose or calcium homeostasis. As some peptides exert similar effects, but others elicit opposite responses, the regulation of the CgA processing is critical to maintain homeostasis, whereas an unbalanced production of peptides that exert opposing effects can have a pathogenic role in several diseases. These clinical implications entail that CgA and its derived peptides are now used as diagnostic and prognostic markers or to monitor the response to pharmacological intervention not only in endocrine tumors, but also in cardiovascular, inflammatory, and neuropsychiatric diseases.

Effects of essence of chicken on cognitive brain function: a near-infrared spectroscopy study

The aim of this study was to investigate the effects of the essence of chicken on brain function by near-infrared spectroscopy. Twelve healthy elderly subjects took the essence of chicken or a placebo for 7 d in a double-blind cross-over design study. Changes in oxy-hemoglobin concentrations in the bilateral prefrontal areas of the brain were measured while the subjects performed the simple reaction task, the Groton Maze Learning Test, and the working memory task. In the latter case, there were significant interactions in the changes in oxy-hemoglobin concentrations between treatment and period of intake according to two-way repeated ANOVA. The changes in oxy-hemoglobin concentrations significantly increased in several regions of the prefrontal areas of the brain in those taking essence of chicken for 7 d. These results suggest that essence of chicken is useful as a nutritional supplement to enhance or maintain brain function in the elderly.

Trends in research related to "Shinrin-yoku" (taking in the forest atmosphere or forest bathing) in Japan

"Shinrin-yoku", which can be defined as "taking in the forest atmosphere or forest bathing", has been receiving increasing attention in Japan in recent years for its capacity to provide relaxation and reduce stress. Since 2004, the authors of this paper have been involved in an investigation designed to ascertain the physiological effects of "Shinrin-yoku" within the framework of the "Therapeutic Effects of Forests" project. We have conducted physiological experiments, both in actual forests and in the laboratory, to elucidate the physiological effects on individuals of exposure to the total environment of forests or to only certain elements of this environment, such as the odor of wood, the sound of running stream water, and the scenery of the forest. We have obtained physiological measurements of central nervous activity, autonomic nervous activity, and biomarkers reflecting stress response that can be applied in this line of approach. Using these measurements, we have summarized the separate elements of forests in terms of the five senses. We have also reviewed a selection of field studies and introduced a number of results from ongoing projects as well as those from early studies. Future perspectives are also discussed.

Increased salivary chromogranin A in women with severe negative mood states in the premenstrual phase

The present study investigated whether salivary chromogranin A (CgA), a psychological stress marker associated with sympathetic nervous system activity, changes during the menstrual cycle in women with different degrees of premenstrual psychoemotional symptoms. Forty-five women (28.6 ± 1.3 years) with regular menstrual cycles participated in this study. Salivary CgA and cortisol were measured during the follicular and late-luteal phases. The authors used the Profile of Mood State (POMS) to assess current mood states of subjects in each menstrual phase and divided the subjects into three groups depending on increase of total mood disturbance (TMD), a global measure of affective states of POMS from the follicular to the late-luteal phase: Low (4.1 ± 0.7%), Middle (18.7 ± 1.2%) and High (51.7 ± 7.4%). Results showed no intramenstrual cycle differences in salivary CgA in the Low and Middle groups. Women in the High group, in contrast, had a significantly higher level of salivary CgA in the late-luteal phase compared to that of the follicular phase. Additionally, salivary CgA level significantly and positively correlated with TMD and four emotional subscales: tension-anxiety, depression-dejection, anger-hostility and confusion in the late-luteal phase. No intergroup or menstrual-cycle difference occurred in the salivary cortisol. This study indicates a significant late-luteal increase in salivary CgA, reflecting an increase of sympathetic nerve activity in women who experience a substantial increase (>30%) in a cluster of negative psychoemotional symptoms premenstrually. Furthermore, salivary CgA, as opposed to salivary cortisol, could serve as a reliable noninvasive biomarker to more sensitively evaluate neuropsychophysiological fluctuations during the menstrual cycle.

Altered levels of fecal chromogranins and secretogranins in IBS: relevance for pathophysiology and symptoms?

OBJECTIVES

Chromogranins (Cg) and secretogranins (Sg) are proteins ubiquitous in secretory cells of the enteric, endocrine, and immune systems, and may reflect activity of these systems. We therefore performed a hypothesis generating study to evaluate the association between fecal levels of CgA, CgB, SgII, and SgIII, with the clinical and pathophysiological phenotype of irritable bowel syndrome (IBS) patients.

METHODS

Analyses of CgA, CgB, SgII, SgIII, and calprotectin in fecal samples of 82 IBS patients and 29 healthy controls were performed. All IBS subjects completed validated questionnaires to assess gastrointestinal and psychological symptom severity, and underwent rectal barostat test and colonic transit time measurement.

RESULTS

IBS patients demonstrated higher levels of fecal CgA (P=0.009), SgII (P<0.001), and SgIII (P<0.001), but lower levels of CgB (P<0.001) compared with controls. SgII had good discriminative validity to positively identify IBS patients, with an area under the receiver operating characteristics (ROC) curve (AUROC) of 0.86 (95% confidence interval (CI): 0.78-0.94). SgIII and CgB both had fairly good discriminative validity to positively identify IBS patients, with an AUROC of 0.79 (95% CI: 0.71-0.87) and 0.78 (95% CI: 0.69-0.87), respectively. There were negative correlations between the colonic transit time and fecal levels of CgA (r=-0.53, P<0.001), SgII (r=-0.55, P<0.001), and SgIII (r=-0.28, P=0.03). Perceived abdominal pain was moderately associated with levels of CgA (r=0.32, P=0.004), SgII (r=0.31, P=0.006), and SgIII (r=0.24, P=0.04). Calprotectin levels were not associated with the levels of granins or with the clinical or pathophysiological phenotype of IBS patients.

CONCLUSIONS

Fecal levels of Cg and Sg may be related to the underlying pathophysiology of IBS and of potential importance for symptoms of the patients. Granins also show promise to serve as future biomarkers of IBS. Further studies are needed to explore the potential role of granins in IBS patients.

Determination of the lactate threshold by means of salivary biomarkers: chromogranin A as novel marker of exercise intensity

This study examined intra-individual variations in salivary lactate (sLac), alpha-amylase (sAA) and chromogranin A (sCgA) with reference to the accumulation of blood lactate (bLac) during incremental maximal exercise in swimmers. Samples of blood and saliva were collected simultaneously from 12 male professional athletes during an incremental test that consisted of eight series of 100 m in front crawl with increasing velocity (0.03 m s(-1) each) and 70-s intervals. The concentration of blood and salivary lactate was determined by an electro-enzymatic assay, whereas sAA and CgA were analysed by Western blotting. Inflection points in the concentration of bLAc, sLac, sAA and CgA were found in all subjects. The accumulation of lactate in saliva followed the same pattern observed in blood with a high correlation between the two (r = 0.91). Similar results were observed between the dynamics of sAA (r = 0.81) and sCgA (r = 0.82) in relation to bLac. These findings support the usefulness of saliva for the determination of the lactate threshold and provide the first demonstration of sCgA as a novel marker of exercise intensity in well-trained men.

Back massage therapy promotes psychological relaxation and an increase in salivary chromogranin A release

Massage therapy promotes psychosocial relaxation, reduces stress and has been reported to improve the immune function. As such, massage therapy is currently used in palliative care for the relief of anxiety and pain. Although psychosocial status has been evaluated using subjective psychological tests, such as State-Trait Anxiety Inventory (STAI), subjective psychological tests are of limited value if the subjects fail to report reliably. Salivary biomarkers have been recently suggested as useful objective markers for assessing psychosocial status. To determine whether salivary biomarkers are useful objective indices for assessing the effects of back massage on the mental status of 25 young healthy female volunteers, we measured heart rate and salivary biomarkers (α-amylase activity, cortisol, and chromogranin A) and assessed the STAI score before and after the back massage. Back massage significantly reduced the heart rate and STAI; however, salivary amylase and cortisol levels did not change. In contrast, the level of salivary chromogranin A significantly increased. We therefore conclude that changes in the salivary biomarkers tested here may not indicate changes in psychological status following massage therapy. However, the increase in chromogranin A release may contribute to the immunologically beneficial effects of massage therapy as chromogranin A has antibacterial and antifungal activity.

The effectiveness of the Uchida-Kraepelin test for psychological stress: an analysis of plasma and salivary stress substances

Background

The hypothalamic-pituitary-adrenocortical (HPA) axis and sympathetic adrenomedullary (SAM) system are the major stress-response pathways. Plasma adrenocorticotropic hormone (ACTH) represents HPA axis activity, while plasma catecholamines are used as markers of the SAM system. Salivary alpha amylase (AA), chromogranin A (CgA), and immunoglobulin A (IgA) are candidate markers of stress activation, although their role has not been established. The Uchida-Kraepelin (U-K) test is a questionnaire that requires intense concentration and effort, and has been used as a tool to induce mental stress. However, it is not clear whether or not the test is effective as a psychological/mental stressor.

Methods

In this study, normal young women took the U-K test and serial measurements of plasma ACTH and catecholamines (dopamine, noradrenaline, and adrenaline) (n = 10), as well as salivary AA, CgA, and IgA (n = 16) before, during and after the test.

Results

We found no changes in any of these parameters at any time point during or after the U-K test.

Conclusion

Our findings indicate that the U-K test is not a suitable for measuring the psychological/mental stress of young women because the plasma data showed that it did not affect the HPA axis and SAM system. The U-K test should be employed carefully as a psychological/mental stressor due to insufficient scientific evidence of its effectiveness. In addition, salivary AA, CgA, and IgA should not simply be compared with previous reports, because the mechanism of secretion and normal range of each salivary parameter remain unknown. Salivary AA, CgA, and IgA may not be suitable candidate markers of psychological/mental stress.

Changes in salivary physiological stress markers induced by muscle stretching in patients with irritable bowel syndrome

Background

Psychophysiological processing has been reported to play a crucial role in irritable bowel syndrome (IBS) but there has been no report on modulation of the stress marker chromogranin A (CgA) resulting from muscle stretching. We hypothesized that abdominal muscle stretching as a passive operation would have a beneficial effect on a biochemical index of the activity of the sympathetic/adrenomedullary system (salivary CgA) and anxiety.

Methods

Fifteen control and eighteen untreated IBS subjects underwent experimental abdominal muscle stretching for 4 min. Subjects relaxed in a supine position with their knees fully flexed while their pelvic and trunk rotation was passively and slowly moved from 0 degrees of abdominal rotation to about 90 degrees or the point where the subject reported feeling discomfort.

Changes in the Gastrointestinal Symptoms Rating Scale (GSRS), State Trait Anxiety Inventory (STAI), Self-rating Depression Scale (SDS), ordinate scale and salivary CgA levels were compared between controls and IBS subjects before and after stretching. A three-factor analysis of variance (ANOVA) with period (before vs. after) as the within-subject factor and group (IBS vs. Control), and sex (men vs. female) as the between-subject factors was carried out on salivary CgA.

Results

CgA showed significant interactions between period and groups (F[1, 31] = 4.89, p = 0.03), and between groups and sex (F[1, 31] = 4.73, p = 0.03). Interactions between period and sex of CgA secretion were not shown (F[1, 3] = 2.60, p = 0.12). At the baseline, salivary CgA in IBS subjects (36.7 ± 5.9 pmol/mg) was significantly higher than in controls (19.9 ± 5.5 pmol/mg, p < 0.05). After the stretching, salivary CgA significantly decreased in the IBS group (25.5 ± 4.5 pmol/mg), and this value did not differ from that in controls (18.6 ± 3.9 pmol/mg).

Conclusion

Our results suggest the possibility of improving IBS pathophysiology by passive abdominal muscle stretching as indicated by CgA, a biochemical index of the activity of the sympathetic/adrenomedullary system.

Dimenhydrinate effect on cerebral oxygen status and salivary chromogranin-A during cognitive tasks

To investigate the effects of dimenhydrinate on cerebral oxygen status (COS; cerebral oxygenated hemoglobin concentration changes) and salivary chromogranin-A (CgA) during a cognitive test battery, a double-blind, placebo-controlled, randomized, crossover protocol was used to examine the effect of 50 mg of dimenhydrinate or placebo in 12 subjects. This test battery includes tests of both reaction time and fundamental cognitive ability and was used in the assessment of pilots. Poor cognitive performance was observed in the subjects taking dimenhydrinate. We used two-channel near-infrared spectroscopy to investigate the effects of dimenhydrinate on the COS. With the one exception of shifting attention task in the left forehead, no significant difference was found between dimenhydrinate and placebo during the tasks of the test battery. Under placebo treatment, on the other hand, CgA levels were significantly elevated during cognitive testing when compared with baseline. However, CgA levels were not significantly elevated above baseline following dimenhydrinate. The present study is one of the first to demonstrate that the first-generation antihistamine drugs altered the responses of salivary CgA during cognitive tasks. The changes in salivary CgA secretion, as a result of dimenhydrinate administration, may serve as a sensitive biomarker of a psychological status such as a drug-induced sedation during the performance of a cognitive test battery. Further studies, however, are required to examine the usefulness of this sensitive biomarker in investigation of psychological agents during cognitive tasks.

Evaluation of stress reactions during upper gastrointestinal endoscopy in elderly patients: assessment of mental stress using chromogranin A

OBJECTIVE

Salivary chromogranin A (CgA) was recently reported to be a useful marker of mental stress. In this study, mental stress during upper gastrointestinal endoscopy was evaluated by measuring salivary CgA levels in young and elderly subjects.

METHODS

The subjects were 9 healthy subjects aged less than 50 years (young group) and 15 subjects aged 70 years or older (elderly group). The heart rate, blood pressure, blood oxygen saturation level, and salivary CgA concentration were measured before and after upper gastrointestinal endoscopy and compared.

RESULTS

In the young group, the CgA level decreased significantly (p<0.05) during endoscopy compared with the level during rest before endoscopy. In the elderly group, it also decreased significantly (p<0.05) during endoscopy compared with the level during rest before endoscopy. However, CgA levels were significantly higher (p<0.05) in the elderly group than in the young group both before and during endoscopy. The decrease in CgA levels was significantly greater (p<0.05) in the young group than in the elderly group.

CONCLUSIONS

In this study, mental stress associated with endoscopy appears to be higher in elderly subjects than in younger subjects. Attention to complications due to increased stress is considered to be necessary in elderly patients during endoscopy.

Oral treatment with L-lysine and L-arginine reduces anxiety and basal cortisol levels in healthy humans

Dietary supplementation with an essential amino acid L-lysine has been shown to reduce chronic anxiety in humans with low dietary intake of L-lysine. A combination of L-lysine and L-arginine has been documented to normalize hormonal stress responses in humans with high trait anxiety. The present study was carried out in one hundred eight healthy Japanese adults. The aim of study was to find out whether a week-long oral treatment with L-lysine (2.64 g per day) and L-arginine (2.64 g per day) reduces trait and stress-induced state anxiety and basal levels of stress hormones. We confirmed that, without regard to gender, the amino acid treatment significantly reduced both trait anxiety and state anxiety induced by cognitive stress battery. In addition, we found that the treatment with L-lysine and L-arginine decreased the basal levels of salivary cortisol and chromogranin-A (a salivary marker of the sympatho-adrenal system) in male subjects. These results of this double-blind, placebo controlled and randomized study confirm the previous findings in humans and animals and point to a combination of L-lysine and L-arginine as a potentially useful dietary intervention in otherwise healthy humans with high subjective levels of mental stress and anxiety.