Salivary Stress Biomarkers Research Articles

Salivary biomarkers to monitor stress due to aggression after weaning in piglets

In this study, the changes of salivary stress biomarkers were contrasted with skin lesions during weaning in piglets. The stress biomarkers evaluated were cortisol (as the reflection of hypothalamic-pituitary-adrenal (HPA) axis), chromogranin A (CgA) and alpha amylase (sAA) (both as the reflection of sympathoadrenal-medullary (SAM) axis). In addition, the accumulation of skin lesions were assessed as proxy measures of aggression. One hundred and two Danbred piglets (51 female and 51 male) from primiparous and multiparous sows were studied from birth to two days post-weaning. Saliva sampling and lesion scoring were performed one day pre-weaning (−1), and one (+1) and two days post-weaning (+2). Our results show that on +1, there was a significant (P < .0001) increase in salivary cortisol, CgA and skin lesions; whereas on +2, there was a significant increase (P < .0001) in salivary CgA and skin lesions. CgA was correlated with the skin lesion score (r = 0.4; P < .0001). sAA did not significantly change at any sampling time. It can be concluded that stress associated to weaning, is associated with changes in salivary CgA and cortisol stress biomarkers and an increase in skin lesions. However, CgA shows higher correlation with skin lesions which indicates that stress due to fighting activates the SAM stress pathway. Therefore, a combination of physiological biomarkers (CgA and cortisol) and proxy of aggression (skin lesions) is preferable than the use of a single biomarker or behavioural indicator when monitoring the social stress response associated to weaning in piglets.

Relationship between Parafunctional Habits and Salivary Biomarkers.

Objectives:Parafunctional habits, as one of the etiological factors of temporomandibular disorders (TMD), are an individual’s response to increased stress. During stress and depression, biomarkers such as cortisol and salivary alpha-amylase (SAA) are secreted in the saliva. The present study aimed to investigate whether there is a correlation between salivary stress biomarkers and parafunctional habits.Materials and Methods:Thirty-two cases, from May to September 2015, were selected based on two standard stress questionnaires, namely the depression anxiety stress Scale-21 (DASS-21) and the Beck Anxiety Inventory (BAI). Saliva samples were collected to examine the level of unstimulated salivary cortisol and SAA. The significance of the results was assessed via student’s t-test and Mann-Whitney test (α=0.05).Results:The mean concentrations of cortisol and SAA in unstimulated saliva were significantly higher in the case group than in the control group (P=0.01 and 0.44, respectively). The mean scores of anxiety, stress, and depression were significantly higher in the case group than in the control group (P<0.05).Conclusion:It seems that the levels of salivary cortisol and SAA, as well as stress, anxiety, and depression scores, are higher in patients with parafunctional habits.

Salivary Biomarkers of Parenting Stress in Mothers Under Community Criminal Justice Supervision.

Community criminal justice supervised mothers are an underserved population who experience high rates of psychological distress and unique parenting challenges, but little is known about physiological stress system function in this population. We tested the salivary biomarkers of the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis function as predictors of subjective maternal stress. We recruited 23 mothers (age: M = 35.6 years, SD = 9.3 years; 35% Hispanic, 22% Black, 22% White, 22% multiracial) who were court mandated to a residential treatment center. We measured salivary alpha-amylase (AA) and cortisol, which index SNS and HPA activity, respectively, before and after a naturalistic reminder of a stressful parenting experience. We assessed self-reported parenting stress using the Parenting Stress Index-Short Form (PSI-SF) subscales Parental Distress, Parent-Child Dysfunctional Interactions, and Difficult Child. We used regression to test AA and cortisol mean levels and reactivity as predictors of subscale scores. Mean, but not reactive, salivary stress biomarker levels were associated with parenting stress domains. Mean cortisol levels predicted scores on the Parent-Child Dysfunctional Interaction subscale (adj. R = .48), whereas mean AA predicted Difficult Child subscale scores (adj. R = .28). Our results demonstrate the potential predictive utility of AA and cortisol as salivary biomarkers of maternal stress in community-supervised mothers. Given that maternal stress is associated with criminal recidivism and child behavioral health in this population, these biomarkers could potentially inform interventions to improve dyadic health and social outcomes.

Salivary biomarkers of inflammation and oxidative stress in healthy adults

ObjectivesDiagnostic value of saliva depends on the reproducibility of data in repeatedly collected samples and predictable correlations between saliva and blood. We aimed to investigate the reliability, blood reflectance, and influence of blood contamination in the analysis of inflammatory and oxidative stress biomarkers in saliva samples. DesignIn total, 37 healthy young male participants (26.7 ± 2.2 years) were included. Unstimulated whole saliva and blood samples were collected on the first visit, and saliva samples were collected again after 2–3 days. The concentrations of total protein and inflammatory [C-reactive protein (CRP), IL-1β, IL-6, and TNF-α] and oxidative stress [8-hydroxy-2’-deoxyguanosine (8-OHdG), malondialdehyde (MDA), and total antioxidant capacity (TAC)] biomarkers in saliva and blood, and as well as blood contamination biomarkers (transferrin and hemoglobin) in saliva were analyzed. ResultsThe intra-class correlations of all examined biomarkers except TNF-α were fair to excellent. Significant positive correlations between CRP and IL-6 and between total protein and TAC were stable in the saliva samples collected on different days. Notably, IL-6 was the only biomarker that showed a significant correlation between saliva and blood. As the concentration of salivary transferrin increased, the saliva/blood ratios of total protein and TAC also increased. The concentration of salivary hemoglobin did not affect the saliva/blood ratios of biomarkers. ConclusionsThe findings of this study are limited to healthy young males. For clinical applications, studies on salivary diagnostics should be performed for individual disease and health conditions, demographic characteristics, and biomarkers.

Salivary Biomarkers of Oxidative Stress in Children with Chronic Kidney Disease.

There are still missing non-invasive biomarkers of chronic kidney disease (CKD) in children. Therefore, the aim of the study was to evaluate oxidative stress indicators in the non-stimulated (NWS) and stimulated saliva (SWS) of CKD children (n = 25) and healthy controls (n = 25). Salivary antioxidants (catalase (CAT), peroxidase (Px), superoxide dismutase (SOD), uric acid (UA), reduced glutathione (GSH), albumin), redox status (total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI)), and oxidative damage products (advanced glycation end products (AGE), advanced oxidation protein products (AOPP), malondialdehyde (MDA)) were evaluated. We have demonstrated the significantly higher activity of SWS GPx and SOD, as well as elevated concentrations of UA and albumin in NWS and SWS of CKD children vs. the control group. TAC, TOS and OSI were significantly higher only in SWS, while oxidative damage products (AGE, AOPP and MDA) were significantly higher in both NWS and SWS of CKD children. ROC analysis showed a considerably high diagnostic value of AOPP in both NWS and SWS of CKD children compared to controls (AUC = 0.92; 0.98). CKD is responsible for disturbances in salivary antioxidant systems and oxidative damage to proteins and lipids. Salivary AOPP can be a potential biomarker of CKD in children.

Effect of 528 Hz Music on the Endocrine System and Autonomic Nervous System

This study examined the stress-reducing effect on the endocrine system and the autonomic nervous system of music with a frequency of 528 Hz, which has recently attracted attention as a “healing” type of music. Nine healthy participants (one man and eight women, aged 26 - 37 years) listened to 528 Hz and standard 440 Hz music on separate days. We measured salivary biomarkers of stress (cortisol, chromogranin A, and oxytocin) before and after exposure to music, and continuously recorded the activity of the autonomic nervous system. The Profile of Mood State, 2nd edition, was also administered as a subjective indicator of stress. In the 528 Hz condition, mean levels of cortisol significantly decreased, chromogranin A tended to decrease, and oxytocin significantly increased after music exposure. However, no significant change was observed in any salivary biomarkers in the 440 Hz condition. The ratio of low frequency to high frequency autonomic nervous system activity significantly decreased after exposure to both types of music, and the coefficient of variation of R-R intervals also significantly decreased, but only after exposure to 528 Hz music. Tension-anxiety and Total Mood Disturbance scores were significantly reduced after exposure to 528 Hz music, while there was no significant difference following 440 Hz music. These results suggest that the influence of music on the autonomic nervous system and endocrine system varies depending on the frequency of the music, and furthermore, that 528 Hz music has an especially strong stress-reducing effect, even following only five minutes of exposure.

Salivary stress biomarkers and anxiety symptoms in children with and without temporomandibular disorders.

The etiology of temporomandibular disorders (TMD), which are considered as a heterogeneous group of psychophysiological disturbances, remains a controversial issue in clinical dentistry. This study aimed to evaluate whether the salivary alpha-amylase (sAA), cortisol levels, and anxiety symptoms differ between children with and without TMD. Initially, 316 young subjects were screened in public schools (nonreferred sample); 76 subjects aged 7-14 years were selected and comprised the TMD and control groups with 38 subjects each matched by sex, age, and the presence/absence of sleep bruxism. Four saliva samples were collected: upon waking, 30 min and 1 h after awakening (fasting), and at night (at 8 PM) on 2 alternate days to examine the diurnal profiles of cortisol and sAA. Anxiety symptoms were screened using the Multidimensional Anxiety Scale for Children (MASC-Brazilian version). Shapiro-Wilk test, Student's t-test/Mann-Whitney U test, and correlation tests were used for data analysis. No significant differences were observed in the salivary cortisol area under the curve (AUCG mean ± SD = 90.22 ± 63.36 × 94.21 ± 63.13 µg/dL/min) and sAA AUCG (mean ± SD = 2544.52 ± 2142.00 × 2054.03 ± 1046.89 U/mL/min) between the TMD and control groups, respectively (p > 0.05); however, the clinical groups differed in social anxiety domain (t = 3.759; CI = 2.609, 8.496), separation/panic (t = 2.243; CI = 0.309, 5.217), physical symptoms (U = 433.500), and MASC total score (t = -3.527; CI = -23.062, -6.412), with a power of the test >80% and large effect size (d = 0.80), with no significant correlation between the MASC total score, cortisol, and sAA levels. Although children with TMD scored higher in anxiety symptoms, no difference was observed in the salivary stress biomarkers between children with and without TMD.

A New Insight of Effect of Ampicillin-Gentamicin Through Chlorinative Stress Mechanism in Saliva of Newborn at Risk of Sepsis

Clinical diagnosis of sepsis in neonate is difficult, because many signs of sepsis are nonspecific. There are several salivary biomarkers of stress as objective indicators of stress reactions.This study was designed to investigate the effect of ampicillin-gentamicin treatment to chlorinative stress parameters insaliva of newborn at risk of sepsis. Four chlorinative stress parameters were used, hydrogen peroxide (H2O2) levels, myeloperoxidase (MPO) activity, advanced oxidation protein products (AOPPs) levels, and chlorinative index (CI). This study was performed in May until September 2016. Saliva samples were taken from 26 newborns at risk of sepsis treated in Ulin General Hospital, Banjarmasin, South Kalimantan, Indonesia. All newborns were given ampicillin-gentamicin three until ten days. The H2O2 levels, MPO activity, AOPPs levels, and CI were measured from the saliva taken from both pre and post treatment. Statistical analysis of the parameters were obtained from before and after the ampicillin-gentamicin treatment, using Mann-Whitney test. The used ofampicillin-gentamicin for treatment of newborns at risk of sepsis showed significant decrease in the H2O2 levels, MPO acitivity, AOPPs levels, and significant increases in the CI. From this results, it can be concluded that Ampicillin-gentamicin could reduce the chlorinative stress in newborn at risk of sepsis

Effects of Fiber Supplementation for Four Weeks on Athletic Performance in Japanese College Athletes: A Case Study—Measurement of the Athletic Performance, Salivary Biomarkers of Stress, and Mood, Affect Balance

Aim: In this study, we explored the effects of dietary fiber on athletic performance. Methods: Twenty healthy college athletes (male/female, 1/1) consumed 6 grams of dietary fiber (Fiberpro, Taiyo Lab Inc., Tokyo) daily for four weeks and were evaluated for their athletic performance, salivary biomarkers of stress (α-amylase activity pre-post exercise, cortisol, melatonin, and secretory immunoglobulin A (SIgA) levels), and mood/affect using the Profile of Mood State 2nd edition (POMS 2®). Measurements were taken at baseline (before supplementation), at Week 4 (after 4 weeks of supplementation), and at Week 8 (4 weeks after the completion of supplementation). Results: Results showed that athletic performance and exercise-induced elevation in salivary α-amylase activity improved with Fiberpro supplementation in both men and women. Further, the Anger-Hostility scale in POMS was significantly elevated in men; in women, an increase in Vigor-Activity score, a single index of positive mood, was noted. These findings suggest that Fiberpro may induce differential affective responses in men and women. Meanwhile, Fiberpro did not affect the normal diurnal changes in salivary melatonin and SIgA levels, but it appeared to augment the normal circadian patterns of cortisol, an effect that persisted for a month without Fiberpro intake. We propose that boosting fiber intake in young, healthy athletes may improve gut microbiota and confer resilience against stress.

Salivary stress biomarkers of recent nicotine use and dependence

ABSTRACTBackground: Although stress plays a critical role in vulnerability to nicotine use and dependence, the stress response factors that contribute to smoking behaviors remain poorly elucidated. To minimize the confounding effects of chronic nicotine use, assessing individuals with relatively short smoking histories is critical for characterizing the neurobiological substrates associated with nicotine dependence early in the course of illness. Objectives: This pilot study examined sympathetic nervous system (alpha-amylase) and hypothalamic–pituitary–adrenal axis (cortisol, dehydroepiandrosterone) responses to the Trier Social Stress Test (TSST) in young adult smokers. Associations among objective indices of recent smoking (salivary cotinine, carbon monoxide in the breath [CO]), behavioral measures of nicotine dependence and withdrawal, and salivary biomarkers in response to the TSST were investigated. Methods: Smokers (N = 64; 28 males, 36 females) provided saliva samples at 30 min intervals for 2 h prior to the TSST and every 10 min for 1 h following the TSST. Results: Alpha-amylase responses to the TSST were positively associated with salivary cotinine levels but negatively associated with CO levels. Individuals with a lower level of nicotine dependence had increased cortisol responses to the stressor, whereas those with a higher level of nicotine dependence did not show any cortisol changes in response to the stressor. Conclusions: These findings indicate that different mechanisms may be involved at different levels of nicotine dependence severity. Recent nicotine use and lower dependence severity may be associated with increased activation of the stress response systems. In contrast, more severe levels of dependence may downregulate stress response systems.

P-57 - Salivary and serum biomarkers of oxidative stress in patients with oral premalignant lesions

P-57 - Salivary and serum biomarkers of oxidative stress in patients with oral premalignant lesions

P-59 - Salivary biomarkers of oxidative stress and local invasiveness in oral cancer

Crimean–Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis. Clinical reports indicate the severity of CCHF is milder in children than adults. The chemokines are important chemo-attractant mediators of the host immune system.The main aim of the study was to identify whether or not there were any differences in chemokine levels between the pediatric and adult patients and control groups, and whether there was any correlation with disease severity.The serum levels of select chemokines including chemokine (C-C) ligand 2 (CCL2), CCL3, CCL4, chemokine (C-X-C) ligand 8 (CXCL8), CXCL9, and granulocyte-colony stimulating factor (G-CSF) in 29 adult and 32 pediatric CCHF patients and in 35 healthy children and 40 healthy adult control groups were studied by flow cytometric bead immunoassay method.Great variability was detected in the serum levels of the chemokines for both the adult and pediatric patients and controls. With the exception of G-CSF, the median serum levels of CCL2, CCL3, CCL4, CXCL8, and CXCL9 were found to be significantly higher in the adult patients compared to adult controls (2364.7 vs. 761 pg/ml; 714.1 vs. 75.2 pg/ml; 88.6 vs. 25.5 pg/ml; 217.9 vs. 18.3 pg/ml; 875 vs. 352.2 pg/ml, respectively, p < 0.0001 for all comparisons). Among the chemokines the median CCL4 and G-CSF levels were significantly higher in the pediatric patients compared to pediatric controls (40.3 vs. 7.1 pg/ml, p < 0.0001; 0.1 vs. 0.1 pg/ml, p = 0.049, respectively).The results of this study showed prominent chemokine raising in adult CCHF patients compared to children CCHF patients.

Relationship between salivary stress biomarker levels and cigarette smoking in healthy young adults: an exploratory analysis.

BackgroundThis study investigated the relationships among salivary stress biomarkers, cigarette smoking, and mood states.MethodsThe study population comprised 49 healthy sixth-year dental students at Fukuoka Dental College (39 men, 10 women; age, 23–31 years). Lifetime exposure to smoking was calculated using the Brinkman index (BI). Resting saliva samples were collected, and concentrations of cortisol, secretory immunoglobulin A (SIgA), interleukin (IL)-1β, interleukin-6, and tumor necrosis factor (TNF)-α were determined. Mood states (tension-anxiety, depression-dejection, anger-hostility, fatigue, confusion, and vigor) over the previous week were assessed using the Profile of Mood States - Brief Japanese Version.ResultsSalivary IL-1β levels were significantly higher in smokers than non-smokers (P = 0.044), regardless of the BI or mood state. A significant positive correlation was evident between the TNF-α level and the BI (P = 0.036), and the SIgA level was positively correlated with the BI (P = 0.067) but did not reach statistical significance. In terms of mood states, higher fatigue scores and lower vigor scores were observed in smokers. The TNF-α level and vigor score were negatively correlated (r = –0.229, P = 0.135), but the correlation did not reach statistical significance. However, the SIgA level and fatigue score were significantly positively correlated (r = 0.410, P = 0.005).ConclusionsThe TNF-α and SIgA levels were both positively correlated with the BI. Furthermore, the TNF-α level was negatively correlated with the vigor score, whereas the SIgA level was positively correlated with the fatigue score. Thus, salivary levels of TNF-α and SIgA may be used as biomarkers of mood states in healthy young smokers.

Salivary Stress Biomarkers-Are They Predictors of Academic AssessmentExams Stress?

Purpose: The present study was conducted on undergraduate dental students to asses and compare the levels of salivary stress biomarkers including cortisol, immulnoglobulin-A and α-amylase enzyme during periods of academic assessments and nonassessments and to relate these biomarkers to students' academic performance. Methods: Saliva samples were collected from undergraduate dental students; one before taking a final assessment exam and another during non-assessment period. Salivary stress biomarkers concentrations were obtained using Enzyme-linked Immunosorbent Assay (ELISA). Results: The level of salivary stress biomarkers including s-cortisol, α-amylase, and immulnoglobulin-A significantly increased during periods of assessment exams as compared to non-assessment (p=0,000, 0.001, and 0.003 consecutively). The study found a significant correlation between salivary α-amylase and academic performance especially among male students (p=0.008) and those in their final academic year (p=0.040). Conclusion: We conclude that the stress of academic assessment can markedly increase the level of salivary stress biomarkers. Students who show less academic performance generally depict higher levels of salivary α-amylase, especially male students and those in their final academic year.

Road and rail traffic noise induce comparable extra-aural effects as revealed during a short-term memory test.

To examine extraaural effects as induced by 20 min of road (ROAD) and 20 min of rail (RAIL) traffic noise with same loudness (75 dBA), a laboratory study was carried out. The study (N=54) consisted of 28 high and 26 low-annoyed healthy individuals as determined by a traffic annoyance test. To control attention, all individuals performed a nonauditory short-term memory test during the noise exposures. A within-subject design, with phases of ROAD, RAIL, and CALM (memory test only), alternated by phases of rest, was defined. Heart rate (HR), systolic blood pressure (sBP), total peripheral resistance (TPR), as well as three autonomic variables, preejection period (PEP), 0.15–0.4 Hz high-frequency component of HR variability (HF), and salivary stress biomarker alpha amylase (sAA) were measured. In relation to CALM, HR increased (RAIL +2.1%, ROAD +2.5%), sBP tended to increase against the end of noise exposure, PEP decreased (RAIL −0.7%, ROAD −0.8%), HF decreased (RAIL −3.4%, ROAD −2.9%), and sAA increased (RAIL +78%, ROAD +69%). No differences were found between RAIL and ROAD, indicating that both noise stressors induced comparable extraaural effects. Factor annoyance showed significant during CALM. Here a reduced sympathetic drive (higher PEP values) combined with an increased vascular tone (higher TPR values) was found at the high-annoyed subgroup.

Prognostic Value of 8-Hydroxy-2'-Deoxyguanosine and Human Neutrophil Elastase/α1-Proteinase Inhibitor Complex as Salivary Biomarkers of Oxidative Stress in Chronic Periodontitis.

8-Hydroxy-2'-deoxyguanosine (8-OHdG) and human neutrophil elastase/α1-proteinase inhibitor (HNE/α1-PI) complex have been regarded as reliable biomarkers of oxidative stress in inflammatory conditions. This study investigates whether the salivary levels of these two analytes may be linked with periodontal health status. One hundred ten patients with chronic periodontitis (CP) and 50 healthy controls were selected. Periodontal status was assessed by criteria based on probing depth, clinical attachment level, and extent and severity of periodontal breakdown. 8-OHdG and HNE/α1-PI salivary levels were analyzed by enzyme-linked immunosorbent assay. The association of these analytes with CP was analyzed individually and adjusted for confounding factors using a multivariate binary logistic regression model. Significantly higher levels of both markers were detected in the CP group in comparison to controls. Weak-to-moderate positive significant correlations between salivary biomarkers and clinical parameters were observed. After binary logistic regression analysis, salivary levels of 8-OHdG >17.35 ng/mL and HNE/α1-PI complex >158.28 ng/mL were independently associated with disease status. Interaction effects among candidate prognostic variables were also noted. Increased salivary levels of 8-OHdG and HNE/α1-PI complex may be strong, independent prognostic indicators of the amount and extent of oxidative stress-induced periodontal breakdown. In addition, unstimulated whole saliva samples might reflect a synergistic biologic interactive effect of HNE/α1-PI associated with the aging and smoking cumulative characteristics of periodontal damage.

Spiritual Pain in Meals on Wheels' Clients.

Background: Meals on Wheels’ clients are at risk for spiritual pain due to advanced age, social isolation, and failing health. They are also prone to stress, depression, and loneliness, placing them at risk for adverse biological disruptions and health outcomes. The purpose of the study was to examine associations of spiritual pain with psychosocial factors (stress, depression, loneliness, religious coping) and salivary biomarkers of stress and inflammation (cortisol, IL-1β) in Meals on Wheels’ clients. Methods: Data were collected cross-sectionally from 88 elderly (mean age 75.4). Spiritual pain, stress, depression, loneliness, and religious coping were measured with standardized instruments, and salivary biomarkers were assessed with enzyme immunoassays. Results: Spiritual pain was significantly and positively correlated with stress (r = 0.35, p ≤ 0.001), depression (r = 0.27, p = 0.01), and negative religious coping (r = 0.27, p = 0.01). Correlations with loneliness, positive religious coping, and salivary biomarkers were non-significant. Conclusion: Spiritual pain is an important concept in this population. Research should be expanded to understand the significance of spiritual pain in conjunction with psychosocial and biological variables and its potential impact on physical, mental, and cognitive health outcomes in the elderly.

The stress response and exploratory behaviour in Yucatan minipigs (Sus scrofa): Relations to sex and social rank

According to the coping styles hypothesis, an individual demonstrates an integrated behavioural and physiological response to environmental challenge that is consistent over time and across situations. Individual consistency in behavioural responses to challenge has been documented across the animal kingdom. Comparatively few studies, however, have examined inter-individual variation in the physiological response, namely glucocorticoid and catecholamine levels, the stress hormones secreted by the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, respectively. Variation in coping styles between individuals may be explained in part by differences in social rank and sex. Using 20 Yucatan minipigs (Sus scrofa) we: (1) investigated the existence of consistent inter-individual variation in exploratory behaviour and the hormonal stress response, and tested for correlations as predicted by the coping styles hypothesis; and (2) evaluated whether inter-individual behavioural and hormonal variation is related to social rank and sex. Salivary stress biomarkers (cortisol, alpha-amylase, chromogranin A) were assessed in the presence and absence of a stressor consisting of social isolation in a crate for 10min. Principal components analysis on a set of behavioural variables revealed two traits, which we labelled exploratory tendency and neophobia. Neither exploratory tendency nor neophobia predicted the physiological stress response. Subordinate pigs exhibited higher catecholamine levels compared to dominant conspecifics. We observed sex differences in the repeatability of salivary stress markers and reactivity of the stress systems. The results do not provide support for the existence of behavioural–physiological coping styles in pigs. Sex is an important determinant of the physiological stress response and warrants consideration in research addressing behavioural and hormonal variation.

Classifying Stress From Heart Rate Variability Using Salivary Biomarkers as Reference.

An accurate and noninvasive stress assessment from human physiology is a strenuous task. In this paper, a pattern recognition system to learn complex correlates between heart rate variability (HRV) features and salivary stress biomarkers is proposed. Using the Trier social stress test, heart rate and salivary measurements were obtained from volunteers under varying levels of stress induction. Measurements of salivary alpha-amylase and cortisol were used as objective measures of stress, and were correlated with the HRV features using fuzzy ARTMAP (FAM). In improving the predictive ability of the ARTMAPs, techniques, such as genetic algorithms for parameter optimization and voting ensembles, were employed. The ensemble of FAMs can be used for predicting stress responses of salivary alpha-amylase or cortisol using heart rate measurements as the input. Using alpha-amylase as the stress indicator, the ensemble was able to classify stress from heart rate features with 75% accuracy, and 80% accuracy when cortisol was used.

Religious-Commitment Signaling and Impression Management amongst Pentecostals: Relationships to Salivary Cortisol and Alpha-Amylase

Religious-commitment signaling is thought to indicate willingness to cooperate with a religious group. It follows that a desire to signal affiliation and reap concomitant benefits would lend itself to acting in socially desirable ways. Success or failure in such areas, especially where there is conscious intent, should correspond to proximal indicators of well-being, such as psychosocial or biological stress. To test this model, we assessed religious-commitment signaling and socially desirable responding among a sample of Pentecostals with respect to salivary biomarkers of stress and arousal. Results indicate that cortisol levels on worship and non-worship days were significantly influenced by religious-commitment signaling when moderated by impression management, a conscious form of socially desirable responding. No significant influences on salivary alpha-amylase were detected. These findings are important for understanding how religious-commitment signaling mechanisms may influence stress response when moderated by socially desirable responding and the role of communal orientation to psychosocial health.