Cooperation with closely bonded individuals reduces cortisol levels in long-tailed macaques

Many animal species cooperate with conspecifics in various social contexts. While ultimate causes of cooperation are being studied extensively, its proximate causes, particularly endocrine mechanisms, have received comparatively little attention. Here, we present a study investigating the link between the hormone cortisol, cooperation and social bonds in long-tailed macaques (Macaca fascicularis). We tested 14 macaques in a dyadic cooperation task (loose-string paradigm), each with two partners of different social bond strength and measured their salivary cortisol before and after the task. We found no strong link between the macaques' cortisol level before the task and subsequent cooperative success. By contrast, we did find that the act of cooperating in itself led to a subsequent decrease in cortisol levels, but only when cooperating with closely bonded individuals. Two control conditions showed that this effect was not due to the mere presence of such an individual or the pulling task itself. Consequently, our study shows an intricate way in which the hypothalamic-pituitary-adrenal axis is involved in cooperation. Future studies should reveal whether and how our findings are driven by the anxiolytic effect of oxytocin, which has been associated with social bonding.

Conditions for assessing cortisol in sheep: the total form in blood v. the free form in saliva

Cortisol is often used as a stress indicator in animal behaviour research. Cortisol is commonly measured in plasma and can also be measured in saliva. Saliva contains only the free form of cortisol, which is biologically active, and saliva sampling is not invasive and may therefore be less stressful. Our study aims to guide the choice between the measurements of cortisol in plasma v. saliva depending on experimental conditions. We analysed the effect of the level of cortisol in plasma on the concentration of cortisol in saliva compared to plasma and the effect of saliva sampling v. jugular venepuncture on the cortisol response. In Experiment 1, blood and saliva were collected simultaneously under conditions in which the expected cortisol release in blood varied: in an undisturbed situation or after the isolation of lambs from their pens or the administration of exogenous ACTH (six animals per treatment). In Experiment 2, we subjected lambs to saliva sampling, venepuncture or neither of these for 8 days to evaluate how stressful the sampling method was and whether the animals habituated to it by comparing the responses between the first and last days (four animals per treatment). All animals were equipped with jugular catheters to allow regular blood sampling without disturbance. Samples were collected 15 min before any treatment was applied, then at various time points up to 135 min in Experiment 1 and 45 min in Experiment 2. In Experiment 1, we observed a strong correlation between salivary and plasma cortisol concentrations (r = 0.81, P < 0.001). The ratio between salivary and plasma cortisol concentrations was 0.106 on average. This ratio was higher and more variable when the cortisol concentration in plasma was below 55 nmol/l. In Experiment 2, venepuncture induced a larger cortisol response than saliva sampling or no intervention on day 1 (P < 0.02); this difference was not observed on day 8, suggesting that sheep habituated to venepuncture. We recommend the measurement of cortisol in saliva to avoid stressing animals. However, when the expected concentration in plasma is below 55 nmol/l, the cortisol in saliva will reflect only the free fraction of the cortisol, which may be a limitation if the focus of the experiment is on total cortisol. In addition, if cortisol is measured in plasma and blood is collected by venepuncture, we recommend that sheep be habituated to venepuncture, at least to the handling required for a venepuncture.

Salivary Cortisol Interactions in Search and Rescue Dogs and their Handlers

Simple Summary

Stress affects both people and animals every day. Working dogs are exposed to the same stressors as their handlers during work. Our research was conducted during search and rescue dog exams. The aim of the study was to investigate if handler stress during the exam affects his or her dog’s stress level. We observed a strong relationship of salivary cortisol between the dogs and their handlers, which was most prevalent in female dogs and female handlers.

Abstract

Search and rescue dogs are an important link in the search for missing persons. The aim of the study was to assess exam stress in search and rescue dogs and their handlers. The study included 41 rescue teams taking exams of field and rubble specialties. The level of cortisol, which is the main glucocorticosteroid modulating stress reactions in humans and dogs, was analyzed. The biological material used to assess the hormone concentration was saliva collected in a non-invasive way. In total, 164 test samples were collected: two from the dog and two from the handler before and immediately after the exam. Rescue exams were shown to significantly increase salivary cortisol in both dogs and their handlers. Strong interactions between cortisol levels in human–dog teams were also found with a more pronounced effect in female dog–female handler dyads.

Minimally Invasive Markers of Stress and Production Parameters in Dairy Cows before and after the Installation of a Voluntary Milking System

Automatic milking systems (AMS) are a low-labour alternative to conventional parlours, with previous studies demonstrating that cows vary in their ability to cope with the change to AMS. Cortisol expression can be combined with other measures to assess stress: saliva and hair have the advantage of requiring minimally invasive sampling. No work has investigated the long-term impact of introduction of AMS. The aims of the study were to assess short-term and chronic stress associated with a change in milking system by measuring salivary and hair cortisol levels and to assess the impact on health and production parameters. Cows from one farm changing their milking system were recruited to the study and sampled for saliva (n = 10) and hair (n = 12) before and after installation. Cortisol levels were measured using a salivary cortisol enzyme immunoassay kit. Body condition, lameness and milk parameters of the whole herd were regularly assessed. Salivary cortisol showed no diurnal pattern but was affected by lameness and gestation. Non-lame cows showed a reduction in salivary cortisol after AMS introduction (p < 0.001). Hair cortisol levels increased after AMS, but it was unclear if this change was seasonal. Milk yield increased by 13% and somatic cell count reduced by 28%. Body condition score was consistently good, but lameness remained high throughout the study. Production values alone do not represent high welfare. The high lameness and associated cortisol levels suggest that cow stress requires consideration when changing milking systems.

Salivary Cortisol Determination on Smartphone-Based Differential Pulse Voltammetry System

Cortisol is commonly used as a significant biomarker of psychological or physical stress. With the accelerated pace of life, non-invasive cortisol detection at the point of care (POC) is in high demand for personal health monitoring. In this paper, an ultrasensitive immunosensor using gold nanoparticles/molybdenum disulfide/gold nanoparticles (AuNPs/MoS2/AuNPs) as transducer was explored for non-invasive salivary cortisol monitoring at POC with the miniaturized differential pulse voltammetry (DPV) system based on a smartphone. Covalent binding of cortisol antibody (CORT-Ab) onto the AuNPs/MoS2/AuNPs transducer was achieved through the self-assembled monolayer of specially designed polyethylene glycol (PEG, SH-PEG-COOH). Non-specific binding was avoided by passivating the surface with ethanolamine. The miniaturized portable DPV system was utilized for human salivary cortisol detection. A series current response of different cortisol concentrations decreased and exhibited a linear range of 0.5-200 nM, the detection limit of 0.11 nM, and high sensitivity of 30 μA M-1 with a regression coefficient of 0.9947. Cortisol was also distinguished successfully from the other substances in saliva. The recovery ratio of spiked human salivary cortisol and the variation of salivary cortisol level during one day indicated the practicability of the immunosensor based on the portable system. The results demonstrated the excellent performance of the smartphone-based immunosensor system and its great potential application for non-invasive human salivary cortisol detection at POC.

Cortisol secretion pattern in overweight/obese and normal-weight infants: a cross-sectional study

Background The salivary circadian diurnal cortisol plays an important role in growth and development. Inappropriate levels may induce changes associated with an increased risk of obesity later in life. It is unknown if there are differences in cortisol secretion pattern between overweight/obese infants when compared with theirs peers in infancy. Thus, this study aimed to compare the salivary cortisol secretion pattern in overweight/obese and normal-weight infants. Methods Thirty-three (overweight/obese = 17 and normal weight = 16) infants between 6 and 24 months of age had saliva samples collected upon awakening (T1), 30 min after waking (T2), at 12:00 am or before the baby's meal (T3), and prior to bedtime (T4). Highly sensitive enzyme immunoassays were used for cortisol analyses. Results Salivary cortisol levels were similar between the groups: T1 (p = 0.22; 95% confidence interval [CI]: -5.65, 1.37), T2 (p = 0.24; 95% CI: -8.23, 2.17), T3 (p = 0.95; 95% CI: -3.16, 2.96), and T4 (p = 0.81; 95% CI: -1.39, 1.08); and no differences were observed between area under the curve (AUC) (p = 0.80; 95% CI: -4.58-13.66). The cortisol level reduced in T4 (95% CI: 1.35-2.96) compared to T1 (95% CI: 5.15-8.49) and T2 in the overweight/obese group (p < 0.001; 95% CI: 6.02-11.04). In the normal-weight group, the cortisol reduced in T3 (95% CI: 2.86-8.18) compared to T1 (95% CI: 5.64-12.28) and decreased until T4 (p = 0.001; 95% CI: 1.25-3.37). Conclusions The overweight/obese infant group presented a different pattern of cortisol secretion, although cortisol levels did not differ between the control group.

Determination of reference values for salivary cortisol in healthy infants aged 0-12 months

INTRODUCTION

Salivary cortisol is a useful tool as a biomarker of stress in pediatrics because it allows for non-invasive sampling. There is little information about its use in children, and no reference values for healthy infants have been reported in Argentina. Reference values should be established at each site as the basis for subsequent tests in infants, for whom salivary cortisol appears to be the most relevant objective tool to assess stress at present.

OBJECTIVE

To determine reference values for salivary cortisol in healthy infants aged 0-12 months.

METHODS

Descriptive, cross-sectional study that assessed morning salivary cortisol levels in healthy male and female infants aged 0-12 months that attended Hospital Pirovano for a health checkup between March 2017 and March 2018. Fasting saliva samples were collected between 8 and 9 a.m. and were processed using electrochemiluminescence. Results were reported as mean and standard deviation.

RESULTS

A total of 140 infants were included, and 96 samples were collected. Mean morning salivary cortisol levels were 5.46 nmol/L (95 % confidence interval: 4.66-6.38), standard deviation: 2.15. No correlation to age was observed, so it was not necessary to divide the reference range into age groups. No significant differences were observed in terms of sex, gestational age, birth weight, type of delivery or type of feeding.

CONCLUSION

The reference range of morning salivary cortisol levels in healthy infants aged 0-12 months was reported.

Dexamethasone Suppression Test May Predict More Severe/Violent Suicidal Behavior

INTRODUCTION

Several studies demonstrated that the hypothalamic-pituitary-adrenal (HPA) axis is dysregulated in suicide attempters. Prospective studies found that people with an abnormal response at the dexamethasone suppression test (DST) are more likely to commit suicide. However, whether DST may predict suicide attempts remains less clear. A possible strategy to address this question is to consider the suicide attempt lethality.

OBJECTIVES

(1) To compare the pre- and post-DST cortisol levels in serious/violent suicide attempters and in non-serious/non-violent suicide attempters, and (2) to investigate whether cortisol level can predict new suicide attempts or their lethality.

METHODS

The study included 70 recent suicide attempters (25 with a serious or violent attempt) who were followed for two years. Three saliva samples for cortisol measurement were obtained at 8a.m., 3p.m., and 9p.m. before the DST (pre-DST). Then, at 11 p.m., 1 mg of dexamethasone was given orally. The following day (post-DST), three saliva samples were collected at the same hours as before. The post-DST-pre-DST salivary cortisol Δ index was calculated for each collection time. The Risk-Rescue Ratio Scale (RRRS) and the Suicidal Intent Scale (SIS) were used to characterize the suicide attempt at inclusion and those occurring during the follow-up.

RESULTS

Post-DST cortisol level at 9 p.m. was higher in patients with an initial violent or serious suicide attempt than in non-violent/non-serious attempters (p < .010). Higher post-DST cortisol at 9p.m. was associated with lower RRRS rescue score and higher clinical impression of suicide severity at inclusion. Among the 66 patients who completed the follow-up, 26 attempted suicide again at least once. Higher pre-DST cortisol at 8a.m. predicted new suicide attempts during the follow-up (OR = 2.15 [1.11, 4.15]), and higher cortisol Δ index at 9p.m. was associated with higher suicide intent during the follow-up.

CONCLUSIONS

Our results suggest that HPA axis hyper-reactivity monitored with the DST is a marker of violent/serious suicide attempt with lower rescue possibility. Furthermore, higher changes between pre-DST and post-DST cortisol levels may predict higher suicide intent. These findings might help to characterize the biological features of nearest suicide phenotypes.

[CME: Endogenous Hypercortisolism (Endogenous Cushing's Syndrome)]

CME: Endogenous Hypercortisolism (Endogenous Cushing's Syndrome) Abstract. Endogenous Cushing's syndrome (eCS) represents a rare disease entity. At the beginning symptoms and signs often are non-specific. However, untreated eCS is associated with a substantial morbidity and mortality rate. This article provides an actual overview about the etiology, clinical presentation and diagnosis of eCS with special focus on specific screening tests.

Combined Effect of Walking and Forest Environment on Salivary Cortisol Concentration

We investigated the effects of walking in a forest environment on salivary cortisol concentrations. Seventy-four young male participants walked for 15 min in forested and urban environments, and saliva was collected before and after walking. Our previous study reported salivary cortisol concentrations after walking only. This study was aimed at clarifying the combined effects of walking and environment by comparing post-walking data with pre-walking data. Walking in a forest environment decreased mean cortisol concentration from 9.70 to 8.37 nmol/L, whereas walking in an urban environment barely changed mean cortisol concentration, from 10.28 to 10.01 nmol/L. Two-way repeated analysis of variance revealed a significant interaction effect between the environment and walking (p < 0.001) in addition to the main effects of each (p < 0.001 and p = 0.001, for walking and environment, respectively). For further analysis, the proportion of participants who exhibited decreased cortisol after forest-walking was compared with the previously reported proportion of participants who exhibited decreased cortisol after viewing forest landscapes. Although the proportion of positive responders was slightly higher after walking (69%) than it was after viewing (60%), this difference was not statistically significant (p = 0.093). The present study revealed a significant combined effect of walking and the environment on cortisol concentrations.

Self-Reported Parenting Stress and Cortisol Awakening Response Following Mindfulness-Based Stress Reduction Intervention for Parents of Children With Developmental Delays: A Pilot Study

BACKGROUND

Many parents of children with developmental delays (DDs) experience high levels of parental stress, and young children with DDs are likely to exhibit clinical levels of behavioral problems. The reciprocal relationship between the two issues makes these families vulnerable to stress-related health risks. To address this, the current study aims to investigate the effectiveness of mindfulness-based stress reduction (MBSR) at reducing parent stress, as measured by both psychological self-report and a physiological biomarker.

METHOD

A pretest-posttest design with a 6-month follow-up assessment was used to establish effectiveness with analyses of within-subject effects. Parents (N = 47) of children (2.5-5 years of age) with DDs participated in a standard 8-week MBSR intervention. Measures included the Parenting Daily Hassles, a self-report measure of perceived frequency and intensity of parenting stress, and salivary samples for measurement of the cortisol awakening response (CAR), a biological marker of stress response.

RESULTS

Both self-reported parenting stress and CAR decreased following MBSR for parents of children with DDs. The greatest difference in means over time was between baseline and follow-up, where changes in effect size were even stronger for biological markers than for self-report measures.

CONCLUSION

The MBSR intervention reduced both perceived and physiologic stress. Health-care professionals caring for these families might consider encouraging parents to participate in MBSR as both treatment and prevention of parenting stress.

Repetitive Negative Thinking, Depressive Symptoms, and Cortisol in Cancer Caregivers and Noncaregivers

OBJECTIVES

To examine the effect of informal cancer caregiving and repetitive negative thinking (RNT) on depressive symptoms and salivary cortisol levels.

SAMPLE & SETTING

The sample was recruited from a hospital bone marrow unit and caregiver support organizations. It included 60 informal cancer caregivers (52% partners) of individuals with cancer who provided care for a median of 27.5 hours per week for 12 months, and 46 noncaregiver participants.

METHODS & VARIABLES

In this cross-sectional study, participants completed questionnaires assessing RNT and depressive symptoms and provided saliva samples to measure cortisol levels.

RESULTS

Cancer caregiving and RNT, but not the interaction, were associated with more depressive symptoms. RNT, but not cancer caregiving, was associated with salivary cortisol. A disordinal interaction effect suggests that cancer caregiving was associated with lower cortisol levels, and RNT in noncaregivers was associated with higher cortisol levels.

IMPLICATIONS FOR NURSING

Given that RNT is related to depressive symptoms and cortisol, connecting cancer caregivers who experience RNT to resources and the development and evaluation of brief nurse-led interventions to reduce RNT in informal cancer caregivers seems warranted.

Increasing Dietary Carbohydrate as Part of a Healthy Whole Food Diet Intervention Dampens Eight Week Changes in Salivary Cortisol and Cortisol Responsiveness

It is largely unknown whether and how whole food diets influence psychological stress and stress system responsiveness. To better understand the effects of whole diets on stress system responsiveness, we examined randomized control trial effects of a whole food diet based on the Dietary Guidelines for Americans (DGA) on cortisol responsiveness. A randomized, double-blind, controlled 8-week intervention was conducted in overweight and obese women to examine differentiated effects between two diet intervention groups: one based on the 2010 DGA and the other one based on a typical American diet (TAD). During a test week that occurred at baseline and again after 8 weeks of the intervention, we assessed salivary cortisol collected at 14 selected times across the day, including upon awakening, at bedtime, and during a test visit, and administered a standardized social stress task (Trier Social Stress Test, TSST). There were no statistical differences between the diet groups in salivary cortisol at baseline or after 8 weeks. However, when considering differences in dietary carbohydrate, but not fat or protein, from the pre-intervention (habitual) to the intervention period, there was a significant (P = 0.0001) interaction between diet group, intervention week, saliva sample, and level of intervention-based change in carbohydrate consumption. This interaction was reflected primarily by an 8-week reduction in salivary cortisol during a period just prior to (log Δ −0.35 ± 0.12 nmol/L) and 30 (log Δ −0.49 ± 0.12 nmol/L), 60 (log Δ −0.50 ± 0.13 nmol/L), 90 (log Δ −0.51 ± 0.13 nmol/L), and 120 (log Δ −0.4476 ± 0.1231 nmol/L) min after the TSST in the DGA group having the highest increase (90th percentile) in carbohydrate consumption. In support of this finding, we also found significant (P < 0.05) and inverse linear associations between dietary carbohydrate and log salivary cortisol, with the strongest negative association (β: −0.004 ± 0.0015, P = 0.009) occurring at 30 min post-TSST, but only in the DGA group and at week 9 of the intervention. Together, increasing dietary carbohydrate as part of a DGA-based diet may reduce circulating cortisol and dampen psychological stress-related cortisol responsiveness.

Salivary cortisol and dehydroepiandrosterone as oral biomarkers to determine stress in patients with recurrent aphthous stomatitis

Background

Recurrent aphthous stomatitis (RAS) is one of the most common oral ulcerative diseases with a multifactorial etiology. Although psychological stress is an exacerbating factor, the role of salivary stress hormones, cortisol, and dehydroepiandrosterone (DHEA) in this oral disease has not been extensively reported. The study aimed to estimate and compare the salivary cortisol and DHEA levels in RAS patients and healthy control group with the aid of ELISA microplate reader.

Subjects and Methods

Sixty patients were enrolled in our study, which included 30 patients with clinically diagnosed RAS and 30 healthy controls. Two mL of unstimulated whole saliva was collected and salivary cortisol and DHEA levels were measured using ELISA kit, and the values were read by microplate ELISA reader and recorded in both groups.

Results and Conclusion

The mean salivary cortisol and DHEA levels were elevated in the RAS patients compared to the healthy controls and were statistically significant. Salivary cortisol and DHEA can serve as oral biomarkers to determine stress in patients with RAS. However, the present study necessitates further studies with larger sample size and an improved protocol to ascertain the actual role of these presumed oral biomarkers as well as anxiety and stress as triggers in the pathogenesis of RAS.

The effects of combined exposure to noise and heat on human salivary cortisol and blood pressure

Purpose. Noise and heat are the most important physical hazardous agents that can affect physiological parameters. This study investigated the independent and combined effects of noise and heat exposure on human saliva cortisol and blood pressure. Methods. In this experimental study, 72 students were exposed to noise (at sound pressure levels of 45, 75, 85 and 95 dB(A)) and heat (at wet bulb globe temperatures [WBGTs] of 22, 29 and 34 °C) for 30 min. Samples of saliva and blood pressure were taken before and after each independent and combined exposure. Results. The results revealed that the average saliva cortisol and blood pressure in male and female subjects increased significantly after independent exposure to noise at 95 dB(A) and a WBGT of 34 °C. The combined exposure to noise and heat increased saliva cortisol and blood pressure, which was statistically significant for three combinations of 95 dB(A) at 34 °C, 95 dB(A) at 29 °C and 85 dB(A) at 34 °C. Conclusions. Combined exposure to noise and heat could affect saliva cortisol and blood pressure in both male and female groups. Further studies are recommended to capture other combinations of physical hazardous agents, especially in the field.

A study protocol of a single-center investigator-blinded randomized parallel group study to investigate the effect of an acclimatization visit on children's behavior during inhalational sedation in a United Arab Emirates pediatric dentistry postgraduate setting as measured by the levels of salivary Alpha Amylase and Cortisol

INTRODUCTION

Inhalation sedation is a proven safe method for reducing children's dental anxiety and has been used worldwide for decades. There is controversy regarding the use of acclimatization or familiarization visits for dental sedation treatment pathways for children. This may increase acceptance to the treatment based on desensitization and acclimatization principles underpinning many behavior management techniques. This study aims to identify whether, an inhalation sedation acclimatization visit is effective in reducing the stress level in anxious children as measured by salivary Alpha Amylase and Cortisol levels.

METHODS

The study is a single-center, single blinded, parallel group 2 arm clinical trial. Children in need of inhalation sedation aged 5 to 15 years from September 2019 through March 2020 attending the Postgraduate Pediatric Clinic at the Hamdan Bin Mohammed College of Dental Medicine, in Dubai, will be allocated randomly and equally to either:At the initial visit a salivary sample will be collected at the beginning of the visit and the sedation need score will be recorded using the pediatric indicator of sedation need. Treatment for both groups will commence at the second visit. Salivary samples will be collected 15 minutes before the start of the treatment and 15 minutes after the conclusion of the treatment. The following outcomes will be recorded: completion of dental treatment, anxiety scores at baseline and after treatment using Frankl rating behavior scale and physiological anxiety related changes will be recorded using salivary Alpha Amylase and Cortisol levels. Mean changes of physiologic anxiety levels and corresponding 95% confidence intervals will be determined to compare the 2 treatments (sedation with familiarization and sedation without familiarization).

DISCUSSION

This is will be the first study to measure the effect of the acclimatization visit of nitrous oxide inhalation sedation on the level of physiological anxiety and the behavior of the pediatric patients during treatment.

The creative thinking cognitive process influenced by acute stress in humans: an electroencephalography study

This study examined the underlying neural mechanism of acute stress affecting creative thinking. Twenty-six male participants underwent the Alternative Uses Test before and after acute stress test (Montreal Imaging Stress Task). Compared to before stress, stressed participants responded with higher salivary cortisol and salivary alpha-amylase. The electroencephalogram results indicated a general decrease in upper-frequency alpha power after stress, compared with that of before stress. The decrease in upper-frequency alpha power observed in the first stage after exposure to stress was related to memory and attention. Additionally, stress also reduced the differences between individuals with different creative abilities. In summary, these findings indicated that acute stress impaired creative thinking and primarily affected the earlier phase of the process of creative cognition. This study provides some practical implications for educational practice and corporate innovation in that a more relaxed environment promotes creative output. Lay Summary Acute stress impaired creative thinking performance and mainly affects the earlier phase of the process of creative cognition. Additionally, stress seems to reduce the differences between individuals with different creative abilities.

Acute stress enhances the sensitivity for facial emotions: a signal detection approach

Facial emotion recognition is an important prerequisite for social cognition. There is, however, limited evidence on how the ability to detect facial emotions is influenced by acute stress and the associated physiological reactions. In this study, two groups of healthy male participants were either exposed to a psychosocial stressor - an adaptation of the Trier Social Stress Test in virtual reality (n = 23) - or a non-stressful control task in the virtual environment (n = 20). Afterwards, both groups completed a computerized facial recognition task based on the signal detection theory presenting happy vs. angry faces with three different expression intensities. Saliva samples were taken at seven time points over the course of the experiment and used to analyze concentrations of free salivary cortisol and alpha amylase. Analyses using repeated-measures analyses of variance revealed a significant increase in emotion detection performance and significantly shorter response latencies in the stress group independent of emotional valence or emotion intensity. However, increased task performance in the stress group could not be predicted by stress-induced cortisol or alpha amylase secretion. The results suggest that enhanced detection of emotional cues after stress might be an adaptive response as an increased sensitivity to social cues might help individuals to detect potential threats or sources of social support in their social environment. Lay Summary Socially evaluative stress facilitates the subsequent recognition of emotions. After having performed a task in a virtual environment, two groups of participants were asked to detect emotion expressions on pictures of faces that were presented to them on a computer screen. Statistical comparison of groups indicates that the group that had previously been subjected to a stressful job interview showed better results and became faster in detecting displayed emotions than the control group that had previously performed a non-stressful task.

Salivary cortisol is not associated with incident insulin resistance or type 2 diabetes mellitus

BACKGROUND

Excessive glucocorticoid secretion has been associated with type 2 diabetes mellitus (T2DM) and other features of the metabolic syndrome. We aimed to evaluate whether basal or evening salivary cortisol may predict the occurrence of incident insulin resistance (IR) or T2DM.

METHOD

This was a prospective, population-based study derived from the CoLaus/PsyCoLaus study including 1525 participants (aged 57.7 ± 10.3 years; 725 women). A total of 1149 individuals were free from T2DM at baseline. Fasting plasma glucose and insulin were measured after a follow-up of 5.3 years. Basal and evening salivary cortisol were measured at baseline. The association between basal or evening salivary cortisol level and incidence of IR or T2DM were analyzed by logistic regression, and the results were expressed for each independent variable as ORs and 95% CI.

RESULTS

After a median follow-up of 5.3 years, a total of 376 subjects (24.7%) developed IR and 32 subjects (2.1%) developed T2DM. Basal and evening salivary cortisol divided in quartiles were not associated with incidence of IR or T2DM. Multivariable analysis for age, gender, body mass index, physical activity and smoking status showed no association between basal or evening salivary cortisol and incidence of IR or T2DM.

CONCLUSION

In the CoLaus/PsyCoLaus study of healthy adults, neither basal nor evening salivary cortisol was associated with incident IR or T2DM.

Female Volleyball Players Are More Prone to Cortisol Anticipatory Stress Response than Sedentary Women

Background and Objectives: Top-level sports performance places heavy physical and psychological demands on elite-level athletes, which can be a source of increased levels of stress. Therefore, high-level volleyball players may present altered cardiovascular and endocrinological stress response during stressful events. Although many previous studies have examined the response to stress on athletes, most of them regarded only males, while the impact of the female menstrual cycle has rarely been taken into account. We aimed to study psychophysiological response to anticipatory stressor through analysis of heart rate, self-reported anxiety level, and salivary cortisol in healthy young female athletes by minimalizing the effect of confounders. Materials and Methods: A total of 55 females (25 members of the best league for female volleyball players in Poland and 30 sedentary-lifestyle control subjects) in the follicular phase of their menstrual cycle were exposed to mental arithmetic tasks as an experimental imitation of the stressor. Volleyball players were significantly taller than sedentary individuals (177.1 ± 3.4 cm vs. 173.3 ± 3.4 cm, respectively, p = 0.034), but did not differ in weight (73.6 ± 5.2 kg vs. 70 ± 4.23 kg, respectively, p = 0.081), body mass index (BMI) (23.5 ± 1.13 vs. 24.1 ± 1.45, respectively, p = 0.060), and age (22 ± 1.11 vs. 23 ± 1.14 years, respectively, p = 0.2). Their stress responses were assessed through self-reported anxiety levels and physiological measurements of salivary cortisol concentrations and heart rate (HR). Results: For HR, significant effects of time (F_(2,120) = 21.34, p < 0.001, η² = 0.26) were found, but not for training status (F_(1,60) = 2.69, p = 0.106, η² = 0.04). For cortisol levels, the analysis showed the main effects of time (F_(3,180) = 11.73, p < 0.001, η² = 0.16) and training status (F_(1,60) = 4.69, p = 0.034, η² = 0.07) and a significant interaction between training status and time (F_(3,180) = 3.07, p = 0.029, η² = 0.05). Post-hoc analyses showed higher cortisol concentrations among volleyball players following the math task (all p < 0.001), as well as higher cortisol concentrations in S2, S3, and S4 compared to S1 in volleyball players (all p < 0.001). We observed also a significant increase in state anxiety in both groups (all p < 0.001), but no differences in state anxiety levels between groups. Conclusion: Female volleyball players may not differ in subjective graduation of stressors; however, exposure to training-based stressors seems to promote cortisol response to the anticipated stressor.

Frontal brain delta-beta correlation, salivary cortisol, and social anxiety in children

BACKGROUND

Correlated activity of slow-wave (e.g. delta) and fast-wave (e.g. beta) frontal brain oscillations is thought to be an electrophysiological correlate of individual differences in neuroendocrine activity and anxiety in adult samples. We know, however, relatively little about the physiological and functional correlates of delta-beta coupling in children.

METHOD

We examined whether longitudinal patterns of children's basal salivary cortisol and social anxiety across two visits separated by 1 year were associated with frontal brain delta-beta correlation in children (M_age  = 7.59 years, SD = 1.70). At Time 1 (T1), resting baseline electroencephalogram (EEG) recordings were collected from the children and delta and beta power was measured, and at both T1 and Time 2 (T2), basal salivary cortisol was measured, and parents reported on children's symptoms of social anxiety.

RESULTS

Using latent class growth curve analysis, we found that children's salivary cortisol across visits was characterized by a high, stable class (53%), and a low, unstable class (47%), and children's social anxiety was characterized by a high, stable class (50%) and a low, stable class (50%). Using Fisher's r-to-z transformation, we found that frontal EEG delta-beta correlation was significantly stronger among children with high, stable salivary cortisol levels (compared to the low, unstable class; z = 2.11, p = .02), and among children with high, stable social anxiety levels (compared to the low, stable class; z = 1.72, p = .04).

CONCLUSIONS

These findings demonstrate that longitudinal patterns of neuroendocrine stress activity and social anxiety may be associated with the correlation of EEG power in slow and fast frontal brain oscillations as early as childhood.

The correlation between sleep bruxism, salivary cortisol, and psychological status in young, Caucasian healthy adults

Objective: To analyze the association between sleep bruxism (SB), salivary cortisol, and psychological state in healthy adults.Methods: Sixty healthy students (with or without SB) were included in the study. The subjects completed a questionnaire that evaluated the presence of SB and analyzed the general and work-related psychological states and job-related frustration. Clinical examinations of TMJs and dental wear were performed. The salivary cortisol was determined using ELISA technique.Results: Subjects with SB had a general status characterized by anxiety or stress compared to subjects without SB. They also presented a work-induced depressive or anxious attitude compared to healthy individuals. The salivary cortisol levels were higher in subjects with SB and in females and were correlated with subjects' general anxiety, but not with a job-induced psychological state.Conclusion: SB is correlated with general and job-induced psychological changes. Salivary cortisol could be a non-invasive marker for the evaluation of SB severity.

Healthy Birth Practice #6: Keep Mother and Newborn Together-It's Best for Mother, Newborn, and Breastfeeding

Mothers and newborns have an emotional and physiological need to be together at the moment of birth and during the hours and days that follow. Keeping mothers and newborns together is a safe and healthy birth practice. Evidence supports immediate, undisturbed skin-to-skin care after vaginal birth and during and after cesarean surgery for all medically stable mothers and newborns, regardless of feeding preference; and, no routine separation during the days after birth. Childbirth educators and other health-care professionals have an ethical responsibility to support this essential healthy birth practice through education, advocacy, and implementation of evidence-based maternity practices.

Effects of preferred music therapy on peer attachment, depression, and salivary cortisol among early adolescents in Taiwan

AIMS

To explore the effects of preferred music therapy on peer attachment, depression, and salivary cortisol among early adolescents.

BACKGROUND

As adolescents enter puberty, they start to seek partnering relationships among peers. Peer attachment is central for adolescents and greatly influences their physical and psychological development.

DESIGN

A pre-test-posttest control group design.

METHODS

The data were collected from July - October 2016. A total of 65 individuals were included. The treatment group received 40 min of music therapy twice per week over the course of 10 weeks. The control group maintained its typical routine. The research data were collected using structured questionnaires, including basic information, the Inventory of Peer Attachment, the Beck Depression Inventory-II questionnaires, and salivary cortisol concentrations. Statistical analysis methods included percentages, chi-square tests, t tests, analyses of covariance, and the Johnson-Neyman technique.

RESULTS

There were statistically significant differences in peer attachment, depression, and salivary cortisol levels in the music group compared to the control group (p < 0.05). Additionally, the findings showed that early adolescents with more severe depression experienced greater improvement through preferred music therapy.

CONCLUSION

The results allude to the beneficial effects of receiving preferred music therapy in terms of the peer attachment, depression, and salivary cortisol levels of early adolescents. Adjustments should be made based on the characteristics of student groups to develop suitable and safe music therapy and to reduce the risks of poor mental health.

Rigor and Reproducibility: A Systematic Review of Salivary Cortisol Sampling and Reporting Parameters Used in Cancer Survivorship Research

Salivary cortisol is a commonly used biomarker in cancer survivorship research; however, variations in sampling protocols and parameter reporting limit comparisons across studies. Standardized practices to provide rigor and reproducibility of diurnal salivary cortisol sampling and reporting are not well established. Previous systematic reviews examining relationships between diurnal salivary cortisol and clinical outcomes have resulted in mixed findings. It remains unclear which sampling protocols and reporting parameters offer the greatest utility for clinical research. This review examines diurnal salivary cortisol sampling protocols and reporting parameters to evaluate whether a standardized approach is recommended. A comprehensive search of intervention studies among adult cancer survivors including diurnal salivary cortisol resulted in 30 articles for review. Sampling protocols ranged from 1 to 4 days with the majority of studies sampling cortisol for 2 days. Sampling instances ranged from 2 to 7 times per day, with the majority collecting at 4 time points per day. Diurnal cortisol slope and cortisol awakening response (CAR) were the most commonly reported parameters associated with clinical outcomes. Flattened cortisol slopes, blunted CARs, and elevated evening cortisol concentrations were associated with poorer psychosocial and physiological outcomes. Based on our review, we propose that a rigorous, standardized diurnal salivary cortisol sampling protocol should include sampling at key diurnal times across ≥3 consecutive days to report diurnal cortisol parameters (i.e., CAR and slope) and objective measures of participant protocol adherence. Diminishing budgetary resources and efforts to minimize participant burden dictate the importance of standardized cortisol sampling protocols and reporting parameters.