Sex differences in salivary cortisol in response to acute stressors among healthy participants, in recreational or pathological gamblers, and in those with posttraumatic stress disorder

Diurnal Profiles of the Endocrine Stress Response in Internet Gaming Disorder

BACKGROUND

Differences in subjective stress perception and acute response of the hypothalamic-pituitary-adrenal axis have been reported in internet gaming disorder (IGD). The present study aimed to further investigate alterations in diurnal profiles of the endocrine stress response system in IGD compared to healthy controls (HCs).

METHODS

The diurnal course of endocrine markers (salivary cortisol and α-amylase) was investigated in a clinical sample of n = 29 adolescents with IGD compared to n = 26 HC. Further, the effect of unrestricted gaming versus restricted gaming was examined within the IGD group.

RESULTS

No significant differences in salivary cortisol and α-amylase were observed comparing adolescents with IGD and HC. In addition, in the IGD group, there were no significant differences in salivary cortisol and α-amylase between conditions of unrestricted gaming versus restricted gaming. Compared to the HC group, the IGD group showed a significantly higher body mass index.

CONCLUSIONS

Our results indicate no alteration in diurnal profiles of the endocrine stress response in IGD.

Sex Differences in the Neurobiology of Fear and Anxiety

Although women are diagnosed with anxiety and stress-related disorders at twice the rate of men, there remains a lack of clarity around how to enhance treatment within each sex to reduce disparate rates of anxiety. However, in recent years, a growing literature has identified neural, cognitive, and physiological mechanisms that contribute to sex differences in fear and anxiety, with the promise of informing tailored treatment approaches. Here, we review recent findings, focusing on human studies among healthy populations as well as among patients with generalized anxiety, social anxiety disorder, post-traumatic stress disorder, and panic disorder. The literature reveals nuanced differences in the types of stimuli that preferentially evoke anxiety and stress responses in women and men, as well as sex differences in threat neurocircuitry that mediates the behavioral, physiological, and subjective components of fear and anxiety.

Drinking severity mediates the relationship between hypothalamic connectivity and rule-breaking/intrusive behavior differently in young women and men: an exploratory study

Background

The hypothalamus is a key hub of the neural circuits of motivated behavior. Alcohol misuse may lead to hypothalamic dysfunction. Here, we investigated how resting-state hypothalamic functional connectivities are altered in association with the severity of drinking and clinical comorbidities and how men and women differ in this association.

Methods

We employed the data of the Human Connectome Project. A total of 870 subjects were included in data analyses. The severity of alcohol use was quantified for individual subjects with the first principal component (PC1) identified from principal component analyses of all drinking measures. Rule-breaking and intrusive scores were evaluated with the Achenbach Adult Self-Report Scale. We performed a whole-brain regression of hypothalamic connectivities on drinking PC1 in all subjects and men/women separately and evaluated the results at a corrected threshold.

Results

Higher drinking PC1 was associated with greater hypothalamic connectivity with the paracentral lobule (PCL). Hypothalamic PCL connectivity was positively correlated with rule-breaking score in men (r=0.152, P=0.002) but not in women. In women but not men, hypothalamic connectivity with the left temporo-parietal junction (LTPJ) was negatively correlated with drinking PC1 (r=-0.246, P<0.001) and with intrusiveness score (r=-0.127, P=0.006). Mediation analyses showed that drinking PC1 mediated the relationship between hypothalamic PCL connectivity and rule-breaking score in men and between hypothalamic LTPJ connectivity and intrusiveness score bidirectionally in women.

Conclusions

We characterized sex-specific hypothalamic connectivities in link with the severity of alcohol misuse and its comorbidities. These findings extend the literature by elucidating the potential impact of problem drinking on the motivation circuits.

Association between stress and eating behaviour among Malaysian adolescents prior to examination

Studies have shown the prevalence of mental health and obesity among adolescents is at increasing trend due to urbanisation and changes in lifestyle. This study is to investigate the level of stress and its impact on eating behaviour among Malaysian adolescents. A total of 797 multi-ethnic Malaysian secondary school student participated in this cross-sectional study. Data was collected two weeks prior to final year examination. A validated Cohen Perceived Stress Scale questionnaire was used to assess the stress level with subsample analysis of 261 participants' saliva cortisol level. A validated Child Eating Behaviour questionnaire was used to explore eating behaviours. There were 29.1% adolescents having high stress with the mean saliva cortisol 3.8 nmol/L. A positive correlation was observed between perceived stress and emotional overeating; stronger among urban (r = 0.32), female (r = 0.31), underweight (r = 0.34) and moderately stressed adolescents (r = 0.24). In addition, a positive correlation was found between perceived stress and food responsiveness; strongest among Malay (r = 0.23), male (r = 0.24), underweight (r = 0.30) and adolescents with high perceived stress (r = 0.24). The perceived stress level prior to exam period affects the emotional eating and external eating patterns of adolescents.

Pathophysiological aspects of complex PTSD - a neurobiological account in comparison to classic posttraumatic stress disorder and borderline personality disorder

Despite a great diagnostic overlap, complex posttraumatic stress disorder (CPTSD) has been recognised by the ICD-11 as a new, discrete entity and recent empirical evidence points towards a distinction from simple posttraumatic stress disorder (PTSD) and borderline personality disorder (BPD). The development and maintenance of these disorders is sustained by neurobiological alterations and studies using functional magnetic resonance imaging (fMRI) may further contribute to a clear differentiation of CPTSD, PTSD and BPD. However, there are no existing fMRI studies directly comparing CPTSD, PTSD and BPD. In addition to a summarization of diagnostic differences and similarities, the current review aims to provide a qualitative comparison of neuroimaging findings on affective, attentional and memory processing in CPTSD, PTSD and BPD. Our narrative review alludes to an imbalance in limbic-frontal brain networks, which may be partially trans-diagnostically linked to the degree of trauma symptoms and their expression. Thus, CPTSD, PTSD and BPD may underlie a continuum where similar brain regions are involved but the direction of activation may constitute its distinct symptom expression. The neuronal alterations across these disorders may conceivably be better understood along a symptom-based continuum underlying CPTSD, PTSD and BPD. Further research is needed to amend for the heterogeneity in experimental paradigms and sample criteria.

The Association between Self-Rated Health Status, Psychosocial Stress, Eating Behaviors, and Food Intake According to the Level of Sunlight Exposure in Korean Adults

Sunlight exposure has been reported to have various beneficial effects on human health. This study investigated the relationship between self-rated health status, psychosocial stress, eating behaviors, and food intake according to sunlight exposure in 948 adults. Sunlight exposure was classified as less than one hour, less than three hours, and greater than three hours. Of the participants, 49.2% had fewer than three hours of daily exposure to sunlight. Regarding participants exposed to sunlight for less than one hour, the largest response was that they did not engage in outdoor activities on weekdays or weekends, and the rate of being outdoors in the shade on sunny days was the highest in this group at 42.7%. Furthermore, the participants exposed to sunlight for less than one hour had a lower health response than the other two groups, and there were significantly more participants classified in the stress risk group. Regarding eating habits, those with less than an hour of exposure to sunlight frequently ate fried foods, fatty foods, added salt, and snacks, and had significantly lower total dietary scores or three regular meals. Additionally, their frequency of consumption of cereals, milk and dairy products, orange juice, and pork was also significantly lower than the other groups. Thus, it is necessary to provide sufficient guidelines for adequate sunlight exposure and food intake because participants with low sunlight exposure may have low vitamin D synthesis and insufficient food intake.

Altrenogest treatment reduces the stress response of three-year-old warmblood mares during their initial equestrian training

Horse mares are frequently treated with the progestin altrenogest with the aim to suppress estrous behavior and its negative impact on equestrian performance. Progestogens, however, also have sedative effects in males, and females of different species. The aim of our study was therefore to investigate altrenogest-induced changes in the stress response of female horses during initial equestrian training. Three-yr-old Warmblood mares were randomly assigned to treatment with altrenogest (ALT; 0.044 mg/kg once daily; n = 6) or sunflower oil (CON; n = 5) for 12 wk during training. At predefined steps of the training program (free movement, lunging without and with side reins, lunging with saddle, mounting of a rider, free riding, riding by an unfamiliar rider) salivary cortisol concentration, and heart rate were determined from 60 min before to 120 min after training. The same procedures were performed during repeated gynecologic examinations and 2 novel object tests. Bodyweight and body condition scores (BCS) were assessed at 4-wk intervals. During all training units, salivary cortisol concentration and heart rate increased (P < 0.001), but the increase was smaller in group ALT mares (time x treatment P < 0.001). Gynecologic examinations and novel object tests induced a much smaller increase in cortisol and heart rate (P < 0.001) than equestrian training with no difference between groups ALT and CON. Initially, bodyweight, and BCS decreased during training. The subsequent increase was larger in group ALT vs CON (time x treatment P < 0.05). In conclusion, altrenogest reduced the stress response of 3-yr-old mares to equestrian training. The use of altrenogest during equestrian competitions should therefore be reconsidered.

OUP accepted manuscript

The Coronavirus disease of 2019 (COVID-19) and measures to curb it created population-level changes in male-dominant impulsive and risky behaviors such as violent crimes and gambling. One possible explanation for this is that the pandemic has been stressful, and males, more so than females, tend to respond to stress by altering their focus on immediate versus delayed rewards, as reflected in their delay discounting rates. Delay discounting rates from healthy undergraduate students were collected twice during the pandemic. Discounting rates of males (n=190) but not of females (n=493) increased during the pandemic. Using machine learning, we show that prepandemic functional connectome predict increased discounting rates in males (n=88). Moreover, considering that delay discounting is associated with multiple psychiatric disorders, we found the same neural pattern that predicted increased discounting rates in this study, in secondary datasets of patients with major depression and schizophrenia. The findings point to sex-based differences in maladaptive delay discounting under real-world stress events, and to connectome-based neuromarkers of such effects. They can explain why there was a population-level increase in several impulsive and risky behaviors during the pandemic and point to intriguing questions about the shared underlying mechanisms of stress responses, psychiatric disorders and delay discounting.

IMVEST, an immersive multimodal virtual environment stress test for humans that adjusts challenge to individual's performance

Laboratory stressors are essential tools to study the human stress response. However, despite considerable progress in the development of stress induction procedures in recent years, the field is still missing standardization and the methods employed frequently require considerable personnel resources. Virtual reality (VR) offers flexible solutions to these problems, but available VR stress-induction tests still contain important sources of variation that challenge data interpretation. One of the major drawbacks is that tasks based on motivated performance do not adapt to individual abilities. Here, we provide open access to, and present, a novel and standardized immersive multimodal virtual environment stress test (IMVEST) in which participants are simultaneously exposed to mental -arithmetic calculations- and environmental challenges, along with intense visual and auditory stimulation. It contains critical elements of stress elicitation – perceived threat to physical self, social-evaluative threat and negative feedback, uncontrollability and unpredictability – and adjusts mathematical challenge to individual's ongoing performance. It is accompanied by a control VR scenario offering a comparable but not stressful situation. We validate and characterize the stress response to IMVEST in one-hundred-and-eighteen participants. Both cortisol and a wide range of autonomic nervous system (ANS) markers – extracted from the electrocardiogram, electrodermal activity and respiration – are significantly affected. We also show that ANS features can be used to train a stress prediction machine learning model that strongly discriminates between stress and control conditions, and indicates which aspects of IMVEST affect specific ANS components.

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Laboratory stressors are an essential tool to study the stress response in humans.

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We present a novel immersive multimodal virtual environment stress test (IMVEST).

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IMVEST adapts to individual performance.

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Induces acute increase in stress markers.

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Stress responses do not depend on performance differences.

Sex Differences in Peritraumatic Inflammatory Cytokines and Steroid Hormones Contribute to Prospective Risk for Nonremitting Posttraumatic Stress Disorder

Women are at higher risk for developing posttraumatic stress disorder (PTSD) compared to men, yet little is known about the biological contributors to this sex difference. One possible mechanism is differential immunological and neuroendocrine responses to traumatic stress exposure. In the current prospective study, we aimed to identify whether sex is indirectly associated with the probability of developing nonremitting PTSD through pro-inflammatory markers and whether steroid hormone concentrations influence this effect. Female (n = 179) and male (n = 197) trauma survivors were recruited from an emergency department and completed clinical assessment within 24 h and blood samples within ∼three hours of trauma exposure. Pro-inflammatory cytokines (IL-6, IL-1 β , TNF, IFNγ), and steroid hormone (estradiol, testosterone, progesterone, cortisol) concentrations were quantified in plasma. Compared to men, women had a higher probability of developing nonremitting PTSD after trauma (p = 0.04), had lower pro-inflammatory cytokines and testosterone (p's<0.001), and had higher cortisol and progesterone (p's<0.001) concentrations. Estradiol concentrations were not different between the sexes (p = 0.24). Pro-inflammatory cytokines were a significant mediator in the relationship between sex and probability of developing nonremitting PTSD (p < 0.05), such that men had higher concentrations of pro-inflammatory cytokines which were associated with lower risk of nonremitting PTSD development. This effect was significantly moderated by estradiol (p < 0.05), as higher estradiol levels in men were associated with higher pro-inflammatory cytokine concentrations and lower risk for developing nonremitting PTSD. The current results suggest that sex differences in the pro-inflammatory cytokine response to trauma exposure partially mediate the probability of developing nonremitting PTSD, and that the protective ability to mount an pro-inflammatory cytokine response in men may depend on higher estradiol levels in the aftermath of trauma exposure.

Blunted salivary cortisol response to psychosocial stress in women with posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is characterized by alterations in the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS). There is evidence for a blunted HPA axis reactivity to psychosocial stress. Less is known about how the SNS reacts to psychosocial stress. Here, we compared the HPA axis and SNS responses to psychosocial stress and a non-stressful condition in patients with PTSD and in healthy individuals. Twenty-one women with PTSD and 32 healthy women participated in the Trier social stress test (TSST) and placebo TSST (P-TSST). We measured salivary cortisol, alpha amylase activity and blood pressure before and after the tests. Subjective perceived stress response was also assessed. We found a blunted cortisol response to the TSST in patients with PTSD compared with healthy participants 10 min (t (51) = -2.58, p = .01) and 25 min (t (51) = -2.16, p = .04) after TSST. We found no evidence for an increased SNS reactivity after psychosocial stress in patients with PTSD (all p > .05). Patients with PTSD, but not healthy participants, reported more dissociative symptoms (t (20) = -2.31, p = .03) and being more tired (t (20) = 2.90, p = .01) directly after TSST compared with the placebo condition. Our results suggest a blunted HPA stress reactivity and an increased subjective perceived stress response in female patients with PTSD. Longitudinal studies could test if these altered stress responses constitute a predisposition to or a cause of PTSD. Future studies should investigate whether these results are transferable to men.

Stress perception following childhood adversity: Unique associations with adversity type and sex

Childhood adversity is associated with poor mental and physical health outcomes across the life span. Alterations in the hypothalamic-pituitary-adrenal axis are considered a key mechanism underlying these associations, although findings have been mixed. These inconsistencies suggest that other aspects of stress processing may underlie variations in this these associations, and that differences in adversity type, sex, and age may be relevant. The current study investigated the relationship between childhood adversity, stress perception, and morning cortisol, and examined whether differences in adversity type (generalized vs. threat and deprivation), sex, and age had distinct effects on these associations. Salivary cortisol samples, daily hassle stress ratings, and retrospective measures of childhood adversity were collected from a large sample of youth at risk for serious mental illness including psychoses (n = 605, mean age = 19.3). Results indicated that childhood adversity was associated with increased stress perception, which subsequently predicted higher morning cortisol levels; however, these associations were specific to threat exposures in females. These findings highlight the role of stress perception in stress vulnerability following childhood adversity and highlight potential sex differences in the impact of threat exposures.

Hormonal responses in gambling versus alcohol abuse: A review of human studies

The endocrine system plays an essential role in communication between various organs of the body to maintain homeostasis. Both substance use disorders (SUDs) and non-substance abuse disrupt this system and lead to hormonal dysregulations. Here, we focus on the comparison between the function of the endocrine system in gambling disorders and alcohol addiction to understand the commonalities and differences in their neurobiological and psychological underpinnings. We review human research to compare findings on gambling addiction and alcohol dependence pertaining to the dynamic interplay between testosterone and cortisol. Understanding and classifying similarities in hormonal responses between behavioural addiction and SUDs may facilitate development of treatments and therapeutic interventions across different types of addictive disorders, while describing differences may shed light on therapeutic interventions for specific disorders. Although research on gambling addiction is in its infancy, such evaluation may still have a positive effect for addiction research, thereby stimulating discovery of "crossover" pharmacotherapies with benefits for both SUDs and nonsubstance addictions.

Endogenous cannabinoid levels and suicidality in combat veterans

Combat veterans are at elevated suicide risk. The goal of this study was to test the hypothesis that combat veterans who have made a suicide attempt post-deployment can be distinguished from combat veterans who have never made a suicide attempt based on differences in psychological and biological variables. For the latter, we focused on endogenous cannabinoids, neuroendocrine markers that are associated with stress. Demographic and clinical parameters of suicide attempters and non-attempters were assessed. Blood samples were assayed for anandamide (AEA), 2-arachidonoylglycerol (2-AG), and cortisol. Suicide attempters had higher Scale for Suicidal Ideation (SSI) scores in comparison to non-attempters. Controlling for gender, 2-AG levels were higher among suicide attempters in comparison to non-attempters. Cortisol levels positively correlated with 2-AG levels and negatively correlated with SSI scores among non-attempters but not among attempters. AEA levels negatively correlated with SSI scores among attempters but not among non-attempters. Our results indicate that there are psychological and biological differences between combat veterans with or without a history of suicidal attempt. Our findings also suggest that clinically observed differences between the groups may have a neurobiological basis.

Sex differences in factors associated with post-traumatic stress disorder in acute type A aortic dissection patients

BACKGROUND

Emergency surgery for acute type A aortic dissection (AAAD) is associated with a high risk for posttraumatic stress disorder (PTSD), and the risk factors for PTSD symptoms development in AAAD patients of different sexes remain unclear.

OBJECTIVE

To identify the risk factors for PTSD symptoms separately in the females and males following AAAD.

METHODS

A sample population of 214 patients who had AAAD surgery was recruited. Patients' sociodemographic and disease-specific data were collected during hospitalization.

RESULTS

In this study, PTSD symptoms was present in 22.1% of the male patients and 20.0% of the female patients (P = 0.739). For the male patients with AAAD, PTSD symptoms were significantly positively associated with HADS-D score (P = 0.029), while those with university education and above (P = 0.039), stronger subjective support (P = 0.010) and greater optimism (P = 0.001) had significantly lower possibility for the presence of PTSD symptoms. For the female patients with AAAD, support availability (P = 0.031) was significantly negatively associated with PTSD symptoms while HADS-D score (P = 0.033) was significantly positively associated with PTSD symptoms.

CONCLUSION

Risk factors for PTSD symptoms differ in male patients and female patients following AAAD.

Neuroendocrine and Inflammatory Effects of Childhood Trauma Following Psychosocial and Inflammatory Stress in Women with Remitted Major Depressive Disorder

The dysregulation of the inflammatory and neuroendocrine systems seen in major depressive disorder (MDD) may persist after remission and this is associated with a higher risk of relapse. This vulnerable subgroup may be characterized by a history of childhood trauma. In a single-blind randomized placebo-controlled crossover study, 21 women with remitted recurrent MDD and 18 healthy controls were exposed to psychosocial stress (Trier social stress test) or inflammatory stress (typhoid vaccine), or both, to investigate the effects of childhood trauma on the neuroendocrine and inflammatory responses. Childhood trauma was assessed using the Childhood Trauma Questionnaire and participants were dichotomized into a traumatized and non-traumatized group. Serum adrenocorticotropic hormone (ACTH), cortisol, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were measured at regular intervals after each intervention. The effects of trauma, time, and intervention on these parameters were modeled by fitting linear mixed models. Childhood trauma in itself did not have a main effect on the outcome measurements. However, an interactional effect of trauma with stressor type was found in the remitted MDD group: trauma was associated with higher cortisol levels only after adding immunological to psychosocial stress, and with lower TNF-α levels in response to vaccination. This suggests the existence of a vulnerable trauma-associated MDD endophenotype.

Social isolation as a promising animal model of PTSD comorbid suicide: neurosteroids and cannabinoids as possible treatment options

Post-traumatic stress disorder (PTSD) is a psychiatric condition characterized by drastic alterations in mood, emotions, social abilities and cognition. Notably, one aspect of PTSD, particularly in veterans, is its comorbidity with suicide. Elevated aggressiveness predicts high-risk to suicide in humans and despite the difficulty in reproducing a complex human suicidal behavior in rodents, aggressive behavior is a well reproducible behavioral trait of suicide. PTSD animal models are based on a peculiar phenotype, including exaggerated fear memory and impaired fear extinction associated with neurochemical dysregulations in the brain circuitry regulating emotion. The endocannabinoid and the neurosteroid systems regulate emotions and stress responses, and recent evidence shows these two systems are interrelated and critically compromised in neuropsychiatric disorders. For instance, levels of the neurosteroid, allopregnanolone, as well as those of the endocannabinoids, anandamide and its congener, palmitoylethanolamide are decreased in PTSD. Similarly, the endocannabinoid system and neurosteroid biosynthesis are altered in suicidal individuals. Selective serotonin reuptake inhibitors (SSRIs), the only FDA-approved treatments for PTSD, fail to help half of the treatment-seeking patients. This highlights the need for developing biomarker-based efficient therapies. One promising alternative to SSRIs points to stimulation of allopregnanolone biosynthesis as a treatment and a valid end-point to predict treatment response in PTSD patients. This review highlights running findings on the role of the endocannabinoid and neurosteroid systems in PTSD and suicidal behavior both in a preclinical and clinical perspective. A specific focus is given to predictive PTSD/suicide animal models. Ultimately, we discuss the idea that disruption of neurosteroid and endocannabinoid biosynthesis may offer a novel promising biomarker axis to develop new treatments for PTSD and, perhaps, suicidal behavior.

Meta-analysis of blood cortisol levels in individuals with first-episode psychosis

OBJECTIVE

Schizophrenia is associated with abnormal neuroimmunoendocrine function. There is evidence for hypothalamic-pituitary-adrenal (HPA) axis abnormalities in individuals with first-episode psychosis (FEP). However, some previous meta-analyses have focused on heterogeneous sample sources and patient populations. We performed a meta-analysis of baseline (i.e., one sample) blood cortisol levels in individuals with FEP and minimal exposure to antipsychotics.

METHOD

Articles were identified by searching PubMed, PsycInfo, Web of Science, and Science Direct, and the reference lists of these studies.

RESULTS

Twenty-six studies (comprising twenty-seven samples) met the inclusion criteria. Blood cortisol levels were significantly increased in individuals with FEP compared to controls with a small-to-medium effect size (standard mean difference [SMD] = 0.37, 95% CI 0.16-0.57, p < 0.001). In meta-regression analyses, geography was a significant moderator of this association, with larger effects seen in studies conducted in Asia versus the Middle East.

CONCLUSION

We found elevated blood cortisol levels in individuals with FEP, providing additional, complementary evidence for abnormal HPA axis function in this disorder. This finding, which does not inform on mechanism, is consistent with the "neural diathesis-stress" model of psychosis. Given the immunomodulatory effects of cortisol, methodologically rigorous longitudinal studies of cortisol parameters, inflammatory markers, and psychopathology in this patient population are warranted.

Long-term transportation noise exposure and incidence of ischaemic heart disease and stroke: a cohort study

BACKGROUND

There is limited evidence from longitudinal studies on transportation noise from different sources and development of ischaemic heart disease (IHD) and stroke.

OBJECTIVES

This cohort study assessed associations between exposure to noise from road traffic, railway or aircraft and incidence of IHD and stroke.

METHODS

In a cohort of 20 012 individuals from Stockholm County, we estimated long-term residential exposure to road traffic, railway and aircraft noise. National Patient and Cause-of-Death Registers were used to identify IHD and stroke events. Information on risk factors was obtained from questionnaires and registers. Adjusted HR for cardiovascular outcomes related to source-specific noise exposure were computed using Cox proportional hazards regression.

RESULTS

No clear or consistent associations were observed between transportation noise and incidence of IHD or stroke. However, noise exposure from road traffic and aircraft was related to IHD incidence in women, with HR of 1.11 (95% CI 1.00 to 1.22) and 1.25 (95% CI 1.09 to 1.44) per 10 dB L_den, respectively. For both sexes taken together, we observed a particularly high risk of IHD in those exposed to all three transportation noise sources at≥45 dB L_den, with a HR of 1.57 (95% CI 1.06 to 2.32), and a similar tendency for stroke (HR 1.42; 95% CI 0.87 to 2.32).

CONCLUSION

No overall associations were observed between transportation noise exposure and incidence of IHD or stroke. However, there appeared to be an increased risk of IHD in women exposed to road traffic or aircraft noise as well as in those exposed to multiple sources of transportation noise.

β-Hydroxy β-methylbutyrate free acid alters cortisol responses, but not myofibrillar proteolysis, during a 24-h fast

This study was a randomised, double-blind, placebo-controlled cross-over trial examining the effects of β-hydroxy β-methylbutyrate free acid (HMB-FA) supplementation on muscle protein breakdown, cortisol, testosterone and resting energy expenditure (REE) during acute fasting. Conditions consisted of supplementation with 3 g/d HMB-FA or placebo during a 3-d meat-free diet followed by a 24-h fast. Urine was collected before and during the 24-h fast for analysis of 3-methylhistidine:creatinine ratio (3MH:CR). Salivary cortisol, testosterone, their ratio (T:C), and the cortisol awakening response were assessed. ANOVA was used to analyse all dependent variables, and linear mixed models were used to confirm the absence of carryover effects. Eleven participants (six females, five males) completed the study. Urinary HMB concentrations confirmed compliance with supplementation. 3MH:CR was unaffected by fasting and supplementation, but the cortisol awakening response differed between conditions. In both conditions, cortisol increased from awakening to 30 min post-awakening (P=0·01). Cortisol was reduced from 30 to 45 min post-awakening with HMB-FA (-32 %, d=-1·0, P=0·04), but not placebo (PL) (-6 %, d=-0·2, P=0·14). In males, T:C increased from 0 to 24 h of fasting with HMB-FA (+162 %, d=3·0, P=0·001), but not placebo (+13 %, d=0·4, P=0·60), due to reductions in cortisol. REE was higher at 24 h of fasting than 16 h of fasting independent of supplementation (+4·0 %, d=0·3, P=0·04). In conclusion, HMB-FA may affect cortisol responses, but not myofibrillar proteolysis, during acute 24-h fasting.

Sex differences in interleukin-6 stress responses in people with Type 2 diabetes

People with Type 2 diabetes (T2D) show dysregulated inflammatory responses to acute stress, but the effect of sex on inflammatory responses in T2D remains unclear. The purpose of this study was to investigate differences in interleukin (IL)-6 stress responses between older men and women with T2D. One hundred and twenty-one people (76 men; mean age = 64.09, SD = 7.35, 45 women; mean age = 63.20, SD = 6.70) with doctor-verified T2D took part in this laboratory-based stress testing study. Participants carried out acute mental stress tasks, and blood was sampled at baseline, immediately poststress, 45 min poststress, and 75 min poststress to detect plasma IL-6 concentrations. IL-6 change scores were computed as the difference between the baseline measurement and the three time points poststress. Main effects and interactions were tested using mixed model analysis of covariance. We found a significant main effect of time on IL-6 levels, and a significant Sex × Time interaction. In adjusted analyses including the three change scores and all the covariates, the significant Sex × Time interaction was maintained; IL-6 responses were greater in women at 45 and 75 min poststress compared with men, adjusting for age, body mass index, smoking, household income, glycated hemoglobin, oral antidiabetic medication, insulin/other injectable antidiabetic medication, depressive symptoms, and time of day of testing. Different inflammatory stress response pathways are present in men and women with T2D, with women producing larger IL-6 increases. The long-term implications of these differences need to be elucidated in future studies.

Cytokine secretion responsiveness of lymphomonocytes following cortisol cell exposure: Sex differences

The stress hormone cortisol has been recognized as a coordinator of immune response. However, its different ability to modulate the release of inflammatory mediators in males and females has not been clarified yet. Indeed, the dissection of cortisol specific actions may be difficult due to the complex hormonal and physio-pathological individual status. Herein, the release of inflammatory mediators following increasing cortisol concentrations was investigated in an in vitro model of primary human male and female lymphomonocytes. The use of a defined cellular model to assess sex differences in inflammatory cytokine secretion could be useful to exclude the effects of divergent and fluctuating sex hormone levels occurring in vivo. Herein, the cells were challenged with cortisol concentrations resembling the plasma levels achieving in physiological and stressful conditions. The production of cytokines and other molecules involved in inflammatory process was determined. In basal conditions, male cells presented higher levels of some pro-inflammatory molecules (NF-kB and IDO-1 mRNAs, IL-6 and kynurenine) than female cells. Following cortisol exposure, the levels of the pro-inflammatory cytokines, IL-6 and IL-8, were increased in male cells. Conversely, in female cells IL-6 release was unchanged and IL-8 levels were decreased. Anti-inflammatory cytokines, IL-4 and IL-10, did not change in male cells and increased in female cells. Interestingly, kynurenine levels were higher in female cells than in male cells following cortisol stimulus. These results highlighted that cortisol differently affects male and female lymphomonocytes, shifting the cytokine release in favour of a pro-inflammatory pattern in male cells and an anti-inflammatory secretion profile in female cells, opening the way to study the influences of other stressful factors involved in the neurohumoral changes occurring in the response to stress conditions.

O Uso de Biomarcadores em Pesquisas de Marketing

Resumo A aproximação do marketing com a neurociência tem gerado expectativa tanto na academia quanto no mercado, em especial na última década. Apesar do interesse e das promessas de resultados, lacunas de conhecimento neurobiológico são percebidas acerca de formas de coleta e análise de dados. Este estudo apresenta e compara algumas ferramentas neurocientíficas que são fundamentadas em respostas não cognitivas do cérebro humano. A coleta e a análise de biomarcadores, como hormônios e níveis de atividade elétrica muscular, podem ser utilizadas em pesquisas de comportamento humano relacionadas ao consumo ou em outras interações com ações de marketing. A metodologia de aplicação dessas ferramentas, medidas resultantes e possíveis interpretações de comportamento também são discutidas, com ênfase em futura agenda de pesquisa.

Stress and psychological constructs related to eating behavior are associated with anthropometry and body composition in young adults

BACKGROUND

The transition to college is associated with weight gain, but the relation between eating behavior indicators and anthropometric outcomes during this period remains unclear.

OBJECTIVE

We aimed to evaluate sex differences in stress, emotional eating, tendency to overeat, and restrained eating behavior, and determine whether the psycho-behavioral constructs assessed immediately prior to starting college are associated with anthropometry and adiposity at the start of college, and with first-semester weight gain.

METHODS

A prospective study administered the Three Factor Eating Questionnaire (TFEQ), Satter Eating Competence Inventory, and Perceived Stress Scale (PSS) to 264 participants one month before college. Body composition was assessed via dual energy X-ray absorptiometry (DXA) at the start of college, and anthropometry (weight, height, waist circumference [WC]) was collected at the beginning and end of the first semester. Ordinary least squares regression tested the cross-sectional association of baseline psychological and behavioral scales with baseline DXA and anthropometry, and the longitudinal association with change in anthropometry.

RESULTS

Among 264 participants, 91% (241) had baseline data, and 66% (173) completed follow-up. In sex-adjusted linear regression models, baseline TFEQ disinhibited and emotional (DE; EE) eating sub-scales were positively associated with baseline weight (P = 0.003; DE, P = 0.014; EE), body mass index (BMI, P = 0.002; DE, P = 0.001; EE), WC (P = 0.004; DE, P = 0.006; EE) and DXA fat mass index (P = 0.023; DE, P = 0.014; EE). Baseline PSS was positively associated with subsequent changes in weight and WC among males only (P_interaction = 0.0268 and 0.0017 for weight and WC, respectively).

CONCLUSION

College freshmen with questionnaire scores indicating a greater tendency to overeat in response to external cues and emotions tended to have greater weight, BMI, and WC at the start of college. Males with higher perceived stress at college entrance subsequently gained significantly more weight in the first semester, but no such relation was evident in females.

Hair cortisol in relation to acute and post-traumatic stress symptoms in children and adolescents

BACKGROUND

We report on the preliminary results of two independent studies that (1) compare the hair cortisol concentrations (HCC) of healthy controls with patients displaying post-traumatic stress symptoms (PTSS, study 1+2), (2) investigate whether pre-trauma HCC are predictive for the development of acute stress symptoms (ASS) and PTSS (study 1) and (3) determine whether HCC correlate with PTSS in a clinical sample of children (study 2).

METHODS

In study 1, the clinical symptoms of 35 minors were examined one (T1) and seven weeks (T2) after surgery following an accident. Hair samples were taken after the accident that reflect cortisol secretion over the past three months before the accident (healthy controls). In study 2, HCC and PTSS symptoms were cross-sectionally assessed in 22 minors who had experienced a psychological trauma.

RESULTS

The HCC of patients with PTSS were lower than the HCC of healthy controls (study 1+2). Secondary analyses showed that HCC were significantly lower in male PTSS patients than in male healthy controls, whereas the HCC in females were comparably low in both groups. Pre-trauma HCC did not predict the total ASS and PTSS scores (study 1) and HCC were not directly related to the total PTSS scores (study 2).

Advanced Parental Age Impaired Fear Conditioning and Hippocampal LTD in Adult Female Rat Offspring

Advanced maternal or paternal age is associated with increased risks of cognitive and emotional disorders. Chronic stress is also a common experience in human life that causes psychiatric diseases. However, the synergistic effects of these two factors on offspring are rarely studied. In the present study, the offspring of both young (3-4 months) and old (12-14 months) rat parents were given CUMS for 21 days at the age of 4 weeks. The effects of advanced parental age and chronic unpredictable mild stress (CUMS) on emotional and cognitive behaviors and the related cellular mechanisms were investigated by using behavioral and electrophysiological techniques. We found that CUMS decreased sucrose consumption, increased anxiety, and impaired learning and memory in offspring from both old and young breeders. However, advanced parental age impaired fear memory and spatial memory mainly in female offspring. The serum corticosterone of female offspring was lower than males, but advanced parental age significantly elevated serum corticosterone in female offspring in response to electrical foot shocks. In addition, hippocampal LTD was severely impaired in female offspring from older parents. Our results indicated that female offspring from older breeders might be more sensitive to stress, and the hippocampal function was more vulnerable. These results might provide experimental basis for the prevention and treatment of advanced parental age related psychiatric disorders in future.

Stress vulnerability in male youth with Internet Gaming Disorder

Internet Gaming Disorder [IGD] was introduced as new behavioral addiction in DSM-5 Section 3. Vulnerability to stress is a potential predisposing factor for IGD. Given a lack of preexisting empirical data, the study investigated differences in the psychological and neurobiological response to acute stress in patients with IGD. 24 young men (mean age 18.38 years; range 13-25 years) fulfilling DSM-5 criteria for IGD and 25 matched controls underwent the Trier Social Stress Test [TSST]. Participants provided hair samples for the analysis of basal hypothalamic-pituitary-adrenal [HPA] axis activity and clinical interviews were conducted to assess psychopathology. During the experiment, participants reported on their subjective stress experience and momentary affect, provided samples of salivary cortisol and their heart rate was continuously recorded. Patients with IGD reported greater everyday and chronic stress, as well as psychopathological comorbidity. No differences were found on measures of hair cortisol. Compared to controls, IGD patients showed an attenuated cortisol response (χ²₍₇₎=25.75, p<0.001) and greater negative affect (χ²₍₇₎=17.25, p=0.016) in response to acute stress. Heart rate (χ²₍₁₎=5.49, p=0.019), negative affect (χ²₍₁₎=5.60, p=0.018) and subjective stress (χ²₍₁₎=5.55, p=0.019) were transiently increased in IGD patients. After adjusting for sportive activities, IGD patients showed transiently decreased cortisol (χ²₍₁₎=5.20, p=0.022), potentially indicating general HPA-axis dysfunction beyond altered reactivity. Stress reactivity showed correlations with IGD symptom severity. Findings illustrate differences in acute psychological and neurobiological stress reactivity in patients with IGD. Alterations of the stress response system may be involved in the development and maintenance of IGD.

Reliability of Potential Pain Biomarkers in the Saliva of Healthy Subjects: Inter-Individual Differences and Intersession Variability

AIM

Salivary cortisol, α-amylase (sAA), secretory IgA (sIgA), testosterone, and soluble fraction of receptor II of TNFα (sTNFαRII) could serve as objective pain measures, but the normal variability of these potential biomarkers is unknown.

PATIENTS & METHODS

Saliva was collected with the passive secretion method from 34, pain-free subjects in two single samples at least 24 hours apart. Biomarker variation and intersession reliability were assessed with the intraclass correlation coefficient (ICC). Also, we calculated the within-subject standard deviation (Sw) and the reproducibility (2.77 × Sw) of intersession measures.

RESULTS

Salivary cortisol, sAA, sIgA, testosterone, and sTNFαRII yielded the following ICCs: 0.53, 0.003, 0.88, 0.42 and 0.83, respectively. We found no statistically significant systematic differences between sessions in any biomarker except for testosterone, which showed a decrease on the second day (p<0.001). The reproducibility for salivary cortisol, sAA, sIgA, testosterone, and sTNFαRII were 0.46 ng/ml, 12.88 U/ml, 11.7 μg/ml, 14.54 pg/ml and 18.29 pg/ml, respectively. Cortisol, testosterone and TNFαRII measurement variability showed a positive correlation with the magnitude (p<0.002), but no relationship was found for sAA and sIgA.

CONCLUSIONS

Salivary sIgA and sTNFαRII show a remarkable good reproducibility and, therefore, could be useful as pain biomarkers. When using the passive secretion method, intersession variations in salivary sIgA of more than 11.7 μg/ml may reflect true biomarker change. In the case of sTNFαRII this will depend of the magnitude. The estimates herein provided should help investigators and clinicians differentiate actual biomarker modification from measurement variability.

Evolution of Sex Differences in Trait- and Age-Specific Vulnerabilities

Traits that facilitate competition for reproductive resources or that influence mate choice generally have a heightened sensitivity to stressors. They have evolved to signal resilience to infectious disease and nutritional and social stressors, and they are compromised by exposure to man-made toxins. Although these traits can differ from one species or sex to the next, an understanding of the dynamics of competition and choice can in theory be used to generate a priori predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species. I provide a review of these dynamics and illustrate associated vulnerabilities in nonhuman species. The age- and sex-specific vulnerability of such traits is then illustrated for stressor-related disruptions of boys’ and girls’ physical growth and play behavior, as well as for aspects of boys’ and girls’ and men’s and women’s personality, language, and spatial abilities. There is much that remains to be determined, but enough is now known to reframe trait sensitivity in ways that will allow scientists and practitioners to better identify and understand vulnerable human traits, and eventually ameliorate or prevent their expression.

Could Watching TV Be Good for You? Examining How Media Consumption Patterns Relate to Salivary Cortisol

This research explores whether media diet influences health, not through its effects on cognition and behavior but rather through its effects on biomarkers of stress, which are implicated in a host of acute and chronic illnesses. Two hundred and forty young adults completed assessments of their media consumption habits followed at least 2 days later by measures of the stress-related hormone cortisol. Results suggest that frequency of consuming different media and genres may decrease cortisol under certain conditions and increase them under others. Further, the patterns of results were wholly different from those found for perceived stress. The implications of these findings for health-related media effects and theoretical development are discussed.

The Effect of 20 Minutes Scuba Diving on Cognitive Function of Professional Scuba Divers

BACKGROUND

Physical activity increases the performance of the nervous system by stimulating the body's metabolism and improving the efficiency of the ATP production system.

OBJECTIVES

In the present study, the effect of twenty minutes scuba diving in high depth (10m) on cognitive function and stress system activity was investigated.

METHODS

Twelve professional scuba divers with a mean age of 23 ± 1 year, weight of 80 ± 2.5 kg and height of 1.79 ± 3.5 cm resident in the city of Mashhad participated in the test. Their cognitive functions were measured 60 min before and 20 min after diving and the data were evaluated using the PASAT software. In the present study, parameters such as general mental health, sustained attention, average response speed, and mental fatigue were measured. Moreover, in order to determine the activity of the stress system, their salivary cortisol was collected before and after diving.

RESULTS

Results revealed that, the general mental health of these scuba divers was normal and it did not undergo a remarkable change after diving. Their average response speed and sustained attention had a significant decrease after scuba diving. Mental fatigue after diving increased. Also, salivary cortisol level significantly increased after diving.

CONCLUSIONS

According to our data, it seems that scuba diving as stress stimulant increases cortisol level and therefore reduces cognitive performance after diving.

Corticotropin-releasing factor increases ascending colon volume after a fructose test meal in healthy humans: a randomized controlled trial

BACKGROUND

Poorly absorbed fermentable carbohydrates can provoke irritable bowel syndrome (IBS) symptoms by escaping absorption in the small bowel and being rapidly fermented in the colon in some susceptible subjects. IBS patients often are anxious and stressed, and stress accelerates small bowel transit, which may exacerbate malabsorption.

OBJECTIVE

In this study we investigated the effect of an intravenous injection of corticotropin-releasing factor (CRF) on fructose malabsorption and the resulting volume of water in the small bowel.

DESIGN

We performed a randomized, placebo-controlled crossover study of CRF compared with saline injection in 11 male and 10 female healthy subjects, examining the effect on the malabsorption of a 40-g fructose test meal and its transit through the gut, which was assessed by serial MRI and breath hydrogen measurement. Orocecal transit was assessed with the use of the lactose [(13)C]ureide breath test and the adrenal response to CRF was assessed by serial salivary cortisol measurements.

RESULTS

CRF injection caused a significant increase in salivary cortisol, which lasted for 135 min. Small bowel water content (SBWC) rose from baseline, peaking at 45 min after fructose ingestion, whereas breath hydrogen peaked later, at 75 min. The area under the curve for SBWC from -15 min to 135 min was significantly lower after CRF compared with saline [mean difference: 5911 mL · min (95% CI: 18.4, 11,803 mL · min), P = 0.049]. Considering all subjects, the percentage change in ascending colon volume rose significantly after CRF. This increase was significant for male (P = 0.026), but not female, volunteers.

CONCLUSIONS

CRF constricts the small bowel and increases fructose malabsorption, as shown by increased ascending colon volumes. This mechanism may help to explain the increased sensitivity of some stressed individuals to fructose malabsorption. This trial was registered at clinicaltrials.gov as NCT01763281.

The Influences of Daily Stressors on Morning Cortisol Levels in Midlife and Older Retirees: The Moderating Roles of Age and Gender

Objectives: This study extends the field of retirement and health by examining the impacts of daily stressors on morning cortisol levels in 253 retirees between 55 and 75 years of age ( M = 66.80, SD = 4.96) and the moderating roles of age and gender. Method: Participants derived from the second wave of the Daily Diary Study portion of the National Survey of Midlife Development in the United States (MIDUS-II). Across eight consecutive evenings, participants completed telephone interviews about their daily experiences and provided saliva samples across 4 days. Results: Findings from the multilevel models showed that in the context of navigating the day-to-day responsibilities, older retirees were at a greater risk for subsequent hypothalamic pituitary adrenal (HPA) dysregulation than younger retirees. Discussion: Together, better identification of the associations between daily stressors and physiological functioning will help contribute to the knowledge on ways to promote greater quality of life in retirement.

Biologic effects of stress and bonding in mother-infant pairs

OBJECTIVE

Maternal stress in humans influences behavior of children and can be assessed using biological markers. Mothers and their one-month-old infants were recruited from an existing study to examine baseline maternal serum oxytocin and hypothalamic-pituitary-adrenal axis response to infant blood heel stick stress as measured by salivary cortisol in the dyads. Objectives were to explore (1) relationships between mother and infant cortisol levels, (2) gender differences in infant biologic cortisol response, and (3) the association of cortisol levels in the dyads and maternal oxytocin levels

METHODS

Forty-two mother-infant dyads provided biologic samples and self-report data. Maternal oxytocin samples were obtained. Initial salivary cortisol was assessed in both the mother and infant, followed by a heel stick blood draw. Twenty minutes later, salivary cortisol was collected again from dyads.

RESULTS

Self-report measures were negative for depression and risk for childhood neglect. Although oxytocin and baseline cortisol in the infants was higher in mothers that did some breast-feeding, there was no statistically significant difference (p = 0.2 and p = 0.1, respectively). Analyses showed (a) higher baseline cortisol in mothers was related to higher baseline cortisol in infants (p ≤ 0.0001), (b) following the stressor, female infants had a larger positive change in cortisol, after adjusting for baseline cortisol (p = 0.045), and (c) there was no relationship between dyad cortisol levels and maternal oxytocin.

CONCLUSIONS

Maternal and infant biologic stress measures are related. Female infants have a larger hypothalamic-pituitary-adrenal response to a blood draw stressor as measured by salivary cortisol than male infants.

Stressful Life Events and Risk of Depression 25 Years Later: Race and Gender Differences

BACKGROUND

Although stressful life events (SLEs) predict subsequent risk of developing a major depressive episode (MDE), limited information exists on whether or not race and gender alters the predictive role of SLE on risk of MDE over a long-term period. The current study explored race and gender differences in the long-term predictive role of SLE at baseline (1986) on subsequent risk of MDE 25 years later (2011) in a nationally representative cohort in the United States.

METHODS

Using a life course epidemiological approach, this longitudinal study borrowed data from the Americans' Changing Lives (ACL) Study 1986-2011. Main predictor of interest was baseline SLE over the last 3 years measured at 1986. Main outcome was risk of MDE [Composite International Diagnostic Interview (CIDI)] 25 years later (2011). Covariates included demographics, socioeconomics, depressive symptoms [Center for Epidemiological Studies-Depression Scale (CES-D)], chronic medical conditions, and health behaviors measured at baseline (1986). Gender and race were the focal moderators. We employed logistic regressions in the pooled sample, and specific to race and gender, to test whether or not SLE × race and SLE × gender interactions are significant.

RESULTS

In the pooled sample, baseline SLE (1986) predicted risk of MDE 25 years later (2011). We also found a gender by SLE interaction, suggesting a stronger predictive role of SLE for subsequent clinical depression for men compared to women. Race did not modify the predictive role of SLE on subsequent risk of MDE 25 years later.

CONCLUSION

How SLE predicts MDE 25 years later differs for men and women, with a stronger predictive role for men compared to women. More research is needed to better understand the complex links between gender, sex, stress, and depression.

Family conflict and lower morning cortisol in adolescents and adults: modulation of puberty

We aimed to explore the association between family conflict and HPA axis activity, especially with respect to the potential modulating effect of puberty. A total of 205 adolescents and 244 adult parents were recruited. Family conflict was assessed by the family conflict subscale of the Family Environmental Scale and serial salivary cortisol was measured in all participants. A marginally lower AUCg at 30 minutes after wake up in the morning and a significant lower AUCg at 60 minutes and 90 minutes in adult parents with high family conflict was found when compared to those with low family conflict. In adolescents, there were significant interaction effects between pubertal status and family conflict on AUCg (interaction p values <0.05). Among the adolescents with low family conflict, those at late/post pubertal status had higher AUCg than their pre/early pubertal counterparts but this difference was not observed in the adolescents with high family conflict. Adverse family environment is associated with HPA axis dysfunction in adults and late/post pubertal adolescents and pubertal maturation plays a critical role in modulating the association between family environment and HPA axis function.

Personality, Executive Control, and Neurobiological Characteristics Associated with Different Forms of Risky Driving

Background

Road crashes represent a huge burden on global health. Some drivers are prone to repeated episodes of risky driving (RD) and are over-represented in crashes and related morbidity. However, their characteristics are heterogeneous, hampering development of targeted intervention strategies. This study hypothesized that distinct personality, cognitive, and neurobiological processes are associated with the type of RD behaviours these drivers predominantly engage in.

Methods

Four age-matched groups of adult (19–39 years) males were recruited: 1) driving while impaired recidivists (DWI, n = 36); 2) non-alcohol reckless drivers (SPEED, n = 28); 3) drivers with a mixed RD profile (MIXED, n = 27); and 4) low-risk control drivers (CTL, n = 47). Their sociodemographic, criminal history, driving behaviour (by questionnaire and simulation performance), personality (Big Five traits, impulsivity, reward sensitivity), cognitive (disinhibition, decision making, behavioural risk taking), and neurobiological (cortisol stress response) characteristics were gathered and contrasted.

Results

Compared to controls, group SPEED showed greater sensation seeking, disinhibition, disadvantageous decision making, and risk taking. Group MIXED exhibited more substance misuse, and antisocial, sensation seeking and reward sensitive personality features. Group DWI showed greater disinhibition and more severe alcohol misuse, and compared to the other RD groups, the lowest level of risk taking when sober. All RD groups exhibited less cortisol increase in response to stress compared to controls.

Discussion

Each RD group exhibited a distinct personality and cognitive profile, which was consistent with stimulation seeking in group SPEED, fearlessness in group MIXED, and poor behavioural regulation associated with alcohol in group DWI. As these group differences were uniformly accompanied by blunted cortisol stress responses, they may reflect the disparate behavioural consequences of dysregulation of the stress system. In sum, RD preference appears to be a useful marker for clarifying explanatory pathways to risky driving, and for research into developing more personalized prevention efforts.

Stress psychobiology in the context of addiction medicine: from drugs of abuse to behavioral addictions

In this chapter, we briefly review the basic biology of psychological stress and the stress response. We propose that psychological stress and the neurobiology of the stress response play in substance use initiation, maintenance, and relapse. The proposed mechanisms for this include, on the one hand, the complex interactions between biological mediators of the stress response and the dopaminergic reward system and, on the other hand, mediators of the stress response and other systems crucial in moderating key addiction-related behaviors such as endogenous opioids, the sympathetic-adrenal-medullary system, and endocannabinoids. Exciting new avenues of study including genomics, sex as a moderator of the stress response, and behavioral addictions (gambling, hypersexuality, dysfunctional internet use, and food as an addictive substance) are also briefly presented within the context of stress as a moderator of the addictive process.

Stress-induced cortisol is associated with generation of non-negative interpretations during cognitive reappraisal

Background

Enhanced processing of emotional stimuli after stress exposure is reported to be associated with stress-induced cortisol. Because enhanced emotional information processing could make cognitive emotion regulation more difficult, it was hypothesized that stress-induced cortisol would be associated with non-negative interpretation generation associated with the cognitive reappraisal processes.

Methods

A total of 36 participants (Mean age = 21.3 years, SD = 1.8) watched video clips of depression-related stressful situations before and after the administration of a stress induction task. They were then asked to generate as many non-negative interpretations as possible to reduce the depressive mood. Saliva samples were obtained before and after the stress induction task to measure change in the cortisol level.

Results

Participants were allocated post-hoc to either a responder (n = 19) or non-responder group (n = 17) based on the cortisol response to the stress induction task. The number of non-negative interpretations generated following the stress induction task was reduced only in the cortisol responders. The number of post-stress non-negative interpretations was fewer in the responder group when compared by sex, baseline cortisol level, and the number of pre-stress non-negative interpretations, statistically controlled.

Conclusions

Although baseline cortisol and sex may have impacted the results, the results suggest that stress-induced cortisol is associated with difficulty in non-negative interpretation generation during the cognitive reappraisal process.

Effects of season, age, sex, and housing on salivary cortisol concentrations in horses

Analysis of salivary cortisol is increasingly used to assess stress responses in horses. Because spontaneous or experimentally induced increases in cortisol concentrations are often relatively small for stress studies, proper controls are needed. This requires an understanding of the factors affecting salivary cortisol over longer times. In this study, we have analyzed salivary cortisol concentration for 6 mo in horses (n = 94) differing in age, sex, reproductive state, and housing. Salivary cortisol followed a diurnal rhythm with the highest concentrations in the morning and a decrease throughout the day (P < 0.001). This rhythm was disrupted in individual groups on individual days; however, alterations remained within the range of diurnal changes. Comparison between months showed highest cortisol concentrations in December (P < 0.001). Cortisol concentrations increased in breeding stallions during the breeding season (P < 0.001). No differences in salivary cortisol concentrations between nonpregnant mares with and without a corpus luteum existed. In stallions, mean daily salivary cortisol and plasma testosterone concentrations were weakly correlated (r = 0.251, P < 0.01). No differences in salivary cortisol between female and male young horses and no consistent differences between horses of different age existed. Group housing and individual stabling did not affect salivary cortisol. In conclusion, salivary cortisol concentrations in horses follow a diurnal rhythm and are increased in active breeding sires. Time of the day and reproductive state of the horses are thus important for experiments that include analysis of cortisol in saliva.

Rapid comparison of metabolites in humans and rats of different sexes using untargeted UPLC-TOFMS and an in-house software platform

Metabolite differences between sexes have rarely been observed in a global manner, but it has recently been made possible by the advancement in metabolomics techniques. In this study, untargeted ultraperformance liquid chromatography coupled to time-of-flight mass spectrometry and an in-house software platform were used for a rapid comparison of sex differences in urinary metabolites in humans and in urinary and serum metabolites in Sprague Dawley (SD) rats. In addition, the species differences of urinary metabolites between humans and SD rats were also observed. Principle component analysis showed that all the observed metabolite sex differences were more distinct in SD rats than in humans, indicating that the sex differences of human urinary metabolites is small compared with that of SD rats. In SD rats, the observed metabolite sex differences were more distinct in urine than in serum, indicating the importance of urine analysis for metabolomics studies. The species differences in the urinary metabolites of humans and SD rats were much more distinct than any of the observed sex differences. Many sex- and species-related markers were discovered and putatively identified. In both humans and SD rats, steroid metabolites appeared to constitute a major sex difference in urinary metabolites. This provides new proof of the special importance of steroid metabolites in sex differences from an untargeted metabolomics investigation, which is rare for sex differences. Contrary patterns involving adrenocortical activity appeared to exist between rodents and humans, which agrees with previous reports. In the serum metabolites of SD rats, sex differences in ascorbic acid or its isomer and pantothenic acid or its isomer, but not in steroid metabolites, were prominent. Human-specific α-N- phenylacetyl-l-glutamine and androsterone glucuronide were among the putative identities of the markers discriminating humans and SD rats. This study demonstrated the feasibility of an in-house software platform and provides metabolite-related information on sex and species differences.

Long-term impact of earthquake stress on fasting glucose control and diabetes prevalence among Chinese adults of Tangshan

OBJECTIVE

To investigate the long-term influence of stresses from the 1976 Tangshan earthquake on blood glucose control and the incidence of diabetes mellitus in Chinese people of Tangshan.

METHODS

1,551 adults ≥ 37 years of age were recruited for this investigation in Tangshan city of China, where one of the deadliest earthquakes occurred in 1796. All subjects finished a questionnaire. 1,030 of them who experienced that earthquake were selected into the exposure group, while 521 were gathered as the control group who have not exposed to any earthquake. The numbers of subjects who were first identified with diabetes or had normal FBG but with diabetic history were added for the calculation of diabetes prevalence. Statistic-analysis was applied on the baseline data, and incidences of IFG as well as diabetes among all groups.

RESULTS

Statistic comparisons indicate there is no significant difference on average fasting glucose levels between the control group and the exposure group. However, the prevalence of IFG and diabetes among the exposure group displays significant variance with the control group. The prevalence of diabetes among exposure groups is significantly higher than the control group. Women are more likely to have diabetes after experiencing earthquake stresses compared to men. The earthquake stress was linked to higher diabetes incidence as an independent factor.

CONCLUSIONS

The earthquake stress has long-term impacts on diabetes incidence as an independent risk factor. Emerging and long-term managements regarding the care of IFG and diabetes in populations exposed to earthquake stress should be concerned.