Public speaking stress-induced neuroendocrine responses and circulating immune cell redistribution in irritable bowel syndrome

Emotional stress responsivity of patients with IBS - a systematic review

OBJECTIVE

Irritable bowel syndrome (IBS) is a highly prevalent disorder of the gut-brain interaction characterized by abdominal discomfort and pain associated with altered bowel habits in the absence of structural abnormalities. Chronic psychological stress is considered a risk factor for the development of IBS. The multifactorial pathogenesis involves complex interactions between biological, psychological and social factors, yet the underlying mechanisms have not been fully understood.

METHODS

We systematically reviewed the literature from the databases MEDLINE, Embase and PsycINFO to assess stress responsivity of patients with IBS in comparison to healthy individuals, specifically focusing acute psychological stressors.

RESULTS

A total of 37 case-control studies were included in the narrative synthesis. Findings comprised subjective changes in emotion (k = 18) and of gastrointestinal symptoms (k = 8) as well as objective parameters of gastrointestinal motility (k = 10), autonomic nervous system (k = 23), hypothalamic-pituitary-adrenal axis (k = 11), functional brain activity (k = 7) and immune system (k = 3). Mental stress was found to increase IBS-specific symptomatology and alter gastrointestinal motility. Some patients with IBS showed stress-induced emotional hyperresponsivity and different patterns of neural activation. Autonomic and endocrine stress responses depend on the type of stressor and showed no clear evidence of differential reactivity, partly due to confounding factors. Data on acute immunological changes remains sparse and requires further investigation.

CONCLUSIONS

Current evidence suggests altered stress reactivity in patients with IBS however, it remains unclear whether it can be attributed to the syndrome itself or the high prevalence of psychiatric comorbidities.

A mindfulness group intervention in newly diagnosed persons with multiple sclerosis: A pilot study

BACKGROUND

Relapsing MS (RMS) is a lifelong disease without a cure, usually diagnosed between 20-40 years of age. Being newly diagnosed with RMS is a highly stressful event due to the unpredictable disease course after diagnosis. Thus, it is imperative that persons with MS have the skills and support to cope with the negative physical and emotional effects of the disease. The objective of this study was to assess whether a mindfulness-based intervention (MBI) would improve coping skills and thus lessen the negative consequences of stress due to being newly diagnosed with RMS.

METHODS

This was a single-blind (assessor), randomized, prospective study of a 10-week MBI vs. usual standard of care in persons newly diagnosed (within 1 year) with RMS, recruited from one tertiary care MS clinic in London (ON), Canada. The MBI was administered in group format with a trained MBI facilitator. Primary outcomes included the Brief COPE measure and the Hospital Anxiety and Depression Scale (HADS) subscales. Secondary outcomes included measures of perceived stress, cognitive function, fatigue, and quality of life. Exploratory (tertiary) outcomes included serum markers of inflammation and stress. Subjects were assessed at baseline, post intervention (or equivalent) and 6 months later. A repeated measures multivariate analysis of covariance (MANCOVA) was used, with baseline scores employed as covariates and the test scores, to compare longitudinal changes, immediately after the MBI sessions and 6 months later.

RESULTS

Twenty-five subjects were recruited (16 MBI, 9 controls) for two (Fall and Spring) MBI interventions over 1.5 years. All controls completed the study, while 4 MBI participants did not, leaving 21 subjects in the analysis. Most were women (17, 81%), with a mean age of 37.1 ± 9.4 years. Two thirds had already started a DMT at the time of consent; the median EDSS was 2.0 (0.0-4.0). The groups were well matched on baseline characteristics, with the exception of months since diagnosis (MBI 6.4 ± 6.5 vs. control 3.6 ± 2.8, p=0.023). All controls completed the study, while 4 MBI participants did not. The MBI group improved significantly on the COPE measure when compared to the control group (p=0.024) pre and post intervention; the MBI group also improved significantly on the HADS depression subscale (p=0.007). There was no significant difference over time on the HADS anxiety subscale (p=0.179). The effect size on COPE was 0.56 and 0.40 on HADS-D. On the secondary outcomes, there was a significant improvement on the Perceived Stress Scale (p=0.015). The exploratory outcomes were not significantly different. None of the outcomes were significant at the six-month follow-up.

CONCLUSION

This pilot study demonstrates that an MBI may improve coping, depression and perceived stress in newly diagnosed (within one year) persons with RMS in the short term. Future research to confirm these results, as well as further investigate measures to extend the benefit beyond the immediate intervention.

Low self-reported stress despite immune-physiological changes in paramedics during rescue operations

Despite the high stress levels, paramedics seem to ignore or even negate the stress. This can be detrimental and lead to stress-related diseases. Therefore, we investigated the divergence between physiological and psychological stress responses of paramedics. Participants were 16 paramedics and 17 white-collar workers. We assessed psychological stress parameters, cortisol awakening response (CAR), and quantified immune parameters. In paramedics, electrocardiogram (ECG) was measured during one complete 24-hour shift. Our results revealed that CAR was higher in paramedics compared to controls. An alteration of immune parameters was observed even during days of free time. Also, ECG recordings showed acute stress in paramedics during rescue situations. Questionnaires revealed that rescue-service specific stressors affect psychological outcomes. However, paramedics reported significantly less mental stress and higher levels of depersonalization than controls. Taken together, our results suggest higher stress in paramedics compared to controls. However, paramedics negate their daily stress. Our findings underline therefore the importance to develop stress-management interventions for paramedics including sensitization for their stress reactions.

Concordant pattern of the HPA axis response to visceral stimulation and CRH administration

The physiological and psychological mechanisms explaining the individual variability in the stress response are poorly understood. We tested the hypothesis that hypothalamic-pituitary- adrenal (HPA) axis responses to colorectal stimulation affect HPA axis reactivity to corticotropin-releasing hormone (CRH), the visceral pain threshold, and perceived stress. We examined 31 healthy volunteers and 27 individuals with irritable bowel syndrome. According to the ACTH response to colorectal stimulation, the participants were classified into three groups: flattened, decreased, and increased. We found significant differences in the abdominal pain threshold, discomfort threshold, and sensitivity to anxiety among the groups. There were significant differences in the ACTH change and peak level after CRH administration among the groups. The area under the curve of the cortisol response to CRH was significantly different among the groups. The increased group showed a higher basal ACTH level, earlier peak level in the CRH administration test, and higher stress rating during the experiment. The increased group had an exaggerated psychological and physiological stress response, whereas the decreased group had a higher anticipatory endocrine response, stress, and sensitivity to anxiety. Further studies are needed to determine factors including gut microbiota on the individual difference in HPA response.

Manipulating Levels of Socially Evaluative Threat and the Impact on Anticipatory Stress Reactivity

Previous work suggests that relative increases in socially evaluative threat modulate the psychobiological stress response. However, few studies have compared stressors which manipulate the level of socially evaluative threat to which the participant is exposed. Here we present two studies. In the first, we assessed the integrity of an ecologically valid, laboratory stressor (direct socially evaluated multitasking) and its effects on acute psychobiological reactivity and ability to evoke an anticipatory response prior to participation. Specifically, we assessed whether the expectation and experience of direct social evaluation (multitasking while standing and facing an evaluator) evokes greater reactivity than indirect evaluation (over-the-shoulder evaluation). In the second study, we sought to replicate the findings regarding acute stress reactivity whilst extending the assessment window to assess the extent to which the stressor evokes anticipatory responses. As hypothesized, greater reactivity was observed following direct social evaluation compared with indirect observation. Increases in anxiety, heart rate and blood pressure were demonstrated across both studies and the paradigm therefore provides an ecologically valid technique for the activation of psychological and cardiovascular stress responding. Additionally, anticipation of experiencing socially evaluated multitasking led to increases in anxiety, tension, and worry prior to the event itself, supporting previous suggestions that threat anticipation may prolong the activation of stress mechanisms. In the present studies we assessed whether the expectation and experience of direct social evaluation evokes greater reactivity than indirect evaluation. The findings have demonstrated that direct social evaluation of multitasking is a more potent stressor than multitasking with indirect evaluation. Furthermore, our findings indicate that the period of anticipation of stressful events may be critical to understanding the process of stress regulation, and as such we recommend extending the sampling window to allow for the investigation of these processes.

Stress and the brain-gut axis in functional and chronic-inflammatory gastrointestinal diseases: A transdisciplinary challenge

The broad role of stress in the brain-gut axis is widely acknowledged, with implications for multiple prevalent health conditions that are characterized by chronic gastrointestinal symptoms. These include the functional gastrointestinal disorders (FGID), such as irritable bowel syndrome and functional dyspepsia, as well as inflammatory bowel diseases (IBD) like ulcerative colitis and Crohn's disease. Although the afferent and efferent pathways linking the gut and the brain are modulated by stress, the fields of neurogastroenterology and psychoneuroendocrinology (PNE)/ psychoneuroimmunology (PNI) remain only loosely connected. We aim to contribute to bringing these fields closer together by drawing attention to a fascinating, evolving research area, targeting an audience with a strong interest in the role of stress in health and disease. To this end, this review introduces the concept of the brain-gut axis and its major pathways, and provides a brief introduction to epidemiological and clinical aspects of FGIDs and IBD. From an interdisciplinary PNE/PNI perspective, we then detail current knowledge regarding the role of chronic and acute stress in the pathophysiology of FGID and IBD. We provide an overview of evidence regarding non-pharmacological treatment approaches that target central or peripheral stress mechanisms, and conclude with future directions, particularly those arising from recent advances in the neurosciences and discoveries surrounding the gut microbiota.

Negative Events During Adulthood Are Associated With Symptom Severity and Altered Stress Response in Patients With Irritable Bowel Syndrome

BACKGROUND & AIMS

Irritable bowel syndrome (IBS) is a stress-sensitive disorder associated with dysregulation of the hypothalamic-pituitary-adrenal axis. We studied the cumulative effect of events during adulthood on this pathway in patients with IBS.

METHODS

We studied 129 patients with IBS, based on Rome III criteria (mean age 28.1 years, 66% women), and 108 healthy individuals (controls; mean age 29.8 years, 60% women) who completed the Life Experiences Survey from August 2013 to September 2017. Data were collected on the presence and effects of events since age 18, IBS severity scores, and IBS-related quality of life. For a subset of subjects, we measured serum cortisol and adrenocorticotropic hormone (ACTH) production in response to administration of corticotropin-releasing factor and ACTH.

RESULTS

Compared with controls, patients with IBS perceived more adulthood life events as negative and had a significantly higher negative life event impact score (14.17 ± 12.04 vs 10.83 ± 9.98; P=.022). In patients with IBS, the presence of more-negatively perceived adulthood life events was associated with worse IBS symptom severity (β = 1.53, 95% CI, 0.21-2.84; P = .025) and IBS-related quality of life (β = -0.70; 95% CI, -1.02 to -0.38; P < .001). Negatively perceived adulthood life events were associated with reduced production of ACTH in response to corticotropin-releasing factor in patients with IBS compared with controls (P < .05).

CONCLUSION

In a study of more than 200 subjects, we associated more-negatively perceived events during adulthood with an increased risk for IBS, worse symptom severity and quality of life, and a dysregulated stress response. Understanding the effects of events that cause stress in adults and their perceived effects on IBS may help guide disease management.

Effects of acute psychological stress on placebo and nocebo responses in a clinically relevant model of visceroception

There is evidence to suggest a role of emotions in placebo and nocebo effects, but whether acute psychological stress changes the magnitude of placebo or nocebo responses has not been tested. In a clinically relevant model of visceroception, we assessed effects of acute psychological stress on changes in urgency and pain in response to positive or negative treatment suggestions. In 120 healthy volunteers, perceived urge-to-defecate and pain in response to individually calibrated rectal distensions were measured with visual analogue scales during a BASELINE. Participants then underwent the Trier Social Stress Test (N = 60) or a simple cognitive task (control, N = 60) and were randomized to positive (placebo), negative (nocebo), or neutral treatment information regarding intravenous administration of saline. The series of distensions was repeated, and changes in visual analogue scales from BASELINE to TEST were compared between groups using analysis of covariance and planned post hoc tests. Treatment information emerged as a main factor (P <0.001), supporting treatment information effects for both urgency and pain. Effects for urgency were modulated by stress (interaction effect: P <0.05): Positive information reduced urgency (P = 0.025), while negative information increased urgency (P = 0.026) only in stressed groups. For pain, effects of stress emerged for nocebo responses, which were only evident in stressed groups (P = 0.009). This is the first experimental study supporting effects of acute psychological stress on placebo and nocebo responses in visceroception. Results call for mechanistic as well as patient studies to assess how psychological stress shapes patients' treatment expectations and thereby affects health outcomes.

Current insights into the innate immune system dysfunction in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional bowel disorder associated with abdominal pain and alterations in bowel habits. The presence of IBS greatly impairs patients' quality of life and imposes a high economic burden on the community; thus, there is intense pressure to reveal its elusive pathogenesis. Many etiological mechanisms have been implicated, but the pathophysiology of the syndrome remains unclear. As a result, novel drug development has been slow and no pharmacological intervention is universally accepted. A growing evidence implicates the role of low-grade inflammation and innate immune system dysfunction, although contradictory results have frequently been presented. Mast cells (MC), eosinophils and other key immune cells together with their mediators seem to play an important role, at least in subgroups of IBS patients. Cytokine imbalance in the systematic circulation and in the intestinal mucosa may also characterize IBS presentation. Toll-like receptors and their emerging role in pathogen recognition have also been highlighted recently, as dysregulation has been reported to occur in patients with IBS. This review summarizes the current knowledge regarding the involvement of any immunological alteration in the development of IBS. There is substantial evidence to support innate immune system dysfunction in several IBS phenotypes, but additional studies are required to better clarify the underlying pathogenetic pathways. IBS heterogeneity could potentially be attributed to multiple causes that lead to different disease phenotypes, thus explaining the variability found between study results.

The stress concept in gastroenterology: from Selye to today

More than eighty years after Hans Selye (1907-1982) first developed a concept describing how different types of environmental stressors affect physiological functions and promote disease development (called the "general adaptation syndrome") in 1936, we herein review advances in theoretical, mechanistic, and clinical knowledge in stress research, especially in the area of gastroenterology, and summarize progress and future perspectives arising from an interdisciplinary psychoneurobiological framework in which genetics, epigenetics, and other advanced ( omics) technologies in the last decade continue to refine knowledge about how stress affects the brain-gut axis in health and gastrointestinal disease. We demonstrate that neurobiological stress research continues to be a driving force for scientific progress in gastroenterology and related clinical areas, inspiring translational research from animal models to clinical applications, while highlighting some areas that remain incompletely understood, such as the roles of sex/gender and gut microbiota in health and disease. Future directions of research should include not only the genetics of the stress response and resilience but also epigenetic contributions.

Effect of prolonged stress on the adrenal hormones of individuals with irritable bowel syndrome

Background

The purpose of this study was to investigate the effect of prolonged stress on the salivary adrenal hormones (cortisol, dehydroepiandrosterone [DHEA], DHEA-sulfate [DHEA-S]) of individuals with irritable bowel syndrome (IBS).

Methods

The participants were female college students, including 10 with IBS and 16 without IBS (control group), who were scheduled for a 2-week teaching practice at a kindergarten. Participants were asked to collect saliva for determining adrenal hormones immediately and 30 min after awakening and before sleep, 2 weeks before the practice, the first week of the practice, the second week of the practice, and a few days after the practice.

Results

Regarding cortisol/DHEA ratio, significantly increased levels were found during the first week of the practice, and a significant interaction between group and time was found; the ratio at 30 min after awakening in the IBS group was higher than that in the control group. For the other adrenal hormone indexes, no significant differences due to the presence of IBS were found.

Conclusions

Individuals with IBS showed an elevated cortisol/DHEA ratio after awakening compared with individuals without IBS, and the elevated ratio peaked under the prolonged stress. The present study suggests that the cortisol effect is dominant in individuals with IBS under prolonged stress.

A sustained hypothalamic-pituitary-adrenal axis response to acute psychosocial stress in irritable bowel syndrome

BACKGROUND

Despite stress being considered a key factor in the pathophysiology of the functional gastrointestinal (GI) disorder irritable bowel syndrome (IBS), there is a paucity of information regarding the ability of IBS patients to respond to acute experimental stress. Insights into the stress response in IBS could open the way to novel therapeutic interventions. To this end, we assessed the response of a range of physiological and psychological parameters to the Trier Social Stress Test (TSST) in IBS.

METHOD

Thirteen female patients with IBS and 15 healthy female age-matched control participants underwent a single exposure to the TSST. Salivary cortisol, salivary C-reactive protein (CRP), skin conductance level (SCL), GI symptoms, mood and self-reported stress were measured pre- and post-exposure to the TSST.

RESULTS

The hypothalamic-pituitary-adrenal (HPA) axis response to the TSST was sustained in IBS, as shown by a greater total cortisol output throughout (p = 0.035) and higher cortisol levels measured by an area under the curve with respect to ground (AUCG) analysis (p = 0.044). In IBS patients, GI symptoms increased significantly during the recovery period following exposure to the TSST (p = 0.045). Salivary CRP and SCL activity showed significant changes in relation to stress but with no differential effect between experimental groups.

CONCLUSIONS

Patients with IBS exhibit sustained HPA axis activity, and an increase in problematic GI symptoms in response to acute experimental psychosocial stress. These data pave the way for future interventional studies aimed at identifying novel therapeutic approaches to modulate the HPA axis and GI symptom response to acute psychosocial stress in IBS.

Peri-transplant psychosocial factors and neutrophil recovery following hematopoietic stem cell transplantation

Objective

Multiple psychosocial factors appear to affect cancer progression in various populations; however, research investigating the relationship between psychosocial factors and outcomes following hematopoietic stem cell transplantation (HCT) is scarce. Subject to adverse immunological and psychological conditions, HCT patients may be especially vulnerable to psychosomatic health sequelae; therefore, we studied whether optimism and anxiety influence the pertinent clinical outcome of days to neutrophil engraftment (DTE).

Method

54 adults undergoing either autologous or allogeneic HCT completed self-report questionnaires measuring optimism and anxiety. We assessed the association between these psychosocial variables and DTE.

Results

Greater optimism and less anxiety were associated with the favorable outcome of fewer DTE in autologous HCT recipients, though this relationship was no longer significant when reducing the sample size to only subjects who filled out their baseline survey by the time of engraftment.

Conclusion

Our findings are suggestive that optimism and anxiety may be associated with time to neutrophil recovery in autologous, but not allogeneic, adult HCT recipients. Further investigation in larger, more homogeneous subjects with consistent baseline sampling is warranted.

Physiological underpinnings of irritable bowel syndrome: neurohormonal mechanisms

The gastrointestinal tract is a vast neuroendocrine organ with extensive extrinsic and intrinsic neural circuits that interact to control its function. Circulating and paracrine hormones (amine and peptide) provide further control of secretory, absorptive, barrier, motor and sensory mechanisms that are essential to the digestion and assimilation of nutrients, and the transport and excretion of waste products. Specialized elements of the mucosa (including enteroendocrine cells, enterocytes and immune cells) and the microbiome interact with other intraluminal contents derived from the diet, and with endogenous chemicals that alter the gut's functions. The totality of these control mechanisms is often summarized as the brain-gut axis. In irritable bowel syndrome (IBS), which is the most common gastrointestinal disorder, there may be disturbances at one or more of these diverse control mechanisms. Patients present with abdominal pain in association with altered bowel function. This review documents advances in understanding the pathophysiological mechanisms in the brain-gut axis in patients with IBS. It is anticipated that identification of one or more disordered functions in clinical practice will usher in a renaissance in the management of IBS, leading to effective therapy tailored to the needs of the individual patient.

Effect of Jiaweisinisan on morphology of the gastric mucosa of rats following chronic psychological stress

AIM: To study the protective effect of Jiaweisinisan (JWSNS) on the gastric mucosa of rats following physical and mental stress and to explore the possible mechanisms involved.

METHODS: Rats were randomly divided into normal group, model group, low-, medium-, and high-dose JWSNS groups, and omeprazole group. Gastric ulcer was induced in rats using a chronic psychological stress method. After JWSNS intervention, gastric juice pH value was measured, mucosal ulcer index (UI) was evaluated, morphological and ultrastructural changes in gastric tissue were observed by light microscopy and transmission electron microscopy. The levels of gastrin (GAS) and vasoactive intestinal peptide (VIP) in gastric tissue were determined by immunoradiometric assay, and mRNA expression of GASR in gastric and VIPR2 in jejunal tissue was detected by RT-PCR.

RESULTS: Compared to the model group, gastric UI was significantly lower in the normal group, low-, medium-, and high-dose JWSNS groups, and omeprazole group (0.32 ± 1.58, 13.70 ± 2.26, 8.50 ± 3.88, 4.67 ± 3.08, 12.00 ± 2.73 vs 25.33 ± 4.33, all P < 0.05). Compared to the omeprazole group, gastric UI was significantly lower in the medium- and high-dose JWSNS groups (both P < 0.05). The gastric mucosa of rats in the model group showed obvious injury compared to the normal group. Varying degrees of relief of gastric mucosa injury was observed in the JWSNS groups. Treatment with JWSNS also significantly improved ultrastructural changes in gastric tissue. Compared to the model group, levels of GAS in the gastric antrum were significantly higher in the normal group, low-, medium-, and high-dose JWSNS groups, and omeprazole group (39.23 ± 5.54, 15.74 ± 4.56, 27.52 ± 4.28, 38.27 ± 4.18, 28.30 ± 5.53 vs 8.33 ± 4.63, all P < 0.05). Compared to the omeprazole group, levels of GAS in the gastric antrum were significantly higher in the high-dose JWSNS group (P < 0.05). Compared to the model group, levels of VIP in the gastric antrum were significantly lower in the normal group, medium-, and high-dose JWSNS groups, and omeprazole group (36.32 ± 1.68, 60.50 ± 3.85, 39.67 ± 2.98, 59.00 ± 2.89 vs 89.33 ± 4.43, all P < 0.05). Compared to the omeprazole group, levels of VIP in the gastric antrum were significantly lower in the high-dose JWSNS group (P < 0.05). Compared to the model group, expression of GASR mRNA in gastric tissue increased significantly (1.00 ± 0.10, 0.25 ± 0.02, 0.53 ± 0.03, 0.62 ± 0.05, 0.43 ± 0.03 vs 0.19 ± 0.05, all P < 0.05) and that of VIPR2 mRNA in jejunal tissue decreased significantly (1.00 ± 0.20, 1.83 ± 0.30, 2.39 ± 0.36, 1.15 ± 0.33, 1.79 ± 0.35 vs 3.40 ± 0.57, all P < 0.05) in the normal group, low-, medium-, and high-dose JWSNS groups, and omeprazole group. Compared to the omeprazole group, expression of GASR mRNA in gastric tissue increased significantly (P < 0.05) and that of VIPR2 mRNA in jejunal tissue decreased significantly (P < 0.01) in the high-dose JWSNS group.

CONCLUSION: JWSNS has a good protective effect on the gastric mucosa of rats following physical and mental stress.

Brain-Gut Interactions in IBS

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder with an estimated prevalence of 10–20%. Current understanding of the pathophysiology of IBS is incomplete due to the lack of a clearly identified pathological abnormality and due to the lack of reliable biomarkers. Possible mechanisms believed to contribute to IBS development and IBS like symptoms include physical stressors, such as infection or inflammation, psychological, and environmental factors, like anxiety, depression, and significant negative life events. Some of these mechanisms may involve the brain-gut axis (BGA). In this article we review the current knowledge on the possible involvement of the BGA in IBS and discuss new directions for potential future therapies of IBS.

Anticipation of public speaking and sleep and the hypothalamic-pituitary-adrenal axis in women with irritable bowel syndrome

BACKGROUND

Evidence suggests that subgroups of patients with irritable bowel syndrome (IBS) are hyper-responsive to a variety of laboratory stress conditions.

METHODS

This study compared sleep quality and night time plasma adrenocorticotropic hormone (ACTH) and serum cortisol levels in response to anticipation of public speaking between 43 women with IBS and 24 healthy control women. In addition, comparisons were made between subgroups within the IBS sample based on predominant stool patterns, 22 IBS-constipation and 21 IBS-diarrhea. Subjects slept three nights in a sleep laboratory, and on the third night serial blood samples were drawn every 20 min from 08:00 PM until awakening. As the subjects had different sleep onsets, each subject's results were synchronized to the first onset of stage 2 sleep.

KEY RESULTS

Compared the healthy control group, women with IBS had significantly worse sleep efficiency, and higher cortisol but not ACTH levels over the night. However, there were no IBS bowel pattern subgroup differences. Among IBS subjects, cortisol levels early in the night were higher than found in our previous study with a similar protocol but without the threat of public speaking. These results suggest that a social stressor, such as public speaking prior to bedtime, increases cortisol but not ACTH levels suggesting HPA dysregulation in women with IBS.

CONCLUSIONS & INFERENCES

This response to a social stressor contributes to our understanding of the relationship of stress to symptom expression in IBS.

Altered psychobiological responsiveness in women with irritable bowel syndrome

OBJECTIVE

Although stress has been considered an important pathophysiological factor in irritable bowel syndrome (IBS), there is incomplete understanding of its physiological mechanisms. The current study was designed to compare diurnal hypothalamic-pituitary-adrenal (HPA) axis activity in IBS patients and controls and their psychobiological response to a psychosocial stressor.

METHODS

Basal and stimulated HPA axis activity was assessed in 57 women with IBS and 20 matched controls. Psychiatric comorbidity was assessed using a standardized clinical interview. Salivary morning cortisol and diurnal profile were obtained, and the Trier Social Stress Test (TSST) was administered. Levels of cortisol and adrenocorticotropic hormone (ACTH) were measured before and within 1 hour after the stressor. Overall stress experience and stress related to the TSST were assessed using standardized questionnaires.

RESULTS

All subjects showed intact circadian variation of cortisol. However, IBS patients with predominant diarrhea exhibited substantially heightened cortisol levels at awakening (p < .03) and a blunted cortisol awakening response. In response to the TSST, patients exhibited significantly blunted cortisol (p < .05) and slightly attenuated ACTH secretion compared with controls. During the recovery period, ACTH levels were significantly lower (p < .04) in patients than those in healthy subjects. Women with IBS perceived higher stress susceptibility than control subjects did (p < .01).

CONCLUSIONS

The enhanced morning cortisol levels in one subgroup of IBS patients may indicate an association between basal HPA axis activity and predominant bowel habit. The downregulated HPA axis reactivity in IBS after the TSST suggests a downregulated sensitivity of the endocrine system. On the contrary, all subjective stress ratings were increased in the IBS group, which may indicate increased stress susceptibility.

Adrenal hormone response and psychophysiological correlates under psychosocial stress in individuals with irritable bowel syndrome

OBJECTIVE

In this study, we investigated levels and relative ratios of adrenal hormones (including cortisol, dehydroepiandrosterone [DHEA], and DHEA-sulfate [DHEA-S]) and their psychophysiological correlates under acute psychosocial stress in individuals with irritable bowel syndrome (IBS).

METHODS

Fifty-three college students participated in the study (male: 42, female: 11; mean age: 22.64years), including 13 individuals with IBS (IBS group) and 40 individuals without IBS (control group). The participants were exposed to a standardized laboratory stressor, which included delivering a speech and performing a mental arithmetic task. We measured subjective stress levels and salivary cortisol, DHEA, and DHEA-S levels at relevant time points before, during, and after the tasks.

RESULTS

DHEA-S level and the DHEA-S/DHEA ratio in the IBS group were significantly lower than those in the control group, and the cortisol/DHEA-S ratio in the IBS group was higher than that in the control group throughout the experiment. In the IBS group, the appraisal of a threat was positively correlated with cortisol levels (r=0.61), and the appraisal of controllability was negatively correlated with cortisol levels (r=-0.64) and with the cortisol/DHEA ratio (r=-0.71). The control group showed a significant positive correlation between the appraisal of threat and cortisol levels (r=0.32).

CONCLUSION

The present study indicates that individuals with IBS had lower DHEA-S levels, and that their stressful cognitive appraisals under acute psychosocial stress caused the effects of cortisol to dominate. This adrenal hormone response may be involved in exacerbating abdominal symptoms in individuals with IBS.

Effect of self-management intervention on cortisol and daily stress levels in irritable bowel syndrome

Self-management programs that include cognitive behavioral strategies have been shown to improve gastrointestinal (GI) symptoms, psychological distress, and quality of life (QoL) in persons with irritable bowel syndrome (IBS). However, less is known about the physiological impact of such a change. As part of a randomized controlled trial using a comprehensive self-management (CSM) intervention (n = 126) compared to usual care (UC; n = 62), cortisol levels were measured in 4 weekly first morning urine samples at baseline and at 3-, 6-, and 12-month follow-up. In addition, diary (28 days) ratings of stress were recorded at baseline, 3, 6, and 12 months. The omnibus test of all three outcome times showed no differences in urine cortisol levels between the CSM and UC groups (p = .400); however, at 3 months the CSM group had significantly higher cortisol levels than the UC group (p = .012). The CSM group reported lower daily stress levels (p = .046 from the omnibus test of all 3 time points) than the UC group, with the effect getting stronger over time. Despite marked improvements in reported stress and previously reported GI and psychological distress symptoms at later follow-ups, the CSM program did not reduce urine cortisol levels in adults with IBS. These results suggest that the first-void urine cortisol levels are not reflective of self-reported daily stress in this patient population.

The role of stress on physiologic responses and clinical symptoms in irritable bowel syndrome

Studies support the concept that irritable bowel syndrome (IBS) is a biopsychosocial disorder that can be explained by a neurobiological model which postulates stress-induced alterations in central stress and arousal circuits and activation of parallel motor outputs from brain regions that can affect bodily function and behavior. Sustained stress can result in chronic overactivity or underactivity of allostatic (or adaptive) systems, including the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system, metabolic, and immune systems, can occur. Animal and human studies have demonstrated that chronic or sustained stress is associated with the onset and exacerbation of symptoms of IBS. Chronic stress is also an independent predictor of developing post-infectious IBS. IBS patients specifically show stress-induced alterations in gastrointestinal motility, rectal perception, autonomic tone and HPA axis responses, although these findings are not entirely consistent among studies. This can be in part due to differences in study methodology or to various factors that can affect these physiologic responses. A greater recognition and understanding of the effects of stress in IBS may help identify targets for future drug development and also help guide more effective management of IBS symptoms.

Abdominal pain in Irritable Bowel Syndrome: a review of putative psychological, neural and neuro-immune mechanisms

Chronic abdominal pain is a common symptom of great clinical significance in several areas of medicine. In many cases no organic cause can be established resulting in the classification as functional gastrointestinal disorder. Irritable Bowel Syndrome (IBS) is the most common of these conditions and is considered an important public health problem because it can be disabling and constitutes a major social and economic burden given the lack of effective treatments. IBS aetiology is most likely multi-factorial involving biological, psychological and social factors. Visceral hyperalgesia (or hypersensitivity) and visceral hypervigilance, which could be mediated by peripheral, spinal, and/or central pathways, constitute key concepts in current research on pathophysiological mechanisms of visceral hyperalgesia. The role of central nervous system mechanisms along the "brain-gut axis" is increasingly appreciated, owing to accumulating evidence from brain imaging studies that neural processing of visceral stimuli is altered in IBS together with long-standing knowledge regarding the contribution of stress and negative emotions to symptom frequency and severity. At the same time, there is also growing evidence suggesting that peripheral immune mechanisms and disturbed neuro-immune communication could play a role in the pathophysiology of visceral hyperalgesia. This review presents recent advances in research on the pathophysiology of visceral hyperalgesia in IBS, with a focus on the role of stress and anxiety in central and peripheral response to visceral pain stimuli. Together, these findings support that in addition to lower pain thresholds displayed by a significant proportion of patients, the evaluation of pain appears to be altered in IBS. This may be attributable to affective disturbances, negative emotions in anticipation of or during visceral stimulation, and altered pain-related expectations and learning processes. Disturbed "top-down" emotional and cognitive pain modulation in IBS is reflected by functional and possibly structural brain changes involving prefrontal as well as cingulate regions. At the same time, there is growing evidence linking peripheral and mucosal immune changes and abdominal pain in IBS, supporting disturbed peripheral pain signalling. Findings in post-infectious IBS emphasize the interaction between centrally-mediated psychosocial risk factors and local inflammation in predicting long-term IBS symptoms. Investigating afferent immune-to-brain communication in visceral hyperalgesia as a component of the sickness response constitutes a promising future research goal.

Meta-analysis and meta-regression of hypothalamic-pituitary-adrenal axis activity in functional somatic disorders

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is the most investigated biological risk marker in functional somatic disorders (FSDs), such as chronic fatigue syndrome (CFS), fibromyalgia (FM), and irritable bowel syndrome (IBS). Our aim was to assess whether there is an association between basal hypocortisolism and FSD and to identify potential moderators of this association. Meta-analysis on 85 studies revealed that although basal cortisol levels were generally lower in FSD subjects compared to controls, this association did not reach statistical significance (SMD -0.07, 95% CI -0.17 to 0.04, p=0.241). However, when the three FSD were assessed separately, statistically significant basal hypocortisolism was observed in CFS subjects compared to controls (SMD -0.14, 95% CI -0.28 to 0.00, p=0.047), but not in FM or IBS. When all potential moderators were entered into a meta-regression analysis, only type of FSD and female gender were significant independent predictors of basal hypocortisolism. In conclusion, we did not find evidence to consider all three main FSD as hypocortisolemic disorders, as significant reduction in basal cortisol compared to healthy controls was only found in CFS and in females with FM, but not in IBS.

Patients with irritable bowel syndrome have altered emotional modulation of neural responses to visceral stimuli

BACKGROUND & AIMS

In patients with irritable bowel syndrome (IBS), pain amplification and hypervigilance might result from altered affective-motivational modulation of the pain response. We investigated the effects of emotional context on the behavioral and neural response to visceral stimuli in IBS patients.

METHODS

We used functional magnetic resonance imaging (fMRI) to assess the blood oxygen level-dependent response to nonpainful and painful rectal distensions in 15 female IBS patients and 12 healthy women. Distensions were delivered during psychologic stress or relaxation; data were compared with those in a neutral condition (control). Group and context-dependent differences in the processing of visceral stimulation were assessed at behavioral and the neuronal levels. Secondary analyses of group differences were performed using anxiety scores as a covariate because of higher anxiety symptoms among patients with IBS.

RESULTS

During rectal stimulation, IBS patients demonstrated more pronounced stress-induced modulation of neural activation in multiple brain regions, including the insula, midcingulate cortex, and ventrolateral prefrontal cortex. In response to relaxation, IBS patients demonstrated reduced modulation of distension-induced activation in the insula. During relaxation, the difference observed between groups could be accounted for by higher anxiety symptoms in patients with IBS; differential effects of stress in the insula and prefrontal regions were not attributable to anxiety.

CONCLUSIONS

IBS patients appear to have disrupted emotional modulation of neural responses to visceral stimuli, possibly reflecting the neural basis for altered visceral interoception by stress and negative emotions.

Pathogenesis of IBS: role of inflammation, immunity and neuroimmune interactions

IBS is one of the most common functional gastrointestinal disorders worldwide and is thought to be the result of disturbed neural function along the brain-gut axis. The mechanisms behind this disturbance are not clear, but important roles for low-grade inflammation and immunological alterations in the development of symptoms compatible with IBS have become evident. The development of long-standing gastrointestinal symptoms after infectious gastroenteritis and patients with IBD in remission frequently having functional gastrointestinal symptoms support this hypothesis. An increased innate immune activity in the intestinal mucosa and in blood is found in subpopulations of patients with IBS. Mast cells and monocytes seem to be particularly important. In addition, studies have demonstrated that IBS may be associated with an activated adaptive immune response. Increased epithelial barrier permeability and an abnormal gut flora might lead to increased activation of the intestinal immune system. Functional and anatomical evidence for abnormal neuroimmune interactions has been found in patients with IBS. The link between immune alterations and severity of gastrointestinal symptoms and the positive effect of anti-inflammatory treatments in IBS further highlight the relevance of neuroimmune interactions in this condition.

Hypothalamic--pituitary-- adrenal axis dysregulation in women with irritable bowel syndrome in response to acute physical stress

Irritable bowel syndrome (IBS) supports the concept of a dysregulated hypothalamic-pituitary-adrenal (HPA) axis. This study investigates the neuroendocrine and psychological responses to the acute physical stress of a lumbar puncture (LP) in women with diarrhea-predominant IBS by assessing central and peripheral HPA activity and affective measures. Blood samples have been collected at baseline and immediately post- and 1 hr following LP from 13 women with IBS and 13 controls. Plasma adrenocorticotropic hormone (ACTH), cortisol, epinephrine, and norepinephrine levels are analyzed. A single measure of cerebrospinal fluid (CSF) concentrations of corticotropin-releasing factor (CRF(CSF)) and norepinephrine(CSF) is noted. Affective assessments are used to rate anxiety and depression with the Hospital Anxiety and Depression Scale (HADS) and acute mood state is rated using the Stress Symptom Rating questionnaire (stress, anxiety, anger, arousal). The women with IBS display blunted ACTH and cortisol responses to the LP along with a profile of affective responsiveness suggestive of chronic psychosocial stress, although no CRF(CSF) differences between groups are observed.

Childhood trauma is associated with hypothalamic-pituitary-adrenal axis responsiveness in irritable bowel syndrome

BACKGROUND & AIMS

A history of early adverse life events (EALs) is associated with a poorer outcome and higher levels of distress in adult patients with functional gastrointestinal disorders. An EAL is thought to predispose individuals to develop a range of chronic illnesses by inducing persistent changes in the central stress response systems, including the hypothalamic-pituitary-adrenal (HPA) axis. We sought to determine if EALs affect the HPA axis response to a visceral stressor in irritable bowel syndrome (IBS) patients and healthy controls, and to determine if this is affected by sex or related to symptoms or quality of life.

METHODS

Forty-four IBS patients (25 women, 19 men) and 39 healthy controls (21 women, 18 men) were assessed for gastrointestinal and psychological symptoms and EALs by validated questionnaires and interview. All subjects underwent a visceral stressor (sigmoidoscopy). Salivary cortisol was collected at baseline and serially for 1 hour poststressor.

RESULTS

Twenty-one IBS patients and 18 controls had EALs. In subjects with and without IBS, an EAL was associated with higher mean (+/-SD) cortisol levels (0.32 +/- 0.2 vs 0.20 +/- 0.1 microg/dL; P = .003) and higher area under the curve (28.1 +/- 17 vs 18.6 +/- 13 microg x min/dL; P = .005) after the stressor compared with subjects without EALs. In IBS, a faster resolution of cortisol to basal values corresponded to lower symptom severity (r = -0.36, P < .05) and better disease-specific quality of life (r = 0.33, P < .05).

CONCLUSIONS

HPA axis hyperresponsiveness to a visceral stressor is related more to a history of EALs than to the presence of IBS. However, HPA axis reactivity has a moderating effect on IBS symptoms.

Recent insights on central processing and psychological processes in functional gastrointestinal disorders

There is increasing evidence for a key role of psychological processes and their central nervous system substrates in functional gastrointestinal disorders, although the exact nature of the relationship remains only partially understood. However, progress in this key area of psychosomatic medicine is rapidly being made. In this review article, we will give an overview of recent advances in understanding the complex mechanisms by which psychological processes and functional gastrointestinal disorder symptoms reciprocally influence each other. Various lines of evidence from different branches of biomedical and psychological science will be discussed, particularly epidemiology, patho- and psychophysiology and functional brain imaging, focusing on the most recent and novel findings. We will conclude this paper with a paragraph on new insights into treatment.

Irritable bowel syndrome: towards biomarker identification

Irritable bowel syndrome (IBS), the most common functional gastrointestinal disorder referred to gastroenterologists, affects 7-10% of the general population worldwide. The lack of suitable disease-defining biological markers coupled with a poorly understood underlying pathophysiology complicates patient diagnosis and seriously hampers drug discovery efforts. Over the past few years, a number of potential biomarkers have emerged, and in this review we critically evaluate such candidates. In particular, we highlight the increasing number of studies supporting a low-grade immune activation in IBS and consider how the latest preclinical developments can contribute to the development of more robust and reliable biological markers of this disorder. The successful identification of biomarkers is critical to progressing our understanding of IBS and addressing the unmet therapeutic needs of this debilitating condition.

Exposure to severe wartime conditions in early life is associated with an increased risk of irritable bowel syndrome: a population-based cohort study

OBJECTIVES

Stressful events during early life have been suggested to play an important role in the development of the irritable bowel syndrome (IBS). In this study, we evaluate whether an exposure to severe wartime conditions during gestation and in early life are associated with an increased prevalence of IBS.

METHODS

We assessed the prevalence of IBS using the Rome II questionnaire among 816 men and women (aged 58+/-1 years) who were born as term singletons in Wilhelmina Gasthuis, Amsterdam, The Netherlands around the time of World War II.

RESULTS

Of a total of 816 participants, 9.6% (n=78, 52F) met the criteria for IBS. Exposure to severe wartime conditions in utero was not associated with the prevalence of IBS in adulthood (8.3%). Early-life exposure to severe wartime conditions was associated with an increased prevalence of IBS. The prevalence of IBS among individuals exposed up to 0.5 years of age, 1 year of age, and 1.5 years of age was 8.1%, 12.5%, and 15.3%, respectively. The increased IBS prevalence was not associated with an increased stress response.

CONCLUSIONS

Our data indicate that exposure to severe wartime conditions in early life is associated with an increased risk of developing IBS. To what extent this is attributable to the stressful environment of war, to severe undernutrition, or to the increased prevalence of infectious diseases is, however, unclear.

Effects of psychological stress on the cerebral processing of visceral stimuli in healthy women

The aim of the study was to analyse effects of psychological stress on the neural processing of visceral stimuli in healthy women. The brain functional magnetic resonance imaging blood oxygen level-dependent response to non-painful and painful rectal distensions was recorded from 14 healthy women during acute psychological stress and a control condition. Acute stress was induced with a modified public speaking stress paradigm. State anxiety was assessed with the State-Trait-Anxiety Inventory; chronic stress was measured with the Perceived Stress Questionnaire. During non-painful distensions, activation was observed in the right posterior insular cortex (IC) and right S1. Painful stimuli revealed activation of the bilateral anterior IC, right S1, and right pregenual anterior cingulate cortex. Chronic stress score was correlated with activation of the bilateral amygdala, right posterior IC (post-IC), left periaqueductal grey (PAG), and right dorsal posterior cingulate gyrus (dPCC) during non-painful stimulation, and with activation of the right post-IC, right PAG, left thalamus (THA), and right dPCC during painful distensions. During acute stress, state anxiety was significantly higher and the acute stress - control contrast revealed activation of the right dPCC, left THA and right S1 during painful stimulation. This is the first study to demonstrate effects of acute stress on cerebral activation patterns during visceral pain in healthy women. Together with our finding that chronic stress was correlated wit the neural response to visceral stimuli, these results provide a framework for further studies addressing the role of chronic stress and emotional disturbances in the pathophysiology of visceral hyperalgesia.

Disturbed stress responses in women with polycystic ovary syndrome

BACKGROUND

We analyzed the neuroendocrine and immune cell responses to psychosocial stress in PCOS patients compared to BMI-matched healthy controls.

METHODS

Responses to public speaking stress were analyzed in 32 PCOS patients and 32 BMI-matched healthy controls. At baseline, during, and 10- and 45-min after stress, state anxiety, cardiovascular responses, cortisol, ACTH, as well as circulating leukocyte subpopulations were analyzed, together with hsCRP and serum IL-6 concentrations.

RESULTS

In response to public speaking stress, both groups showed significant but comparable increases in state anxiety, and blood pressure (all p<0.001; time effects). The ACTH and cortisol stress responses were significantly enhanced in PCOS (both p<0.05; interaction effect). In addition, heart rate was significantly higher in PCOS (p<0.05; group effect). PCOS patients displayed a reduced upregulation of IL-6 levels in response to stress (p<0.05; interaction effect). Baseline levels of circulating leukocyte subpopulations, IL-6 and hsCRP concentrations did not differ between BMI-matched controls and PCOS patients. PCOS patients were characterized by markedly increased psychological distress.

CONCLUSIONS

PCOS patients showed enhanced HPA-axis and heart rate reactivity as well as a reduced upregulation of IL-6 in response to stress. The altered stress reactivity in PCOS patients may constitute a link between depression, overweight, and the cardiovascular and diabetes risks associated with the diagnosis.

Effects of obesity on neuroendocrine, cardiovascular, and immune cell responses to acute psychosocial stress in premenopausal women

OBJECTIVE

To analyze the neuroendocrine and immune cell responses to acute psychosocial stress in obese compared to non-obese premenopausal women.

METHODS

N=15 obese (BMI> or =30) and N=24 (BMI<30) non-obese premenopausal women underwent public speaking stress. State anxiety, ACTH, cortisol, and the redistribution of immune cells were measured before, during, and 10 and 45min after public speaking. Serum hsCRP and serum IL-6 levels were analyzed before, and IL-6 additionally 45min after stress.

RESULTS

In response to public speaking stress, both groups showed significant but comparable increases in state anxiety, plasma ACTH, and blood pressure (all p<0.01; time effects). The cortisol stress response was significantly enhanced in obese women (p<0.05; interaction effect). In addition, heart rate and diastolic blood pressure were significantly higher in obese women 10min following stress (p<0.05, t-tests). Public speaking stress led to a significant increase in IL-6 concentrations (p<0.001; time effect), and obese women displayed higher IL-6 levels both pre- and post-stress (p<0.05; group effect; between-group t-tests: pre-stress p<0.05; post-stress p<0.01). Baseline numbers of circulating leukocytes, granulocytes, CD3+ cells and hsCRP concentration were significantly higher in obese women (between-group t-tests: all p<0.05, but the groups did not differ in the stress-induced redistribution of circulating leukocyte subpopulations.

CONCLUSIONS

Our data reveal a strong association of obesity with chronic low-grade inflammation in premenopausal women. This pro-inflammatory state, together with altered neuroendocrine and cardiovascular stress responsiveness, may conceivably constitute one of the mechanisms linking psychological stress and the long-term health risks associated with obesity.

Interaction between DRD2 C957T polymorphism and an acute psychosocial stressor on reward-related behavioral impulsivity

The dopamine D2 receptor (DRD2) C957T polymorphism CC genotype is associated with decreased striatal binding of DRD2 and executive function and working memory impairments in healthy adults. We investigated the relationships between C957T and acute stress with behavioral phenotypes of impulsivity in 72 young adults randomly allocated to either an acute psychosocial stress or relaxation induction condition. Homozygotes for 957C showed increased reward responsiveness after stress induction. They were also quicker when making immediate choices on the delay discounting task when stressed, compared with homozygotes who were not stressed. No effects were found for response inhibition, a dimension of impulsivity not related to extrinsic rewards. These data suggest that C957T is associated with a reward-related impulsivity endophenotype in response to acute psychosocial stress. Future studies should examine whether the greater sensitivity of 957C homozygotes to the effects of stress is mediated through dopamine release.

Women with diarrhoea-predominant irritable bowel syndrome show an increased pressure response to 35% carbon dioxide stress challenge

The responses to inhalation of 35% carbon dioxide (CO(2)) as a stressor were compared in female irritable bowel syndrome (IBS) patients and healthy controls to assess potential differences in cardiovascular, neuroendocrine and behavioural responses to stress. A total of 22 women (12 patients with ROME II defined diarrhoea-predominant IBS and 10 aged-matched controls) were challenged with a single vital capacity breath of 35% CO(2) (with 65% oxygen). Beat-to-beat blood pressure and heart rate were recorded prior to, during and after the inhalation. Serum cortisol concentration and behavioural ratings were measured pre- and post-inhalation. A typical pattern of responses to CO(2) was observed, characterised by a reduction in heart rate and increases in serum cortisol and anxiogenic symptoms; however, these responses did not differ between groups. Both groups also demonstrated an increase in systolic blood pressure; however, this response was significantly enhanced in IBS patients compared to healthy controls (P < 0.05). These findings demonstrate that females with diarrhoea-predominant IBS have an exaggerated pressor response to 35% CO(2) stress challenge, suggesting a more stress-responsive sympathetic nervous system.

Behavioral phenotypes of impulsivity related to the ANKK1 gene are independent of an acute stressor

BACKGROUND

The A1 allele of the ANKK1 TaqIA polymorphism (previously reported as located in the D2 dopamine receptor (DRD2) gene) is associated with reduced DRD2 density in the striatum and with clinical disorders, particularly addiction. It was hypothesized that impulsivity represents an endophenotype underlying these associations with the TaqIA and that environmental stress would moderate the strength of the gene-behavior relationship.

METHODS

TaqIA genotyping was conducted on 72 healthy young adults who were randomly allocated to either an acute psychosocial stress or relaxation induction condition. Behavioral phenotypes of impulsivity were measured using a card-sorting index of reinforcement sensitivity and computerized response inhibition and delay discounting tasks.

RESULTS

Separate analyses of variance revealed associations between the A1 allele and two laboratory measures of impulsivity. The presence of the TaqIA allele (A1+) was associated with slower card-sorting in the presence of small financial reinforcers, but was overcome in a second administration after either a five-minute rest or psychosocial stress induction. A1+ participants also demonstrated significantly poorer response inhibition and faster response times on a computerized stop inhibition task, independent of acute stress exposure.

CONCLUSION

These findings indicate the A1 allele is associated with an endophenotype comprising both a "rash impulsive" behavioral style and reinforcement-related learning deficits. These effects are independent of stress.

Patterns of sympathetic responses induced by different stress tasks

Stress tasks are used to induce sympathetic nervous system (SNS) arousal. However, the efficacy and the patterns of SNS activation have not been systematically compared between different tasks. Therefore, we analyzed SNS activation during the following stress tasks: Presentation of negative, positive, and - as a control - neutral affective pictures, Color-Word interference test (CWT), mental arithmetic under time limit, singing a song aloud, and giving a spontaneous talk. We examined 11 healthy subjects and recorded the following SNS parameters: Activation of emotional sweating by quantitative sudometry, skin vasoconstriction by laser-Doppler flowmetry, heart rate by ECG, blood pressure by determination of pulse wave transit time (PWTT), and electromyographic (EMG) activity of the trapezius muscle. Moreover, subjective stress ratings were acquired for each task using a visual analog scale. All tasks were felt significantly stressful when compared to viewing neutral pictures. However, SNS activation was not reliable: Affective pictures did not induce a significant SNS response; singing, giving a talk and mental arithmetic selectively increased heart rate and emotional sweating. Only the CWT globally activated the SNS. Regarding all tasks, induction of emotional sweating, increase of heart rate and blood pressure significantly correlated with subjective stress ratings, in contrast to EMG and skin vasoconstriction.Our results show that the activation of the SNS widely varies depending on the stress task. Different stress tasks differently activate the SNS, which is an important finding when considering sympathetic reactions - in clinical situations and in research.

Stress-related peripheral neuroendocrine-immune interactions in women with ulcerative colitis

OBJECTIVES

The mechanisms underlying the interaction of psychological stress with the disease course in inflammatory bowel diseases remain unclear. We analyzed the neuroendocrine and cellular immune responses to public speaking stress, and the in vitro adrenergic and glucocorticoid modulation of cytokine production by peripheral blood cells (PBCs) in women with ulcerative colitis (UC) compared to healthy female controls.

METHODS

In 22 female UC patients with inactive disease or mild disease activity and 24 healthy females we analyzed the neuroendocrine and cellular immune responses to public speaking stress and the vitro beta-adrenergic and glucocorticoid regulation of IL-10 and TNF-alpha production by PBCs.

RESULTS

Public speaking stress-induced neuroendocrine and sympatho-adrenal activation, as well as the redistribution of circulating leukocytes were comparable in UC and controls. Significant but comparable public speaking stress-induced increases in LPS-stimulated TNF-alpha and IL-10, as well as in CD2/CD28-stimulated IFN-gamma were observed in both groups. UC demonstrated significantly reduced baseline IFN-gamma production, as well as significantly lower basal cortisol and prolactin levels. The in vitro beta-adrenergic stimulation of PBCs revealed reduced IL-10 response in UC.

CONCLUSIONS

Psychosocial stress-induced activation of the neuroendocrine and sympatho-adrenal systems remain unaltered in UC, suggesting that the mechanism(s) mediating effects of psychological stress on disease activity are likely operative downstream at the level of the intestine. However, UC patients show disturbances in basal endocrine and cytokine measures. Together with our in vitro evidence of disturbed adrenergic regulation of IL-10 production by stimulated PBCs in UC, these may indicate the existence of subtle disturbance of peripheral cellular neuroendocrine-immune interactions in UC.