Influence of experimentally induced anxiety on gastric sensorimotor function in humans

Meal related symptoms in youth with chronic abdominal pain: Relationship to anxiety, depression, and sleep dysfunction

OBJECTIVE

The objective of the current study was to describe meal-related symptoms in youth with chronic abdominal pain fulfilling criteria for a disorder of gut-brain interaction (DGBI) and their associations with anxiety, depression, and sleep disturbances.

METHODS

This was a retrospective evaluation of 226 consecutive patients diagnosed with an abdominal pain-associated DGBI. As part of routine care, all had completed a standardized symptom history, the Sleep Disturbances Scale for Children (utilized to assess for disorders of initiation and maintenance of sleep and excessive daytime somnolence) and the Behavior Assessment System for Children-Third Edition (utilized to assess for anxiety and depression). Four meal related symptoms were assessed: early satiety, postprandial bloating, postprandial abdominal pain, and postprandial nausea.

RESULTS

Overall, 87.6% of patients reported at least one meal related symptom and the majority reported at least three symptoms. All meal related symptoms were significantly related to each other. Postprandial pain and nausea were more often reported by females. Early satiety, postprandial bloating, and postprandial nausea, but not postprandial pain demonstrated significant though variable associations with anxiety, depression, disorders of initiation and maintenance of sleep, and disorders of excessive somnolence, but only in adolescents.

CONCLUSIONS

Meal related symptoms are very common in youth with abdominal pain-associated DGBIs. Early satiety, bloating, and postprandial nausea demonstrate variable associations with anxiety, depression, and disordered sleep while increased postprandial pain was not associated with psychologic or sleep dysfunction, suggesting a different pathway for symptom generation.

A nervous wait: Instagram's sensitive-content screens cause anticipatory anxiety but do not mitigate reactions to negative content

Online platforms like Instagram cover potentially distressing imagery with a sensitive-content screen (blurred imagery plus a content warning). Previous research suggests people typically choose to "uncover" and view screened content. In three studies, we investigated whether the presence of screens mitigates the negative emotional impact of viewing content. In Study 1, participants viewed positive and neutral images, and screens (with an option to view the negative images beneath) for a 5-minute period. In Study 2, half the participants saw a grey mask in place of the typical sensitive-content screen. In addition, each image appeared for a fixed period (5 s) and participants had no option to uncover it. Study 3 was like Study 2 except half the participants saw negative images preceded by a sensitive-content screen and half saw negative images without screens. Overall, participants reported a significant increase in state anxiety and negative affect from pre-to post task when they were exposed to sensitive-content screens, whether or not they were also exposed to the negative imagery beneath. Our data suggest sensitive-content screens cause negative responses - state anxiety and negative affect - that do not translate to an emotional benefit when people view negative content.

The role of psychological factors in functional gastrointestinal disorders: a systematic review and meta-analysis

PURPOSE

To systematically reevaluate the role of psychological factors in functional gastrointestinal disorders (FGIDs) and thus provide a scientific basis for the psychological treatment of FGIDs.

METHODS

A literature search was conducted using the PubMed, Embase, Web of Science, and Cochrane Library databases from January 2018 to August 2022 for researches on psychological factors affecting patients with functional gastrointestinal disorders. Meta-analysis was carried out with Stata17.0 after the screening, extraction, and evaluation of article quality.

RESULTS

The search included 22 articles with 2430 patients in the FGIDs group and 12,397 patients in the healthy controls. Meta-analysis showed anxiety [(pooled SMD = 0.74, 95%CI: 0.62 ~ 0.86, p < 0.000) (pooled OR = 3.14, 95%CI: 2.47 ~ 4.00, p < 0.000)], depression [(pooled SMD = 0.79, 95%CI: 0.63 ~ 0.95, p < 0.000) (pooled OR = 3.09, 95%CI: 2.12 ~ 4.52, p < 0.000)], mental disorders (pooled MD =  -5.53, 95%CI: -7.12 ~  -3.95, p < 0.05), somatization (pooled SMD = 0.92, 95%CI: 0.61 ~ 1.23, p < 0.000), and sleep disorders (pooled SMD = 0.69, 95%CI: 0.04 ~ 1.34, p < 0.05) are risk factors for functional gastrointestinal disorders.

CONCLUSION

There is a significant association between psychological factors and FGIDs. Interventions such as anti-anxiety drugs, antidepressants, and behavioral therapy are of great clinical significance in reducing FGIDs risk and improving prognosis.

Deceptive and open-label placebo effects in experimentally induced guilt: a randomized controlled trial in healthy subjects

Placebos are known to yield significant effects in many conditions. We examined deceptive and open-label placebo effects on guilt, which is important for self-regulation and a symptom of mental disorders. Following an experimental induction of guilt, healthy subjects were randomized to deceptive placebo (DP; n = 35), open-label placebo (OLP; n = 35), or no treatment (NT; n = 39). The primary outcome was guilt responses assessed in area under the curve (AUC). Secondary outcomes were shame, guilt, and affect. We hypothesized that DP and OLP would reduce guilt compared to NT. Guilt responses were higher in the NT group than in the placebo groups (estimate = 2.03, 95% CI = 0.24-3.82, d = 0.53), whereas AUC guilt did not differ significantly between the placebo groups (estimate = -0.38, 95% CI = -2.52-1.76, d = -0.09). Placebos are efficacious in reducing acute guilt responses, regardless of the placebo administration (i.e., open vs. deceptive). Furthermore, we observed narrative-specific effects with significant changes of guilt but not shame, pride, or affect. These results indicate not only that guilt is amenable to placebos but also that placebos can be administered in an ethical and potentially emotion-specific manner.

Factors that Impact Day-to-Day Esophageal Acid Reflux Variability and Its Diagnostic Significance for Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a common disease affecting a significant number of adults both globally and in the USA. GERD is clinically diagnosed based on patient-reported symptoms, and the gold standard for diagnosis is ambulatory reflux monitoring, a tool particularly utilized in the common scenario of non-response to therapy or atypical features. Over the past 20 years, there has been a shift toward extending the duration of reflux monitoring, initially from 24 to 48 h and more recently to 96 h, primarily based on a demonstrated increase in diagnostic yield. Further, multiple studies demonstrate clinically relevant variability in day-to-day acid exposure levels in nearly 30% of ambulatory reflux monitoring studies. For these reasons, an ongoing clinical dilemma relates to the optimal activities patients should engage in during prolonged reflux monitoring. Thus, the aims of this review are to detail what is known about variability in daily acid exposure, discuss factors that are known to influence this day-to-day variability (i.e., sleep patterns, dietary/eating habits, stress, exercise, and medications), and finally provide suggestions for patient education and general GERD management to reduce variation in esophageal acid exposure levels.

Clinical and Psychological Factors Predict Outcome in Patients With Functional Dyspepsia: A Prospective Study

BACKGROUND & AIMS

Symptoms of functional dyspepsia (FD) fluctuate over time but there are limited data on the impact of factors on change in dyspepsia symptom severity over time. We aimed to evaluate the demographic, clinical, and psychological factors associated with change in dyspepsia symptom severity.

METHODS

Consecutive patients with FD presenting to a tertiary care center completed questionnaires assessing clinical and psychological symptoms at the time of the initial visit (baseline) and 3- to 6-month follow-up evaluations. FD and irritable bowel syndrome (IBS) were diagnosed using Rome IV criteria. FD severity was measured using patient assessment of gastrointestinal symptom severity. Patient-reported outcome measures information scales were used to assess the severity of anxiety, depression, and sleep disturbance.

RESULTS

Of 128 FD patients, 64 (50%) also met Rome IV criteria for IBS. In the final multivariable model, lower baseline sleep disturbance, improvement in anxiety scores, absence of IBS, and a lower number of medications taken for gastrointestinal symptoms were associated with improvement in dyspepsia scores (P < .05 for all). Conversely, higher baseline dyspepsia severity was associated with greater improvement in dyspepsia severity at follow-up evaluation (P < .001).

CONCLUSIONS

Improvement in FD symptom severity over 3 to 6 months was associated with improvement of anxiety, lower sleep disturbance at baseline, absence of IBS, and higher baseline dyspepsia severity.

Differential beta desynchronisation responses to dynamic emotional facial expressions are attenuated in higher trait anxiety and autism

Daily life demands that we differentiate between a multitude of emotional facial expressions (EFEs). The mirror neuron system (MNS) is becoming increasingly implicated as a neural network involved with understanding emotional body expressions. However, the specificity of the MNS's involvement in emotion recognition has remained largely unexplored. This study investigated whether six basic dynamic EFEs (anger, disgust, fear, happiness, sadness, and surprise) would be differentiated through event-related desynchronisation (ERD) of sensorimotor alpha and beta oscillatory activity, which indexes sensorimotor MNS activity. We found that beta ERD differentiated happy, fearful, and sad dynamic EFEs at the central region of interest, but not at occipital regions. Happy EFEs elicited significantly greater central beta ERD relative to fearful and sad EFEs within 800 - 2,000 ms after EFE onset. These differences were source-localised to the primary somatosensory cortex, which suggests they are likely to reflect differential sensorimotor simulation rather than differential attentional engagement. Furthermore, individuals with higher trait anxiety showed less beta ERD differentiation between happy and sad faces. Similarly, individuals with higher trait autism showed less beta ERD differentiation between happy and fearful faces. These findings suggest that the differential simulation of specific affective states is attenuated in individuals with higher trait anxiety and autism. In summary, the MNS appears to support the skills needed for emotion processing in daily life, which may be influenced by certain individual differences. This provides novel evidence for the notion that simulation-based emotional skills may underlie the emotional difficulties that accompany affective disorders, such as anxiety.

The Usefulness of Symptom-based Subtypes of Functional Dyspepsia for Predicting Underlying Pathophysiologic Mechanisms and Choosing Appropriate Therapeutic Agents

Functional dyspepsia (FD) is considered to be a heterogeneous disorder with different pathophysiological mechanisms or pathogenetic factors. In addition to traditional mechanisms, novel concepts regarding pathophysiologic mechanisms of FD have been proposed. Candidates of therapeutic agents based on novel concepts have also been suggested. FD is a symptom complex and currently diagnosed by symptom-based Rome criteria. In the Rome criteria, symptom-based subtypes of FD including postprandial distress syndrome and epigastric pain syndrome are recommended to be used, based on the assumption that each subtype is more homogenous in terms of underlying pathophysiologic mechanisms than FD as a whole. In this review, the usefulness of symptombased subtypes of FD for predicting underlying pathophysiologic mechanisms and choosing appropriate therapeutic agents was evaluated. Although several classic pathophysiologic mechanisms are suggested to be associated with individual dyspeptic symptoms, symptom-based subtypes of FD are not specific for a certain pathogenetic factor or pathophysiologic mechanism, and may be frequently associated with multiple pathophysiologic abnormalities. Novel concepts on the pathophysiology of FD show complex interactions between pathophysiologic mechanisms and pathogenetic factors, and prediction of underlying mechanisms of individual patients simply by the symptom pattern or symptom-based subtypes may not be accurate in a considerable proportion of cases. Therefore, subtyping by the Rome criteria appears to have limited value to guide therapeutic strategy, suggesting that the addition of objective parameters or subclassification reflecting physiologic or pathologic tests may be necessary for the targeted therapeutic approaches, particularly when therapeutic agents targeting novel mechanisms are available.

The role of serotonin in the control of esophageal sensitivity assessed by multimodal stimulation in health

BACKGROUND

Esophageal hypersensitivity is considered an important pathophysiological mechanism in refractory gastroesophageal reflux disease (GERD) patients. Serotonin (5-HT) plays an important role in the regulation of GI (gastrointestinal) secretion, motility and sensitivity. Previous studies found that altered 5-HT availability has no clear effects on esophageal/GI sensations. Our aim was therefore to investigate the role of 5-HT in esophageal sensitivity in healthy volunteers (HV).

METHODS

Esophageal sensitivity to thermal, mechanical, electrical, and chemical stimuli was assessed in 3 different placebo-controlled studies. In the first study, the effect of citalopram (40 mg; 5-HT reuptake inhibitor; intravenous) was investigated (n = 14). In the second study, the effect of buspirone (20 mg; 5HT1A agonist; oral) was investigated (n = 10). In the third study, acute tryptophan depletion (ATD) was used to decrease 5-HT levels to investigate the effect of reduced 5-HT availability on esophageal sensitivity (n = 15).

KEY RESULTS

No difference was observed in esophageal sensitivity after the administration of citalopram or buspirone (all p > 0.06). In contrast, pain perception threshold to chemical stimulation was increased after ATD (p = 0.017, Cohen's d+ = 0.67). No effect was found on the first perception or pain tolerance threshold. ATD had no influence on esophageal sensitivity to thermal, mechanical, and electrical stimulation compared with placebo.

CONCLUSIONS AND INFERENCES

ATD, which induces 5-HT depletion, significantly decreased pain perception threshold during chemical stimulation, without affecting sensitivity to mechanical, thermal, or electrical stimulation. These findings confirm the involvement of 5-HT in the control of esophageal acid sensitivity, but identifying the receptors involved requires more ligands and studies.

Efficacy evaluation of acupuncture combined with Liujunzi Decoction in the treatment of functional dyspepsia: A protocol of randomized controlled trial

BACKGROUND

Functional dyspepsia (FD) is a common and frequently-occurring disease in internal medicine. It is known that Liujunzi decoction and acupuncture are widely used in the treatment of FD, but there are few studies on the combination of Liujunzi decoction and acupuncture in the treatment of FD, and its safety and efficacy are still controversial. Therefore, the purpose of this study is to evaluate the efficacy and safety of acupuncture combined with Liujunzi decoction in the treatment of FD.

METHODS

We designed a prospective randomized controlled trial. The study protocol was approved by the Clinical Research Ethics Committee of our hospital. Patients with FD were randomly assigned to the treatment group of acupuncture combined with Liujunzi Decoction (the experimental group) and the treatment group of Liujunzi Decoction (the control group) in a ratio of 1:1. Outcome indicators were Nepean Dyspepsia Index, the MOS item short from health survey, and adverse reactions. Finally, SPSS 18.0 software would be used for statistical analysis of the data.

DISCUSSION

This study will evaluate the efficacy and safety of acupuncture combined with Liujunzi Decoction in the treatment of FD and provide clinical basis for the use of acupuncture combined with Liujunzi Decoction in the treatment of FD.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/67GKN.

Gastric Motor Functions in Patients With Mood Disorders and Functional Gastroduodenal Symptoms

OBJECTIVE

Functional gastroduodenal symptoms (FGDSs) may result from perturbations in gastric emptying (GE) and gastric accommodation (GA), which are variably affected by acute stress. This study aimed to examine whether individuals who have both mood disorder and FGDS exhibit differences in GE and GA using standardized, validated, and reproducible noninvasive methods.

METHODS

Using a data retrieval program, 1554 individuals at a single center were identified after having undergone measurements of GE by scintigraphy of a 99mTc-radiolabeled egg (320 kcal, 30% fat meal) and GA by single-photon emission computed tomography to assess the underlying pathophysiology in FGDS. An extensive medical record review identified 267 of these individuals as having diagnoses of depression, anxiety, or comorbid anxiety/depression (CAD). Differences in GE and GA as related to the presence of anxiety or depressive disorders were analyzed using one-way analysis of variance on ranks and Mann-Whitney tests for the two-group comparisons.

RESULTS

Sixty-three patients with anxiety, 134 with depression, and 70 with CAD were identified. GE at 1 hour was slower (p = .04) and GE at 2 hours numerically decreased (p = .07) for depression compared with anxiety. GA was diminished for CAD compared with anxiety (p = .04) and depression (p = .009). There were no differences in fasting gastric volume or GE at 4 hours.

CONCLUSIONS

In this study examining GE and GA in anxiety and depressive disorders among patients with FGDS, the combined presence of anxiety and depression was associated with impaired GA compared with patients with depression or anxiety alone, and early GE seemed to be slower in those with depression compared with patients with anxiety.

Imaging Brain Mechanisms of Functional Somatic Syndromes: Potential as a Biomarker?

When patients present with persistent bodily complaints that cannot be explained by a symptom-linked organic pathology (medically unexplained symptoms), they are diagnosed with 'functional' somatic syndromes (FSS). Despite their prevalence, the management of FSS is notoriously challenging in clinical practice. This may be because FSS are heterogeneous disorders in terms of etiopathogenesis. They include patients with primarily peripheral dysfunction, primarily centrally driven somatic symptoms, and a mix of both. Brain-imaging studies, particularly data-driven pattern recognition methods using machine learning algorithms, could provide brain-based biomarkers for these clinical conditions. In this review, we provide an overview of our brain imaging data on brain-body interactions in one of the most well-known FSS, irritable bowel syndrome (IBS), and discuss the possible development of a brain-based biomarker for FSS. Anticipation of unpredictable pain, which commonly elicits fear in FSS patients, induced increased activity in brain areas associated with hypervigilance during rectal distention and non-distention conditions in IBS. This was coupled with dysfunctional inhibitory influence of the medial prefrontal cortex (mPFC) and pregenual anterior cingulate cortex (pACC) on stress regulation systems, resulting in the activated autonomic nervous system (ANS) and neuroendocrine system stimulated by corticotropin-releasing hormone (CRH). IBS subjects with higher alexithymia, a risk factor for FSS, showed stronger activity in the insula during rectal distention but reduced subjective sensitivity. Reduced top-down regulation of the ANS and CRH system by mPFC and pACC, discordance between the insula response to stimulation and subjective sensation of pain, and stronger threat responses in hypervigilance-related areas may be a candidate brain-based biomarker.

Timing of Nutrient Ingestion after Mild to Moderate Cycling Exercise Does Not Affect Gastric Emptying Rate in Humans

This study examined the effect of carbohydrate drink ingestion timing on gastrointestinal tract blood flow and motility after mild cycling exercise. Eight healthy participants were randomly assigned to ingest a liquid solution with 75 g glucose at either 5 min (PE-5) or 30 min (PE-30) after a single bout of leg cycling exercise according to target heart rate (approximately 120 beats/min). As the control trial (Con), participants ingested the same liquid solution without exercise. Celiac artery blood flow (BF), superior mesenteric artery BF, and gastric emptying rate were assessed by ultrasonography before and for 60 min after ingesting the glucose solution. Blood lactate, glucose, and plasma insulin were also measured at baseline and for 60 min after ingesting the glucose solution. Celiac artery BF significantly decreased from resting baseline immediately after exercise in both the PE-5 and PE-30 trials, and then returned to resting baseline just before the ingestion of glucose solution in the PE-30 trial. After ingesting the glucose solution, changes in celiac artery BF, superior mesenteric artery BF, % gastric emptying rate, blood lactate, blood glucose, and plasma insulin were not significantly different among the three trials. The timing of nutrient ingestion after mild exercise does not seem to impact the subsequent gastrointestinal motility, blood flow, and glycemic responses.

Anxiety may be a risk factor for experiencing gastrointestinal symptoms during endurance races: An observational study

Scarce research has examined the links between stress, anxiety, and gastrointestinal (GI) symptoms during competition, despite that they are positively correlated in the general population. A total of 186 endurance athletes completed the Perceived Stress Scale (PSS)-14, Anxiety Sensitivity Index (ASI)-3, and State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA) before races. Afterwards, they reported the severity of in-race GI symptoms. Associations between high levels of stress and anxiety (defined as the top tertile) and GI distress (≥3 on a 0-10 scale) were examined using logistic regression. Athletes with high PSS-14 scores did not have greater odds of GI symptoms, except nausea (odds ratio [OR] = 2.21, 95% confidence interval [CI] 1.02-4.78). High scores on the STICSA-trait were associated with nausea (OR = 3.43, 95% CI 1.57-7.50) and regurgitation/reflux (OR = 3.31, 95% CI 1.26-8.73). Among a sub-sample of 125 participants that completed STICSA-state questionnaires, higher anxiety was associated with nausea (OR = 5.57, 95% CI 1.96-15.83), regurgitation/reflux (OR = 3.75, 95% CI 1.17-12.00), fullness (OR = 2.98, 95% CI 1.05-8.49), and cramping (OR = 3.99, 95% CI 1.36-11.68). The ORs remained relatively stable after adjusting for age, gender, experience, body mass index, type of race, and race duration. ASI-3 scores were not associated with symptoms. Individuals with higher levels of anxiety, especially on the morning of a race, may be prone GI distress, particularly nausea, regurgitation/reflux, and cramping.

Therapeutic potential of serotonin 4 receptor for chronic depression and its associated comorbidity in the gut

The latest estimates from world health organization suggest that more than 450 million people are suffering from depression and other psychiatric conditions. Of these, 50-60% have been reported to have progression of gut diseases. In the last two decades, researchers introduced incipient physiological roles for serotonin (5-HT) receptors (5-HTRs), suggesting their importance as a potential pharmacological target in various psychiatric and gut diseases. A growing body of evidence suggests that 5-HT systems affect the brain-gut axis in depressive patients, which leads to gut comorbidity. Recently, preclinical trials of 5-HT4R agonists and antagonists were promising as antipsychotic and prokinetic agents. In the current review, we address the possible pharmacological role and contribution of 5-HT4R in the pathophysiology of chronic depression and associated gut abnormalities. Physiologically, during depression episodes, centers of the sympathetic and parasympathetic nervous system couple together with neuroendocrine systems to alter the function of hypothalamic-pituitary-adrenal (HPA) axis and enteric nervous system (ENS), which in turn leads to onset of gastrointestinal tract (GIT) disorders. Consecutively, the ENS governs a broad spectrum of physiological activities of gut, such as visceral pain and motility. During the stages of emotional stress, hyperactivity of the HPA axis alters the ENS response to physiological and noxious stimuli. Consecutively, stress-induced flare, swelling, hyperalgesia and altered reflexes in gut eventually lead to GIT disorders. In summary, the current review provides prospective information about the role and mechanism of 5-HT4R-based therapeutics for the treatment of depressive disorder and possible consequences for the gut via brain-gut axis interactions. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.

Relationship of Cannabis Use Disorder and Irritable Bowel Syndrome (IBS): An Analysis of 6.8 Million Hospitalizations in the United States

Background: Irritable bowel syndrome (IBS) is a chronic multifactorial gastrointestinal condition that substantially affects the quality of life. Research have suggested an increasing trend in cannabis use to alleviate IBS-related psychiatric symptoms. Objectives: We aim to investigate the association of psychiatric comorbidities and cannabis use disorders (CUD) in hospitalized IBS patients. Methods: We analyzed 31,272 IBS hospitalizations in patients (aged 15-54 years) from the Nationwide Inpatient Sample (NIS). We utilized logistic regression to evaluate the adjusted odds ratio (aOR) of CUD and psychiatric comorbidities. Results: Anxiety (26.3%) and depressive (24.8%) disorders were prevalent and increased the odds for IBS-hospitalization by 2.5 and 1.8 times respectively. Tobacco use disorder was most prevalent (24.5%) followed by CUD (3.7%). After controlling for demographics, psychiatric and medical comorbidities, and other substance use disorders, CUD had higher odds for IBS hospitalizations (aOR 1.407, 95% CI 1.32-1.50). IBS hospitalizations with CUD increased by 32.8% from 2010 to 2014. CUD patients were younger (15-24 years, aOR 5.4, 95% CI 4.27-6.77), males (aOR 1.8, 95% CI 1.59-2.09) and African Americans (aOR 2.8, 95% CI 1.45-2.23) and from low-income families (aOR 1.9, 95% CI 1.58-2.39). Conclusions: We found that patients with CUD have 40.7% higher odds for IBS-hospitalizations with a rising trend of CUD and related psychiatric comorbidities which may further worsen IBS and health quality of life. With limited evidence of efficacy and safety of cannabis in IBS, larger, randomized controlled studies are required to examine its therapeutic efficacy.

The Role of Interoception in the Pathogenesis and Treatment of Anorexia Nervosa: A Narrative Review

Anorexia nervosa (AN) is a psychiatric illness characterized by extreme overvaluation of weight and disturbed eating. Despite having the highest mortality rate of any psychiatric illness, the etiology and neurobiology of AN are poorly understood. A growing body of research has begun to elucidate the role of reward processing, as well as cognitive and limbic networks, in the symptomology of AN. However, these advances have so far failed to contribute therapeutically, suggesting a new understanding may be necessary. A disturbance in the interoceptive system, involved in perceiving and interpreting the physiological condition of the body, has recently been proposed as a central mechanism of pathology in AN, through links to hunger and satiety, risk prediction errors, emotional awareness, and body dysmorphia. This review summarizes the existing literature in order to clarify possible underlying mechanisms and proposes a novel model of the neuro-circuitry of AN. Detailed neuroanatomical studies and new methods for studying interoception may allow further refinement of this model and the development of improved treatment.

Integrative Approach to Pediatric Nausea

Nausea is a bothersome symptom that is commonly seen in the pediatric population. The pathophysiology of nausea is complex and involves the central nervous system, the enteric nervous system, gastrointestinal tract motility, and psychologic influences. Pharmacologic and nonpharmacologic therapies are available for treating nausea. Mind-body interventions (hypnosis, biofeedback), botanicals and supplements (ginger, enteric-coated peppermint oil), aromatherapy, and acupuncture have emerging evidence for effectively treating pediatric nausea. [Pediatr Ann. 2019;48(6):e236-e242.].

The Effects of High-Temperature Weather on Human Sleep Quality and Appetite

High-temperature weather appears in high frequency, big strength, and long duration in the summer. It is therefore important to study the effects of high-temperature weather on sleep quality and appetite. Ten healthy college students were selected as subjects. The experiment conditions were divided by the daily maximum temperature into 28 °C, 32 °C, 36 °C, and 38 °C. The objective sleep quality was measured by an intelligent sleep monitoring belt, and the subjective sleep quality was measured by a questionnaire survey. The subjective appetites were assessed by a visual analog scale (VAS), and the objective appetites were assessed by the meal weight and the meal time. For sleep quality, the objective results indicated that the sleep quality at 32 °C was the best, followed by 28 °C, while the sleep quality at 36 °C and 38 °C was the worst. Significant effects were mainly reflected in sleep duration and shallow sleep. The subjective results showed that temperature had significant effects on sleep calmness, difficulty in falling asleep, sleep satisfaction, and sleep adequateness. For appetite, the VAS results indicated that high temperatures mainly led to a reduction of appetite at lunch time. The meal weights of lunch were larger than those of supper except for 28 °C, and the meal time of lunch and supper was longer than that of breakfast. The meal time of lunch was longer than that of supper except for 36 °C. This paper can provide a study method and reference data for the sleep quality and appetite of human in high-temperature weather.

Timing of post-resistance exercise nutrient ingestion: effects on gastric emptying and glucose and amino acid responses in humans

This study examined the effects of post-resistance exercise protein ingestion timing on the rate of gastric emptying (GE) and blood glucose (BG) and plasma branched-chain amino acid (BCAA) responses. In all, eleven healthy participants randomly ingested 400 ml of a nutrient-rich drink containing 12 g carbohydrates and 20 g protein at rest (Con), at 5 min (post-exercise (PE)-5) or at 30 min (PE-30) after a single bout of strenuous resistance exercises. The first and second sets comprised ten repetitions at 50 % of each participant's one-repetition maximum (1RM). The third, fourth and fifth sets comprised ten repetitions at 75 % of 1RM, and the sixth set involved repeated repetitions until exhaustion. Following ingestion of the nutrient-rich drink, we assessed the GE rate using 13C-sodium acetate breath test and evaluated two parameters according to the T max-calc (time when the recovery per hour is maximised), which is a standard analytical method, and T 1/2 (time when the total cumulative dose of [13CO2] reaches one-half). T max-calc and T 1/2 were slower for the PE-5 condition than for either the PE-30 or Con condition (T max-calc; Con: 53 (sd 7) min, PE-5: 83 (sd 16) min, PE-30: 62 (sd 9) min, T 1/2; Con: 91 (sd 7) min, PE-5: 113 (sd 21) min, PE-30: 91 (sd 11) min, P<0·05). BG and BCAA responses were also slower for the PE-5 condition than for either the PE-30 or Con condition. Ingesting nutrients immediately after strenuous resistance exercise acutely delayed GE, which affected BG and plasma BCAA levels in blood circulation.

Plausibility criteria for putative pathophysiological mechanisms in functional gastrointestinal disorders: a consensus of experts

BACKGROUND AND AIMS

The functional gastrointestinal disorders (FGIDs) are extremely common conditions associated with a considerable personal, social and health economic burden. Managing FGIDs in clinical practice is challenging because of the uncertainty of symptom-based diagnosis, the high frequency of overlap between these conditions and the limited efficacy of available therapies. It has often been argued that successful drug development and management of FGIDs requires knowledge of the underlying pathophysiology. Numerous and highly variable candidate pathophysiological mechanisms have been implicated in the generation of FGID symptoms, but there is no current consensus on how to best define the relevance of these disturbances.

METHODS

A group of international experts on FGIDs developed plausibility criteria that should be fulfilled by relevant pathophysiological mechanisms in FGIDs.

RESULTS

Five criteria are proposed: (1) the presence of the abnormality in a subset of patients, (2) temporal association between proposed mechanism and symptom(s), (3) correlation between the level of impairment of the mechanism and symptom(s), (4) induction of the symptom(s) by provoking the pathophysiological abnormality in healthy subjects and (5) treatment response by a therapy specifically correcting the underlying disorder or congruent natural history of symptoms and dysfunction in the absence of specific therapy. Based on strength of evidence for these five criteria according to the Grading of Recommendations Assessment, Development and Evaluation system, a plausibility score can be calculated for each mechanism.

CONCLUSION

Evaluation of the strength of evidence for candidate pathophysiological abnormalities fulfilling these five plausibility criteria will help to identify the most relevant mechanisms to target for novel diagnostic approaches and for the development of new therapies.

Functional dyspepsia

Functional dyspepsia is one of the most prevalent functional gastrointestinal disorders. Functional dyspepsia comprises three subtypes with presumed different pathophysiology and aetiology: postprandial distress syndrome (PDS), epigastric pain syndrome (EPS) and a subtype with overlapping PDS and EPS features. Functional dyspepsia symptoms can be caused by disturbed gastric motility (for example, inadequate fundic accommodation or delayed gastric emptying), gastric sensation (for example, sensations associated with hypersensitivity to gas and bloating) or gastric and duodenal inflammation. A genetic predisposition is probable but less evident than in other functional gastrointestinal disorders, such as irritable bowel syndrome (IBS). Psychiatric comorbidity and psychopathological state and trait characteristics could also play a part, although they are not specific to functional dyspepsia and are less pronounced than in IBS. Possible differential diagnoses include Helicobacter pylori infection and peptic ulceration. Pharmacological therapy is mostly based on the subtype of functional dyspepsia, such as prokinetic and fundus-relaxing drugs for PDS and acid-suppressive drugs for EPS, whereas centrally active neuromodulators and herbal drugs play a minor part. Psychotherapy is effective only in a small subset of patients, whereas quality of life can be severely affected in nearly all patients. Future therapies might include novel compounds that attempt to treat the underlying gastric and duodenal inflammation.

Intravenous Corticotropin-releasing Hormone Administration Increases Esophageal Electrical Sensitivity in Healthy Individuals

Background/Aims

When a person is experiencing stress, corticotropin-releasing hormone (CRH) can modulate gut physiologies, such as visceral sensation or gastrointestinal motility, and its intravenous administration mimics stress-induced physiological changes. However, the influence of CRH on the esophagus is yet unknown. Accordingly, we investigated whether intravenous CRH administration increases esophageal sensitivity to electrical stimulation in healthy Japanese subjects.

Methods

Twenty healthy subjects were recruited. We quantified the initial perception threshold (IPT) every 15 minutes after CRH injection. Venous blood was collected with a cannula, and both plasma adrenocorticotropic hormone (ACTH) and cortisol were measured at pre-stimulation, 0, 30, 60, 90, and 120 minutes. The results from each time point were compared against a baseline IPT obtained before electrical stimulation was initiated.

Results

When compared to the baseline IPT value (16.9 ± 4.5), CRH significantly decreased electrical threshold of the esophagus at 30, 45, 60, 75 minutes (14.1 ± 4.2, 13.1 ± 5.0, 12.1 ± 5.7, 14.0 ± 5.8 minutes, P 〈 0.01, respectively) after CRH injection, suggesting that CRH increased esophageal sensitivity to the electrical stimulus. CRH also significantly increased plasma ACTH levels at 30 minutes (50.3 ± 17.7, P 〈 0.01), and cortisol levels at 30 minutes (22.0 ± 6.7 minutes, P 〈 0.01) and 60 minutes (20.3 ± 6.7 minutes, P 〈 0.01) after CRH injection, when compared to the pre-stimulation ACTH and cortisol values.

Conclusion

Intravenous CRH administration increased esophageal electrical sensitivity in normal subjects, emphasizing the important role of stress in esophageal sensitivity.

Timing of postexercise carbohydrate-protein supplementation: roles of gastrointestinal blood flow and mucosal cell damage on gastric emptying in humans

It is well known that protein ingestion immediately after exercise greatly stimulates muscle protein synthesis during the postexercise recovery phase. However, immediately after strenuous exercise, the gastrointestinal (GI) mucosa is frequently injured by hypoperfusion in the organ/tissue, possibly resulting in impaired GI function (e.g., gastric emptying; GE). The aim of this study was to examine the effect of GI blood flow on the GE rate. Eight healthy young subjects performed an intermittent supramaximal cycling exercise for 30 min, which consisted of a 120% V̇o_2peak for 20 s, followed by 20 W for 40 s. The subjects ingested 300 ml of a nutrient drink containing carbohydrate-protein at either 5 min postexercise in one trial (PE-5) or 30 min postexercise in another trial (PE-30). In the control trial (Con), the subjects ingested the same drink without exercise. The celiac artery blood flow (CABF) and superior mesenteric artery blood flow (SMABF) and GE rate were assessed by ultrasonography. Before drink ingestion in PE-5, CABF significantly decreased from baseline, whereas in PE-30, it returned to baseline. Following drink ingestion in PE-5, CABF did not change from baseline, but it significantly increased in PE-30 and Con. SMABF increased significantly later in PE-5 than in PE-30 and Con. The GE rate was consistently slower in PE-5 than in PE-30 and Con. In conclusion, the CABF response after exercise seems to modulate the subsequent GE rate and SMABF response.NEW & NOTEWORTHY A carbohydrate-protein drink was ingested at either 5 min (i.e., profoundly decreased celiac artery blood flow; CABF) or 30 min (i.e., already recovered CABF) postexercise. In the 5-min postexercise trial, the gastric emptying (GE) rate and superior mesenteric artery blood flow (SMABF) response were slower than those in the 30-min postexercise trial. The GE rate and SMABF response may be altered depending on the postexercise CABF response.

Acotiamide improves stress-induced impaired gastric accommodation

BACKGROUND

Gastric accommodation is a reflex reaction related to gastric reservoir function. Psychological stress, such as anxiety, inhibits gastric accommodation in humans. Acotiamide enhances the effect of acetylcholine in the enteric nervous system, enhances gastric contractility, and accelerates delayed gastric emptying. However, the effect of acotiamide on stress-induced impaired gastric accommodation remains unclear. Therefore, we examined the effect of acotiamide on gastric accommodation and stress-induced impaired gastric accommodation using a conscious guinea pig model.

METHODS

A polyethylene bag was inserted through the distal region of the gastric body into the proximal stomach of 5-week-old male Hartley guinea pigs. Gastric accommodation was evaluated by measuring the intrabag pressure in the proximal stomach after oral administration of a liquid meal. In the stress model, animals were subjected to water-avoidance stress. Acotiamide (Z-338) or nizatidine was administered subcutaneously. Fecal output was determined as the number of fecal pellets.

KEY RESULTS

Administration of the liquid meal significantly decreased intrabag pressure, indicating induction of gastric accommodation. Acotiamide treatment prolonged liquid meal-induced gastric accommodation and significantly increased the number of fecal pellets compared to controls. Water-avoidance stress significantly inhibited liquid meal-induced gastric accommodation. Pretreatment with acotiamide significantly improved stress-induced impaired gastric accommodation. The number of fecal pellets in the acotiamide group increased significantly compared to controls. Acotiamide, but not nizatidine, significantly decreased gastric emptying.

CONCLUSIONS & INFERENCES

Acotiamide prolongs gastric accommodation and improves stress-induced impaired gastric accommodation, indicating a potential role for acotiamide in the treatment of functional dyspepsia through its effects on gastric accommodation reactions.

Tolerable pain reduces gastric fundal accommodation and gastric motility in healthy subjects: a crossover ultrasonographic study

Background

Obstacles to pain management include patients’ reluctance to inform healthcare provides about their pain, and differences in the pain management aims between patients and healthcare providers. The objective of this study was to evaluate whether tolerable pain influences gastric fundal accommodation and gastric motility in healthy subjects.

Methods

We undertook a crossover comparison study to evaluate gastric fundal accommodation and gastric motility in 74 healthy subjects in the presence or absence of tolerable pain. The intensity of tolerable pain was defined as the upper limit of pain compatible with comfortable daily life. Pain was generated by clipping a clothes pin to the ear lobe, and the intensity of pain was adjusted by inserting the gauze between the ear lobe and the pin. Gastric fundal accommodation and gastric motility were assessed by external ultrasonography. The cross-sectional area of the proximal stomach was measured after subjects had taken 100 mL-liquid meals four times, then the amplitude and frequency of antral contractions were measured.

Results

The median numerical rating scale of tolerable pain was 3 (interquartile rang 2–4). Gastric fundal accommodation, gastric motility and gastric emptying were all significantly impaired by tolerable pain (P < 0.001 for all comparisons).

Conclusions

Even tolerable pain can reduce gastric fundal accommodation and gastric motility, which could result in anorexia or decreased quality of life. Our findings provide important insights into pain management education for patients tolerating pain and healthcare providers encouraging patients to tolerate pain. This study was registered retrospectively.

Relationship of body weight with gastrointestinal motor and sensory function: studies in anorexia nervosa and obesity

Background

Whether gastrointestinal motor and sensory function is primary cause or secondary effect of abnormal body weight is uncertain. Moreover, studies relating continuous postprandial sensations of satiation to measurable pathology are scarce. This work assessed postprandial gastrointestinal function and concurrent sensations of satiation across a wide range of body weight and after weight change.

Methods

Patients with anorexia nervosa (AN) and obesity (OB) were investigated in reference to normal weight controls (HC). AN were additionally investigated longitudinally. Gastric emptying, antral contractions and oro-cecal transit after ingestion of a solid meal were investigated by MRI and ¹³C-lactose-ureide breath test. The dependency of self-reported sensations of satiation on the varying degree of stomach filling during gastric emptying was compared between groups.

Results

24 AN (BMI 14.4 (11.9–16.0) kg/m²), 16 OB (34.9 (29.6–41.5) kg/m²) and 20 HC (21.9 (18.9–24.9) kg/m²) were studied. Gastric half-emptying time (t₅₀) was slower in AN than HC (p = 0.016) and OB (p = 0.007), and a negative association between t₅₀ and BMI was observed between BMI 12 and 25 kg/m² (p = 0.007). Antral contractions and oro-cecal transit were not different. For any given gastric content volume, self-reported postprandial fullness was greater in AN than in HC or OB (p < 0.001). After weight rehabilitation, t₅₀ in AN tended to become shorter (p = 0.09) and postprandial fullness was less marked (p < 0.01).

Conclusions

A relationship between body weight and gastric emptying as well as self-reported feelings of satiation is present. AN have slower gastric emptying and heightened visceral perception compared to HC and OB. Longitudinal follow-up after weight rehabilitation in AN suggests these abnormalities are not a primary feature, but secondary to other factors that determine abnormal body weight.

Trial registration

Registered July 20, 2009 at ClinicalTrials.gov (NCT00946816).

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0560-y) contains supplementary material, which is available to authorized users.

Sleep disturbance and enhanced esophageal capsaicin sensitivity in patients with gastroesophageal reflux disease

BACKGROUND AND AIM

Esophageal infusion of capsaicin-containing red pepper sauce induced heartburn symptoms in patients with gastroesophageal reflux disease (GERD). We aimed to test the hypothesis whether sleep disturbance modulates esophageal sensitivity to capsaicin infusion in patients with GERD.

METHODS

We enrolled 40 patients with their sleep quality measured by the Pittsburg Sleep Quality Index with > 5 indicating sleep disturbance. Esophageal sensation to capsaicin infusion was documented via measures of lag time to initial heartburn perception, heartburn intensity rating, and sensitivity score by esophageal infusion of capsaicin-containing red pepper sauce. Objective sleep measures were assessed by ambulatory actigraphy.

RESULTS

We found 22 patients with sleep disturbance. The patients with sleep disturbance had shorter lag time to initial heartburn perception (P = 0.03) and greater sensory intensity rating (P = 0.02). The sensitivity score for capsaicin infusion was greater in patients with sleep disturbance when compared with those without sleep disturbance (P = 0.04). Actigraphy measures revealed that patients with sleep disturbance also had poor sleep efficiency (P = 0.04), longer average awakening time (P = 0.03), and greater total activity account (P = 0.04). The lag time for perceiving capsaicin infusion was positively correlated with total sleep time (r = 0.43, P = 0.03).

CONCLUSIONS

We have shown that GERD patients with sleep disturbance have significantly enhanced heartburn perception to capsaicin infusion as compared with those with normal sleep. Our findings suggest that sleep disturbance is associated with esophageal hypersensitivity to capsaicin infusion in patients with GERD.

Functional Heartburn Overlaps With Irritable Bowel Syndrome More Often than GERD

OBJECTIVES

We aimed to evaluate the prevalence of irritable bowel syndrome (IBS) in patients with typical reflux symptoms as distinguished into gastroesophageal reflux disease (GERD), hypersensitive esophagus (HE), and functional heartburn (FH) by means of endoscopy and multichannel intraluminal impedance (MII)-pH monitoring. The secondary aim was to detect pathophysiological and clinical differences between different sub-groups of patients with heartburn.

METHODS

Patients underwent a structured interview based on questionnaires for GERD, IBS, anxiety, and depression. Off-therapy upper-gastrointestinal (GI) endoscopy and 24 h MII-pH monitoring were performed in all cases. In patients with IBS, fecal calprotectin was measured and colonoscopy was scheduled for values >100 mg/kg to exclude organic disease. Multivariate logistic regression analysis was performed to identify independent risk factors for FH.

RESULTS

Of the 697 consecutive heartburn patients who entered the study, 454 (65%) had reflux-related heartburn (GERD+HE), whereas 243 (35%) had FH. IBS was found in 147/454 (33%) GERD/HE but in 187/243 (77%) FH patients (P<0.001). At multivariate analysis, IBS and anxiety were independent risk factors for FH in comparison with reflux-related heartburn (GERD+HE).

CONCLUSIONS

IBS overlaps more frequently with FH than with GERD and HE, suggesting common pathways and treatment. HE showed intermediate characteristic between GERD and FH.

The 5-HT1A receptor agonist buspirone improves esophageal motor function and symptoms in systemic sclerosis: a 4-week, open-label trial

BACKGROUND

Acute administration of the oral 5-HT1A receptor agonist buspirone, which is commonly used as an anxiolytic drug, may improve compromised lower esophageal sphincter function. In an open-label trial we assessed the effects of buspirone on esophageal motor function and symptoms in patients with esophageal involvement associated with systemic sclerosis (SSc).

METHODS

Thirty consecutive patients with SSc and symptomatic esophageal involvement, despite treatment with proton pump inhibitors, underwent high resolution manometry and chest computed tomography for assessment of motor function and esophageal dilatation, respectively. Regurgitation, heartburn, dysphagia, and chest pain severity was subjectively scored by visual analog scales. Manometric parameters (primary endpoint) and symptom severity (secondary endpoint) were re-examined after 4-week daily administration of 20 mg buspirone. Other medications remained unchanged.

RESULTS

Eight patients did not complete the trial because of buspirone-associated dizziness (n = 2), or nausea (n = 2), or reluctancy to undergo final manometry. In the remaining 22 patients lower esophageal sphincter (LES) resting pressure increased from 7.7 ± 3.9 to 12.2 ± 4.6 mmHg (p = 0.00002) after buspirone administration; other manometric parameters did not change. Statistical analysis revealed negative correlation between individual increases in resting LES pressure and supra-aortic esophageal diameter (r = -0.589, p = 0.017), suggesting a more beneficial effect in patients with less severely affected esophageal function. Heartburn and regurgitation scores decreased at 4 weeks compared to baseline (p = 0.001, and p = 0.022, respectively).

CONCLUSION

Our findings warrant more conclusive evaluation with a double-blind controlled study; however, buspirone could potentially be given under observation for objective improvement in all patients with SSc who report reflux symptoms despite undergoing standard treatment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02363478 Registered: 21-02-2014.

Impairment of gastric accommodation induced by water-avoidance stress is mediated by 5-HT2B receptors

BACKGROUND

Psychological stress has been shown to impair gastric accommodation (GA), but its mechanism has not been elucidated. This study was conducted to clarify the role of 5-HT2B receptors in a guinea pig model of stress-induced impairment of GA.

METHODS

Gastric accommodation was evaluated by measuring the intrabag pressure in the proximal stomach after administration of a liquid meal. The guinea pigs were subjected to water-avoidance stress. The role of 5-HT2B receptors in impairment of GA was investigated by administering a 5-HT2B receptor agonist (BW723C86) or antagonist (SB215505), the traditional Japanese medicine rikkunshito (RKT), a muscarinic M3 receptor antagonist (1,1-dimethyl-4-diphenylacetoxypiperidium iodide [4-DAMP]), or a nitric oxide synthase inhibitor (Nω -nitro-L-arginine [L-NNA]).

KEY RESULTS

In normal animals, liquid meal-induced GA was inhibited by BW723C86, but was not affected by SB215505. The inhibition of GA by BW723C86 was reversed by co-administration of 4-DAMP. Compared to normal animals, GA in stressed animals was significantly inhibited. SB215505 and RKT significantly suppressed stress-induced impairment of GA. After meal administration, the level of cyclic guanosine monophosphate in gastric fundus tissue increased by approximately twofold in normal animals, but did not change in stressed animals. The inhibition of GA by L-NNA was suppressed by SB215505 or RKT. At a dose that did not affect GA in normal animals, BW723C86 exacerbated the impairment of GA in stressed animals.

CONCLUSIONS AND INFERENCES

Stress-induced impairment of GA may be mediated by an increased responsiveness of 5-HT2B receptors, and activation of the 5-HT2B receptor signaling pathway may have an inhibitory effect on nitric oxide function.

Efficacy of Mirtazapine in Patients With Functional Dyspepsia and Weight Loss

BACKGROUND & AIMS

A subset of patients with functional dyspepsia (FD) present with early satiation and weight loss, for which there are no established therapeutic options. We investigated the efficacy of mirtazapine (an antidepressant and antagonist of the histamine receptor H1, the α2 adrenergic receptor, and the serotonin receptors 5-HT2C and 5-HT-3) in patients with FD and weight loss.

METHODS

We conducted a randomized, placebo-controlled pilot trial that studied 34 patients with FD (29 women; mean age, 35.9 ± 2.3 years) with weight loss >10% of original body weight (mean loss, 12.4 ± 2.3 kg) without depression or anxiety. After a run-in period, patients were randomly assigned to groups given placebo (n = 17) or mirtazapine 15 mg each day for 8 weeks (n = 17) in a double-blind manner. Subjects were evaluated during a 2-week baseline and 8-week treatment for dyspepsia symptom severity, quality of life (on the basis of the Nepean Dyspepsia Index), and gastrointestinal-specific anxiety; they were given a nutrient challenge test and weighed. Data were analyzed by using linear mixed models, followed by planned contrasts with adaptive step-down Bonferroni multiple testing correction.

RESULTS

Two patients in each group dropped out. At weeks 4 and 8, mirtazapine significantly reduced mean dyspepsia symptom severity scores compared with week 0 (P = .003 and P = .017, respectively); there was no significant reduction in the placebo group (P > .37 for weeks 4 and 8). The difference in change from week 0 between mirtazapine and placebo showed a trend with a large effect size at week 4 (P = .059) that was not significant at week 8 (P = .55). However, improvements from week 0 to weeks 4 and 8 were significantly larger in the mirtazapine group than placebo group for early satiation, quality of life, gastrointestinal-specific anxiety, weight, and nutrient tolerance (mostly with large effect sizes).

CONCLUSIONS

In a randomized, placebo-controlled trial, mirtazapine significantly improved early satiation, quality of life, gastrointestinal-specific anxiety, nutrient tolerance, and weight loss in patients with FD. ClinicalTrials.gov number: NCT01240096.

Biopsychosocial Aspects of Functional Gastrointestinal Disorders

In this paper, we provide a general framework for understanding the functional gastrointestinal disorders (FGID) from a biopsychosocial perspective. More specifically, we provide an overview of the recent research on how the complex interactions of environmental, psychological, and biological factors contribute to the development and maintenance of the FGID. We emphasize that considering and addressing all these factors is a conditio sine qua non for appropriate treatment of these conditions. First, we provide an overview of what is currently known about how each of these factors - the environment, including the influence of those in an individual's family, the individual's own psychological states and traits, and the individual's (neuro)physiological make-up - interact to ultimately result in the generation of FGID symptoms. Second, we provide an overview of commonly used assessment tools which can assist clinicians in obtaining a more comprehensive assessment of these factors in their patients. Finally, the broader perspective outlined earlier is applied to provide an overview of centrally acting treatment strategies, both psychological and pharmacological, which have been shown to be efficacious to treat FGID.

A family caregiver's relaxation enhances the gastric motility function of the patient: a crossover study

BACKGROUND

The primary purpose of this study was to assess the effect of a caregiver's relaxation on the gastric motility function of the patient. The secondary purpose was to evaluate changes in the caregiver's willingness to perform self-care following feedback on the results of the primary purpose.

METHODS

Subjects were 26 patients with a decreased level of consciousness who received gastrostomy tube feeding and their 26 family caregivers. We compared the patient's gastric motility under the condition of having his or her hand held with and without caregiver relaxation (crossover study). Changes in the caregiver's willingness to perform self-care following feedback on the results was evaluated using self-administered questionnaires. Hypnosis was used for relaxation. The outcomes assessed for gastric motility function were the motility index and gastric emptying rate by ultrasonography examination.

RESULTS

Hand-holding by the family caregiver while he or she was receiving relaxation enhanced the patient's gastric motility function. By giving feedback on the results, the caregiver's willingness to adopt self-care was increased and his or her sense of guilt was reduced.

CONCLUSIONS

This study suggested that a caregiver's relaxation increases the gastric motility function of the patient and that gettinng feedback including the positive results increases the caregiver's willingness to perform self-care, which consequently reduce the caregiver burden.

Acute Anxiety and Anxiety Disorders Are Associated With Impaired Gastric Accommodation in Patients With Functional Dyspepsia

BACKGROUND & AIMS

Functional dyspepsia (FD) is associated with impaired gastric accommodation, as well as gastric hypersensitivity, delayed emptying, and psychosocial comorbidities. In healthy people, acute anxiety impairs gastric accommodation, which is traditionally quantified as the average increase in gastric volume after a meal over 1 hour. However, this quantification approach does not address the complex time course of the gastric accommodation response to a meal. We modeled gastric accommodation in patients with FD as a function of postprandial time, to investigate whether it is associated with psychosocial factors (state anxiety, anxiety disorder, depression) and gastric sensorimotor function (sensitivity, emptying).

METHODS

We studied gastric sensorimotor function in 259 consecutive patients diagnosed with FD based on Rome II at the University Hospitals Leuven from January 2002 through February 2009. Subjects underwent a gastric barostat and breath test; psychiatric comorbidity was assessed by questionnaires. Subjects completed the State-Trait Anxiety Inventory to measure levels of state anxiety immediately before and after gastric barostat analysis. The time course of the accommodation response was analyzed using mixed models. Psychological and sensorimotor variables were added to the model as continuous (state anxiety) or dichotomous (gastric sensitivity and emptying, anxiety disorders, depression) covariates, including their interaction with the time effects.

RESULTS

In subjects with FD, delayed emptying (β = 50.3 ± 15.9; P = .002) and lower state anxiety (β = -1.7 ± 0.7; P = .012) were associated with an upward shift of the accommodation curve. There was a significant interaction between comorbid anxiety disorder and linear (β = 8.2 ± 3.5; P = .02), quadratic (β = -0.4 ± 0.1; P = .004), and cubic (β = 0.005 ± 0.002; P = .002) effects of time: patients with a comorbid anxiety disorder had significantly slower initial increases in gastric volume to a lower maximum, and a slower return to baseline, compared with patients without anxiety disorder. Depression and gastric sensitivity were not associated significantly with gastric accommodation.

CONCLUSIONS

In patients with FD, state anxiety and comorbid anxiety disorders are associated with impaired accommodation; gastric emptying also is associated with accommodation in these patients. These findings help elucidate the complex interactions between psychological processes and disorders, gastric sensorimotor dysfunction, and symptom reporting in patients with FD.

Efficiency of Very Low Doses of Antibodies to S100 Protein in the Complex Therapy of Functional Dyspepsia in Children

We showed the data on clinical efficiency of low doses of antibodies to brain-specific protein S100 in the complex therapy of schoolchildren with painful variant of functional dyspepsia syndrome. Significant positive effects of the substance on the dynamics of epigastric pain, in particular, its duration, were found. The maximum clinical effect was observed in children with emotional disorders (~1/3 of all examined children). Along with significant decrease in frequency appearance and duration of pain syndrome, the substance also normalized emotional state and improved attention concentration in children.

Central nervous system control of gastrointestinal motility and secretion and modulation of gastrointestinal functions

Although the gastrointestinal (GI) tract possesses intrinsic neural plexuses that allow a significant degree of autonomy over GI functions, the central nervous system (CNS) provides extrinsic neural inputs that regulate, modulate, and control these functions. While the intestines are capable of functioning in the absence of extrinsic inputs, the stomach and esophagus are much more dependent upon extrinsic neural inputs, particularly from parasympathetic and sympathetic pathways. The sympathetic nervous system exerts a predominantly inhibitory effect upon GI muscle and provides a tonic inhibitory influence over mucosal secretion while, at the same time, regulates GI blood flow via neurally mediated vasoconstriction. The parasympathetic nervous system, in contrast, exerts both excitatory and inhibitory control over gastric and intestinal tone and motility. Although GI functions are controlled by the autonomic nervous system and occur, by and large, independently of conscious perception, it is clear that the higher CNS centers influence homeostatic control as well as cognitive and behavioral functions. This review will describe the basic neural circuitry of extrinsic inputs to the GI tract as well as the major CNS nuclei that innervate and modulate the activity of these pathways. The role of CNS-centered reflexes in the regulation of GI functions will be discussed as will modulation of these reflexes under both physiological and pathophysiological conditions. Finally, future directions within the field will be discussed in terms of important questions that remain to be resolved and advances in technology that may help provide these answers.

Anxiety Is Linked to New-Onset Dyspepsia in the Swedish Population: A 10-Year Follow-up Study

BACKGROUND & AIMS

Functional dyspepsia (FD) is associated with anxiety but it is not clear if one causes the other. We investigated whether anxiety and depression precede the onset of FD (based on the modified Rome III criteria) and gastroesophageal reflux symptoms (GERS) in a population-based follow-up study.

METHODS

Participants from the Kalixanda study (n = 3000), randomly selected from the national population register of Sweden, were given the validated Abdominal Symptom Questionnaire 1998-2001; 1000 of these participants then were selected randomly to undergo esophagogastroduodenoscopy and were given the Abdominal Symptom Questionnaire along with the Hospital Anxiety and Depression Scale questionnaire. All eligible subjects who underwent endoscopy (n = 887) were invited to participate in a follow-up study in June-August 2010 and were given the same questionnaires. Data were analyzed by logistic regression.

RESULTS

Of the 703 subjects who completed the follow-up questionnaires (79.3%); 110 were found to have FD at baseline (15.6%) and 93 at the follow-up examination (13.3%); 48 of these were new cases of FD. GERS without organic disease was reported by 273 individuals (38.8%) at baseline and by 280 at follow-up examination (39.8%); 93 cases were new. Major anxiety was associated with FD at the follow-up evaluation (odds ratio [OR], 6.30; 99% confidence interval [CI], 1.64-24.16). Anxiety was associated with postprandial distress syndrome at baseline (OR, 4.83; 99% CI, 1.24-18.76) and at the follow-up examination (OR, 8.12; 99% CI, 2.13-30.85), but not with epigastric pain syndrome. Anxiety at baseline was associated with new-onset FD at the follow-up examination (OR, 7.61; 99% CI, 1.21-47.73), but not with GERS.

CONCLUSIONS

In a study of the Swedish population, anxiety at baseline, but not depression, increased the risk for development of FD by 7.6-fold in the next 10 years. Anxiety did not affect risk for GERS.

Accumulated mental stress study using the meridians of traditional Chinese medicine with photoplethysmography

OBJECTIVES

To investigate accumulated mental stress according to the concept of the meridians of Traditional Chinese Medicine (TCM). This stress was quantified by using pulse spectrum analysis of finger-tip photoplethysmography (PPG). Stress accumulation is one of the main causes of cardiovascular disease and depression in humans, resulting in chronic physiologic malfunctions; however, few studies have thoroughly assessed the quantitative evaluation of accumulative stress using the concept of TCM.

DESIGN

This study investigated accumulated mental stress from the perspective of TCM based on an 8-day experiment. The theory of organ resonance was integrated into the proposed PPG sensing instrument to capture the nine harmonics of TCM. Participants were given daily mental arithmetic tasks over 1 week to simulate stress accumulation, and trends in the proportion of the nine harmonics of TCM were extracted over several days and analyzed to identify the affective factors related to cumulative stress.

RESULTS

The experimental results showed that the kidney harmonic proportion (C2) and stomach harmonic proportion (C5) were significant only on the first few days because of a physiologic phenomenon of temporary stimulation. Most important, the trend of the liver harmonic proportion (C1) from days 3 to 8 dramatically increased and became gradually saturated because of the influence of accumulated mental stress.

CONCLUSIONS

The results strongly suggest that pulse spectrum analysis of the PPG signal provides physiologically and pathologically important information on accumulated mental stress and can be useful for TCM analysis.

Impact of eating attitude and impairment of physical quality of life between tertiary clinic and primary clinic functional dyspepsia outpatients in Japan

BACKGROUND/AIMS

There is no available data on factors associated with healthcare-seeking behavior for functional dyspepsia (FD) symptoms at ei-ther tertiary or primary clinics in Japan. Therefore, we aimed to compare clinical symptoms and life styles such as sleep dis-orders and eating attitude in FD patients visiting general practitioners at primary clinics with those consulting gastro-enterologists at tertiary clinics to clarify healthcare-seeking patterns in Japanese patients.

METHODS

Fifty-one FD outpatients in a tertiary clinic (college hospital), 50 FD outpatients visiting primary clinics and 50 healthy volunteers were enrolled. Clinical symptoms, quality of life, sleep disorders, eating attitude and anxiety were estimated using the Gastroin-testinal Symptom Rating Scale (GSRS), Social Functioning-8 (SF-8) test, Pittsburg Sleep Quality Index (PSQI) test and State-Trait Anxiety Inventory (STAI) for FD outpatients and healthy volunteers.

RESULTS

FD outpatients exhibited higher mean scores of GSRS than healthy volunteers. The SF-8 physical component summary scores in the tertiary clinic group were significantly lower than those in the primary clinic group. GSRS scores were significantly (P < 0.001, P = 0.002) associated with global PSQI scores in FD outpatients as well as with STAI-trait scores (P = 0.006, P = 0.001) compared to healthy volunteers. The frequency of eating between meals in the primary clinic group was significantly (P < 0.05) higher than that in the tertiary clinic group.

CONCLUSIONS

It may be important for clarification of healthcare-seeking behavior to determine the difference in both impairment of physical quality of life and eating attitudes between tertiary clinic and primary clinic FD outpatients in Japan.(J Neurogastroenterol Motil 2014;20:506-515).

Relationship of gastrointestinal symptoms and psychosocial distress to gastric retention in children

OBJECTIVES

To determine whether gastrointestinal (GI) symptoms (abdominal pain, nonpain GI symptoms, nausea) and/or psychosocial distress differ between children with/without gastroparesis and whether the severity of GI symptoms and/or psychosocial distress is related to the degree of gastroparesis.

STUDY DESIGN

Children aged 7-18 years (N = 100; 63 female patients) undergoing a 4-hour gastric emptying scintigraphy study completed questionnaires evaluating GI symptoms, anxiety, and somatization for this prospective study. Spearman correlation, Mann-Whitney, t-test, and χ(2) tests were used as appropriate for statistical analysis.

RESULTS

Children with gastroparesis (n = 25) were younger than those with normal emptying (12.6 ± 3.5 vs 14.3 ± 2.6 years, P = .01). Because questionnaire responses from 7- to 10-year-old children were inconsistent, only patient-reported symptoms from 11- to 18-year-olds were used. Within this older group (n = 83), children with gastroparesis (n = 17) did not differ from children with normal emptying in severity of GI symptoms or psychosocial distress. In children with gastroparesis, gastric retention at 4 hours was related inversely to vomiting (r = -0.506, P = .038), nausea (r = -0.536, P = .019), difficulty finishing a meal (r = -0.582, P = .014), and Children's Somatization Inventory score (r = -0.544, P = .024) and positively correlated with frequency of waking from sleep with symptoms (r = 0.551, P = .022).

CONCLUSIONS

The severity of GI symptoms and psychosocial distress do not differ between children with/without gastroparesis who are undergoing gastric emptying scintigraphy. In those with gastroparesis, gastric retention appears to be inversely related to dyspeptic symptoms and somatization and positively related to waking from sleep with symptoms.

The psyche and gastric functions

Although the idea that gastric problems are in some way related to mental activity dates back to the beginning of the last century, until now it has received scant attention by physiologists, general practitioners and gastroenterologists. The major breakthrough in understanding the interactions between the central nervous system and the gut was the discovery of the enteric nervous system (ENS) in the 19th century. ENS (also called 'little brain') plays a crucial role in the regulation of the physiological gut functions. Furthermore, the identification of corticotropin-releasing factor (CRF) and the development of specific CRF receptor antagonists have permitted to characterize the neurochemical basis of the stress response. The neurobiological response to stress in mammals involves three key mechanisms: (1) stress is perceived and processed by higher brain centers; (2) the brain mounts a neuroendocrine response by way of the hypothalamic-pituitary-adrenal axis (HPA) and the autonomic nervous system (ANS), and (3) the brain triggers feedback mechanisms by HPA and ANS stimulation to restore homeostasis. Various stressors such as anger, fear, painful stimuli, as well as life or social learning experiences affect both the individual's physiologic and gastric function, revealing a two-way interaction between brain and stomach. There is overwhelming experimental and clinical evidence that stress influences gastric function, thereby outlining the pathogenesis of gastric diseases such as functional dyspepsia, gastroesophageal reflux disease and peptic ulcer disease. A better understanding of the role of pathological stressors in the modulation of disease activity may have important pathogenetic and therapeutic implications.

Sleep disorders in functional dyspepsia and future therapy

Sleep disorder is a common medical problem. Sleep disorder has been associated with several diseases, including pulmonary disease, gastroesophageal reflux disease (GERD) and fibromyalgia. Interest in sleep phenomenology and gastrointestinal functioning has recently increased, because sleep disorder causes significant morbidity, as evidenced by the increased need for general medical and mental health treatment for emotional problems. A number of studies have found an association between sleep disorders and functional gastrointestinal (GI) disorders. Although arousal from sleep serves several protective roles, such as increase in the speed of esophageal clearance and in airway refluxes to prevent aspiration, awakening from sleep unfortunately induces impairment of sleep quality. Some investigations about the relationship between psychogenic factors and gut motility are controversial. In addition, reports of alterations in gut motility during sleep have also been contradictory. We have evaluated sleep disorder in functional dyspepsia (FD) patients using Pittsburgh Sleep Quality Index (PSQI) score. In our recent data, PSQI score of FD patients was significantly higher compared to that in healthy volunteers. Another study has reported that the distribution of subjects who thought that they got enough sleep was significantly lower for the FD/irritable bowel syndrome (IBS) subjects than for control subjects. Several studies have reported that anti-acid therapy and prokinetic agents are effective for certain FD patients. In addition, previous study has reported tricyclic antidepressants (TCA) drugs are effective for some FD patients. Finally, new drug, actiamide, a muscarinic antagonist and cholinesterase inhibitor, significantly improves Postprandial Distress Syndrome (PDS) symptoms. It might be critical issues for determination of precise mechanism for functional gastrointestinal disorders to clarify the relationship between gut motility and sleep disorders.

Effects of Kampo on functional gastrointestinal disorders

This article reviews the effectiveness of Kampo (traditional Japanese herbal medicine) in the treatment of functional gastrointestinal disorders, especially functional dyspepsia (FD) and irritable bowel syndrome (IBS). The results of four randomized, controlled trials (RCTs) suggested the usefulness of rikkunshito in relieving the subjective symptoms of patients with FD. Rikkunshito significantly improved not only gastric symptoms, such as epigastiric discomfort, but also extra-gastric symptoms, such as general fatigue, when compared with control drugs. The therapeutic effects of rikkunshito were more evident when it was prescribed to patients with “kyosho”, i.e., low energy. Two RCTs suggested the efficacy of keishikashakuyakuto for IBS.

Basic research studies have demonstrated that these Kampo medicines have multiple sites of action to improve subjective symptoms. For example, rikkunshito improves gastric motility dysfunction, including impaired adaptive relaxation and delayed gastric emptying, gastric hypersensitivity, and anorexia via facilitation of ghrelin secretion. It also exhibits anti-stress effects, i.e., it attenuates stress-induced exacerbation of gastric sensation and anorexia, as well as the hypothalamic-pituitary-adrenocortical axis and sympathetic activation. Keishikashakuyakuto exhibited not only an antispasmodic effect on intestinal smooth muscle, but also antidepressant-like effects. Case series suggest that other Kampo prescriptions are also effective for FD and IBS. However, further studies are necessary to evaluate their efficacy.

Proton pump inhibitor responders who are not confirmed as GERD patients with impedance and pH monitoring: who are they?

BACKGROUND

A short-course of proton pump inhibitors (PPIs) is often used to confirm gastroesophageal reflux disease (GERD). However, some patients with PPI responsive heartburn do not seem to have evidence of GERD on impedance-pH monitoring (MII-pH). The aim of the study was to evaluate patients with reflux symptoms and a negative endoscopy, who well respond to PPIs with MII-pH.

METHODS

We enrolled 312 patients with GERD symptoms and negative endoscopy: 144 reported well-controlled symptoms after 8-week PPIs and 155 were non-responders. Symptom relief was evaluated with GERD Impact Scale and visual analog scale score. All patients underwent MII-pH off-therapy. Thirteen patients were excluded from analysis. Patients were grouped as follows: non-erosive reflux disease (NERD; increased acid exposure time, AET); hypersensitive esophagus (HE; normal AET, positive symptom association, SI/SAP); MII-pH-/PPI+ (normal AET, negative SI/SAP) in the responder group; MII-pH-/PPI- in non-responders.

KEY RESULTS

MII-pH in PPI responders (symptom relief during PPI therapy > 75%) showed: 79/144 NERD (54.9%); 37/144 HE (25.7%); 28/144 MII-pH-/PPI+ (19.4%). MII-pH-/PPI+ patients reported the same symptom relief when compared with NERD and HE. In non-responder (symptom relief during PPI therapy < 50%) group, 27/155 patients were NERD (17.4%); 53/155 were HE (34.2%); 75/155 were MII-pH-/PPI- (48.4%). NERD diagnosis was significantly higher in responder group (p < 0.01).

CONCLUSIONS & INFERENCES

In a substantial subgroup of patients responding to PPI with typical reflux symptoms, the diagnosis of GERD cannot be confirmed with pH-impedance monitoring. Proton pump inhibitor response and presence of typical symptoms are thus not reliable predictors of the diagnosis and antireflux surgery should always be preceded by reflux monitoring.