Distension-induced gastric accommodation in functional dyspepsia: effect of autonomic manipulation

The Interplay Between Stress and Fullness in Patients With Functional Dyspepsia and Healthy Controls: An Exploratory Experience Sampling Method Study

OBJECTIVE

Fullness is a cardinal symptom in functional dyspepsia (FD). The use of real-time symptom assessment might provide more insight into factors, such as daily stress, that can influence fullness. Therefore, this study aimed to use the experience sampling method (a real-time, repeated-measurement method making use of repeated questionnaires available at random moments for a limited amount of time) to assess the association between stress and fullness in patients with FD and healthy controls (HCs).

METHODS

Thirty-five patients with FD (25 female, mean age = 44.7 years) and 34 HCs (24 female, mean age = 44.1 years) completed the experience sampling method (a maximum of 10 random moments per day) for 7 consecutive days. Stress and fullness were rated on an 11-point Numeric Rating Scale. Data between patients with FD and HCs were statistically compared using a Student samples t test and linear mixed-effects models with repeated measures (level 1) nested within participants (level 2).

RESULTS

Average fullness scores were 2.23 (standard error = 0.37) points higher in patients with FD compared with HCs (p < .001). Average stress scores were 1.37 (standard error = 0.30) points higher in patients with FD compared with HCs (p = .002).In FD, fullness scores increased with 0.14 for every 1-point increase in concurrent stress scores (p = .010). Fullness scores at t = 0 increased with 0.12 for every 1-point increase in stress scores at t = -1 (p = .019). T = 0 stress scores were not associated with change in t = -1 fullness scores. No associations between concurrent symptom scores were found for HCs.

CONCLUSIONS

Concurrent and preceding stress scores are positively associated with fullness scores in patients with FD, but not in HCs. These findings indicate that increased levels of stress may precede feelings of fullness in patients with FD.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04204421.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis.

METHODS

A Delphi consensus was initiated with 41 experts from 22 European countries who conducted a literature summary and voting process on 87 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 36 statements.

RESULTS

The panel agreed with the definition in terms of its cardinal symptoms (early satiation, postprandial fullness, epigastric pain, and epigastric burning), its subdivision into epigastric pain syndrome and postprandial distress syndrome, and the presence of accessory symptoms (upper abdominal bloating, nausea, belching), and overlapping conditions. Also, well accepted are the female predominance of FD, its impact on quality of life and health costs, and acute gastrointestinal infections, and anxiety as risk factors. In terms of pathophysiological mechanisms, the consensus supports a role for impaired gastric accommodation, delayed gastric emptying, hypersensitivity to gastric distention, Helicobacter pylori infection, and altered central processing of signals from the gastroduodenal region. There is consensus that endoscopy is mandatory for establishing a firm diagnosis of FD, but that in primary care, patients without alarm symptoms or risk factors can be managed without endoscopy. There is consensus that H. pylori status should be determined in every patient with dyspeptic symptoms and H. pylori positive patients should receive eradication therapy. Also, proton pump inhibitor therapy is considered an effective therapy for FD, but no other treatment approach reached a consensus. The long-term prognosis and life expectancy are favorable.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on the definition, diagnosis and management of FD.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on functional dyspepsia

Background

Functional dyspepsia (FD) is one of the most common conditions in clinical practice. In spite of its prevalence, FD is associated with major uncertainties in terms of its definition, underlying pathophysiology, diagnosis, treatment, and prognosis.

Methods

A Delphi consensus was initiated with 41 experts from 22 European countries who conducted a literature summary and voting process on 87 statements. Quality of evidence was evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 36 statements.

Results

The panel agreed with the definition in terms of its cardinal symptoms (early satiation, postprandial fullness, epigastric pain, and epigastric burning), its subdivision into epigastric pain syndrome and postprandial distress syndrome, and the presence of accessory symptoms (upper abdominal bloating, nausea, belching), and overlapping conditions. Also, well accepted are the female predominance of FD, its impact on quality of life and health costs, and acute gastrointestinal infections, and anxiety as risk factors. In terms of pathophysiological mechanisms, the consensus supports a role for impaired gastric accommodation, delayed gastric emptying, hypersensitivity to gastric distention, Helicobacter pylori infection, and altered central processing of signals from the gastroduodenal region. There is consensus that endoscopy is mandatory for establishing a firm diagnosis of FD, but that in primary care, patients without alarm symptoms or risk factors can be managed without endoscopy. There is consensus that H. pylori status should be determined in every patient with dyspeptic symptoms and H. pylori positive patients should receive eradication therapy. Also, proton pump inhibitor therapy is considered an effective therapy for FD, but no other treatment approach reached a consensus. The long‐term prognosis and life expectancy are favorable.

Conclusions and Inferences

A multinational group of European experts summarized the current state of consensus on the definition, diagnosis and management of FD.

Current knowledge

Functional dyspepsia is one of the most common conditions encountered in clinical practice.

There is a lack of guidance for clinicians in guiding diagnosis and treatment of this prevalent condition.

No treatments are currently approved for the treatment of functional dyspepsia in Europe.

What is new here

A Delphi panel consisting of 41 experts from 22 European countries established the level of consensus on 87 statements regarding functional dyspepsia.

The statements reaching consensus serve to guide clinicians in recognizing, diagnosing and treating FD in clinical practice.

Endoscopy is mandatory for establishing a firm diagnosis of functional dyspepsia D, but in primary care patients without alarm symptoms or risk factors can be managed without endoscopy.

Helicobacter pylori status should be determined in every patient with dyspeptic symptoms and H. Pylori positive patients should receive eradication therapy.

Proton pump inhibitor‐therapy is considered an effective therapy for FD, but no other treatment approach reached consensus support.

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.

From ischochymia to gastroparesis: proposed mechanisms and preferred management of dyspepsia over the centuries

Dyspeptic symptoms are common with most patients suffering functional disorders that remain a therapeutic challenge for medical practitioners. Within the last three decades, gastric infection, altered motility, and hypersensitivity have gained and lost traction in explaining the development of functional dyspepsia. Considering these shifts, the aim of this review was to analyze changing understanding of and approaches to dyspepsia over a longer time period. Monographs, textbooks, and articles published during the last three centuries show that our understanding of normal gastric function has improved dramatically. With increased insight came new ideas about disease mechanisms, diagnostic options, and treatments. Despite shifts over time, the importance of functional abnormalities was recognized early on and explained in the context of societal influences and stressors, anxieties, and biological influences, thus resembling the contemporary biopsychosocial model of illness. Symptoms were often attributed to changes in secretion, motility, and sensation or perception with technological innovation often influencing proposed mechanisms and treatments. Many of the principles or even agents applied more than a century ago are still part of today's approach. This includes acid suppression, antiemetics, analgesics, and even non-pharmacologic therapies, such as gastric decompression or electrical stimulation of the stomach. This historical information does not only help us understand how we arrived at our current state of knowledge and standards of care, it also demonstrates that enthusiastic adoption of various competing explanatory models and the resulting treatments often did not survive the test of time. In view of the benign prognosis of dyspepsia, the data may function as a call for caution to avoid the potential harm of overly aggressive approaches or treatments with a high likelihood of adverse effects.

Effect of rikkunshito on gastric sensorimotor function under distention

BACKGROUND

The herbal medicine rikkunshito is effective for the treatment of gastrointestinal symptoms in patients with functional dyspepsia. Although some basic studies on the effects of rikkunshito have been reported in rats, its effects on human gastric function have not yet been clarified. Psychosocial stress induces visceral hypersensitivity and elements of rikkunshito may reasonably affect or suppress this process. We conducted a study to verify the hypothesis that rikkunshito improves stress-induced gastric hypersensitivity and/or changes in gastric wall tone.

METHODS

Nine healthy volunteers (five males, four females) participated in the study. The counterbalanced regimen consisted of a 2-week period of oral administration of 7.5 g day(-1) rikkunshito, then a 2-week period without treatment. Fundic sensorimotor function was examined using a gastric barostat twice on the day after each period. Virtual reality stress was imposed during the measurements of gastric tone and electrocardiogram.

KEY RESULTS

Stress induced a significant increase in heart rate (P = 0.041), gastric volume (P = 0.008), and phasic volume events (P = 0.049) and a decrease in sensory (P = 0.038), discomfort (P = 0.011), and pain (P = 0.041) thresholds of the stomach. Rikkunshito significantly reduced epigastric fullness (P = 0.037) and perceived stress (P = 0.034) following stimulation of the pain threshold, regardless of stress without the drug. Stress reduced gastric volume at the sensory threshold and increased anxiety at the discomfort threshold, and these responses were significantly inhibited by rikkunshito (P = 0.026, P = 0.022, respectively).

CONCLUSIONS & INFERENCES

These findings suggest that rikkunshito may improve symptoms and impaired gastric accommodation under distention stimuli of the proximal stomach superimposed by stress.

Proton pump inhibitor versus prokinetic therapy in patients with functional dyspepsia: is therapeutic response predicted by Rome III subgroups?

BACKGROUND

The comparative effectiveness of proton pump inhibitor versus prokinetic therapy in relieving the symptoms of patients with functional dyspepsia remains unknown. Whether the Rome III subgroups predict therapeutic response has not been investigated.

METHODS

This was an open-label, parallel randomized controlled trial. A total of 329 adult outpatients fulfilling the Rome III criteria for functional dyspepsia were randomly allocated to receive either lansoprazole 30 mg once daily (n = 166) or mosapride 5 mg thrice daily (n = 163) for 2 weeks. Enrolled patients were evaluated with the validated Hong Kong Index questionnaire for symptom severity at baseline and at the end of the trial. The primary outcome was symptom relief as defined by the Hong Kong Index, and the secondary outcome was decrease of symptom scores. Post-hoc multivariate logistic regression analysis was conducted to identify independent predictors for therapeutic response.

RESULTS

After 2-week therapy, 50.6% (84/166) and 47.85% (78/163) of the patients treated with lansoprazole and mosapride, respectively, achieved significant symptom relief (odds ratio 1.12, 95% confidence interval 0.72-1.72, p = 0.62). Differences in decreases of symptom scores between lansoprazole and mosapride receivers were also insignificant (-0.08, 95% confidence interval -1.25 to 1.09, p = 0.89). Therapeutic responses to either pharmacotherapy did not differ in the subgroup of patients fulfilling the criteria for epigastric pain syndrome (n = 256) or in those fulfilling the criteria for postprandial distress syndrome (n = 161). Multivariate logistic regression confirmed that the treatment allocation and Rome III subgroup were unrelated to treatment outcome.

CONCLUSIONS

The effectiveness of proton pump inhibitor therapy and that of prokinetic therapy in functional dyspepsia are not different, and cannot be predicted by Rome III subgroups (ClinicalTrials.gov number, NCT00663897).

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.

Characterisation of colonic accommodation in Wistar Kyoto rats with impaired gastric accommodation

Defective colonic and gastric accommodations have been related to altered viscerosensitivity in irritable bowel syndrome and to functional dyspepsia, respectively. We assessed colonic accommodation in rats with impaired gastric accommodation to determine if altered accommodation can be regarded as a widespread pathophysiological alteration within the gastrointestinal (GI) tract. Colonic accommodation during colorectal distension (CRD) was assessed in Wistar Kyoto rats (WKY), an animal model of impaired gastric accommodation, and in Sprague-Dawley (SD) and Wistar rats, considered normal. CRD (10-80 mmHg)-induced visceral pain responses were also evaluated in the same strains of rats. During gastric distension, WKY rats had lower intra-gastric volume (0.96 +/- 0.22 ml) than SD (1.85 +/- 0.19 ml, P < 0.05) or Wistar rats (2.80 +/- 0.26 ml, P < 0.05), indicating impaired gastric accommodation. In the same animals, pressure-volume curves were constructed during CRD as a measure of colonic accommodation. During short-lasting (1 min) phasic CRD (2-20 mmHg), the pressure-volume curve in WKY rats was displaced to the right compared with SD or Wistar rats, indicative of reduced colonic accommodation (maximal volume: SD, 1.22 +/- 0.05 ml; Wistar, 1.07 +/- 0.04 ml; WKY, 0.87 +/- 0.07 ml; P < 0.01). Pre-treatment with atropine normalised the pressure-volume responses in WKY rats. No differences among strains were observed during the 2-min phasic or ramp-tonic CRD. Visceral pain responses during CRD (10-80 mmHg) were, overall, similar in the three strains, although WKY rats showed lower thresholds for pain (28.0 +/- 4.9 mmHg) than SD (42.3 +/- 6.6 mmHg, P = 0.072) or Wistar rats (48.3 +/- 6.0 mmHg, P < 0.05). WKY rats, although having impaired gastric accommodation, have the ability to fully accommodate the colon to increasing pressures. In WKY rats, impaired accommodation of the smooth muscle might not be a widespread phenomenon along the GI tract but rather a local disturbance.