Role of autonomic dysfunction in patients with functional dyspepsia

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.

Clinical application of kampo medicine (rikkunshito) for common and/or intractable symptoms of the gastrointestinal tract

Gastroenterological reflux disease and functional dyspepsia are usually treatable using Western medical practices. Nonetheless, some cases present with intractable symptoms that are not amenable to these therapies. Treatment with kampo, a traditional Japanese medicine, recently has been proposed as an alternative therapy for use in combination with the Western practices. In general, traditional Japanese medicines have been used empirically for intractable symptoms correctively designated as “general malaises.” Accumulating lines of evidence, including basic and clinical researches, have demonstrate detailed mechanisms where traditional Japanese medicines exert pharmacological action to improve symptoms. Therefore, traditional Japanese medicines have been gaining use by various medical doctors as the specific modes of pharmacological action are recognized. This review covers both the pharmacological functions and the clinical efficacies of rikkunshito for use in treating disorders of the gastrointestinal tract.

Abdominal bloating: pathophysiology and treatment

Abdominal bloating is a very common and troublesome symptom of all ages, but it has not been fully understood to date. Bloating is usually associated with functional gastrointestinal disorders or organic diseases, but it may also appear alone. The pathophysiology of bloating remains ambiguous, although some evidences support the potential mechanisms, including gut hypersensitivity, impaired gas handling, altered gut microbiota, and abnormal abdominal-phrenic reflexes. Owing to the insufficient understanding of these mechanisms, the available therapeutic options are limited. However, medical treatment with some prokinetics, rifaximin, lubiprostone and linaclotide could be considered in the treatment of bloating. In addition, dietary intervention is important in relieving symptom in patients with bloating.

Kampo medicines for gastrointestinal tract disorders: a review of basic science and clinical evidence and their future application

Treatment with kampo, the Japanese traditional medicine, is a form of pharmacological therapy that combines modern Western and traditional Asian medical practices. In Japan, various traditional medicines are often combined with Western medicines and prescribed for patients with diseases such as gastroesophageal reflux disease, functional dyspepsia, chronic gastritis, irritable bowel syndrome, and post-operative ileus. Based on numerous past observations, Japanese traditional medicines are thought to be particularly useful in the treatment of medically unexplained physical symptoms such as nausea, abdominal discomfort, and anorexia. However, the detailed mechanism by which they mediate their pharmacological action is yet unknown. In addition, the clinical evidence to support their use is insufficient. This review focuses on the basic evidence of the pharmacological action and the clinical efficacies of kampo medicines accumulated over several past decades. In addition, we introduce both the current novel insights into kampo medicines and the therapeutic approach employed when they are used to treat various disorders of the gastrointestinal tract.

Developmental origins of functional dyspepsia-like gastric hypersensitivity in rats

BACKGROUND & AIMS

Gastric hypersensitivity (GHS) contributes to epigastric pain in patients with functional dyspepsia (FD); the etiology and cellular mechanisms of this dysfunction remain unknown. We investigated whether inflammatory insult to the colons of neonatal rats induced GHS in adult life.

METHODS

We used cellular, molecular, and in vivo approaches to investigate the mechanisms of GHS in adult rats subjected to neonatal colonic insult by intraluminal administration of trinitrobenzene sulfonic acid; controls received saline. Six to 8 weeks later, rats were evaluated for GHS and tissue was collected for molecular experiments.

RESULTS

Inflammatory insult to the colon on post-natal day 10 caused an aberrant increase of corticosterone on post-natal day 15 and induced GHS in adult life. We called these FD-like rats. Inhibition of glucocorticoid receptors after neonatal insult blocked the induction of GHS in adult rats. The aberrant increase of plasma corticosterone in neonates increased the plasma concentration of norepinephrine, nerve growth factor in the gastric fundus muscularis externae, brain-derived neurotrophic factor in the thoracic dorsal root ganglia and spinal cord, and down-regulated K(v)1.1 messenger RNA in thoracic dorsal root ganglia without affecting the expression of K(v)1.4, Na(v)1.8, TrpA1, TrpV1, or P2X3 in FD-like rats. Inhibition of glucocorticoid receptors during neonatal insult or the inhibition of adrenergic receptors, nerve growth factor, or brain-derived neurotrophic factor in FD-like rats suppressed GHS. The intrathecal administration of small interfering RNAs against K(v)1.1 increased GHS in naive rats.

CONCLUSIONS

Inflammatory insult to the colons of rat pups leads to GHS in adult life. GHS is caused by altered expression of genes encoding neurotrophins and ion channels, and altered activity of the sympathetic nervous system.

The role of psychosocial factors and psychiatric disorders in functional dyspepsia

In this Review, after a brief historical introduction, we first provide an overview of epidemiological studies that demonstrate an association between functional dyspepsia and psychological traits, states or psychiatric disorders. These studies suggest an important intrinsic role for psychosocial factors and psychiatric disorders, especially anxiety and depression, in the aetiopathogenesis of functional dyspepsia, in addition to their putative influence on health-care-seeking behaviour. Second, we describe pathophysiological evidence on how psychosocial factors and psychiatric disorders might exert their role in functional dyspepsia. Novel insights from functional brain imaging studies regarding the integration of gut-brain signals, processed in homeostatic-interoceptive brain regions, with input from the exteroceptive system, the reward system and affective and cognitive circuits, help to clarify the important role of psychological processes and psychiatric morbidity. We therefore propose an integrated model of functional dyspepsia as a disorder of gut-brain signalling, supporting a biopsychosocial approach to the diagnosis and management of this disorder.

Increased severity of dyspeptic symptoms related to mental stress is associated with sympathetic hyperactivity and enhanced endocrine response in patients with postprandial distress syndrome

BACKGROUND

Mental stress (MS) may alter gastric sensory-motor function. The aim of the study was to assess postprandial autonomic nervous system activity and stress hormones in response to acute mental stress in dyspeptic patients.

METHODS

A total of 25 patients with postprandial distress syndrome (PDS; 11 mol L(-1), age 35.9 ± 9.3 years) and 12 healthy controls (5 mol L(-1), age 25.8 ± 4.6 years) underwent electrogastrography and (13) C-octanoate gastric emptying study using a 480 kcal solid meal. Heart rate variability (LF/HF ratio) and corticotrophin-releasing factor, adrenocorticotropic hormone (ACTH), and cortisol serum levels were also evaluated. Dyspeptic symptoms were scored by analogue visual scale and expressed as symptoms total score (TS). The protocol was repeated twice in each subject, with and without a mental stress test before the meal.

KEY RESULTS

Mental stress significantly increased postprandial symptoms severity in patients (TS: stress 111 ± 18 vs basal 50 ± 10; P < 0.05). Low-/high-frequency component ratio was significantly higher in patients after MS at 120 min (stress 5.46 ± 0.41 vs basal 3.41 ± 0.64; P < 0.01) and 180 min (stress 5.29 ± 0.2 vs basal 3.58 ± 0.19; P < 0.05). During stress session, in patients we found a significantly higher ACTH level than baseline at 30, 60, 90, 150, 210, 240, and 270 min and a significantly higher cortisol level at 30, 60, 90, 120, 210, and 270 min. Gastric emptying rate and electrical activity were not influenced by MS.

CONCLUSIONS & INFERENCES

In PDS patients, administration of MS before meal increases symptoms severity by inducing sympathetic hyperactivity and increased stress hormones levels. As the gastric emptying looks not altered, we conclude that these neurohormonal responses mainly affect sensitive function.

Clinical classification of subgroups according to the Rome III criteria cannot be used to distinguish the associated respective pathophysiology in Japanese patients with functional dyspepsia

OBJECTIVE

Patients who meet the Rome III criteria for functional dyspepsia (FD) are generally classified into the following two subgroups, those with postprandial distress syndrome (PDS) and those with epigastric pain syndrome (EPS), in order to treat the dyspeptic symptoms caused by the respective pathophysiological conditions. However, whether simple classification of FD can accurately distinguish the pathophysiological differences between PDS and EPS remains to be clarified because the pathophysiology of FD is characterized and complicated by various factors.

METHODS

After classifying FD patients who were not receiving medication at the initial visit, we assessed and compared the following pathophysiological factors between the PDS and EPS groups: (1) the gastric reservoir and emptying functions using a radioisotope method (n=75), (2) the autonomic nervous system (ANS) function using electrocardiography (n=45), (3) gastric mucosal atrophy and intestinal metaplasia using histological examinations (n=47), (4) endoscopic findings of the stomach, such as superficial changes, abnormal gastroesophageal flap valves (n=67) and (5) Helicobacter pylori infection (n=48).

RESULTS

The FD patients exhibited higher rates of an impaired reservoir function (49.3%), gastric emptying disorders (54.7%) and relative hyperactivity of the sympathetic nervous system (31.9%) than the control subjects. However, endoscopic and histological changes of the stomach were similar in both the FD patients and control subjects. In addition, no differences were observed in the above-mentioned factors between the PDS and EPS groups.

CONCLUSION

The simple classification of FD patients into two subgroups according to the Rome III criteria following diagnosis does not indicate any differences in the pathophysiology related to the respective dyspeptic symptoms of FD patients.

Autonomic dysfunction and inflammatory bowel disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic immune-mediated intestinal disorder, and its etiology and pathogenesis are not well clarified. The pathogenesis of IBD is multifactorial, and the nerve system may participate in the development of IBD by modulating immune responses. Recently, autonomic dysfunction in IBD patients has been intensively studied. It has been reported that IBD patients suffer from autonomic dysfunction, and the severity of autonomic dysfunction correlates with disease activity of IBD, suggesting that autonomic dysfunction is a potential marker for IBD disease activity and also a potential target for IBD treatment. In this paper, we review the recent advances in understanding the relationship between autonomic dysfunction and IBD.

The effect of a meal and water loading on heart rate variability in children with functional dyspepsia

BACKGROUND

Alteration in autonomic function has been implicated as a possible pathophysiologic mechanism in functional dyspepsia (FD) in adults.

METHODS

This was a two-part study. For the first part of the study, nine children with FD and 28 controls underwent heart rate variability (HRV) analysis for 30 min baseline and for 60 min following a test meal. For the second part of the study, eight children with FD and 26 controls underwent HRV analysis for 30 min baseline and for 60 min following rapid water loading. HRV analysis yielded measures for power in the high frequency (HF) band (vagal activity), power in the low frequency (LF) band (mainly sympathetic activity), and LF/HF (sympathovagal balance).

RESULTS

HRV parameters did not differ between FD patients and controls in either baseline period or following water loading. Following the meal, HF was higher and LF and LF/HF were lower in FD patients as compared to controls. Baseline LF/HF was positively correlated with the water load volume in controls and negatively correlated with the water load volume in FD patients.

CONCLUSION

FD in children is associated with an abnormal autonomic response best demonstrated following a meal. The relationship between baseline sympathovagal balance and water load volume in FD patients is distinctly different from the relationship in control children.

Efficacy and safety of ecabet sodium on functional dyspepsia: A prospective, double-blinded, randomized, multi-center controlled trial

AIM: To compare ecabet sodium and cimetidine in relieving symptoms of functional dyspepsia.

METHODS: We performed a multi-center, prospective, randomized, double-blinded controlled trial to compare the clinical efficacy of ecabet sodium and cimetidine in patients with functional dyspepsia. Two-hundred and seventy-two patients with dyspeptic symptoms fulfilling the Rome-II criteria were enrolled from 7 centers. In the study group (115 patients), 1.5 g ecabet sodium was given twice a day. In the control group (121 patients), 400 mg cimetidine was given twice a day. Symptoms and parameters of quality of life were analyzed at baseline, 3, 14, and 28 d after initiating the treatment.

RESULTS: Two-hundred and thirty-six patients completed the clinical trial. After 4 wk of treatment, the rates of improvement in patients with dyspeptic symptoms were not different between two groups (77.4% in the ecabet group and 79.3% in the cimetidine group, respectively, P > 0.05). Likewise, the rates of symptomatic improvement were not different at 3 d and 14 d. The parameters of quality of life did not change significantly during the study period in both groups. There was no clinically significant adverse event in both groups.

CONCLUSION: In patients with functional dyspepsia, ecabet sodium has similar clinical efficacy with cimetidine.

A prospective study of oesophageal 24-h ambulatory pH monitoring in patients with functional dyspepsia

BACKGROUND

The diagnostic utility of 24-h oesophageal ambulatory pH monitoring in patients with functional dyspepsia has not been well established.

AIMS

We performed a prospective study of oesophageal pH monitoring in patients with functional dyspepsia in order to assess whether a positive pH test might predict response to proton pump inhibitor therapy in a subset of functional dyspepsia patients.

PATIENTS

Forty Helicobacter pylori-negative functional dyspepsia patients (35 males and 5 females, mean age (+/-S.E.M.) of 54+/-2.4 years) with predominantly unspecified dyspepsia subtype and normal distal oesophageal biopsies.

METHODS

All subjects were randomised in a double-blind fashion to either omeprazole 20 mg/day or placebo daily for four weeks after 24-h pH monitoring.

RESULTS

Twenty-four-hour pH monitoring was abnormal in 9 of the 21 patients (43%) in the omeprazole group and 5/19 (26%) of the placebo group (p=NS). Patients who reported symptomatic improvement on the Gastrointestinal Symptom Rating Scale were no more likely to have abnormal scores on pH monitoring than patients who did not have symptomatic response.

CONCLUSIONS

Although approximately one-third of functional dyspepsia patients will have abnormal profiles on 24-h ambulatory oesophageal pH monitoring, an abnormal score does not appear to predict response to proton pump inhibitor therapy in patients with unspecified functional dyspepsia.

Gastrointestinal hormone abnormalities and G and D cells in functional dyspepsia patients with gastric dysmotility

AIM: To investigate the relationship between gastric dysmotility, gastrointestinal hormone abnormalities, and neuroendocrine cells in gastrointestinal mucosa in patients with functional dyspepsia (FD).

METHODS: Gastric emptying was assessed with solid radiopaque markers in 54 FD patients, and the patients were divided into two groups according to the results, one with delayed gastric emptying and the other with normal gastric emptying. Seventeen healthy volunteers acted as normal controls. Fasting and postprandial plasma levels and gastroduodenal mucosal levels of gastrointestinal hormones gastrin, somatostatin (SS) and neurotensin (NT) were measured by radioimmunoassay in all the subjects. G cells (gastrin-producing cells) and D cells (SS-producing cells) in gastric antral mucosa were immunostained with rabbit anti-gastrin polyclonal antibody and rabbit anti-SS polyclonal antibody, respectively, and analyzed quantitatively by computerized image analysis.

RESULTS: The postprandial plasma gastrin levels, the fasting and postprandial plasma levels and the gastric and duodenal mucosal levels of NT were significantly higher in the FD patients with delayed gastric emptying than in those with normal gastric emptying and normal controls. The number and gray value of G and D cells and the G cell/D cell number ratio did not differ significantly between normal controls and the FD patients with or without delayed gastric emptying.

CONCLUSION: Our findings suggest that the abnormalities of gastrin and NT may play a role in the pathophysiology of gastric dysmotility in FD patients, and the abnormality of postprandial plasma gastrin levels in FD patients with delayed gastric emptying is not related to the changes both in the number and gray value of G cells and in the G cell/D cell number ratio in gastric antral mucosa.

Functional dyspepsia: motor abnormalities, sensory dysfunction, and therapeutic options

Functional dyspepsia is a common condition, but as yet, the underlying etiology is unclear. In this article, upper gastrointestinal motor and sensory physiology are reviewed and the current evidence for motor and/or sensory functional abnormalities causing dyspeptic symptoms is presented. The complex interrelationship between abnormal motor activity and sensation is explored, as well as the potential roles for autonomic dysfunction and psychological state in modulating gastrointestinal sensation and motor function. Finally, based on clinical trial evidence, a treatment pathway for functional dyspepsia is suggested.

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Autonomic nerve dysfunction in pathologically obese patients

BACKGROUND

Obese patients frequently present clinical symptoms related to gastrointestinal motility alterations and autonomic nervous system dysfunction.

AIM

To evaluate the possible correlation between cardiovascular autonomic nervous dysfunction and oesophageal motility in pathologically obese patients.

PATIENTS AND METHODS

Enrolled in the study were 22 patients with a body mass index of 45.72 +/- 7.48 and 10 control subjects, all within 20% of their ideal weight. Oesophageal motility was measured by stationary manometry and scintigraphic transit. Tests for the evaluation of autonomic nervous system were: Valsalva ratio, deep breathing, sustained handgrip, sudormotor axon reflex test and spectral analysis of the variability of R-R interval.

RESULTS

The mean pressure of oesophageal peristaltic waves in patients and controls was 39.36 +/- 14 mmHg and 73 +/- 12 mmHg, respectively The scintigraphic mean transit time was 22.96 +/- 16.26 seconds in patients and 10.23 +/- 16.26 seconds in controls (p < 0.001). Spectral analysis of the variability of the R-R interval showed an increase in the parasympathetic component both in the lying and standing position compared to controls. The other autonomic nervous system function tests showed no significant difference between obese patients and controls.

CONCLUSIONS

These results suggest that obese patients present a reduction of oesophageal transit and autonomic nervous system dysfunction albeit no direct correlation was found between these phenomena.

Gastric emptying and duodeno-gastro-oesophageal reflux in gastro-oesophageal reflux disease

BACKGROUND

Previous studies present conflicting results regarding relationship between gastric emptying and gastro-oesophageal reflux disease. Reflux of duodenal content to oesophagus is generally considered to be associated with more severe disease.

AIM

To assess presence of a gastric emptying disorder in persons with reflux of duodenal contents to oesophagus and to identify any correlation with gastric emptying and oesophageal motility.

METHODOLOGY

A total of 15 subjects with (B+) and 15 subjects without (B-) bile reflux to oesophagus determined by 24-hour bilirubin monitoring were studied with scintigraphic solid gastric emptying and 24-hour oesophageal manometry.

RESULTS

There was no difference in lag phase [median 23.7 (range 10.8-44.0) vs 24.6 (8.1-40.1) min], half emptying time [74.6 (48.0-93.6) vs 82.8 (54.4-153.9) min] or emptying rate [0.89 (0.59-1.34) vs 0.83 (0.36-1. 15)%/min] for B- and B+ subjects, respectively. In addition, there was no difference in emptying rate of gastric fundus between B- and B+ subjects. Subjects with bile reflux had less effective oesophageal contractions of oesophageal body [9.4(3.3-37)%] compared to subjects without bile reflux [32(19-47)%, p = 0.002]. However, there was no correlation between oesophageal motility and gastric emptying.

CONCLUSION

Results suggest that a gastric emptying disorder is a less likely contributing cause of bile reflux to the oesophagus, but bile reflux is associated with less effective oesophageal motility.