Delayed Gastric Emptying in Functional Dyspepsia

Autonomic and cytokine mechanisms of acute electroacupuncture in a rodent model of functional dyspepsia

BACKGROUND

Cytokines have been presumed to play an important role in the pathophysiology of functional dyspepsia (FD). Electroacupuncture (EA) has been used for FD treatment; however, its mechanisms remain largely unknown. This study aimed to (1) compare the plasma levels of cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10, in "FD" rats with normal control rats; (2) investigate whether EA, using chronically implanted electrodes, could inhibit the release of these cytokines; and (3) explore the correlation of cytokine levels with plasma norepinephrine (NE) levels and gastric emptying (GE).

METHODS

A rodent model of FD was established via neonatal treatment with intragastric iodoacetamide. After 8 weeks, the rats were implanted with electrodes at acupoint ST36 for EA. The plasma levels of cytokines and NE were measured using enzyme-linked immunosorbent assay. We explored the correlations of cytokine levels with NE levels and GE.

KEY RESULTS

(i) "FD" rats demonstrated increased levels of TNF-α, IL-1β, and IL-6 (p < 0.05 each) compared with the control rats. (ii) EA significantly decreased the plasma levels of TNF-α, IL-1β, and IL-6 in "FD" rats (p < 0.05 each) compared with sham EA. (iii) The plasma levels of NE were positively correlated with those of IL-6 (r = 0.86, p < 0.05) and IL-1β (r = 0.81, p < 0.05), whereas NE levels and GE were negatively correlated with IL-10 levels (r = -0.870, p < 0.05 and r = -0.791, p < 0.05, respectively).

CONCLUSIONS

EA inhibits the release of proinflammatory cytokines probably via the suppression of sympathetic activity in "FD" rats.

Routine assessment of gastrointestinal symptom using a validated questionnaire in the clinical setting to assess the probability of organic or functional gastrointestinal diseases

BACKGROUND

Patients presenting with gastrointestinal symptoms can be challenging in terms of determining etiology and management strategies. Identifying likely organic pathology is important since it can be treated and may result in further, long-term harm to the patient if not treated. Currently, organic pathology is often identified via invasive procedures such as endoscopy or referral to a medical imaging service. We report on an approach that offers a first step at identifying patients with an organic gastrointestinal disease based on the SAGIS, a validated symptom questionnaire.

METHODS

8,922 patients referred to a tertiary care hospital were classified as having either functional gastrointestinal disease or an organic gastrointestinal disease. A model was developed to distinguish organic from functional symptoms on one random split half of the sample and validated on the other half. The incremental benefit of including psychological conditions and extra-gastrointestinal conditions was also evaluated.

KEY RESULTS

Functional gastrointestinal patients scored higher on average than organic patients on all dimensions of the SAGIS and reported higher rates of psychological and extra-gastrointestinal conditions. All five dimensions of the SAGIS provided statistically independent discrimination of organic from functional diagnoses with good overall discrimination (AUC = 0.75). However, there was no noticeable incremental benefit of adding either psychological or extra-gastrointestinal conditions. Model performance was highly reproducible.

CONCLUSIONS AND INFERENCES

The proposed algorithm for identifying likely organic gastrointestinal disease applied to symptoms as recorded in the SAGIS questionnaire provides a useful tool for the clinician in deciding what or if further diagnostic testing is required.

Electroacupuncture via chronically implanted electrodes improves gastric dysmotility mediated by autonomic-cholinergic mechanisms in a rodent model of functional dyspepsia

BACKGROUND

Electroacupuncture (EA) has been shown to be effective in reducing symptoms in patients with functional dyspepsia (FD). However, its mechanisms remain largely unknown. The aim of this study was to investigate mechanisms of the prokinetic effects of EA in a rodent model of FD.

METHODS

A FD model was established by neonatal treatment of iodoacetamide (IA). Eight weeks later, the rats were implanted with electrodes in the stomach for the measurement of gastric slow waves (GSW) and electrodes into acupoints ST36 for EA. Autonomic functions were assessed by the spectral analysis of heart rate variability.

KEY RESULTS

(i) The IA-treated rats ("FD" rats) showed increased dysrhythmia in both fasting and fed states (P < .01) as well as during rectal distention (P < .02). EA reduced the percentage of dysrhythmia (P < .05 for both fasting and fed) and normalized RD-induced impairment in GSW in "FD" rats. Atropine blocked the effect of EA on GSW. (ii) "FD" rats showed delayed gastric emptying (P = .001 vs control) that was accelerated with EA (P = .01, vs sham-EA). (iii) "FD" rats showed increased plasma norepinephrine (P = .006, vs control) that was suppressed with EA (P = .003) and reduced vagal activity that was improved with EA.

CONCLUSIONS AND INFERENCES

Gastric motility (GSW and GE) is impaired in rats treated with IA, possibly attributed to impaired autonomic functions. EA improves GSW and accelerates GE mediated via the autonomic and cholinergic mechanisms.

Ablation of Tacr2 in mice leads to gastric emptying disturbance

BACKGROUND

Tacr2 is one of the G protein-coupled receptors(GPCRs) that mediate the biological actions of tachykinins. It is abundantly expressed in the gastrointestinal (GI) system and is thought to play an important role in GI motility, secretion, and visceral sensitivity. Previously, the physiological and pathophysiological functions of Tacr2 were mainly studied using Tacr2 selective agonists or antagonists. Here, we seek to investigate the effect of Tacr2 disruption in mice to provide further insights.

METHODS

The Tacr2 knockout mice were generated by homologous recombination and the phenotypic changes of the Tacr2-null mice were analyzed and compared with their wild type (wt) littermates.

KEY RESULTS

Increased food retention was detected in Tacr2^-/- mice. The stomach of Tacr2^-/- mice had thinner muscularis externa and less neurons in the myenteric plexus. The stomach and small intestine exhibited longer duration of electrical field stimulation (EFS)-induced inhibition in the gastric fundus and decreased frequency of migrating motor complex (MMC), respectively. Neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP) were significantly up-regulated due to Tarc2 deficiency, contributing to enhanced nitric oxide (NO) signaling in the stomach of Tacr2^-/- mice. Intraperitoneal application of 7-nitroindazole (7-NI) to Tacr2^-/- mice effectively relieved the gastric emptying disturbance. Moreover, Creb and NF-κB signalings were involved in the regulation of these physiological changes initiated by Tacr2 deficiency.

CONCLUSIONS & INFERENCES

Tacr2 negatively regulated the expression of nNOS and VIP both in vivo and in vitro. Its ablation in mice elevated the expression of nNOS and VIP, enhanced NO signaling and changed the Creb and NF-κB signalings, finally leading to the gastric emptying disturbance of Tacr2^-/- mice.

Electroacupuncture combined with mosapride alleviates symptoms in diabetic patients with gastroparesis

The present study compared the clinical effectiveness of electroacupuncture (EA), monotherapy and combination therapy involving the administration of EA and mosapride in diabetic patients with severe or mild symptoms suggestive of gastroparesis. A total of 56 patients with type 2 diabetes who had symptoms suggestive of gastroparesis for >3 months were divided into two groups according to the Gastroparesis Cardinal Symptom Index (GCSI) score, including 33 in the mild group (GCSI score <3.5) and 23 in the severe group (GCSI score ≥3.5). Initially, all patients received EA monotherapy for 14 days. An effective response was defined as a reduction of the overall baseline GCSI score by >25% after treatment. The non-responding patients then received a combination treatment with EA and mosapride. Gastric emptying was assessed by the 13C-octanoic acid breath test at the beginning and end of each treatment session. Two patients in the severe group dropped out of the study during the initial treatment session. The results revealed that 34 early-responding patients (30 from the mild group and 4 from the severe group) treated with EA monotherapy, and 20 non-early-responding patients receiving combination therapy with EA and mosapride showed clinically significant improvements. Analysis of data from the mild subgroup demonstrated that EA treatment specifically improved symptoms of nausea, vomiting, stomach fullness, excessive fullness and bloating. There was no statistically significant difference in the gastric half-emptying time among patients prior to and after EA monotherapy. These preliminary results suggested that EA may be an option for improving mild symptoms in patients with diabetic gastroparesis, whereas combination therapy involving EA and pharmaceutics is required in patients with severe symptoms.

Itopride for gastric volume, gastric emptying and drinking capacity in functional dyspepsia

AIM

To study the effect of itopride on gastric accommodation, gastric emptying and drinking capacity in functional dyspepsia (FD).

METHODS

Randomized controlled trial was conducted to check the effect of itopride on gastric accommodation, gastric emptying, capacity of tolerating nutrient liquid and symptoms of FD. We recruited a total of 31 patients having FD on the basis of ROME III criteria. After randomization, itopride was received by 15 patients while 16 patients received placebo. Gastric accommodation was determined using Gastric Scintigraphy. 13C labeled octanoic breadth test was performed to assess gastric emptying. Capacity of tolerating nutrient liquid drink was checked using satiety drinking capacity test. The intervention group comprised of 150 mg itopride. Patients in both arms were followed for 4 wk.

RESULTS

Mean age of the recruited participant 33 years (SD = 7.6) and most of the recruited individuals, i.e., 21 (67.7%) were males. We found that there was no effect of itopride on gastric accommodation as measured at different in volumes in the itopride and control group with the empty stomach (P = 0.14), at 20 min (P = 0.38), 30 min (P = 0.30), 40 min (P = 0.43), 50 min (P = 0.50), 60 min (P = 0.81), 90 min (P = 0.25) and 120 min (P = 0.67). Gastric emptying done on a sub sample (n = 11) showed no significant difference (P = 0.58) between itopride and placebo group. There was no significant improvement in the capacity to tolerate liquid in the itopride group as compared to placebo (P = 0.51). Similarly there was no significant improvement of symptoms as assessed through a composite symptom score (P = 0.74). The change in QT interval in itopride group was not significantly different from placebo (0.10).

CONCLUSION

Our study found no effect of itopride on gastric accommodation, gastric emptying and maximum tolerated volume in patients with FD.

DA-9701: A New Multi-Acting Drug for the Treatment of Functional Dyspepsia

Motilitone^® (DA-9701) is a new herbal drug that was launched for the treatment of functional dyspepsia in December 2011 in Korea. The heterogeneous symptom pattern and multiple causes of functional dyspepsia have resulted in multiple drug target strategies for its treatment. DA-9701, a compound consisting of a combination of Corydalis Tuber and Pharbitidis Semen, has being developed for treatment of functional dyspepsia. It has multiple mechanisms of action such as fundus relaxation, visceral analgesia, and prokinetic effects. Furthermore, it was found to significantly enhance meal-induced gastric accommodation and increase gastric compliance in dogs. DA-9701 also showed an analgesic effect in rats with colorectal distension induced visceral hypersensitivity and an antinociceptive effect in beagle dogs with gastric distension-induced nociception. The pharmacological effects of DA-9701 also include conventional effects, such as enhanced gastric emptying and gastrointestinal transit. The safety profi le of DA-9701 is also preferable to that of other treatments.

Effectiveness and safety of levosulpiride in the treatment of dysmotility-like functional dyspepsia

The objective of this study was to assess the effectiveness and safety of levosulpiride in patients with dysmotility-like functional dyspepsia including nonerosive reflux esophagitis in conditions of daily practice. The study was conducted as a prospective, open-label, multicenter design in 342 patients with dysmotility-like functional dyspepsia (n=279) and nonerosive reflux disease (n=63), who received levosulpiride 25 mg 3 times daily orally for 4 weeks. Individual symptoms (pain/discomfort, fullness, bloating, early satiety, pyrosis, regurgitation, and nausea/vomiting) and a global symptom score were assessed at 15, 30, and 60 days after starting treatment. Adverse events also were recorded. There were 151 men and 191 women (mean age 38.8 years) who referred dyspeptic symptoms for a mean of 10.2 (10.7) months. A total of 66.4% patients were treated with 75 mg/day levosulpiride and 33.6% with 50 mg/day. At the 15-day visit, a decrease greater than 50% in the global symptom score was observed. The frequency and intensity of individual symptoms showed a statistically significant decrease (p<0.001) at all visits compared with baseline. At the 30-day visit, all symptoms had almost disappeared, a trend that was maintained until the last visit. Treatment with levosulpiride was well tolerated and only 40 adverse events were recorded (galactorrhea 26.7%, somnolence 17.8%, fatigue 11.1%, headache 11.5%) and no patient had to abandon the study due to side effects. In conclusion, levosulpiride is an effective and safe drug in the treatment of dysmotility-like functional dyspepsia and non-erosive reflux disease.

Electroacupuncture accelerates solid gastric emptying and improves dyspeptic symptoms in patients with functional dyspepsia

The aims of this study were to investigate the effects of electroacupuncture (EA) at ST36 and PC6 points on solid gastric emptying and dyspeptic symptoms in patients with functional dyspepsia. Nineteen patients with functional dyspepsia (FD) were involved in the study, consisting of two parts: (1) acute effects of EA on solid gastric emptying in FD patients with delayed gastric emptying and (2) short-term (2-week) effects of EA on symptoms in FD patients with normal gastric emptying. Results were as follows. (1) Ten of the19 patients showed delayed gastric emptying of solids, and acute EA significantly improved delayed gastric emptying; the halftime for gastric emptying was reduced from 150.3+/-48.4 to 118.9+/-29.6 min (P=0.007). (2) In the nine patients with normal gastric emptying, 2-week EA significantly decreased the symptom score, from 8.2+/-3.3 at baseline to 1.6+/-1.1 (P < 0.001) at the end of treatment. We conclude that EA at the ST36 and PC6 points accelerates solid gastric emptying in FD patients with delayed gastric emptying and relieves dyspeptic symptoms in FD patients with normal gastric emptying.

Recent insights into digestive motility in functional dyspepsia

Functional gastrointestinal disorders, such as functional dyspepsia (FD) and irritable bowel syndrome, are common pathologies of the gut. FD is a clinical syndrome defined as chronic or recurrent pain or discomfort of unknown origin in the upper abdomen. The pathophysiological mechanisms responsible for FD have not been fully elucidated, but new ideas regarding its pathophysiology and the significance of the pathophysiology with respect to the symptom pattern of FD have emerged. In particular, there is growing interest in alterations in gastric motility, such as accommodation to a meal or gastric emptying, and visceral sensation in FD. The mechanisms underlying impaired gastroduodenal motor function are unclear, but possible factors include abnormal neurohormonal function, autonomic dysfunction, visceral hypersensitivity to acid or mechanical distention, Helicobacter pylori infection, acute gastrointestinal infection, psychosocial comorbidity, and stress. Although the optimum treatment for FD is not yet clearly established, acid-suppressive drugs, prokinetic agents, eradication of H. pylori, and antidepressants have been widely used in the management of patients with FD. The therapeutic efficacy of prokinetics such as itopride hydrochloride and mosapride citrate in the treatment of FD is supported by the results of relatively large and well-controlled studies. In addition, recent research has yielded new therapeutic agents and modalities for dysmotility in FD, including agonists/antagonists of various sensorimotor receptors, activation of the nitrergic pathway, kampo medicine, acupuncture, and gastric electric stimulation. This review discusses recent research on the pathophysiology of and treatment options for FD, with special attention given to digestive dysmotility.

Drug treatment of functional dyspepsia

Symptomatic improvement of patients with functional dyspepsia after drug therapy is often incomplete and obtained in not more than 60% of patients. This is likely because functional dyspepsia is a heterogeneous disease. Although great advance has been achieved with the consensus definitions of the Rome I and II criteria, there are still some aspects about the definition of functional dyspepsia that require clarification. The Rome criteria explicitly recognise that epigastric pain or discomfort must be the predominant complaint in patients labelled as suffering from functional dyspepsia. However, this strict definition can create problems in the daily primary care clinical practice, where the patient with functional dyspepsia presents with multiple symptoms. Before starting drug therapy it is recommended to provide the patient with an explanation of the disease process and reassurance. A thorough physical examination and judicious use of laboratory data and endoscopy are also indicated. In general, the approach to treat patients with functional dyspepsia based on their main symptom is practical and effective. Generally, patients should be treated with acid suppressive therapy using proton-pump inhibitors if the predominant symptoms are epigastric pain or gastroesophageal reflux symptoms. Although the role of Helicobacter pylori (H pylori) in functional dyspepsia continues to be a matter of debate, recent data indicate that there is modest but clear benefit of eradication of H pylori in patients with functional dyspepsia. In addition, H pylori is a gastric carcinogen and if found it should be eliminated. Although there are no specific diets for patients with FD, it may be helpful to guide the patients on healthy exercise and eating habits.