Assessment of gastric emptying using a low fat meal: establishment of international control values

Neokestose suppresses the increase in plasma glucose caused by oral administration of sucrose in a streptozotocin‑induced diabetic rat

Neokestose is considered to have a prebiotic function. However, the physiological activity of neokestose remains unknown. Neokestose has a blastose, a sucrose analog, in its structure. We previously demonstrated that oral administration of blastose to diabetic rats suppressed the increase in plasma glucose (PG) concentration after sucrose administration. Therefore, neokestose might have a similar effect. In this study, we investigated the effects of neokestose on PG concentrations and the mechanism of its action. We first administered neokestose orally to streptozotocin-induced diabetic rats and observed that the expected consequent increase in PG concentration was significantly suppressed. Next, we examined the inhibitory effect of neokestose on glycosidase activity, but observed only a slight inhibitory effect. Therefore, we hypothesized that neokestose might be hydrolyzed by gastric acid to produce blastose. We performed an acid hydrolysis of neokestose using artificial gastric juice. After acid hydrolysis, peaks corresponding to neokestose and its decomposition products including blastose were observed. Therefore, we suggest that neokestose and blastose, a decomposition product, synergistically inhibit glycosidase activity. These findings support the potential use of neokestose as a useful functional oligosaccharide that can help manage plasma glucose concentrations in patients with diabetes mellitus.

The goals for successful development of treatment in gastroparesis

BACKGROUND

Gastroparesis is a motility disorder of the stomach characterized by cardinal symptoms and delayed gastric emptying of solid food in the absence of mechanical obstruction. There is significant unmet need in its management, and essentially there are no medications approved for its treatment over four decades.

PURPOSE

The objectives of this review are to develop an understanding of the goals of treatment, the evidence-based criteria for treatment success based on the current scientific understanding of gastroparesis as well as patient response outcomes, and to propose evidence-based principles for the successful development of treatments for gastroparesis. Specifically, we discuss the pathophysiologic targets in gastroparesis, eligibility criteria for clinical trial participation based on validated gastric emptying studies, and the patient response outcome measures that have been validated to appraise effects of treatment on clinically relevant outcomes. These considerations lead to recommendations regarding eligibility, design, and duration of proof-of-efficacy studies, and to endorsing the American Neurogastroenterology and Motility Society Gastroparesis Cardinal Symptom Index Daily Diary as a validated patient response outcome and to justification of the shortening of proof-of-efficacy, placebo-controlled clinical trials to 4 weeks treatment duration after a baseline period. We believe that such approaches will increase the likelihood of successful assessment of efficacy of novel approaches to treating patients with gastroparesis.

Low Vitamin D Levels in Patients with Symptoms of Gastroparesis: Relationships with Nausea and Vomiting, Gastric Emptying and Gastric Myoelectrical Activity

Patients with gastroparesis (Gp) often have diets deficient in calories, electrolytes, and vitamins. Vitamin D levels have been reported to be low in some patients with Gp but has not been systematically studied.

AIMS

To determine vitamin D levels and relationships among symptoms, gastric emptying and gastric myoelectrical activity (GMA) in patients with symptoms of Gp.

METHODS

25-hydroxy-vitamin D was measured in patients at enrollment in the Gastroparesis Clinical Consortium Registry. Gastroparesis Cardinal Symptoms Index (GCSI), gastric emptying, and GMA before and after water load satiety test (WLST) were measured. GMA, expressed as percentage distribution of activity in normal and dysrhythmic ranges, was recorded using electrogastrography.

RESULTS

Overall, vitamin D levels were low (< 30 ng/ml) in 288 of 513 (56.1%) patients with symptoms of Gp (206 of 376 (54.8%) patients with delayed gastric emptying (Gp) and 82 of 137 (59.9%) patients with symptoms of Gp and normal gastric emptying). Low vitamin D levels were associated with increased nausea and vomiting (P < 0.0001), but not with fullness or bloating subscores. Low vitamin D levels in patients with Gp were associated with greater meal retention at four hours (36% retention) compared with Gp patients with normal vitamin D levels (31% retention; P = 0.05). Low vitamin D in patients with normal gastric emptying was associated with decreased normal 3 cpm GMA before (P = 0.001) and increased tachygastria after WLST (P = 0.01).

CONCLUSIONS

Low vitamin D levels are present in half the patients with symptoms of gastroparesis and are associated with nausea and vomiting and gastric neuromuscular dysfunction.

Gastric Emptying Scintigraphy Protocol Optimization Using Machine Learning for the Detection of Delayed Gastric Emptying

PURPOSE

The purpose of this study is to examine the feasibility of a machine learning (ML) system for optimizing a gastric emptying scintigraphy (GES) protocol for the detection of delayed gastric emptying (GE), which is considered a primary indication for the diagnosis of gastroparesis.

METHODS

An ML model was developed using the JADBio AutoML artificial intelligence (AI) platform. This model employs the percent GE at various imaging time points following the ingestion of a standardized radiolabeled meal to predict normal versus delayed GE at the conclusion of the 4 h GES study. The model was trained and tested on a cohort of 1002 patients who underwent GES using a 70/30 stratified split ratio for training vs. testing. The ML software automated the generation of optimal predictive models by employing a combination of data preprocessing, appropriate feature selection, and predictive modeling analysis algorithms.

RESULTS

The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was employed to evaluate the predictive modeling performance. Several models were developed using different combinations of imaging time points as input features and methodologies to achieve optimal output. By using GE values at time points 0.5 h, 1 h, 1.5 h, 2 h, and 2.5 h as input predictors of the 4 h outcome, the analysis produced an AUC of 90.7% and a balanced accuracy (BA) of 80.0% on the test set. This performance was comparable to the training set results (AUC = 91.5%, BA = 84.7%) within the 95% confidence interval (CI), demonstrating a robust predictive capability. Through feature selection, it was discovered that the 2.5 h GE value alone was statistically significant enough to predict the 4 h outcome independently, with a slightly increased test set performance (AUC = 92.4%, BA = 83.3%), thus emphasizing its dominance as the primary predictor for delayed GE. ROC analysis was also performed for single time imaging points at 1 h and 2 h to assess their independent predictiveness of the 4 h outcome. Furthermore, the ML model was tested for its ability to predict "flipping" cases with normal GE at 1 h and 2 h that became abnormal with delayed GE at 4 h.

CONCLUSIONS

An AI/ML model was designed and trained for predicting delayed GE using a limited number of imaging time points in a 4 h GES clinical protocol. This study demonstrates the feasibility of employing ML for GES optimization in the detection of delayed GE and potentially shortening the protocol's time length without compromising diagnostic power.

Scintigraphy of Gastrointestinal Motility: Best Practices in Assessment of Gastric and Bowel Transit in Adults

Various radiologic examinations and other diagnostic tools exist for evaluating gastrointestinal diseases. When symptoms of gastrointestinal disease persist and no underlying anatomic or structural abnormality is identified, the diagnosis of functional gastrointestinal disorder is frequently applied. Given its physiologic and quantitative nature, scintigraphy often plays a central role in the diagnosis and treatment of patients with suspected functional gastrointestinal disorder. Most frequently, after functional gallbladder disease is excluded, gastric emptying scintigraphy (GES) is considered the next step in evaluating patients with suspected gastric motility disorder who present with upper gastrointestinal symptoms such as dyspepsia or bloating. GES is the standard modality for detecting delayed gastric emptying (gastroparesis) and the less commonly encountered clinical entity, gastric dumping syndrome. Additionally, GES can be used to assess abnormalities of intragastric distribution, suggesting specific disorders such as impaired fundal accommodation or antral dysfunction, as well as to evaluate gastric emptying of liquid. More recently, scintigraphic examinations for evaluating small bowel and large bowel transit have been developed and validated for routine diagnostic use. These can be performed individually or as part of a comprehensive whole-gut transit evaluation. Such scintigraphic examinations are of particular importance because clinical assessment of suspected functional gastrointestinal disorder frequently fails to accurately localize the site of disease, and those patients may have motility disorders involving multiple portions of the gastrointestinal tract. The authors comprehensively review the current practice of gastrointestinal transit scintigraphy, with diseases and best imaging practices illustrated by means of case review. ©RSNA, 2024 See the invited commentary by Maurer and Parkman in this issue.

Randomized, crossover trial: comparing the effects of standardized egg-white meal and Vital® on global gastric emptying parameters and intragastric meal distribution in healthy Asian participants

BACKGROUND AND AIM

Measurements of gastric emptying and accommodation for alternative test-meal protocol during gastric emptying scintigraphy (GES), such as high-calorie nutrient drinks, are not fully established. We aimed to compare the effects of standardized egg-white meal (EWM) versus high-calorie nutrient drink (Vital®; Abbott Laboratories) on global GES parameters and intragastric meal distribution at immediate scan (IMD0h).

METHODS

Of 84 screened participants, 60 asymptomatic healthy Asian population (38 females; 24.0 ± 1.5 years; 23.8 ± 2.6 kg/m2) were recruited in this 2 × 2 (AB/BA) crossover trial. Participants were randomized to a 4-h GES with 99mTc-radiolabeled EWM (~255.8 kcal), followed by a 200 mL Vital® (300 kcal), or vice versa, separated by a 2-week washout period. Global meal retention (GMR), power-exponential model emptying parameters (half-emptying [T1/2], lag phases [Tlag2%, Tlag5%, Tlag10%]), and IMD0h were determined and compared.

RESULTS

GMRs for both test meals were within the international standard references for solid GES. Compared to EWM, Vital® exhibited significantly lower GMRs (faster emptying) from 0.5 to 3 h (all P < 0.001) but comparable at 4 h (P = 0.153). Similar observations were found for the model-based T1/2 and the different Tlag thresholds (all P < 0.001). Furthermore, IMD0h was found to be lower with Vital®, indicating lower gastric accommodation (faster antral filling) immediately post-ingestion (P < 0.001). Both test meals showed significant moderate-to-strong positive associations at the late-phase GE (GMR 2-4 h, T1/2) (all P < 0.05).

CONCLUSIONS

Overall, Vital® is an acceptable alternative test meal to the EWM for GES; however, exercise caution when interpreting early-phase GE. The normative values for global GES parameters and IMD0h are also established.

A physiologically-based digital twin for alcohol consumption-predicting real-life drinking responses and long-term plasma PEth

Alcohol consumption is associated with a wide variety of preventable health complications and is a major risk factor for all-cause mortality in the age group 15-47 years. To reduce dangerous drinking behavior, eHealth applications have shown promise. A particularly interesting potential lies in the combination of eHealth apps with mathematical models. However, existing mathematical models do not consider real-life situations, such as combined intake of meals and beverages, and do not connect drinking to clinical markers, such as phosphatidylethanol (PEth). Herein, we present such a model which can simulate real-life situations and connect drinking to long-term markers. The new model can accurately describe both estimation data according to a χ2 -test (187.0 < Tχ2 = 226.4) and independent validation data (70.8 < Tχ2 = 93.5). The model can also be personalized using anthropometric data from a specific individual and can thus be used as a physiologically-based digital twin. This twin is also able to connect short-term consumption of alcohol to the long-term dynamics of PEth levels in the blood, a clinical biomarker of alcohol consumption. Here we illustrate how connecting short-term consumption to long-term markers allows for a new way to determine patient alcohol consumption from measured PEth levels. An additional use case of the twin could include the combined evaluation of patient-reported AUDIT forms and measured PEth levels. Finally, we integrated the new model into an eHealth application, which could help guide individual users or clinicians to help reduce dangerous drinking.

Efficacy and Safety of Gastric Per-Oral Endoscopic Myotomy (G-POEM): A Systematic Review and Meta-Analysis

BACKGROUND

Gastric per-oral endoscopic myotomy (G-POEM) is an innovative treatment that has become increasingly utilized for patients with refractory gastroparesis. The aim of this systematic review and meta-analysis was to evaluate the safety and effectiveness of G-POEM for the treatment of gastroparesis.

METHODS

Individualized search strategies were developed through February 2021 in accordance with the PRISMA and MOOSE guidelines. This meta-analysis was performed by calculating pooled proportions and mean difference preprocedure and postprocedure with rates estimated using random effects models. Measured outcomes included technical success, clinical success, improvement in gastroparesis cardinal symptom index (GCSI), change in gastric emptying rate, alterations in impedance planimetry (functional lumen imaging probe [FLIP]) assessment, and adverse events.

RESULTS

A total of 20 studies (n=797 patients; 67.41% female) were included. The mean age was 48.92±11.61 y, with an average duration of 4.24±1.11 y since gastroparesis diagnosis. Technical success was 98.47% [(95% CI: 97.14, 99.19);I2=0.00] with a mean myotomy length of 3.78±1.16 cm. In terms of clinical success, mean preprocedure GCSI scores were 3.38±0.37 and improved significantly postprocedure [weighted mean difference -1.56 (95% CI: -1.89 to -1.24); I2=82.53; P<0.001]. Gastric retention after 4 hours demonstrated ~50% improvement (preprocedure 43.08±9.24% versus postprocedure 22.97±10.19%; P<0.001). FLIP assessment with 40 mL and 50 mL balloons demonstrated a significant increase in diameter, distensibility index, and cross-sectional area postprocedure (all P<0.05). Procedure-associated adverse events occurred among 10.92% [(95% CI 5.09 to 19.32); I2=82.85] of patients.

CONCLUSION

G-POEM appears safe and highly effective for the treatment of patients with refractory gastroparesis regardless of symptom predominance or etiology.

Factors Associated With Delayed Gastric Emptying in Symptomatic Diabetic and Non-diabetic Patients: A Retrospective Observational Study

Background Gastroparesis, characterized by delayed gastric emptying without mechanical obstruction, is a significant complication, especially in diabetic individuals. It manifests through symptoms such as abdominal bloating, feelings of fullness, and pain. This study investigates the prevalence of gastroparesis among non-diabetic and diabetic patients, exploring associations with demographic data, hemoglobin A1C (HbA1C) levels, and symptoms. Methodology This retrospective, observational, cohort study included patients with gastroparesis symptoms who underwent a nuclear gastric emptying study from January 2021 to April 2023. The study analyzed demographic data, symptoms, and HbA1c levels to identify correlations with delayed gastric emptying. Results Of 157 patients, 34.4% exhibited delayed gastric emptying. Diabetic patients comprised 29.3% of the sample, with a notable disease duration of over 10 years in 77.3% of cases. Symptoms such as nausea, vomiting, epigastric pain, and early satiety were prevalent, with significant associations between delayed emptying and female gender, higher HbA1c, and vomiting. Conclusions Delayed gastric emptying is significantly associated with female gender, elevated HbA1c levels, and when vomiting is the presenting symptom. Highlighting the importance of awareness among healthcare providers and the community, the findings encourage collaborative efforts for further gastroparesis research to better understand the predictive factors and mechanisms.

Applications of gastric peroral endoscopic myotomy in the treatment of upper gastrointestinal tract disease

Gastric peroral endoscopic myotomy (G-POME) is an emerging minimally invasive endoscopic technique involving the establishment of a submucosal tunnel around the pyloric sphincter. In 2013, Khashab et al used G-POME for the first time in the treatment of gastroparesis with enhanced therapeutic efficacy, providing a new direction for the treatment of gastroparesis. With the recent and rapid development of G-POME therapy technology, progress has been made in the treatment of gastroparesis and other upper digestive tract diseases, such as congenital hypertrophic pyloric stenosis and gastric sleeve stricture, with G-POME. This article reviews the research progress and future prospects of G-POME for the treatment of upper digestive tract gastrointestinal diseases.

Fourier Phase Analysis of Dynamic Antral Contraction Scintigraphy: New Software, Reference Values, and Comparisons to Conventional Gastric Emptying

Dynamic antral contraction scintigraphy (DACS) has been used to evaluate for gastric dysmotility by measuring antral contraction frequency and ejection fraction (EF). Fourier phase image analysis has the potential to assess gastric antral contractions for dyssynchrony as has been used for analyzing nuclear cardiology ventriculography (multigated acquisition studies) for cardiac dyssynchrony. The aims of this study were to determine whether Fourier phase analysis helps to characterize antral motility physiology, whether Fourier phase analysis correlates with conventional gastric emptying scintigraphy (GES), and which DACS parameters may aid in diagnosing gastric dysmotility, particularly delayed gastric emptying (GE). Methods: DACS and GES of healthy volunteers (n = 22) were compared with patients (n = 99) with symptoms of gastroparesis. New DACS Fourier phase analysis software was developed. Results: GE was delayed (n = 53) or normal (n = 46) in patients. There was a linear correlation between the time for the stomach to empty 50% of the meal and the percentage total proximal and distal in-phase antral pixels at 30 min (r = 0.37, P = 0.0001) and 60 min (r = 0.26, P = 0.007). In healthy volunteers, the mean proximal-to-distal ratio of in-phase antral pixels increased from 1.67 (30 min) to 2.65 (120 min) (P = 0.035), and EF increased from 23% (30 min) to 32% (120 min) (P = 0.022). Multivariable regressions of percentage total proximal and distal in-phase antral pixels (30 min) and EF (60 min) were the best predictors of abnormal GE (adjusted odds ratio, 3.30 [95% CI, 1.21-9.00] and 2.97 [95% CI, 1.08-8.21], respectively). Conclusion: This study used Fourier phase analysis to analyze DACS in healthy volunteers and patients with symptoms of gastroparesis. In addition to establishing reference values, new physiologic information on antral motility was obtained. In healthy volunteers, there was an increasing proximal-to-distal ratio of in-phase antral pixels and antral EF over time after meal ingestion. The percentage total proximal and distal in-phase antral pixels at both 30 and 60 min correlated well with GE values for the time for the stomach to empty 50% of the meal. For symptomatic patients, the percentage total proximal and distal in-phase antral pixels at 30 min and the EF at 60 min after meal ingestion correlated with delayed GE on conventional GES. Thus, Fourier phase analysis of DACS appears to have potential to further aid in diagnosing gastric dysmotility in GES.

Change in Management After Radionuclide Gastric Emptying Studies Showing Slow Emptying

The radionuclide gastric emptying study is the gold standard for the diagnosis of gastroparesis. Methods: We performed a retrospective analysis of 510 patients to evaluate how often a diagnosis of slow gastric emptying determined by gastric emptying scintigraphy (GES) changes clinical management at our institution. Results: We found evidence of gastroparesis in 100 patients. A change in management was recommended for 62% within 1 mo of the GES. Conclusion: Our results illustrate the importance of performing GES on patients with clinically suspected gastroparesis.

The spectrum of gastrointestinal functional bowel disorders in joint hypermobility syndrome and in an academic referral center

Joint hypermobility syndrome (JHS) is a non-inflammatory hereditary disorder of connective tissue with varied clinical presentations, including frequent joint dislocations, hyperextensible skin, easy bruising, and abnormal paper-thin scar formation. Many of these patients have unexplained gastrointestinal (GI) symptoms. Our aim was to evaluate the prevalence of JHS in a tertiary gastroenterology motility clinic and the spectrum of functional bowel disorders in JHS patients. In this retrospective case series, we screened the medical records of 277 patients seen over 4 years at an academic GI Motility Center. The patients who met the criteria for JHS by Beighton hypermobility score were evaluated for the presence of functional GI disorders by Rome IV criteria. They also underwent gastric emptying study and glucose breath testing for small intestinal bacterial overgrowth. The prevalence of JHS in the study population was 9.7%. The mean age was 27 years, and 92.5% were female. The symptoms experienced by these patients include nausea/vomiting (89%), abdominal pain (70%), constipation (48%), and bloating (18.5%). The disorders associated with JHS include gastroparesis (52%), irritable bowel syndrome (55.5%), and gastroesophageal reflux disease (30%). Also, 10 patients (37%) were diagnosed with postural hypotension tachycardia syndrome secondary to autonomic dysfunction. Approximately 10% of patients with suspected functional bowel disorders have hypermobility syndrome. Hence, it is crucial to familiarize gastrointestinal practitioners with the criteria utilized to diagnose JHS and the methods to identify physical examination findings related to this condition.

Optimal measurement of gastric emptying of solids in gastroparesis or functional dyspepsia: evidence to establish standard test

OBJECTIVE

Symptoms in gastroparesis (Gp) and functional dyspepsia (FD) overlap; using egg protein substitute to measure gastric emptying of solids (GES), ~40% of patients are reclassified from Gp to FD, and vice versa. Our aim was to assess inter-individual and intra-individual coefficients of variation (COV) in GES in symptomatic patients with Gp or FD with documented slow or normal GES, respectively.

DESIGN

Scintigraphic GES (T1/2 and GE% at 2 and 4 hours) using a 320 kcal real egg meal (30% fat) was tested in the following: single measurements in 20 patients with diabetes mellitus (10 each type 1 and type 2); repeat GES to estimate COVintra measured: 3 days apart in 9 Gp, 4 weeks apart in 21 Gp and 18 with FD with normal GE assigned to placebo and in 70 patients at 94.3 weeks (median) apart.

RESULTS

COVinter for GE% at 4 hours and GE T1/2 were respectively 14.2% and 23.5% in FD and 27.5% and 33% in Gp; COVintra for GE% at 4 hours and GE T1/2 up to 4 weeks apart were 23.4% and 37.9% in FD and 20.1% and 33% in Gp. GE% at 2 hours showed less consistent results. However, >85% retained original diagnosis as normal or delayed. From clinical GES to baseline research for Gp group, repeat GES (after treatment) showed the COVintra for GE% at 4 hours was 37.3% at median 94.3 weeks, with 26/70 changed diagnoses.

CONCLUSION

The 320 kcal (30% fat) GES scintigraphic test provides consistent diagnosis in >85% and should be the standard test for suspected gastric emptying disorders.

Relationships among intragastric meal distribution during gastric emptying scintigraphy, water consumption during water load satiety testing, and symptoms of gastroparesis

Gastric emptying scintigraphy (GES) measures total gastric retention after a solid meal and can assess intragastric meal distribution (IMD). Water load satiety test (WLST) measures gastric capacity. Both IMD immediately after meal ingestion [ratio of proximal gastric counts after meal ingestion to total gastric counts at time 0 (IMD0)] and WLST (volume of water ingested over 5 min) are indirect measures of gastric accommodation. In this study, IMD0 and WLST were compared with each other and to symptoms of gastroparesis to gauge their clinical utility for assessing patients with symptoms of gastroparesis. Patients with symptoms of gastroparesis underwent GES to obtain gastric retention and IMD0, WLST, and filled out patient assessment of upper GI symptoms. A total of 234 patients with symptoms of gastroparesis were assessed (86 patients with diabetes, 130 idiopathic, 18 postfundoplication) and 175 (75%) delayed gastric emptying. Low IMD0 <0.568 suggesting initial rapid transit to the distal stomach was present in 8% and correlated with lower gastric retention, less heartburn, and lower volumes consumed during WLST. Low WLST volume (<238 mL) was present in 20% and associated with increased severity of early satiety, postprandial fullness, loss of appetite, and nausea. Low IMD0 is associated with less gastric retention and less heartburn. Volume of water consumed during WLST, while associated with IMD0, has associations with early satiety, postprandial fullness, loss of appetite, and nausea. Thus, IMD0 and WLST appear to overlap somewhat in their assessment of gastric physiology in adults with symptoms of gastroparesis but relate to different dyspeptic symptoms.NEW & NOTEWORTHY IMD0 and WLST were assessed for their clinical utility in assessing patients with symptoms of gastroparesis. Low IMD0 is associated with less gastric retention and less heartburn. Volume of water consumed during WLST, while associated with IMD0, has associations with early satiety, postprandial fullness, loss of appetite, and nausea. IMD0 and WLST appear to overlap somewhat in their assessment of gastric physiology in adults with symptoms of gastroparesis but relate to different dyspeptic symptoms.

Atypical Causes of Gastroparesis: Prevalence, Gastric Emptying, and Clinical Features

BACKGROUND

Gastroparesis is commonly attributed to idiopathic or diabetic causes.

GOALS

We aimed to describe atypical causes of gastroparesis and examine the clinical features and severity of delayed gastric emptying compared with idiopathic and diabetic causes.

STUDY

Between 2018 and 2021, gastroparesis patients being evaluated at our tertiary care center completed a 4-hour gastric emptying scintigraphy and questionnaires assessing for gastrointestinal disorders, including patient assessment of upper gastrointestinal symptoms. Patients were divided into groups relating to gastroparesis cause: diabetic, postsurgical (PSGp), connective tissue (CTGp), neurological and idiopathic.

RESULTS

Two hundred fifty-six patients with delayed emptying on gastric emptying scintigraphy completed the questionnaires. Gastroparesis causes included 149 (58.2%) idiopathic, 60 (23.4%) diabetic, 29 (11.3%) postsurgical, 13 (5.1%) connective tissue, and 5 (2.0%) neurological. In each group, most patients were female and White. Gastric retention at 4 hours was significantly greater in patients with diabetic (39.3±25.7% P <0.001), postsurgical (41.3±24.0% P =0.002), and connective tissue gastroparesis (37.8±20.0% P =0.049) compared with patients with idiopathic gastroparesis (25.5±17.6%). In PSGp, diabetic and idiopathic causes, the main symptoms were early satiety and postprandial fullness, whereas in CTGp, bloating and abdominal distension were the predominant symptoms. Vomiting severity was significantly greater in patients with diabetes compared with idiopathic gastroparesis (2.9±1.9 vs. 2.1±1.8 P =0.006).

CONCLUSIONS

Atypical causes contributed to gastroparesis in 47 of 256 (18.4%) patients with delayed gastric emptying. Gastric emptying was significantly more delayed in PSGp and CTGp patients. PSGp patients mainly experienced stomach fullness and early satiety, whereas CTGp patients had predominantly bloating and distension.

Gastric peroral endoscopic myotomy for management of refractory gastroparesis in patients with gastric neurostimulator devices: a multicenter retrospective case control study

BACKGROUND AND AIMS

Gastric neurostimulation (GNS) and gastric peroral myotomy (G-POEM), therapies for refractory gastroparesis, are associated with suboptimal outcomes. We studied the role of G-POEM as a salvage therapy in patients with refractory symptoms after GNS implantation.

METHODS

This was a multicenter, retrospective, matched case-control study. Consecutive patients with a GNS device and who underwent G-POEM as a salvage therapy for clinical failure (cases) and patients without GNS implantation and who underwent G-POEM for refractory gastroparesis (control) between October 2018 and August 2021 were included. The primary outcome was clinical success after G-POEM.

RESULTS

A total of 123 patients (mean age 45.7 ± 14.7 years; 88 female subjects [72%]) underwent G-POEM therapy during the study: 41 cases and 82 controls. Clinical success was achieved in 66% in the case group and 65% in the control group (P = .311), during a median total clinical follow-up time of 11.8 (interquartile range, 2.4-6.3) months. In the case group, the mean Gastroparesis Cardinal Symptom Index score decreased from 2.8 ± 1.8 to 1.5 ± 1.9 (P = .024), and gastric retention at 4 hours improved from 45% ± 25.8% to 16.6% ± 13.1% (P = .06). The mean delta improvement in the subscales of nausea/vomiting (1.3 ± .6 vs .9 ± 1.1, P = .044) and bloating (1.6 ± 1.3 vs 1.2 ± 1.4, P = .041) were significantly higher in cases than in controls.

CONCLUSIONS

Among patients with refractory symptoms after GNS, G-POEM can be a reasonable salvage therapy to provide further symptomatic relief with evidence of a potential additive effect of both G-POEM and GNS.

A computational model of the effects of macronutrients absorption and physical exercise on hormonal regulation and metabolic homeostasis

Regular physical exercise and appropriate nutrition affect metabolic and hormonal responses and may reduce the risk of developing chronic non-communicable diseases such as high blood pressure, ischemic stroke, coronary heart disease, some types of cancer, and type 2 diabetes mellitus. Computational models describing the metabolic and hormonal changes due to the synergistic action of exercise and meal intake are, to date, scarce and mostly focussed on glucose absorption, ignoring the contribution of the other macronutrients. We here describe a model of nutrient intake, stomach emptying, and absorption of macronutrients in the gastrointestinal tract during and after the ingestion of a mixed meal, including the contribution of proteins and fats. We integrated this effort to our previous work in which we modeled the effects of a bout of physical exercise on metabolic homeostasis. We validated the computational model with reliable data from the literature. The simulations are overall physiologically consistent and helpful in describing the metabolic changes due to everyday life stimuli such as multiple mixed meals and variable periods of physical exercise over prolonged periods of time. This computational model may be used to design virtual cohorts of subjects differing in sex, age, height, weight, and fitness status, for specialized in silico challenge studies aimed at designing exercise and nutrition schemes to support health.

Imaging in Gastroparesis: Exploring Innovative Diagnostic Approaches, Symptoms, and Treatment

Gastroparesis (GP) is a chronic disease characterized by upper gastrointestinal symptoms, primarily nausea and vomiting, and delayed gastric emptying (GE), in the absence of mechanical GI obstruction. The underlying pathophysiology of GP remains unclear, but factors contributing to the condition include vagal nerve dysfunction, impaired gastric fundic accommodation, antral hypomotility, gastric dysrhythmias, and pyloric dysfunction. Currently, gastric emptying scintigraphy (GES) is considered the gold standard for GP diagnosis. However, the overall delay in GE weakly correlates with GP symptoms and their severity. Recent research efforts have focused on developing treatments that address the presumed underlying pathophysiological mechanisms of GP, such as pyloric hypertonicity, with Gastric Peroral Endoscopic Myotomy (G-POEM) one of these procedures. New promising diagnostic tools for gastroparesis include wireless motility capsule (WMC), the 13 carbon-GE breath test, high-resolution electrogastrography, and the Endoluminal Functional Lumen Imaging Probe (EndoFLIP). Some of these tools assess alterations beyond GE, such as muscular electrical activity and pyloric tone. These modalities have the potential to characterize the pathophysiology of gastroparesis, identifying patients who may benefit from targeted therapies. The aim of this review is to provide an overview of the current knowledge on diagnostic pathways in GP, with a focus on the association between diagnosis, symptoms, and treatment.

Gastrointestinal Symptoms Profile in Gastroparesis Compared to Other Functional and Organic Gastrointestinal Diseases

OBJECTIVES

The primary objective was to compare the patient-reported gastrointestinal symptoms profiles of pediatric patients with gastroparesis to pediatric patients with 1 of 7 other functional gastrointestinal disorders and organic gastrointestinal diseases using the Pediatric Quality of Life Inventory (PedsQL) Gastrointestinal Symptoms Scales.

METHODS

The gastrointestinal symptoms profiles of 64 pediatric patients with gastroparesis who manifested abnormal gastric retention based on gastric emptying scintigraphy testing were compared to 582 pediatric patients with 1 of 7 physician-diagnosed gastrointestinal disorders (functional abdominal pain, irritable bowel syndrome, functional dyspepsia, gastroesophageal reflux disease, functional constipation, Crohn disease, ulcerative colitis). The PedsQL Gastrointestinal Symptoms Scales encompass 10 individual multi-item scales which measure stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea/fecal incontinence, with an overall total gastrointestinal symptoms score.

RESULTS

The gastrointestinal symptoms profile analysis identified significantly worse overall total gastrointestinal symptoms scores between pediatric patients with gastroparesis compared to all other gastrointestinal groups except for irritable bowel syndrome (most P s < 0.001), with significant differences for stomach discomfort when eating compared to all 7 other gastrointestinal groups (most P s < 0.001). Nausea and vomiting were significantly worse for gastroparesis compared to all other gastrointestinal groups except for functional dyspepsia (all P s < 0.001).

CONCLUSIONS

Pediatric patients with gastroparesis self-reported significantly worse overall total gastrointestinal symptoms compared to all other gastrointestinal diagnostic groups except for irritable bowel syndrome, with stomach discomfort when eating and nausea and vomiting symptoms exhibiting the greatest differences compared to most gastrointestinal diagnostic groups.

Gastroparesis: Myths, Misconceptions, and Management

Gastroparesis (GP), a historically vexing disorder characterized by symptoms of nausea, vomiting, abdominal pain, early satiety, and/or bloating, in the setting of an objective delay in gastric emptying, is often difficult to treat and carries a tremendous burden on the quality of patients' lives, as well as the healthcare system in general. Though the etiology of GP has been fairly well defined, much work has been done recently to better understand the pathophysiology of GP, as well as to identify novel effective and safe treatment options. As our understanding of GP has evolved, many myths and misconceptions still abound in this rapidly changing field. The goal of this review is to identify myths and misconceptions regarding the etiology, pathophysiology, diagnosis, and treatment of GP, in the context of the latest research findings which have shaped our current understanding of GP. Recognition and dispelling of such myths and misconceptions is critical to moving the field forward and ultimately advancing the clinical management of what will hopefully become a better understood and more manageable disorder in the future.

Normative Values for Body Surface Gastric Mapping Evaluations of Gastric Motility Using Gastric Alimetry: Spectral Analysis

INTRODUCTION

Body surface gastric mapping (BSGM) is a new noninvasive test of gastric function. BSGM offers several novel and improved biomarkers of gastric function capable of differentiating patients with overlapping symptom profiles. The aim of this study was to define normative reference intervals for BSGM spectral metrics in a population of healthy controls.

METHODS

BSGM was performed in healthy controls using Gastric Alimetry (Alimetry, New Zealand) comprising a stretchable high-resolution array (8 × 8 electrodes; 196 cm 2 ), wearable Reader, and validated symptom-logging App. The evaluation encompassed a fasting baseline (30 minutes), 482 kCal meal, and 4-hour postprandial recording. Normative reference intervals were calculated for BSGM metrics including the Principal Gastric Frequency, Gastric Alimetry Rhythm Index (a measure of the concentration of power in the gastric frequency band over time), body mass index (BMI)-adjusted amplitude (μV), and fed:fasted amplitude ratio. Data were reported as median and reference interval (5th and/or 95th percentiles).

RESULTS

A total of 110 subjects (55% female, median age 32 years [interquartile range 24-50], median BMI 23.8 kg/m 2 [interquartile range 21.4-26.9]) were included. The median Principal Gastric Frequency was 3.04 cycles per minute; reference interval: 2.65-3.35 cycles per minute. The median Gastric Alimetry Rhythm Index was 0.50; reference interval: ≥0.25. The median BMI-adjusted amplitude was 37.6 μV; reference interval: 20-70 μV. The median fed:fasted amplitude ratio was 1.85; reference interval ≥1.08. A higher BMI was associated with a shorter meal-response duration ( P = 0.014).

DISCUSSION

This study provides normative reference intervals for BSGM spectral data to inform diagnostic interpretations of abnormal gastric function.

Buspirone for early satiety and symptoms of gastroparesis: A multi-centre, randomised, placebo-controlled, double-masked trial (BESST)

BACKGROUND

Patients with gastroparesis and related disorders have symptoms including early satiety, postprandial fullness and bloating. Buspirone, a 5-HT1 receptor agonist, may improve fundic accommodation.

AIM

To determine if buspirone treatment improves early satiety and postprandial fullness in patients with symptoms of gastroparesis.

METHODS

This 4-week multi-centre clinical trial randomised patients with symptoms of gastroparesis and moderate-to-severe symptoms of fullness (Gastroparesis Cardinal Symptom Index [GCSI] early satiety/postprandial fullness subscore [ES/PPF]) to buspirone (10 mg orally) or placebo three times per day. The primary outcome was a change in the ES/PPF from baseline to 4 weeks. The primary analysis was per protocol intention-to-treat ANCOVA of between-group baseline vs. 4-week differences (DoD) in ES/PPF adjusted for baseline ES/PPF. Results are reported using both nominal and Bonferroni (BF) p values.

RESULTS AND CONCLUSIONS

Ninety-six patients (47 buspirone, 49 placeboes; 92% female, 50% delayed gastric emptying, 39% diabetic) were enrolled. There was no between-groups difference in the 4-week ES/PPF primary outcome: -1.16 ± 1.25 (SD) on buspirone vs -1.03 ± 1.29 (SD) on placebo (mean DoD: -0.11 [95% CI: -0.68, 0.45]; p = 0.69). Buspirone performed better than placebo in patients with severe-to-very severe bloating at baseline compared to patients with none to moderate: (ES/PPF DoD = -0.65 vs. 1.58, pTX*GROUP  = 0.003; pBF  = 0.07). Among individual GCSI symptoms, only bloating appeared to improve with buspirone vs. placebo.

CONCLUSIONS

Patients with moderate-to-severe early satiety/postprandial fullness and other symptoms of gastroparesis did not benefit from buspirone treatment to improve the ES/PPF primary outcome compared with placebo. There was a suggestion of the benefit of buspirone in patients with more severe bloating.

TRIAL REGISTRATION

ClinicalTrials.gov NCT0358714285.

Ten controversies in gastroparesis and a look to the future

BACKGROUND

Gastroparesis is a complex, challenging gastrointestinal disorder presenting with upper gastrointestinal symptoms, especially nausea and vomiting, with significant impact on patients' quality of life. After ruling out mechanical obstruction, it is essential to identify delay in gastric emptying for definitive diagnosis. The most common causes are idiopathic (no identified etiology), diabetes mellitus, and postsurgical status. Management of gastroparesis focuses on dietary modifications and treatment directed to symptom relief. Unfortunately, approximately one-third of patients are refractory to pharmacological therapy, and the effectiveness of the few nonpharmacological options has been questioned.

PURPOSE

Extensive review of the literature identifies several uncertainties or controversies regarding the differential diagnosis based on the spectrum of symptoms, the lack of availability of reliable diagnostic test, and questions regarding effective therapeutic options. In this review, we discuss ten controversies regarding gastroparesis: clinical presentation, diagnosis, overlap syndromes, pathophysiology, etiology, as well as pharmacological and nonpharmacological therapeutic options. In addition, we briefly review studies exploring pathological, inflammatory, and molecular disturbances affecting the intrinsic neuromuscular elements that may be involved in the pathophysiology of gastroparesis and may constitute possible therapeutic targets in the future. Finally, we tabulate future research opportunities to resolve these controversies in the management of patients with gastroparesis.

Gastrointestinal-Specific symptom anxiety in patients with gastroparesis: Relationships to symptom severity and quality of life

BACKGROUND

Gastrointestinal (GI)-specific anxiety has been identified as a treatment target in irritable bowel syndrome. However, GI-specific anxiety has been understudied in other GI functional/motility disorders. Among adults with gastroparesis, we aimed to: (1) initially validate a measure of GI-specific anxiety, the Visceral Sensitivity Index (VSI); and (2) evaluate the relationship between GI-specific anxiety and gastroparesis symptom severity and quality of life, compared to measures of anxiety, depression, and somatization.

METHODS

Consecutive adult patients (N = 100) with gastroparesis presenting for initial consultation completed a series of self-report measures including the VSI. We conducted a confirmatory factor analysis of the VSI one-factor structure and tested internal consistency and convergent validity. We then performed hierarchical linear regression analyses to explore associations between VSI and gastroparesis symptom severity and overall quality of life.

KEY RESULTS

Confirmatory factor analysis revealed that the original VSI one-factor structure overall fit well [χ2 (90) = 220.1, p < 0.0001; SRMR = 0.08; RMSEA = 0.12; CFI = 0.96]. The VSI also had excellent internal consistency (α = 0.99) and convergent validity (r = 0.29-0.56; all p < 0.01). Higher GI-specific anxiety was significantly associated with greater gastroparesis symptom severity, including nausea/vomiting, fullness/satiety, and upper abdominal pain scores beyond depression, anxiety, or somatization (all p = <0.01-0.01). Additionally, higher GI-specific anxiety was significantly associated with lower mental health-related quality of life, beyond gastroparesis symptom severity, depression, anxiety, or somatization (p = 0.01).

CONCLUSIONS & INFERENCES

The VSI is an adequate measure of GI-specific anxiety in patients with gastroparesis. Higher GI-specific anxiety was associated with increased patient-reported gastroparesis symptom severity and decreased quality of life, beyond depression/anxiety.

Characteristics and outcomes of patients with gastroparesis using enteral and/or exclusive parenteral nutrition

BACKGROUND

Patients with gastroparesis (Gp) may need enteral nutrition (EN) or exclusive parenteral nutrition (PN). Among patients with Gp, we aimed to (1) identify the frequency of EN and exclusive PN use and (2) explore characteristics of patients using EN and/or exclusive PN compared with those using oral nutrition (ON), including changes over 48 weeks.

METHODS

Patients with Gp underwent history and physical examination, gastric emptying scintigraphy, water load satiety testing (WLST), and questionnaires assessing gastrointestinal symptoms and quality of life (QOL). Patients were observed 48 weeks.

RESULTS

Of 971 patients with Gp (idiopathic, 579; diabetic, 336; post-Nissen fundoplication, 51), 939 (96.7%) were using ON only, 14 (1.4%) using exclusive PN, and 18 (1.9%) using EN. Compared with patients receiving ON, patients receiving exclusive PN and/or EN were younger, had lower body mass index, and had greater symptom severity. Patients receiving exclusive PN and/or EN had lower physical QOL but not mental QOL or Gp-related QOL scores. Patients receiving exclusive PN and/or EN ingested less water during WLST but did not have worse gastric emptying. Of those who had been receiving exclusive PN and/or EN, 50% and 25%, respectively, resumed ON at 48-week follow-up.

CONCLUSIONS

This study describes patients with Gp requiring exclusive PN and/or EN for nutrition support, who represent a small (3.3%) but important subset of patients with Gp. Unique clinical and physiological parameters are associated with this subset and provide insight into the use of nutrition support in Gp.

Review article: Functional dyspepsia-a gastric disorder, a duodenal disorder or a combination of both?

BACKGROUND

Functional dyspepsia (FD) is one of the most frequent conditions in gastroenterological outpatient health care. Most recent research in FD has shifted its focus to duodenal pathophysiological mechanisms, although current treatments still focus mainly the stomach.

AIM

The aim of the study was to provide a comprehensive overview of the pathophysiology of FD focusing on a paradigm shift from gastric towards duodenal mechanisms.

METHODS

We conducted a literature search in PubMed for studies describing mechanisms that could possibly cause FD.

RESULTS

The pathophysiology of FD remains incompletely understood. Recent studies show that duodenal factors such as acid, bile salt exposure and eosinophil and mast cell activation correlate with symptom pattern and burden and can be associated with gastric sensorimotor dysfunction. The evolving data identify the duodenum an interesting target for new therapeutic approaches. Furthermore, the current first-line treatment, that is proton pump inhibitors, reduces duodenal low-grade inflammation and FD symptoms.

CONCLUSION

Future research for the treatment of FD should focus on the inhibition of duodenal mast cell activation, eosinophilia and loss of mucosal integrity.

Efficacy and Safety of Drugs for Gastroparesis: Systematic Review and Network Meta-analysis

BACKGROUND & AIMS

Although there have been multiple drugs tested in gastroparesis, their relative efficacy and safety are unknown. We evaluated this in a network meta-analysis of randomized controlled trials (RCTs).

METHODS

We searched the literature to September 7, 2022. We judged the efficacy of drugs based on global symptoms of gastroparesis; individual symptoms, including nausea, vomiting, abdominal pain, bloating, or fullness; and safety according to total adverse events and adverse events leading to withdrawal. We extracted data as intention-to-treat analyses, assuming dropouts to be treatment failures and reporting pooled relative risks (RRs) of not improving with 95% confidence intervals (CIs), ranking drugs according to P-score.

RESULTS

We identified 29 RCTs (3772 patients). Based on global symptoms, clebopride ranked first for efficacy (RR, 0.30; 95% CI, 0.16-0.57; P-score = .99) followed by domperidone (RR, 0.68; 95% CI, 0.48-0.98; P-score = .76). No other drug was superior to placebo. Only 2 drug classes were efficacious: in rank order, oral dopamine antagonists (RR, 0.58; 95% CI, 0.44-0.77; P-score = .96) and tachykinin-1 antagonists (RR, 0.69; 95% CI, 0.52-0.93; P-score = .83). For individual symptoms, oral metoclopramide ranked first for nausea (RR 0.46; 95% CI, 0.21-1.00; P-score = .95), fullness (RR 0.67; 95% CI, 0.35-1.28; P-score = .86), and bloating (RR 0.53; 95% CI, 0.30-0.93; P-score = .97), based on only 1 small trial. Only prucalopride was more likely to be associated with adverse events than placebo.

CONCLUSIONS

In a network meta-analysis, oral dopamine antagonists and tachykinin-1 antagonists were more efficacious than placebo for gastroparesis, but confidence in the evidence was low to moderate for most comparisons. There is an unmet need for efficacious therapies for gastroparesis.

Gastroparesis: An Evidence-Based Review for the Bariatric and Foregut Surgeon

Gastroparesis is a gastric motility disorder characterized by delayed gastric emptying. It is a rare disease and difficult to treat effectively; management is a dilemma for gastroenterologists and surgeons alike. We conducted a systematic review of the literature to evaluate current diagnostic tools as well as treatment options. We describe key elements in the pathophysiology of the disease, in addition to current evidence on treatment alternatives, including nutritional considerations, medical and surgical options, and related outcomes.

Hair Loss in Patients with Gastroparesis: A Sign of Nutritional Deficiency in Gastroparesis?

INTRODUCTION

Some patients with gastroparesis (Gp) report hair loss. The aim of this study was to investigate the prevalence of patient-reported hair loss in Gp patients, analyze hair loss association to severity of Gp and nutritional deficiencies, and study effects of multivitamin treatment on hair loss.

METHODS

Patients with Gp were questioned about hair characteristics, Gp symptoms, and diet. Patients with hair loss had blood drawn for vitamin levels. Patients with hair loss were treated with daily multivitamin and assessed 8 weeks later.

RESULTS

Hair loss was reported in 65 of 143 patients with Gp (45.5%), occurring similarly in idiopathic and diabetic Gp. Hair loss was most commonly noticed while washing and/or combing hair. Patients with hair loss had more severe nausea, abdominal pain, stomach fullness, loss of appetite, abdominal discomfort, bloating, retching, stomach distension, vomiting, early satiety, postprandial fullness, and constipation. Hair loss patients lost more weight over prior 6 months. Patients with hair loss had similar gastric retention on gastric emptying scintigraphy. Overall, 29 of 61 (47.5%) patients with hair loss had at least one abnormal bloodwork result. After 8 weeks of treatment with a daily multivitamin, 17 of 41 (41%) patients had improvement in hair loss.

CONCLUSION

Hair loss occurred in 46% of patients with Gp, being associated with more severe symptoms, loss of weight, and several vitamin deficiencies, although not a specific one. Treatment with multivitamins improved hair loss in 40% of patients. Presence of hair loss in patients with Gp should prompt nutritional evaluation and supplementation.

Diagnostic Methods for Evaluation of Gastric Motility-A Mini Review

Gastric motility abnormalities are common in patients with disorders of gut-brain interaction, such as functional dyspepsia and gastroparesis. Accurate assessment of the gastric motility in these common disorders can help understand the underlying pathophysiology and guide effective treatment. A variety of clinically applicable diagnostic methods have been developed to objectively evaluate the presence of gastric dysmotility, including tests of gastric accommodation, antroduodenal motility, gastric emptying, and gastric myoelectrical activity. The aim of this mini review is to summarize the advances in clinically available diagnostic methods for evaluation of gastric motility and describe the advantages and disadvantages of each test.

Bridging the Gap between Food Effects under Clinical Trial Conditions and Real Life: Modeling Delayed Gastric Emptying of Drug Substances and Gastric Content Volume Based on Meal Characteristics

Delayed gastric emptying is known to have a major impact on drug absorption. While the test meal recommended by the FDA and EMA to study food effects represents a worst-case scenario, it does not reflect the reality of the patients. Physiologically based pharmacokinetic (PBPK) models could bridge the gap between clinical settings of food effect studies and the diverse nonclinical situations by simulating the effect of meals with different compositions and volumes. A mathematical equation based on a stretched exponential function was reparameterized to describe the gastric emptying process of mixed solid meals. The model was fitted to literature data including the gastric emptying data of 23 meals from 15 studies. Using a multiple linear regression model, we were able to predict the two function parameters from the meal characteristics caloric content and the percentage of calories derived from fat. After implementation into the PBPK software PK-Sim, the model, together with a separate compartment for liquid gastric contents, was compared to commercially available software. The model is able to simulate the gastric emptying of mixed solid meals containing drugs based on specific meal characteristics. A second compartment allows for distribution between liquid and solid components and rapid gastric emptying along the Magenstrasse.

Effect of liquid and solid test meals on symptoms and gastric myoelectrical activity in patients with gastroparesis and functional dyspepsia

BACKGROUND

Patients with gastroparesis (GP) and functional dyspepsia (FD) have similar symptoms, but the pathophysiology of postprandial symptoms remains uncertain.

AIMS

To compare symptoms and gastric myoelectrical activity (GMA) after liquid and solid test meals in patients with GP and FD.

METHODS

Patients enrolled in the Gastroparesis Clinical Research Consortium Registry were studied. Clinical characteristics were measured with standard questionnaires. GP was determined by 4-h solid-phase gastric scintigraphy. GMA was measured using electrogastrography before and after ingestion of a water load or nutrient bar on separate days. Symptoms were measured on visual analog scales. GMA responses to the water load for individual patients were also determined.

RESULTS

284 patients with GP and 113 with FD were identified who ingested both test meals. Patients with GP and FD had similar maximal tolerated volumes of water [mean (SD) 378 (218) ml vs. 402 (226) ml, p = 0.23] and reported similar intensity of fullness, nausea, bloating, and abdominal discomfort after the test meals. Twenty-six percent and 19% of the patients with GP and FD, respectively, ingested subthreshold (<238 ml) volumes of water (p = 0.15). Gastric dysrhythmias were recorded in 66% of the GP and 65% of the FD patients after the water load. Symptoms and GMA were similar in both groups after ingestion of the nutrient bar.

CONCLUSION

The similarity in GMA responses and symptoms after ingestion of solid or liquid test meals suggests GP and FD are closely related gastric neuromuscular disorders.

Standard Adult Gastric Emptying Scintigraphy Criteria Is Applicable for Partial Meal Ingestion

BACKGROUND/AIMS

Gastric emptying scintigraphy is commonly performed to assess for dysmotility. A standardized meal with associated threshold criteria was established in 2000 to enable robust interpretation. However, no guidance is available to interpret results when patients do not ingest the entire meal. The purpose of this study is to determine the continued appropriateness of the threshold criteria in contemporary clinical practice and its relevance for partially ingested meals.

METHODS

This retrospective study analyzed patients (n = 1365 total) who underwent solid-phase gastric emptying scintigraphy at an academic medical center. Patients were stratified based on their completion of the standard meal. Patients were further stratified into normal and delayed gastric emptying cohorts based on the current criteria. Percent gastric retention values at 1, 2, 3, and 4 h were compared.

RESULTS

Median (95% upper reference) normal gastric retention values for the complete standard meal were 64% (87%) at 1 h, 25% (60%) at 2 h, 13% (54%) at 3 h and 4% (9%) at 4 h. Consumption of at least 50% of the standard meal yielded similar retention; 53% (86%) at 1 h, 19% (58%) at 2 h, 6% (29%) at 3 h and 3% (10%) at 4 h. There was no significant age- or gender-specific differences using the current criteria, and no differences were observed based on diabetic status. Retention values matched well with the current criteria and validated with data-driven clustering.

CONCLUSION

Adult normative standards for gastric emptying scintigraphy are appropriate for differentiating normal and delayed populations and can be applied to partial meals with at least 50% completion.

Electroacupuncture Enhances Gastric Accommodation via the Autonomic and Cytokine Mechanisms in Functional Dyspepsia

BACKGROUND

Due to complex pathophysiology of functional dyspepsia, medications to treat functional dyspepsia are not effective for all patients. Transcutaneous electrical acustimulation (TEA) is an potentially effective therapy for functional dyspepsia without proofs of definite mechanisms.

AIMS

We aimed to investigate the therapeutic impacts of TEA on postprandial distress syndrome (PDS) and explore potential neuroimmune mechanisms.

METHODS

We conducted a double-blinded, randomized, controlled trial in 30 PDS patients randomized for 4-week TEA or sham-TEA. Dyspeptic symptoms, gastric accommodation, gastric emptying and heart rate variability (HRV) were assessed. Duodenal mucosal inflammation was also evaluated.

RESULTS

The dyspeptic symptoms were improved with TEA compared with sham-TEA (P = 0.03). The initial satiety volume and the maximum tolerable volume (MTV) were both improved after the TEA treatment, compared with the sham-TEA group (P all < 0.05). The gastric emptying time (T1/2) was not altered with TEA or sham-TEA. The TEA treatment increased vagal activity and decreased sympathovagal ratio assessed by HRV (P all < 0.01). The IL-6 expression in bulb mucosa was downregulated by the TEA treatment compared to the baseline (P < 0.05).

CONCLUSIONS

Noninvasive TEA improves gastric accommodation and dyspeptic symptoms, possibly by downregulating the IL-6 expression in duodenal bulb mucosa via the vagal efferent pathway.

Gastroparesis and Functional Dyspepsia: Spectrum of Gastroduodenal Neuromuscular Disorders or Unique Entities?

Gastroparesis is defined by delayed gastric emptying in the absence of mechanical obstruction of the stomach. Patients experience symptoms of nausea, vomiting, abdominal pain, fullness, and early satiety. The recognition of the disorder has progressed due to availability of gastric emptying scintigraphy and advancements made in understanding its pathophysiology and treatment options. The clinical presentation and treatment of gastroparesis overlap with a more commonly recognized disorder of gut-brain interaction, functional dyspepsia. Recent studies have reenergized the discussion whether these two are separate entities or perhaps reflect a spectrum of gastroduodenal neuromuscular disorders. The societal guidelines conflict on the utility of gastric emptying scintigraphy in assessment of patients with upper gastrointestinal symptoms. A better appraisal of similarities and differences between gastroparesis and functional dyspepsia will allow targeted treatment for these disorders. This is particularly important as specific pharmacological and endoscopic treatment options are being developed for gastroparesis which are unlikely to be helpful for functional dyspepsia. This review makes the case for considering these disorders in a spectrum where identification of both would most ideally position us toward providing the optimal clinical care.

Factors Associated With Placebo Treatment Response in Functional Dyspepsia Clinical Trials

INTRODUCTION

Controlling for potential placebo effects is an important aspect of gaining an accurate estimate of how much the therapy alone changes patient symptoms or other end points. When the placebo effect is large, this can lead to only a small fraction of changes seen in the active therapy group being attributed to the therapy itself. This problem has been well studied in some disorders of brain-gut interaction but not in functional dyspepsia where placebo response rates of 40% and higher have been reported. Understanding risk factors for placebo response might lead to changes in trial design that could reduce the magnitude of the problem. This study sought to identify risk factors for the placebo effect in a functional dyspepsia clinical trial with a longer-term aim of suggesting trial design changes that might minimize the problem.

METHODS

A secondary analysis of the clinical trial data was undertaken using 2 arms deemed to involve placebo therapy. Potential predictors were drawn from a wide range of patient characteristics including psychological, clinical, and physiological features.

RESULTS

Predictors of a stronger placebo effect on the gastrointestinal symptom rating scale included higher functional dyspepsia symptom burden at baseline (b = -0.101), coexisting irritable bowel syndrome (b = -0.436), and higher scores on the Nepean Dyspepsia Index eat/drink domain (-0.005). Baseline symptom burden and coexisting irritable bowel syndrome were found to be independent placebo predictors, explaining 13% of the variance in change in gastrointestinal symptom rating scale. Anxiety, childhood sexual abuse, sleep amount, and frequent abdominal pain were also found to be predictors of change in individual symptom scores.

DISCUSSION

The findings of this study yield actionable insights into trial methodology that may help to reduce the magnitude of the placebo effect in future functional dyspepsia treatment trials.

Quantitative gastrointestinal function and corresponding symptom profiles in autonomic neuropathy

Purpose

Peripheral neuropathies with autonomic nervous system involvement are a recognized cause of gastrointestinal dysmotility for a wide spectrum of diseases. Recent advances in wireless motility capsule testing allow improved sampling of regional and whole gut motility to aid in the diagnosis of gastrointestinal motility disorders and may provide additional insight into segment-specific enteric involvement of peripheral neuropathies affecting autonomic nervous system function.

Methods

We utilized standardized autonomic nervous system (ANS) reflex assessment and wireless motility capsule testing to evaluate 20 individuals with idiopathic autonomic neuropathy and unexplained gastrointestinal symptoms. Additionally, we examined the relationship between quantifiable autonomic neuropathy and gastrointestinal dysmotility at specific neuroanatomical levels. Symptom profiles were evaluated using the 31-item Composite Autonomic Symptom Score questionnaire (COMPASS-31) and compared to wireless motility capsule data.

Results

We found that transit times were predominately abnormal (delayed) in the foregut (10 of 20; 50%), while contractility abnormalities were far more prominent in the hindgut (17 of 20; 85%), and that motility and symptom patterns, as assessed by the COMPASS-31 GI domain items, generally corresponded. Finally, we also found that there was neuroanatomical overlap in the presence of autonomic reflex abnormalities and WMC-based transit and/or contractility abnormalities.

Conclusions

We found that transit times were predominately abnormal in the foregut and midgut, while contractility abnormalities were far more prominent in the hindgut in individuals with idiopathic autonomic neuropathy. There was a high rate of agreement in segmental wireless motility capsule data with neuroanatomically corresponding standardized ANS function measures (e.g., cardiovagal, sudomotor, adrenergic). Expanded sudomotor testing, including additional neuroanatomical segments, could provide additional indirect assessment of visceral involvement in ANS dysfunction.

Migraine and Gastroparesis

PURPOSEOF REVIEW

Migraine is a chronic and disabling disease affecting a significant proportion of the world's population. There is evidence that gastroparesis, a gastrointestinal (GI) dysmotility disorder in which transit of gastric contents is delayed, can occur in the setting of migraine. This article aims to review recent literature on overlap in the pathophysiology and clinical manifestations of migraine and gastroparesis and highlight management considerations when these disorders coexist.

RECENT FINDINGS

There has been increasing recognition of the importance of the connection between the GI tract and the brain, and mounting evidence for the overlap in the pathophysiology of migraine and gastroparesis specifically. There exists a complex interplay between the central, autonomic, and enteric nervous systems. Studies show that gastroparesis may be present during and between acute migraine attacks necessitating modification of management to optimize outcomes. Gastric dysmotility in the setting of migraine can impact absorption of oral migraine medications and alternate formulations should be considered for some patients. Noninvasive vagus nerve stimulation has been FDA cleared for migraine treatment and is also being studied in gastroparesis. Dysfunction of the autonomic nervous system is a significant feature in the pathophysiology of gut motility and migraine, making treatments that modulate the vagus nerve attractive for future research.

A New Paradigm Shift in Gastroparesis Management

Gastroparesis, once regarded as a rare disease, is difficult to diagnose and challenging to treat; there were many breakthrough advances in the 2010s, shifting the paradigm of the understanding of this complex entity and its management. Similar to diabetes, its increasing prevalence reflects increased accessibility to diagnostic modalities and suggests that gastroparesis was underacknowledged in the past. Major developments in the three main aspects of the disease include the discovery of smooth muscle cells, interstitial cells of Cajal, PDGFRα+ cells syncytium, rather than interstitial cells of Cajal alone, as the main gastric pacemaker unit; the development of validated point-of-care diagnostic modalities such as a wireless motility capsule, the carbon 13-labeled breath test, and impedance planimetry; and the introduction of novel minimally invasive therapeutic options such as newer pharmacologic agents and gastric peroral endoscopic pyloromyotomy. All aspects of these advances will be discussed further in this review.

Antroduodenal motility recording identifies characteristic patterns in gastroparesis related to underlying etiology

BACKGROUND

Gastroparesis (GP) is a gastrointestinal disorder associated with significant morbidity and healthcare costs. GP patients form a heterogeneous population with diverse etiology, and treatment is often challenging due to a poorly understood underlying pathophysiology. The aim of the present study was to assess antroduodenal motility patterns among the different GP etiologies.

METHODS

We reviewed antroduodenal manometry (ADM) recordings of patients with confirmed GP between 2009 and 2019. ADM measurements were evaluated for fed period duration, number of phase III contractions and migrating motor complexes (MMCs), motility index (MI), and presence of neuropathic patterns.

KEY RESULTS

A total of 167 GP patients (142 women, median age 45 [31-57]) were included. The following etiologies were identified: idiopathic n = 101; post-surgery n = 36; and diabetes n = 30. Fed period duration was significantly longer in idiopathic (p &lt; 0.01) and diabetic GP patients (p &lt; 0.05) compared with post-surgery GP patients. Furthermore, the number and duration of phase III contractions and the number of MMCs were significantly lower in idiopathic and diabetic patients compared with post-surgery GP patients (p &lt; 0.01). Likewise, absence of MMCs during 6-h recording was more often observed in idiopathic and diabetes GP patients compared with post-surgery GP patients (resp. p &lt; 0.01 and p &lt; 0.05).

CONCLUSIONS AND INFERENCES

Antroduodenal motility patterns are different among GP etiologies. A dysmotility spectrum was identified with different patterns ranging from post-surgery GP to idiopathic and diabetic GP.

Comprehensive characterization of antral and pyloric contractions by high resolution manometry: applied physiology in suspected gastroparesis

Delayed gastric emptying may result from diverse pathophysiological mechanisms including antral hypomotility and pylorospasm. With increasing use of gastric peroral endoscopic myotomy and preliminary evidence of efficacy, our aim was to assess the motor functions of the distal antrum and pylorus in patients with symptoms of gastroparesis using high-resolution antropyloroduodenal manometry (HR-ADM). Sixteen patients with symptoms suggestive of gastroparesis underwent HR-ADM with 13 sensors, 1 cm apart, placed across the antropyloroduodenal (APD) junction and 2 sensors, 10 cm apart, in descending and distal duodenum. The 1-h postprandial motility was quantitated as contraction frequency/minute, average amplitude, and motility index (MI). Six healthy volunteers served as controls. In the patient group, the HR-ADM identified postprandial antral hypomotility, isolated pyloric pressure waves, and tonic elevation of baseline pressure in pylorus. Patients had significantly reduced frequency of the full-hour postprandial antral contractions/minute compared with healthy volunteers [1.52 (0.97, 1.67) vs. 2.04 (1.70, 2.67), P = 0.005], as well as reduced MI [9.65 (8.29, 10.31) vs. 11.04 (10.65, 11.63), P = 0.002]. The average contraction amplitude was numerically, but not significantly reduced [51.9 (21.9, 74.9) vs. 73.0 (59.8, 82.7), P = 0.14]. Bland-Altman plots showed similar distribution of antral contraction frequency and MI during the first and second postprandial 30-min periods for both patients and controls. High-resolution ADM can characterize a variety of postprandial antral contractile and pyloric motility dysfunctions. This technique shows promise to provide guidance for the selection of optimal treatment of patients with gastroparesis.NEW & NOTEWORTHY Current selection of different treatments for patients with gastroparesis is empiric or based on trial and error, though pyloric distensibility and diameter may predict response to pyloric interventions. High-resolution antropyloroduodenal manometry (HR-ADM) can characterize a variety of postprandial antral contractile and pyloric motility dysfunctions in patients with suspected gastroparesis. HR-ADM shows promise to provide guidance for selection and individualization of treatments such as prokinetic agents or pyloric interventions for patients with gastroparesis based on documented pathophysiology.

Meal Eating Characteristics of Patients with Gastroparesis

BACKGROUND

Patients with gastroparesis often consume only small meals due to early satiety.

AIMS

(1) Describe meal eating characteristics of patients with gastroparesis; (2) Relate meal eating characteristics to symptoms, gastric emptying (GE), and body weight.

METHODS

Patients with gastroparesis filled out questionnaires including Patient Assessment of Upper GI Symptoms (PAGI-SYM), and questionnaire about meal habits and body weight. Patients underwent gastric emptying scintigraphy.

RESULTS

Of 192 gastroparesis patients, 93% endorsed early satiety (ES) with severity of 3.7 ± 1.5 (scored from 0-5) and 93% endorsed postprandial fullness (PPF) with severity of 3.9 ± 1.3. Time spent consuming meals averaged 13.6 ± 17.7 min. Main reasons patients stopped eating were fullness (61%), nausea (48%), and abdominal pain (31%). Time spent eating correlated inversely with severity of nausea (r = -0.18, p < 0.05), stomach fullness (r = -0.21, p < 0.01), PPF (r = -0.23, p < 0.01), loss of appetite (r = -0.34, p < 0.01). Postprandial fullness lasted for 316 ± 344 min. Duration of PPF correlated with nausea (r = 0.30, p < 0.01), retching (r = 0.29, p < 0.01), vomiting (r = 0.28, p < 0.01), stomach fullness (r = 0.33, p < 0.01), loss of appetite (r = 0.35, p < 0.01), and constipation (r = 0.27, p < 0.01). Underweight patients had increased inability to finish a normal size meal (p < 0.01), loss of appetite (p < 0.01), and lower abdominal pain/discomfort (p < 0.05). Patients had lost 3.06 ± 10.60 kgs from their baseline weight. Weight loss correlated with nausea (r = 0.26, p < 0.01), ES (r = 0.30, p < 0.01), loss of appetite (r = 0.28, p < 0.01).

CONCLUSIONS

Early satiety and postprandial fullness were common with high severity. The main reasons for meal cessation were early satiety, nausea, and abdominal pain. Body weight and change in body weight were associated with symptoms of gastroparesis.

Gastrointestinal Symptoms Profile in Pediatric Patients With Gastroparesis Compared to Healthy Controls

OBJECTIVES

The primary objective was to compare the patient-reported gastrointestinal symptoms profiles of pediatric patients with gastroparesis to matched healthy controls using the Pediatric Quality of Life Inventory™ (PedsQL™) Gastrointestinal Symptoms Scales. The secondary objectives were to compare pediatric patients with gastroparesis to pediatric patients with gastroparesis-like symptoms and normal gastric emptying and to compare pediatric patients with gastroparesis-like symptoms and normal gastric emptying to matched healthy controls.

METHODS

The PedsQL™ Gastrointestinal Symptoms Scales were completed by 64 pediatric patients with gastroparesis, 59 pediatric patients with gastroparesis-like symptoms and normal gastric emptying, and 200 age, gender, and race/ethnicity matched healthy controls. The PedsQL™ Gastrointestinal Symptoms Scales encompass 10 individual multi-item scales which measure stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea/fecal incontinence. Based on gastric emptying scintigraphy testing, those with abnormal gastric retention were classified as having gastroparesis.

RESULTS

The gastrointestinal symptoms profile analysis identified large differences between those with gastroparesis compared to healthy controls (most P <0.001), with the largest effect sizes for upper gastrointestinal symptoms including stomach pain, stomach discomfort when eating, food and drink limits, nausea, and vomiting. Those with gastroparesis self-reported similar gastrointestinal symptoms to those with normal gastric emptying, except for increased constipation.

CONCLUSIONS

Pediatric patients with gastroparesis self-reported broad multidimensional gastrointestinal symptoms profiles in comparison to healthy controls with large differences, indicating the critical need for more highly efficacious interventions to bring patient functioning within the normal range of healthy functioning.

Outcomes of combined pyloric botulinum toxin injection and balloon dilation in dyspepsia with and without delayed gastric emptying

Background

Pyloric botulinum toxin injection has improved symptoms in children with delayed gastric emptying. We aimed to determine the clinical response to combined endoscopic intra-pyloric botulinum toxin injection and pyloric balloon dilation (IPBT-BD) in patients with dyspepsia.

Methods

Electronic medical records were reviewed to gather demographic data, symptoms, and follow-up on patients with dyspepsia. Cases were defined as those who underwent IPBT-BD in addition to their ongoing management. Controls received pharmacotherapy, behavioral intervention, or dietary management alone. Clinical response was defined as no change, partial, or complete improvement in symptoms within 12 months. Propensity score matching based on age, gender, and symptom duration was used to pair cases and controls.

Results

In total, 79 cases and 83 controls were identified. After propensity matching, 63 patients were included in each group. The mean age for cases was 14.5 ± 3.9y; 62% were females and 98% were Caucasian. Further, 83% of 46 cases and 94% of 49 controls who had scintigraphy scans showed delayed gastric emptying. After matching, 76% of cases showed partial or complete improvement compared with 49% controls within 12 months (P = 0.004). Younger children tended to respond more favorably to the procedure (P = 0.08).

Conclusions

In our propensity-matched analysis, combined IPBT-BD in addition to pharmacotherapy, behavioral, or dietary management clearly showed a benefit over these modalities alone. This favorable response lasted up to 12 months.