Towards a less costly but accurate test of gastric emptying and small bowel transit

An overview of Ehlers Danlos syndrome and the link between postural orthostatic tachycardia syndrome and gastrointestinal symptoms with a focus on gastroparesis

There has been an increasingly reported association between Ehlers-Danlos syndrome (EDS), postural orthostatic tachycardia syndrome (POTS) and gastrointestinal disorders. EDS is a hereditary connective tissue disorder which may manifest as a spectrum of symptoms stemming from collagen defects. The prevalence of EDS is estimated to affect 1 in 5000 individuals which underscores its clinical significance. Notably the hypermobile form (hEDS) accounts for the majority of cases. POTS is characterized by orthostatic intolerance with an increase in heart rate on standing in the absence of hypotension. This condition predominantly affects women between 15 and 45 years of age. Gastrointestinal symptoms in the form of reflux, bloating and abdominal pain significant impact this population. Gastroparesis is a chronic disorder involving symptoms of delayed gastric emptying and may be closely associated with hEDS and POTS, and may be underreported. Autonomic dysfunction associated with hEDS has been proposed as the likely mechanism underlying POTS and gastrointestinal dysfunction though a clear pathophysiological process has not been established.

Extensive scintigraphic gastric motor function testing with concurrent symptom recording predicts prospectively measured daily dyspeptic symptoms

BACKGROUND

Absent "organic" disease, dyspeptic symptoms may arise from abnormal gastric sensation, accommodation, motility or emptying (GE). Extensive gastric sensorimotor evaluation is rarely undertaken because testing is prolonged, invasive, poorly tolerated or unavailable.

AIMS

To investigate whether gastric antral motor function, evaluated with scintigraphy, predicts GE. To explore whether motor testing with symptom recording predicts day-to-day symptoms in patients with dyspepsia.

METHODS

GE was determined using a scintigraphic solid-meal protocol (296 kcal, 35% fat). Antral motility was estimated from 10 min of scintigraphic time-activity curves acquired 40 min after meal consumption. An antral motility index (MI) was derived from contraction amplitude and frequency. Intra-gastric distribution of the meal on scintograms at 1 h (IGD1) was determined. Meal-induced symptoms were evaluated by questionnaire. Patients completed the Gastroparesis Cardinal Symptom Index Daily Diary (GCSI-DD) for 14 days.

RESULTS

Twelve healthy participants and 23 prospectively recruited patients completed the study. Nine patients had delayed, and 2 had rapid, GE. In univariate analysis MI explained 42% of GE half-time. In multivariate analysis MI and GE half-time explained 25% of the variance in meal-induced symptoms. While scintigraphic evaluation of gastric motor function with symptom recording explained 80% of the variance in the GCSI-DD, meal-induced symptoms were the only significant predictor. However, among patients with delayed GE, MI, GE half-time, IGD1, and meal-induced symptoms all significantly predicted GCSI-DD.

CONCLUSIONS

Antral motility predicts GE. In exploratory analyses, only meal-induced symptoms predicted daily symptoms among patients with dyspepsia. However, motor function also predicted symptoms in patients with delayed GE.

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.

Small Bowel Transit Scintigraphy in Children With Pediatric Intestinal Pseudo-Obstruction

INTRODUCTION

Objective evidence of small intestinal dysmotility is a key criterion for the diagnosis of pediatric intestinal pseudo-obstruction (PIPO). Small bowel scintigraphy (SBS) allows for objective measurement of small bowel transit (SBT), but limited data are available in children. We aimed to evaluate the utility of SBS in children suspected of gastrointestinal dysmotility.

METHODS

Patients undergoing gastric emptying studies for suspected foregut dysmotility, including PIPO, from 2016 to 2022 at 2 tertiary children's hospitals were recruited to an extended protocol of gastric emptying studies to allow for assessment of SBT. PIPO was classified based on antroduodenal manometry (ADM). SBT was compared between PIPO and non-PIPO patients. Scintigraphic parameters were assessed and correlated against ADM scores.

RESULTS

Fifty-nine patients (16 PIPO and 43 non-PIPO diagnoses) were included. SBS was performed with liquid and solid meals in 40 and 26 patients, respectively. As compared to the non-PIPO group, PIPO patients had a significantly lower median percentage of colonic filling at 6 hours, with both liquid (48% vs 83%) and solid tests (5% vs 65%). SBT in PIPO patients with myopathic involvement was significantly slower than in patients with neuropathic PIPO, both for liquid and solid meal. A significant correlation was found between solid SBT and ADM scores (r = -0.638, P = 0.036).

DISCUSSION

SBS provides a practically feasible assessment of small intestinal motility. It shows a potential utility to help diagnose and characterize PIPO. SBS seems most discriminative in PIPO patients with myopathic involvement. Studies in a larger pediatric population and across different ages are required.

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.

Magnetic resonance imaging as a non-invasive tool to assess gastric emptying in mice

BACKGROUND

Methods to study gastric emptying in rodents are time consuming or terminal, preventing repetitive assessment in the same animal. Magnetic resonance imaging (MRI) is a non-invasive technique increasingly used to investigate gastrointestinal function devoid of these shortcomings. Here, we evaluated MRI to measure gastric emptying in control animals and in two different models of gastroparesis.

METHODS

Mice were scanned using a 9.4 Tesla MR scanner. Gastric volume was measured by delineating the stomach lumen area. Control mice were scanned every 30 min after ingestion of a 0.2 g meal and stomach volume was quantified. The ability of MRI to detect delayed gastric emptying was evaluated in models of morphine-induced gastroparesis and streptozotocin-induced diabetes.

KEY RESULTS

Magnetic resonance imaging reproducibly detected increased gastric volume following ingestion of a standard meal and progressively decreased with a half emptying time of 59 ± 5 min. Morphine significantly increased gastric volume measured at t = 120 min (saline: 20 ± 2 vs morphine: 34 ± 5 mm³ ; n = 8-10; p < 0.001) and increased half emptying time using the breath test (saline: 85 ± 22 vs morphine: 161 ± 46 min; n = 10; p < 0.001). In diabetic mice, gastric volume assessed by MRI at t = 60 min (control: 23 ± 2 mm³ ; n = 14 vs diabetic: 26 ± 5 mm³ ; n = 18; p = 0.014) but not at t = 120 min (control: 21 ± 3 mm³ ; n = 13 vs diabetic: 18 ± 5 mm³ ; n = 18; p = 0.115) was significantly increased compared to nondiabetic mice.

CONCLUSIONS AND INFERENCES

Our data indicate that MRI is a reliable and reproducible tool to assess gastric emptying in mice and represents a useful technique to study gastroparesis in disease models or for evaluation of pharmacological compounds.

Diagnostic Modalities Used in Diagnosing Gastroparesis: A Clinical Review

Gastroparesis is associated with abnormal gastric motility characterized by delayed gastric emptying without any obvious mechanical gastric outlet obstruction or blockage. Gastroparesis is associated with significant morbidity and mortality. It is pertinent to make a timely diagnosis of gastroparesis so that prompt treatment can be initiated. The purpose of this clinical review article is to help the internist and the primary care providers to get a better idea of various diagnostic modalities used in diagnosing gastroparesis. We have also discussed the advantages and disadvantages of various diagnostic modalities based on the latest evidence.

Classification of Gastroparesis from Glycemic Variability in Type 1 Diabetes: A Proof-of-Concept Study

BACKGROUND AND OBJECTIVE

Delayed gastric emptying is a substantial challenge for people with diabetes, affecting quality of life and blood glucose regulation. The complication is underdiagnosed, and current diagnostic tests are expensive or time consuming or have modest accuracy. The assessment of glycemic variations has potential use in gastroparesis screening. The aim of this study was to investigate the differences in glycemic variability between type 1 diabetes patients with gastroparesis and without a diagnosis of gastroparesis and the potential for using a classification model to differentiate between groups.

METHODS

Continuous glucose monitoring (CGM) from 425 patients with diabetes was included in the analytic cohort, including 16 patients with a diagnosis of gastroparesis and 409 without a known gastroparesis diagnosis. Sixteen features (9 daytime features and 7 nighttime features) describing glucose dynamics were extracted to assess differences between patients with and without a diagnosis of gastroparesis. A logistic regression model was trained using forward selection and cross-validation.

RESULTS

In total, 3 features were included in the model utilizing forward selection of features and cross-validation: mean absolute glucose (MAG), span, and standard deviation during the night. The Receiver operating characteristic (ROC) AUC for the classification model was 0.76.

CONCLUSIONS

Gastroparesis seems to have an impact on glucose variability, especially during the night. Moreover, CGM could possibly be used as a part of the screening process for delayed gastric emptying, but more studies are needed to determine a realistic accuracy.

Gastrointestinal motility disorders in patients with multiple sclerosis: A single-center study

BACKGROUND

Most prevalent gastrointestinal symptoms in multiple sclerosis (MS) relate to lower bowel dysfunction, often in association with bladder manifestations.

OBJECTIVE

To assess clinical and objective gastrointestinal motor dysfunctions in patients with MS.

METHODS

This was a single-center, retrospective study of 166 patients evaluated between 1996 and 2020. We reviewed characterization of the MS, gastrointestinal and neurological symptoms, measurements of gastrointestinal and colonic transit, and anorectal manometry.

KEY RESULTS

At the time of the gastrointestinal evaluations of the 166 patients with MS (138 women; 83%), 111 were in the relapsing-remitting phase and 52 were in the progressive phase. In 3 patients, disease phase was not assigned due to insufficient data. Constipation was identified in 82% (136/166) of patients. Most [103/116 (88%)] patients with bladder symptoms also had constipation or fecal incontinence. Delayed gastric emptying at 4 h and colonic transit at 24 h was identified in 16% and 7% of the cohort, respectively; 22% had accelerated gastric emptying. On anorectal manometry, resting anal sphincter pressure >90 mm Hg and rectoanal pressure differential below -50mm Hg suggested evacuation disorder in patients with constipation.

CONCLUSIONS AND INFERENCES

In addition to slow colonic transit and anorectal dysfunction leading to constipation in MS, 22% of patients had accelerated gastric emptying.

Gastroparesis

Gastroparesis is characterized by symptoms suggestive of, and objective evidence of, delayed gastric emptying in the absence of mechanical obstruction. This review addresses the normal emptying of solids and liquids from the stomach and details the myogenic and neuromuscular control mechanisms, including the specialized function of the pyloric sphincter, that result in normal emptying, based predominantly on animal research. A clear understanding of fundamental mechanisms is necessary to comprehend derangements leading to gastroparesis, and additional research on human gastric muscles is needed. The section on pathophysiology of gastroparesis considers neuromuscular diseases that affect nonsphincteric gastric muscle, disorders of the extrinsic neural control, and pyloric dysfunction that lead to gastroparesis. The potential cellular basis for gastroparesis is attributed to the effects of oxidative stress and inflammation, with increased pro-inflammatory and decreased resident macrophages, as observed in full-thickness biopsies from patients with gastroparesis. Predominant diagnostic tests involving measurements of gastric emptying, the use of a functional luminal imaging probe, and high-resolution antral duodenal manometry in characterizing the abnormal motor functions at the gastroduodenal junction are discussed. Management is based on supporting nutrition; dietary interventions, including the physical reduction in particle size of solid foods; pharmacological agents, including prokinetics and anti-emetics; and interventions such as gastric electrical stimulation and pyloromyotomy. These are discussed briefly, and comment is added on the potential for individualized treatments in the future, based on optimal gastric emptying measurement and objective documentation of the underlying pathophysiology causing the gastroparesis.

Gastric Emptying Scans: Poor Adherence to National Guidelines

BACKGROUND

Accurately diagnosing gastroparesis relies upon gastric emptying scintigraphy (GES) being performed correctly. Jointly published protocol guidelines have long been available; however, the extent to which practitioners adhere to these guidelines is unknown.

AIMS

This study aimed to assess national compliance with established GES protocol guidelines.

METHODS

We developed a questionnaire addressing the key protocol measures outlined in the Consensus Recommendations for Gastric Emptying Scintigraphy. Survey questions addressed patient information collection (15), patient preparation and procedure protocol (16), meal content and preparation (7), imaging (3), interpretation (4), reporting (7), and institutional demographic data (7). The anonymous questionnaire was distributed electronically to members of the Society of Nuclear Medicine and Medical Imaging (SNMMI) and non-member recipients of the SNMMI daily email newsletter. One response per medical institution was permitted.

RESULTS

A total of 121 out of 872 potential medical institutions (MI) responded (13.9%); 49 (40.4%) were academic/teaching medical centers. The annual number (mean) of GES procedures was 199.9 (range 5-2000 GES/year). On average, MI performed 33.5/52 (64%) of protocol measures according to guidelines while academic medical centers performed 31.5/52 (61%) of protocol measures according to guidelines. Only 4 out of 88 MI (4.5%) performed GES while adhering to three critical measures: validated study duration; controlled blood glucose levels; and proper restriction of medications.

CONCLUSIONS

Low compliance with GES protocol guidelines, even among academic medical centers, raises the likely possibility of misdiagnosis and improper management of upper gastrointestinal symptoms. These results highlight a need for increased awareness of protocol guidelines for gastric scintigraphy.

Gastric Sensory and Motor Functions and Energy Intake in Health and Obesity-Therapeutic Implications

Sensory and motor functions of the stomach, including gastric emptying and accommodation, have significant effects on energy consumption and appetite. Obesity is characterized by energy imbalance; altered gastric functions, such as rapid gastric emptying and large fasting gastric volume in obesity, may result in increased food intake prior to reaching usual fullness and increased appetite. Thus, many different interventions for obesity, including different diets, anti-obesity medications, bariatric endoscopy, and surgery, alter gastric functions and gastrointestinal motility. In this review, we focus on the role of the gastric and intestinal functions in food intake, pathophysiology of obesity, and obesity management.

Enhancing Scintigraphy for Evaluation of Gastric, Small Bowel, and Colonic Motility

This article reviews the latest enhancements in standards and technology for performing gastric emptying and associated small bowel and colon transit scintigraphic studies. It discusses how developments in appropriate use criteria, American Medical Association Current Procedural Terminology coding, and advanced commercial software permit clinicians to obtain more comprehensive physiologic studies of gastric, small bowel, and colon gastrointestinal motility disorders. It shows how gastrointestinal scintigraphy has expanded to permit assessments of global and regional (fundic and antral) gastric motility and how it permits a single study (whole-gut transit scintigraphy), including measurement of solid and liquid gastric emptying and small bowel and colon transit.

Gastrointestinal motility evaluation in children with orthostatic intolerance: Mayo Clinic experience

OBJECTIVE

Orthostatic intolerance (OI) and autonomic dysfunction (AD) are common in adolescents and young adults. Patients experience multisystem symptoms including gastrointestinal (GI), postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension (OH), or only symptoms of OI (SOI) without significant findings on 70-degree head-up tilt testing (HUT). We hypothesize that patients with POTS, OH, and SOI show differences in GI symptoms and motility test and that heart rate (HR) changes on HUT predict severity of GI dysmotility.

STUDY DESIGN

From medical records of patients (<18 years) with OI, we collected demographics, presenting symptoms, GI manifestations, and GI motility testing. Data were compared between the 3 groups (POTS, OH, and SOI). We assessed changes in HR on HUT with changes on GI motility evaluation.

RESULTS

Two hundred twenty-nine patients were included (73% females). Abdominal pain (65%), nausea (49%), vomiting (18%), and constipation (24%) were the most common GI symptoms. In patients who had motility evaluation, there were 27% (53/193) with delayed gastric emptying (GE) at 4 hours, 35% (32/92) with delayed colonic transit (CT), 55% (17/31) with reduced gastric accommodation (GA), and 75% (21/28) with dyssynergic defecation (DD). Among 100 POTS, 34 OH, and 95 SOI patients, no significant differences in GI symptoms or motility tests were identified and HR changes on HUT were not associated with changes on motility tests.

CONCLUSION

GI symptoms are frequent in adolescents with OI and are associated with delayed GE, reduced GA, delayed CT, and presence of DD.

Diabetic Gastroparesis

This review covers the epidemiology, pathophysiology, clinical features, diagnosis, and management of diabetic gastroparesis, and more broadly diabetic gastroenteropathy, which encompasses all the gastrointestinal manifestations of diabetes mellitus. Up to 50% of patients with type 1 and type 2 DM and suboptimal glycemic control have delayed gastric emptying (GE), which can be documented with scintigraphy, 13C breath tests, or a wireless motility capsule; the remainder have normal or rapid GE. Many patients with delayed GE are asymptomatic; others have dyspepsia (i.e., mild to moderate indigestion, with or without a mild delay in GE) or gastroparesis, which is a syndrome characterized by moderate to severe upper gastrointestinal symptoms and delayed GE that suggest, but are not accompanied by, gastric outlet obstruction. Gastroparesis can markedly impair quality of life, and up to 50% of patients have significant anxiety and/or depression. Often the distinction between dyspepsia and gastroparesis is based on clinical judgement rather than established criteria. Hyperglycemia, autonomic neuropathy, and enteric neuromuscular inflammation and injury are implicated in the pathogenesis of delayed GE. Alternatively, there are limited data to suggest that delayed GE may affect glycemic control. The management of diabetic gastroparesis is guided by the severity of symptoms, the magnitude of delayed GE, and the nutritional status. Initial options include dietary modifications, supplemental oral nutrition, and antiemetic and prokinetic medications. Patients with more severe symptoms may require a venting gastrostomy or jejunostomy and/or gastric electrical stimulation. Promising newer therapeutic approaches include ghrelin receptor agonists and selective 5-hydroxytryptamine receptor agonists.

First translational consensus on terminology and definitions of colonic motility in animals and humans studied by manometric and other techniques

Alterations in colonic motility are implicated in the pathophysiology of bowel disorders, but high-resolution manometry of human colonic motor function has revealed that our knowledge of normal motor patterns is limited. Furthermore, various terminologies and definitions have been used to describe colonic motor patterns in children, adults and animals. An example is the distinction between the high-amplitude propagating contractions in humans and giant contractions in animals. Harmonized terminology and definitions are required that are applicable to the study of colonic motility performed by basic scientists and clinicians, as well as adult and paediatric gastroenterologists. As clinical studies increasingly require adequate animal models to develop and test new therapies, there is a need for rational use of terminology to describe those motor patterns that are equivalent between animals and humans. This Consensus Statement provides the first harmonized interpretation of commonly used terminology to describe colonic motor function and delineates possible similarities between motor patterns observed in animal models and humans in vitro (ex vivo) and in vivo. The consolidated terminology can be an impetus for new research that will considerably improve our understanding of colonic motor function and will facilitate the development and testing of new therapies for colonic motility disorders.

EnsurePlus as an Alternative to the Standardized Egg Gastric-Emptying Meal

OBJECTIVES

The purpose of this study was to establish normal gastric-emptying values for EnsurePlus in healthy subjects and to determine whether it is an acceptable alternative to the recommended standardized Tc-sulfur colloid egg meal.

METHODS

Twenty-one healthy subjects underwent gastric-emptying scintigraphy with In-DTPA EnsurePlus. Normal gastric emptying values were established for 1, 2, 3, and 4 hours after meal ingestion. The gastric-emptying results were compared with another group of normal subjects (n = 18) who ingested the standardized egg meal.

RESULTS

The mean (95% upper reference limit) percentages for gastric retention for EnsurePlus were as follows: 69.9% (87.1%) at 1 hour, 35.1% (64.3%) at 2 hours, 13.5% (23.2%) at 3, and 8.9% (13.5%) at 4 hours. There were time-related differences in the gastric emptying of the EnsurePlus compared with the egg meal. In the first and second hours, there were no difference between EnsurePlus and the egg meal in terms of percentage retention (P = 0.92 at 1 hour, P = 0.05 at 2 hours). However, at 3 and 4 hours after meal ingestion, the mean percentage gastric retention of the EnsurePlus was significantly higher than the egg meal (P < 0.001).

CONCLUSION

EnsurePlus is a good and acceptable alternative to the standardized egg meal.

A single-center audit of the indications and clinical impact of prolonged ambulatory small intestinal manometry

BACKGROUND

Small bowel manometry is a diagnostic test available only in a few specialized referral centers. Its exact place in the management of refractory symptoms is controversial.

METHODS

The records of all patients who underwent 24-hour ambulatory duodenojejunal manometry over a 6-year period were retrospectively reviewed. We studied the clinical indications for small bowel manometry, and reviewed the impact of manometric findings on the clinical outcome. One hundred and forty-six studies were performed in 137 patients (46M, 91F) with a mean age of 44.9 ± 15.7 years. Mean follow-up duration was 15.1 ± 22.6 months. Appropriate endoscopic, radiological and gastric scintigraphy studies were performed in all patients prior to small bowel manometry. Criteria for abnormal motor activity were based on Bharucha's classification.

KEY RESULTS

The indications for small bowel manometry were chronic abdominal pain (n = 43), slow-transit constipation (n = 17), refractory gastroparesis (n = 16), chronic diarrhea (n = 7), recurrent episodes of subocclusion (n = 16), postsurgical evaluation (n = 36), suspicion of gut involvement in systemic disease (n = 9), and unexplained nausea (n = 2). The most common finding was a normal 24-hour ambulatory small bowel manometry (n = 113). Thirty-three studies yielded abnormal findings which included extrinsic neuropathy (n = 6), intrinsic neuropathy (n = 18), intestinal myopathy (n = 2), and subocclusion (n = 7). Ambulatory small bowel manometry excluded a generalized motility disorder in 77% and had a significant impact on the subsequent clinical course in 23%.

CONCLUSIONS & INFERENCES

Ambulatory small bowel manometry is a useful and safe diagnostic tool to complement traditional investigative modalities in patients with severe unexplained abdominal symptoms.

Effects of naloxegol on whole gut transit in opioid-naïve healthy subjects receiving codeine: A randomized, controlled trial

BACKGROUND

Nausea, vomiting, and constipation (OIC) are common adverse effects of acute or chronic opioid use. Naloxegol (25 mg) is an approved peripherally active mu-opiate opioid receptor antagonist.

AIM

To compare the effects on pan-gut transit of treatment with codeine, naloxegol, or combination in healthy volunteers.

METHODS

We conducted a randomized, double-blind, placebo-controlled, single-center, parallel-group study in 72 healthy opioid-naïve adults, randomized to: codeine (30 mg q.i.d.), naloxegol (25 mg daily), codeine and naloxegol, or matching placebo. During 3 days of treatment, we measured gastric emptying (GE) T1/2 , colonic filling at 6 hours (CF6), colonic geometric center at 24 and 48 hours, and ascending colon emptying (ACE) T1/2 .

KEY RESULTS

Participants were 59.7% women, median BMI 25.0 kg/m2 , and median age 33.8 years. Codeine significantly retarded GE T1/2, CF6, overall colonic transit, and ACE T1/2 . There was significant difference (P = .026) in GE T1/2 between codeine (144.0 min [IQR 110.5-238.6]) and naloxegol (95.5 min [89.1-135.4]). There was a significant overall group difference in CF6 (P = .023), with significant difference (P = .019) between codeine (11.0% [0.0-45.0]) and naloxegol (51% [18.8-76.2]). However, no significant differences were found between codeine-treated participants concomitantly receiving placebo or naloxegol.

CONCLUSIONS AND INFERENCES

Short-term administration of naloxegol (25 mg) in healthy, opioid-naïve volunteers does not reverse the retardation of gastric, small bowel, or colonic transit induced by acute administration of codeine. Further studies with naloxegol at higher dose are warranted to assess the ability to reverse the retardation of transit caused by acute administration of codeine in opioid-naïve subjects.

Clinical utility of gastric emptying scintigraphy: Patient and physician perspectives

BACKGROUND

The use of gastric emptying scintigraphy (GES) in the evaluation of patients with dyspeptic symptoms is controversial. Our aim was to investigate objective and subjective parameters of clinical utility of GES from the perspectives of both the patient and the ordering physician.

METHODS

Socio-demographic features, healthcare resource utilization, gastroparetic symptoms and quality of life (QoL) were obtained from consecutive patients referred for GES immediately prior to GES and again 4 months later. The ordering physician received a brief survey 2 weeks after the GES regarding their perceptions on whether the test provided them with clinically useful information.

KEY RESULTS

One hundred and seventy-two (mean age ± SD 52.0 ± 17.9; 78% female) of 266 patients enrolled completed both the baseline and follow-up questionnaires and comprised our study population. At baseline, patients with abnormal GES had significantly higher gastroparesis symptom scores and reduced QoL. At the 4-month follow-up, an improvement in symptoms and QoL was seen, but the degree of improvement was not significantly different between those with a normal or abnormal GES. One hundred and ninety-seven ordering physicians completed the survey and perceived that GES, particularly when abnormal, provided new information (91%) and resulted in a change in diagnosis (58%) and management (60%).

CONCLUSIONS & INFERENCES

Although patients with an abnormal GES generally had worse symptoms and lower QoL, the results of GES did not help to identify those with improved or worsened symptoms or QoL at follow-up. Nevertheless, the ordering physicians generally felt that the results of GES were helpful in managing these patients.

Effects of Antidepressants on Gastric Function in Patients with Functional Dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a highly prevalent functional bowel disorder. The effects of antidepressant therapy (ADTx) on gastric sensorimotor function in FD patients are poorly understood.

AIMS

Determine whether FD and subtypes with abnormalities in gastric function respond differently to ADTx compared to those with normal physiology.

METHODS

This multicenter, prospective trial randomized FD patients to 12 weeks of amitriptyline (AMI; 50 mg), escitalopram (ESC; 10 mg), or matching placebo. Demographics, symptoms, psychological distress, gastric emptying, and satiation were measured. Gastric accommodation (GA) using single-photon emission computed tomography imaging was performed in a subset of patients. An intent to treat analysis included all randomized subjects. The effect of treatment on gastric emptying was assessed using ANCOVA. A post hoc appraisal of the data was performed categorizing patients according to the Rome III subgrouping (PDS and EPS).

RESULTS

In total, 292 subjects were randomized; mean age=44 yrs. 21% had delayed gastric emptying. Neither antidepressant altered gastric emptying, even in those with baseline delayed gastric emptying. GA increased with ADTx (P=0.02). Neither antidepressant affected the maximal-tolerated volume (MTV) of the nutrient drink test although aggregate symptom scores improved compared to placebo (P=0.04). Patients with the combined EPS-PDS subtype (48%) had a lower MTV on the nutrient drink test compared to the EPS group at baseline (P=0.02). Postprandial bloating improved with both AMI (P=0.03) and ESC (P=0.02).

CONCLUSIONS

Amitriptyline (50 mg) improves FD symptoms but does not delay gastric emptying, even in patients with baseline delayed gastric emptying. GA improved with low-dose ADTx; the precise mechanism of action is unknown warranting further study.

Gastric Motor Dysfunction in Patients With Functional Gastroduodenal Symptoms

OBJECTIVES

The pathophysiology of dyspeptic symptoms is complex. The aim of this study was to evaluate the association of gastric emptying (GE), gastric accommodation (GA), and respiratory sinus arrhythmia (RSA, to assess vagal dysfunction) in a large cohort with functional gastroduodenal symptoms.

METHODS

We reviewed demographic, clinical features, and results of gastric motor and vagal function studies of 1,287 patients (74.0% females, mean age 43.1±15.4 years) who had undergone both single photon emission computed tomography GA and scintigraphic GE. Accommodation was based on postprandial to fasting gastric volume ratio (VR). Electrocardiograms were available and analyzed for RSA in 300 patients.

RESULTS

There were 29.8% patients with normal GE and GA, 21.9% with abnormal GA only, 27.1% with abnormal GE only, and 21.1% with abnormal GA and GE. There were numerical differences in GA among patients with normal, accelerated, and delayed GE (P=0.062, by χ²). Increased GA (VR >3.85) was more prevalent in patients with delayed GE compared to accelerated GE (14.0% vs. 6.8%, P=0.004). Decreased VRs (median 2.9) were observed with accelerated GE compared to normal GE (median 3.1, P<0.05). Nausea and vomiting were more prevalent (in contrast to the less prevalent bloating) in patients with delayed compared to accelerated or normal GE (all P<0.05). In patients with diminished RSA, there was higher prevalence of reduced GA (41.5%) compared to those with preserved RSA (29.2%, P=0.031). Multivariable analysis showed associations of the main abdominal symptoms with gender, body mass index, gastric emptying, diabetes, and prior abdominal surgery.

CONCLUSIONS

Patients with symptoms of functional gastroduodenal disorders may have one or more gastric motor dysfunctions and reduced RSA; among the patients with abnormal gastric motor functions, vomiting suggests delayed GE, whereas reduced RSA is associated with reduced GA.

Testing for Chronic Diarrhea

Chronic diarrhea is a frequently encountered symptom in clinical practice. The etiologies for chronic diarrhea are diverse and broad with varying clinical implications. A useful method of categorizing chronic diarrhea to guide a diagnostic work-up is a pathophysiology-based framework. Chronic diarrhea may be categorized as malabsorptive, secretory, osmotic, and inflammatory or motility related. Frequently, overlap between categories may exist for any given diarrhea etiology and diagnostic testing must occur with an understanding of the differential diagnosis. Investigations to achieve a diagnosis for chronic diarrhea range from screening blood and stool tests to more directed testing such as diagnostic imaging, and endoscopic and histological evaluation. The pathophysiology-based framework proposed in this chapter will allow the clinician to select screening tests followed by targeted tests to minimize cost and complications to the patient, while providing a highly effective method to achieve an accurate diagnosis.

Measurement of Gastrointestinal and Colonic Motor Functions in Humans and Animals

Accurately measuring the complex motor behaviors of the gastrointestinal tract has tremendous value for the understanding, diagnosis and treatment of digestive diseases. This review synthesizes the literature regarding current tests that are used in both humans and animals. There remains further opportunity to enhance such tests, especially when such tests are able to provide value in both the preclinical and the clinical settings.

Effect of Amitriptyline and Escitalopram on Functional Dyspepsia: A Multicenter, Randomized Controlled Study

BACKGROUND & AIMS

Antidepressants are frequently prescribed to treat functional dyspepsia (FD), a common disorder characterized by upper abdominal symptoms, including discomfort or postprandial fullness. However, there is little evidence of the efficacy of these drugs in patients with FD. We performed a randomized, double-blind, placebo-controlled trial to evaluate the effects of antidepressant therapy on symptoms, gastric emptying (GE), and meal-induced satiety in patients with FD.

METHODS

We performed a study at 8 North American sites of patients who met the Rome II criteria for FD and did not have depression or use antidepressants. Patients (n = 292; 44 ± 15 years old, 75% were female, 70% with dysmotility-like FD, and 30% with ulcer-like FD) were randomly assigned to groups given placebo, 50 mg amitriptyline, or 10 mg escitalopram for 10 weeks. The primary end point was adequate relief of FD symptoms for ≥5 weeks of the last 10 weeks (of 12). Secondary end points included GE time, maximum tolerated volume in Nutrient Drink Test, and FD-related quality of life.

RESULTS

An adequate relief response was reported by 39 subjects given placebo (40%), 51 given amitriptyline (53%), and 37 given escitalopram (38%) (P = .05, after treatment, adjusted for baseline balancing factors including all subjects). Subjects with ulcer-like FD given amitriptyline were >3-fold more likely to report adequate relief than those given placebo (odds ratio = 3.1; 95% confidence interval: 1.1-9.0). Neither amitriptyline nor escitalopram appeared to affect GE or meal-induced satiety after the 10-week period in any group. Subjects with delayed GE were less likely to report adequate relief than subjects with normal GE (odds ratio = 0.4; 95% confidence interval: 0.2-0.8). Both antidepressants improved overall quality of life.

CONCLUSIONS

Amitriptyline, but not escitalopram, appears to benefit some patients with FD, particularly those with ulcer-like (painful) FD. Patients with delayed GE do not respond to these drugs. ClinicalTrials.gov ID: NCT00248651.

Epidemiology and natural history of gastroparesis

Gastroparesis is characterized by delayed gastric emptying and symptoms thereof in the absence of gastric outlet obstruction. Most studies on the epidemiology of gastroparesis have been conducted in selected case series rather than in the population at large. In the only community-based study of gastroparesis in diabetes mellitus (DM), the average cumulative incidence of symptoms and delayed gastric emptying over 10 years was higher in type 1 DM (5%) than in type 2 DM (1%) and controls (1%). In the United States, the incidence of hospitalizations related to gastroparesis increased substantially between 1995 and 2004, and particularly after 2000.

Increased nutrient sensitivity and plasma concentrations of enteral hormones during duodenal nutrient infusion in functional dyspepsia

OBJECTIVES

Functional dyspepsia is predominantly attributed to gastric sensorimotor dysfunctions. The contribution of intestinal chemosensitivity to symptoms is not understood. We evaluated symptoms and plasma hormones during enteral nutrient infusion and the association with impaired glucose tolerance and quality-of-life (QOL) scores in patients with functional dyspepsia vs. healthy controls.

METHODS

Enteral hormonal responses and symptoms were measured during isocaloric and isovolumic dextrose and lipid infusions into the duodenum in 30 patients with functional dyspepsia (n=27) or nausea and vomiting (n=3) and 35 healthy controls. Infusions were administered in randomized order over 120 min each, with a 120-min washout. Cholecystokinin, glucose-dependent insulinotropic peptide, glucagon-like peptide 1 (GLP1), and peptide YY were measured during infusions.

RESULTS

Moderate or more severe symptoms during lipid (4 controls vs. 14 patients) and dextrose (1 control vs. 12 patients) infusions were more prevalent in patients than controls (P≤0.01), associated with higher dyspepsia symptom score (P=0.01), worse QOL (P=0.01), and greater plasma hormone concentrations (e.g., GLP1 during lipid infusion). Moderate or more severe symptoms during enteral infusion explained 18%, and depression score explained 21%, of interpatient variation in QOL. Eight patients had impaired glucose tolerance, associated with greater plasma GLP1 and peptide YY concentrations during dextrose and lipid infusions, respectively.

CONCLUSIONS

Increased sensitivity to enteral dextrose and lipid infusions was associated with greater plasma enteral hormone concentrations, more severe daily symptoms, and worse QOL in functional dyspepsia. These observations are consistent with the hypothesis that enteral hormones mediate increased intestinal sensitivity to nutrients in functional dyspepsia.

Wireless motility capsule test in children with upper gastrointestinal symptoms

OBJECTIVE

To compare scintigraphic gastric emptying and antroduodenal manometry (ADM) studies with the wireless motility capsule test in symptomatic pediatric patients.

STUDY DESIGN

Patients aged 8-17 years with severe upper gastrointestinal symptoms (ie, nausea, vomiting, retching, abdominal pain) referred for ADM were recruited. A standardized protocol for ADM was used. On a different day, participants were given a standardized meal and then swallowed the wireless motility capsule. A wireless receiver unit worn during the study recorded transmitted data. If not performed previously, a 2-hour scintigraphic gastric emptying study was completed at the time of ADM testing.

RESULTS

A total of 22 patients were recruited, of whom 21 had complete scintigraphic gastric emptying study data and 20 had complete ADM data. The wireless motility capsule test had 100% sensitivity and 50% specificity in detecting gastroparesis compared with the 2-hour scintigraphic gastric emptying study. The wireless motility capsule test detected motor abnormalities in 17 patients, compared with 10 detected by ADM. Dichotomous comparison yielded a diagnostic difference between ADM and the wireless motility capsule test (P<.01). Migrating motor complexes were recognized in all patients by both ADM and the wireless motility capsule test. The wireless motility capsule test was well tolerated in all patients, and there were no side effects.

CONCLUSION

In symptomatic pediatric patients, the wireless motility capsule test is highly sensitive compared with scintigraphic gastric emptying studies in detecting gastroparesis, and seems to be more sensitive than ADM in detecting motor abnormalities.

Randomised clinical trial: the effects of daikenchuto, TU-100, on gastrointestinal and colonic transit, anorectal and bowel function in female patients with functional constipation

BACKGROUND

Daikenchuto, a Japanese herbal medicine used for post-operative ileus and constipation, dose dependently stimulates gastrointestinal (GI) motility and decreases rectal compliance and sensation. Effects of TU-100 (commercial form of daikenchuto) in adults with constipation are unknown.

AIM

To compare the effects of oral TU-100, 2.5 g t.d.s. or 5 g t.d.s. and placebo t.d.s. on GI and colonic transit (CT), rectal compliance (RC) and sensation thresholds (RST), anal sphincter pressures (ASP) and bowel function in female patients with functional constipation (FC).

METHODS

We conducted a single-centre, randomised, parallel-group, double-blind, pharmacodynamic study; 45 female patients with FC without evidence of rectal evacuation disorder were assigned to 28 days' treatment with oral placebo or TU-100 (Tsumura USA, Princeton, NJ, USA). Demographic data and CT were measured at baseline and randomisation stratified by baseline CT (GC> or <1.9) and by BMI (<25 or ≥25 kg/m(2) ). At the end of treatment period, we measured GI and CT by scintigraphy, RST and RC by barostat, ASP by manometry, psychosensory sensations, bowel function by daily diary and quality of life (QOL). The study had power to detect effect sizes of 33% (CT), 40% (RC) and 46% (RST). Statistical analysis included BMI as covariate.

RESULTS

TU-100 had no significant effects on GI or CT, RC, ASP, recto-anal pressure difference, or RST. The 5 g t.d.s./day dose was associated with lower RST for first sensation and gas (unadjusted P: 0.045 and 0.024 respectively). There were no treatment effects on psychosensory symptoms, stool frequency, stool consistency or QOL.

CONCLUSION

Mechanisms underlying the observed clinical benefit of TU-100 remain unclear (ClinicalTrials.gov NCT01139216).

Gastroparesis in children: the benefit of conducting 4-hour scintigraphic gastric-emptying studies

BACKGROUND AND AIM

Scintigraphic gastric emptying study (GES) is the criterion standard for diagnosis of gastroparesis. Adult studies demonstrated that extending GES to 4 hours increases its ability to diagnose delayed gastric emptying. Most pediatric centers assess GES up to 2 hours postmeal. The aim of the present study was to assess the effect of extending GES from 2 to 4 hours in evaluation of children with suspected gastroparesis.

METHODS

We conducted a chart review of all children who had a 4-hour GES with standard radiolabeled solid meal in 2009-2010. Results of GES at 1, 2, and 4 hours were compared. Patients were diagnosed as having gastroparesis using adult criteria: if gastric retention of meal was >90%, 60%, and 10% at 1, 2 and 4 hours, respectively. A telephone survey assessed GES time at top 20 pediatric gastroenterology centers in the United States. Cost of evaluation of patients diagnosed as having gastroparesis was estimated. Full-time equivalents of nuclear medicine technicians and number of nuclear medicine studies done at Ann & Robert H. Lurie Children's Hospital of Chicago from 2007 to 2010 were examined.

RESULTS

A total of 71 patients (32 boys, average age 10.8 years) were studied. Sixty-two percent (n=44) children had abnormal GES; 23% (8/35) of them who had normal values at 2 hours had abnormal GES at 4 hours (P<0.0001). Twenty-eight percent of patients had delayed GES at 1 hour: all persisted to have abnormal GES at 2 and 4 hours. Cost of evaluation of a child for gastroparesis was $9014. Only 5 of the top 20 pediatric gastroenterology centers in the United States conducted 4-hour GES. Transitioning from 2 hours to 4 hours only required scheduling adjustments and did not result in limitation in the number of scheduled patients.

CONCLUSIONS

Extending GES to 4 hours results in a considerable increase in diagnosis of gastroparesis.

Severity of dyspeptic symptoms correlates with delayed and early variables of gastric emptying

BACKGROUND

A simplified report of gastric retention values at select times is now recommended for scintigraphic gastric emptying test (GET).

AIMS

The purpose of this study was to assess correlation between severity of gastroparetic symptoms and all variables of GET, compared to select variables in clinical use.

METHODS

This was a prospective study of patients referred for scintigraphic GET. The Gastroparesis Cardinal Symptom Index questionnaire was obtained prior to the scintigraphy. Variables determined were lag time, half emptying time (T1/2), retention at 30 min, 1, 2 and 4 h. Statistical analysis was by Spearman rank correlation and Wilcoxon rank test with a significance set at p ≤ 0.05.

RESULTS

Seven hundred seventeen patients had GET from 03/09 to 03/11. Results are from 325 patients who did not take medications known to affect GET were analyzed (64.9 % females, mean age 47 ± 18.9 years, 21.8 % diabetics, 78.2 % non-diabetic, of which 7.6 % were post-surgical, primarily post-fundoplication). Combined gastric retention at 2 and 4 h detected delayed GET in 83.5 % non-diabetics and 76.6 % of diabetics. Rapid GET was present in 11 % of patients at 30 min and 4 % at 1 h. Significant positive correlation was observed between nausea, vomiting, loss of appetite and variables of GET, but not with the half-time of emptying (T1/2). Bloating negatively correlated with retention at 2 h. There was no association between duration of symptoms and GET variables.

CONCLUSIONS

Gastroparetic symptoms correlate with different retention times of GET, but not with T1/2. However, symptoms poorly distinguish between categories of gastroparesis or status of gastric emptying. Delayed GE is best detected by 2 and 4 h retention times, while 30 min and 1 h retention times detect rapid GE.

Idiopathic gastroparesis: case report and literature review of diagnostic and treatment modalities

Gastroparesis is a disorder characterized by a delay in gastric emptying of a meal in the absence of a mechanical gastric outlet obstruction. The most common etiologies include diabetes, postsurgical and idiopathic. Idiopathic Gastroparesis is at least as common as diabetic Gastroparesis in most case series. Diagnosis of Gastroparesis is based on the presence of symptoms such as nausea, vomiting, postprandial abdominal fullness, and on an objectively determined delay in gastric emptying. The true prevalence of Gastroparesis is unknown. Gastric emptying can be assessed by scintigraphy and stable isotope breath tests. Management of Gastroparesis consists of dietary and lifestyle measures, possible pharmacological interventions (prokinetics, antiemetics, intrapyloric botulinum toxin injection) and/or interventions that focus on adequate nutrient intake either through a nasoduodenal tube, percutaneous gastrostomy, or jejunostomy. New advances in drug therapy and gastric electrical stimulation techniques have been introduced and might provide new hope to patients. Presented here is an interesting case of idiopathic Gastroparesis along with its management and review of the literature.

Comparison of calculations to estimate gastric emptying half-time of solids in humans

BACKGROUND

Measuring solid gastric emptying (GE) at 4 h is used to identify gastroparesis. GE half-time (GE T(1/2) ) is useful to assess overall and early GE.

AIM

To examine the validity of hourly imaging as a measurement of GE T(1/2) compared with estimates from more detailed imaging.

METHODS

155 human subjects (99 female, 56 male) underwent scintigraphic GE of a solid-liquid meal. We calculated the GE T(1/2) using linear interpolation based on a full set of abdominal images obtained over 4 h, and the GE T(1/2) based on images at 1, 2, 3, and 4 after the meal with interpolation of data.

KEY RESULTS

Differences in GE T(1/2) values (entire set of scan times compared with just the hourly scans) were small [overall median (5th, 95th percentiles) = -0.2[-7.5, 4.6] min] with slightly greater differences in males compared with females. The agreement between the two methods was very high [concordance correlation coefficient (CCC) (95% CI) = .993 (0.990, 0.995)] and a Bland-Altman plot indicated the variation in the results between the two methods did not change appreciably across the range of GE studied (within ±10 in for all but four subjects). Calculated GE T(1/2) values, omitting the 3-h data from the hourly measurements, were associated with similar high accuracy overall and for fast GE, but were less accurate with slow GE.

CONCLUSIONS & INFERENCES

sults of GE T(1/2) solids, using hourly imaging over 4 , are accurate in the range 75-235 n which reflects the typical range of GE of solids in health and disease.

Performance characteristics of scintigraphic measurement of gastric emptying of solids in healthy participants

BACKGROUND

Gastric emptying (GE) is measured in pharmacodynamic and diagnostic studies. Our aim was to assess inter- and intra-subject coefficients of variation (COV) of scintigraphic GE measurements in healthy subjects, and associations of GE with gender and body mass index (BMI).

METHODS

Data from participants with scintigraphic measurements of gastric emptying of solids were analyzed. Primary endpoints were gastric emptying T(1/2) (GE T(1/2) ) and GE at 1, 2, 3, and 4 h.

KEY RESULTS

The patient cohort consisted of 105 males and 214 females; at least two studies were performed in 47 subjects [16 males (M), 32 females (F)]. Inter-subject COV (COV(inter) ) for GE T(1/2) were similar in M and F: overall 24.5% (M 26.0%, F 22.5%); COV are predictably lowest for GE at 4 h (COV(inter) 9.6%). COV(intra) for T(1/2) and GE at 4 h were overall 23.8% and 12.6%, and were similar to COV(inter) values. Gender (but not age or BMI) was significantly associated with GE T1/2 [P < 0.001, F 127.6 ± 28.7 (SD) min; M 109.9 ± 28.6 min] and with GE at 1 h and 2 h. Repeat GE T(1/2) values in 47 participants were significantly correlated (r = 0.459, P < 0.001) with median difference of -6 min (mean -1.6, range -56 to 72 min). Bland-Altman plots showed Δ GE T(1/2) similarly distributed across mean GE T(1/2) 100-155 min, and across studies conducted 90-600 days apart.

CONCLUSIONS & INFERENCES

Inter-subject variations in scintigraphic GE results are only slightly higher than the intra-subject measurements, which are also reproducible over time in healthy volunteers. Gender, but not BMI, is significantly associated with GE results.

Methods for the assessment of small-bowel and colonic transit

Transit assessment of the small intestine and colon is relevant in the study of physiology, pathophysiology, and pharmacodynamics, and there is increasing use of small-bowel and colonic transit measurements in clinical practice as well. The main methods that are applied in clinical practice are substrate-hydrogen breath tests for small-bowel transit and radiopaque markers for colonic transit. Over the past 2-3 decades, scintigraphy has become the preferred standard in research studies, particularly for studies of pathophysiology and pharmacodynamics. New approaches include experimental stable isotope measurement of orocecal transit and the recently approved method using a wireless motility capsule that is validated as an accurate measurement of small-bowel and colonic transit.

Impaired gastric emptying and small bowel transit in children with mitochondrial disorders

OBJECTIVES

The primary aim of our study was to evaluate gastric emptying (GE) and intestinal transit time (ITT) in children with mitochondrial disorders (MD), and secondarily to evaluate the effect of prokinetics in those with prolonged GE.

METHODS

We enrolled subjects 3 to 18 years with MD and having any of the following gastrointestinal (GI) symptoms: abdominal pain, vomiting, constipation, diarrhea, or gastroesophageal reflux. Abdominal pain was scored by visual analog pain scale (1-10). Age-appropriate diet was labeled with radioactive technetium-99 sulfur colloid and its movement tracked along the GI tract. Delayed GE based on our institutional standards was defined as half emptying time >90 minutes for a solid and >60 minutes for a semisolid meal. Prolonged ITT was defined as >4 hours for the tracer to pass from mouth to cecum. A prokinetic was instituted to those with delayed GE, and the study was repeated if possible in 4 to 8 weeks.

RESULTS

Of the 26 subjects, 18 (69%) had delayed GE (median GE 99 minutes) and 12 (46%) had prolonged ITT. The study was repeated in 9 subjects after administering a prokinetic for >1 month. GE normalized in only 3 subjects (median GE on treatment 128 minutes). Mean abdominal pain score, which was 4.8 (max 10) in the 9 subjects, did not improve (5.6 after prokinetic therapy).

CONCLUSIONS

A high prevalence of delayed GE and prolonged ITT was seen in children with MD having GI symptoms, and these abnormalities were poorly responsive to prokinetic therapy.

Effect of a glucagon-like peptide 1 analog, ROSE-010, on GI motor functions in female patients with constipation-predominant irritable bowel syndrome

The glucagon-like peptide 1 (GLP-1) analog ROSE-010 reduced pain during acute exacerbations of irritable bowel syndrome (IBS). Our objective was to assess effects of ROSE-010 on several gastrointestinal (GI) motor and bowel functions in constipation-predominant IBS (IBS-C). In a single-center, randomized, parallel-group, double-blind, placebo-controlled, dose-response study, we evaluated safety, pharmacodynamics, and pharmacokinetics in female patients with IBS-C. ROSE-010 (30, 100, or 300 μg sc) or matching placebo was administered once daily for 3 consecutive days and on 1 day 2-10 days later. We measured GI and colonic transit by validated scintigraphy and gastric volumes by single-photon emission computed tomography. The primary end points were half time of gastric emptying of solids, colonic transit geometric center at 24 h, and gastric accommodation volume. Analysis included intent-to-treat principle, analysis of covariance (with body mass index as covariate), and Dunnett-Hsu test for multiple comparisons. Exposure to ROSE-010 was approximately dose-proportional across the dose range tested. Demographic data in four treatment groups of female IBS-C patients (total 46) were not different. Gastric emptying was significantly retarded by 100 and 300 μg of ROSE-010. There were no significant effects of ROSE-010 on gastric volumes, small bowel or colonic transit at 24 h, or bowel functions. The 30- and 100-μg doses accelerated colonic transit at 48 h. Adverse effects were nausea (P < 0.001 vs. placebo) and vomiting (P = 0.008 vs. placebo). Laboratory safety results were not clinically significant. In IBS-C, ROSE-010 delayed gastric emptying of solids but did not retard colonic transit or alter gastric accommodation; the accelerated colonic transit at 48 h with 30 and 100 μg of ROSE-010 suggests potential for relief of constipation in IBS-C.

A randomised, placebo-controlled trial comparing the effects of tapentadol and oxycodone on gastrointestinal and colonic transit in healthy humans

BACKGROUND

Tapentadol is a mu-opioid receptor agonist and norepinephrine reuptake inhibitor. In clinical trials, tapentadol provided somatic pain relief comparable to mu-opioids such as oxycodone, with significantly less gastrointestinal adverse effects. The acute effects of tapentadol on gastrointestinal and colonic transit are unclear.

AIM

To compare acute effects of oral tapentadol and oxycodone on gastric, small bowel and colonic transit of solids in 38 healthy human subjects.

METHODS

In a randomised, parallel-group, double-blind, placebo-controlled study of the effects of identical-appearing tapentadol immediate release (IR), 75 mg t.d.s., or oxycodone IR, 5 mg t.d.s., for 48 h, we measured gastric (GE), small bowel (SBT measured as colonic filling at 6 h) and colonic transit by validated scintigraphy. Drug was commenced on the evening before the start of the transit test. The primary endpoints were overall colonic transit (geometric centre, GC) at 24 h and GE half-time (t1/2 ). ancova of transit data included gender or BMI as covariates. Adverse effects were summarised.

RESULTS

At the doses tested, oxycodone and tapentadol significantly delayed GE t1/2 and SBT, but not overall colonic transit, compared to placebo. Transit profiles in all regions were not significantly different between oxycodone and tapentadol at the doses tested. Both oxycodone and tapentadol were associated with nausea and central effects attributable to central opiate effects.

CONCLUSIONS

Tapentadol significantly delayed gastric emptying t1/2 and small bowel transit, similar to oxycodone. These data suggest that acute administration of tapentadol may not have significant advantages over standard mu-opioids, in terms of the potential to avoid upper gastrointestinal motor dysfunction.

Gastric emptying scintigraphy: is four hours necessary?

INTRODUCTION

Recommendations for gastric emptying scintigraphy (GES) suggest imaging over 4 hours to better define gastroparesis.

AIMS

To determine the value of defining delayed gastric emptying at time points earlier than 4 hours.

METHODS

GES was performed with ingestion of a liquid egg white meal with imaging at 0, 0.5, 1, 2, 3, and 4 hours. Patients completed the Patient Assessment of Gastrointestinal Symptoms questionnaire immediately before GES.

RESULTS

Of 1499 patients undergoing GES from September 2007 to January 2010 (76.2% were female, mean age of 45.5±0.5 y, 21.3% had diabetes, 9.5% had earlier gastric surgery), 160 (10.7%) had increased gastric retention at 1 hour (>90%), 404 (27%) had increased retention at 2 hours (>60%), 576 (38.4%) had increased retention at 3 hours (>30%), and 629 (42%) had increased retention at 4 hours (>10%). Gastric retention at 4 hours correlated with retention at 3 hours (r=0.890; P<0.001), 2 hours (r=0.738; P<0.001), and 1 hour (r=0.510; P<0.001). Symptoms correlated better with the gastric retention at later time points. The symptoms correlating with gastric retention at 4 hours included early satiety (r=0.170; P<0.01), vomiting (r=0.143; P<0.01), feeling excessively full after meals (r=0.123; P<0.01), and loss of appetite (r=0.122; P<0.01).

CONCLUSIONS

Gastric retention at 4 hours correlates well with gastric retention at 3 hours, good at 2 hours, but only fair with gastric retention at 1 hour. Gastric retention at 1 hour may miss 36% of patients found to have delayed gastric emptying at 4 hours. Symptoms (early satiety, vomiting, feeling excessively full after meals, and loss of appetite) correlated better with the gastric retention at later time points.

Prevalence of hidden gastroparesis in the community: the gastroparesis "iceberg"

BACKGROUND/AIMS

The prevalence of diagnosed gastroparesis is 24.2/100,000 inhabitants, but a large group of people with gastroparesis-like symptoms have never had a gastric emptying (GE) test. Some of them may have undiagnosed gastroparesis. Our aim was to estimate the prevalence of hidden gastroparesis in the community.

METHODS

The study was conducted in 2 parts: (1) Patients referred for a scintigraphic GE test completed a validated questionnaire (Bowel Disease Questionnaire). Multiple linear regression models to predict 2 hours and 4 hours GE rates were developed. (2) A revised Bowel Disease Questionnaire was mailed to a random sample of 4,194 Olmsted County residents. GE rates were estimated with the models for each subject and delayed GE was considered when they were lower than normal values. Hidden gastroparesis was defined in community subjects with predicted delayed GE that had not been diagnosed with gastroparesis prior to the survey.

RESULTS

The regression models for GE rates were constructed using data from 450 patients. In addition to age and gender, the symptoms found significant were nausea/vomiting, early satiety, upper abdominal pain, bloating, loss of appetite and weight loss more than 7 pounds. 2,298 (55%) community subjects returned a questionnaire. Five subjects were excluded due to a prior diagnosis of gastroparesis. When models were applied to the community survey data, 42 (1.8%) subjects were estimated to have delayed GE.

CONCLUSIONS

Delayed GE was estimated to occur in 1.8% of community subjects. Since the prevalence of diagnosed gastroparesis is low (0.02%), many subjects with gastroparesis may remain undiagnosed.

Gastrointestinal transit in patients with systemic sclerosis

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis and collagen deposits. Gastrointestinal symptoms of SSc, including abdominal pain, bloating and discomfort, are common but diffuse and their pathophysiology remains obscure.

AIM

To investigate the pathophysiology of abdominal pain and discomfort in individuals with SSc.

METHODS

A total of 15 individuals with SSc (13 women, median age 58 years), all suffering from diffuse abdominal symptoms, and 17 healthy volunteers (12 women, median age 52 years) were evaluated with the Motility Tracking System, MTS-1, measuring gastric emptying (GE) and velocity through the small intestine. SSc patients were also examined for bacterial overgrowth using the hydrogen breath test and with radiopaque markers to determine the total gastrointestinal transit time (GITT).

RESULTS

Assessed with the MTS-1, the velocity through the proximal small intestine was significantly reduced in SSc patients (median 0.525 m/h, range 0.11-1.15) when compared to healthy subjects (median 0.91 m/h, range 0.51-1.74) (p = 0.02). Prolonged GE was found in 4 SSc patients (27%) but in none of the healthy volunteers (p = 0.04). Only 3 SSc patients (21%) had positive breath tests for small intestinal bacterial overgrowth. GITT was >3 days in 8 patients (53%). Slow small intestinal transit was associated with a prolonged GITT (p < 0.05).

CONCLUSION

Velocity through the small intestine is significantly reduced in SSc patients with diffuse abdominal symptoms.

Application of the lactose 13C-ureide breath test for measurement of equine orocaecal transit time

REASONS FOR PERFORMING STUDY

Application of the lactose (13) C-ureide breath test (LUBT) for measurement of equine orocaecal transit time (OCTT) has not been reported previously. The ability to assess OCTT noninvasively, and to investigate its relationship to gastric emptying rate and small intestinal transit, would be of both clinical and research value.

OBJECTIVES

1) Assessment of the LUBT in healthy horses, with comparison of induced versus noninduced test protocols. 2) Application of a new dual stable isotope breath test (lactose (13) C-ureide and (13) C-octanoic acid) for gastrointestinal transit measurement.

HYPOTHESIS

The LUBT will allow quantification of equine OCTT, and test efficacy will be enhanced by prior administration of lactose (12) C-ureide as shown in vitro. The dual tracer breath test will permit simultaneous measurement of gastric emptying, OCTT and small bowel transit times.

METHODS

Induced and noninduced LUBTs were performed in 3 healthy mature horses in randomised order using a standard test meal and protocol. Combined LUBT and (13) C-octanoic acid breath tests ((13) C-OABT) were performed in 4 individuals on 4 occasions at weekly intervals. Expiratory isotopic recovery was modelled to allow generation of gastric emptying data, small bowel transit times and caecal transit parameters.

RESULTS

The induction protocol for the LUBT increased the rate and magnitude of expiratory (13) CO(2) significantly. Mean ± s.d. values for OCTT, caecal lag phase (t(lag) ) and caecal t(1/2) using the induced LUBT were 3.24 ± 0.65 h, 5.62 ± 1.22 h and 6.31 ± 1.21 h, respectively. Dual stable isotope tests resulted in the production of 2 discrete peaks in expiratory (13) CO(2) in 15/16 tests from which gastric t(1/2), OCTT and small bowel transit (SBT) parameters could be calculated.

CONCLUSIONS

The induced LUBT provides a reliable noninvasive measure of equine OCTT and can be paired with the (13) C-OABT to provide further information about small intestinal motility.

Gastric motor disturbances in patients with idiopathic rapid gastric emptying

BACKGROUND

The mechanisms of 'idiopathic' rapid gastric emptying, which are associated with functional dyspepsia and functional diarrhea, are not understood. Our hypotheses were that increased gastric motility and reduced postprandial gastric accommodation contribute to rapid gastric emptying.

METHODS

Fasting and postprandial (300kcal nutrient meal) gastric volumes were measured by magnetic resonance imaging (MRI) in 20 healthy people and 17 with functional dyspepsia; seven had normal and 10 had rapid gastric emptying. In 17 healthy people and patients, contractility was analyzed by spectral analysis of a time-series of gastric cross-sectional areas. Logistic regression models analyzed whether contractile parameters, fasting volume, and postprandial volume change could discriminate between health and patients with normal or rapid gastric emptying.

KEY RESULTS

While upper gastrointestinal symptoms were comparable, patients with rapid emptying had a higher (P=0.002) body mass index than normal gastric emptying. MRI visualized propagating contractions at ∼3cpm in healthy people and patients. Compared with controls (0.32±0.04, Mean±SEM), the amplitude of gastric contractions in the entire stomach was higher (OR 4.1, 95% CI 1.2-14.0) in patients with rapid (0.48±0.06), but not normal gastric emptying (0.20±0.06). Similar differences were observed in the distal stomach. However, the propagation velocity, fasting gastric volume, and the postprandial volume change were not significantly different between patients and controls.

CONCLUSIONS & INFERENCES

MRI provides a non-invasive and refined assessment of gastric volumes and contractility in humans. Increased gastric contractility may contribute to rapid gastric emptying in functional dyspepsia.

Proximal and overall gastric emptying of solids in patients with reduced gastric volume accommodation compared to matched controls

BACKGROUND

Interventions such as gastric surgery and erythromycin result in displacement of solids to the distal stomach and acceleration of overall and proximal gastric emptying. The effect of non-surgical impairment of gastric accommodation on gastric emptying is unclear. Non-surgical impairment of gastric accommodation is associated with accelerated gastric emptying.

AIM

To compare measurements of proximal and overall gastric emptying in patients with reduced postprandial gastric volume accommodation with the emptying rates in age- and gender-matched controls with normal postprandial gastric volume accommodation.

METHODS

We evaluated overall and proximal gastric emptying in nine patients with impaired gastric accommodation and age-equivalent and gender-matched controls. Gastric volumes and emptying were measured using validated SPECT and dual gamma camera scintigraphy, respectively. We compared group differences in overall and proximal gastric emptying t (1/2) by t test.

RESULTS

Patients with impaired postprandial gastric volume accommodation had greater fasting gastric volume. The proportion of food emptied from the proximal stomach immediately after meal ingestion was lower and t (1/2) of proximal gastric emptying correspondingly longer in the group with reduced postprandial gastric accommodation. In contrast, differences were not detected in overall gastric emptying in the two groups, and the ratio of overall to proximal gastric emptying t (1/2) was greater in the group with impaired volume accommodation.

CONCLUSIONS

Proximal stomach emptying is reduced in patients with impaired postprandial volume accommodation; this difference occurs predominantly during the time of meal ingestion. Compensatory mechanisms that result in normal overall gastric emptying require further elucidation.