Physiology of the LES.

The purpose of this review is to consider the neuromuscular mechanism of LES contractility both by itself and in relation to the esophagogastric junction (EGJ) complex in order to appreciate the intricacies of EGJ valvular function.

The adult eosinophilic oesophagitis quality of life questionnaire: a new measure of health-related quality of life.

BACKGROUND: Eosinophilic oesophagitis (EoO) is a chronic disease characterised by significant symptoms and challenging treatment regimens. Health-related quality of life (HRQOL) is a useful way to direct patient care. EoO symptoms and treatment may impact patient HRQOL. Currently, there is no reliable and valid measure of adult EoO patient HRQOL. AIM: To validate the Adult Eosinophilic Oesophagitis Quality of Life (EoO-QOL-A) questionnaire as a measure of HRQOL in this population. METHODS: The EoO patients aged 18-70 recruited via an out-patient GI clinic and two EoO advocacy groups completed the preliminary EoO-QOL-A, demographic and clinical information, and measures of general HRQOL, psychological distress and EoO symptom severity. A subset of patients completed test-retest assessments. Scale reliability, internal consistency, factor structure, concurrent and convergent validity were evaluated. RESULTS: A total of 201 patients have participated. The study sample was primarily Caucasian, college-educated, and evenly split by gender. The average duration of disease was 7 years with duration of symptoms of 26 months prior to diagnosis. Patients reported were using both pharmacological and dietary treatments. Factor analysis yielded a 37-item, 5-factor structure: Eating/Diet Impact, Social Impact, Emotional Impact, Disease Anxiety and Choking Anxiety. The EoO-QOL-A demonstrated excellent internal consistency, split-half and test-retest reliability. Concurrent and convergent validity were supported by moderate correlations with established HRQOL measures, psychological distress and oesophageal symptoms. CONCLUSIONS: The EoO-QOL-A is a valid and reliable disease-specific HRQOL measure for adult EoO patients. Developing the Adult Eosinophilic Oesophagitis Quality of Life is an important step in guiding treatment practices, improving disease education and standardising research protocols.

Inter-observer reproducibility and analysis of gastric volume measurements and gastric emptying assessed with magnetic resonance imaging.

BACKGROUND: Magnetic resonance (MR) imaging provides direct, non-invasive measurements of gastric function and emptying. The inter-observer variability (IOV) of MR volume measurements and the most appropriate analysis of MR data have not been established. To assess IOV of total gastric volume (TGV) and gastric content volume (GCV) measurements from MR images and the ability of standard power exponential (PowExp), and a novel linear exponential (LinExp) model to describe MR data. METHODS: Ten healthy volunteers received three different volumes of a liquid nutrient test meal (200-800 mL) on 3 days in a randomized order. Magnetic resonance scans were acquired using a 1.5T system every 1-5 min for 60 min. Total gastric volume and GCV were measured independently by three observers. Volume data were fitted by PowExp and LinExp models to assess postprandial volume change and gastric emptying half time (T(50) ). KEY RESULTS: An initial rise in GCV and TGV was often observed after meal ingestion, thereafter GCV and TGV decreased in an approximately linear fashion. Inter-observer variability decreased with greater volumes from 12% at 200 mL to 6% at 600 and 800 mL. Inter-observer variability for T(50) was <5%. PowExp and LinExp models provided comparable estimates of T(50) ; however, only LinExp described dynamic volume change in the early postprandial period. CONCLUSIONS & INFERENCES: Gastric MR provides quantitative measurements of postprandial volume change with low IOV, unless the stomach is nearly empty. The novel LinExp model describes the dynamic volume changes in the early postprandial period more accurately than the PowExp model used in existing gastric emptying studies.

Esophageal symptoms questionnaire for the assessment of dysphagia, globus, and reflux symptoms: initial development and validation.

Esophageal symptoms often co-occur. A validated self-report measure encompassing multiple esophageal symptoms is necessary to determine their frequency and severity both independently and in association with each other. Such a questionnaire could streamline the diagnostic process and guide patient management. We aimed to develop an integrative measure that provides a clinical 'snapshot' of common esophageal symptoms. Internal reliability and content validity of a 38-item self-report Esophageal Symptoms Questionnaire (ESQ), measuring the frequency and severity of typical esophageal symptoms using Likert-rating scales were assessed in 211 patients presenting to gastroenterology and ENT outpatient tertiary care clinics. Reproducibility, concurrent and predictive validity were evaluated using the reduced-item ESQ. The 38-item ESQ had high internal reliability. Principal component analyses and item reduction methods identified three components, to which 30 of 38 items contributed significantly, providing 59% of total variance. The test-retest correlations were moderate-to-strong for 24 of 30 new items (r(s) ≥ 0.44, P < 0.05). The resultant subscales measuring dysphagia (ESQ-D), globus (ESQ-G), and reflux (ESQ-R) compared well against concurrent physician's 'working' diagnosis (odds ratio 1.04-1.09). The receiver operating characteristics were adequate-to-good for ESQ-D (area under the curve [AUC]= 0.87) and ESQ-G (AUC = 0.74), but poor for ESQ-R (AUC = 0.61) although it matched the content of the validated Reflux Disease Questionnaire. The brief 30-item ESQ shows good internal reliability and content validity as a summary of the extent of dysphagia, globus and reflux symptoms. As a tool measuring more than one esophageal symptom, ESQ could guide patient management by indicating which of the coexisting symptoms needs to be addressed first.

3D-high resolution manometry of the esophagogastric junction.

BACKGROUND: The esophagogastric junction (EGJ) is a complex structure that challenges accurate manometric recording. This study aimed to define EGJ pressure morphology relative to the squamocolumnar junction (SCJ) during respiration with 3D-high resolution manometry (3D-HRM). METHODS: A 7.5-cm long 3D-HRM array with 96 independent solid-state pressure sensors (axial spacing 0.75 cm, radial spacing 45°) was used to record EGJ pressure in 15 normal subjects. Concurrent videofluoroscopy was used to localize the SCJ marked with an endoclip. Ex vivo experiments were done on the effect of bending the probe to match that seen fluoroscopically. KEY RESULTS: 3D-high resolution manometry EGJ pressure recordings were dominated by an asymmetric pressure peak superimposed on the lower esophageal sphincter (LES) attributable to the crural diaphragm (CD). Median peak CD pressure at expiration and inspiration (51 and 119 mmHg, respectively) was much greater in 3D-HRM than evident in HRM with circumferential pressure averaging. Esophagogastric junction length, defined as the zone of circumferential pressure exceeding that of adjacent esophagus or stomach was also substantially shorter (2.4 cm) than evident in conventional HRM. No consistent circumferential EGJ pressure was evident distal to the SCJ in 3D-HRM recordings and ex vivo experiments suggested that the intra-gastric pressure peak seen contralateral to the CD related to bending the assembly rather than the sphincter per se. CONCLUSIONS & INFERENCES: 3D-high resolution manometry demonstrated a profoundly asymmetric and vigorous CD component to EGJ pressure superimposed on the LES. Esophagogastric junction length was shorter than evident with conventional HRM and the distal margin of the EGJ sphincteric zone closely correlated with the SCJ.

An alginate-antacid formulation (Gaviscon Double Action Liquid) can eliminate or displace the postprandial 'acid pocket' in symptomatic GERD patients.

BACKGROUND: Recently, an 'acid pocket' has been described in the proximal stomach, particularly evident postprandially in GERD patients, when heartburn is common. By creating a low density gel 'raft' that floats on top of gastric contents, alginate-antacid formulations may neutralise the 'acid pocket'. AIM: To assess the ability of a commercial high-concentration alginate-antacid formulation to neutralize and/or displace the acid pocket in GERD patients. METHODS: The 'acid pocket' was studied in ten symptomatic GERD patients. Measurements were made using concurrent stepwise pH pull-throughs, high resolution manometry and fluoroscopy in a semi-recumbent posture. Each subject was studied in three conditions: fasted, 20 min after consuming a high-fat meal and 20 min later after a 20 mL oral dose of an alginate-antacid formulation (Gaviscon Double Action Liquid, Reckitt Benckiser Healthcare, Hull, UK). The relative position of pH transition points (pH >4) to the EGJ high-pressure zone was analysed. RESULTS: Most patients (8/10) exhibited an acidified segment extending from the proximal stomach into the EGJ when fasted that persisted postprandially. Gaviscon neutralised the acidified segment in six of the eight subjects shifting the pH transition point significantly away from the EGJ. The length and pressure of the EGJ high-pressure zone were minimally affected. CONCLUSIONS: Gaviscon can eliminate or displace the 'acid pocket' in GERD patients. Considering that EGJ length was unchanged throughout, this effect was likely attributable to the alginate 'raft' displacing gastric contents away from the EGJ. These findings suggest the alginate-antacid formulation to be an appropriately targeted postprandial GERD therapy.

Manometric features of eosinophilic esophagitis in esophageal pressure topography.

BACKGROUND: Although most of the patients with eosinophilic esophagitis (EoE) have mucosal and structural changes that could potentially explain their symptoms, it is unclear whether EoE is associated with abnormal esophageal motor function. The aims of this study were to evaluate the esophageal pressure topography (EPT) findings in EoE and to compare them with controls and patients with gastro-esophageal disease (GERD). METHODS: Esophageal pressure topography studies in 48 EoE patients, 48 GERD patients, and 50 controls were compared. The esophageal contractile pattern was described for ten 5-mL swallows for each subject and each swallow was secondarily characterized based on the bolus pressurization pattern: absent, pan-esophageal pressurization, or compartmentalized distal pressurization. KEY RESULTS: Thirty-seven percent of EoE patients were classified as having abnormal esophageal motility. The most frequent diagnoses were of weak peristalsis and frequent failed peristalsis. Although motility disorders were more frequent in EoE patients than in controls, the prevalence and type were similar to those observed in GERD patients (P=0.61, chi-square test). Pan-esophageal pressurization was present in 17% of EoE and 2% of GERD patients while compartmentalized pressurization was present in 19% of EoE and 10% of GERD patients. These patterns were not seen in control subjects. CONCLUSIONS & INFERENCES: The prevalence of abnormal esophageal motility in EoE was approximately 37% and was similar in frequency and type to motor patterns observed in GERD. Eosinophilic esophagitis patients were more likely to have abnormal bolus pressurization patterns during swallowing and we hypothesize that this may be a manifestation of reduced esophageal compliance.

Do patients with globus sensation respond to hypnotically assisted relaxation therapy? A case series report.

Globus sensation is a bothersome and difficult symptom to treat. The aims of this study were to evaluate the acceptability and utility of hypnotically-assisted relaxation (HAR) in decreasing the perception of globus sensation and the effect of HAR on interdeglutitive upper esophageal sphincter (UES) pressure. Sixteen subjects with persistent globus sensation unresponsive to therapy for reflux disease and with normal esophageal/laryngeal imaging studies were invited to participate in a 7-session clinical protocol. Before and after HAR, subjects completed standard questionnaires including the esophageal symptoms questionnaire. High-resolution manometric assessment of respiratory augmentation and average resting UES pressure were assessed before and after HAR. Ten of the 16 subjects agreed to participate in the protocol. All participants were women with median age 51.5 (range 30-72 years). The participants found HAR acceptable and completed the entire 7-session trial. Globus symptom severity varied widely pre-treatment (median=52.5, range 16-72), and 9 of 10 subjects reported a reduction in globus symptomatology following treatment (median=14.0, range 3-19; P=.007). Only 1 subject exhibited abnormal respiratory augmentation of UES pressure (>27 mm Hg) prior to treatment and was normal following treatment (9.9 mm Hg). Resting UES pressure was normal in all subjects (<118 mm Hg). Group respiratory augmentation and average resting UES pressure were unaffected by HAR (P=.48, .89). This case series suggests that HAR can provide a substantial improvement in globus sensation irrespective of cause. UES function was unaffected. We suggest that HAR therapy is an acceptable and useful intervention for patients with globus sensation.

The contractile deceleration point: an important physiologic landmark on oesophageal pressure topography.

BACKGROUND: This study aimed to correlate oesophageal bolus transit with features of oesophageal pressure topography (OPT) plots and establish OPT metrics for accurately measuring peristaltic velocity. METHODS: About 18 subjects underwent concurrent OPT and fluoroscopy studies. The deglutitive Contractile Front Velocity (CFV) in OPT plots was subdivided into an initial fast phase (CFV(fast)) and subsequent slow phase (CFV(slow)) separated by a user-defined deceleration point (CDP). Fluoroscopy studies were analyzed for the transition from the initial rapidly propagated luminal closure associated with peristalsis to slow bolus clearance characteristic of phrenic ampullary emptying and to identify the pressure sensors at the closure front and at the hiatus. Oesophageal pressure topography measures were correlated with fluoroscopic milestones of bolus transit. Oesophageal pressure topography studies from another 68 volunteers were utilized to develop normative ranges for CFV(fast) and CFV(slow). KEY RESULTS: A distinct change in velocity could be determined in all 36 barium swallows with the fast and slow contractile segments having a median velocity of 4.2 cm s(-1) and 1.0 cm s(-1), respectively. The CDP noted on OPT correlated closely with formation of the phrenic ampulla making CFV(fast) (mean 5.1 cm s(-1)) correspond closely to peristaltic propagation and CFV(slow) (mean 1.7 cm s(-1)) to ampullary emptying. CONCLUSIONS & INFERENCES: The deceleration point in the CFV on OPT plots accurately demarcated the early region in which the CFV reflects peristaltic velocity (CFV(fast)) from the later region where it reflects the progression of ampullary emptying (CFV(slow)). These distinctions should help objectify definitions of disordered peristalsis, especially spasm, and improve understanding of impaired bolus transit across the oesophagogastric junction.

Effects of postgastric 13C-acetate processing on measurement of gastric emptying: a systematic investigation in health.

Uniform postgastric processing of the gastric emptying (GE) marker 13C-acetate (Ac) is an unverified assumption behind its widespread application to measure GE. This study assessed the postgastric processing of Ac administered by intraduodenal (i.d.) infusion simulating different physiological conditions. 13CO2 in breath was assessed in three groups of six volunteers after i.d. administration of A: Different caloric densities (0.75/1.5/3 kcal min(-1) in a 200 mL meal at constant 1 mg Ac min(-1) simulating a physiological range of nutrient delivery rates; B: different tracer delivery rates (0.5/1.0/2.5 mg Ac min(-1) simulating delayed, normal and increased GE; C1: a 500 mL meal resulting in same marker and caloric delivery compared to protocol A; C2: 50 mL water bolus injections of 12.5/25/50/100 mg Ac and C3 bolus injections of 50 mg Ac in 50/100/200 mL water in randomized order. A: 13CO2 excretion was independent of caloric load (P = 0.59). B: The dynamic of 13CO2 excretion was modulated by tracer elimination which was in turn dependent on the speed of tracer delivery, i.e. with faster deliveries resulting in lower 13CO2 recovery during infusion (P < 0.001). C: Increasing Ac doses resulted in decreased 13CO2 recovery (P < 0.001) over the first hour. 13CO2 recovery kinetics was independent of the volume delivered. This study shows 13C-acetate absorption and metabolism is independent of the volume and caloric delivery of test meals. The 'lag' in estimates of GE derived from 13CO2 breath tests is due to a postgastric, dose-dependent delay to 13CO2 elimination. This can be corrected for in analytical derivations of GE parameters based on 13C-acetate breath test measurements.

Transient lower oesophageal sphincter relaxation in achalasia: everything but LOS relaxation.

In conducting clinical high-resolution oesophageal pressure topography (HROPT) studies we observed that after subjects sat upright between series of supine and upright test swallows, they frequently had a transient lower oesophageal sphincter relaxation (TLOSR). When achalasia patients were studied in the same protocol, they exhibited a similar HROPT event leading to the hypothesis that achalasics had incomplete TLOSRs. We reviewed clinical HROPT studies of 94 consecutive non-achalasics and 25 achalasics. Studies were analyzed for a TLOSR-like event during the study and, when observed, that TLOSR-like event was characterized for the degree and duration of distal oesophageal shortening, the degree of LOS relaxation, associated crural diaphragm (CD) inhibition, oesophageal pressurization and upper oesophageal sphincter (UOS) relaxation. About 64/94 (68%) non-achalasics and 15/24 (63%) of achalasics had a pressure topography event after the posture change characterized by a prolonged period of distal oesophageal shortening and/or LOS relaxation. Events among the non-achalasics and achalasics were similar in terms of magnitude and duration of shortening and all were associated with CD inhibition. Similar proportions had associated non-deglutitive UOS relaxations. The only consistent differences were the absence of associated LOS relaxation and the absence of HROPT evidence of reflux among the achalasics leading us to conclude that their events were incomplete TLOSRs. Achalasic patients exhibit a selective defect in the TLOSR response suggesting preservation of all sensory, central and efferent aspects of the requisite neural substrate with the notable exception of LOS relaxation, a function of inhibitory (nitrergic) myenteric plexus neurons.

Effects of clonidine and sumatriptan on postprandial gastric volume response, antral contraction waves and emptying: an MRI study.

Gastric emptying (GE) may be driven by tonic contraction of the stomach ('pressure pump') or antral contraction waves (ACW) ('peristaltic pump'). The mechanism underlying GE was studied by contrasting the effects of clonidine (alpha(2)-adrenergic agonist) and sumatriptan (5-HT(1) agonist) on gastric function. Magnetic resonance imaging provided non-invasive assessment of gastric volume responses, ACW and GE in nine healthy volunteers. Investigations were performed in the right decubitus position after ingestion of 500 mL of 10% glucose (200 kcal) under placebo [0.9% NaCl intravenous (IV) and subcutaneous (SC)], clonidine [0.01 mg min(-1) IV, max 0.1 mg (placebo SC)] or sumatriptan [6 mg SC (placebo IV)]. Total gastric volume (TGV) and gastric content volume (GCV) were assessed every 5 min for 90 min, interspersed with dynamic scan sequences to measure ACW activity. During gastric filling, TGV increased with GCV indicating that meal volume dictates initial relaxation. Gastric contents volume continued to increase over the early postprandial period due to gastric secretion surpassing initial gastric emptying. Clonidine diminished this early increase in GCV, reduced gastric relaxation, decreased ACW frequency compared with placebo. Gastric emptying (GE) rate increased. Sumatriptan had no effect on initial GCV, but prolonged gastric relaxation and disrupted ACW activity. Gastric emptying was delayed. There was a negative correlation between gastric relaxation and GE rate (r(2 )=49%, P < 0.001), whereas the association between ACW frequency and GE rate was inconsistent and weak (r2=15%, P = 0.05). These findings support the hypothesis that nutrient liquid emptying is primarily driven by the 'pressure pump' mechanism.

Characterization of gastric volume responses and liquid emptying in functional dyspepsia and health by MRI or barostat and simultaneous C-acetate breath test.

The assessment of gastric accommodation and emptying by different methodologies provides inconsistent results. We aimed to compare magnetic resonance imaging (MRI), barostat and 13C-acetate breath test (BT) for the assessment of gastric volume responses and emptying in healthy controls (HC) and patients with functional dyspepsia (FD). Eight HC and eight FD patients underwent: (i) continuous BT with simultaneous MRI in the upright position after ingestion of isocaloric, 300 kcal, 200 and 800 mL meals, both labelled with 100 mg of (13)C-acetate; and (ii) BT with gastric barostat after ingestion of the 200 mL meal. MRI measured total gastric volume and gastric content volume (GCV) at baseline, after filling and during emptying. Meal emptying half-times (T(1/2)) for MRI and BT were calculated (mean +/- SD). We found: (i) Initial GCV was lower in FD than in HC (762 +/- 22 vs 810 +/- 52 mL, P < 0.04) after the 800 mL meal but not the 200 mL meal. T(1/2)(MRI) was shorter for the 800 mL than the 200 mL meal (P < 0.001), but similar in HC and FD (200 mL: HC 117 +/- 30 min vs FD 138 +/- 42 min, ns; 800 mL: HC 71 +/- 16 min vs FD 78 +/- 27 min, ns). In contrast, T(1/2)(BT) was similar between meals and groups (200 mL: HC 111 +/- 11 min vs FD 116 +/- 19 min; 800 mL: HC 114 +/- 14 min vs FD: 113 +/- 17 min). (ii) Barostat measurements showed similar postprandial volume increases between groups. We conclude that direct measurements by MRI provide a sensitive, non-invasive assessment of gastric accommodation and emptying after a meal. In contrast to MRI, BT did not detect faster emptying of high-volume compared to low-volume liquid nutrient meals in HC or FD.

Oesophageal peristaltic transition zone defects: real but few and far between.

This study analysed the association between oesophageal transition zone (TZ) defects [characterized by a delay and/or spatial gap between the terminus of the proximal oesophageal (striated muscle) contraction and the initiation of the distal oesophageal (smooth muscle) contraction] and dysphagia in a large patient cohort. Four hundred consecutive patients (178 with dysphagia) and 75 controls were studied with 36-channel high-resolution manometry (HRM). The resultant pressure topography plots were first analysed for impaired oesophagogastric junction (OGJ) relaxation, distal segment contractile abnormalities, and proximal contractile abnormalities using normal values from the 75 controls. If these aspects of oesophageal motility were deemed normal, the TZ was characterized by length and duration between the proximal and distal contractions using a 20 mmHg isobaric contour to establish the segment boundaries. Patients were then classified according to whether or not they exhibited TZ defects (spatial separation or delay) and the occurrence of unexplained dysphagia. Of the 400 patients, 267 were suitable for TZ analysis and of these 55 had a spatial or temporal TZ measurement exceeding the 95th percentile of the controls (2 cm, 1 s). Exactly 34.6% of the patients (n = 19) with spatial and/or temporal TZ defects had unexplained dysphagia, which was significantly more than seen with normal TZ dimensions (19.8%). Although far less common than distal peristaltic or OGJ abnormailites, TZ defects may be related to dysphagia in a minority of patients (<4% in this series) and should be considered a distinct oesophageal motility disorder.

The Bravo pH capsule system.

Limitations of existing pH recording methodology have been the impetus for the emergence of new technologies focused on improving ambulatory pH monitoring. The Bravo pH capsule system (Bravo, Medtronic, Shoreview, MN) is one of the recent advances that utilize a wireless system to improve patient compliance and extend the period of monitoring. These changes could potentially improve diagnostic accuracy along with patient acceptance. Given this fact, the following review will evaluate the potential benefits that wireless pH monitoring may have over conventional catheter based pH monitoring based on the available data. In addition, we will also focus on the technical aspects related to its safety, tolerability and diagnostic accuracy.

Contribution of sensitivity, volume and tone to visceral perception in the upper gastrointestinal tract in man: emphasis on testing.

Upper gastrointestinal (GI) symptoms occur frequently in the general population, making them among the most common indications responsible for patients consulting the healthcare system. Consequently, understanding and characterization of the upper GI symptoms is important for the diagnosis and assessment of organ dysfunction. In practice, assessment of clinical symptoms is difficult and it is still to a large extent unclear how sensitivity, volume and tone contribute to visceral perception in the upper GI tract. The goal of advanced research in upper GI symptoms is to obtain a better understanding of the mechanisms involved in transduction, transmission, and perception under normal and pathophysiological conditions. An important step towards this goal is understanding the information provided by and the inherent limitations of the currently available measuring techniques. This article focuses on the sensory testing of the oesophagus, and methods and concepts used to assess the relation between gastric volumes or tone and upper GI symptoms. It also summarizes the contributions of these techniques towards identifying the components responsible for the generation of upper GI symptoms.

Serotonergic and non-serotonergic targets in the pharmacotherapy of visceral hypersensitivity.

Visceral hypersensitivity is considered a key mechanism in the pathogenesis of functional gastrointestinal (GI) disorders. Targeting visceral hypersensitivity seems an attractive approach to the development of drugs for functional GI disorders. This review summarizes current knowledge on targets for the treatment of visceral hypersensitivity, and the status of current and future drug and probiotic treatment development, and the role of pharmacogenomic factors.

Use of Technegas as a radiopharmaceutical for the measurement of gastric emptying.

Many radiopharmaceuticals and test meals that are used to measure gastric emptying are less than optimal. A vegetable-based solid meal, such as rice, labelled with a radiopharmaceutical that also has the capacity to measure gastric emptying of liquids, is likely to be ideal. The role of Technegas as a radioisotopic marker to measure gastric emptying of rice and liquids was evaluated. Technegas-labelled rice was incubated in 0.9% saline, 1 M HCl and simulated gastric fluid (3.2 g/l pepsinogen, pH 2-3) to assess stability of the label. In eight healthy volunteers gastric emptying of two meals - 200 g rice (370 kcal) and 75 g dextrose dissolved in 300 ml water (300 kcal), both labelled with 20 MBq of Technegas - was measured scintigraphically. Over 4 h, the average label stability was 93.7%+/-0.5% in 0.9% saline, 91.0%+/-0.4% in 1 M HCl and 93.6%+/-0.7% in simulated gastric juice. The lag phase was longer for rice than dextrose (25+/-7 min vs 4+/-2 min; P<0.05), but there was no difference in the post-lag emptying rate (2.1+/-0.3 kcal/min vs 1.7+/-0.2 kcal/min; P=0.2) between the two meals. We conclude that Technegas is a suitable radiopharmaceutical for measurement of gastric emptying of rice and nutrient-containing liquids.

Hyperglycemia attenuates the gastrokinetic effect of erythromycin and affects the perception of postprandial hunger in normal subjects.

OBJECTIVE: The major aims of this study were to determine in normal subjects whether the effects of erythromycin on gastric emptying, postprandial hunger, and fullness are modified by the blood glucose concentration. RESEARCH DESIGN AND METHODS: A total of 10 normal subjects (aged 20-39 years) underwent concurrent measurements of gastric emptying, blood glucose, hunger, and fullness on four separate occasions: twice during euglycemia (approximately 4 mmol/l) and twice during hyperglycemia (approximately 15 mmol/l). Either erythromycin (3 mg/kg) or saline (0.9%) was administered intravenously immediately before ingestion of a radioisotopically labeled solid meal. RESULTS: Gastric emptying was slower (P < 0.0001) during hyperglycemia when compared with euglycemia after both erythromycin and saline administration. During hyperglycemia, erythromycin reduced the lag phase (77.8 +/- 12.6 vs. 20.3 +/- 7.3 min; P < 0.05) but had no effect on the postlag emptying rate (0.32 +/- 0.077% per min vs. 0.24% per min). Hunger decreased (P < 0.001) and fullness increased (P < 0.001) after the meal. Postprandial hunger was less during hyperglycemia after saline infusion (P < 0.05) but not after erythromycin. Hunger was greater after erythromycin during both hyperglycemia and euglycemia (P < 0.05). CONCLUSIONS: At a blood glucose concentration of approximately 15 mmol/l, 1) gastric emptying of a solid meal is slower, when compared with euglycemia, even after administration of erythromycin; 2) the effect of erythromycin on gastric emptying of a solid meal is attenuated; and 3) the perception of postprandial hunger is reduced.