Variability of the 13C-octanoic acid breath test for gastric emptying of solids in healthy children

Nausea is the only symptom associated with delayed gastric emptying in pediatric functional dyspepsia patients

OBJECTIVES

Functional dyspepsia (FD) is a heterogeneous functional gastrointestinal disorder (FGID) with a highly prevalent symptom complex. The aim of our study is to investigate the relation between symptoms of FD and results of gastric emptying (GE) breath test in children.

METHODS

This study included patients (6-17 years old) presented at the general gastroenterology outpatient clinic with dyspeptic symptoms (Rome IV criteria) and underwent careful history taking with clinical examination. A GE breath test with a 13 C-octanoic acid labeled (250 kcal) solid meal was performed and dyspepsia symptom scores, clarified using pictograms for postprandial fullness, bloating, belching, nausea, vomiting, epigastric pain and burning, were obtained every 15 min ranging from 0 to 4 for a total of 240 min. The severity of the complaints (overall and individual symptoms) as displayed by the symptom questionnaire was compared between normal and delayed GE groups. The relationship between GE time and the severity of FD symptoms was assessed using Mann-Whitney test.

RESULTS

Thirty nine FD patients (55% girls; mean age: 11.9 ± 3.3 years) participated in the study. Of these, 43% had delayed GE. The overall symptom severity in patients with delayed GE was similar to the symptoms of patients with a normal GE rate (149.5 ± 12.7 points vs. 123.9 ± 9.0; p = 0.19). Individual symptoms scores showed only nausea to be significantly increased in the group with delayed GE (21.5 ± 1.9 points vs. 33.2 ± 4.6; p = 0.048, p < 0.1).

CONCLUSION

Especially in children with nausea as presenting symptom of FD, a low threshold should be withheld to perform a GE breath test.

Review of paediatric gastrointestinal physiology relevant to the absorption of orally administered medicines

Despite much progress in regulations to improve paediatric drug development, there remains a significant need to develop better medications for children. For the design of oral dosage forms, a detailed understanding of the specific gastrointestinal (GI) conditions in children of different age categories and how they differ from GI conditions in adults is essential. Several review articles have been published addressing the ontogeny of GI characteristics, including luminal conditions in the GI tract of children. However, the data reported in most of these reviews are of limited quality because (1) information was cited from very old publications and sometimes low quality sources, (2) data gaps in the original data were filled with textbook knowledge, (3) data obtained on healthy and sick children were mixed, (4) average data obtained on groups of patients were mixed with data obtained on individual patients, and (5) results obtained using investigative techniques that may have altered the outcome of the respective studies were considered. Consequently, many of these reviews draw conclusions that may be incorrect. The aim of the present review was to provide a comprehensive and updated overview of the available original data on the ontogeny of GI luminal conditions relevant to oral drug absorption in the paediatric population. To this end, the PubMed and Web of Science metadatabases were searched for appropriate studies that examined age-related conditions in the oral cavity, esophagus, stomach, small intestine, and colon. Maturation was observed for several GI parameters, and corresponding data sets were identified for each paediatric age group. However, it also became clear that the ontogeny of several GI traits in the paediatric population is not yet known. The review article provides a robust and valuable data set for the development of paediatric in vitro and in silico biopharmaceutical tools to support the development of age-appropriate dosage forms. In addition, it provides important information on existing data gaps and should provide impetus for further systematic and well-designed in vivo studies on GI physiology in children of specific age groups in order to close existing knowledge gaps and to sustainably improve oral drug therapy in children.

European guideline on indications, performance and clinical impact of 13 C-breath tests in adult and pediatric patients: An EAGEN, ESNM, and ESPGHAN consensus, supported by EPC

Introduction

¹³C‐breath tests are valuable, noninvasive diagnostic tests that can be widely applied for the assessment of gastroenterological symptoms and diseases. Currently, the potential of these tests is compromised by a lack of standardization regarding performance and interpretation among expert centers.

Methods

This consensus‐based clinical practice guideline defines the clinical indications, performance, and interpretation of ¹³C‐breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 43 experts from 18 European countries. Consensus on individual statements and recommendations was established if ≥ 80% of reviewers agreed and <10% disagreed.

Results

The guideline gives an overview over general methodology of ¹³C‐breath testing and provides recommendations for the use of ¹³C‐breath tests to diagnose Helicobacter pylori infection, measure gastric emptying time, and monitor pancreatic exocrine and liver function in adult and pediatric patients. Other potential applications of ¹³C‐breath testing are summarized briefly. The recommendations specifically detail when and how individual ¹³C‐breath tests should be performed including examples for well‐established test protocols, patient preparation, and reporting of test results.

Conclusion

This clinical practice guideline should improve pan‐European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, this guideline identifies areas of future clinical research involving the use of ¹³C‐breath tests.

Gastric emptying in healthy children using the Spirulina breath test: The impact of gender, body size, and pubertal development

BACKGROUND

There are no pediatric norms for gastric emptying (GE) measured by nuclear scintigraphy. The ¹³ C-labeled, stable isotope GE breath test (GEBT) is a non-radioactive alternative. We aimed to determine normative GEBT ranges in a cohort of healthy children and examine the influence of age, gender, puberty, and body surface area (BSA).

METHODS

Healthy children ages 8-18 years completed the [¹³ C]-Spirulina platensis GEBT after an overnight fast. Breath samples were collected at baseline, every 15 min × 1 h, then every 30 min for 4 h total. The ¹³ CO₂ excretion rate was determined by the change in ¹³ CO₂ /¹² CO₂ over time in each breath sample, expressed as kPCD (Percent ¹³ C Dose excreted/min). A mixed model with random time was used for multivariable analysis and outcome fit into a quadratic model.

KEY RESULTS

The 100 subjects completed the test meal within allotted time. Median (IQR) age was 13.5 (11.3-15.5) years; 51% were female. Females had lower ¹³ CO₂ excretion rates (slower GE) than males across time (p < 0.001) while decreased excretion rates correlated with higher BSA (p = 0.015). Gender differences were also noted within pubertal stages with females showing slower GE. Multivariable analysis suggested that pre-pubertal children have faster GE than both peri- and post-pubertal groups (p < 0.0001).

CONCLUSIONS & INFERENCES

Gender, puberty, and BSA influence GE rates in healthy children more than age. Although further data are needed, pubertal stage and hormonal influences may be unique factors to consider when assessing GE in children.

13 C-gastric emptying breath tests: Clinical use in adults and children

¹³ C-gastric emptying breath tests (¹³ C-GEBT) are validated, reliable, and non-invasive tools for measurement of gastric emptying (GE) velocity of solids and liquids without radiation exposure or risk of toxicity. They are recommended and routinely used for clinical purposes in adult as well as pediatric patients and can be readily performed onsite or even at the patient's home. However, the underlying methodology is rather complex and test results can be influenced by dietary factors, physical activity, concurrent diseases, and medication. Moreover, epidemiological factors can influence gastric emptying as well as production and exhalation of ¹³ CO₂ , which is the ultimate metabolic product measured for all ¹³ C-breath tests. Accordingly, in this issue of Neurogastroenterology & Motility, Kovacic et al. report performance of the ¹³ C-Spirulina breath test in a large group of healthy children and show significant effects of gender, pubertal status, and body size on test results. The purpose of this mini-review is to evaluate the clinical use of ¹³ C-GEBT in adults and children, exploring available protocols, analytical methods, and essential prerequisites for test performance, as well as the role of GE measurements in the light of the current discussion on relevance of delayed GE for symptom generation.

Targeting postprandial glycaemia in children with diabetes: Opportunities and challenges

Postprandial glycaemia makes a substantial contribution to overall glycaemic control in diabetes, particularly in patients whose preprandial glycaemia is relatively well controlled and glycated haemoglobin (HbA1c) only modestly elevated. Our review addresses the determinants of postprandial glycaemia and how it may be targeted therapeutically in children with diabetes. Postprandial glycaemia is influenced by preprandial glycaemia, macronutrients and their absorption, insulin delivery and sensitivity, the action of the enteroendocrine system, and the rate of gastric emptying. Contemporary continuous glucose monitoring systems reveal patterns of post prandial glycaemia and allow management to be guided more precisely. Delays in blood glucose determination, insulin delivery and its absorption remain challenges in the rapidly evolving closed loop continuous subcutaneous insulin and glucagon delivery systems developed for children with type 1 diabetes. Augmentation of the incretin system through nutritional preloads or incretin mimetics targets postprandial glycaemia by slowing gastric emptying as well as insulinotropic and glucagonostatic effects. These treatments are of particular relevance to children with type 2 diabetes. Following the development of targeted therapies in adults, postprandial blood glucose control will now be increasingly targeted in the treatment of diabetes in children.

The Effect of Gastrostomy Placement on Gastric Function in Children: a Prospective Cohort Study

BACKGROUND

A gastrostomy placement is frequently performed in pediatric patients who require long-term enteral tube feeding. Unfortunately, postoperative complications such as leakage, feeding intolerance, and gastroesophageal reflux frequently occur. These complications may be due to postoperative gastric dysmotility. Our aim was to evaluate the effect of gastrostomy placement on gastric emptying in children.

METHODS

A prospective study was performed including 50 children undergoing laparoscopic gastrostomy. Before and 3 months after gastrostomy, assessment was performed using the 13C-octanoic acid breath test, 24-h pH monitoring, and reflux symptom questionnaires.

RESULTS

Gastric half-emptying time significantly increased from the 57th to the 79th percentile (p < 0.001) after gastrostomy (p < 0.001). Fifty percent of patients with normal preoperative gastric emptying develop delayed gastric emptying (DGE, P > 95) after gastrostomy (p = 0.01). Most patients (≥75%) with leakage and/or feeding intolerance after gastrostomy had DGE after operation. A decrease in gastric emptying was associated with an increase in esophageal acid exposure time (r = 0.375, p < 0.001).

CONCLUSION

Gastrostomy placement in children causes a significant delay in gastric emptying. Postoperative DGE was associated with gastroesophageal reflux and was found in most patients with postoperative leakage and feeding intolerance. These negative physiologic effects should be taken into account when considering gastrostomy placement in children.

Validation of Ultrasonography for Assessment of Gastric Emptying Time in Healthy Cats by Radionuclide Scintigraphy

Background

The prevalence of gastric emptying (GE) disorders in cats is unknown due to lack of clinically applicable diagnostic tests.

Objectives

The principal aim of this study was to assess correlation between scintigraphic and ultrasonographic measurements of GE time (GET) in healthy cats. Additionally, variability of ultrasonographic GET, and correlation between scintigraphy and ultrasonographic parameters of gastric motility were evaluated.

Animals

Eight healthy domestic shorthair cats.

Methods

Prospective study. Scintigraphic GET was determined using a solid test meal containing 4 mCi ^99mTc‐mebrofenin. Each cat had 3 separate ultrasonographic assessments of GE, performed independent of scintigraphic assessment, after solid test meal consumption. The motility index (MI) of antral contractions was plotted against time and time for each fraction of the area under the MI curve determined. Ultrasonographic GET and MI were correlated to scintigraphic GET.

Results

Scintigraphic GET (mean ± SD) for 25, 50, and 75% GE was 103 ± 32 minutes, 196 ± 45 minutes, and 288 ± 62 minutes, whereas sonographic GET for 25, 50, and 75% GE was 106 ± 13 minutes, 203 ± 19 minutes, and 305 ± 27 minutes. There was good correlation between scintigraphic and sonographic GET (r = 0.72–0.82) at 45–90% fractional GE and between scintigraphic GET and time of corresponding MI curve fraction (r = 0.78–0.86) at 40–90% fraction of the MI curve. There was moderate intraindividual variability for sonographic GET and MI curve fraction times as well as significant variation among individuals.

Conclusions and clinical importance

Ultrasonography is a valid alternative to scintigraphy for assessment of solid‐phase GE and allows assessment of postprandial gastric motility in healthy cats.

Gastric emptying of solids in children: reference values for the (13) C-octanoic acid breath test

BACKGROUND

(99m) Technetium scintigraphy ((99m) TS) is the 'gold standard' for measuring gastric emptying (GE), but it is associated with a radiation exposure. For this reason, the (13) C-octanoic acid breath test ((13) C-OBT) was developed for measuring GE of solids. The objective of this study was to determine normal values for gastric half-emptying time (t1/2 GE) of solids in healthy children.

METHODS

Gastric emptying of a standardized solid test meal consisting of a pancake evaluated with (99m) TS and (13) C-OBT was compared in 22 children aged between 1 and 15 years with upper gastrointestinal symptoms. Subsequently, the (13) C-OBT was used to determine normal values for GE of the same solid test meal in 120 healthy children aged between 1 and 17 years.

KEY RESULTS

The results showed a significant correlation (r = 0.748, p = 0.0001) between t1/2 GE measured with both techniques in the group of children with upper gastrointestinal symptoms. In the group of healthy children, mean t1/2 GE was 157.7 ± 54.0 min (range 71-415 min), but t1/2 GE decreased with age between 1 and 10 years and remained stable afterward. There was no influence of gender, weight, height, body mass index, and body surface area on t1/2 GE.

CONCLUSIONS & INFERENCES

Normal values for GE of solids measured with the (13) C-OBT using a standardized methodology were determined in healthy children. We propose to use this method and corresponding reference ranges to study GE of solids in children with gastrointestinal problems.

Gastric emptying and disease activity in inflammatory bowel disease

BACKGROUND

Gastric emptying (GE) is delayed in a subset of patients with inflammatory bowel disease (IBD). We have shown before that altered release of gastrointestinal hormones may contribute to GE disturbances, but overall effects of disease activity remain unclear. Thus, we aimed to evaluate GE in patients with IBD during active disease and following therapy.

DESIGN

A total of 20 healthy subjects (HC) and 26 patients with IBD hospitalized because of an acute episode of their disease (Crohn's disease (CD) n = 13, ulcerative colitis (UC) n = 13) underwent a standardized (13) C-octanoic acid GE breath test (baseline test). Plasma glucose, cholecystokinin (CCK), peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were measured periodically throughout the test. A total of 16 patients underwent a second GE test after 3-4 months of therapy.

RESULTS

At baseline, nine patients with IBD had pathologically delayed GE half-time (T½ > 150 min) (P = 0·028 vs. HC). Moreover, T½ was significantly longer in the total group of patients with IBD than in HC (129 ± 12 min vs. 96 ± 7, P = 0·030). Postprandial GLP-1 responses were elevated in IBD (P = 0·002 vs. HC) and correlated with T½ (P = 0·05). Following therapy clinical activity indices and T½ were decreased in IBD (P ≤ 0·01 vs. baseline), and T½ no longer differed from HC (P > 0·5). Moreover, GLP-1 plasma levels decreased significantly (P = 0·031).

CONCLUSIONS

Higher disease activity in IBD is associated with prolonged GE and increased release of GLP-1. Following effective therapy, GE is accelerated and GLP-1 release decreases significantly. Thus, increased release of GLP-1 from the inflamed mucosa might contribute to GE disturbances in IBD.

Gastric Emptying Is More Rapid in Adolescents With Type 1 Diabetes and Impacts on Postprandial Glycemia

CONTEXT

Gastric emptying is a critical determinant of postprandial glycemic control in health and type 1 diabetes. There are few studies that assess the relationship between gastric emptying and postprandial glycaemia in adolescents with type 1 diabetes.

OBJECTIVE

The objectives of the study were to quantify gastric emptying in adolescents with type 1 diabetes and examine its relationship to postprandial glycaemia and autonomic function.

DESIGN

This was a case-control study. Gastric half-emptying time of a solid meal was measured by a (13)C-octanoate breath test. Cardio-autonomic function was measured by heart rate variability. Chronic and postprandial gastrointestinal symptoms were evaluated by questionnaire and visual analog scales. Blood glucose concentrations were monitored frequently during the study.

SETTING

The study was conducted at a tertiary pediatric hospital in South Australia.

PARTICIPANTS

Thirty adolescents (aged 15 ± 2.5 y) with type 1 diabetes and age- and sex-matched controls (gastric emptying, n = 20; heart rate variability, n = 135) participated in the study.

MAIN OUTCOME

Gastric half-emptying time was the main outcome in the study.

RESULTS

Gastric emptying was more rapid in subjects with type 1 diabetes than controls [median half emptying time 78 (interquartile range 61-99) vs 109 (interquartile range 71-124) min, P = .02]. The postprandial rise in blood glucose at 60 minutes was strongly related to gastric half-emptying time (R = -0.65, P = .0001). Gastric emptying was slower in subjects with fasting hyperglycemia but was not related to heart rate variability. Nausea, bloating, and anxiety were related to fasting glycemia (P = .03).

CONCLUSION

Rapid gastric emptying is a major determinant of postprandial glycemia in adolescents with type 1 diabetes. This observation has significant implications for therapy.

Gastric emptying of solids and its relationship with microalbuminuria in children and adolescents with type 1 diabetes mellitus

BACKGROUND

The aims of the present study were to determine the frequency of delayed gastric emptying in children and adolescents with type 1 diabetes mellitus (T1DM) and to investigate the relationship between gastric emptying rate and other contributing factors (e.g. serum HbA1c, duration of diabetes and microalbuminuria) in these patients.

METHODS

This was a clinical trial evaluating the rate of gastric emptying of solid meals in 33 children and adolescents with T1DM and in 26 healthy peers using a radionuclide method. Three consecutive overnight urine collections were used to calculate the albumin excretion rate.

RESULTS

There was no significant difference in the gastric half-emptying time (GE t½ ) between patients and controls (151.7 ± 154.5 vs 109.8 ± 60.5 min, respectively; P=0.885) or the frequency of delayed gastric emptying (36.4% vs 30.8%, respectively; P=0.433). There was a moderately positive correlation between GE t½ and the duration of diabetes (r=0.380; P=0.029). There was no correlation between GE t½ and microalbumin levels in T1DM patients. In these patients, the body mass index standard deviation scores were significantly lower than in patients with normal gastric emptying (-0.13 ± 0.87 vs 0.7 ± 1.23, respectively; P=0.044).

CONCLUSION

Progression of delayed gastric emptying is more likely to be related to a longer duration of diabetes than glycemic control in children and adolescents with T1DM. Patients with delayed gastric emptying are thinner compared with patients with a normal rate of gastric emptying; they may also be asymptomatic.

Funktions- und Laboruntersuchungen

Zur Analyse abgeatmeter Gase muss endexspiratorische Luft gewonnen werden, ohne Vermischung mit frühexspiratorischer Luft (sonst Korrektur mit Messung des CO2-Partialdrucks, s. unten). Ältere Kinder blasen nach Anhalten der Atmung über 15 s durch tiefe Ausatmung über einen Strohhalm endexspiratorische Luft in ein Glasröhrchen, das dann luftdicht verschlossen wird (Vacutainer), oder über ein Mundstück oder eine Maske direkt in ein H2-Messgerät oder in Beutel. Bei Säuglingen und Kleinkindern kann mit einer Maske oder einer Sonde, die bis zum nasopharyngealen Übergang vorgeschoben wird, mit einer Spritze atemsynchron exspiratorische Luft abgesaugt und in Vacutainer oder direkt in das Messgerät eingegeben werden. In Vacutainern sind Proben über mehr als 30 Tage stabil und können auch zur Analyse verschickt werden.

Variability associated with repeated measurements of gastrointestinal tract motility in dogs obtained by use of a wireless motility capsule system and scintigraphy

OBJECTIVE

To compare repeatability of measurements of gastrointestinal tract motility in healthy dogs obtained by use of a wireless motility capsule (WMC) and scintigraphy.

ANIMALS

6 healthy adult dogs (mean +/- SD body weight, 21.5 +/- 1.8 kg).

PROCEDURES

A radiolabeled test meal was offered immediately after oral administration of a WMC. Serial static scintigraphic abdominal images were acquired for 270 minutes. A dedicated remote receiver was used for data collection from the WMC until the WMC was expelled in the feces. Each dog was evaluated 3 times at intervals of 1 to 2 weeks.

RESULTS

Mean gastric emptying half-time measured by use of scintigraphy (T(1/2)-GES) for each dog ranged from 99.9 to 181.2 minutes. Mean gastric emptying time (GET) measured by use of the WMC (GET-WMC) in each dog ranged from 385.3 to 669.7 minutes. Mean coefficient of variation was 11.8% for T(1/2)-GES and 7.8% for GET-WMC. The intraclass correlation coefficient was 69% for T(1/2)-GES and 71% for GET-WMC. Results for a nested analysis of covariance suggested that both methods were comparable for the evaluation of gastric emptying.

CONCLUSIONS AND CLINICAL RELEVANCE

Scintigraphy and a WMC system had similar variation for assessment of gastric emptying. Moderate intraindividual variability was detected for both methods and must be considered when interpreting test results for individual dogs. Repeatability of measurements obtained by use of the WMC was equivalent to that obtained by use of scintigraphy. The WMC system offers a nonradioactive, user-friendly method for assessment of gastric emptying in dogs.

Procedures in the 13C octanoic acid breath test for measurement of gastric emptying: analysis using Bland-Altman methods

OBJECTIVE

The (13)C octanoic acid breath test (OBT) was first developed as an alternative method of measuring gastric emptying (GE) to scintigraphy. There has been much debate about the test duration and how often measurements need to be taken. This study aims to address these issues.

MATERIAL AND METHODS

For 78 GE tests using the (13)C OBT, GE lag phase (T(lag)) was calculated while sampling more frequently than the recommended every 15 min. Comparisons between T(lag) were completed using Bland-Altman plots. Similarly, 4 or 6 h test durations were assessed to establish if they yield the same GE half time (T(half)). From one volunteer, samples were taken every 1 min for the first 30 min and then every 15 min until 6 h. GE times were then calculated using different combinations of sampling times. Evidence of a visible T(lag) was also explored from this data.

RESULTS

Findings indicated that taking samples every 5 min for the first 30 min instead of every 15 min did not change the GE T(lag) based on Bland-Altman plots. The correlation between these two methods was also high (r(2) = 0.9957). The findings showed that the difference between the two sampling durations 4 and 6 h was large and the correlation between the methods was low (r(2) = 0.8335). Samples taken at a rate of one breath per min indicated lack of a visible T(lag).

CONCLUSIONS

Sampling for the (13)C OBT should be completed every 15 min for 6 h.

Gastric emptying of solids is slower in functional dyspepsia unrelated to Helicobacter pylori infection in female children and teenagers

AIM

To evaluate gastric emptying of solids in children and adolescents with functional dyspepsia with and without Helicobacter pylori infection.

PATIENTS AND METHODS

The study included 27 female patients (mean age 13.38 +/- 2.81 y) with functional dyspepsia according to Rome II criteria who were selected after upper gastrointestinal endoscopy found no major mucosal abnormality. Fragments were collected from the esophagus, gastric antrum, and gastric body for histological examination and rapid urease test. H. pylori infection was diagnosed according to the rapid urease test and histological appearance. The histological appearance of the gastric mucosa was evaluated according to modified Sydney criteria. A C-octanoic breath test was performed after a test meal (2 slices of toasted bread, 10 g margarine, and 1 egg with 100 microL of the tracer dipped in the yolk) with 13 points of air collection in 4 hours.

RESULTS

Infection with H. pylori was observed in 12 of 27 patients (44.4%). The gastric emptying half-time was shorter in infected patients than in uninfected patients (mean +/- SD 153.4 +/- 20.0 min vs 179.2 +/- 32.2 min; P = 0.019), as was the lag phase (106.3 +/- 22.6 vs 126.6 +/- 22.7 min; P = 0.038). There was no relationship between gastric emptying (half-time and lag phase) and degree of histological abnormality. Vomiting and nausea were associated with slower gastric emptying in patients without H. pylori gastritis more often than in infected patients.

CONCLUSIONS

The study suggests that delayed gastric emptying can play an important role in a subgroup of dyspeptic patients, particularly those without H. pylori infection who have nausea and vomiting.