Gastric emptying and Helicobacter pylori infection in duodenal ulcer disease

Stable Isotopes and 13CO2 Breath Tests for Investigating Gastrointestinal Functions

In medical investigation there is a need for non-invasive methods. Moreover, patients ask for easy methods that are simple to perform and medical doctors demand reliable techniques. With the advent of stable isotopes a new area of tracer technology became available. In gastroenterology, 13CO2 breath tests are used which fullfill all the conditions needed in modern clinical research and investigation.

Dynamic carbon 13 breath tests for the study of liver function and gastric emptying

In gastroenterological practice, breath tests (BTs) are diagnostic tools used for indirect, non-invasive assessment of several pathophysiological metabolic processes, by monitoring the appearance in breath of a metabolite of a specific substrate. Labelled substrates originally employed radioactive carbon 14 (¹⁴C) and, more recently, the stable carbon 13 isotope (¹³C) has been introduced to label specific substrates. The ingested ¹³C-substrate is metabolized, and exhaled ¹³CO₂ is measured by mass spectrometry or infrared spectroscopy. Some ¹³C-BTs evaluate specific (microsomal, cytosolic, and mitochondrial) hepatic metabolic pathways and can be employed in liver diseases (i.e. simple liver steatosis, non-alcoholic steato-hepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug and alcohol effects).

Another field of clinical application for ¹³C-BTs is the assessment of gastric emptying kinetics in response to liquids (¹³C-acetate) or solids (¹³C-octanoic acid in egg yolk or in a pre-packed muffin or the ¹³C-Spirulina platensis given with a meal or a biscuit). Studies have shown that ¹³C-BTs, used for gastric emptying studies, yield results that are comparable to scintigraphy and can be useful in detecting either delayed- (gastroparesis) or accelerated gastric emptying or changes of gastric kinetics due to pharmacological effects. Thus, ¹³C-BTs represent an indirect, cost-effective and easy method of evaluating dynamic liver function and gastric kinetics in health and disease, and several other potential applications are being studied.

Novel soy germ pasta enriched in isoflavones ameliorates gastroparesis in type 2 diabetes: a pilot study

OBJECTIVE

To determine the effect of soy germ pasta enriched in biologically active isoflavone aglycons on gastric emptying in type 2 diabetic patients with gastroparesis.

RESEARCH DESIGN AND METHODS

This randomized double-blind, placebo-controlled study compared soy germ pasta with conventional pasta for effects on gastric emptying. Patients (n = 10) with delayed gastric emptying consumed one serving per day of each pasta for 8 weeks, with a 4-week washout. Gastric emptying time (t1/2) was measured using the [(13)C]octanoic acid breath test at baseline and after each period, and blood glucose and insulin concentrations were determined after oral glucose load.

RESULTS

Soy germ pasta significantly accelerated the t1/2 in these patients (161.2 ± 17.5 min at baseline vs. 112.6 ± 11.2 min after treatment, P = 0.009). Such change differed significantly (P = 0.009) from that for conventional pasta (153.6 ± 24.2 vs. 156.2 ± 27.4 min), without affecting glucose or insulin concentrations.

CONCLUSIONS

These findings suggest that soy germ pasta may offer a simple dietary approach to managing diabetic gastropathy.

A novel continuous breath test versus scintigraphy for gastric emptying rate measurement

BACKGROUND

Gastric scintigraphy (GS) is considered the gold standard for gastric emptying rate (GER) measurement; however, it requires expensive equipment and special licensing for radioactive substances.

AIM

To compare a new nonradioactive, real-time, continuous breath test (CBT) method with GS for the GER measurement.

METHODS

Simultaneous GER analysis by both GS and CBT was carried out on 8 dyspeptic patients and 6 healthy controls. After a 14 hour fast, participants ate a standard meal of 250 Kcal double labeled with 1 mCi of Tc-99m and 100 μg of C-13 labeled octanoic acid. The participants underwent simultaneous GS for 120 minutes on single-detector γ camera and CBT carried out by attaching the nasal cannula of the system (Oridion, BreathID, Israel), which automatically and continuously collected and analyzed breath samples with real time display. A linear fit model was used to calculate gastric empting half-time. A half-time of more than 100 minutes for GS and 80 minutes for CBT were considered pathologic. The GS and CBT were compared by κ test of agreement in normal/abnormal results.

RESULTS

Good correlation was found for GER measurements between GS and the CBT methods with a linear correlation coefficient of R=0.74. The κ test indicated excellent agreement with value of 0.86 for the qualitative determination of pathologic and normal results.

CONCLUSIONS

The novel CBT provides reliable and reasonably accurate data for on-line GER estimate, in a simple manner suitable for medical clinics or bedside setting, without the use of radioactive substances.

Gastric emptying is altered with the presence of gastritis

Helicobacter pylori infection and gastritis can cause symptoms suggestive of altered gastrointestinal function; however, it is unclear if H. pylori influences gastric motility. This study assessed gastric emptying rates in mouse models of gastritis. Gastritis was induced in C57BL/6 mice via ethanol treatment or via challenge with H. pylori or H. felis. Gastric emptying rates of nutrient and non-nutrient liquids were assessed with the non-invasive (13)C-breath test, and the results were compared to healthy mice. Gastric emptying of the non-nutrient liquid was unaltered with the presence of gastritis; however, gastric emptying of the nutrient liquid was accelerated after a 4-week infection with H. pylori. H. felis infection and ethanol treatment caused a more severe gastritis and disruptions to the normal gastric emptying. Changes to gastric emptying in mouse models of gastritis are associated with the presence of nutrients. Altered gastric emptying may contribute to symptoms commonly reported in humans with gastritis.

Effects of Helicobacter pylori eradication therapy on gastric emptying measured using the 13C-octanoic acid breath test and the acetaminophen method

BACKGROUND

The relationship between Helicobacter pylori eradication and gastric emptying has been reported; however, the effect of eradication therapy on gastric emptying is still unclear. This study evaluated the relationship between three gastric emptying techniques, the scintigraphic technique, the 13C-octanoic acid breath test, and the acetaminophen method, measured simultaneously, and the effect of H. pylori eradication therapy on gastric emptying and abdominal symptoms in patients with functional dyspepsia who were H. pylori positive.

METHODS

Fifty-three consecutive patients with positive H. pylori infection were enrolled in this study. In the first 14 patients, gastric emptying was measured using the three gastric emptying techniques. In 42 patients cured of H. pylori infection, the 13C-octanoic acid breath test and the acetaminophen method were performed before and 3 months after eradication.

RESULTS

Significant correlations were found between the scintigraphic technique, the 13C-octanoic acid breath test, and the acetaminophen method. Gastric emptying determined by the 13C-octanoic acid breath test and the acetaminophen method was not changed after eradication, on average. In 14 (33.3%) patients a decrease in symptom score after eradication was observed. In four (9.5%) patients, accelerated gastric emptying after eradication may have led to a reduction in the abdominal symptoms.

CONCLUSIONS

The 13C-octanoic acid breath test and the acetaminophen method are appropriate for investigating gastric emptying. A causal relationship between improvement of symptoms and accelerated gastric emptying was not found, and the efficacy of H. pylori eradication therapy in patients with functional dyspepsia was minimally exhibited.

13C-urea breath test: reproducibility and association with the severity of Helicobacter pylori-associated antral gastritis

BACKGROUND

The purpose of the present paper was to assess the reproducibility of the (13)C-urea breath test ((13)C-UBT) and its ability to reflect the level of Helicobacter pylori-associated inflammation.

METHODS

Asymptomatic H. pylori-positive subjects (n = 21) performed the (13)C-UBT six times. The H. pylori-positive symptomatic subjects (n = 55) performed the (13)C-UBT and had antral biopsies taken for histopathology, culture, urease activity assay and myeloperoxidase activity assay.

RESULTS

No significant intraindividual variation in (13)C-UBT results were observed for the asymptomatic subjects. The (13)C-UBT results were significantly higher in symptomatic subjects with a moderate to severe gastritis compared to a mild gastritis and to no inflammation (34.5 +/- 4.4 vs 17.7 +/- 2.8 vs 1.7 +/- 0.1, respectively, P < 0.01). The (13)C-UBT results significantly correlated with urease (r = 0.55) and myeloperoxidase activity (r = 0.82) but not with bacterial load. conclusion: The (13)C-UBT is a reproducible determinant of H. pylori infection and non-invasively assesses the severity of antral inflammation.

Diabetes-related changes in contractile responses of stomach fundus to endothelin-1 in streptozotocin-induced diabetic rats

The contractile response of the stomach fundus to endothelin-1 (ET-1) was examined in streptozotocin (STZ)-induced diabetic rats. In STZ-diabetic rats (versus age-matched control rats) (a) ET-1 caused a longer-lasting contraction of stomach fundus strips, and (b) in the dose-response curve, the ET-1-induced contraction was significantly greater for a given concentration (3 x 10(-7) to 10(-7) M). Although repeated application of ET-1 led to desensitization, the desensitization was less pronounced in STZ-diabetic rats than in the controls. The density of the binding sites for [(125)I]-ET-1 was increased in the diabetic stomach fundus (versus the controls), but Kd values were similar between the two groups. The ET(B) receptor mRNA expression level was significantly increased in the diabetic stomach fundus. These results suggest that the diabetes-related enhancement of the ET-1-induced contraction of the stomach fundus may be due to an increase in the ET(B) receptor population.

Effect of Helicobacter pylori eradicated therapy on water gastric emptying in patients with active duodenal ulcer

BACKGROUND AND AIMS

It remains debatable if duodenal ulcer (DU) or Helicobacter pylori infection has a definite impact on human gastric emptying (GE). We explored the nature of water GE in active DU patients before and after ulcer healing and the influence of H. pylori eradication on GE.

METHODS

A home made applied potential tomography (APT) was used to measure liquid GE. Twelve electrodes were placed in a circular array around the upper abdomen of studied subjects. After drinking 500 mL of ion-free water, paired electrodes injected electrical current and the remaining 10 electrodes recorded signals, one-by-one in a rotating order. Based on tomographical calculation, the serial changes of averaged signals from altered resistivities were constructed to display GE. Initially, 64 H. pylori infected active DU patients were enrolled. After APT measurement, one-week triple therapy (omeprazole, amoxicillin and clarithromycin) was dispensed. Patients were asked back to determine ulcer/H. pylori status and GE on a scheduled date 3 months later. Finally, 58 patients finished the trial with valid and readable GE data obtained.

RESULTS

The ulcer healing and H. pylori eradicated rates were 91.4% and 82.8%, respectively. In general, liquid GE was prolonged in all DU patients at follow up. Of 48 eradicated patients, 35.4% manifested either enhanced or delayed GE before treatment, whereas only five (10.4%) had abnormal GE after treatment (P < 0.0001). In contrast, this characteristically normalized GE was not found in non-eradicated patients.

CONCLUSIONS

Water GE of active DU patients ranges from enhanced to delayed, while an effective H. pylori triple therapy is useful not only for healing ulcers, but also for restoring abnormal GE.

Helicobacter pylori infection in patients with liver cirrhosis: facts and fictions

Helicobacter pylori infection could play a role in different clinical alterations observed in cirrhosis, from gastroduodenal lesions to hepatic encephalopathy. Although its prevalence in cirrhotics is similar to that in controls, H. pylori infection is responsible for the increased prevalence of peptic ulcer observed in these patients. The ammonia production by H. pylori urease does not seem to increase blood ammonia levels during cirrhosis, indicating that its role in hepatic encephalopathy could be marginalized in clinical practice. Dual and triple therapies have been shown to be equally effective for H. pylori eradication in these patients.

Delayed gastric emptying and gastric autoimmunity in type 1 diabetes

OBJECTIVE

Delayed gastric emptying and/or gastrointestinal symptoms occur in 30-50% of diabetic patients. Known contributing factors are autonomic neuropathy and acute hyperglycemia, but the role of gastric autoimmunity has never been investigated, although 15-20% of type 1 diabetic patients exhibit parietal cell antibodies (PCAs). We studied gastric motility in diabetes in relation to PCA status, autonomic nerve function, HbA(1c), thyroid-stimulating hormone (TSH), Helicobacter pylori (HP), acid production, and gastric histology.

RESEARCH DESIGN AND METHODS

Gastric emptying of solids and liquids (measured by (13)C-octanoic acid and (13)C-glycine breath tests, respectively) was tested in euglycemic conditions in 42 type 1 diabetic patients (male/female: 29/13; 15 PCA+; mean age 40 +/- 15 years; mean HbA(1c) 7.8 +/- 0.9%). Gastrointestinal symptoms, autonomic nerve function (Ewing tests), PCA status (indirect immunofluorescence), gastric histology, and acid secretion (pentagastrin) were assessed.

RESULTS

Solid gastric emptying was delayed in 40% and liquid emptying in 36% of patients. Gastric motility did not correlate with symptoms. PCA status, gastric morphology, and acid secretion were similar in those with and without gastroparesis. HbA(1c) level (beta = 1.34, P = 0.011) was the only risk factor for delayed solid emptying in a logistic regression model testing HbA(1c), autonomic nerve function, PCA, HP status, age, sex, diabetes duration, and TSH. Half-emptying time for liquids correlated with TSH level (r = 0.83, P < 0.0001) and autonomic neuropathy score (r = -0.79, P = 0.001).

CONCLUSIONS

We found that approximately 50% of type 1 diabetic patients studied had delayed gastric emptying that did not correlate with symptoms. Gastric autoimmunity did not contribute to diabetic gastroparesis. Metabolic control was worse in patients with delayed solid emptying.

Effects of eradication therapy on gastric emptying in patients with Helicobacter pylori-positive duodenal ulcers

In this study 28 patients with Helicobacter pylori-positive duodenal ulcers were treated with a 7-day triple-therapy regimen (omeprazole, clarithromycin, amoxycillin). Gastric emptying time was measured scintigraphically before and after therapy. Only 13 patients attended regularly for their endoscopic and scintigraphic follow-ups. Gastric emptying time was 57.6+/-16.5 min in 28 patients before therapy, and 44.4+/-13.9 min after therapy (44.7+/-7.9 min in the control group). The present study demonstrated gastric emptying time to be longer in the ulcer patients compared with healthy controls and that, after eradication therapy, gastric emptying time became almost normal in the ulcer patients.

Novel testing of human gastric motor and sensory functions: rationale, methods, and potential applications in clinical practice

Sensitive and reproducible tests are essential to investigate the mechanisms of gastric motility and sensation in healthy humans and patients with unexplained upper gastrointestinal symptoms. Electrogastrography, manometry, scintigraphic emptying, and barostat studies with an intragastric balloon were initially used to understand physiology and pathophysiology of gastric motility. However, manometry and barostat studies are time-consuming, costly, and invasive, thus reducing their widespread clinical application. To overcome these shortcomings, several novel approaches have been proposed: water/nutrient drink test, paracetamol absorption test, 13C-octanoic acid or spirulina breath tests, ultrasonography, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and tensostat. The water/nutrient (satiety) test is a noninvasive test proposed as an alternative to sensory studies performed with an intragastric balloon. The satiety test cannot measure gastric accommodation; interpretation of sensory tests usually has required independent assessment of accommodation or compliance. The tensostat can be used as a gastric sensation test because it measures gastric wall tension, which is related to the perception of gastric distention. To measure gastric emptying, the paracetamol absorption test, 13C breath tests, ultrasound, or MRI can be used. The paracetamol absorption test can measure the gastric emptying of liquids. 13C breath test can measure the gastric emptying of solids or liquids and can achieve accuracy comparable with gastric scintigraphy. Ultrasonography requires special skills, and MRI requires costly equipment. To measure gastric accommodation to a meal, ultrasound, MRI, and SPECT have been proposed. The recently introduced SPECT requires an intravenous injection of 99mTc-pertechnetate, which the gastric mucosa specifically takes up, and specialized imaging and analysis, which have potential to be automated. Thus, novel, noninvasive approaches assess different dimensions of gastric motility and sensation testing. With further development of these techniques, refinement of their conduct and analysis, and validation of clinical usefulness, they are likely to be applicable in clinical practice to enhance cost-effective, evidence-based management of upper gastrointestinal symptoms. Such applications may provide an alternative to sequential empirical trials for symptoms.

Study on gastric empty disorder after the gastric ulcer healing and therapeutic effect of cisapride

Gastric emptying time of liquid meal was detected by using ultrasonography in 28 gastric ulcer patients with continual or recurrent dyspepsia symptoms after the ulcer healing. Sixteen out of 28 patients (57.1%) with a delay of gastric emptying time (T1/2) were randomly divided into two groups: 8 cases were treated with cisapride 5 mg three times a day and 8 cases with cisapride 10 mg three times a day respectively. The results showed that cisapride could relieve the symptoms with the effective rate being 68.8% in the two groups. T1/2 in the patients after treatment with cisapride was significantly shorter than before treatment (P < 0.001). It was concluded that there is a delay of T1/2 in some patients with gastric ulcer healing. Cisapride could promote gastric empty of liquid meal and relieve the symptoms efficiently. The effect of lower dose of cisapride is similar to that of higher dose.

[The 13C-urea breath test in Helicobacter pylori gastric infection in children]

Helicobacter pylori gastric infection in children is a public health problem. Classical diagnostic tools such as endoscopy are excessively invasive in the usual clinical context. Serology at this age has multiple drawbacks. The urea-13C breath test seems today the most appropriate alternative method. The principle of the test relies upon the indirect detection of H pylori through its high urease activity. The test uses a stable (ie, non radioactive) isotope, which allows its repeated use. The main indications are the detection and the follow-up of H pylori infection.

The 13C-urea breath test as a predictor of intragastric bacterial load and severity of Helicobacter pylori gastritis

BACKGROUND

The urea breath test (UBT) has been proposed as the most accurate test for diagnosing Helicobacter pylori infection. The aim of this work was to evaluate the accuracy of the UBT and to compare the results with histologic and endoscopic findings in H. pylori infected patients.

METHODS

One-hundred-and-seventy-two consecutive dyspeptic outpatients were studied by means of endoscopy (with histology and culture), UBT (75 mg 13C-urea), and serology. Gastritis was classified in accordance with the Sydney criteria. In H. pylori positive patients, the bacterial load was assessed semiquantitatively, the number of bacteria in histologic specimens being counted. UBT results were expressed either as percentage cumulative dose of 13CO2 excreted at 1 h (CD60) or delta over baseline at 30' (DOB30).

RESULTS

Of 172 patients, 126 (73%) were H. pylori positive on histology or culture. Using a cut-off value of 3.3/1000 for DOB30, the sensitivity, specificity and accuracy of the UBT were 96%, 93.5%, and 95.3%, respectively. A significant correlation was observed between DOB30 values and intragastric bacterial load (r = 0.32). Moreover, a significant difference in DOB30 values was found between patients sorted by the depth of inflammation (chi(2) = 4.36, p = 0.036). No correlation was observed between DOB30 and endoscopic findings in H. pylori positive subjects.

CONCLUSIONS

The UBT is an accurate non-invasive diagnostic tool and can be used to predict both the intragastric bacterial load and the severity of related gastritis.