Simultaneous measurement of gastric emptying with a simple muffin meal using [13C]octanoate breath test and scintigraphy in normal subjects and patients with dyspeptic symptoms

The objective of this study was to determine how the [¹³C]octanoate breath test (OBT) using a muffin meal correlates with gastric emptying scintigraphy (GES) in normal subjects and patients with dyspeptic symptoms. Ten normal subjects and 23 patients with dyspeptic symptoms underwent simultaneous GES and [¹³C]OBT. After an overnight fast, a muffin labeled with [^99mTc]sulfur colloid and [¹³C]octanoate was ingested along with water labeled with [¹¹¹In]DTPA. Breath samples and scintigraphic images were obtained at baseline and at regular postprandial intervals over 6 hr. In the normal subjects, the mean GES T1/2 of solids and liquids were 64 ± 17 and 55 ± 27 minutes, respectively. The calculated OBT T1/2 using the 6-hr breath collection was 138 ± 15 min and correlated with T1/2 for solids by GES (r = 0.664; P = 0.051), but did not correlate with T1/2 for liquids by GES (r = 0.13; P = 0.738). In dyspeptic patients, the T1/2 for GES was 87 ± 53 min and 81 ± 70 min for solids and liquids, respectively. The mean OBT T1/2 was 155 ± 57 min and correlated with GES T1/2 for solids (r = 0.86; P < 0.001) and GES T1/2 for liquids (r = 0.73; P < 0.001). Delayed gastric emptying (GE) of the muffin meal was identified by scintigraphy in seven patients. The sensitivity and specificity for OBT identifying delayed GE were 86% and 94%. Use of the initial truncated 4-hr OBT results also revealed a significant correlation between OBT and GES T1/2 for solids (r = 0.86; P < 0.001) with sensitivity and specificity for detecting delayed GE of 86% and 94%, respectively. In addition, a linear regression model was able to reduce the number of collection points to four, while maintaining the same sensitivity and specificity. In conclusion, the OBT for GE, using an easily prepared muffin meal, significantly correlates with GES for solids. This muffin-based OBT is a sensitive and specific method to detect delayed GE in dyspeptic patients.     

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

Abstract

Objective. The ¹³C 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 ¹³C 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 (r² = 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 (r² = 0.8335). Samples taken at a rate of one breath per min indicated lack of a visible T_lag. Conclusions. Sampling for the ¹³C OBT should be completed every 15 min for 6 h.     

Effect of Meal Size and Test Duration on Gastric Emptying and Gastric Myoelectrical Activity as Determined with Simultaneous [13C]Octanoate Breath Test and Electrogastrography in Normal Subjects Using a Muffin Meal

Our purpose was to determine the effect of meal size on gastric emptying (GE) as measured by octanoate breath test (OBT), to determine the effect of the duration of breath collections on assessment of GE by OBT, and to determine the effect of meal size on gastric myoelectrical activity as measured by electrogastrography (EGG). Fourteen normal subjects underwent two modified [¹³C]OBTs using muffin meals of 250 or 350 kcal mixed with 100 mg [¹³C]sodium octanoate. T _1/2 for GE was determined for both the entire postprandial 6-hr breath collection and a truncated initial 4-hr data set. EGG was recorded for 30 min prior to the muffin meal and 4 hr postprandially. Using the 6-hr breath collection data, the T _1/2 was 177 ± 7 (mean ± sem) for the 350-kcal meal compared to 153 ± 7 min (P < 0.01) for the 250-kcal meal. Using the 4-hr data, the T _1/2 for the 350-kcal meal was 244 ± 32 min compared to 165 ± 12 min (P < 0.05) for the 250-kcal meal. The ratio of postprandial to fasting EGG power of the dominant frequency for the 350-kcal meal (1.9 ± 0.4) was higher than that for the 250-kcal meal (1.3 ± 0.6). T _1/2 for the 350-kcal meal using 4- and 6-hr data was significantly correlated with the 4-hr power ratio (r = 0.68 and 0.67; P < 0.05, respectively), but poorly correlated for the 250-kcal meal. In conclusions, GE and EGG are affected by meal size. Using the muffin-based [¹³C]OBT, T _1/2 for the 350-kcal meal was significantly longer than for a 250-kcal meal. Longer T _1/2 values were obtained with shorter breath sampling durations. The postprandial to fasting power ratio for the 350-kcal meal was greater than that for the 250-kcal meal.     

[13C]0ctanoic acid breath test for non-invasive assessment of gastric emptying in diabetic patients: Validation and relationship to gastric symptoms and cardiovascular autonomic function

Summary Since there is a need for a widely applicable non-invasive test to assess gastric emptying in diabetic patients, we evaluated the sensitivity, specificity, and reproducibility of the [¹³C]octanoic acid breath test as compared with scintigraphy. Moreover, we examined the relationship between the breath test indices and gastric symptoms, cardiovascular autonomic function, and metabolic parameters. Forty healthy control subjects and 34 diabetic patients were studied. Three indices of gastric emptying, assessed by the breath test, were computed: half-emptying time (t_1/2breath), gastric emptying coefficient (GEC), and lag phase. Furthermore, the half-emptying time, measured by scintigraphy (t_1/2scint), was calculated and gastric symptoms and cardiovascular autonomic neuropathy (CAN) were scored. The coefficients of variation of day-to-day reproducibility in 10 healthy subjects were 29.6 % for t_1/2breath, 7.4 % for GEC, and 46.5 % for lag phase. An abnormal delay for t_1/2scint (> 100 min) or t_1/2breath (> 200 min) was noted in 12 patients. Based on the results for t_1/2scint, the sensitivity of t_1/2breath and GEC was 75 % and the specificity was 86 %. Both t_1/2breath (r _s = 0.523; p < 0.05) and GEC (r ₂ = − 0.594; p < 0.05) were significantly associated with the gastric symptom score. A significant relationship to the CAN score was demonstrated for t_1/2breath (r _s = 0.448; p < 0.05), GEC (r _s = − 0.467; p < 0.05), and t_1/2scint (r _s = 0.602; p < 0.05). There were no significant associations of the breath test indices with the blood glucose levels during the test, HbA_1c, age, and duration of diabetes. In patients with abnormal t_1/2scint (n = 12) not only was t_1/2breath significantly prolonged and GEC reduced, but also the scores of CAN and gastric symptoms were significantly increased as compared with those who had a normal t_1/2scint (n = 22). We conclude that the [¹³C]octanoic acid breath test represents a suitable measure of delayed gastric emptying in diabetic patients which is associated with the severity of gastric symptoms and CAN but not affected by the blood glucose level. [Diabetologia (1996) 39: 823–830]     

Gastric emptying of a solid-liquid meal measured with 13C octanoic acid breath test and real-time ultrasonography: a comparative study

OBJECTIVES: The 13C octanoic acid breath test (OBT) has been proposed as a reliable noninvasive test to measure gastric emptying. OBT has been compared with scintigraphy; however, there are no data comparing it with gastric emptying measured with real-time ultrasonography (RUS) The aim of the study was to correlate gastric emptying of a solid-liquid meal, with OBT and RUS simultaneously evaluated in a group of normal volunteers. METHODS: A total of 14 normal subjects ingested a standard test meal (one scrambled egg with two slices of white bread, 10 g of butter, and 300 ml of tap water). The egg yolk was mixed with 0.1 ml of 13C octanoic acid. Breath samples for 13CO2 analysis were collected in breath bags and were analyzed by means of isotope-selective nondispersive infrared spectrometry (IRIS). RUS was simultaneously performed by calculating the antral area following a previous validated method. Breath samples and antral area were taken at baseline and every 15 min after the meal during the first 2 h and every 30 min for another 2 h. Lag time (Tlag) and gastric half emptying time (T(1/2)) were calculated for OBT and RUS. Data were analyzed by the Student's t test for paired data, correlation coefficient, and regression line. RESULTS: The results show a statistically significant longer Tlag and T(1/2) for OBT in comparison with RUS (p < 0.001). A significant correlation and positive regression line was computed between OBT and RUS for Tlag and for T(1/2). CONCLUSIONS: Our results show that OBT overestimates gastric emptying parameters of a solid-liquid meal in comparison with RUS. However, both techniques give data in good correlation. Because OBT is less operator-dependent than RUS, it may be useful in comparative gastric emptying studies.     

Gastric emptying characteristics of a novel (13)C-octanoate-labeled muffin meal

GOALS: Determine the gastric emptying characteristics of a novel, 350-kcal test meal consisting of two muffins, using scintigraphy and the 13C-octanoate breath test (OBT). STUDY: Healthy volunteers underwent three studies on separate days within a 1-week period. On day 1, we measured emptying of the 350-kcal muffin test meal labeled simultaneously with 99mTc sulfur colloid and 13C-octanoate. On day 2, reproducibility of the OBT using a single-labeled 350-kcal test meal was assessed. On day 3, the effect of erythromycin on the 350-kcal OBT was determined. RESULTS: The mean (+/-SD) half-emptying time (T1/2) as measured by scintigraphy was 104 +/- 24 minutes, versus 212 +/- 52 minutes by OBT. There was a strong correlation between T1/2 determined by scintigraphy and the breath test (r = 0.83). Multiple linear regression analysis identified a significant relationship between T1/2 determined by scintigraphy and the 90-and 180-minute breath samples. There was a strong correlation (r = 0.830, slope = 0.732 +/- 0.120 [SE], intercept = 26.4 +/- 12.7) between the T1/2 obtained using the regression equation and the actual T1/2 obtained by scintigraphy. The mean T1/2 (+/-SD) for replicate determinations using the OBT was 209 +/- 52 minutes, compared with 196 +/- 42 minutes on days 1 and 2, respectively (not significant, p = 0.28, paired Student t test). Treatment with erythromycin on day 3 produced a significant decrease in T1/2 (155 +/- 49 minutes, p = 0.002). CONCLUSIONS: The 350-kcal muffin meal OBT provides a convenient, nonscintigraphic way of measuring solid-phase gastric emptying. Multiple linear regression appears promising as a method of analyzing OBT data and may allow for an abbreviated breath test protocol.     

Gastric emptying of liquid and solid meals at various temperatures Effect of meal temperature for gastric emptying

Background  Patients with functional dyspepsia frequently show delayed gastric emptying, and dietary advice is frequently given for its improvement. If meal temperature influences gastric emptying, advice regarding the meal temperature may become a possible component of dietary therapy. However, little information exists concerning the thermal effect of meals on gastric emptying. The aim of this study was to determine the thermal effect of liquid and solid meals on gastric emptying. Methods  The gastric emptying of liquid and solid test meals was examined in healthy volunteers (liquid, n = 25, mean age = 35.7 ± 9.6 years, male-to-female ratio = 22:3; solid, n = 25, mean age = 35.2 ± 8.8 years, male-to-female ratio = 20:5). Gastric emptying after the ingestion of liquid or solid meals at three different temperatures (4, 37, and 60°C) was investigated with the [¹³C]-labeled acetate breath test. The lag phase time (T _max-calc) and the half-emptying time (T _1/2) were calculated from the ¹³CO₂ breath excretion curve as indices of gastric emptying. Results  The values of T _max-calc at 60°C with both the liquid and solid meals were significantly smaller than those at 37°C (P < 0.05). However, there was no difference in the T _1/2 values. In the analysis of the percent excretion of ¹³CO₂ in 1 h (% dose/h) data with the liquid meal test in the earlier phase within 30 min, significantly larger values were found at 60°C than at the other temperatures. These findings suggest that a hot meal significantly accelerates gastric emptying. Conclusions  Meal temperature may be considered as a component of dietary therapy for patients with functional dyspepsia.     

Measuring gastric emptying of semisolids in children using the C-acetate breath test: a validation study

Background and aim. Radioscintigraphy is the gold standard for evaluation of gastric emptying in children, but requires exposure to ionising radiation. Therefore, the aim of the study was to validate the non-radioactive ¹³C-acetate breath test in children in comparison to radioscintigraphy as reference method.Patients. Twenty-nine children with dyspeptic or respiratory symptoms were tested for gastric emptying disorders simultaneously performing the ¹³C-acetate breath test and radioscintigraphy.Methods. A semisolid oatmeal was doubly labelled with 150 mg ¹³C-acetate and 50 MBq ^99mTechnetium. Breath samples were collected every 5–10 min for 4 h. After mass spectrometrical ¹³C-analysis, curve fitting of the ¹³C-cumulative recovery to the modified power exponential function Y=m(1−e^−kt)^β calculated the half emptying times of the breath test (t_1/2^breath). Scintigraphic image acquisition began immediately after the ingestion of the ^99mTechnetium-labelled testmeal at a rate of one frame every 60 s for 1 h.Results. Six children showed delayed gastric emptying in scintigraphy (t_1/2^scinti>60 min). All these children had prolonged half emptying times t_1/2^breath in the ¹³C-acetate breath test. Using a cut-off t_1/2^breath>90 min, the ¹³C-acetate breath test had a sensitivity of 100% and a specificity of 85%. Scintigraphic and breath test half emptying times were linearly correlated (Y=0.80x+47.68, r=0.76, P<0.00001).Conclusions. The ¹³C-acetate breath test proves to be a reliable, non-radioactive alternative for measuring gastric emptying in children.     

Reliability of the [13C]‐acetate breath test in the measurement of gastric emptying of ethanol solutions: a methodological study

Background: The [ ¹³ C]‐acetate breath test is a clinically well‐established test for measuring gastric emptying of liquids and correlates significantly with scintigraphy. However, no studies have been undertaken to examine the relationship between gastric emptying measured by the [ ¹³ C]‐acetate breath test and ultrasonography. Furthermore, it is not known how ethanol may affect gastric emptying as measured by the [ ¹³ C]‐acetate breath test. This is particularly important because of the additional steps of absorption, metabolism and exhalation of the tracer involved in the [ ¹³ C]‐acetate breath test compared to the simple measurement of gastric emptying by ultrasonography. The aim of the present study was to examine the relationship between the gastric half emptying times measured by the [ ¹³ C]‐acetate breath test and by ultrasonography and to determine the effect of ethanol on the comparability between both methods. Methods: On separate days, 10 healthy, fasted randomly selected subjects received the following solutions by gastric tube: 500?mL water, 4% and 10% (v/v) ethanol, 5.5% and 11.4 % (w/v) glucose. Gastric half emptying times of the test solutions were simultaneously determined using the [ ¹³ C]‐acetate breath test and ultrasonography of the fundus and the antrum. Results: The gastric emptying rates determined by ultrasonography of the fundus correlated significantly with the results obtained using the [ ¹³ C]‐acetate breath test for all test solutions (r?=?0.64–0.92, P?r?=?0.94, P?=?0.001) was used. The difference between the mean half‐emptying times obtained using the [ ¹³ C]‐acetate breath test and ultrasonography of the fundus was 55?±?1.8?min. This difference was significantly longer when 4% and 10% (v/v) ethanol solutions were given (61.2?±?3.3 and 71.2?±?2.9?min) compared to water (P?Conclusions: A good correlation was found between gastric emptying as measured by the [ ¹³ C]‐acetate breath test and ultrasonography of the fundus. Measurements that were obtained using the [ ¹³ C]‐acetate breath test demonstrate a longer gastric half emptying time compared with those obtained using ultrasonography. This difference is even more marked when ethanol solutions are used. Presumably, this is because ethanol affects the absorption and/or the hepatic metabolism of the tracer. The [ ¹³ C]‐acetate breath test is therefore not a reliable gastric emptying test for comparison of different solutions, especially when ethanol‐containing liquids are used.     

Acute Effect of Nicotine Patch on Gastric Emptying of Liquid and Solid Contents in Healthy Subjects

The effect of nicotine on gastric emptyingremains controversial. Gastric emptying is delayed inchronic smokers after smoking high-dose nicotinecigarettes, but it is unchanged after chewing nicotinegums. No information is available on the effect oftransdermal nicotine patches on the gastric emptying ofsolid and liquid contents in healthy nonsmokers. Ourobjective was to prospectively evaluate the effect of the nicotine patch on gastric emptying ofliquid and solid contents in healthy nonsmokers. Tenhealthy nonsmoking volunteers under-went a baselinedual-isotope gastric scintigraphy with[¹¹¹In]-diethylenetriaminepantaacetic acid (DTPA) and [^99mTc]sulfurcolloid isotopes to evaluate prospectively the gastricemptying of liquid and solid contents, respectively. Thegastric scintigraphy was repeated after placing a transdermal nicotine patch (Habitrol) for 12 hrdesigned to deliver 14 mg of nicotine per day. Plasmanicotine level was measured prior to baseline gastricscintigraphy and after 12 hr placing the nicotine patch. Plasma nicotine was absent in allsubjects at baseline and but was significantly elevatedafter 12 hr of nicotine patch (P < 0.009). The meanhalf-emptying times (T_1/2) for the gastricemptying of liquids before and after nicotine patchplacement were 31.2 ± 23.3 and 25.6 ± 8.4min, respectively (P = 0.498). The mean T_1/2sfor the gastric emptying of solids before and afternicotine patch placement were 70.1 ± 34.0 and 59.7± 31.4 min, respectively (P = 0.202). There wasno correlation between the plasma nicotine level andgastric emptying of liquid and solid contents(correlation coefficient = –0.23 and –0.01, respectively).In conclusion, acute transdermal delivery of nicotinedoes not affect the gastric emptying of solid and liquidcontents in healthy nonsmoking subjects.     

Oesophageal dysmotility, delayed gastric emptying and autonomic neuropathy correlate to disturbed glucose homeostasis

Aims/hypothesis Among diabetic patients, glucose homeostasis may be affected by abnormal gastrointestinal motility and autonomic neuropathy. This study analysed whether oesophageal dysmotility, delayed gastric emptying or autonomic neuropathy affect glucose homeostasis.Materials and methods Oesophageal manometry and gastric emptying scintigraphy were performed in 20 diabetic patients. Heart-rate variation during deep breathing (expiration/inspiration [E/I] ratio) and continuous subcutaneous glucose concentrations for a period of 72 h were also monitored in the same patients.Results Oesophageal dysmotility was found in eight of 14 patients. Eleven of 20 patients had delayed gastric emptying (abnormal gastric emptying half-time [T ₅₀]) and nine of 18 had an abnormal E/I ratio. Complaints of abdominal fullness were predictive of delayed gastric emptying. A low peristaltic speed of the oesophagus was associated with impaired T ₅₀ (r _s =−0.67; p=0.02). One hour after breakfast, subcutaneous glucose levels decreased in patients with delayed gastric emptying but continued to rise in those with normal emptying. Consequently, the median glucose level 2.5 h after breakfast was lower in the former (9.1 [4.2–12.5] vs 14.3 [11.2–17.7] mmol/l; p<0.05). Glucose fluctuations during the 72 h were significantly higher in patients with an abnormal E/I ratio than in those with a normal E/I ratio (coefficient of variation: 41 [46–49] vs 28 [27–34]%; p=0.008).Conclusions/interpretation Abdominal fullness predicted delayed gastric emptying that was associated with diminished glucose uptake after breakfast. Low oesophageal peristaltic speed was associated with slow gastric emptying whereas parasympathetic neuropathy was associated with increased glucose variations.These results were presented as an oral presentation at the EASD meeting in Athens 2005.     

Effect of euglycaemic hyperinsulinaemia on gastric emptying and gastrointestinal hormone responses in normal subjects

Summary Several studies have shown that hyperglycaemia slows gastric emptying in normal subjects and patients with diabetes mellitus but whether hyperinsulinaemia per se has an effect remains debatable. In the present study we have assessed the effect of hyperinsulinaemia on gastric emptying of a solid and liquid meal in normal subjects. Ten men were studied three times in random order. After an overnight fast, subjects were infused with 0.9 % NaCl on two occasions and on the third with insulin, at 40 mU · m⁻²· min⁻¹ with 20 % glucose simultaneously to maintain euglycaemia. Steady-state glucose infusion rate was ensured before the subjects ate a standard meal of a pancake labelled with ^99mTc and milkshake labelled with ¹¹¹In-DTPA. Gamma-scintigraphic images were then obtained every 20 min for the next 3 h. There were no significant differences between the mean half-emptying times (T₅₀) of the solid and liquid during the two saline infusions (129.6 ± 28.5 vs 128.4 ± 23.8 min for the solid and 25.4 ± 7.0 vs 34.7 ± 18.0 min for the liquid, mean ± SD). Hyperinsulinaemia delayed both solid (mean T₅₀ 149.6 ± 30.7, p = 0.031) and liquid emptying (mean T₅₀ 39.8 ± 13.9, p = 0.042). There were no significant differences in the cholecystokinin and glucagon-like peptide 1 responses to the meal during either saline or insulin infusions. There was a tendency towards a greater insulin response to the meal during the hyperinsulinaemic study. Thus, hyperinsulinaemia delayed emptying of both the solid and liquid components of the meal. [Diabetologia (1998) 41: 474–481] Received: 22 July 1997 and in revised form: 3 December 1997     

Euglycaemic hyperinsulinaemia does not affect gastric emptying in Type I and Type II diabetes mellitus

Summary Hyperglycaemia slows gastric emptying in both normal subjects and patients with diabetes mellitus. The mechanisms mediating this effect, particularly the potential role of insulin, are uncertain. Hyperinsulinaemia has been reported to slow gastric emptying in normal subjects during euglycaemia. The purpose of this study was to evaluate the effect of euglycaemic hyperinsulinaemia on gastric emptying in Type I (insulin-dependent) and Type II (non-insulin-dependent) diabetes mellitus. In six patients with uncomplicated Type I and eight patients with uncomplicated Type II diabetes mellitus, measurements of gastric emptying were done on 2 separate days. No patients had gastrointestinal symptoms or cardiovascular autonomic neuropathy. The insulin infusion rate was 40 mU · m^–2· min^–1 on one day and 80 mU · m^–2· min^–1 on the other. Gastric emptying and intragastric meal distribution were measured using a scintigraphic technique for 3 h after ingestion of a mixed solid/liquid meal and results compared with a range established in normal volunteers. In both Type I and Type II patients the serum insulin concentration had no effect on gastric emptying or intragastric meal distribution of solids or liquids. When gastric emptying during insulin infusion rates of 40 mU · m^–2· min^–1 and 80 mU · m^–2· min^–1 were compared the solid T₅₀ was 137.8 ± 24.6 min vs 128.7 ± 24.3 min and liquid T₅₀ was 36.7 ± 19.4 min vs 40.4 ± 15.7 min in the Type I patients; the solid T₅₀ was 94.9 ± 19.1 vs 86.1 ± 10.7 min and liquid T₅₀ was 21.8 ± 6.9 min vs 21.8 ± 5.9 min in the Type II patients. We conclude that hyperinsulinaemia during euglycaemia has no notable effect on gastric emptying in patients with uncomplicated Type I and Type II diabetes; any effect of insulin on gastric emptying in patients with diabetes is likely to be minimal. [Diabetologia (1999) 42: 365–372] Received: 3 September 1998 and in revised form: 3 November 1998     

Gastric emptying: a comparison of three methods

Objective. A better understanding of the clinical relevance of delayed gastric emptying (e.g. in diabetes) requires a simple, easily accessible and inexpensive method for measuring it. Two “new” methods for measuring gastric emptying of liquids (the paracetamol absorption test and the ¹³C-acetate breath test) are compared with the gold standard (gastric emptying scintigraphy (GES)). Material and methods. The three techniques were used simultaneously in 10 healthy subjects. A gastric emptying time-retention curve was drawn for each technique and the results were compared at the 75%, 50% and 25% retention quartiles. Results. Agreement was found between the paracetamol absorption test and GES (p=0.95; Hotelling's T² test). Using the Wagner-Nelson one compartment correction produced a retention curve for the ¹³C-acetate breath test statistically significantly below GES (p<0.01). Conclusion. In healthy subjects, the paracetamol absorption test produced results comparable to those of liquid GES, but not to the results of the ¹³C-acetate breath test.     

Emptying of the gastric substitute,glucagon-like peptide-1 (GLP-1), and reactive hypoglycemia after total gastrectomy

Postprandial glucagon-like peptide-1 (GLP-1), pancreatic glucagon, and insulin were measured in 27 tumor-free patients 43 months (median) after total gastrectomy and in four controls using a⁹⁹technetium-labeled 100-g carbohydrate solid test meal. Emptying of the gastric substitute was measured by scintigraphy. Fourteen patients suffered from early dumping symptoms, and five of them also reported symptoms suggestive of reactive hypoglycemia (late dumping). The median emptying half-time (T1/2) of the gastric substitute was 480 sec. Sigstad's dumping score was 8.5±1.6 (mean±se) in patients with rapid emptying (T1/2<480 sec), and 3.0±1.5 in patients with slow emptying of the gastric substitute (P=0.02). The peak postprandial concentration of GLP-1 was 44±20 pmol/liter in controls, 172±50 in patients without reactive hypoglycemia, and 502±116 in patients whose glucose fell below 3.8 mmol/liter during the second postprandial hour. Plasma GLP-1 concentrations peaked at 15 min, and insulin concentrations at 30 min after the end of the meal. A close correlation between integrated GLP-1 responses and integrated insulin responses (r=0.68) was observed. Multiple regression revealed that three factors were significantly associated with the integrated glucose concentrations during the second hour (60–120 min): Early (first 30 min) integrated GLP-1 (inverse correlation;P=0.006), age (P=0.006), and early integrated pancreatic glucagon (P=0.005). There was a close (inverse) relationship ofT1/2 with early integrated GLP-1 and pancreatic glucagon, but not with insulin. Gel filtration of pooled postprandial plasma of gastrectomized individuals revealed that all glucagon-like immunoreactivity eluted atK _d 0.30 (K _d , coefficient of distribution), the elution position of glicentin. Almost all of the GLP-1 like immunoreactivity eluted atK _d 0.60, the elution position of gut GLP-1. The authors contend that GLP-1-induced insulin release and inhibition of pancreatic glucagon both contribute to the reactive hypoglycemia encountered in some patients following gastric surgery. Rapid emptying seems to be one causative factor for the exaggerated GLP-1 release in these subjects.     

Effects of Posture on Gastric Emptying, Transpyloric Flow, and Hunger After a Glucose Drink in Healthy Humans

Previous studies suggest that posture has relatively little effect on gastric emptying of high-nutrient liquids; these studies have, however, only assessed overall rates of gastric emptying, whereas gastric emptying is known to be predominantly a pulsatile phenomenon. In healthy subjects perceptions of appetite, such as hunger, are inversely related to antral area and content; hence, changes in intragastric meal distribution induced by posture may affect appetite. Gastric emptying is a major determinant of postprandial glycemia. The aims of this study were to evaluate the effects of posture on patterns of transpyloric flow (TF), gastric emptying (GE), antral area (AA), hunger, and the glycemic response to oral glucose. Eight healthy young subjects (five males, three females; mean age, 24.0 ± 2.4 years; BMI, 21.2 ± 0.6 kg/m²) were studied twice in random order, once in the sitting position and once in the lying (supine) position. After consuming 600 ml water with 75 g glucose, labeled with 20 MBq ^99mTc-sulfur colloid, subjects had simultaneous measurements of (i) TF during consumption of the drink by Doppler ultrasonography, (ii) GE with scintigraphy, (iii) AA at t = −5 and t = 30 min by ultrasonography, and (iv) perceptions of appetite with a visual analogue scale. During drink ingestion TF was greater in the sitting, compared with the lying, position (586 ± 170 vs. 177 ± 65 [cm/sec]×sec; P < 0.05). Posture affected intragastric distribution; more of the drink was retained in the distal stomach in the sitting position (e.g., at 30 min: sitting, 29 ± 3%, vs. lying, 12 ± 3%; P < 0.0001) but had no effect on the overall rate of GE or the blood glucose response. AA at t = 30 min (P < 0.005) was greater in the sitting position; there was an inverse relationship between hunger and AA at 30 min (r = −0.53, P < 0.05). We conclude that posture influences initial TF and intragastric distribution, but not the overall rate of GE of, or the glycemic response to, a large-volume nutrient liquid. The increases in AA and content in the sitting position are associated with a reduction in hunger.     

Relationship between oral glucose tolerance and gastric emptying in normal healthy subjects

Summary The relationships between gastric emptying and intragastric distribution of glucose and oral glucose tolerance were evaluated in 16 healthy volunteers. While sitting in front of a gamma camera the subjects drank 350 ml water containing 75 g glucose and 20 MBq ^99mTc-sulphur colloid. Venous blood samples for measurement of plasma glucose, insulin and gastric inhibitory polypeptide were obtained at — 2, 2, 5, 10, 15, 30, 45, 60, 75, 90, 105, 120 and 150 min. Gastric emptying approximated a linear pattern after a short lag phase (3.3±0.8 min). The 50% emptying time was inversely related to the proximal stomach 50% emptying time (r=–0.55, p<0.05) and directly related to the retention in the distal stomach at 120 min (r=0.72, p<0.01). Peak plasma glucose was related to the amount emptied at 5 min (r=0.58, p<0.05) and the area under the blood glucose curve between 0 and 30 min was related to the amount emptied at 30 min (r=0.58, p<0.05). In contrast, plasma glucose at 120 min was inversely related to gastric emptying (r=–0.56, p<0.05) and plasma insulin at 30 min (r=–0.53, p<0.05). Plasma insulin at 120 min was inversely related (r=–0.65, p<0.01) to gastric emptying. The increase in plasma gastric inhibitory polypeptide at 5 min was related directly to gastric emptying (r=0.53, p<0.05). These results indicate in normal subjects that (i) gastric emptying accounts for about 34 % of the variance in peak plasma glucose after a 75-g oral glucose load (ii) plasma glucose levels at 120 min are inversely, rather than directly, related to gastric emptying (iii) the distal stomach influences gastric emptying of glucose.     

Noninvasive evaluation of gastric emptying and gastric wall thickness in SLE patients

Objective: The objective of this study is to evaluate the gastric emptying in patients with systemic lupus erythematosus (SLE) with gastrointestinal involvement using three-dimensional (3D) ultrasonography.

Methods: The gastric emptying times at 25% (T1), 50% (T2), and 75% (T3) of SLE patients with gastrointestinal involvement (n?=?40) and healthy controls (n?=?80) were evaluated and compared. In addition, the correlations among the gastric wall thickness, SLE disease activity index (SLEDAI), and upper gastrointestinal symptoms were calculated.

Results: The gastric wall thickness was correlated with the SLEDAI (r?=?0.928, p?<?0.001) and the upper gastrointestinal symptom index (r?=?0.848, p?<?0.001). The emptying times T1, T2, and T3 of the SLE patients were 17.08?±?2.65?min (mean?±?standard deviation), 39.85?±?6.54?min, and 83.58?±?7.12?min, respectively. For healthy controls, they were 19.65?±?5.39?min, 41.08?±?7.51?min, and 70.34?±?8.03?min. The T1 of the SLE patients was shorter (p?<?0.01), while the T3 was longer (p?<?0.001). Moreover, T3 in the SLE group had the best correlation with the upper gastrointestinal symptom index (r?=?0.553, p?<?0.001). T1 in the SLE group was anti-correlated with early satiety (r?=??0.366, p?<?0.05).

Conclusions: Combining the emptying times T1 and T3, as well as the gastric wall thickness, the SLEDAI and the upper gastrointestinal symptoms index can provide accurate clinical diagnosis of SLE with gastric involvement.     

不透X线标志物法和13C-辛酸呼气试验法检测胃固体排空的评价

目的 比较不透X线标志物法（ROMs）和^13C-辛酸呼气试验法（OBT）检测胃固体排空方法的相关性。方法 对32例胆汁反流性胃炎（BRG）组和27例对照组（HC）同时应用^13C-辛酸呼气试验及不透X线标志物法进行胃排空检测,将所测参数输入计算机,用专用软件分析。结果 不透X线标志物法与^13C-辛酸呼气试验法测定的胃排空结果具有很好的相关性（P〈0．001）,两种检测方法均显示BRG组的固体胃排空较HC组明显延迟（P〈0．05）。结论 不透X线标志物法是一种非侵入性检测胃固体排空的方法,操作简单,与^13C-辛酸呼气试验法比较,具有较好的敏感性、特异性及准确性。BRG患者有明显的胃排空延迟,这可能是其发生病理性胆汁反流的一个重要原因。     

Aperitif Effects on Gastric Emptying: A Crossover Study Using Continuous Real-Time 13C Breath Test (BreathID System)

The aim of this study was to determine whether there is a correlation between aperitif and gastric emptying. Ten healthy male volunteers participated in this randomized, two-way crossover study. Under two conditions (after drinking an aperitif versus not), the ¹³C breath test was performed for 4 h with a liquid meal (200 kcal/200 ml) containing 100 mg ¹³C acetate. We used 50 ml of umeshu as the aperitif. This is a traditional Japanese plum liqueur, and contains 7 ml alcohol (14%). In the aperitif group, T _1/2, T _lag, and T _peak were significantly delayed [T _1/2 (132: 113–174) versus (112: 92–134) (P = 0.0069); T _lag (80: 63–94) versus (55: 47–85) (P = 0.0069); and T _peak (81: 62–96) versus (54: 34–84) (P = 0.0069), (median: range, aperitif versus control, min)]. Gastric emptying was significantly delayed in the aperitif group as compared with the control group. This study revealed that even a small amount of alcohol such as an aperitif may contribute to delayed gastric emptying.