Measurement of gastric emptying in diabetes

Shorter-acting glucagon-like peptide-1 receptor agonists are associated with increased development of gastro-oesophageal reflux disease and its complications in patients with type 2 diabetes mellitus: a population-level retrospective matched cohort study

BACKGROUND

Shorter half-life glucagon-like peptide-1 receptor agonists (GLP-1 RAs) delay gastric emptying (DGE) more than GLP-1 RAs with longer half-lives. DGE is a known risk factor for gastro-oesophageal reflux disease (GERD) and its complications.

AIM

To determine whether short-acting or long-acting GLP-1 RAs are associated with an increased risk of new GERD or GERD-related complications DESIGN: We used the TriNetX global database to identify adult patients with type 2 diabetes mellitus and generated two cohorts totalling 1 543 351 patients on (1) GLP-1 RA or (2) other second-line diabetes medication. Using propensity-score matching, Kaplan-Meier Analysis and Cox-proportional hazards ratio (HR), we analysed outcomes and separately examined outcomes in patients starting short-acting (≤1 day) and long-acting (≥5 days) GLP-1 RAs.

RESULTS

177 666 patients were in each propensity-matched cohort. GLP-1 RA exposure was associated with an increased risk (HR 1.15; 95% CI 1.09 to 1.22) of erosive reflux disease (ERD). However, this was solely due to short-acting (HR 1.215; 95% CI 1.111 to 1.328), but not long-acting (HR 0.994; 95% CI 0.924 to 1.069) GLP-1 RA exposure. Short-acting GLP-1 RAs were also associated with increased risk of oesophageal stricture (HR 1.284; 95% CI 1.135 to 1.453), Barrett's without dysplasia (HR 1.372; 95% CI 1.217 to 1.546) and Barrett's with dysplasia (HR 1.505; 95% CI 1.164 to 1.946) whereas long-acting GLP-1 RAs were not. This association persisted in sensitivity analyses, and when individually examining the short-acting GLP-1 RAs liraglutide, lixisenatide and exenatide.

CONCLUSION

Starting shorter-acting GLP-1 RAs is associated with increased risks of GERD and its complications.

Preoperative Carbohydrate Drink Intake Increases Glycemic Variability in Patients with Type 2 Diabetes Mellitus in Total Joint Arthroplasty: A Prospective Randomized Trial

BACKGROUND

Preoperative carbohydrate treatment attenuates insulin resistance and improves metabolism to an anabolic state. Despite these benefits, impaired glycemic control and aspiration risk related to gastroparesis represent concerns for patients with diabetes undergoing surgery. This randomized controlled trial investigated the effects of oral carbohydrate therapy on perioperative glucose variability, metabolic responses, and gastric volume in diabetic patients undergoing elective total hip or knee arthroplasty.

METHODS

Fifty diabetic patients scheduled to undergo elective total knee or hip arthroplasty during August 2019-October 2020 were randomly assigned to a control or carbohydrate therapy (CHO) group. CHO group of patients received a 400-mL carbohydrate drink 2-3 h before anesthesia; control group of patients underwent overnight fasting from midnight, one night before surgery. Blood glucose levels were measured before intake of the carbohydrate drink, before spinal anesthesia, preoperatively, immediately postoperatively, and 1 h postoperatively. Insulin level and gastric volume were measured before spinal anesthesia.

RESULTS

The glucose variability of patients in the CHO group was significantly higher than that of those in the control group (16.5 vs. 10.1%, P = 0.008). Similarly, insulin resistance was higher in the CHO group than in the control group (8.5 vs. 2.7, P < 0.001). The gastric volume did not differ significantly between the groups (61.3 vs. 15.2 ml, P = 0.082).

CONCLUSIONS

Preoperative oral carbohydrate therapy increases glucose variability and insulin resistance in diabetic patients. Therefore, carbohydrate beverages should be cautiously administered to diabetic patients, considering metabolic and safety aspects. Trial registration number ClinicalTrials.gov (No. NCT04013594).

The efficacy and safety of itopride in feeding intolerance of critically ill patients receiving enteral nutrition: a randomized, double-blind study

BACKGROUND

Enteral feeding intolerance (EFI) is a frequent problem in the Intensive care unit (ICU) and is associated with poor clinical outcomes leading to worse prognosis in terms of mortality and ICU stay. Nowadays, prokinetic drugs are the mainstay of therapy in EFI. However, available prokinetics have uncertain efficacy and safety profiles. Itopride, is a prokinetic agent which is different and unique from the available prokinetics because of its dual mode of action as well as its tolerability and safety. The current study compared the efficacy and safety of Itopride against metoclopramide for EFI in critically ill patients. Moreover, it tested the utility and applicability of ultrasonography to measure gastric residual volume (GRV) in this population.

METHODS

This randomized, double-blind study included 76 EFI patients who were randomly assigned to either Itopride or metoclopramide group. The primary outcome was to measure GRV by ultrasonography. Secondary outcomes included the percentage ratio of enteral feed volume, energy and protein received by patients over 7 days of treatment, ICU length of stay, safety parameters and occurrence of infectious complications or vomiting.

RESULTS

Thirty-five patients of each group completed the study. At day 7, itopride significantly decreased GRV compared with metoclopramide group (p = 0.001). Moreover, there was a significant increase in the ratios of received enteral nutrition feed volume, calories, and protein after the one-week therapy in the itopride group more than the metoclopramide group (p = 0.001), (p = 0.002), (p = 0.01), respectively and there were no differences in any secondary outcomes or adverse events between the two groups.

CONCLUSION

In critically ill patients with EFI, itopride was well tolerated with superior efficacy to metoclopramide. In addition, we demonstrated that ultrasonography is a simple, non-invasive, inexpensive, and undemanding method for GRV measurements and can offer reliable assessments in the gastric emptying modality.

TRIAL REGISTRATION

The trial was registered in ClinicalTrials.gov (NCT03698292). Date: October 5, 2018.

68Ga-NOTA PET imaging for gastric emptying assessment in mice

BACKGROUND

Positron emission tomography (PET) has the potential for visualization and quantification of gastric emptying (GE). The traditional Chinese medicine (TCM) has been recognized promising for constipation. This study aimed to establish a PET imaging method for noninvasive GE measurement and to evaluate the efficacy of a TCM on delayed GE caused by constipation using PET imaging.

METHODS

[⁶⁸Ga]Ga-NOTA was synthesized as the tracer and sesame paste with different viscosity were selected as test meals. The dynamic PET scans were performed after [⁶⁸Ga]Ga-NOTA mixed with test meals were administered to normal mice. Two methods were utilized for the quantification of PET imaging. A constipation mouse model was treated with maren chengqi decoction (MCD), and the established PET imaging scans were performed after the treatment.

RESULTS

[⁶⁸Ga]Ga-NOTA was synthesized within 20 min, and its radiochemical purity was > 95%. PET images showed the dynamic process of GE. %ID/g, volume, and total activity correlated well with each other. Among which, the half of GE time derived from %ID/g for 4 test meals were 3.92 ± 0.87 min, 13.1 ± 1.25 min, 17.8 ± 1.31 min, and 59.7 ± 3.11 min, respectively. Constipation mice treated with MCD showed improved body weight and fecal conditions as well as ameliorated GE measured by [⁶⁸Ga]Ga-NOTA PET.

CONCLUSIONS

A PET imaging method for noninvasive GE measurement was established with stable radiotracer, high image quality, and reliable quantification methods. The efficacy of MCD on delayed GE was demonstrated using PET.

A mathematical model of food intake

The metabolic, hormonal and psychological determinants of the feeding behavior in humans are numerous and complex. A plausible model of the initiation, continuation and cessation of meals taking into account the most relevant such determinants would be very useful in simulating food intake over hours to days, thus providing input into existing models of nutrient absorption and metabolism. In the present work, a meal model is proposed, incorporating stomach distension, glycemic variations, ghrelin dynamics, cultural habits and influences on the initiation and continuation of meals, reflecting a combination of hedonic and appetite components. Given a set of parameter values (portraying a single subject), the timing and size of meals are stochastic. The model parameters are calibrated so as to reflect established medical knowledge on data of food intake from the National Health and Nutrition Examination Survey (NHANES) database during years 2015 and 2016.

Gastrointestinal Mechanisms Underlying the Cardiovascular Effect of Metformin

Metformin, the most widely prescribed drug therapy for type 2 diabetes, has pleiotropic benefits, in addition to its capacity to lower elevated blood glucose levels, including mitigation of cardiovascular risk. The mechanisms underlying the latter remain unclear. Mechanistic studies have, hitherto, focused on the direct effects of metformin on the heart and vasculature. It is now appreciated that effects in the gastrointestinal tract are important to glucose-lowering by metformin. Gastrointestinal actions of metformin also have major implications for cardiovascular function. This review summarizes the gastrointestinal mechanisms underlying the action of metformin and their potential relevance to cardiovascular benefits.

Effects of Lixisenatide Versus Liraglutide (Short- and Long-Acting GLP-1 Receptor Agonists) on Esophageal and Gastric Function in Patients With Type 2 Diabetes

OBJECTIVE

Short-acting glucagon-like peptide 1 receptor agonists (GLP-1 RAs) decelerate gastric emptying more than long-acting GLP-1 RAs. Delayed gastric emptying is a risk factor for gastroesophageal reflux disease. We aimed to measure esophageal reflux and function as well as gastric emptying and acid secretion during treatment with short-acting (lixisenatide) and long-acting (liraglutide) GLP-1 RAs.

RESEARCH DESIGN AND METHODS

A total of 57 subjects with type 2 diabetes were randomized to a 10-week treatment with lixisenatide or liraglutide. Changes from baseline in the number of reflux episodes during 24-h pH registration in the lower esophagus, lower esophagus sphincter pressure, gastric emptying (¹³C-sodium octanoate acid breath test), and gastric acid secretion (¹³C-calcium carbonate breath test) were analyzed.

RESULTS

Gastric emptying half-time was delayed by 52 min (Δ 95% CI 16, 88) with lixisenatide (P = 0.0065) and by 25 min (3, 46) with liraglutide (P = 0.025). There was no difference in the number of reflux episodes (mean ± SEM 33.7 ± 4.1 vs. 40.1 ± 5.3 for lixisenatide and liraglutide, respectively, P = 0.17) or the extent of gastroesophageal reflux (DeMeester score) (35.1 ± 6.7 vs. 39.7 ± 7.5, P = 0.61), with similar results for the individual GLP-1 RAs. No significant changes from baseline in other parameters of esophageal motility and lower esophageal sphincter function were observed. Gastric acidity decreased significantly by -20.7% (-40.6, -0.8) (P = 0.042) with the GLP-1 RAs.

CONCLUSIONS

Lixisenatide exerted a more pronounced influence on gastric emptying after breakfast than liraglutide. Neither lixisenatide nor liraglutide had significant effects on esophageal reflux or motility. Gastric acid secretion appears to be slightly reduced by GLP-1 RAs.

Magnitude of slowing gastric emptying by glucagon-like peptide-1 receptor agonists determines the amelioration of postprandial glucose excursion in Japanese patients with type 2 diabetes

AIMS/INTRODUCTION

Pharmacological levels of glucagon-like peptide-1 (GLP-1) can decelerate gastric emptying (GE) and reduce postprandial glucose levels. Most previous studies have used liquid meals to evaluate GE. We evaluated the effects of GLP-1 receptor agonists (GLP-1 RAs) on GE and postprandial glucose excursion in Japanese type 2 diabetes mellitus patients using a combination of solid and liquid meals.

MATERIALS AND METHODS

In this single-center, prospective, open-label study, nine healthy individuals and 17 patients with type 2 diabetes mellitus consumed a 460-kcal combination of a solid and liquid meal labeled with 13 C-acetic acid. GE was measured from t = 0 to 150 min in a continuous 13 C breath test. Eight participants with type 2 diabetes mellitus were administered GLP-1 RAs, and we examined the relationship between GE and blood glucose excursion.

RESULTS

There were no differences in the average GE coefficient (GEC) and lag time between the healthy and type 2 diabetes mellitus groups. However, the type 2 diabetes mellitus group showed larger GEC variations (P < 0.05). The coefficient of variation of R-R intervals was a significant predictor of GEC in type 2 diabetes mellitus patients (P < 0.01). The short-acting GLP-1 RA reduced the GEC at 1 month (P = 0.012), whereas the long-acting GLP-1 RA did not significantly change the GEC after treatment. A positive relationship was observed between postprandial glucose excursion from T0 min to T60 min and the GEC (r2  = 0.75; P < 0.01).

CONCLUSIONS

The reduction in GE rate by the administration of GLP-1 RAs can predict the improvement in postprandial glucose excursion in type 2 diabetes mellitus patients.

A Higher Preoperative Glycemic Profile Is Associated with Rapid Gastric Emptying After Sleeve Gastrectomy for Obese Subjects

BACKGROUND

Recent reports have shown that sleeve gastrectomy (SG) accelerates gastric emptying (GE), but the etiology remains unclear. This study aimed to investigate the factors affecting GE before and after SG.

METHODS

We enrolled 35 normal weight healthy subjects and 23 obese patients receiving SG. The normal individuals and obese patients before and 3 months after SG received oatmeal-based scintigraphy to measure GE. Gastrointestinal symptoms and circulating levels of peptide YY (PYY) were also measured.

RESULTS

There were no differences in the GE parameters, including simple half-time at 3 h and percentage of gastric retention at 0.5, 1, 2, and 3 h between healthy controls and pre-SG obese subjects. SG led to accelerated GE, more gastrointestinal symptoms, and increased fasting PYY levels postoperatively. Based on our previously established normal GE values, 18 (78.3%) obese patients with rapid postoperative GE had higher levels of preoperative fasting glucose and glycated hemoglobin, and homeostasis model assessment of the insulin resistance index than those with normal postoperative GE. Twelve (52.2%) obese patients had preoperative diabetes mellitus (DM), and only four (17.4%) remained diabetic after SG. The post-SG gastric retention at 0.5 and 1 h was lower in patients with preoperative DM than in those without preoperative DM. Neither severity of gastrointestinal symptoms nor fasting PYY levels were associated with postoperative GE alterations.

CONCLUSION

Most of the obese patients had accelerated GE after SG. A higher preoperative glycemic profile was associated with rapid post-SG GE.

Influence of the physical exercise on decrease in the gastric emptying and alter appetite and food behavior in rats dexamethasone-treatment

The chronic use of Dexamethasone (Dex) induced hyperglycemia and insulin resistance. On the other hand, physical exercise attenuates the symptoms induced by Dex in many physiological systems. However, the effect of the exercise on the changes in gastric motility induced by dexamethasone remains unknown. We hypothesized that low-intensity aerobic exercise modulates the metabolic effects induced by Dex-treatment by modifying the gastrointestinal function and feeding behavior in rats. Male rats were distributed into the following groups: Control (Ctrl), Dex (1.0 mg/kg, i.p.), Exercise (Ctrl + Exercise 5%) and (Dex1.0 + Exercise 5%). The exercise protocol was swimming for 5 consecutive days. We assessed the murinometric and nutritional indices, food intake, blood glucose by (ipGTT) and the gastric emptying rate of a liquid test meal were assessed in all rats. We observed a significant decrease (p < .05) in the gastric emptying in Dex1.0 group in relation to Ctrl group. The exercise prevented decrease in the gastric emptying (p < .05) in Dex1.0 + EX5% group when compared with Dex1.0 groups. The Dex1.0 group induced a significantly increase (p < .05) in glycaemia vs Ctrl group. The hyperglycemia was improving (p < .05) in the Dex1.0 + Ex5% compared with Dex1.0 groups. We observed a positive correlation (p < .05, and r = 0.7065) between gastric retention vs glycaemia in the Dex1.0 groups. The Dex1.0 reduced (p < .05) the body weight and altered body composition, promoting hypophagia. IL-6 increased (p < .05) at gastric fundus in Ex5% compared with Ctrl groups. In conclusion, the use of Dex1.0 decreases gastric emptying, promotes hyperglycemia and modifies feeding behavior. The low-intensity exercise prevents hyperglycemia, thus improving gastric dysmotility without improving the anthropometric parameters.

Insulin and incretin hormone responses to rapid versus slow ingestion of a standardized solid breakfast in healthy subjects

People with repeated rapid meal ingestion have been reported to have increased risk of insulin resistance, impaired glucose tolerance and obesity. To explore whether speed of eating a breakfast influences the postprandial rise of glucose, insulin and the incretin hormones, 24 healthy subjects (12 men and 12 women, mean age 62 years) ingested a standardized solid breakfast consisting of 524 kcal (60% from carbohydrate, 20% from protein, 20% from fat) over 5 or 12 minutes on separate days in random order. Breakfast ingestion increased circulating glucose and insulin with maximal levels seen at 30 minutes after start of meal ingestion with no significant difference in the two tests. Similarly, breakfast increased circulating levels of total (reflecting secretion) glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) with, again, no difference between the tests. Furthermore, gastric emptying, as revealed by the indirect paracetamol test, did not differ between the tests. We therefore conclude that the speed of breakfast ingestion does not affect the postprandial rise of glucose, insulin or incretin hormones in healthy subjects.

Evaluation of Gastric Emptying by Transabdominal Ultrasound after Oral Administration of Semisolid Cellulose-Based Gastric Ultrasound Contrast Agents

Many previous studies have found that transabdominal ultrasound may allow precise measurement of gastric emptying of liquid meals. However, the clinical use of this technique has been hampered by the limitation that transabdominal ultrasound might not accurately measure gastric emptying of solid meals. It is more important to measure gastric emptying of solids instead of liquids, as gastric emptying of solids is more often delayed than gastric emptying of liquids in gastric motility disorders. Recently, transabdominal ultrasound after oral administration of a cellulose-based gastric contrast agents (TUS-OSCA) has been suggested to be effective in initial screening of gastric lesions. The aim of this study was to explore the accuracy of TUS-OSCA in the evaluation of gastric emptying of a semisolid meal. Twenty healthy young patients (10 males and 10 females aged 25.5 ± 2.5 y) were studied. Concurrent measurements of gastric emptying by scintigraphy and TUS-OSCA were performed after ingestion of 350 mL semisolid ultrasound agent labeled with 20 MBq ^99mTc-sulfur colloid. There was no significant difference in the overall curves for gastric emptying time between scintigraphy and TUS-OSCA. There was a good correlation between the gastric 50% emptying times determined by scintigraphy (89.4 ± 1.8 min) and TUS-OSCA (92.5 ± 1.7 min). The correlation coefficient was r = 0.922 (p = 0.000). Current results indicate that TUS-OSCA is accurate, and the results are similar to those obtained by scintigraphy for gastric emptying of a semisolid meal.

Perioperative management of adult diabetic patients. Preoperative period

In diabetic patients undergoing surgery, we recommend assessing glycaemic control preoperatively by assessing glycated haemoglobin (HbA1c) levels and recent capillary blood sugar (glucose) levels, and to adjust any treatments accordingly before surgery, paying particular attention to specific complications of diabetes. Gastroparesis creates a risk of stasis and aspiration of gastric content at induction of anaesthesia requiring the use of a rapid sequence induction technique. Cardiac involvement can be divided into several types. Coronary disease is characterised by silent myocardial ischaemia, present in 30-50% of T2D patients. Diabetic cardiomyopathy is a real cause of heart failure. Finally, cardiac autonomic neuropathy (CAN), although rarely symptomatic, should be investigated because it causes an increased risk of cardiovascular events and a risk of sudden death. Several signs are suggestive of CAN, and confirmation calls for close perioperative surveillance. Chronic diabetic kidney disease (diabetic nephropathy) aggravates the risk of perioperative acute renal failure, and we recommend measurement of the glomerular filtration rate preoperatively. The final step of the consultation concerns the management of antidiabetic therapy. Preoperative glucose infusion is not necessary if the patient is not receiving insulin. Non-insulin drugs are not administered on the morning of the intervention except for metformin, which is not administered from the evening before. The insulins are injected at the usual dose the evening before. The insulin pump is maintained until the patient arrives in the surgical unit. It should be remembered that insulin deficiency in a T1D patient leads to ketoacidosis within a few hours.

Bidirectional Relationship between Gastric Emptying and Plasma Glucose Control in Normoglycemic Individuals and Diabetic Patients

Gastric emptying and glycemic control pathways are closely interrelated processes. Gastric chyme is transferred into the duodenum with velocities depending on its solid or liquid state, as well as on its caloric and nutritional composition. Once nutrients enter the intestine, the secretion of incretins (hormonal products of intestinal cells) is stimulated. Among incretins, glucagon-like peptide-1 (GLP-1) has multiple glycemic-regulatory effects that include delayed gastric emptying, thus triggering a feedback loop lowering postprandial serum glucose levels. Glycemic values also influence gastric emptying; hyperglycemia slows it down, and hypoglycemia accelerates it, both limiting glycemic fluctuations. Disordered gastric emptying in diabetes mellitus is understood today as a complex pathophysiological condition, with both irreversible and reversible components and high intra- and interindividual variability of time span and clinical features. While limited delays may be useful for reducing postprandial hyperglycemias, severely hindered gastric emptying may be associated with higher glycemic variability and worsened long-term glycemic control. Therapeutic approaches for both gastric emptying and glycemic control include dietary modifications of meal structure or content and drugs acting as GLP-1 receptor agonists. In the foreseeable future, we will probably witness a wider range of dietary interventions and more incretin-based medications used for restoring both gastric emptying and glycemic levels to nearly physiological levels.

Short-acting glucagon-like peptide-1 receptor agonists as add-on to insulin therapy in type 1 diabetes: A review

A large proportion of patients with type 1 diabetes do not reach their glycaemic target of glycated hemoglobin (HbA1c) <7.0% (53 mmol/mol) and, furthermore, an increasing number of patients with type 1 diabetes are overweight and obese. Treatment of type 1 diabetes is based on insulin therapy, which is associated with well-described and unfortunate adverse effects such as hypoglycaemia and increased body weight. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are the focus of increasing interest as a possible adjunctive treatment to insulin in type 1 diabetes because of their glucagonostatic and extrapancreatic effects. So far, the focus has mainly been on the long-acting GLP-1RAs, but the risk-benefit ratio emerging from studies evaluating the effect of long-acting GLP-1RAs as adjunctive therapy to insulin therapy in patients with type 1 diabetes has been disappointing. This might be attributable to a lack of glucagonostatic effect of these long-acting GLP-1RAs in type 1 diabetes, alongside development of tachyphylaxis to GLP-1-induced retardation of gastric emptying. In contrast, the short-acting GLP-1RAs seem to have a preserved and sustained effect on glucagon secretion and gastric emptying in patients with type 1 diabetes, which could translate into effective lowering of postprandial glucose excursions; however, these observations regarding short-acting GLP-1RAs are all derived from small open-label trials and should thus be interpreted with caution. In the present paper we review the potential role of GLP-1RAs, in particular short-acting GLP-1RAs, as add-on to insulin in the treatment of type 1 diabetes.

Characterizing the dynamic interaction among gastric emptying, glucose absorption, and glycemic control in nondiabetic obese adults

The effects of altered gastric emptying on glucose absorption and kinetics are not well understood in nondiabetic obese adults. The aim of this work was to develop a physiology-based model that can characterize and compare interactions among gastric emptying, glucose absorption, and glycemic control in nondiabetic obese and lean healthy adults. Dynamic glucose, insulin, and gastric emptying (measured with breath test) data from 12 nondiabetic obese and 12 lean healthy adults were available until 180 min after an oral glucose tolerance test (OGTT) with 10, 25, and 75 g of glucose. A physiology-based model was developed to characterize glucose kinetics applying nonlinear mixed-effects modeling with NONMEM7.3. Glucose kinetics after OGTT was described by a one-compartment model with an effect compartment to describe delayed insulin effects on glucose clearance. After the interactions between individual gastric emptying and glucose absorption profiles were accounted for, the glucose absorption rate was found to be similar in nondiabetic obese and lean controls. Baseline glucose concentration was estimated to be only marginally higher in nondiabetic obese subjects (4.9 vs. 5.2 mmol/l), whereas insulin-dependent glucose clearance in nondiabetic obese subjects was found to be cut in half compared with lean controls (0.052 vs. 0.029 l/min) and the insulin concentration associated with 50% of insulin-dependent glucose elimination rate was approximately twofold higher in nondiabetic obese subjects compared with lean controls (7.1 vs. 15.3 μU/ml). Physiology-based models can characterize and compare the dynamic interaction among gastric emptying, glucose absorption and glycemic control in populations of interest such as lean healthy and nondiabetic obese adults.

The effect of sleeve gastrectomy on GLP-1 secretion and gastric emptying: a prospective study

BACKGROUND

Rapid gastric emptying has been proposed to justify the increase in glucagon-like polypeptide-1 (GLP-1) after laparoscopic sleeve gastrectomy (LSG).

OBJECTIVES

To assess gastric emptying changes after LSG and their relationship with GLP-1 secretion.

SETTING

San Salvatore Hospital general surgery unit, University of L'Aquila, Italy.

METHODS

52 patients underwent gastric emptying scintigraphy for liquid and solid foods, before and 3 months after LSG. Twenty-six patients were in the liquid group (L group) and the remaining in the solid group (S group). We evaluated the half time of gastric emptying (T_1/2) and percentage of gastric retention (%GR) at 15, 30, and 60 minutes for liquids and at 30, 60, 90, and 120 minutes for solids. GLP-1 plasma concentrations were measured in each group before and after LSG and related to %GR. Statistical analysis was performed by Χ2 test and Pearson correlation(r).

RESULTS

After surgery, T_1/2 was significantly accelerated: 15.2±13 min and 33.5±18 min in the L group and S group, respectively (P<.05). In both groups, GLP-1 plasma concentrations were increased at each blood sampling time: 2.91±2.9 pg/mL, 3.06±3.1 pg/mL and 3.21±2.6 pg/mL at 15, 30, and 60 minutes, respectively, (P<.05) for L group and 2.72±1.5 pg/mL, 2.89±2.1 pg/mL, 2.93±1.8 pg/mL, and 2.95±1.9 pg/mL at 30, 60, 90, and 120 minutes, respectively, (P< .05) for the S group. After LSG, GLP-1 and %GR presented a negative linear correlation (r) at each blood sampling time in both groups.

CONCLUSION

The rapid gastric emptying 3 months after LSG upregulates the production of GLP-1 in the distal bowel. Further studies are needed to confirm these findings.

Gastric emptying, postprandial blood pressure, glycaemia and splanchnic flow in Parkinson’s disease

AIM: To determine gastric emptying, blood pressure, mesenteric artery blood flow, and blood glucose responses to oral glucose in Parkinson’s disease.

METHODS: Twenty-one subjects (13 M, 8 F; age 64.2 ± 1.6 years) with mild to moderate Parkinson’s disease (Hoehn and Yahr score 1.4 ± 0.1, duration of known disease 6.3 ± 0.9 years) consumed a 75 g glucose drink, labelled with 20 MBq ^99mTc-calcium phytate. Gastric emptying was quantified with scintigraphy, blood pressure and heart rate with an automated device, superior mesenteric artery blood flow by Doppler ultrasonography and blood glucose by glucometer for 180 min. Autonomic nerve function was evaluated with cardiovascular reflex tests and upper gastrointestinal symptoms by questionnaire.

RESULTS: The mean gastric half-emptying time was 106 ± 9.1 min, gastric emptying was abnormally delayed in 3 subjects (14%). Systolic and diastolic blood pressure fell (P < 0.001) and mesenteric blood flow and blood glucose (P < 0.001 for both) increased, following the drink. Three subjects (14%) had definite autonomic neuropathy and 8 (38%) had postprandial hypotension. There were no significant relationships between changes in blood pressure, heart rate or mesenteric artery blood flow with gastric emptying. Gastric emptying was related to the score for autonomic nerve function (R = 0.55, P < 0.01). There was an inverse relationship between the blood glucose at t = 30 min (R = -0.52, P < 0.05), while the blood glucose at t = 180 min was related directly (R = 0.49, P < 0.05), with gastric emptying.

CONCLUSION: In mild to moderate Parkinson’s disease, gastric emptying is related to autonomic dysfunction and a determinant of the glycaemic response to oral glucose.

Meal sequence and glucose excursion, gastric emptying and incretin secretion in type 2 diabetes: a randomised, controlled crossover, exploratory trial

AIMS/HYPOTHESIS

Investigation of dietary therapy for diabetes has focused on meal size and composition; examination of the effects of meal sequence on postprandial glucose management is limited. The effects of fish or meat before rice on postprandial glucose excursion, gastric emptying and incretin secretions were investigated.

METHODS

The experiment was a single centre, randomised controlled crossover, exploratory trial conducted in an outpatient ward of a private hospital in Osaka, Japan. Patients with type 2 diabetes (n = 12) and healthy volunteers (n = 10), with age 30-75 years, HbA1c 9.0% (75 mmol/mol) or less, and BMI 35 kg/m(2) or less, were randomised evenly to two groups by use of stratified randomisation, and subjected to meal sequence tests on three separate mornings; days 1 and 2, rice before fish (RF) or fish before rice (FR) in a crossover fashion; and day 3, meat before rice (MR). Pre- and postprandial levels of glucose, insulin, C-peptide and glucagon as well as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide were evaluated. Gastric emptying rate was determined by (13)C-acetate breath test involving measurement of (13)CO2 in breath samples collected before and after ingestion of rice steamed with (13)C-labelled sodium acetate. Participants, people doing measurements or examinations, and people assessing the outcomes were not blinded to group assignment.

RESULTS

FR and MR in comparison with RF ameliorated postprandial glucose excursion (AUC-15-240 min-glucose: type 2 diabetes, FR 2,326.6 ± 114.7 mmol/l × min, MR 2,257.0 ± 82.3 mmol/l × min, RF 2,475.6 ± 87.2 mmol/l × min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 1,419.8 ± 72.3 mmol/l × min, MR 1,389.7 ± 69.4 mmol/l × min, RF 1,483.9 ± 72.8 mmol/l × min) and glucose variability (SD-15-240 min-glucose: type 2 diabetes, FR 1.94 ± 0.22 mmol/l, MR 1.68 ± 0.18 mmol/l, RF 2.77 ± 0.24 mmol/l [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 0.95 ± 0.21 mmol/l, MR 0.83 ± 0.16 mmol/l, RF 1.18 ± 0.27 mmol/l). FR and MR also enhanced GLP-1 secretion, MR more strongly than FR or RF (AUC-15-240 min-GLP-1: type 2 diabetes, FR 7,123.4 ± 376.3 pmol/l × min, MR 7,743.6 ± 801.4 pmol/l × min, RF 6,189.9 ± 581.3 pmol/l × min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 3,977.3 ± 324.6 pmol/l × min, MR 4,897.7 ± 330.7 pmol/l × min, RF 3,747.5 ± 572.6 pmol/l × min [p < 0.05 for MR vs RF and MR vs FR]). FR and MR delayed gastric emptying (Time50%: type 2 diabetes, FR 83.2 ± 7.2 min, MR 82.3 ± 6.4 min, RF 29.8 ± 3.9 min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 66.3 ± 5.5 min, MR 74.4 ± 7.6 min, RF 32.4 ± 4.5 min [p < 0.05 for FR vs RF and MR vs RF]), which is associated with amelioration of postprandial glucose excursion (AUC-15-120 min-glucose: type 2 diabetes, r = -0.746, p < 0.05; healthy, r = -0.433, p < 0.05) and glucose variability (SD-15-240 min-glucose: type 2 diabetes, r = -0.578, p < 0.05; healthy, r = -0.526, p < 0.05), as well as with increasing GLP-1 (AUC-15-120 min-GLP-1: type 2 diabetes, r = 0.437, p < 0.05; healthy, r = 0.300, p = 0.107) and glucagon (AUC-15-120 min-glucagon: type 2 diabetes, r = 0.399, p < 0.05; healthy, r = 0.471, p < 0.05). The measured outcomes were comparable between the two randomised groups.

CONCLUSIONS/INTERPRETATION

Meal sequence can play a role in postprandial glucose control through both delayed gastric emptying and enhanced incretin secretion. Our findings provide clues for medical nutrition therapy to better prevent and manage type 2 diabetes.

TRIAL REGISTRATION

UMIN Clinical Trials Registry UMIN000017434.

FUNDING

Japan Society for Promotion of Science, Japan Association for Diabetes Education and Care, and Japan Vascular Disease Research Foundation.

Mixed meal ingestion diminishes glucose excursion in comparison with glucose ingestion via several adaptive mechanisms in people with and without type 2 diabetes

AIMS

To study the integrative impact of macronutrients on postprandial glycaemia, β-cell function, glucagon and incretin hormones in humans.

METHODS

Macronutrients were ingested alone (glucose 330 kcal, protein 110 kcal or fat 110 kcal) or together (550 kcal) by healthy subjects (n = 18) and by subjects with drug-naïve type 2 diabetes (T2D; n = 18). β-cell function and insulin clearance were estimated by modelling glucose, insulin and C-peptide data. Secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were measured, and paracetamol was administered to estimate gastric emptying.

RESULTS

In both groups, the mixed-meal challenge diminished glucose excursion compared with glucose challenge alone, and insulin levels, but not C-peptide levels, rose more than after the mixed meal than after glucose alone. β-cell function was augmented, insulin clearance was reduced and glucagon levels were higher after the mixed meal compared with glucose alone. GLP-1 and GIP levels increased after all challenges and GIP secretion was markedly higher after the mixed meal than after glucose alone. The appearance of paracetamol was delayed after the mixed-meal challenge compared with glucose alone.

CONCLUSIONS

Adding protein and fat macronutrients to glucose in a mixed meal diminished glucose excursion. This occurred in association with increased β-cell function, reduced insulin clearance, delayed gastric emptying and augmented glucagon and GIP secretion. This suggests that the macronutrient composition regulates glycaemia through both islet and extra-islet mechanisms in both healthy subjects and in subjects with T2D.

Gastric Emptying in the Elderly

Aging is characterized by a diminished homeostatic regulation of physiologic functions, including slowing of gastric emptying. Gastric and small intestinal motor and humoral mechanisms in humans are complex and highly variable: ingested food is stored, mixed with digestive enzymes, ground into small particles, and delivered as a liquefied form into the duodenum at a rate allowing efficient digestion and absorption. In healthy aging, motor function is well preserved whereas deficits in sensory function are more apparent. The effects of aging on gastric emptying are relevant to the absorption of oral medications and the regulation of appetite, postprandial glycemia, and blood pressure.

Effects of exogenous glucagon-like peptide-1 on blood pressure, heart rate, gastric emptying, mesenteric blood flow and glycaemic responses to oral glucose in older individuals with normal glucose tolerance or type 2 diabetes

AIMS/HYPOTHESIS

A postprandial fall in BP occurs frequently in older individuals and in patients with type 2 diabetes. The magnitude of this decrease in BP is related to the rate of gastric emptying (GE). Intravenous administration of glucagon-like peptide-1 (GLP-1) attenuates the hypotensive response to intraduodenal glucose in healthy older individuals. We sought to determine the effects of exogenous GLP-1 on BP, GE, superior mesenteric artery (SMA) flow and glycaemic response to oral ingestion of glucose in healthy older individuals and patients with type 2 diabetes.

METHODS

Fourteen older volunteers (six men, eight women; age 72.1 ± 1.1 years) and ten patients with type 2 diabetes (six men, four women; age 68.7 ± 3.4 years; HbA1c 6.6 ± 0.2% [48.5 ± 2.0 mmol/mol]; nine with blood glucose managed with metformin, two with a sulfonylurea and one with a dipeptidyl-peptidase 4 inhibitor) received an i.v. infusion of GLP-1 (0.9 pmol kg(-1) min(-1)) or saline (154 mmol/l NaCl) for 150 min (t = -30 min to t = 120 min) in randomised order. At t = 0 min, volunteers consumed a radiolabelled 75 g glucose drink. BP was assessed with an automated device, GE by scintigraphy and SMA flow by ultrasonography. Blood glucose and serum insulin were measured.

RESULTS

GLP-1 attenuated the fall in diastolic BP after the glucose drink in older individuals (p < 0.05) and attenuated the fall in systolic and diastolic BP in patients with type 2 diabetes (p < 0.05). GE was faster in patients with type 2 diabetes than in healthy individuals (p < 0.05). In both groups, individuals had slower GE (p < 0.001), decreased SMA flow (p < 0.05) and a lower degree of glycaemia (p < 0.001) when receiving GLP-1.

CONCLUSIONS/INTERPRETATION

Intravenous GLP-1 attenuates the hypotensive response to orally administered glucose and decreases SMA flow, probably by slowing GE. GLP-1 and 'short-acting' GLP-1 agonists may be useful in the management of postprandial hypotension.