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Gastroenterology Jan 2022Gastroparesis is characterized by symptoms suggestive of, and objective evidence of, delayed gastric emptying in the absence of mechanical obstruction. This review... (Review)
Review
Gastroparesis is characterized by symptoms suggestive of, and objective evidence of, delayed gastric emptying in the absence of mechanical obstruction. This review addresses the normal emptying of solids and liquids from the stomach and details the myogenic and neuromuscular control mechanisms, including the specialized function of the pyloric sphincter, that result in normal emptying, based predominantly on animal research. A clear understanding of fundamental mechanisms is necessary to comprehend derangements leading to gastroparesis, and additional research on human gastric muscles is needed. The section on pathophysiology of gastroparesis considers neuromuscular diseases that affect nonsphincteric gastric muscle, disorders of the extrinsic neural control, and pyloric dysfunction that lead to gastroparesis. The potential cellular basis for gastroparesis is attributed to the effects of oxidative stress and inflammation, with increased pro-inflammatory and decreased resident macrophages, as observed in full-thickness biopsies from patients with gastroparesis. Predominant diagnostic tests involving measurements of gastric emptying, the use of a functional luminal imaging probe, and high-resolution antral duodenal manometry in characterizing the abnormal motor functions at the gastroduodenal junction are discussed. Management is based on supporting nutrition; dietary interventions, including the physical reduction in particle size of solid foods; pharmacological agents, including prokinetics and anti-emetics; and interventions such as gastric electrical stimulation and pyloromyotomy. These are discussed briefly, and comment is added on the potential for individualized treatments in the future, based on optimal gastric emptying measurement and objective documentation of the underlying pathophysiology causing the gastroparesis.
Topics: Animals; Enteric Nervous System; Gastric Emptying; Gastroparesis; Humans; Predictive Value of Tests; Pylorus; Treatment Outcome
PubMed: 34717924
DOI: 10.1053/j.gastro.2021.10.028 -
Sports Medicine (Auckland, N.Z.) Mar 2017The gastrointestinal (GI) tract plays a critical role in delivering carbohydrate and fluid during prolonged exercise and can therefore be a major determinant of... (Review)
Review
The gastrointestinal (GI) tract plays a critical role in delivering carbohydrate and fluid during prolonged exercise and can therefore be a major determinant of performance. The incidence of GI problems in athletes participating in endurance events is high, indicating that GI function is not always optimal in those conditions. A substantial body of evidence suggests that the GI system is highly adaptable. Gastric emptying as well as stomach comfort can be "trained" and perceptions of fullness decreased; some studies have suggested that nutrient-specific increases in gastric emptying may occur. Evidence also shows that diet has an impact on the capacity of the intestine to absorb nutrients. Again, the adaptations that occur appear to be nutrient specific. For example, a high-carbohydrate diet will increase the density of sodium-dependent glucose-1 (SGLT1) transporters in the intestine as well as the activity of the transporter, allowing greater carbohydrate absorption and oxidation during exercise. It is also likely that, when such adaptations occur, the chances of developing GI distress are smaller. Future studies should include more human studies and focus on a number of areas, including the most effective methods to induce gut adaptations and the timeline of adaptations. To develop effective strategies, a better understanding of the exact mechanisms underlying these adaptations is important. It is clear that "nutritional training" can improve gastric emptying and absorption and likely reduce the chances and/or severity of GI problems, thereby improving endurance performance as well as providing a better experience for the athlete. The gut is an important organ for endurance athletes and should be trained for the conditions in which it will be required to function.
Topics: Athletes; Diet; Dietary Carbohydrates; Exercise; Gastric Emptying; Humans; Physical Endurance; Physical Exertion
PubMed: 28332114
DOI: 10.1007/s40279-017-0690-6 -
The Surgical Clinics of North America Apr 2017Postgastrectomy syndromes result from altered form and function of the stomach. Gastrectomy disrupts reservoir capacity, mechanical digestion and gastric emptying. Early... (Review)
Review
Postgastrectomy syndromes result from altered form and function of the stomach. Gastrectomy disrupts reservoir capacity, mechanical digestion and gastric emptying. Early recognition of symptoms with prompt evaluation and treatment is essential. Many syndromes resolve with minimal intervention or dietary modifications. Re-operation is not common but often warranted for afferent and efferent loop syndromes and bile reflux gastritis. Preoperative nutritional assessment and treatment of common vitamin and mineral deficiencies after gastrectomy can reduce the incidence of chronic complications. An integrated team approach to risk assessment, patient education, and postoperative management is critical to optimal care of patients with gastric cancer.
Topics: Afferent Loop Syndrome; Anastomosis, Roux-en-Y; Bile Reflux; Diarrhea; Dietary Supplements; Dumping Syndrome; Gastric Emptying; Gastric Stump; Gastritis; Gastroparesis; Humans; Malnutrition; Postgastrectomy Syndromes; Reoperation
PubMed: 28325187
DOI: 10.1016/j.suc.2016.11.005 -
Nutrition in Clinical Practice :... Feb 2021Enteral feeding intolerance (EFI) is a common feature in critically ill patients worldwide. However, there is no clear, widely agreed-upon definition available, with... (Review)
Review
Enteral feeding intolerance (EFI) is a common feature in critically ill patients worldwide. However, there is no clear, widely agreed-upon definition available, with various studies rarely using the same definition. The term EFI is frequently used to describe vomiting or large gastric residual volumes associated with enteral feeding as a result of gastroparesis/delayed gastric emptying. However, the syndrome of EFI may represent the consequence of various pathophysiological mechanisms, and this heterogeneity may explain varying associations with outcomes. In clinical practice, a pragmatic definition may be useful. A pragmatic definition of EFI is that a clinician has decided to reduce the amount of enteral nutrition specifically because features of gastrointestinal dysfunction appeared during enteral feeding. For research purposes, a more detailed definition of EFI is required to improve knowledge and explore interventions that may improve patient-centered outcomes. The objective of this review is to summarize available evidence on existing definitions, pathophysiological mechanisms, and the clinical relevance of EFI in critically ill patients. Based on current knowledge, we propose a conceptual framework for a definition of EFI for a future consensus process.
Topics: Critical Illness; Enteral Nutrition; Gastric Emptying; Gastrointestinal Diseases; Humans; Infant, Newborn; Stomach
PubMed: 33242218
DOI: 10.1002/ncp.10599 -
American Journal of Physiology.... May 2021This study was designed to investigate whether transcutaneous auricular vagal nerve stimulation (taVNS) would be able to improve major pathophysiologies of functional...
This study was designed to investigate whether transcutaneous auricular vagal nerve stimulation (taVNS) would be able to improve major pathophysiologies of functional dyspepsia (FD) in patients with FD. Thirty-six patients with FD (21 F) were studied in two sessions (taVNS and sham-ES). Physiological measurements, including gastric slow waves, gastric accommodation, and autonomic functions, were assessed by the electrogastrogram (EGG), a nutrient drink test and the spectral analysis of heart rate variability derived from the electrocardiogram (ECG), respectively. Thirty-six patients with FD (25 F) were randomized to receive 2-wk taVNS or sham-ES. The dyspeptic symptom scales, anxiety and depression scores, and the same physiological measurements were assessed at the beginning and the end of the 2-wk treatment. In comparison with sham-ES, acute taVNS improved gastric accommodation ( = 0.008), increased the percentage of normal gastric slow waves (%NSW, fasting: = 0.010; fed: = 0.007) and vagal activity (fasting: = 0.056; fed: = 0.026). In comparison with baseline, 2-wk taVNS but not sham-ES reduced symptoms of dyspepsia ( = 0.010), decreased the scores of anxiety ( = 0.002) and depression ( < 0.001), and improved gastric accommodation ( < 0.001) and the %NSW (fasting: < 0.05; fed: < 0.05) by enhancing vagal efferent activity (fasting: = 0.015; fed: = 0.048). Compared with the HC, the patients showed increased anxiety ( < 0.001) and depression ( < 0.001), and decreased gastric accommodation ( < 0.001) and %NSW ( < 0.001) as well as decreased vagal activity (fasting: = 0.047). The noninvasive taVNS has a therapeutic potential for treating nonsevere FD by improving gastric accommodation and gastric pace-making activity via enhancing vagal activity. Treatment of functional dyspepsia is difficult due to various pathophysiological factors. The proposed method of transcutaneous auricular vagal nerve stimulation improves symptoms of both dyspepsia and depression/anxiety, and gastric functions (accommodation and slow waves), possibly mediated via the enhancement of vagal efferent activity. This noninvasive and easy-to-implement neuromodulation method will be well received by patients and healthcare providers.
Topics: Adolescent; Adult; Aged; Autonomic Nervous System; Dyspepsia; Female; Gastric Emptying; Gastrointestinal Motility; Humans; Male; Middle Aged; Stomach; Treatment Outcome; Vagus Nerve; Vagus Nerve Stimulation; Young Adult
PubMed: 33624527
DOI: 10.1152/ajpgi.00426.2020 -
The Lancet. Gastroenterology &... Dec 2017Liraglutide, a long-acting GLP-1 receptor agonist, is approved for treatment of obesity; however, the mechanisms of action of liraglutide are incompletely understood. We... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Liraglutide, a long-acting GLP-1 receptor agonist, is approved for treatment of obesity; however, the mechanisms of action of liraglutide are incompletely understood. We compared effects of liraglutide versus placebo on gastric motor functions, satiation, satiety, and weight in obese individuals over 16 weeks.
METHODS
We did a randomised, double-blind, placebo-controlled pilot trial at a single centre (Mayo Clinic, Rochester, MN, USA). Participants were randomly allocated (1:1) by a computer generated randomisation schedule with no stratification to receive subcutaneous liraglutide (3·0 mg) or placebo, with standardised nutritional and behavioural counselling. Allocation was concealed from participants and study investigators. Otherwise healthy, local residents aged 18-65 years with body-mass index (BMI) 30 kg/m or higher were included. Liraglutide or placebo was escalated by 0·6 mg/day each week for 5 weeks and continued until week 16. The primary outcome was change in gastric emptying (delay relative to baseline) of solids T (time taken for half the radiolabelled meal to empty from the stomach), measured at 5 weeks and 16 weeks in all patients who received at least one dose of study drug, with missing data imputed. Secondary outcomes included weight loss at weeks 5 and 16, satiation (volume to fullness and maximum tolerated volume), satiety, and fasting and postprandial gastric volumes at 16 weeks. This trial is registered with ClinicalTrials.gov, number NCT02647944, and is closed to new participants.
FINDINGS
Between Dec 18, 2015, and Sept 1, 2016, 40 adults were enrolled and randomly allocated (19 to the liraglutide group; 21 to the placebo group). Compared with placebo, liraglutide delayed gastric emptying of solids at 5 weeks (median 70 min [IQR 32 to 151] vs 4 min [-21 to 18]; p<0·0001) and 16 weeks (30·5 min [-11 to 54] vs -1 min [-19 to 7]; p=0·025). There was also significantly greater weight loss in the liraglutide group than in the placebo group (at 5 weeks: median 3·7 kg [IQR 2·8 to 4·8] vs 0·6 kg [-0·3 to 1·4], p<0·0001; at 16 weeks: 5·3 kg [5·2 to 6·8] vs 2·5 kg [0·1 to 4·2], p=0·0009). Satiation, as assessed by maximum tolerated volume at 16 weeks, was lower in the liraglutide group (median 750 mL [IQR 651 to 908]) compared with the placebo group (1126 mL [944-1185]; p=0·054). No significant differences were noted between groups in terms of volume to fullness, satiety, or fasting and postprandial gastric volumes at week 16. Post-hoc analysis showed that the T of gastric emptying of solids at 5 weeks correlated with change in weight loss at week 16 with liraglutide (Rs 0·567, p=0·018). Nausea was the most common adverse event in the liraglutide group (12 of 19) compared with placebo (four of 21).
INTERPRETATION
Effects of liraglutide on weight loss are associated with delay in gastric emptying of solids; measurement of gastric emptying (eg, at 5 weeks of treatment) may be a biomarker of responsiveness and may help to select individuals for prolonged treatment with this class of drug.
FUNDING
US National Institutes of Health grant R56-DK67071.
Topics: Adolescent; Adult; Aged; Double-Blind Method; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Obesity; Pilot Projects; Satiation; Weight Loss; Young Adult
PubMed: 28958851
DOI: 10.1016/S2468-1253(17)30285-6 -
Gastroenterology Clinics of North... Mar 2015Gastroparesis is a chronic symptomatic disorder of the stomach characterized by delayed emptying without evidence of mechanical obstruction. Idiopathic gastroparesis... (Review)
Review
Gastroparesis is a chronic symptomatic disorder of the stomach characterized by delayed emptying without evidence of mechanical obstruction. Idiopathic gastroparesis refers to gastroparesis of unknown cause not from diabetes; not from prior gastric surgery; not related to other endocrine, neurologic, rheumatologic causes of gastroparesis; and not related to medications that can delay gastric emptying. There is overlap in the symptoms of idiopathic gastroparesis and functional dyspepsia. Patients with idiopathic gastroparesis often have a constellation of symptoms including nausea, vomiting, early satiety, postprandial fullness, and upper abdominal pain. Current treatment options of dietary management, prokinetics agents, antiemetic agents, and symptom modulators do not adequately address clinical need for idiopathic gastroparesis.
Topics: Combined Modality Therapy; Diet Therapy; Electric Stimulation Therapy; Gastric Emptying; Gastrointestinal Agents; Gastroparesis; Humans
PubMed: 25667023
DOI: 10.1016/j.gtc.2014.11.015 -
Diabetes, Obesity & Metabolism Apr 2023To evaluate the effect of once-weekly subcutaneous semaglutide 1.0 mg on the late digestive period of gastric emptying (GE) after ingestion of a standardized solid test... (Randomized Controlled Trial)
Randomized Controlled Trial
AIM
To evaluate the effect of once-weekly subcutaneous semaglutide 1.0 mg on the late digestive period of gastric emptying (GE) after ingestion of a standardized solid test meal by using technetium scintigraphy, the reference method for this purpose.
METHODS
We conducted a single-blind, placebo-controlled trial in 20 obese women with polycystic ovary syndrome (PCOS; mean [range] age 35 [32.3-40.8] years, body mass index 37 [30.7-39.8] kg/m ) randomized to subcutaneous semaglutide 1.0 mg once weekly or placebo for 12 weeks. GE was assessed after ingestion of [ c] colloid in a pancake labelled with radiopharmaceutical by scintigraphy using sequential static imaging and dynamic acquisition at baseline and at Week 13. Estimation of GE was obtained by repeated imaging of remaining [ c] activity at fixed time intervals over the course of 4 hours after ingestion.
RESULTS
From baseline to the study end, semaglutide increased the estimated retention of gastric contents by 3.5% at 1 hour, 25.5% at 2 hours, 38.0% at 3 hours and 30.0% at 4 hours after ingestion of the radioactively labelled solid meal. Four hours after ingestion, semaglutide retained 37% of solid meal in the stomach compared to no gastric retention in the placebo group (P = 0.002). Time taken for half the radiolabelled meal to empty from the stomach was significantly longer in the semaglutide group than the placebo group (171 vs. 118 min; P < 0.001).
CONCLUSION
Semaglutide markedly delayed 4-hour GE in women with PCOS and obesity.
Topics: Humans; Female; Adult; Gastric Emptying; Polycystic Ovary Syndrome; Single-Blind Method; Obesity
PubMed: 36511825
DOI: 10.1111/dom.14944 -
Neurogastroenterology and Motility Apr 2019There have been many recent advances in the understanding of various aspects of the physiology of gastric motility and gastric emptying. Earlier studies had discovered... (Review)
Review
There have been many recent advances in the understanding of various aspects of the physiology of gastric motility and gastric emptying. Earlier studies had discovered the remarkable ability of the stomach to regulate the timing and rate of emptying of ingested food constituents and the underlying motor activity. Recent studies have shown that two parallel neural circuits, the gastric inhibitory vagal motor circuit (GIVMC) and the gastric excitatory vagal motor circuit (GEVMC), mediate gastric inhibition and excitation and therefore the rate of gastric emptying. The GIVMC includes preganglionic cholinergic neurons in the DMV and the postganglionic inhibitory neurons in the myenteric plexus that act by releasing nitric oxide, ATP, and peptide VIP. The GEVMC includes distinct gastric excitatory preganglionic cholinergic neurons in the DMV and postganglionic excitatory cholinergic neurons in the myenteric plexus. Smooth muscle is the final target of these circuits. The role of the intramuscular interstitial cells of Cajal in neuromuscular transmission remains debatable. The two motor circuits are differentially regulated by different sets of neurons in the NTS and vagal afferents. In the digestive period, many hormones including cholecystokinin and GLP-1 inhibit gastric emptying via the GIVMC, and in the inter-digestive period, hormones ghrelin and motilin hasten gastric emptying by stimulating the GEVMC. The GIVMC and GEVMC are also connected to anorexigenic and orexigenic neural pathways, respectively. Identification of the control circuits of gastric emptying may provide better delineation of the pathophysiology of abnormal gastric emptying and its relationship to satiety signals and food intake.
Topics: Animals; Enteric Nervous System; Gastric Emptying; Gastrointestinal Motility; Ghrelin; Humans; Motilin; Neurons
PubMed: 30740834
DOI: 10.1111/nmo.13546 -
Nature Reviews. Endocrinology Feb 2015The rate of gastric emptying is a critical determinant of postprandial glycaemia and, accordingly, is fundamental to maintaining blood glucose homeostasis. Disordered... (Review)
Review
The rate of gastric emptying is a critical determinant of postprandial glycaemia and, accordingly, is fundamental to maintaining blood glucose homeostasis. Disordered gastric emptying occurs frequently in patients with longstanding type 1 diabetes mellitus and type 2 diabetes mellitus (T2DM). A complex bidirectional relationship exists between gastric emptying and glycaemia--gastric emptying accounts for ∼35% of the variance in peak postprandial blood glucose concentrations in healthy individuals and in patients with diabetes mellitus, and the rate of emptying is itself modulated by acute changes in glycaemia. Clinical implementation of incretin-based therapies for the management of T2DM, which diminish postprandial glycaemia, in part by slowing gastric emptying, is widespread. Other therapies for patients with T2DM, which specifically target gastric emptying include pramlintide and dietary-based treatment approaches. A weak association exists between upper gastrointestinal symptoms and the rate of gastric emptying. In patients with severe diabetic gastroparesis, pathological changes are highly variable and are characterized by loss of interstitial cells of Cajal and an immune infiltrate. Management options for patients with symptomatic gastroparesis remain limited in their efficacy, which probably reflects the heterogeneous nature of the underlying pathophysiology.
Topics: Gastric Emptying; Humans; Hyperglycemia; Hypoglycemic Agents; Postprandial Period
PubMed: 25421372
DOI: 10.1038/nrendo.2014.202