Visceral hypersensitivity and impaired accommodation in refractory diabetic gastroparesis

Diabetic gastroenteropathy: a pan-alimentary complication

Autonomic neuropathy contributes to the pathophysiology of diabetic gastroenteropathy, which impacts the entire gastrointestinal tract alongside pancreatic and gallbladder functions. This is evident in the widespread morphological remodelling of the enteric nervous system, smooth muscle cells, interstitial cells of Cajal and vascular supply, causing pan-enteric motor, sensory and secretory disturbances. The gastrointestinal symptoms caused by these changes are often burdensome and non-specific and frequently coexist with poor glycaemic management and even malnutrition, impacting quality of life negatively. The Gastroparesis Cardinal Symptom Index and the Gastrointestinal Symptom Rating Scale are validated questionnaires for assessing gastrointestinal symptoms. However, clinical supplementary objective measures are essential. Transit time assessments are frequently used and typically evaluated using gastric emptying scintigraphy, breath tests or colonic radiopaque markers, but they cannot measure contractile activity or fluid transport. The primary treatment goals are to prevent further disease progression and to obtain symptomatic relief. Treatments include improved glycaemic management and dietary modifications, while pharmacological treatments target gastrointestinal symptoms, small intestinal bacterial overgrowth and exocrine pancreatic insufficiency. Invasive interventions may involve gastric peroral pyloromyotomy or the implantation of a gastric neurostimulator to manage pharmacologically refractory gastroparesis. This review describes the prevalence, pathophysiology, clinical presentation, assessment and treatment of diabetic gastrointestinal dysfunction within each segment of the gastrointestinal tract and directly connected exocrine organs.

Extensive scintigraphic gastric motor function testing with concurrent symptom recording predicts prospectively measured daily dyspeptic symptoms

BACKGROUND

Absent "organic" disease, dyspeptic symptoms may arise from abnormal gastric sensation, accommodation, motility or emptying (GE). Extensive gastric sensorimotor evaluation is rarely undertaken because testing is prolonged, invasive, poorly tolerated or unavailable.

AIMS

To investigate whether gastric antral motor function, evaluated with scintigraphy, predicts GE. To explore whether motor testing with symptom recording predicts day-to-day symptoms in patients with dyspepsia.

METHODS

GE was determined using a scintigraphic solid-meal protocol (296 kcal, 35% fat). Antral motility was estimated from 10 min of scintigraphic time-activity curves acquired 40 min after meal consumption. An antral motility index (MI) was derived from contraction amplitude and frequency. Intra-gastric distribution of the meal on scintograms at 1 h (IGD1) was determined. Meal-induced symptoms were evaluated by questionnaire. Patients completed the Gastroparesis Cardinal Symptom Index Daily Diary (GCSI-DD) for 14 days.

RESULTS

Twelve healthy participants and 23 prospectively recruited patients completed the study. Nine patients had delayed, and 2 had rapid, GE. In univariate analysis MI explained 42% of GE half-time. In multivariate analysis MI and GE half-time explained 25% of the variance in meal-induced symptoms. While scintigraphic evaluation of gastric motor function with symptom recording explained 80% of the variance in the GCSI-DD, meal-induced symptoms were the only significant predictor. However, among patients with delayed GE, MI, GE half-time, IGD1, and meal-induced symptoms all significantly predicted GCSI-DD.

CONCLUSIONS

Antral motility predicts GE. In exploratory analyses, only meal-induced symptoms predicted daily symptoms among patients with dyspepsia. However, motor function also predicted symptoms in patients with delayed GE.

Small intestinal bacterial overgrowth in diabetic gastroenteropathy

BACKGROUND

Although diabetic gastroenteropathy (DGE) is associated with small intestinal bacterial overgrowth (SIBO), most studies have evaluated SIBO with a hydrogen breath test, which may be affected by altered transit in DGE. The risk factors for the consequences of SIBO in DGE are poorly understood. We aimed to evaluate the prevalence of, risk factors for, and gastrointestinal symptoms associated with SIBO in patients with DGE.

METHODS

In 75 patients with DGE and dyspepsia, we tested for SIBO (≥105 colony forming units /mL of aerobic and/or anaerobic bacteria in a duodenal aspirate) and assessed gastric emptying (GE) of solids, symptoms during a GE study and during an enteral lipid challenge (300 kcal/2 h), and daily symptoms with a Gastroparesis Cardinal Symptom Index diary for 2 weeks. Symptoms and GE were compared in patients with versus without SIBO.

KEY RESULTS

Of 75 patients, 34 (45%) had SIBO, which was not associated with the use of proton pump inhibitors, daily symptoms, GE, or symptoms during a GE study. During enteral lipid challenge, severe nausea (p = 0.006), fullness (p = 0.02) and bloating (p = 0.009) were each associated with SIBO. Twenty patients (59%) with versus 13 (32%) without SIBO had at least one severe symptom during the lipid challenge (p = 0.006).

CONCLUSIONS & INFERENCES

Among patients with DGE 45% had SIBO, which was associated with symptoms during enteral lipid challenge but not with delayed GE, symptoms during a GE study, or daily symptoms. Perhaps bacterial products and even fatty acids are recognized by and activate mast cells that drive the increased lipid sensitivity in SIBO.

The role of diet in diabetes gastroparesis treatment: a systematic review and meta-analysis

Background

Diabetic gastroparesis is a common complication in patient with diabetes. Dietary intervention has been widely used in the treatment of diabetic gastroparesis. The aim of this study is to evaluate the role of diet in the treatment of diabetic gastroparesis.

Methods

This systematic review was conducted a comprehensive search of randomized controlled trials using dietary interventions for the treatment of diabetic gastroparesis up to 9 November 2023. The primary outcomes were gastric emptying time and clinical effect, while fasting blood glucose, 2-hour postprandial blood glucose and glycosylated hemoglobin were secondary outcomes. Data analysis was performed using RevMan 5.4 software, and publication bias test was performed using Stata 15.1 software.

Results

A total of 15 randomized controlled trials involving 1106 participants were included in this review. The results showed that patients with diabetic gastroparesis benefit from dietary interventions (whether personalized dietary care alone or personalized dietary care+routine dietary care). Compared with routine dietary care, personalized dietary care and personalized dietary care+routine dietary care can shorten the gastric emptying time, improve clinical efficacy, and reduce the level of fasting blood glucose, 2-hour postprandial blood glucose and glycosylated hemoglobin.

Conclusions

Limited evidence suggests that dietary intervention can promote gastric emptying and stabilize blood glucose control in patients with diabetic gastroparesis. Dietary intervention has unique potential in the treatment of diabetic gastroparesis, and more high-quality randomized controlled trials are needed to further validate our research results.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023481621.

Prevalence and Risk Factors of Constipation Symptoms among Patients Undergoing Colonoscopy: A Single-Center Cross-Sectional Study

INTRODUCTION

Constipation is one of the most common gastrointestinal symptoms. It may compromise quality of life and social functioning and result in increased healthcare use and costs. We aimed to evaluate the prevalence and risk factors of constipation symptoms, as well as those of refractory constipation symptoms among patients who underwent colonoscopy.

METHODS

Over 4.5 years, patients who underwent colonoscopy and completed questionnaires were analyzed. Patients' symptoms were evaluated using the Gastrointestinal Symptoms Rating Scale.

RESULTS

Among 8,621 eligible patients, the prevalence of constipation symptoms was 33.3%. Multivariate analysis revealed female sex (odds ratio [OR] 1.7, p < 0.001), older age (OR 1.3, p < 0.001), cerebral stroke with paralysis (OR 1.7, p = 0.009), chronic renal failure (OR 2.6, p < 0.001), ischemic heart disease (OR 1.3, p = 0.008), diabetes (OR 1.4, p < 0.001), chronic obstructive pulmonary disease (OR 1.5, p = 0.002), benzodiazepine use (OR 1.7, p < 0.001), antiparkinsonian medications use (OR 1.9, p = 0.030), and opioid use (OR 2.1, p = 0.002) as independent risk factors for constipation symptoms. The number of patients taking any medication for constipation was 1,134 (13.2%); however, refractory symptoms of constipation were still present in 61.4% of these patients. Diabetes (OR 1.5, p = 0.028) and irritable bowel syndrome (OR 3.1, p < 0.001) were identified as predictors for refractory constipation symptoms.

CONCLUSIONS

Constipation occurred in one-third of patients, and more than half of patients still exhibited refractory symptoms of constipation despite taking laxatives. Multiple medications and concurrent diseases seem to be associated with constipation symptoms.

A Randomized, Controlled Trial of Efficacy and Safety of Cannabidiol in Idiopathic and Diabetic Gastroparesis

BACKGROUND & AIMS

Cannabis (delta-9-tetrahydrocannabinol), a nonselective cannabinoid-receptor agonist, relieves nausea and pain. Cannabidiol (CBD), a cannabinoid receptor 2 inverse agonist with central effects, also reduces gut sensation and inflammation. We compared the effects of 4 weeks of treatment with pharmaceutical CBD vs placebo in patients with idiopathic or diabetic (diabetes mellitus) gastroparesis.

METHODS

We performed a randomized, double-blinded, placebo-controlled study of CBD twice daily (Epidiolex escalated to 20 mg/kg/d; Jazz Pharmaceuticals, Dublin, Ireland) in patients with nonsurgical gastroparesis with delayed gastric emptying of solids (GES). Symptoms were assessed by the Gastroparesis Cardinal Symptom Index Daily Diary. After 4 weeks of treatment, we measured GES, gastric volumes, and Ensure (Abbott Laboratories, Abbott Park, IL) satiation test (1 kcal/mL, 30 mL/min) to assess volume to comfortable fullness and maximum tolerance. Patients underwent specific FAAH and CNR1 genotyping. Statistical analysis compared 2 treatments using analysis of variance including baseline measurements and body mass index as covariates.

RESULTS

Among 44 patients (32 idiopathic, 6 diabetes mellitus type 1, and 6 diabetes mellitus type 2), 5 patients did not tolerate full-dose escalation; 3 withdrew before completing 4 weeks of treatment (2 placebo, 1 CBD); 95% completed 4 weeks of treatment and diaries. Compared with placebo, CBD reduced the total Gastroparesis Cardinal Symptom Index score (P = .008), inability to finish a normal-sized meal (P = .029), number of vomiting episodes/24 hours (P = .006), and overall symptom severity (P = .034). Patients treated with CBD had a higher volume to comfortable fullness and maximum tolerance and slower GES. FAAH rs34420 genotype significantly impacted nutrient drink ingestion. The most common adverse events reported were diarrhea (14 patients), fatigue (8 patients), headache (8 patients), and nausea (7 patients).

CONCLUSIONS

CBD provides symptom relief in patients with gastroparesis and improves the tolerance of liquid nutrient intake, despite slowing of GES.

CLINICALTRIALS

gov NCT #03941288.

microRNA-181a contributes to gastric hypersensitivity in rats with diabetes by regulating TLR4 expression

Aim: The aim of this study is to investigate the mechanism and interaction of microRNA-181a (miR-181a), toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) in gastric hypersensitivity in diabetic rats. Methods: Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ; 65 mg/kg) in female SD rats. Gastric balloon distension technique was used to measure diabetic gastric hypersensitivity. Gastric-specific (T7-T10) dorsal root ganglion (DRG) neurons were acutely dissociated to measure excitability with patch-clamp techniques. Western blotting was employed to measure the expressions of TLR4, TRAF6 and NF-κB subunit p65 in T7-T10 DRGs. The expressions of microRNAs in T7-T10 DRGs were measured with quantitative real-time PCR and fluorescence in situ hybridization. Dual-luciferase reporter gene assay was used to detect the targeting regulation of microRNAs on TLR4. Results: (1) Diabetic rats were more sensitive to graded gastric balloon distention at 2 and 4 weeks. (2) The expression of TLR4 was significantly up-regulated in T7-T10 DRGs of diabetic rats. Intrathecal injection of CLI-095 (TLR4-selective inhibitor) attenuated diabetic gastric hypersensitivity, and markedly reversed the hyper-excitability of gastric-specific DRG neurons. (3) The expressions of miR-181a and miR-7a were significantly decreased in diabetic rats. MiR-181a could directly regulate the expression of TLR4, while miR-7a couldn't. (4) Intrathecal injection of miR-181a agomir down-regulated the expression of TLR4, reduced the hyper-excitability of gastric-specific neurons, and alleviated gastric hypersensitivity. (5) p65 and TLR4 were co-expressed in Dil-labeled DRG neurons. (6) Inhibition of p65 attenuated diabetic gastric hypersensitivity and hyper-excitability of gastric-specific DRG neurons. (7) The expression of TRAF6 was significantly up-regulated in diabetic rats. CLI-095 treatment also reduced the expression of TRAF6 and p65. Conclusion: The reduction of microRNA-181a in T7-T10 DRGs might up-regulate TLR4 expression. TLR4 activated NF-κB through MyD88-dependent signaling pathway, increased excitability of gastric-specific DRG neurons, and contributed to diabetic gastric hypersensitivity.

Novel insights into the pathogenic impact of diabetes on the gastrointestinal tract

Type 2 and type 1 diabetes are common endocrine disorders with a progressively increasing incidence worldwide. These chronic, systemic diseases have multiorgan implications, and the whole gastrointestinal (GI) tract represents a frequent target in terms of symptom appearance and interdependent pathophysiological mechanisms. Metabolic alterations linked with diabetic complications, neuropathy and disrupted hormone homeostasis can lead to upper and/or lower GI symptoms in up to 75% of diabetic patients, with multifactorial involvement of the oesophagus, stomach, upper and lower intestine, and of the gallbladder. On the other hand, altered gastrointestinal motility and/or secretions are able to affect glucose and lipid homeostasis in the short and long term. Finally, diabetes has been linked with increased cancer risk at different levels of the GI tract. The presence of GI symptoms and a comprehensive assessment of GI function should be carefully considered in the management of diabetic patients to avoid further complications and to ameliorate the quality of life. Additionally, the presence of gastrointestinal dysfunction should be adequately managed to improve metabolic homeostasis, the efficacy of antidiabetic treatments and secondary prevention strategies.

Gastric function in diabetic gastroparesis assessed by ultrasound and scintigraphy

BACKGROUND

Gastroparesis is a severe diabetes complication characterized by delayed gastric emptying. We examined patients with symptoms of diabetic gastroparesis using gastric emptying scintigraphy and ultrasound drink test. The primary aim was to investigate how ultrasound could provide information about gastric motility features in diabetic gastroparesis.

MATERIAL AND METHODS

We prospectively included 58 patients with diabetes (48 type 1) with symptoms of gastroparesis and 30 healthy controls. Patients were examined with ultrasound of the stomach in a seated position after drinking 500 ml low-caloric meat soup, at the same time recording dyspeptic symptoms. The following day, they were examined with gastric emptying scintigraphy, defining gastroparesis as >10% retention after 4 h.

KEY RESULTS

We found motility disturbances in the proximal stomach measured by ultrasound in patients with diabetic gastroparesis. A linear mixed effects model including repeated ultrasound measurements revealed a slower decrease of the proximal stomach size in gastroparesis compared to healthy controls (p < 0.01), and the proximal diameter at 20 min was correlated to scintigraphy at 4 h (r = 0.510, p = 0.001). The antrum in patients with diabetic gastroparesis was twice as large compared to healthy controls (p = 0.009), and fasting antral size was correlated to gastric emptying scintigraphy (r = 0.329, p = 0.013). Both diabetes patients with and without gastroparesis had impaired accommodation (p = 0.011).

CONCLUSIONS AND INFERENCES

On ultrasound, we found delayed reduction of proximal stomach size and impaired accommodation after a liquid meal in patients with gastroparesis, emphasizing the role of the proximal stomach. Furthermore, we found antral distention in gastroparesis patients.

Relationship Between Gastric Emptying Rate and Simultaneously Assessed Symptoms in Functional Dyspepsia

METHODS

During a GE test (breath test with ¹³C-octanoic acid labelled 250 kcal solid meal), the severity of 6 symptoms (postprandial fullness, epigastric pain and burning, bloating, nausea and belching) was assessed, every 15 min, before meal-intake and 4h postprandially. The sum of individual symptom scores generated the meal-related symptoms score; the sum of all symptoms generated overall meal-related symptom severity (OSS). Data were compared in patients with normal and delayed GE (cut-off T_1/2≥ 109 min). Data are shown as mean±SEM.

RESULTS

504 patients were included, of which 382 patients (67% female, age 43.8±0.8 years, BMI 23.3±0.2 kg/m²) had normal and 122 patients (77% female, age 42.7±1.5 years, BMI 23.2±0.6 kg/m²) had delayed GE. OSS tended to be higher in patients with delayed GE (81.8±3.4 vs. 99.5±7.1, p=.05). Only nausea was significantly higher in patients with delayed GE (11±0.8 vs. 16±1.6, p=.01). No correlations were observed between GE rate and any of the symptoms (OSS: r=0.06, p=.2; nausea: r=0.06, p=.1). The symptom severity time course showed a significant difference only for nausea, with increased severity ratings 90 min after the meal (p<.01) in delayed GE compared to normal GE patients.

CONCLUSION

The severity of symptoms in functional dyspepsia and idiopathic gastroparesis, even when assessed during the GE test meal, is not correlated to gastric emptying rate. (Ethics committee University Hospital of Leuven study number S55426).

Gastrointestinal transit and contractility in diabetic constipation: A wireless motility capsule study on diabetes patients and healthy controls

BACKGROUND

Diabetic constipation is traditionally attributed to slow colonic transit, despite limited evidence. More than half of patients find treatment unsatisfactory. To improve treatment, there is a need for better diagnostic understanding of the condition.

OBJECTIVE

In this wireless motility capsule study, we aimed to investigate gastrointestinal transit and contractility in diabetes patients with and without constipation, and in healthy controls.

METHODS

We prospectively included type 1 or type 2 diabetes patients with gastrointestinal symptoms. Based on the Gastrointestinal Symptom Rating Scale we distinguished into two groups: with constipation and without constipation. Non-diabetic controls were asymptomatic. All were examined with wireless motility capsule, determining transit times and contractility parameters.

RESULTS

57 patients (42 women, 46 with type 1 diabetes) and 26 healthy controls (14 women) were included. We found no difference in transit times between diabetes patients with and without constipation. Compared to healthy controls (35:55, h:min), whole-gut transit was slower in both diabetes patients with constipation (66:15, p = 0.03) and without constipation (71:16, p < 0.001). Small bowel motility index correlated rs  = -0.32 (p = 0.01) with constipation symptoms.

CONCLUSIONS

Diabetes patients with constipation had similar transit times as those without constipation. Both groups had slower whole-gut transit than healthy controls. Constipation was associated with reduced small bowel, but not colonic contractility. Our results imply that other mechanisms than slow colonic transit may be more important in the pathogenesis of diabetic constipation.

Diabetic diarrhoea: A study on gastrointestinal motility, pH levels and autonomic function

BACKGROUND

Chronic diarrhoea is a common, but poorly investigated diabetes complication. Autonomic neuropathy is a leading pathophysiological theory founded on old, small studies. Studies of gastrointestinal motility and pH levels are lacking.

OBJECTIVES

Using new diagnostic methods, we aimed to find out if diabetic diarrhoea was associated with alterations in gastrointestinal motility, pH levels and autonomic function.

METHODS

Fifty-seven patients (42 women, 46 with type 1 diabetes) were prospectively included. Symptoms were evaluated with the gastrointestinal symptom rating scale, defining ≥4 points as cases with diarrhoea. Patients scoring <4 were used as controls. We used the wireless motility capsule to measure gastrointestinal transit times, pH levels and contractility parameters. Autonomic function was assessed by measuring heart rate variability, baroreflex sensitivity and orthostatic hypotension.

RESULTS

Seventeen patients (30%) had diarrhoea. Compared with controls, cases had slower gastric emptying (21:46 vs. 4:14, h:min, p = 0.03) and faster colonic transit (18:37 vs. 54:25, p < 0.001). Cases had increased intraluminal pH in the antrum (2.4 vs. 1.2, p = 0.009), caecum (7.3 vs. 6.4, p = 0.008) and entire colon (7.1 vs. 6.7, p = 0.05). They also had a decreased pH difference across the pylorus (3.3 vs. 4.9, p = 0.004) and ileocaecal junction (0.6 vs 1.0, p = 0.009). The groups did not differ in autonomic function, but diastolic blood pressure drop correlated r_s = -0.34 (p = 0.04) with colonic transit time.

CONCLUSIONS

Patients with diabetic diarrhoea had altered gastrointestinal transit and intraluminal pH levels, but minimal changes in autonomic function. Our results suggest that tests of gastrointestinal function are clinically useful in diabetic diarrhoea.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis

BACKGROUND

Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis.

METHODS

A Delphi consensus was undertaken by 40 experts from 19 European countries who conducted a literature summary and voting process on 89 statements. Quality of evidence was evaluated using grading of recommendations assessment, development, and evaluation criteria. Consensus (defined as ≥80% agreement) was reached for 25 statements.

RESULTS

The European consensus defined gastroparesis as the presence of symptoms associated with delayed GE in the absence of mechanical obstruction. Nausea and vomiting were identified as cardinal symptoms, with often coexisting postprandial distress syndrome symptoms of dyspepsia. The true epidemiology of gastroparesis is not known in detail, but diabetes, gastric surgery, certain neurological and connective tissue diseases, and the use of certain drugs recognized as risk factors. While the panel agreed that severely impaired gastric motor function is present in these patients, there was no consensus on underlying pathophysiology. The panel agreed that an upper endoscopy and a GE test are required for diagnosis. Only dietary therapy, dopamine-2 antagonists and 5-HT4 receptor agonists were considered appropriate therapies, in addition to nutritional support in case of severe weight loss. No consensus was reached on the use of proton pump inhibitors, other classes of antiemetics or prokinetics, neuromodulators, complimentary, psychological, or more invasive therapies. Finally, there was consensus that gastroparesis adversely impacts on quality of life and healthcare costs and that the long-term prognosis of gastroparesis depends on the cause.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on definition, symptom characteristics, pathophysiology, diagnosis, and management of gastroparesis.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis

BACKGROUND

Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis.

METHODS

A Delphi consensus was undertaken by 40 experts from 19 European countries who conducted a literature summary and voting process on 89 statements. Quality of evidence was evaluated using grading of recommendations assessment, development, and evaluation criteria. Consensus (defined as ≥80% agreement) was reached for 25 statements.

RESULTS

The European consensus defined gastroparesis as the presence of symptoms associated with delayed GE in the absence of mechanical obstruction. Nausea and vomiting were identified as cardinal symptoms, with often coexisting postprandial distress syndrome symptoms of dyspepsia. The true epidemiology of gastroparesis is not known in detail, but diabetes, gastric surgery, certain neurological and connective tissue diseases, and the use of certain drugs recognized as risk factors. While the panel agreed that severely impaired gastric motor function is present in these patients, there was no consensus on underlying pathophysiology. The panel agreed that an upper endoscopy and a GE test are required for diagnosis. Only dietary therapy, dopamine-2 antagonists and 5-HT4 receptor agonists were considered appropriate therapies, in addition to nutritional support in case of severe weight loss. No consensus was reached on the use of proton pump inhibitors, other classes of antiemetics or prokinetics, neuromodulators, complimentary, psychological, or more invasive therapies. Finally, there was consensus that gastroparesis adversely impacts on quality of life and healthcare costs and that the long-term prognosis of gastroparesis depends on the cause.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on definition, symptom characteristics, pathophysiology, diagnosis, and management of gastroparesis.

Efficacy and Safety of Ghrelin Agonists in Patients with Diabetic Gastroparesis: A Systematic Review and Meta-Analysis

Background/Aims

Ghrelin agonists are emerging prokinetic agents for treating gastroparesis. Although recent clinical trials have demonstrated their efficacy in patients with diabetic gastroparesis (DG), the impact of such agents on symptoms and gastric dysmotility remains unclear. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of ghrelin agonists in patients with DG.

Methods

A search of common electronic databases (MEDLINE, Embase, and Cochrane Central Register of Controlled Trials) was preformed, using keyword combinations that referenced ghrelin and DG and retrieving all eligible randomized controlled trials (RCTs) of ghrelin agonists versus placebo in patients with DG. The primary outcome measure was the change in patient-reported overall gastroparesis symptom scores. Secondary outcomes included the change in gastric emptying time, specific symptoms related to gastroparesis, and adverse events. A random-effects model was applied to all study outcomes. Heterogeneity among studies was determined by the chi-square test and I² statistics.

Results

We selected six RCTs of patients with DG (n=557) for meta-analysis. Ghrelin agonist administration (vs placebo) significantly improved overall gastroparesis symptoms (standardized mean difference, –0.34; 95% confidence interval, –0.56 to –0.13) and significantly improved symptoms related to gastroparesis, including nausea, vomiting, early satiety, and abdominal pain. Adverse events recorded for ghrelin agonists and placebo did not differ significantly. There was no significant heterogeneity among eligible studies.

Conclusions

Compared with placebo, ghrelin agonists are effective and well-tolerated for the treatment of DG.

Enhancing Scintigraphy for Evaluation of Gastric, Small Bowel, and Colonic Motility

This article reviews the latest enhancements in standards and technology for performing gastric emptying and associated small bowel and colon transit scintigraphic studies. It discusses how developments in appropriate use criteria, American Medical Association Current Procedural Terminology coding, and advanced commercial software permit clinicians to obtain more comprehensive physiologic studies of gastric, small bowel, and colon gastrointestinal motility disorders. It shows how gastrointestinal scintigraphy has expanded to permit assessments of global and regional (fundic and antral) gastric motility and how it permits a single study (whole-gut transit scintigraphy), including measurement of solid and liquid gastric emptying and small bowel and colon transit.

Pathophysiology, Aetiology and Treatment of Gastroparesis

Gastroparesis is characterized by delayed gastric emptying, with symptoms such as nausea, vomiting and abdominal pain, in the absence of mechanical obstruction. In most cases, it is idiopathic although diabetes mellitus is another leading cause. The physiology of gastric emptying is a complex process which is influenced by various inputs including the central nervous system, enteric nervous system and gut hormones. Developments in our understanding of gastroparesis have now demonstrated dysfunction in these systems, thus disrupting normal gastric emptying. Once mechanical obstruction is excluded, gastric scintigraphy remains the gold standard for diagnosis although wireless motility capsule and breath testing are alternative methods for diagnosis. Treatment for gastroparesis is challenging, and widely available therapies are often limited either by their poor evidence for efficacy or concerns over their long-term safety profile. Novel prokinetic agents have shown initial promise in clinical trials, and new endoscopic techniques such as gastric per-oral endoscopic myotomy are emerging. These new treatment modalities may provide an option in refractory gastroparesis with the adage of reduced morbidity compared to surgical treatments.

Satiety testing in diabetic gastroparesis: Effects of insulin pump therapy with continuous glucose monitoring on upper gastrointestinal symptoms and gastric myoelectrical activity

BACKGROUND

Symptoms induced by caloric or non-caloric satiety test meals and gastric myoelectrical activity (GMA) have not been studied in patients with diabetic gastroparesis (DGP) before and after intense glucose management.

AIMS

We determined the effects of continuous subcutaneous insulin infusion (CSII) with continuous glucose monitoring (CGM) on GI symptoms, volume consumed, and GMA induced by the caloric meal satiety test (CMST) and water load satiety test (WLST) in DGP.

METHODS

Forty-five patients with DGP underwent CMST and WLST at baseline and 24 weeks after CSII with CGM. Subjects ingested the test meals until they were completely full. Visual analog scales were used to quantify pre- and postmeal symptoms, and GMA was recorded with cutaneous electrodes and analyzed visually and by computer. KEY RESULTS: At baseline and 24-week visits, nausea, bloating, abdominal discomfort, and fullness were immediately increased after CMST and WLST (Ps < 0.01). The meal volumes ingested were significantly less than normal controls at both visits in almost one-third of the subjects. After the CMST, the percentage 3 cycle per minute GMA increased and bradygastria decreased compared with WLST (Ps < 0.05). After treatment for 24 weeks meal volumes ingested, postmeal symptoms and GMA were no different than baseline. CONCLUSIONS AND INFERENCES: (a) Satiety test meals elicited symptoms of nausea, bloating, and abdominal discomfort; (b) CMST stimulated more symptoms and changes in GMA than WLST; and (c) CSII with CGM for 24 weeks did not improve symptoms, volumes ingested, or GMA elicited by the two satiety test meals in these patients with diabetic GP. Satiety tests in diabetic gastropresis are useful to study acute postprandial symptoms and GMA, but these measures were not improved by intensive insulin therapy.

Duodenal nutrient exposure contributes to enhancing gastric accommodation

BACKGROUND

The gastric accommodation reflex consists of a relaxation which creates a reservoir for the ingested food before emptying to the duodenum occurs. The mechanisms that control gastric accommodation are not fully understood. This study aims to use intragastric pressure (IGP) measurement and pyloric balloon obstruction to determine the contribution of duodenal nutrient exposure to gastric accommodation and meal-induced satiation.

METHODS

Two conditions were tested in 11 healthy subjects (28.3 ± 3.2 years; 23.6 ± 0.7 kg/m² ; four females). IGP was measured during an intragastric nutrient drink (ND) infusion at a constant rate (60 mL/min) in the presence of a deflated (control) or inflated (pyloric obstruction) balloon placed into the pylorus. During the study, subjects filled out Likert scales for satiation scores and visual analogue scale for 9 epigastric symptoms (hunger, expected amount to eat, satiation, bloating, fullness, nausea, belching, gastric cramps, and pain) before and during ND infusion until maximal satiation.

KEY RESULTS

During pyloric obstruction, the IGP drop and the area above the IGP curve (AAC) were significantly smaller compared with the control condition (6.7 ± 1.0 mm Hg vs3.6 ± 0.8 mm Hg, P = .03 and 69.7 ± 13.5 mm Hg × min vs 20.1 ± 9.0 mm Hg × min, P = .001, respectively). Pyloric obstruction decreased nutrient tolerance compared with the control condition (787.9 ± 73.1 mL vs 970.9 ± 79.2 mL, respectively, P < .05). Pyloric obstruction increased symptoms of bloating (1.3 ± 0.4 vs 2.6 ± 0.6; P = .04), fullness (2.3 ± 0.5 vs 3.6 ± 0.3; P = .03), and nausea (0.4 ± 0.2 vs 1.3 ± 0.4; P = .04) compared to control.

CONCLUSION & INFERENCES

Duodenal nutrient exposure contributes to enhancing gastric accommodation. Preventing the passage of nutrients from the stomach to the duodenum inhibits gastric accommodation and increases meal-induced satiation, bloating, nausea, and fullness.

Association Between Symptoms, Quality of Life, and Gastric Emptying in Dyspeptic Patients

Background/Aims

Association between symptoms, quality of life and gastric emptying in dyspepsia is inconsistent in the literature. The aim of our study is to investigate if gastric emptying is associated with specific symptoms and quality of life in dyspeptic patients.

Methods

We reviewed retrospectively gastric emptying measured by ¹³C-labelled octanoate breath testing for more than 6 hours in 198 consecutive patients with dyspepsia complaints. Gastrointestinal symptoms were assessed using a 5-points Likert scale and by a symptomatic composite score, whereas quality of life was measured by the GIQLI.

Results

In our cohort, 90 patients (45%) had a delayed gastric emptying (half emptying time above 166 minutes when assessed over 6–8 hours). There was no difference in symptoms or quality of life between patients with or without delayed gastric emptying. However, patients with severely delayed gastric emptying (half emptying time above 200 minutes) had increased postprandial fullness (P = 0.012), abdominal pain (P = 0.026), bloating (P = 0.044), early satiety (P = 0.018), symptomatic composite score (P = 0.005), and a lower quality of life (P = 0.018). This association was no longer observed if the calculation of gastric emptying was limited to the first 4-hour samples.

Conclusions

There is no association between symptoms, quality of life and gastric emptying in an overall dyspeptic population. However, there is an association between symptoms, quality of life of delayed gastric emptying in the subgroup of patients with severely delayed gastric emptying. An 8-hour measurement of gastric emptying should be recommended.

Diabetic Gastroparesis

This review covers the epidemiology, pathophysiology, clinical features, diagnosis, and management of diabetic gastroparesis, and more broadly diabetic gastroenteropathy, which encompasses all the gastrointestinal manifestations of diabetes mellitus. Up to 50% of patients with type 1 and type 2 DM and suboptimal glycemic control have delayed gastric emptying (GE), which can be documented with scintigraphy, 13C breath tests, or a wireless motility capsule; the remainder have normal or rapid GE. Many patients with delayed GE are asymptomatic; others have dyspepsia (i.e., mild to moderate indigestion, with or without a mild delay in GE) or gastroparesis, which is a syndrome characterized by moderate to severe upper gastrointestinal symptoms and delayed GE that suggest, but are not accompanied by, gastric outlet obstruction. Gastroparesis can markedly impair quality of life, and up to 50% of patients have significant anxiety and/or depression. Often the distinction between dyspepsia and gastroparesis is based on clinical judgement rather than established criteria. Hyperglycemia, autonomic neuropathy, and enteric neuromuscular inflammation and injury are implicated in the pathogenesis of delayed GE. Alternatively, there are limited data to suggest that delayed GE may affect glycemic control. The management of diabetic gastroparesis is guided by the severity of symptoms, the magnitude of delayed GE, and the nutritional status. Initial options include dietary modifications, supplemental oral nutrition, and antiemetic and prokinetic medications. Patients with more severe symptoms may require a venting gastrostomy or jejunostomy and/or gastric electrical stimulation. Promising newer therapeutic approaches include ghrelin receptor agonists and selective 5-hydroxytryptamine receptor agonists.

Abdominal Pain in Patients with Gastroparesis: Associations with Gastroparesis Symptoms, Etiology of Gastroparesis, Gastric Emptying, Somatization, and Quality of Life

Abdominal pain can be an important symptom in some patients with gastroparesis (Gp).

AIMS

(1) To describe characteristics of abdominal pain in Gp; (2) describe Gp patients reporting abdominal pain.

METHODS

Patients with idiopathic gastroparesis (IG) and diabetic gastroparesis (DG) were studied with gastric emptying scintigraphy, water load test, wireless motility capsule, and questionnaires assessing symptoms [Patient Assessment of Upper GI Symptoms (PAGI-SYM) including Gastroparesis Cardinal Symptom Index (GCSI)], quality of life (PAGI-QOL, SF-36), psychological state [Beck Depression Inventory (BDI), State-Trait Anxiety Index (STAI), PHQ-15 somatization scale].

RESULTS

In total, 346 Gp patients included 212 IG and 134 DG. Ninety percentage of Gp patients reported abdominal pain (89% DG and 91% IG). Pain was primarily in upper or central midline abdomen, described as cramping or sickening. Upper abdominal pain was severe or very severe on PAGI-SYM by 116/346 (34%) patients, more often by females than by males, but similarly in IG and DG. Increased upper abdominal pain severity was associated with increased severity of the nine GCSI symptoms, depression on BDI, anxiety on STAI, somatization on PHQ-15, the use of opiate medications, decreased SF-36 physical component, and PAGI-QOL, but not related to severity of delayed gastric emptying or water load ingestion. Using logistic regression, severe/very severe upper abdominal pain associated with increased GCSI scores, opiate medication use, and PHQ-15 somatic symptom scores.

CONCLUSIONS

Abdominal pain is common in patients with Gp, both IG and DG. Severe/very severe upper abdominal pain occurred in 34% of Gp patients and associated with other Gp symptoms, somatization, and opiate medication use. ClinicalTrials.gov Identifier: NCT01696747.

GI Dysfunctions in Diabetic Gastroenteropathy, Their Relationships With Symptoms, and Effects of a GLP-1 Antagonist

CONTEXT

Delayed gastric emptying (GE) is common but often asymptomatic in diabetes. The relationship between symptoms, glycemia, and neurohormonal functions, including glucagonlike peptide 1 (GLP-1), are unclear.

OBJECTIVES

To assess whether GE disturbances, symptoms during a GE study, and symptoms during enteral lipid infusion explain daily symptoms and whether GLP-1 mediates symptoms during enteral lipid infusion.

DESIGN

In this randomized controlled trial, GE, enteral lipid infusion, gastrointestinal (GI) symptoms during these assessments, autonomic functions, glycosylated hemoglobin (HbA1c), and daily GI symptoms (2-week Gastroparesis Cardinal Symptom Index diary) were evaluated. During enteral lipid infusion, participants received the GLP-1 antagonist exendin 9-39 or placebo.

SETTING

Single tertiary referral center.

PARTICIPANTS

24 healthy controls and 40 patients with diabetic gastroenteropathy.

MAIN OUTCOME MEASURES

GE, symptoms during enteral lipid infusion, and the effect of exendin 9-39 on the latter.

RESULTS

In patients, GE was normal (55%), delayed (33%), or rapid (12%). During lipid infusion, GI symptoms tended to be greater (P = 0.06) in patients with diabetes mellitus (DM) than controls; exendin 9-39 did not affect symptoms. The HbA1c was inversely correlated with the mean symptom score during the GE study (r = -0.46, P = 0.003) and lipid infusion (r = -0.47, P < 0.01). GE and symptoms during GE study accounted for 40% and 32%, respectively, of the variance in daily symptom severity and quality of life.

CONCLUSIONS

In DM gastroenteropathy, GE and symptoms during a GE study explain daily symptoms. Symptoms during enteral lipid infusion were borderline increased but not reduced by a GLP-1 antagonist.

Towards a Fuller Assessment of Gastric Motility in Patients With Upper GI Dyspepsia: Time to Accommodate!

There is increasing recognition of the importance of assessing patients with unexplained upper gastrointestinal symptoms for impaired gastric accommodation. New therapeutic approaches to treat impaired accommodation are being developed. This increasing interest in diagnosing and treating impaired gastric accommodation emphasizes the need to have a clinically available method to measure the gastric accommodation response. In this editorial, gastric accommodation is discussed along with the currently available methods for its assessment. We summarize our thoughts on what are the next steps needed to make a readily accessible method for assessing gastric accommodation more widely available.

Prediabetes and gastrointestinal (GI) symptoms; a cross-sectional study

AIMS

Prediabetes associate with known micro and macrovascular complications of diabetes. Also gastrointestinal symptoms are present in diabetics higher than general population. The aim of this study was evaluation of gastrointestinal symptoms in subjects with prediabetes.

METHODS

This analytical cross-sectional study was conducted on 130 persons 30-65 years old, 65 pre-diabetic patients and 65 persons without glucose disorders from 2014 to 2015 in YAZD province. FBS and HbA1c used for diagnosis prediabetes. Demographic and medical history were collected. A questionnaire according to Rome III Criteria was used to collect digestive information (diarrhea, abdominal pain, constipation, abdominal bloating, heartburn, increased gas passing, nausea, intermittent diarrhea and constipation in the last 6 months ago). Frequency of GI symptoms in subjects with and without glucose disorders were compared. Data were analyzed by SPSS software Version 20. Data were reported as mean ± standard deviation or frequency and T-test, Chi Square and Spearman correlation coefficient tests were used. P-value less than 0.05 were considered statistically significant.

RESULTS

Higher frequency of bloating, early satiety, nausea, heartburn, gas passing and constipation are seen in the pre-diabetes group than in the control group; (p-value 0.0001, 0.0001, 0.0001, 0.0001, 0.001 and 0.0001 respectively). 96.9% in prediabetics had at least one gastrointestinal symptom, while in the normal groups 50% had at least one GI symptom (p-value: 0.0001).

CONCLUSIONS

Gastrointestinal symptoms were seen in prediabetics higher than healthy persons. So, prediabetes can not be considered an entirely benign and asymptomatic condition. Lifestyle interventions maybe necessary at this state.

Characterization of Upper Gastrointestinal Symptoms, Gastric Motor Functions, and Associations in Patients with Diabetes at a Referral Center

OBJECTIVES

Our aim was to characterize upper gastrointestinal (UGI) symptoms and associations in individuals with diabetes mellitus (DM) who had undergone evaluation of gastric emptying (GE) and accommodation (GA) at a referral center.

METHODS

From the Mayo Clinic Rochester electronic medical records of adults with diabetes types 1 and 2 (DM1 and DM2) evaluated between January 1997 and December 2015, we extracted demographics, UGI symptoms, current medications, treatments for diabetes, GE solids by scintigraphy, GA by single photon emission computed tomography (SPECT), and diabetes complications. We compared subgroups with delayed (GE at 2 h <25% or GE at 4 h <75%), rapid (GE at 1 h > 35%), and normal GE, as well as reduced (<428 mL) and normal GA.

RESULTS

We reviewed 108 patients (60.2% females, median age 49.0 years). Overall, 71.3% had DM2; one-third of these were insulin dependent and had fairly well-controlled diabetes (median HbA1c 6.7% (IQR 6.2; 7.9)). Manifestations of diabetic triopathy (peripheral neuropathy, nephropathy, and retinopathy) were uncommon at presentation with UGI symptoms. Nausea was the most common symptom (80.6%). There were single or combined GE (total 56%: rapid in 37%, slow in 19%) and GA (total 39%) abnormalities; there was normal GA and GE in 28%; 40.3% of the DM2 patients had accelerated GE at 1 h. GE at 1 h is associated with nausea/vomiting, and fasting gastric volume is associated with bloating.

CONCLUSIONS

Among referred diabetic patients with UGI symptoms, GE and GA testing identifies potential targets for individualizing treatment and avoidance of empirical trials for the 28% with no disturbance of GE and GA.

Gastric Peroral Endoscopic Myotomy (G-POEM) as a Treatment for Refractory Gastroparesis: Long-Term Outcomes

BACKGROUND AND AIMS

Gastric peroral endoscopic myotomy (G-POEM) has been regarded as a novel and minimally invasive therapy for refractory gastroparesis. This study reports the long-term outcomes and possible predictive factors for successful outcomes after G-POEM in an Asian population.

METHODS

This is a retrospective single-centre study of 16 patients who underwent G-POEM for refractory gastroparesis from August 2016 to October 2017. This study included 11 males and 5 females; in addition, 13 patients had postsurgical gastroparesis, and 3 patients had diabetes. The patients included had severe and refractory gastroparesis, as indicated by a Gastroparesis Cardinal Symptom Index (GCSI) score ≥20, and evidence of a delay on gastric emptying scintigraphy (GES). The primary outcome parameter was an assessment of the long-term clinical efficacy of the procedure. The secondary outcome parameter was the detection of possible predictive factors for success and the determination of cut-off values for such predictors.

RESULTS

Technical success was achieved in 100% of the patients, with a mean procedure time of 45.25±12.96 min. The long-term clinical response was assessed in all patients during a median follow-up of 14.5 months. Clinical success was achieved in 13 (81.25%) patients. There was a significant reduction in the GCSI scores and GES values after the procedure compared to the baseline values, with P values of <0.0001 and 0.012, respectively. Univariate regression analysis showed that the GCSI and GES had significant associations with the future clinical outcomes of the patients, but this finding was not confirmed in multivariate analysis. A GCSI cut-off score of ≤30 had a high sensitivity and a negative predictive value (NPV) of 100% for predicting a successful procedure. GES (half emptying time ≤221.6 min and 2-hour retention ≤78.6%) had a high specificity and a positive predictive value (PPV) of 100%.

CONCLUSIONS

G-POEM is a safe and effective treatment option with a long-term efficacy of 81.6%. GCSI and GES could serve as good predictive measures.

New developments in the treatment of gastroparesis and functional dyspepsia

Functional dyspepsia (FD) and gastroparesis are frequent causes of upper gastrointestinal symptoms such as postprandial fullness, early satiation, epigastric pain or burning, upper abdominal bloating, bothersome belching, nausea and vomiting. The underlying pathophysiological mechanisms are heterogeneous and involved mechanisms such as abnormal gastric motility (accommodation, emptying), visceral hypersensitivity, low grade mucosal inflammation and cellular changes in enteric nerves, muscle or interstitial cells of Cajal. Patient-reported outcomes for evaluating treatment efficacy in these conditions were recently developed and validated. Prokinetic agents, which enhance gastric motility, are used for treating both gastroparesis and FD. In FD, besides acid suppressive therapy and Helicobacter pylori eradication, neuromodulators and drugs that enhance gastric accommodation can be applied. In gastroparesis, anti-emetics may also provide symptom relief. Novel approaches under evaluation in these conditions are the fundus relaxing agents acotiamide and buspirone and the antidepressant mirtazapine in FD. For gastroparesis, recently studied agents include the prokinetic ghrelin agonist relamorelin, the prokinetic serotonergic agents velusetrag and prucalopride, the anti-emetic aprepitant and per-endoscopic pyloric myotomy procedures.

Implication of neurohormonal-coupled mechanisms of gastric emptying and pancreatic secretory function in diabetic gastroparesis

Recently, diabetic gastroparesis (DGP) has received much attention as its prevalence is increasing in a dramatic fashion and management of patients with DGP represents a challenge in the clinical practice due to the limited therapeutic options. DGP highlights an interrelationship between the gastric emptying and pancreatic secretory function that regulate a wide range of digestive and metabolic functions, respectively. It well documented that both gastric emptying and pancreatic secretion are under delicate control by multiple neurohormonal mechanisms including extrinsic parasympathetic pathways and gastrointestinal (GI) hormones. Interestingly, the latter released in response to various determinants that related to the rate and quality of gastric emptying. Others and we have provided strong evidence that the central autonomic nuclei send a dual output (excitatory and inhibitory) to the stomach and the pancreas in response to a variety of hormonal signals from the abdominal viscera. Most of these hormones released upon gastric emptying to provide feedback, and control this process and simultaneously regulate pancreatic secretion and postprandial glycemia. These findings emphasize an important link between gastric emptying and pancreatic secretion and its role in maintaining homeostatic processes within the GI tract. The present review deals with the neurohormonal-coupled mechanisms of gastric emptying and pancreatic secretory function that implicated in DGP and this provides new insights in our understanding of the pathophysiology of DGP. This also enhances the process of identifying potential therapeutic targets to treat DGP and limit the complications of current management practices.

Glass half empty? Lessons learned about gastroparesis

Gastroparesis is defined as a combination of chronic dyspeptic symptoms and delayed emptying of a solid test meal. It remains a difficult-to-treat disorder with a significant impact on quality of life. Although gastroparesis is defined by delayed emptying, several important studies did not find a correlation between this biomarker and symptom severity or treatment success. Thus, some of the more recent trials explored strategies that ranged from antiemetics to antidepressants. Although dietary management showed benefit, most of the other interventions were barely superior to placebo or were not superior at all. Placebo responses were often quite high and this complicates the assessment of active agents. While it complicates the design and interpretation of clinical trials, high response rates for active and sham interventions indicate that we can achieve symptom relief in many patients and thus give them some reassurance. If indeed most therapies are only marginally better than placebo, the differences in adverse effects should be weighed more strongly, a point that is especially important in view of the controversy surrounding metoclopramide. Mechanistic studies introduced the network of macrophages as another potentially important player in the development of gastroparesis. Results are too preliminary and are largely based on preclinical data but show up- and downregulation of cellular elements controlling gastric function. Thus, future developments may teach us how they interfere with some of these mechanisms in clinical settings, potentially making gastroparesis a reversible process.

Gastrointestinal Symptoms in Diabetes: Prevalence, Assessment, Pathogenesis, and Management

If you haven't measured something, you really don't know much about it.-Karl Pearson (attributed)Gastrointestinal (GI) symptoms represent an important and often unappreciated cause of morbidity in diabetes, although the significance of this burden across the spectrum of patients and the underlying pathophysiology, including the relationship of symptoms with glycemic control, remain poorly defined. The relevance of GI symptoms and the necessity for their accurate assessment have increased with the greater focus on the gut as a therapeutic target for glucose lowering. This review addresses the prevalence, assessment, pathogenesis, and management of GI symptoms in diabetes, beginning with broad principles and then focusing on specific segments of the GI tract. We initially performed a literature search of PubMed by using synonyms and combinations of the following search terms: "gastrointestinal symptoms", "diabetes", "prevalence", "pathogenesis", "diagnosis", and "management". We restricted the search results to English only. Review papers and meta-analyses are presented as the highest level of evidence where possible followed by randomized controlled trials, uncontrolled trials, retrospective and observational data, and expert opinion.

Relating gastric scintigraphy and symptoms to motility capsule transit and pressure findings in suspected gastroparesis

BACKGROUND

Wireless motility capsule (WMC) findings are incompletely defined in suspected gastroparesis. We aimed to characterize regional WMC transit and contractility in relation to scintigraphy, etiology, and symptoms in patients undergoing gastric emptying testing.

METHODS

A total of 209 patients with gastroparesis symptoms at NIDDK Gastroparesis Consortium centers underwent gastric scintigraphy and WMCs on separate days to measure regional transit and contractility. Validated questionnaires quantified symptoms.

KEY RESULTS

Solid scintigraphy and liquid scintigraphy were delayed in 68.8% and 34.8% of patients; WMC gastric emptying times (GET) were delayed in 40.3% and showed 52.8% agreement with scintigraphy; 15.5% and 33.5% had delayed small bowel (SBTT) and colon transit (CTT) times. Transit was delayed in ≥2 regions in 23.3%. Rapid transit was rarely observed. Diabetics had slower GET but more rapid SBTT versus idiopathics (P ≤ .02). GET delays related to greater scintigraphic retention, slower SBTT, and fewer gastric contractions (P ≤ .04). Overall gastroparesis symptoms and nausea/vomiting, early satiety/fullness, bloating/distention, and upper abdominal pain subscores showed no relation to WMC transit. Upper and lower abdominal pain scores (P ≤ .03) were greater with increased colon contractions. Constipation correlated with slower CTT and higher colon contractions (P = .03). Diarrhea scores were higher with delayed SBTT and CTT (P ≤ .04).

CONCLUSIONS & INFERENCES

Wireless motility capsules define gastric emptying delays similar but not identical to scintigraphy that are more severe in diabetics and relate to reduced gastric contractility. Extragastric transit delays occur in >40% with suspected gastroparesis. Gastroparesis symptoms show little association with WMC profiles, although lower symptoms relate to small bowel or colon abnormalities.

Alpha-lipoic Acid suppresses P2X receptor activities and visceral hypersensitivity to colorectal distention in diabetic rats

The present study was designed to investigate the roles of P2X3 receptors in dorsal root ganglion (DRG) neurons in colonic hypersensitivity and the effects of alpha-lipoic acid (ALA) on P2X3 receptor activity and colonic hypersensitivity of diabetic rats. Streptozotocin (STZ) was used to induce diabetic model. Abdominal withdrawal reflex (AWR) responding to colorectal distention (CRD) was recorded as colonic sensitivity. ATP-induced current density of colon-specific DRG (T13-L2 DRGs) neurons was measured with whole-cell patch clamp. The expression of P2X3Rs of T13-L2 DRGs was measured by western blot analysis. The results showed that AWR scores significantly increased after STZ injection. P2X3R expression and ATP current density of T13-L2 DRG neurons were enhanced in diabetic rats. Intraperitoneal injection with ALA once a day for 1 week remarkably reduced P2X3R expression and ATP current density in diabetic rats. Importantly, ALA treatment attenuated colonic hypersensitivity in diabetic rats. Our data suggest that STZ injection increases expression and function of P2X3 receptors of colon-specific DRG neurons, thus contributing to colonic hypersensitivity in diabetic rats. Administration of ALA attenuates diabetic colonic hypersensitivity, which is most likely mediated by suppressing expression and function of P2X3 receptors in DRGs of diabetic rats.

Ravages of Diabetes on Gastrointestinal Sensory-Motor Function: Implications for Pathophysiology and Treatment

Symptoms related to functional and sensory abnormalities are frequently encountered in patients with diabetes mellitus. Most symptoms are associated with impaired gastric and intestinal function. In this review, we discuss basic concepts of sensory-motor dysfunction and how they relate to clinical findings and gastrointestinal abnormalities that are commonly seen in diabetes. In addition, we review techniques that are available for investigating the autonomic nervous system, neuroimaging and neurophysiology of sensory-motor function. Such technological advances, while not readily available in the clinical setting, may facilitate stratification and individualization of therapy in diabetic patients in the future. Unraveling the structural, mechanical, and sensory remodeling in diabetes disease is based on a multidisciplinary approach that can bridge the knowledge from a variety of scientific disciplines. The final goal is to increase the understanding of the damage to GI structures and to sensory processing of symptoms, in order to assist clinicians with developing an optimal mechanics based treatment.

Baseline features and differences in 48 week clinical outcomes in patients with gastroparesis and type 1 vs type 2 diabetes

BACKGROUND

In studies of diabetic gastroparesis, patients with type 1 and type 2 diabetes mellitus (T1DM, T2DM) are often combined for analyses. We compared gastroparesis severity, healthcare utilization, psychological function, and quality of life in T1DM vs T2DM gastroparesis patients.

METHODS

Questionnaire, laboratory, and scintigraphy data from patients with gastroparesis and T1DM and T2DM from seven centers of the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium Registry were compared at enrollment and after 48 weeks. Multiple regression models assessed baseline and follow-up differences between diabetes subtypes.

KEY RESULTS

At baseline, T1DM patients (N = 78) had slower gastric emptying, more hospitalizations, more gastric stimulator implantations, higher hemoglobin A1c (HbA1c), and more anxiety vs T2DM patients (N = 59). Independent discriminators of patients with T1DM vs T2DM included worse gastroesophageal reflux disease, less bloating, more peripheral neuropathy, and fewer comorbidities (p ≤ 0.05). On follow-up, gastrointestinal (GI) symptom scores decreased only in T2DM (p < 0.05), but not in T1DM patients who reported greater prokinetic, proton pump inhibitor, anxiolytic, and gastric stimulator usage over 48 weeks (p ≤ 0.03). Gastrointestinal symptoms at baseline and 48 weeks with both subtypes were not associated with HbA1c, peripheral neuropathy, psychological factors, or quality of life.

CONCLUSIONS & INFERENCES

Baseline symptoms were similar in T1DM and T2DM patients, even though T1DM patients had worse gastric emptying delays and higher HbA1c suggesting other factors mediate symptom severity. Symptom scores at 48 weeks decreased in T2DM, but not T1DM patients, despite increased medical and surgical treatment utilization by T1DM patients. Defining causes of different outcomes in diabetic gastroparesis warrants further investigation.

Relationship Between Control of Glycemia and Gastric Emptying Disturbances in Diabetes Mellitus

BACKGROUND & AIMS

Hyperglycemia is implicated as a major risk factor for delayed gastric emptying in diabetes mellitus and vice versa. However, the extent to which hyperglycemia can affect gastric emptying and vice versa and the implications for clinical practice are unclear. We systematically reviewed the evidence for this bidirectional relationship and the effects of pharmacotherapy for diabetes on gastric emptying.

METHODS

Full-length articles investigating the relationship between diabetes mellitus and gastroparesis were reviewed primarily to quantify the relationship between blood glucose concentrations and gastrointestinal sensorimotor functions, particularly gastric emptying, and gastrointestinal symptoms. The effects of drugs and hormones that affect glycemia on gastrointestinal sensorimotor functions were also evaluated.

RESULTS

Acute severe hyperglycemia delayed gastric emptying relative to euglycemia in type 1 diabetes; the corresponding effects in type 2 diabetes are unknown. Limited evidence suggests that even mild hyperglycemia (8 mmol/L) can delay gastric emptying in type 1 diabetes. Long-term hyperglycemia is an independent risk factor for delayed gastric emptying in type 1 diabetes. There is little evidence that delayed gastric emptying causes hypoglycemia in diabetes and no evidence that improved control of glycemia improves gastric emptying or vice versa. Glucagon-like peptide-1 agonists but not dipeptidylpeptidase-4 inhibitors given acutely delay gastric emptying, but tachyphylaxis may occur.

CONCLUSIONS

Although acute severe and chronic hyperglycemia can delay gastric emptying, there is limited evidence that delayed gastric emptying is an independent risk factor for impaired glycemic control or hypoglycemia in diabetes. The impact of improved glycemic control on gastric emptying and vice versa in diabetes is unknown.

Functional Dyspepsia and Gastroparesis

BACKGROUND

Upper gastrointestinal disorders typically present with common symptoms. The most relevant non-mucosal diseases are gastroparesis, functional dyspepsia and rumination syndrome. The literature pertaining to these 3 conditions was reviewed.

KEY MESSAGES

Gastroparesis is characterized by delayed gastric emptying in the absence of mechanical obstruction of the stomach. The cardinal symptoms include postprandial fullness (early satiety), nausea, vomiting and bloating. The most frequently encountered causes of these symptoms are mechanical obstruction (pyloric stenosis), iatrogenic disease, gastroparesis, functional dyspepsia, cyclical vomiting and rumination syndrome. The most common causes of gastroparesis are neuropathic disorders such as diabetes, idiopathic, post-vagotomy and scleroderma among myopathic disorders. Principles of management of gastroparesis include exclusion of mechanical obstruction with imaging and iatrogenic causes with careful medication and past surgical history. Prokinetics and anti-emetics are the mainstays of treatment. Functional dyspepsia is characterized by the same symptoms as gastroparesis; in addition to delayed gastric emptying, pathophysiological abnormalities include accelerated gastric emptying, impaired gastric accommodation and gastric or duodenal hypersensitivity to distension and nutrients. Novel treatments include tricyclic antidepressants in patients with normal gastric emptying, acotiamide (acetyl cholinesterase inhibitor) and 5-HT1A receptor agonists such as buspirone. Rumination syndrome is characterized by repetitive regurgitation of gastric contents occurring within minutes after a meal. Episodes often persist for 1-2 h after the meal, and the regurgitant consists of partially digested food that is recognizable in its taste. Regurgitation is typically effortless or preceded by a sensation of belching. This has been summarized as a 'meal in, meal out, day in, day out' behavior for weeks or months, differentiating rumination from gastroparesis. Patients often have a background of psychological disorder or a prior eating disorder. Treatment is based on behavioral modification.

CONCLUSION

Precise identification of the cause and pathophysiology of upper gastrointestinal symptoms is essential for optimal management.

Diabetic neuropathy in the gut: pathogenesis and diagnosis

The activity of the digestive tract is usually regulated to match its content: physiological stimuli in the gut induce modulatory reflexes that control digestive function so that digestion is normally not perceived. However, under certain circumstances, digestive stimuli may activate sensory afferents and give rise to conscious sensations. Both reflex and sensory signals are modulated by a balance of excitatory and inhibitory mechanisms. Patients with diabetes may develop a neuropathy affecting the control of gastric and/or intestinal motor function and the sensory innervation as well. During fasting the stomach is contracted and relaxes to accommodate a meal. After ingestion the stomach progressively recontracts and this contraction gently produces gastric emptying. Impairment of excitatory pathways affects the contraction of the stomach, which may result in delayed gastric emptying and vomiting of retained food. Conversely, alteration of the inhibitory neural pathways results in impaired relaxation of the stomach in response to a meal; in this case increased wall tension may produce early satiation, fullness and nausea. Diabetic neuropathy may distort the control of intestinal motility, which can lead to diverse symptoms such as diarrhoea, constipation, intestinal distension and abdominal pain. Neuropathy in diabetes may also affect the sensory nerves of the gut, and depending on which pathways are involved, perception may be increased or reduced. In summary, in patients with diabetic neuropathy, disorders of gut motor function are associated with sensory abnormalities, and the combination of impaired pathways determines the clinical consequences. This review summarises a presentation given at the 'Diagnosis and treatment of autonomic diabetic neuropathy in the gut' symposium at the 2015 annual meeting of the EASD. It is accompanied by another mini-review on a topic from this symposium (by Hans Törnblom, DOI: 10.1007/s00125-015-3829-9 ) and a commentary by the Session Chair, Péter Kempler (DOI: 10.1007/s00125-015-3826-y ).

The normoglycaemic biobreeding rat: a spontaneous model for impaired gastric accommodation

OBJECTIVE

Impaired gastric accommodation is reported in patients with functional dyspepsia (FD). Previous findings in postinfectious patients with FD suggest that low-grade inflammation and dysfunction of nitrergic nerves play a role in impaired accommodation. To date, spontaneous animal models to study the relationship between these changes are lacking. We hypothesise that the normoglycaemic BioBreeding diabetes-prone (BB-DP) rat provides an animal model of inflammation-induced impaired gastric motor function.

DESIGN

Control diabetes-resistant biobreeding, normoglycaemic and hyperglycaemic BB-DP rats were sacrificed at the age of 30, 70 and 220 days and gastric fundus tissue was harvested to study nitrergic motor control, inflammation and expression of neuronal isoform of nitric oxide synthase (nNOS) and inducible isoform of nitric oxide synthase (iNOS). Nutrient-induced changes in intragastric pressure (IGP) were measured in normoglycaemic BB-DP rats to study accommodation.

RESULTS

No differences in nitrergic function and inflammation were observed between BB-DP and control rats at 30 days. The nitrergic component of the fundic muscle relaxation was reduced in BB-DP rats of 70 and 220 days. This was accompanied by a significant loss of nNOS proteins. IGP significantly increased during nutrient infusion in BB-DP rats of 220 days, indicating impaired accommodation. Infiltration of polymorphonuclear cells, increased myeloperoxidase activity and increased expression of iNOS was observed in the fundic mucosa and muscularis propria of 70-day-old and 220-day-old BB-DP rats.

CONCLUSIONS

BB-DP rats of 220 days display altered fundic motor control and impaired accommodation, which is least partially explained by loss of nitrergic function. This may be related to inflammatory changes in the neuromuscular layer, suggesting that normoglycaemic BB-DP rats provide a spontaneous model for inflammation-induced impaired gastric accommodation.

The stomach in health and disease

The stomach is traditionally regarded as a hollow muscular sac that initiates the second phase of digestion. Yet this simple view ignores the fact that it is the most sophisticated endocrine organ with unique physiology, biochemistry, immunology and microbiology. All ingested materials, including our nutrition, have to negotiate this organ first, and as such, the stomach is arguably the most important segment within the GI tract. The unique biological function of gastric acid secretion not only initiates the digestive process but also acts as a first line of defence against food-borne microbes. Normal gastric physiology and morphology may be disrupted by Helicobacter pylori infection, the most common chronic bacterial infection in the world and the aetiological agent for most peptic ulcers and gastric cancer. In this state-of-the-art review, the most relevant new aspects of the stomach in health and disease are addressed. Topics include gastric physiology and the role of gastric dysmotility in dyspepsia and gastroparesis; the stomach in appetite control and obesity; there is an update on the immunology of the stomach and the emerging field of the gastric microbiome. H. pylori-induced gastritis and its associated diseases including peptic ulcers and gastric cancer are addressed together with advances in diagnosis. The conclusions provide a future approach to gastric diseases underpinned by the concept that a healthy stomach is the gateway to a healthy and balanced host. This philosophy should reinforce any public health efforts designed to eradicate major gastric diseases, including stomach cancer.

Current advances in treatment of gastroparesis

INTRODUCTION

Gastroparesis is a syndrome defined by delayed gastric emptying in the absence of mechanical obstruction. Gastroparesis has significant symptomatology and negative impacts on the patient's quality of life.

AREAS COVERED

This article reviews current treatment options for gastroparesis, recent advances in treatment and future directions that treatment may head. Current options are broadly divided into prokinetics and symptom modulators. Within each group, current modalities as well as recent advances are discussed according to agent mechanism of action. Lastly, findings regarding the cellular pathophysiology involved in gastroparesis will be briefly reviewed along with their implications for future treatments.

EXPERT OPINION

The numerous motor functions and neural inputs that control gastric motility are complex and not fully understood. Our lack of understanding of its pathophysiology has led to treatment options which are empirical, palliative and often ineffective. Newly intensified interest in the cellular pathophysiology behind gastroparesis provides promise for a new era of treatments. Identification of common cellular changes in gastroparesis has provided targets for treatment that may allow us to one day better treat the symptoms of gastroparesis related to its underlying pathophysiology. This is the future of gastroparesis therapy.

Clinical presentation and pathophysiology of gastroparesis

Gastroparesis is a heterogeneous disorder defined by delay in gastric emptying. Symptoms of gastroparesis are nonspecific, including nausea, vomiting, early satiety, bloating, and/or abdominal pain. Normal gastric motor function and sensory function depend on a complex coordination between the enteric and central nervous system. This article discusses the pathophysiology of delayed gastric emptying and the symptoms of gastroparesis, including antropyloroduodenal dysmotility, impaired gastric accommodation, visceral hypersensitivity, and autonomic dysfunction. The underlying pathophysiology of gastroparesis is complex and multifactorial. The article discusses how a combination of these factors leads to symptoms of gastroparesis.

Gastric emptying and glycaemia in health and diabetes mellitus

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.

Measurement of gastric emptying in diabetes

There has been a substantial evolution of concepts related to disordered gastric emptying in diabetes. While the traditional focus has hitherto related to the pathophysiology and management of upper gastrointestinal symptoms associated with gastroparesis, it is now apparent that the rate of gastric emptying is central to the regulation of postprandial glycemia. This recognition has stimulated the development of dietary and pharmacologic approaches to optimize glycemic control, at least in part, by slowing gastric emptying. With the increased clinical interest in this area, it has proved necessary to expand the traditional indications for gastric emptying studies, and consider the relative strengths and limitations of available techniques. Scintigraphy remains the 'gold standard' for the measurement of gastric emptying, however, there is a lack of standardization of the technique, and the optimal test meal for the evaluation of gastrointestinal symptoms may be discordant from that which is optimal to assess impaired glycemic control. The stable isotope breath test provides an alternative to scintigraphy and can be performed in an office-based setting. The effect of glucagon-like peptide-1 (GLP-1) and its agonists to reduce postprandial glycemia is dependent on the baseline rate of gastric emptying, as well as the magnitude of slowing. Because the effect of exogenous GLP-1 to slow gastric emptying is subject to tachyphylaxis with sustained receptor exposure, 'short acting' or 'prandial' GLP-1 agonists primarily target postprandial glycemia through slowing of gastric emptying, while 'long acting' or 'non-prandial' agents lower fasting glucose primarily through insulinotropic and glucagonostatic mechanisms. Accordingly, the indications for the therapeutic use of these different agents are likely to vary according to baseline gastric emptying rate and glycemic profiles.

Management of gastroparesis: beyond basics

OPINION STATEMENT

Gastroparesis is defined as the presence of delayed gastric emptying in the absence of mechanical obstruction, with a variety of upper gastrointestinal symptoms. Although measurement of gastric emptying is necessary for the diagnostic labeling, this finding has little impact in terms of explaining the symptom pattern and determining the prognosis and therapeutic approach. Clinical management is based on ruling out of mechanical causes and serum electrolyte imbalances, followed by initial medical treatment with a gastroprokinetic agent in most cases. However, the evidence that these drugs provide substantial symptomatic benefit is weak. Recent attempts to establish efficacy with newer prokinetics, including serotonin-4, motilin, and ghrelin receptor agonists, have seen few successes, but a new group of agents is under evaluation. More recently, also, no benefit was found with treatment with a tricyclic antidepressant in idiopathic gastroparesis. In refractory cases, especially when there is weight loss, invasive therapeutics such as insertion of feeding tubes, intrapyloric injection of botulinum toxin, implantable gastric electrical stimulation, or surgical (partial) gastrectomy are occasionally considered, but there is little evidence of efficacy, and these are not devoid of potentially major complications. Gastroparesis is likely to remain a challenging condition in the clinic in the foreseeable future.