Diabetic Gastroparesis and Nondiabetic Gastroparesis

Gastroparesis: The Complex Interplay with Microbiota and the Role of Exogenous Infections in the Pathogenesis of the Disease

Gastroparesis (GP) is a disorder of gastric functions that is defined by objective delayed gastric emptying in the absence of mechanical obstruction. This disease is characterized by symptoms such as nausea, post-prandial fullness, and early satiety. GP significantly impacts patients' quality of life and contributes to substantial healthcare expenses for families and society. However, the epidemiological burden of GP is difficult to evaluate, mainly due its significant overlap with functional dyspepsia (FD). GP and FD represent two similar diseases. The pathophysiology of both disorders involves abnormal gastric motility, visceral hypersensitivity, and mucosal inflammation. Moreover, both conditions share similar symptoms, such as epigastric pain, bloating, and early satiety. The latest evidence reveals that dysbiosis is directly or indirectly connected to gut-brain axis alterations, which are the basis of pathogenesis in both FD and GP. Furthermore, the role of microbiota in the development of gastroparesis was demonstrated by some clinical studies, which found that the use of probiotics is correlated with improvements in the gastric emptying time (GET). Infections (with viruses, bacteria, and protozoa) represent a proven etiology for GP but have not been sufficiently considered in current clinical practice. Previous viral infections can be found in about 20% of idiopathic GP cases. Moreover, delayed gastric emptying during systemic protozoal infections represents a huge concern for compromised patients, and few data exist on the topic. This comprehensive narrative review analyzes the relationship between microorganisms and GP. We explore, on the one hand, the correlation between gut microbiota dysbiosis and GP pathogenesis, including treatment implications, and, on the other hand, the association between exogenous infections and the etiology of the disease.

17β-Estradiol Suppresses Gastric Inflammatory and Apoptotic Stress Responses and Restores nNOS-Mediated Gastric Emptying in Streptozotocin (STZ)-Induced Diabetic Female Mice

Gastroparesis (Gp) is a severe complication of diabetes mellitus (DM) observed predominantly in women. It is characterized by abnormal gastric emptying (GE) without mechanical obstruction in the stomach. Nitric oxide (NO) is an inhibitory neurotransmitter produced by neuronal nitric oxide synthase (nNOS). It plays a critical role in gastrointestinal (GI) motility and stomach emptying. Here, we wanted to demonstrate the protective effects of supplemental 17β-estradiol (E2) on NO-mediated gastric function. We showed E2 supplementation to alleviate oxidative and inflammatory stress in streptozotocin (STZ)-induced diabetic female mice. Our findings suggest that daily administration of E2 at therapeutic doses is beneficial for metabolic homeostasis. This restoration occurs via regulating and modulating the expression/function of glycogen synthase kinase-3β (GSK-3β), nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), Phase II enzymes, MAPK- and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB)-mediated inflammatory cytokines (IL-1β, IL-6, TNFα, IGF-1), and gastric apoptotic regulators. We also showed E2 supplementation to elevate GCH-1 protein levels in female diabetic mice. Since GCH-1 facilitates the production of tetrahydrobiopterin (BH4, cofactor for nNOS), an increase in GCH-1 protein levels in diabetic mice may improve their GE and nitrergic function. Our findings provide new insights into the impact of estrogen on gastric oxidative stress and intracellular inflammatory cascades in the context of Gp.

Gastroparesis-Related Symptoms in Patients With Type 2 Diabetes Mellitus: Early Detection, Risk Factors, and Prevalence

Background The symptoms of gastroparesis, such as bloating, postprandial fullness, early satiety, nausea, and abdominal discomfort, progressively worsen the quality of life of the affected individuals. The diagnosis is established on the assessment of gastric function that confirms delayed gastric emptying in the absence of structural etiologies. This study aimed to detect gastroparesis-related clinical symptoms early in patients with type 2 diabetes mellitus (T2DM), investigate the concomitant risk factors, and evaluate the prevalence. Methodology This study was conducted at the Department of Medicine and Diabetes Outdoor Clinic of Sheikh Zayed Hospital, Rahim Yar Khan from February 13, 2022, to February 11, 2023. The study involved 175 patients with T2DM who reported gastroparesis-related symptoms. The demographic and clinical characteristics, symptom severity, complications, related risk factors, duration of disease, medications, body mass index (BMI), fasting plasma glucose, and glycated hemoglobin (HbA1C) levels were assessed. The severity of diabetic gastroparesis was established using the disease-specific Patient Assessment of Gastrointestinal Disorders-Symptom Severity Index (PAGI-SYM) and the Gastroparesis Cardinal Symptom Index (GCSI). The five-point scale of the PAGI-SYM and the four-degree severity scores of GCSI were assessed. Neuropathy disability scores and motor evacuation functions were analyzed. Data were analyzed from these questionnaires, special proforma, and patient interviews. Results The clinical features of diabetic gastroparesis were observed in 44% of T2DM patients with mild-grade gastroparesis in 38 (21.7%), moderate in 30 (17.1%), and severe-grade gastroparesis-related symptoms in nine (5.2%) patients. The main manifestations were early satiety (45.1%), stomach fullness (44.5%), bloating (38.3%), and nausea (33.1%). Diabetic gastroparesis symptoms were considerably linked to disease duration of more than 10 years (p = 0.02), high HbA1c (p = 0.001), increased fasting blood glucose (p = 0.003), polyneuropathy, cigarette smoking, and history of comorbid conditions (p = 0.009). Obesity and the female gender were the forecasters of the manifestation of at least one cardinal gastroparesis symptom. Conclusions Gastric emptying is significant in the pathogenesis of gastroparesis-related symptoms. Disease duration of more than 10 years, poor glycemic control with hyperglycemia, high HbA1C, polyneuropathy, and cigarette smoking must be considered as predictors for early detection and risk factors for the advancement of gastroparesis in T2DM. Gastroparesis-related common symptoms of early satiety, bloating, and stomach fullness were considerably linked to the additional risk factors of hypercholesteremia, chronic microvascular complications, concomitant cardiovascular diseases, and a positive family history of diabetes mellitus. There was no relationship between BMI, age, types of treatment, and the degree of gastroparesis severity. The prevalence and severity of gastroparesis symptoms were particularly high among obese females with poor glycemic control and longer disease duration.

Frequency of GLP-1 receptor agonists use in diabetic patients diagnosed with delayed gastric emptying and their demographic profile

Advances in the management of diabetes mellitus have come a long way in the 21st century. One of the most important developments in diabetes management has been the discovery of glucagon-like peptide-1 (GLP-1) receptor agonists. The most common side effects of GLP-1 receptor (GLP-1R) agonists are nausea and vomiting which have been attributed to delayed gastric emptying. While the effects of GLP-1R agonists on gastric emptying have prompted further research in this field, there are limited studies evaluating their effects on patients with pre-existing gastroparesis. Additionally, the frequency of GLP-1R agonist use among patients with gastroparesis has not been assessed in the past and this study aims to identify that percentage along with evaluating for possible iatrogenic gastroparesis. A retrospective review of all the gastric emptying studies performed at one academic medical center between January 2019 and January 2021 was performed. We found that although patients on GLP-1R agonists were more likely to have delayed gastric emptying, we could not establish a statistical significance. This could be due to the small sample size in the study. However, GLP-1R agonists use was associated with delayed gastric emptying in patients with diabetes for <10 years. Moreover, a significant proportion (24%) of patients with diabetes with delayed gastric emptying were on a GLP-1R agonist. Recently, semaglutide (GLP-1R agonist) gained Food and Drug Administration approval as a weight loss medication in both patients with and without diabetes. This should prompt further research to evaluate the safety profile of these medications in patients with and without pre-existing gastroparesis.

Clinical and endoscopic characteristics of acute esophageal necrosis and severe reflux esophagitis

The similarities and differences between acute esophageal necrosis and severe reflux esophagitis have not been elucidated. We compared Los Angeles classification Grade C reflux esophagitis, Grade D reflux esophagitis, and acute esophageal necrosis to consider the similarities and differences between acute esophageal necrosis and severe reflux esophagitis.We retrospectively reviewed records of patients who underwent esophagogastroduodenoscopy at a tertiary referral center from January 2012 to December 2019. Data on patients diagnosed as Grade C reflux, Grade D reflux, or acute esophageal necrosis for the first time were extracted for analysis.A total of 213 patients were enrolled in the study, composed of 130 Grade C reflux, 74 Grade D reflux, and 9 acute esophageal necrosis patients. Compared to Grade C reflux patients, Grade D reflux and acute esophageal necrosis patients were more likely to be transfused (P = .013 and P = .011, respectively), to have duodenal ulcers (P = .025 and P = .049, respectively), and to have psychiatric illnesses (P = .022 and P = .018, respectively). Compared to both Grade C and D reflux, acute esophageal necrosis patients were more likely to present with shock (P = .003 and P < .001, respectively), have type 1 diabetes (P = .030 and P = .004, respectively), and present in winter (P < .001 and P < .001, respectively). Significant step-wise differences (Grade C < Grade D < acute esophageal necrosis) were observed in the need for admission (P < .001 and P = .009), coffee ground emesis (P < .001 and P = .022), and stigmata of hemorrhage on endoscopy (P = .002 and P < .001). Admission (P = .003) and coffee ground emesis (P = .003) independently predicted either Grade D reflux or acute esophageal necrosis over Grade C reflux on multivariate analysis.Shock, type 1 diabetes, and winter may predict acute esophageal necrosis, while the need for admission and coffee ground emesis may predict Grade D reflux or acute esophageal necrosis.

New device for active gastric mechanical stimulation

BACKGROUND

Gastroparesis is a chronic stomach disorder and effective treatment is the aim of different strategies. Alternative therapies consist of an electrical stimulation of the stomach to evoke a response in the gastric activity. We present the development and in vivo application of an electromagnet system to induce a mechanical stimulus in the stomach aiming for gastric contractile responses.

METHODS

The electromagnet system consisted of an implantable magnet and an external drive coil. We implanted the magnet at the greater curvature of the gastric body in rats. We applied an alternating current to the drive coils, inducing mechanical stimulation of the gastric wall. We measured the gastric contraction activity and gastric electrical activity in response to the stimulus using AC biosusceptometry and electrogastrography. Moreover, we used the phenol red to evaluate the stimulus effects on gastrointestinal transit.

KEY RESULTS

The stimulus increased the spectral intensity and signal-to-noise ratio significantly of gastric contraction activity and gastric electrical activity. Furthermore, we found a lower phenol red retention in the stomach in rats without stimulus. No significant differences were found in frequency and root mean square amplitude.

CONCLUSIONS & INFERENCES

We developed a new simple electromagnet system that evoked a contraction and gastric electrical response using a mechanical stimulus and decreased gastric emptying time. The system is an accessible tool and may contribute to gastroparesis studies in animals.

Medication-Induced Gastroparesis: A Case Report

Gastroparesis is a commonly diagnosed gastrointestinal disorder with a high prevalence globally and high disease burden to those afflicted with it. Etiologies are variable with idiopathic and diabetes being the most common causes of gastroparesis. Management of gastroparesis depends on the etiology, and accurate diagnosis is required for better targeted therapy. Medication-induced gastroparesis is reversible, and discontinuing the medication is generally curative. This case report discusses 2 cases of medication-induced gastroparesis which were initially diagnosed as diabetic gastroparesis, and thorough history taking revealed the cause to be medication induced. Repeat studies following medication discontinuation revealed improvement in symptoms and resolution of gastroparesis. Further research needs to be done to assess the frequency of misdiagnosing diabetic patients with gastroparesis due to medications, specifically glucagon-like peptide-1 receptor agonists which are increasingly being used in diabetics.

Diabetic gastroenteropathy: An underdiagnosed complication

This article is an extensive review that provides an update on the pathophysiology, symptoms, diagnosis, and treatment of diabetic gastroenteropathy. There is no reported prevalence, but it has been described that patients with type 1 diabetes have a cumulative incidence at 10 years of 5.2%, and type 2 patients, 1%. Also, in the group of type 1 diabetes, it has been observed that women are more likely to present this condition (5.8% vs 3.5%). Many factors are associate with its development (e.g., hyperglycemia, vagal dysfunction, loss of expression of neural nitric oxide synthase in the myenteric plexus, alterations in the Cajal interstitial cell network, and oxidative stress). Gastrointestinal discomfort could be perceived 70% higher in diabetic patients, describing that 25% of diabetic patients experience gastrointestinal symptoms. Diabetic enteropathy could affect any portion of the gastrointestinal tract, but esophageal alterations were described in more than 60% of diabetic patients, also 60% of them present constipation, and 20%, diarrhea. Gastric emptying scintigraphy is useful to evaluate gastroparesis, therefore, gastric retention of more than 60% at 2 h has a sensitivity of 100% and specificity of 20% for diagnosis; however, other studies such as breath tests, with a sensitivity of 89% and a specificity of 80%, or the endoscopic capsule contribute to the diagnosis. There is no cure; however, management must be multidisciplinary, focused on slowing the progression of diabetic gastroenteropathy, reducing symptoms, and restoring function; that includes nutritional recommendation, maintain glucose levels kept below 180 mg/dL, use of prokinetics, anti-emetics; nowadays, it has been special interest in surgical treatment, such as pyloroplasty, also gastric electrical stimulation appears to be another alternative.

One-year results of gastric peroral endoscopic myotomy for refractory gastroparesis: a French multicenter study

BACKGROUND

Data on the long-term outcomes of gastric peroral endoscopic myotomy (G-POEM) for refractory gastroparesis are lacking. We report the results of a large multicenter long-term follow-up study of G-POEM for refractory gastroparesis.

METHODS

This was a retrospective multicenter study of all G-POEM operations performed in seven expert French centers for refractory gastroparesis with at least 1 year of follow-up. The primary endpoint was the 1-year clinical success rate, defined as at least a 1-point improvement in the Gastroparesis Cardinal Symptom Index (GCSI).

RESULTS

76 patients were included (60.5 % women; age 56 years). The median symptom duration was 48 months. The median gastric retention at 4 hours (H4) before G-POEM was 45 % (interquartile range [IQR] 29 % - 67 %). The median GCSI before G-POEM was 3.6 (IQR 2.8 - 4.0). Clinical success was achieved in 65.8 % of the patients at 1 year, with a median rate of reduction in the GCSI score of 41 %. In logistic regression analysis, only a high preoperative GCSI satiety subscale score was predictive of clinical success (odds ratio [OR] 3.41, 95 % confidence interval [CI] 1.01 - 11.54; P = 0.048), while a high rate of gastric retention at H4 was significantly associated with clinical failure (OR 0.97, 95 %CI 0.95 - 1.00; P = 0.03).

CONCLUSIONS

The results confirm the efficacy of G-POEM for the treatment of refractory gastroparesis, as evidenced by a 65.8 % clinical success rate at 1 year. Although G-POEM is promising, prospective sham-controlled trials are urgently needed to confirm its efficacy and identify the patient populations who will benefit most from this procedure.

Inhibition of GSK-3β restores delayed gastric emptying in obesity-induced diabetic female mice

Diabetic gastroparesis (DG) is a clinical syndrome characterized by delayed gastric emptying (DGE). Loss of nuclear factor erythroid 2-related factor 2 (Nrf2) is associated with reduced neuronal nitric oxide synthase-α (nNOSα)-mediated gastric motility and DGE. Previous studies have shown that nuclear exclusion and inactivation of Nrf2 is partly regulated by glycogen synthase kinase 3β (GSK-3β). In the current study, the molecular signaling of GSK-3β-mediated Nrf2 activation and its mechanistic role on DG were investigated in high-fat diet (HFD)-induced obese/Type 2 diabetes (T2D) female mice. Adult female C57BL/6J mice were fed with HFD or normal diet (ND) with or without GSK-3β inhibitor (SB 216763, 10 mg/kg body wt ip) start from the 14th wk and continued feeding mice for an additional 3-wk time period. Our results show that treatment with GSK-3β inhibitor SB attenuated DGE in obese/T2D mice. Treatment with SB restored impaired gastric 1) Nrf2 and phase II antioxidant enzymes through PI3K/ERK/AKT-mediated pathway, 2) tetrahydrobiopterin (BH₄, cofactor of nNOS) biosynthesis enzyme dihydrofolate reductase, and 3) nNOSα dimerization in obese/T2 diabetic female mice. SB treatment normalized caspase 3 activity and downstream GSK-3β signaling in the gastric tissues of the obese/T2 diabetic female mice. In addition, GSK-3β inhibitor restored impaired nitrergic relaxation in hyperglycemic conditions. Finally, SB treatment reduced GSK3 marker, pTau in adult primary enteric neuronal cells. These findings emphasize the importance of GSK-3β on regulating gastric Nrf2 and nitrergic mediated gastric emptying in obese/diabetic rodents.NEW & NOTEWORTHY Inhibition of glycogen synthase kinase 3β (GSK-3β) with SB 216763 attenuates delayed gastric emptying through gastric nuclear factor erythroid 2-related factor 2 (Nrf2)-phase II enzymes in high-fat diet-fed female mice. SB 216763 restored impaired gastric PI3K/AKT/ β-catenin/caspase 3 expression. Inhibition of GSK-3β normalized gastric dihydrofolate reductase, neuronal nitric oxide synthase-α expression, dimerization and nitrergic relaxation. SB 216763 normalized both serum estrogen and nitrate levels in female obese/Type 2 diabetes mice. SB 216763 reduced downstream signaling of GSK-3β in enteric neuronal cells in vitro.

Gastric Electrical Stimulators Causing Erosion Through the Colonic Wall

Gastroparesis is a chronic motor disorder of the stomach characterized by the demonstration of delayed gastric emptying without obstruction and a grouping of symptoms including nausea, vomiting, early satiety, postprandial fullness, bloating and abdominal pain. When conservative medical management is not effective, gastric electrical stimulation is an effective alternative. Gastric electrical stimulation, in general, has had a low complication rate as of yet, with the most common being infection of the implanted device. We present a complication in which the gastric electrical stimulator electrodes eroded through the colonic wall.

Gastroparesis: New insights into an old disease

Gastroparesis (Gp) is a chronic disease characterized by a delayed gastric emptying in the absence of mechanical obstruction. Although this condition has been reported in the literature since the mid-1900s, only recently has there been renewed clinical and scientific interest in this disease, which has a potentially great impact on the quality of life. The aim of this review is to explore the pathophysiological, diagnostic and therapeutical aspects of Gp according to the most recent evidence. A comprehensive online search for Gp was carried out using MEDLINE and EMBASE. Gp is the result of neuromuscular abnormalities of the gastric motor function. There is evidence that patients with idiopathic and diabetic Gp may display a reduction in nitrergic inhibitory neurons and in interstitial cells of Cajal and/or telocytes. As regards diagnostic approach, 99-Technetium scintigraphy is currently considered to be the gold standard for Gp. Its limits are a lack of standardization and a mild risk of radiation exposure. The C13 breath testing is a valid and safe alternative method. ¹³C acid octanoic and the ¹³C Spirulina platensis recently approved by the Food and Drug Administration are the most commonly used diagnostic kits. The wireless motility capsule is a promising technique, but its use is limited by costs and scarce availability in many countries. Finally, therapeutic strategies are related to the clinical severity of Gp. In mild and moderate Gp, dietary modification and prokinetic agents are generally sufficient. Metoclopramide is the only drug approved by the Food and Drug Administration for Gp. However, other older and new prokinetics and antiemetics can be considered. As a second-line therapy, tricyclic antidepressants and cannabinoids have been proposed. In severe cases the normal nutritional approach can be compromised and artificial nutrition may be needed. In drug-unresponsive Gp patients some alternative strategies (endoscopic, electric stimulation or surgery) are available.

Update on pediatric gastroparesis: A review of the published literature and recommendations for future research

BACKGROUND

Due to scarcity of scientific literature on pediatric gastroparesis, there is a need to summarize current evidence and identify areas requiring further research. The aim of this study was to provide an evidence-based review of the available literature on the prevalence, pathogenesis, clinical presentation, diagnosis, treatment, and outcomes of pediatric gastroparesis.

METHODS

A search of the literature was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines with the following databases: PubMed, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, and Web of Science. Two independent reviewers screened abstracts for eligibility.

KEY RESULTS

Our search yielded 1085 original publications, 135 of which met inclusion criteria. Most articles were of retrospective study design. Only 12 randomized controlled trials were identified, all of which were in infants. The prevalence of pediatric gastroparesis is unknown. Gastroparesis may be suspected based on clinical symptoms although these are often non-specific. The 4-hour nuclear scintigraphy scan remains gold standard for diagnosis despite lack of pediatric normative comparison data. Therapeutic approaches include dietary modifications, prokinetic drugs, and postpyloric enteral tube feeds. For refractory cases, intrapyloric botulinum toxin and surgical interventions such as gastric electrical stimulation may be warranted. Most interventions still lack rigorous supportive data.

CONCLUSIONS

Diagnosis and treatment of pediatric gastroparesis are challenging due to paucity of published evidence. Larger and more rigorous clinical trials are necessary to improve outcomes.

Gastrectomy versus stomach left in situ with Roux-en-Y reconstruction for the treatment of gastroparesis

BACKGROUND

Gastroparesis is a debilitating functional disorder of the stomach marked by delayed gastric emptying in the absence of mechanical obstruction. Patients with severe, refractory symptoms may ultimately be managed with Roux-en-Y reconstruction; however, it is unclear whether the stomach should be left in situ, similar to a conventional gastric bypass, or resected as in gastrectomy.

METHODS

All patients undergoing Roux-en-Y for the treatment of gastroparesis (GP) at our institution from September 2010 through March 2018 were retrospectively reviewed. Patients with prior gastric resection or whose primary operative indication was not gastroparesis were excluded from analysis.

RESULTS

Twenty-six patients underwent Roux-en-Y with stomach left in situ (RY-SIS) and twenty-seven patients underwent gastrectomy with Roux-en-Y reconstruction during the study period. The mean age was 49.7 years in the RY-SIS cohort and 48.5 years in the gastrectomy cohort. Etiology of GP was similar between the two cohorts. Patients undergoing gastrectomy were more likely to have previous interventions for GP (63.0% vs. 26.9%). RY-SIS was associated with a shorter operative time (155 vs. 223 min), less blood loss (24 vs. 130 mL), and shorter length of stay (4.0 vs. 7.2 days). Twelve patients (44.4%) had complications within 30 days following gastrectomy compared to two patients (7.7%) following RY-SIS (p = 0.001). Patients in the RY-SIS cohort were more likely to require further subsequent surgical intervention for GP (23.1% vs. 3.7%, p = 0.04). At last follow-up, there were no differences in reported GP symptoms or symptom scoring.

CONCLUSIONS

Gastrectomy was associated with greater perioperative morbidity compared to leaving the stomach in situ. Symptomatic improvement at intermediate follow-up was equivalent following either procedure. However, patients undergoing RY-SIS were more likely to require subsequent surgical intervention, suggesting that gastrectomy may be a more definitive operation for the management of medically refractory gastroparesis.