Compliance of the proximal stomach and dyspeptic symptoms in patients with type I diabetes mellitus

The relationship between peritoneal membrane permeability and dyspepsia in peritoneal dialysis patients

OBJECTIVE

The aim of this study is to determine whether there is a relationship between peritoneal membrane permeability and dyspepsia in peritoneal dialysis patients.

PATIENTS AND METHODS

This study included 95 peritoneal dialysis patients aged 18 and older. The presence of dyspepsia in patients was recorded according to the 2016 ROME-IV Functional Dyspepsia Diagnostic Criteria. Subsequently, the Glasgow Dyspepsia Severity Score questionnaire was administered to assess the severity of dyspepsia. Endoscopy was performed for those who agreed to exclude organic pathology, or the results of endoscopy conducted within the last 2 years were recorded. Furthermore, stool samples were examined for H. pylori to exclude organic causes of dyspepsia. PET (peritoneal equilibration test) and Kt/V values of patients were calculated using the "PD Adequest" computer software. PET values were categorized as low and low-normal for low permeability and high and high-normal for high permeability.

RESULTS

Dyspepsia was detected in 51.6% of all peritoneal dialysis patients. H. pylori was found positive in 11.6% of all patients and 12.2% of those with dyspeptic symptoms. There was no significant difference in the rate of H. pylori occurrence between low and high permeability groups. The Glasgow Dyspepsia Severity Score did not differ significantly between H. pylori-positive and -negative patients. Dyspepsia was more frequent and severe in the low permeability group. Dyspepsia in the low permeability group was mostly considered as functional dyspepsia due to the predominance of normal endoscopic findings.

CONCLUSION

Dyspepsia is a common health problem in approximately half of peritoneal dialysis patients. Dyspepsia observed in those with low peritoneal membrane permeability is generally of functional origin. Furthermore, the frequency and severity of dyspepsia are higher in individuals with low permeability. When planning peritoneal dialysis for these patients, the current status should be taken into consideration, and patients should be informed about necessary precautions and recommendations.

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.

Gastrointestinal Symptoms in Type 1 Diabetes: Relationship With Autoimmune and Microvascular Complications

PURPOSE

To assess reported rates of gastrointestinal (GI) symptoms and their association with autoimmune diseases and microvascular complications in adults and children with type 1 diabetes.

METHODS

The Gastrointestinal Symptom Scale was used to assess GI symptom type and severity in 2370 patients with type 1 diabetes aged 8 to 45 years evaluated as part of a clinical trial screening for celiac disease (CD). The presence and severity of GI symptoms and relationships with demographic, clinical, and other diabetes-related factors were evaluated.

RESULTS

Overall, 1368 adults (57.7%) aged 19 to 45 years and 1002 (42.3%) pediatric patients aged 8 to 18 years were studied. At least 1 GI symptom was reported in 34.1% of adults as compared with 21.7% of children (P < 0.0001). Common symptoms in children included upper and lower abdominal pain while adults more frequently reported lower GI symptoms. Participants with GI symptoms had higher hemoglobin A1c (HbA1c) levels (68 ± 14mmol/mol; 8.35 ± 1.37%) than those without symptoms (66 ± 15mmol/mol; 8.22 ± 1.40%; P = 0.041). Patients with microvascular complications (nephropathy, retinopathy, and/or neuropathy) were 1.8 times more likely to report GI symptoms (95% CI: 1.26-2.60; P < 0.01) after adjusting for age and sex. No association was observed between GI symptoms and the presence of autoimmune conditions, including thyroid and biopsy-confirmed CD (odds ratio = 1.1; 95% CI: 0.86-1.42; P = 0.45).

MAIN CONCLUSIONS

These results highlight that GI symptoms are an important clinical morbidity and are associated with increasing age, duration of type 1 diabetes, HbA1c, and microvascular complications but not with autoimmune comorbidities including CD.

Disturbed gastric motility in patients with long-standing diabetes mellitus

Purpose: Gastric dysmotility has been reported in patients with long-standing diabetes mellitus (DM). Some patients with DM are diagnosed as diabetes gastroparesis and have several upper gastrointestinal (GI) symptoms such as appetite loss and abdominal pain. This study aimed to identify the relationship between gastric motility and upper GI symptoms in patients with long-standing DM. Method: This study was conducted among 23 patients with DM and 15 healthy controls. All the patients with DM were receiving insulin treatment and had at least one history of incidence of diabetic nephropathy, retinopathy or neuropathy. Gastric motility was evaluated using electrogastrography (EGG) and gastric emptying using the ¹³C-acetic acid breath test. The most severe upper gastrointestinal symptoms were assessed in all patients. Results: Compared to healthy controls, patients with long-standing DM showed a significantly lower percentage of normogastria at the postprandial state with a lower power ratio in EGG. Gastric emptying was significantly delayed in patients with DM in the overall analysis. Sixteen patients with DM (69.6%) demonstrated abnormalities in either gastric myoelectrical activity or gastric emptying. Among patients with abnormal EGG or delayed gastric emptying, 12 had some GI symptoms, compared with 3 patients with normal gastric motility. No significant correlation was observed between the gastric emptying parameters and HbA1c values. Conclusion: Patients with long-standing DM showed gastric dysmotility, including impaired gastric myoelectrical activity and delayed gastric emptying. Gastric dysmotility appears to be closely correlated with upper GI symptoms in patients with long-standing DM.

Targeting Treatment of Gastroparesis: Use of Clinical Tests to Guide Treatments

Gastroparesis presents with nausea, vomiting, and other upper gut symptoms, and is diagnosed by confirming delayed gastric emptying. A related condition, chronic unexplained nausea and vomiting, has similar symptoms but with normal emptying. Both conditions are managed using therapies with diverse mechanisms of action. Even though prokinetic treatments are proposed to improve gastroparesis by accelerating gastric emptying, there is limited evidence that they provide benefit by virtue of transit stimulating effects. Other tests can delineate alterations in other gut sensorimotor parameters in patients with suspected gastroparesis, but their relation to symptoms and their capability to guide treatment are largely unproved.

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.

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.

CCR2 upregulation in DRG neurons plays a crucial role in gastric hyperalgesia associated with diabetic gastropathy

Background

Diabetic gastropathy is a complex neuromuscular dysfunction of the stomach that commonly occurs in diabetes mellitus. Diabetic patients often present with upper gastrointestinal symptoms, such as epigastric discomfort or pain. The aim of this study was to assess gastric sensation in streptozocin-induced diabetes mellitus (DM) rats and to determine the contribution of C-C motif chemokine receptor 2 (CCR2) signaling to gastric hyperalgesia.

Results

DM rats showed signs of neuropathy (cutaneous mechanical hyperalgesia) from two weeks after streptozocin administration until the end of the experiment. Accelerated solid gastric emptying was observed at two weeks after streptozocin administration compared to the controls. Intense gastric hyperalgesia also developed in DM rats at two weeks after streptozocin administration, which was significantly reduced after intrathecal administration of the CCR2 antagonist INCB3344. Immunochemical analysis indicated that CCR2 expression was substantially upregulated in small and medium-sized dorsal root ganglia neurons of DM rats, although the protein level of monocyte chemoattractant protein-1, the preferred ligand for CCR2, was not significantly different between the control and DM groups.

Conclusions

These data suggest that CCR2 activation in nociceptive dorsal root ganglia neurons plays a role in the pathogenesis of gastric hyperalgesia associated with diabetic gastropathy and that CCR2 antagonist may be a promising treatment for therapeutic intervention.

Lower gastrointestinal symptoms are associated with worse glycemic control and quality of life in type 1 diabetes mellitus

OBJECTIVES

Lower gastrointestinal symptoms are not well characterized in people with type 1 diabetes, and the effects on quality of life and glycemic control are unknown. This study aimed to determine the prevalence of lower gastrointestinal symptoms and the effects on glycemic control and quality of life, and to investigate for underlying causes.

RESEARCH DESIGN AND METHODS

This is a prospective, cohort study in secondary care. Patients with type 1 diabetes completed a gastrointestinal symptom questionnaire and the Short Form 36 V.2 quality of life questionnaire and had their hemoglobin A1c measured. Patients with diarrhea were offered reassessment and investigation as per the national guidelines. Controls without diabetes were used to compare symptom prevalence and quality of life scores.

RESULTS

706 with type 1 diabetes (mean age 41.9 years) and 604 controls (mean age 41.9 years) were enrolled. Gastrointestinal symptoms were significantly more frequent in type 1 diabetes compared with controls, in particular constipation (OR 2.4), diarrhea (OR 2.5), alternating bowel habit (OR 2.1), abdominal pain (OR 1.4), floating stools (OR 2.7), bloating (OR 1.4) and flatulence (OR 1.3) (all p<0.05). Previous pancreatitis was more frequent in type 1 diabetes (OR 4.6), but other gastrointestinal conditions were not. Gastrointestinal symptoms were associated with poorer glycemic control (p<0.01) and worse quality of life particularly in those with diarrhea. Investigation of those with diarrhea, including those with alternating bowel habit, (n=105), identified a cause in 72.3% with subsequent change in management.

CONCLUSIONS

Gastrointestinal symptoms are twice as common in type 1 diabetes and associated with poorer quality of life and glycemic control. Investigation of diarrhea in people with type 1 diabetes leads to a high yield of treatable conditions and a change in management in about three-quarters.

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.

Emerging strategies for the treatment of gastroparesis

Gastroparesis is a syndrome of delayed gastric emptying in the absence of mechanical obstruction. Symptoms can be debilitating, affect nutritional states, and significantly impact patients' quality of life. The management of these patients can prove quite difficult to many providers. This article will review the current management recommendations of gastroparesis, discuss investigational medications and interventions, and summarize future directions of therapies targeting the underlying disease process. Current therapies are subdivided into those improving gastric motility and those directly targeting symptoms. Non-pharmacologic interventions, including gastric stimulator implantation and intra-pyloric botulinum toxic injection are reviewed. A discussion of expert opinion in the field, a look into the future of gastroparesis management, and a key point summary conclude the article.

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.

Impairments of the primary afferent nerves in a rat model of diabetic visceral hyposensitivity

Background

Diabetic neuropathy in visceral organs such as the gastrointestinal (GI) tract is still poorly understood, despite that GI symptoms are among the most common diabetic complications. The present study was designed to explore the changes in visceral sensitivity and the underlying functional and morphological deficits of the sensory nerves in short-term diabetic rats. Here, we compared the colorectal distension (CRD)-induced visceromotor response (VMR, an index of visceral pain) in vivo, the mechanosensitivity of colonic afferents ex vivo as well as the expression of protein gene product (PGP) 9.5 and calcitonin gene-related peptide (CGRP) in colon between diabetic (3–6 weeks after streptozotocin injection) and control (age-matched vehicle injection) rats.

Results

VMR was markedly decreased in the diabetic compared to the control rats. There was a significant decrease in multiunit pelvic afferent nerve responses to ramp distension of the ex vivo colon and single unit analysis indicated that an impaired mechanosensitivity of low-threshold and wide dynamic range fibers may underlie the afferent hyposensitivity in the diabetic colon. Fewer PGP 9.5- or CGRP-immunoreactive fibers and lower protein level of PGP 9.5 were found in the colon of diabetic rats.

Conclusions

These observations revealed the distinctive feature of colonic neuropathy in short-term diabetic rats that is characterized by a diminished sensory innervation and a blunted mechanosensitivity of the remnant sensory nerves.

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.

Future directions in the treatment of gastroparesis

Understanding of gastroparesis is evolving, in part because of systematic studies on the pathology, pathophysiology, and outcomes. It is clear that simply accelerating gastric emptying may not effectively control symptoms in this syndrome and more creative approaches are required that address aberrant sensation (vagal and spinal) as well as regional disturbances in motility. Further, with the growing recognition of a possible inflammatory basis, the prospects of disease modifying now seem realistic.

Measurement of gastric emptying by radiopaque markers in patients with diabetes: correlation with scintigraphy and upper gastrointestinal symptoms

BACKGROUND

Scintigraphy, the gold standard to measure gastric emptying, is expensive and not widely available. Therefore, we compared emptying of radiopaque markers (ROM) from the stomach, by use of fluoroscopy, with scintigraphy in patients with insulin-treated diabetes.

METHODS

On the same day we measured gastric emptying of 20 ROM using fluoroscopy and scintigraphic emptying of a standard solid meal. The subjects also completed a validated gastrointestinal (GI) symptom questionnaire.

KEY RESULTS

We included 115 patients with insulin-treated diabetes (median age 53, range 21-69 years; 59 women). A moderately strong correlation was demonstrated between scintigraphic (% retained at 2 h) and ROM emptying (markers retained at 6 h) (r = 0.47; P < 0.0001). Eighty-three patients had delayed gastric emptying with scintigraphy, whereas only 29 patients had delayed emptying of ROM. Of the 29 patients with delayed emptying of ROM, 28 also had delayed scintigraphic emptying. The sensitivity and specificity of the ROM test was 34% and 97%, respectively. Significant correlations were only noted between scintigraphic gastric emptying and GI symptom severity, with the strongest correlations for fullness/early satiety (r = 0.34; P < 0.001) and nausea/vomiting (r = 0.30; P < 0.001).

CONCLUSIONS & INFERENCES

A gastric emptying test with ROM is a widely available screening method to detect delayed gastric emptying in patients with diabetes, where a positive result seems reliable. However, a normal ROM test does not exclude delayed gastric emptying, and if the clinical suspicion of gastroparesis remains, scintigraphy should be performed. Results from scintigraphy also correlate with GI symptom severity, which ROM test did not.

Peripheral and central nervous contribution to gastrointestinal symptoms in diabetic patients with autonomic neuropathy

BACKGROUND & AIMS

Long-term diabetes mellitus (DM) has been associated with neuronal changes in the enteric, peripheral and/or central nervous system. Moreover, abnormal visceral sensation and gastrointestinal (GI) symptoms are seen in up to 75% of patients. To explore the role of diabetic autonomic neuropathy (DAN) in patients with long-standing DM, we investigated psychophysical responses and neuronal activity recorded as evoked brain potentials and dipolar source modelling.

METHODS

Fifteen healthy volunteers and 14 type-1 DM patients with DAN were assessed with a symptom score index characterizing upper GI abnormalities. Multichannel (62) electroencephalography was recorded during painful electrical stimulation of the lower oesophagus. Brain activity to painful stimulations was modelled using Brain Electrical Source Analysis (besa).

RESULTS

Diabetic patients had higher stimulus intensities to evoke painful sensation (p ≤ 0.001), longer latencies of N2 and P2 components (both p ≤ 0.001), and lower amplitudes of P1-N2 and N2-P2 complexes (p ≤ 0.001; p = 0.02). Inverse modelling of brain sources showed deeper bilateral insular dipolar source localization (p = 0.002). Symptom score index was negatively correlated with the depth of insular activity (p = 0.004) and positively correlated with insular dipole strength (p = 0.03).

CONCLUSION

DM patients show peripheral and central neuroplastic changes. Moreover, the role of abnormal insular processing may explain the appearance and persistence of GI symptoms related to DAN. This enhanced understanding of DAN may have future clinical and therapeutical implications.

Esophageal distension parameters as potential biomarkers of impaired gastrointestinal function in diabetes patients

BACKGROUND

Gastrointestinal (GI) symptoms, such as nausea, vomiting, bloating, postprandial fullness, and abdominal pain, are frequent in patients with diabetes mellitus (DM). The pathogenesis is complex and multi-factorial. To determine easy accessible and valid biomarkers for disordered GI function in DM patients, we aimed to study esophageal mechanical parameters and their relation to symptoms typically arising from the digestive tract.

METHODS

Seventeen patients with longstanding DM and GI symptoms and 13 healthy controls were studied using ultrasound monitored esophageal distension. The sensory response was recorded and their symptoms registered. Biomechanical parameters, such as compliance and stiffness were computed from luminal diameters during distension based on the ultrasound images and from pressure data. Biomechanical and sensory parameters were correlated with the clinical data.

KEY RESULTS

Diabetes patients had reduced esophageal sensitivity compared with controls (P = 0.046). The esophageal compliance was reduced (P = 0.004) and the esophageal stiffness was increased (P = 0.004) in the diabetes patients. Among patients, both postprandial fullness/early satiety and bloating correlated negatively to the esophageal compliance parameters (all P < 0.05).

CONCLUSIONS & INFERENCES

Patients with long-standing DM and GI symptoms had reduced esophageal sensitivity together with reduced compliance and increased stiffness, which were correlated to the patients' GI symptoms. Biomechanical parameters obtained during distension may serve as biomarker for similar pathophysiologic effects of diabetes in the stomach and small bowel. They may contribute to our understanding of the pathophysiology underlying GI dysfunction and symptoms in patients with longstanding DM.

Gastrointestinal symptoms in diabetes mellitus, and their relation to anxiety and depression

BACKGROUND

Prevalence of gastrointestinal (GI) symptoms is increased in patients with diabetes mellitus. In general, GI symptoms are influenced by psychological factors such as anxiety and depression, but little is known about this association in diabetic patients.

AIM

We tested the hypothesis that anxiety and depression have major impact on GI symptoms in diabetic patients.

METHODS

280 diabetic patients and 355 non-diabetic, age and sex matched controls were studied by validated questionnaires: (1) PAGI-SYM and GSRS for common GI symptoms and (2) HADS for anxiety and depression. Data were compared using logistic regression analysis.

RESULTS

Patients with diabetes scored significantly (p<0.05) higher on the symptoms diarrhea (OR 1.64, 95% CI 1.05-2.56), early satiety (OR 2.50, 95% CI 1.39-4.49) and bloating (OR 1.58, 95% CI 1.03-2.43), but not on other symptoms. Prevalence of anxiety and depression (HADS scores ≥ 8) in diabetics and controls was respectively 27.5% and 20.6% for anxiety (p<0.05), and 19.6% and 13.4% for depression (p<0.05). After adjusting for anxiety and depression only the GI symptom "early satiety" remained significantly more prevalent in the patients with diabetes.

CONCLUSIONS

The prevalence of the gastrointestinal symptoms diarrhea, bloating and early satiety, and of anxiety and depression is significantly increased in our cohort of predominantly patients with longstanding type 2 diabetes mellitus compared to controls. When adjusted for anxiety and depression, only the gastrointestinal symptom "early satiety" remained more prevalent in these diabetic patients, pointing to a somatic based origin. Thus, in our diabetic population psychological factors to a large extent are associated with gastrointestinal symptoms and should be taken into account when considering treatment of the gastrointestinal symptoms.

Prevalence of gastroparesis-related symptoms in an unselected cohort of patients with Type 1 diabetes

BACKGROUND

The prevalence of diabetic gastroparesis is not well defined because of discrepancy between objective measurements, i.e. gastric emptying time, and symptoms experienced by patients. Furthermore most studies have been performed on small selected cohorts.

OBJECTIVE

To determine the prevalence of clinical symptoms of diabetic gastroparesis in a large unselected cohort of out-patients with Type 1 diabetes.

METHODS

1028 patients with Type 1 diabetes attending a specialized diabetes clinic were mailed a validated questionnaire; "patient assessment of upper gastrointestinal disorders-symptom severity index", in which a subset of questions measures symptoms of gastroparesis (GCSI; Gastroparesis Cardinal Symptom Index). Response rate was 74.4% (n=765). All patients were classified according to presence or absence of late diabetic complications and clinical and paraclinical data were obtained.

RESULTS

A GCSI Total Score ≥1.90 signified definite symptoms of gastroparesis (n=102) and patient charts were investigated for concomitant illness and/or medication influencing gastric emptying. In 30 patients an alternative etiology was revealed, leaving 72 (9.8%) patients with symptoms related to diabetic gastroparesis. Only 8 patients were previously diagnosed. HbA(1c) levels were significantly higher in patients with diabetic gastroparesis (8.4±1.3 vs. 8.2±1.2 respectively, p=0.02). Furthermore, patients with diabetic gastroparesis had more retinopathy (p=0.006) and peripheral polyneuropathy (16.7% vs. 6.7%, p<0.001) and there was a trend for diabetic nephropathy being more common (p=0.08).

CONCLUSIONS

Symptoms of diabetic gastroparesis affect approximately 10% of patients with Type 1 diabetes in a specialized diabetes clinic and are associated with poor glycemic control and other late diabetic complications.

Neostigmine-induced contraction and nitric oxide-induced relaxation of isolated ileum from STZ diabetic guinea pigs

Both delayed gastrointestinal transit and autonomic neuropathy have been documented in patients with diabetes mellitus. The mechanism of neostigmine, an agent that mimics release of acetylcholine from autonomic neurons by prokinetic agents, to contract smooth muscle, despite dysfunctional enteric neural pathways, was determined using isolated ilea from STZ-treated and control guinea pigs. Both bethanechol- and neostigmine-induced contractions were stronger in diabetic ileum. Bethanechol-induced contractions of control but not diabetic ileum were increased by low dose scopolamine suggesting reduced activation of presynaptic muscarinic autoreceptors in diabetic ileum. The muscarinic receptor antagonist 4-DAMP strongly, but the nicotinic receptor antagonist hexamethonium only weakly, reduced neostigmine-induced contractions of control and diabetic ilea. The amount of acetylcholine, inferred from tissue choline content, was increased in diabetic ileum. Nicotinic neural and noncholinergic postjunctional smooth muscle receptors contributed more strongly to neostigmine-induced contractions in diabetic than control ileum. Relaxation of diabetic ileum by exogenous nitric oxide generated from sodium nitroprusside was comparable to control ileum, but smooth muscle relaxation by l-arginine using neuronal nitric oxide synthase to generate nitric oxide was weaker in diabetic ileum with evidence for a role for inducible nitric oxide synthase. Despite autonomic neuropathy, neostigmine strongly contracted ileum from diabetic animals but by a different mechanism including stronger activation of postjunctional muscarinic receptors, greater synaptic acetylcholine, stronger activation of noncholinergic excitatory pathways, and weaker activation of inhibitory pathways. A selective medication targeting a specific neural pathway may more effectively treat disordered gastrointestinal transit in patients with diabetes mellitus.

Characteristics of patients with chronic unexplained nausea and vomiting and normal gastric emptying

BACKGROUND & AIMS

Chronic nausea and vomiting with normal gastric emptying is a poorly understood syndrome; we analyzed its characteristics.

METHODS

We collected and analyzed data from 425 patients with chronic nausea and vomiting, enrolled at 6 centers by the Gastroparesis Clinical Research Consortium in the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Registry.

RESULTS

Among the patients, 319 (75%) had delayed emptying, defined by the results of a standardized, low-fat meal, and 106 had normal gastric emptying. Patients with or without delayed emptying did not differ in age, sex, or race, although those with normal gastric emptying were less likely to be diabetic. Symptom severity indexes were similar between groups for nausea, retching, vomiting, stomach fullness, inability to complete a meal, feeling excessively full after meals, loss of appetite, bloating, and visibly larger stomach. There were no differences in health care utilization, quality of life indexes, depression, or trait anxiety scores. However, state anxiety scores were slightly higher among patients with delayed gastric emptying. Total gastroparesis cardinal symptom index scores were not correlated with gastric retention after 2 or 4 hours in either group. Patients with the syndrome were not adequately captured by the stand-alone criteria for the Rome III diagnoses of chronic idiopathic nausea and functional vomiting. With rare exceptions, the diagnosis remained stable after a 48-week follow-up period.

CONCLUSIONS

Patients with nausea and vomiting with normal gastric emptying represent a significant medical problem and are, for the most part, indistinguishable from those with gastroparesis. This syndrome is not categorized in the medical literature--it might be a separate clinical entity.

Diabetic gastroparesis-backwards and forwards

Diabetic gastroparesis was once thought to be rare, associated with a poor prognosis, and to affect only patients with type 1 diabetes and irreversible autonomic neuropathy. A landmark study conducted by Horowitz et al. and published in JGH in 1986 paved the way for further studies to examine the pathophysiology, natural history and prognosis of diabetic gastroparesis, as well as its optimal management. This review summarizes the developments in knowledge gained over the last ∼25 years that have led to understanding about normal and disordered gastric emptying in diabetes, with a particular emphasis on the inter-relationship between the rate of gastric emptying and the regulation of blood glucose.

Regional differences in neostigmine-induced contraction and relaxation of stomach from diabetic guinea pig

Delayed gastric emptying and autonomic neuropathy have been documented in patients with diabetes mellitus. Some medications used to treat delayed gastric emptying enhance release of acetylcholine from autonomic neurons to strengthen gastric contractions. Autonomic coordination among gastric regions may be altered in diabetes resulting in poor outcomes in response to prokinetic drugs. Fundus, antrum, and pylorus from STZ or control guinea pigs were treated with neostigmine to mimic release of acetylcholine from autonomic neurons by prokinetic agents. In diabetic animals, neostigmine-induced contractions were weaker in fundus and pylorus but similar in antrum. The muscarinic receptor antagonist 4-DAMP or the nicotinic receptor antagonist hexamethonium reduced neostigmine-induced contractions. Activation of presynaptic muscarinic receptors on nitrergic neurons was impaired in fundus and antrum from diabetic animals. Nerve-stimulated contractions and relaxations, number of nNOS myenteric neurons, and tissue choline content were reduced in fundus from diabetic animals. Despite reduced number of myenteric neurons, tissue choline content was increased in antrum from diabetic animals. Since cholinergic motility of each gastric region was affected differently by diabetes, prokinetic drugs that nondiscriminately enhance acetylcholine release from autonomic neurons may not effectively normalize delayed gastric emptying in patients with diabetes and more selective medications may be warranted.

Gastrointestinal symptoms in type-1 diabetes: is it all about brain plasticity?

BACKGROUND AND AIMS

Autonomic neuropathy seems to play a central role in the development of gastrointestinal symptoms in diabetes. In order to explore the neuronal mechanisms behind the symptoms we evaluated the brain processing of painful visceral stimuli.

METHODS

Evoked brain potentials were recorded to assess the response to painful oesophageal electrical stimuli in 15 healthy volunteers and 14 type-1 diabetes patients with autonomic neuropathy and related gastrointestinal symptoms. Source reconstruction analysis (fixed Multiple Signal Classification (MUSIC) algorithm) was applied to estimate the location of the evoked electrical activity in the brain.

RESULTS

The patients had increased oesophageal sensory thresholds compared to the controls (P=0.004). The latencies of the evoked brain potentials at vertex (Cz) were increased (P=0.007) and amplitudes reduced (P=0.011) in diabetics. Compared with controls the patients had a posterior shift of the electrical sources in the anterior cingulate cortex at 54 ms, and additional sources close to the posterior insula at 95 ms and in medial frontal gyrus at 184 ms.

CONCLUSIONS

There is evidence of altered central processing to visceral stimulation, and both peripheral and central mechanisms seem involved. Central neuronal reorganisation may contribute to our understanding of the gastrointestinal symptoms in patients with diabetic autonomic neuropathy and this may guide development and evaluation of new treatment modalities.

Mechanisms of symptomatic improvement after gastric electrical stimulation in gastroparetic patients

The aims were to investigate the effects of gastric electrical stimulation (GES) on autonomic function, gastric distention and tone, and central control mechanisms in gastroparetic patients. Ten gastroparetic patients refractory to standard medical therapy participated in this study and data were collected at baseline, within two weeks before surgery for implantation of GES system, and at follow-up sessions between 6 and 12 weeks after GES therapy was initiated. In each session, electrocardiogram, electrogastrogram (EGG) and gastric barostat measurements were conducted before and after a caloric liquid meal. Positron Emission Tomography (PET) brain scans were performed on a separate day. During GES therapy there was a significant increase in the discomfort threshold for mean pressure from 21 mmHg at baseline to 25 mmHg at follow-up, and for mean volume from 561 mL to 713 mL. A significant increase in the postprandial EGG power (amplitude) was observed between baseline and follow up. The sympathovagal balance was significantly decreased after GES therapy, indicating a significant increase in vagal activity. The cumulative PET data showed an increase in quantitative radioactive counts relative to the standardized data base in both the thalamic and caudate nuclei after chronic GES therapy. We conclude that our data suggest that the symptomatic improvement achieved by GES in gastroparesis is best explained by activation of vagal afferent pathways to influence CNS control mechanisms for nausea and vomiting accompanied by enhanced vagal efferent autonomic function and decreased gastric sensitivity to volume distention which enhances postprandial gastric accommodation.

Factors associated with symptom response to pyloric injection of botulinum toxin in a large series of gastroparesis patients

Case series report symptom reductions after pyloric botulinum toxin injection in gastroparesis, but small controlled trials show no benefit. Factors that enhance response to therapy are undefined. A retrospective analysis of 179 gastroparetics undergoing pyloric botulinum toxin injection from 2001 to 2007 assessed responses relating to drug dosing, demographic factors, comorbidities, and gastric function. Overall, there was a decrease in gastroparetic symptoms 1-4 months after pyloric botulinum toxin injection in 92 patients (51.4%). Increasing the botulinum toxin dose significantly improved clinical responses of patients who provided information on symptoms after therapy (100 units: 54.2%; 200 units: 76.7%; P=0.02). Other factors that improved response to botulinum toxin included female gender, age <50 years, and nondiabetic nonpostsurgical etiology (all P<0.05). Eighty-seven patients received 307 follow-up injections. A clinical response to a second injection was observed in 73.4% of evaluable patients. In conclusion, responses to pyloric botulinum toxin depended on dose and were maintained on repeat injection. Subgroup analyses defined subgroups likely to benefit. These findings provide the foundation for large, controlled trials of high-dose botulinum toxin in selected gastroparesis subsets.

Diabetes mellitus and gastric emptying: questions and issues in clinical practice

It is long known that both type 1 and type 2 diabetes can be associated with changes in gastric emptying; a number of publications have linked diabetes to delayed gastric emptying of variable severity and often with poor relationship to gastrointestinal symptomatology. In contrast, more recent studies have reported accelerated gastric emptying when adjusted for glucose concentration in patients with diabetes, indicating a reciprocal relationship between gastric emptying and ambient glucose concentrations. This review proposes that gastroparesis or gastroparesis diabeticorum, a severe condition characterized by a significant impairment of gastric emptying accompanied by severe nausea, vomiting, and malnutrition, is often overdiagnosed and not well contrasted with delays in gastric emptying. The article offers a clinically relevant definition of gastroparesis that should help differentiate this rare condition from (often asymptomatic) delays in gastric emptying. The fact that delayed gastric emptying can also be observed in non-diabetic individuals under experimental conditions in which hyperglycaemia is artificially induced suggests that a delay in gastric emptying rate when blood glucose concentrations are high is actually an appropriate physiological response to hyperglycaemia, slowing further increases in blood glucose. The article discusses the strengths and weaknesses of various methodologies for assessing gastric emptying, especially with respect to the diabetes population, and reviews newer diabetes therapies that decelerate the rate of gastric emptying. These therapies may be a beneficial tool in managing postprandial hyperglycaemia because they attenuate rapid surges in glucose concentrations by slowing the delivery of meal-derived glucose.

Relationship between dyspeptic symptoms and proximal stomach function in diabetic patients

AIM: To investigate the relationship between dyspeptic symptoms and proximal stomach function in diabetic patients (DM).

METHODS: Forty-four DM patients were enrolled in the study. After scoring symptoms, the patients were divided into two groups: those with dyspepsia (n = 24) and those without gastrointestinal symptoms (n = 20). The water load test was performed to determine the function of proximal stomach. The area and circumference of proximal (cardia) and distal stomach (antrum) were measured by ultrasonography.

RESULTS: Of 24 diabetic patients with dyspepsia, 18 (75%) had abdominal distention, 16 (66.7%) had epigastric discomfort (66.7%) and 16 (66.7%) had constipation. Proximal stomach function was impaired more seriously in patients with dyspepsia. There was no correlation between proximal stomach function and total dyspeptic symptom score. The scores of epigastric discomfort and abdominal distention were negatively correlated with the changes in the area and circumference of gastric fundus when different water loads were given.

CONCLUSION: Abdominal distention, epigastric discomfort and constipation are common dyspeptic symptoms in diabetic patients. The presence of epigastric discomfort and abdominal distension indicates the impairment of proximal stomach function.

Diabetic gastroparesis: diagnosis and management

Gastric emptying is frequently abnormal in patients with long-standing type 1 and type 2 diabetes mellitus. Symptoms commonly associated with disordered gastric emptying include nausea, vomiting, bloating and epigastric pain, while patients are also at risk of malnutrition, weight loss, impaired drug absorption, disordered glycaemic control and poor quality of life. Although often attributed to the presence of irreversible autonomic neuropathy, acute hyperglycaemia represents a potentially reversible cause of gastric dysfunction in diabetes. Scintigraphy represents the gold standard for measuring gastric emptying. The management of diabetic gastroparesis is less than optimal, partly because the pathogenesis has not been clearly defined. Treatment approaches include dietary modification and optimization of glycaemia, and the use of prokinetic drugs, while novel therapies such as gastric electrical stimulation are the subject of ongoing investigation.

Tests of gastric neuromuscular function

Tests of gastric neuromuscular function are used to evaluate patients with symptoms referable to the upper digestive tract. These symptoms can be associated with alterations in the rates of gastric emptying, impaired accommodation, heightened gastric sensation, or alterations in gastric myoelectrical function and contractility. Management of gastric neuromuscular disorders requires an understanding of pathophysiology and treatment options as well as the appropriate use and interpretation of diagnostic tests. These tests include measures of gastric emptying; contractility; electrical activity; regional gastric motility of the fundus, antrum, and pylorus; and tests of sensation and compliance. Tests are also being developed to improve our understanding of the afferent sensory pathways from the stomach to the central nervous system that mediate gastric sensation in health and gastric disorders. This article reviews tests of gastric function and provides a basic description of the tests, the methodologies behind them, descriptions of the physiology that they assess, and their clinical utility.

Coupling and propagation of normal and dysrhythmic gastric slow waves during acute hyperglycaemia in healthy humans

Acute hyperglycaemia in healthy humans disrupts slow wave rhythm similar to that observed in diabetic gastropathy, but hyperglycaemic effects on regional dysrhythmias, power, coupling and propagation are unexplored. Using mucosal mapping, we aimed to demonstrate that hyperglycaemia elicits region-specific tachygastria and evokes slow wave uncoupling between adjacent regions. Catheters with bipolar electrodes were affixed 10.5, 6 and 2 cm from the pylorus during endoscopy with midazolam in 10 healthy humans. Recordings were obtained for 1 h under basal conditions and for 1 h with hyperglycaemic clamping to 250 mg dL(-1). In basal recordings, proximal and distal slow wave frequencies were similar [2.91 +/- 0.05 vs 2.81 +/- 0.09 cycles per minute (cpm)]. Tachygastria (>3.6 cpm) was present 1.7 +/- 1.1% of the time proximally and 3.3 +/- 1.8% distally and localized to one lead 67% of the time. Proximal to distal gradients in signal power and power variability were observed. Coupling between adjacent sites was 78 +/- 2% with propagation velocities of 1.3 +/- 0.1 cm s(-1). 2 +/- 1% of segments showed >50% uncoupling. Hyperglycaemic clamping increased mean proximal (3.18 +/- 0.11 cpm) and distal (3.50 +/- 0.12 cpm) frequencies and proximal (15 +/- 6%) and distal (32 +/- 9%) tachygastria (all P < 0.01) that localized to one lead 80% of the time. During periods of normal frequency, coupling decreased proximally (54 +/- 6%) and distally (47 +/- 4%) (P < 0.01). 55 +/- 8% of segments showed >50% uncoupling (P < 0.01). In conclusion, gastric slow waves show stable, highly coupled rhythms under basal conditions. Hyperglycaemia elicits isolated tachygastrias and uncoupling of normal slow waves that are most prominent distally. These findings provide a foundation for studying slow wave conduction defects in diabetic gastropathy.

Central neuronal mechanisms of gastric electrical stimulation in diabetic gastroparesis

OBJECTIVE

The mechanisms underlying symptom improvement in gastric electrical stimulation (GES) are not fully understood. Modulation of the central nervous system excitability may be involved. The objective of the study was to investigate the central effects of GES, including the possible modulation of the visceral sensory nervous system.

MATERIAL AND METHODS

A gastric electrical stimulator was implanted in seven diabetic patients with medically refractory gastroparesis. A double-blinded protocol was used to investigate the patients at baseline and one month after recovery with the stimulator turned on and off (1-month periods). The following assessments were carried out: mechanical, thermal and electrical stimulations with sensory recordings in the esophagus and duodenum, and standardized, self-administered, daily symptom questionnaires.

RESULTS

No difference was found between baseline and the on- and off periods in overall gut pain thresholds across all stimulus modalities in the esophagus (p=0.63), duodenum (p=0.19) or esophagus and duodenum combined (p=0.76). No difference in the sensory response to mechanical stimulation was found in the esophagus before (all p>0.31) and after (all p>0.43) smooth muscle relaxation with butylscopolamine. Similar findings were observed in the duodenum. No differences were found in thermal sensitivity (esophagus (p=0.67) and duodenum (p=0.17)), sensory response to electrical stimulation (esophagus (p=0.57) and duodenum (p=0.52)) or induced somatic referred pain areas (esophagus (p=0.75) and duodenum (p=0.51)). No difference was seen in the induced somatic referred pain areas or self-reported symptoms.

CONCLUSIONS

No evidence was found for GES-induced modulation of the visceral sensory system and central excitability. However, GES has been proven to modulate the central nervous system in animal studies, necessitating further human experiments in order unambiguously to establish the possible central effects of GES.

Effects of amitriptyline on gastric sensorimotor function and postprandial symptoms in healthy individuals: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Low-dose tricyclic antidepressants have been used to treat chronic somatic and gastrointestinal pain disorders, including refractory functional dyspepsia. However, there are only limited data on the effects of these drugs on upper gastrointestinal function.

AIM

To compare the effects of two doses of amitriptyline (AMT) and placebo on gastric accommodation, emptying, satiation, and postprandial symptoms in healthy volunteers.

METHODS

Using a parallel-group, double-blind, placebo-controlled design, 41 healthy volunteers were randomized to AMT 25 mg, AMT 50 mg, or placebo for 2 wk. During the final 3 days of therapy, the following end points were assessed: fasting and postprandial gastric volumes, 2- and 4-h gastric emptying, time and volume to maximum satiation using a nutrient drink test, and postprandial symptoms 30 min later using 10-cm visual analog scales. AMT and metabolite levels were measured.

RESULTS

AMT slowed gastric emptying at 2 h (median 75% for placebo, 57% for AMT 25 mg, 67% for AMT 50 mg; P= 0.037) and 4 h (median 98% for placebo, 96% for AMT 25 mg, 92% for AMT 50 mg; P= 0.003). AMT did not affect gastric volumes or satiation volume, but it did reduce nausea scores at 30 min in a dose-dependent manner (median 2.1 for placebo, 0.9 for AMT 25 mg, and 0.0 for AMT 50 mg; P= 0.009).

CONCLUSION

In healthy volunteers, AMT slows gastric emptying of solids, but it does not significantly affect gastric volumes or satiation. AMT reduces nausea after challenge with a high calorie liquid load.

Management of gastroparesis

Gastroparesis presents with nausea, vomiting, early satiety and abdominal discomfort, as well as a range of nongastrointestinal manifestations in association with delays in gastric emptying. The disorder may be a consequence of systemic illnesses, such as diabetes mellitus, occur as a complication of gastroesophageal surgery or develop in an idiopathic fashion and may mimic other disorders with normal gastric emptying. Some cases of idiopathic gastroparesis present after a viral infection. Management relies primarily on therapies that accelerate gastric emptying or reduce vomiting, although endoscopic or surgical options are available for refractory cases. Current research is focusing on the cellular and molecular mechanisms underlying development of delayed gastric emptying, as well as factors unrelated to motor dysfunction that may elicit some symptoms. Future pharmaceuticals will target the contractile and nonmotor defects via novel pathways. Novel electrical stimulation techniques will be employed either alone or in combination with medications.

Visceral hypersensitivity and impaired accommodation in refractory diabetic gastroparesis

The pathophysiology of persistent gastrointestinal (GI) symptoms in patients with diabetic gastroparesis is poorly understood. Our aim was to evaluate gastric sensation and accommodation to a meal in patients with diabetic gastroparesis and refractory symptoms. We performed intermittent, phasic balloon distensions of the stomach using a gastric barostat device in 18 patients with diabetes and gastroparesis unresponsive to prokinetic therapy and in 13 healthy volunteers. We assessed the biomechanical, sensory and accommodation responses of the stomach, during fasting and after liquid meal. During balloon distension, the sensory thresholds for discomfort were lower (P < 0.02) in patients with diabetes than those in controls, in both the fasting and the postprandial states. The accommodation response to a meal was significantly impaired (P = 0.01) in patients with diabetes when compared to controls, although fasting gastric tone was similar (P = 0.08). Patients with diabetic gastroparesis and refractory GI symptoms demonstrate sensori-motor dysfunction of the stomach, comprising either impaired accommodation, gastric hypersensitivity or both. An objective evaluation of these biomechanical and sensory properties may provide valuable mechanistic insights that could guide therapy.

Type 1 diabetes and gastroparesis: diagnosis and treatment

Patients with gastroparesis present with gastrointestinal symptoms and non-gastrointestinal manifestations in association with objective delays in gastric emptying. The condition complicates the course of many patients with type 1 diabetes mellitus, usually in those with longstanding poor glycemic control with other associated diabetic complications. The diagnosis is made by directed evaluation to exclude organic diseases that can mimic the clinical presentation of gastroparesis, coupled with verification of gastric retention. Current therapy relies on dietary modifications, medications to stimulate gastric evacuation, and agents to reduce vomiting. Endoscopic and surgical options are increasingly used in patients who are refractory to drug treatment.

Dyspepsia in childhood and adolescence: insights and treatment considerations

Functional dyspepsia (FD) is common in children, with as many as 80% of those being evaluated for chronic abdominal pain reporting symptoms of epigastric discomfort, nausea, or fullness. It is known that patients with persistent complaints have increased comorbidities such as depression and anxiety. The interaction with psychopathologic variables has been found to mediate the association between upper abdominal pain and gastric hypersensitivity. These observations suggest that abnormal central nervous system processing of gastric stimuli may be a relevant pathophysiologic mechanism in FD. Despite increased understanding, no specific therapy has emerged; however, recent nonpharmacological-based options such as hypnosis may be effective. Novel approaches, including dietary manipulation and use of nutraceuticals such as ginger and Iberogast (Medical Futures Inc., Ontario, Canada), may also be considered.

Impaired contractility and remodeling of the upper gastrointestinal tract in diabetes mellitus type-1

AIM: To investigate that both the neuronal function of the contractile system and structural apparatus of the gastrointestinal tract are affected in patients with longstanding diabetes and auto mic neuropathy.

METHODS: The evoked esophageal and duodenal contractile activity to standardized bag distension was assessed using a specialized ultrasound-based probe. Twelve type-1 diabetic patients with autonomic neuropathy and severe gastrointestinal symptoms and 12 healthy controls were studied. The geometry and biomechanical parameters (strain, tension/stress, and stiffness) were assessed.

RESULTS: The diabetic patients had increased frequency of distension-induced contractions (6.0 ± 0.6 vs 3.3 ± 0.5, P < 0.001). This increased reactivity was correlated with the duration of the disease (P = 0.009). Impaired coordination of the contractile activity in diabetic patients was demonstrated as imbalance between the time required to evoke the first contraction at the distension site and proximal to it (1.5 ± 0.6 vs 0.5 ± 0.1, P = 0.03). The esophageal wall and especially the mucosa-submucosa layer had increased thickness in the patients (P < 0.001), and the longitudinal and radial compressive stretch was less in diabetics (P < 0.001). The esophageal and duodenal wall stiffness and circumferential deformation induced by the distensions were not affected in the patients (all P > 0.14).

CONCLUSION: The impaired contractile activity with an imbalance in the distension-induced contractions likely reflects neuronal abnormalities due to autonomic neuropathy. However, structural changes and remodeling of the gastrointestinal tract are also evident and may add to the neuronal changes. This may contribute to the pathophysiology of diabetic gut dysfunction and impact on future management of diabetic patients with gastrointestinal symptoms.

Gastroparesis: symptoms, evaluation, and treatment

Gastroparesis presents with gastrointestinal symptoms and nongastrointestinal manifestations in association with objective delays in gastric emptying. The condition may complicate several systemic disorders or may be idiopathic in nature. The diagnosis is made by directed evaluation to exclude organic diseases, which can mimic the clinical presentation of gastroparesis coupled with quantification of gastric emptying. Current therapies rely on dietary modifications, medications to stimulate gastric evacuation, and agents to reduce vomiting. Endoscopic and surgical options are increasingly used for cases refractory to medication treatment.

Mechanisms of disease: the pathological basis of gastroparesis--a review of experimental and clinical studies

The pathogenesis of gastroparesis is complicated and poorly understood. This lack of understanding remains a major impediment to the development of effective therapies for this condition. Most of the scientific information available on the pathogenesis of gastroparesis has been derived from experimental studies of diabetes in animals. These studies suggest that the disease process can affect nerves (particularly those producing nitric oxide, but also the vagus nerve), interstitial cells of Cajal and smooth muscle. By contrast, human data are sparse, outdated and generally inadequate for the validation of data obtained from experimental models. The available data do, however, suggest that multiple cellular targets are involved. In practice, though, symptoms seldom correlate with objective measures of gastric function and there is still a lot to learn about the pathophysiology of gastroparesis. Future studies should focus on understanding the molecular pathways that lead to gastric dysfunction, in animal models and in humans, and pave the way for the development of rational therapies.

Gastric electrical stimulation with parameters for gastroparesis enhances gastric accommodation and alleviates distention-induced symptoms in dogs

Gastric electrical stimulation (GES) improves symptoms in patients with gastroparesis. We sought to determine if stimulation at fundus with parameters used for gastroparesis could affect gastric accommodation and distention-induced symptoms in dogs. Nine dogs were implanted with a gastric cannula at the anterior stomach and 1 pair of stimulation electrodes in the fundus. Assessment of gastric accommodation and a series of gastric distention were performed using a barostat. Stimulation parameters were of short pulse trains of 14 Hz, 5 mA, 0.3 ms, and 0.1 s on, 5 s off. GES at fundus significantly decreased fasting gastric tone. Fasting gastric volume was significantly increased from 56.3+/-10.4 mL at baseline to 102.4+/-23.1 mL with stimulation (P=.011). Postprandial gastric accommodation was significantly enhanced with stimulation. The extent of accommodation increased from 249.3+/-39.9 mL in the control session to 325.8+/-25.1 mL with stimulation (P=.011). Symptom scores induced by balloon distention of the stomach were significantly lower during stimulation in comparison with those of baseline (P=.016). In conclusion, GES with parameters for gastroparesis enhances postprandial gastric accommodation and reduces visceral perception in normal dogs. This effect, if seen also in humans, may explain in part the symptomatic improvement associated with GES therapy in patients with gastroparesis.

Gastroparesis: clinical update

Gastroparesis refers to chronically abnormal gastric motility characterized by symptoms suggestive of mechanical obstruction and delayed gastric emptying in the absence of mechanical obstruction. It may be idiopathic or attributable to neuropathic or myopathic abnormalities, such as diabetes mellitus, postvagotomy, postviral infection, and scleroderma. Dietary and behavioral modification, prokinetic drugs, and surgical interventions have been used in managing patients with gastroparesis. Although mild gastroparesis is usually well managed with these treatment options, severe gastroparesis may be very difficult to control and may require referral to a specialist center if symptoms are intractable despite pharmacological therapy and dietetic support. New advances in drug therapy, botulinum toxin injection, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. This article critically reviews the advances in the field from the perspective of the clinician.

Treatment of gastroparesis: a multidisciplinary clinical review

This clinical review on the treatment of patients with gastroparesis is a consensus document developed by the American Motility Society Task Force on Gastroparesis. It is a multidisciplinary effort with input from gastroenterologists and other specialists who are involved in the care of patients with gastroparesis. To provide practical guidelines for treatment, this document covers results of published research studies in the literature and areas developed by consensus agreement where clinical research trials remain lacking in the field of gastroparesis.

Gastric compliance in bulimia nervosa

Bulimia nervosa (BN) is a psychiatric illness characterized by eating binges followed by inappropriate behavioral attempts to compensate for the binges, usually vomiting or laxative abuse. Patients with BN have disturbances in the development of satiety during a meal as well as disturbances in functions of the upper gastrointestinal tract such as slowed gastric emptying, impaired gastric accommodation reflex and blunted cholecystokinin release. The present study examined gastric compliance and sensory responses to gastric distention in women with BN and controls. Sixteen women with BN and 13 healthy control subjects swallowed an inflatable bag that was placed in the proximal stomach. The bag was inflated to produce increasing steps of pressure against the stomach wall, before and after consumption of a 200 ml (200 Kcal) liquid meal. Pressure and volume were recorded for 2-min periods, beginning at 0 mm Hg pressure and increasing in steps of 2 mm Hg until subjects reported discomfort, gastric volume reached 600 ml, or pressure reached 20 mm Hg. At each pressure step subjects made sensory ratings. Gastric compliance was calculated as the slope of the best-fit straight line of each subject's gastric volume vs. gastric pressure. There was a significant postmeal increase in gastric compliance in both groups of subjects but there was no difference in compliance between patients with BN and controls. Patients with BN appeared to have diminished sensitivity to gastric distention. In conclusion, although other studies have described gastrointestinal abnormalities associated with BN, the current study found gastric compliance of patients with BN to be normal.