'Gastric' hypoglycaemia--an important concept in diabetes management

Pathogenesis and management of diabetic gastroparesis: An updated clinically oriented review

BACKGROUND AND AIMS

Diabetic gastroparesis (DGp) is a common and preventable complication of uncontrolled diabetes mellitus (D.M.) and significantly affects the Quality of Life of patients. Diagnosis and management present as a clinical challenge due to the disease's complexity and limited effective therapeutic options. This review aims to comprehensively outline the pathogenesis, diagnosis, and management of diabetic gastroparesis, evaluating evolving approaches to guide clinicians and provide future recommendations.

METHODS

A literature review was conducted on scholarly databases of PubMed, Google Scholar, Scopus and Web of Science encompassing published articles, gray literature and relevant clinical guidelines. Data were synthesized and analyzed to provide a comprehensive overview of diabetic gastroparesis, focusing on pathogenesis, diagnosis, and management.

RESULTS

The review intricately explores the pathogenesis contributing to diabetic gastroparesis, emphasizing autonomic neuropathy, oxidative stress, inflammation, hormonal dysregulation, microbiota alterations, and gastrointestinal neuropathy. Primary management strategies are underscored, including lifestyle modifications, symptom relief, and glycemic control. The discussion encompasses pharmacological and surgical options, highlighting the importance of a multidisciplinary approach involving various healthcare professionals for comprehensive patient care.

CONCLUSION

This review offers a thorough understanding of pathogenesis, diagnosis, and management of diabetic gastroparesis, underlining evolving approaches for clinicians. A multidisciplinary approach is crucial to address both the physical and mental health aspects of diabetes and its complications.

Inter-relationships between gastric emptying and glycaemia: Implications for clinical practice

Gastric emptying (GE) exhibits a wide inter-individual variation and is a major determinant of postprandial glycaemia in health and diabetes; the rise in blood glucose following oral carbohydrate is greater when GE is relatively more rapid and more sustained when glucose tolerance is impaired. Conversely, GE is influenced by the acute glycaemic environment acute hyperglycaemia slows, while acute hypoglycaemia accelerates it. Delayed GE (gastroparesis) occurs frequently in diabetes and critical illness. In diabetes, this poses challenges for management, particularly in hospitalised individuals and/or those using insulin. In critical illness it compromises the delivery of nutrition and increases the risk of regurgitation and aspiration with consequent lung dysfunction and ventilator dependence. Substantial advances in knowledge relating to GE, which is now recognised as a major determinant of the magnitude of the rise in blood glucose after a meal in both health and diabetes and, the impact of acute glycaemic environment on the rate of GE have been made and the use of gut-based therapies such as glucagon-like peptide-1 receptor agonists, which may profoundly impact GE, in the management of type 2 diabetes, has become commonplace. This necessitates an increased understanding of the complex inter-relationships of GE with glycaemia, its implications in hospitalised patients and the relevance of dysglycaemia and its management, particularly in critical illness. Current approaches to management of gastroparesis to achieve more personalised diabetes care, relevant to clinical practice, is detailed. Further studies focusing on the interactions of medications affecting GE and the glycaemic environment in hospitalised patients, are required.

Leite AZ, Correa-Giannella ML, Nery M, Queiroz MS. Diet consistency modification improves postprandial glycemic and gastroparesis symptoms

Abstract

Diabetic gastroparesis (DGP) is an autonomic neuropathy resulting from long-standing poorly controlled diabetes, and it is also linked to fluctuations in glycemic control due to variability on nutrient absorption.

Objectives

Considering the scarcity of information, the aim of this study was to identify the impact of modifications on diet consistency on post-prandial glucose variability using a continuous glucose monitoring (CGM) and its effect on the perception and severity of gastrointestinal symptoms.

Methods

This proof-of-concept study was carried out in a cross-sectional cohort of six individuals with type 1 diabetes mellitus with confirmed diagnosis of DGP. Two types of diet were used to evaluate glycemic control and DGP symptoms, general consistency standard meal (SD) and modified consistency test diet (MD), associated with an application of rapid acting insulin at the time of food intake. Glycemic control was evaluated by CGM, and the Gastroparesis Cardinal Symptom Index (GCSI) was applied after meals.

Results

The CGM curve was different for MD + insulin and SD + insulin. There was a smaller increment of interstitial glucose with 2 h after MD + insulin, returning almost to the basal level 4 h later. Patients scored significantly lower GCSI after MD + insulin compared to the same index after they received SD + insulin. Moreover, there was a decrease in important clinical scores present in the index, like: "Not able to finish meal", "Loss of appetite" and "Stomach or belly feels larger".

Conclusion

This study showed that a modified diet can improve postprandial glycemic excursion and the perception and severity of gastroparesis symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01117-w.

Serial Measurements of Refractive Index, Glucose and Protein to Assess Gastric Liquid Nutrient Transport—A Proof-of-Principal Study

Delayed gastric emptying contributes to complications as aspiration or malnutrition. Among patients suffering from acute neurological diseases, motility disorders are prevalent but poorly understood. Thus, methods to measure gastric emptying are required to allow for appropriate adaptions of individual enteral nutrition algorithms. For enterally fed patients repetitive concentration measurements of gastric content have been proposed to assess gastric emptying. This approach can be used to calculate the gastric residual volume (GRV) and transport of nutrition formula (NF), but it has not yet been implemented in clinical routine. The aim of this study was to investigate whether refractometry or other likewise straightforward analytical approaches produce the best results under in vitro conditions mimicking the gastric milieu. We measured NF in different known concentrations, either diluted in water or in simulated gastric fluid (SGF), with each of the following methods: refractometer, handheld glucose meter, and Bradford protein assay. Then, in enterally fed patients suffering from acute neurological disease, we calculated GRVs and nutrition transport and tested possible associations with clinical parameters. In water dilution experiments, NF concentrations could be assessed with the readout parameters of all three methods. Refractometry yielded the most precise results over the broadest range of concentrations and was biased least by the presence of SGF (detection range for Fresubin original fibre, given as volume concentration/normalized error of regression slope after incubation with water or SGF: 0–100 vs. 0–100%/0.5 vs. 3.9%; glucose-measurement: 5–100 vs. 25–100%/7.9 vs. 6.1%; Bradford-assay: 0–100 vs. 0–100%/7.8 vs. 15.7%). Out of 28 enterally fed patients, we calculated significant slower nutrition transport in patients with higher blood glucose (Rho −0.391; p = 0.039) and in patients who received high-dose sufentanil (Rho −0.514; p = 0.005). Also, the calculated nutrition transport could distinguish patients with and without feeding intolerance (Median 6 vs. 17 ml/h; Mann-Whitney test: p = 0.002). The results of our study prove that serial refractometry is a suitable and cost-effective method to assess gastric emptying and to enhance research on gastrointestinal complications of stroke.

Gastrointestinal autonomic neuropathy in diabetes

Gastrointestinal autonomic neuropathy represents an important and diverse, but poorly appreciated, manifestation of diabetic autonomic neuropathy that impacts negatively on quality of life. There is no test to assess gastrointestinal autonomic nerve damage directly in humans; cardiovascular autonomic reflex tests are often used as a surrogate, but are suboptimal. Gastrointestinal symptoms are common in diabetes, but usually correlate only weakly with disordered motility. Diabetic gastroparesis, or abnormally delayed gastric emptying, occurs frequently and is the best characterized manifestation of gastrointestinal autonomic neuropathy. There is a bi-directional relationship between postprandial glycaemia and the rate of gastric emptying. However, autonomic neuropathy can affect the function of any gut segment from the esophagus to the anus. Current management options for gastrointestinal autonomic neuropathy are, for the main part, empirical and sub-optimal.

Study on the Mechanisms of Banxia Xiexin Decoction in Treating Diabetic Gastroparesis Based on Network Pharmacology

In China, Banxia Xiexin decoction (BXD) is applied to treat diabetic gastroparesis (DGP), but its key active ingredients and mechanisms against DGP are unclear. This study is designated to reveal the molecular mechanisms of BXD in treating DGP by adopting a creative approach known as network pharmacology to explore the active ingredients and therapeutic targets of BXD. In our study, 730 differentially expressed genes of DGP were obtained, and 30 potential targets of BXD against DGP were screened out (including ADRB2, DRD1, FOS, MMP9, FOSL1, FOSL2, JUN, MAP2, DRD2, MYC, F3, CDKN1A, IL6, NFKBIA, ICAM1, CCL2, SELE, DUOX2, MGAM, THBD, SERPINE1, ALOX5, CXCL11, CXCL2, CXCL10, RUNX2, CD40LG, C1QB, MCL1, and ADCYAP1). Based on the findings, BXD contains 60 compounds with therapeutic effect on DGP, including the key active ingredients such as quercetin, wogonin, baicalein, beta-sitosterol, and kaempferol. Sixty-eight pathways including TNF signaling pathway, IL-17 signaling pathway, and AGE-RAGE signaling pathway were significantly enriched. In this study, the mechanisms of BXD in treating DGP are affirmed to be a complex network with multi-target and multi-pathway, which provides a reference for future experimental studies.

The Role of Diabetes Mellitus in Diseases of the Gallbladder and Biliary Tract

BACKGROUND

The increasing prevalence of diabetes mellitus worldwide continues to pose a heavy burden. Though its gastrointestinal impact is appropriately recognized, the lesser known associations may be overlooked.

OBJECTIVE

We aim to review the negative implications of diabetes on the gallbladder and the biliary tract.

METHODS

A MEDLINE® database search of literature was conducted with emphasis on the previous five years, combining keywords such as "diabetes," "gallbladder," and "biliary".

RESULTS

The association of diabetes to the formation of gallstones, gallbladder cancer, and cancer of the biliary tract are discussed along with diagnosis and treatment.

CONCLUSION

Though we uncover the role of diabetic neuropathy in gallbladder and biliary complications, the specific individual diabetic risk factors behind these developments is unclear. Also, in addition to diabetes control and surgical gallbladder management, the treatment approach also requires further focus.

Diabetic Gastroparesis and Glycaemic Control

PURPOSE OF REVIEW

Gastroparesis is an important complication of diabetes that may have a major impact on the quality of life as a result of upper gastrointestinal symptoms and impaired glycaemic control. Current management strategies include optimising blood glucose control, dietary modifications and supportive nutrition. Pharmacologic approaches with drugs that have prokinetic and/or antiemetic effects are also used widely; however, current available treatments have major limitations. There is increasing recognition that the rate of gastric emptying (GE) is a key determinant of the glycaemic response to a meal.

RECENT FINDINGS

There is ongoing uncertainty regarding the impact of longstanding hyperglycaemia on GE, which requires clarification. New diagnostic techniques have been developed to better characterise the mechanisms underlying gastroparesis in individual patients, and these have the potential to lead to more personalised therapy. Management of gastroparesis is complex and suboptimal; novel approaches are desirable. This review summarises recent advances in the understanding of diabetic gastroparesis, with an emphasis on the current therapies that influence GE, and the bidirectional relationship between glycaemic control and GE.

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.

Postprandial Glucose Control in Type 1 Diabetes: Importance of the Gastric Emptying Rate

The achievement of optimal post-prandial (PP) glucose control in patients with type 1 diabetes (T1DM) remains a great challenge. This review summarizes the main factors contributing to PP glucose response and discusses the likely reasons why PP glucose control is rarely achieved in T1DM patients. The macronutrient composition of the meal, the rate of gastric emptying and premeal insulin administration are key factors affecting the PP glucose response in T1DM. Although the use of continuous insulin infusion systems has improved PP glucose control compared to conventional insulin therapy, there is still need for further ameliorations. T1DM patients frequently present a delayed gastric emptying (GE) that produces a lower but more prolonged PP hyperglycemia. In addition, delayed GE is associated with a longer time to reach the glycemic peak, with a consequent mismatch between PP glucose elevation and the timing of premeal insulin action. On this basis, including GE time and meal composition in the algorithms for insulin bolus calculation of the insulin delivery systems could be an important step forward for optimization of PP glucose control in T1DM.

Hypoglycaemia and gastric emptying

Hypoglycaemia is arguably the most important complication of insulin therapy in type 1 and type 2 diabetes. Counter-regulation of hypoglycaemia is dependent on autonomic function and frequent hypoglycaemia may lead to reductions in both autonomic warning signals and the catecholamine response, the so-called "impaired awareness of hypoglycaemia". It is now appreciated that gastric emptying is a major determinant of the glycaemic response to carbohydrate-containing meals in both health and diabetes, that disordered (especially delayed) gastric emptying occurs frequently in diabetes, and that acute hypoglycaemia accelerates gastric emptying substantially. However, the potential relevance of gastric emptying to the predisposition to, and counter-regulation of, hypoglycaemia has received little attention. In insulin-treated patients, the rate of gastric emptying influences the timing of the postprandial insulin requirement, and gastroparesis is likely to predispose to postprandial hypoglycaemia. Conversely, the marked acceleration of gastric emptying induced by hypoglycaemia probably represents an important counter-regulatory response to increase the rate of carbohydrate absorption. This review summarizes the current knowledge of the inter-relationships between hypoglycaemia and gastric emptying, with a focus on clinical implications.

Diabetic gastroparesis: current challenges and future prospects

Diabetic gastroparesis (DMGP) is a condition of delayed gastric emptying after gastric outlet obstruction has been excluded. Symptoms of nausea, vomiting, early satiety, bloating, and abdominal pain are associated with DMGP. Uncontrolled symptoms can lead to overall poor quality of life and financial burdens on the healthcare system. A combination of antiemetics and prokinetics is used in symptom control; metoclopramide is the main prokinetic available for clinical use and is the only U.S. Food and Drug Administration-approved agent in the United States. However, a black box warning in 2009 reporting its association with tardive dyskinesia and recommending caution in chronically using this agent beyond 3 months has decreased its role in clinical practice. There is an unmet need for new prokinetics with good efficacy and safety profiles. Currently, there are several new drugs with different mechanisms of action in the pipeline that are under investigation and show promising preliminary results. Surgically combining gastric electrical stimulation with pyloroplasty is considered "gold" standard. Advances in therapeutic endoscopic intervention with gastric per-oral endoscopic pyloromyotomy have also been shown to improve gastric emptying and gastroparesis (GP) symptoms. In this review, we will comment on the challenges encountered when managing patients with DMGP and provide an update on advances in drug development and endoscopic and surgical interventions.

Gastric Emptying Impacts the Timing of Meal Glucose Peak in Subjects With Uncomplicated Type 1 Diabetes

CONTEXT

Diabetes mellitus is associated with gastrointestinal (GI) motility dysfunction, ranging from delayed to accelerated gastric emptying (GE).

OBJECTIVE

To evaluate GE in patients with type 1 diabetes mellitus (T1DM) without chronic complications and to investigate its relation with postprandial glucose and GI hormone responses.

DESIGN

Cross-sectional study.

SETTING/PARTICIPANTS

Forty-two patients with T1DM free of chronic complications referred to Federico II University and 31 healthy controls similar for age, sex, and body mass index.

INTERVENTIONS/MAIN OUTCOME MEASURES

GE was assessed by using the 13C-octanoate breath test with a standardized solid meal. During the meal, plasma glucose, ghrelin, and glucagon-like peptide 1 (GLP-1) responses were assessed, and GI symptoms were evaluated by a specific questionnaire.

RESULTS

Patients with T1DM showed a significantly slower GE half-emptying time (GE t1/2) (113 ± 34 minutes) than did controls (89 ± 17 minutes; P < 0.001). Thirty-six percent of T1DM showed a delayed GE (t1/2 > 120 minutes), whereas all controls showed a normal GE. When patients with T1DM were stratified according to GE t1/2, postmeal glucose response was significantly different between those with delayed and those with normal GE (P = 0.013). In particular, patients with T1DM and delayed GE showed a significantly longer mean time to peak glucose than did patients with normal GE (P = 0.004). In addition, GE t1/2 was an independent predictor of the time to peak glucose (β = 0.329; P = 0.025). GLP-1 and ghrelin responses to the test meal, as well as the prevalence of GI symptoms, were similar between patients with T1DM and controls and between patients with T1DM with normal GE and those with delayed GE.

CONCLUSIONS

Delayed GE time is associated with a longer time to peak glucose. GE evaluation could be useful for individualizing the timing of preprandial insulin bolus in patients with T1DM.

The Investigation and Treatment of Diabetic Gastroparesis

PURPOSE

This review provides an update on the investigations and treatment options for gastroparesis.

METHODS

A comprehensive literature search of Medline, PubMed, Embase and OVID was conducted which included all systematic reviews and research articles that focused on the diagnosis, investigations and management diabetic gastroparesis.

FINDINGS

Dietary modifications and pharmacologic treatment with prokinetics to increase gastric motility form the mainstay of treatment. However, the use of prokinetics is limited by adverse effects and serious adverse effects, leaving metoclopramide as the only drug approved by the US Food and Drug Administration for the treatment of gastroparesis. Newer therapies, including motilin receptor agonists, ghrelin receptor agonists, and neurokinin receptor antagonists, are currently being investigated. Transpyloric stenting, gastric electrical stimulation, and gastric per-oral endoscopic myotomy provide mechanical options for intervention, and surgical interventions in severe intractable gastroparesis include laparoscopic pyloroplasty or gastrectomy.

IMPLICATIONS

Advances to better understand the pathophysiology and management of diabetic gastroparesis have been limited, especially with discordance between symptoms and severity of delay in gastric emptying. Established treatment options are limited; however, recent pharmacologic and surgical interventions show promise.

Reported gastroparesis in adults with type 1 diabetes (T1D) from the T1D Exchange clinic registry

OBJECTIVE

To better understand the prevalence and impact of gastroparesis in the T1D Exchange clinic registry database.

METHODS

The analysis included 7107 adult participants with T1D across 45 sites (median age 46years. and median duration 24years). Linear and logistic regression models were used to assess the association of gastroparesis vs. no gastroparesis (obtained from medical record) with demographic characteristics, glycemic control and diabetes complications.

RESULTS

Among 7107 registry participants, 340 (4.8%) had a clinical diagnosis of gastroparesis. Females were more likely to have gastroparesis compared with males (5.8% vs. 3.5%, P<0.001). Participants with gastroparesis compared with those without gastroparesis were older (median age 49.4 vs. 45.3years, P<0.001), had a longer duration of T1D (median duration 32 vs. 23years, P<0.001), higher mean HbA1c (8.1% vs. 7.7% [65 vs. 61mmol/mol], P<0.001), more frequent severe hypoglycemia (25% vs. 11% with ≥1 event in the past 12months, P<0.001), lower socio-economic status, less likely to be using CGM and insulin pump and greater prevalence of microvascular and neuropathic complications than participants without gastroparesis.

CONCLUSION

Gastroparesis is associated with higher risk of severe hypoglycemia despite higher HbA1c levels than in T1D patients without gastroparesis. The increased presence of multiple long-term complications and overall poor glycemic control in these subjects emphasizes the need to establish diagnostic protocols for earlier diagnosis, achieve tighter glycemic control with more extensive use of insulin pumps and continuous glucose monitoring, and the need for wider availability of medical therapies for treatment of diabetic gastroparesis.

Diabetic autonomic neuropathy

Diabetes mellitus is the commonest cause of an autonomic neuropathy in the developed world. Diabetic autonomic neuropathy causes a constellation of symptoms and signs affecting cardiovascular, urogenital, gastrointestinal, pupillomotor, thermoregulatory, and sudomotor systems. Several discrete syndromes associated with diabetes cause autonomic dysfunction. The most prevalent of these are: generalized diabetic autonomic neuropathy, autonomic neuropathy associated with the prediabetic state, treatment-induced painful and autonomic neuropathy, and transient hypoglycemia-associated autonomic neuropathy. These autonomic manifestations of diabetes are responsible for the most troublesome and disabling features of diabetic peripheral neuropathy and result in a significant proportion of the mortality and morbidity associated with the disease.

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.

Gastric emptying and glycaemia in health and diabetes mellitus

The rate of gastric emptying is a critical determinant of postprandial glycaemia and, accordingly, is fundamental to maintaining blood glucose homeostasis. Disordered gastric emptying occurs frequently in patients with longstanding type 1 diabetes mellitus and type 2 diabetes mellitus (T2DM). A complex bidirectional relationship exists between gastric emptying and glycaemia--gastric emptying accounts for ∼35% of the variance in peak postprandial blood glucose concentrations in healthy individuals and in patients with diabetes mellitus, and the rate of emptying is itself modulated by acute changes in glycaemia. Clinical implementation of incretin-based therapies for the management of T2DM, which diminish postprandial glycaemia, in part by slowing gastric emptying, is widespread. Other therapies for patients with T2DM, which specifically target gastric emptying include pramlintide and dietary-based treatment approaches. A weak association exists between upper gastrointestinal symptoms and the rate of gastric emptying. In patients with severe diabetic gastroparesis, pathological changes are highly variable and are characterized by loss of interstitial cells of Cajal and an immune infiltrate. Management options for patients with symptomatic gastroparesis remain limited in their efficacy, which probably reflects the heterogeneous nature of the underlying pathophysiology.

Measurement of gastric emptying in diabetes

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

Glucose absorption in small intestinal diseases

Recent developments in the field of diabetes and obesity management have established the central role of the gut in glucose homeostasis; not only is the gut the primary absorptive site, but it also triggers neurohumoral feedback responses that regulate the pre- and post-absorptive phases of glucose metabolism. Structural and/or functional disorders of the intestine have the capacity to enhance (e.g.: diabetes) or inhibit (e.g.: short-gut syndrome, critical illness) glucose absorption, with potentially detrimental outcomes. In this review, we first describe the normal physiology of glucose absorption and outline the methods by which it can be quantified. Then we focus on the structural and functional changes in the small intestine associated with obesity, critical illness, short gut syndrome and other malabsorptive states, and particularly Type 2 diabetes, which can impact upon carbohydrate absorption and overall glucose homeostasis.

Pathophysiology and pharmacotherapy of gastroparesis: current and future perspectives

INTRODUCTION

Gastroparesis is an important clinical disorder characterised by delayed gastric emptying in the absence of mechanical outlet obstruction. Idiopathic, diabetes and postsurgical causes represent the most common aetiologies. The condition commonly manifests as upper gastrointestinal symptoms, including nausea, vomiting, postprandial fullness, early satiety, abdominal pain and bloating.

AREAS COVERED

This paper provides a review of the prevalence, pathophysiology and clinical features associated with gastroparesis, with a particular focus on current pharmacological management options and novel and emerging therapies. A literature search was undertaken using the search terms: gastroparesis, diabetic gastroparesis, idiopathic gastroparesis, gastric emptying, prokinetic, metoclopramide, domperidone, erythromycin, motilin, alemcinal, KC11458, mitemcinal, ghrelin, TZP-101, TZP-102, RM-131, tegaserod, prucalopride, naronapride, velusetrag, levosulpiride, itopride, botulinum toxin, gastric electrical stimulation, Enterra.

EXPERT OPINION

Strategies for the management of gastroparesis include correction of malnutrition, dehydration and electrolyte imbalance, relief of symptoms by appropriate use of prokinetic and antiemetic agents and, in patients with gastroparesis associated with diabetes or critical illness-induced hyperglycaemia, optimisation of glycaemic control. Conventional prokinetic agents form the mainstay of treatment. While novel pharmacotherapies are in development, compelling evidence for their efficacy, particularly in symptom relief, remains to be established.

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.

Diabetic gastroparesis: recent insights into pathophysiology and implications for management

Delayed gastric emptying affects a substantial proportion of patients with long-standing diabetes, and when associated with symptoms and/or disordered glycemic control, affects quality of life adversely. Important clinicopathological insights have recently been gained by the systematic analysis of gastric biopsies from patients with severe diabetic gastroparesis, which may stimulate the development of new therapies in the coming decade. Experience with prokinetic therapies and treatments, such as pyloric botulinum toxin injection and gastric electrical stimulation, has established that relief of symptoms does not correlate closely with acceleration of delayed gastric emptying, and that well-designed controlled trials are essential to determine the efficacy of emerging therapies.

Effects of CB1 and CRF1 receptor antagonists on binge-like eating in rats with limited access to a sweet fat diet: lack of withdrawal-like responses

Positive reinforcement (e.g., appetitive, rewarding properties) has often been hypothesized to maintain excessive intake of palatable foods. Recently, rats receiving intermittent access to high sucrose diets showed binge-like intake with withdrawal-like signs upon cessation of access, suggesting negative reinforcement mechanisms contribute as well. Whether intermittent access to high fat diets also produces withdrawal-like syndromes is controversial. The present study therefore tested the hypothesis that binge-like eating and withdrawal-like anxiety would arise in a novel model of binge eating based on daily 10-min access to a sweet fat diet (35% fat kcal, 31% sucrose kcal). Within 2-3 weeks, female Wistar rats developed binge-like intake comparable to levels seen previously for high sucrose diets (~40% of daily caloric intake within 10 min) plus excess weight gain and adiposity, but absent increased anxiety-like behavior during elevated plus-maze or defensive withdrawal tests after diet withdrawal. Binge-like intake was unaffected by pretreatment with the corticotropin-releasing factor type 1 (CRF(1)) receptor antagonist R121919, and corticosterone responses to restraint stress did not differ between sweet-fat binge rats and chow-fed controls. In contrast, pretreatment with the cannabinoid type 1 (CB(1)) receptor antagonist SR147778 dose-dependently reduced binge-like intake, albeit less effectively than in ad lib chow or sweet fat controls. A priming dose of the sweet fat diet did not precipitate increased anxiety-like behavior, but rather increased plus-maze locomotor activity. The results suggest that CB(1)-dependent positive reinforcement rather than CRF(1)-dependent negative reinforcement mechanisms predominantly maintain excessive intake in this limited access model of sweet-fat diet binges.

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.

Management strategies for gastrointestinal, erectile, bladder, and sudomotor dysfunction in patients with diabetes

There are substantial advances in understanding disordered gastrointestinal autonomic dysfunction in diabetes. It occurs frequently. The underlying pathogenesis is complex involving defects in multiple interacting cell types of the myenteric plexus as well. These defects may be irreversible or reversible. Gastrointestinal symptoms represent a major and generally underestimated source of morbidity for escalating health care costs in diabetes. Acute changes in glycaemia are both determinants and consequences of altered gastrointestinal motility. 35-90% of diabetic men have moderate-to-severe erectile dysfunction (ED). ED shares common risk factors with CVD. Diagnosis is based on medical/sexual history, including validated questionnaires. Physical examination and laboratory testing must be tailored to patient's complaints and risk factors. Treatment is based on PDE5-inhibitors (PDE5-I). Other explorations may be useful in patients who do not respond to PDE5-I. Patients at high cardiovascular risk should be stabilized by their cardiologists before sexual activity is considered or ED treatment is recommended. Estimates on bladder dysfunction prevalence are 43-87% of type 1 and 25% of type 2 diabetic patients, respectively. Common symptoms include dysuria, frequency, urgency, nocturia and incomplete bladder emptying. Diagnosis should use validated questionnaire for lower urinary tract symptoms. The type of bladder dysfunction is readily characterized with complete urodynamic testing. Sudomotor dysfunction is a cause of dry skin and is associated with foot ulcerations. Sudomotor function can be assessed by thermoregulatory sweat testing, quantitative sudomotor axon reflex test, sympathetic skin response, quantitative direct/indirect axon reflex testing and the indicator plaster.

Electrogastrography abnormalities appear early in children with diabetes type 1

OBJECTIVE

The objective of the study was to evaluate gastric myoelectrical activity in young patients with diabetes and to correlate it with their metabolic control [fasting blood glucose, glycosylated haemoglobin, and fructosamine] and BMI during a 3 years follow-up.

METHODS

Surface electrogastrography (EGG) was performed on 49 children with diabetes aged 10.3±4.4 (mean±SD) years and 17 age-matched healthy controls after fasting glucose, glycosylated haemoglobin, and fructosamine were measured. EGG parameters [percentage of bradygastria, 3 cycles per minute, tachygastria, dominant frequency instability coefficient, and power ratio] were analysed and compared with blood analysis.

RESULTS

Patients with diabetes exhibited an increase in preprandial bradygastria 7.9±8.8 cpm (mean±SD) compared with controls 2.1±1.0 (P=0.011), with an associated decrease in preprandial normogastria (72.2±14.5 vs. 82.7±14.7; P=0.013). Normogastric power ratio (postprandial/ preprandial power) was significantly increased in the children with diabetes compared with controls (mean: 6.67 vs. 3.14, P=0.034). A longer duration of diabetes was associated with an increased risk of EGG abnormalities (P=0.036). Marked hyperglycaemia at the time of study was associated with postprandial bradygastria (P=0.01) and power ratio bradygastria (P=0.042). Changes in glycosylated haemoglobin, fructosamine and BMI did not affect EGG parameters.

CONCLUSIONS

EGG abnormalities, presented early in a high proportion of diabetic children, are related to the acute hyperglycaemia. These abnormalities are not consistently present in the follow-up studies and not related to the glycosylated haemoglobin and fructosamine. Diabetic autonomic neuropathy is therefore an unlikely pathogenic factor for EGG abnormalities in children with diabetes.

Measurement of gastric emptying of a high-nutrient liquid by 3D ultrasonography in diabetic gastroparesis

BACKGROUND

Gastric emptying (GE) is delayed in 30-50% of patients with longstanding diabetes. Scintigraphy represents the 'gold standard' for measurement of GE, but is associated with a radiation burden. Three-dimensional (3D) ultrasonography has recently been demonstrated to provide a valid measure of liquid GE in healthy subjects; however, the technique has not been validated in patients with gastroparesis. The primary aim of this study was to compare measurements of GE of a high-nutrient glucose drink by 3D ultrasonography and scintigraphy in diabetic gastroparesis.

METHODS

Ten patients (eight type 1, two type 2, 6M, 4F, aged 46.1 ± 4.5 years, BMI 29.1 ± 1.6 kg m(-2), duration 19.6 ± 3.3 years) with diabetic gastroparesis [defined as retention at 100 min of solid (100 g minced beef) ≥ 61% and/or 50% emptying time (T50) of liquid (150 mL 10% dextrose) ≥ 31 min], were studied. Concurrent measurements of GE by scintigraphy and 3D ultrasonography were performed following ingestion of 75 g glucose in 300 mL water labeled with 20 MBq (99m) Tc-sulfur colloid.

KEY RESULTS

There was no significant difference in GE between the two techniques (T50s: scintigraphy - 103.3 ± 10.0 min VS 3D ultrasonography - 98.8 ± 10.4 min; P = 0.60). There was a significant correlation between scintigraphic and ultrasonographic T50s (r = 0.67, P = 0.03). The limits of agreement for the T50s were -57.22 min and +48.22 min (mean difference -4.5 min). Blood glucose after the drink was greater when GE was relatively more rapid (e.g. at t = 60 min; scintigraphy: r = -0.65, P = 0.04; 3D ultrasonography: r = -0.78, P = 0.008).

CONCLUSIONS & INFERENCES

Three-dimensional ultrasonography appears to provide a valid, and non-invasive, measure of GE of high-nutrient liquids in diabetic gastroparesis.

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.

Diabetic gastroparesis and its impact on glycemia

Diabetes is the most common cause of gastroparesis and it is now recognized that the relationship between gastric emptying and glycemia is complex and intertwined. Postprandial blood glucose levels influence, and are influenced by, the rate of gastric emptying, highlighting the difficulty in determining which is the cause and which is the effect. Novel diagnostic techniques and therapeutic strategies have been developed for the management of diabetic gastroparesis. This article highlights recent advances in knowledge about diabetic gastroparesis, with an emphasis on the inter-relationships between disordered gastric motor function on glycemia and vice versa, as well as therapeutic strategies for optimizing glycemic control using modulation of gastric emptying.

Diabetic neuropathies: update on definitions, diagnostic criteria, estimation of severity, and treatments

Preceding the joint meeting of the 19th annual Diabetic Neuropathy Study Group of the European Association for the Study of Diabetes (NEURODIAB) and the 8th International Symposium on Diabetic Neuropathy in Toronto, Canada, 13-18 October 2009, expert panels were convened to provide updates on classification, definitions, diagnostic criteria, and treatments of diabetic peripheral neuropathies (DPNs), autonomic neuropathy, painful DPNs, and structural alterations in DPNs.

Diabetic gastroparesis: Therapeutic options

Gastroparesis is a condition characterized by delayed gastric emptying and the most common known underlying cause is diabetes mellitus. Symptoms include nausea, vomiting, abdominal fullness, and early satiety, which impact to varying degrees on the patient's quality of life. Symptoms and deficits do not necessarily relate to each other, hence despite significant abnormalities in gastric emptying, some individuals have only minimal symptoms and, conversely, severe symptoms do not always relate to measures of gastric emptying. Prokinetic agents such as metoclopramide, domperidone, and erythromycin enhance gastric motility and have remained the mainstay of treatment for several decades, despite unwanted side effects and numerous drug interactions. Mechanical therapies such as endoscopic pyloric botulinum toxin injection, gastric electrical stimulation, and gastrostomy or jejunostomy are used in intractable diabetic gastroparesis (DG), refractory to prokinetic therapies. Mitemcinal and TZP-101 are novel investigational motilin receptor and ghrelin agonists, respectively, and show promise in the treatment of DG. The aim of this review is to provide an update on prokinetic and mechanical therapies in the treatment of DG.

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.

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.

Effectiveness of prokinetic agents against diseases external to the gastrointestinal tract

Prokinetic agents are effective not only for disease of the gastrointestinal (GI) tract but also for those external to the GI tract such as the central nervous system, and the respiratory, urologic, and metabolic organs. This article reviews the effectiveness of prokinetic agents against diseases external to the GI tract. Studies were identified by computerized and manual searches of the available literature. A Medline search was performed (1975-July, 2008) using the following medical subject headings: prokinetic agent, metoclopramide, domperidone, trimebutine, cisapride, itopride, mosapride, tegaserod, and human. The identified diseases for which prokinetic agents may be effective are various: bronchial asthma, chronic cough, hiccup, spontaneous bacterial peritonitis, cholelithiasis, diabetes mellitus, acute migraine, Parkinson's disease, anorexia nervosa, Tourette's disorder, urologic sequelae of spinal cord injury and of radical hysterectomy for cervical cancer, laryngeal dysfunction and so on. These agents are also useful for prevention of aspiration pneumonia during anesthesia, and in tube-fed patients. Prokinetic agents should be a valuable addition to our currently limited pharmacological armamentarium not only for functional bowel disease, but also for diseases external to the GI tract.

Pathophysiology and management of gastroparesis

Gastroparesis is characterized by upper gastrointestinal symptoms associated with delayed gastric emptying, without mechanical obstruction. However, symptoms do not correlate well with the magnitude of delay in gastric emptying. Diabetes mellitus and surgery are the most common causes, although more than 30% of cases are idiopathic. Coordination of insulin action with nutrient delivery is important in diabetics, as postprandial blood glucose levels and gastric emptying are interdependent, and gastroparesis probably represents a major cause of poor glycemic control. Scintigraphy is the gold standard for measuring gastric emptying. Current treatment mainly involves the use of prokinetic drugs. Pyloric botulinum toxin injection and gastric electrical stimulation require more evidence from controlled studies before their use can be recommended. Surgical options remain inadequately studied.

Effects of fat supplementation on glycaemic response and gastric emptying in adolescents with Type 1 diabetes

AIMS

To compare the glycaemic response to meals with different fat content in adolescents with Type 1 diabetes mellitus (T1DM) and to investigate associations with gastric emptying.

METHODS

In this randomized, cross-over study, paired results were obtained from seven adolescents with T1DM who ingested on different days two meals with the same carbohydrate and protein content, but different fat and energy content (2 and 38 g fat, 320 and 640 kcal, respectively). Paracetamol was mixed into the meals and gastric emptying was estimated by the paracetamol absorption method. All subjects were normoglycaemic and given 7 IU insulin aspart at commencement of ingestion. Postprandial blood samples were taken during 4 h.

RESULTS

The areas under the curves for plasma glucose and serum paracetamol concentrations were larger after the low-fat than after the high-fat meal during the first 2 h (P = 0.047 and P = 0.041, respectively). The difference between meals in time-to-peak in glucose and paracetamol concentrations did not reach statistical significance (high-fat vs. low-fat meal: 210 min (120-240) vs. 120 min (50-240), P = 0.080 and 120 min (75-180) vs. 60 min (60-120), P = 0.051, respectively). Changes in glucose concentrations correlated with simultaneous changes in paracetamol concentrations (P < 0.001).

CONCLUSIONS

For the first time, we have shown that the initial glycaemic response is reduced after a meal with higher compared with a meal with lower fat content in adolescents with T1DM given a rapid-acting insulin analogue preprandially. The type and dose of preprandial insulin may need adjustment to the fat content of the meal to reach postprandial normoglycaemia.

Effect of itopride on gastric emptying in longstanding diabetes mellitus

Delayed gastric emptying (GE) occurs in 30-50% of patients with longstanding type 1 or 2 diabetes, and represents a major cause of morbidity. Current therapeutic options are limited. We aimed at evaluating the effects of itopride on GE in patients with longstanding diabetes. Twenty-five patients (20 type 1, 5 type 2; 10 males, 15 females; mean age 45.2 +/- 2.7 years; body mass index 27.5 +/- 0.9 kg m(-2); duration of diabetes 20.2 +/- 2.4 years) were enrolled in a double-blind, placebo-controlled, randomized, crossover trial. Subjects received both itopride (200 mg) and placebo t.i.d. for 7 days, with a washout of 7-14 days. GE (scintigraphy), blood glucose (glucometer) and upper gastrointestinal (GI) symptoms (questionnaire) were measured following each treatment period. The test meal comprised 100 g ground beef (99mTc-sulphur colloid) and 150 mL of 10% dextrose [67Ga-ethylenediaminetetraacetic acid (EDTA)]. There was a slight trend for itopride to accelerate both solid (P = 0.09) and liquid (P = 0.09) GE. With itopride treatment, the emptying of both solids and liquids tended to be more accelerated, as the emptying with placebo was slower (solids: r = 0.39, P = 0.057; liquids: r = 0.44, P < 0.03). Twelve (48%) patients had delayed solid and/or liquid GE on placebo and in this group, itopride modestly accelerated liquid (P < 0.05), but not solid (P = 0.39), emptying. Itopride had no effect on mean blood glucose during the GE measurement (placebo: 9.8 +/- 0.6 mmol L(-1) vs itopride: 9.6 +/-0.6 mmol L(-1)), or GI symptoms (placebo: 1.4 +/- 0.4 vs itopride: 1.8 +/- 0.5). Itopride, in a dose of 200 mg t.i.d. for 7 days, tends to accelerate GE of liquids and solids in longstanding diabetes. The magnitude of this effect appears to be modest and possibly dependent on the rate of GE without itopride.

[Gastroparesis and its treatment options]

Gastroparesis is a disorder of gastric emptying that occurs in the absence of mechanical obstruction. Its cardinal features include nausea, vomiting, bloating, early satiety and discomfort. Weight loss, dehydration, electrolyte disturbances and malnutrition may develop in severe cases. The majority of cases is idiopathic, long standing diabetes mellitus is responsible for about 25-30% of cases. Diabetic gastroparesis may render glucose control extremely difficult, its treatment represents a major challenge. Besides frequent, small meals and psychological support, several drug options are available, however, their efficacy is limited and only a few randomized studies have been performed to date. Prokinetic agents (erythromycin, domperidone, metoclopramide) and antiemetics (phenothiazines, serotonin antagonists, butyrophenones) are the most wide-spread medicaments. Among the novel, recently developed agents, 5-HT4 serotonin receptor agonists and dopamine D2 receptor antagonists are the most promising. Injection of botulinum toxin into the pyloric sphincter resulted in faster gastric emptying and symptom alleviation in some studies. Gastric electric stimulation appears to be one of the most effective options, both low and high-frequency stimulation may alleviate symptoms. Gastrostomy/jejunostomy and other surgical interventions are considered as "last resort".

Gastric emptying, diabetes, and aging

Gastric emptying is mildly slowed in healthy aging, although generally remains within the normal range for young people. The significance of this is unclear, but may potentially influence the absorption of certain drugs, especially when a rapid effect is desired. Type 2 diabetes is common in the elderly, but there is little data regarding its natural history, prognosis, and management. This article focuses on the interactions between gastric emptying and diabetes, how each is influenced by the process of aging, and the implications for patient management.

Pathophysiology and management of diabetic gastropathy: a guide for endocrinologists

Delayed gastric emptying is frequently observed in patients with long-standing type 1 and type 2 diabetes mellitus, and potentially impacts on upper gastrointestinal symptoms, glycaemic control, nutrition and oral drug absorption. The pathogenesis remains unclear and management strategies are currently suboptimal. Therapeutic strategies focus on accelerating gastric emptying, controlling symptoms and improving glycaemic control. The potential adverse effects of hyperglycaemia on gastric emptying and upper gut symptoms indicate the importance of normalising blood glucose if possible. Nutritional and psychological supports are also important, but often neglected. A number of recent pharmacological and non-pharmacological therapies show promise, including gastric electrical stimulation. As with all chronic illnesses, a multidisciplinary approach to management is recommended, but there are few data regarding long-term outcomes.

An update on autonomic neuropathy affecting the gastrointestinal tract

Gastrointestinal symptoms and disordered gut motility occur frequently in the diabetic population and are generally regarded as manifestations of gastrointestinal "autonomic dysfunction," although the relationships between both symptoms and dysmotility with abnormal cardiovascular autonomic function are weak. It is now recognized that the blood glucose concentration is both a determinant of and determined by gastrointestinal function. An improved definition of the underlying pathophysiology should facilitate the development of therapies that are targeted more effectively.