Similarities and differences between diabetic and idiopathic gastroparesis

Outcomes and Factors Associated With Reduced Symptoms in Patients With Gastroparesis

BACKGROUND & AIMS

Gastroparesis is a chronic clinical syndrome characterized by delayed gastric emptying. However, little is known about patient outcomes or factors associated with reduction of symptoms.

METHODS

We studied adult patients with gastroparesis (of diabetic or idiopathic type) enrolled in the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium Gastroparesis Registry, seen every 16 weeks and treated according to the standard of care with prescribed medications or other therapies at 7 tertiary care centers. Characteristics associated with reduced symptoms, based on a decrease of 1 or more in the gastroparesis cardinal symptom index (GCSI) score after 48 weeks of care, were determined from logistic regression models. Data were collected from patients for up to 4 years (median, 2.1 y).

RESULTS

Of 262 patients, 28% had reductions in GCSI scores of 1 or more at 48 weeks. However, there were no significant reductions in GCSI score from weeks 48 through 192. Factors independently associated with reduced symptoms at 48 weeks included male sex, age 50 years and older, initial infectious prodrome, antidepressant use, and 4-hour gastric retention greater than 20%. Factors associated with no reduction in symptoms included overweight or obesity, a history of smoking, use of pain modulators, moderate to severe abdominal pain, a severe gastroesophageal reflex, and moderate to severe depression.

CONCLUSIONS

Over a median follow-up period of 2.1 years, 28% of patients treated for gastroparesis at centers of expertise had reductions in GCSI scores of 1 or greater, regardless of diabetes. These findings indicate the chronic nature of gastroparesis. We identified factors associated with reduced symptoms that might be used to guide treatment. ClinicalTrials.gov no: NCT00398801.

Characterization of Electrophysiological Propagation by Multichannel Sensors

OBJECTIVE

The propagation of electrophysiological activity measured by multichannel devices could have significant clinical implications. Gastric slow waves normally propagate along longitudinal paths that are evident in recordings of serosal potentials and transcutaneous magnetic fields. We employed a realistic model of gastric slow wave activity to simulate the transabdominal magnetogastrogram (MGG) recorded in a multichannel biomagnetometer and to determine characteristics of electrophysiological propagation from MGG measurements.

METHODS

Using MGG simulations of slow wave sources in a realistic abdomen (both superficial and deep sources) and in a horizontally-layered volume conductor, we compared two analytic methods (second-order blind identification, SOBI and surface current density, SCD) that allow quantitative characterization of slow wave propagation. We also evaluated the performance of the methods with simulated experimental noise. The methods were also validated in an experimental animal model.

RESULTS

Mean square errors in position estimates were within 2 cm of the correct position, and average propagation velocities within 2 mm/s of the actual velocities. SOBI propagation analysis outperformed the SCD method for dipoles in the superficial and horizontal layer models with and without additive noise. The SCD method gave better estimates for deep sources, but did not handle additive noise as well as SOBI.

CONCLUSION

SOBI-MGG and SCD-MGG were used to quantify slow wave propagation in a realistic abdomen model of gastric electrical activity.

SIGNIFICANCE

These methods could be generalized to any propagating electrophysiological activity detected by multichannel sensor arrays.

The stomach in health and disease

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

Gastroparesis: definitions and diagnosis

Gastroparesis is a chronic symptomatic disorder of the stomach characterized by delayed emptying without evidence of mechanical obstruction. Symptoms of gastroparesis include nausea, vomiting, early satiety, postprandial fullness, and upper abdominal pain. The 3 main causes are diabetic, postsurgical, and idiopathic. Diagnosis is confirmed by demonstrating delayed gastric emptying. Gastric emptying rates measured by gastric motor testing generally correlate poorly with symptoms and quality of life in patients with gastroparesis. It may be appropriate to reconsider the definition of gastroparesis, recognizing it as a broader spectrum of gastric neuromuscular dysfunction.

Relationship between glycemic control and gastric emptying in poorly controlled type 2 diabetes

BACKGROUND & AIMS

Acute hyperglycemia delays gastric emptying in patients with diabetes. However, it is not clear whether improved control of glycemia affects gastric emptying in these patients. We investigated whether overnight and short-term (6 mo) improvements in control of glycemia affect gastric emptying.

METHODS

We studied 30 patients with poorly controlled type 2 diabetes (level of glycosylated hemoglobin, >9%). We measured gastric emptying using the [(13)C]-Spirulina platensis breath test on the patients' first visit (visit 1), after overnight administration of insulin or saline, 1 week later (visit 2), and 6 months after intensive therapy for diabetes. We also measured fasting and postprandial plasma levels of C-peptide, glucagon-like peptide 1, and amylin, as well as autonomic functions.

RESULTS

At visit 1, gastric emptying was normal in 10 patients, delayed in 14, and accelerated in 6; 6 patients had gastrointestinal symptoms; vagal dysfunction was associated with delayed gastric emptying (P < .05). Higher fasting blood levels of glucose were associated with shorter half-times of gastric emptying (thalf) at visits 1 (r = -0.46; P = .01) and 2 (r = -0.43; P = .02). Although blood levels of glucose were lower after administration of insulin (132 ± 7 mg/dL) than saline (211 ± 15 mg/dL; P = .0002), gastric emptying thalf was not lower after administration of insulin, compared with saline. After 6 months of intensive therapy, levels of glycosylated hemoglobin decreased from 10.6% ± 0.3% to 9% ± 0.4% (P = .0003), but gastric emptying thalf did not change (92 ± 8 min before, 92 ± 7 min after). Gastric emptying did not correlate with plasma levels of glucagon-like peptide 1 and amylin.

CONCLUSIONS

Two-thirds of patients with poorly controlled type 2 diabetes have mostly asymptomatic yet abnormal gastric emptying. Higher fasting blood levels of glucose are associated with faster gastric emptying. Overnight and sustained (6 mo) improvements in glycemic control do not affect gastric emptying.

Idiopathic gastroparesis

Gastroparesis is a chronic symptomatic disorder of the stomach characterized by delayed emptying without evidence of mechanical obstruction. Idiopathic gastroparesis refers to gastroparesis of unknown cause not from diabetes; not from prior gastric surgery; not related to other endocrine, neurologic, rheumatologic causes of gastroparesis; and not related to medications that can delay gastric emptying. There is overlap in the symptoms of idiopathic gastroparesis and functional dyspepsia. Patients with idiopathic gastroparesis often have a constellation of symptoms including nausea, vomiting, early satiety, postprandial fullness, and upper abdominal pain. Current treatment options of dietary management, prokinetics agents, antiemetic agents, and symptom modulators do not adequately address clinical need for idiopathic gastroparesis.

End of the road for a dysfunctional end organ: laparoscopic gastrectomy for refractory gastroparesis

INTRODUCTION

Gastroparesis is a functional disorder resulting in debilitating nausea, esophageal reflux, and abdominal pain and is frequently refractory to medical treatment. Therapies such as pyloroplasty and neurostimulators can improve symptoms. When medical and surgical treatments fail, palliative gastrectomy is an option. We examined outcomes after gastrectomy for postoperative, diabetic, and idiopathic gastroparesis.

METHODS

A prospective database was queried for gastrectomies performed for gastroparesis from 1999 to 2013. Primary outcomes were improvements in pre- versus postoperative symptoms at last follow-up, measured on a five-point scale. Secondary outcome was operative morbidity.

RESULTS

Thirty-five patients underwent laparoscopic total or near-total gastrectomies for postoperative (43 %), diabetic (34 %), or idiopathic (23 %) gastroparesis. Antiemetics and prokinetics afforded minimal relief for one third of patients. There were no mortalities. Six patients suffered a leak, all treated with surgical reintervention. With a median follow-up of 6 months, nausea improved or resolved in 69 %. Chronic abdominal pain improved or resolved in 70 %. Belching and bloating resolved for 79 and 89 %, respectively (p < 0.01).

CONCLUSIONS

Regardless of etiology, medically refractory gastroparesis can be a devastating disease. Near-total gastrectomy can ameliorate or relieve nausea, belching, and bloating. Chronic abdominal pain commonly resolved or improved with resection. Despite attendant morbidity, gastrectomy can effectively palliate symptoms of gastroparesis.

Symptomatic management for gastroparesis: antiemetics, analgesics, and symptom modulators

Although prokinetic agents typically are used for gastroparesis, antiemetic, analgesic, and neuromodulatory medications may help manage nausea, vomiting, pain, or discomfort. Antiemetic benefits are supported by few case reports. An open series reported symptom reductions with transdermal granisetron in gastroparesis. Opiates are not advocated in gastroparesis because they worsen nausea and delay emptying. Neuromodulators have theoretical utility, but the tricyclic agent nortriptyline showed no benefits over placebo in an idiopathic gastroparesis study raising doubts about this strategy. Neurologic and cardiac toxicities of these medications are recognized. Additional controlled study is warranted to define antiemetic, analgesic, and neuromodulator usefulness in gastroparesis.

Clinical presentation and pathophysiology of gastroparesis

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

Diabetic gastroparesis

Gastroparesis is a complication of long-standing type 1 and type 2 diabetes mellitus. Symptoms associated with gastroparesis include early satiety, prolonged postprandial fullness, bloating, nausea and vomiting, and abdominal pain. Mortality is increased in patients with diabetic gastroparesis. A subset of patients with diabetic gastroparesis have pylorospasm that results in obstructive gastroparesis. Current treatment approaches include improving glucose control with insulin and prescribing antinauseant drugs, prokinetic agents, and gastric electric stimulation. Future directions include improved diet counseling based on gastric emptying rate, continuous insulin delivery systems with glucose sensor-augmented monitoring, and drugs for correcting gastric neural and electric abnormalities.

Epidemiology and natural history of gastroparesis

Gastroparesis is characterized by delayed gastric emptying and symptoms thereof in the absence of gastric outlet obstruction. Most studies on the epidemiology of gastroparesis have been conducted in selected case series rather than in the population at large. In the only community-based study of gastroparesis in diabetes mellitus (DM), the average cumulative incidence of symptoms and delayed gastric emptying over 10 years was higher in type 1 DM (5%) than in type 2 DM (1%) and controls (1%). In the United States, the incidence of hospitalizations related to gastroparesis increased substantially between 1995 and 2004, and particularly after 2000.

Conversion from twice-daily to once-daily tacrolimus in simultaneous pancreas-kidney transplant patients

BACKGROUND

Data on the effectiveness of once-daily tacrolimus (Tac-QD) in simultaneous pancreas-kidney (SPK) transplant patients are limited, which is of particular concern because diabetic gastroparesis may affect absorption. The aim of this study was to evaluate the clinical impact of converting SPK patients from twice-daily (Tac-BD) to Tac-QD.

METHODS

From November 2008 to August 2011, 27 SPK recipients (out of 130) were converted from Tac-BD to Tac-QD. Demographics, prescribed doses, trough levels, and creatinine, glucose, and HbA1c values were collected prospectively at the time of conversion and at 1, 2, 3, 6, and 12 months after conversion.

RESULTS

The mean time from transplantation to conversion was 35.81 ± 27.31 months, with 20 patients (74.07%) converted to Tac-QD >12 months after transplantation. There were no significant differences in the tacrolimus dose and trough levels before and after conversion and at all points during the follow-up. Creatinine, glucos,e and HbA1c levels remained stable throughout. Eight patients (29.63%) with gastroparesis had clinical outcomes, drug doses, and trough levels similar to all other patients.

CONCLUSIONS

Stable SPK recipients can safely be converted from Tac-BD to Tac-QD, with no clinical impact on the transplant function. Gastroparesis does not appear to influence tacrolimus dose requirements or trough levels.

Macrophages in diabetic gastroparesis--the missing link?

BACKGROUND

Diabetic gastroparesis results in significant morbidity for patients and major economic burden for society. Treatment options for diabetic gastroparesis are currently directed at symptom control rather than the underlying disease and are limited. The pathophysiology of diabetic gastroparesis includes damage to intrinsic and extrinsic neurons, smooth muscle, and interstitial cells of Cajal (ICC). Oxidative damage in diabetes appears to be one of the primary insults involved in the pathogenesis of several complications of diabetes, including gastroparesis. Recent studies have highlighted the potential role of macrophages as key cellular elements in the pathogenesis of diabetic gastroparesis. Macrophages are important for both homeostasis and defense against a variety of pathogens. Heme oxygenase 1 (HO1), an enzyme expressed in a subset of macrophages has emerged as a major protective mechanism against oxidative stress. Activation of macrophages with high levels of HO1 expression protects against development of delayed gastric emptying in animal models of diabetes, while activation of macrophages that do not express HO1 are linked to neuromuscular cell injury. Targeting macrophages and HO1 may therefore be a therapeutic option in diabetic gastroparesis.

PURPOSE

This report briefly reviews the pathophysiology of diabetic gastroparesis with a focus on oxidative damage and how activation and polarization of different subtypes of macrophages in the muscularis propria determines development of delay in gastric emptying or protects against its development.

Time trends in gastroparesis treatment

INTRODUCTION

While delayed emptying is the defining criterion for gastroparesis, prokinetics often only have a limited impact on symptoms and have been associated with potentially serious adverse effects. The goal of this study was to determine how this information and regulatory changes affected gastroparesis management.

METHODS

The electronic medical records of patients seen between 2003 and 2012 in the outpatient clinic of a large tertiary center were retrieved based on the billing diagnosis of gastroparesis. Demographic, clinical, and survival data were abstracted.

RESULTS

A total of 709 patients were identified, with diabetes (21.2 %) and prior surgery (9.8 %) being the most common identifiable causes. The majority of patients (56 %) had idiopathic gastroparesis. The cohort was female predominant (79.5 %) with an average age of 45.4 ± 0.6 years. At the index encounter, 61.8 % received prokinetics. About one-third (37.7 %) used antiemetics at least intermittently. Between 2003 and 2012, prokinetic use dropped from 81 to 43 %, while the use of antiemetics increased from 14 to 41 %. Similarly, there was a significant increase in prescribed opioids and antidepressants. During the period of the study, 44 patients (6.2 %) died. Increasing age, a higher comorbidity burden, anxiety, and medication use were associated with higher mortality risks.

CONCLUSION

This large outpatient cohort suggests that treatment trends move away from prokinetics and focus on symptom-oriented therapy and/or confounding mood disorders.

Management of gastroparesis: beyond basics

OPINION STATEMENT

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

Early human experience with per-oral endoscopic pyloromyotomy (POP)

INTRODUCTION

Gastroparesis is a condition characterized by delayed gastric emptying, and a constellation of symptoms, including nausea, vomiting, early satiety, and bloating. Although current surgical options such as pyloroplasty have been shown to be effective, an endoscopic submucosal myotomy technique may be applied to divide the pyloric sphincter without surgical access. Such endoscopic technique may provide the benefits of a natural orifice procedure, and improve gastric emptying in gastroparetic patients.

METHODS AND PROCEDURES

Per-oral pyloromyotomy (POP) was performed in seven female patients aged 33-65 years (mean 51 years). All patients had a pre-operative work-up that included upper endoscopy, and a gastric emptying study. A pH study, and esophageal manometry were also performed when a concomitant fundoplication was considered.

RESULTS

POP was technically successful in all seven cases. There were no immediate procedural complications. Perioperative, complications included: one patient with an upper GI bleed 2 weeks post-procedure, necessitating transfusions, and endoscopic clipping of a pyloric channel ulcer; one patient who experienced difficulty swallowing post operatively, delaying discharge by 1 day; and one patient who developed a hospital-acquired pneumonia, delaying discharge by several days. Six of the seven patients experienced significant symptomatic improvement following the procedure. Three month follow-up nuclear medicine solid-phase gastric emptying studies are currently available for 5 of the 7 patients. Normal gastric emptying at 4 h was noted in four of five patients (80 %). One patient did not respond to endoscopic management subsequently underwent an uneventful laparoscopic pyloroplasty, which also failed to significantly improve her symptoms.

CONCLUSION

POP is a technically safe and feasible endoscopic procedure. Early follow-up suggests promising symptomatic improvement as well as objective improvement in gastric emptying. Additional clinical experience is required to establish the role of this technique in the management of gastroparesis.

From ischochymia to gastroparesis: proposed mechanisms and preferred management of dyspepsia over the centuries

Dyspeptic symptoms are common with most patients suffering functional disorders that remain a therapeutic challenge for medical practitioners. Within the last three decades, gastric infection, altered motility, and hypersensitivity have gained and lost traction in explaining the development of functional dyspepsia. Considering these shifts, the aim of this review was to analyze changing understanding of and approaches to dyspepsia over a longer time period. Monographs, textbooks, and articles published during the last three centuries show that our understanding of normal gastric function has improved dramatically. With increased insight came new ideas about disease mechanisms, diagnostic options, and treatments. Despite shifts over time, the importance of functional abnormalities was recognized early on and explained in the context of societal influences and stressors, anxieties, and biological influences, thus resembling the contemporary biopsychosocial model of illness. Symptoms were often attributed to changes in secretion, motility, and sensation or perception with technological innovation often influencing proposed mechanisms and treatments. Many of the principles or even agents applied more than a century ago are still part of today's approach. This includes acid suppression, antiemetics, analgesics, and even non-pharmacologic therapies, such as gastric decompression or electrical stimulation of the stomach. This historical information does not only help us understand how we arrived at our current state of knowledge and standards of care, it also demonstrates that enthusiastic adoption of various competing explanatory models and the resulting treatments often did not survive the test of time. In view of the benign prognosis of dyspepsia, the data may function as a call for caution to avoid the potential harm of overly aggressive approaches or treatments with a high likelihood of adverse effects.

Granisetron transdermal system improves refractory nausea and vomiting in gastroparesis

BACKGROUND

Symptoms of gastroparesis include nausea and vomiting, which can markedly diminish quality of life. Nausea and vomiting can also make treatment with oral antiemetics problematic.

AIM

Our aim was to determine whether treatment-resistant nausea and vomiting in patients with gastroparesis improve after granisetron transdermal patch (GTP) therapy.

METHODS

In an open-label pilot study, patients with gastroparesis and symptoms of nausea and vomiting refractory to conventional treatment were treated with GTP. After 2 weeks, patients were asked to assess their therapeutic response using the Clinical Patient Grading Assessment Scale (CPGAS; +7 = completely better; 0 = no change; -7 = very considerably worse). Responders were defined as CPGAS score >0, non-responders as ≤0.

RESULTS

Patients (n = 36) were treated with GTP. Of these 36 patients, one patient discontinued treatment due to the GTP not adhering to the skin. Of the remaining 35 patients, 18 improved, 15 remained the same, and two worsened. The average CPGAS score was +1.8 ± 0.4 (SEM) (P < 0.05 vs 0). Of the 18 patients with improvement, the average CPGAS score was +3.7 ± 0.3 (SEM), corresponding to "somewhat" to "moderately better" improvement in nausea/vomiting. Side effects occurred in nine patients: four developed constipation, three patients had skin rash, and two reported headaches.

CONCLUSIONS

GTP was moderately effective in reducing refractory symptoms of nausea and/or vomiting from gastroparesis in 50% of patients. Mild side effects were reported by 25% of patients. GTP may be an effective treatment for nausea and vomiting in gastroparesis, and further study is warranted.

Effect of Yiqi Yangyin Huayu Tongluo Recipe on apoptosis of gastric smooth muscle cells in rats with diabetic gastroparesis

AIM: To explore the effect of Yiqi Yangyin Huayu Tongluo Recipe on oxidative stress and apoptosis of gastric smooth muscle cells in rats with diabetic gastroparesis.

METHODS: Thirty Sprague-Dawley male rats were randomly divided into three groups: a normal control (NC) group, a diabetic model (DM) group and a Chinese medicine (ZY) group. Diabetes was induced by injecting streptozotocin (STZ). The Chinese medicine group was treated with traditional Chinese medicine, while the other two groups received the same volume of saline. Six weeks later, rate of gastric emptying was measured with phenol red; levels of malondialdehyde (MDA) and activity of superoxide dismutase (SOD) in gastric tissues were detected; apoptosis of gastric smooth muscle cells was detected by TUNEL assay; and expression of Bcl-2 and Bax mRNAs was examined by real-time PCR.

RESULTS: Compared with the NC group, the rates of gastric emptying in the DM and ZY groups decreased significantly (62.64% ± 4.51% vs 18.65% ± 4.30%, 26.84% ± 2.35%, P < 0.05 for both), while the gastric emptying rate was significantly higher in the ZY group than in the DM group (P < 0.05). Compared with the NC group, gastric MDA contents were significantly elevated in the DM and ZY groups (2.12 nmol/mgprot ± 0.08 nmol/mgprot vs 7.55 nmol/mgprot ± 0.27 nmol/mgprot, 2.82 nmol/mgprot ± 0.16 nmol/mgprot, P < 0.05 for both), while gastric MDA content was significantly lower in the ZY group than in the DM group (P < 0.05). SOD activity was reduced significantly in the DM and ZY groups in comparison with the NC group (48.18 U/mgprot ± 1.46 U/mgprot, 73.66 U/mgprot ± 0.55 U/mgprot vs 120.20 U/mgprot ± 1.21 U/mgprot, P < 0.05 for both), while SOD activity was significantly higher in the ZY group than in the DM group (P < 0.05). The apoptotic index (AI) of gastric smooth muscle cells was significantly increased in the DM and ZY groups compared with the NC group (10.84% ± 1.18%, 1.73% ± 0.09% vs 0.28% ± 0.25%, P < 0.05 for both), while the AI was significantly lower in the ZY group than in the DM group (P < 0.05). The levels of Bcl-2 mRNA in the DM and ZY groups were significantly lower compared with the NC group (1.65 ± 0.28 vs 0.59 ± 0.09, 1.10 ± 0.27, P < 0.05 for both), while the level of Bcl-2 mRNA was significantly higher in the ZY group than in the DM group (P < 0.05). The expression of Bax mRNA in the DM group was significantly higher than that in the NC group (1.96 ± 0.28 vs 0.87 ± 0.83, P < 0.05), while there was no significant difference between the NC group and ZY group (0.87 ± 0.83 vs 1.13 ± 0.11, P > 0.05). Compared with the DM group, the expression of Bax mRNA in the ZY group was significantly decreased (1.96 ± 0.28 vs 1.13 ± 0.11, P < 0.05).

CONCLUSION: Yiqi Yangyin Huayu Tongluo Recipe can improve gastric motility by increasing antioxidative action, decreasing oxidative stress and inhibiting apoptosis in rats with diabetic gastroparesis.

Emerging drugs for the treatment of gastroparesis

INTRODUCTION

Gastroparesis presents with symptoms of gastric retention with findings of delayed gastric emptying on diagnostic testing. Manifestations of gastroparesis are disabling in severe cases and lead to significant health resource utilization. Current therapies often are ineffective, may exhibit tolerance on chronic administration or produce prominent side effects in large patient subsets.

AREAS COVERED

This review assessed literature on drugs with theoretical efficacy in gastroparesis including medications that accelerate gastric emptying, reduce nausea and vomiting, or act as neuromodulators to reduce gastric sensitivity. Numerous agents exhibit diverse actions to modify gastric sensorimotor function in animal models; however, few medications are in controlled testing in gastroparesis. Prokinetic drugs with promise for this condition include investigational serotonin 5-HT4 agonists, motilin agonists, dopamine D2 antagonists, ghrelin agonists and an agent with combined muscarinic antagonist and acetylcholinesterase inhibitory effects. Other antiemetics and complementary and alternative formulations may be effective for some symptoms.

EXPERT OPINION

Development of effective novel therapies of gastroparesis without the neurotoxicity and cardiac arrhythmogenic effects of current agents will mandate a better definition of the gastric and extragastric factors responsible for the pathogenesis of the varied clinical manifestations of this disorder.

Gastroparesis: from concepts to management

While the symptoms of gastroparesis are common, an accurate diagnosis is based on a combination of those symptoms with a documented delay in gastric emptying. Typical symptoms include nausea, vomiting, early satiety, postprandial fullness, bloating, and abdominal discomfort. Patients with gastroparesis face many diagnostic and therapeutic challenges. The most common origins of gastroparesis are idiopathic causes and diabetes mellitus. The increased use of certain medications in medicine today, including opiates and drugs with anticholinergic properties, can alter gastrointestinal functions and mimic symptoms of gastroparesis. Accordingly, alternative explanations for symptoms and altered gastrointestinal function need to be considered. Numerous clinical sequelae, including weight loss and severe protein-calorie malnutrition, may be seen in advanced stages of gastroparesis. This article provides an overview of gut sensorimotor function to help the reader better understand the clinical presentation of patients with dyspepsia and those who may have accompanying delayed gastric emptying that meets criteria for gastroparesis. Techniques available for diagnosing motor dysfunction and the principles of gastroparesis management are reviewed. Nutrition recommendations and a review of pharmacologic agents, nonpharmacologic techniques, and novel treatment modalities are provided.

Rectal sensitivity in diabetes patients with symptoms of gastroparesis

In a clinical setting, diabetic autonomic complications (cardiac, gastrointestinal, urogenital, etc.) are often handled as separate entities. We investigated rectal sensitivity to heat, mechanical distension, and electrical stimulations in 20 patients with diabetes and symptoms of gastroparesis, to evaluate the extent of visceral neuronal damage. Furthermore, to evaluate the relation between the nervous structures we examined gastric emptying and cardiac autonomic function with the hypothesis being an association between these. We found that 60% of patients had delayed gastric empting. Rectal hyposensitivity was a general finding as they tolerated 67% higher thermal, 42% more mechanical, and 33% higher electrical current intensity compared to healthy controls. In patients, most heart rate variability parameters were reduced; they reported significantly more gastrointestinal symptoms and a reduced quality of life in all SF-36 domains. Shortened RR interval correlated with reduced rectal temperature sensitivity, and gastric retention rate was negatively associated with symptoms of nausea and vomiting. To conclude, in these patients with signs and symptoms of diabetic gastroparesis, rectal sensitivity was reduced, and heart rate variability was impaired. Thus, we suggest regarding diabetic autonomic neuropathy as a diffuse disorder. Symptoms of widespread autonomic dysfunction and sensory disorders should be expected and treated in these patients.

Vomiting and dysphagia predict delayed gastric emptying in diabetic and nondiabetic subjects

BACKGROUND

Gastroparesis is a heterogeneous disorder most often idiopathic, diabetic, or postsurgical in nature. The demographic and clinical predictors of gastroparesis in Israeli patients are poorly defined.

METHODS

During the study period we identified all adult patients who were referred to gastric emptying scintigraphy (GES) for the evaluation of dyspeptic symptoms. Of those, 193 patients who were referred to GES from our institution were retrospectively identified (76 (39%) males, mean age 60.2 ± 15.6 years). Subjects were grouped according to gastric half-emptying times (gastric T 1/2). Demographic and clinical data were extracted from electronic medical records or by a phone interview.

KEY RESULTS

Gastric emptying half-times were normal (gastric T 1/2 0-99 min) in 101 patients, abnormal (gastric T 1/2 100-299 min) in 67 patients, and grossly abnormal (gastric T 1/2 ≥ 300 min) in 25 patients. Vomiting and dysphagia, but neither early satiety nor bloating, correlated with delayed gastric emptying. Diabetes was associated with grossly abnormal gastric T 1/2. Idiopathic gastroparesis was associated with a younger age at GES. No correlation was observed between gastric T 1/2 values and gender, smoking, H. pylori infection, HBA1C, or microvascular complication of diabetes. CONCLUSIONS INFERENCES: Vomiting and dysphagia are predictive of delayed gastric emptying in both diabetic and nondiabetic subjects. Diabetes is associated with more severe gastroparesis.

Effect of nortriptyline on symptoms of idiopathic gastroparesis: the NORIG randomized clinical trial

IMPORTANCE

Gastroparesis remains a challenging syndrome to manage, with few effective treatments and a lack of rigorously controlled trials. Tricyclic antidepressants are often used to treat refractory symptoms of nausea, vomiting, and abdominal pain. Evidence from well-designed studies for this use is lacking.

OBJECTIVE

To determine whether treatment with nortriptyline results in symptomatic improvement in patients with idiopathic gastroparesis.

DESIGN, SETTING, AND PARTICIPANTS

The NORIG (Nortriptyline for Idiopathic Gastroparesis) trial, a 15-week multicenter, parallel-group, placebo-controlled, double-masked, randomized clinical trial from the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium (GpCRC), comparing nortriptyline with placebo for symptomatic relief in idiopathic gastroparesis. One hundred thirty patients with idiopathic gastroparesis were enrolled between March 2009 and June 2012 at 7 US academic medical centers. Patient follow-up was completed in October 2012. Inclusion criteria included delayed gastric emptying and moderate to severe symptom scores using the Gastroparesis Cardinal Symptom Index (GCSI). INTERVENTIONS Nortriptyline vs placebo. Study drug dose was increased at 3-week intervals (10, 25, 50, 75 mg) up to 75 mg at 12 weeks.

MAIN OUTCOMES AND MEASURES

The primary outcome measure of symptomatic improvement was a decrease from the patient's baseline GCSI score of at least 50% on 2 consecutive 3-week GCSI assessments during 15 weeks of treatment.

RESULTS

The primary symptomatic improvement outcome did not differ between 65 patients randomized to nortriptyline vs 65 patients randomized to placebo: 15 (23% [95% CI, 14%-35%]) in the nortriptyline group vs 14 (21% [95% CI, 12%-34%]) in the placebo group (P = .86). Treatment was stopped more often in the nortriptyline group (19 [29% {95% CI, 19%-42%}]) than in the placebo group (6 [9%] {95% CI, 3%-19%}]) (P = .007), but numbers of adverse events were not different (27 [95% CI, 18-39] vs 28 [95% CI, 19-40]) (P = .89).

CONCLUSIONS AND RELEVANCE

Among patients with idiopathic gastroparesis, the use of nortriptyline compared with placebo for 15 weeks did not result in improvement in overall symptoms. These findings do not support the use of nortriptyline for idiopathic gastroparesis.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00765895.

A ghrelin agonist fails to show benefit in patients with diabetic gastroparesis: let's not throw the baby out with the bath water

Ghrelin is the endogenous ligand for the growth hormone secretagogue-1a receptor and is a potential target for treatment of gastroparesis. This viewpoint assesses the potential role of ghrelin agonists in the treatment of gastroparesis through a review of the early phase, randomized, controlled trials of ghrelin agonists in patients with diabetes and, either, delayed gastric emptying at the time of the trial or symptoms at the time of the trial, and prior documentation of delayed gastric emptying of solids. Whereas recent experience with ghrelin agonists that have a macrocycle structure (TZP-101, TZP-102) has not confirmed earlier promising results, there is little evidence that ghrelin receptors downregulate with repeated treatment, in contrast to motilin receptors. Phase IIa clinical trials performed with a different agent (RM-131, which is a small molecule ghrelin agonist) suggest that, as a class, ghrelin agonists may be efficacious in stimulating gastric emptying. It is premature to dismiss ghrelin agonists as potential therapies for gastroparesis.

Regional differences in healthcare delivery for gastroparesis

AIM

Few studies have examined the effects of various interventions in gastroparesis. The goal of the present study was to determine whether inpatient management and outcomes differed among states across the United States.

METHODS

Using population statistics and the State Inpatient Database (Agency for Healthcare Research and Quality), regional differences in admissions for gastroparesis, inpatient mortality, length of stay, nursing home transfers, and rates of endoscopy, gastrostomy placement, and nutritional support were assessed.

RESULTS

Admissions for gastroparesis ranged from 24.3 ± 0.8/100,000 in Utah to 117.1 ± 9.7/100,000 in Maryland, with mortality rates similarly varying fourfold from 0.5 ± 0.1/100,000 in Colorado to 2.3 ± 0.1/100,000 in Florida. Intervention rates differed between states (endoscopy: 6.8 ± 0.8 % in Wyoming versus 23.1 ± 0.4 % in Florida; gastrostomy: 0.8 ± 0.1 % in North Carolina versus 3.3 ± 0.8 % in Hawaii; nutritional support: 1.2 ± 0.2 % in West Virginia versus 7.0 ± 0.6 % in New Jersey). Admissions rates were independently predicted by high overall hospitalizations within a state. Higher population density, median incomes and admissions to for-profit hospitals correlated with endoscopy rates. Coexisting heart failure and male gender were associated with higher likelihood of gastrostomy placement, while initiation of nutritional support was predicted by physician supply and insurance status. Age cohort, Medicare coverage, poverty rates and endoscopic testing independently predicted mortality, while length of stay correlated with diagnostic and therapeutic interventions.

CONCLUSIONS

There is a significant variability in admissions, interventions and outcomes for gastroparesis. While biological factors, such as comorbidities and age, contribute to this variability, the data suggest that socioeconomic variables significantly affect approaches to gastroparesis treatment in the United States.

Pain and opioid use in chronic liver disease

BACKGROUND

Pain is common in patients with liver disease, difficult to treat, and poorly understood.

AIMS

The aim of this study was to determine factors associated with pain and prescription opioid use in a large cohort of patients with confirmed chronic liver disease.

METHODS

This was a retrospective cohort study of consecutive patients with chronic liver disease visiting a tertiary-care hepatology clinic. Pain was determined by self-report and rated numerically from 0 to 10. Symptoms of mood and sleep disorders and emotional distress were based on a symptom checklist. Etiology and stage of liver disease and use of prescribed opioids were abstracted from the electronic medical record. Logistic regression was used to establish factors associated with pain and prescription opioid use.

RESULTS

Among 1,286 patients with chronic liver disease, 34 % had pain and 25 % used opioids. The strongest predictor of pain in multivariate modeling was emotional distress (OR 3.66, 95 % CI 2.40-5.64), followed by non-white race (OR 1.87, 95 % CI 1.24-2.79), mood symptoms (OR 1.47, 95 % CI 1.04-2.07), sleep disturbance/fatigue (OR 1.70, 95 % CI 1.24-2.32), and advanced liver disease (Child class B: OR 1.73, 95 % CI 1.15-2.60; Child class C: OR 2.78, 95 % CI 1.49-5.24) compared to no cirrhosis. Emotional distress, mood-related symptoms, and advanced liver disease were also significant predictors of prescription opioid use, as were age, nicotine use, and etiology of liver disease.

CONCLUSIONS

This large cohort study demonstrates the high prevalence of pain and opioid use in chronic liver disease. While disease variables contribute to pain, psychological symptoms were most strongly associated with pain and opioid use, providing rationale and target for therapeutic interventions.

Gastrointestinal complications of diabetes mellitus

Diabetes mellitus affects virtually every organ system in the body and the degree of organ involvement depends on the duration and severity of the disease, and other co-morbidities. Gastrointestinal (GI) involvement can present with esophageal dysmotility, gastro-esophageal reflux disease (GERD), gastroparesis, enteropathy, non alcoholic fatty liver disease (NAFLD) and glycogenic hepatopathy. Severity of GERD is inversely related to glycemic control and management is with prokinetics and proton pump inhibitors. Diabetic gastroparesis manifests as early satiety, bloating, vomiting, abdominal pain and erratic glycemic control. Gastric emptying scintigraphy is considered the gold standard test for diagnosis. Management includes dietary modifications, maintaining euglycemia, prokinetics, endoscopic and surgical treatments. Diabetic enteropathy is also common and management involves glycemic control and symptomatic measures. NAFLD is considered a hepatic manifestation of metabolic syndrome and treatment is mainly lifestyle measures, with diabetes and dyslipidemia management when coexistent. Glycogenic hepatopathy is a manifestation of poorly controlled type 1 diabetes and is managed by prompt insulin treatment. Though GI complications of diabetes are relatively common, awareness about its manifestations and treatment options are low among physicians. Optimal management of GI complications is important for appropriate metabolic control of diabetes and improvement in quality of life of the patient. This review is an update on the GI complications of diabetes, their pathophysiology, diagnostic evaluation and management.

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.

Factors influencing admission and outcomes in gastroparesis

BACKGROUND

Current data suggest that gastroparesis is associated with an increased mortality, with reported rates ranging from 4% to nearly 40%. Considering this variability, the goal of this study was to determine mortality rates and risk factors for adverse outcomes in gastroparesis.

METHODS

Using the diagnosis code for gastroparesis, admission rates, duration of hospitalizations, discharge status, and inpatient mortality were determined for emergency department encounters and admissions compiled in the Nationwide Emergency Department Sample and Nationwide Inpatient Sample of the Agency for Healthcare Research and Quality. Comorbid conditions, procedural evaluations, age cohort, and gender distribution were examined as potential risk factors.

KEY RESULTS

More than 50% of the emergency encounters for gastroparesis resulted in admission with age, cardiovascular, renal, and infectious disorders, but not diabetes mellitus being associated with higher admission rates. Inpatient mortality was 1.2 ± 0.1%, was not negatively affected by diabetes mellitus as comorbidity, and increased with coexisting infections and with more aggressive therapy. Discharge status was similarly affected by comorbidities, treatment complications, and more aggressive therapy.

CONCLUSIONS & INFERENCES

These results demonstrate that gastroparesis does not come with a high mortality risk, with most deaths being due to comorbid conditions. Although gastrostomies and/or nutritional support were used in only a minority of admissions, the associated increase in morbidity and mortality highlights the need to carefully select the right candidates for such interventions and to discuss the common occurrence of adverse outcomes with patients.

Prognosis of diabetic gastroparesis--a 25-year evaluation

AIM

To evaluate the prognosis of diabetic gastroparesis.

METHODS

Eighty-six patients with diabetes had measurements of gastric emptying of a mixed meal using a dual isotope test of solid and liquid meal components, mean blood glucose levels, HbA1c , upper gastrointestinal symptoms and autonomic nerve function performed in 1984-1989. These patients were followed up in 2011, after a mean period of ~25 years.

RESULTS

Of the 86 patients, gastric emptying of solid (the percentage remaining in the stomach at 100 min) was delayed in 35 (41%), and of liquid (the time taken for 50% of the liquid to empty) was delayed in 38 (44%). In 2011, 53 patients were known to be alive, 29 had died and four were lost to follow-up. In those who had died, both age at baseline (P < 0.001) and the score for autonomic nerve dysfunction (P < 0.001) were greater than those who were alive, while there was no difference in emptying of either the solid or liquid between the two groups. When patients with delayed gastric emptying were divided according to the median value ('delayed' and 'markedly delayed'), mortality tended to be greater in the 'markedly delayed' group for both solids (P = 0.12) and liquids (P = 0.09). Of the 82 patients who could be followed up, 23 of the 35 (66%) with delayed gastric emptying of solid and 25 of 38 (66%) with delayed gastric emptying of liquid were alive. After adjustment for age and autonomic dysfunction, there was no association between gastric emptying of either solid or liquid and death.

CONCLUSIONS

Over a period of ~25 years, diabetic gastroparesis is apparently not usually associated with a poor prognosis, or increased mortality.

ABBREVIATIONS

T100 min, the percentage remaining in the stomach at 100 mins; T50%, the time taken for 50% of the liquid to empty.

Cholecystectomy and clinical presentations of gastroparesis

BACKGROUND

Many patients with gastroparesis have had their gallbladders removed.

AIM

To determine if clinical presentations of patients with gastroparesis differ in those with prior cholecystectomy compared to patients who have not had their gallbladder removed.

METHODS

Gastroparetic patients were prospectively enrolled in the NIDDK Gastroparesis Registry. Detailed history and physical examinations were performed; patients filled out questionnaires including patient assessment of GI symptoms.

RESULTS

Of 391 subjects with diabetic or idiopathic gastroparesis (IG), 142 (36 %) had a prior cholecystectomy at the time of enrollment. Patients with prior cholecystectomy were more often female, older, married, and overweight or obese. Cholecystectomy had been performed in 27/59 (46 %) of T2DM compared to 19/78 (24 %) T1DM and 96/254 IG (38 %) (p = 0.03). Patients with cholecystectomy had more comorbidities, particularly chronic fatigue syndrome, fibromyalgia, depression, and anxiety. Postcholecystectomy gastroparesis patients had increased health care utilization, and had a worse quality of life. Independent characteristics associated with prior cholecystectomy included insidious onset (OR = 2.06; p = 0.01), more comorbidities (OR = 1.26; p < 0.001), less severe gastric retention (OR(severe) = 0.68; overall p = 0.03) and more severe symptoms of retching (OR = 1.19; p = 0.02) and upper abdominal pain (OR = 1.21; p = 0.02), less severe constipation symptoms (OR = 0.84; p = 0.02), and not classified as having irritable bowel syndrome (OR = 0.51; p = 0.02). Etiology was not independently associated with a prior cholecystectomy.

CONCLUSIONS

Symptom profiles in patients with and without cholecystectomy differ: postcholecystectomy gastroparesis patients had more severe upper abdominal pain and retching and less severe constipation. These data suggest that prior cholecystectomy is associated with selected manifestations of gastroparesis.

Clinical guideline: management of gastroparesis

This guideline presents recommendations for the evaluation and management of patients with gastroparesis. Gastroparesis is identified in clinical practice through the recognition of the clinical symptoms and documentation of delayed gastric emptying. Symptoms from gastroparesis include nausea, vomiting, early satiety, postprandial fullness, bloating, and upper abdominal pain. Management of gastroparesis should include assessment and correction of nutritional state, relief of symptoms, improvement of gastric emptying and, in diabetics, glycemic control. Patient nutritional state should be managed by oral dietary modifications. If oral intake is not adequate, then enteral nutrition via jejunostomy tube needs to be considered. Parenteral nutrition is rarely required when hydration and nutritional state cannot be maintained. Medical treatment entails use of prokinetic and antiemetic therapies. Current approved treatment options, including metoclopramide and gastric electrical stimulation (GES, approved on a humanitarian device exemption), do not adequately address clinical need. Antiemetics have not been specifically tested in gastroparesis, but they may relieve nausea and vomiting. Other medications aimed at symptom relief include unapproved medications or off-label indications, and include domperidone, erythromycin (primarily over a short term), and centrally acting antidepressants used as symptom modulators. GES may relieve symptoms, including weekly vomiting frequency, and the need for nutritional supplementation, based on open-label studies. Second-line approaches include venting gastrostomy or feeding jejunostomy; intrapyloric botulinum toxin injection was not effective in randomized controlled trials. Most of these treatments are based on open-label treatment trials and small numbers. Partial gastrectomy and pyloroplasty should be used rarely, only in carefully selected patients. Attention should be given to the development of new effective therapies for symptomatic control.

Gastroparesis on the rise: incidence vs awareness?

BACKGROUND

Recent reports provide a conflicting picture with a stable prevalence of gastroparesis (GP) in a population-based study, but a more than doubling in hospitalizations for gastroparesis within the last 10 years. We hypothesized that this apparent discrepancy is due to changes in disease recognition and coding rather than prevalence.

METHODS

Using data from the Nationwide Inpatient Sample, Healthcare cost and utilization project, Agency for Healthcare Research and Quality, we examined time trends of resource utilization for GP and related disorders.

KEY RESULTS

Between 1994 and 2009, annual hospitalizations for gastroparesis as primary diagnosis increased more than 18-fold from 918 to 16,736. In the same time frame, hospitalizations for not otherwise specified functional disorders of the stomach decreased by nearly 50% from 13,430 to 6480 per year.

CONCLUSIONS & INFERENCES

Although hospitalizations rates and emergency encounters for gastroparesis have increased dramatically within the last 2 decades, there was a concomitant decrease in resource utilization for other functional disorders of the stomach, suggesting that increased awareness contributed to this trend, which represents a shift in diagnoses rather than a true difference in the incidence and/or prevalence of these illnesses.

Gastroparesis

PURPOSE OF REVIEW

Gastroparesis is a common disorder that produces symptoms of gastric retention in the absence of physical obstruction. Extensive research into the clinical features, pathophysiology, diagnostic evaluation, and therapy of gastroparesis in the past several years has offered insight into the condition. This review provides updated information on gastroparesis focusing on new findings from the past few years.

RECENT FINDINGS

Large database studies have characterized clinical profiles in idiopathic and diabetic gastroparesis and are defining roles of gastric and extragastric factors in symptom genesis. Dietary deficiencies in gastroparesis have been clarified. Histologic study of full thickness gastric tissue in severe gastroparesis shows heterogeneous enteric neuronal, smooth muscle, interstitial cell, and inflammatory abnormalities. Advances in gastric emptying testing include wireless motility capsules and nonradioactive breath tests. The importance of glycemic control in diabetic gastroparesis is a focus of current investigation. Novel therapies include new prokinetics (ghrelin agonists), increased focus on antiemetic agents including antidepressants, and next generation gastric stimulators. Studies are being initiated to delineate the natural history of gastroparesis.

SUMMARY

Much has been learned recently on the causes, clinical presentations, and management of gastroparesis. Current ongoing investigation provides promise for further gains in the years ahead.

Sensory neuromodulators in functional nausea and vomiting: predictors of response

BACKGROUND

Tricyclic antidepressants (TCAs) are known to benefit subjects with functional nausea and vomiting (FNV), but it is not known if alternate neuromodulators are also beneficial. We retrospectively evaluated outcomes and clinical predictors of response in FNV subjects treated with any neuromodulator, including TCAs.

METHODS

We identified 94 subjects (43.8±1.4 year, 79 F) with FNV (Rome III criteria) over a 12 year period, treated with neuromodulators and followed up for 8.5±1.1 months. Clinical presentation, demographics and gastric emptying study (GES) findings (when available) were extracted. Likert scales determined symptom severity at baseline and symptom response or remission at follow-up. Outcomes and predictors of response were evaluated using univariate and multivariate analyses.

RESULTS

At least moderate symptom improvement was reported by 72.3%, and 22.3% had symptom remission. Proportions achieving moderate improvement and remission, and mean outcome Likert scores were similar regardless of neuromodulator agent used or GES status. On univariate and multivariate logistic regression analysis, baseline symptom severity affected symptom response, and pain negatively impacted symptom remission to treatment (p≤0.04 for each); GES status failed to predict treatment response or remission.

CONCLUSIONS

Symptom improvement with neuromodulators may be seen in over two-thirds of subjects with FNV regardless of the specific agent administered. Response may be suboptimal in pain predominant presentations.

What are the important subsets of gastroparesis?

Gastroparesis is often divided into subsets based on etiology and pathophysiology; however, the utility of these subsets in the diagnosis and treatment of gastro-paresis is not well defined. The objectives are to consider the subsets of gastroparesis from the perspectives of etiology and pathogenesis, pathophysiology, histopathology, and clinical associations, with particular focus on similarities and differences between diabetic and idiopathic gastroparesis and consideration of the potential subset of painful gastroparesis. We conclude that idiopathic and diabetic gastroparesis has similar initial presentations and manifestations, except that idiopathic gastroparesis tends to be associated more frequently with pain. Myopathic disorders are uncommon. Extrinsic denervation was considered the most common etiology; however, with the decline in surgery for peptic ulceration and in-depth study of full-thickness gastric biopsies, the most common intrinsic defects are being recognized in the interstitial cells of Cajal (ICC-opathy) and with immune infiltration and neuronal changes (intrinsic neuropathic gastroparesis). Histomorphological differences at the microscopic level between diabetic and idiopathic gastroparesis are still of unclear significance. Two gastroparesis subsets worthy of special mention, because they are potentially reversible with identification of the cause, are postviral gastroparesis, which has a generally good prognosis, and iatrogenic gastroparesis, especially in patients with non-surgical gastroparesis, such as diabetics exposed to incretins such as pramlintide and exenatide.

Gastroparesis: concepts, controversies, and challenges

Patients with gastroparesis often present a challenge to the treating physician. Postprandial symptoms with nausea and vomiting may not only lead to nutritional and metabolic consequences, but also cause significant disruptions to social activities that often center around food. While the definition of gastroparesis focuses on impaired gastric emptying, treatment options that affect gastric function are limited and often disappointing. The female predominance, the mostly idiopathic nature of the illness with a common history of abuse, and coexisting anxiety or depression show parallels with other functional disorders of the gastrointestinal tract. These parallels provided the rationale for some initial studies investigating alternative therapies that target the brain rather than the stomach. This emerging shift in medical therapy comes at a time when clinical studies suggest that gastric electrical stimulation may exert its effects by modulating visceral sensory processing rather than altering gastric motility. Physiologic and detailed anatomic investigations also support a more complex picture with different disease mechanisms, ranging from impaired accommodation to apparent visceral hypersensitivity or decreased interstitial cells of Cajal to inflammatory infiltration of myenteric ganglia. Delayed gastric emptying remains the endophenotype defining gastroparesis. However, our treatment options go beyond prokinetics and may allow us to improve the quality of life of affected individuals.