Diabetic gastroparesis: recent insights into pathophysiology and implications for management

Morpho-topographic features of the course of gastric wall muscle fibers in the esophagogastric junction during sleeve gastrectomy

Sleeve gastrectomy, also known as vertical gastrectomy, is one of the most common and popular bariatric surgeries in the world. This surgery has become particularly popular in recent decades due to its effectiveness in reducing weight and improving associated metabolic disorders. However, despite the high effectiveness of this surgery, stapling line failure remains one of the most serious complications that can lead to severe consequences such as peritonitis, sepsis, and prolonged hospital stay. The study of the morphotopographic features of the course of the muscle fibers of the gastric wall in the area of the esophagogastric junction is relevant for understanding the mechanisms of suture failure and developing preventive measures. The aim of the study was to evaluate the morphotopographic features of the course of the gastric wall muscle fibers in the esophagogastric junction during sleeve gastrectomy. A comprehensive study of the anatomical and functional characteristics of the gastric muscle layer in the area of the esophagogastric junction was carried out. A significant change in the architectonics of the muscular layer is noted in the esophagogastric junction zone. The circular muscles predominate here, which indicates the functional adaptation of this area to the regulation of food passage. Taking into account the transition from the anatomical zone of the esophagus to the stomach, the appearance of new muscle layers was revealed due to the physiological specificity of the hollow organ. By sequential dissection of the muscle layers, using the methods of histological analysis and macroscopic morphometry, specific features of muscle fibers that affect the formation of the staple line were revealed, namely, a mostly parallel course of fibers in the area of the angle of His and crossed distally from it, the thickness of the muscle layer at the level of the angle of His prevails over the distal level. Thus, the results obtained are important for improving the surgical technique of sleeve gastrectomy, in particular, the choice of the optimal location and direction of the suture – the formation of a continuous “layer” of crossed muscle fibers of the gastric body, the transition of longitudinal esophageal muscle fibers to the bottom and the large curvature of the stomach, which, together with circular fibers, acquire a perpendicular orientation to the level of staple suture application.

Alpinia officinarum Hance extract ameliorates diabetic gastroparesis by regulating SCF/c-kit signaling pathway and rebalancing gut microbiota

Diabetic gastroparesis (DGP) is a common complication of type 2 diabetes mellitus (T2DM). Alpinia officinarum Hance (AOH) is one of the most commonly used both as a food and folk medicines, which is rich in diarylheptanoids and flavonoids. The gastroprotection and hypoglycemic effect make AOH has great potential in developing of anti-DGP complementary medicine. However, the molecular mechanisms of AOH that act against DGP are yet to be elucidated. In this study, we evaluated the therapeutic effects, the potential molecular mechanism, and the changes of gut microbiota of AOH in DGP. The 5 components of the AOH were analyzed, and the potential signaling pathway of AOH improving DGP was predicted by molecular docking. Subsequently, DGP rat model was constructed using high-fat-irregular-diet, AOH intervention significantly reduced blood glucose levels, increased gastrointestinal propulsion rate, and improved gastric histological morphology in DGP rats. Meanwhile, AOH has been shown to regulate the SCF/c-kit signaling pathway and rebalance the gut microbiota, which may be closely related to its role in improving DGP. Taken together, AOH may play a protective role on DGP through multiple mechanisms, which might pave the road for development and utilization of AOH.

Gastroparesis: An Evidence-Based Review for the Bariatric and Foregut Surgeon

Gastroparesis is a gastric motility disorder characterized by delayed gastric emptying. It is a rare disease and difficult to treat effectively; management is a dilemma for gastroenterologists and surgeons alike. We conducted a systematic review of the literature to evaluate current diagnostic tools as well as treatment options. We describe key elements in the pathophysiology of the disease, in addition to current evidence on treatment alternatives, including nutritional considerations, medical and surgical options, and related outcomes.

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.

Impaired nitrergic relaxation in pyloric sphincter of the 6-OHDA Parkinson's disease rat

Patients with Parkinson's disease (PD) often suffer from delayed gastric emptying, but the underlying mechanism remains unclear. We have shown previously that a PD rat model comprising bilateral substantia nigra destruction by 6-hydroxydopamine (6-OHDA rats) exhibits gastroparesis with alteration of neural nitric oxide synthase (nNOS) and acetylcholine in gastric corpus. However, changes in pyloric motility in the 6-OHDA rats have not been characterized. Solid gastric emptying test, immunofluorescence, Western blot, and in vitro pyloric motility recordings were used to assess pyloric motor function in the 6-OHDA rats. The 6-OHDA-treated rats displayed delayed solid gastric emptying and a lower basal pyloric motility index. In the 6-OHDA rats, high K⁺-induced transient contractions were weaker in pyloric sphincters. Electric field stimulation (EFS)-induced pyloric sphincter relaxation was lower in the 6-OHDA rats. N^G-nitro-l-arginine methyl ester (l-NAME), a nonselective inhibitor of NOS, markedly inhibited the EFS-induced relaxation in both control and 6-OHDA rats. Pretreatment of tetrodotoxin abolished the effect of EFS on the pyloric motility. In addition, nNOS-positive neurons were extensively distributed in the pyloric myenteric plexus, whereas the number of nNOS-immunoreactive neurons and the protein expression of nNOS were significantly decreased in the pyloric muscularis of 6-OHDA rats. However, sodium nitroprusside-induced pyloric relaxations were similar between the control and 6-OHDA rats. These results indicate that the pyloric sphincters of 6-OHDA rats exhibit both weakened contraction and relaxation. The latter may be due to reduced nNOS in the pyloric myenteric plexus. The dysfunction of the pyloric sphincter might be involved in the delayed gastric emptying.NEW & NOTEWORTHY Reduced nitrergic neurons in pyloric myenteric plexus potently contributed to the attenuated relaxation in 6-hydroxydopamine (6-OHDA) rats, subsequently affecting gastric emptying. SNP could well improve the relaxation of pylori in 6-OHDA rats. The present study provides new insight into the diagnosis and treatment of delayed gastric emptying in patients with PD.

Atractylenolide‑1 alleviates gastroparesis in diabetic rats by activating the stem cell factor/c‑kit signaling pathway

Diabetic gastroparesis (DGP), also known as delayed gastric emptying, is a common complication of diabetes mellitus. There are numerous clinical symptoms associated with DGP, as well as high treatment costs and markedly reduced patient quality of life. However, the pathogenesis of DGP is not clear, thus effective treatment methods are yet to be established. In the present study, a DGP rat model was established in Sprague‑Dawley rats by the intraperitoneal injection of streptozotocin (STZ). DGP model rats were treated with different doses of atractylenolide‑1 to detect alterations in gastrointestinal function, including gastroparesis, gastric emptying, gastric motility, gastric peristalsis and gastric blood flow. Compared with the DGP group, atractylenolide‑1 treatment significantly reduced glycaemia and the level of glycated hemoglobin, as well as restoring gastrointestinal function. Gastroparesis, gastric emptying, gastric motility, gastric peristalsis and gastric blood flow were significantly impaired in the STZ‑induced group compared with the vehicle control group. Moreover, the STZ‑induced group displayed downregulated expression levels of the DGP indicator KIT proto‑oncogene, receptor tyrosine kinase (c‑kit), as investigated by immunohistochemistry, and stem cell factor (SCF) protein, as assessed using ELISA, significantly enhanced rat interstitial cells of Cajal (ICC) apoptosis, and significantly altered levels of oxidative stress‑related markers (malondialdehyde and superoxide dismutase) in the serum and gastric tissues compared with the vehicle control group. By contrast, treatment with atractylenolide‑1 significantly counteracted the effects of DGP on peristalsis, inhibited apoptosis and suppressed oxidative stress by regulating the expression of heme oxygenase 1 in STZ‑induced DGP model rats. Further research indicated that atractylenolide‑1 regulated oxidative stress reactions and improved gastric function by activating the SCF/c‑kit signaling pathway. Collectively, the results of the present study suggested that atractylenolide‑1 promoted ICC survival and preserved the structure of the gastric tissue network in a DGP rat model via the SCF/c‑kit signaling pathway, providing novel insights for the treatment of DGP.

Autonomic Peripheral Neuropathy

PURPOSE OF REVIEW

This article provides a summary of the autonomic neuropathies, including neuropathies associated with diabetes mellitus, neuropathies due to amyloid deposition, immune-mediated autonomic neuropathies (including those associated with a paraneoplastic syndrome), inherited autonomic neuropathies, and toxic autonomic neuropathies. The presenting features, diagnostic investigations, and natural history of these neuropathies are discussed.

RECENT FINDINGS

Recent findings in autonomic peripheral neuropathy include data on the epidemiology and atypical presentations of diabetic autonomic neuropathy, treatment-induced neuropathy of diabetes mellitus, the presentation of immune-mediated neuropathies, and advances in hereditary neuropathy associated with amyloidosis and other hereditary neuropathies.

SUMMARY

Knowledge and recognition of the clinical features of the autonomic neuropathies, combined with appropriate laboratory and electrophysiologic testing, will facilitate accurate diagnosis and management.

Colonic motility in patients with type 1 diabetes and gastrointestinal symptoms

BACKGROUND

Gastrointestinal (GI) symptoms are common in patients with diabetes mellitus (DM). The electromagnetic 3D-Transit system allows assessment of regional transit times and motility patterns throughout the GI tract. We aimed to compare GI transit times and detailed motility patterns of the colon in patients with DM and GI symptoms to those of healthy controls (HC). We further aimed to determine whether any abnormalities in motility were reversible by cholinergic stimulation.

METHODS

We compared 18 patients with DM with 20 HC by means of the 3D-Transit system. Patients were studied before and during oral administration of 60 mg pyridostigmine.

KEY RESULTS

Compared to HC, patients had prolonged gastric emptying (DM: 3.3 hours (interquartile range (IQR) 2.6-4.6); HC: 2.3 hours (IQR 1.7-2.7) (P < .01)), colonic transit time (DM: 52.6 hours (IQR 23.3-83.0); HC: 22.4 hours (IQR 18.9-43.6) (P = .02)), and whole gut transit time (DM: 69.4 hours (IQR 32.9-103.6); HC: 30.3 hours (IQR 25.2-49.9) (P < .01)). In addition, compared to HC, patients had prolonged transit time in the ascending colon (DM: 20.5 hours (IQR 11.0-44.0); HC: 8.0 hours (IQR 3.8-21.0) (P < .05)) and more slow retrograde movements in the colon (DM: 2 movements (IQR 1-4); HC: 1 movement (IQR 0-1) (P = .01)). In patients, pyridostigmine increased the number of bowel movements (P < .01) and reduced small intestine transit times (P < .05).

CONCLUSIONS

Patients with DM and GI symptoms have longer than normal GI transit times. This is only partly reversible by pyridostigmine. The increased number of retrograde colonic movements in patients could potentially explain the abnormally long transit time in proximal colon.

Endoscopic Botulinum Toxin for Gastroparesis: Results of a Retrospective Series

Beneficial effects of pyloric botulinum toxin injection have been described in a subgroup of gastroparesis patients. Our aim is to evaluate whether clinical, manometric and/or scintigraphic parameters are able to predict treatment outcome. Forty patients (67% female, age 49 (36–56) years) with decompensated gastroparesis treated with botulinum toxin were included in this retrospective analysis. Objective parameters were high-resolution antroduodenal manometry, gastric emptying rate (scintigraphy), and weight change. Subjective treatment outcome was assessed with a Global Physician Assessment Scale. Binary logistic regression analysis was performed to identify predictors for treatment outcome. Fourteen patients (35%) were symptom-responders, and 65% of patients were short-term weight-responders. For both subjective and objective treatment outcome, no differences were found in manometric and scintigraphic variables between responders and non-responders. Neither clinical nor manometric or scintigraphic variables could predict subjective and objective treatment outcome. In conclusion, symptom improvement is achieved in a subgroup of gastroparesis patients treated with endoscopic pyloric botulinum toxin. Although the majority of patients were able to maintain their baseline weight at short-term follow-up, a substantial group of patients needed nutritional interventions on long-term follow-up. However, none of the demographic, clinical, scintigraphic, or antroduodenal manometry variables were able to predict either subjective or objective treatment outcome.

Diabetic Gastroparesis: Principles and Current Trends in Management

This article is a comprehensive review of diabetic gastroparesis, defined as delayed or disordered gastric emptying, including basic principles and current trends in management. This review includes sections on anatomy and physiology, diagnosis and differential diagnosis as well as management and current guidelines for treatment of diabetic gastroparesis. Diabetic gastroparesis (DGp) is a component of autonomic neuropathy resulting from long-standing poorly controlled type 1 and type 2 diabetes. The diagnostic workup of DGp first excludes obstruction and other causes including medications that may mimic delayed/disordered gastric emptying. Targeting nutrition, hydration, symptomatic relief and glycemic control are mainstays of treatment for DGp. Additionally, optimal treatment of DGp includes good glycemic management, often involving customizing insulin delivery using basal-bolus insulin and technology, including sensor-augmented pumps and continuous glucose monitoring systems. Prokinetic medications may be helpful in DGp symptoms, although only limited number of medications is currently available in the USA. Selected medication-refractory patients with DGp may benefit from gastric neuromodulation, and some from surgical interventions including pyloric therapies that can also be done endoscopically. As is true of any of the diabetic complications, prevention of DGp by early and optimal glycemic control is more cost-effective.Funding: Hansa Medcell, India.

Feasibility of intraperitoneal placental-derived mesenchymal stem cell injection in stomachs of diabetic mice

BACKGROUND AND AIM

Diabetic gastropathy is associated with loss of interstitial cells of Cajal and autonomic neuropathy. Effective management for diabetic gastropathy is still unavailable. This study was aimed to confirm the pathogenetic changes in diabetic gastropathy and to examine the effect of treatment with placental-derived mesenchymal stem cells (PDMSCs) in stomachs of animal models.

METHODS

Fourteen non-obese diabetic/ShiLtJ mice of 8 weeks were bled until week 30. Diabetes mellitus developed in 10 out of 14 mice, which all survived with insulin. The mice were grouped into three groups: nondiabetic group (n = 4), diabetic sham group (n = 5), and diabetic PDMSC group (n = 5) all of which were treated with intraperitoneal PDMSCs injection at week 30. All mice were killed at week 34, and the stomachs were examined by immunohistochemical stain with c-kit and neuronal nitric oxide synthase antibodies.

RESULTS

The number of c-kit positive cells in stomach decreased significantly in the diabetic sham group compared with that in the nondiabetic group (21.2 ± 6.7 vs 88.0 ± 29.3, P = 0.006) but increased with PDMSC treatment (21.2 ± 6.7 vs 64.0 ± 15.1, P = 0.02). The positive rate of neuronal nitric oxide synthase in neural plexus was also significantly lower in the diabetic sham group than in the nondiabetic group (22.3% ± 18.5% vs 48.0% ± 22.7%, P = 0.003) but increased with PDMSC treatment (22.3% ± 18.5% vs 43.3% ± 20.5%, P = 0.03).

CONCLUSIONS

Interstitial cells of Cajal and neural plexus decreased in stomachs of mice with diabetes mellitus but were significantly repaired with intraperitoneal injection of PDMSC.

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

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

Characterization of smooth muscle, enteric nerve, interstitial cells of Cajal, and fibroblast-like cells in the gastric musculature of patients with diabetes mellitus

AIM

To investigate histologic abnormalities in the gastric smooth muscle of patients with diabetes mellitus (DM).

METHODS

Full-thickness gastric specimens were obtained from patients undergoing surgery for gastric cancer. H&E stain and Masson’s Trichrome stain were performed to assess the degree of fibrosis. Immunohistochemical staining using various antibodies was also performed [antibodies against protein gene product 9.5 (PGP9.5), neuronal nitric oxide synthase (nNOS), vasoactive intestinal peptide (VIP), neurokinin-1 (NK1) receptor, c-Kit, and platelet-derived growth factor receptor-alpha, (PDGFRα)]. Immunofluorescent staining and evaluation with confocal microscopy were also conducted.

RESULTS

Twenty-six controls and 35 diabetic patients (21 short-duration patients and 14 long-duration patients) were included. There were no significant differences in basic demographics between the two groups except in mean body mass index (BMI) (higher in the DM group). Proportions of moderate-to-severe intercellular fibrosis in the muscle layer were significantly higher in the DM group than in the control group (P < 0.01). On immunohistochemical staining, c-Kit- and PDGFRα-positive immunoreactivity were significantly decreased in the DM group compared with the control group (P < 0.05). There were no statistically significant differences in PGP9.5, nNOS, VIP, and neurokinin 1 expression. On immunofluorescent staining, cellularity of interstitial cells of Cajal (ICC) was observed to decrease with increasing duration of DM.

CONCLUSION

Our study suggests that increased intercellular fibrosis, loss of ICC, and loss of fibroblast-like cells are found in the smooth muscle of DM patients. These abnormalities may contribute to changes in gastric motor activity in patients with DM.

Gene-environment interactions and the enteric nervous system: Neural plasticity and Hirschsprung disease prevention

Intestinal function is primarily controlled by an intrinsic nervous system of the bowel called the enteric nervous system (ENS). The cells of the ENS are neural crest derivatives that migrate into and through the bowel during early stages of organogenesis before differentiating into a wide variety of neurons and glia. Although genetic factors critically underlie ENS development, it is now clear that many non-genetic factors may influence the number of enteric neurons, types of enteric neurons, and ratio of neurons to glia. These non-genetic influences include dietary nutrients and medicines that may impact ENS structure and function before or after birth. This review summarizes current data about gene-environment interactions that affect ENS development and suggests that these factors may contribute to human intestinal motility disorders like Hirschsprung disease or irritable bowel syndrome.

Gastric and pyloric sphincter muscle function and the developmental-dependent regulation of gastric content emptying in the rat

Feeding intolerance is a common issue in the care of preterm neonates. The condition manifests as delayed emptying of gastric contents and represents a therapeutic challenge, since the factors accounting for its manifestations are unknown. The main goal of this study was to comparatively investigate the age-related function of rat gastric and pyloric smooth muscle and their putative regulators. We hypothesized that a reduced gastric muscle contraction potential early in life contributes to the delayed gastric emptying of the newborn. Newborn and adult rat gastric (fundus) and pyloric sphincter tissues were comparatively studied in vitro. Shortening of the tissue-specific dissociated smooth muscle cell was evaluated, and expression of the key regulatory proteins Rho-associated kinase 2 and myosin light chain kinase was determined. Gastric and pyloric smooth muscle cell shortening was significantly greater in the adult than the respective newborn counterpart. Expression of myosin light chain kinase and Rho-associated kinase 2 was developmentally regulated and increased with age. Pyloric sphincter muscle expresses a higher neuronal nitric oxide synthase and phosphorylated vasodilator-stimulated phosphoprotein content in newborn than adult tissue. Compared with later in life, the newborn rat gastropyloric muscle has a Ca(2+)-related reduced potential for contraction and the pyloric sphincter relaxation-dependent modulators are overexpressed. To the extent that these rodent data can be extrapolated to humans, the delayed gastric emptying in the newborn reflects reduced stomach muscle contraction potential, as opposed to increased pyloric sphincter tone.

Effect of electroacupuncture on gastric interstitial cells of Cajal in a rat model of diabetic gastroparesis

The aim of the present study was to observe the effect of electroacupuncture (EA) on the gastric interstitial cells of Cajal (ICCs) in a rat model of diabetic gastroparesis (DGP). The gastric tissues were collected from 75 rats, which had been divided into three equal groups (n=25/group): Blank, model and EA. Hematoxylin and eosin and immunohistochemical staining were used to observe the cellular morphology and distribution of c-kit-positive gastric ICCs; light microscopy was used to count the number of ICCs; and electron microscopy was used to observe the ultrastructure of the rat ICCs. Compared with the model group, the gastromucosal glandular and smooth muscle cells of the EA group were more regularly arranged, with fewer vacuoles; there was an increased cellular gap and the vacuolar degeneration on the gastric walls was mild. Image analysis showed that the blank group exhibited the greatest number of c-kit-positive ICCs, and the number of c-kit-positive ICCs in the blank group was significantly different from that in the model and EA groups (P<0.01): Blank group > EA group > model group. In conclusion, DGP rats exhibited a reduced number of gastric ICCs, altered ultrastructural morphology and a reduced number of cell organelles, particularly mitochondria, compared with the blank group. EA may help to reverse the various pathological changes of gastric ICCs in rat models of DGP.

Effectiveness and safety of Helicobacter pylori eradication in treating diabetic gastroparesis patients with Helicobacter pylori infection: Meta-analysis

AIM: To evaluate the effectiveness and safety of Helicobacter pylori (H. pylori) eradication in treating diabetic gastroparesis (DGP) patients with H. pylori infection.

METHODS: Online databases (PubMed, EMbase, Cochrane Library, Wangfang, CNKI and CBMdice) were searched for randomized controlled trials investigating therapeutic effects of H. pylori eradication vs conventional treatment. Outcomes were analyzed with RevMan 5.3.

RESULTS: Six randomized controlled trials containing 508 patients were included. The results of meta-analysis showed that H. pylori eradication was superior to conventional treatment for DGP patients in clinical effects (RR = 1.33, 95%CI: 1.21-1.47, P < 0.00001). The incidence of adverse events was similar between the two therapies (P = 0.39).

CONCLUSION: Compared with the conventional treatment, H. pylori eradication has more significant clinical effects and comparable incidence of adverse events.

Distribution of advanced glycation end products and their receptor in the stomach of diabetic rats

AIM: To observe the distribution of advanced glycation end products (AGEs) and their receptor (RAGE) in the stomach of diabetic rats.

METHODS: Diabetes mellitus (DM) and control (CON) rats were reared for eight weeks. Fasting plasma glucose (FPG), glycated serum protein (GSP) and gastric layer thickness were measured. The expression of AGEs and RAGE was detected by immunohistochemical staining.

RESULTS: The thickness of the mucosa (781.47 μm ± 137.82 μm vs 709.85 μm ± 169.41 μm) and submucosa (233.39 μm ± 134.05 μm vs 109.32 μm ± 44.43 μm) increased significantly in the DM group compared with the CON group (P < 0.05). The expression of AGEs and RAGE in the mucosa (5.66 ± 1.90 vs 2.25 ± 0.52, 2.79 ± 0.54 vs 1.70 ± 0.30) and muscle (37.37 ± 7.38 vs 24.32 ± 4.02, 4.26 ± 0.80 vs 3.59 ± 0.37) layers of the stomach was significantly higher in the DM group than in the CON group (P < 0.05).

CONCLUSION: The expression of AGEs and RAGE is up-regulated in the stomach of diabetic rats. The increased levels of AGE and RAGE in gastric tissue may contribute to diabetic gastrointestinal dysfunction.

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.

Itopride combined with α-lipoic acid for diabetic gastroparesis: Curative effect and impact on motilin and gastrin

AIM: To observe the efficacy of itopride hydrochloride combined with α-lipoic acid in the treatment of diabetic gastroparesis (DGP) and their effect on motilin and gastrin.

METHODS: Sixty patients with DGP who had gastrointestinal symptoms were treated with α-lipoic acid and itopride (α-lipoic acid 0.6 g + 250 mL 0.9% saline intravenously for 14 d + itopride 50 mg orally before meals, three times a day), and 50 patients were treated with itopride alone (itopride 50 mg orally before meals, three times a day). After two weeks of treatment, clinical symptoms including postprandial abdominal fullness, belching, acid reflux, anorexia, nausea and vomiting were observed, the gastric emptying rate was determined, the efficacy was evaluated, and the changes in the levels of motilin and gastrin were detected.

RESULTS: Improvement of clinical symptoms was observed in both groups, and the total effective rate was 91.6% in the combination therapy group and 78.0% in the monotherapy group. Gastric emptying rate was significantly higher in the combination group than in the monotherapy group (P < 0.05). Motilin and gastrin levels were reduced after treatment in both groups, and the decrease was more significant in the combination group.

CONCLUSION: For patients with DGP, α-lipoic acid and itopride combination therapy can better improve symptoms of gastroparesis, increase gastric emptying, and decrease the levels of motilin and gastrin compared with treatment with itopride alone.

Postprandial plasma glucose response and gastrointestinal symptom severity in patients with diabetic gastroparesis

Gastroparesis is a well-known diabetic complication. The pathogenesis is not fully understood. However, it is important to early diagnose these patients. This study evaluated the plasma glucose response after a test meal, and gastrointestinal (GI) symptom severity in patients with clinical suspicion of diabetic gastroparesis, and assessed its usefulness to predict gastroparesis. In all, 83 subjects with insulin-treated diabetes mellitus (DM) type 1 and 2 were included; 53 subjects had gastroparesis and 30 had normal gastric emptying determined by gastric scintigraphy. GI symptom severity during the preceding 2 weeks was evaluated with a validated questionnaire. The test meal consisted of 100 g meat, 40 g pasta, 150 g carrot, and 5 g oil. The subjects ingested the meal under fasting conditions, and plasma glucose was followed during 180 minutes. Patients with gastroparesis demonstrated a blunted plasma glucose response after a test meal versus patients with normal gastric emptying (P < .005), reflected by lower maximum increase in plasma glucose response and incremental area under the curve of the plasma glucose, but a similar time to the maximum plasma glucose level. All GI symptoms were more severe in patients with gastroparesis. GI symptom severity had the best discriminative value to identify patients with gastroparesis with an area under the receiver operating curve of 0.83 (optimal cutoff: sensitivity 87%, specificity 80%). Patients with diabetic gastroparesis have a blunted postprandial plasma glucose response. Combining this information with the presence of GI symptoms can help clinicians identify diabetic patients with gastroparesis.

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.

Xiangshaliujunzi Decoction for the treatment of diabetic gastroparesis: A systematic review

AIM: To assess the current clinical evidence of the effectiveness of Xiangshaliujunzi Decoction (XSLJZD) for the treatment of diabetic gastroparesis (DGP).

METHODS: Randomized controlled trials (RCTs) were retrieved from seven major electronic databases including Medline, the Cochrane Library, Embase, Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure, Chinese Scientific Journal Database (VIP), and Wanfang Databases, using search dates from the beginning of the databases to May 2013. No language limitations were applied. We included RCTs that used XSLJZD or a modified XSLJZD compared with a control group for the treatment of DGP. The control groups included conventional treatment (Western medicinal treatment), placebo, and no treatment (blank), but not acupuncture. The main outcome index was clinical effectiveness, which was based on the gastric emptying test and variations in the gastrointestinal (GI) symptoms between the treatment and control groups after intervention. Data extraction, analysis, and quality assessment were conducted according to the Cochrane Handbook for Systematic Review of Interventions, Version 5.1.0.

RESULTS: Ten RCTs involving 867 patients (441 in the experimental groups, and 426 in the control groups) were identified, and the overall methodological quality was evaluated as generally low. In the treatment groups, all 10 trials used herbs alone as the treatment, whereas all control groups used prokinetic medicine. The period of intervention ranged from 2 to 8 wk. Three classes were used to evaluate treatment efficacy: significant effective, effective, and ineffective, and all trials used the clinical effective rate (based on the gastric emptying test and changes in GI symptoms) to evaluate efficacy. The data showed that the effects of XSLJZD for the treatment of DGP were superior to the control group (n = 867, RR =1.33, 95%CI: 1.24-1.42, Z = 8.11, P < 0.00001). Two trials recorded adverse events, and one trial reported follow-up.

CONCLUSION: XSLJZD could restore the gastric emptying rate and improve symptoms. However, the evidence remains weak due to the poor methodological quality of the included studies.

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.

Methods for clinical evaluation of diabetic gastroparesis

An effective clinical assessment method is necessary for the development of new drugs. Currently, main methods for clinical evaluation of diabetic gastroparesis (DGP) include evaluation of gastric emptying, patients' subjective evaluation of disease severity and the change in pathogenic factors. However, there are many problems that need to address; the methods for the evaluation of gastric emptying have not been widely used, there is no uniform standard for the patients' subjective evaluation, and the pathogenic factors for DGP are not completely clear. In this article we will review the methods for clinical evaluation of DGP, with the emphasis on the above problems.