Gastric myoelectrical activity and gastric emptying in diabetic patients with dyspeptic symptoms

Electrogastrography in patients with gastric motility disorders

Electrogastrography (EGG) is a novel diagnostic modality for assessing the gastrointestinal tract (GI) that generates spontaneous electrical activity and monitors gastric motility. The aim of this study was to compare patients with functional dyspepsia (FD) and diabetic gastroparesis (D-GP) with healthy controls (CT) to use established findings on abnormalities of gastric motility based on EGG characteristics. In this study, 50 patients with FD, 50 D-GP patients, and 50 CT subjects were studied to compare EGG with discrete wavelet transform models (DWT) to extract signal characteristics using a variety of different qualitative and quantitative metrics from pre-prandial and postprandial states. As a result, higher statistically significant (p < 0.05*) were found in the DWT models based on power spectral density (PSD) analysis in both states. We also present that the correlations between EGG metrics and the presence of FD, D-GP, and CT symptoms were inconsistent. This paper represents that EGG assessments of FD and D-GP patients differ from healthy controls in terms of abnormalities of gastric motility. Additionally, we demonstrate that diverse datasets showed adequate gastric motility responses to a meal. We anticipate that our method will provide a comprehensive understanding of gastric motility disorders for better treatment and monitoring in both clinical and research settings. In conclusion, we present potential future opportunities for precise gastrointestinal electrophysiological disorders.

Review of paediatric gastrointestinal physiology relevant to the absorption of orally administered medicines

Despite much progress in regulations to improve paediatric drug development, there remains a significant need to develop better medications for children. For the design of oral dosage forms, a detailed understanding of the specific gastrointestinal (GI) conditions in children of different age categories and how they differ from GI conditions in adults is essential. Several review articles have been published addressing the ontogeny of GI characteristics, including luminal conditions in the GI tract of children. However, the data reported in most of these reviews are of limited quality because (1) information was cited from very old publications and sometimes low quality sources, (2) data gaps in the original data were filled with textbook knowledge, (3) data obtained on healthy and sick children were mixed, (4) average data obtained on groups of patients were mixed with data obtained on individual patients, and (5) results obtained using investigative techniques that may have altered the outcome of the respective studies were considered. Consequently, many of these reviews draw conclusions that may be incorrect. The aim of the present review was to provide a comprehensive and updated overview of the available original data on the ontogeny of GI luminal conditions relevant to oral drug absorption in the paediatric population. To this end, the PubMed and Web of Science metadatabases were searched for appropriate studies that examined age-related conditions in the oral cavity, esophagus, stomach, small intestine, and colon. Maturation was observed for several GI parameters, and corresponding data sets were identified for each paediatric age group. However, it also became clear that the ontogeny of several GI traits in the paediatric population is not yet known. The review article provides a robust and valuable data set for the development of paediatric in vitro and in silico biopharmaceutical tools to support the development of age-appropriate dosage forms. In addition, it provides important information on existing data gaps and should provide impetus for further systematic and well-designed in vivo studies on GI physiology in children of specific age groups in order to close existing knowledge gaps and to sustainably improve oral drug therapy in children.

Clinical features and gastric myoelectrical activity in patients with idiopathic and post-surgical rapid gastric emptying who present with unexplained chronic nausea

BACKGROUND

The cause of chronic nausea can be difficult to diagnose. Idiopathic rapid gastric emptying (iRGE) can cause nausea, but limited literature exists on clinical and pathophysiological features. In contrast, dumping syndrome or post-surgical rapid gastric emptying (psRGE) is well-known and may present with early phase vasomotor symptoms, diarrhea, and late phase reactive hypoglycemia. Our aim is to compare clinical and gastric motility characteristics in patients with iRGE and psRGE and unexplained chronic nausea.

METHODS

A retrospective study was conducted on patients with unexplained chronic nausea and RGE (<30% retention of a standard isotope-labeled solid meal at 1-h). Gastric myoelectrical activity (GMA) was recorded during water load satiety tests (WLST) using validated electrogastrogram (EGG) recording methods.

KEY RESULTS

Thirty iRGE and sixteen psRGE patients with unexplained chronic nausea were identified; average 1-hour meal retention was 18.6% and 16.2%, respectively. Nausea, bloating, early satiety, and bowel function were similar in the two groups; fewer iRGE patients had abdominal pain and none had vasomotor symptoms. Normal 3 cpm GMA was recorded in 44% of iRGE vs 29% of psRGE, tachygastria in 13% vs 43%, bradygastria in 25% vs 14%, and mixed in 19% vs 14% (p values >0.05). Abnormal WLST volume (<300 ml) was found in 69% of iRGE and 43% of psRGE (p = 0.36).

CONCLUSIONS & INFERENCES

(a) iRGE and psRGE patients may present with unexplained chronic nausea rather than classic vasomotor symptoms and diarrhea. (b) iRGE and psRGE patients had similar gastric dysrhythmias and accommodation dysfunction, which may contribute to RGE.

Effect of diabetes mellitus on pharmacokinetic and pharmacodynamic properties of drugs

The effects of diabetes mellitus on the pharmacokinetics and pharmacodynamics of drugs have been well described in experimental animal models; however, only minimal data exist for humans and the current knowledge regarding the effects of diabetes on these properties remains unclear. Nevertheless, it has been observed that the pharmacokinetics and pharmacodynamics of drugs are changed in subjects with diabetes. It has been reported that diabetes may affect the pharmacokinetics of various drugs by affecting (i) absorption, due to changes in subcutaneous adipose blood flow, muscle blood flow and gastric emptying; (ii) distribution, due to non-enzymatic glycation of albumin; (iii) biotransformation, due to regulation of enzymes/transporters involved in drug biotransformation; and (iv) excretion, due to nephropathy. Previously published data also suggest that diabetes-mediated changes in the pharmacokinetics of a particular drug cannot be translated to others. Although clinical studies exploring the effect of diabetes on pharmacodynamics are still very limited, there is evidence that disease-mediated effects are not limited only to pharmacokinetics but also alter pharmacodynamics. However, for many drugs it remains unclear whether these influences reflect diabetes-mediated changes in pharmacokinetics rather than pharmacodynamics. In addition, even though diabetes-mediated pharmacokinetics and pharmacodynamics might be anticipated, it is important to study the effect on each drug and not generalize from observed data. The available data indicate that there is a significant variability in drug response in diabetic subjects. The discrepancies between individual clinical studies as well as between ex vivo and clinical studies are probably due to (i) the restricted and focused population of subjects in clinical studies; (ii) failure to consider type, severity and duration of the disease; (iii) histopathological characteristics generally being missing; and (iv) other factors such as varying medication use, dietary protein intake, age, sex and obesity. The obesity epidemic in the developed world has also inadvertently influenced the directions of pharmacological research. This review attempts to map new information gained since Gwilt published his paper in Clinical Pharmacokinetics in 1991. Although a large body of research has been conducted and significant progress has been made, we still have to conclude that the available information regarding the effect of diabetes on pharmacokinetics and pharmacodynamics remains unclear and further clinical studies are required before we can understand the clinical significance of the effect. An understanding of diabetes-mediated changes as well as of the source of the variability should lead to the improvement of the medical management and clinical outcomes in patients with this widespread disease.

Effects of Chinese herb complex Jianpiwan and Baohewan on gastrointestinal motility in rats

AIM: To investigate the effects of Jianpiwan and Baohewan on gastrointestinal motility in rats.

METHODS: Using dextran blue 2000 as a gastrointestinal internal marker its relative remaining rate in stomach and its pushing ratio of the bowel, we observed the effects of Jianpiwan and Baohewan on the emptying of stomach and the driving of bowel in normal and splenic asthenic rats.

RESULTS: Baohewan and Jianpiwan had evidently promoting effect on emptying of stomach in normal and splenic asthenic rats 0.029±0.033 vs 0.059±0.035; 0.018±0.010 vs 0.059±0.035; 0.036±0.028 vs 0.089±0.042; 0.029±0.026 vs 0.089±0.042 (P < 0.05). Baohewan had better effect than Jianpiwan on the driving of bowel in normal rats 58.8±11.3 vs 51.6±9.7 (P < 0.05). For splenic asthenic rats whose vermiculation was reinforced, Baohewan still had promoting effect 63.5±6.1 vs 54.1±12.3 (P < 0.05) and Jianpiwan can slow the vermiculation and help it recover to normal leves 43.0±7.1 vs 54.1±12.3 (P < 0.05).

CONCLUSION: Baohewan and Jianpiwan have promoting and adjusting effects on gastrointestinal motility in rats.