Ultrasonographic gastric emptying in protein energy malnutrition: effect of type of meal and nutritional recovery

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.

Anabolic competence: Assessment and integration of the multimodality interventional approach in disease-related malnutrition

Disease-related malnutrition (DRM) is a frequent clinical problem, characterized by loss of lean body mass and decreased function, including muscle function and immunocompetence. In DRM, nutritional intervention is necessary, but it has not consistently been shown to be sufficient. Other factors, for example, physical activity and hormonal or metabolic influencers of the internal milieu, are also important in the treatment of DRM. A prerequisite for successful treatment of DRM is the positive balance between anabolism and catabolism. The aim of this review was to approach DRM using this paradigm of anabolic competence, for conceptual and practical reasons. Anabolic competence is defined as "that state which optimally supports protein synthesis and lean body mass, global aspects of muscle and organ function, and immune response." Anabolic competence and interdisciplinary, multimodality interventions create a practical foundation to approach DRM in a proactive comprehensive way. Here, we describe the paradigm of anabolic competence, and its operationalization by measuring factors related to anabolic competence and suited for clinical management of patients with DRM.

Gastric Emptying in the Elderly

Aging is characterized by a diminished homeostatic regulation of physiologic functions, including slowing of gastric emptying. Gastric and small intestinal motor and humoral mechanisms in humans are complex and highly variable: ingested food is stored, mixed with digestive enzymes, ground into small particles, and delivered as a liquefied form into the duodenum at a rate allowing efficient digestion and absorption. In healthy aging, motor function is well preserved whereas deficits in sensory function are more apparent. The effects of aging on gastric emptying are relevant to the absorption of oral medications and the regulation of appetite, postprandial glycemia, and blood pressure.

Development of a paediatric population-based model of the pharmacokinetics of rivaroxaban

Background

Venous thromboembolism has been increasingly recognised as a clinical problem in the paediatric population. Guideline recommendations for antithrombotic therapy in paediatric patients are based mainly on extrapolation from adult clinical trial data, owing to the limited number of clinical trials in paediatric populations. The oral, direct Factor Xa inhibitor rivaroxaban has been approved in adult patients for several thromboembolic disorders, and its well-defined pharmacokinetic and pharmacodynamic characteristics and efficacy and safety profiles in adults warrant further investigation of this agent in the paediatric population.

Objective

The objective of this study was to develop and qualify a physiologically based pharmacokinetic (PBPK) model for rivaroxaban doses of 10 and 20 mg in adults and to scale this model to the paediatric population (0–18 years) to inform the dosing regimen for a clinical study of rivaroxaban in paediatric patients.

Methods

Experimental data sets from phase I studies supported the development and qualification of an adult PBPK model. This adult PBPK model was then scaled to the paediatric population by including anthropometric and physiological information, age-dependent clearance and age-dependent protein binding. The pharmacokinetic properties of rivaroxaban in virtual populations of children were simulated for two body weight-related dosing regimens equivalent to 10 and 20 mg once daily in adults. The quality of the model was judged by means of a visual predictive check. Subsequently, paediatric simulations of the area under the plasma concentration–time curve (AUC), maximum (peak) plasma drug concentration (C_max) and concentration in plasma after 24 h (C_24h) were compared with the adult reference simulations.

Results

Simulations for AUC, C_max and C_24h throughout the investigated age range largely overlapped with values obtained for the corresponding dose in the adult reference simulation for both body weight-related dosing regimens. However, pharmacokinetic values in infants and preschool children (body weight <40 kg) were lower than the 90 % confidence interval threshold of the adult reference model and, therefore, indicated that doses in these groups may need to be increased to achieve the same plasma levels as in adults. For children with body weight between 40 and 70 kg, simulated plasma pharmacokinetic parameters (C_max, C_24h and AUC) overlapped with the values obtained in the corresponding adult reference simulation, indicating that body weight-related exposure was similar between these children and adults. In adolescents of >70 kg body weight, the simulated 90 % prediction interval values of AUC and C_24h were much higher than the 90 % confidence interval of the adult reference population, owing to the weight-based simulation approach, but for these patients rivaroxaban would be administered at adult fixed doses of 10 and 20 mg.

Conclusion

The paediatric PBPK model developed here allowed an exploratory analysis of the pharmacokinetics of rivaroxaban in children to inform the dosing regimen for a clinical study in paediatric patients.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-013-0090-5) contains supplementary material, which is available to authorized users.

Effect of nutritional rehabilitation on gastric motility and somatization in adolescents with anorexia

OBJECTIVE

To examine gastric function, as well as the presence of somatic complaints, anxiety symptoms, and functional gastrointestinal disorders (FGIDs), in adolescents with anorexia nervosa (AN) before and after nutritional rehabilitation.

STUDY DESIGN

Sixteen females with AN and 22 healthy controls with similar demographic profiles were included. Gastric emptying (measured as residual gastric volume) and gastric accommodation (measured as postprandial antral diameter) were assessed with abdominal ultrasonography. Participants completed the Children's Somatization Inventory (CSI), the Screen for Child Anxiety-Related Emotional Disorders, and the Questionnaire on Pediatric Gastrointestinal Symptoms-Rome III version. All testing was repeated 3-4 months later.

RESULTS

Body mass index in the AN group improved over time (P = .012). Fasting gastric parameters were similar in the 2 groups. Maximum postprandial antral diameter was significantly greater in controls compared with the AN group (P = .008). Only adolescents with AN demonstrated a significant increase in maximum postprandial diameter at repeat testing (P = .009). There was no difference in residual gastric volume between the 2 groups. Initial CSI scores were higher in adolescents with AN (P < .0001), including higher scores for nausea and abdominal pain. CSI scores were significantly lower in adolescents with AN (P = .035). Initial scores on the Screen for Child Anxiety-Related Emotional Disorders were significantly higher in adolescents with AN (P = .0005), but did not change over time. Adolescents with AN met significantly more criteria for FGIDs (P = .003).

CONCLUSION

Adolescents with AN have impaired gastric accommodation that improves after nutritional rehabilitation, have significantly more somatic complaints, and meet more criteria for anxiety disorders and FGIDs. After nutritional rehabilitation, somatization improves and FGIDs become less common, but symptoms of anxiety persist.

Measuring of gastric emptying in Egyptian pediatric patients with portal hypertension by using real-time ultrasound

BACKGROUND/AIM

Among the various methods for evaluating gastric emptying, the real-time ultrasound is safe, does not require intubation, or rely on either radiologic or radionuclide technique. The aim of our work was to measure the gastric emptying in pediatric patients with portal hypertension by using the real-time ultrasound.

PATIENTS AND METHODS

Forty patients with portal hypertension with mean age 7 ± 2.8 years and 20 healthy children as a control group underwent gastric emptying study by using real-time ultrasound. The cross-sectional area of the gastric antrum was measured in the fasting state and then each subject was allowed to drink tap water then calculated by using formula area (π longitudinal Χ anteroposterior diameter/4). The intragastric volume was assumed to be directly proportional to the cross-sectional area of the antrum.

RESULTS

The mean gastric emptying half-time volume was significantly delayed in portal hypertension patients (40 ± 6.8 min) compared with the control subjects (27.1 ± 3.6) min (P<0.05). Patients with extrahepatic portal vein obstruction had significant delayed gastric emptying in comparison to patients with portal hypertension due to other etiologies (36.14 ± 4.9 vs 44.41 ± 6.04 min; P<0.01).

CONCLUSION

Ultrasound is a noninvasive and a reliable method for measuring gastric emptying in pediatric patients. Gastric emptying was significantly delayed in patients with portal hypertension. Etiology of portal hypertension may influence gastric emptying time in patients with chronic liver disease.

Effect of honey on gastric emptying of infants with protein energy malnutrition

BACKGROUND

Patients with protein-energy malnutrition (PEM) have delayed gastric emptying time (GET) which may affect nutritional rehabilitation. This study was designed to examine the effect of honey on GET during nutritional rehabilitation of PEM patients.

PATIENTS AND METHODS

Thirty patients were enrolled and randomly assigned to one of two equal groups. One group received conventional nutritional rehabilitation therapy and the other received honey in addition. They were compared with 20 age- and sex-matched controls. History taking, clinical examination and laboratory tests were performed for enrolled cases and GET was assessed using abdominal ultrasonography. These parameters were performed before and 2 weeks after nutritional rehabilitation.

RESULTS

The GET was significantly delayed in the PEM groups compared with the controls. Further significant delay occurred in the honey supplemented group after nutritional rehabilitation, while the un-supplemented group showed significant shortening of GET. The improvement of anthropometric measurements and laboratory parameters was equally noticed in the two PEM groups upon nutritional rehabilitation but their rate of change was distinctly higher, although non-significant, in the group supplemented with honey.

CONCLUSION

Honey supplementation increased GET in PEM patients with positive effect on the improvement in the anthropometric measurements and serum albumin which makes us wonder that this delay in GET might be primarily a compensatory phenomenon and it was augmented by the use of honey. Larger scale studies with longer term follow up are recommended to further clear this point and assess any changes in the absorptive indices in honey supplemented PEM patients.

Serum ghrelin in infants with protein-energy malnutrition

BACKGROUND

Ghrelin is an appetite and weight physiologic controller. The question is whether there is a relation between ghrelin and protein-energy malnutrition (PEM). Our aim was to assess serum ghrelin in these patients and its relation to different patient variables.

METHODS

A cross-sectional study was conducted on 30 PEM infants (12 marasmic=Ia, 10 kwashiorkor=Ib and 8 marasmic kwashiorkor=Ic) and 15 age and sex matched controls (II). Plasma ghrelin was measured in all subjects using radioimmunoassay with thorough medical history and clinical assessment.

RESULTS

The mean serum ghrelin levels were significantly higher among the 3 patient subgroups than controls with no significant inter-subgroup differences. The presence of intestinal parasitic infestations or edema, type of milk feeding and gender had no significant effects on serum ghrelin levels.

CONCLUSION

Serum ghrelin is elevated in PEM as an adapting consequence of the malnutrition rather than a primary event. Although this elevation may not be helpful to correct the growth failure because of deficient nutrients, it may prove to have a role in the catch up phenomenon after the recovery. Further research should be directed toward therapeutic trials of ghrelin in the recovery phase.

Factors associated with abnormal gastric emptying in alcohol-related chronic pancreatitis

BACKGROUND

Patients with alcohol-related chronic pancreatitis (ARCP) may present with abnormal gastric emptying (GE), which has been ascribed mainly to nutrient maldigestion. Nevertheless, many patients also have diabetes with autonomic dysfunction and malnutrition and the role of these factors on abnormal GE has not been investigated.

GOALS

To determine the influences of malabsorption, diabetes, malnutrition, and autonomic dysfunction on GE abnormalities in patients with ARCP.

STUDY

Forty ARCP outpatients and 18 healthy controls were studied. GE was measured by scintigraphy after a standard, liquid, nutrient meal labeled with Technetium-phytate. Autonomic function was evaluated by cardiovascular tests. The influence of each factor on abnormal GE was assessed by Bayesian multiple regression analysis.

RESULTS

In the ARCP group, GE was abnormal in 19 patients (47.5%), who showed either accelerated (N=12) or delayed emptying (N=7). Diabetes was highly prevalent (P<0.01) in ARCP patients with either rapid or delayed GE (18/19). Multiple regression analysis showed that not only diabetes, but also autonomic dysfunction has significant effects on abnormal GE, whereas malabsorption and malnutrition seemed not to be associated to abnormal emptying.

CONCLUSIONS

A substantial proportion of patients with ARCP may have abnormal GE. Either delayed or accelerated GE seem to be related to underlying diabetes mellitus and autonomic neuropathy rather than to nutrient malabsorption and malnutrition.