Effects of lipase inhibition on gastric emptying and alcohol absorption in healthy subjects

The rate of alcohol absorption is dependent on gastric emptying (GE). As the slowing of GE by fat is dependent on lipolysis, orlistat may increase the rise in blood alcohol when alcohol is consumed with, or after, fat. The aim of the study was to evaluate the effects of orlistat on GE and blood alcohol after an alcohol-containing drink following a fat ‘preload’, in healthy subjects. Ten healthy males consumed 120 ml cream with or without 120 mg orlistat, 30 min before an alcohol-containing drink labelled with 20 MBq [99 mTc]sulfur colloid on 2 d. GE, plasma alcohol and blood glucose were measured. GE was slightly faster with orlistat (P<0·05) compared with control. Plasma alcohol at 15 min was slightly higher with orlistat (0·034 (sem 0·006) g/100 ml) v. control (0·029 (sem 0·005) g/100 ml) (P<0·05), but there was no effect on the area under the curve 0–240 min. The increase in blood glucose was greater with orlistat, for example, at 15 min (1·07 (sem 0·2) mmol/l) v. control (0·75 (sem 0·2) mmol/l) (P=0·05). The rise in blood glucose and plasma alcohol were related (for example, at 15 min r 0·49; P=0·03). In conclusion, lipase inhibition accelerates GE of an alcohol-containing drink following a fat ‘preload’ with a minor increase in the initial rise in plasma alcohol.Reawika Chaikomin, Antonietta Russo, Christopher K. Rayner, Christine Feinle-Bisset, Deirdre G. O’Donovan, Michael Horowitz and Karen L. Jone

Effects of a Protein Preload on Gastric Emptying, Glycemia, and Gut Hormones After a Carbohydrate Meal in Diet-Controlled Type 2 Diabetes

OBJECTIVE: We evaluated whether a whey preload could slow gastric emptying, stimulate incretin hormones, and attenuate postprandial glycemia in type 2 diabetes. RESEARCH DESIGN AND METHODS: Eight type 2 diabetic patients ingested 350 ml beef soup 30 min before a potato meal; 55 g whey was added to either the soup (whey preload) or potato (whey in meal) or no whey was given. RESULTS: Gastric emptying was slowest after the whey preload (P < 0.0005). The incremental area under the blood glucose curve was less after the whey preload and whey in meal than after no whey (P < 0.005). Plasma glucose-dependent insulinotropic polypeptide, insulin, and cholecystokinin concentrations were higher on both whey days than after no whey, whereas glucagon-like peptide 1 was greatest after the whey preload (P < 0.05). CONCLUSIONS: Whey protein consumed before a carbohydrate meal can stimulate insulin and incretin hormone secretion and slow gastric emptying, leading to marked reduction in postprandial glycemia in type 2 diabetes.Jing Ma, Julie E. Stevens, Kimberly Cukier, Anne F. Maddox, Judith M. Wishart, Karen L. Jones, Peter M. Clifton, Michael Horowitz, and Christopher K. Rayne

Waking up the gut in critically ill patients

Multiorgan failure frequently develops in critically ill patients. While therapeutic efforts in such patients are often focused on the lungs, on the cardiovascular system as well as on the kidneys, it is important to also consider the functional alterations in gut motility and hormone secretion. Given the central regulatory functions of many gut hormones, such as glucagon-like peptide 1, glucagon-like peptide 2, ghrelin and others, exogenous supplementation of some of these factors may be beneficial under conditions of critical illness. From a pragmatic point of view, the most feasible way towards a restoration of gut hormone secretion in critically ill patients is to provide enteral nutritional supply as soon as possible

Impaired Hyperglycemia-Induced Delay in Gastric Emptying in Patients With Type 1 Diabetes Deficient for Islet Amyloid Polypeptide

OBJECTIVE—Slowing of gastric emptying by hyperglycemia, a physiological response to minimize postprandial hyperglycemia, may be impaired in patients with type 1 diabetes. The causes and consequences on glucose homeostasis are unknown

Using naso- and oro-intestinal catheters in physiological research for intestinal delivery and sampling in vivo:practical and technical aspects to be considered

Intestinal catheters have been used for decades in human nutrition, physiology, pharmacokinetics, and gut microbiome research, facilitating the delivery of compounds directly into the intestinal lumen or the aspiration of intestinal fluids in human subjects. Such research provides insights about (local) dynamic metabolic and other intestinal luminal processes, but working with catheters might pose challenges to biomedical researchers and clinicians. Here, we provide an overview of practical and technical aspects of applying naso- and oro-intestinal catheters for delivery of compounds and sampling luminal fluids from the jejunum, ileum, and colon in vivo. The recent literature was extensively reviewed, and combined with experiences and insights we gained through our own clinical trials. We included 60 studies that involved a total of 720 healthy subjects and 42 patients. Most of the studies investigated multiple intestinal regions (24 studies), followed by studies investigating only the jejunum (21 studies), ileum (13 studies), or colon (2 studies). The ileum and colon used to be relatively inaccessible regions in vivo. Custom-made state-of-the-art catheters are available with numerous options for the design, such as multiple lumina, side holes, and inflatable balloons for catheter progression or isolation of intestinal segments. These allow for multiple controlled sampling and compound delivery options in different intestinal regions. Intestinal catheters were often used for delivery (23 studies), sampling (10 studies), or both (27 studies). Sampling speed decreased with increasing distance from the sampling syringe to the specific intestinal segment (i.e., speed highest in duodenum, lowest in ileum/colon). No serious adverse events were reported in the literature, and a dropout rate of around 10% was found for these types of studies. This review is highly relevant for researchers who are active in various research areas and want to expand their research with the use of intestinal catheters in humans in vivo.</p

Gastrointestinal motility and glycaemic control in diabetes

Gastric emptying, and small intestinal glucose exposure and absorption, are potentially important determinants of postprandial blood glucose homeostasis and energy intake. The studies presented in this thesis were designed to provide novel insights into the interrelationships of upper gastrointestinal function with glycaemia and appetite in both health and type 2 diabetes. The issues which were addressed relate in particular to : ( i ) the physiology, regulation and measurement of gastric and small intestinal motility, ( ii ) the relationships between small intestinal glucose exposure, incretin hormone release, antropyloroduodenal motility and appetite, and ( iii ) the impact of gastric and small intestinal motility on glycaemia. The study reported in chapter 4 evaluated the effect of variations in small intestinal glucose delivery on blood glucose, plasma insulin, and incretin hormone ( GLP - 1 and GIP ) concentrations in healthy subjects. While initially rapid, and subsequently slower, duodenal glucose delivery potentiated incretin and insulin responses when compared to constant delivery of an identical glucose load, the overall glycaemic excursion was not improved. These observations add to the rationale for the use of dietary and pharmacological strategies designed to reduce postprandial glycaemic excursions in health and type 2 diabetes by slowing gastric emptying, rather than initially accelerating it. Fat is a potent inhibitor of gastric emptying. In chapter 5, the acute effect of slowing gastric emptying by fat, on postprandial glycaemia in type 2 diabetes, has been evaluated. Ingestion of a small amount of olive oil, as a 'preload' 30 min before a carbohydrate meal, was shown to markedly slow gastric emptying, affect intragastric meal distribution, delay the postprandial rises in blood glucose, plasma insulin, and GIP, and stimulate GLP - 1. In contrast, the effects of including the same amount of oil within the meal, on gastric emptying, as well as glycaemic and incretin responses, were relatively modest. As blood glucose levels had not returned to baseline by 210 min ( the end of each experiment ), effects on the overall glycaemic ( or insulinaemic ) response could not be determined ; this represents a priority for future studies. The energy content of a meal is a major determinant of its rate of gastric emptying. The study reported in chapter 6 demonstrated that the substitution of an artificial sweetener ( "diet" mixer ) for sucrose ( "regular" mixer ) in a mixed alcoholic beverage has a major impact on the rate of gastric emptying and alcohol absorption in healthy adults. A low calorie alcohol - containing drink ( made with "diet" mixer ) emptied from the stomach much more rapidly and resulted in higher blood alcohol concentrations when compared with a relatively high calorie alcoholic drink ( made with "regular" mixer ). These observations highlight the need for community awareness of factors, other than the alcohol content of a beverage, which should be taken into account in considering safe levels of consumption and the potential for inebriation. Upper gastrointestinal motor function and incretin hormone ( GLP - 1 and GIP ) secretion are known to be major determinants of postprandial glycaemia and insulinaemia, however, the impact of small intestinal flow events on glucose absorption and incretin release has not been evaluated. In the study reported in chapter 7, intraduodenal pressures and impedance signals were recorded simultaneously in healthy humans, while glucose was infused into the duodenum in the presence and absence of the anticholinergic drug, hyoscine butylbromide. The frequency of duodenal flow events ( evaluated by impedance ) was suppressed by hyoscine much more than that of duodenal pressure waves, or propagated pressure wave sequences ( evaluated by manometry ). Blood glucose and plasma 3 - OMG concentrations ( the latter provide an index of glucose absorption ) were lower during hyoscine than saline. Plasma insulin, GLP - 1, and GIP concentrations were initially lower during hyoscine. The disparity between impedance measurements and manometry in detecting alterations in flow during hyoscine infusion was marked and, accordingly, supports the potential utility of small intestinal impedance monitoring to evaluate alterations in gastrointestinal transit in various disease states. The observations also indicate that the frequency of small intestinal flow events is a determinant of both glucose absorption and incretin release. Intraduodenal administration of the local anaesthetic, benzocaine, has been shown to attenuate the release of cholecystokinin ( CCK ) by small intestinal lipid, and the perceptions of fullness, discomfort, and nausea induced by gastric distension during small intestinal lipid infusion, implying that local neural mechanisms may regulate CCK release in response to intraduodenal nutrients. In chapter 8, the effects of intraduodenal administration of benzocaine on : ( i ) blood glucose, incretin hormone and insulin concentrations ( ii ) antropyloroduodenal motility, and ( iii ) gut sensations and appetite, in response to an intraduodenal glucose infusion, were evaluated in healthy subjects. Benzocaine attenuated the perceptions of abdominal bloating and nausea, but had no effect on antro - pyloro duodenal motility, blood glucose concentrations, or incretin responses. These observations indicate that the induction of sensations by small intestinal glucose is mediated by local neural pathways. GLP - 1 is released from L - cells whose density is greatest in the distal jejunum and ileum, GIP predominantly from duodenal K cells, and cholecystokinin ( CCK ) from I cells, which appear confined to the duodenum and jejunum. The study reported in chapter 9 evaluated the effects of infusion of glucose into different gut regions ( mid - jejunal vs duodenal ) on incretin hormones, CCK, appetite and energy intake in healthy subjects. There was no difference in the incretin responses between infusion at the two sites ( 85 cm apart ), however the stimulation of CCK and suppression of hunger and energy intake, were greater with the duodenal compared to the jejunal infusion. These observations indicate that the site of small intestinal glucose exposure is a determinant of CCK release and appetite. Both glucose and fat are known to be potent stimuli for incretin secretion, but the effect of protein is uncertain. Protein may also stimulate insulin secretion directly via absorption of amino acids. In the study reported in chapter 10, gastric emptying, and the blood glucose, insulin and incretin responses, alter a 300 mL drink containing 50 g glucose, 25 g protein, or both 50 g glucose and 25 g protein, were evaluated in healthy subjects. This study established that the addition of protein to an oral glucose load improved the glycaemic response, predominantly by slowing gastric emptying. However, protein also stimulated incretin and insulin secretion. These observations have implications for the use of protein in the dietary management of type 2 diabetes. The relationship between glycaemia, incretin hormones, appetite suppression and modulation of antropyloroduodenal motility with duodenal glucose delivery is poorly defined. In chapter 11, the effects of intraduodenal glucose infusions at different caloric rates ( of 1 kcal / min, 2 kcal / min and 4 kcal / min, or control ( saline ) ) on antropyloroduodenal motility, plasma GLP - 1, GIP and CCK, appetite and energy intake have been evaluated in healthy subjects. While there was a rise in blood glucose in response to all the intraduodenal glucose loads, there was no significant difference in the response to infusions at 2 kcal / min and 4 kcal / min. An initial, transient, small rise in GLP - 1 was evident, in response to all glucose loads, but a sustained and progressive rise only occurred with the 4 kcal / min infusion. In contrast, a load - dependent stimulation of GIP occurred in response to all glucose infusions. The stimulation of CCK was much greater in response to the 4 kcal / min infusion. While antral pressures were suppressed by all rates of glucose infusion, the stimulation of basal pyloric pressure was load - dependent. Energy intake was suppressed only by the 4 kcal / min infusion. This may potentially reflect the substantially greater stimulation of CCK, consistent with the observations reported in chapter 9. This study establishes that there is a substantial discordance in the acute effects of small intestinal glucose on glycaemia, incretin hormones, CCK, motility and appetite. It is planned to perform measurements of plasma insulin on the stored samples - these results were, unfortunately, not available at the time of the submission of this thesis and are critical to the overall interpretation of the data.Thesis (Ph.D.)--University of Adelaide, School of Medicine, Discipline of Medicine, 2007

Upper gastrointestinal function and glycemic control in diabetes mellitus

Recent evidence has highlighted the impact of glycemic control on the incidence and progression of diabetic micro- and macrovascular complications, and on cardiovascular risk in the non-diabetic population. Postprandial blood glucose concentrations make a major contribution to overall glycemic control, and are determined in part by upper gastrointestinal function. Conversely, poor glycemic control has an acute, reversible effect on gastrointestinal motility. Insights into the mechanisms by which the gut contributes to glycemia have given rise to a number of novel dietary and pharmacological strategies designed to lower postprandial blood glucose concentrations.Reawika Chaikomin, Christopher K Rayner, Karen L Jones, Michael Horowit

Effect of Ayuraved Siriraj Herbal Recipe “Wattana†on Gastric Emptying Rate

Background: Wattana, an herbal recipe from Ayuraved Siriraj, has been used as an analeptic remedy, enhancing fitness, anti-aging, increasing appetite and attenuating abnormal gastric motility since 1982. One of the factors that induce abnormal gastric motility is delayed gastric emptying rate (GER). Objective: To evaluate the effect of Wattana on GER in healthy volunteers. Methods: Seventeen healthy male volunteers (age 26.76 ± 1.16 years, body mass index (BMI) 20.30 ± 0.43 kg/ m2 ; mean ± SEM) were studied on two separate days, with a wash out period of at least one week. After an overnight fast, each subject consumed 3 tablets of Wattana or placebo with 150 ml water, 10 minutes before drinking 15 g glucose in 150 ml water. Then 1 g paracetamol with 150 ml water was consumed 20 minutes after that. Blood samples were collected 11 times in three hours (at 0, 15, 30, 45, 60, 75, 90, 105, 120, 150 and 180 minutes) for gastric emptying evaluation. The feeling of hunger, fullness, abdominal discomfort, bloating, and nausea were assessed by visual analog scale (VAS). Serum paracetamol concentrations were analyzed, mean serum paracetamol concentrations, peak serum concentrations (Cmax), time to peak serum concentrations (Tmax) and area under the serum paracetamol concentration-time curve (AUC) and VAS score were determined. Results: Mean serum paracetamol concentrations after Wattana consumption tended to be higher than after placebo. There was no significant difference in Tmax, AUC and VAS score between Wattana or placebo consumption. However, Cmax after Wattana was significantly higher than placebo (p = 0.044). It was noticed that all volunteers felt sleepy after Wattana consumption. Conclusion: Wattana showed no effect on gastric emptying rate, but tended to increase the paracetamol absorption in the small intestine. A sedating effect of Wattana was noted