Biomedical subjects

Andre J P M Smout

Publications and source records attributed to Andre J P M Smout.

11 recordsLinked to original sources

PubMed2007

Concurrent duodenal manometric and impedance recording to evaluate the effects of hyoscine on motility and flow events, glucose absorption, and incretin release.

Upper gastrointestinal motor function and incretin hormone secretion are major determinants of postprandial glycemia and insulinemia. However, the impact of small intestinal flow events on glucose absorption and incretin release is poorly defined. Intraluminal impedance monitoring is a novel technique that allows flow events to be quantified. Eight healthy volunteers were studied twice, in random order. A catheter incorporating six pairs of electrodes at 3-cm intervals, and six corresponding manometry sideholes, was positioned in the duodenum. Hyoscine butylbromide (20 mg) or saline was given as an intravenous bolus, followed by a continuous intravenous infusion of either hyoscine (20 mg/h) or saline over 60 min. Concurrently, glucose and 3-O-methylglucose (3-OMG) were infused into the proximal duodenum (3 kcal/min), with frequent blood sampling to measure glucose, 3-OMG, insulin, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). The frequency of duodenal pressure waves and propagated pressure wave sequences was reduced by hyoscine in the first 10 min (P<0.01 for both), but not after that time. In contrast, there were markedly fewer duodenal flow events throughout 60 min with hyoscine (P<0.005). Overall, blood glucose (P<0.01) and plasma 3-OMG concentrations (P<0.05) were lower during hyoscine than saline, whereas plasma insulin, GLP-1, and GIP concentrations were initially (t=20 min) lower during hyoscine (P<0.05). In conclusion, intraluminal impedance measurement may be more sensitive than manometry in demonstrating alterations in duodenal motor function. A reduction in the frequency of duodenal flow events is associated with a decreased rate of glucose absorption and incretin release in healthy subjects.

3-O-Methylglucose↗

PubMed2006

Relationship between pressure wave amplitude and esophageal bolus clearance assessed by combined manometry and multichannel intraluminal impedance measurement.

OBJECTIVES: Esophageal wave amplitude is an important determinant of esophageal clearance. A threshold of 30 mmHg is widely accepted as the threshold for effective clearance in the distal esophagus. However, the precise relationship between wave amplitude and clearance has received relatively little attention. The aim of this study was to assess the impact of peristaltic wave amplitude on esophageal volume clearance using multiple intraluminal impedance (MII) measurement. METHODS: Concurrent manometry and MII were performed on 42 healthy asymptomatic volunteers and 13 patients with ineffective esophageal motility. Esophageal motility was measured at four sites 5-cm apart, starting 2 cm above the lower esophageal sphincter. MII was measured at corresponding sites with electrodes incorporated into the manometric assembly. Ten 5-mL liquid (saline) boluses and ten 5-mL low impedance viscous boluses were tested in each subject. Pressure wave amplitude was determined at each site as well as peristaltic success of the responses. Bolus clearance was measured from individual recording segment and from the esophagus as a whole. RESULTS: The proportion of liquid boluses cleared at each site was directly related to wave amplitude and did not increase significantly above a threshold of 25 mmHg in the proximal esophagus, 22 mmHg in the mid-esophagus, and 30 mmHg in the distal esophagus. Corresponding wave amplitudes for total esophageal clearance were 35-40 mmHg. There was a good correlation between the wave amplitude at one site of the esophagus and those of the rest of the esophagus. For both liquid and viscous boluses, the likelihood of impaired clearance was directly related to the number of segments with hypotensive pressure waves. CONCLUSION: The findings confirm the validity of the wave amplitude threshold required for effective liquid bolus clearance and have established the amplitude threshold for clearance of viscous boluses. However, the number of hypotensive pressure waves required for the definition of ineffective motility may be too low.

Adolescent↗

PubMed2006

The release of GLP-1 and ghrelin, but not GIP and CCK, by glucose is dependent upon the length of small intestine exposed.

Previous observations suggest that glucagon-like peptide-1 (GLP-1) is released into the bloodstream only when dietary carbohydrate enters the duodenum at rates that exceed the absorptive capacity of the proximal small intestine to contact GLP-1 bearing mucosa in more distal bowel. The aims of this study were to determine the effects of modifying the length of small intestine exposed to glucose on plasma concentrations of GLP-1 and also glucose-dependent insulinotropic peptide (GIP), insulin, cholecystokinin (CCK) and ghrelin, and antropyloric pressures. Glucose was infused at 3.5 kcal/min into the duodenum of eight healthy males (age 18-59 yr) over 60 min on the first day into an isolated 60-cm segment of the proximal small intestine ("short-segment infusion"); on the second day, the same amount of glucose was infused with access to the entire small intestine ("long-segment infusion"). Plasma GLP-1 increased and ghrelin decreased (P < 0.05 for both) during the long-, but not the short-, segment infusion. By contrast, increases in plasma CCK and GIP did not differ between days. The rises in blood glucose and plasma insulin were greater during the long- than during the short-segment infusion (P < 0.05). During the long- but not the short-segment infusion, antral pressure waves (PWs) were suppressed (P < 0.05). Isolated pyloric PWs and basal pyloric pressure were stimulated on both days. In conclusion, the release of GLP-1 and ghrelin, but not CCK and GIP, is dependent upon >60 cm of the intestine being exposed to glucose.

Adolescent↗

PubMed2006

Functional esophageal disorders.

Functional esophageal disorders represent processes accompanied by typical esophageal symptoms (heartburn, chest pain, dysphagia, globus) that are not explained by structural disorders, histopathology-based motor disturbances, or gastroesophageal reflux disease. Gastroesophageal reflux disease is the preferred diagnosis when reflux esophagitis or excessive esophageal acid exposure is present or when symptoms are closely related to acid reflux events or respond to antireflux therapy. A singular, well-defined pathogenetic mechanism is unavailable for any of these disorders; combinations of sensory and motor abnormalities involving both central and peripheral neural dysfunction have been invoked for some. Treatments remain empirical, although the efficacy of several interventions has been established in the case of functional chest pain. Management approaches that modulate central symptom perception or amplification often are required once local provoking factors (eg, noxious esophageal stimuli) have been eliminated. Future research directions include further determination of fundamental mechanisms responsible for symptoms, development of novel management strategies, and definition of the most cost-effective diagnostic and treatment approaches.

Animals↗

PubMed2006

Recent developments in gastrointestinal motility.

In the past decade, the results of many studies on gastrointestinal motility and perception have been published that may be relevant to the clinician. A new classification of oesophageal motor disorders has been proposed in which "ineffective oesophageal motility" largely replaces the former "non-specific oesophageal motor disorders". Recent studies have shown that the incidence of transient lower oesophageal sphincter relaxations can be reduced pharmacologically, and this may open doors to a new therapeutic approach in gastro-oesophageal reflux disease. The mechanisms through which hiatus hernia promotes reflux have become clearer. The recently developed technique of intraluminal impedance monitoring has made it possible to study oesophageal transit, non-acid reflux and its role in the generation of reflux symptoms, as well as the characteristics of belching. Measurement of gastric emptying by means of a non-radioactive isotope and breath-testing has become widely available but, unfortunately, this development has not yet been accompanied by the advent of new therapeutic options for gastroparesis. The term "enteric dysmotility" has been coined for the condition in which upper abdominal symptoms are associated with distinct small intestinal bowel motility disorders in the absence of ileus-like episodes. The role of high-amplitude propagated contractions in the pathogenesis of constipation has been further defined. In cases of suspected sphincter of Oddi dysfunction, manometry of both sphincters (IBD and pancreatic) is now felt to be advisable.

Constipation↗

PubMed2006

Five-year subjective and objective results of laparoscopic and conventional Nissen fundoplication: a randomized trial.

OBJECTIVE: The purpose of this prospective study was to compare the subjective and objective outcome of laparoscopic (LNF) and conventional Nissen fundoplication (CNF) up to 5 years after surgery as obtained in a multicenter randomized controlled trial. SUMMARY OF BACKGROUND DATA: LNF is regarded as surgical treatment of first choice for refractory gastroesophageal reflux disease by many surgeons based on several short- and mid-term studies. The long-term efficacy of Nissen fundoplication, however, is still questioned as objective data gathered from prospective studies are lacking. METHODS: From 1997 to 1999, 177 patients were randomized to undergo LNF or CNF. Five years after surgery, all patients were requested to fill in questionnaires and to undergo esophageal manometry and 24-hour pH-metry. RESULTS: A total of 148 patients agreed to participate in the follow-up study: 79 patients after LNF and 69 after CNF. Of these, 97 patients (48 LNF, 49 CNF) consented to undergo esophageal manometry and 24-hour pH-metry. At 5 years follow-up, 20 patients had undergone reoperation: 12 after LNF (15%) and 8 after CNF (12%). There was no difference in subjective outcome, with overall satisfaction rates of 88% and 90%, respectively. Total esophageal acid exposure times (pH < 4) were 2.1% +/- 0.5% and 2.0% +/- 0.6%, respectively (P = 0.21). Antisecretory medication was taken daily in 14% and 16%, respectively (P = 0.29). There was no correlation between medication use and acid exposure and indices of symptom-reflux association (symptom index and symptom association probability). No significant differences between subjective and objective results at 3 to 6 months and results obtained at 5 years after surgery were found. CONCLUSIONS: The effects of LNF and CNF on general state of health and objective reflux control are sustained up to 5 years after surgery and the long-term results of LNF and CNF are comparable. A substantial minority of patients in both groups had a second antireflux operation or took antisecretory drugs, although the use of those medications did not appear to be related to abnormal esophageal acid exposure.

Adult↗

PubMed2005

Dose-related effects of lauric acid on antropyloroduodenal motility, gastrointestinal hormone release, appetite, and energy intake in healthy men.

We recently reported that intraduodenal infusion of lauric acid (C12) (0.375 kcal/min, 106 mM) stimulates isolated pyloric pressure waves (IPPWs), inhibits antral and duodenal pressure waves (PWs), stimulates release of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), and suppresses energy intake and that these effects are much greater than those seen in response to isocaloric decanoic acid (C10) infusion. Administration of C12 was, however, associated with nausea, confounding interpretation of the results. The aim of this study was to evaluate the effects of different intraduodenal doses of C12 on antropyloroduodenal (APD) motility, plasma CCK and GLP-1 concentrations, appetite, and energy intake. Thirteen healthy males were studied on 4 days in double-blind, randomized fashion. APD pressures, plasma CCK and GLP-1 concentrations, and appetite perceptions were measured during 90-min ID infusion of C12 at 0.1 (14 mM), 0.2 (28 mM), or 0.4 (56 mM) kcal/min or saline (control; rate 4 ml/min). Energy intake was determined at a buffet meal immediately following infusion. C12 dose-dependently stimulated IPPWs, decreased antral and duodenal motility, and stimulated secretion of CCK and GLP-1 (r > 0.4, P < 0.05 for all). C12 (0.4 kcal/min) suppressed energy intake compared with control, C12 (0.1 kcal/min), and C12 (0.2 kcal/min) (P < 0.05). These effects were observed in the absence of nausea. In conclusion, intraduodenal C12 dose-dependently modulated APD motility and gastrointestinal hormone release in healthy male subjects, whereas effects on energy intake were only apparent with the highest dose infused (0.4 kcal/min), possibly because only at this dose was modulation of APD motility and gastrointestinal hormone secretion sufficient for a suppressant effect on energy intake.

Adult↗

PubMed2005

Evaluation of interactions between CCK and GLP-1 in their effects on appetite, energy intake, and antropyloroduodenal motility in healthy men.

There is evidence that CCK and glucagon-like peptide-1 (GLP-1) mediate the effects of nutrients on appetite and gastrointestinal function and that their interaction may be synergistic. We hypothesized that intravenous CCK-8 and GLP-1 would have synergistic effects on appetite, energy intake, and antropyloroduodenal (APD) motility. Nine healthy males (age 22 +/- 1 yr) were studied on four separate days in a double-blind, randomized fashion. Appetite and APD pressures were measured during 150-min intravenous infusions of 1) isotonic saline (control), 2) CCK-8 (1.8 pmol.kg(-1).min(-1)), 3) GLP-1 (0.9 pmol.kg(-1).min(-1)), or 4) both CCK-8 (1.8 pmol.kg(-1).min(-1)) and GLP-1 (0.9 pmol.kg(-1).min(-1)). At 120 min, energy intake at a buffet meal was quantified. CCK-8, but not GLP-1, increased fullness, decreased desire to eat and subsequent energy intake, and increased the number and amplitude of isolated pyloric pressure waves and basal pyloric pressure (P < 0.05). Both CCK-8 and GLP-1 decreased the number of antral and duodenal pressure waves (PWs) (P < 0.05), and CCK-8+GLP-1 decreased the number of duodenal PWs more than either CCK-8 or GLP-1 alone (P < 0.02). This was not the case for appetite or isolated pyloric PWs. In conclusion, at the doses evaluated, exogenously administered CCK-8 and GLP-1 had discrepant effects on appetite, energy intake, and APD pressures, and the effects of CCK-8+GLP-1, in combination, did not exceed the sum of the effects of CCK-8 and GLP-1, providing no evidence of synergism.

Adolescent↗

PubMed2005

Reproducibility of multichannel intraluminal electrical impedance monitoring of gastroesophageal reflux.

OBJECTIVE: Esophageal impedance measurement is a novel method for gastroesophageal reflux monitoring. Reproducibility is an important aspect of every biomedical test. The aim of this study was therefore to asses the reproducibility of gastroesophageal reflux monitoring using impedance measurements. METHODS: Impedance and pH signals were recorded in 20 healthy volunteers during 90-min postprandial periods on two separate days. Hourly rates of gas, liquid, and mixed gas-liquid reflux episodes were measured in each recording period as well as percentage of time with pH < 4 and rate of acid reflux episodes. As a quantitative description of inter- and intraindividual variation for each variable, the mean percentage of covariation (100 x SD/mean: %COV) was calculated. As a second measure for reproducibility, Kendall's coefficients of concordance (W values) were calculated. RESULTS: For all variables, interindividual %COV was at least 50% higher than intraindividual %COV. Statistically significant concordances were found for gas reflux (W = 0.81, p= 0.04) and mixed reflux (W = 0.85, p= 0.03) while concordance for liquid reflux tended to be significant (W = 0.75, p= 0.08). This was comparable to the reproducibility of the number of acid reflux episodes and percentage of time with pH < 4 (W = 0.78, p= 0.05 and W = 0.88, p= 0.02, respectively). CONCLUSIONS: Postprandial gastroesophageal reflux data assessed with impedance monitoring are as reproducible as assessed with pH monitoring.

Adult↗

PubMed2004

Effects of intraduodenal fatty acids on appetite, antropyloroduodenal motility, and plasma CCK and GLP-1 in humans vary with their chain length.

The gastrointestinal effects of intraluminal fats may be critically dependent on the chain length of fatty acids released during lipolysis. We postulated that intraduodenal administration of lauric acid (12 carbon atoms; C12) would suppress appetite, modulate antropyloroduodenal pressure waves (PWs), and stimulate the release of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) more than an identical dose of decanoic acid (10 carbon atoms; C10). Eight healthy males (19-47 yr old) were studied on three occasions in a double-blind, randomized fashion. Appetite perceptions, antropyloroduodenal PWs, and plasma CCK and GLP-1 concentrations were measured during a 90-min intraduodenal infusion of 1) C12, 2) C10, or 3) control (rate: 2 ml/min, 0.375 kcal/min for C12/C10). Energy intake at a buffet meal, immediately after completion of the infusion, was also quantified. C12, but not C10, suppressed appetite perceptions (P < 0.001) and energy intake (control: 4,604 +/- 464 kJ, C10: 4,109 +/- 588 kJ, and C12: 1,747 +/- 632 kJ; P < 0.001, C12 vs. control/C10). C12, but not C10, also induced nausea (P < 0.001). C12 stimulated basal pyloric pressures and isolated pyloric PWs and suppressed antral and duodenal PWs compared with control (P < 0.05 for all). C10 transiently stimulated isolated pyloric PWs (P = 0.001) and had no effect on antral PWs but markedly stimulated duodenal PWs (P = 0.004). C12 and C10 increased plasma CCK (P < 0.001), but the effect of C12 was substantially greater (P = 0.001); C12 stimulated GLP-1 (P < 0.05), whereas C10 did not. In conclusion, there are major differences in the effects of intraduodenal C12 and C10, administered at 0.375 kcal/min, on appetite, energy intake, antropyloroduodenal PWs, and gut hormone release in humans.

Adult↗

PubMed2004

Upper gastrointestinal responses to intraduodenal nutrient in type 1 diabetes mellitus.

BACKGROUND: Abnormal nutrient-related small-intestinal feedback may contribute to disordered gastric motility and upper gastrointestinal symptoms in patients with diabetes. AIM: To evaluate the motor, sensory and incretin responses to intraduodenal nutrients in patients with type 1 diabetes and in controls. METHODS: Eight type 1 diabetes patients (two with autonomic neuropathy) and nine controls were studied during euglycaemia. A manometric catheter was positioned across the pylorus, and nutrient was infused intraduodenally (90 kcal over 30 min). Blood glucose and plasma glucagon-like peptide 1 and gastric inhibitory polypeptide were measured, and sensations were assessed with visual analogue questionnaires. RESULTS: During nutrient infusion, neither the number of antral waves nor the stimulation of phasic or basal pyloric pressures differed between patients and controls. Upper gut sensations and areas under the plasma incretin peptide curves did not differ between the groups. CONCLUSIONS: During euglycaemia, the upper gastrointestinal motor, sensory and incretin peptide responses to small-intestinal nutrient are comparable in patients with relatively uncomplicated type 1 diabetes and in healthy subjects.

Adult↗