Pooled-data analysis identifies pyloric pressures and plasma cholecystokinin concentrations as major determinants of acute energy intake in healthy, lean men

Background: The interaction of nutrients with the small intestine modulates gastropyloroduodenal motility, stimulates the release of gut hormones, and suppresses appetite and energy intake. Objective: We evaluated which, if any, of these variables are independent determinants of acute energy intake in healthy, lean men. Design: We pooled data from 8 published studies that involved a total of 67 healthy, lean men in whom antropyloroduodenal pressures, gastrointestinal hormones, and perceptions were measured during intraduodenal nutrient or intravenous hormone infusions. In all of the studies, the energy intake at a buffet lunch was quantified immediately after the infusions. To select specific motor, hormone, or perception variables for inclusion in a multivariable mixed-effects model for determination of independent predictors of energy intake, we assessed all variables for collinearity and determined within-subject correlations between energy intake and these variables by using bivariate analyses adjusted for repeated measures. Results: Although correlations were shown between energy intake and antropyloroduodenal pressures, plasma hormone concentrations, and gastrointestinal perceptions, only the peak number of isolated pyloric-pressure waves, peak plasma cholecystokinin concentration, and area under the curve of nausea were identified as independent predictors of energy intake (all P < 0.05), so that increases of 1 pressure wave, 1 pmol/L, and 1 mm · min were associated with reductions in energy intake of 36, 88, and 0.4, respectively. Conclusion: We identified specific changes in gastrointestinal motor and hormone functions (ie, stimulation of pyloric pressures and plasma cholecystokinin) and nausea that are associated with the suppression of acute energy intake.Radhika V Seimon, Kylie Lange, Tanya J Little, Ixchel M Brennan, Amelia N Pilichiewicz, Kate L Feltrin, Astrid J Smeets, Michael Horowitz and Christine Feinle-Bisse

Relationship between symptoms and dietary patterns in patients with functional dyspepsia

Background & Aims: Patients with functional dyspepsia (FD) often report that their symptoms are related to food ingestion. However, there is a lack of information about differences in eating patterns and nutrient intake between these patients and healthy individuals or the association with specific symptoms. We performed a prospective trial to evaluate the relationship between FD symptoms and dietary factors. Methods: Twenty patients with FD (17 women) and 21 healthy subjects (18 women) completed detailed diet diaries, recording all foods eaten, drinks consumed, and times of consumption, as well as the occurrence, timing, and severity of dyspeptic symptoms (ie, nausea, discomfort, fullness, bloating, upper-abdominal/epigastric pain) for 7 days. Data from the diet diaries were analyzed for the number of meals, light meals, snacks and drinks, energy intake, and macronutrient distribution. Results: Patients with FD ate fewer meals (P &lt; .01) and consumed less total energy (P = .1) and fat (P = .1) than healthy subjects. Their symptoms were modest in severity (score out of 10; 5 [range, 3–8]) and occurred within 31 minutes (range, 8–64 min) of eating. Fullness was related directly to the amount of fat ingested (z, 1.91; P &lt; .05) and overall energy intake (z, 2.12; P &lt; .05) and related inversely to the amount of carbohydrate ingested (z, −1.9; P = .05). Similarly, bloating was related to the amount of fat ingested (z, 1.68; P = .09). There was no significant relationship between symptom severity and any of the dietary variables measured. Conclusions: Management of patients with FD might be improved by instructing them to consume smaller meals with reduced fat content.Amelia N. Pilichiewicz, Michael Horowitz, Gerald J. Holtmann, Nicholas J. Talley and Christine Feinle–Bissethttp://www.elsevier.com/wps/find/journaldescription.cws_home/672743/description#descriptio

Effects of gastric distension on blood pressure and superior mesenteric artery blood flow responses to intraduodenal glucose in healthy older subjects

Postprandial hypotension occurs frequently and is associated with increased morbidity. Gastric distension may attenuate the postprandial fall in blood pressure (BP). Using a barostat, we sought to determine the effects of gastric distension on BP, heart rate (HR), and superior mesenteric artery (SMA) blood flow responses to intraduodenal glucose in eight (6 men, 2 women) healthy older (65–75 yr old) subjects. BP and HR were measured using an automated device and SMA blood flow was measured using Doppler ultrasound on 4 days in random order. SMA blood flow was calculated using the radius of the SMA and time-averaged mean velocity. Subjects were intubated with a nasoduodenal catheter incorporating a duodenal infusion port. On 2 of the 4 days, they were intubated orally with a second catheter, incorporating a barostat bag, positioned in the fundus and set at 8 mmHg above minimal distending pressure. Each subject received a 60-min (0–60 min) intraduodenal infusion of glucose (3 kcal/min) or saline (0.9%); therefore, the four study conditions were as follows: intraduodenal glucose + barostat (glucose + distension), intraduodenal saline + barostat (saline + distension), intraduodenal glucose (glucose), and intraduodenal saline (saline). Systolic and diastolic BP fell during glucose compared with saline (P = 0.05 and P = 0.003, respectively) and glucose + distension (P = 0.01 and P = 0.05, respectively) and increased during saline + distension compared with saline (P = 0.04 and P = 0.006, respectively). The maximum changes in systolic BP were –14 ± 5, +11 ± 2, –3 ± 4, and +15 ± 3 mmHg for glucose, saline, glucose + distension, and saline + distension, respectively. There was an increase in HR during glucose and glucose + distension (maximum rise = 14 ± 2 and 14 ± 3 beats/min, respectively), but not during saline or saline + distension. SMA blood flow increased during glucose and glucose + distension (2,388 ± 365 and 1,673 ± 187 ml/min, respectively), but not during saline, and tended to decrease during saline + distension (821 ± 115 and 864 ± 116 ml/min, respectively). In conclusion, gastric distension has the capacity to abolish the fall in BP and attenuate the rise in SMA blood flow induced by intraduodenal glucose in healthy older subjects.Lora Vanis, Diana Gentilcore, Trygve Hausken, Amelia N. Pilichiewicz, Kylie Lange, Christopher K. Rayner, Christine Feinle-Bisset, James H. Meyer, Michael Horowitz, and Karen L. Jone