Is there a role for gastric accommodation and satiety in asymptomatic obese people?

Semaglutide delays 4-hour gastric emptying in women with polycystic ovary syndrome and obesity

AIM

To evaluate the effect of once-weekly subcutaneous semaglutide 1.0 mg on the late digestive period of gastric emptying (GE) after ingestion of a standardized solid test meal by using technetium scintigraphy, the reference method for this purpose.

METHODS

We conducted a single-blind, placebo-controlled trial in 20 obese women with polycystic ovary syndrome (PCOS; mean [range] age 35 [32.3-40.8] years, body mass index 37 [30.7-39.8] kg/m² ) randomized to subcutaneous semaglutide 1.0 mg once weekly or placebo for 12 weeks. GE was assessed after ingestion of [^99mT c] colloid in a pancake labelled with radiopharmaceutical by scintigraphy using sequential static imaging and dynamic acquisition at baseline and at Week 13. Estimation of GE was obtained by repeated imaging of remaining [^99mT c] activity at fixed time intervals over the course of 4 hours after ingestion.

RESULTS

From baseline to the study end, semaglutide increased the estimated retention of gastric contents by 3.5% at 1 hour, 25.5% at 2 hours, 38.0% at 3 hours and 30.0% at 4 hours after ingestion of the radioactively labelled solid meal. Four hours after ingestion, semaglutide retained 37% of solid meal in the stomach compared to no gastric retention in the placebo group (P = 0.002). Time taken for half the radiolabelled meal to empty from the stomach was significantly longer in the semaglutide group than the placebo group (171 vs. 118 min; P < 0.001).

CONCLUSION

Semaglutide markedly delayed 4-hour GE in women with PCOS and obesity.

Correlation Between Preoperative Gastric Volume and Weight Loss After Laparoscopic Sleeve Gastrectomy

Purpose

Long-term studies reported inadequate weight loss or weight regain after laparoscopic sleeve gastrectomy (LSG). This study investigated a possible relationship between preoperative gastric volume (GV) measured by CT volumetry and weight loss one year after LSG.

Methods

This prospective study included 120 patients scheduled for LSG. 3D CT gastric volumetry was done before surgery. The weight loss in the first year was serially recorded. The primary outcome measure was the correlation between preoperative GV and postoperative weight loss after one year. The secondary outcomes were the correlation between preoperative GV and other patients’ characteristics as age and body mass index (BMI).

Results

Weight and BMI decreased significantly up to 12 months. The percentage of excess weight loss (%EWL) at 6 and 12 months was significantly higher than at three months. Preoperative GV was 1021 ± 253, ranging from 397 to 1543 mL. GV was not related to sex, age, weight, height, postoperative weight, and BMI.

Conclusion

Preoperative gastric volume cannot predict weight loss one year after LSG. It is not correlated with age, sex, or preoperative weight, and BMI.

High-fat Diet Enhances Gastric Contractility, but Abolishes Nesfatin-1-induced Inhibition of Gastric Emptying

BACKGROUND/AIMS

Gastrointestinal motility changes contribute to development and maintenance of obesity. Nesfatin-1 (NES-1) is involved in central appetite control. The aim is to elucidate effects of NES-1 and high-fat diet (HFD) on gastrointestinal motility and to explore myenteric neuron expressions of tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), and neuronal nitric oxide synthase (nNOS) in HFDinduced oxidative injury.

METHODS

Sprague-Dawley rats were fed with normal diet (ND) or HFD. Gastric emptying rate was measured following NES-1 (5 pmol/rat, intracerebroventricular) preceded by subcutaneous injections of glucagon-like peptide 1 (GLP-1), cholecystokinin 1 (CCK-1), and gastrin/CCK-2 receptor antagonists. In carbachol-contracted gastric and ileal strips, contractile changes were recorded by adding NES- 1 (0.3 nmol/L), GLP-1, CCK-1, and gastrin/CCK-2 antagonists.

RESULTS

Neither HFD nor NES-1 changed methylcellulose emptying, but NES-1 delayed saline emptying in cannulated ND-rats. Inhibitory effect of NES-1 on gastric emptying in ND-rats was reversed by all antagonists, and abolished in HFD-rats. In HFD-rats, carbachol-induced contractility was enhanced in gastric, but inhibited in ileal strips. HFD increased body weight, while serum triglycerides, alanine transaminase, aspartate aminotransferase, glucose, and levels of malondialdehyde, glutathione, myeloperoxidase activity, and luminolchemiluminescence in hepatic, ileal, and adipose tissues were similar in ND- and HFD-rats, but only lucigenin-chemiluminescence was increased in HFD-rats. Vasoactive intestinal peptide (VIP) and TH immunoreactivities were depressed and nNOS immunoreactivity was increased in gastric tissues of HFD-rats, while VIP and TH were enhanced, but nNOS was reduced in their intestines.

CONCLUSIONS

HFD caused mild systemic inflammation, disrupted enteric innervation, enhanced gastric contractility, inhibited ileal contractility, and eliminated inhibitory effect of NES-1 on gastric motility.

Sleeve Volume and Preoperative Gastric Volume Assessment Using Three-dimensional MDCT Gastrography and Their Correlation to Short-term Post-Sleeve Gastrectomy Weight Loss

PURPOSE

Several factors including preoperative stomach capacity and sleeve volume impact weight loss after laparoscopic sleeve gastrectomy (LSG). We aimed at measuring these volumes using multidetector computed tomography (MDCT) gastrography and correlating them with postoperative weight losses.

MATERIALS AND METHODS

Morbidly obese patients prepared for LSG during 2018 were included in the study. MDCT gastrography was performed 1 week before, 6 and 12 months after LSG. Preoperative gastric volume and postoperative sleeve volumes were measured. Correlation with preoperative BMI and postoperative %TWL was performed. The change in sleeve volume at 6 and 12 months was assessed.

RESULTS

A total of 98 patients (62 F) were included. Mean preoperative BMI was47 ± 7 kg/m². Follow-up was achieved in 89 patients (91%) and 82 patients (83%) at 6 and 12 months, respectively. Mean %TWL was 24 ± 3 and 32.8 ± 3 at 6 and 12 months, respectively (p < 0.05). Preoperative gastric volume ranged from 800 to 1800 ml (mean ± SD, 1310 ± 307) and dropped significantly to range from 140 to 170 ml (158 ± 9) and from 165 to 210 ml (181 ± 12) at 6 and 12 months postoperatively, respectively. Pouch was not significantly dilated at 12 vs. 6 months postoperatively. Preoperative gastric volume was significantly correlated with preoperative BMI (p = 0.006*) but not with postoperative weight losses. Correlation between postoperative pouch volumes and weight losses at 6 and 12 months postoperatively showed no significance.

CONCLUSION

Sleeve pouch is significantly smaller than preoperative stomach, but not significantly correlated to weight loss. Restriction is an important, but not the only factor controlling weight loss after LSG.

Change of appetite in patients with functional digestive disorder. Association with psychological disorders: A cross-sectional study

BACKGROUND AND AIMS

Changes in appetite are a frequent complaint in patients with functional gastrointestinal disorders (FGIDs). The aims of this study are to evaluate whether the changes in appetite are associated with specific FGIDs and to explore associations of these changes with symptoms of anxiety or depression.

METHODS

This study included 1009 consecutive FGID patients (71% female), aged 48.9 years who all filled out a Rome III questionnaire for the evaluation of FGIDs, submitted to a psychological evaluation of symptoms of anxiety, and completed the Beck Depression Inventory questionnaire. The patients were classified according to their appetite change using a 7-point grading scale and split into three groups: those with appetite loss, those with no change in appetite, and those with increased appetite.

RESULTS

Among the 1009, 496 patients (49%) reported a change in appetite, of which 332 (33%) patients reported a decrease in appetite and 164 (16%) patients reported an increase in appetite. Appetite was not affected in 51% of patients. Changes in appetite depended on gender, body mass index and psychometric evaluation scores. Increased appetite did not have specific FGIDs associations, while decreased appetite was associated with esophageal, gastroduodenal, bowel, and anorectal symptoms. The presence of depressive symptoms was also a predictor for the majority of FGIDs in decreased appetite, while anxiety trait was significant for globus and dysphagia.

CONCLUSIONS

Decreased appetite was associated with FGIDs, especially in the presence of depressive symptoms. A reduced appetite would help to predict psychological disorders associated with FGIDs.

FINANCIAL DISCLOSURE

None declared.

LEGAL REGISTRATION

This study was a registered study in the French National Drug Agency (ANSM, Agence Nationale de Securité du Medicamentet des produits de santé, Study Number 2016-A01120-51).

COMPETING INTERESTS

Michel Bouchoucha, Marinos Fysekidis, Florence Mary, Gheorghe Airinei, Cyriaque Bon, and Robert Benamouzig have no competitive interests.

Relationship of gastric emptying or accommodation with satiation, satiety, and postprandial symptoms in health

The contributions of gastric emptying (GE) and gastric accommodation (GA) to satiation, satiety, and postprandial symptoms remain unclear. We aimed to evaluate the relationships between GA or GE with satiation, satiety, and postprandial symptoms in healthy overweight or obese volunteers (total n = 285, 73% women, mean BMI 33.5 kg/m²): 26 prospectively studied obese, otherwise healthy participants and 259 healthy subjects with previous similar GI testing. We assessed GE of solids, gastric volumes, calorie intake at buffet meal, and satiation by measuring volume to comfortable fullness (VTF) and maximum tolerated volume (MTV) by using Ensure nutrient drink test (30 ml/min) and symptoms 30 min after MTV. Relationships between GE or GA with satiety, satiation, and symptoms were analyzed using Spearman rank (r_s ) and Pearson (R) linear correlation coefficients. We found a higher VTF during satiation test correlated with a higher calorie intake at ad libitum buffet meal (r_s = 0.535, P < 0.001). There was a significant inverse correlation between gastric half-emptying time (GE T_1/2) and VTF (r_s = -0.317, P < 0.001) and the calorie intake at buffet meal (r_s = -0.329, P < 0.001), and an inverse correlation between GE Tlag and GE25% emptied with VTF (r_s = -0.273, P < 0.001 and r_s = -0.248, P < 0.001, respectively). GE T_1/2 was significantly associated with satiation (MTV, R = -0.234, P < 0.0001), nausea (R = 0.145, P = 0.023), pain (R = 0.149, P = 0.012), and higher aggregate symptom score (R = 0.132, P = 0.026). There was no significant correlation between GA and satiation, satiety, postprandial symptoms, or GE. We concluded that GE of solids, rather than GA, is associated with postprandial symptoms, satiation, and satiety in healthy participants.NEW & NOTEWORTHY A higher volume to comfortable fullness postprandially correlated with a higher calorie intake at ad libitum buffet meal. Gastric emptying of solids is correlated to satiation (volume to fullness and maximum tolerated volume) and satiety (the calorie intake at buffet meal) and symptoms of nausea, pain, and aggregate symptom score after a fully satiating meal. There was no significant correlation between gastric accommodation and either satiation or satiety indices, postprandial symptoms, or gastric emptying.

A Magnetic Soft Endoscopic Capsule-Inflated Intragastric Balloon for Weight Management

Overweight and obesity have been identified as a cause of high risk diseases like diabetes and cancer. Although conventional Intragastric Balloons (IGBs) have become an efficient and less invasive method for overweight and obesity treatment, the use of conventional tools such as catheter or endoscope to insert and remove the IGBs from the patient's body causes nausea, vomiting, discomfort, and even gastric mucous damage. To eliminate these drawbacks, we develop a novel magnetic soft capsule device with gas-filled balloon inflation. The balloon is made from a thin and biocompatible material that can be inflated to a desired volume using biocompatible effervescent chemicals. In addition, both the outer balloon and inner capsule are designed to be soft and chemical resistance. The soft capsule shell is fabricated using scaffold-solvent approach while the outer balloon utilizes a novel fabrication approach for 3D spherical structure. A prototype of the proposed capsule and balloon is given. Experiments are successfully carried out in stimulated gastric environment and fresh porcine stomach to validate the effectiveness and reliability of the proposed approach.

High fat diet induced changes in gastric vagal afferent response to adiponectin

Food intake is regulated by vagal afferent signals from the stomach. Adiponectin, secreted primarily from adipocytes, also has a role in regulating food intake. However, the involvement of vagal afferents in this effect remains to be established. We aimed to determine if adiponectin can modulate gastric vagal afferent (GVA) satiety signals and further whether this is altered in high fat diet (HFD)-induced obesity. Female C57BL/6J mice were fed either a standard laboratory diet (SLD) or a HFD for 12weeks. Plasma adiponectin levels were assayed, and the expression of adiponectin in the gastric mucosa was assessed using real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The location of adiponectin protein within the gastric mucosa was determined by immunohistochemistry. To evaluate the direct effect of adiponectin on vagal afferent endings we determined adiponectin receptor expression in whole nodose ganglia (NDG) and also specifically in GVA neurons using retrograde tracing and qRT-PCR. An in vitro preparation was used to determine the effect of adiponectin on GVA response to mechanical stimulation. HFD mice exhibited an increased body weight and adiposity and showed delayed gastric emptying relative to SLD mice. Plasma adiponectin levels were not significantly different in HFD compared to SLD mice. Adiponectin mRNA was detected in the gastric mucosa of both SLD and HFD mice and presence of protein was confirmed immunohistochemically by the detection of adiponectin immunoreactive cells in the mucosal layer of the stomach. Adiponectin receptor 1 (ADIPOR1) and 2 (ADIPOR2) mRNA was present in both the SLD and HFD whole NDG and also specifically traced gastric mucosal and muscular neurons. There was a reduction in ADIPOR1 mRNA in the mucosal afferents of the HFD mice relative to the SLD mice. In HFD mice adiponectin potentiated gastric mucosal afferent responses to mucosal stroking, an effect not observed in SLD mice. Adiponectin reduced the responses of tension receptors to circular stretch to a similar extent in both SLD and HFD mice. In conclusion, adiponectin modulates GVA satiety signals. This modulatory effect is altered in HFD-induced obesity. It remains to be conclusively determined whether this modulation is involved in the regulation of food intake and what the whole animal phenotypic consequence is.

Effect of intragastric injection of botulinum toxin A for the treatment of obesity: a meta-analysis and meta-regression

BACKGROUND

Controversies persist regarding the effect of intragastric injection of botulinum toxin A for the treatment of obesity.

OBJECTIVE

To assess the efficacy of intragastric botulinum toxin injection for the treatment of obesity.

DESIGN

A systematic literature review was conducted by using the core databases. Pre- and posttreatment body weight data were extracted and analyzed by using Hedges' g. A random-effects model was applied. The methodological quality of the enrolled studies was assessed by the risk of bias table and Newcastle-Ottawa Scale. Publication bias was evaluated via the funnel plot, trim and fill method, Egger's test, and rank correlation test.

SETTING

Meta-analysis of 8 studies.

PATIENTS

A total of 115 patients (79 treated vs 36 placebo).

INTERVENTION

Intragastric botulinum toxin A injection.

MAIN OUTCOME MEASUREMENTS

Hedges' g, calculated from pre- and posttreatment body weight data and comparison of body weight changes between treatment and placebo group.

RESULTS

The treatment group was associated with weight loss in a pre/post comparative approach and compared with the placebo group (Hedges' g: -0.443; 95% confidence interval, -0.845 to -0.040; P = .031; and Hedges' g: -0.521; 95% confidence interval, -0.956 to -0.085; P = .019). Wide area injection including the fundus or body rather than the antrum only was associated with weight loss. Multiple injections (>10) were associated with weight loss. However, a large amount of botulinum toxin A (500 IU) was not associated with weight loss. Sensitivity analyses showed consistent results. Meta-regression for the botulinum toxin A dose and number of injections showed consistent results. Publication bias was not detected.

CONCLUSION

In this analysis, intragastric injection of botulinum toxin A is effective for the treatment of obesity.

Peripheral mechanisms in appetite regulation

Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide input to the highly organized hypothalamic circuitry and vagal complex of nuclei to determine cessation of energy intake during meal ingestion, and the return of appetite and hunger after fasting. Understanding these mechanisms is key to the physiological control of feeding and the derangements that occur in obesity and their restoration with treatment (as shown by the effects of bariatric surgery).

Quantitative gastrointestinal and psychological traits associated with obesity and response to weight-loss therapy

BACKGROUND & AIMS

Weight loss after pharmacotherapy varies greatly. We aimed to examine associations of quantitative gastrointestinal and psychological traits with obesity, and to validate the ability of these traits to predict responses of obese individuals to pharmacotherapy.

METHODS

In a prospective study, we measured gastric emptying of solids and liquids, fasting and postprandial gastric volume, satiation by nutrient drink test (volume to fullness and maximal tolerated volume), satiety after an ad libitum buffet meal, gastrointestinal hormones, and psychological traits in 328 normal-weight, overweight, or obese adults. We also analyzed data from 181 previously studied adults to assess associations betwecen a subset of traits with body mass index and waist circumference. Latent dimensions associated with overweight or obesity were appraised by principal component analyses. We performed a proof of concept, placebo-controlled trial of extended-release phentermine and topiramate in 24 patients to validate associations between quantitative traits and response to weight-loss therapy.

RESULTS

In the prospective study, obesity was associated with fasting gastric volume (P = .03), accelerated gastric emptying (P < .001 for solids and P = .011 for liquids), lower postprandial levels of peptide tyrosine tyrosine (P = .003), and higher postprandial levels of glucagon-like peptide 1 (P < .001). In a combined analysis of data from all studies, obesity was associated with higher volume to fullness (n = 509; P = .038) and satiety with abnormal waist circumference (n = 271; P = .016). Principal component analysis identified latent dimensions that accounted for approximately 81% of the variation among overweight and obese subjects, including satiety or satiation (21%), gastric motility (14%), psychological factors (13%), and gastric sensorimotor factors (11%). The combination of phentermine and topiramate caused significant weight loss, slowed gastric emptying, and decreased calorie intake; weight loss in response to phentermine and topiramate was significantly associated with calorie intake at the prior satiety test.

CONCLUSIONS

Quantitative traits are associated with high body mass index; they can distinguish obesity phenotypes and, in a proof of concept clinical trial, predicted response to pharmacotherapy for obesity. ClinicalTrials.gov Number: NCT01834404.

Gastrointestinal symptoms in morbid obesity

Background: Several reports have shown an increased prevalence of gastrointestinal (GI) symptoms in obese subjects in community-based studies. To better understand the role of the GI tract in obesity, and because there are limited clinic-based studies, we documented the prevalence of upper and lower GI symptoms in morbidly obese individuals in a clinic setting.

Objective: The aim of our study was to compare the prevalence of GI symptoms in morbidly obese individuals in a weight management clinic with non-obese individuals with similar comorbidities as morbidly obese individuals in an Internal Medicine clinic.

Methods: Class II and III obese patients BMI >35 kg/m² (N = 114) and 182 non-obese patients (BMI <25 kg/m²) completed the GI symptoms survey between August 2011 and April 2012 were included in this study. The survey included 24 items pertaining to upper and lower GI symptoms. The participants rated the frequency of symptoms as absent (never, rarely) or present (occasionally, frequently). The symptoms were clustered into five categories: oral symptoms, dysphagia, gastroesophageal reflux, abdominal pain, and bowel habits. Responses to each symptom cluster were compared between obese group and normal weight groups using logistic regression.

Results: Of the 24 items, 18 had a higher frequency in the obese group (p < 0.005 for each). After adjusting for age and gender, the obese patients were more likely to have upper GI symptoms: any oral symptom (OR = 2.3, p = 0.0013), dysphagia (OR 2.9, p = 0.0006), and any gastroesophageal reflux (OR 3.8, p < 0.0001). Similarly, the obese patients were more likely to have lower GI symptoms: any abdominal pain (OR = 1.7, p = 0.042) and altered bowel habits (OR = 2.8, p < 0.0001).

Conclusion: These observations suggest a statistically significant increase in frequency of both upper and lower GI symptoms in morbidly obese patients when compared to non-obese subjects.

Blunted Peripheral and Central Responses to Gastric Mechanical and Electrical Stimulations in Diet-induced Obese Rats

Background/Aims

The increase in the prevalence of obesity is attributed to increased food intake and decreased physical activity in addition to genetic factors. Altered gut functions have been reported in obese subjects, whereas, little is known on the possible alterations in brain-gut interactions in obesity. The aim of the study was to explore possible alterations in gastric myoelectrical activity, gastric emptying, autonomic functions and central neuronal responses to gastric stimulations in diet-induced obese rats.

Methods

Gastric myoelectrical activity, gastric emptying and heart rate variability were recorded in lean and obese rats; extracellular neuronal activity in the ventromedial hypothalamus and its responses to gastric stimulations were also assessed.

Results

(1) Gastric emptying was significantly accelerated but gastric myoelectrical activity was not altered in obese rats; (2) the normal autonomic responses to feeding were absent in obese rats, suggesting an impairment of postprandial modulation of autonomic functions; and (3) central neuronal responses to gastric stimulations (both balloon distention and electrical stimulation) were blunted in obese rats, suggesting impairment in the brain-gut interaction.

Conclusions

In diet-induced obese rats, gastric emptying is accelerated, postprandial modulations of autonomic functions is altered and central neuronal responses to gastric stimulations are attenuated. These alterations in peripheral, autonomic and brain-gut interactions may help better understand pathogenesis of obesity and develop novel therapeutic approaches for obesity.

Osteocalcin and the Regulation of Glucose Metabolism

Uncarboxylated osteocalcin enhances insulin and adiponectin release and improves glucose tolerance in mice. Data in humans do not unequivocally support a role for osteocalcin in glucose homeostasis. Changes in the amount of uncarboxylated osteocalcin induced by vitamin K or warfarin treatment are not associated with changes in glucose and insulin concentrations. Interventional studies in humans, designed to detect small changes in insulin secretion and action attributable to changes in uncarboxylated osteocalcin, will be required to reliably detect effects of osteocalcin on glucose metabolism and to better understand its interaction with adiposity and adipokines.

Upper gastrointestinal symptoms in obese patients and their outcomes after bariatric surgery

Obesity is considered an important risk factor for the development of gastrointestinal (GI) disorders, likely through alterations of GI motility. Even though gastroesophageal reflux disease is the condition mainly studied at present, the prevalence of other upper GI symptoms is also augmented in obese patients. Owing to their chronic trend, these disorders have a bearing on public spending and their correct diagnosis would avoid unnecessary cost-consuming investigations. Furthermore, bariatric surgery dramatically changes GI anatomy and physiology, influencing GI symptom outcomes. The aim of this review is to categorize the available results in a pathophysiological framework in an attempt to set up the correct clinical GI management of obese patients before and after bariatric surgery. This would be helpful in tentatively reducing their considerable economic burden on public health services.

Performance characteristics of scintigraphic measurement of gastric emptying of solids in healthy participants

BACKGROUND

Gastric emptying (GE) is measured in pharmacodynamic and diagnostic studies. Our aim was to assess inter- and intra-subject coefficients of variation (COV) of scintigraphic GE measurements in healthy subjects, and associations of GE with gender and body mass index (BMI).

METHODS

Data from participants with scintigraphic measurements of gastric emptying of solids were analyzed. Primary endpoints were gastric emptying T(1/2) (GE T(1/2) ) and GE at 1, 2, 3, and 4 h.

KEY RESULTS

The patient cohort consisted of 105 males and 214 females; at least two studies were performed in 47 subjects [16 males (M), 32 females (F)]. Inter-subject COV (COV(inter) ) for GE T(1/2) were similar in M and F: overall 24.5% (M 26.0%, F 22.5%); COV are predictably lowest for GE at 4 h (COV(inter) 9.6%). COV(intra) for T(1/2) and GE at 4 h were overall 23.8% and 12.6%, and were similar to COV(inter) values. Gender (but not age or BMI) was significantly associated with GE T1/2 [P < 0.001, F 127.6 ± 28.7 (SD) min; M 109.9 ± 28.6 min] and with GE at 1 h and 2 h. Repeat GE T(1/2) values in 47 participants were significantly correlated (r = 0.459, P < 0.001) with median difference of -6 min (mean -1.6, range -56 to 72 min). Bland-Altman plots showed Δ GE T(1/2) similarly distributed across mean GE T(1/2) 100-155 min, and across studies conducted 90-600 days apart.

CONCLUSIONS & INFERENCES

Inter-subject variations in scintigraphic GE results are only slightly higher than the intra-subject measurements, which are also reproducible over time in healthy volunteers. Gender, but not BMI, is significantly associated with GE results.

Peripheral neural targets in obesity

Interest in pharmacological treatments for obesity that act in the brain to reduce appetite has increased exponentially over recent years, but failures of clinical trials and withdrawals due to adverse effects have so far precluded any success. Treatments that do not act within the brain are, in contrast, a neglected area of research and development. This is despite the fact that a vast wealth of molecular mechanisms exists within the gut epithelium and vagal afferent system that could be manipulated to increase satiety. Here we discuss mechano- and chemosensory pathways from the gut involved in appetite suppression, and distinguish between gastric and intestinal vagal afferent pathways in terms of their basic physiology and activation by enteroendocrine factors. Gastric bypass surgery makes use of this system by exposing areas of the intestine to greater nutrient loads resulting in greater satiety hormone release and reduced food intake. A non-surgical approach to this system is preferable for many reasons. This review details where the opportunities may lie for such approaches by describing nutrient-sensing mechanisms throughout the gastrointestinal tract.

Interoception across modalities: on the relationship between cardiac awareness and the sensitivity for gastric functions

The individual sensitivity for ones internal bodily signals ("interoceptive awareness") has been shown to be of relevance for a broad range of cognitive and affective functions. Interoceptive awareness has been primarily assessed via measuring the sensitivity for ones cardiac signals ("cardiac awareness") which can be non-invasively measured by heartbeat perception tasks. It is an open question whether cardiac awareness is related to the sensitivity for other bodily, visceral functions. This study investigated the relationship between cardiac awareness and the sensitivity for gastric functions in healthy female persons by using non-invasive methods. Heartbeat perception as a measure for cardiac awareness was assessed by a heartbeat tracking task and gastric sensitivity was assessed by a water load test. Gastric myoelectrical activity was measured by electrogastrography (EGG) and subjective feelings of fullness, valence, arousal and nausea were assessed. The results show that cardiac awareness was inversely correlated with ingested water volume and with normogastric activity after water load. However, persons with good and poor cardiac awareness did not differ in their subjective ratings of fullness, nausea and affective feelings after drinking. This suggests that good heartbeat perceivers ingested less water because they subjectively felt more intense signals of fullness during this lower amount of water intake compared to poor heartbeat perceivers who ingested more water until feeling the same signs of fullness. These findings demonstrate that cardiac awareness is related to greater sensitivity for gastric functions, suggesting that there is a general sensitivity for interoceptive processes across the gastric and cardiac modality.

Assessment of gastric motor function in childhood functional dyspepsia and obesity

BACKGROUND

The aim was to compare gastric emptying rate and nutrient tolerance during a satiety drinking test in children with functional dyspepsia (FD) and obesity and to study the relationship between daily caloric intake and the satiety drinking test.

METHODS

A total of 28 dyspeptic children (22 girls, mean age 12.5 ± 3.1 years) and 15 obese children (five girls, 13.3 ± 1.8 years) were studied. The patients underwent an octanoic acid gastric emptying breath test and a satiety drinking test. Prior to both tests, a dyspepsia questionnaire was filled out to calculate the mean calorie intake.

KEY RESULTS

The most prevalent dyspeptic symptoms were early satiety (96.4%), postprandial fullness (89.2%), and epigastric pain (78.6%), followed by nausea (50%). All dyspeptic and obese children (n = 43) started the satiety drinking test and 41 children completed the test until a score of 5 was reached. The maximum ingested volume in FD was significantly lower than in obesity or in age-matched healthy controls (252 ± 85 vs 479 ± 199 and 359 ± 29 mL respectively, both P < 0.05). As a group, dyspeptic children had significantly slower gastric emptying than obese children (89.7 ± 54.8 min vs 72.5 ± 26.0 min, P = 0.05). Daily calorie intake was significantly higher in obese children than that in dyspeptic children (2325 ± 469 vs 1503 ± 272 cal, P < 0.0001). The endpoint of the satiety drinking test was significantly correlated with body weight or BMI (both R = 0.41, P = 0.04), but not with daily calorie intake, gastric emptying rate or age.

CONCLUSIONS & INFERENCES

The satiety drinking test is a potentially useful non-invasive tool in the investigation of children with FD and obesity.

Repeated gastric distension alters food intake and neuroendocrine profiles in rats

The consumption of a large food bolus leads to stomach distension. Gastric distension potently signals the termination of a meal by stimulating gastric mechanoreceptors and activating neuroendocrine circuitry. The ability to terminate a meal is altered in disorders such as bulimia nervosa (BN), binge-eating disorder (BED) and certain subtypes of obesity in which large quantities of food are frequently ingested. When a large meal is consumed, the stomach is rapidly stretched. We modeled this rapid distension of the stomach in order to determine if the neuroendocrine abnormalities present in these disorders, including increased gastric capacit3y, leptin dysregulation, and alterations in neuropeptide Y (NPY), and proopiomelanocortin (POMC) expression, were influenced by the rapid stretch aspect of repeatedly consuming a large meal. To test the effects of repeated gastric distension (RGD) on neuroendocrine factors involved in energy homeostasis, a permanent intra-gastric balloon was implanted in rats, and briefly inflated daily for 4 weeks. Though body weights and daily food intakes remained equivalent in RGD and control rats, a significant delay in the onset of feeding was present during the first and second, but not the third and fourth weeks of inflations. Despite equivalent body weights and daily caloric consumption, RGD animals had significantly decreased leptin levels (p<0.05), and tended to have increased fasting arcuate NPY levels (p=0.08), which were suppressed more than control animals following food intake (control and RGD decreases from baseline were 184.95% and 257.42%, respectively). NPY expression in the nucleus of the solitary tract followed a similar pattern. These data demonstrate that the act of regularly distending the stomach can have effects on the regulation of energy balance that are independent from those related to caloric consumption, and may be related to disorders such as BN, BED, and certain types of obesity in which meal termination is impaired.

Diet-induced adaptation of vagal afferent function

Afferent signals from the stomach play an important role in inhibition of food intake during a meal. The gastric hormone ghrelin can influence gastric satiety signalling by altering the sensitivity of gastric vagal afferents. Changes in diet, including food restriction and high fat diet (HFD) alter satiety signalling. We hypothesised that the function of gastric vagal afferent endings are affected by both a period of food restriction and a high fat diet, and that the inhibitory effect of ghrelin on vagal afferents is influenced by the different feeding conditions. We found that both fasting and HFD reduced the responses of gastric vagal tension receptors to distension, but not responses of mucosal receptors to mucosal contact. We traced vagal afferents anterogradely to their terminals in the mucosa where we found they were in close apposition to ghrelin-containing cells. Ghrelin receptor mRNA was expressed in vagal afferent cell bodies of the nodose ganglia, and increased in response to caloric restriction, but decreased in HFD mice. In control mice, ghrelin decreased the sensitivity of tension but not mucosal receptors. After caloric restriction or high fat diet, ghrelin inhibited mucosal receptors, and the inhibition of mechanosensitive tension receptors was enhanced. Therefore, both caloric restriction and HFD decrease mechanosensory vagal afferent signals, and augment the inhibitory effect of ghrelin on vagal afferents, but different mechanisms mediate the short- and longer-term changes.

Evaluation of liquid ingestion after bariatric surgery

CONTEXT: Bariatric surgery is an effective treatment for obesity; however, after surgery the patient may have difficulty in swallowing liquid and solid foods. OBJECTIVES: To evaluate liquid ingestion in patients who had undergone bariatric surgery. METHOD: We studied 43 volunteers with normal body mass index (BMI) (BMI: 18.5-24.9 kg/m²), 55 subjects with class III obesity (BMI: >40.0 kg/m²), and 48 subjects with bariatric surgery for treatment of class III obesity. The method chosen for evaluation was the water swallowing test. The subjects drank in triplicate 50 mL of water while being precisely timed and the number of swallows were counted. RESULTS: There was no difference between subjects with normal BMI and subjects with class III obesity. During the first 2 months after bariatric surgery the patients showed an increase in the time needed to drink the entire volume, in the number of swallows, and in the inter-swallow interval, and a decrease in the volume swallowing capacity (volume/swallowing) and swallowing flow rate (volume swallowed/second). After 2 months, the results of the swallowing measurements moved in the direction of normal values. CONCLUSION: Bariatric surgery may cause more intense alterations of liquid bolus swallowing within 2 months after the procedure, which moved to normal values after this time.

Satiety: have we neglected dietary non-nutrients?

Satiety, which is the inhibition of eating following the end of a meal, is influenced by a number of food characteristics, including compositional and structural factors. An increased understanding of these factors and the mechanisms whereby they exert their effects on satiety may offer a food-based approach to weight management. Water and gas, which are often neglected in nutrition, are major components of many foods and contribute to volume, and to sensory and other characteristics. A review of previous short-term studies that evaluated the effects of water or gas in foods on satiety showed that while satiety was generally increased, effects on subsequent intakes were not always apparent. These studies were diverse in terms of design, timings and food matrices, which precludes definitive conclusions. However, the results indicate that solids may be more effective at increasing satiety than liquids, but gas may be as effective as water. Although increased gastric distension may be the main mechanism underlying these effects, pre-ingestive and ingestive impacts on cognitive, anticipatory and sensory responses also appear to be involved. Furthermore, there is limited evidence that water on its own may be effective at increasing satiety and decreasing intakes when drunk before, but not with, a meal. Longer-term extrapolation suggests that increasing food volumes with water or gas may offer weight-management strategies. However, from a practical viewpoint, the effects of water and gas on satiety may be best exploited by using these non-nutrients to manipulate perceived portion sizes, without increasing energy contents.

Gastrointestinal motility disorders and acupuncture

During the last decades, numerous studies have been performed to investigate the effects and mechanisms of acupuncture or electroacupuncture (EA) on gastrointestinal motility and patients with functional gastrointestinal diseases. A PubMed search was performed on this topic and all available studies published in English have been reviewed and evaluated. This review is organized based on the gastrointestinal organ (from the esophagus to the colon), components of gastrointestinal motility and the functional diseases related to specific motility disorders. It was found that the effects of acupuncture or EA on gastrointestinal motility were fairly consistent and the major acupuncture points used in these studies were ST36 and PC6. Gastric motility has been mostly studied, whereas much less information is available on the effect of EA on small and large intestinal motility or related disorders. A number of clinical studies have been published, investigating the therapeutic effects of EA on a number of functional gastrointestinal diseases, such as gastroesophageal reflux, functional dyspepsia and irritable bowel syndrome. However, the findings of these clinical studies were inconclusive. In summary, acupuncture or EA is able to alter gastrointestinal motility functions and improve gastrointestinal motility disorders. However, more studies are needed to establish the therapeutic roles of EA in treating functional gastrointestinal diseases.

Peripheral mechanisms in the control of appetite and related experimental therapies in obesity

The function of the stomach and the gut hormonal responses to food ingestion constitute highly integrated homeostatic responses that maintain euglycemia and normal digestion. This intrinsic feedback involves vagal and hormonal mechanisms. Important signals such as GLP-1 and PYY that arise peripherally induce satiation and also delay gastric emptying or increase insulin secretion. Novel therapies are being developed to mimic or enhance these feedback mechanisms and to control appetite as a means to treat obesity.

Proximal gastric function in volunteers with different types of simple obesity: an analysis of 67 cases

AIM: To analyze the characteristics of changes in proximal gastric function in volunteers with different types of simple obesity.

METHODS: Sixty-seven volunteers with simple obesity were divided into three groups, namely, group A (volunteers with binge eating), group B (volunteers with normal diet) and group C (volunteers with functional dyspepsia). Thirty-two non-obese healthy volunteers formed the control group (group D). Gastric barostat studies were then performed to record the changes in gastric capacity, intragastric pressure and gastric compliance in response to mechanical distension.

RESULTS: The initial volume (IV) and maximal tolerance volume (MV) in group A were significantly larger than those in group D (t = -6.63 and -5.20, respectively; both P < 0.01), whereas these two parameters in group C were significantly lower than those in group D (t = 3.48 and 2.11, respectively; both P < 0.01). The initial intragastric pressure (IP) and the maximal tolerance pressure (MP) in group C were significantly lower than those in group D (t = 2.09 and 2.08, respectively; both P < 0.05). The initial gastric compliance (IC) and the maximal tolerance compliance (MC) in group A were significantly higher than those in group D (t = 2.44 and -5.56, respectively; both P < 0.01), whereas these two parameters in group C were significantly than those in group D (t = 2.44 and 2.32, respectively; both P < 0.05).

CONCLUSION: The main reason for the development of obesity in binge eaters is due to an increase in gastric capacity, compliance and accommodation as well as a delay in satiety.

Associations among binge eating behavior patterns and gastrointestinal symptoms: a population-based study

BACKGROUND

The psychological symptoms associated with binge eating disorder (BED) have been well documented. However, the physical symptoms associated with BED have not been explored. Gastrointestinal (GI) symptoms such as heartburn and diarrhea are more prevalent in obese adults, but the associations remain unexplained. Patients with bulimia have increased gastric capacity. The objective of the study was to examine if the severity of binge eating episodes would be associated with upper and lower GI symptoms.

METHODS

Population-based survey of community residents through a mailed questionnaire measuring GI symptoms, frequency of binge eating episodes and physical activity level. The association of GI symptoms with frequency of binge eating episodes was assessed using logistic regression models adjusting for age, gender, body mass index (BMI) and physical activity level.

RESULTS

In 4096 subjects, BED was present in 6.1%. After adjusting for BMI, age, gender, race, diabetes mellitus, socioeconomic status and physical activity level, BED was independently associated with the following upper GI symptoms: acid regurgitation (P<0.001), heartburn (P<0.001), dysphagia (P<0.001), bloating (P<0.001) and upper abdominal pain (P<0.001). BED was also associated with the following lower GI symptoms: diarrhea (P<0.001), urgency (P<0.001), constipation (P<0.01) and feeling of anal blockage (P=0.001).

CONCLUSION

BED appears to be associated with the experience of both upper and lower GI symptoms in the general population, independent of the level of obesity. The relationship between increased GI symptoms and physiological responses to increased volume and calorie loads, nutritional selections and rapidity of food ingestion in individuals with BED deserves further study.

Effects of intramural administration of Botulinum Toxin A on gastric emptying and eating capacity in obese patients

BACKGROUND

Intraparietal gastric administration of Botulinum Toxin A has been studied in open trials to induce satiety and increase weight loss of obese patients with contradictory results. In previous studies only the antrum was the target for Botulinum Toxin A, whereas the fundus, which exerts important activity on gastric accommodation, was excluded. In this study we report the effects of injection into both gastric regions on solid gastric capacity and emptying of the stomach.

MATERIALS AND METHODS

In this study we extended our previous investigations to include 30 obese patients who received Botulinum Toxin A (120 U into the antrum and 80 U into the fundus) or saline by intraparietal endoscopic injection. The two groups were homogeneous for age, gender, body weight and body mass index. Body weight and body mass index, solid gastric emptying (T(1/2) and T(lag) at the octanoic acid breath test) and maximal gastric capacity for solids (kcal) were determined before injection and 2 months later. The results were expressed as mean values (S.E.M.). t-Test or Wilcoxon test was used for statistical analysis, p<0.05 being considered significant.

RESULTS

Both treatments induced a significant reduction of body weight and body mass index but Botulinum Toxin A exerted a significantly greater effect (body weight -11.8+/-0.9 kg vs. -5.5+/-1.1 kg, p<0.0002; body mass index -4.1+/-0.2 vs. -2.2+/-0.4, p<0.001). The maximal gastric capacity for solids was also reduced by both Botulinum Toxin A and placebo, the former being significantly more effective (679+/-114 kcal vs. 237+/-94 kcal, p<0.008). Botulinum Toxin A also significantly increased T(1/2) from 83.4+/-3.9 to 101.6+/-9.9 min, p<0.03) but T(lag) was unchanged. Placebo had no effect on either of these parameters.

CONCLUSIONS

Our results demonstrated that Botulinum Toxin A makes weight loss easier in obese patients. It acts by increasing the solid gastric emptying time and reducing the solid eating capacity of the stomach.

Intragastric injection of botulinum toxin for the treatment of obesity. Where are we?

Obesity has reached epidemic proportions particularly in western countries. Most non-surgical treatments of this condition are disappointing. Since 2005, several studies evaluating the effect of Botulinum Toxin type A (BT-A) in gastric antrum by means of endoscopy for the treatment of obesity have been published. This treatment modality was based on the observation that gastric injection of BT-A in laparatomized rats induced a significant reduction of food intake and body weight. Nowadays, 6 studies have been published yielding conflicting results. Differences in selection of patients, doses of BT-A, method of administration of the toxin and instruments of evaluation of some parameters among these studies may be the cause of divergent results. We discuss herein some important features of these studies pointing out on differences among them. At the same time, based on the knowledge of physiological characteristics of normal and abnormal gastric function related with feeding, we discuss the probable causes of failure observed in these trials. Finally, we give some guidelines concerning the way that future research in this field may follow, not without calling attention to disadvantages of this treatment.

Implications of altered gastrointestinal motility in obesity

The onset of obesity occurs as a result of an imbalance between nutrient consumption/absorption and energy expenditure. Gastrointestinal (GI) motility plays a critical role in the rate of consumption of foods, digestion, and absorption of nutrients. Various segments of the GI tract coordinate in a complex yet precise way, to control the process of food consumption, digestion, and absorption of nutrients. GI motility not only regulates the rates at which nutrients are processed and absorbed in the gut, but also, via mechanical and neurohormonal methods, participates in the control of appetite and satiety. Altered GI motility has frequently been observed in obese patients, the significance of which is incompletely understood. However, these alterations can be considered as potential contributing factors in the development and maintenance of obesity and changed eating behavior. Therapies aimed at regulating or counteracting the observed changes in GI motility are being actively explored and applied clinically in the management of obese patients.

Adjustable totally implantable intragastric prosthesis (ATIIP)-Endogast for treatment of morbid obesity: one-year follow-up of a multicenter prospective clinical survey

BACKGROUND

The Adjustable Totally Implantable Intragastric Prosthesis (ATIIP)-Endogas is a new mini-invasive technique for the treatment of morbid obesity. The ATIIP is conducted using a surgical and endoscopic procedure. The permanent presence of an air-inflated prosthesis inside the gastric corpus-fundus area and the fixation of the stomach to the abdominal wall are the two main principles in the technique. The prosthesis is connected to a subcutaneous totally implantable system. The aim of the ATIIP is to induce early satiety and reduction of meal intake. This study presents the preliminary results of 1-year follow-up of a multicenter prospective clinical survey.

METHODS

From November 2004 to March 2007, 57 patients underwent ATIIP: 28 males (49%) and 29 females (51%), with mean age 43.6 years (18-69) and mean BMI 48.9 (33.7-81.2). Follow-up was 1-28 months.

RESULTS

Feasibility was 100%, reproducibility 100%, and acceptability found no vomitting. Mean volume of the prosthesis was 210 ml of air (first 3 months, 40 patients). Mean %EWL was 22.3% (3 mos, 40 pts), 28.7% (6 mos, 38 pts), and 39.2% (12 mos, 20 pts). Early postoperative complication was local subcutaneous infection in 7 pts (12.2%). In 16 pts who had a subcutaneous drain and empirical antibiotic therapy until the 4th postoperative day, local infection occurred in 1 patient (6.2%). Late postoperative complications occurred in 3 pts (5.2%) who developed port erosion.

CONCLUSIONS

Preliminary results indicate that the ATIIP is feasible, reproducible, safe with low risk of complications and has encouraging results in weight loss. Morbidly obese patients >60 years old and the super-obese (BMI>50) are specific indications.

Modulation by high-fat diets of gastrointestinal function and hormones associated with the regulation of energy intake: implications for the pathophysiology of obesity

The presence of fat in the small intestine slows gastric emptying, stimulates the release of many gastrointestinal hormones, and suppresses appetite and energy intake as a result of the digestion of fats into free fatty acids; the effects of free fatty acids are, in turn, dependent on their chain length. Given these effects of fat, it is paradoxical that high dietary fat intakes have been linked to increased energy intake and body weight and are considered to play a significant role in the pathogenesis of obesity. However, increasing evidence indicates that a chronic increase in dietary fat is associated with an attenuation of the feedback signals arising from the small intestine induced by fat, with a consequent relative acceleration of gastric emptying, modulation of gastrointestinal hormone secretion, and attenuation of the suppression of energy intake. This review addresses the gastrointestinal factors involved in the regulation of appetite and energy intake, with a particular focus on 1) the gastrointestinal mechanisms triggered by small intestinal fat that modulate energy intake, 2) the potential role of a high dietary fat intake in the development of obesity, and 3) implications for the prevention and management of obesity.

Appetite and obesity: a gastroenterologist's perspective

This review focuses on the gastrointestinal tract's control of appetite and interventions directed to the gut that are effective in the treatment of obesity. It examines the evidence linking gut hormones to the control of both appetite and upper gastrointestinal motility, the evidence that stomach function is altered and contributes to satiation in obesity and outlines the principles of therapy for obesity which are directed at the gastrointestinal tract. These therapies impair fat absorption or alter stomach functions through pharmacological, device, endoscopic, or surgical approaches. Gastroenterologists need to understand the role of factors controlling appetite in order to effectively manage the increasing number of obese patients and the ways the gut function may be altered as a result of the treatments and their complications.

Psychometric properties of the State and Trait Food Cravings Questionnaires among overweight and obese persons

A crucial problem in studies involving food cravings is the lack of a psychometrically sound measure for use among overweight and obese populations. The degree to which the Food Cravings Questionnaires-Trait (FCQ-T) and State (FCQ-S) evidenced acceptable psychometric properties among overweight and obese participants was assessed. In study 1, 109 participants completed the FCQ-T and FCQ-S. Item-total correlations, test-retest reliability, internal consistency, and factor structures were examined. Results indicate good internal consistency and partially support the factor structures. In study 2, the construct and predictive validity of the FCQ-S were examined. Twenty-eight women completed the FCQ-S 15 min after finishing a standardized breakfast and then twice more, 90 min apart. Subsequent ad libitum food intake was recorded. Results suggest that the FCQ-S is sensitive to state changes in food cravings, but that the magnitude of the changes was moderate. The FCQ-S was not a good predictor of subsequent food intake. The FCQ-T and FCQ-S may be useful in studies that examine triggers of and interventions for excessive food intake.

Using computed tomography scans to develop an ex-vivo gastric model

The objective of this research was to use abdominal computed tomography (CT) scans to non-invasively quantify anthropometrical data of the human stomach and to concomitantly create an anatomically correct and distensible ex-vivo gastric model. Thirty-three abdominal CT scans of human subjects were obtained and were imported into reconstruction software to generate 3D models of the stomachs. Anthropometrical data such as gastric wall thickness, gastric surface area and gastric volume were subsequently quantified. A representative 3D computer model was exported into a selective laser sintering (SLS) rapid prototyping machine to create an anatomically correct solid gastric model. Subsequently, a replica wax template of the SLS model was created. A negative mould was offset around the wax template such that the offset distance was equivalent to that of the gastric wall thickness. A silicone with similar mechanical properties to the human stomach was poured into the offset. The lost wax manufacturing technique was employed to create a hollow distensible stomach model. 3D computer gastric models were generated from the CT scans. A hollow distensible silicone ex-vivo gastric model with similar compliance to that of the human stomach was created. The anthropometrical data indicated that there is no significant relationship between BMI and gastric surface area or gastric volume. There were inter- and intra-group differences between groups with respect to gastric wall thickness. This study demonstrates that abdominal CT scans can be used to both non-invasively determine gastric anthropometrical data as well as create realistic ex-vivo stomach models.

Effect of different macronutrients in excess on gastric sensory and motor functions and appetite in normal-weight, overweight, and obese humans

BACKGROUND

The effects of supplementation with different macronutrients on gastric sensory and motor functions are unclear.

OBJECTIVE

We aimed to compare the effects of 2 wk of supplementation with different classes of macronutrients on gastric function, satiation, and appetite in healthy and overweight subjects.

DESIGN

In a parallel-group, double-blind study, 52 (14 men, 38 women) healthy normal-weight, overweight, and obese participants [body mass index (BMI; in kg/m(2)): 19.4-47.0] aged 18-64 y were randomly assigned to consume different isocaloric diets (n = 13 per diet group) adjusted for BMI and activity level. The standard diet provided 20% of energy as protein, 30% as fat, and 50% as carbohydrate. The high-protein, high-fat, and high-carbohydrate diets contained 500 additional kcal in each nutrient class. On 3 separate days, we measured gastric emptying of solids, gastric volumes, postprandial symptoms, appetite, and food choice with validated methods. Age, sex, BMI, and baseline satiation were covariates in the analysis of covariance.

RESULTS

Fat supplementation was associated with increased maximum tolerated volume (MTV) in subjects with a high baseline MTV (P < 0.05), irrespective of BMI. Gastric emptying and volumes, postprandial symptoms, total calories, and food choices at an ad libitum meal were not significantly different after each dietary preload. Fasting gastric volumes tended to be higher with the high-fat than with the high-carbohydrate or high-protein diets (P <or= 0.1). Gastric emptying and volumes and satiation were not significantly different between the BMI categories (< and >30).

CONCLUSION

Supplementation with 500 kcal fat in excess of required calories for 2 wk increased food tolerance in healthy normal-weight and obese subjects with a high baseline MTV without significantly changing gastric motor functions.

Proximal gastric motility in critically ill patients with type 2 diabetes mellitus

AIM: To investigate the proximal gastric motor response to duodenal nutrients in critically ill patients with long-standing type 2 diabetes mellitus.

METHODS: Proximal gastric motility was assessed (using a barostat) in 10 critically ill patients with type 2 diabetes mellitus (59 ± 3 years) during two 60-min duodenal infusions of Ensure^® (1 and 2 kcal/min), in random order, separated by 2 h fasting. Data were compared with 15 non-diabetic critically ill patients (48 ± 5 years) and 10 healthy volunteers (28 ± 3 years).

RESULTS: Baseline proximal gastric volumes were similar between the three groups. In diabetic patients, proximal gastric relaxation during 1 kcal/min nutrient infusion was similar to non-diabetic patients and healthy controls. In contrast, relaxation during 2 kcal/min infusion was initially reduced in diabetic patients (p < 0.05) but increased to a level similar to healthy humans, unlike non-diabetic patients where relaxation was impaired throughout the infusion. Duodenal nutrient stimulation reduced the fundic wave frequency in a dose-dependent fashion in both the critically ill diabetic patients and healthy subjects, but not in critically ill patients without diabetes. Fundic wave frequency in diabetic patients and healthy subjects was greater than in non-diabetic patients.

CONCLUSION: In patients with diabetes mellitus, proximal gastric motility is less disturbed than non-diabetic patients during critical illness, suggesting that these patients may not be at greater risk of delayed gastric emptying.

Gastric sensorimotor functions and hormone profile in normal weight, overweight, and obese people

BACKGROUND & AIMS

Peptide YY (PYY) levels are reported to be decreased in obesity. The relation between gastric functions, satiation, and gut hormones in obesity is incompletely understood. The aim of this study was to compare gastric volumes, emptying, maximum tolerated volumes, postchallenge symptoms, and selected gut hormones in normal, overweight, or obese healthy volunteers.

METHODS

In 73 nonbulimic normal, overweight, or obese participants weighing less than 137 kg, we measured gastric emptying of solids and liquids by scintigraphy (gastric emptying half-time [GE t(1/2)]); gastric volumes by single-photon emission computed tomography; maximum tolerated volumes and symptoms by satiation test; and plasma leptin, ghrelin, insulin, glucagon-like peptide 1, and PYY levels. Groups were compared using 1-way analysis of covariance adjusted for sex. Univariate associations among measured responses were assessed using Spearman correlations. Multiple linear regression models, adjusting for weight and sex, assessed the independent ability of gastric functions and hormones to predict satiation volume.

RESULTS

Obese and overweight subjects had significantly lower postprandial gastric volumes, higher fasting and postprandial insulin and leptin levels, and lower fasting ghrelin and lower postprandial reduction in ghrelin levels. PYY levels were not different in obese or overweight subjects compared with controls. The GE t(1/2) was correlated inversely with postprandial PYY; increased body weight was associated with faster GE t(1/2) of solids (r(s) = 0.33, P = .005) and liquids (r(s) = 0.24, P = .04). Postprandial changes in gastric volume and PYY were independent predictors of satiation (both P = .01).

CONCLUSIONS

Overweight or obesity are associated with lower postprandial gastric volumes and normal PYY levels. Gastric emptying influences postprandial PYY levels. Postprandial PYY and gastric volume independently predict satiation volume in nonbulimic people across a wide body mass index range.

Treatment of morbid obesity by intraparietogastric administration of botulinum toxin: a randomized, double-blind, controlled study

OBJECTIVE

The stomach is the main target organ for bariatric surgery, but no medical treatment has been developed to increase satiety and decrease food intake via gastric pathways. The aim of our study was to investigate whether or not the intraparietogastric administration of botulinum toxin A (BTX), able to modify the motility patterns of the stomach, could be useful for treatment of obesity.

DESIGN

Double blind controlled study.

SUBJECTS

Twenty-four morbidly obese patients (mean weight (s.e.m.) 116.1+/-4.89 kg, mean body mass index (BMI) 43.6+/-1.09 kg/m(2)) were blindly randomized to receive 200 IU BTX or placebo into the antrum and fundus of the stomach by intraparietal endoscopic administration.

MEASUREMENTS

We evaluated weight loss, BMI changes, satiety score, the maximal gastric capacity for liquids and the gastric emptying time (octanoic acid breath test).

RESULTS

The two groups were homogeneous for anthropometric characteristics. Eight weeks after treatment, BTX patients had significantly higher weight loss (11+/-1.09 vs 5.7+/-1.1 kg, P<0.001) and BMI reduction (4+/-0.36 vs 2+/-0.58 kg/m(2), P<0.001) and a higher satiety score on a visual analogic scale (7.63+/-0.38 vs 4.72+/-0.44, P<0.001) than controls. Furthermore, BTX patients showed a significantly greater reduction in maximal gastric capacity for liquids (266.6+/-48 vs 139+/-31, P<0.001) and a greater prolongation in gastric emptying time (+18.93+/-8 vs -2.2+/-6.9 min, P<0.05). No significant side effects or neurophysiologic changes were found.

CONCLUSIONS

Topical intragastric BTX was effective in reducing food intake and body weight in morbidly obese patients.

New imaging in neurogastroenterology: an overview

Advances in imaging are being introduced initially as research tools and subsequently as clinical diagnostic tests. These investigations include modifications of the standard gastric emptying by scintigraphy to include application of intraluminal ultrasound to image sustained contractions and longitudinal shortening in the oesophagus, 2- and 4-h images, volumetric measurements to measure gastric volume, magnetic resonance (MR) imaging to appraise the structure and function of the rectal evacuation process, and brain imaging as a surrogate for the investigation of the brain's contribution to functional gastrointestinal disorders and chronic pain syndromes. There is a need for rigorous validation and measurement of the performance characteristics of these tests. Given the impact of gastric emptying at 4 h and single photon emission computerized tomography (SPECT) imaging for measuring gastric volumes on research and clinical practice, it is anticipated that, once validated, these different techniques are likely to have a significant impact on neurogastroenterology and, potentially, replace more invasive procedures.

Proximal stomach function in obesity with normal or abnormal oesophageal acid exposure

There is an increased prevalence of gastro-oesophageal reflux and symptoms in obese patients. Information about the proximal stomach in obese patients with reflux is lacking. Gastric volume and compliance are similar between obese and lean subjects. To study the proximal stomach function and perception in obese patients with normal or abnormal oesophageal acid exposure, thirty-one obese patients, with normal or abnormal oesophageal acid exposure, underwent medical evaluation of oesophageal and gastrointestinal symptoms by a questionnaire and measurement of proximal stomach function and perception by an electronic barostat and a standardized questionnaire. Nineteen obese patients had abnormal oesophageal acid exposure. The percentage of total time with pH <4 is significantly related to the presence of hiatal hernia, the oesophageal intensity-frequency symptom score and gender, i.e. higher percentage in men. The perception cumulative score was significantly different between patients with normal and abnormal oesophageal acid exposure after adjusting for covariates (gender, body mass index, age, minimal distending pressure, gastric tone and gastric compliance). Gastric tone and compliance were significantly related to the perception cumulative score. In conclusion, patients with abnormal oesophageal acid exposure have increased gastric perception. A significant relation among gastric tone, gastric compliance and upper gastrointestinal sensations was shown.

Short-Term Effect of Eggs on Satiety in Overweight and Obese Subjects

OBJECTIVE

To test the hypotheses that among overweight and obese participants, a breakfast consisting of eggs, in comparison to an isocaloric equal-weight bagel-based breakfast, would induce greater satiety, reduce perceived cravings, and reduce subsequent short-term energy intake.

SUBJECTS

Thirty women with BMI's of at least 25 kg/M2 between the ages of 25 to 60 y were recruited to participate in a randomized crossover design study in an outpatient clinic setting.

DESIGN

Following an overnight fast, subjects consumed either an egg or bagel-based breakfast followed by lunch 3.5 h later, in random order two weeks apart. Food intake was weighed at breakfast and lunch and recorded via dietary recall up to 36 h post breakfast. Satiety was assessed using the Fullness Questionnaire and the State-Trait Food Cravings Questionnaire, state version.

RESULTS

During the pre-lunch period, participants had greater feelings of satiety after the egg breakfast, and consumed significantly less energy (kJ; 2405.6 +/- 550.0 vs 3091.3 +/- 445.5, Egg vs Bagel breakfasts, p < 0.0001), grams of protein (16.8 +/- 4.2 vs 22.3 +/- 3.4, Egg vs Bagel breakfasts, p < 0.0001), carbohydrate 83.1 +/- 20.2 vs 110.9 +/- 18.7, Egg vs Bagel breakfasts, p < 0.0001), and fat 19.4 +/- 5.1 vs 22.8 +/- 3.2, Egg vs Bagel breakfasts, p < 0.0001) for lunch. Energy intake following the egg breakfast remained lower for the entire day (p < 0.05) as well as for the next 36 hours (p < 0.001).

CONCLUSIONS

Compared to an isocaloric, equal weight bagel-based breakfast, the egg-breakfast induced greater satiety and significantly reduced short-term food intake. The potential role of a routine egg breakfast in producing a sustained caloric deficit and consequent weight loss, should be determined.

Visceral response to acute retrograde gastric electrical stimulation in healthy human

AIM: To investigate the visceral response to acute retrograde gastric electrical stimulation (RGES) in healthy humans and to derive optimal parameters for treatment of patients with obesity.

METHODS: RGES with a series of effective parameters were performed via a bipolar mucosal electrode implanted along the great curvature 5 cm above pylorus of stomach in 12 healthy human subjects. Symptoms associated with dyspepsia and other discomfort were observed and graded during RGES at different settings, including long pulse and pulse train. Gastric myoelectrical activity at baseline and during different settings of stimulation was recorded by a multi-channel electrogastrography.

RESULTS: The gastric slow wave was entrained in all the subjects at the pacing parameter of 9 cpm in frequency, 500 ms in pulse width, and 5 mA in amplitude. The frequently appeared symptoms during stimulation were satiety, bloating, discomfort, pain, sting, and nausea. The total symptom score for each subject significantly increased as the amplitude or pulse width was adjusted to a higher scale in both long pulse and pulse train. There was a wide diversity of visceral responses to RGES among individuals.

CONCLUSION: Acute RGES can result in a series of symptoms associated with dyspepsia, which is beneficial to the treatment of obesity. Optimal parameter should be determined according to the individual sensitivity to electrical stimulation.