Independent influences of body mass and gastric volumes on satiation in humans

Macrophages and Mast Cells in the Gastric Mucosa of Patients with Obesity Undergoing Sleeve Gastrectomy

Background. Adipose tissue macrophages (ATMs) and mast cells (MCs) play a role in immune responses. More recently, their involvement in tumor angiogenesis and chronic inflammatory conditions in patients with obesity has been discovered. Furthermore, a higher BMI (Body Mass Index) value corresponds to a higher inflammatory state. In particular, gastric tissue in obesity (GTO) is characterized by Macrophages, Mast Cells Positive to Triptase (MCPT), and neo-formed microvessels (MVD). Materials and Methods. We collected gastric tissue samples from December 2021 to December 2022. The patients selected had a BMI > 35 kg/m2 with different comorbidities. Regarding the surgery, surgeons executed a Laparoscopic Sleeve Gastrectomy (LapSG). Gastric tissue was analyzed by immunohistochemistry and morphometrical assay, comparing "obese-related" gastric tissue to normal gastric tissue. Furthermore, tissue parameters were correlated with important clinicopathological features. Results. We collected thirty gastric tissue samples from thirty patients with obesity. Blood tests, Electrocardiogram (ECG), esophagogastroduodenoscopy (EGDS) associated with a urea breath test, and chest X.R. were performed. A significant correlation between ATMs, MCPT, MVD, and BMI was found in GTO. Pearson t-test analysis was conducted (r ranged from 0.67 to 0.71; p-value < 0.05). Conclusions. These preliminary data suggest that ATMs, MCPT, and MVD related to BMI can play a role in both gastric tissue angiogenesis and inflammation inducing a tissue change that could lead to gastric inflammation or cancer diseases.

Bioresorbable shape-adaptive structures for ultrasonic monitoring of deep-tissue homeostasis

Monitoring homeostasis is an essential aspect of obtaining pathophysiological insights for treating patients. Accurate, timely assessments of homeostatic dysregulation in deep tissues typically require expensive imaging techniques or invasive biopsies. We introduce a bioresorbable shape-adaptive materials structure that enables real-time monitoring of deep-tissue homeostasis using conventional ultrasound instruments. Collections of small bioresorbable metal disks distributed within thin, pH-responsive hydrogels, deployed by surgical implantation or syringe injection, allow ultrasound-based measurements of spatiotemporal changes in pH for early assessments of anastomotic leaks after gastrointestinal surgeries, and their bioresorption after a recovery period eliminates the need for surgical extraction. Demonstrations in small and large animal models illustrate capabilities in monitoring leakage from the small intestine, the stomach, and the pancreas.

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.

Increased Meal Size but Reduced Meal-Stimulated Plasma Cholecystokinin Concentrations in Women With Obesity

To better understand the physiological basis of obesity in women, we investigated whether obesity or menstrual cycle phase affects laboratory test-meal size or meal-stimulated plasma cholecystokinin (CCK) concentration. Women with healthy weight (body mass index [BMI] of 18.5-24.9 kg/m2, N = 16) or obesity (BMI 30-39.9 kg/m2, N = 20) were tested once in the late-follicular or peri-ovulatory phase (LF/PO) and once in the mid-luteal phase (ML). Meals of ham sandwiches were offered and blood was sampled. Menstrual cycle phases were verified with participants' reports of menses and measurements of progesterone and luteinizing hormone (LH) concentrations. Women with obesity ate significantly larger meals than women with healthy weight, (mean, 711 [95% CI, 402-1013] kJ, P = 0.001, during the LF/PO and 426 [105-734] kJ, P = 0.027, larger during the ML). Women with healthy weight ate smaller meals during LF/PO than ML (decrease, 510 [192-821 kJ], P = 0.008), but women with obesity did not (decrease, 226 [-87-542] kJ, P = 0.15). CCK concentrations 18 to 30 minutes after meal onset were lower in women with obesity than in women with healthy weight during LF/PO (3.6 [3.1-4.1] vs 6.1 [4.5-7.7] pmol/L; P = 0.004), but not during ML, with a significant interaction effect (1.8 [1.2-2.4] pmol/L, P = 0.048). Women with obesity consumed larger meals than women with healthy weight but displayed reduced meal-stimulated plasma CCK concentrations. These data are consistent with the hypothesis that a defect in CCK secretion compromises satiation in obese women and contributes to the development or maintenance of 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.

Gastrointestinal peptides in eating-related disorders

Food intake is tightly controlled by homeostatic signals sensitive to metabolic need for the regulation of body weight. This review focuses on the peripherally-secreted gastrointestinal peptides (i.e., ghrelin, cholecystokinin, glucagon-like peptide 1, and peptide tyrosine tyrosine) that contribute to the control of appetite and discusses how these peptides or the signals arising from their release are disrupted in eating-related disorders across the weight spectrum, namely anorexia nervosa, bulimia nervosa, and obesity, and whether they are normalized following weight restoration or weight loss treatment. Further, the role of gut peptides in the pathogenesis and treatment response in human weight conditions as identified by rodent models are discussed. Lastly, we review the incretin- and hormone-based pharmacotherapies available for the treatment of obesity and eating-related disorders.

Six intragastric balloons: Which to choose?

Endoscopically placed intragastric balloons (IGBs) have played a significant role in obesity treatment over the last 30 years, successfully bridging the gap between lifestyle modification/pharmacotherapy and bariatric surgery. Since they provide a continuous sensation of satiety that helps the ingestion of smaller portions of food, facilitating maintenance of a low-calorie diet, they have generally been considered an effective and reversible, less invasive, non-surgical procedure for weight loss. However, some studies indicate that balloons have limited sustainable effectiveness for the vast majority attempting such therapy, resulting in a return to the previous weight after balloon removal. In this review we try to summarize the pros and cons of various balloon types, to guide decision making for both the physician and the obese individual looking for effective treatment. We analyzed the six most commonly used IGBs, namely the liquid-filled balloons Orbera, Spatz3, ReShape Duo and Elipse, and the gas-filled Heliosphere and Obalon - also including comments on the adjustable Spatz3, and the swallowable Obalon and Elipse - to optimize the choice for maximum efficacy and safety.

Accentuated early postprandial satiety in people with SCI versus able-bodied controls

In persons with spinal cord injury (SCI), reduced fat-free mass and movement-related energy expenditure increase obesity risk. Although plausible mechanisms exist, it remains unknown whether impaired appetite regulation potentiates obesity risk in SCI. This study compared postprandial responses of appetite-related hormones, appetite perceptions and the sensitivity of appetite to covert preload energy manipulation in persons with SCI and able-bodied (AB) controls. In a counterbalanced order, 12 men with high-level SCI (≥T6 vertebrae) and 12 AB controls completed two trials, consuming covert high-energy (HE; 2513 kJ) and low-energy (LE; 1008 kJ) preloads on separate occasions. Subjective appetite perceptions were assessed at 30 min intervals following preload consumption (up to 150 min) and energy intake was determined from ad libitum test meals. Appetite-related hormone (total PYY, GLP-1 and acylated ghrelin) responses were measured in the HE trial only. Within the early postprandial phase (0-60 min), subjective ratings of fullness (d = 0.83) and satisfaction (d = 0.87) were higher (P ≤ 0.028) in the group with SCI. No group differences in PYY, GLP-1 or acylated ghrelin were detected in a fasted state or postprandially (d ≤ 0.64; p ≥ 0.053). Ad libitum energy intake was lower in the SCI group (1086 vs. 1713 kJ, respectively, d = 1.00; P = 0.020) but no effect of trial (preload) was found. These findings suggest that, following isocaloric preloads, postprandial satiety may be augmented, rather than attenuated, in people with SCI.

Nutrient Drinking Test as Biomarker in Functional Dyspepsia

INTRODUCTION

Functional dyspepsia (FD) is a prevalent condition with multifactorial pathophysiology, including impaired gastric accommodation (GA), hypersensitivity to gastric distention, and delayed gastric emptying. Drink tests (DT) have been proposed as a potential biomarker for the presence and severity of gastric sensorimotor dysfunction. Thus, we aimed to summarize the state of knowledge on different DT and their potential as a biomarker for FD.

METHODS

A PubMed and MEDLINE search was conducted for English language articles, reviews, meta-analyses, case series, and randomized controlled trials, including also published meeting abstracts.

RESULTS

Several DT have been described in literature (e.g., different type of liquid, number of calories used, pace of drinking, and subject's awareness of the amount of liquid drunk). FD patients ingest significantly less volume in the different variants of the tests. The slow nutrient ("satiety drinking") test (SDT) studies show the most consistent separation between health and FD and correlation with GA. However, sensitivity to distention may be correlated with rapid DT. SDTs were used to evaluate the effect of several pharmacological agents, often showing concordance between their effects on GA and tolerated nutrient volume. This correlation was not found mainly for agents with central actions.

DISCUSSION

An SDT is a potential diagnostic biomarker in FD, reflecting GA. Additional studies are required to confirm its role as a predictive biomarker for treatment outcome in FD.

Obesity Primer for the Practicing Gastroenterologist

With worsening of the obesity pandemic, gastroenterologists will see more patients with this chronic disease. Given the association between obesity and several gastrointestinal conditions and the interplay between obesity pathophysiology and gut hormones, gastroenterologists can play an important role in the management of this disease. Furthermore, because more patients undergo bariatric surgery, an understanding of postsurgical anatomy and medical and endoscopic management of bariatric surgical complications is essential. This article provides clinical tools for the assessment and management of obesity for the general gastroenterologist. Tables containing high-yield practical information are also provided for quick reference.

Old Paradoxes and New Opportunities for Appetite Control in Obesity

Human obesity is accompanied by alterations in the blood concentrations of multiple circulating appetite regulators. Paradoxically, most of the appetite-inhibitory hormones are elevated in nonsyndromic obesity, while most of the appetite stimulatory hormones are reduced, perhaps reflecting vain attempts of regulation by inefficient feedback circuitries. In this context, it is important to understand which appetite regulators exhibit a convergent rather than paradoxical behavior and hence are likely to contribute to the maintenance of the obese state. Pharmacological interventions in obesity should preferentially consist of the supplementation of deficient appetite inhibitors or the neutralization of excessive appetite stimulators. Here, we critically analyze the current literature on appetite-regulatory peptide hormones. We propose a short-list of appetite modulators that may constitute the best candidates for therapeutic interventions.

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.

Gastric Sensory and Motor Functions and Energy Intake in Health and Obesity-Therapeutic Implications

Sensory and motor functions of the stomach, including gastric emptying and accommodation, have significant effects on energy consumption and appetite. Obesity is characterized by energy imbalance; altered gastric functions, such as rapid gastric emptying and large fasting gastric volume in obesity, may result in increased food intake prior to reaching usual fullness and increased appetite. Thus, many different interventions for obesity, including different diets, anti-obesity medications, bariatric endoscopy, and surgery, alter gastric functions and gastrointestinal motility. In this review, we focus on the role of the gastric and intestinal functions in food intake, pathophysiology of obesity, and obesity management.

Body weight in patients with idiopathic gastroparesis

BACKGROUND

The classic clinical picture of gastroparesis is a symptomatic patient losing weight. In addition, a number of patients with delayed gastric emptying are obese and/or gaining weight. Our aim was to investigate the factors impacting body weight in patients with idiopathic gastroparesis.

METHODS

In patients with idiopathic gastroparesis, detailed history and weight were acquired at enrollment and after 48 weeks. Questionnaires assessed symptoms, food intake, physical activity, and quality of life. Patients underwent laboratory testing, gastric emptying scintigraphy, and water load testing.

RESULTS

Of 138 patients with idiopathic gastroparesis, 10% were underweight (BMI < 18.5), 39% were normal weight (BMI 18.5-25), 20% were overweight with BMI 25 to 30 kg/m² , and 29% were obese with BMI > 30 kg/m² . Body weight at enrollment was positively associated with oral caloric consumption (P < .001), following a gastroparesis diet (P = .04), nutrition consultation (P = .001), upper abdominal pain (P = .01); and negatively associated with energy expenditure (P = .05), alcohol use (P = .003) and severity of bloating (P < .001). When followed over 48 weeks, 53% patients stayed stable (within 5% of baseline weight), 30% gained, and 17% lost weight. Weight gain over 48 weeks was positively associated with oral caloric consumption (P = .003) and constipation severity (P = .005) at enrollment, and negatively associated with lower abdominal pain severity (P = .007) at enrollment, and associated with improvement in inability to finish meal score (P < .001) at 48 weeks.

CONCLUSIONS

In this series of patients with idiopathic gastroparesis, 10% were underweight whereas 29% were obese. Over 48 weeks, 30% of patients increased their body weight ≥ 5%. Diet, activity, and symptoms are important factors associated with body weight in patients with idiopathic gastroparesis.

Evaluation of endoscopic ultrasound-guided gastric botulinum toxin injections in the treatment of obesity

Background

Obesity is rapidly emerging as one of the greatest challenges of human health. Many randomized trials and open-label human studies described conflicting results of gastric intra-muscular injections of botulinum toxin type A (BTA). Endoscopic ultrasound (EUS) guidance can assure BTA injection into the subserosal layer and muscularis propria of the gastric wall which may optimize the efficacy of injection. The aim of the study is to assess the efficacy and safety of EUS-guided gastric BTA injections in weight reduction for obese subjects.

Results

The present study included 25 patients (2 males and 23 females with mean age 35.84 ± 7.776). For nutrient drink tests, median maximum tolerated volumes (MTVs) decreased from 720 cc (range 480–1680) as a baseline value 2 weeks before BTA injection to 360 cc (range 140–820) at 16 weeks after injection. Mean body weight reduction was 11.92 kg (10.8%) after 16 weeks of BTA injection. Mean body weight continued to decrease during the study period from a baseline value of 110 to 98 kg with significant reduction of mean BMI from baseline value of 41.2 to 36.7 at 16 weeks after BTA injection (p < 0.001). The study was completed without major adverse events.

Conclusion

EUS-guided BTA injection into the antral subserosa and muscularis propria could be an effective technique for weight reduction, or as a bridge for surgery, which can be done safely with minimal complications.

Trial registration

NCT03901040

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.

Anhedonia and functional dyspepsia in obese patients: Relationship with binge eating behaviour

BACKGROUND

Obese patients (Ob) with a binge eating disorders (BED) behavior pattern have a higher prevalence of postprandial distress syndrome (PDS) compared to Ob without a BED behavior pattern, while an increase of PDS has been described in Ob after sleeve gastrectomy (SG). Hedonic response to a meal is dissociable from satiation in healthy subjects. Anhedonia is the lowered ability to experience pleasure. There are no studies investigating the presence of anhedonia in Ob with and without SG and its relationship to PDS symptoms.

AIM

To assess the relationship among anhedonia, BED and upper gastrointestinal symptoms in two group of morbidly Ob with and without SG.

METHODS

Eighty-one Ob without SG, 45 Ob with SG and 55 healthy controls (HC) were studied. All subjects fulfilled the binge eating scale (BES) to investigate BED, the validated 14 items Snaith-Hamilton pleasure scale (SHAPS) to assess Anhedonia as well as the Beck Depression Inventory-II (BDI II) and State Trait Anxiety Inventory (STAI) questionnaires to screen for depression and anxiety. All patients underwent a standardized questionnaire investigating the intensity-frequency scores (0-6) of upper gastrointestinal symptoms and were diagnosed for the presence of functional dyspepsia (FD) and its subtypes according to ROME IV criteria.

RESULTS

Ob without SG who were positive for BED had a 4.7 higher risk of FD compared to Ob without SG who were negative for BED (OR: 4.7; 95.0%CI 1.23-18.24; P = 0.02). STAI-Y2 scores were significantly higher in Ob without SG positive for BED (42.2 ± 1.5 vs Ob negative for BED: 39.6 ± 1 .0, P = 0.04), while SHAPS scores and BDI II did not differ in the two groups (1.16 ± 1.30 vs 0.89 ± 1.02, P = 0.49). A lower prevalence of BED (BES > 17: 11.4% vs 40.7%, P = 0.001) and BDI-II (6.8 ± 1.2 vs 13.8 ± 1.9, P = 0.005) was reported in Ob with SG than Ob without SG, on the contrary total mean scores of STAI-Y1 and STAI-Y2 were significantly higher in Ob with SG than Ob without SG. Thirty-five percent of Ob with SG fulfilled the diagnosis of FD. SHAPS mean scores and the prevalence of anhedonia did not differ among the two groups (18.2 vs 8.1%, P = 0.2). Fifty-four percent of Ob with SG achieved surgical success excess weight loss > 50%. Excess weight loss was negatively related to SHAPS total mean scores [adjusted B: -7. 099 (95%CI: -13.91 to -0.29), P = 0.04].

CONCLUSION

Ob without SG showed a higher prevalence of PDS, mood disorders and anxiety when positive for BE behavior compared to those negative for BE behavior, whereas no differences were found in SHAPS score. Ob with SG showed a higher prevalence of PDS compared to Ob without SG. Concerning psychological aspect, BED and depression are less frequent in the Ob with SG, while both state and trait anxiety are significantly higher. Moreover, the more an Ob with SG is anhedonic, less surgical success was achieved.

The investigation of diet recovery after distal gastrectomy

This study aims to investigate the adaptation process of the alimentary tract after distal gastrectomy and understand the impact of remnant stomach volume (RSV) on diet recovery.One year after gastrectomy, although patients' oral intake had increased, the RSV was decreased and small bowel motility was enhanced. Patients with a larger RSV showed no additional benefits regarding nutritional outcomes.We prospectively enrolled patients who underwent distal gastrectomy with Billroth II reconstruction to treat gastric cancer at a tertiary hospital cancer center between September 2009 and February 2012. Demographic data, diet questionnaires, computed tomography (CT), and contrast fluoroscopy findings were collected. Patients were divided into 2 groups according to the RSV calculated using CT gastric volume measurements (large vs small). Dietary habits and nutritional status were compared between the groups.Seventy-eight patients were enrolled. Diet volume recovered to 90% of baseline by the 36 postoperative month, and RSV was 70% of baseline at 6 months after surgery and gradually decreased over time. One year after surgery, small bowel transit time was 75% compared to the 1st postoperative month (P < .05); however, transit time in the esophagus and remnant stomach showed no change in any studied interval. Compared to patients with a small RSV, those with a large RSV showed no differences in diet volume, habits, or other nutritional benefits (P > .05).Diet recovery for distal gastrectomy patients was achieved by increased small bowel motility. The size of the remnant stomach showed no positive impact on nutritional outcomes.

Six Weeks of Morning Fasting Causes Little Adaptation of Metabolic or Appetite Responses to Feeding in Adults with Obesity

OBJECTIVE

The aim of this study was to determine the effects of sustained morning fasting or breakfast consumption on metabolism, energy intake, and appetite in healthy adults with obesity.

METHODS

An independent-measures randomized controlled trial with baseline and follow-up laboratory assessment days separated by a 6-week intervention of either morning fasting (0 kcal until 12:00 pm) or daily breakfast (> 700 kcal by 11:00 am) was performed. Measures included metabolic outcomes (glucose, insulin, nonesterified fatty acids), hormones regulating appetite (total/acylated ghrelin, peptide YY, leptin), and energy expenditure (diet-induced thermogenesis) parameters throughout a laboratory test day and ad libitum intake following a fixed breakfast.

RESULTS

Allocation to fasting versus breakfast resulted in minimal adaptation as reflected by the metabolic outcomes or the majority of appetite regulatory outcomes for either area under curve or time-course-based measures (P > 0.05). Ad libitum lunch intake was not different (P = 0.13), nor was diet-induced thermogenesis or a composite appetite score (both P > 0.10). However, there was a reduced total area under the curve for peptide YY (P = 0.05) and increased postprandial hunger ratings (P = 0.05) in the breakfast group.

CONCLUSIONS

There was little evidence of metabolic adaptation to acute feeding or negative consequences from sustained morning fasting. This indicates that previously observed differences between breakfast consumers and skippers may be acute effects of feeding or may have resulted from other lifestyle factors.

Food Intake and Eating Behavior After Bariatric Surgery

Obesity is an escalating global chronic disease. Bariatric surgery is a very efficacious treatment for obesity and its comorbidities. Alterations to gastrointestinal anatomy during bariatric surgery result in neurological and physiological changes affecting hypothalamic signaling, gut hormones, bile acids, and gut microbiota, which coalesce to exert a profound influence on eating behavior. A thorough understanding of the mechanisms underlying eating behavior is essential in the management of patients after bariatric surgery. Studies investigating candidate mechanisms have expanded dramatically in the last decade. Herein we review the proposed mechanisms governing changes in eating behavior, food intake, and body weight after bariatric surgery. Additive or synergistic effects of both conditioned and unconditioned factors likely account for the complete picture of changes in eating behavior. Considered application of strategies designed to support the underlying principles governing changes in eating behavior holds promise as a means of optimizing responses to surgery and long-term outcomes.

The effect of breakfast with different macronutrient composition on PYY, ghrelin, and ad libitum intake 4 h after breakfast in Indonesian obese women

OBJECTIVES

Gut hormones, such as PYY and ghrelin, are associated with appetite control and obesity. Protein is thought to be the most satiating nutrient and could affect the production of several gut hormones. The purpose of the current study was to find the effect of breakfast with different protein composition on PYY, ghrelin, and ad libitum intake 4 h after breakfast.

RESULTS

This clinical trial involves 22 obese women participants. Subjects were given three types of breakfast: low protein consumption (12.4% protein), medium protein (23.5% protein), and high protein (40.6% protein). PYY and ghrelin levels were measured at 0, 15, 60, 120, and 180 min after breakfast. Ad libitum meal was given 4 h after breakfast and measured after. This study found that there is no significant difference in PYY and ghrelin level at each measurement time between different type of breakfast. This study also found no significant difference of ad libitum energy intake between different type of breakfast. Trial registration ClinicalTrials.gov NCT03697486, 3 December 2018. Retrospectively registered.

Investigation of the long-term sustainability of changes in appetite after weight loss

Background/Objective

Diet-induced weight loss (WL) leads to a compensatory increase in appetite and changes in the plasma concentration of appetite-regulating hormones are likely to play a role. Whether these changes are transient or sustained remains unclear. This study aimed to assess if changes in subjective and objective appetite markers observed with WL are sustained after 1 year (1Y).

Subjects/Methods

In total 100 (45 males) individuals with obesity (BMI: 37 ± 4 kg/m², age: 43 ± 10 years) underwent 8 weeks (wks) of a very-low energy diet (VLED), followed by 4 wks refeeding, and a 1Y maintenance program. Fasting/postprandial subjective ratings of hunger, fullness, desire to eat, and prospective food consumption (PFC) were assessed, and plasma concentration of active ghrelin (AG), total peptide YY (PYY), active glucagon-like peptide 1, cholecystokinin (CCK), and insulin measured, at baseline, week 13 (Wk13) and 1Y.

Results

At Wk13, 16% WL (−18 ± 1 kg, P < 0.001) was associated with a significant increase in fasting and postprandial hunger ratings (P < 0.01 and P < 0.05, respectively), and postprandial fullness (P < 0.01) combined with a reduction in PFC (P < 0.001). These were accompanied by a significant rise in basal and postprandial AG concentrations (P < 0.001, for both), a reduction in postprandial CCK (P < 0.01) and in basal and postprandial insulin (P < 0.001). At 1Y follow-up, with sustained WL (15%; −16 ± 1 kg, P < 0.001), fasting hunger and postprandial fullness ratings remained increased (P < 0.05 for both), and postprandial PFC reduced (P < 0.001). Basal and postprandial AG remained elevated and insulin reduced (P < 0.001, for all), while postprandial CCK was increased (P < 0.01) and PYY decreased (P < 0.001).

Conclusion

With a 15% sustained WL at 1Y, the drive to eat in the fasting state is increased, but this may be balanced out by raised postprandial feelings of fullness. To assist with WL maintenance, new strategies are required to manage increased hunger and drive to eat.

The Influence of the Orbera Intragastric Balloon Filling Volumes on Weight Loss, Tolerability, and Adverse Events: a Systematic Review and Meta-Analysis

BACKGROUND

The Orbera intragastric balloon (IGB) has been approved by the US Food and Drug Administration for use in patients with a body mass index (BMI) between 30 and 40 kg/m² and is in wide use worldwide as a primary and bridge obesity management tool. The balloon filling volume (BFV) ranges between 400 and 700 mL of saline. Our objective was to determine whether there is an association between BFV and clinically relevant endpoints, namely weight loss outcomes, balloon tolerability, and adverse events.

METHODS

A systematic review of studies investigating the use of the Orbera IGB system for obesity treatment was performed. Data was examined using random effects modelling and meta-regression analyses.

RESULTS

Forty-four studies (n = 5549 patients) reported BFV and % total body weight loss (TBWL) at 6 months. Pooled %TBWL at 6 months was 13.2% [95% CI 12.3-14.0]. A funnel plot demonstrated a low risk of publication bias. Meta-regression showed no statistically significant association between filling volume and %TBWL at 6 months (p = 0.268). Higher BFV was associated with lower rates of esophagitis (slope = -0.008, p < 0.001) and prosthesis migration (slope = -0.015, p < 0.001). There was no association between BFV and early removal (p = 0.1), gastroesophageal reflux symptom (p = 0.64), or ulcer rates (p = 0.09).

CONCLUSIONS

No association was observed between Orbera IGB filling volume and weight loss outcomes. Higher volumes appear to be associated with lower migration and esophagitis rates; thus, a balloon filling volume of 600-650 mL is recommended.

Contractile Protein Expression and Phosphorylation and Contractility of Gastric Smooth Muscles from Obese Patients and Patients with Obesity and Diabetes

Ingested food is received, mixed, and ground into chyme by distinct gastric motility patterns. Diabetes impairs gastric muscle function, but the mechanisms underlying diabetes-induced gastric muscle dysfunction are unknown. Here, we compared the expression and phosphorylation of Ca²⁺ sensitization and contractile proteins in human gastric muscles from obese nondiabetic and diabetic patients. We also compared the spontaneous phasic contractions and the contractile responses evoked by electrical field stimulation of cholinergic motor neurons. Fundus and antrum muscles were obtained from sleeve gastrectomies and were used in in vitro myobath contractile studies and for capillary electrophoresis and immunodetection of γ-actin, CPI-17, pT38-CPI-17, MYPT1, pT853-MYPT1, pT696-MYPT1, myosin light chain (MYL9), pS19-MYL9, myosin light chain kinase (MYLK), protein phosphatase-1δ (PP1δ), and Rho-associated kinase (ROCK2). In diabetic fundus muscles, MYLK, ROCK2, and PP1δ expression was unchanged; MYPT1 and CPI-17 expression was decreased; and the pT853/MYPT1 and pT38/CPI-17 ratios, but not the pT696/MYPT1 ratio, were increased. Although MYL9 expression was increased, the pS19/MYL9 ratio was unchanged in diabetic fundus muscles. In diabetic antrum muscles, MYLK and MYL9 expression was unchanged, but ROCK2, CPI-17, and PP1δ expression was decreased. The pT38/CPI-17 ratio was unchanged, while the pS19/MYL9, pT853/MYPT1, and pT696/MYPT1 ratios were decreased, consistent with the reduced ROCK2 expression. The frequencies of spontaneous phasic contractions from nondiabetic and diabetic gastric fundus and antrum muscles did not significantly differ from each other, regardless of age, sex, or diabetic status. The fold increases in the contractions of diabetic fundus and antrum muscles in response to increased frequencies of electrical field stimulation were significantly lower compared to nondiabetic fundus and antrum muscles. The altered contractile responses and the protein expression and phosphorylation in gastric muscles of obese patients with diabetes illustrate the importance of understanding how smooth muscle Ca²⁺ sensitization mechanisms contribute to gastric motility.

Influence of the Resected Gastric Volume on the Weight Loss After Laparoscopic Sleeve Gastrectomy

BACKGROUND

The relation between the resected gastric volume and the weight loss after laparoscopic sleeve gastrectomy appears conflicting in the literature. Both the residual and the resected volumes represent the total gastric volume, and if the weight loss is related to one of the two volumes, it should be related to the other. While some reports indicate that the weight loss is related to the resected gastric volume, others state that the weight loss is not related to the residual volume. The aim is to investigate the influence of the resected gastric volume on the weight loss after surgery.

METHODS

The study included 287 consecutive patients. Gastrectomy was performed encroaching over a 38-Fr calibrating tube all the way to the angle of His. Filling volume of the resected stomach, with tap water, was measured. Patients were analyzed into group 1 with BMI ≤50 kg/m(2) and group 2 >50 kg/m(2).

RESULTS

Females represented 74 % of cases. Mean age was 32.9 ± 9.5 years; preoperative BMI = 48.7 ± 7.9 kg/m(2). The mean resected gastric volume was 1525 ± 408 ml, and it was significantly lower in females compared to that in males (1443 ± 311 vs 1824 ± 502 ml, p < 0.001). Data were analyzed in two groups: group 1 with BMI ≤5050 kg/m(2) and group 2 >50 kg/m(2). Both groups were similar in preoperative BMI (p = 0.399) and excess weight percent (EW%) (p = 0.33). Group 2 had a resected gastric volume (1663 ± 424.7 ml) greater than that of group 1 (1440 ± 347 ml; p < 0.001). The percentage of excess weight loss (EWL%) was 57.9 ± 14.5 % at 6 months (62.7 ± 13.5 % vs 48.34 ± 11.29 %, p < 0.001), 77 ± 19 % at 12 months (84 ± 19.6 % vs 68 ± 14.2 %, p = 0.001), 76.6 ± 7.4 % at 18 months (79.7 ± 4.8 vs 74.7 ± 8.2 %, p = 0.5), and 75.8 ± 11.5 % at 24 months (81.7 ± 11.17 vs 70 ± 11 %, p = 0.8) (group 1 vs group 2, respectively). At 12 months, 86 % patients achieved more than 50 % EWL% (100 % of group 1 vs 60 % of group 2). Preoperative BMI correlated with resected gastric volume (r = 0.239, p = 0.004). In multiple regression, the initial BMI was a predictor of EWL% at 6 and 12 months (r partial = -0.65, p < 0.0001) while the resected gastric volume was not.

CONCLUSIONS

The resected gastric volume is related to the total gastric volume when the technique is standardized and the residual volume is calibrated using a consistent technique. It is not in itself a predictor of weight loss, but it is related to the initial BMI which predicts the weight loss.

Gastrointestinal Complications of Obesity

Obesity usually is associated with morbidity related to diabetes mellitus and cardiovascular diseases. However, there are many gastrointestinal and hepatic diseases for which obesity is the direct cause (eg, nonalcoholic fatty liver disease) or is a significant risk factor, such as reflux esophagitis and gallstones. When obesity is a risk factor, it may interact with other mechanisms and result in earlier presentation or complicated diseases. There are increased odds ratios or relative risks of several gastrointestinal complications of obesity: gastroesophageal reflux disease, erosive esophagitis, Barrett's esophagus, esophageal adenocarcinoma, erosive gastritis, gastric cancer, diarrhea, colonic diverticular disease, polyps, cancer, liver disease including nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, gallstones, acute pancreatitis, and pancreatic cancer. Gastroenterologists are uniquely poised to participate in the multidisciplinary management of obesity as physicians caring for people with obesity-related diseases, in addition to their expertise in nutrition and endoscopic interventions.

Relationship of body weight with gastrointestinal motor and sensory function: studies in anorexia nervosa and obesity

Background

Whether gastrointestinal motor and sensory function is primary cause or secondary effect of abnormal body weight is uncertain. Moreover, studies relating continuous postprandial sensations of satiation to measurable pathology are scarce. This work assessed postprandial gastrointestinal function and concurrent sensations of satiation across a wide range of body weight and after weight change.

Methods

Patients with anorexia nervosa (AN) and obesity (OB) were investigated in reference to normal weight controls (HC). AN were additionally investigated longitudinally. Gastric emptying, antral contractions and oro-cecal transit after ingestion of a solid meal were investigated by MRI and ¹³C-lactose-ureide breath test. The dependency of self-reported sensations of satiation on the varying degree of stomach filling during gastric emptying was compared between groups.

Results

24 AN (BMI 14.4 (11.9–16.0) kg/m²), 16 OB (34.9 (29.6–41.5) kg/m²) and 20 HC (21.9 (18.9–24.9) kg/m²) were studied. Gastric half-emptying time (t₅₀) was slower in AN than HC (p = 0.016) and OB (p = 0.007), and a negative association between t₅₀ and BMI was observed between BMI 12 and 25 kg/m² (p = 0.007). Antral contractions and oro-cecal transit were not different. For any given gastric content volume, self-reported postprandial fullness was greater in AN than in HC or OB (p < 0.001). After weight rehabilitation, t₅₀ in AN tended to become shorter (p = 0.09) and postprandial fullness was less marked (p < 0.01).

Conclusions

A relationship between body weight and gastric emptying as well as self-reported feelings of satiation is present. AN have slower gastric emptying and heightened visceral perception compared to HC and OB. Longitudinal follow-up after weight rehabilitation in AN suggests these abnormalities are not a primary feature, but secondary to other factors that determine abnormal body weight.

Trial registration

Registered July 20, 2009 at ClinicalTrials.gov (NCT00946816).

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0560-y) contains supplementary material, which is available to authorized users.

Upper gastrointestinal sensitivity to meal-related signals in adult humans - relevance to appetite regulation and gut symptoms in health, obesity and functional dyspepsia

Both the stomach and small intestine play important roles in sensing the arrival of a meal, and its physico-chemical characteristics, in the gastrointestinal lumen. The presence of a meal in the stomach provides a distension stimulus, and, as the meal empties into the small intestine, nutrients interact with small intestinal receptors, initiating the release of gut hormones, associated with feedback regulation of gastrointestinal functions, including gut motility, and signaling to the central nervous system, modulating eating behaviours, including energy intake. Lipid appears to have particularly potent effects, also in close interaction with, and modulating the effects of, gastric distension, and involving the action of gut hormones, particularly cholecystokinin (CCK). These findings have not only provided important, and novel, insights into how gastrointestinal signals interact to modulate subjective appetite perceptions, including fullness, but also laid the foundation for an increasing appreciation of the role of altered gastrointestinal sensitivities, e.g. as a consequence of excess dietary intake in obesity, or underlying the induction of gastrointestinal symptoms in functional dyspepsia (a condition characterized by symptoms, including bloating, nausea and early fullness, amongst others, after meals, particularly those high in fat, in the absence of any structural or functional abnormalities in the gastrointestinal tract). This paper will review the effects of dietary nutrients, particularly lipid, on gastrointestinal function, and associated effects on appetite perceptions and energy intake, effects of interactions of gastrointestinal stimuli, as well as the role of altered gastrointestinal sensitivities (exaggerated, or reduced) in eating-related disorders, particularly obesity and functional dyspepsia.

The causal role of breakfast in energy balance and health: a randomized controlled trial in obese adults

BACKGROUND

The causal nature of associations between breakfast and health remain unclear in obese individuals.

OBJECTIVE

We sought to conduct a randomized controlled trial to examine causal links between breakfast habits and components of energy balance in free-living obese humans.

DESIGN

The Bath Breakfast Project is a randomized controlled trial with repeated measures at baseline and follow-up among a cohort in South West England aged 21-60 y with dual-energy X-ray absorptiometry-derived fat mass indexes of ≥13 kg/m(2) for women (n = 15) and ≥9 kg/m(2) for men (n = 8). Components of energy balance (resting metabolic rate, physical activity thermogenesis, diet-induced thermogenesis, and energy intake) were measured under free-living conditions with random allocation to daily breakfast (≥700 kcal before 1100) or extended fasting (0 kcal until 1200) for 6 wk, with baseline and follow-up measures of health markers (e.g., hematology/adipose biopsies).

RESULTS

Breakfast resulted in greater physical activity thermogenesis during the morning than when fasting during that period (difference: 188 kcal/d; 95% CI: 40, 335) but without any consistent effect on 24-h physical activity thermogenesis (difference: 272 kcal/d; 95% CI: -254, 798). Energy intake was not significantly greater with breakfast than fasting (difference: 338 kcal/d; 95% CI: -313, 988). Body mass increased across both groups over time but with no treatment effects on body composition or any change in resting metabolic rate (stable within 8 kcal/d). Metabolic/cardiovascular health also did not respond to treatments, except for a reduced insulinemic response to an oral-glucose-tolerance test over time with daily breakfast relative to an increase with daily fasting (P = 0.05).

CONCLUSIONS

In obese adults, daily breakfast leads to greater physical activity during the morning, whereas morning fasting results in partial dietary compensation (i.e., greater energy intake) later in the day. There were no differences between groups in weight change and most health outcomes, but insulin sensitivity increased with breakfast relative to fasting. This trial was registered at www.isrctn.org as ISRCTN31521726.

The stomach in health and disease

The stomach is traditionally regarded as a hollow muscular sac that initiates the second phase of digestion. Yet this simple view ignores the fact that it is the most sophisticated endocrine organ with unique physiology, biochemistry, immunology and microbiology. All ingested materials, including our nutrition, have to negotiate this organ first, and as such, the stomach is arguably the most important segment within the GI tract. The unique biological function of gastric acid secretion not only initiates the digestive process but also acts as a first line of defence against food-borne microbes. Normal gastric physiology and morphology may be disrupted by Helicobacter pylori infection, the most common chronic bacterial infection in the world and the aetiological agent for most peptic ulcers and gastric cancer. In this state-of-the-art review, the most relevant new aspects of the stomach in health and disease are addressed. Topics include gastric physiology and the role of gastric dysmotility in dyspepsia and gastroparesis; the stomach in appetite control and obesity; there is an update on the immunology of the stomach and the emerging field of the gastric microbiome. H. pylori-induced gastritis and its associated diseases including peptic ulcers and gastric cancer are addressed together with advances in diagnosis. The conclusions provide a future approach to gastric diseases underpinned by the concept that a healthy stomach is the gateway to a healthy and balanced host. This philosophy should reinforce any public health efforts designed to eradicate major gastric diseases, including stomach cancer.

Caloric intake capacity as measured by a standard nutrient drink test helps to predict weight loss after bariatric surgery

BACKGROUND

Instruments that enable to select individuals that will benefit most from bariatric surgery (BS) are necessary to increase its cost-efficiency. Our goal was to assess if intake capacity, measured with a standardized test, predicts response to BS.

METHODS

Patients with criteria for BS were randomly allocated to laparoscopic gastric bypass (LRYGB) or sleeve gastrectomy (LSG). We measured caloric intake capacity before and 1 year after surgery using a standardized nutrient drink test. We evaluated if pre-surgery satiation could predict satiation and weight loss (%) 1 year after surgery using multiple regression modeling. Descriptive statistics are given as mean ± SD.

RESULTS

Fourteen women (48 ± 9 years old, BMI 41 ± 3 kg/m(2)) were evaluated before and 11 ± 2.6 months after surgery (seven LRYGB, seven LSG). Caloric intake capacity diminished after surgery (-950 ± 85 kcal on average [70 ± 8 % decrease over basal intake capacity]; p=0.002) and similarly in both LRYGB (72 ± 7 % decrease) and LSG groups (68 ± 8 % decrease); p=0.5. There was a significant weight reduction after surgery (-32 ± 10 kg [30 ± 8 % of total basal weight]) with a mean post-surgery BMI of 29 ± 2 kg/m(2). The best predictive model of weight loss (%) after surgery (R (2)=89 %, p=0.0009) included: BMI (p=0.0004), surgery type (p=0.01) and pre-surgery intake capacity (p=0.006). Weight loss was higher in heavier patients and those undergoing LRYGB. Patients with higher intake capacity had a poorer outcome independently of basal BMI and surgery type.

CONCLUSIONS

Caloric intake capacity, as measured by a standard nutrient drink test, helps to predict weight loss after bariatric surgery. This test might be useful in algorithms of obesity treatment decision.

Sleeve gastrectomy effects on hunger, satiation, and gastrointestinal hormone and motility responses after a liquid meal test

BACKGROUND

The relation between hunger, satiation, and integrated gastrointestinal motility and hormonal responses in morbidly obese patients after sleeve gastrectomy has not been determined.

OBJECTIVE

The objective was to assess the effects of sleeve gastrectomy on hunger, satiation, gastric and gallbladder motility, and gastrointestinal hormone response after a liquid meal test.

DESIGN

Three groups were studied: morbidly obese patients (n = 16), morbidly obese patients who had had sleeve gastrectomy (n = 8), and nonobese patients (n = 16). The participants fasted for 10 h and then consumed a 200-mL liquid meal (400 kcal + 1.5 g paracetamol). Fasting and postprandial hunger, satiation, hormone concentrations, and gastric and gallbladder emptying were measured several times over 4 h.

RESULTS

No differences were observed in hunger and satiation curves between morbidly obese and nonobese groups; however, sleeve gastrectomy patients were less hungry and more satiated than the other groups. Antrum area during fasting in morbidly obese patients was statistically significant larger than in the nonobese and sleeve gastrectomy groups. Gastric emptying was accelerated in the sleeve gastrectomy group compared with the other 2 groups (which had very similar results). Gallbladder emptying was similar in the 3 groups. Sleeve gastrectomy patients showed the lowest ghrelin concentrations and higher early postprandial cholecystokinin and glucagon-like peptide 1 peaks than did the other participants. This group also showed an improved insulin resistance pattern compared with morbidly obese patients.

CONCLUSIONS

Sleeve gastrectomy seems to be associated with profound changes in gastrointestinal physiology that contribute to reducing hunger and increasing sensations of satiation. These changes include accelerated gastric emptying, enhanced postprandial cholecystokinin and glucagon-like peptide 1 concentrations, and reduced ghrelin release, which together may help patients lose weight and improve their glucose metabolism after surgery. This trial was registered at clinicaltrials.gov as NCT02414893.

Effect of extended morning fasting upon ad libitum lunch intake and associated metabolic and hormonal responses in obese adults

Background/Objectives:

Breakfast omission is positively associated with obesity and increased risk of disease. However, little is known about the acute effects of extended morning fasting upon subsequent energy intake and associated metabolic/regulatory factors in obese adults.

Subjects/Methods:

In a randomised cross-over design, 24 obese men (n=8) and women (n=16) extended their overnight fast by omitting breakfast consumption or ingesting a typical carbohydrate-rich breakfast of 2183±393 kJ (521±94 kcal), before an ad libitum pasta lunch 3 h later. Blood samples were obtained throughout the day until 3 h post lunch and analysed for hormones implicated in appetite regulation, along with metabolic outcomes and subjective appetite measures.

Results:

Lunch intake was unaffected by extended morning fasting (difference=218 kJ, 95% confidence interval −54 kJ, 490 kJ; P=0.1) resulting in lower total intake in the fasting trial (difference=−1964 kJ, 95% confidence interval −1645 kJ, −2281 kJ; P<0.01). Systemic concentrations of peptide tyrosine–tyrosine and leptin were lower during the afternoon following morning fasting (P⩽0.06). Plasma-acylated ghrelin concentrations were also lower following the ad libitum lunch in the fasting trial (P<0.05) but this effect was not apparent for total ghrelin (P⩾0.1). Serum insulin concentrations were greater throughout the afternoon in the fasting trial (P=0.05), with plasma glucose also greater 1 h after lunch (P<0.01). Extended morning fasting did not result in greater appetite ratings after lunch, with some tendency for lower appetite 3 h post lunch (P=0.09).

Conclusions:

We demonstrate for the first time that, in obese adults, extended morning fasting does not cause compensatory intake during an ad libitum lunch nor does it increase appetite during the afternoon. Morning fasting reduced satiety hormone responses to a subsequent lunch meal but counterintuitively also reduced concentrations of the appetite-stimulating hormone-acylated ghrelin during the afternoon relative to lunch consumed after breakfast.

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 morbidity in obesity

Obesity is a complex disease that results from increased energy intake and decreased energy expenditure. The gastrointestinal system plays a key role in the pathogenesis of obesity and facilitates caloric imbalance. Changes in gastrointestinal hormones and the inhibition of mechanisms that curtail caloric intake result in weight gain. It is not clear if the gastrointestinal role in obesity is a cause or an effect of this disease. Obesity is often associated with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Obesity is also associated with gastrointestinal disorders, which are more frequent and present earlier than T2DM and CVD. Diseases such as gastroesophageal reflux disease (GERD), cholelithiasis, or nonalcoholic steatohepatitis are directly related to body weight and abdominal adiposity. Our objective is to assess the role of each gastrointestinal organ in obesity and the gastrointestinal morbidity resulting in those organs from the effects of obesity.

Gastric and intestinal satiation in obese and normal weight healthy people

OBJECTIVE

The gastrointestinal tract plays a key role in feelings of satiation. It is known that there is a reciprocal interaction between the stomach and intestine, but it is not known which factors are of gastric origin and which are intestinal. This three-step study therefore sought to provide illumination on satiation parameters with respect to body mass.

METHOD

In the first part, the time needed to reach maximal satiation and total caloric intake was calculated after participants (20 normal weight, 20 obese) imbibed a standardized nutrient drink. In the second part gastric emptying of solids and liquids was evaluated using the (13)C-breath test (participants: 16 normal weight, 9 obese for gastric emptying of solids; 15 normal weight, 14 obese for gastric emptying of liquids). And in the third part, fasting and post-prandial plasma glucagon-like peptide-1 (GLP-1), peptide tyrosine tyrosine (PYY) and ghrelin levels were measured after a standardized nutrient drink (participants: 20 normal weight, 20 obese).

RESULTS

Our results show that, when compared to those of normal weight, obese participants reached maximal satiation sooner (P=0.006), their total intake of calories was higher (P=0.013), and their gastric emptying rates were delayed (P<0.001). Furthermore, their post-prandial increase in plasma GLP-1 and PYY was reduced, (P<0.001 for both), as was their ghrelin suppression (P=0.001).

DISCUSSION

We conclude that, in obese subjects gastric emptying can be impaired with delayed interaction of nutrients with the intestine resulting in decreased GLP-1 and PYY secretion. This could imply that obese participants would require more calories before their maximal satiation is reached and they stop eating.

Bodyweight in patients with idiopathic gastroparesis: roles of symptoms, caloric intake, physical activity, and body metabolism

BACKGROUND

Most gastroparetic patients are underweight probably because of frequently experienced early satiety, nausea, and vomiting. Some gastroparesis (GP) patients, however, are overweight, for reasons that are not well understood. The aim of this study was to evaluate the factors that influence bodyweight such as resting energy and exercise-related expenditure, symptoms of early satiety, nausea and vomiting, and caloric intake in patients with idiopathic GP and in healthy controls.

METHODS

Thirty-nine healthy controls and 29 subjects with idiopathic GP were studied. Resting energy expenditure (indirect calorimetry), body composition (bioelectrical impedance), dietary intake (Block Food Frequency Questionnaire), symptoms (Patient Assessment of Upper GI Symptoms), and physical activity (Paffenbarger exercise survey) were assessed.

KEY RESULTS

Both median caloric intake (1242 vs 1804 kcal; p = 0.005) and caloric expenditure (486 vs 2172 kcal; p < 0.01) were significantly lower in patients with GP as compared to controls although BMI (25.8 ± 5.8 vs 24.3 ± 4.0 kg/m²) and resting energy expenditure (1327 ± 293 vs 1422 ± 243 kcal) were similar. On the other hand, the 12 GP patients who had gained weight (GW) since diagnosis had lower symptom severity (12.9 ± 4.4 vs 19.3 ± 6.3; p < 0.05), consumed more calories (1342 vs 1134 kcal; p = 0.08) and expended less calories for activity per week (406 vs 644 median kcal; p = 0.45) compared to the 17 GP patients who had lost weight or remained weight neutral (LW).

CONCLUSIONS & INFERENCES

Patients with GP, although in energy balance, consumed and expended less calories than healthy controls. A subgroup of patients with GP who were less symptomatic, gained weight because of increased caloric intake and reduced energy expenditure.

Association of melanocortin 4 receptor gene variation with satiation and gastric emptying in overweight and obese adults

Melanocortin 4 receptor (MC4R) has a major role in energy homeostasis. The rs17782313 polymorphism, mapped 188 kb downstream from MC4R, has been associated with satiety, higher body mass index (BMI) and total calorie intake in adults. To assess the association of rs17782313 with gastric functions, satiation, or satiety, we studied 178 predominantly Caucasian overweight and obese people: 120 females, 58 males; mean BMI 33.4 ± 5.3 kg/m(2) (SD); age 37.7 ± 11.2 years. Quantitative traits assessed were gastric emptying (GE) of solids and liquids; fasting and postprandial gastric volume; satiation by maximum tolerated volume and 4 symptoms by 100-mm visual analog scales (VAS); and satiety by ad libitum buffet meal. Associations of genotype and quantitative traits were assessed by analysis of covariance (using gender and BMI as covariates), based on a dominant [TC (n = 72) - CC (n = 12) vs. TT (n = 94)] genetic model. rs17782313(C) was associated with postprandial satiation symptoms (median Δ total VAS 26.5 mm, p = 0.036), reduced proportion of solid GE at 2 h (median Δ 6.7 %, p = 0.008) and 4 h (median Δ 3.2 %, p = 0.006), and longer t ½ (median Δ 6 min, p = 0.034). Associations of rs17782313 with obesity may be explained by reduced satiation and GE. The role of MC4R mechanisms in satiation and gastric function deserves further study.

Effect of nortriptyline on symptoms of idiopathic gastroparesis: the NORIG randomized clinical trial

IMPORTANCE

Gastroparesis remains a challenging syndrome to manage, with few effective treatments and a lack of rigorously controlled trials. Tricyclic antidepressants are often used to treat refractory symptoms of nausea, vomiting, and abdominal pain. Evidence from well-designed studies for this use is lacking.

OBJECTIVE

To determine whether treatment with nortriptyline results in symptomatic improvement in patients with idiopathic gastroparesis.

DESIGN, SETTING, AND PARTICIPANTS

The NORIG (Nortriptyline for Idiopathic Gastroparesis) trial, a 15-week multicenter, parallel-group, placebo-controlled, double-masked, randomized clinical trial from the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium (GpCRC), comparing nortriptyline with placebo for symptomatic relief in idiopathic gastroparesis. One hundred thirty patients with idiopathic gastroparesis were enrolled between March 2009 and June 2012 at 7 US academic medical centers. Patient follow-up was completed in October 2012. Inclusion criteria included delayed gastric emptying and moderate to severe symptom scores using the Gastroparesis Cardinal Symptom Index (GCSI). INTERVENTIONS Nortriptyline vs placebo. Study drug dose was increased at 3-week intervals (10, 25, 50, 75 mg) up to 75 mg at 12 weeks.

MAIN OUTCOMES AND MEASURES

The primary outcome measure of symptomatic improvement was a decrease from the patient's baseline GCSI score of at least 50% on 2 consecutive 3-week GCSI assessments during 15 weeks of treatment.

RESULTS

The primary symptomatic improvement outcome did not differ between 65 patients randomized to nortriptyline vs 65 patients randomized to placebo: 15 (23% [95% CI, 14%-35%]) in the nortriptyline group vs 14 (21% [95% CI, 12%-34%]) in the placebo group (P = .86). Treatment was stopped more often in the nortriptyline group (19 [29% {95% CI, 19%-42%}]) than in the placebo group (6 [9%] {95% CI, 3%-19%}]) (P = .007), but numbers of adverse events were not different (27 [95% CI, 18-39] vs 28 [95% CI, 19-40]) (P = .89).

CONCLUSIONS AND RELEVANCE

Among patients with idiopathic gastroparesis, the use of nortriptyline compared with placebo for 15 weeks did not result in improvement in overall symptoms. These findings do not support the use of nortriptyline for idiopathic gastroparesis.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00765895.

Prevalence of functional gastrointestinal disorders according to Rome III criteria in Italian morbidly obese patients

The relationship between GI symptoms and obesity has yet to be completely clarified.

AIM

To determine in a morbidly obese southern Italy adult population the prevalence of Functional Gastrointestinal Disorders (FGID) and its association with the presence of a Binge Eating (BE) behavior pattern.

METHODS

Consecutive obese patients eligible for bariatric surgery and 100 Healthy Controls (HC) were recruited. All participants were questioned and scored for the presence of FGID according to Rome III criteria and for the presence or the frequency-intensity of a number of upper and lower GI symptoms. BE behavior pattern was assessed.

RESULTS

One-hundred obese patients met the inclusion criteria. The prevalence of FGID was similar between obese patients and HC. There was a significant association between obese patients with BE behavior and postprandial distress syndrome (P = 0.04). Moreover, a significantly higher frequency-intensity score for epigastric fullness (1.23 ± 0.45 versus 0.35 ± 0.13, P = 0.01) was found in obese patients with BE behavior compared to obese patients without.

CONCLUSIONS

Obese patients with a BE behavior pattern showed a significantly higher prevalence of postprandial distress syndrome. A greater knowledge of the GI symptoms associated with obesity along with the pathophysiological mechanisms underlying will be important in the clinical management of these patients.