Potential Hormone Mechanisms of Bariatric Surgery

Stronger control of eating 3 months after sleeve gastrectomy predicts successful weight loss outcomes at one year

Background

Weight loss response to sleeve gastrectomy (SG) is variable and predicting the effectiveness of surgery is challenging and elusive. The aim of our study was to assess and quantify the association between eating control and weight loss outcomes and identify the control of eating (CoE) attributes during the early postoperative period that might predict good vs. poor response to SG at one year.

Methods

A prospective longitudinal cohort study using the Control of Eating Questionnaire (CoEQ) was designed as a series before and at 3-, 6-, and 12-months post-SG. Primary outcomes were changes in CoE attributes and percent of total weight loss (%TWL) 12-months post-surgery. Subjects were categorized based on %TWL as good (GR, ≥25 %) or poor responders (PR, <25 %). A receiver operating characteristic and logistic regression analyses were performed.

Results

We included 41 participants (80.5% females, 51.2% Hispanic, mean age 41.7±10.6, median baseline body mass index (BMI) 43.6 kg/m2 [range 35.2-66.3]) who completed the CoEQ at all four timepoints. The "Difficulty to control eating" score at 3 months revealed the highest area under the curve (AUC) (AUC 0.711; 95%CI 0.524-0.898; p=0.032). In a trade-off between a high Youden index and high sensitivity, the "Difficulty to control eating" score of 7 at 3 months was identified as the optimal cut-off for distinguishing between GRs and PRs. Score ≤7 at 3 months was strongly independently associated with a successful weight loss target of 25%TWL at one-year post-SG (Relative Risk 4.43; 95%CI 1.06-18.54; p=0.042).

Conclusion

"Difficulty to control eating" score at 3 months post-SG is an independent early predictor of optimal response (achieving a successful TWL target of ≥25 % at one-year post-SG). Our results support the utility of this easy-to-administer validated tool for predicting the effectiveness of SG and may assist in identifying individuals with suboptimal response early and helping them with interventions to attain optimal weight loss targets.

Evaluating Fibroblast Growth Factor 21 (FGF21) Levels Post-Gastric Sleeve Surgery in Obese Patients

Background and objectives Obesity is a major global health concern linked with increased risk of chronic diseases. This study aimed to assess the levels of fibroblast growth factor 21 (FGF21) in subjects with obesity after gastric sleeve surgery and explore its correlation with lipid and glycemic parameters. Methods This retrospective cohort study included 28 obese male subjects aged 25 to 50 years, undergoing gastric sleeve surgery. Plasma levels of FGF21 were measured by enzyme-linked immunosorbent assay (ELISA) before and six to 12 months after surgery. Other parameters including body mass index (BMI), fasting glucose, lipid profile, and insulin were also assessed and homeostatic model assessment (HOMA) was used to estimate insulin resistance. Results There was a significant increase in systemic FGF21 levels after surgery (45.12 vs. 126.16 pg/mL, p = 0.007). There was also a notable reduction in BMI (51.55 vs. 39.14, p < 0.001), insulin levels (20.06 vs. 8.85 mIU/L, p < 0.001), HOMA scores (6.94 to 2.49, p < 0.001), and glucose levels (7.33 vs. 6.08, p = 0.039). Lipid profile analysis post-surgery showed an increase in total cholesterol (4.38 vs. 5.09 mmol/L, p < 0.001) and high-density lipoprotein (HDL) (0.88 vs. 1.52 mmol/L, p < 0.001), with a decrease in triglycerides (1.75 vs. 1.01 mmol/L, p = 0.007). FGF21 positively correlated with growth hormone (GH), p = 0.0015, r = 0.59, and with insulin like growth factor 1 (IGF-1), p = 0.03, r = 0.431. Conclusion FGF21 levels were increased following gastric sleeve surgery in obese male patients and were positively correlated with growth hormone and insulin IGF-1. These findings provide insights into the metabolic alterations following bariatric surgery and highlight the potential role of FGF21 as an important molecule in obesity management and treatment.

Marginal Ulcer Incidence and the Population of Gastrin Producing G cells Retained in the Gastric Pouch after Roux-en-Y Gastric Bypass: Is There a Relationship?

INTRODUCTION

Marginal ulcers are the most prevalent endoscopic abnormality after RYGB. The etiology is still poorly understood; however, an increase in acid secretion has been strongly implicated as a causal agent. Although gastrin is the greatest stimulant of acid secretion, to date, the presence of gastrin producing G cells retained in the gastric pouch, related to the occurrence of marginal ulcers, has not been evaluated.

OBJECTIVE

Evaluate the density of G cells and parietal cells in the gastric pouch of RYGB patients with a diagnosis of marginal ulcer on the post-op EGD.

METHOD

We retrospectively evaluated 1104 gastric bypasses performed between 2010 and 2020. Patients with marginal ulcer who met the inclusion criteria and controls were selected from this same population. Endoscopic gastric pouch biopsies were evaluated using immunohistochemical study and HE staining to assess G cell and parietal cell density.

RESULTS

In total, 572 (51.8%) of the patients performed endoscopic follow-up after RYGB. The incidence of marginal ulcer was 23/572 (4%), and 3 patients required revision surgery due to a recalcitrant ulcer. The mean time for ulcer identification was 24.3 months (2-62). G cell count per high-power field (× 400) was statistically higher in the ulcer group (p < 0.05). There was no statistical difference in parietal cell density between groups (p 0.251).

CONCLUSION

Patients with a marginal ulcer after gastric bypass present a higher density of gastrin-producing G cells retained in the gastric pouch.

Duodenal enteroendocrine cells and GIP as treatment targets for obesity and type 2 diabetes

The duodenum is an important source of endocrine and paracrine signals controlling digestion and nutrient disposition, notably including the main incretin hormone glucose-dependent insulinotropic polypeptide (GIP). Bariatric procedures that prevent nutrients from contact with the duodenal mucosa are particularly effective interventions to reduce body weight and improve glycaemic control in obesity and type 2 diabetes. These procedures take advantage of increased nutrient delivery to more distal regions of the intestine which enhances secretion of the other incretin hormone glucagon-like peptide-1 (GLP-1). Preclinical experiments have shown that either an increase or a decrease in the secretion or action of GIP can decrease body weight and blood glucose in obesity and non-insulin dependent hyperglycaemia, but clinical studies involving administration of GIP have been inconclusive. However, a synthetic dual agonist peptide (tirzepatide) that exerts agonism at receptors for GIP and GLP-1 has produced marked weight-lowering and glucose-lowering effects in people with obesity and type 2 diabetes. This appears to result from chronic biased agonism in which the novel conformation of the peptide triggers enhanced signalling by the GLP-1 receptor through reduced internalisation while reducing signalling by the GIP receptor directly or via functional antagonism through increased internalisation and degradation.

Nonclassic Congenital Adrenal Hyperplasia Metabolic Resolution Post Roux-en-Y Gastric Bypass and Associated Weight Loss

Nonclassic congenital adrenal hyperplasia (NCCAH) is characterized by mild cortisol deficiency, excess androgens and adrenocorticotropin (ACTH) production, and often with various features of dysmetabolic syndrome. Elective bariatric surgery is one of the most effective long-term management strategies for severe obesity. Our case presents a 34-year-old woman with symptomatic NCCAH and class III obesity who status post Roux-en-Y gastric bypass (RYGB) had significant weight loss with metabolic resolution of NCCAH, and no longer required glucocorticoid (GC) therapy. At 11 months post operation and off GC therapy, she had a weight deficit of approximately 160 pounds (72.57 kg) with continued metabolic resolution of NCCAH markers including ACTH, 17-hydroxyprogesterone, and androstenedione. Presently, GC therapy remains one of the few available treatments for symptomatic NCCAH; however, long-term GC therapy has the potential for various complications and side effects. Our case presents elective bariatric surgery as a potential and unique treatment option for patients with NCCAH with associated class III obesity. The exact pathophysiologic basis for this effect and its potential role in long-term management of appropriate NCCAH patients requires further study.

The effects of bariatric surgery on cardiac function: a systematic review and meta-analysis

INTRODUCTION

Obesity is associated with alterations in cardiac structure and haemodynamics leading to cardiovascular mortality and morbidity. Culminating evidence suggests improvement of cardiac structure and function following bariatric surgery.

OBJECTIVE

To evaluate the effect of bariatric surgery on cardiac structure and function in patients before and after bariatric surgery.

METHODS

Systematic review and meta-analysis of studies reporting pre- and postoperative cardiac structure and function parameters on cardiac imaging in patients undergoing bariatric surgery.

RESULTS

Eighty studies of 3332 patients were included. Bariatric surgery is associated with a statistically significant improvement in cardiac geometry and function including a decrease of 12.2% (95% CI 0.096-0.149; p < 0.001) in left ventricular (LV) mass index, an increase of 0.155 (95% CI 0.106-0.205; p < 0.001) in E/A ratio, a decrease of 2.012 mm (95% CI 1.356-2.699; p < 0.001) in left atrial diameter, a decrease of 1.16 mm (95% CI 0.62-1.69; p < 0.001) in LV diastolic dimension, and an increase of 1.636% (95% CI 0.706-2.566; p < 0.001) in LV ejection fraction after surgery.

CONCLUSION

Bariatric surgery led to reverse remodelling and improvement in cardiac geometry and function driven by metabolic and haemodynamic factors.

Suboptimal Weight Loss 13 Years After Roux-en-Y Gastric Bypass Is Associated with Blunted Appetite Response

PURPOSE

Bariatric surgery remains the most efficient treatment to achieve a sustained weight loss. However, a large proportion of patients experience suboptimal weight loss (SWL). The exact mechanisms involved remain to be fully elucidated, but the homeostatic appetite control system seems to be involved. The aim of this study was, therefore, to compare the plasma concentration of gastrointestinal hormones, and appetite ratings, between those experiencing SWL and optimal weight loss (OWL) after Roux-en-Y gastric bypass (RYGB).

MATERIALS AND METHODS

Fifty participants from the Bariatric Surgery Observation Study (BAROBS) experiencing either SWL or OWL (< or ≥ 50% of excess weight loss (EWL), respectively) > 13 years post-RYGB were compared to 25 non-surgical controls. Plasma concentrations of acylated ghrelin (AG), total glucagon-like peptide-1 (GLP-1), total peptide YY (PYY), cholecystokinin (CCK), and subjective ratings of hunger, fullness, desire to eat (DTE), and prospective food consumption (PFC) were assessed in the fasting and postprandial (area under the curve (AUC)) states.

RESULTS

Those experiencing OWL presented with higher basal AG and GLP-1 iAUC, and lower AG iAUC compared with SWL and controls. Additionally, both bariatric groups presented with higher PYY and CCK iAUC compared to controls. PFC tAUC was also lower in OWL compared to the SWL group. Total weight loss was positively correlated with GLP-1 tAUC and negatively correlated with fasting and tAUC DTE and PFC tAUC.

CONCLUSIONS

SWL > 13 years post-RYGB is associated with lower basal ghrelin, as well as a weaker satiety response to a meal. Future studies should investigate the causality of these associations.

Reduced risk of de novo Barrett esophagus after bariatric surgery: a national database study

BACKGROUND

Bariatric surgery is an effective treatment for obesity and may decrease the morbidity and mortality of obesity-associated cancers.

OBJECTIVE

We investigated the risk of a new diagnosis of Barrett esophagus (BE) following bariatric surgery compared to screening colonoscopy controls.

SETTING

Large national database including patients who received care in inpatient, outpatient, and specialty care services.

METHODS

A national healthcare database (TriNetX, LLC) was used for this analysis. Cases included adults (aged ≥18 yr) who had undergone either sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB). Controls included adults undergoing screening colonoscopy and an esophagoduodenoscopy on the same day and had never undergone bariatric surgery. Cases and controls were propensity-matched for confounders. The risk of de novo diagnosis of BE at least 1 year after bariatric surgery was compared between cases and controls. Secondary analyses examined the effect of bariatric surgery on metabolic outcomes such as weight loss and body mass index (BMI). The risk of de novo diagnosis of BE in SG was compared with RYGB. Odds ratios (OR) and 95% CI were used to report on these associations.

RESULTS

In the propensity-matched analysis, patients who had undergone a bariatric surgical procedure showed a significantly reduced risk of de novo BE when compared with screening colonoscopy controls (.67 [.48, .94]). There was substantial reduction in weight and BMI in the bariatric surgery group when compared with baseline. There was no significant difference in de novo BE diagnosis between the propensity-matched SG and RYGB groups (.77 [.5, 1.2]).

CONCLUSION

Patients who underwent bariatric surgery (RYGB or SG) had a lower risk of being diagnosed with BE compared with screening colonoscopy controls who did not receive bariatric surgery. This effect appears to be largely mediated by reduction in weight and BMI.

A data-driven computational model for obesity-driven diabetes onset and remission through weight loss

Obesity is a major risk factor for the development of type 2 diabetes (T2D), where a sustained weight loss may result in T2D remission in individuals with obesity. To design effective and feasible intervention strategies to prevent or reverse T2D, it is imperative to study the progression of T2D and remission together. Unfortunately, this is not possible through experimental and observational studies. To address this issue, we introduce a data-driven computational model and use human data to investigate the progression of T2D with obesity and remission through weight loss on the same timeline. We identify thresholds for the emergence of T2D and necessary conditions for remission. We explain why remission is only possible within a window of opportunity and the way that window depends on the progression history of T2D, individual's metabolic state, and calorie restrictions. These findings can help to optimize therapeutic intervention strategies for T2D prevention or treatment.

Evolution of peptide YY analogs for the management of type 2 diabetes and obesity

Peptide YY (PYY) is a gastrointestinal hormone consisting of 36 amino acids, that is predominantly secreted by intestinal l-cells. Originally extracted from pig intestines, it belongs to the pancreatic polypeptide (PP) family, but has functions distinct from those of PP and neuropeptide Y (NPY). PYY is a potential treatment for type 2 diabetes mellitus (T2DM) because of its ability to delay gastric emptying, reduce appetite, decrease weight, and lower blood glucose. However, the clinical use of PYY is limited because it is rapidly cleared by the kidneys and degraded by enzymes. In recent years, researchers have conducted various structural modifications, including amino acid substitution, PEGylation, lipidation, and fusion of PYY with other proteins to prolong its half-life and enhance its biological activity. This study presents an overview of the recent progress on PYY, including its physiological functions, metabolites and structure-activity relationships.

Metabolic remission precedes possible weight regain after gastric bypass surgery

OBJECTIVE

Some patients regain weight to a variable extent from 1 year after Roux-en-Y gastric bypass surgery (RYGB), though rarely reaching preoperative values. The aim of the present study was to investigate whether, when, and to what extent metabolic remission occurs.

METHODS

Fasting metabolite and lipid profiles were determined in blood plasma collected from a nonrandomized intervention study involving 148 patients before RYGB and at 2, 12, and 60 months post RYGB. Both short-term and long-term alterations in metabolism were assessed. Anthropometric and clinical variables were assessed at all study visits.

RESULTS

This study found that the vast majority of changes in metabolite levels occurred during the first 2 months post RYGB. Notably, thereafter the metabolome started to return toward the presurgical state. Consequently, a close-to-presurgical metabolome was observed at the time when patients reached their lowest weight and glucose level. Lipids with longer acyl chains and a higher degree of unsaturation were altered more dramatically compared with shorter and more saturated lipids, suggesting a systematic and reversible lipid remodeling.

CONCLUSIONS

Remission of the metabolic state was observed prior to notable weight regain. Further and more long-term studies are required to assess whether the extent of metabolic remission predicts future weight regain and glycemic deterioration.

Weight Regain after Bariatric Surgery

Bariatric surgery (BS) is currently the most effective treatment for obesity, with long-lasting weight loss and improvement of related co-morbidities [...].

Psychological Profiles and 12-Month Weight Outcomes of Women Evaluated for Reoperative Bariatric Surgery

BACKGROUND

The use of psychological screening instruments prior to bariatric surgery has been well established. However, there is currently no specific literature on psychological screening of candidates for reoperative bariatric surgery.

METHODS

This study evaluated archival data for 40 women who were candidates for reoperative bariatric surgery and completed the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF). Profile analysis examined differences between patient groups who did and did not undergo reoperative surgery. MMPI-2-RF profiles for reoperative patients then were compared to previous samples of preoperative and postoperative patients. Hierarchical linear modeling was used to predict BMI following reoperative surgery over a 12-month period based on MMPI-2-RF scales while controlling for age and initial BMI.

RESULTS

Profile analysis results showed no significant differences on MMPI-2-RF scale scores between reoperative candidates who did and did not undergo a second surgery. With some minor differences attributed to minimization of symptoms, there were no systematic differences in MMPI-2-RF scale scores for reoperative surgery patients compared to preoperative and postoperative patient groups. BMI outcomes over a 12-month period showed that age and initial BMI were significantly better predictors than MMPI-2-RF scores.

CONCLUSIONS

Administration of MMPI-2-RF for reoperative bariatric surgery patients likely is equivalent to its typical use in preoperative screening. Only the MMPI-2-RF Disconstraint scale showed any relationship to BMI outcomes over time following reoperative surgery.

Effect of post-gastric sleeve pyloric length on control of type II diabetes mellitus

Background

Although the effectiveness and safety of laparoscopic sleeve gastrectomy (LSG) have been demonstrated, there is still debate about the best surgical method, with the resection distance from pylorus (DP) being among the most contentious topics. In patients who had LSG for morbid obesity, the effect of the resection distance from the pylorus on the management of type II diabetes mellitus during the postoperative phase was examined.

Patients and methods

After receiving each patient’s agreement, a total of 46 obese individuals were enrolled. Patients were prospectively randomized into two groups, group A (‘AP group’) and group B (‘AR group’), based on the distance between the initial reload firing and the pylorus (4 cm for group A and 2 cm for group B, respectively). Blood sugar levels were measured three, six months, and one year following LSG. After a year of follow-up, the percentage of excess weight loss (%EWL) was calculated.

Results

Postoperative weight was statistically significant lower and EWL% was statistically significant higher in group B: LSG ‘2 cm’ compared to group A: LSG ‘4 cm’. As regard outcomes of type 2 diabetes mellitus after LSG, in spite of nonsignificant statistical value, we reported that there was higher frequency of complete remission after 3, 6 and 12 months in group B: LSG ‘2 cm’ compared to group A: LSG ‘4 cm’ and cases with complete remission were associated with significant higher EWL%.

Conclusion

Patients undergoing laparoscopic sleeve gastrectomy are recommended to have shorter resection distance from pylorus (DP) done. It has been linked to superior surgical results, weight reduction, and diabetes mellitus management with no problems recorded.

Famsin, a novel gut-secreted hormone, contributes to metabolic adaptations to fasting via binding to its receptor OLFR796

The intestine is responsible for nutrient absorption and orchestrates metabolism in different organs during feeding, a process which is partly controlled by intestine-derived hormones. However, it is unclear whether the intestine plays an important role in metabolism during fasting. Here we have identified a novel hormone, famsin, which is secreted from the intestine and promotes metabolic adaptations to fasting. Mechanistically, famsin is shed from a single-pass transmembrane protein, Gm11437, during fasting and then binds OLFR796, an olfactory receptor, to activate intracellular calcium mobilization. This famsin-OLFR796 signaling axis promotes gluconeogenesis and ketogenesis for energy mobilization, and torpor for energy conservation during fasting. In addition, neutralization of famsin by an antibody improves blood glucose profiles in diabetic models, which identifies famsin as a potential therapeutic target for treating diabetes. Therefore, our results demonstrate that communication between the intestine and other organs by a famsin-OLFR796 signaling axis is critical for metabolic adaptations to fasting.

Downregulation of hepatic lncRNA Gm19619 improves gluconeogenesis and lipogenesis following vertical sleeve gastrectomy in mice

Long non-coding RNAs (lncRNAs) are emerging important epigenetic regulators in metabolic processes. Whether they contribute to the metabolic effects of vertical sleeve gastrectomy (VSG), one of the most effective treatments for sustainable weight loss and metabolic improvement, is unknown. Herein, we identify a hepatic lncRNA Gm19619, which is strongly repressed by VSG but highly up-regulated by diet-induced obesity and overnight-fasting in mice. Forced transcription of Gm19619 in the mouse liver significantly promotes hepatic gluconeogenesis with the elevated expression of G6pc and Pck1. In contrast, AAV-CasRx mediated knockdown of Gm19619 in high-fat diet-fed mice significantly improves hepatic glucose and lipid metabolism. Mechanistically, Gm19619 is enriched along genomic regions encoding leptin receptor (Lepr) and transcription factor Foxo1, as revealed in chromatin isolation by RNA purification (ChIRP) assay and is confirmed to modulate their transcription in the mouse liver. In conclusion, Gm19619 may enhance gluconeogenesis and lipid accumulation in the liver.

The Effect of Bariatric Surgery upon Diabetes Mellitus: A Proof of Concept by Using the Case of the Mid-Term Effect of Lap Adjustable Gastric Banding (LAGB) on Patients with Diabetes

Obesity is a worldwide epidemic, with numbers on the rise in the world. Obesity is strongly correlated with increased morbidity and mortality. One of the major factors affecting this increase is comorbid diseases such as diabetes mellitus (DM), which is strongly associated with and dependent on the degree of obesity. Thus, it is not surprising that when efficient surgical treatments were found to battle obesity, researchers soon found them to be relevant and effective for battling DM as well. Laparoscopic Adjustable Gastric Banding (LAGB) is a common surgical treatment for morbid obesity. LAGB has the potential to improve control of the comorbidities of morbid obesity, primarily diabetes mellitus (DM). Our hypothesis was that patients treated with LAGB would have a long-term improvement in the control of DM and that due to its unique mechanism of action, this can lend us a better understanding of how to battle diabetes in an efficient and effective way. This was a cohort study based on patients who underwent LAGB surgery in our institution 4 to 7 years previously and had DM type 2 at the time of surgery. Data were collected from patient’s charts and a telephone interview-based questionnaire including demographics, health status, and quality-of-life assessment (Bariatric Analysis and Reporting Outcome System [BAROS]). Seventy patients participated in the current study. The average follow-up time was 5.1 ± 0.9 years post-surgery. The average weight prior to surgery was 122.0 ± 20.2 kg, and on the day of the interview it was 87.0 ± 17.6 kg (p < 0.001). The average body mass index before surgery was 43.8 ± 5.1, and on the day of the interview it was 31.2 ± 4.8 (p < 0.001). On the day of the interview, 47.1% of the participants were cured of DM (not receiving treatment, whether dietary or pharmacologic). The sum of ranks for diabetes was lower after the surgery (p < 0.001), as was HTN and its treatment (p < 0.001). We have shown in this study that LAGB is an effective treatment for morbid obesity, as well as two comorbidities that come with it—DM type 2 and Hypertension (HTN)—in a longer period than previously shown, and with a unique look at the underlying mechanism of action of this procedure. There is a need for further studies to consolidate our findings and characterize which patients are more prone to enjoy these remarkable surgical benefits.

Changes in interstitial cells and gastric excitability in a mouse model of sleeve gastrectomy

Obesity is a critical risk factor of several life-threatening diseases and the prevalence in adults has dramatically increased over the past ten years. In the USA the age-adjusted prevalence of obesity in adults was 42.4%, i.e., with a body mass index (BMI, weight (kg)/height (m)²) that exceeds 30 kg/m². Obese individuals are at the higher risk of obesity-related diseases, co-morbid conditions, lower quality of life, and increased mortality more than those in the normal BMI range i.e., 18.5–24.9 kg/m². Surgical treatment continues to be the most efficient and scientifically successful treatment for obese patients. Sleeve gastrectomy or vertical sleeve gastrectomy (VSG) is a relatively new gastric procedure to reduce body weight but is now the most popular bariatric operation. To date there have been few studies examining the changes in the cellular components and pacemaker activity that occur in the gastric wall following VSG and whether normal gastric activity recovers following VSG. In the present study we used a murine model to investigate the chronological changes of gastric excitability including electrophysiological, molecular and morphological changes in the gastric musculature following VSG. There is a significant disruption in specialized interstitial cells of Cajal in the gastric antrum following sleeve gastrectomy. This is associated with a loss of gastric pacemaker activity and post-junctional neuroeffector responses. Over a 4-month recovery period there was a gradual return in interstitial cells of Cajal networks, pacemaker activity and neural responses. These data describe for the first time the changes in gastric interstitial cells of Cajal networks, pacemaker activity and neuroeffector responses and the time-dependent recovery of ICC networks and normalization of motor activity and neural responses following VSG.

Changes in appetite, taste, smell, and food aversion in post-bariatric patients and their relations with surgery time, weight loss and regain

PURPOSE

We aimed to study the occurrence of long-term changes in appetite, taste, smell perceptions, and food aversion in patients following bariatric surgery. Additionally, we compared two surgery types, excess weight loss, rate of weight regain, and time since surgery.

METHODS

This cross-sectional study included 146 post-bariatric patients who were without regular medical follow-up (126 post-Roux-en-Y gastric bypass [RYGB] and 20 post-sleeve gastrectomy [SG]), aged 42 ± 8 years, BMI of 32.6 ± 6.3 kg/m², with excess weight loss of 87.5 ± 20.2%, rate of weight regain (RWR) of 15.4 [3.9-30.9]% and time since surgery of 5.0 ± 4.0 years. They answered a questionnaire about sensory and food perceptions at their first medical appointment at our unit.

RESULTS

Changes in appetite (76%), taste (48.6%), and an increased sensation for sweet taste (60.2%) frequently occurred in our sample. Sensory and food aversion perceptions, taste changes to specific foods, and loss level of taste and smell were similar between RYGB and SG. No differences between patients with or without changes in appetite, taste, smell, and food aversion perceptions concerning excess weight loss were observed. The RWR in post-RYGB was lower in those with changes in taste and smell (P = 0.05). Sensory changes were noted in those with shorter time since surgery for both surgeries (P ≤ 0.05).

CONCLUSION

Changes in appetite and taste occurred frequently in our patients even in the long term. Post-RYGB patients with lower RWR had more changes in taste and smell while a shorter time since surgery showed more frequent changes in appetite, taste, and smell.

LEVEL OF EVIDENCE

Level V, cross-sectional study.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04193384).

Bariatric surgery, gastrointestinal hormones, and the microbiome: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) is intended to provide clinicians an overview of bariatric surgery (i.e., bariatric procedures that improve metabolic disease are often termed "metabolic and bariatric surgery"), gastrointestinal hormones, and the microbiome as they relate to patients with obesity.

Methods

The scientific information for this CPS is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

This CPS includes the pros and cons of the most common types of bariatric procedures; the roles of gastrointestinal (GI) hormones in regulating hunger, digestion, and postabsorptive nutrient metabolism; and the microbiome's function and relationship with body weight. This CPS also describes patient screening for bariatric surgery, patient care after bariatric surgery, and treatment of potential nutrient deficiencies before and after bariatric surgery. Finally, this CPS explores the interactions between bariatric surgery, GI hormones, and the microbiome.

Conclusions

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) regarding bariatric surgery, gastrointestinal hormones, and the microbiome is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of obesity. Implementation of appropriate care before and after bariatric surgery, as well as an awareness of GI hormones and the microbiome, may improve the health of patients with obesity, especially patients with adverse fat mass and adiposopathic metabolic consequences.

Anti-Obesity Medications and Investigational Agents: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This "Anti-Obesity Medications and Investigational Agents: An Obesity Medicine Association Clinical Practice Statement 2022" is intended to provide clinicians an overview of Food and Drug Administration (FDA) approved anti-obesity medications and investigational anti-obesity agents in development.

Methods

The scientific information for this Clinical Practice Statement (CPS) is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

This CPS describes pharmacokinetic principles applicable to those with obesity, and discusses the efficacy and safety of anti-obesity medications [e.g., phentermine, semaglutide, liraglutide, phentermine/topiramate, naltrexone/bupropion, and orlistat, as well as non-systemic superabsorbent oral hydrogel particles (which is technically classified as a medical device)]. Other medications discussed include setmelanotide, metreleptin, and lisdexamfetamine dimesylate. Data regarding the use of combination anti-obesity pharmacotherapy, as well as use of anti-obesity pharmacotherapy after bariatric surgery are limited; however, published data support such approaches. Finally, this CPS discusses investigational anti-obesity medications, with an emphasis on the mechanisms of action and summary of available clinical trial data regarding tirzepatide.

Conclusion

This "Anti-Obesity Medications and Investigational Agents: An Obesity Medicine Association Clinical Practice Statement 2022" is one of a series of OMA CPSs designed to assist clinicians in the care of patients with pre-obesity/obesity.

Changes in Gastric Inhibitory Polypeptide (GIP) After Roux-en-Y Gastric Bypass in Obese Patients: a Meta-analysis

This meta-analysis aimed to evaluate changes in GIP after RYGB in obese patients. We searched PubMed, EMBASE, and CENTRAL for relevant studies from database inception through July 2021. Articles were eligible for inclusion if they reported pre-operative and post-operative fasting GIP levels. We found fasting GIP levels had a decreasing tendency. The decrease in fasting glucose and postprandial GIP levels was also observed. Subgroup analysis indicated diabetic subjects tended to have a more obvious fasting GIP reduction compared to non-diabetic individuals. Meta-regression showed that the amount of weight loss (% total body weight), gastric pouch volume, alimentary limb length, and biliopancreatic limb length were not related to fasting GIP decrease. Fasting GIP levels decreased significantly after RYGB in obese people, especially in diabetic patients.

Neurohormonal Changes in the Gut–Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery

Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut–brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut–brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.

Trends in insulin-like growth factor-1 levels after bariatric surgery: a systematic review and meta-analysis

According to studies, there are many inconsistencies in how IGF-1 levels change after bariatric surgery compared to before surgery, as well as its effects. These discrepancies can be attributed to various factors such as age, body mass index (BMI), and duration of intervention. Therefore, the aim of this study was to evaluate the level of insulin-like growth factor-1 (IGF-1) after bariatric surgery. A systematic review and meta-analysis based on the PRISMA guidelines was conducted from inception until 2021. From 1871 articles initially selected, 24 studies with 28 treatment arms met the eligible criteria and were included. Pooled findings from the random-effects model indicated that IGF-1 levels increased significantly [weighted mean difference (WMD) = 8.84 ng/ml; 95% confidence interval (CI) 0.30-17.39; p = 0.043] after bariatric surgery compared to before surgery. No significant heterogeneity was noted among the studies (Cochran Q test, p = 0.90, I² = 0.0%). In subgroup analysis, bariatric surgery significantly increased IGF-1 levels at age <40 years but not at age ≤40 years. Bariatric surgery is capable of increasing the IGF-1 levels compared to the period prior to surgery but with a modest clinical magnitude.

Mechanisms of Weight Loss After Obesity Surgery

Obesity surgery remains the most effective treatment for obesity and its complications. Weight loss was initially attributed to decreased energy absorption from the gut but has since been linked to reduced appetitive behavior and potentially increased energy expenditure. Implicated mechanisms associating rearrangement of the gastrointestinal tract with these metabolic outcomes include central appetite control, release of gut peptides, change in microbiota, and bile acids. However, the exact combination and timing of signals remain largely unknown. In this review, we survey recent research investigating these mechanisms, and seek to provide insights on unanswered questions over how weight loss is achieved following bariatric surgery which may eventually lead to safer, nonsurgical weight-loss interventions or combinations of medications with surgery.

A multi-center study on glucometabolic response to bariatric surgery for different subtypes of obesity

OBJECTIVES

To assess the benefit of a bariatric surgery in four artificial intelligence-identified metabolic (AIM) subtypes of obesity with respect to the improvement of glucometabolism and the remission of diabetes and hyperinsulinemia.

METHODS

This multicenter retrospective study prospectively collected data from five hospitals in China from 2010 to 2021. At baseline 1008 patients who underwent a bariatric surgery were enrolled (median age 31 years; median BMI 38.1kg/m²; 57.40% women) and grouped into the four AIM subtypes. Baseline and follow-up data (506 and 359 patients at 3- and 12-month post-surgery) were collected for longitudinal effect analysis.

RESULTS

Out of the four AIM subgroups, hypometabolic obesity (LMO) group was characterized by decompensated insulin secretion and high incidence of diabetes (99.2%) pre-surgery. After surgery, 62.1% of LMO patients with diabetes achieved remission, lower than the other three subgroups. Still, the bariatric surgery significantly reduced their blood glucose (median HbA1c decreased by 27.2%). The hypermetabolic obesity-hyperinsulinemia (HMO-I) group was characterized by severe insulin resistance and high incidence of hyperinsulinemia (87.8%) pre-surgery, which had been greatly alleviated post-surgery. For both metabolic healthy obesity (MHO) and hypermetabolic obesity-hyperuricemia (HMO-U) groups who showed a relatively healthy glucometabolism pre-surgery, rate of glucometabolic comorbidities improved moderately post-surgery.

CONCLUSION

In terms of glucometabolism, the four AIM subtypes of patients benefited differently from a bariatric surgery, which significantly relieved hyperglycemia and hyperinsulinemia for the LMO and HMO-I patients, respectively. The AIM-based subtypes may help better inform clinical decisions on bariatric surgery and patient counseling pertaining to post-surgery outcomes.

GASTROESOPHAGEAL SYMPTOMS AFTER LAPAROSCOPIC GASTRIC BYPASS: MISTAKES IN PERFORMING THE PROCEDURE?

Laparoscopic Roux-en-Y gastric bypass (LGB) is the recommended procedure for morbidly obese patients with gastroesophageal reflux disease (GERD). However, there have been reported gastroesophageal reflux symptoms or esophagitis after LGB. Few functional esophageal studies have been reported to date.

A nonhuman primate model of vertical sleeve gastrectomy facilitates mechanistic and translational research in human obesity

The obesity epidemic significantly contributes to overall morbidity and mortality. Bariatric surgery is the gold standard treatment for obesity and metabolic dysfunction, yet the mechanisms by which it exerts metabolic benefit remain unclear. Here, we demonstrate a model of vertical sleeve gastrectomy (VSG) in nonhuman primates (NHP) that mimics the complexity and outcomes in humans. We also show that VSG confers weight loss and durable metabolic benefit, where equivalent caloric intake in shams resulted in significant weight gain following surgery. Furthermore, we show that VSG is associated with early, weight-independent increases in bile acids, short-chain fatty acids, and reduced visceral adipose tissue (VAT) inflammation with a polarization of VAT-resident immunocytes toward highly regulatory myeloid cells and Tregs. These data demonstrate that this strongly translational NHP model can be used to interrogate factors driving successful intervention to unravel the interplay between physiologic systems and improve therapies for obesity and metabolic syndrome.

The Effect of Bariatric Surgery on Circulating Levels of Oxidized Low-Density Lipoproteins Is Apparently Independent of Changes in Body Mass Index: A Systematic Review and Meta-Analysis

Background

Obesity is related to dyslipidemia and increased circulating oxidated LDL (ox-LDL) concentrations that may predispose to atherosclerosis. Bariatric surgery may lower the risk of cardiovascular mortality. Elevated plasma ox-LDL has been associated with atherogenesis and atherosclerotic cardiovascular disease (ASCVD) events. The aim of this meta-analysis was to investigate the impact of bariatric surgery on proatherogenic circulating ox-LDL levels in patients with severe obesity.

Methods

Four databases were systematically searched from inception to May 1, 2021. Also, to clarify the heterogeneity of studies with regard to treatment duration, research design, and the demographic features, a random-effects model and the generic inverse variance weighting approach were utilized. To determine the association with the estimated effect size, a random-effect meta-regression approach was performed. Finally, a meta-regression analysis was conducted to explore the influence of, respectively, baseline and changes in body mass index (BMI), baseline ox-LDL, and postsurgery follow-up period with the estimated effect size of surgery on ox-LDL levels.

Results

Meta-analysis of 11 studies including 470 subjects showed a significant decline in circulating ox-LDL following bariatric surgery (SMD: -0.971, 95% CI: -1.317, -0.626, p < 0.001, I²: 89.43%). The results of meta-regression did not show any significant association between the changes in ox-LDL after bariatric surgery and baseline BMI, duration of follow-up or baseline ox-LDL values. However, there was a significant association between ox-LDL alteration and percentage of BMI change.

Conclusion

Bariatric surgery in patients who had severe obesity causes a decrease of circulating ox-LDL that was apparently dependent in BMI changes.

Improvement in mood symptoms ​after post-bariatric surgery among people with obesity: A systematic review and meta-analysis

AIMS

We aimed to examine if bariatric surgery was associated with a reduction in the prevalence of depressive and anxiety symptoms among people with obesity.

MATERIALS AND METHODS

We pooled data from 49 studies involving 11,255 people with obesity who underwent bariatric surgery. The study outcomes were the prevalence of depressive and anxiety symptoms among these patients pre- and post-surgery.

RESULTS

There was a significant reduction in body mass index (BMI) post-operatively (pooled d+: -13.3 kg/m² [95% confidence interval [CI] 15.19, -11.47], p < 0.001). The pooled proportion of patients with anxiety symptoms reduced from 24.5% pre-operatively to 16.9% post-operatively, with an odds ratio (OR) of 0.58 (95% CI 0.51, 0.67, p < 0.001). The reduction remained significant in women aged ≥40 years and irrespective of post-operative BMI. There were significant reductions in Hospital Anxiety and Depression Score (HADS) (anxiety component) by 0.64 (pooled d+: -0.64 [95% CI -1.06, -0.22], p = 0.003) and Generalized Anxiety Disorder Assessment-7 score by 0.54 (pooled d+: -0.54 [95% CI -0.64, -0.44], p < 0.001). The pooled proportion of depressive symptoms reduced from 34.7% pre-operatively to 20.4% post-operatively, with an OR of 0.49 (95% CI 0.37, 0.65, p < 0.001). The reduction remained significant irrespective of patient's age and post-operative BMI. There were also significant reductions in HADS score (depressive component) (pooled d+: -1.34 [95% CI -1.93, -0.76], p < 0.001), Beck's Depression Inventory score (pooled d+: -1.04 [95% CI -1.46, -0.63], p < 0.001) and Patient Health Questionnaire-9 score (pooled d+: -1.11 [95% CI -1.21, -1.01], p < 0.001).

CONCLUSION

Bariatric surgery was associated with significant reduction in the prevalence and severity of depressive and anxiety symptoms among people with obesity.

Change of plasma amylin after bariatric surgery challenged by oral glucose is associated with remission of type 2 diabetes mellitus

BACKGROUND

Gastric bypass (GB) and sleeve gastrectomy (SG) were found to achieve different remission rates in the treatment of type 2 diabetes (T2DM). The alteration in several gut hormones after bariatric surgery has been demonstrated to play a key role for T2DM remission. Nevertheless, amylin, one of the diabetes-associated peptides, so far has an undetermined position on T2DM remission after bariatric surgery.

METHODS

Sixty eligible patients with T2DM (GB, 30; SG, 30) were initially enrolled in the hospital-based randomized trial. Twenty patients (GB, 10; SG, 10) who met the inclusion criteria and agreed to undergo 75-g oral glucose tolerance test (OGTT) were recruited. The recruited subjects underwent anthropometric measurements, routine laboratory tests, and 75-g OGTT before and 1 year after bariatric surgery. Enzyme immunoassays for plasma amylin were analyzed.

RESULTS

All subjects that underwent GB and half of those who underwent SG achieved T2DM remission. Plasma amylin levels significantly decreased 60-90 min after OGTT in the GB group (p < 0.05) and 30-60 minutes after OGTT in the SG group (p < 0.05). Significantly decreased plasma amylin levels were observed at 30-90 minutes after OGTT in the noncomplete remitters of the GB group (p < 0.05). Plasma amylin levels initially increased (p < 0.05) within 30 minutes after OGTT and then decreased (p < 0.05) in the next 30-minute interval in the nonremitters of the SG group.

CONCLUSION

Postoral glucose challenge amylin levels could be as one of the parameters to evaluate T2DM remission after bariatric surgery, especially in those after SG.

Review of Changes in the Reinforcing Effects of Alcohol in Weight Loss Surgery Patients

PURPOSE OF REVIEW

The reinforcing effects of alcohol are well documented, and they have been shown to play a role in the development of alcohol use disorders (AUDs). Also well established is the fact that post-weight loss surgery (WLS) patients are at an increased risk for AUDs. In the current manuscript, we review the notion that the reinforcing effects of alcohol may change from before to after WLS and discuss a number of determinants of alcohol reinforcement change in WLS patients.

RECENT FINDINGS

It has been increasingly well understood that WLS patients are at an increased risk for AUD, but empirical support for the mechanisms that may cause this phenomenon have been lacking. Recently, a model was proposed that offered a number of different potentially causal variables as mechanisms that result in increased risk for AUD in these surgical patients. Change in the extent to which alcohol is reinforcing to WLS patients may be key in determining the likelihood of AUDs in this group. We review a host of biological, psychological, and social variables that ultimately impact how reinforcing alcohol is to WLS patients.

Sleeve Gastrectomy and Roux-En-Y Gastric Bypass. Two Sculptors of the Pancreatic Islet

Several surgical procedures are performed for the treatment of obesity. A main outcome of these procedures is the improvement of type 2 diabetes mellitus. Trying to explain this, gastrointestinal hormone levels and their effect on organs involved in carbohydrate metabolism, such as liver, gut, muscle or fat, have been studied intensively after bariatric surgery. These effects on endocrine-cell populations in the pancreas have been less well studied. We gathered the existing data on these pancreatic-cell populations after the two most common types of bariatric surgery, the sleeve gastrectomy (SG) and the roux-en-Y gastric bypass (RYGB), with the aim to explain the pathophysiological mechanisms underlying these surgeries and to improve their outcome.

Effect of Medical and Surgical Interventions on α-Cell Function in Dysglycemic Youth and Adults in the RISE Study

OBJECTIVE

To compare effects of medications and laparoscopic gastric band surgery (LB) on α-cell function in dysglycemic youth and adults in the Restoring Insulin Secretion (RISE) Study protocols.

RESEARCH DESIGN AND METHODS

Glucagon was measured in three randomized, parallel, clinical studies: 1) 91 youth studied at baseline, after 12 months on metformin alone (MET) or glargine followed by metformin (G/M), and 3 months after treatment withdrawal; 2) 267 adults studied at the same time points and treated with MET, G/M, or liraglutide plus metformin (L+M) or given placebo (PLAC); and 3) 88 adults studied at baseline and after 12 and 24 months of LB or MET. Fasting glucagon, glucagon suppression by glucose, and acute glucagon response (AGR) to arginine were assessed during hyperglycemic clamps. Glucagon suppression was also measured during oral glucose tolerance tests (OGTTs).

RESULTS

No change in fasting glucagon, steady-state glucagon, or AGR was seen at 12 months following treatment with MET or G/M (in youth and adults) or PLAC (in adults). In contrast, L+M reduced these measures at 12 months (all P ≤ 0.005), which was maintained 3 months after treatment withdrawal (all P < 0.01). LB in adults also reduced fasting glucagon, steady-state glucagon, and AGR at 12 and 24 months (P < 0.05 for all, except AGR at 12 months [P = 0.098]). Similarly, glucagon suppression during OGTTs was greater with L+M and LB. Linear models demonstrated that treatment effects on glucagon with L+M and LB were largely associated with weight loss.

CONCLUSIONS

Glucagon concentrations were reduced by L+M and LB in adults with dysglycemia, an effect principally attributable to weight loss in both interventions.

Secretin as a Satiation Whisperer With the Potential to Turn into an Obesity-curbing Knight

The obesity pandemic requires effective preventative and therapeutic intervention strategies. Successful and sustained obesity treatment is currently limited to bariatric surgery. Modulating the release of gut hormones is considered promising to mimic bariatric surgery with its beneficial effects on food intake, body weight, and blood glucose levels. The gut peptide secretin was the first molecule to be termed a hormone; nevertheless, only recently has it been established as a legitimate anorexigenic peptide. In contrast to gut hormones that crosstalk with the brain either directly or by afferent neuronal projections, secretin mediates meal-associated brown fat thermogenesis to induce meal termination, thereby qualifying this physiological mechanism as an attractive, peripheral target for the treatment of obesity. In this perspective, it is of pivotal interest to deepen our as yet superficial knowledge on the physiological roles of secretin as well as meal-associated thermogenesis in energy balance and body weight regulation. Of note, the emerging differences between meal-associated thermogenesis and cold-induced thermogenesis must be taken into account. In fact, there is no correlation between these 2 entities. In addition, the investigation of potential effects of secretin in hedonic-driven food intake, bariatric surgery and chronic treatment using suitable application strategies to overcome pharmacokinetic limitations will provide further insight into its potential to influence energy balance. The aim of this article is to review the facts on secretin's metabolic effects, address prevailing gaps in our knowledge, and provide an overview on the opportunities and challenges of the therapeutic potential of secretin in body weight control.

Are the Changes in Gastrointestinal Hormone Secretion Necessary for the Success of Bariatric Surgery? A Critical Review of the Literature

Ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) are involved in energy balance regulation and glucose homeostasis. Obesity is characterized by lower fasting levels and blunted postprandial responses of ghrelin, GLP-1, and possibly PYY. Both Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) have been shown to increase postprandial GLP-1 and PYY levels. Human studies have shown that enhanced postprandial GLP-1 and PYY release are associated with favorable weight loss outcomes after RYGB. However, studies in knockout mice have shown that GI hormones are not required for the primary metabolic effects of bariatric surgery. Here, we summarize the complex interaction between obesity, bariatric surgery, and GI hormones in order to determine the exact role of GI hormones in the success of bariatric surgery.

Laparoscopic Sleeve Gastrectomy has A Positive Impact on Subclinical Hypothyroidism Among Obese Patients: A Prospective Study

BACKGROUND

The effect of bariatric surgery on postoperative thyroid function remains incompletely understood. In this study, we aimed to evaluate the changes in thyroid functions after gastric sleeve operation for morbidly obese Egyptian patients.

METHODS

This was a prospective study that recruited 128 patients who underwent sleeve gastrectomy through the period from December 2016 to April 2020. We measured thyroid-stimulating hormone (TSH), free thyroxin (FT4), and free triiodothyronine. Subclinical hypothyroidism was defined by a TSH level > 4.5 mIU/L but a normal FT4 level. All patients were followed for 12 months after the procedure.

RESULTS

Preoperatively, 30 (23.4%) patients had subclinical hypothyroidism. The prevalence of subclinical hypothyroidism decreased significantly to reach 7.8% at the end of follow-up (p < 0.001). None of the patients developed de novo hypothyroidism at the end of follow-up. Patients with subclinical hypothyroidism were more likely to be females (p = 0.037) and had significantly higher waist circumference (p < 0.001), DBP (p = 0.02), serum cholesterol (p < 0.001), and serum triglyceride (p < 0.001). However, patients with subclinical hypothyroidism at the end of follow-up had significantly higher BMI at the end of the sixth month (p = 0.048). Similarly, patients with subclinical hypothyroidism at the end of follow-up had significantly higher serum cholesterol (p = 0.002), LDL, (p = 0.038), and serum triglyceride (p < 0.001) at the end of the sixth months of follow-up. A similar trend was noted at the end of the 12th month. The preoperative value of serum TSH correlated significantly with serum cholesterol and triglyceride levels.

CONCLUSION

The positive effect of the LSG procedure on the hypothyroid bariatric population, including enhanced thyroid function, was demonstrated.

Experiences of the Bariatric Pre-Surgery Evaluation Process in a National Health Service—An Interpretative Phenomenological Analysis

There is currently little understanding of bariatric patients’ experiences and expectations of the bariatric pre-surgery evaluation (PSE) process. This is especially true for patients within the National Health Service (NHS) in the UK. Consequently, this study undertakes a qualitative study to explore the experiences and expectations of the bariatric PSE amongst patients who had undergone bariatric surgery within the NHS in the UK, using the Interpretative Phenomenological Analysis. Three inter-related superordinate themes were presented: (i) ‘PSE was challenging but essential’, (ii) ‘Coping processes to deal with the PSE’, and (iii) ‘Staff and service evaluation’. Most participants had conflicting feelings about the PSE process as it had both positive and negative impacts on their wellbeing. The process was considered essential for preparation and successful post-surgery adjustment, though the uncertainty of approval was experienced as very distressing. Consequently, participants utilised both external and internal coping strategies, such as social support, researching, or ‘toeing the line’. Participants’ experiences encouraged them to provide feedback about the staff and service, which revealed a preference for a tailored evaluation process. The emerged themes represent an initial framework for helping healthcare providers and researchers to involve patients in service delivery thereby facilitating a patient-centred approach. A starting point is to audit patients’ perspectives routinely. Further investigations are needed to better define, validate, and understand constructs and processes identified in this study.

How Does Fat Mass Change in the First Year After Bariatric Surgery? A Systemic Review and Meta-Analysis

This systematic review and meta-analysis investigated the time-course effect of different type of bariatric surgeries (BS) up to 1 year post-surgery on fat mass (FM) and body fat percentage (BFP) in patients with morbid obesity. We searched PubMed, Scopus, EMBASE, ISI web of science, and Cochrane databases from October 2002 until May 2020 with no restriction in the English language, to find studies examining the effect of BS on FM (kg) and BFP (%) in morbid obese patients. Meta-analysis of 103 studies carried out on data of 18,166 and 14,575 morbid obese patients following BS, showed that BS was associated with a substantial decrease in FM and BFP, respectively, in 1 month (- 8.17 kg [95% CI - 9.07, - 7.27] and - 1.51% [95% CI - 2.56, - 0.46]), 3 months (- 15.75 [95% CI - 17.49, - 14.0] and - 4.90 [95% CI - 5.97, - 3.83]), 6 months (- 22.51 [95% CI - 23.93, - 21.09] and - 8.56% [95% CI - 9.63, - 7.49]), and 12 months (- 29.69 [95% CI - 31.3, - 28.09] and - 13.49% [95% CI - 14.52, - 12.40]) after the surgery. In conclusion, BS was associated with sustained declines in FM and BFP, from 1 to 12 months, with no indication of plateau phase post-surgery post-operatively. The present study emphasizes that post-bariatric care should have more focus on FM loss during 1-year post-surgery to identify the patients at risk for fat loss plateau.

Low bone mineral density following gastric bypass is not explained by lifestyle and lack of exercise

BACKGROUND

Bariatric surgery, Roux-en-Y gastric bypass (RYGBP) in particular, is associated with weight loss as well as low bone mineral density. Bone mineral density relies upon multiple factors, some of which are lifestyle factors. The aim of this study was to compare lifestyle factors in order to eliminate them as culprits of the suspected difference in BMD in RYGBP operated and controls.

MATERIALS AND METHODS

Study participants included 71 RYGBP-operated women (42.3 years, BMI 33.1 kg/m2) and 94 controls (32.4 years, BMI 23.9 kg/m2). Each completed a DEXA scan, as well as survey of lifestyle factors (e.g. physical activity in daily life, corticosteroid use, and calcium intake). All study participants were premenopausal Caucasian women living in the same area. Blood samples were taken in RYGBP-patients.

RESULTS

BMD was significantly lower in RYGBP, femoral neck 0.98 vs. 1.04 g/cm2 compared to controls, despite higher BMI (present and at 20 years of age) and similar physical activity and calcium intake. In a multivariate analysis, increased time since surgery and age were negatively associated with BMD of the femoral neck and total hip in RYGBP patients.

CONCLUSION

Despite similar lifestyle, RYGBP was followed by a lower BMD compared to controls. Thus, the reduced BMD in RYGBP cannot be explained, seemingly nor prevented, by lifestyle factors. As the reduction in BMD was associated with time since surgery, strict follow-up is a lifelong necessity after bariatric surgery, and especially important in younger bariatric patients.

The Formidable yet Unresolved Interplay between Endometriosis and Obesity

Obesity and endometriosis are two very common entities, yet there is uncertainty on their exact relationship. Observational studies have repeatedly shown an inverse correlation between endometriosis and a low body mass index (BMI). However, obesity does not protect against endometriosis and on the contrary an increased BMI may lead to more severe forms of the disease. Besides, BMI is not accurate in all cases of obesity. Consequently, other anthropometric and phenomic traits have been studied, including body adiposity content, as well as the effect of BMI early in life on the manifestation of endometriosis in adulthood. Some studies have shown that the phenotypic inverse correlation between the two entities has a genetic background; however, others have indicated that certain polymorphisms are linked with endometriosis in females with increased BMI. The advent of metabolic bariatric surgery and pertinent research have led to the emergence of biomolecules that may be pivotal in understanding the pathophysiological interaction of the two entities, especially in the context of angiogenesis and inflammation. Future research should focus on three objectives: detection and interpretation of obesity-related biomarkers in experimental models with endometriosis; integration of endometriosis-related queries into bariatric registries; and multidisciplinary approach and collaboration among specialists.

Diabetes Risk Reduction and Metabolic Surgery

Type 2 diabetes mellitus (T2D) and associated comorbid medical conditions are leading causes of strain on the American health care system. There has been a synchronous rise of obesity to epidemic proportions. If poorly treated, T2D is a scourge for patients, leading to end-organ damage and early mortality. Although T2D is considered best managed with lifestyle modification, medical management, and pharmacotherapy, recent studies have confirmed the superiority of metabolic surgery to conventional treatment algorithms as a path to remission. Increasing access to metabolic surgery will continue to yield benefits to patient health and improve the macroeconomic health of the world.

Gastrointestinal pH, Motility Patterns, and Transit Times After Roux-en-Y Gastric Bypass

BACKGROUND

Studies investigating the underlying pathophysiology are needed to help explain and understand the postoperative complications following Roux-en-Y gastric bypass (RYGB) surgery. This study aimed to characterize segmental gastrointestinal pH profiles, motility measures, and transit times in patients with RYGB.

MATERIALS AND METHODS

Nineteen patients with RYGB underwent a standardized wireless motility capsule assessment. The oro-cecal segment was defined from capsule ingestion until the passage of the ileocecal junction. Segmental median pH, motility index, and transit time were determined for the oro-cecal and colonic segment as well as for the first and last hour of both these segments. For comparison to reference values, data from 17 healthy age- and gender-matched controls was used. A mixed effect model was used to describe differences between groups.

RESULTS

Median pH was high in patients with RYGB during the first hour of the oro-cecal segment (6.45 ± 0.4 vs 3.65 ± 1.55 pH units for healthy controls; P < 0.001), as well as during the entire oro-cecal segment (6.97 ± 0.4 vs 5.51 ± 1.1 pH units; P < 0.001). The same was evident for the median motility index (152 ± 64 vs 35.8 ± 31.1 mmHg*sec/min; P < 0.001 and 130 ± 65.9 vs 89.1 ± 20 mmHg*sec/min; P < 0.012, respectively). Median motility index was low the first hour of the colon (55.2 ± 45.7 vs 122 ± 77.9 mmHg*sec/min; P < 0.002). Additionally, patients had short oro-cecal transit time (5.8 ± 1.6 vs 7.6 ± 1.4 h; P < 0.001) and long colonic transit time (29.4 ± 17.5 vs 19.6 ± 12.2 h; P = 0.048).

CONCLUSIONS

In patients with RYGB, the oro-cecal segment was characterized by an alkaline intraluminal environment, high motility activity, and short transit time. In contrast, colonic transit time was long.

Orosensory Perception of Fat/Sweet Stimuli and Appetite-Regulating Peptides before and after Sleeve Gastrectomy or Gastric Bypass in Adult Women with Obesity

The aim of this study was to explore the impact of bariatric surgery on fat and sweet taste perceptions and to determine the possible correlations with gut appetite-regulating peptides and subjective food sensations. Women suffering from severe obesity (BMI > 35 kg/m2) were studied 2 weeks before and 6 months after a vertical sleeve gastrectomy (VSG, n = 32) or a Roux-en-Y gastric bypass (RYGB, n = 12). Linoleic acid (LA) and sucrose perception thresholds were determined using the three-alternative forced-choice procedure, gut hormones were assayed before and after a test meal and subjective changes in oral food sensations were self-reported using a standardized questionnaire. Despite a global positive effect of both surgeries on the reported gustatory sensations, a change in the taste sensitivity was only found after RYGB for LA. However, the fat and sweet taste perceptions were not homogenous between patients who underwent the same surgery procedure, suggesting the existence of two subgroups: patients with and without taste improvement. These gustatory changes were not correlated to the surgery-mediated modifications of the main gut appetite-regulating hormones. Collectively these data highlight the complexity of relationships between bariatric surgery and taste sensitivity and suggest that VSG and RYGB might impact the fatty taste perception differently.

Do Gut Hormones Contribute to Weight Loss and Glycaemic Outcomes after Bariatric Surgery?

Bariatric surgery is an effective intervention for management of obesity through treating dysregulated appetite and achieving long-term weight loss maintenance. Moreover, significant changes in glucose homeostasis are observed after bariatric surgery including, in some cases, type 2 diabetes remission from the early postoperative period and postprandial hypoglycaemia. Levels of a number of gut hormones are dramatically increased from the early period after Roux-en-Y gastric bypass and sleeve gastrectomy—the two most commonly performed bariatric procedures—and they have been suggested as important mediators of the observed changes in eating behaviour and glucose homeostasis postoperatively. In this review, we summarise the current evidence from human studies on the alterations of gut hormones after bariatric surgery and their impact on clinical outcomes postoperatively. Studies which assess the role of gut hormones after bariatric surgery on food intake, hunger, satiety and glucose homeostasis through octreotide use (a non-specific inhibitor of gut hormone secretion) as well as with exendin 9–39 (a specific glucagon-like peptide-1 receptor antagonist) are reviewed. The potential use of gut hormones as biomarkers of successful outcomes of bariatric surgery is also evaluated.

Resolution of confluent and reticulated papillomatosis after bariatric surgery

Confluent and reticulated papillomatosis (CARP), a rare dermatologic disorder characterized by hyperpigmented papules that subsequently develop into plaques with reticulated margins, is frequently confused with acanthosis nigricans. The aetiology and pathogenesis of CARP is not yet fully understood, but it is often present in individuals with obesity and PCOS. This case report describes an African American adolescent female with obesity with a rash diagnosed as CARP after unsuccessful treatment with antifungals and corticosteroids. Her dermatosis proved recalcitrant to antibiotics and metformin but started to resolve immediately after bariatric surgery. This case report supports insulin resistance as a contributor to CARP's pathogenesis and as well as its association with obesity. Clinically significant weight reduction should be considered in the management of this challenging skin condition.

Gut-adipose tissue crosstalk: A bridge to novel therapeutic targets in metabolic syndrome?

The gut is one of the main endocrine organs in our body, producing hormones acknowledged to play determinant roles in controlling appetite, energy balance and glucose homeostasis. One of the targets of such hormones is the adipose tissue, a major energetic reservoir, which governs overall metabolism through the secretion of adipokines. Disturbances either in nutrient and metabolic sensing and consequent miscommunication between these organs constitute a key driver to the metabolic complications clustered in metabolic syndrome. Thus, it is essential to understand how the disruption of this crosstalk might trigger adipose tissue dysfunction, a strong characteristic of obesity and insulin resistance. The beneficial effects of metabolic surgery in the amelioration of glucose homeostasis and body weight reduction allowed to understand the potential of gut signals modulation as a treatment for metabolic syndrome-related obesity and type 2 diabetes. In this review, we cover the effects of gut hormones in the modulation of adipose tissue metabolic and endocrine functions, as well as their impact in tissue plasticity. Furthermore, we discuss how the modulation of gut secretome, either through surgical procedures or pharmacological approaches, might improve adipose tissue function in obesity and metabolic syndrome.