Early marginal ulceration prevalence following primary RYGB: a rare events model of the MBSAQIP 2015-2021.

PURPOSE: Marginal ulceration (MU) following Roux-en-Y gastric bypass (RYGB) is an established complication, with early MU (within 30-days of operation) being less understood compared to its late counterpart. This study aims to identify risk factors for early MU in patients undergoing primary RYGB. METHODS: Utilizing data from the Metabolic and Bariatric Surgery Accreditation Quality Improvement Project (MBSAQIP 2015-2021), 1,346,468 records were evaluated. After exclusions for revisions, conversions, pediatric cases, nonbinary gender, missing body mass index (BMI) data, and missing operative time; 291,625 cases of primary RYGB were included for full analysis and rare events modeling of early MU. RESULTS: The prevalence of early MU was .29% (n = 850). Higher rates of early MU were associated with BMI, race, history of diabetes mellitus (DM), prior thrombotic complications (deep vein thrombosis (DVT) and pulmonary embolism (PE)), prior percutaneous cardiac intervention (PTC), immunosuppressive therapy, and anticoagulation status. Additionally, procedural aspects like the nonspecialization of the surgeon and longer operative times also correlated with higher early MU rates. Rare-events regression modeling noted significant associations of early MU with younger age, diabetes requiring insulin, history of PTC, DVT, immunosuppressive therapy, and anticoagulation status. CONCLUSION: Early MU remains a relatively rare complication. The lower than previously reported occurrence suggests possible improvements in both patient preparation and surgical technique. The identification of relevant risk factors enables better perioperative and intraoperative management of patients at risk of developing early MU.

Impact of progressive chronic kidney disease stage on postoperative outcomes in metabolic surgery-a propensity-matched analysis using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement database.

BACKGROUND: Metabolic surgery (MS) is effective in improving renal parameters for individuals with obesity and chronic kidney disease (CKD). Despite recognized benefits, concerns linger about the perioperative safety of patients with CKD undergoing MS. This study aimed to identify the CKD stage associated with the most significant increase in postoperative complications. METHODS: The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database (2017-2021) was used to identify patients undergoing laparoscopic gastric sleeve (SG) or Roux-en-Y gastric bypass (RYGB). Propensity matching was used to quantify the risk for adverse outcomes associated with progressive CKD stage. RESULTS: In total, 688,583 patients (483,898 without CKD and 204,685 with CKD stages I-V) were examined. Endpoints included length of stay (LOS) >5 days, infection, serious complications, major adverse cardiovascular events (MACE), and death. Both SG and RYGB exhibited a linear increase in risk of infection and death. For SG, patients who were stage IIIa/IIIb demonstrated the greatest risk for LOS >5 days (odds ratio [OR] 1.23; 95% confidence interval [CI] (1.05-1.45); P = .011), serious complications (OR 2.83; 95% CI 1.87-4.30; P < .001), and MACE (OR 2.82; 95% CI 1.81-4.37; P < .001). For RYGB, patients who were stage IIIa/IIIb the exhibited greatest risk of MACE (OR 1.67; 95% CI 1.06-2.62; P = .027). CONCLUSIONS: Although it is generally accepted that worsening CKD correlates with greater surgical risk, this analysis identified CKD stage III as a major inflection point for risk of LOS >5 days, serious complications, and MACE. These findings are useful for counseling and procedure selection and suggest a need for heightened attention to CKD stage III patients undergoing MS.

Clinical Outcomes of Metabolic Surgery on Diuretic Use in Patients With Heart Failure.

The beneficial impacts of metabolic surgery (MS) on patients with heart failure (HF) are incompletely characterized. We aimed to describe the cardiac and metabolic effects of MS in patients with HF and hypothesized that patients with HF would experience both improved metabolic and HF profiles using glycemic control and diuretic dependency as surrogate markers. In this single-center, university-affiliated academic study in the United States, a review of 2,342 hospital records of patients who underwent MS (2017 to 2023) identified 63 patients with a medical history of HF. Preoperative characteristics, 30-day outcomes, and up to 2-year biometric and metabolic outcomes, medication usage, and emergency department utilization were collected. At 24 months, mean body mass index change was -16 kg/m2 (p <0.001) that corresponded to a mean percentage total body weight loss of 29% (p <0.001). Weight loss was accompanied by significant reductions in hemoglobin A1c (p <0.001) and a 65% decrease in diuretic use at 24 months after surgery (p <0.001). Similarly, emergency visits for cardiac conditions (p = 0.06) and intravenous diuresis (p = 0.07) trended favorably at 1 year after surgery compared with 1 year before surgery but were not statistically significant. In conclusion, in patients with HF who were carefully selected, MS appears to provide significant reduction in oral diuretic dependency, and metabolic improvements with trends toward lower rates of emergency department utilization.

BMI ≥ 70: A Multi-Center Institutional Experience of the Safety and Efficacy of Metabolic and Bariatric Surgery Intervention.

PURPOSE: With the escalating prevalence of obesity, healthcare providers are increasingly managing patients with a body mass index (BMI) exceeding 70. The aim of this study was to describe the perioperative experiences of this demographic group at two institutions. METHODS: An analysis encompassing 84 patients presenting with BMI ≥ 70 kg/m2 from two institutions was conducted. Data included patient demographics, 30-day postoperative outcomes, and weight-loss at different intervals (30 days, 6 months, 1 year). Additionally, rates of emergency department (ED) utilization, readmission, and reoperation in the first postoperative year were examined. RESULTS: Most patients were black (66.7%) and female (86.9%) with a mean age of 41.7 years. The majority underwent laparoscopic sleeve gastrectomy (SG, 88.1%). Patients exhibited a marked decrease in BMI (7.84% at 30 days, 20.13% at 6 months, and 26.83% at 1 year). Average length of stay was comparable across procedure (F(3,80) = 0.016, p = .997). While 30-day complications were minimal (0.7%), 14.4% of patients experienced ED visits within 30 days, escalating to 19.6% by six months and 25% at 1 year. Readmission and reoperation rates at 1 year were 6.45% and 4.83%, respectively. CONCLUSION: With global obesity rates rising, clinicians are being challenged to care for patients with BMI ≥ 70 kg/m2. Analysis of two institutions demonstrated low rates of 30-days complications but increased readmission rates and ED utilization in this patient population. Despite increased resource utilization, the study suggests that BMI ≥ 70 kg/m2 alone should not be a deterrent for surgery, emphasizing the need for nuanced care in this expanding demographic.

Insurance payor status and risk of major adverse cardiovascular and cerebrovascular events after metabolic and bariatric surgery.

BACKGROUND: Patients with Medicare/Medicaid insurance receive metabolic and bariatric surgery (MBS) at lower rates than privately insured (PI) patients. Although studies on some surgical procedures report that Medicare/Medicaid insurance confers increased postoperative complication rates and a longer length of stay, less is known about these outcomes after MBS. Among often-feared postoperative complications are major adverse cardiovascular and cerebrovascular events (MACEs). Although these events are rare after MBS, they have a significant impact on morbidity and mortality. OBJECTIVES: This study aimed to examine the effect of insurance payor status on MACEs after MBS. SETTING: The Healthcare Cost and Utilization Project National Inpatient Sample (HCUP-NIS). METHODS: HCUP-NIS was queried for cases including sleeve gastrectomy or Roux-en-Y gastric bypass between 2012 and 2019. Bivariate associations between patient-level factors and MACEs were assessed via Rao-Scott χ2 tests. Adjusted and unadjusted risks of insurance payor status for MACEs were evaluated using logistic regression. RESULTS: Incidence of MACEs was higher in both Medicare (.75% versus .11%; P < .001) and Medicaid (.15% versus .11%; P < .001) groups than in the PI group. After adjustment for high-risk demographics, high-risk co-morbidities, socioeconomic variables, and hospital factors, insurance status of Medicare (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.23, 2.07; P = .0026) or Medicaid (OR: 1.55, 95% CI: 1.12, 2.16; P = .0026) remained an independent risk factor for MACEs. CONCLUSIONS: Our findings underscore the significance of Medicaid/Medicare payor status as an independent predictor of postoperative MACEs in MBS. The results of this study can have a significant impact on deepening our understanding of socioeconomic and health system-related issues that can be targeted to improve outcomes in both MBS and other surgical specialties.

FGF21 as a mediator of adaptive changes in food intake and macronutrient preference in response to protein restriction.

Free-feeding animals navigate complex nutritional landscapes in which food availability, cost, and nutritional value can vary markedly. Animals have thus developed neural mechanisms that enable the detection of nutrient restriction, and these mechanisms engage adaptive physiological and behavioral responses that limit or reverse this nutrient restriction. This review focuses specifically on dietary protein as an essential and independently defended nutrient. Adequate protein intake is required for life, and ample evidence exists to support an active defense of protein that involves behavioral changes in food intake, food preference, and food motivation, likely mediated by neural changes that increase the reward value of protein foods. Available evidence also suggests that the circulating hormone fibroblast growth factor 21 (FGF21) acts in the brain to coordinate these adaptive changes in food intake, making it a unique endocrine signal that drives changes in macronutrient preference in the context of protein restriction. This article is part of the Special Issue on "Food intake and feeding states".

Limitations of the 2015-2021 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database for emergency bariatric operations.

BACKGROUND: The Metabolic and Bariatric Surgery Quality Improvement Project (MBSAQIP) is the largest bariatric surgery-specific clinical data set. OBJECTIVES: In 2020, the definition of emergency cases was altered to include only revisional or conversion cases and not primary cases. The aim of this study was to examine how this change affects the utility of the data set for emergency case tracking. SETTING: MBSAQIP database. METHODS: Emergency cases were extracted from available MBSAQIP data (2015-2021). A comparison of co-morbidity profiles was done, specifically before and after the recent change to how "emergency" is defined in the data set. RESULTS: Eleven thousand and twenty-nine of the 1,048,575 total cases were coded as "emergency cases." From 2015 to 2019, 10,574 emergency cases were performed (∼2115 cases/yr), markedly decreasing in 2020 and 2021 to 455 cases (∼228 cases/yr). Before 2020, the most common procedures were the unlisted procedure of the stomach (45.14%, n = 3101), gastric band removal (25.3%, n = 2676), and reduction of internal hernia (11.8%, n = 1244). Between 2020 and 2021, this distribution changed with Roux-en-Y gastric bypass (RYGB), the most common emergency procedure (29.23%, n = 133). As expected from the change that captured only revisional cases, the average operative length was greater between 2020 and 2021 (127.6 versus 86.5 min). CONCLUSIONS: Capturable emergency cases declined in 2020, a trend related to changing the definition of emergency as part of MBSAQIP standards. This change excludes data on internal hernia reduction and does not likely reflect a real change in the prevalence of emergency bariatric cases. Because capture for emergency cases has diminished, so has any prior utility of using MBSAQIP data for studying emergency cases.

FGF21 acts in the brain to drive macronutrient-specific changes in behavioral motivation and brain reward signaling.

Dietary protein restriction induces adaptive changes in food preference, increasing protein consumption over carbohydrates or fat. We investigated whether motivation and reward signaling underpin these preferences. In an operant task, protein-restricted male mice increased their responding for liquid protein rewards, but not carbohydrate, fat, or sweet rewards. The protein restriction-induced increase in operant responding for protein was absent in Fgf21-KO mice and mice with neuron-specific deletion of the FGF21 co-receptor beta-Klotho (KlbCam2ka) mice. Fiber photometry recording of VTA dopamine neurons revealed that oral delivery of maltodextrin triggered a larger activation of dopamine neurons as compared to casein in control-fed mice, while casein produced a larger response in protein-restricted mice. This restriction-induced shift in nutrient-specific VTA dopamine signaling was lost in Fgf21-KO mice. These data demonstrate that FGF21 acts in the brain to induce a protein-specific appetite by specifically enhancing the reward value of protein-containing foods and the motivation to consume them.

Sex- and operation-dependent effects on 5-year weight loss results of bariatric surgery.

BACKGROUND: Weight loss response after bariatric surgery is highly variable, and several demographic factors are associated with differential responses to surgery. Preclinical studies demonstrate numerous sex-specific responses to bariatric surgery, but whether these responses are also operation dependent is unknown. OBJECTIVE: To examine sex-specific weight loss outcomes up to 5 years after laparoscopic Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). SETTING: Single center, university, United States. METHODS: Retrospective, observational cohort study including RYGB (n = 5057) and vertical SG (n = 2041) patients from a single, academic health center. Percentage total weight loss (TWL) over time was examined with generalized linear mixed models to determine the main and interaction effects of surgery type on weight loss by sex. RESULTS: TWL demonstrated a strong sex-by-procedure interaction, with women having a significant advantage with RYGB compared with SG (adjusted difference at 5 yr: 8.0% [95% CI: 7.5-8.5]; P < .001). Men also experienced greater TWL over time with RYGB or SG, but the difference was less and clinically insignificant (adjusted difference at 5 yr: 2.9% [2.0-3.8]; P < .001; P interaction between sex and procedure type = .0001). Overall, women had greater TWL than men, and RYGB patients had greater TWL than SG patients (adjusted difference at 5 yr: 3.1% [2.4-3.2] and 6.9% [6.5-7.3], respectively; both P < .0001). Patients with diabetes lost less weight compared with those without (adjusted difference at 5 yr: 3.0% [2.7-3.2]; P < .0001). CONCLUSIONS: Weight loss after bariatric surgery is sex- and procedure-dependent. There is an association suggesting a clinically insignificant difference in weight loss between RYGB and SG among male patients at both the 2- and 5-year postsurgery time points.

Enhanced Patient Portal Engagement Associated with Improved Weight Loss Outcomes in Post-Bariatric Surgery Patients.

Background: Bariatric surgery is an effective intervention for obesity, but it requires comprehensive postoperative self-management to achieve optimal outcomes. While patient portals are generally seen as beneficial in engaging patients in health management, the link between their use and post-bariatric surgery weight loss remains unclear. Objective: This study investigated the association between patient portal engagement and postoperative body mass index (BMI) reduction among bariatric surgery patients. Methods: This retrospective longitudinal study included patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at Vanderbilt University Medical Center (VUMC) between January 2018 and March 2021. Using generalized estimating equations, we estimated the association between active days of postoperative patient portal use and the reduction of BMI percentage (%BMI) at 3, 6, and 12 months post-surgery. Covariates included duration since surgery, the patient's age at the time of surgery, gender, race and ethnicity, type of bariatric surgery, severity of comorbid conditions, and socioeconomic disadvantage. Results: The study included 1,415 patients, mostly female (80.9%), with diverse racial and ethnic backgrounds. 805 (56.9%) patients underwent RYGB and 610 (43.1%) underwent SG. By one-year post-surgery, the mean (SD) %BMI reduction was 31.1% (8.3%), and the mean (SD) number of patient portal active days was 61.0 (41.2). A significantly positive association was observed between patient portal engagement and %BMI reduction, with variations revealed over time. Each 10-day increment of active portal use was associated with a 0.57% ([95% CI: 0.42- 0.72], P < .001) and 0.35% ([95% CI: 0.22- 0.49], P < .001) %BMI reduction at 3 and 6 months postoperatively. The association was not statistically significant at 12 months postoperatively (ß=-0.07, [95% CI: -0.24- 0.09], P = .54). Various portal functions, including messaging, visits, my record, medical tools, billing, resources, and others, were positively associated with %BMI reduction at 3- and 6-months follow-ups. Conclusions: Greater patient portal engagement, which may represent stronger adherence to postoperative instructions, better self-management of health, and enhanced communication with care teams, was associated with improved postoperative weight loss. Future investigations are needed to identify important portal features that contribute to the long-term success of weight loss management.

Weight-independent effects of Roux-en-Y gastric bypass surgery on remission of nonalcoholic fatty liver disease in mice.

OBJECTIVE: Obesity is a driver of non-alcoholic fatty liver disease (NAFLD), and interventions that decrease body weight, such as bariatric surgery and/or calorie restriction (CR), may serve as effective therapies. This study compared the effects of Roux-en-Y gastric bypass surgery (RYGB) and CR on hepatic function in mice with obesity and NAFLD. METHODS: C57BL/6J mice were fed a high-fat diet to promote obesity. At 16 weeks of age, mice were randomized to sham surgery (sham), RYGB, or CR weight matched to RYGB (WM). Body weight/composition, food intake, and energy expenditure (EE) were measured throughout treatment. Liver histopathology was evaluated from H&E-stained sections. Hepatic enzymes and glycogen content were determined by ELISA. Transcriptional signatures were revealed via RNA sequencing. RESULTS: RYGB reduced hepatic lipid content and adiposity while increasing EE and lean body mass relative to WM. Hepatic glycogen and bile acid content were increased after RYGB relative to sham and WM. RYGB activated enterohepatic signaling and genes regulating hepatic lipid homeostasis. CONCLUSIONS: RYGB improved whole-body composition and hepatic lipid homeostasis to a greater extent than CR in mice. RYGB was associated with discrete remodeling of the hepatic transcriptome, suggesting that surgery may be mechanistically additive to CR.

Bariatric surgery alters mitochondrial function in gut mucosa.

BACKGROUND: The obesity pandemic has worsened global disease burden, including type 2 diabetes, cardiovascular disease, and cancer. Metabolic/bariatric surgery (MBS) is the most effective and durable obesity treatment, but the mechanisms underlying its long-term weight loss efficacy remain unclear. MBS drives substrate oxidation that has been linked to improvements in metabolic function and improved glycemic control that are potentially mediated by mitochondria-a primary site of energy production. As such, augmentation of intestinal mitochondrial function may drive processes underlying the systemic metabolic benefits of MBS. Herein, we applied a highly sensitive technique to evaluate intestinal mitochondrial function ex vivo in a mouse model of MBS. METHODS: Mice were randomized to surgery, sham, or non-operative control. A simplified model of MBS, ileal interposition, was performed by interposition of a 2-cm segment of terminal ileum into the proximal bowel 5 mm from the ligament of Treitz. After a four-week recovery period, intestinal mucosa of duodenum, jejunum, ileum, and interposed ileum were assayed for determination of mitochondrial respiratory function. Citrate synthase activity was measured as a marker of mitochondrial content. RESULTS: Ileal interposition was well tolerated and associated with modest body weight loss and transient hypophagia relative to controls. Mitochondrial capacity declined in the native duodenum and jejunum of animals following ileal interposition relative to controls, although respiration remained unchanged in these segments. Similarly, ileal interposition lowered citrate synthase activity in the duodenum and jejunum following relative to controls but ileal function remained constant across all groups. CONCLUSION: Ileal interposition decreases mitochondrial volume in the proximal intestinal mucosa of mice. This change in concentration with preserved respiration suggests a global mucosal response to segment specific nutrition signals in the distal bowel. Future studies are required to understand the causes underlying these mitochondrial changes.

Combination anti-obesity medications to effectively treat bariatric surgery weight regain at an academic obesity center.

Background: Combination anti-obesity medications (AOMs) to treat postoperative bariatric surgery weight regain have limited data on their use in the clinical setting. Understanding the optimal treatment protocol in this cohort will maximize weight loss outcomes. Methods: A retrospective review of bariatric surgery patients (N = 44) presenting with weight regain at a single academic multidisciplinary obesity center who were prescribed AOM(s) plus intensive lifestyle modification for 12 months. Results: Age: 28-76 years old, 93% female, mean weight 110.2 ± 20.3 kg, BMI 39.7 ± 7.4 kg/m2, presenting 5.2 ± 1.6 years post-bariatric surgery [27 (61.4%), 14 (31.8%), and 3 (6.8%) laparoscopic Roux-en-Y gastric bypass (RYGB), laparoscopic vertical sleeve gastrectomy (VSG), and open RYGB, respectively], with 15.1 ± 11.1 kg mean weight gain from nadir. Mean weight loss after medical intervention at 3-, 6-, and 12-month time points was 4.4 ± 4.6 kg, 7.3 ± 7.0 kg, and 10.7 ± 9.2 kg, respectively. At 12 months, individuals prescribed 3 or more AOMs lost more weight than those prescribed one (-14.5 ± 9.0 kg vs. -4.9 ± 5.7 kg, p < 0.05) irrespective of age, gender, number of comorbidities, initial weight or BMI, type of surgery, or GLP1 use. RYGB patients lost less weight overall (7.4% vs. 14.8% VSG respectively; p < 0.05). Conclusions: Combination AOMs may be needed to achieve optimal weight loss results to treat post-operative weight regain.

The Vagus Nerve Mediates Gut-Brain Response to Duodenal Nutrient Administration.

BACKGROUND: Obesity contributes significant disease burden worldwide, including diabetes, cardiovascular disease, and cancer. While bariatric surgery is the most effective and durable obesity treatment, the mechanisms underlying its effects remain unknown. Although neuro-hormonal mechanisms have been suspected to mediate at least some of the gut-brain axis changes following bariatric surgery, studies examining the intestine and its regionally specific post-gastric alterations to these signals remain unclear. MATERIALS AND METHODS: Vagus nerve recording was performed following the implantation of duodenal feeding tubes in mice. Testing conditions and measurements were made under anesthesia during baseline, nutrient or vehicle solution delivery, and post-delivery. Solutions tested included water, glucose, glucose with an inhibitor of glucose absorption (phlorizin), and a hydrolyzed protein solution. RESULTS: Vagus nerve signaling was detectable from the duodenum and exhibited stable baseline activity without responding to osmotic pressure gradients. Duodenal-delivered glucose and protein robustly increased vagus nerve signaling, but increased signaling was abolished during the co-administration of glucose and phlorizin. DISCUSSION: Gut-brain communication via the vagus nerve emanating from the duodenum is nutrient sensitive and easily measurable in mice. Examination of these signaling pathways may help elucidate how the nutrient signals from the intestine are altered when applied to obesity and bariatric surgery mouse models. Future studies will address quantifying the changes in neuroendocrine nutrient signals in health and obesity, with specific emphasis on identifying the changes associated with bariatric surgery and other gastrointestinal surgery.