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.

Benefits of Adjuvant Medical Weight Loss Intervention in Setting of Weight Regain and Inadequate Weight Loss After Weight Loss Surgery.

BACKGROUND: Currently, there is no nationally accepted protocol for addressing weight regain or inadequate weight loss after MBS. OBJECTIVES: To devise, implement, and evaluate a protocol targeting weight regain or inadequate weight loss in MBS patients at our institution. SETTING: Vanderbilt University Medical Center, Nashville, TN, United States. METHODS: Patients at least 6 months following primary sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) who achieved or were trending toward <50% excess body weight loss or who regained ≥10% of their lowest postoperative weight, were identified and referred for medical weight loss (MWL) intervention. Exclusion criteria were body mass index (BMI) ≤ 27 kg/m2, treatment with adjustable gastric banding, and conversion from SG to RYGB. RESULTS: 2274 patients who were >6 months out from surgery were evaluated over 12 months. 93 patients (86% female) met criteria for inclusion. 69 (74%) patients agreed to intervention and were followed for an average of 165 days (SD 106.89 days), demonstrating a mean weight change of -5.11 kg (SD 6.86 kg), and BMI change of -1.81 kg/m2 (SD 2.37 kg/m2). Patients who spent <90 days in a MWL program demonstrated less average weight loss (1.75 kg vs 6.48 kg) (P = .0042), and less change in BMI (-.63 kg/m2 vs -2.29 kg/m2) (P = .0037) when compared to patients who spent >90 days in the MWL intervention. CONCLUSIONS: This study identifies criteria for intervention in patients suffering weight regain or inadequate weight loss after MBS and demonstrates that standardized identification and referral for treatment results in modest weight loss.

Prevalence of thiamine deficiency is significant in patients undergoing primary bariatric surgery.

BACKGROUND: Patients undergoing metabolic and bariatric surgery are prone to developing micronutrient deficiencies, necessitating life-long nutritional supplementation and monitoring. Historically, these deficiencies were thought to be driven by postsurgical changes in absorption. Recent data, though, have demonstrated that obesity alone is also associated with micronutrient deficiencies. Thiamine deficiency, in particular, can lead to permanent neurologic deficits. OBJECTIVE: Identify thiamine deficiency prevalence within the preoperative metabolic and bariatric surgery patient population. SETTING: Single institution academic medical center. METHODS: A retrospective review of deidentified data was examined that included whole blood thiamine measured from consecutive patients from April 2018 to June 2019 (n = 346). Cohort characteristics were assessed including age, operation, preoperative weight, and race/ethnicity. The majority of the cohort were women (83%) with an average age of 44.9 years. Racial representation included White/Caucasian (73%) and Black (21%), while operations included Roux-en-Y gastric bypass (58%), sleeve gastrectomy (31%), and revisions (10%). RESULTS: Thiamine concentration was normally distributed with a mean of 144 nM. Overall, 3.5% of patients had thiamine concentrations below the lower limit of normal of <70 nM, while 35 additional patients (14%) were at risk for thiamine deficiency with concentrations <100 nM. On the average, these patients were of similar age and were all undergoing primary procedures (50% gastric bypass, 50% sleeve gastrectomy). Regression methods demonstrated that patients with thiamine deficiency tended to be females with higher body mass index, even after controlling for sex, height, and preoperative weight. After covariate adjustment, male sex and increasing height were both associated with higher thiamine concentration. CONCLUSION: Previously quoted rates of thiamine deficiency in the preoperative patient are variable, but we describe a significant number of patients with, or at risk of, thiamine deficiency. Male sex and increasing height are likely associated with increased skeletal muscle mass, which is enriched with thiamine. Routine thiamine measurement, either preoperatively or at the time of surgery, is warranted given its limited stores within the body and potential catastrophic complications associated with acute or chronic deficiency.

Cardiovascular risk reduction following metabolic and bariatric surgery.

Cardiovascular disease (CVD) is the world's leading cause of mortality and obesity is a well-recognized risk factor of CVD. Early detection and management of CVD is critical to reduce CVD risk. Especially in patients suffering from obesity with obesity-related CVD risk factors such as hypertension (HTN), dyslipidemia, and diabetes mellitus (DM). A substantial and sustained decrease in body weight after metabolic and bariatric surgery is associated with a significant reduction of cardiovascular risk factors. This article reviews CVD risk models, mechanisms of CVD risk associated with obesity, and overall CVD risk reduction between different metabolic and bariatric procedures.

Change in Total Body Water as a Metric for Predicting Need for Outpatient Intravenous Fluids in Postoperative Bariatric Patients.

BACKGROUND: Dehydration drives a significant proportion of readmissions following bariatric surgery. Routinely performed body composition testing and total body water (TBW) calculations may present a novel method for diagnosing dehydration for outpatient intervention. We sought to determine if a change in TBW from preoperative baseline could help identify bariatric patients requiring outpatient intravenous fluid (IVF) administration for dehydration. METHODS: The VUMC Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database was retroactively queried for all patients undergoing bariatric surgery at an accredited bariatric surgery center from January 1, 2017 to May 31, 2018. Body composition test results presurgery and postsurgery were extracted from the electronic health record. Change in TBW was compared between patients requiring outpatient IVF and those who did not use multivariable logistic regression. RESULTS: 583 patients underwent surgery over the study period (388 laparoscopic Roux-en-Y gastric bypass, 195 sleeve). 62 (10.6%) required outpatient fluid administration for dehydration. After multivariable analysis, patients with an increased hospital length of stay at index operation were more likely to require outpatient IVF (odds ratio [OR] 1.65, 95% CI 1.22-2.2). Preexisting diabetes diagnosis was protective (OR 0.35, 95% CI 0.16-0.74). Neither 1-week nor 1-month change in TBW from preoperative baseline was significantly different between patients receiving outpatient IVF and those who did not. CONCLUSION: Increased hospital length of stay predicts patients at risk of postoperative dehydration requiring IVF administration. Body composition testing and TBW were not useful in distinguishing between populations. Further research is needed to examine the efficacy of outpatient IVF in preventing hospital readmissions for dehydration.

Efficacy and Safety of Recurrent Paraesophageal Hernia Repair with Roux-en-Y Gastric Bypass.

Roux-en-Y gastric bypass (RYGB) has been explored as a revisional option to failed paraesophageal hernia (PEH) repair with fundoplication, particularly in patients suffering from obesity. However, few studies have assessed long-term outcomes of RYGB with revisional PEH repair in regard to acid-suppressing medication use. We retrospectively identified 19 patients who underwent revisional PEH repair with RYGB between 2011 and 2018. The median operative time was 232 minutes with a median hospital length of stay of two days. The median length of follow-up was 24 months. Two patients (10.5%) had complications in the first 30 days, and five patients (26.3%) had complications within one year. Of the 12 patients on preoperative acid suppression, 6 (50%) were either off medication or on reduced dose at 12 months. The median BMI decrease was 14.4 kg/m² at 12 months and did not change significantly afterward. Although rates of acid-suppression medication use did not change overall after revisional PEH repair with RYGB, patients experienced successful long-term management of morbid obesity and sustained weight loss. Revisional PEH repair with RYGB is a safe and effective option, with a complication rate comparable with the reported rates after revisional foregut procedures such as revisional Nissen fundoplication.

Metabolic and Bariatric Surgery: An Effective Treatment Option for Obesity and Cardiovascular Disease.

Obesity is a chronic and debilitating disease that has become a global epidemic. Especially severe in the Unites States, obesity currently affects almost 40% of the population. Obesity has a strong causal relationship with numerous serious comorbidities that impair quality of life, shorten life expectancy, and carry a major economic burden. Obesity has particular relevance to cardiologists because it contributes directly to several major cardiovascular diseases and, consequently, increases overall cardiovascular mortality. Multiple treatment options are available, but metabolic and bariatric surgery offers the most effective and durable treatment for obesity. Moreover, metabolic and bariatric operations alleviate and often completely eliminate numerous comorbidities, particularly type 2 diabetes and other cardiovascular risk factors, such as hypertension and dyslipidemia. With their low risk of complications and morbidity, metabolic and bariatric operations significantly improve quality of life and overall survival, particularly reducing death due to cardiovascular disease.

Effect of laparoscopic Roux-en-Y gastric bypass versus laparoscopic sleeve gastrectomy on fasting gastrointestinal and pancreatic peptide hormones: A prospective nonrandomized trial.

BACKGROUND: Changes in gastrointestinal and pancreatic hormones may play a role in promoting long-term weight reduction and improved glucose metabolism after sleeve gastrectomy and Roux-en-Y gastric bypass. However, few studies have examined the metabolic and endocrine effects of these procedures in Mainland China. OBJECTIVES: To compare the effects of laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) on gastrointestinal and pancreatic peptide hormones. SETTING: University hospital, China. METHODS: A nonrandomized prospective study was conducted in Chinese obese patients undergoing LSG or LRYGB. Of 20 patients in this study, 10 underwent LSG, and 10 underwent LRYGB. Fasting plasma levels of insulin, glucagon, ghrelin, gastric inhibitory peptide, peptide YY, glucagon-like peptide (GLP)-1, and GLP-2 were measured preoperatively and at 1, 3, 6, and 12 months after surgery. This trial was registered at www.clinicaltrials.gov (NCT02963662). RESULTS: During the first year after both operations, mean body mass index and fasting insulin levels steadily decreased at all intervals. Fasting plasma glucose levels significantly decreased at 1 month after surgery, then remained stable in both groups. Glucagon levels significantly decreased at 1, 3, and 6 months after surgery in both groups, but returned to baseline at 12 months. Fasting GLP-1 and peptide YY significantly increased in both groups, but more so after LRYGB. However, GLP-2 did not change in either group. Ghrelin levels significantly decreased after LSG, but not after LRYGB. Gastric inhibitory peptide levels decreased after LRYGB but not after LSG. CONCLUSIONS: LSG and LRYGB resulted in significant and distinct changes in multiple gastrointestinal and pancreatic peptide hormones that are important regulators of obesity and metabolic health.

Gastric bypass reduces biochemical cardiac risk factors.

BACKGROUND: Coronary artery disease (CAD) is the leading cause of death in the United States, with obesity as a leading preventable risk factor for CAD. Certain biochemical markers have demonstrated strong prediction for cardiovascular events. We hypothesized that in addition to weight reduction, gastric bypass will also induce a salutary effect on the biochemical cardiac risk factors. METHODS: At a single academic institution, from 2003 to 2004, we measured the biochemical cardiac risk factors in gastric bypass patients preoperatively and at 3, 6, and 12 months postoperatively. These risk factors included total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, total cholesterol/HDL cholesterol ratio, triglyceride/HDL cholesterol ratio, triglycerides, lipoprotein A, high-sensitivity C-reactive protein, and homocysteine. The data were analyzed using the Wilcoxon signed rank test. RESULTS: The mean age of the 356 patients was 43 years; 84% were women; the mean body mass index was 47 kg/m(2); 33% were diabetic; 50% were hypertensive; 23% were taking lipid-lowering medications; and 2% had known CAD. Significant improvement occurred in the biochemical cardiac factors from preoperatively to 12 months. The beneficial changes were as follows: total cholesterol, 192 mg/dL preoperatively to 166 mg/dL at 12 months; HDL cholesterol, 46 mg/dL preoperatively to 54 mg/dL at 12 months; low-density lipoprotein, 125 mg/dL preoperatively to 88 mg/dL at 12 months; total cholesterol/HDL cholesterol ratio, 4 preoperatively to 3 at 12 months; triglyceride/HDL cholesterol ratio, 3 preoperatively to 2 at 12 months; triglycerides, 133 mg/dL preoperatively to 92 mg/dL at 12 months; lipoprotein A, 14 mg/dL preoperatively to 13 mg/dL at 12 months; high-sensitivity C-reactive protein, 8 mg/L preoperatively to 1 mg/L; and homocysteine, 10 mumol/L preoperatively to 8 mumol/L at 12 months. CONCLUSIONS: The results of our study have shown that gastric bypass significantly improves all biochemical markers of CAD risk, particularly C-reactive protein, which had an 80% reduction. As a result, gastric bypass decreases the cardiac risk by both weight loss and advantageous alterations of biochemical cardiac risk factors.

Endoscopic management of erosion after banded bariatric procedures.

BACKGROUND: Prosthetic materials wrapped around a portion of the stomach have been used to provide gastric restriction in bariatric surgery for many years. Intraluminal erosion of adjustable and nonadjustable gastric bands typically occurs many years after placement and results in various symptoms. Endoscopic management of gastric band erosion has been described and allows for optimal patient outcomes. OBJECTIVES: We will describe our methods and experience with endoscopic management of intraluminal gastric band erosions after bariatric procedures. SETTING: University hospital in the United States. METHODS: A retrospective review of our bariatric surgery database identified patients undergoing removal of gastric bands. A chart review was then undertaken to confirm erosion of prosthetic material into the gastrointestinal tract. Baseline characteristics, operative reports, and follow-up data were analyzed. RESULTS: Sixteen patients were identified with an eroded gastric band: 11 after banded gastric bypass, 3 after laparoscopic adjustable gastric band (LAGB), and 2 after vertical banded gastroplasty. All patients were successfully treated with endoscopic removal of the prosthetic materials using either endoscopic scissors or ligation of the banding material with off-label use of a mechanical lithotripter device. Complications included a postoperative gastrointestinal bleed requiring repeat endoscopy, 1 patient with asymptomatic pneumoperitoneum requiring observation, and 1 with seroma at the site of LAGB port removal. CONCLUSIONS: Endoscopic management of intraluminal prosthetic erosion after gastric banded bariatric procedures can be safe and effective and should be considered when treating this complication. Erosion of the prosthetic materials inside the gastric lumen allows for potential endoscopic removal without free intraabdominal perforation. Endoscopic devices designed for dividing eroded LAGBs may help standardize and increase utilization of this approach.

Prevalence and predictors of atrial fibrillation among patients undergoing bariatric surgery.

BACKGROUND: While AF is a disease of the elderly, it can occur earlier in the presence of risk factors such as obesity. Bariatric surgery patients are significantly younger and more obese than previously described populations with AF. Therefore, it remains to be determined whether current estimates of the prevalence and predictors for AF remain true in the bariatric surgery population. METHODS: We performed a cross-sectional analysis of 1,341 consecutive patients who underwent bariatric surgery from January 2008 to October 2012. Baseline characteristics were compared between patients with and without AF. For additional comparison, 176 patients with AF and body mass index (BMI) >40 kg/m(2) were identified from the Vanderbilt AF Registry. A multivariable logistic regression was performed to identify predictors of AF within the bariatric surgery cohort. RESULTS: The prevalence of AF in the bariatric surgery cohort was 1.9 % (25/1,341). Patients with AF were older (median 56 years (interquartile range [52-64) vs.46 [38-56] years, p < 0.001), were more often male (48 vs. 23 %, p = 0.004), had more comorbidities, but had no difference in BMI (50 kg/m(2) [44-58] vs. 48 [43-54], p = 0.4). In multivariable analysis, the odds of AF increased 2.2-fold by age per decade (95 % CI, 1.4-3.5; p < 0.001) and 2.4-fold by male gender (1.1-5.4, p = 0.03) when adjusted for BMI. BMI was not independently associated with AF (OR 1.15 [95 % CI, 0.98-1.41], p = 0.09). CONCLUSIONS: The prevalence of AF is 1.9 % among patients undergoing bariatric surgery. Risk of AF was found to increase with age and male gender, but not with higher BMI.

Reduction in inflammatory gene expression in skeletal muscle from Roux-en-Y gastric bypass patients randomized to omentectomy.

OBJECTIVES: To examine the effects of Roux-en-Y gastric bypass (RYGB) surgery with and without laparoscopic removal of omental fat (omentectomy) on the temporal gene expression profiles of skeletal muscle. DESIGN: Previously reported were the whole-body metabolic effects of a randomized, single-blinded study in patients receiving RYGB surgery stratified to receive or not receive omentectomy. In this follow up study we report on changes in skeletal muscle gene expression in a subset of 21 patients, for whom biopsies were collected preoperatively and at either 6 months or 12 months postoperatively. METHODOLOGY/PRINCIPAL FINDINGS: RNA isolated from skeletal muscle biopsies of 21 subjects (8 without omentectomy and 13 with omentectomy) taken before RYGB or at 6 and 12 months postoperatively were subjected to gene expression profiling via Exon 1.0 S/T Array and Taqman Low Density Array. Robust Multichip Analysis and gene enrichment data analysis revealed 84 genes with at least a 4-fold expression difference after surgery. At 6 and 12 months the RYGB with omentectomy group displayed a greater reduction in the expression of genes associated with skeletal muscle inflammation (ANKRD1, CDR1, CH25H, CXCL2, CX3CR1, IL8, LBP, NFIL3, SELE, SOCS3, TNFAIP3, and ZFP36) relative to the RYGB non-omentectomy group. Expressions of IL6 and CCL2 were decreased at all postoperative time points. There was differential expression of genes driving protein turnover (IGFN1, FBXW10) in both groups over time and increased expression of PAAF1 in the non-omentectomy group at 12 months. Evidence for the activation of skeletal muscle satellite cells was inferred from the up-regulation of HOXC10. The elevated post-operative expression of 22 small nucleolar RNAs and the decreased expression of the transcription factors JUNB, FOS, FOSB, ATF3 MYC, EGR1 as well as the orphan nuclear receptors NR4A1, NR4A2, NR4A3 suggest dramatic reorganizations at both the cellular and genetic levels. CONCLUSIONS/SIGNIFICANCE: These data indicate that RYGB reduces skeletal muscle inflammation, and removal of omental fat further amplifies this response. TRIAL REGISTRATION: ClinicalTrials.gov NCT00212160.

Decreased dopamine type 2 receptor availability after bariatric surgery: preliminary findings.

BACKGROUND: Diminished dopaminergic neurotransmission contributes to decreased reward and negative eating behaviors in obesity. Bariatric surgery is the most effective therapy for obesity and rapidly reduces hunger and improves satiety through unknown mechanisms. We hypothesized that dopaminergic neurotransmission would be enhanced after Roux-en-Y-Gastric Bypass (RYGB) and Vertical Sleeve Gastrectomy (VSG) surgery and that these changes would influence eating behaviors and contribute to the positive outcomes from bariatric surgery. METHODS: Five females with obesity were studied preoperatively and at approximately 7 weeks after RYGB or VSG surgery. Subjects underwent positron emission tomography (PET) imaging with a dopamine type 2 (DA D2) receptor radioligand whose binding is sensitive to competition with endogenous dopamine. Regions of interest (ROI) relevant to eating behaviors were delineated. Fasting enteroendocrine hormones were quantified at each time point. RESULTS: Body weight decreased as expected after surgery. DA D2 receptor availability decreased after surgery. Regional decreases (mean+/-SEM) were caudate 10+/-3%, putamen 9+/-4%, ventral striatum 8+/-4%, hypothalamus 9+/-3%, substantia nigra 10+/-2%, medial thalamus 8+/-2%, and amygdala 9+/-3%. These were accompanied by significant decreases in plasma insulin (62%) and leptin (41%). CONCLUSION: The decreases in DA D2 receptor availability after RYGB and VSG most likely reflect increases in extracellular dopamine levels. Enhanced dopaminergic neurotransmission may contribute to improved eating behavior (e.g. reduced hunger and improved satiety) following these bariatric procedures.