Faculty Bibliography

BACKGROUND:Bariatric surgery has long been established as an effective treatment option for obesity and diabetes [Kalainov et al. in J Am Acad Orthop Surg [32(10):427-438, 2025] and Ogden et al. in JAMA 311(8):806-806, 2025. 10.1001/jama.2014.732]. Recently, GLP-1 Receptor Agonists' (GLP-1RAs) use has expanded as an alternative therapy for weight loss and diabetes management. While GLP1RAs are known to be safe and effective, few have compared long term outcomes of GLP-1RAs versus the "gold standard" of bariatric surgery among Medicare/Medicaid patients, who make up the largest payer group in the U.S. [Kalainov et al. in J Am Acad Orthop Surg [32(10):427-438, 2025]. METHODS:This was a retrospective, multicenter study of obese, type-2 diabetic patients (T2D) ≥ 18 years old, who initiated weekly injectable semaglutide or tirzepatide or underwent bariatric surgery between January 1st, 2018 to July 31st, 2024. Patients with a baseline BMI ≤ 35, those with prior GLP1-RA use, or any prior bariatric procedure were excluded from analysis. The primary outcome of interest was % total body weight loss 3 months to 3 years post intervention among bariatrics surgery patients vs. GLP1-RA patients (any GLP1-RA prescription and 12 months continuous GLP1-RA prescription). RESULTS:7667 patients were included for analysis (7200 GLP1-RA, 467 bariatric surgery). Bariatric surgery patients were younger (median (IQR): 43 (34, 53) vs. 65 (54, 72); p < 0.001) and more likely to be female (67.5% vs. 60.8%; p < 0.01) and Hispanic (58.7% vs. 19.4%; p < 0.001) while GLP1-RA users were more likely to be white (58.5% vs. 10.7%; p < 0.001). In models adjusting for demographic and clinical characteristics, bariatric surgery was associated with a 22.9% total weight loss 3 years following surgery compared to 2.3% for patients with any GLP1-RA use, and 15.9% vs 2.4% for patients with 12 months consecutive GLP1-RA use (22.9 [21.0-24.8] vs 2.3 [0.5-4.1], 15.9 [6.9-24.9] vs. 2.4 [6.7-11.5]. CONCLUSIONS:Among obese, T2D, publicly insured patients, bariatric surgery was associated with greater weight loss than GLP1-RAs at all measured periods from 3 months to 3 years post op.

BACKGROUND:Bariatric surgery (BS) is associated with improved cardiovascular (CV) outcomes in individuals with obesity. One proposed mechanism is reduced inflammation. S100A9, a pro-inflammatory cytokine, is elevated in obesity. S100A9, particularly expression in platelets, has been associated with CV risk. The impact of BS on circulating and platelet S100A9 in obesity is unknown. METHODS:We studied serum, plasma, and platelet supernatants from subjects with obesity pre- and post-BS (n = 23) and lean volunteers (n = 8). S100A9 levels were quantified using an S100A9 immunoassay. Wilcoxon, Mann-Whitney, and t-tests were performed to assess changes in S100A9 levels pre- and post-operatively and compare levels across sample and subject types. Spearman tests were used to assess correlations between S100A9 levels in different sample types and neutrophil/platelet counts. RESULTS:Serum and plasma S100A9 concentrations were elevated in individuals with obesity relative to lean individuals. Levels decreased to lean subject levels at 1-year post-BS, despite subjects with obesity remaining overweight. Circulating neutrophil counts also decreased post-BS, and post-BS differences in serum S100A9 were eliminated when calculated per-neutrophil. Platelet supernatant S100A9 levels were lower than in serum and plasma and did not change post-BS. Platelet supernatant S100A9 correlated with plasma, but not serum, levels. CONCLUSION/CONCLUSIONS:We found that S100A9 concentrations differ substantially between blood components, are elevated in obesity, and normalize post-BS. Reductions in circulating S100A9 may contribute to reduced inflammation and be largely driven by resolution of obesity-associated neutrophilia. Our data suggest minimal platelet contribution to circulating (or systemic) S100A9, but a local level inflammatory impact cannot be excluded.

BACKGROUND:Early postoperative small bowel obstruction (ESBO) following roux-en-Y gastric bypass (RYGB) is a feared complication, generally estimated to occur in 1-2% of cases. Most surgeons advocate for prompt surgical exploration for ESBO after RYGB. There is currently a paucity of literature regarding conservative management approaches to ESBO after RYGB. OBJECTIVES/OBJECTIVE:To determine the safety and efficacy of non-operative management of early small bowel obstruction following RYGB. SETTING/METHODS:Academic-affiliated municipal hospital. METHODS:We performed a retrospective review of all patients at a single institution who underwent RYGB between July 1, 2020 and April 30, 2024 and were readmitted within 30 days of the procedure due to a small bowel obstruction. Mesenteric defects were closed with permanent suture in 100% of cases. RESULTS:2430 RYGBs were performed, 54 patients (2.2%) developed ESBO. The average interval from time of surgery to diagnosis of ESBO was 7.3 days [range 2-26 days]. The vast majority of patients (n = 43; 80%) were successfully managed conservatively including nasogastric decompression (n = 20; 47%). Most (73%) of the patients requiring reoperation were found to have kinking at the anastomosis or dense adhesions from the cut end of the staple line. CONCLUSIONS:This study demonstrates that non-operative management may be a safe and effective treatment option for the majority of RYGB patients who develop ESBO. Clinical judgement is required to identify those who would benefit from early exploration.

INTRODUCTION/BACKGROUND:GLP-1 receptor agonists (GLP1-RAs) are increasingly prescribed as an alternative to bariatric surgery for weight loss, and may pose as an alternative to conversion Roux-En-Y Gastric Bypass (cRYGB) in patients with insufficient weight loss or weight recurrence after sleeve gastrectomy [A C, N C, A I. Postoperative morbidity and weight loss after revisional bariatric surgery for primary failed restrictive procedure: a systematic review and network meta-analysis. International Journal of Surgery; 2022;Jensen et al. in Obes Surg 33:1017-1025, 2023; Jamal et al. in Obes Surg 34:1324-1332, 2024; Lautenbach A, Wernecke M, Stoll FD, Meyhöfer SM, Meyhöfer S, Aberel J. 1422-P: The potential of semaglutide once-weekly in patients without Type 2 Diabetes with weight regain or insufficient weight loss after bariatric surgery. Diabetes 2022; 71(Supplement_1);]. METHODS AND PROCEDURES/METHODS:Adult patients ≥ 18 years old, who previously underwent a sleeve gastrectomy and were subsequently treated with weekly injectable Semaglutide or Tirzepatide, or treated with conversion from sleeve gastrectomy were included for analysis. Patients converted for GERD, GLP1-RA use with BMI ≤ 35, or pre operative GLP1-RA use were excluded. Post operative weights and Hgb A1C were assessed from 3 months to 3 years post intervention (start of GLP1-RA or surgery). T-test, ANOVA, and chi-squared analysis were used to compare groups, while multivariable linear regression analysis was used to evaluate the effect of bariatric surgery on %TBWL at 3 years post intervention when adjusting for baseline characteristics. RESULTS:4901 patients were included for analysis (3004 cRYGB, 1897 GLP1-RA). There was no difference in pre-intervention weight (242.8 ± 44.4 GLP1-RA vs 242.3 ± 57.8 cRYGB, p = .993). cRYGB patients had a higher baseline Hgba1c (6.19 ± 1.4 vs 5.85 ± 1.2, p < 0.001). cRYGB was associated with significantly greater weight loss at all post operative time points up to 3 years post intervention, (26.1 vs 13.7%, p < 0.001). There was no significant difference in Hgba1c control between treatments at all post intervention time points (all p > 0.05). In the multivariate linear regression analysis, when adjusting for sex, baseline BMI, baseline age, and non-white race, cRYGB was associated with an 11% greater %TBWL compared to those who were treated with a GLP1-RA. CONCLUSIONS:For patients who have had insufficient weight loss or weight recurrence following sleeve gastrectomy, conversion to RYGB offers greater, long-term weight loss compared to GLP1-RAs.

OBJECTIVE:This study examined racial and ethnic differences in percent total weight loss (%TWL) and glycemic improvement following sleeve gastrectomy (SG) and explored the role of socioeconomic and psychosocial factors in postsurgical outcomes. METHODS:This longitudinal study included patients who underwent SG between 2017 and 2020, with follow-up visits over 24 months. RESULTS:Non-Hispanic Black (NHB) participants had lower %TWL at 3, 12, and 24 months compared with Hispanic (H) and non-Hispanic White (NHW) participants. Fat mass index was initially lower in NHB, with smaller reductions over time and significant group differences persisting at 24 months. NHB participants had higher baseline fat-free mass index values; by 24 months, fat-free mass index values were lower in H participants. Hemoglobin A1c decreased across all groups but remained consistently higher in NHB and H compared with NHW at 24 months. NHB participants reported higher perceived discrimination, sleep disturbance, and perceived stress than H and NHW participants at all time points. Employment status predicted %TWL at 12 months. There was a significant interaction between race and ethnicity and employment status observed at 12 and 24 months, suggesting that employment-related disparities could impact surgical outcomes. CONCLUSIONS:NHB participants experienced less favorable outcomes following SG, emphasizing the need for tailored interventions addressing socioeconomic and psychosocial disparities.

BACKGROUND/UNASSIGNED:Cholesterol efflux capacity (CEC) of HDL (high-density lipoprotein) is inversely associated with incident cardiovascular events, independent of HDL cholesterol. Obesity is characterized by low HDL cholesterol and impaired HDL function, such as CEC. Bariatric surgery, including Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), broadly leads to improved cardiovascular outcomes, but impacts on risk factors differ by procedure, with greater improvements in weight loss, blood pressure, and glycemic control after RYGB, but greater improvements in HDL cholesterol and CEC levels after SG. This study sought to determine effects of RYGB and SG on HDL protein and lipid cargo and investigate associations with CEC changes. METHODS/UNASSIGNED:We prospectively studied nondiabetic, premenopausal Hispanic women with severe obesity not using lipid medications undergoing RYGB (n=31) or SG (n=36). Anthropometric measurements and blood sampling were obtained before and at 6 and 12 months after surgery. HDL was isolated from plasma, and quantitative proteomic and lipidomic assessments were performed with LC-MS/MS (liquid chromatography with tandem mass spectrometry). CEC was assessed ex vivo using apoB-depleted serum. RESULTS/UNASSIGNED:Participants experienced similar, significant weight loss over 12 months following bariatric surgery (38.0±10.4 kg) regardless of the procedure. Relative quantities of 47 proteins (34 increased, 13 decreased) and 150 lipids (71 increased, 79 decreased) carried on HDL were significantly altered following either surgical procedure. Proteins with similar aggregate response patterns were clustered into 15 groups (5 increased, 5 decreased, 5 minimal change) and lipids with similar aggregate responses into 25 groups (7 increased, 11 decreased, 7 minimal change). Network mediation analyses suggested that changes in 4 protein and 2 lipid clusters mediated changes in ABCA1 (ATP-binding cassette transporter A1) CEC and that 1 lipid cluster mediated changes in non-ABCA1 CEC. The protein and lipid clusters that mediated changes in CEC were distinct between SG and RYGB. CONCLUSIONS/UNASSIGNED:Bariatric surgery produces substantial changes in HDL lipid and protein cargo, and specific changes may mediate changes in HDL function in CEC. Further study of these mechanisms may lead to improved interventions to reduce cardiovascular risk in patients with obesity.

BACKGROUND:Conversion from sleeve gastrectomy (SG) to Roux-en-Y gastric bypass (RYGB) may be indicated for patients due to insufficient weight loss or weight regain. OBJECTIVES/OBJECTIVE:To assess weight loss outcomes and factors predictive of improved weight loss in patients undergoing RYGB after SG and create an algorithm to estimate postoperative weight loss in these patients. SETTING/METHODS:University Hospital. METHODS:Retrospective review of patients who underwent conversion from SG to RYGB from 2015 to 2022 was performed, assessing pre-and post-operative weights for each procedure. RESULTS:increase yielded 0.8% greater %TBWL [95% CI 0.5-1%, p < 0.0001]) and peak %EWL ≥ 40% after SG (yielding 5.5% more %TBWL, 95%CI 3.9-7.1%, p < 0.0001). Conversely, those who had ≥ 20% weight regain after SG had 4.1% less %TBWL (95%CI 2.5-5.7%, p < 0.0001) after conversion. These factors were used to create BE-CALM, an algorithm to predict %TBWL one year after conversion to RYGB. CONCLUSIONS:Conversion from SG to RYGB is effective for further weight loss. Patients who have higher starting BMI, ≥ 40% %EWL or ≤ 20% weight regain after SG demonstrate the most effective weight loss post-conversion.

PURPOSE/OBJECTIVE:We developed a comprehensive sleeve gastrectomy (SG) weight loss study cohort and biorepository to uncover mechanisms, biomarkers and predictive factors of weight loss, weight maintenance and amelioration of obesity-related comorbidities. For this purpose, we collected psychosocial, anthropometric, clinical data and a variety of samples pre-surgery, intraoperatively and 1.5, 3, 12 and 24 months post-surgery. For longer-term assessment, the collection of psychosocial and anthropometric data was extended to 10 years. Here, we present in-depth characterisation of the cohort and detailed overview of study procedures as a foundation for future analyses. PARTICIPANTS/METHODS:We consented 647 participants between June 2017 and March 2020 from two bariatric surgery clinics in New York City-one major urban hospital and one private hospital. Of 355 participants who provided baseline data, 300 underwent SG. Of these, 79% are females with an average age of 38 years, 68% are Hispanic, 20% are non-Hispanic Black and 11% are non-Hispanic White. FINDINGS TO DATE/RESULTS:We collected intraoperative adipose and stomach tissues from 282 patients and biosamples (blood, urine, saliva, stool) from 245 patients at 1.5 months, 238 at 3 month, 218 at 12 months and 180 at 24 months post-surgery. We are currently collecting anthropometric and psychosocial data annually until 10 years post-surgery. Data analysis is currently underway. FUTURE PLANS/UNASSIGNED:Our future research will explore the variability in weight loss outcomes observed in our cohort, particularly among Black and Hispanic patients in comparison to their White counterparts. We will identify social determinants of health, metabolic factors and other variables that may predict weight loss success, weight maintenance and remission of obesity-related comorbidities. Additionally, we plan to leverage our biorepository for collaborative research studies. We will complete long-term follow-up data by December 2031. We plan to apply for funding to expand biosample collection through year 10 to provide insights into the mechanisms of long-term weight maintenance.