BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are widely used procedures for severe obesity. While both procedures are effective, the long-term risk of major and mino...BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are widely used procedures for severe obesity. While both procedures are effective, the long-term risk of major and minor complications remains uncertain. OBJECTIVES: To compare the incidence and risk factors for early and late complications following LRYGB and LSG. SETTING: Nationwide population-based study utilizing Danish administrative registries. METHODS: Inclusion of all patients undergoing primary LRYGB or LSG from 2008 to 2018 in Denmark. Data were obtained from national health registries, enabling long-term individual-level follow-up. Propensity-score matching was performed 1:2 to minimize baseline differences. Early (≤30 days) and late (>30 days) complications were classified as major and minor based on standardized criteria. Multivariate logistic and Cox regression models were used for assessment of risk factors. RESULTS: Among 18,090 patients, 2851 LRYGB and 1468 LSG patients were included. After 5 years, 3231 (75%) patients were available for follow-up. The risks of early major and minor complications were comparable between groups (P = .155 and P = .163, respectively). LRYGB was associated with increased risk of late complications, both major (hazard ratio [HR] 3.33, 95% confidence interval [CI] 2.40-4.64, P < .001) and minor (HR 1.38, 95% CI 1.22-1.57, P < .001). LRYGB patients had higher rates of internal herniation, marginal ulcers, and nutritional deficiencies, while revisional surgery and cholelithiasis rates were higher after LSG. CONCLUSION: LRYGB and LSG are safe procedures with low rates of major complications; however, LRYGB is associated with higher long-term complication burden. These findings underscore the importance of individualized patient selection and structured follow-up for optimization of outcomes after bariatric surgery.
BACKGROUND: Metabolic and bariatric surgery (MBS) can be challenging in patients with a very high body mass index (BMI). OBJECTIVES: The objective of the study is to evaluate the outcomes of different weight categories i...BACKGROUND: Metabolic and bariatric surgery (MBS) can be challenging in patients with a very high body mass index (BMI). OBJECTIVES: The objective of the study is to evaluate the outcomes of different weight categories in a publicly funded healthcare system with high adherence to current guidelines for perioperative optimization. SETTING: Nationwide, registry-based. METHODS: Based on nationwide data from the Scandinavian Obesity Surgery Registry, patients operated on with Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and biliopancreatic diversion with duodenal switch (BPD/DS) from 2007 until 2024 were included. Patients were stratified according to preoperative BMIs of 35-49 kg/m, 50-59 kg/m, 60-69 kg/m, and ≥70 kg/m. RESULTS: The study included data for 83,057 patients. A postoperative complication occurred for 5855 (7.2%) with no difference between BMI groups. Operation time was longer for higher BMI groups for all procedures. At 2 years, patients lost the highest percentage of their total weight (%TWL) in all BMI categories after BPD/DS (37.9% ± 10.1% to 45.4% ± 15.3%), followed by RYGB (32.4% ± 8.6% to 36.8% ± 10.9%) and SG (26.6% ± 9.5% to 31.3% ± 8.9%). Mortality rates over a median of 9.8 years remained higher in the higher BMI groups (BMI: 50-59, odds ratio [OR] = 1.29 [1.15-1.46]; BMI: 60-69, OR = 1.66 [1.18-2.33]; BMI ≥70, OR = 2.33 [.96-5.68]). CONCLUSION: MBS can be performed safely in patients with obesity class 4 or higher. Higher BMI was associated with longer operating times and superior weight loss, especially after BPD/DS. Despite greater weight loss and similar remission of metabolic co-morbid diseases, patients with higher preoperative BMI still have an increased long-term risk of all-cause mortality.
BACKGROUND: Although postoperative leak is one of the most feared complications after bariatric surgery, trends in its incidence, risk factors, and contemporary management are unclear. OBJECTIVES: Describe trends in the...BACKGROUND: Although postoperative leak is one of the most feared complications after bariatric surgery, trends in its incidence, risk factors, and contemporary management are unclear. OBJECTIVES: Describe trends in the incidence of postoperative leak after bariatric surgery, identify factors associated with postoperative leak, and describe trends in leak management. SETTING: Hospitals in Michigan. METHODS: This retrospective cohort study used a statewide clinical registry to identify adults who underwent primary laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass in a mature quality improvement-driven US healthcare setting between January 1, 2007 and December 31, 2023. The main outcome was postoperative leak within 30 days of surgery. Multivariable logistic regression was used to identify factors associated with postoperative leak. RESULTS: 108,708 patients with a mean age of 45.0 (11.7) years and 86,712 (79.8%) females underwent primary bariatric surgery, of whom 74,268 (68.3%) underwent sleeve gastrectomy and 34,440 (31.7%) underwent gastric bypass. 628 (.58%) leaks occurred. Over the 17-year study period, the incidence of postoperative leak decreased by .06 (95% confidence interval [CI]: .04-.08) percentage points (pp) per year, from 1.06% in 2007 to .45% in 2023. Individually, there was a significant decrease in the incidence of postoperative leak for both procedures (sleeve gastrectomy .06 [95% CI: .03-.10] pp per year; gastric bypass .03 [95% CI: .01-.06] pp per year). Factors associated with higher odds of postoperative leak included prior gastric surgery (adjusted odds ratio [aOR]: 5.92 [95% CI: 2.57-13.65]), gastric bypass (aOR: 2.46 [95% CI: 1.87-3.24]), active or recent smoking (aOR: 1.68 [95% CI: 1.14-2.47]), and diabetes (aOR: 1.35 [95% CI: 1.01-1.80]). Among patients who developed a postoperative leak, 311 (49.5%) were managed operatively, while 317 (50.5%) were managed nonoperatively. CONCLUSIONS: Over the last 2 decades, there was a significant decrease in the incidence of postoperative leak after sleeve gastrectomy and gastric bypass.
BACKGROUND: Post-bariatric hypoglycemia (PBH) is a complication of bariatric surgery in which postprandial hypoglycemia can be severe, frequent, and debilitating. The incidence reported in the literature varies from .1%...BACKGROUND: Post-bariatric hypoglycemia (PBH) is a complication of bariatric surgery in which postprandial hypoglycemia can be severe, frequent, and debilitating. The incidence reported in the literature varies from .1% to 75% of all bariatric procedures, largely due to differences in methodologies and definitions used to identify incident cases. OBJECTIVES/METHODS: To define the burden of PBH, the incidence and prevalence must be ascertained, with accurate definitions of incident cases used. We performed a systematic review of published literature with the following goals: 1) Outline differences between methodologies and definitions used to determine incidence of PBH; 2) Suggest optimal parameters (Level A criteria) to use in defining incident cases; 3) Suggest PBH disease severity classification system; 4) Estimate incidence by severity level based on studies meeting Level A criteria; 5) Model current U.S. prevalence based on incidence rates, surgical census data, and life-expectancy data. RESULTS: Based on our Level A studies analysis, nearly 30% of Roux-en-Y gastric bypass (RYGB) patients and 10% of sleeve gastrectomy (SG) patients develop hypoglycemia after surgery, with 12% of RYGB and 5% of SG patients requiring medical attention. This translates to approximately 160,000 requiring medical management and over 30,000 receiving critical care. CONCLUSION: This significant burden, together with the highly conflicting incidence estimates in published studies underscores the pressing need for standardized assessment methods that will pave the way for improved quality of research, estimates of health care needs and cost, and development of effective treatments.
Wills MV, Lee S, Mocanu V
… +40 more, Lee Y, Kachornvitaya P, Zhu X, Alfaris N, Andromalos L, Apovian C, Behrens E, Birk D, Busetto L, Courcoulas A, Cummings D, Faria SL, Ghanem O, Han SM, Karmali S, Kaplan L, Kow L, le Roux CW, Mahawar K, Gawdat K, Munoz R, Musella M, Nimeri A, O'Kane M, Palermo M, Ponce de Leon Ballesteros G, Salminen P, Sullivan S, Udomsawaengsup S, Tewksbury C, Vidal J, Wilding J, Dang J, Strong A, Navarrete S, Zundel N, Kermansaravi M, Butsch S, Kroh M, Corcelles R
BACKGROUND: Weight recurrence and suboptimal response after metabolic and bariatric surgery (MBS) lack standardized definitions and management approaches, creating barriers to evidence-based treatment decisions and coord...BACKGROUND: Weight recurrence and suboptimal response after metabolic and bariatric surgery (MBS) lack standardized definitions and management approaches, creating barriers to evidence-based treatment decisions and coordinated care across multiple specialties. OBJECTIVES: To establish international expert consensus on terminology, diagnostic approaches, and management strategies for suboptimal response and weight recurrence after MBS. SETTING: International Delphi study across multiple countries and health care systems. METHODS: A two-round modified Delphi study was conducted with 66 international experts across five specialties (MBS, obesity medicine, gastroenterology, endocrinology, dietetics and nutrition, and psychology). A 164-item questionnaire was developed, spanning seven dimensions: conservative management, diagnostic methods, endoscopic interventions, quantitative thresholds, risk factors, surgical interventions, and terminology. Consensus was defined a priori as ≥70% agreement. Inter-rater reliability was assessed using Gwet's AC1 coefficient. RESULTS: Response rates were 54.5% (Round 1) and 57.6% (Round 2). Consensus achievement improved significantly between rounds (26.2% to 40.9% of items). Experts reached unanimous agreement on core management principles including individualized patient care (100%) and the appropriateness of specialists prescribing antiobesity medications (100%). Strong consensus emerged on standardized terminology with "suboptimal" as the preferred term (89.5%) and %TWL as the optimal measurement approach (94.6). For quantitative thresholds, consensus was achieved on surgical nonresponse defined as <10% TWL at 12 months (73.0%), recurrent weight gain as >25% of lost weight from nadir (70.3%), and a 10% change in %EWL from nadir as normal physiologic response (83.8%). Conservative management items achieved the highest consensus rates (80.9%) while quantitative threshold items require additional research (28.1%). Inter-rater reliability improved across all domains, with conservative management achieving substantial agreement (AC1 = .70). CONCLUSION: Expert consensus was achieved on fundamental principles of postbariatric care, including preferred terminology, measurement metrics, and provider roles. These recommendations address important gaps in clinical practice standardization.
Ahmed MB, Khanafer Y, Abdelsalam MA
… +10 more, Dalol A, Rajha HE, Syed A, Hassan AM, Al-Maraghi S, Elzawawi KE, Alsherawi A, Hassanain M, Doi SA, Habib AM
BACKGROUND: Bariatric surgery induces metabolic improvements that extend beyond weight loss, yet the hormonal dynamic underlying these effects remain incompletely characterized. Previous meta-analyses have relied on stat...BACKGROUND: Bariatric surgery induces metabolic improvements that extend beyond weight loss, yet the hormonal dynamic underlying these effects remain incompletely characterized. Previous meta-analyses have relied on static comparisons of hormone levels, limiting insight into the temporal dynamics of endocrine adaptation. OBJECTIVES: To quantify the magnitude and durability of hormonal changes following bariatric surgery and to elucidate how these shifts may refine procedure selection and identify key metabolic pathways. SETTING: Not applicable, as this dose-response meta-analysis (DRMA) synthesized data from previously published studies. METHODS: We conducted a DRMA of 59 studies to model postoperative trajectories of six hormones: glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), PYY, leptin, adiponectin, and ghrelin after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). RESULTS: RYGB led to sustained increases in GLP-1 and PYY and a steady decline in GIP, while SG produced durable suppression of ghrelin and an earlier rise in adiponectin. Leptin declined after both procedures, with a greater drop post-RYGB. Several hormones exhibited nonlinear trends, highlighting the importance of evaluating the durability and timing of postoperative hormonal responses. CONCLUSION: RYGB and SG elicit distinct and durable postoperative hormonal trajectories over time, reflecting divergent physiological mechanisms. These profiles may help guide procedure selection according to metabolic characteristics and support the use of endocrine markers to improve long-term outcomes.
BACKGROUND: Vitamin D deficiency (VDD) affects 30%-70% of patients with obesity, yet its impact on postoperative bone health outcomes after metabolic surgery remains incompletely characterized. OBJECTIVES: To investigate...BACKGROUND: Vitamin D deficiency (VDD) affects 30%-70% of patients with obesity, yet its impact on postoperative bone health outcomes after metabolic surgery remains incompletely characterized. OBJECTIVES: To investigate the differential impact of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on postoperative bone health outcomes, both in the bariatric population with and without pre-existing VDD. SETTINGS: Analysis of TriNetX Global Collaborative Network, a deidentified real-world database from multiple institutes. METHODS: Using the TriNetX, we identified adults with obesity who underwent RYGB or SG from 2008 to 2022, with follow-up extended up to 5 years postsurgery. Propensity score matching (1:1) adjusted for baseline confounders. Primary outcomes included osteopenia, osteoporosis, and fracture-related osteoporosis. RESULTS: After matching, 35,804 patients with preoperative VDD were compared to 35,804 without. Although absolute risk differences were small, VDD patients had significantly higher odds of developing osteopenia (1.9% vs 1.0%; odds ratio [OR] 2.04, 95% confidence interval [CI] 1.79-2.32, P < .001) and osteoporosis (.7% vs .3%; OR 2.54, 95% CI 2.00-3.23, P < .001). Subgroup analyses showed elevated osteopenia risk among VDD patients undergoing RYGB (OR 1.69, 95% CI 1.41-2.02, P < .001) and SG (OR 2.02, 95% CI 1.68-2.42, P < .001), with higher osteoporosis risk in both RYGB (OR 1.94, 95% CI 1.45-2.59, P < .001) and SG (OR 1.91, 95% CI 1.36-2.67, P = .001). No significant differences in fracture-related osteoporosis were found. Postoperative labs showed persistently lower vitamin D and elevated parathyroid hormone levels in VDD patients (all P < .001). Calcium and phosphate levels were marginally higher in VDD patients. CONCLUSIONS: Preoperative VDD was linked to increased postmetabolic surgery osteopenia/osteoporosis risk. Findings support routine screening, tailored supplementation, and long-term bone monitoring. Prospective studies with standardized imaging are needed to clarify long-term skeletal outcomes.
BACKGROUND: Bariatric surgery increases the risk of anemia, but long-term data from large cohorts are sparse, and it is unclear if certain groups are at a higher risk. OBJECTIVES: Define factors associated with anemia at...BACKGROUND: Bariatric surgery increases the risk of anemia, but long-term data from large cohorts are sparse, and it is unclear if certain groups are at a higher risk. OBJECTIVES: Define factors associated with anemia at 5 years of follow-up after bariatric surgery. SETTING: Data from a national quality register. METHODS: This cross-sectional study uses Scandinavian Obesity Surgery Registry data on primary Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) procedures in Sweden from 2007 to 2020. Hemoglobin and ferritin were analyzed preoperatively and up to 10 years postoperatively. Factors associated with anemia were evaluated using hemoglobin and ferritin samples 5 years postsurgery. RESULTS: The study included 73,612 patients (RYGB: 80.7%, SG: 19.3%). Hemoglobin and/or ferritin data were available for 18,993 patients 5 years postsurgery, of whom 3508 patients (18.5%) had anemia and 691 patients (27.0%) subnormal ferritin levels. Anemia and subnormal ferritin were more prevalent after RYGB than SG (19.6% versus 11.3%, adjusted odds ratio [aOR] = .58 and 24.1% versus 15.6%, aOR = .43). Females had a higher prevalence of anemia than males (20.6% versus 11.1%, aOR = .50). Young age was associated with a higher risk of anemia (31.0%), as was large postoperative weight loss (highest quartile 25.2%). Results regarding iron supplementation were not conclusive. CONCLUSIONS: The prevalence of anemia, likely secondary to iron deficiency, increases up to 10 years post bariatric surgery. Female sex, young age at surgery, large weight loss, and undergoing RYGB were associated with an increased risk of anemia, indicating a need for targeted strategies for vitamin and mineral supplementation in these groups.
BACKGROUND: Bariatric surgery is currently one of the most performed elective laparoscopic procedures. Continuous refinement elevates standards. OBJECTIVES: This retrospective cohort study aimed to determine aspirational...BACKGROUND: Bariatric surgery is currently one of the most performed elective laparoscopic procedures. Continuous refinement elevates standards. OBJECTIVES: This retrospective cohort study aimed to determine aspirational benchmarks for laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) in an unselected cohort, developing adjusted reference values for groups at risk of severe complications. SETTING: Nationwide registry study including every bariatric facility in Sweden. METHODS: Using data from the Scandinavian Obesity Surgery Registry encompassing Swedish primary LRYGB and LSG procedures from 2012 to 2021, the Achievable Benchmark of Care methodology was employed to establish reference values for quality-related surgical outcomes, notably severe complications. The data included perioperative and postoperative data up to 30 days after surgery. Logistic regression identified risk factors for severe complications (Clavien-Dindo > II). Adjusted benchmarks were developed for relevant subgroups using the Achievable Benchmark of Care methodology. RESULTS: The study included 36,846 LRYGB and 15,246 LSG patients. Severe postoperative complications occurred in 3.6% (interquartile range: 2.5%-5.1%) of LRYGB cases, with a benchmark of 1.5%. Risk factors included prior deep vein thrombosis and ongoing antidepressant use. In the LSG group, 1.9% (interquartile range: .5%-3.7%) experienced severe complications, compared to a benchmark of .4%. Risk factors encompassed age, body mass index, smoking, dyspepsia, and diabetes. Only diabetes in the LSG group increased the benchmark to 1.2% for severe complications. CONCLUSIONS: These benchmarks, developed from validated national registry data, are more demanding than previous global benchmarks. They prompt reflection on surgical quality and will hopefully inspire further quality improvement initiatives across bariatric surgery providers.
Up to 22% of bariatric and metabolic surgery (BMS) candidates experience trauma or stressor-related symptoms and/or diagnoses (trauma-related distress), such as post-traumatic stress disorder (PTSD), yet research assessi...Up to 22% of bariatric and metabolic surgery (BMS) candidates experience trauma or stressor-related symptoms and/or diagnoses (trauma-related distress), such as post-traumatic stress disorder (PTSD), yet research assessing their impact on surgical outcomes remains limited. To our knowledge, this is the first systematic review examining how presurgical trauma-related distress affects postsurgical BMS outcomes. Five electronic databases and five grey literature sources were searched from inception to April 2025 for quantitative studies of adults undergoing BMS with current symptoms or diagnoses of trauma-related distress. Studies had to report associations between presurgical trauma-related distress and postsurgical outcomes. The Newcastle-Ottawa Scale was used to assess study quality. Narrative synthesis and vote counting by direction of effect was utilized. Nine observational studies (n = 5457) met inclusion criteria, ranging from poor to fair quality. PTSD was not statistically associated with postoperative weight loss in any study (n = 4). In one study, PTSD was associated with other mental health disorders, including major depressive disorder. Another study showed that people presenting with PTSD had worse mental health-related quality of life (QoL) than controls. Adjustment disorders showed no significant effect on postoperative weight loss (n = 1). Despite the high prevalence of trauma in this population, high-quality research on its impact on BMS outcomes is scarce, with methodological heterogeneity further limiting robust conclusions. The limited available evidence suggests PTSD and adjustment disorders do not significantly affect post-surgical weight loss, but QoL may be reduced in this population. Future research should employ standardized trauma measures, larger samples, and long-term follow-up to clarify how active trauma-related distress impacts BMS outcomes.
BACKGROUND: The efficacy of metabolic and bariatric surgery (MBS) in the treatment of sarcopenic obesity (SO) remains unclear. OBJECTIVES: The purpose of this systematic review and meta-analysis was to evaluate the effic...BACKGROUND: The efficacy of metabolic and bariatric surgery (MBS) in the treatment of sarcopenic obesity (SO) remains unclear. OBJECTIVES: The purpose of this systematic review and meta-analysis was to evaluate the efficacy of MBS in the SO population to provide some reference value for the implementation of reasonable intervention in this population. SETTING: All over the world. METHODS: PubMed, Embase, Web of Science, and ClinicalTrials.gov were searched for relevant articles up to September 2025. The standard mean difference (SMD) and its 95% confidence interval (CI) were used for the quantitative synthesis of continuous variables, and the risk ratio (RR) and its 95% CI were used for the quantitative analysis of categorical variables. The primary outcomes were the variations of body weight and body mass index from initial to follow-up, the proportion of total weight loss, the proportion of excess weight loss, and the remission of comorbidities. RESULTS: After screening, 7 studies involving 1704 patients were included in our final meta-analysis. The results of our analysis showed that the SO group had more significant variations in body weight (SMD = .89, 95% CI: .32-1.46, P = .002) and body mass index (SMD = 1.08, 95% CI: .41-1.76, P = .0016). There was a trend toward higher percentage of total weight loss and percentage of excess weight loss in the SO versus non-SO groups (SMD = .30, 95% CI: .06-.66, P = .09; SMD = .57, 95% CI: .28-1.42, P = .08). In terms of the remission of comorbidities, the 2 groups were similar (all P values > .05). In addition, the incidence of postoperative complications was similar between the 2 groups (RR = 1.78, 95% CI: .93-3.41, P > .05). CONCLUSIONS: In the SO population, MBS was associated with comparable efficacy and safety outcomes, including moderate weight loss, improvement in comorbidities, and no significant increase in postoperative complications.
BACKGROUND: Initial satisfaction with bariatric surgery is generally high but tends to diminish over time. Impairments in health-related quality of life (HRQoL) likely contribute to this decline. Still, the extent to whi...BACKGROUND: Initial satisfaction with bariatric surgery is generally high but tends to diminish over time. Impairments in health-related quality of life (HRQoL) likely contribute to this decline. Still, the extent to which HRQoL domains influence overall satisfaction after surgery remains unclear. OBJECTIVES: We examined the associations between a comprehensive HRQoL model and overall satisfaction after bariatric surgery and whether a smaller set of obesity-specific HRQoL measures could sufficiently account for this outcome. SETTING: General hospitals, Norway. METHODS: We conducted a cross-sectional analysis of 373 patients, with time since bariatric surgery ranging from 3 months to 10 years. Partial least squares (PLS) regression models were employed, with overall satisfaction as the dependent variable and 30 distinct HRQoL outcomes as independent variables. We also evaluated whether a smaller model of obesity-specific HRQoL measures could adequately explain variations in overall satisfaction while maintaining robust explanatory power. RESULTS: The full HRQoL PLS regression model explained 39.3% of the variance in overall satisfaction. A simplified model with four obesity-specific measures explained 35.6%, which increased to 43.1% when body mass index (BMI) was added. The logistic regression analysis indicated that poorer obesity-specific HRQoL and a higher BMI were independently associated with lower overall satisfaction, with an area under the curve of .90, indicating excellent model performance. CONCLUSION: A simplified obesity-specific HRQoL model, along with BMI, was strongly associated with overall satisfaction after bariatric surgery, suggesting that a few HRQoL outcomes may effectively capture its key determinants.
BACKGROUND: The perioperative effect of preoperative administration of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in individuals with obesity scheduled to receive metabolic and bariatric surgery (MBS) remains...BACKGROUND: The perioperative effect of preoperative administration of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in individuals with obesity scheduled to receive metabolic and bariatric surgery (MBS) remains uncertain. OBJECTIVES: The objective of this systematic review and meta-analysis was to evaluate the efficacy of preoperative GLP-1 RAs in patients with obesity undergoing MBS. SETTING: All over the world. METHODS: Original studies were searched from the inception of PubMed, Embase, and Web of Science up to September 2025. Primary outcomes were the variation of weight from the initial to the preoperative period and postoperative total weight loss percentage (TWL%). Secondary outcomes included the incidence of postoperative complications, postoperative glycated hemoglobin level, and the proportion of patients with remission of diabetes. RESULTS: After screening, 10 studies consisting of 5461 subjects were included in the final meta-analysis. The results showed that preoperative GLP-1 RAs were associated with a moderate reduction in preoperative weight (total median of weight reduction: 4.87 kg vs 3.84 kg; SMD: .4, 95% CI: -.37 to 1.18, P < .01) but did not significantly affect postoperative TWL% (SMD: -.20, 95% CI: -.27 to -.13, P = .21). Preoperative administration of GLP-1 RAs did not significantly increase the incidence of postoperative complications (RR: 1.62, 95% CI: .76-3.45, P = .12) nor improve the comorbidities (P = .23). CONCLUSIONS: Our study indicates that preoperative GLP-1 RAs are generally safe for patients with obesity undergoing MBS. However, this benefit only correlates with a certain degree of preoperative weight loss, and its effect on postoperative weight loss and improvement of comorbidities are limited.