Comparative Effectiveness of Gastric Bypass and Vertical Sleeve Gastrectomy for Hypertension Remission and Relapse: The ENGAGE CVD Study

Assessing clinical and metabolic responses related to hyperlipidemia, MASLD and type 2 diabetes: sleeve versus RYGB

OBJECTIVE

Both Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are effective at inducing weight loss, but more information is needed on their comparative effectiveness at improving clinical/biochemical outcomes related to the presence of hyperlipidemia, metabolic dysfunction-associated steatotic liver disease (MASLD), or type 2 diabetes (T2D) at baseline. Here we aimed to assess this in real-world practice.

METHODS

This is a prospective cross-sectional and cohort study of 142 patients who underwent RYGB or LSG as per clinical practice. Clinical/biochemical data were collected at baseline, prior to surgery and 12 months post-bariatric surgery. Liver biopsy was performed during surgery to diagnose MASLD. The main outcome was 12-month changes in lipid parameters, mainly total cholesterol, between types of surgery.

RESULTS

A TOTAL OF: 107 participants underwent RYGB and 35 underwent LSG. Both groups were similar at baseline except for a higher proportion of males and waist circumference in the LSG group. At 12 months postsurgery, RYGB versus LSG resulted in a significantly lower body mass index, triglycerides, total cholesterol, and low-density lipoprotein. However, alanine aminotransferase was significantly lower in those who underwent LSG. In subgroup analyses RYGB was superior at improving lipid-related parameters in those with hyperlipidemia, whereas LSG was superior at reducing alanine aminotransferase in those with MASLD.

CONCLUSIONS

RYGB versus LSG leads to greater reductions in body mass index and lipid parameters, especially in those with hyperlipidemia, whereas LSG showed greater improvements in liver enzymes in those with MASLD.

Going beyond randomised controlled trials to assess treatment effect heterogeneity across target populations

Methods have been developed for transporting evidence from randomised controlled trials (RCTs) to target populations. However, these approaches allow only for differences in characteristics observed in the RCT and real-world data (overt heterogeneity). These approaches do not recognise heterogeneity of treatment effects (HTE) according to unmeasured characteristics (essential heterogeneity). We use a target trial design and apply a local instrumental variable (LIV) approach to electronic health records from the Clinical Practice Research Datalink, and examine both forms of heterogeneity in assessing the comparative effectiveness of two second-line treatments for type 2 diabetes mellitus. We first estimate individualised estimates of HTE across the entire target population defined by applying eligibility criteria from national guidelines (n = 13,240) within an overall target trial framework. We define a subpopulation who meet a published RCT's eligibility criteria ('RCT-eligible', n = 6497), and a subpopulation who do not ('RCT-ineligible', n = 6743). We compare average treatment effects for pre-specified subgroups within the RCT-eligible subpopulation, the RCT-ineligible subpopulation, and within the overall target population. We find differences across these subpopulations in the magnitude of subgroup-level treatment effects, but that the direction of estimated effects is stable. Our results highlight that LIV methods can provide useful evidence about treatment effect heterogeneity including for those subpopulations excluded from RCTs.

Antihypertensive Medication Use Trajectories After Bariatric Surgery: A Matched Cohort Study

BACKGROUND

Metabolic and bariatric surgery (MBS) is the most effective and durable treatment for obesity. We aimed to compare the trajectories of antihypertensive medication (AHM) use among obese individuals treated and not treated with MBS.

METHODS

Adults with a body mass index of ≥35 kg/m2 were identified in the Merative Database (US employer-based claims database). Individuals treated with versus without MBS were matched 1:1 using baseline demographic and clinical characteristics as well as AHM utilization. Monthly AHM use was examined in the 3 years after the index date using generalized estimating equations. Subanalyses investigated rates of AHM discontinuation, AHM initiation, and apparent treatment-resistant hypertension.

RESULTS

The primary cohort included 43 206 adults who underwent MBS matched with 43 206 who did not. Compared with no MBS, those treated with MBS had sustained, markedly lower rates of AHM use (31% versus 15% at 12 months; 32% versus 17% at 36 months). Among patients on AHM at baseline, 42% of patients treated with MBS versus 7% treated medically discontinued AHM use (P<0.01). The risk of apparent treatment-resistant hypertension was 3.41× higher (95% CI, 2.91-4.01; P<0.01) 2 years after the index date in patients who did not undergo MBS. Among those without hypertension treated with MBS versus no MBS, 7% versus 21% required AHM at 2 years.

CONCLUSIONS

MBS is associated with lower rates of AHM use, higher rates of AHM discontinuation, and lower rates of AHM initiation among patients not taking AHM. These findings suggest that MBS is both an effective treatment and a preventative measure for hypertension.

Post-surgical psychiatric symptoms, maladaptive eating patterns, and lifestyle behaviors associated with weight recurrence after bariatric surgery

BACKGROUND

A significant proportion of patients who undergo bariatric surgery experience weight recurrence; however, the most important areas to target to prevent weight recurrence remain unknown.

OBJECTIVES

The purpose was to examine whether psychiatric symptoms, maladaptive eating behaviors, and lifestyle factors were associated with weight recurrence.

SETTING

Single healthcare system.

METHODS

Individuals who underwent bariatric surgery were invited to complete a web-based survey in which they reported their current weight and completed measures of psychiatric symptoms, maladaptive eating behaviors, and lifestyle behaviors. Participants were included if they were at least 2 years postsurgery. Weight recurrence was measured from the 1-year follow-up to the survey date.

RESULTS

Participants (n = 169) were predominantly female and White or Black, with a mean age of 45 years. The rate of significant weight recurrence was 23.1%. Those who underwent sleeve gastrectomy were more likely to experience weight recurrence (odds ratio [OR] = 12.99; P = .01). In bivariate analyses, anxiety and depressive symptoms, emotional eating, loss of control eating, binge eating, and night eating were associated with weight recurrence (P < .05). Those who did not eat mindfully, take 20 minutes to eat, or get adequate sleep were also more likely to have weight recurrence (P < .05). In a multivariate model, only a lack of mindful eating (OR = 4.84; P = .03) and inadequate sleep (OR = 7.30; P = .02) remained statistically significant predictors.

CONCLUSION

Engaging in mindful eating and obtaining adequate sleep may protect against weight recurrence following bariatric surgery. Clinicians may want to screen and monitor these behaviors.

Comparison of Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass: A Randomized Clinical Trial

Importance

Laparoscopic sleeve gastrectomy (SG) and laparoscopic Roux-en-Y gastric bypass (RYGB) are widely used bariatric procedures for which comparative efficacy and safety remain unclear.

Objective

To compare perioperative outcomes in SG and RYGB.

Design, Setting, and Participants

In this registry-based, multicenter randomized clinical trial (Bypass Equipoise Sleeve Trial), baseline and perioperative data for patients undergoing bariatric surgery from October 6, 2015, to March 31, 2022, were analyzed. Patients were from university, regional, county, and private hospitals in Sweden (n = 20) and Norway (n = 3). Adults (aged ≥18 years) eligible for bariatric surgery with body mass indexes (BMIs; calculated as weight in kilograms divided by height in meters squared) of 35 to 50 were studied.

Interventions

Laparoscopic SG or RYGB.

Main Outcomes and Measures

Perioperative complications were analyzed as all adverse events and serious adverse events (Clavien-Dindo grade >IIIb). Ninety-day mortality was also assessed.

Results

A total of 1735 of 14 182 eligible patients (12%; 1282 [73.9%] female; mean (SD) age, 42.9 [11.1] years; mean [SD] BMI, 40.8 [3.7]) were included in the study. Patients were randomized and underwent SG (n = 878) or RYGB (n = 857). The mean (SD) operating time was shorter in those undergoing SG vs RYGB (47 [18] vs 68 [25] minutes; P < .001). The median (IQR) postoperative hospital stay was 1 (1-1) day in both groups. The 30-day readmission rate was 3.1% after SG and 4.0% after RYGB (P = .33). There was no 90-day mortality. The 30-day incidence of any adverse event was 40 (4.6%) and 54 (6.3%) in the SG and RYGB groups, respectively (odds ratio, 0.71; 95% CI, 0.47-1.08; P = .11). Corresponding figures for serious adverse events were 15 (1.7%) for the SG group and 23 (2.7%) for the RYGB group (odds ratio, 0.63; 95% CI, 0.33-1.22; P = .19).

Conclusions and Relevance

This randomized clinical trial of 1735 patients undergoing primary bariatric surgery found that both SG and RYGB were performed with a low perioperative risk without clinically significant differences between groups.

Trial Registration

ClinicalTrials.gov Identifier: NCT02767505.

Long term outcomes of metabolic/bariatric surgery in adults

The prevalence of obesity continues to rise around the world, driving up the need for effective and durable treatments. The field of metabolic/bariatric surgery has grown rapidly in the past 25 years, with observational studies and randomized controlled trials investigating a broad range of long term outcomes. Metabolic/bariatric surgery results in durable and significant weight loss and improvements in comorbid conditions, including type 2 diabetes. Observational studies show that metabolic/bariatric surgery is associated with a lower incidence of cardiovascular events, cancer, and death. Weight regain is a risk in a fraction of patients, and an association exists between metabolic/bariatric surgery and an increased risk of developing substance and alcohol use disorders, suicidal ideation/attempts, and accidental death. Patients need lifelong follow-up to help to reduce the risk of these complications and other nutritional deficiencies. Different surgical procedures have important differences in risks and benefits, and a clear need exists for more long term research about less invasive and emerging procedures. Recent guidelines for the treatment of obesity and metabolic conditions have been updated to reflect this growth in knowledge, with an expansion of eligibility criteria, particularly people with type 2 diabetes and a body mass index between 30.0 and 34.9.

Suicide attempts after bariatric surgery: comparison to a nonsurgical cohort of individuals with severe obesity

BACKGROUND

The rate of suicide is higher among individuals following bariatric surgery compared with the general population; however, it is not clear whether risk is associated with bariatric surgery beyond having severe obesity.

OBJECTIVE

To compare the risk of a suicide attempt among those who had bariatric surgery versus a nonsurgical cohort with severe obesity.

SETTING

Aggregate count data were collected from 5 healthcare systems.

METHODS

Individuals were identified in the surgical cohort if they underwent bariatric surgery between 2009 and 2017 (n = 35,522) and then were compared with a cohort of individuals with severe obesity who never had bariatric surgery (n = 691,752). Suicide attempts were identified after study enrollment date using International Classification of Diseases, Ninth and Tenth Editions (ICD-9 and ICD-10) diagnosis codes from 2009 to 2021.

RESULTS

The relative risk of a suicide attempt was 64% higher in the cohort with bariatric surgery than that of the nonsurgical cohort (2.2% versus 1.3%; relative risk = 1.64; 95% CI, 1.53-1.76). Within the cohort with bariatric surgery, suicide attempts were more common among the 18- to 39-year age group (P < .001), women (P = .002), Hawaiian-Pacific Islanders (P < .001), those with Medicaid insurance (P < .001), and those with a documented mental health condition at baseline (in the previous 2 years; P < .001).

CONCLUSIONS

The relative risk of suicide attempts was higher among those who underwent bariatric surgery compared with a nonsurgical cohort, though absolute risk remained low. Providers should be aware of this increased risk. Screening for suicide risk after bariatric surgery may be useful to identify high-risk individuals.

How does a local instrumental variable method perform across settings with instruments of differing strengths? A simulation study and an evaluation of emergency surgery

Local instrumental variable (LIV) approaches use continuous/multi-valued instrumental variables (IV) to generate consistent estimates of average treatment effects (ATEs) and Conditional Average Treatment Effects (CATEs). There is little evidence on how LIV approaches perform according to the strength of the IV or with different sample sizes. Our simulation study examined the performance of an LIV method, and a two-stage least squares (2SLS) approach across different sample sizes and IV strengths. We considered four 'heterogeneity' scenarios: homogeneity, overt heterogeneity (over measured covariates), essential heterogeneity (unmeasured), and overt and essential heterogeneity combined. In all scenarios, LIV reported estimates with low bias even with the smallest sample size, provided that the instrument was strong. Compared to 2SLS, LIV provided estimates for ATE and CATE with lower levels of bias and Root Mean Squared Error. With smaller sample sizes, both approaches required stronger IVs to ensure low bias. We considered both methods in evaluating emergency surgery (ES) for three acute gastrointestinal conditions. Whereas 2SLS found no differences in the effectiveness of ES according to subgroup, LIV reported that frailer patients had worse outcomes following ES. In settings with continuous IVs of moderate strength, LIV approaches are better suited than 2SLS to estimate policy-relevant treatment effect parameters.

Shorter History of Hypertension as a Predictor of Hypertension Remission after 3-years of Bariatric Surgery: Data from the GATEWAY Trial

BACKGROUND

Previous evidence explored predictors of hypertension (HTN) remission after bariatric but data are limited to observational studies and lack of ambulatory blood pressure monitoring (ABPM). This study was aimed to evaluate the rate of HTN remission after bariatric surgery using ABPM and to define predictors of mid-term HTN remission.

METHODS

We included patients enrolled in the surgical arm of the GATEWAY randomized trial. HTN remission was defined as controlled blood pressure (< 130 × 80 mmHg) evaluated by 24-h ABPM while no need of anti-hypertensive medications after 36 months. A multivariable logistic regression model was used to assess the predictors of HTN remission after 36 months.

RESULTS

46 patients submitted Roux-en-Y gastric bypass (RYGB). HTN remission occurred in 39% (n = 14 out of 36 patients with complete data at 36 months). Patients with HTN remission had shorter HTN history than no remission group (5.9 ± 5.5 vs. 12.5 ± 8.1 years; p = 0.01). The baseline insulin levels were lower in patients who presented HTN remission, although not statistically significant (OR: 0.90; CI 95%: 0.80-0.99; p = 0.07). In the multivariate analysis, the HTN history (years) was the only independent predictor of HTN remission (OR: 0.85; 95% CI: 0.70-0.97; p = 0.04). Therefore, for each additional year of HTN history, the chance of HTN remission decreases by approximately 15% after RYGB.

CONCLUSION

After 3 years of RYGB, HTN remission defined by ABPM was common and independently associated with a shorter HTN history. These data underscore the need of early effective approach of obesity aiming greater impact in its comorbidities.

Comparison of hypertension remission and relapse after sleeve gastrectomy and one-anastomosis gastric bypass: a prospective cohort study

This study aimed to assess the remission and relapse of hypertension (HTN) in hypertensive individuals who underwent sleeve gastrectomy (SG) and one-anastomosis gastric bypass (OAGB) and identify the predictors of HTN remission and relapse following bariatric surgery. A prospective cohort study with a follow-up of 3 years was conducted on severely obese patients between 2013 and 2018. Hypertension remission was defined as the normalization of blood pressure (BP) with the discontinuation of medical treatment, and HTN relapse was defined as the need for the onset of antihypertensive drugs or the occurrence of BP impairment. A total of 787 hypertensive patients were included in this study. The cumulative incidence of HTN remission and relapse were 83.9% (95% CI: 81.6-86.5) and 31.4% (95% CI: 25.6-38.2), respectively. Remission and relapse were not significantly different among the patients undergoing either surgery (SG or OAGB). A higher remission rate was linked to a younger age and the use of fewer antihypertensive medications pre-operation. However, failure to successfully lose weight during the first year postoperative and weight regain predicted a higher risk of HTN relapse after 3 years. Following bariatric surgery, BP drops initially but then gradually rises. These alterations are responsible for about 31% relapse after 3 years in those who initially achieve remission. Patients who are younger and use less antihypertensive medications before surgery may benefit the most from bariatric surgery in terms of HTN. First-year successful weight loss and control of weight regain may prevent HTN relapse in the following years.

French recommendations on the prevention and treatment of osteoporosis secondary to bariatric surgery

INTRODUCTION

This article presents the initial recommendations of the Groupe de Recherche et d'Information sur les Ostéoporoses (Osteoporosis Research and Information Group [GRIO]) and the Société Française de Rhumatologie (French Rheumatology Society [SFR]) on the prevention and treatment of osteoporosis secondary to bariatric surgery.

METHODS

The recommendations were produced by a working group comprising 4 expert rheumatologists, 3 medically qualified nutritionists, 2 obesity surgeons, 1 physical activity specialist, and 1 patient-association representative.

RESULTS

The following generally recommended measures apply to all patients with an indication for bariatric surgery or who have already undergone bariatric surgery: normalize calcium and protein intake, attain a 25(OH) vitamin D concentration of between 30 and 60ng/mL; prevent the risk of falls, and introduce a suitable regimen of physical activity. An initial assessment of fracture risk should be routinely performed - ideally before the first bariatric surgery procedure - (i) in the case of RYGB and biliopancreatic diversion, regardless of age, (ii) in patients at high risk of fracture, regardless of age, and (iii) in all menopausal women and all men ≥ 50 years old, regardless of the type of bariatric surgical procedure. The fracture risk assessment is based on a determination of osteoporosis risk factors and bone mineral density measurements. Anti-osteoporosis treatment - zoledronic acid as the first line of treatment - is indicated for menopausal women and men ≥ 50 years old with (i) a history of severe fracture, regardless of T-score, (ii) a history of non-severe fracture and a T-score ≤ -1, and (iii) no history of fracture and a T-score ≤ -2.

CONCLUSIONS

There is an increased risk of fracture after bariatric surgery. Clinicians should focus their attention on patients at high fracture risk such as postmenopausal women and men older than 50 years. More research is necessary to direct and support guidelines.

Remission and Relapse of Dyslipidemia After Vertical Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass in a Racially and Ethnically Diverse Population

IMPORTANCE

The comparative effectiveness of the most common operations in the long-term management of dyslipidemia is not clear.

OBJECTIVE

To compare 4-year outcomes associated with vertical sleeve gastrectomy (VSG) vs Roux-en-Y gastric bypass (RYGB) for remission and relapse of dyslipidemia.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective comparative effectiveness study was conducted from January 1, 2009, to December 31, 2016, with follow-up until December 31, 2018. Participants included patients with dyslipidemia at the time of surgery who underwent VSG (4142 patients) or RYGB (2853 patients). Patients were part of a large integrated health care system in Southern California. Analysis was conducted from January 1, 2018, to December 31, 2021.

EXPOSURES

RYGB and VSG.

MAIN OUTCOMES AND MEASURES

Dyslipidemia remission and relapse were assessed in each year of follow-up for as long as 4 years after surgery.

RESULTS

A total of 8265 patients were included, with a mean (SD) age of 46 (11) years; 6591 (79.8%) were women, 3545 (42.9%) were Hispanic, 1468 (17.8%) were non-Hispanic Black, 2985 (36.1%) were non-Hispanic White, 267 (3.2%) were of other non-Hispanic race, and the mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 44 (7) at the time of surgery. Dyslipidemia outcomes at 4 years were ascertained for 2168 patients (75.9%) undergoing RYGB and 3999 (73.9%) undergoing VSG. Remission was significantly higher for those who underwent RYGB (824 [38.0%]) compared with VSG (1120 [28.0%]) (difference in the probability of remission, 0.10; 95% CI, 0.01-0.19), with no differences in relapse (455 [21.0%] vs 960 [24.0%]). Without accounting for relapse, remission of dyslipidemia after 4 years was 58.9% (1279) for those who underwent RYGB and 51.9% (2079) for those who underwent VSG. Four-year differences between operations were most pronounced for patients 65 years or older (0.39; 95% CI, 0.27-0.51), those with cardiovascular disease (0.43; 95% CI, 0.24-0.62), or non-Hispanic Black patients (0.13; 95% CI, 0.01-0.25) and White patients (0.13; 95% CI, 0.03-0.22).

CONCLUSIONS AND RELEVANCE

In this large, racially and ethnically diverse cohort of patients who underwent bariatric and metabolic surgery in clinical practices, RYGB was associated with higher rates of dyslipidemia remission after 4 years compared with VSG. However, almost one-quarter of all patients experienced relapse, suggesting that patients should be monitored closely throughout their postoperative course to maximize the benefits of these operations for treatment of dyslipidemia.

Local Instrumental Variable Methods to Address Confounding and Heterogeneity when Using Electronic Health Records: An Application to Emergency Surgery

Background

Electronic health records (EHRs) offer opportunities for comparative effectiveness research to inform decision making. However, to provide useful evidence, these studies must address confounding and treatment effect heterogeneity according to unmeasured prognostic factors. Local instrumental variable (LIV) methods can help studies address these challenges, but have yet to be applied to EHR data. This article critically examines a LIV approach to evaluate the cost-effectiveness of emergency surgery (ES) for common acute conditions from EHRs.

Methods

This article uses hospital episodes statistics (HES) data for emergency hospital admissions with acute appendicitis, diverticular disease, and abdominal wall hernia to 175 acute hospitals in England from 2010 to 2019. For each emergency admission, the instrumental variable for ES receipt was each hospital’s ES rate in the year preceding the emergency admission. The LIV approach provided individual-level estimates of the incremental quality-adjusted life-years, costs and net monetary benefit of ES, which were aggregated to the overall population and subpopulations of interest, and contrasted with those from traditional IV and risk-adjustment approaches.

Results

The study included 268,144 (appendicitis), 138,869 (diverticular disease), and 106,432 (hernia) patients. The instrument was found to be strong and to minimize covariate imbalance. For diverticular disease, the results differed by method; although the traditional approaches reported that, overall, ES was not cost-effective, the LIV approach reported that ES was cost-effective but with wide statistical uncertainty. For all 3 conditions, the LIV approach found heterogeneity in the cost-effectiveness estimates across population subgroups: in particular, ES was not cost-effective for patients with severe levels of frailty.

Conclusions

EHRs can be combined with LIV methods to provide evidence on the cost-effectiveness of routinely provided interventions, while fully recognizing heterogeneity.

Highlights

Care of the Patient After Metabolic and Bariatric Surgery

Weight loss surgery, also known as metabolic and bariatric surgery (MBS), is an effective weight loss treatment and is associated with reduced mortality and improvements in obesity-related health conditions and quality of life. Postsurgical anatomical and physiologic changes include decreased absorption of micronutrients and alterations in gut-brain hormonal regulation that affect many aspects of health. Patients require ongoing monitoring of their physical and mental health for lasting success. Internists, particularly primary care clinicians, are in an ideal position to monitor for nonserious complications in the short and long term, adjust management of chronic diseases accordingly, and monitor for mental health changes. This article reviews key issues that internists should be aware of for supporting patients' health in the short and long term after MBS.