Bariatric surgery: the challenges with candidate selection, individualizing treatment and clinical outcomes

Demographic and clinical predictors of bariatric surgery patients: A retrospective cohort study

INTRODUCTION

The significant rise in bariatric procedures (BPs) reflects the global increase in obesity. In Saudi Arabia, obesity prevalence is notably high at 35.6%, surpassing the global average. This retrospective cohort study primarily aims to identify demographic and clinical predictors influencing BP uptake among individuals at a single healthcare centre in Jeddah, Saudi Arabia. Secondarily, it evaluates the effectiveness of BPs, particularly laparoscopic sleeve gastrectomy (LSG), in reducing body mass index (BMI) and obesity-related comorbidities.

PATIENTS AND METHODS

Data were extracted from the hospital's registry between October 2023 and June 2024. The study population included obese adults of varying ages, genders and comorbidities who underwent bariatric surgery. However, the single-centre design limited generalisability, long-term outcome data were unavailable and contextual factors, such as socioeconomic status and health literacy, were not captured.

RESULTS

A cohort of 208 patients was analysed, 64.9% females and 34.2% males, with a mean age of 36 ± 11.2 years. The pre-operative BMI was 44.10 ± 6.2 kg/m² (P = 0.462), which decreased to 35.1 ± 6.5 kg/m² (P = 0.577) postoperatively, reflecting a mean reduction of 9.03 ± 4.9 kg/m² (20.5%) (P = 0.255). LSG was the most performed BP at 93.3%. The most prevalent obesity-related comorbidities identified were hypertension, diabetes and GIT disease including gall bladder disorders (15.9%, 13.9% and 13.5%, respectively).

CONCLUSIONS

This study highlights the increasing prevalence of BP, particularly among young, predominantly female patients. LSG demonstrated substantial effectiveness, achieving a 20.5% reduction in BMI and improvement in obesity-related comorbidities. Future research could explore more patient demographics that could not be analysed in this study.

The Ability of Healthcare Professionals to Predict Patient Outcomes Following Bariatric Surgery

INTRODUCTION

Patients with obesity seeking bariatric surgery undergo an extensive evaluation by a multidisciplinary team of healthcare professionals' (HCPs) to assess patient compliance among other factors and determine their eligibility for surgery. However, the HCPs' assessments are not devoid of bias that may affect eligibility and preoperative decisions. This study aimed to investigate team members' ability to predict patient outcomes following bariatric surgery.

MATERIALS AND METHODS

HCPs and other clinic staff at an academic institution completed a survey on postoperative outcomes prediction of adult patients seeking bariatric surgery from 2019 to 2020. HCPs and staff predictions for weight loss at 6 mo and 1 y, 30-d complications, and comorbidity resolution were compared with actual patient outcomes. Linear and logistic regression models were used, adjusting for preoperative body mass index, American Society of Anesthesiologists classification, and procedure type.

RESULTS

1503 predictions on 618 patients were collected, of whom 293 underwent surgery with at least 6 mo of follow-up. On adjusted analysis, the predictions on weight loss were not associated with body mass index reduction at 6 mo or 1 y (1-y data available for 155 patients). However, HCPs accurately predicted the length of stay (LOS) (coeff = 0.24, 95% CI = 0.07-0.41) and comorbidity resolution (aOR = 1.68, 95% CI = 1.21-2.33), while clinic staff only predicted the LOS (coeff = 0.30, 95% CI = 0.08-0.53).

CONCLUSIONS

While HCPs predicted the resolution of comorbidities and LOS, their predictions failed to correlate with weight loss outcomes following bariatric surgery. Additionally, there was no association between predictions and 30-d complications, readmissions, or emergency department visits. The HCPs' perspectives during patients' preoperative supervised weight loss program, while important, should not bias the decision-making process, particularly proceeding with surgery.

Refractory Hypocalcemia Following Total Thyroidectomy in an Adult Patient With Bariatric Surgery

Obesity poses a global health challenge with significant individual and societal impacts. Bariatric surgery, including Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion/duodenal switch (BPD/DS), is effective for long-term weight management but can lead to serious nutritional deficiencies, particularly hypocalcemia. This report presents the rare case of a 35-year-old woman with severe, recurrent hypocalcemia following BPD/DS surgery, complicated by iatrogenic hypoparathyroidism from prior thyroidectomy. Despite aggressive oral and intravenous calcium and vitamin D supplementation, the patient's hypocalcemia remained refractory, necessitating multiple hospitalizations. Laboratory studies confirmed severe hypocalcemia, low parathyroid hormone (PTH), and deficiencies in fat-soluble vitamins, complicating her clinical management. As conventional treatments failed, the patient underwent surgical revision from BPD/DS to RYGB anatomy, aimed at improving calcium absorption by restoring functional small bowel length. Postoperatively, her serum calcium levels normalized, and she was successfully discharged on oral calcium supplementation, with stable calcium levels at follow-up. This case underscores the challenges of managing hypocalcemia in patients with BPD/DS anatomy and hypoparathyroidism. The greater malabsorption associated with BPD/DS can severely impair calcium absorption, leading to refractory hypocalcemia. This report is the first documented case where surgical conversion from BPD/DS to RYGB effectively treated this condition. The findings underscore the critical need for preoperative risk assessment for, and careful postoperative management of, hypoparathyroidism in bariatric surgery patients with complex medical histories. This case report outlines a potential treatment pathway for managing refractory hypocalcemia, emphasizing the importance of preserving calcium-absorbing bowel function in patients with BPD/DS anatomy. It provides valuable insights into treating severe hypocalcemia and demonstrates a successful surgical intervention that could inform the management of similar cases.

Long-Term Effectiveness and Outcomes of Bariatric Surgery: A Comprehensive Review of Current Evidence and Emerging Trends

Obesity is a global epidemic associated with an increased risk of severe health conditions such as type 2 diabetes, cardiovascular diseases, and certain cancers. Bariatric surgery has become a pivotal treatment for severe obesity, offering significant improvements in weight loss and comorbidity resolution. This comprehensive review aims to assess the long-term effectiveness and outcomes of various bariatric surgical procedures, highlighting current evidence and emerging trends in the field. We extensively reviewed the literature, including randomized controlled trials, cohort studies, and meta-analyses, to evaluate long-term weight loss, resolution of obesity-related comorbidities, quality of life (QoL), and complications associated with different bariatric procedures. Bariatric surgery has demonstrated substantial and sustained weight loss over the long term, with varying degrees of effectiveness among different procedures. Gastric bypass and sleeve gastrectomy are associated with significant improvements in comorbidities such as type 2 diabetes and hypertension. QoL outcomes are generally positive, improving physical health, mental well-being, and social functioning. However, long-term complications, including nutritional deficiencies and the need for reoperations, remain challenges. Emerging trends such as minimally invasive techniques and nonsurgical interventions show promise in enhancing patient outcomes. Bariatric surgery remains a highly effective intervention for managing severe obesity and its related health issues. While long-term outcomes are generally favorable, continued advancements in surgical techniques and postoperative care are crucial for optimizing results and minimizing complications. Future research should focus on personalized approaches to patient management and the development of novel treatment modalities to further improve outcomes in the long term.

Short-Term Changes in Weight, Body Composition, and Metabolic Biomarkers After Laparoscopic Sleeve Gastrectomy in Patients with Obesity: A Comparative Prospective Study

PURPOSE

To investigate the changes in weight, body composition, and metabolic biomarkers in patients with obesity after laparoscopic sleeve gastrectomy (LSG) and compare those changes between patients with and without metabolic syndrome (MS).

MATERIALS AND METHODS

This retrospective longitudinal study included 76 patients who underwent LSG, among whom 32 had complete 1-year postoperative body composition and metabolic biomarkers. Body composition was measured by quantitative CT. Weight changes were compared between the MS and non-MS groups at 1-, 3-, 6-, and 12-month post-LSG in all patients; changes in body compositions and metabolic biomarkers from one day pre-LSG to 12-month post-LSG were also compared in those 32 patients.

RESULTS

MS occurred in 46% (35/76) of all patients and 44% (14/32) of patients with complete follow-up data. Excess weight loss was lower in the MS group than that in the non-MS group at 1-, 3-, 6-, and 12-month post-LSG; the 12-month difference was significant (MS vs. non-MS: 0.91 ± 0.22 vs. 1.07 ± 0.42, P = 0.04). The greatest rate of visceral fat area (VFA) change occurred 12-month post-LSG in both the non-MS [0.62(0.55,0.7)] and MS [0.6(0.51,0.63)] groups. The most significant reduction in ectopic fat occurred in liver fat (LF) [non-MS, 0.45(0.22,0.58); MS, 0.39(0.23,0.58)].

CONCLUSION

LGS significantly improves weight, body composition, and metabolic biomarkers in populations with obesity, regardless of whether they have MS. Among the body composition, VFA and LF were the most significantly improved body composition measurements.

Predicting operative time for metabolic and bariatric surgery using machine learning models: a retrospective observational study

BACKGROUND

Predicting operative time is essential for scheduling surgery and managing the operating room. This study aimed to develop machine learning (ML) models to predict the operative time for metabolic and bariatric surgery (MBS) and to compare each model.

METHODS

The authors used the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database between 2016 and 2020 to develop ML models, including linear regression, random forest, support vector machine, gradient-boosted tree, and XGBoost model. Patient characteristics and surgical features were included as variables in the model. The authors used the mean absolute error, root mean square error, and R 2 score to evaluate model performance. The authors identified the 10 most important variables in the best-performing model using the Shapley Additive exPlanations algorithm.

RESULTS

In total, 668 723 patients were included in the study. The XGBoost model outperformed the other ML models, with the lowest root mean square error and highest R 2 score. Random forest performed better than linear regression. The relative performance of the ML algorithms remained consistent across the models, regardless of the surgery type. The surgery type and surgical approach were the most important features to predict the operative time; specifically, sleeve gastrectomy (vs. Roux-en-Y gastric bypass) and the laparoscopic approach (vs. robotic-assisted approach) were associated with a shorter operative time.

CONCLUSIONS

The XGBoost model best predicted the operative time for MBS among the ML models examined. Our findings can be useful in managing the operating room scheduling and in developing software tools to predict the operative times of MBS in clinical settings.

Prior bariatric surgery is associated with lower mortality and resource utilization following small bowel obstruction

Background

Small bowel obstruction (SBO) is a complication of bariatric surgery. However, outcomes of surgical intervention for SBO among patients with prior bariatric surgery remain ill-defined. We used a nationally representative cohort to characterize the outcomes of the SBO management approach in patients with a prior bariatric operation.

Methods

All adult hospitalizations for SBO were tabulated from the 2018-2020 National Readmissions Database. Patients with a prior history of bariatric surgery comprised the Bariatric cohort (others: Non-Bariatric). Multivariable models were subsequently developed to evaluate the association of prior bariatric surgery with outcomes of interest.

Results

Of an estimated 299,983 hospitalizations for SBO, 15,788 (5.3 %) had a history of prior bariatric surgery. Compared to Non-Bariatric, Bariatric patients were younger (54 [46-62] vs 57 [47-64] years, P < 0.001) and were more frequently privately insured (45.1 vs 39.4 %, P < 0.001). On average, the Bariatric more frequently underwent operative management, relative to Non-Bariatric (44.8 vs 29.7 %, P < 0.001). Following risk adjustment, among those surgically managed, Bariatric demonstrated lower odds of mortality (Adjusted Odds Ratio [AOR] 0.69, 95 % Confidence Interval [CI] 0.55-0.87) compared to Non-Bariatric. Bariatric also demonstrated lower odds of infectious and renal complications. Furthermore, the Bariatric cohort had lower costs, length of stay, and non-home discharge.

Conclusions

Patients with prior bariatric surgery demonstrated a lower likelihood of mortality, decreased complications, and reduced resource utilization, relative to others. As the incidence of bariatric surgery continues to rise, future work is needed to minimize the incidence of SBO among these patients, especially in the current era of value-based healthcare.

No Difference in Revision Rates up to 10 years Following Total Hip Arthroplasty in Patients Who Had Prior Bariatric Surgery When Compared to Patients Who Had Class III Obesity: A Propensity Matched Analysis

BACKGROUND

There is no clear research showcasing bariatric surgery's (BS's) impact on long-term surgical complications following total hip arthroplasty (THA). Therefore, this study compared the 10-year cumulative incidence and risk of revision following THA in patients who underwent BS when compared to the general population and class III obesity patients who did not undergo BS.

METHODS

Patients who underwent elective THA from 2010 to 2021 were identified using an all-payer claims database. Patients who underwent BS prior to THA were separately matched to a control of the general population and those who had class III obesity (body mass index ≥40) by age, sex, Charlson Comorbidity Index, and diabetes using a 1:4 ratio. Kaplan-Meier analyses generated 10-year cumulative incidence rates, and a Cox proportional hazard ratio (HR) model generated HRs and 95% confidence intervals (CIs).

RESULTS

When compared to the general control, patients who have a history of BS had an elevated 10-year risk of all-cause revision (HR 1.31, 95% CI: 1.16 to 1.47, P < .001), prosthetic joint infection (HR: 1.62, CI: 1.30 to 2.04; P < .001), mechanical loosening (HR: 1.20, CI: 1.01 to 1.44; P = .040), and dislocation/instability (HR: 1.35, CI: 1.09 to 1.68; P = .007). There was no difference in the 10-year risk of all-cause revision or other indications for revision in the BS cohort compared to the matched class III obesity cohort (P = .142).

CONCLUSIONS

Those who underwent BS before THA had comparable 10-year revision rates when compared to those who had class III obesity and higher rates compared to the general population. This suggests BS may not reduce the 10-year surgical risks associated with obesity when compared to a class III obese surgical population.

Serum levels of Vanin-2 increase with obesity in relation to inflammation of adipose tissue and may be a predictor of bariatric surgery outcomes

Objective

Excessive obesity can lead to dysfunction in adipose tissue, which contributes to the development of comorbidities associated with obesity, such as type 2 diabetes (T2D), cardiovascular and cerebrovascular disease, among others. Previous research has mainly focused on the Vanin family in systemic inflammatory diseases or predicting its role in tumor prognosis, while neglecting its role as a secretory protein in adipose tissue inflammation and metabolism. The objective of this study was to compare the changes in Vanin-2 levels in the circulating blood of normal and obese individuals, and to assess its correlation with inflammatory factors in vivo. Furthermore, the study aimed to systematically evaluate its effectiveness in human weight loss surgery.

Methods

Serum concentrations of Vanin-2 and inflammatory indicators were measured in 518 volunteers. Furthermore, the concentrations of Vanin-2 were measured both before and after weight loss through a dietetic program or laparoscopic sleeve gastrectomy (LSG). Additionally, we assessed the levels of insulin, adiponectin, and inflammation-related factors. The hormonal profile and changes in body weight were evaluated at baseline and 3 months after surgery.

Results

Serum levels of Vanin-2 were found to be significantly increased in individuals with overweight/obesity (OW/OB) group (controls 438.98 ± 72.44, OW/OB 530.89 ± 79.39 ug/L; p < 0.001). These increased levels were associated with IL-18, BMI, FAT%, and HOMA-IR. However, levels of Vanin-2 remained unchanged after conventional dietary treatment. On the other hand, weight loss induced by LSG resulted in a significant decrease in Vanin-2 concentrations from 586.44 ± 48.84 to 477.67 ± 30.27 ug/L (p < 0.001), and this decrease was associated with the Vanin-2 concentrations observed before the operation.

Conclusion

Serum Vanin-2 is a highly effective biomarker for assessing adipose tissue inflammation in obesity and has the potential to serve as a predictor of bariatric surgery outcomes.

Assessment of electronic patient education materials for adolescent bariatric surgery candidates: An environment scan

Objective

Adolescents who opt for metabolic and bariatric surgery (MBS) will use the internet to learn about the procedure. The objective of this study is to assess the suitability of electronic patient education materials (ePEM) of North American centers that perform adolescent bariatric surgery.

Methods

Canadian and American bariatric centers that perform adolescent MBS were identified from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program and Google web-based searches. Suitability of ePEM for the adolescent readership was evaluated using the Suitability Assessment of Materials (SAM).

Results

Sixty-five centers were evaluated from June to July 2020 with 41% citing adolescent specific material. Six percent of the ePEM were evaluated as 'not suitable', 69% were evaluated as 'adequate', and 25% were evaluated as 'superior'.

Conclusion

Adequate ePEM scoring was obtained, but centers had little resources tailored to adolescent patients. Further research is needed to evaluate all the resources provided to adolescents (i.e., resources provided by the health team) to ensure the tools are appropriate for the adolescent readership.

Innovation

This environmental scan provided insights to ePEM available for adolescents considering MBS.

The DECON pilot project investigates predictive markers for successful bariatric surgery

Obesity is a chronic, multifactorial disease which is linked to a number of adverse endocrinological and metabolic conditions. Currently, bariatric surgery is one of the most effective treatments for individuals diagnosed with severe obesity. However, the current indications for bariatric surgery are based on inadequate metrics (i.e., BMI) which do not account for the complexity of the disease, nor the heterogeneity among the patient population. Moreover, there is a lack of understanding with respect to the biological underpinnings that influence successful and sustained weight loss post-bariatric surgery. Studies have implicated age and pre-surgery body weight as two factors that are associated with favorable patient outcomes. Still, there is an urgent medical need to identify other potential factors that could improve the specificity of candidate selection and better inform the treatment plan of patients with obesity. In this report, we present and describe the cohort of the DECON pilot project, a multicenter study which aims to identify predictive biomarkers of successful weight loss after bariatric surgery.

Opioid Analgesics after Bariatric Surgery: A Scoping Review to Evaluate Physiological Risk Factors for Opioid-Related Harm

The persisting use of opioids following bariatric surgery has emerged as a prevalent complication, heightening the probability of opioid-related harm (ORM), such as opioid-related fatalities and prescription opioid use disorder (OUD). A comprehensive review of PubMed literature from 1990 to 2023 was conducted to pinpoint physiological influences on postoperative ORM. As a result, we found that patients undertaking bariatric operations often exhibit an inherently higher risk for substance use disorders, likely attributable to genetic predisposition and related neurobiological changes that engender obesity and addiction-like tendencies. Furthermore, chronic pain is a common post-bariatric surgery complaint, and the surgical type impacts opioid needs, with increased long-term opioid use after surgeries. Additionally, the subjective nature of pain perception in patients with obesity can distort pain reporting and the corresponding opioid prescription both before and after surgery. Furthermore, the postoperative alterations to the gastrointestinal structure can affect the microbiome and opioid absorption rates, resulting in fluctuating systemic exposure to orally ingested opioids. The prospect of ORM development post-bariatric surgery appears amplified due to a preexisting susceptibility to addictive habits, surgically induced pain, modified gut-brain interaction and pain management and the changed pharmacokinetics post-surgery. Further research is warranted to clarify these potential risk variables for ORM, specifically OUD, in the bariatric population.

Uncovering Barriers and Facilitators of Weight Loss and Weight Loss Maintenance: Insights from Qualitative Research

Long-term weight loss maintenance is often difficult to achieve. This review analysed qualitative data on self-perceived barriers and facilitators of weight loss and weight loss maintenance among weight loss intervention participants. A literature search was conducted using electronic databases. Qualitative studies written in English and published between 2011-2021 were eligible for inclusion if they explored the perspectives and experiences of individuals who received standardised dietary and behavioural support for weight loss. Studies were excluded if weight loss was achieved through self-directed methods, only increasing physical activity, or surgical or pharmacological interventions. Fourteen studies were included, totaling 501 participants from six countries. Thematic analysis was used to identify four aggregate themes: internal factors (i.e., motivation and self-efficacy), programme-specific factors (i.e., the intervention diet), social factors (i.e., supporters and saboteurs), and environmental factors (i.e., an obesogenic environment). Our findings demonstrate that internal, social, and environmental factors all influence weight loss success, as well as the acceptability of the weight loss intervention. Future interventions may be more successful if they prioritise participant acceptability and engagement by, for example, providing tailored interventions, a structured relapse management plan, strategies to enhance autonomous motivation and emotional self-regulation, and extended contact during weight loss maintenance.

Virtual Reality as a Surgical Care Package for Patients Undergoing Weight Loss Surgery: A Narrative Review of the Impact of an Emerging Technology

While bariatric surgery is regarded as the most effective treatment for people with severe and morbid obesity, its pathway is regarded as a complex one due to the multidisciplinary approaches required from pre-surgery education until long-term management. This is essential to maintain weight loss and improve the quality of life after bariatric surgery. Although these approaches are broadened, patient education, pre-operative preparation, behavioural therapy, rehabilitation, and dietary changes are regarded as the main domains in such complex care. With the increase in technological adaptation in medical services, virtual reality (VR) has shown many benefits that can be utilized in the care of bariatric patients undergoing surgery. However, VR has not been innovated to be a multidomain care package in which bariatric patients could benefit throughout their journey from the pre-operative optimization, recovery, and long-term follow-up. This review aims to give a brief description of some of the applications of VR technology and question whether it has the potential to be considered as a virtual ecosystem to improve the bariatric patients’ experience and pathway throughout surgery and follow-up.

Frank Stinchfield Award: Does Bariatric Surgery Prior to Primary Total Hip Arthroplasty Really Improve Outcomes?

BACKGROUND

Optimal management of morbid obesity before total hip arthroplasty (THA) remains debated. Recently, bariatric procedures have become more common with advancements in surgical techniques. We hypothesized that bariatric surgery prior to primary THA would mitigate acute postoperative complications and improve implant survivorship.

METHODS

A retrospective review from 1995 to 2020 identified 88 primary THA procedures in 71 unique patients who previously underwent bariatric surgery (73% Roux-en-Y). This cohort was matched 1:1:1 for age, gender, surgical year, American Society of Anesthesiologists score, and Charlson Comorbidity Index to cohorts of patients with body mass index (BMI) <40 kg/m² and BMI ≥40 kg/m². Revisions, reoperations, and acute complications were compared. Subgroup analysis then evaluated historical (pre-2012) relative to contemporary (2012 and after) bariatric procedures.

RESULTS

Revision rates for bariatric patients were higher relative to controls with low (hazard ratio [HR] 19, P < .01) and high BMI (HR 8, P < .01). Reoperation rates showed a similar increase for bariatric patients when compared to low (HR 9, P < .01) and high BMI (HR 4, P = .01) patients. Moreover, bariatric patients had an increased dislocation risk compared to the low (HR 7, P = .03) and high BMI (HR 17, P < .01) patients. Contemporary bariatric techniques had similar complications, revisions, and reoperations relative to historical procedures.

CONCLUSION

Morbidly obese patients undergoing THA have increased risks of certain complications, but it is unclear if bariatric surgery improves this risk. This study found that patients undergoing bariatric surgery have worse implant survivorship and higher dislocation rates compared to patients with naturally low and high BMIs. Further investigation into the post-bariatric metabolic state is warranted.

LEVEL OF EVIDENCE

Prognostic Level IV.

Does Bariatric Surgery Prior to Primary Total Knee Arthroplasty Improve Outcomes?

BACKGROUND

Recent advancements in bariatric surgical techniques have increased its utilization for the management of morbid obesity prior to total knee arthroplasty (TKA). We hypothesized that bariatric surgery prior to primary TKA would mitigate postoperative complications and improve implant survivorship.

METHODS

A retrospective review from 1992-2020 identified 205 bariatric surgery patients with subsequent primary TKA. This cohort was matched 1:1:1 to patients without bariatric surgery and with BMI <40 kg/m² and BMI ≥40 kg/m². Revisions, reoperations, and 90-day complications were evaluated. Subgroup analysis evaluated bariatric patients with BMI >40 kg/m² at TKA, the time between surgeries, and compared historical to contemporary bariatric techniques.

RESULTS

Bariatric patients demonstrated higher revision rates than low (HR 4, P < .01) and high BMI (HR 9, P < .01) controls, and increased reoperations when compared to the low (HR 2, P < .01) and high BMI (HR 6, P < .01) groups. Reoperation for instability was more common in bariatric patients than low (HR 15, P = .01) and high BMI (HR 17, P < .01) groups. Reoperation for infection was higher in bariatric patients relative to the high BMI (HR 6, P = .03), but not the low BMI cohort (HR 3, P = .06). There was no difference in 90-day complications (P = .33). Bariatric patients with high BMI and contemporary bariatric procedures did not significantly impact complications or survivorship, but bariatric surgery >2 years before TKA was associated with higher revision rates (P = .01).

CONCLUSION

This study found that bariatric surgery patients who undergo primary TKA have worse implant survivorship, mostly related to infection and instability. Further investigation into perioperative optimization is warranted.

LEVEL OF EVIDENCE

Prognostic Level IV.

Bariatric surgery, gastrointestinal hormones, and the microbiome: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) is intended to provide clinicians an overview of bariatric surgery (i.e., bariatric procedures that improve metabolic disease are often termed "metabolic and bariatric surgery"), gastrointestinal hormones, and the microbiome as they relate to patients with obesity.

Methods

The scientific information for this CPS is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

This CPS includes the pros and cons of the most common types of bariatric procedures; the roles of gastrointestinal (GI) hormones in regulating hunger, digestion, and postabsorptive nutrient metabolism; and the microbiome's function and relationship with body weight. This CPS also describes patient screening for bariatric surgery, patient care after bariatric surgery, and treatment of potential nutrient deficiencies before and after bariatric surgery. Finally, this CPS explores the interactions between bariatric surgery, GI hormones, and the microbiome.

Conclusions

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) regarding bariatric surgery, gastrointestinal hormones, and the microbiome is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of obesity. Implementation of appropriate care before and after bariatric surgery, as well as an awareness of GI hormones and the microbiome, may improve the health of patients with obesity, especially patients with adverse fat mass and adiposopathic metabolic consequences.

Implications of Bariatric Surgery on the Pharmacokinetics of Antiretrovirals in People Living with HIV

Bariatric surgery is increasingly applied among people living with HIV to reduce obesity and the associated morbidity and mortality. In people living with HIV, sufficient antiretroviral exposure and activity should always be maintained to prevent development of resistance and disease progression. However, bariatric surgery procedures bring various gastrointestinal modifications including changes in gastric volume, and acidity, gastrointestinal emptying time, enterohepatic circulation and delayed entry of bile acids. These alterations may affect many aspects of antiretroviral pharmacokinetics. Some drug characteristics may result in subtherapeutic exposure and the potential related risk of treatment failure and resistance. Antiretrovirals that require low pH, administration of fatty meals, longer intestinal exposure, and an enterohepatic recirculation for their absorption may be most impacted by bariatric surgery procedures. Additionally, some antiretrovirals can interact with the polyvalent cations in supplements or drugs inhibiting gastric acid, thereby preventing their use as these comedications are commonly prescribed post-bariatric surgery. Predicting pharmacokinetics on the basis of drug characteristics solely proved to be challenging, therefore pharmacokinetic studies remain crucial in this population. Here, we discuss general implications of bariatric surgery on antiretroviral outcomes in people living with HIV as well as drug properties that are relevant for the choice of antiretroviral treatment in this special patient population. Additionally, we summarise studies that evaluated the pharmacokinetics of antiretrovirals post-bariatric surgery. Finally, we performed a comprehensive analysis of theoretical considerations and published pharmacokinetic and pharmacodynamic data to provide recommendations on antiretrovirals for people living with HIV undergoing bariatric surgery.

Descriptive analysis of reported adverse events associated with anti-obesity medications using FDA Adverse Event Reporting System (FAERS) databases 2013-2020

Background Obesity is a globally growing health problem, and its treatment has been challenging. The use of anti-obesity medications (AOMs) has been associated with severe adverse events (AEs). Several AOMs have been withdrawn from the market owing to documented AEs. Aim To describe, estimate and characterize the frequency of AEs attributable to the use of the AOMs, and investigate previously unreported potential AEs associated with AOMs. Method Using the US FDA Adverse Event Reporting System (FAERS) between January 2013 and June 2020, a retrospective, descriptive analysis was conducted to analyze all major reported AEs and outcomes including death, life-threatening, hospitalization, disability, and required intervention or congenital anomaly. The total numbers of AEs reports, cases, adverse reactions and outcomes were calculated for each medication. Results A total of 18,675 unique AEs reports associated with AOMs used for 15,143 patients. The mean age was 49.8 years [SD 1.83], while most patients were female adults (73.4%). The most frequently reported AEs were nausea and vomiting, followed by dizziness and headache, drug ineffectiveness, cardiovascular diseases, and kidney complications. There were 21,229 unique outcomes, including 1039 deaths (fatality ratio of 4.9% of all analyzed reports), 1613 (7.6%) life-threatening events, 7426 (35%) hospitalizations, and 1249 (5.9%) disability cases. Phentermine/topiramate fatal cases represent 6% of the overall medication's reported AEs. Cardiovascular AEs represented 31%, 23%, and 22% of phentermine, liraglutide, and phentermine/topiramate total AEs, respectively. Conclusion The analysis of FAERS database revealed numerous serious AEs associated with AOMs. These AEs can lead to serious cardiovascular and kidney complications. It is necessary to continue and systematically monitor safety of AOMs' to optimize patient anti-obesity therapy.

Metabolic and Psychological Features are Associated with Weight Loss 12 Months After Sleeve Gastrectomy

CONTEXT

Laparoscopic sleeve gastrectomy (LSG) is a recognized effective procedure of bariatric surgery, but a poor response in weight loss may still represent a clinical problem. To date there are no validated predictors useful to better perform patient selection.

OBJECTIVE

To establish the association of baseline anthropometric, metabolic, and psychologic features with the percent total weight loss (%TWL) and percent excess weight loss (%EWL) 12 months after surgery.

DESIGN

Retrospective longitudinal analysis of a set of data about obese patients attending the outpatient service of a single obesity center from June 2016 to June 2019.

PATIENTS

A total of 106 obese patients underwent LSG with presurgery evaluation and follow-up at 12 months after surgery.

MAIN OUTCOME

Weight loss 12 months after LSG.

RESULTS

Patients who achieved a %TWL higher than the observed median (≥34%) were younger, with a lower fasting plasma glucose and glycated hemoglobin, with a lower prevalence of hypertension and with a lower score in the impulsiveness scale, compared with patients with a %TWL < 34%. Similar findings were found when %EWL was considered. Multivariable stepwise regression analysis showed that younger age, lower impulsiveness, higher-than-normal urinary free cortisol, and lower HbA1c were associated with higher %TWL, explaining about 31.5% of the weight loss.

CONCLUSION

Metabolic and psychologic features at baseline were independently associated with weight loss and explained a non-negligible effect on the response to LSG. These data suggest that careful metabolic and psychologic profiling could help in sharper indications and personalized pre- and postsurgical follow-up protocols in candidates for LSG.

Experiences of the Bariatric Pre-Surgery Evaluation Process in a National Health Service—An Interpretative Phenomenological Analysis

There is currently little understanding of bariatric patients’ experiences and expectations of the bariatric pre-surgery evaluation (PSE) process. This is especially true for patients within the National Health Service (NHS) in the UK. Consequently, this study undertakes a qualitative study to explore the experiences and expectations of the bariatric PSE amongst patients who had undergone bariatric surgery within the NHS in the UK, using the Interpretative Phenomenological Analysis. Three inter-related superordinate themes were presented: (i) ‘PSE was challenging but essential’, (ii) ‘Coping processes to deal with the PSE’, and (iii) ‘Staff and service evaluation’. Most participants had conflicting feelings about the PSE process as it had both positive and negative impacts on their wellbeing. The process was considered essential for preparation and successful post-surgery adjustment, though the uncertainty of approval was experienced as very distressing. Consequently, participants utilised both external and internal coping strategies, such as social support, researching, or ‘toeing the line’. Participants’ experiences encouraged them to provide feedback about the staff and service, which revealed a preference for a tailored evaluation process. The emerged themes represent an initial framework for helping healthcare providers and researchers to involve patients in service delivery thereby facilitating a patient-centred approach. A starting point is to audit patients’ perspectives routinely. Further investigations are needed to better define, validate, and understand constructs and processes identified in this study.

Nutritional Assessment and Preparation for Adult Bariatric Surgery Candidates: Clinical Practice

Bariatric surgery (BS) has proven to be highly efficacious in the treatment of obesity and its comorbidities. However, careful patient selection is critical for its success. Thus, patients should undergo medical, behavioral, and nutritional assessment by a multidisciplinary team. From the nutritional point of view, BS candidates should undergo nutritional assessment, preparation, and education by a registered dietitian in the preoperative period. Currently, detailed specified and comprehensive information on these topics is lacking. The present narrative review aimed to summarize the available literature concerning both the preoperative nutritional assessment components and the preoperative nutritional preparation and education components of patients planning to undergo BS. Current literature indicates that proper management before BS should include a comprehensive nutritional assessment, in which it is advisable to perform a clinical interview to assess patients' medical background, weight management history, eating patterns and pathologies, oral health, physical activity habits, nutritional status, supplementation usage, BS knowledge, surgery expectations and anthropometric measurements. Nutritional preparation and educational strategies should include an individualized preoperative weight-loss nutrition program, improvement of glycemic control, micronutrients deficiencies correction, eating and lifestyle habits adaptation, physical activity initiation, and strengthening knowledge on obesity and BS. At this stage, more well-designed intervention and long-term cohort studies are needed in order to formulate uniform evidence-based nutritional guidelines for patients who plan to undergo BS, including populations at higher nutritional risk. Moreover, postoperative outcomes of presurgical nutritional intervention programs should be studied.

Evaluation of statin discontinuation stratified by primary versus secondary prevention following bariatric surgery: a retrospective cohort study

BACKGROUND

Bariatric surgery leads to an improvement in hyperlipidemia and a subsequent decline in the use of hyperlipidemia-related medications, including statins. In patients with a history of atherosclerotic cardiovascular disease (ASCVD), it is recommended to continue statins; however, it is unknown whether there is a differential risk for statin discontinuation in patients with and without a history of ASCVD.

OBJECTIVES

To estimate the rates and factors associated with statin discontinuation following bariatric surgery.

SETTING

Large U.S. administrative claims database of privately insured beneficiaries, January 2005 through December 2017.

METHODS

We identified patients aged ≥19 years who were statin users at the time of bariatric surgery. Patients were stratified into primary prevention and secondary prevention (patients with a history of ASCVD) groups. Time to statin discontinuation was defined as the first 90-day gap after exhausting the last day's supply of the last statin prescription. Factors associated with statin discontinuation were assessed using the Cox proportional hazards regression model.

RESULTS

We identified 19,332 statin users at the time of bariatric surgery, of whom 84% (16,221) used statins for primary prevention. At 6 months, 62% and 53% of patients in the primary and the secondary prevention treatment groups, respectively, discontinued statin use. Patients in the primary prevention treatment group were 18% more likely to discontinue statin therapy compared with the patients in the secondary prevention treatment group (hazard ratio, 1.18; 95% confidence interval, 1.13-1.24) according to a multivariable analysis.

CONCLUSIONS

Our findings suggest that the rate of discontinuation of statin therapy after bariatric surgery was more pronounced in the primary versus secondary prevention treatment group.

Amylin and Calcitonin: Potential Therapeutic Strategies to Reduce Body Weight and Liver Fat

The hormones amylin and calcitonin interact with receptors within the same family to exert their effects on the human organism. Calcitonin, derived from thyroid C cells, is known for its inhibitory effect on osteoclasts. Calcitonin of mammalian origin promotes insulin sensitivity, while the more potent calcitonin extracted from salmon additionally inhibits gastric emptying, promotes gallbladder relaxation, increases energy expenditure and induces satiety as well as weight loss. Amylin, derived from pancreatic beta cells, regulates plasma glucose by delaying gastric emptying after meal ingestion, and modulates glucagon secretion and central satiety signals in the brain. Thus, both hormones seem to have metabolic effects of relevance in the context of non-alcoholic fatty liver disease (NAFLD) and other metabolic diseases. In rats, studies with dual amylin and calcitonin receptor agonists have demonstrated robust body weight loss, improved glucose tolerance and a decreased deposition of fat in liver tissue beyond what is observed after a body weight loss. The translational aspects of these preclinical data currently remain unknown. Here, we describe the physiology, pathophysiology, and pharmacological effects of amylin and calcitonin and review preclinical and clinical findings alluding to the future potential of amylin and calcitonin-based drugs for the treatment of obesity and NAFLD.

Developing Integrated Clinical Pathways for the Management of Clinically Severe Adult Obesity: a Critique of NHS England Policy

PURPOSE OF THE REVIEW

Pathways for obesity prevention and treatment are well documented, yet the prevalence of obesity is rising, and access to treatment (including bariatric surgery) is limited. This review seeks to assess the current integrated clinical pathway for obesity management in England and determine the major challenges.

RECENT FINDINGS

Evidence for tier 2 (community-based lifestyle intervention) and tier 3 (specialist weight management services) is limited, and how it facilitates care and improve outcomes in tier 4 remains uncertain. Treatment access, rigidity in pathways, uncertain treatment outcomes and weight stigma seems to be major barriers to improved care. More emphasis must be placed on access to effective treatments, treatment flexibility, addressing stigma and ensuring treatment efficacy including long-term health outcomes. Prevention and treatment should both receive significant focus though should be considered to be largely separate pathways. A simplified system for weight management is needed to allow flexibility and the delivery of personalized care including post-bariatric surgery care for those who need it.

Emotion perception and theory of mind in obesity: a systematic review on the impact of social cognitive deficits on dysfunctional eating behaviors

The aim of this paper was to summarize our current understanding of emotion perception and Theory of Mind (ToM) in obesity and how they relate to dysfunctional eating behaviors (DEB), frequently found in candidates for bariatric surgery. The literature was searched using the electronic databases PsychInfo, Medline, and Web of Science databases, and by additional hand searches through reference lists and specialist eating disorders journals. Relevant studies were included if they were written in English, included participants suffering from obesity and evaluation with tasks assessing social cognition, such as emotion recognition and perception, as well as ToM. Twelve studies analyzed for this systematic review suggest that deficits in such social cognitive domains may lie behind many emotional and social difficulties present in people with obesity, be they bariatric or not, which usually favor DEB. Our review suggests that people with obesity of all ages score significantly less than controls on instruments assessing emotion recognition and ToM, justifying a possible relationship between social cognitive impairments and dysfunctional eating behaviors, such as binges, emotional eating, and addition to food, frequently seen in people with obesity. These findings have important implications for our understanding of the social cognitive foundations of eating behavior in individuals with obesity. They can help not only the presurgical behavioral assessment, but also guide postoperative follow-up of this population.

Computational Tools for the Reliability Assessment and the Engineering Design of Procedures and Devices in Bariatric Surgery

Obesity is one of the main health concerns worldwide. Bariatric Surgery (BS) is the gold standard treatment for severe obesity. Nevertheless, unsatisfactory weight loss and complications can occur. The efficacy of BS is mainly defined on experiential bases; therefore, a more rational approach is required. The here reported activities aim to show the strength of experimental and computational biomechanics in evaluating stomach functionality depending on bariatric procedure. The experimental activities consisted in insufflation tests on samples of swine stomach to assess the pressure-volume behaviour both in pre- and post-surgical configurations. The investigation pertained to two main bariatric procedures: adjustable gastric banding (AGB) and laparoscopic sleeve gastrectomy (LSG). Subsequently, a computational model of the stomach was exploited to validate and to integrate results from experimental activities, as well as to broad the investigation to a wider scenario of surgical procedures and techniques. Furthermore, the computational approach allowed analysing stress and strain fields within stomach tissues because of food ingestion. Such fields elicit mechanical stimulation of gastric receptors, contributing to release satiety signals. Pressure-volume curves assessed stomach capacity and stiffness according to the surgical procedure. Both AGB and LSG proved to reduce stomach capacity and to increase stiffness, with markedly greater effect for LSG. At an internal pressure of 5 kPa, outcomes showed that in pre-surgical configuration the inflated volume was about 1000 mL, after AGB the inflated volume was slightly lower, while after LSG it fell significantly, reaching 100 mL. Computational modelling techniques showed the influence of bariatric intervention on mechanical stimulation of gastric receptors due to food ingestion. AGB markedly enhanced the mechanical stimulation within the fundus region, while LSG significantly reduced stress and strain intensities. Further computational investigations revealed the potentialities of hybrid endoscopic procedures to induce both reduction of stomach capacity and enhancement of gastric receptors mechanical stimulation. In conclusion, biomechanics proved to be useful for the investigation of BS effects. Future exploitations of the biomechanical methods may largely improve BS reliability, efficacy and penetration rate.

Weight loss during medical weight management does not predict weight loss after bariatric surgery: a retrospective cohort study

BACKGROUND

Many bariatric surgical centers mandate achieving weight loss targets through medical weight management (MWM) programs before offering bariatric surgery, but the evidence for this is unclear.

OBJECTIVES

To examine the relationship between weight changes during (1) MWM, and (2) preoperative low-energy-diet (LED), and weight changes at 12 and 24 months after surgery.

SETTING

Multicenter community- and acute-based MWM services referring to one regional bariatric center, United Kingdom.

METHODS

A retrospective cohort study of patients who attended MWM and then underwent a primary laparoscopic bariatric procedure (adjustable gastric banding [LAGB], or Roux-en-Y gastric bypass [RYGB]) in a single bariatric center in the United Kingdom between 2013 and 2015. Data were collected from patient electronic records.

RESULTS

Two hundred eight patients were included (LAGB n = 128, RYGB n = 80). Anthropometric data were available for 94.7% and 88.0% of participants at 12 and 24 months, respectively. There was no relationship between weight loss during MWM and after surgery at either 12 or 24 months. Weight loss during the preoperative LED predicted greater weight loss after LAGB (β = .251, P = .006) and less weight loss after RYGB (β = -.390, P = .003) at 24 months, after adjusting for age, sex, ethnicity, baseline weight, and LED duration.

CONCLUSIONS

Weight loss in MWM does not predict greater weight loss outcomes up to 24 months after LAGB or RYGB. Greater weight loss during the preoperative LED predicted greater weight loss after LAGB and less weight loss after RYGB. Our results suggest that patients should not be denied bariatric surgery because of not achieving weight loss in MWM. Weight loss responses to preoperative LEDs as a predictor of postsurgical weight loss requires further investigation.

The Effects of Polyphenol Supplementation in Addition to Calorie Restricted Diets and/or Physical Activity on Body Composition Parameters: A Systematic Review of Randomized Trials

Background: Both, calorie restricted diets (CRD) and physical activity (PA) are conventional obesity therapies but their effectiveness is usually limited in the long-term. Polyphenols are bioactive compounds that have shown to possess some anti-obesity properties. The synergic effects between dietary polyphenols and CRD or PA on body weight and fat are supported by several animal studies, but evidence in human is still inconsistent. Thus, our aim was to review the combined effects of polyphenol supplementation with CRD and/or PA on body weight and fat, body mass index (BMI) and waist circumference (WC) in overweight or obese adults. Methods: Electronic databases (PubMed, Web of Science and Cochrane CENTRAL) were searched for randomized clinical trials (RCT) examining the combination of polyphenols with CRD and/or PA (up to December 31st, 2019). Articles were included if they had a duration of intervention ≥ 4 weeks. Both, quality and risk of bias of the included studies were assessed using the Cochrane RoB2 Tool. Results: The review included 4 and 11 RCTs investigating the anti-obesity effects of polyphenol supplementation combined with CRD and PA, respectively. Isoflavone supplementation may increase fat loss during exercise among post-menopausal women in non-Asian studies. In the rest of RCTs regarding polyphenol supplementation and CRD or PA, no additive changes were found. Conclusion: The results do not yet support polyphenol supplementation as a complementary strategy for enhancing the effectiveness of CRD and PA on weight and fat loss. However, this review suggests that isoflavone and soy products combined with lifestyle changes, especially exercise, provide additional anti-obesity effects in postmenopausal women. The potential role of polyphenols alone or, especially, in addition to conventional therapies (CRD and PA) mostly remains uncertain; and therefore, larger and longer RCTs examining these effects are needed. Protocol Registration: PROSPERO CRD42020159890.

The rise of one anastomosis gastric bypass: insights from surgeons and dietitians

One anastomosis gastric bypass/Mini Gastric Bypass (OAGB/MGB) is an emerging bariatric surgery (BS) technique. We evaluated and compared attitudes of bariatric surgeons and dietitians towards the considerations for choosing BS-type ("Decision-making"), the contributing factors to the rise of OAGB/MGB in Israel ("OAGB/MGB-rise") and notions regarding the occurrence of gastrointestinal (GI) symptoms and nutritional deficiencies following OAGB/MGB. Anonymous online surveys were distributed. The participants were asked to rate by a 10-point Likert scale (0 = not at all; 100 = very much/often) their attitudes towards "Decision-making", "OAGB/MGB-rise" and occurrence of GI symptoms and nutritional deficiencies following OAGB/MGB. For "Decision-making" and "OAGB/MGB-rise", items were considered prioritized where ≥ 50% of the group considered them as 'very-important' (rating ≥ 80). Data on age, sex, years-in-practice and main workplace were also collected. A total of 106 professionals participated in the survey (42 surgeons; 64 dietitians). The respective mean age, years-in-practice and sex were 52.3 ± 8.7 vs. 42.3 ± 9.0 years, 21.0 ± 10.8 vs. 15.5 ± 9.2 years and 85.7% vs. 3.1% males. The inter-observer agreement for prioritized items related to "Decision-making" was fair (Kappa = 0.250; P = 0.257) and both groups prioritized patient's BMI, comorbidities and compliance. The inter-observer agreement for prioritized items related to "OAGB/MGB-rise" was moderate (Kappa = 0.550; P = 0.099) and both groups prioritized ease of performance, shorter operation duration and failure of former restrictive BS. Surgeons reported lower occurrence of nutritional deficiencies and GI symptoms as adverse effects of OAGB/MGB (P ≤ 0.033). The study highlights the views of bariatric surgeons and dietitians concerning factors that underpin the rise of OABG/MGB in Israel and possible rates of GI symptoms and nutritional deficiencies associated with this modality.

Sleeve Gastrectomy Compared with Gastric Bypass for Morbidly Obese Patients with End Stage Renal Disease: a Decision Analysis

INTRODUCTION

The use of bariatric surgery has increased for morbidly obese patients with end stage renal disease (ESRD) for whom listing on the waitlist is often restricted until a certain BMI threshold is achieved. Effective weight loss for this population improves access to life-saving renal transplantation. However, it is unclear whether sleeve gastrectomy (SG) vs Roux-en-Y gastric bypass (RYGB) is a more effective therapy for these patients.

METHODS

A decision analytic Markov state transition model was created to simulate the life of morbidly obese patients with ESRD who were deemed ineligible to be waitlisted for renal transplantation unless they achieved a BMI less than 35 kg/m². Life expectancy following weight management (MWM), RYGB, and SG were estimated. Base case patients were defined as having a pre-intervention BMI of 45 kg/m². Sensitivity analysis of initial BMI was performed. Markov parameters were extracted from literature review.

RESULTS

RYGB improved survival compared with SG and MWM. RYGB patients had higher rates of transplantation, leading to improved mean long-term survival. Base case patients who underwent RYGB gained 1.3 additional years of life compared with patient's who underwent SG and 2.6 additional years of life compared with MWM.

CONCLUSIONS

RYGB improves access to renal transplantation and thereby increases long-term survival compared with SG and MWM. The use of SG may be incongruent with the goal of improving access to renal transplantation for morbidly obese patients.

Adolescent Bariatric Surgery: Effects of Socioeconomic, Demographic, and Hospital Characteristics on Cost, Length of Stay, and Type of Procedure Performed

BACKGROUND

Despite the efficacy of bariatric surgery in adolescents and the increasing rates of adolescent obesity, the use of bariatric surgery remains low. Treatment cost and length of stay (LOS) could be influencing the utilization of bariatric surgery.

METHODS

We used the Kids' Inpatient Database (KID) from 2006, 2009, and 2012. Adolescents with a primary diagnosis of obesity who underwent bariatric surgery were included. Multinomial logistic and linear regression modeling was used to determine the association of the predictor variables with type of procedure and treatment cost and LOS, respectively.

RESULTS

We identified 1799 adolescents who underwent bariatric surgery. The majority of the subjects were female (77%) and White (60%). The most commonly performed procedure was Roux-en-Y gastric bypass (56%). Race, region, hospital teaching status, and hospital ownership affected the type of procedure performed. Self-pay patients were less likely to undergo Roux-en-Y gastric bypass (RYGB) than sleeve gastrectomy (SG) when compared to patients with private insurance. Teaching hospitals were less likely to perform RYGB or AGB than SG when compared to non-teaching hospitals. Treatment cost was significantly affected by income, teaching hospital status, hospital size, and surgery type. LOS was affected by income quartile, region, and surgery type.

CONCLUSION

Socioeconomic and demographic factors as well as hospital characteristics affect not only the LOS and treatment cost, but also the type of bariatric surgery performed in adolescents. Identifying and understanding the factors influencing procedure choice, treatment cost, and LOS can improve care and healthcare resource utilization.

Class 3 Obesity in a Multidisciplinary Metabolic Weight Management Program: The Effect of Preexisting Type 2 Diabetes on 6-Month Weight Loss

INTRODUCTION

Class 3 obesity (BMI ≥ 40 kg/m²) is a growing health problem worldwide associated with considerable comorbidity including Type 2 diabetes mellitus (T2DM). The multidisciplinary medical management of obesity can be difficult in T2DM due to potential weight gain from medications including sulphonylureas and insulin. However, newer weight-neutral/losing diabetes medications can aid additional weight loss. The aim of this study was to compare weight loss outcomes of patients with and without T2DM, and in patients with T2DM, to compare diabetes outcomes and change in medications at 6 months.

METHODS

All patients entering a multidisciplinary weight management metabolic program in a publicly funded hospital clinic in Sydney between March 2018 and March 2019, with BMI ≥ 40 kg/m² and aged ≥18 years were included. Data was collected from patient clinical and electronic notes at baseline and 6 months.

RESULTS

Of the 180 patients who entered the program, 53.3% had T2DM at baseline. There was no difference in percentage weight loss in those with or without T2DM (4.2 ± 4.9% vs. 3.6 ± 4.7%, p = 0.35). Additionally, T2DM patients benefited from a 0.47% reduction in HbA1c (p < 0.01) and a reduction in the number of medications from baseline to 6 months (1.8 ± 1.0/patient vs. 1.0 ± 1.2/patient, p < 0.001). T2DM patients who started on weigh-neutral/losing medications in the program lost more weight than those started on weight-gaining medications (7.7 ± 5.3% vs. 2.4 ± 3.8%, p = 0.015).

CONCLUSIONS

Patients with class 3 obesity had significant weight loss at 6 months in this program. Patients with T2DM at baseline had comparable weight loss at 6 months, a significant improvement in glycaemic control, and a reduction in diabetes medication load. Additionally, patients with T2DM who were started on weight-neutral/losing medications lost significantly more weight than those started on weight-gaining medications, and these medications should be preferentially used in class 3 obesity and comorbid T2DM.

Risk of Operative and Nonoperative Interventions Up to 4 Years After Roux-en-Y Gastric Bypass vs Vertical Sleeve Gastrectomy in a Nationwide US Commercial Insurance Claims Database

IMPORTANCE

There are few nationwide studies comparing the risk of reintervention after contemporary bariatric procedures.

OBJECTIVE

To compare the risk of intervention after Roux-en-Y gastric bypass (RYGB) vs vertical sleeve gastrectomy (VSG).

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used a nationwide US commercial insurance claims database. Adults aged 18 to 64 years who underwent a first RYGB or VSG procedure between January 1, 2010, and June 30, 2017, were matched on US region, year of surgery, most recent presurgery body mass index (BMI) category (based on diagnosis codes), and baseline type 2 diabetes. The prematch pool included 4496 patients undergoing RYGB and 8627 patients undergoing VSG, and the final weighted matched sample included 4476 patients undergoing RYGB and 8551 patients undergoing VSG.

EXPOSURES

Bariatric surgery procedure type (RYGB vs VSG).

MAIN OUTCOMES AND MEASURES

The primary outcome was any abdominal operative intervention after the index procedure. Secondary outcomes included the following subtypes of operative intervention: biliary procedures, abdominal wall hernia repair, bariatric conversion or revision, and other abdominal operations. Nonoperative outcomes included endoscopy and enteral access. Time to first event was compared using multivariable Cox proportional hazards regression modeling.

RESULTS

Among 13 027 patients, the mean (SD) age was 44.4 (10.3) years, and 74.1% were female; 13.7% had a preoperative BMI between 30 and 39.9, 45.8% had a preoperative BMI between 40 and 49.9, and 24.2% had a preoperative BMI of at least 50. Patients were followed up for up to 4 years after surgery (median, 1.6 years; interquartile range, 0.7-3.2 years), with 41.9% having at least 2 years of follow-up and 16.3% having at least 4 years of follow-up. Patients undergoing VSG were less likely to have any subsequent operative intervention than matched patients undergoing RYGB (adjusted hazard ratio [aHR], 0.80; 95% CI, 0.72-0.89) and similarly were less likely to undergo biliary procedures (aHR, 0.77; 95% CI, 0.67-0.90), abdominal wall hernia repair (aHR, 0.60; 95% CI, 0.47-0.75), other abdominal operations (aHR, 0.71; 95% CI, 0.61-0.82), and endoscopy (aHR, 0.54; 95% CI, 0.49-0.59) or have enteral access placed (aHR, 0.58; 95% CI, 0.39-0.86). Patients undergoing VSG were more likely to undergo bariatric conversion or revision (aHR, 1.83; 95% CI, 1.19-2.80).

CONCLUSIONS AND RELEVANCE

In this nationwide study, patients undergoing VSG appeared to be less likely than matched patients undergoing RYGB to experience subsequent abdominal operative interventions, except for bariatric conversion or revision procedures. Patients considering bariatric surgery should be aware of the increased risk of subsequent procedures associated with RYGB vs VSG as part of shared decision-making around procedure choice.

The effect of surrogate procedure volume on bariatric surgery outcomes: do common laparoscopic general surgery procedures matter?

BACKGROUND

A growing body of evidence shows that experience and acquired skills from surrogate surgical procedures may be transferrable to a specific index operation. It is unclear whether this applies to bariatric surgery. This study aims to determine whether there is a surrogate volume effect of common laparoscopic general surgery procedures on all-cause bariatric surgical morbidity.

METHODS

This was a population-based study of all patients aged ≥ 18 who received a bariatric procedure in Ontario from 2008 to 2015. The main outcome of interest was all-cause morbidity during the index admission. All-cause morbidity included any documented complication which extended length of stay by 24 h or required reoperation. Bariatric cases included laparoscopic Roux-en-Y gastric bypass, sleeve gastrectomy, and biliopancreatic diversion with duodenal switch. Non-bariatric cases included three common laparoscopic general surgery procedures.

RESULTS

13,836 bariatric procedures were performed by 29 surgeons at nine centers of excellence. A reduction in all-cause morbidity was seen when bariatric surgeons exceeded 75 cases annually (OR 0.82, 95% CI 0.69-0.98, P = 0.023), with further reduction in increasing bariatric volume. However, the volume of non-bariatric surgeries did not significantly affect bariatric all-cause morbidity rates amongst bariatric surgeons, even when exceeding 100 cases (OR 0.84, 95% CI 0.61-1.12, P = 0.222).

CONCLUSIONS

The present study suggests that experience and skills acquired in performing non-bariatric laparoscopic general surgery does not appear to affect all-cause morbidity in bariatric surgery. Therefore, only a surgeon's bariatric procedure volume should considered be a quality marker for outcomes after bariatric surgery.

Change in gastrointestinal symptoms over the first 5 years after bariatric surgery in a multicenter cohort of adolescents

BACKGROUND

Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) are effective for weight loss in adolescents with severe obesity. However, little is known about adverse gastrointestinal symptoms (GIS) following these operations in adolescents. The objective was to examine GIS over 5 years after surgery and differences by surgery type.

METHODS

We prospectively studied 228 adolescents (161 RYGB, 67 VSG) undergoing bariatric surgery. Gastrointestinal symptoms were assessed before surgery, at 6-months, and yearly to 5 years after surgery. Symptom severity was dichotomized for analysis. Analysis of post-surgery symptoms involved linear models adjusting for baseline symptoms, BMI, early post-operative complication, sex, and race.

RESULTS

Participants at surgery were 17 ± 1.6 years with preoperative BMI 53 ± 9.4 kg/m². From 6 months to 5 years, gastroesophageal reflux symptoms (GERS), nausea, bloating, and diarrhea increased. Crude prevalence rates of GERS increased from 4% (1% RYGB, 11% VSG) at 6-months post-surgery to 14% (10% RYGB, 26% VSG) at 5-years. In adjusted analyses, the VSG group experienced 4-fold (4.85 95% CI 2.63, 8.91, p < 0.0001) greater odds of GERS compared to RYGB.

CONCLUSIONS

Adolescents who underwent VSG experienced greater risk of GERS compared to those undergoing RYGB. Adolescents undergoing VSG should be counseled preoperatively about GERS and objectively monitored postoperatively for gastroesophageal reflux when indicated.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, Identifier: NCT00474318, https://clinicaltrials.gov/ct2/show/NCT00474318?term=Teen-LABS&rank=1.

TYPE OF STUDY

Treatment Study.

LEVEL OF EVIDENCE

Level II.

'The only chance of a normal weight life': A qualitative analysis of online forum discussions about bariatric surgery

Background

The only effective weight loss treatment for severe obesity is bariatric surgery, with Roux-en-Y gastric bypass being the most common method. Patients often have unrealistic expectations of surgery and expect a “miracle cure” even though the procedure requires major lifelong lifestyle changes. Most patients access information about the procedure online, and come into contact with others who have had the surgery.

Objective

The objective of this study was to describe shared values, feelings, and thoughts among visitors to a web-based forum for those undergoing bariatric surgery.

Methods

In this cross-sectional observation study using qualitative contents analysis, the material consisted of an online discussion forum thread about bariatric surgery, with 498 posts. These were saved in a document, read and re-read. Through coding of meaningful units of text, themes were established.

Results

Four themes were constructed during data analysis: a) A new life—anticipating dramatic changes of body and mind; b) Negotiating the system and playing the waiting game; c) A means to an end—managing the pre-operative diet; and d) Managing the attitudes of others. Posters described the process of bariatric surgery as a journey, riddled with roadblocks, setbacks and trials, but also with joy and expectations of a new life.

Conclusion

Professionals who encounter this group should be aware of their need for support throughout the process, and investigate the possibility of both pre- and postoperative support groups, either online or face-to-face. The results also show that the posters on the forum had very high, and often unrealistic, expectations on how the surgery would change their lives. It is important for those who encounter this group before surgery to be aware of this tendency and to take measures to ensure that patients undergo the surgery with realistic expectations.

Surgical Training and Standardised Management Guidelines Improved the 30-Day Complication Rate After Abdominoplasty for Massive Weight Loss

Background

An increasing number of patients need reconstructive surgery after massive weight loss. The hypothesis was that surgical experience together with standardised management guidelines significantly decreases early complication rates after abdominoplasty for massive weight loss. The primary aim was to assess the 30-day complication rate after abdominoplasty following increased surgical training and experience. The secondary aim was to assess whether optimised management guidelines have an impact on the complication rate and patient safety.

Methods

The outcome of 69 consecutive abdominoplasties operated by surgeons in 2011 (Group A) and 70 consecutive patients operated by plastic surgeons in 2010–2012 (Group B) was compared. Another Group of 70 consecutive patients operated by surgeons in 2013–2014 (Group C) was assessed since standardised guidelines for pre- and post-operative treatments and refinement of surgical technique had been introduced. The same surgeons participated in operations of Groups A and C. χ²-test and Fisher’s exact test were applied to dichotomous data. Logistic regression test and ANOVA were used.

Results

Group C had more comorbidities and was significantly older. 48 patients in Group A (70%), 31 in Group B (44%) and 13 patients in Group C (19%) had early complications. A significantly decreased rate of complications occurred with improved guidelines and surgical training and experience. (A vs. C p < 0.001 and A vs. B p = 0.008).

Conclusions

Our results indicate that the rate of early complications after abdominoplasty for massive weight loss can be significantly reduced with improved surgical experience and standardised management guidelines.

Registered at Clinical Trial.gov (ID: NCT02679391).

"I didn't have to prove to anybody that I was a good candidate": a case study framing international bariatric tourism by Canadians as circumvention tourism

Background

Medical tourism is a practice where patients travel internationally to purchase medical services. Medical tourists travel abroad for reasons including costly care, long wait times for care, and limited availability of desired procedures stemming from legal and/or regulatory restrictions. This paper examines bariatric (weight loss) surgery obtained abroad by Canadians through the lens of ‘circumvention tourism’ – typically applied to cases of circumvention of legal barriers but here applied to regulatory circumvention. Despite bariatric surgery being available domestically through public funding, many Canadians travel abroad to obtain these surgeries in order to circumvent barriers restricting access to this care. Little, however, is known about why these barriers push some patients to obtain these surgeries abroad and the effects of this circumvention.

Methods

Semi-structured phone interviews were conducted with 20 former Canadian bariatric tourists between February and May of 2016. Interview questions probed patients’ motivations for seeking care abroad, as well as experiences with attempting to obtain care domestically and internationally. Interviews were digitally recorded, transcribed verbatim, and then thematically analyzed.

Results

Three key barriers to access were identified: (1) structural barriers resulting in limited locally available options; (2) strict body mass index cut-off points to qualify for publicly-funded surgery; and (3) the extended wait-time and level of commitment required of the mandatory pre-operative program in Canada. It was not uncommon for participants to experience a combination, if not all, of these barriers.

Conclusions

Collectively, these barriers restricting domestic access to bariatric care in Canada may leave Canadian patients with a sense that their health care system is not adequately addressing their specific health care needs. In circumventing these barriers, patients may feel empowered in their health care opportunities; however, significant concerns are raised when patients bypass protections built into the health system. Given the practical limitations of a publicly funded health care system, these barriers to care are likely to persist. Health professionals and policy makers in Canada should consider these barriers in the future when examining the implications medical tourism for bariatric surgery holds for Canadians.

Early major complications after bariatric surgery in the USA, 2003-2014: a systematic review and meta-analysis

The effectiveness of bariatric surgery has been well-studied. However, complications after bariatric surgery have been understudied. This review assesses <30-d major complications associated with bariatric procedures, including anastomotic leak, myocardial infarction and pulmonary embolism. This review included 71 studies conducted in the USA between 2003 and 2014 and 107,874 patients undergoing either gastric bypass, adjustable gastric banding or sleeve gastrectomy, with mean age of 44 years and pre-surgery body mass index of 46.5 kg m^-2 . Less than 30-d anastomotic leak rate was 1.15%; myocardial infarction rate was 0.37%; pulmonary embolism rate was 1.17%. Among all patients, mortality rate following anastomotic leak, myocardial infarction and pulmonary embolism was 0.12%, 0.37% and 0.18%, respectively. Among surgical procedures, <30-d after surgery, sleeve gastrectomy (1.21% [95% confidence interval, 0.23-2.19%]) had higher anastomotic leak rate than gastric bypass (1.14% [95% confidence interval, 0.84-1.43%]); gastric bypass had higher rates of myocardial infarction and pulmonary embolism than adjustable gastric banding or sleeve gastrectomy. During the review, we found that the quality of complication reporting is lower than the reporting of other outcomes. In summary, <30-d rates of the three major complications after either one of the procedures range from 0% to 1.55%. Mortality following these complications ranges from 0% to 0.64%. Future studies reporting complications after bariatric surgery should improve their reporting quality.

Body fat mass and distribution as predictors of metabolic outcome and weight loss after Roux-en-Y gastric bypass

BACKGROUND

Bariatric surgery such as Roux-en-Y gastric bypass (RYGB) remains the most effective treatment of obesity and associated co-morbidities. Body fat distribution associates with metabolic function.

OBJECTIVE

To investigate if preoperative body fat mass and distribution measured by dual-energy x-ray absorptiometry (DXA) predict weight loss and metabolic outcome after RYGB, and to compare predictive value of DXA with simple anthropometric measures.

SETTING

Four Swedish hospitals within the Stockholm area.

METHODS

Two hundred fifteen women scheduled for RYGB were included. Evaluations before and 2 years after RYGB included determination of insulin sensitivity by the homeostatic model assessment of insulin resistance, blood pressure, plasma lipids, and anthropometric measures, such as waist-to-hip-ratio and fat percentage estimated by formula. Body fat mass and distribution were determined by DXA.

RESULTS

Follow-up rate was 77.2% (n = 166). All clinical, anthropometric, and DXA measures were improved/reduced postsurgery (all P<.0001). Android/gynoid fat mass ratio and waist-to-hip-ratio predicted improved homeostatic model assessment of insulin resistance (P = .0028 and .0014), independently of body mass index and age. Body fat percentage, measured by DXA or estimated by formula, predicted percent weight loss (P<.0001 and .0083). Body mass index predicted percent weight loss and percent excess body mass index lost (P = .0022 and<.0001). DXA and anthropometric measures performed equally as predictors, except for DXA measured fat percentage that was slightly better than formula estimated.

CONCLUSION

DXA provided predictive values similar to those by basic anthropometric measures, suggesting a limited additional value of preoperative DXA to predict metabolic improvement and weight loss after RYGB in women.

The Influence of the Orbera Intragastric Balloon Filling Volumes on Weight Loss, Tolerability, and Adverse Events: a Systematic Review and Meta-Analysis

BACKGROUND

The Orbera intragastric balloon (IGB) has been approved by the US Food and Drug Administration for use in patients with a body mass index (BMI) between 30 and 40 kg/m² and is in wide use worldwide as a primary and bridge obesity management tool. The balloon filling volume (BFV) ranges between 400 and 700 mL of saline. Our objective was to determine whether there is an association between BFV and clinically relevant endpoints, namely weight loss outcomes, balloon tolerability, and adverse events.

METHODS

A systematic review of studies investigating the use of the Orbera IGB system for obesity treatment was performed. Data was examined using random effects modelling and meta-regression analyses.

RESULTS

Forty-four studies (n = 5549 patients) reported BFV and % total body weight loss (TBWL) at 6 months. Pooled %TBWL at 6 months was 13.2% [95% CI 12.3-14.0]. A funnel plot demonstrated a low risk of publication bias. Meta-regression showed no statistically significant association between filling volume and %TBWL at 6 months (p = 0.268). Higher BFV was associated with lower rates of esophagitis (slope = -0.008, p < 0.001) and prosthesis migration (slope = -0.015, p < 0.001). There was no association between BFV and early removal (p = 0.1), gastroesophageal reflux symptom (p = 0.64), or ulcer rates (p = 0.09).

CONCLUSIONS

No association was observed between Orbera IGB filling volume and weight loss outcomes. Higher volumes appear to be associated with lower migration and esophagitis rates; thus, a balloon filling volume of 600-650 mL is recommended.