Examining the Rates of Obesity and Bariatric Surgery in the United States

Characterizing barriers and facilitators of metabolic bariatric surgery tourism: a systematic review

BACKGROUND

Metabolic bariatric surgery tourism continues to rise and has become a growing concern for bariatric surgeons globally. With varying degrees of regulation, counselling and success, those that develop complications may have to deal with a multitude of challenges often distant from their country of operation. The aim of this study was to characterize the barriers and facilitators influencing individuals to undergo metabolic bariatric surgery tourism, in order to better understand the implications to the National Health Service and other healthcare systems.

METHODS

A systematic literature search, restricted to the English language, was performed to identify relevant studies. All studies were included until December 2022, the last search date. Study quality was assessed with the validated mixed-methods appraisal tool. A Braun and Clarke thematic analysis was undertaken to identify themes and subthemes.

RESULTS

A total of five studies met the inclusion criteria. Identified themes included: availability, accessibility, cost, eligibility, reputation, and stigma; the available evidence was of varying quality.

CONCLUSION

This work identifies a series of subthemes influencing the decision to undertake metabolic bariatric surgery tourism. The results highlight the limited literature available in understanding the complex motivational insights; the scale of the problem in the current healthcare system; cost and long-term outcomes. A National Emergency Bariatric Surgery audit would allow generation of more robust data to explore further the issues of clinical relationships and networks and to guide policy making.

Impact of Bariatric Surgery on the Prevalence and Outcomes of Atrial Fibrillation in Obese Patients

Obesity has been identified as a significant factor contributing to the development of numerous cardiovascular conditions and as a result, the cardiovascular community has prioritized efforts to address obesity and reduce its associated risks. However, despite these efforts, the prevalence of obesity continues to rise steadily, and is projected to double in the upcoming years. Atrial fibrillation is among the most prevalent and extensively researched cardiovascular comorbidities associated with obesity. Several mechanisms have been postulated, including scar tissue formation and fat deposition, which ultimately leads to atrial remodeling and subsequent arrhythmogenesis. Numerous strategies have been implemented to prevent and manage obesity, encompassing lifestyle adjustments, dietary modifications, pharmacological treatments, and surgical interventions. Bariatric surgery has garnered significant recognition over the years due to its promising outcomes, including a decrease in the overall prevalence of atrial fibrillation and other cardiovascular comorbidities in general in obese patients. This study focuses on the current trends regarding the impact of bariatric surgery on obese patients with atrial fibrillation.

Performance of Endoscopic Sleeve Gastroplasty by Obesity Class in the United States Clinical Setting

INTRODUCTION

Endoscopic sleeve gastroplasty (ESG) has gained popularity over the past decade and has been adopted in both academic and private institutions globally. We present outcomes of the largest cohort of patients from the United States undergoing ESG and evaluate these according to obesity class.

METHODS

We performed a retrospective analysis of adult patients who underwent ESG. Medical information was abstracted from the electronic record with weight records up to 2 years after ESG. Percent total body weight loss (%TBWL) at 6, 12, 18, and 24 months was calculated based on baseline weight at the procedure. SPSS (version 29.0) was used for all statistical analyses.

RESULTS

A total of 1,506 patients from 7 sites were included (501 Class I obesity, 546 Class II, and 459 Class III). Baseline demographics differed according to obesity class due to differences in age, body mass index (BMI), height, sex distribution, and race. As early as 6 months post-ESG, mean BMI for each class dropped to the next lower class and remained there through 2 years. %TWBL achieved in the Class III group was significantly greater when compared with other classes at all time points. At 12 months, 83.2% and 60.9% of patients had ≥10% and ≥15% TBWL for all classes. There were no differences in adverse events between classes.

DISCUSSION

Real-world data from a large cohort of patients of all BMI classes across the United States shows significant and sustained weight loss with ESG. ESG is safe to perform in a higher obesity class with acceptable midterm efficacy.

Multiple NTS neuron populations cumulatively suppress food intake

Several discrete groups of feeding-regulated neurons in the nucleus of the solitary tract (nucleus tractus solitarius; NTS) suppress food intake, including avoidance-promoting neurons that express Cck (NTSCck cells) and distinct Lepr- and Calcr-expressing neurons (NTSLepr and NTSCalcr cells, respectively) that suppress food intake without promoting avoidance. To test potential synergies among these cell groups, we manipulated multiple NTS cell populations simultaneously. We found that activating multiple sets of NTS neurons (e.g. NTSLepr plus NTSCalcr [NTSLC], or NTSLC plus NTSCck [NTSLCK]) suppressed feeding more robustly than activating single populations. While activating groups of cells that include NTSCck neurons promoted conditioned taste avoidance (CTA), NTSLC activation produced no CTA despite abrogating feeding. Thus, the ability to promote CTA formation represents a dominant effect but activating multiple non-aversive populations augments the suppression of food intake without provoking avoidance. Furthermore, silencing multiple NTS neuron groups augmented food intake and body weight to a greater extent than silencing single populations, consistent with the notion that each of these NTS neuron populations plays crucial and cumulative roles in the control of energy balance. We found that silencing NTSLCK neurons failed to blunt the weight-loss response to vertical sleeve gastrectomy (VSG) and that feeding activated many non-NTSLCK neurons, however, suggesting that as-yet undefined NTS cell types must make additional contributions to the restraint of feeding.

Predicting readmission after bariatric surgery using machine learning

BACKGROUND

While bariatric surgery is an effective method for achieving long-term weight loss, postoperative readmissions are associated with negative clinical outcomes and significant costs.

OBJECTIVES

We aimed to use machine learning (ML) algorithms to predict readmissions and compare results to logistic regression.

SETTING

Hospitals participating in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, United States.

METHODS

Patients who underwent sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and biliopancreatic diversion with duodenal switch between 2016 and 2020 were selected from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database. Patient variables reported by the MBSAQIP database were analyzed by ML algorithms random forest (RF), gradient boosting (XGB), and deep neural networks (NN), and the results of the predictive models were compared to logistic regression using area under the receiver operating characteristic curve (AUROC).

RESULTS

Our study included 863,348 patients, of which 39,068 (4.52%) were readmitted. AUROC scores were XGB .785 (95% CI .784-.786), RF .785 (95% CI .784-.785), and NN .754 (95% CI .753-.754), compared with .62 (95% CI .62-.621) for logistic regression (LR) (P < .001). The sensitivity and specificity for XGB, the best performing model, were 73.81% and 70%, compared with 52.94% and 70% for logistic regression. The most important variables were intervention or reoperation prior to discharge, unplanned ICU admission, initial procedure, and the intraoperative transfusion.

CONCLUSIONS

ML demonstrates significant advantages over logistic regression when predicting 30-day readmission following bariatric surgery. With external validation, models could identify the best candidates for early discharge or targeted postdischarge resources.

Psychological Profiles and 12-Month Weight Outcomes of Women Evaluated for Reoperative Bariatric Surgery

BACKGROUND

The use of psychological screening instruments prior to bariatric surgery has been well established. However, there is currently no specific literature on psychological screening of candidates for reoperative bariatric surgery.

METHODS

This study evaluated archival data for 40 women who were candidates for reoperative bariatric surgery and completed the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF). Profile analysis examined differences between patient groups who did and did not undergo reoperative surgery. MMPI-2-RF profiles for reoperative patients then were compared to previous samples of preoperative and postoperative patients. Hierarchical linear modeling was used to predict BMI following reoperative surgery over a 12-month period based on MMPI-2-RF scales while controlling for age and initial BMI.

RESULTS

Profile analysis results showed no significant differences on MMPI-2-RF scale scores between reoperative candidates who did and did not undergo a second surgery. With some minor differences attributed to minimization of symptoms, there were no systematic differences in MMPI-2-RF scale scores for reoperative surgery patients compared to preoperative and postoperative patient groups. BMI outcomes over a 12-month period showed that age and initial BMI were significantly better predictors than MMPI-2-RF scores.

CONCLUSIONS

Administration of MMPI-2-RF for reoperative bariatric surgery patients likely is equivalent to its typical use in preoperative screening. Only the MMPI-2-RF Disconstraint scale showed any relationship to BMI outcomes over time following reoperative surgery.

Hypocalcemia after parathyroidectomy in patients with a history of bariatric surgery

PURPOSE

A growing body of literature has suggested that a history of bariatric surgery increases the risk of hypocalcemia after subsequent thyroidectomy, however little is known about the risk after parathyroidectomy. The purpose of this study was to determine the incidence of hypocalcemia after parathyroidectomy in patients with prior bariatric surgery.

METHODS

The TriNetX Research Network was queried using diagnosis and procedure codes to identify patients with a history of bariatric surgery who were subsequently diagnosed with primary hyperparathyroidism (PHP) and underwent parathyroidectomy between 2012 and 2022. The rate of hypocalcemia after parathyroidectomy was compared between those with a history of bariatric surgery and controls who underwent parathyroidectomy alone, matched for demographics, body mass index (BMI) ≥ 30 kg/m², and history of calcium or vitamin D supplementation.

RESULTS

There were 34,483 included patients diagnosed with PHP who underwent parathyroidectomy. Of this cohort, 1.4% (n = 472) had prior bariatric surgery. There were 90% females and 10% males in this subset of patients, and the average age was 58 years. Compared to matched controls who underwent parathyroidectomy alone, these patients had a significantly increased risk of hypocalcemia within 0-1 month (RR, 95% CI, P) (17.2% vs. 9.3%; 1.8, 1.3-2.6, P < 0.001), 1-6 months (8.5% vs. 2.5%; 3.3, 1.8-6.3, P < 0.001) and 6-12 months (6.8% vs. 2.3%; 2.9, 1.5-5.7, P < 0.001) following surgery.

CONCLUSION

The current study is the first to indicate that patients with a history of bariatric surgery are at increased risk for short-term and permanent hypocalcemia after parathyroidectomy. Further research is required to determine optimal prevention and treatment strategies to decrease associated morbidity in this subset of patients.

Body mass index and risk of mortality in patients undergoing bariatric surgery

BACKGROUND

Prior literature has demonstrated that bariatric surgery is a safe approach for patients with morbid obesity. However, the relationship between body mass index (BMI) and risk of mortality in these patients has not been fully elucidated. Primary objective of this study was to evaluate the relationship between BMI and risk of mortality using data obtained from a national database, with a special focus on patients with BMI ≥ 70.0 kg/m².

METHODS

A retrospective cohort study of patients with morbid obesity (BMI ≥ 40 kg/m²) undergoing first-time bariatric surgery between 2015 and 2018 was performed using data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program. Primary outcome was intra-operative death or death within 30 days post-operatively. Patients were categorized into quartiles according to BMI. Multivariable analysis was performed to evaluate the association of BMI with risk of mortality. Relative risk (RR) and 95% confidence interval (CI) are provided as measures of strength of association and precision, respectively.

RESULTS

A total of 463, 436 patients were included with a 30-day mortality rate of 0.11%. Mean BMI (SD) was 48.2 (7.3) kg/m²; 1.5% of patients had BMI ≥ 70.0 kg/m². On multivariable analysis, highest quartile patients had a significantly higher risk of mortality than lowest quartile patients. For patients with BMI ≥ 70.0 kg/m², the risk of mortality was more pronounced with an eightfold increase compared to the lowest quartile. In patients with BMI ≥ 70.0 kg/m², although sleeve gastrectomy (SG) was the most common procedure, the risk of mortality was significantly higher in patients undergoing Roux-en-Y gastric bypass (RYGB).

CONCLUSIONS

BMI is associated with increased risk of 30-day mortality. The effect of BMI is more pronounced in patients with BMI ≥ 70.0 kg/m². In these patients, RYGB is associated with increased risk of mortality compared to SG.

Risk factors of lower birth weight, small-for-gestational-age infants, and preterm birth in pregnancies following bariatric surgery: a scoping review

PURPOSE

Bariatric surgery increases the risk of lower birth weight, small-for-gestational-age (SGA) infants, and preterm birth in a subsequent pregnancy. However, the factors that contribute to these adverse birth outcomes are unclear. This review aimed to collate available information about risk factors of lower birth weight, SGA, and preterm birth following bariatric surgery.

METHODS

A literature search was conducted using five databases (PubMed, PsycINFO, EMBASE, Web of Science, and Cochrane Library) to obtain relevant studies.

RESULTS

A total number of 85 studies were included. Studies generally excluded surgery-to-conception interval, pregnancy complications, cigarette use, and maternal age as influencing factors of birth weight, SGA, or preterm birth. In contrast, most studies found that malabsorptive procedures, lower gestational weight gain, lower glucose levels, abdominal pain, and insufficient prenatal care were associated with an elevated risk of adverse birth outcomes. Findings were mixed regarding the effects of surgery-to-conception weight loss, pre-pregnancy body mass index, micronutrient deficiency, and lipid levels on birth outcomes. The examination of maternal microbiome profiles, placental function, alcohol use, and exercise was limited to one study; therefore, no conclusions could be made.

CONCLUSION

This review identified factors that appear to be associated (e.g., surgery type) or not associated (e.g., surgery-to-conception interval) with birth outcomes following bariatric surgery. The mixed findings and the limited number of studies on several variables (e.g., micronutrients, exercise) highlight the need for further investigation. Additionally, future studies may benefit from exploring interactions among risk factors and expanding to assess additional exposures such as maternal mental health.

Neighborhood deprivation and residential property values do not affect weight loss at 1 or 3 years after bariatric surgery

OBJECTIVE

This study examined the association between individual- and neighborhood-level sociodemographic factors and surgical weight loss at 1 year (short term) and 3 years (long term).

METHODS

Data were obtained from the baseline survey of the BELONG (Bariatric Experience Long Term) prospective longitudinal cohort study. Individual-level self-reported data on sex, race and ethnicity, education, and household income were obtained by survey. Data from the 2010 US Census were used to calculate area Neighborhood Deprivation Index score and median value of owner-occupied housing units at the census tract level.

RESULTS

Patients (N = 1341) had a mean age of 43.4 (SD 11.3) years, were mostly female (86%), were mostly Black or Hispanic (52%), had some college education (83%), and had annual household incomes ≥$51,000 (55%). Percentage total weight loss was 25.8% (SD 9.0%) at year 1 and 22.2% (SD 10.5%) at year 3. Race and ethnicity and age were significant predictors of weight loss at 1 and 3 years with a small effect of self-reported household income at year 1. There were no significant associations between census tract-level Neighborhood Deprivation Index score or value of owner-occupied housing units and weight loss at either time point.

CONCLUSIONS

Health systems could improve the chances of weight-loss maintenance after surgery by addressing factors related to racial and ethnic disparities and to income disparities.

Cost of Surgical Treatment of Obesity and Its Impact on Healthcare Expense-Nationwide Data from a Polish Registry

Weight loss surgery is linked to health benefits and may reduce the cost to the public healthcare systems. The aim of this study was to assess the cost and cost-structure in the one-year periods before and after a bariatric surgery in the Polish nationwide registry. The study included 2390 obese adults which underwent surgical treatment for obesity in 2017. The cost structure and the total costs per patient for one year before bariatric surgery, preoperatively, and for one year after surgery were analyzed. The total cost of the postoperative period was about PLN 3 million lower than during the preoperative period. After bariatric surgery, a reduction of approximately 59% in costs associated with hospital treatment was observed. The costs of outpatient specialist services, hospital treatment, psychiatric care, and addiction treatment also significantly decreased. There was a negative correlation between the changes in the cost of treatment of patients undergoing obesity surgery and their age. The health care cost during the period of one year after bariatric surgery is lower than in the year preceding the surgery (a greater cost difference is observed in younger people). This is mainly influenced by the reduction in costs associated with hospital treatment.

Integrated Care Model of Adiposity-Related Chronic Diseases

PURPOSE OF REVIEW

Although obesity is a disease, most patients with obesity do not undergo effective treatment nor adhere to long-term care. We examine the barriers that patients with obesity confront when searching for effective treatment and propose an integrated care model of adiposity-related chronic diseases in a cardio-renal metabolic unit.

RECENT FINDINGS

The current care of obesity is fragmented between primary care providers, medical specialists and metabolic bariatric surgeons with little or no coordination of care between these providers. The current care of obesity heavily focuses on weight loss as the primary aim of treatment thereby reenforcing the weight stigma and turning patients away from effective therapy like metabolic bariatric surgery. An interdisciplinary cardio-renal metabolic unit that, besides weight loss, emphasizes prevention/remission of adiposity-related chronic diseases may deliver thorough and rewarding care to most patients with obesity.

Hypocalcemia After Thyroidectomy in Patients with Prior Bariatric Surgery: A Propensity Score Matched Analysis from a National Administrative Database

Background: Studies have suggested that patients with prior gastric bypass may be at increased risk for hypocalcemia following thyroidectomy. Unfortunately, most of these studies are limited to case reports and small series. This study represents the largest sample size to date to assess the incidence of post-thyroidectomy hypocalcemia in patients with a history of bariatric surgery. Methods: The TriNetX Research Network was queried to retrospectively identify patients with prior bariatric surgery who underwent total thyroidectomy between 2011 and 2021. The incidence of hypocalcemia following surgery was compared with patients who underwent total thyroidectomy, and hemithyroidectomy with no history of bariatric surgery. Results: We identified 446 patients with a history of bariatric surgery and subsequent thyroidectomy, 29,346 patients with total thyroidectomy, and 19,603 patients with hemithyroidectomy alone. The one-month incidence of hypocalcemia was 54.7% in those with a history of bariatric surgery who underwent thyroidectomy, 43.9% in those with thyroidectomy alone (relative risk, RR = 1.2 [confidence interval, CI 1.1-1.4], p < 0.001), and 8.1% in those with hemithyroidectomy only (RR = 6.8 [CI 6.1-7.4], p < 0.001). Permanent hypocalcemia was documented in 11.4% of patients with prior bariatric surgery who underwent thyroidectomy, 7.7% of those with thyroidectomy only (RR = 1.5 [CI 1.1-1.9], p = 0.003), and 2.9% of patients with hemithyroidectomy alone (RR = 3.9 [CI 3.0-5.2], p < 0.001). Significant differences persisted after matching demographics, prior need for supplementation, and risk factors for hypocalcemia after thyroidectomy. When stratified by bariatric procedure, patients with a history of Roux-en-Y gastric bypass (RYGB) (n = 35) had a greater, although not statistically significant, risk of short-term hypocalcemia (51.4%; RR = 1.2 [CI 0.8-1.6], p = 0.37), and a significantly increased risk of permanent hypocalcemia (20.0%; RR = 2.6 [CI 1.3-5.1], p = 0.005) compared with thyroidectomy alone. Sleeve gastrectomy (SG) (n = 40) was not associated with an increased risk of short-term (40.0%; RR = 0.9 [CI 0.6-1.3], p = 0.62) or permanent (7.5%; RR = 1.0 [CI 0.3-2.9], p = 0.96) hypocalcemia. Conclusions: Prior RYGB, but not SG, may increase the risk of permanent hypocalcemia after thyroidectomy. Additional research is necessary to determine optimal prevention and treatment strategies to reduce morbidity in this population.

Cohort profile: The Bariatric Experience Long Term (BELONG): a long-term prospective study to understand the psychosocial, environmental, health and behavioural predictors of weight loss and regain in patients who have bariatric surgery

PURPOSE

The Bariatric Experience Long Term (BELONG) prospective study cohort was created to address limitations in the literature regarding the relationship between surgical weight loss and psychosocial, health, behaviour and environmental factors. The BELONG cohort is unique because it contains 70% gastric sleeve and 64% patients with non-white race/ethnicity and was developed with strong stakeholder engagement including patients and providers.

PARTICIPANTS

The BELONG cohort study included 1975 patients preparing to have bariatric surgery who completed a baseline survey in a large integrated health system in Southern California. Patients were primarily women (84%), either black or Hispanic (59%), with a body mass index (BMI) of 45.1±7.4 kg/m², age 43.3±11.5 years old, and 32% had at least one comorbidity.

FINDINGS TO DATE

A total of 5552 patients were approached before surgery between February 2016 and May 2017, and 1975 (42%) completed a baseline survey. A total of 1203 (73%) patients completed the year 1 and 1033 (74%) patients completed the year 3 postoperative survey. Of these survey respondents, 1341 at baseline, 999 at year 1, and 951 at year 3 were included in the analyses of all survey and weight outcome data. A total of 803 (60% of eligible patients) had survey data for all time points. Data collected were self-reported constructs to support the proposed theoretical model. Height, weight and BMI were abstracted from the electronic medical record to obtain the main outcomes of the study: weight loss and regain.

FUTURE PLANS

We will collect self-reported constructs and obtain height, weight and BMI from the electronic medical record 5 years after bariatric surgery between April 2022 and January 2023. We will also collect patient experiences using focus groups of 8-12 patients each throughout 2022.

Neurohormonal Changes in the Gut–Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery

Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut–brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut–brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.

The role of obesity and bariatric surgery-induced weight loss in breast cancer

Obesity is a complex metabolic condition considered a worldwide public health crisis, and a deeper mechanistic understanding of obesity-associated diseases is urgently needed. Obesity comorbidities include many associated cancers and are estimated to account for 20% of female cancer deaths in the USA. Breast cancer, in particular, is associated with obesity and is the focus of this review. The exact causal links between obesity and breast cancer remain unclear. Still, interactions have emerged between body mass index, tumor molecular subtype, genetic background, and environmental factors that strongly suggest obesity influences the risk and progression of certain breast cancers. Supportive preclinical research uses various diet-induced obesity models to demonstrate that weight loss, via dietary interventions or changes in energy expenditure, reduces the onset or progression of breast cancers. Ongoing and future studies are now aimed at elucidating the underpinning mechanisms behind weight-loss-driven observations to improve therapy and outcomes in patients with breast cancer and reduce risk. This review aims to summarize the rapidly emerging literature on obesity and weight loss strategies with a focused discussion of bariatric surgery in both clinical and preclinical studies detailing the complex interactions between metabolism, immune response, and immunotherapy in the setting of obesity and breast cancer.