Patterns of Weight Loss Medication Utilization and Outcomes Following Bariatric Surgery

Adjuvant and Neo-Adjuvant Anti-Obesity Medications and Bariatric Surgery: A Scoping Review

PURPOSE OF REVIEW

To comprehensively summarize the current body of literature on the topic of adjuvant and neoadjuvant pharmacotherapy used in combination with bariatric surgery.

RECENT FINDINGS

Anti-obesity medications (AOMs) have been used since the mid-1900s; however, their use in combination with bariatric surgery is a newer area of research that is rapidly growing. Pharmacotherapy may be used before (neoadjuvant) or after (adjuvant) bariatric surgery. Recent literature suggests that adjuvant AOMs may address weight regain and inadequate weight loss following bariatric surgery. Research on neoadjuvant AOM used to optimize weight loss before bariatric surgery is more limited. A literature review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Thirty-four studies were included after screening and exclusion of irrelevant records. Included studies were as follows: seven prospective studies on adjuvant AOM use, 23 retrospective studies on adjuvant AOM use, one prospective study on adjuvant and neoadjuvant AOM use, one retrospective study on adjuvant or neoadjuvant AOM use, one prospective study on neoadjuvant AOM use, and one case series on neoadjuvant AOM use. In the following scoping review, each of these studies is discussed with the goal of presenting a complete synthesis of the current body of literature on AOM use in combination with bariatric surgery.

Evaluating the use of adjuvant and neoadjuvant terminology in bariatric surgery: a scoping review

BACKGROUND

Weight regain and inadequate weight loss are common after bariatric surgery. Literature is emerging regarding the use of pharmacotherapy with bariatric surgery as a potential solution to these adverse effects. Pharmacotherapy may be used before (neoadjuvant) or after (adjuvant) bariatric surgery, although this terminology has not been standardized. As a rapidly growing area of research, there is opportunity to standardize terminology for future ease of research, data synthesis, and communication. This review aimed to comprehensively evaluate the use of the terms "adjuvant" and "neoadjuvant" to describe pharmacotherapy used in combination with bariatric surgery and propose standardized terminology for future research.

METHODS

Literature search was conducted systematically and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if they were published after 1999; were randomized controlled trials, prospective/retrospective cohort studies, or case series; and used human subjects that were adults at least 18 years of age. The use of the terms "neoadjuvant" and "adjuvant" was analyzed over time.

RESULTS

Thirty-four publications were included. Thirty-two (94.1%) studied the use of adjuvant pharmacotherapy after bariatric surgery. Four (11.8%) studied the use of pharmacotherapy before bariatric surgery, and 1 used the term "neoadjuvant" to describe medications used before bariatric surgery. Eight publications used the term "adjuvant" to describe medications used after bariatric surgery.

CONCLUSION

Standardized terminology is needed to ease future understanding, evidence synthesis, and dissemination of work. We propose that the terms "neoadjuvant" and "adjuvant" become the standard terminology to describe pharmacotherapy use before and after bariatric surgery, respectively.

The risk and benefit of revisional vs. primary metabolic- bariatric surgery and drug therapy - A narrative review

Metabolic and bariatric surgery (MBS) leads to long-term weight loss, reduced risk of cardiovascular events and cancer, and reduced mortality. Sleeve gastrectomy and Roux-en-Y gastric bypass are currently the most common surgical techniques. Weight loss after MBS was previously believed to work through restriction and malabsorption, however, mechanistic studies show that MBS techniques with long term efficacy instead alter physiological signaling between the gut and the brain. In revisional MBS, the initial surgical technique is corrected, modified, or converted to a new one. The indication for revisional MBS can be to achieve further weight loss or improvement in obesity comorbidity, but it may be necessary due to complications (e.g., gastroesophageal reflux or obstruction). Revisional MBS is associated with an increased risk of surgical complications and often less weight loss compared to the results following primary surgery. This narrative review summarizes data from revisional MBS where information is often presented with inconsistent definitions for indications and outcomes, making comparison between strategies difficult. In summary, we suggest careful weighing of potential benefits and risks with revisional MBS, bearing in mind the option of add-on therapy with new anti-obesity drugs.

Weight Regain after Metabolic Surgery: Beyond the Surgical Failure

Patients undergoing metabolic surgery have factors ranging from anatomo-surgical, endocrine metabolic, eating patterns and physical activity, mental health and psychological factors. Some of the latter can explain the possible pathophysiological neuroendocrine, metabolic, and adaptive mechanisms that cause the high prevalence of weight regain in postbariatric patients. Even metabolic surgery has proven to be effective in reducing excess weight in patients with obesity; some of them regain weight after this intervention. In this vein, several studies have been conducted to search factors and mechanisms involved in weight regain, to stablish strategies to manage this complication by combining metabolic surgery with either lifestyle changes, behavioral therapies, pharmacotherapy, endoscopic interventions, or finally, surgical revision. The aim of this revision is to describe certain aspects and mechanisms behind weight regain after metabolic surgery, along with preventive and therapeutic strategies for this complication.

Treatment with Antiobesity Drugs in Weight Regain After Bariatric Surgery: a Retrospective Cohort Study

BACKGROUND

Bariatric surgery is the most efficient treatment for obesity. However, in some cases, weight regain can occur. Currently, it is unknown the best antiobesity medication (AOM) for such clinical situation. This study aims to evaluate the effect of AOM in patients with weight regain after bariatric surgery.

METHODS

A retrospective cohort study from December 2010 to July 2019 with patients submitted to bariatric surgery that had weight regain and received AOM for at least 2 years.

RESULTS

Of 96 patients that had weight regain in the analyzed period and received AOM, 16 were excluded from the analysis due to non-compliance (n = 7), treatment failure (n = 5), intolerable side effects with all available AOM (n = 2), or interaction with other medications (n = 2). Eighty patients were included in the analysis. The mean age was 59.0 ± 10.1 years, 88.8% were female, 91.2% white, and most of them were submitted to gastric bypass (87.6%). The mean preoperative and nadir weight after surgery were 127.9 ± 25.5 kg and 84.7 ± 22.8 kg, respectively. At the initiation of AOM, the mean baseline weight was 99.4 ± 23.1 kg. After 2 years of follow-up, there was significant weight loss in the groups treated with topiramate-alone (- 3.2 kg), topiramate plus sibutramine (- 6.1kg), and orlistat-alone or in combination (- 3.9kg). No statistical difference was observed in the sibutramine-alone group.

CONCLUSION

Topiramate (alone or associated with sibutramine) and orlistat (alone or in combination) promoted significant weight loss after 2 years of use in patients submitted to bariatric surgery with weight regain.

Management of Weight Regain Following Bariatric Surgery: Behavioral Intervention and Pharmacotherapy

INTRODUCTION

Bariatric surgery is the most effective intervention currently available for significant and durable weight loss, but weight regain after surgery is not uncommon. This paper focuses on updates in behavioral interventions and pharmacotherapy to combat weight regain after bariatric surgery.

AREAS COVERED

This paper critically reviews both prospective and retrospective studies assessing pharmacotherapy in post-bariatric surgical patients published within the past 5 years. It also evaluates updates in behavioral therapies and delivery of the therapies in this patient population.

EXPERT OPINION

Weight regain after bariatric surgery is common. Patients who experience weight regain should be evaluated and treated by a multidisciplinary team. Antiobesity pharmacotherapy should be considered for those who qualify as an adjunct to lifestyle modifications, along with behavioral interventions such as cognitive behavioral therapy.

Obesity and Bariatric Surgery in Australia: Future Projection of Supply and Demand, and Costs

Introduction

The prevalence of obesity is increasing in developed countries, including Australia. There is evidence that bariatric surgery is effective in losing weight and reducing risk of chronic diseases. However, access to bariatric surgery remains limited in the public health sector.

Method

We modelled population-based estimates of the likely numbers of people eligible for bariatric surgery in Australia using the recent Australian New Zealand Metabolic and Obesity Surgery Society (ANZMOSS) framework and estimated the potential costs that would be incurred from primary and subsequent reoperations in both public and private sector.

Results

The annual number of newly eligible patients is expected to rise, and hence the gap in demand is increasing relative to current baseline supply. If a 5-year program to treat all currently eligible patients was implemented, the maximum yearly demand is projected to be 341,343 primary surgeries, more than eight times the existing capacity of public and private sector, which can only offer 41,534 surgeries/year. A nine-fold increase is expected if we treat currently eligible patients over a 5-year program and all newly eligible patients as they occur each year.

Conclusion

Our results highlighted the currently highly skewed distribution of bariatric surgeries between the private and public sectors. Improving access would bring substantial benefits to many Australians, given the demonstrated cost-effectiveness and cost savings. This requires a major increase in resourcing for publicly-funded access to bariatric surgery in the first instance. A national review of priorities and resourcing for all modes of obesity treatment is required in Australia.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-022-06188-5.

Obesity Surgery

BACKGROUND

In 2017, the prevalence of obesity (BMI ≥= 30 kg/m2) in Germany was approximately 16%. Obesity increases an individual's risk of developing type 2 diabetes (T2DM) and arterial hypertension; it also increases overall mortality. Consequently, effective treatment is a necessity. Approximately 20 000 bariatric operations are performed in Germany each year.

METHODS

This review is based on pertinent publications retrieved by a selective search in the PubMed and Cochrane databases and on current German clinical practice guidelines.

RESULTS

The types of obesity surgery most commonly performed in Germany, Roux-en-Y gastric bypass and sleeve gastrectomy, lead to an excess weight loss of 27-69% ≥= 10 years after the procedure. In obese patients with T2DM, the diabetes remission rate ≥= 10 years after these procedures ranges from 25% to 62%. Adjusted regression analyses of data from large registries have shown that the incidence of malignancies is 33% lower in persons who have undergone obesity surgery compared to control subjects with obesity (unadjusted incidence 5.6 versus 9.0 cases per 1000 person-years). The operation can cause vitamin deficiency, surgical complications, gastroesophageal reflux, and dumping syndrome. Therefore, lifelong follow-up is necessary.

CONCLUSION

In view of an increasing number of patients undergoing bariatric surgery, it will probably not be feasible in the future for lifelong follow-up to be provided exclusively in specialized centers.

Pharmacologic management of weight regain following bariatric surgery

While bariatric surgery restults in significant long-term weight loss for most patients with obesity, post-surgical weight gain affects a considerable percentage of patients to varying degrees of severity. Furthermore, a small but significant percentage of patients experience inadequate post-surgical weight loss. Although many studies have examined the role of anti-obesity medications to address post-operative weight regain, an evidence-based consensus has not yet been achieved because of the heterogeneity of populations studied and the studies themselves. Observational studies in the post-bariatric surgery population consistently demonstrate the benefit of medical weight management after bariatric surgery, with most evidence highlighting liraglutide, topiramate, and phentermine/topiramate. New anti-obesity medications are anticipated to be helpful for post-surgical weight optimization given their efficacy in the non-surgical population.

Obesity: Overview of Weight Management

INTRODUCTION

Obesity is a chronic illness that requires a multifaceted personalized treatment approach.

METHODS & FINDINGS

Using current guidelines and recent studies in weight management, this article reviews the multiple components of weight management: lifestyle intervention (dietary intervention, physical activity, and behavioral interventions), pharmacotherapy, endoscopic procedures, and surgical procedures. This review briefly discusses specific diets and dietary strategies, compensatory mechanisms acting against weight loss, recent changes to Food and Drug Administration approved antiobesity medications, and technological advances in weight management delivery.

CONCLUSION

Current literature is lacking large studies on the safety and efficacy of combination therapies involving pharmacotherapy plus 1 or more procedures.