Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations

Individualized Metabolic Surgery Score: Procedure Selection Based on Diabetes Severity

OBJECTIVE

To construct and validate a scoring system for evidence-based selection of bariatric and metabolic surgery procedures according to severity of type 2 diabetes (T2DM).

BACKGROUND

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) account for >95% of bariatric procedures in United States in patients with T2DM. To date, there is no validated model to guide procedure selection based on long-term glucose control in patients with T2DM.

METHODS

A total of 659 patients with T2DM who underwent RYGB and SG at an academic center in the United States and had a minimum 5-year follow-up (2005-2011) were analyzed to generate the model. The validation dataset consisted of 241 patients from an academic center in Spain where similar criteria were applied.

RESULTS

At median postoperative follow-up of 7 years (range 5-12), diabetes remission (HbA1C <6.5% off medications) was observed in 49% after RYGB and 28% after SG (P < 0.001). Four independent predictors of long-term remission including preoperative duration of T2DM (P < 0.0001), preoperative number of diabetes medications (P < 0.0001), insulin use (P = 0.002), and glycemic control (HbA1C < 7%) (P = 0.002) were used to develop the Individualized Metabolic Surgery (IMS) score using a nomogram. Patients were then categorized into 3 stages of diabetes severity. In mild T2DM (IMS score ≤25), both procedures significantly improved T2DM. In severe T2DM (IMS score >95), when clinical features suggest limited functional β-cell reserve, both procedures had similarly low efficacy for diabetes remission. There was an intermediate group, however, in which RYGB was significantly more effective than SG, likely related to its more pronounced neurohormonal effects. Findings were externally validated and procedure recommendations for each severity stage were provided.

CONCLUSIONS

This is the largest reported cohort (n = 900) with long-term postoperative glycemic follow-up, which, for the first time, categorizes T2DM into 3 validated severity stages for evidence-based procedure selection.

Adaptive Immunity and Metabolic Health: Harmony Becomes Dissonant in Obesity and Aging

Adipose tissue (AT) is the primary energy reservoir organ, and thereby plays a critical role in energy homeostasis and regulation of metabolism. AT expands in response to chronic overnutrition or aging and becomes a major source of inflammation that has marked influence on systemic metabolism. The chronic, sterile inflammation that occurs in the AT during the development of obesity or in aging contributes to onset of devastating diseases such as insulin resistance, diabetes, and cardiovascular pathologies. Numerous studies have shown that inflammation in the visceral AT of humans and animals is a critical trigger for the development of metabolic syndrome. This work underscores the well-supported conclusion that the inflammatory immune response and metabolic pathways in the AT are tightly interwoven by multiple layers of relatively conserved mechanisms. During the development of diet-induced obesity or age-associated adiposity, cells of the innate and the adaptive immune systems infiltrate and proliferate in the AT. Macrophages, which dominate AT-associated immune cells in mouse models of obesity, but are less dominant in obese people, have been studied extensively. However, cells of the adaptive immune system, including T cells and B cells, contribute significantly to AT inflammation, perhaps more in humans than in mice. Lymphocytes regulate recruitment of innate immune cells into AT, and produce cytokines that influence the helpful-to-harmful inflammatory balance that, in turn, regulates organismal metabolism. This review describes inflammation, or more precisely, metabolic inflammation (metaflammation) with an eye toward the AT and the roles lymphocytes play in regulation of systemic metabolism during obesity and aging. © 2017 American Physiological Society. Compr Physiol 7:1307-1337, 2017.

Pharmacological management of type 2 diabetes: what's new in 2017?

INTRODUCTION

Novelties in the management of type 2 diabetes are dominated by the commercialisation of new glucose-lowering agents, which offer alternatives to older antidiabetic medications, and by the publication of several prospective placebo-controlled outcome trials, which demonstrated not only cardiovascular safety but also cardiovascular and renal protection with some new medications. Areas covered: Updates regarding the use of glucose-lowering agents are discussed from a clinical point of view. Some new viewpoints concern older antidiabetic agents such as metformin, sulfonylureas and glitazones whose benefit-risk balance has been revisited, especially in high risk patients. The recent data regarding DPP-4 inhibitors (gliptins) focused on the safety profile of this pharmacological class, including in patients with impaired renal function. The highlight concerns the cardiovascular (and renal) protection by some GLP-1 receptor agonists (liraglutide, semaglutide) and SGLT2 inhibitors (empagliflozin, canagliflozin) in patients with high cardiovascular risk. Finally, efficacy and safety of new combinations and advances in insulin therapy will be briefly discussed. Expert commentary: The recent data from randomized controlled trials, meta-analyses and observational real-life studies should trigger a revision of the algorithm for the treatment of hyperglycemia in type 2 diabetes, especially in patients with high cardiovascular and/or renal risk.

Short- and long-term mortality after bariatric surgery: A systematic review and meta-analysis

AIMS

The objective of this study was to investigate short- (≤ 30 days) and long-term (≥ 2 years) all-cause mortality after bariatric surgery among adult patients with obesity.

MATERIALS AND METHODS

For short-term mortality, eligible studies comprised randomized controlled trials (RCTs) reporting perioperative mortality. For long-term mortality, eligible studies comprised RCTs and observational studies comparing mortality between obese patients after bariatric surgery and non-operated controls. Random-effects models using a Bayesian or frequentist approach were used to pool effect estimates of short- and long-term mortality, respectively.

RESULTS

Short-term all-cause mortality based on 38 RCTs involving 4030 patients was 0.18% (95% CI, 0.04%-0.38%) and was higher for open surgeries (0.31%; 95% CI, 0.03%-0.97%) and similar in mixed surgeries (0.17%; 95% CI, 0.03%-0.43%) and restrictive surgeries (0.17%; 95% CI, 0.03%-0.45%). For long-term mortality, 12 observational studies involving 27 258 operated patients and 97 154 non-operated obese controls were included. Of these, 8 studies were eligible for the meta-analysis, which showed a reduction of 41% in all-cause mortality (hazard ratio, 0.59; 95% CI, 0.52-0.67; P < .001). Additionally, operated patients were 0.42 times as likely (95% CI, 0.25-0.72, P < .001) and 0.47 times as likely (95% CI, 0.36-0.63, P < .001) as non-operated obese controls to die from cardiovascular diseases and cancer, respectively.

CONCLUSIONS

Bariatric surgery is associated with low short-term mortality and may be associated with long-term reductions in all-cause, cardiovascular and cancer-related mortality.

The role of bariatric surgery to treat diabetes: current challenges and perspectives

Bariatric surgery is emerging as a powerful weapon against severe obesity and type 2 diabetes mellitus (T2DM). Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to treat T2DM, especially in light of accumulating evidence that surgery with gastrointestinal manipulations may result in T2DM remission (metabolic surgery). The major mechanisms mediating the weight loss-independent effects of bariatric surgery comprise effects on tissue-specific insulin sensitivity, β-cell function and incretin responses, changes in bile acid composition and flow, modifications of gut microbiota, intestinal glucose metabolism and increased brown adipose tissue metabolic activity. Shorter T2DM duration, better preoperative glycemic control and profound weight loss, have been associated with higher rates of T2DM remission and lower risk of relapse. In the short and medium term, a significant amount of weight is lost, T2DM may completely regress, and cardiometabolic risk factors are dramatically improved. In the long term, metabolic surgery may achieve durable weight loss, prevent T2DM and cancer, improve overall glycemic control while leading to significant rates of T2DM remission, and reduce total and cause-specific mortality. The gradient of efficacy for weight loss and T2DM remission comparing the four established surgical procedures is biliopancreatic diversion >Roux-en-Y gastric bypass >sleeve gastrectomy >laparoscopic adjustable gastric banding. According to recently released guidelines, bariatric surgery should be recommended in diabetic patients with class III obesity, regardless of their level of glycemic control, and patients with class II obesity with inadequately controlled T2DM despite lifestyle and optimal medical therapy. Surgery should also be considered in patients with class I obesity and inadequately controlled hyperglycemia despite optimal medical treatment.

Relevance of weight in the management of patients with type 2 diabetes mellitus: towards an adipocentric approach to diabetes

In recent decades, there has been a worldwide parallel increase in the prevalence of obesity and type 2 diabetes mellitus (T2DM), which is not surprising, given that increased visceral fat is the main risk factor for the development of T2DM in genetically predisposed individuals. An intervention focused on intensive blood glucose control in T2DM with classic drugs increases the risk of weight gain and the rate of hypoglycaemia. In contrast, weight loss through lifestyle changes, drugs and/or surgery simultaneously improves most cardiovascular (CV) risk factors, including hyperglycemia. Intensive intervention on lifestyle induces an overall benefit in patients with T2DM, but long-term weight loss is modest and has not been shown to reduce CV morbidity and mortality. The emergence of new therapeutic classes for T2DM and obesity, which simultaneously improve HbA1c, weight and other CV risk factors without inducing hypoglycaemia, represents a major change in the management of patients with diabesity. A sodium-glucose cotransporter-2 inhibitor and a GLP-1 receptor agonist have recently been shown to decrease CV and total mortality in type 2 diabetic patients with CV disease. Furthermore, bariatric surgery rapidly induces remission or improvement of T2DM in a large percentage of patients and reduces diabetes-related mortality. The emergence of new therapies raises the possibility of changing the current glucose-centred therapeutic strategy for a weight-centred approach.

Bile acids and bariatric surgery

Bariatric surgery, specifically Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), are the most effective and durable treatments for morbid obesity and potentially a viable treatment for type 2 diabetes (T2D). The resolution rate of T2D following these procedures is between 40 and 80% and far surpasses that achieved by medical management alone. The molecular basis for this improvement is not entirely understood, but has been attributed in part to the altered enterohepatic circulation of bile acids. In this review we highlight how bile acids potentially contribute to improved lipid and glucose homeostasis, insulin sensitivity and energy expenditure after these procedures. The impact of altered bile acid levels in enterohepatic circulation is also associated with changes in gut microflora, which may further contribute to some of these beneficial effects. We highlight the beneficial effects of experimental surgical procedures in rodents that alter bile secretory flow without gastric restriction or altering nutrient flow. This information suggests a role for bile acids beyond dietary fat emulsification in altering whole body glucose and lipid metabolism strongly, and also suggests emerging roles for the activation of the bile acid receptors farnesoid x receptor (FXR) and G-protein coupled bile acid receptor (TGR5) in these improvements. The limitations of rodent studies and the current state of our understanding is reviewed and the potential effects of bile acids mediating the short- and long-term metabolic improvements after bariatric surgery is critically examined.

Considerations and treatment options for patients with comorbid atrial fibrillation and diabetes mellitus

INTRODUCTION

Atrial fibrillation (AF) and diabetes mellitus (DM) are common worldwide and their incidence is increasing, representing a significant public health and economic burden as well as an increase in individual increased morbidity and mortality risk profiles. Both conditions are closely related, as patients with DM are at increased risk of incident AF, and AF patients with DM are at higher risk of cardiovascular events compared to non-AF patients. Areas covered: This review article aims to provide an overview of the current evidence linking DM and AF, as well as the impact of obesity, weight loss and stroke on these coexisting conditions. Second, the effects of new oral anti hyperglycaemic medications on cardiovascular risk will be considered. Expert opinion: In conclusion, coexisting AF and DM represent a high risk population of patients requiring aggressive risk factor identification and treatment optimisation. The multifactorial interplay between these conditions requires individual assessment of patient risk profiles with the aim of minimising the impact of each modifiable risk factor.

Gut microbiome and serum metabolome alterations in obesity and after weight-loss intervention

Emerging evidence has linked the gut microbiome to human obesity. We performed a metagenome-wide association study and serum metabolomics profiling in a cohort of lean and obese, young, Chinese individuals. We identified obesity-associated gut microbial species linked to changes in circulating metabolites. The abundance of Bacteroides thetaiotaomicron, a glutamate-fermenting commensal, was markedly decreased in obese individuals and was inversely correlated with serum glutamate concentration. Consistently, gavage with B. thetaiotaomicron reduced plasma glutamate concentration and alleviated diet-induced body-weight gain and adiposity in mice. Furthermore, weight-loss intervention by bariatric surgery partially reversed obesity-associated microbial and metabolic alterations in obese individuals, including the decreased abundance of B. thetaiotaomicron and the elevated serum glutamate concentration. Our findings identify previously unknown links between intestinal microbiota alterations, circulating amino acids and obesity, suggesting that it may be possible to intervene in obesity by targeting the gut microbiota.

The FAT Score, a Fibrosis Score of Adipose Tissue: Predicting Weight-Loss Outcome After Gastric Bypass

CONTEXT

Bariatric surgery (BS) induces major and sustainable weight loss in many patients. Factors predicting poor weight-loss response (PR) need to be identified to improve patient care. Quantification of subcutaneous adipose tissue (scAT) fibrosis is negatively associated with post-BS weight loss, but whether it could constitute a predictor applicable in clinical routine remains to be demonstrated.

OBJECTIVE

To create a semiquantitative score evaluating scAT fibrosis and test its predictive value on weight-loss response after Roux-en-Y gastric bypass (RYGB).

METHODS

We created a fibrosis score of adipose tissue (FAT score) integrating perilobular and pericellular fibrosis. Using this score, we characterized 183 perioperative scAT biopsy specimens from severely obese patients who underwent RYGB (n = 85 from a training cohort; n = 98 from a confirmation cohort). PR to RYGB was defined as <28% of total weight loss at 1 year (lowest tertile). The link between FAT score and PR was tested in univariate and multivariate models.

RESULTS

FAT score was directly associated with increasing scAT fibrosis measured by a standard quantification method (P for trend <0.001). FAT score interobserver agreement was good (κ = 0.76). FAT score ≥2 was significantly associated with PR. The association remained significant after adjustment for age, diabetes status, hypertension, percent fat mass, and interleukin-6 level (adjusted odds ratio, 3.6; 95% confidence interval, 1.8 to 7.2; P = 0.003).

CONCLUSION

The FAT score is a new, simple, semiquantitative evaluation of human scAT fibrosis that may help identify patients with a potential limited weight-loss response to RYGB.

[Obesities: What's new in 2016?]

Since 1997, the World Health Organisation considered obesity, defined as an excess of fat mass, as a disease. Many plans have been set up to fight against obesity in industrialised countries. However, the prevalence of obesity is still increasing. The goal of this paper is to report some of the major scientific publications in terms of epidemiology, physiopathology or therapeutic in the field of obersity mainly published during year 2015-2016 or presented at ENDO meeting 2016.

Diabetes mellitus and stroke: A clinical update

Cardiovascular disease including stroke is a major complication that tremendously increases the morbidity and mortality in patients with diabetes mellitus (DM). DM poses about four times higher risk for stroke. Cardiometabolic risk factors including obesity, hypertension, and dyslipidaemia often co-exist in patients with DM that add on to stroke risk. Because of the strong association between DM and other stroke risk factors, physicians and diabetologists managing patients should have thorough understanding of these risk factors and management. This review is an evidence-based approach to the epidemiological aspects, pathophysiology, diagnostic work up and management algorithms for patients with diabetes and stroke.

Obesity

Excessive fat deposition in obesity has a multifactorial aetiology, but is widely considered the result of disequilibrium between energy intake and expenditure. Despite specific public health policies and individual treatment efforts to combat the obesity epidemic, >2 billion people worldwide are overweight or obese. The central nervous system circuitry, fuel turnover and metabolism as well as adipose tissue homeostasis are important to comprehend excessive weight gain and associated comorbidities. Obesity has a profound impact on quality of life, even in seemingly healthy individuals. Diet, physical activity or exercise and lifestyle changes are the cornerstones of obesity treatment, but medical treatment and bariatric surgery are becoming important. Family history, food environment, cultural preferences, adverse reactions to food, perinatal nutrition, previous or current diseases and physical activity patterns are relevant aspects for the health care professional to consider when treating the individual with obesity. Clinicians and other health care professionals are often ill-equipped to address the important environmental and socioeconomic drivers of the current obesity epidemic. Finally, understanding the epigenetic and genetic factors as well as metabolic pathways that take advantage of 'omics' technologies could play a very relevant part in combating obesity within a precision approach.

Type 2 diabetes in adolescents: a severe phenotype posing major clinical challenges and public health burden

Type 2 diabetes in adolescence manifests as a severe progressive form of diabetes that frequently presents with complications, responds poorly to treatment, and results in rapid progression of microvascular and macrovascular complications. Although overall still a rare disease, adolescent type 2 diabetes now poses major challenges to paediatric and adult diabetes services in many countries. Therapeutic options are heavily curtailed by a dearth of knowledge about the condition, with low numbers of participants and poor trial recruitment impeding research. Together with lifestyle modification, metformin remains the first-line therapy for adolescents with type 2 diabetes, although the majority rapidly progress to treatment failure and insulin therapy. Early bariatric surgery is controversial but has great potential to transform outcomes. Health systems must respond by both concentrating patients in specialist clinical services integrated with translational research programmes, but also by joining up with local health and social care services to improve engagement and uptake of services.

Gut-Brain Cross-Talk in Metabolic Control

Because human energy metabolism evolved to favor adiposity over leanness, the availability of palatable, easily attainable, and calorically dense foods has led to unprecedented levels of obesity and its associated metabolic co-morbidities that appear resistant to traditional lifestyle interventions. However, recent progress identifying the molecular signaling pathways through which the brain and the gastrointestinal system communicate to govern energy homeostasis, combined with emerging insights on the molecular mechanisms underlying successful bariatric surgery, gives reason to be optimistic that novel precision medicines that mimic, enhance, and/or modulate gut-brain signaling can have unprecedented potential for stopping the obesity and type 2 diabetes pandemics.

Bariatric surgery may reduce the risk of Alzheimer's diseases through GLP-1 mediated neuroprotective effects

Obesity and diabetes are associated with deficits in multiple neurocognitive domains and increased risk for dementia. Over the last two decades, there has been a significant increase in bariatric and metabolic surgery worldwide, driven by rising intertwined pandemics of obesity and diabetes, along with improvement in surgical techniques. Patients undergoing bariatric surgery achieve a significant decrease in their excess weight and a multitude of sequela associated with obesity, diabetes, and metabolic syndrome. Glucagon-like peptide 1 (GLP-1) is an intestinal peptide that has been implicated as one of the weight loss-independent mechanisms in how bariatric surgery affects type 2 diabetes. GLP-1 improves insulin secretion, inhibits apoptosis and induce pancreatic islet neogenesis, promotes satiety, and can regulate heart rate and blood pressure. Moreover, numerous studies have demonstrated potential neuroprotective and neurotrophic effects of GLP-1. Increased GLP-1 activity has been shown to increase cortical activity, promote neuronal growth, and inhibit neuronal degeneration. Specifically, in experimental studies on Alzheimer's disease, GLP-1 decreases amyloid deposition and neurofibrillary tangles. Furthermore, recent studies have also suggested that GLP-1 based therapies, new class of antidiabetic drugs, have favorable effects on neurodegenerative disorders such as Alzheimer's disease. We present a hypothesis that bariatric surgery can help delay or even prevent the onset of Alzheimer's disease in long-term by increasing the levels of GLP-1. This hypothesis has a potential for many studies from basic science projects to large population studies to fully understand the neurological and cognitive consequences of bariatric surgery and associated rise in GLP-1.

Using genetics to inform new therapeutics for diabetes

The genetic architecture of diabetes has been extensively studied. Numerous genetic markers for diabetes have been reported. However, the translation of such knowledge into clinical interventions has been inadequate. Areas covered: We performed a literature search on various frontiers in diabetes treatment that could be improved using genetic information: (1) understanding the mechanisms of existing antidiabetic drugs, (2) repurposing existing drugs for the treatment of diabetes, (3) complementing clinical trial findings; (4) finding novel treatment approaches; (5) better estimation of the efficacy of metabolic surgery. Expert commentary: The translation of genetic information to clinical intervention requires further study, including the development of an appropriate genetic risk score algorithm for type 2 diabetes. Genomic studies provide empirical explanations for clinical trial findings. Moreover, the mechanisms of antidiabetic drugs should be thoroughly investigated to enable clinical trials and pharmacogenomics studies of these drugs. As metabolic surgery becomes more prevalent for the treatment of diabetes, genetic approaches may improve patient prioritization.

Intestinal Adaptations after Bariatric Surgery: Consequences on Glucose Homeostasis

The gastrointestinal (GI) tract can play a direct role in glucose homeostasis by modulating the digestion and absorption of carbohydrates and by producing the incretin hormones. In recent years, numerous studies have focused on intestinal adaptation following bariatric surgeries. Changes in the number of incretin (glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide) producing cells have been reported, which could result in the modified hormonal response seen after surgery. In addition, the rate of absorption and the intestinal regions exposed to sugars may affect the time course of appearance of glucose in the blood. This review gives new insights into the direct role of the GI tract in the metabolic outcomes of bariatric surgery, in the context of glucose homeostasis.

Metabolic and Bariatric Surgery for Obesity

Metabolic and bariatric surgery (MBS) leads to weight loss in obese individuals and reduces comorbidities such as type 2 diabetes. MBS is superior to medical therapy in reducing hyperglycemia in persons with type 2 diabetes, and has been associated with reduced mortality and incidences of cardiovascular events and cancer in obese individuals. New guidelines have been proposed for the use of MBS in persons with type 2 diabetes. We review the use of MBS as a treatment for obesity and obesity-related conditions and, based on recent evidence, propose that health care systems make the appropriate changes to increase accessibility for eligible patients.

Bile reflux of the remnant stomach following Roux-en-Y gastric bypass: an etiology of chronic abdominal pain treated with remnant gastrectomy

BACKGROUND

Bile reflux gastritis of the remnant stomach following Roux-en-Y gastric bypass (RYGB) causing chronic abdominal pain has not been reported. We report a series of symptomatic patients with remnant gastritis treated effectively with remnant gastrectomy (RG).

OBJECTIVE

The objective was to report our experience with bile reflux remnant gastritis after RYGB and our outcomes following RG.

SETTING

Community teaching hospital.

METHODS

All patients undergoing RG were retrospectively reviewed for presenting symptoms, diagnostic workup, pathology, complications, and symptom resolution.

RESULTS

Nineteen patients underwent RG for bile reflux gastritis at a mean of 4.4 years (52.3 mo, range 8.5-124 mo) after RYGB. All patients were female and presented with pain, primarily epigastric (18/19; 95%), and described as burning (11/19; 58%), with 10 (53%) reporting nausea. Endoscopy was performed preoperatively on all patients with successful remnant inspection in 13 (68%), using push endoscopy (n = 10) or operative assist (n = 3), with 12 (of 13; 92%) biopsy-positive for reactive gastropathy. Seventeen (90%) completed a hepatobiliary scintigraphy scan with 100% positivity demonstrating bile reflux across the pylorus. Surgical approach was laparoscopic or robotic in 18 (95%) with a hospital length of stay of 2.7 days (range 0-12 d), with no major complications or readmissions. Pathology of the remnant confirmed reactive gastropathy in 90% (n = 17). Ninety percent of patients (n = 17) reported sustained symptom resolution, and 11% of patients (n = 2) remained symptomatic at last follow-up. We followed all patients for a mean of 6.6 years (1-194 mo).

CONCLUSION

Bile reflux gastritis of the remnant stomach is a new consideration for chronic abdominal pain months to years following RYGB. Hepatobiliary scintigraphy imaging and endoscopic biopsy are highly suggestive. RG is safe and effective treatment.

Roles of the gut in the metabolic syndrome: an overview

The metabolic syndrome is a cluster of risk factors (central obesity, hyperglycaemia, dyslipidaemia and arterial hypertension), indicating an increased risk of diabetes, cardiovascular disease and premature mortality. The gastrointestinal tract is seldom discussed as an organ system of principal importance for metabolic diseases. The present overview connects various metabolic research lines into an integrative physiological context in which the gastrointestinal tract is included. Strong evidence for the involvement of the gut in the metabolic syndrome derives from the powerful effects of weight-reducing (bariatric) gastrointestinal surgery. In fact, gastrointestinal surgery is now recommended as a standard treatment option for type 2 diabetes in obesity. Several gut-related mechanisms that potentially contribute to the metabolic syndrome will be presented. Obesity can be caused by hampered release of satiety-signalling gut hormones, reduced meal-associated energy expenditure and microbiota-assisted harvest of energy from nondigestible food ingredients. Adiposity per se is a well-established risk factor for hyperglycaemia. In addition, a leaky gut mucosa can trigger systemic inflammation mediating peripheral insulin resistance that together with a blunted incretin response aggravates the hyperglycaemic state. The intestinal microbiota is strongly associated with obesity and the related metabolic disease states, although the mechanisms involved remain unclear. Enterorenal signalling has been suggested to be involved in the pathophysiology of hypertension and postprandial triglyceride-rich chylomicrons; in addition, intestinal cholesterol metabolism probably contributes to atherosclerosis. It is likely that in the future, the metabolic syndrome will be treated according to novel pharmacological principles interfering with gastrointestinal functionality.

Surgical Treatment of Obesity and Diabetes

Sleeve gastrectomy, gastric bypass, gastric banding, and duodenal switch are the most common bariatric procedures performed worldwide. Ninety-five percent of bariatric operations are performed with minimally invasive laparoscopic technique. Perioperative morbidities and mortalities average around 5% and 0.2%, respectively. Long-term weight loss averages around 15% to 25% or about 80 to 100 lbs (40-50 kg). Comorbidities, including type 2 diabetes, hypertension, dyslipidemia, sleep apnea, arthritis, gastroesophageal reflux disease, and nonalcoholic fatty liver disease, improve or resolve after bariatric surgery.

What Bariatric Surgery Can Teach Us About Endoluminal Treatment of Obesity and Metabolic Disorders

Bariatric surgical procedures, including gastric bypass, vertical sleeve gastrectomy, and biliopancreatic diversion, are the most effective and durable treatments for obesity. In addition, These operations induce metabolic changes that provide weight-independent improvement in type 2 diabetes, fatty liver disease and other metabolic disorders. Initially thought to work by mechanical restriction of food intake or malabsorption of ingested nutrients, these procedures are now known to work through complex changes in neuroendocrine and immune signals emanating from the gut, including peptide hormones, bile acids, vagal nerve activity, and metabolites generated by the gut microbiota, all collaborating to reregulate appetite, food preference, and energy expenditure. Development of less invasive means of achieving these benefits would allow much greater dissemination of effective, gastrointestinal (GI)-targeted therapies for obesity and metabolic disorders. To reproduce the benefits of bariatric surgery, however, these endoscopic procedures and devices will need to mimic the physiological rather than the mechanical effects of these operations.

Comparison of economic and clinical outcomes between patients undergoing laparoscopic bariatric surgery with powered versus manual endoscopic surgical staplers

AIMS

To compare economic and clinical outcomes between patients undergoing laparoscopic Roux-en-Y gastric bypass (LRY) or laparoscopic sleeve gastrectomy (LSG) with use of powered vs manual endoscopic surgical staplers.

MATERIALS AND METHODS

Patients (aged ≥21 years) who underwent LRY or LSG during a hospital admission (January 1, 2012-September 30, 2015) were identified from the Premier Perspective Hospital Database. Use of powered vs manual staplers was identified from hospital administrative billing records. Multivariable analyses were used to compare the following outcomes between the powered and manual stapler groups, adjusting for patient and hospital characteristics and hospital-level clustering: hospital length of stay (LOS), total hospital costs, medical/surgical supply costs, room and board costs, operating room costs, operating room time, discharge status, bleeding/transfusion during the hospital admission, and 30, 60, and 90-day all-cause readmissions.

RESULTS

The powered and manual stapler groups comprised 9,851 patients (mean age = 44.6 years; 79.3% female) and 21,558 patients (mean age = 45.0 years; 78.0% female), respectively. In the multivariable analyses, adjusted mean hospital LOS was 2.1 days for both the powered and manual stapler groups (p = .981). Adjusted mean total hospital costs ($12,415 vs $13,547, p = .003), adjusted mean supply costs ($4,629 vs $5,217, p = .011), and adjusted mean operating room costs ($4,126 vs $4,413, p = .009) were significantly lower in the powered vs manual stapler group. The adjusted rate of bleeding and/or transfusion during the hospital admission (2.46% vs 3.22%, p = .025) was significantly lower in the powered vs manual stapler group. The adjusted rates of 30, 60, and 90-day all-cause readmissions were similar between the groups (all p > .05). Sub-analysis by manufacturer showed similar results.

LIMITATIONS

This observational study cannot establish causal linkages.

CONCLUSIONS

In this analysis of patients who underwent LRY or LSG, the use of powered staplers was associated with better economic outcomes, and a lower rate of bleeding/transfusion vs manual staplers in the real-world setting.

Hydrothermal Duodenal Mucosal Resurfacing: Role in the Treatment of Metabolic Disease

The duodenum has become recognized as a metabolic signaling center that is involved in regulating insulin action and, therefore, insulin resistance states such as type 2 diabetes. Bariatric surgery and other manipulations of the upper intestine, in particular the duodenum, have shown that limiting nutrient exposure or contact in this key region exerts powerful metabolic effects. Early human clinical trial data suggest that endoscopic hydrothermal duodenal mucosal resurfacing is well tolerated in human subjects and has an acceptable safety profile. This article describes the rationale for this endoscopic approach and its early human use, including safety, tolerability, and early efficacy.

What is the impact on the healthcare system if access to bariatric surgery is delayed?

BACKGROUND

Bariatric surgery has been available as part of the Brazilian Public Health System for patients with body mass index>40 kg/m² (or>35 kg/m² with co-morbidities) since 1999. However, access to surgery is challenging, with eligible patients waiting up to 7 years before surgery.

OBJECTIVE

Our objective was to compare costs and effectiveness of different waiting times before surgery versus prompt surgery.

SETTINGS

Public practice.

METHODS

A Markov microsimulation model compared 5 different strategies: no surgery, prompt surgery, and delaying surgery for 1, 2, 4, and 7 years. Markov tracker variables and states reflected changes in body mass index, type 2 diabetes status (including remission and relapse), and cardiovascular events. Time horizon was 20 years; discount rate, 5%; and the perspective of the Brazilian Public Health System. Effectiveness was calculated as quality adjusted life years.

RESULTS

Prompt surgery was the least costly and most effective strategy compared with any delay. Costs increased and effectiveness diminished progressively with the length of delays. Waiting 7 years for surgery was the most expensive and least effective strategy. Prompt surgery maintained dominance in 99.9%, 90.7%, 96.1%, and 94.2% of simulations in probabilistic sensitivity analyses versus 1-, 2-, 4-, and 7-year delays, respectively. Immediate surgery was very cost effective compared with no surgery in the case base. In the scenario with all patients having type 2 diabetes, immediate surgery was dominant to any strategy, including the no surgery group.

CONCLUSIONS

Delaying bariatric operations is more expensive and less effective compared with prompt surgery and very cost effective compared with no surgery. Public health systems should pursue strategies to accelerate access to surgery to decrease obesity related complications and mortality of patients, but also to improve cost effectiveness.

Basal Glucose Can Be Controlled, but the Prandial Problem Persists-It's the Next Target!

Both basal and postprandial elevations contribute to the hyperglycemic exposure of diabetes, but current therapies are mainly effective in controlling the basal component. Inability to control postprandial hyperglycemia limits success in maintaining overall glycemic control beyond the first 5 to 10 years after diagnosis, and it is also related to the weight gain that is common during insulin therapy. The "prandial problem"-comprising abnormalities of glucose and other metabolites, weight gain, and risk of hypoglycemia-deserves more attention. Several approaches to prandial abnormalities have recently been studied, but the patient populations for which they are best suited and the best ways of using them remain incompletely defined. Encouragingly, several proof-of-concept studies suggest that short-acting glucagon-like peptide 1 agonists or the amylin agonist pramlintide can be very effective in controlling postprandial hyperglycemia in type 2 diabetes in specific settings. This article reviews these topics and proposes that a greater proportion of available resources be directed to basic and clinical research on the prandial problem.

Pharmacotherapy of 'treatment resistant' type 2 diabetes

INTRODUCTION

Despite type 2 diabetes (T2D) management offers a variety of pharmacological interventions targeting different defects, numerous patients remain with persistent hyperglycaemia responsible for severe complications. Unlike resistant hypertension, treatment resistant T2D is not a classical concept although it is a rather common observation in clinical practice. Areas covered: This article proposes a definition for 'treatment resistant diabetes', analyses the causes of poor glucose control despite standard therapy, briefly considers the alternative approaches to glucose-lowering pharmacotherapy and finally describes how to overcome poor glycaemic control, using innovative oral or injectable combination therapies. Expert opinion: Before considering intensifying the pharmacotherapy of a patient with poorly controlled T2D, it is important to verify treatment adherence, target obesity and consider various non pharmacological improvement quality interventions. If treatment resistant diabetes is defined as not achieving glycated haemoglobin target despite oral triple therapy with a third glucose-lowering agent added to metformin-sulfonylurea dual treatment, the combination of a dipeptidyl peptidase-4 (DPP-4) inhibitor and a sodium glucose cotransporter type 2 (SGLT2) inhibitor may offer new opportunities before considering injectable therapies. Insulin basal therapy (± metformin) may be optimized by the addition of a SGLT2 inhibitor or a glucagon-like peptide-1 (GLP-1) receptor agonist.

Critical role for GLP-1 in symptomatic post-bariatric hypoglycaemia

AIMS/HYPOTHESIS

Post-bariatric hypoglycaemia (PBH) is a rare, but severe, metabolic disorder arising months to years after bariatric surgery. It is characterised by symptomatic postprandial hypoglycaemia, with inappropriately elevated insulin concentrations. The relative contribution of exaggerated incretin hormone signalling to dysregulated insulin secretion and symptomatic hypoglycaemia is a subject of ongoing inquiry. This study was designed to test the hypothesis that PBH and associated symptoms are primarily mediated by glucagon-like peptide-1 (GLP-1).

METHODS

We conducted a double-blinded crossover study wherein eight participants with confirmed PBH were assigned in random order to intravenous infusion of the GLP-1 receptor (GLP-1r) antagonist. Exendin (9-39) (Ex-9), or placebo during an OGTT on two separate days at the Stanford University Clinical and Translational Research Unit. Metabolic, symptomatic and pharmacokinetic variables were evaluated. Results were compared with a cohort of BMI- and glucose-matched non-surgical controls (NSCs).

RESULTS

Infusion of Ex-9 decreased the time to peak glucose and rate of glucose decline during OGTT, and raised the postprandial nadir by over 70%, normalising it relative to NSCs and preventing hypoglycaemia in all PBH participants. Insulin AUC and secretion rate decreased by 57% and 71% respectively, and peak postprandial insulin was normalised relative to NSCs. Autonomic and neuroglycopenic symptoms were significantly reduced during Ex-9 infusion.

CONCLUSIONS/INTERPRETATION

GLP-1r blockade prevented hypoglycaemia in 100% of individuals, normalised beta cell function and reversed neuroglycopenic symptoms, supporting the conclusion that GLP-1 plays a primary role in mediating hyperinsulinaemic hypoglycaemia in PBH. Competitive antagonism at the GLP-1r merits consideration as a therapeutic strategy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02550145.

Assessing the real-world effect of laparoscopic bariatric surgery on the management of obesity-related comorbidities: A retrospective matched cohort study using a US Claims Database

AIMS

To evaluate the real-world effect of laparoscopic bariatric surgery, comprising adjustable gastric banding (LAGB), laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG), on the management of obesity-related comorbidities.

METHODS

Patients who underwent laparoscopic bariatric surgeries between 2006 and 2013 were identified from the Optum Clinformatics administrative claims database. Those surgical patients were matched to medically managed patients (controls) on selected patient characteristics. Comorbidity management was assessed every 6 months up to 5 years after the surgery or an assigned index date for control subjects (follow-up), by evaluating the number of medication classes used to treat type 2 diabetes, hypertension and dyslipidaemia, as well as by evaluating the percentages of patients free of medications for these comorbidities.

RESULTS

Patients who underwent LAGB (n = 4208, mean age 46.3 years), LRYGB (n = 4308, mean age 46.4 years) or LSG (n = 545, mean age 45.1 years) and patients in the control cohort (n = 9061, mean age 46.4 years) were similar in age, and the majority of patients in each study cohort were female (69.4%-75.8%). Compared with control subjects, patients who had laparoscopic bariatric surgery had significantly lower medication usage for obesity-related comorbidities, a trend that was evident at 6 months and that continued for up to 5 years of follow-up. Sub-analyses of changes in selected laboratory test values over follow-up corroborated the primary analyses.

CONCLUSIONS

Patients who had laparoscopic bariatric surgery used fewer medications for type 2 diabetes, hypertension and dyslipidaemia and had significant improvement in cardiometabolic risk factors for up to 5 years of follow-up compared with matched control subjects.

Eligibility and Success Criteria for Bariatric/Metabolic Surgery

Obesity is a worldwide main health concern, with a high treatment failure. This chapter focuses on the definition of obesity, based on excessive fat accumulation and thus underscores the importance of body composition, and the clinical tools currently used to diagnose it, mainly body mass index that is only a proxy measure of body composition. It also highlights the importance of the personal commitment to comply to a healthy diet and physical activity recommendations since surgery is most effective when accompanied by lifestyle modifications. Additionally, it addresses the description of types of patients who could benefit most from surgical management of excessive body fat percentage and metabolic derangements, as well as on the indications for surgery that are currently valid.