Philip R. Schauer

Metabolic Surgery to Treat Type 2 Diabetes: Clinical Outcomes and Mechanisms of Action

Several gastrointestinal (GI) operations that were designed to promote weight loss can powerfully ameliorate type 2 diabetes mellitus (T2DM). Although T2DM is traditionally viewed as a chronic, relentless disease in which delay of end-organ complications is the major treatment goal, GI surgery offers a novel endpoint: complete disease remission. Ample data confirm the excellent safety and efficacy of conventional bariatric operations-especially Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding-to treat T2DM in severely obese patients. Use of experimental procedures as well as conventional bariatric operations is increasingly being explored in less obese diabetic patients, with generally favorable results, although further assessment of risk:benefit profiles is needed. Mounting evidence indicates that certain operations involving intestinal diversions improve glucose homeostasis through varied mechanisms beyond reduced food intake and body weight, for example by modulating gut hormones. Research to elucidate such mechanisms should facilitate the design of novel pharmacotherapeutics and dedicated antidiabetes GI manipulations. Here we review evidence regarding the use and study of GI surgery to treat T2DM, focusing on available published reports as well as results from the Diabetes Surgery Summit (DSS) in Rome and the World Congress on Interventional Therapies for T2DM in New York City.

The Diabetes Surgery Summit consensus conference: recommendations for the evaluation and use of gastrointestinal surgery to treat type 2 diabetes mellitus.

Objectives:To develop guidelines for the use of gastrointestinal surgery to treat type 2 diabetes and to craft an agenda for further research. Background:Increasing evidence demonstrates that bariatric surgery can dramatically ameliorate type 2 diabetes. Not surprisingly, gastrointestinal operations are now being used throughout the world to treat diabetes in association with obesity, and increasingly, for diabetes alone. However, the role for surgery in diabetes treatment is not clearly defined and there are neither clear guidelines for these practices nor sufficient plans for clinical trials to evaluate the risks and benefits of such “diabetes surgery.” Methods:A multidisciplinary group of 50 voting delegates from around the world gathered in Rome, Italy for the first International Conference on Gastrointestinal Surgery to Treat Type 2 Diabetes–(the “Diabetes Surgery Summit”). During the meeting, available scientific evidence was examined and critiqued by the entire group to assess the strength of evidence and to draft consensus statements. Through an iterative process, draft statements were then serially discussed, debated, edited, reassessed, and finally presented for formal voting. After the Rome meeting, statements that achieved consensus were summarized and distributed to all voting delegates for further input and final approval. These statements were then formally critiqued by representatives of several sientific societies at the 1st World Congress on Interventional Therapies for T2DM (New York, Sept 2008). Input from this discussion was used to generate the current position statement. Results:A Diabetes Surgery Summit (DSS) Position Statement consists of recommendations for clinical and research issues, as well as general concepts and definitions in diabetes surgery. The DSS recognizes the legitimacy of surgical approaches to treat diabetes in carefully selected patients. For example, gastric bypass was deemed a reasonable treatment option for patients with poorly controlled diabetes and a body mass index ≥30 kg/m2. Clinical trials to investigate the exact role of surgery in patients with less severe obesity and diabetes are considered a priority. Furthermore, investigations on the mechanisms of surgical control of diabetes are strongly encouraged, as they may help advance the understanding of diabetes pathophysiology. Conclusions:The DSS consensus document embodies the foundations of “diabetes surgery,” and represents a timely attempt by leading scholars to improve access to surgical options supported by sound evidence, while also preventing harm from inappropriate use of unproven procedures.

Minimally invasive bariatric surgery

Minimally invasive bariatric surgery / , Minimally invasive bariatric surgery / , کتابخانه دیجیتال جندی شاپور اهواز

Intellectual disability and bariatric surgery: A case study on optimization and outcome

The 2008 AACE/ASMBS/TOS guidelines for bariatric surgery identify a lack of comprehension of risks, benefits, expected outcomes, alternatives, and lifestyle changes required with bariatric surgery as a contraindication [1] and the updated 2013 guidelines focus on the need for informed consent [2]. Such contraindications were also noted, in part, by the National Institutes of Health consensus statement on weight loss surgery 420 years ago stating that candidates should be “well-informed and motivated” [3]. Given that those with intellectual and/or developmental disabilities may have difficulty achieving these goals, many programs do not consider such patients surgical candidates. In a survey of present practices, 81.6% of programs consider severe intellectual disability (Intelligence Quotient [IQ] o 50) to be a definite contraindication and 13.6% consider it a possible contraindication [4]. Mild to moderate disability (IQ between 70 and 50) is considered a definite contraindication by 45.7% of programs and a possible contraindication for an additional 46.9% or respondents. Only 6.2% of bariatric surgery centers do not think of this level of disability as any type of contraindication [4]. In contrast, individuals with intellectual disabilities are more likely to be obese than control populations and more likely to have related co-morbidities, such as type 2 diabetes mellitus, hypertension, hyperlipidemia, coronary heart disease, chronic obstructive pulmonary disease, and osteoarthritis [5]. Thus, a subset of individuals who may be of greater need of weight loss surgery may also be less likely to receive it.

The Socioeconomic Impact of Morbid Obesity and Factors Affecting Access to Obesity Surgery

Bariatric surgery has been shown in many studies to be the most effective long-term treatment for severe obesity and obesity-related comorbidities. Economic analysis has demonstrated cost-effectiveness as well as cost-savings in select subgroups of patients. Despite the health and economic benefits of bariatric surgery, relatively few eligible patients receive this treatment. This disparity in access to care must be addressed by health policy decision-makers.

American Society for Metabolic and bariatric surgery (ASMBS) centers of excellence program

In 2003, in response to the public perception of dramatic variability in outcomes after bariatric surgery, the American Society for Metabolic and Bariatric Surgery (ASMBS) established a quality assurance initiative known as the Bariatric Surgery Center of Excellence (BSCOE). Previously, no minimal standards existed for hospitals or surgeons to perform bariatric surgery. ASMBS established an independent, nonprofi t organization known as the Surgical Review Corporation (SRC) to establish quality criteria for hospitals and surgeons as well as to evaluate, certify, and monitor individual hospitals and surgeons. The primary goal of the BSCOE is to allow patients, referring physicians, and health insurance carriers to identify hospitals and surgeons that are performing bariatric surgery at a high standard. The secondary goal is to ensure continued quality improvement in all qualifying BSCOE sites. To qualify as a BSCOE, surgeon practices and hospitals are required to submit documentation supporting the fact that they meet facility and practice standards. All sites must pass a rigorous onsite inspection in order to acquire fi nal approval. In addition, all certifi ed BSCOEs must collect and submit selected outcome data periodically for analysis. The following are the specifi c requirements for obtaining full approval as a BSCOE. The Bariatric COE program is designed to ensure that:

Prevention Is Better Than Cure: The Next Frontier for Bariatric Surgery?

Patients with type 2 diabetes mellitus (T2DM) do not die of hyperglycemia; instead, the complications of this multisystem disease drive morbidity and mortality. The trend toward earlier-onset diabetes significantly magnifies concern. Until recently, T2DM was considered a chronic and progressive disease. With better pharmacotherapy and the widely endorsed use of bariatric surgery to treat T2DM specifically, level 1 evidence indicates that surgery not only attenuates disease progression but also often induces remission of hyperglycemia (13). The question is whether bariatric surgery improves only hyperglycemia or fundamentally changes the course of the disease. OBrien and colleagues (4) addressed this question by investigating the relationship between bariatric surgery and incident microvascular complications of T2DM. They did a retrospective matched cohort study based in 4 integrated health systems in the United States. The investigators selected 4024 patients with T2DM who had bariatric surgery and matched them on age, sex, body mass index, hemoglobin A1c level, insulin use, diabetes duration, and intensity of health care use with 11059 nonsurgical participants. Using adjusted Cox regression analysis, they investigated time to incident microvascular disease, defined by the first occurrence of diabetic retinopathy, neuropathy, or nephropathy. Bariatric surgery reduced incident microvascular disease by 49% at 7 years, and reductions were significant for neuropathy, nephropathy, and retinopathy. Such a remarkable decrease in microvascular complications has rarely been shown by any form of diabetes therapy. The key limitations were the use of electronic health record databases, which could misclassify microvascular disease, and the nonrandomized selection bias, whereby patients who chose to have a surgical procedure might have unrecognized outcome advantages compared with nonsurgical control participants. This further emphasizes the need for a randomized controlled trial to test the hypothesis put forward by this large, well-done cohort study. The authors refer to the discontinuation of fenofibrate and angiotensin-receptor blockers after bariatric surgery and these medications association with reduced microvascular complications. The effectiveness of bariatric surgery combined with medications therefore remains to be determined. Such a combination may put surgery on turbocharge and realize even larger effects than either treatment alone. Finally, the reduction in nephropathy should be interpreted with caution. Cohort studies suggest that kidney damage, as measured by urine albumincreatinine ratios, is attenuated after bariatric surgery (5). However, the authors measured kidney function using a biomarker reliant on serum creatinine. Substantial weight loss will reduce serum creatinine levels even if kidney function remains stable or slightly declines, because serum creatinine also depends on muscle mass. Thus, as weight decreases, so does muscle mass and subsequently serum creatinine level (6). It is reassuring, however, that markers of kidney function did not deteriorate after surgery; when all of the evidence is put together, bariatric surgery likely does prevent nephropathy. The authors conclude that bariatric surgery in adults with T2DM reduced the incidence of neuropathy, nephropathy, and retinopathy. These findings are consistent with many smaller cohort studies that used the same surgical procedures, but also with such cohort studies as the Longitudinal Assessment of Bariatric Surgery-2 study and the Swedish Obese Subjects study, which used older operations, such as vertical-banded gastroplasty or fixed gastric banding (79). The consistency of these findings is reassuring because all of the data suggest that bariatric surgery can be used to prevent microvascular complications of diabetes. Again, only a randomized controlled trial would provide more definitive evidence. The heterogeneity of the surgical procedures calls into question the mechanism of effect and whether other nonsurgical treatments that may achieve similar weight loss and metabolic control would be equally effective. New surgical procedures, medical devices, and combinations of medications with devices or operations should now be held to this standard of not only improving glycemic control but also addressing T2DM as a systemic disease. Future studies need to show whether new interventions can reduce the incidence of complications of T2DM. Whether surgery can be used to treat established microvascular complications of T2DM was beyond the remit of the present study. However, the findings do raise the question of whether surgery can also reverse microvascular disease. Pancreatic transplantation has been shown to reverse established microvascular complications of type 1 diabetes (10). Bariatric surgery may have far more powerful effects on T2DM because it not only reduces glycemia but also significantly improves hypertension, dyslipidemia, and inflammation. Thus, bariatric surgery may reduce established complications of T2DM, but current supporting evidence is limited. For health care policy, these findings imply that bariatric surgery should now be considered an effective T2DM treatment not only to alleviate hyperglycemia but also to prevent the complications that account for the morbidity and mortality of the disease. Many diabetes clinics previously used bariatric surgery only for patients with T2DM and severe obesity, with surgery primarily focused on reducing obesity. With this new data from OBrien and colleagues, we can now consider surgery a treatment of diabetes beyond glycemia. Bariatric surgery can now be intended to prevent complications of T2DM. Bariatric surgery is safe and is, at present, our most evidence-based treatment to put hyperglycemia from T2DM into remission (3). We are on the verge of having the data to tell our patients with T2DM in the clinic that we can offer them a treatment that significantly reduces the feared complications of this dreadful disease. Surgery should not be a last resort but instead should be used earlier, because prevention is definitely better than cure.

Obesity: The Elephant in the Room

Obesity has become an important public health problem in industrialized countries throughout the world. Body Mass Index (BMI = weight (kg)/(height (m))2) is the primary measurement used to categorize obese patients (Table 20.1). Excess body weight (EBW) is defined as the amount of weight present in excess of Ideal Body Weight (IBW) (as determined by Metropolitan Life Tables). In 1991, the National Institutes of Health defined morbid obesity as a BMI of 35 kg/m2 or greater with severe obesity-related comorbidity, or a BMI of 40 kg/m2 or greater without comorbidity [NIH conference (Ann Intern Med 115:956–961, 1991)].