Bariatric Surgery to Prevent and Treat Diabetes

The obesity epidemic has become a significant issue worldwide. Type 2 diabetes mellitus (T2DM) is related and its prevalence is also on the rise. Bariatric surgery as part of a comprehensive weight management strategy is highly efficacious in treating obese individuals and promoting weight loss. The resultant loss of excess body weight is frequently associated with improvement of comorbid factors such T2DM. This review focuses on both restrictive and malabsorptive bariatric surgical procedures and explores their roles in preventing and treating T2DM. Currently, the use of bariatric surgery as a prevention strategy for T2DM in obese individuals is understudied; however, there is early evidence to suggest a protective effect. In addition, this review summarizes emerging evidence linking bariatric surgery and improvement of T2DM in diabetic obese patients.     

Medical and surgical management of obesity and diabetes: what's new?

We conducted a narrative review of the medical and surgical management of people with obesity and diabetes. Results of this review showed that a 5–10% loss in body weight can be achieved with a change in lifestyle, diet and behaviour and with approved pharmacological therapies in people with obesity and diabetes. New targeted therapies are now available for patients with previously untreatable genetic causes of obesity. Compared to medical treatment, metabolic and bariatric surgery is associated with significantly higher rates of remission from type 2 diabetes and lower rates of incident macrovascular and microvascular complications and mortality. The National Institute for Health and Care Excellence and the American Diabetes Association endorse metabolic and bariatric surgery in obese adults with type 2 diabetes and there may also be a role for this in obese individuals with type 1 diabetes. The paediatric committee of the American Society for Metabolic and Bariatric Surgery have recommended metabolic and bariatric surgery in obese adolescents with type 2 diabetes. Earlier and more aggressive treatment with metabolic and bariatric surgery in obese or overweight people with diabetes can improve morbidity and mortality.     

Adipositaschirurgie

Every fifth German is obese, which means that 20% of male and 21.1% of female adults have a BMI of more than 30. In total 1.02 million adults in Germany are morbidly obese (BMI>40). This pandemic situation of obesity and morbid obesity is similar to the incidence of obesity in North America. In consideration of the increasing incidence of obesity the long-term success rate of conservative obesity treatment of 1?C2% does not ease this situation. Widespread prevention programs are not planned. The current only, as well long-term, effective therapy against morbid obesity is bariatric surgery. There is an arsenal of restrictive (e.g. gastric band, gastric sleeve) and combinations of restrictive and malabsorptive procedures (Roux-en-Y gastric bypass, biliopancreatic diversion) available to treat morbid obesity. Bariatric surgery can not only induce excess weight loss of 75?C80% but also a remission of co-morbidities, such as type 2 diabetes mellitus or metabolic syndrome. Even the tremendously reduced life expectancy of morbidly obese patients could be adapted to normal weight subjects by bariatric surgery.     

Cardiovascular benefits of bariatric surgery in morbidly obese patients

Morbid obesity is associated with increased morbidity and represents a major healthcare problem with increasing incidence worldwide. Bariatric surgery is considered an effective option for the management of morbid obesity. We searched MEDLINE, Current Contents and the Cochrane Library for papers published on bariatric surgery in English from 1 January 1990 to 20 July 2010. We also manually checked the references of retrieved articles for any pertinent material. Bariatric surgery results in resolution of major comorbidities including type 2 diabetes mellitus, hypertension, dyslipidemia, metabolic syndrome, non‐alcoholic fatty liver disease, nephropathy, left ventricular hypertrophy and obstructive sleep apnea in the majority of morbidly obese patients. Through these effects and possibly other independent mechanisms bariatric surgery appears to reduce cardiovascular morbidity and mortality. Laparoscopic Roux‐en‐Y gastric bypass (LRYGB) appears to be more effective than laparoscopic adjustable gastric banding (LAGB) in terms of weight loss and resolution of comorbidities. Operation‐associated mortality rates after bariatric surgery are low and LAGB is safer than LRYGB. In morbidly obese patients bariatric surgery is safe and appears to reduce cardiovascular morbidity and mortality.     

Could the mechanisms of bariatric surgery hold the key for novel therapies?: report from a Pennington Scientific Symposium

Bariatric surgery is the most effective method for promoting dramatic and durable weight loss in morbidly obese subjects. Furthermore, type 2 diabetes is resolved in over 80% of patients. The mechanisms behind the amelioration in metabolic abnormalities are largely unknown but may be due to changes in energy metabolism, gut peptides and food preference. The goal of this meeting was to review the latest research to better understand the mechanisms behind the ‘magic’ of bariatric surgery. Replication of these effects in a non‐surgical manner remains one of the ultimate challenges for the treatment of obesity and diabetes. Promising data on energy metabolism, gastrointestinal physiology, hedonic response and food intake were reviewed and discussed.     

Obesity and diabetes mellitus

Prevention of obesity is the first step in management of diabetes mellitus type 2, but prevention programmes have had poor long-term efficacy. The cornerstones of treatment in obese type 2 diabetic patients are diet, physical activity and behavioural modifications. A small weight loss results in improvement of type 2 diabetic patients. The obese type 2 diabetic patient shows extra impediments to weight loss, such as the adverse effects of diabetic medications. New drugs, as orlistat and sibutramine, can offer some additional help, by providing the benefit associated with weight loss. Bariatric surgery can produce major long-term weight loss in severely obese patients.     

The Obesity Paradox in Diabetes

Obesity and diabetes are chronic diseases frequently linked together. Durable weight loss is uncommon with medical/behavioral approaches. For severe obesity, bariatric surgery is the only treatment resulting in sustained weight loss. Bariatric surgery may be considered for adults with BMI?≥?35 kg/m² and type 2 diabetes, especially if the diabetes or associated comorbidities are difficult to control with lifestyle and pharmacological therapy. Bariatric surgery reduces the incidence of diabetes in overweight insulin-resistant subjects and is associated with remission of diabetes in a large proportion of patients. In considering the usefulness of bariatric surgery, it is also important to recognize that long-term follow-up is required before assigning a beneficial therapeutic effect in patients with diabetes because of the potential for weight regain that has been observed. As diabetes is a lifelong disease, it is important to emphasize that a certain percentage of patients will suffer from relapse of their diabetes.     

Bariatric Surgery: Impact on Pregnancy Outcomes

The dramatic increase in the prevalence of obesity in women of reproductive age has resulted in approximately 1 in 5 women being obese when they conceive. Bariatric surgery has been shown to be the most effective long-term weight loss strategy in obese women in this age group. Clinicians should be aware of the effects of bariatric surgery on fertility and future pregnancies. Regarding certain complications, pregnancy after bariatric surgery appears to be safer than pregnancy in the obese. In patients where nutrition is properly maintained and monitored, the risks for obesity-related obstetric complications, such as gestational diabetes mellitus and hypertension, are significantly reduced, but possibly at the expense of an increase in neonates born small-for-gestational-age. At the present, definitive conclusions cannot be drawn concerning the risk for Caesarian delivery, differences in type of bariatric procedure, or the optimal surgery-to-conception interval.     

Bariatric surgery and the kidneys

Overweight and obesity are connected with increased risk of obesity related co-morbidities, such as T2DM, hypertension, cardiovascular diseases, dyslipidaemia and others, as well as in higher risk of some malignant diseases. In obese population there is 2.5-3.3 fold increased risk of renal cell carcinoma in comparison with non-obese population of similar age. It has been proven in many studies that for severely obese patients there is no other more effective treatment of their obesity and co-morbidities than bariatric. Bariatric surgery decreases mortality risks, treat existing, obesity related co-morbidities, and can act as prevention of onset of new obesity related co-morbidities. Moreover at the end bariatric surgery lowers economic burden of health care systems. Nowadays, bariatric surgery is considered to be standard treatment option and pathway in complex management of morbidly obese patients.     

The impact of bariatric surgery in patients with type-2 diabetes mellitus

Over 220 million individuals have type-2 diabetes mellitus (T2DM) worldwide. Obesity has been identified as a significant risk factor for the development of T2DM. Overweight or obese individuals develop insulin resistance with resultant hyperinsulinemia. This process may progress to impaired glucose intolerance and eventual T2DM. There is strong evidence indicating that bariatric surgery may produce sustainable long-term weight loss in obese individuals. Bariatric surgery consists of surgical operations classified as either primarily restrictive or malabsorptive. Restrictive bariatric procedures include gastric banding or sleeve gastrectomy, while malabsorptive procedures included gastric bypass and biliopancreatic diversion. Malabsorptive procedures have been shown to be superior in producing dramatic weight loss along with resolution or improvement of T2DM. Interestingly, improvement of diabetes has been shown to occur shortly following malabsorptive bariatric surgery, prior to significant weight loss, suggesting that hormone-mediated mechanisms may be involved. As the prevalence of obesity and T2DM continues to rise, so may the role of bariatric surgery to combat this growing epidemic.     

Lifestyle Management for Enhancing Outcomes after Bariatric Surgery

Bariatric surgery has been safe and effective for treatment of severe obesity and comorbidities like type 2 diabetes mellitus (T2D). Nonetheless, weight loss and health outcomes vary considerably across individuals. Although the factors associated with outcomes are not fully understood, postoperative weight loss following any type of bariatric surgery is largely dependent on the extent to which patients can make and sustain changes in eating and activity. Therefore, lifestyle management including diet, exercise, and behavior modification is critical to helping patients achieve long-term weight loss. Pharmacotherapy and reoperation may also play a role after bariatric surgery. In this article, we highlight recent research findings in all of these areas to provide suggestions for how to enhance outcomes following bariatric surgery. Research on the mechanisms for weight loss and improvements in T2D following the different surgical procedures is needed to support the development of more personalized approaches to the multidisciplinary management of severe obesity.     

Considerations for bariatric surgery in patients with cirrhosis

With the ever increasing global obesity pandemic, clinical burden from obesity related complications are anticipated in parallel. Bariatric surgery, a treatment approved for weight loss in morbidly obese patients, has reported to be associated with good outcomes, such as reversal of type two diabetes mellitus and reducing all-cause mortality on a long term basis. However, complications from bariatric surgery have similarly been reported. In particular, with the onslaught of non-alcoholic fatty liver disease(NAFLD) epidemic, in associated with obesity and metabolic syndrome, there is increasing prevalence of NAFLD related liver cirrhosis, which potentially connotes more risk of specific complications for surgery. Bariatric surgeons may encounter, either expectedly or unexpectedly, patients with non-alcoholic steatohepatitis(NASH) and NASH related cirrhosis more frequently. As such, the issues and considerations surrounding their medical care/surgery warrant careful deliberation to ensure the best outcomes. These considerations include severity of cirrhosis, liver synthetic function, portal hypertension and the impact of surgical factors. This review explores these considerations comprehensively and emphasizes the best approach to managing cirrhotic patients in the context of bariatric surgery.     

Metabolic surgery for the treatment of type 2 diabetes in patients with BMI lower than 35 kg/m2: Why caution is still needed

Bariatric surgery has shifted from being a risky procedure to an evidence‐based one, with proven benefits on all‐cause mortality, cardiovascular disease, cancer, and diabetes control. The procedure has an overall positive result on type 2 diabetes mellitus (T2DM), with a substantial number of patients achieving disease remission. This has resulted in several studies assessing possible weight‐independent effects of bariatric surgery on glycemic improvement, in addition to recommendation of the procedure to patients with class 1 obesity and T2DM, for whom the procedure was classically not indicated, and adoption of a new term, “metabolic surgery,” to highlight the overall metabolic benefit of the procedure beyond weight loss. Recently, the Diabetes Surgery Summit (DSS) has included metabolic surgery in its T2DM treatment algorithm. Although the discussion brought by this consensus is highly relevant, the recommendation of metabolic surgery for patients with uncontrolled T2DM and a body mass index of 30 to 35 kg/m² still lacks enough evidence. This article provides an overall view of the metabolic benefits of bariatric/metabolic surgery in patients with class 1 obesity, compares the procedure against clinical treatment, and presents our rationale for defending caution on recommending the procedure to less obese individuals.     

肠促胰岛素在减肥手术治疗肥胖2型糖尿病患者中的作用

肥胖和2型糖尿病的患病率呈逐年增高的趋势.减肥手术作为减轻体质量的有效方法,近年来逐渐得到广泛的应用.其主要分为限制型手术、吸收不良型手术及联合型手术.减肥手术在减轻体质量的同时也使肥胖患者的糖尿病得到了缓解,但其缓解糖尿病的机制目前尚不完全清楚.除了体质量减轻、摄食减少外,关于肠促胰岛素在减肥手术中的作用也受到了越来越多的重视.本文对减肥手术的术式、疗效、安全性及治疗糖尿病的可能机制进行讨论.     

Surgical treatment of obesity

More than half of the European population are overweight (body mass index (BMI) > 25 and < 30 kg/m2) and up to 30% are obese (BMI > or = 30 kg/m2). Being overweight and obesity are becoming endemic, particularly because of increasing nourishment and a decrease in physical exercise. Insulin resistance, type 2 diabetes, dyslipidemia, hypertension, cholelithiasis, certain forms of cancer, steatosis hepatis, gastroesophageal reflux, obstructive sleep apnea, degenerative joint disease, gout, lower back pain, and polycystic ovary syndrome are all associated with overweight and obesity. The endemic extent of overweight and obesity with its associated comorbidities has led to the development of therapies aimed at weight loss. The long-term effects of diet, exercise, and medical therapy on weight are relatively poor. With respect to durable weight reduction, bariatric surgery is the most effective long-term treatment for obesity with the greatest chances for amelioration and even resolution of obesity-associated complications. Recent evidence shows that bariatric surgery for severe obesity is associated with decreased overall mortality. However, serious complications can occur and therefore a careful selection of patients is of utmost importance. Bariatric surgery should at least be considered for all patients with a BMI of more than 40 kg/m2 and for those with a BMI of more than 35 kg/m2 with concomitant obesity-related conditions after failure of conventional treatment. The importance of weight loss and results of conventional treatment will be discussed first. Currently used operative treatments for obesity and their effectiveness and complications are described. Proposed criteria for bariatric surgery are given. Also, some attention is devoted to more basic insights that bariatric surgery has provided. Finally we deal with unsolved questions and future directions for research.     

Bariatric Surgery: Effects on the Metabolic Complications of Obesity

Bariatric surgery is increasing at an enormous rate in all countries but the indications for the operation on the basis of metabolic derangements are not clear, as only one controlled randomized trial specifically for a comorbidity has been performed. Thus, it is not clear if bariatric surgery should be offered to all obese patients with long standing type 2 diabetes or poorly controlled hypertension or hypertriglyceridemia, even though these conditions clearly respond in most patients to bariatric surgery and weight loss. It would appear that patients with early type 2 diabetes with reasonable control and a greater body mass index gain more benefit from the operation. More randomized trials are required.     

Morbid obesity and type 2 diabetes alter intestinal fatty acid uptake and blood flow

Aims

Bariatric surgery is the most effective treatment to tackle morbid obesity and type 2 diabetes, but the mechanisms of action are still unclear. The objective of this study was to investigate the effects of bariatric surgery on intestinal fatty acid (FA) uptake and blood flow.

Materials and Methods

We recruited 27 morbidly obese subjects, of whom 10 had type 2 diabetes and 15 were healthy age‐matched controls. Intestinal blood flow and fatty acid uptake from circulation were measured during fasting state using positron emission tomography (PET). Obese subjects were re‐studied 6 months after bariatric surgery. The mucosal location of intestinal FA retention was verified in insulin resistant mice with autoradiography.

Results

Compared to lean subjects, morbidly obese subjects had higher duodenal and jejunal FA uptake (P < .001) but similar intestinal blood flow (NS). Within 6 months after bariatric surgery, obese subjects had lost 24% of their weight and 7/10 diabetic subjects were in remission. Jejunal FA uptake was further increased (P < .03). Conversely, bariatric surgery provoked a decrease in jejunal blood flow (P < .05) while duodenal blood flow was preserved. Animal studies showed that FAs were taken up into enterocytes, for the most part, but were also transferred, in part, into the lumen.

Conclusions

In the obese, the small intestine actively takes up FAs from circulation and FA uptake remains higher than in controls post‐operatively. Intestinal blood flow was not enhanced before or after bariatric surgery, suggesting that enhanced intestinal FA metabolism is not driven by intestinal perfusion.     

Bariatric surgery,bone loss,obesity and possible mechanisms

Bariatric surgery remains the most effective treatment for severely obese patients. However, the potential long‐term effects of bariatric surgical procedures on health, including bone health, are only partially understood. The goal of this review was to present data on the impact of bariatric surgery on bone metabolism and to analyse possible reasons for the loss of bone mass that frequently occurs after bariatric surgery. Such factors include nutritional deficiencies, rapid weight loss per se, effects of fat‐derived adipokines and gut‐derived appetite‐regulatory hormones. However, the relative roles of these factors in skeletal regulation and the mechanisms by which they work are not yet fully defined. Our review was focussed on the complex relationship between body weight, fat mass and bone mass, as well as peripheral and central mediators potentially involved in the dual regulation of both energy and bone homeostasis. We also review the data on the inverse relationship between central obesity, bone marrow fat and osteoporosis. As the number of bariatric operations increases, it is imperative to recognize mechanisms responsible for bariatric surgery‐induced bone loss, with careful monitoring of bone health including long‐term fracture incidence in patients undergoing these procedures.     

The Impact of Bariatric Surgery on Depression: a Review

More than half of patients with obesity who present for medical or surgical management meet the criteria for a psychiatric illness, commonly a mood disorder. Bariatric surgery leads to significant improvement in depression symptomology and a reduction in the overall prevalence of depression. Studies generally report short-term overall reduction in depression rates between approximately 55 to 65 % within the first two years following surgery. It appears that there is a dose response relationship between weight loss and resolution of depression. There are some conflicting reports in the literature as to the maintenance of depression outcomes following bariatric surgery, with newer, long-term studies reporting the attenuation of depression symptomology improvements. While generally, bariatric surgery is beneficial for depression, there exists a cohort of patients who might actually worsen following surgery. A likely multifactorial consequence of weight regain, unrealistic expectations or other life stresses, this group needs to be monitored closely, as postoperative bariatric surgery patients surgery appear to be at an increased risk of suicide. Overall, a multidisciplinary team including psychiatrists, psychologists and other mental health professionals are vital to optimize patient care in the depressed, obese bariatric surgery patient.     

Bariatric surgery for type 2 diabetes

Bariatric surgery provides substantial, sustained weight loss and major improvements in glycaemic control in severely obese individuals with type 2 diabetes. However, uptake of surgery in eligible patients is poor, and the barriers are difficult to surmount. We examine the indications for and efficacy and safety of conventional bariatric surgical procedures and their effect on glycaemic control in type 2 diabetes. How surgical gastrointestinal interventions achieve these changes is of great research interest, and is evolving rapidly. Old classifications about restriction and malabsorption are inadequate, and we explore understanding of putative mechanisms. Some bariatric procedures improve glycaemic control in people with diabetes beyond that expected for weight loss, and understanding this additional effect could provide insights into the pathogenesis of type 2 diabetes and assist in the development of new procedures, devices, and drugs both for obese and non-obese patients.