IFSO Consensus on Definitions and Clinical Practice Guidelines for Obesity Management-an International Delphi Study

INTRODUCTION

This survey of international experts in obesity management was conducted to achieve consensus on standardized definitions and to identify areas of consensus and non-consensus in metabolic bariatric surgery (MBS) to assist in an algorithm of clinical practice guidelines for the management of obesity.

METHODS

A three-round Delphi survey with 136 statements was conducted by 43 experts in obesity management comprising 26 bariatric surgeons, 4 endoscopists, 8 endocrinologists, 2 nutritionists, 2 counsellors, an internist, and a pediatrician spanning six continents over a 2-day meeting in Hamburg, Germany. To reduce bias, voting was unanimous, and the statements were neither favorable nor unfavorable to the issue voted or evenly balanced between favorable and unfavorable. Consensus was defined as ≥ 70% inter-voter agreement.

RESULTS

Consensus was reached on all 15 essential definitional and reporting statements, including initial suboptimal clinical response, baseline weight, recurrent weight gain, conversion, and revision surgery. Consensus was reached on 95/121 statements on the type of surgical procedures favoring Roux-en-Y gastric bypass, sleeve gastrectomy, and endoscopic sleeve gastroplasty. Moderate consensus was reached for sleeve gastrectomy single-anastomosis duodenoileostomy and none on the role of intra-gastric balloons. Consensus was reached for MBS in patients > 65 and < 18 years old, with a BMI > 50 kg/m2, and with various obesity-related complications such as type 2 diabetes, liver, and kidney disease.

CONCLUSIONS

In this survey of 43 multi-disciplinary experts, consensus was reached on standardized definitions and reporting standards applicable to the whole medical community. An algorithm for treating patients with obesity was explored utilizing a thoughtful multimodal approach.

Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial

BACKGROUND

Retatrutide (LY3437943) is an agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and glucagon receptors. Its dose-response relationships with respect to side effects, safety, and efficacy for the treatment of obesity are not known.

METHODS

We conducted a phase 2, double-blind, randomized, placebo-controlled trial involving adults who had a body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) of 30 or higher or who had a BMI of 27 to less than 30 plus at least one weight-related condition. Participants were randomly assigned in a 2:1:1:1:1:2:2 ratio to receive subcutaneous retatrutide (1 mg, 4 mg [initial dose, 2 mg], 4 mg [initial dose, 4 mg], 8 mg [initial dose, 2 mg], 8 mg [initial dose, 4 mg], or 12 mg [initial dose, 2 mg]) or placebo once weekly for 48 weeks. The primary end point was the percentage change in body weight from baseline to 24 weeks. Secondary end points included the percentage change in body weight from baseline to 48 weeks and a weight reduction of 5% or more, 10% or more, or 15% or more. Safety was also assessed.

RESULTS

We enrolled 338 adults, 51.8% of whom were men. The least-squares mean percentage change in body weight at 24 weeks in the retatrutide groups was -7.2% in the 1-mg group, -12.9% in the combined 4-mg group, -17.3% in the combined 8-mg group, and -17.5% in the 12-mg group, as compared with -1.6% in the placebo group. At 48 weeks, the least-squares mean percentage change in the retatrutide groups was -8.7% in the 1-mg group, -17.1% in the combined 4-mg group, -22.8% in the combined 8-mg group, and -24.2% in the 12-mg group, as compared with -2.1% in the placebo group. At 48 weeks, a weight reduction of 5% or more, 10% or more, and 15% or more had occurred in 92%, 75%, and 60%, respectively, of the participants who received 4 mg of retatrutide; 100%, 91%, and 75% of those who received 8 mg; 100%, 93%, and 83% of those who received 12 mg; and 27%, 9%, and 2% of those who received placebo. The most common adverse events in the retatrutide groups were gastrointestinal; these events were dose-related, were mostly mild to moderate in severity, and were partially mitigated with a lower starting dose (2 mg vs. 4 mg). Dose-dependent increases in heart rate peaked at 24 weeks and declined thereafter.

CONCLUSIONS

In adults with obesity, retatrutide treatment for 48 weeks resulted in substantial reductions in body weight. (Funded by Eli Lilly; ClinicalTrials.gov number, NCT04881760.).

Obstacles and opportunities in managing coexisting obesity and CKD: Report of a scientific workshop cosponsored by the National Kidney Foundation and The Obesity Society

The National Kidney Foundation (NKF) and The Obesity Society (TOS) cosponsored a multispecialty international workshop in April 2021 to advance the understanding and management of obesity in adults with chronic kidney disease (CKD). The underlying rationale for the workshop was the accumulating evidence that obesity is a major contributor to CKD and adverse outcomes in individuals with CKD, and that effective treatment of obesity, including lifestyle intervention, weight loss medications, and metabolic surgery, can have beneficial effects. The attendees included a range of experts in the areas of kidney disease, obesity medicine, endocrinology, diabetes, bariatric/metabolic surgery, endoscopy, transplant surgery, and nutrition, as well as patients with obesity and CKD. The group identified strategies to increase patient and provider engagement in obesity management, outlined a collaborative action plan to engage nephrologists and obesity medicine experts in obesity management, and identified research opportunities to address gaps in knowledge about the interaction between obesity and kidney disease. The workshop's conclusions help lay the groundwork for development of an effective, scientifically based, and multidisciplinary approach to the management of obesity in people with CKD.

Obstacles and Opportunities in Managing Coexisting Obesity and CKD: Report of a Scientific Workshop Cosponsored by the National Kidney Foundation and The Obesity Society

The National Kidney Foundation (NKF) and The Obesity Society (TOS) cosponsored a multispecialty international workshop in April 2021 to advance the understanding and management of obesity in adults with chronic kidney disease (CKD). The underlying rationale for the workshop was the accumulating evidence that obesity is a major contributor to CKD and adverse outcomes in individuals with CKD, and that effective treatment of obesity, including lifestyle intervention, weight loss medications, and metabolic surgery, can have beneficial effects. The attendees included a range of experts in the areas of kidney disease, obesity medicine, endocrinology, diabetes, bariatric/metabolic surgery, endoscopy, transplant surgery, and nutrition, as well as patients with obesity and CKD. The group identified strategies to increase patient and provider engagement in obesity management, outlined a collaborative action plan to engage nephrologists and obesity medicine experts in obesity management, and identified research opportunities to address gaps in knowledge about the interaction between obesity and kidney disease. The workshop's conclusions help lay the groundwork for development of an effective, scientifically based, and multidisciplinary approach to the management of obesity in people with CKD.

Clinical Care Pathway for the Risk Stratification and Management of Patients With Nonalcoholic Fatty Liver Disease

Find AGA's NASH Clinical Care Pathway App for iOS and Android mobile devices at nash.gastro.org. Scan this QR code to be taken directly to the website.Nonalcoholic fatty liver disease (NAFLD) is becoming increasingly common, currently affecting approximately 37% of US adults. NAFLD is most often managed in primary care or endocrine clinics, where clinicians must determine which patients might benefit from secondary care to address hepatic manifestations, comorbid metabolic traits, and cardiovascular risks of the disease. Because NAFLD is largely asymptomatic, and because optimal timing of treatment depends on accurate staging of fibrosis risk, screening at the primary care level is critical, together with consistent, timely, evidence-based, widely accessible, and testable management processes. To achieve these goals, the American Gastroenterological Association assembled a multidisciplinary panel of experts to develop a Clinical Care Pathway providing explicit guidance on the screening, diagnosis, and treatment of NAFLD. This article describes the NAFLD Clinical Care Pathway they developed and provides a rationale supporting proposed steps to assist clinicians in diagnosing and managing NAFLD with clinically significant fibrosis (stage F2-F4) based on the best available evidence. This Pathway is intended to be applicable in any setting where care for patients with NAFLD is provided, including primary care, endocrine, obesity medicine, and gastroenterology practices.

Association of metabolic-bariatric surgery with long-term survival in adults with and without diabetes: a one-stage meta-analysis of matched cohort and prospective controlled studies with 174 772 participants

BACKGROUND

Metabolic-bariatric surgery delivers substantial weight loss and can induce remission or improvement of obesity-related risks and complications. However, more robust estimates of its effect on long-term mortality and life expectancy-especially stratified by pre-existing diabetes status-are needed to guide policy and facilitate patient counselling. We compared long-term survival outcomes of severely obese patients who received metabolic-bariatric surgery versus usual care.

METHODS

We did a prespecified one-stage meta-analysis using patient-level survival data reconstructed from prospective controlled trials and high-quality matched cohort studies. We searched PubMed, Scopus, and MEDLINE (via Ovid) for randomised trials, prospective controlled studies, and matched cohort studies comparing all-cause mortality after metabolic-bariatric surgery versus non-surgical management of obesity published between inception and Feb 3, 2021. We also searched grey literature by reviewing bibliographies of included studies as well as review articles. Shared-frailty (ie, random-effects) and stratified Cox models were fitted to compare all-cause mortality of adults with obesity who underwent metabolic-bariatric surgery compared with matched controls who received usual care, taking into account clustering of participants at the study level. We also computed numbers needed to treat, and extrapolated life expectancy using Gompertz proportional-hazards modelling. The study protocol is prospectively registered on PROSPERO, number CRD42020218472.

FINDINGS

Among 1470 articles identified, 16 matched cohort studies and one prospective controlled trial were included in the analysis. 7712 deaths occurred during 1·2 million patient-years. In the overall population consisting 174 772 participants, metabolic-bariatric surgery was associated with a reduction in hazard rate of death of 49·2% (95% CI 46·3-51·9, p<0·0001) and median life expectancy was 6·1 years (95% CI 5·2-6·9) longer than usual care. In subgroup analyses, both individuals with (hazard ratio 0·409, 95% CI 0·370-0·453, p<0·0001) or without (0·704, 0·588-0·843, p<0·0001) baseline diabetes who underwent metabolic-bariatric surgery had lower rates of all-cause mortality, but the treatment effect was considerably greater for those with diabetes (between-subgroup I² 95·7%, p<0·0001). Median life expectancy was 9·3 years (95% CI 7·1-11·8) longer for patients with diabetes in the surgery group than the non-surgical group, whereas the life expectancy gain was 5·1 years (2·0-9·3) for patients without diabetes. The numbers needed to treat to prevent one additional death over a 10-year time frame were 8·4 (95% CI 7·8-9·1) for adults with diabetes and 29·8 (21·2-56·8) for those without diabetes. Treatment effects did not appear to differ between gastric bypass, banding, and sleeve gastrectomy (I² 3·4%, p=0·36). By leveraging the results of this meta-analysis and other published data, we estimated that every 1·0% increase in metabolic-bariatric surgery utilisation rates among the global pool of metabolic-bariatric candidates with and without diabetes could yield 5·1 million and 6·6 million potential life-years, respectively.

INTERPRETATION

Among adults with obesity, metabolic-bariatric surgery is associated with substantially lower all-cause mortality rates and longer life expectancy than usual obesity management. Survival benefits are much more pronounced for people with pre-existing diabetes than those without.

FUNDING

None.

Management of Obesity in Adults with CKD

Obesity is a leading public health problem that currently affects over 650 million individuals worldwide. Although interest in the adverse effects of obesity has grown exponentially in recent years, less attention has been given to studying its management in individuals with CKD. This relatively unexplored area should be considered a high priority because of the rapid growth and high prevalence of obesity in the CKD population, its broad impact on health and outcomes, and its modifiable nature. This article begins to lay the groundwork in this field by providing a comprehensive overview that critically evaluates the available evidence related to obesity and kidney disease, identifies important gaps in our knowledge base, and integrates recent insights in the pathophysiology of obesity to help provide a way forward in establishing guidelines as a basis for managing obesity in CKD. Finally, the article includes a kidney-centric algorithm for management of obesity that can be used in clinical practice.

Endocannabinoid Receptor-1 and Sympathetic Nervous System Mediate the Beneficial Metabolic Effects of Gastric Bypass

The exact mechanisms underlying the metabolic effects of bariatric surgery remain unclear. Here, we demonstrate, using a combination of direct and indirect calorimetry, an increase in total resting metabolic rate (RMR) and specifically anaerobic RMR after Roux-en-Y gastric bypass (RYGB), but not sleeve gastrectomy (SG). We also show an RYGB-specific increase in splanchnic sympathetic nerve activity and "browning" of visceral mesenteric fat. Consequently, selective splanchnic denervation abolishes all beneficial metabolic outcomes of gastric bypass that involve changes in the endocannabinoid signaling within the small intestine. Furthermore, we demonstrate that administration of rimonabant, an endocannabinoid receptor-1 (CB1) inverse agonist, to obese mice mimics RYGB-specific effects on energy balance and splanchnic nerve activity. On the other hand, arachidonoylethanolamide (AEA), a CB1 agonist, attenuates the weight loss and metabolic signature of this procedure. These findings identify CB1 as a key player in energy regulation post-RYGB via a pathway involving the sympathetic nervous system.

Joint international consensus statement for ending stigma of obesity

People with obesity commonly face a pervasive, resilient form of social stigma. They are often subject to discrimination in the workplace as well as in educational and healthcare settings. Research indicates that weight stigma can cause physical and psychological harm, and that affected individuals are less likely to receive adequate care. For these reasons, weight stigma damages health, undermines human and social rights, and is unacceptable in modern societies. To inform healthcare professionals, policymakers, and the public about this issue, a multidisciplinary group of international experts, including representatives of scientific organizations, reviewed available evidence on the causes and harms of weight stigma and, using a modified Delphi process, developed a joint consensus statement with recommendations to eliminate weight bias. Academic institutions, professional organizations, media, public-health authorities, and governments should encourage education about weight stigma to facilitate a new public narrative about obesity, coherent with modern scientific knowledge.

GWAS on longitudinal growth traits reveals different genetic factors influencing infant, child, and adult BMI

Early childhood growth patterns are associated with adult health, yet the genetic factors and the developmental stages involved are not fully understood. Here, we combine genome-wide association studies with modeling of longitudinal growth traits to study the genetics of infant and child growth, followed by functional, pathway, genetic correlation, risk score, and colocalization analyses to determine how developmental timings, molecular pathways, and genetic determinants of these traits overlap with those of adult health. We found a robust overlap between the genetics of child and adult body mass index (BMI), with variants associated with adult BMI acting as early as 4 to 6 years old. However, we demonstrated a completely distinct genetic makeup for peak BMI during infancy, influenced by variation at the LEPR/LEPROT locus. These findings suggest that different genetic factors control infant and child BMI. In light of the obesity epidemic, these findings are important to inform the timing and targets of prevention strategies.

Polygenic Prediction of Weight and Obesity Trajectories from Birth to Adulthood

Severe obesity is a rapidly growing global health threat. Although often attributed to unhealthy lifestyle choices or environmental factors, obesity is known to be heritable and highly polygenic; the majority of inherited susceptibility is related to the cumulative effect of many common DNA variants. Here we derive and validate a new polygenic predictor comprised of 2.1 million common variants to quantify this susceptibility and test this predictor in more than 300,000 individuals ranging from middle age to birth. Among middle-aged adults, we observe a 13-kg gradient in weight and a 25-fold gradient in risk of severe obesity across polygenic score deciles. In a longitudinal birth cohort, we note minimal differences in birthweight across score deciles, but a significant gradient emerged in early childhood and reached 12 kg by 18 years of age. This new approach to quantify inherited susceptibility to obesity affords new opportunities for clinical prevention and mechanistic assessment.

A Randomized, Double-Blind, Placebo-Controlled Study of Gelesis100: A Novel Nonsystemic Oral Hydrogel for Weight Loss

OBJECTIVE

This study aims to assess the efficacy and safety of Gelesis100, a novel, nonsystemic, superabsorbent hydrogel to treat overweight or obesity.

METHODS

The Gelesis Loss Of Weight (GLOW) study was a 24-week, multicenter, randomized, double-blind, placebo-controlled study in patients with BMI ≥  27 and ≤ 40 kg/m2 and fasting plasma glucose ≥ 90 and ≤ 145 mg/dL. The co-primary end points were placebo-adjusted weight loss (superiority and 3% margin super-superiority) and at least 35% of patients in the Gelesis100 group achieving ≥ 5% weight loss.

RESULTS

Gelesis100 treatment caused greater weight loss over placebo (6.4% vs. 4.4%, P = 0.0007), achieving 2.1% superiority but not 3% super-superiority. Importantly, 59% of Gelesis100-treated patients achieved weight loss of ≥ 5%, and 27% achieved ≥ 10% versus 42% and 15% in the placebo group, respectively. Gelesis100-treated patients had twice the odds of achieving ≥ 5% and ≥ 10% weight loss versus placebo (adjusted OR: 2.0, P = 0.0008; OR: 2.1, P = 0.0107, respectively), with 5% responders having a mean weight loss of 10.2%. Patients with prediabetes or drug-naive type 2 diabetes had six times the odds of achieving ≥ 10% weight loss. Gelesis100 treatment had no apparent increased safety risks.

CONCLUSIONS

Gelesis100 is a promising new nonsystemic therapy for overweight and obesity with a highly desirable safety and tolerability profile.

Cost-effectiveness Analysis of Bariatric Surgery for Patients With Nonalcoholic Steatohepatitis Cirrhosis

IMPORTANCE

Obesity is the most common risk factor for nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease that can lead to cirrhosis and hepatocellular carcinoma. Weight loss can be an effective treatment for obesity and may slow the progression of advanced liver disease.

OBJECTIVE

To assess the cost-effectiveness of bariatric surgery in patients with NASH and compensated cirrhosis.

DESIGN, SETTING, AND PARTICIPANTS

This economic evaluation study used a Markov-based state-transition model to simulate the benefits and risks of laparoscopic sleeve gastrectomy (SG), laparoscopic Roux-en-Y gastric bypass (GB), and intensive lifestyle intervention (ILI) compared with usual care in patients with NASH and compensated cirrhosis and varying baseline weight (overweight, mild obesity, moderate obesity, and severe obesity). Patients faced varied risks of perioperative mortality and complications depending on the type of surgery they underwent. Data were collected on March 22, 2017.

MAIN OUTCOMES AND MEASURES

Life-years, quality-adjusted life-years (QALYs), costs (in 2017 $US), and incremental cost-effectiveness ratios (ICERs) were calculated.

RESULTS

Demographic characteristics of the patient population were based on a previously published prospective study (n = 161). Patients in the model were 41.0% female, and the base case age was 54 years. Compared with usual care, SG was associated with an increase in QALYs of 0.263 to 1.180 (bounds of ranges represent overweight to severe obesity); GB, 0.263 to 1.207; and ILI, 0.004 to 0.216. Sleeve gastrectomy was also associated with an increase in life-years of 0.693 to 1.930; GB, 0.694 to 1.947; and ILI, 0.012 to 0.114. With usual care, expected life-years in overweight, mild obesity, moderate obesity, and severe obesity were 12.939, 11.949, 10.976, and 10.095, respectively. With usual care, QALY in overweight was 6.418; mild obesity, 5.790; moderate obesity, 5.186; and severe obesity, 4.577. Sleeve gastrectomy was the most cost-effective option for patients across all weight classes assessed: ICER for SG in patients with overweight was $66 119 per QALY; mild obesity, $18 716 per QALY; moderate obesity, $10 274 per QALY; and severe obesity, $6563 per QALY. A threshold analysis on the procedure cost of GB found that for GB to be cost-effective, the cost of the surgery must be decreased from its baseline value of $28 734 by $4889 for mild obesity, by $3189 for moderate obesity, and by $2289 for severe obesity. In overweight patients, GB involved fewer QALYs than SG, and thus decreasing the cost of surgery would not result in cost-effectiveness.

CONCLUSIONS AND RELEVANCE

Bariatric surgery could be highly cost-effective in patients with NASH compensated cirrhosis and obesity or overweight. The findings from this analysis suggest that it can inform clinical trials evaluating the effect of bariatric procedures in patients with NASH cirrhosis, including those with a lower body mass index.

The Human Microbiome and Obesity: Moving beyond Associations

Mounting evidence indicates that the gut microbiome responds to diet, antibiotics, and other external stimuli with speed and high precision and in ways that impact a variety of metabolic conditions including obesity and non-alcoholic fatty liver disease. Despite a decade of research establishing a strong association between the gut microbiota and obesity in humans, a causal relationship and the underlying mechanism remain outstanding. Several technological and methodological limitations in obesity and microbiome research have made it difficult to establish causality in this complex relationship. Additionally, limited collaborative interaction between microbiome and obesity researchers has delayed progress. Here, we discuss the current status of microbiome research as it relates to understanding obesity from the perspective of both communities, outline the underlying research challenges, and suggest directions to advance the obesity-microbiome field as a whole, with particular emphasis on the development of microbiome-targeted therapies for obesity prevention and treatment.

Underdocumentation of Obesity by Medical Residents Highlights Challenges to Effective Obesity Care

OBJECTIVE

The goal of this study was to determine attitudes and practices of physicians in training with respect to the evaluation and treatment of obesity.

METHODS

Resident-generated admission and discharge notes of all 1,765 general medicine hospital admissions during 4 nonconsecutive months were analyzed, and any references to weight, obesity, BMI, adiposity, and body fat were identified. The full general resident cohort was then surveyed for perceptions and behaviors related to obesity.

RESULTS

Obesity was considered a highly important medical issue by 98.5% of residents; 90% correctly identified a class II obesity Stunkard phenotype, and 80% accurately calculated a BMI given height and weight in metric units. Residents overestimated inpatient obesity prevalence (estimate = 75%; actual = 35%) and the rate of obesity recording in the hospital admission note (estimate = 94%; actual = 49.5%). A BMI or current weight in the admission note or discharge summary was reported in none of the 1,765 patient records, and only 6% of the patients with obesity had obesity noted in either the inpatient admission or discharge assessment or plan.

CONCLUSIONS

Though residents recognize obesity and its clinical implications, it is underreported in the assessment of inpatients. This low level of documenting obesity and its impact on clinical care planning underscores a missed opportunity to establish appropriate referrals and initiate treatment at a clinically opportune time.

Hepatic connexin 32 associates with nonalcoholic fatty liver disease severity

Emerging data highlight the critical role for the innate immune system in the progression of nonalcoholic fatty liver disease (NAFLD). Connexin 32 (Cx32), the primary liver gap junction protein, is capable of modulating hepatic innate immune responses and has been studied in dietary animal models of steatohepatitis. In this work, we sought to determine the association of hepatic Cx32 with the stages of human NAFLD in a histologically characterized cohort of 362 patients with NAFLD. We also studied the hepatic expression of the genes and proteins known to interact with Cx32 (known as the connexome) in patients with NAFLD. Last, we used three independent dietary mouse models of nonalcoholic steatohepatitis to investigate the role of Cx32 in the development of steatohepatitis and fibrosis. In a univariate analysis, we found that Cx32 hepatic expression associates with each component of the NAFLD activity score and fibrosis severity. Multivariate analysis revealed that Cx32 expression most closely associated with the NAFLD activity score and fibrosis compared to known risk factors for the disease. Furthermore, by analyzing the connexome, we identified novel genes related to Cx32 that associate with NAFLD progression. Finally, we demonstrated that Cx32 deficiency protects against liver injury, inflammation, and fibrosis in three murine models of nonalcoholic steatohepatitis by limiting initial diet-induced hepatoxicity and subsequent increases in intestinal permeability. Conclusion: Hepatic expression of Cx32 strongly associates with steatohepatitis and fibrosis in patients with NAFLD. We also identify novel genes associated with NAFLD and suggest that Cx32 plays a role in promoting NAFLD development. (Hepatology Communications 2018;2:786-797).

Perceptions of Barriers to Effective Obesity Care: Results from the National ACTION Study

OBJECTIVE

ACTION (Awareness, Care, and Treatment in Obesity maNagement) examined obesity-related perceptions, attitudes, and behaviors among people with obesity (PwO), health care providers (HCPs), and employer representatives (ERs).

METHODS

A total of 3,008 adult PwO (BMI ≥ 30 by self-reported height and weight), 606 HCPs, and 153 ERs completed surveys in a cross-sectional design.

RESULTS

Despite several weight loss (WL) attempts, only 23% of PwO reported 10% WL during the previous 3 years. Many PwO (65%) recognized obesity as a disease, but only 54% worried their weight may affect future health. Most PwO (82%) felt "completely" responsible for WL; 72% of HCPs felt responsible for contributing to WL efforts; few ERs (18%) felt even partially responsible. Only 50% of PwO saw themselves as "obese," and 55% reported receiving a formal diagnosis of obesity. Despite HCPs' reported comfort with weight-related conversations, time constraints deprioritized these efforts. Only 24% of PwO had a scheduled follow-up to initial weight-related conversations. Few PwO (17%) perceived employer-sponsored wellness offerings as helpful in supporting WL.

CONCLUSIONS

Although generally perceived as a disease, obesity is not commonly treated as such. Divergence in perceptions and attitudes potentially hinders better management. This study highlights inconsistent understanding of the impact of obesity and need for both self-directed and medical management.

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

BACKGROUND

Despite growing evidence that bariatric/metabolic surgery powerfully improves type 2 diabetes (T2D), existing diabetes treatment algorithms do not include surgical options.

AIM

The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2D.

METHODS

A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal (MEDLINE [1 January 2005-30 September 2015]), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., 28-30 September 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee.

RESULTS

Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2D. Numerous randomized clinical trials, albeit mostly short/midterm, demonstrate that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2D in patients with class III obesity (BMI≥40 kg/m(2)) and in those with class II obesity (BMI 35.0-39.9 kg/m(2)) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for patients with T2D and BMI 30.0-34.9 kg/m(2) if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m(2) for Asian patients.

CONCLUSIONS

Although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2D and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.

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

BACKGROUND

Despite growing evidence that bariatric/metabolic surgery powerfully improves type 2 diabetes (T2D), existing diabetes treatment algorithms do not include surgical options.

AIM

The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2D.

METHODS

A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal (MEDLINE [1 January 2005-30 September 2015]), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., 28-30 September 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee.

RESULTS

Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2D. Numerous randomized clinical trials, albeit mostly short/midterm, demonstrate that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2D in patients with class III obesity (BMI ≥40 kg/m²) and in those with class II obesity (BMI 35.0-39.9 kg/m²) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for patients with T2D and BMI 30.0-34.9 kg/m² if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m² for Asian patients.

CONCLUSIONS

Although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2D and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.

Bariatric surgery for nonalcoholic steatohepatitis: A clinical and cost-effectiveness analysis

Nonalcoholic steatohepatitis (NASH) affects 2%-3% of the US population and is expected to become the leading indication for liver transplantation in the next decade. Bariatric surgery may be an effective but expensive treatment for NASH. Using a state-transition model, our analysis assessed the effectiveness and cost-effectiveness of surgery to manage NASH. We simulated the benefits and harms of laparoscopic Roux-en-Y gastric bypass surgery in patients defined by weight class (overweight, mild obesity, moderate obesity, and severe obesity) and fibrosis stage (F0-F3). Comparators included intensive lifestyle intervention (ILI) and no treatment. Quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios were calculated. Our results showed that surgery and ILI in obese patients (with F0-F3) increased QALYs by 0.678-2.152 and 0.452-0.618, respectively, compared with no treatment. Incremental cost-effectiveness ratios for surgery in all F0-F3 patients with mild, moderate, or severe obesity were $48,836/QALY, $24,949/QALY, and $19,222/QALY, respectively. In overweight patients (with F0-F3), surgery increased QALYs by 0.050-0.824 and ILI increased QALYs by 0.031-0.164. In overweight patients, it was cost-effective to reserve treatment only for F3 patients; the incremental cost-effectiveness ratios for providing surgery or ILI only to F3 patients were $30,484/QALY and $25,367/QALY, respectively.

CONCLUSIONS

Surgery was both effective and cost-effective for obese patients with NASH, regardless of fibrosis stage; in overweight patients, surgery increased QALYs for all patients regardless of fibrosis stage, but was cost-effective only for patients with F3 fibrosis; our results highlight the promise of bariatric surgery for treating NASH and underscore the need for clinical trials in this area. (Hepatology 2017;65:1156-1164).

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.

Endoscopic Duodenal Mucosal Resurfacing for the Treatment of Type 2 Diabetes: 6-Month Interim Analysis From the First-in-Human Proof-of-Concept Study

OBJECTIVE

To assess procedural safety and glycemic indices at 6 months in a first-in-human study of duodenal mucosal resurfacing (DMR), a novel, minimally invasive, upper endoscopic procedure involving hydrothermal ablation of the duodenal mucosa, in patients with type 2 diabetes and HbA_1c ≥7.5% (58 mmol/mol) on one or more oral antidiabetic agents.

RESEARCH DESIGN AND METHODS

Using novel balloon catheters, DMR was conducted on varying lengths of duodenum in anesthetized patients at a single medical center.

RESULTS

A total of 39 patients with type 2 diabetes (screening HbA_1c 9.5% [80 mmol/mol]; BMI 31 kg/m²) were treated and included in the interim efficacy analysis: 28 had a long duodenal segment ablated (LS; ∼9.3 cm treated) and 11 had a short segment ablated (SS; ∼3.4 cm treated). Overall, DMR was well tolerated with minimal gastrointestinal symptoms postprocedure. Three patients experienced duodenal stenosis treated successfully by balloon dilation. HbA_1c was reduced by 1.2% at 6 months in the full cohort (P < 0.001). More potent glycemic effects were observed among the LS cohort, who experienced a 2.5% reduction in mean HbA_1c at 3 months postprocedure vs. 1.2% in the SS group (P < 0.05) and a 1.4% reduction at 6 months vs. 0.7% in the SS group (P = 0.3). This occurred despite net medication reductions in the LS cohort between 0 and 6 months. Among LS patients with a screening HbA_1c of 7.5-10% (58-86 mmol/mol) and on stable antidiabetic medications postprocedure, HbA_1c was reduced by 1.8% at 6 months (P < 0.01).

CONCLUSIONS

Single-procedure DMR elicits a clinically significant improvement in hyperglycemia in patients with type 2 diabetes in the short-term, with acceptable safety and tolerability. Long-term safety, efficacy, and durability and possible mechanisms of action require further investigation.

Clinical Factors Associated With Remission of Obesity-Related Comorbidities After Bariatric Surgery

IMPORTANCE

Little is known about comorbidity remission after bariatric surgery during typical clinical care across diverse and geographically distributed populations.

OBJECTIVE

To estimate the improvement in obesity-related comorbidities after bariatric surgery and to identify clinical factors associated with these responses using a large representative population of patients.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included all patients (N = 33,718) with a recorded Current Procedural Terminology code for Roux-en-Y gastric bypass (RYGB) or adjustable gastric banding (AGB) in the MarketScan Commercial Claims and Encounters Medicare Supplemental Databases from January 1, 2005, to June 30, 2010, and who had continuous enrollment from 6 months or more before to 12 months after surgery.

MAIN OUTCOMES AND MEASURES

Comorbidities before and after surgery were identified using both diagnoses (from International Classification of Diseases, Ninth Revision [ICD-9] codes) and prescription drug fills. Remission was based on a record of the comorbidity within 6 months before surgery, without record of the condition 18 months after surgery, using both ICD-9 codes and medication fills, as applicable. Multivariable logistic regression models were developed to identify factors associated with remission of diabetes and hypertension.

RESULTS

Among the 33,718 patients, 13 comorbidities with at least 1% prevalence before surgery were identified. Both RYGB and AGB led to statistically and clinically significant reductions in these comorbidities; remission rates for all comorbidities were higher after RYGB than AGB. For comorbidities that could be defined using both ICD-9 and prescription drug fill codes, prevalence was higher before and lower after surgery when measured by fill codes. Diagnoses using ICD-9 codes, but not prescription fill codes, increased in the 3 months before surgery. In multivariable logistic regression models for remission of diabetes mellitus after RYGB and AGB, age (RYGB: odds ratio [OR], 0.976; 95% CI, 0.965-0.988 and AGB: OR, 0.982; 95% CI, 0.971-0.933), procedure year (RYGB: OR, 1.11; 95% CI, 1.012-1.218 and AGB: OR, 1.185; 95% CI, 1.039-1.351), preoperative insulin use (RYGB: OR, 0.14; 95% CI, 0.114-0.171; AGB: OR, 0.174; 95% CI, 0.131-0.230), preoperative sulfonylurea use (RYGB: OR, 0.616; 95% CI, 0.505-0.752 and AGB: OR, 0.449; 95% CI, 0.357-0.566), and other antidiabetic medication use (RYGB: OR, 0.747; 95% CI, 0.568-0.981 and AGB: OR, 0.506; 95% CI, 0.359-0.715) were significantly associated with response after both procedures. For remission of hypertension, age (RYGB: OR, 0.964; 95% CI, 0.957-0.972 and AGB: OR, 0.968; 95% CI, 0.959-0.977), number of preoperative antihypertensive medications (RYGB: OR, 0.104; 95% CI, 0.067-0.161 and AGB: OR, 0.239; 95% CI, 0.140-0.408), and preoperative diuretic use (RYGB: OR, 1.729; 95% CI, 1.462-2.045 and AGB: OR, 1.648; 95% CI, 1.380-1.967) were significantly associated with response after both procedures.

CONCLUSIONS AND RELEVANCE

Analysis of a large, representative administrative database confirmed established predictors and revealed novel variables associated with comorbidity remission after bariatric surgery. Incorporating these factors into clinical tools to assess an individual patient's risk-to-benefit profile for these procedures could enhance patient selection and the overall use of surgery for the treatment of obesity and metabolic disease.

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

BACKGROUND

Despite growing evidence that bariatric/metabolic surgery powerfully improves type 2 diabetes (T2D), existing diabetes treatment algorithms do not include surgical options.

AIM

The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2D.

METHODS

A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal (MEDLINE [1 January 2005-30 September 2015]), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., 28-30 September 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee.

RESULTS

Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2D. Numerous randomized clinical trials, albeit mostly short/midterm, demonstrate that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2D in patients with class III obesity (BMI ≥40 kg/m(2)) and in those with class II obesity (BMI 35.0-39.9 kg/m(2)) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for patients with T2D and BMI 30.0-34.9 kg/m(2) if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m(2) for Asian patients.

CONCLUSIONS

Although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2D and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.

Peripheral, but not central, GLP-1 receptor signaling is required for improvement in glucose tolerance after Roux-en-Y gastric bypass in mice

Roux-en-Y gastric bypass (RYGB) causes profound weight loss and remission of diabetes by influencing metabolic physiology, yet the mechanisms behind these clinical improvements remain undefined. After RYGB, levels of glucagon-like peptide-1 (GLP-1), a hormone that enhances insulin secretion and promotes satiation, are substantially elevated. Because GLP-1 signals in both the periphery and the brain to influence energy balance and glucose regulation, we aimed to determine the relative requirements of these systems to weight loss and improved glucose tolerance following RYGB surgery in mice. By pharmacologically blocking peripheral or central GLP-1R signaling, we examined whether GLP-1 action is necessary for the metabolic improvements observed after RYGB. Diet-induced obese mice underwent RYGB or sham operation and were implanted with osmotic pumps delivering the GLP-1R antagonist exendin-(9-39) (2 pmol·kg(-1)·min(-1) peripherally; 0.5 pmol·kg(-1)·min(-1) centrally) for up to 10 wk. Blockade of peripheral GLP-1R signaling partially reversed the improvement in glucose tolerance after RYGB. In contrast, fasting glucose and insulin sensitivity, as well as body weight, were unaffected by GLP-1R antagonism. Central GLP-1R signaling did not appear to be required for any of the metabolic improvements seen after this operation. Collectively, these results suggest a detectable but only modest role for GLP-1 in mediating the effects of RYGB and that this role is limited to its well-described action on glucose regulation.

Cortical and trabecular deterioration in mouse models of Roux-en-Y gastric bypass

Roux-en-Y gastric bypass (RYGB) is a profoundly effective treatment for severe obesity, but results in significant bone loss in patients. Developing a murine model that recapitulates this skeletal phenotype will provide a robust tool with which to study the physiologic mechanisms of this bone loss. We studied adult male C57BL/6J mice who underwent either RYGB or sham operation. Twelve weeks after surgery, we characterized biochemical bone markers (parathyroid hormone, PTH; C-telopeptide, CTX; and type 1 procollagen, P1NP) and bone microarchitectural parameters as measured by microcomputed tomography. RYGB-treated mice had significant trabecular and cortical bone deficits compared with sham-operated controls. Although adjustment for final body weight eliminated observed cortical differences, the trabecular bone volume fraction remained significantly lower in RYGB mice even after weight adjustment. PTH levels were similar between groups, but RYGB mice had significantly higher indices of bone turnover than sham controls. These data demonstrate that murine models of RYGB recapitulate patterns of bone loss and turnover that have been observed in human clinical studies. Future studies that exploit this murine model will help delineate the alterations in bone metabolism and mechanisms of bone loss after RYGB.

Weight Loss After RYGB Is Independent of and Complementary to Serotonin 2C Receptor Signaling in Male Mice

Roux-en-Y gastric bypass (RYGB) typically leads to substantial, long-term weight loss (WL) and diabetes remission, although there is a wide variation in response to RYGB among individual patients. Defining the pathways through which RYGB works should aid in the development of less invasive anti-obesity treatments, whereas identifying weight-regulatory pathways unengaged by RYGB could facilitate the development of therapies that complement the beneficial effects of surgery. Activation of serotonin 2C receptors (5-HT2CR) by serotonergic drugs causes WL in humans and animal models. 5-HT2CR are located on neurons that activate the melanocortin-4 receptors, which are essential for WL after RYGB. We therefore sought to determine whether 5-HT2CR signaling is also essential for metabolic effects of RYGB or whether it is a potentially complementary pathway, the activation of which could extend the benefits of RYGB. Diet-induced obese male mice deficient for the 5-HT2CR and their wild-type littermates underwent RYGB or sham operation. Both groups lost similar amounts of weight after RYGB, demonstrating that the improved metabolic phenotype after RYGB is 5-HT2CR independent. Consistent with this hypothesis, wild-type RYGB-treated mice lost additional weight after the administration of the serotonergic drugs fenfluramine and meta-chlorophenylpiperazine but not the nonserotonergic agent topiramate. The fact that RYGB does not depend on 5-HT2CR signaling suggests that there are important WL mechanisms not fully engaged by surgery that could potentially be harnessed for medical treatment. These results suggest a rational basis for designing medical-surgical combination therapies to optimize clinical outcomes by exploiting complementary physiological mechanisms of action.

The Role of Obesity Training in Medical School and Residency on Bariatric Surgery Knowledge in Primary Care Physicians

Objective. US primary care physicians are inadequately educated on how to provide obesity treatment. We sought to assess physician training in obesity and to characterize the perceptions, beliefs, knowledge, and treatment patterns of primary care physicians. Methods. We administered a cross-sectional web-based survey from July to October 2014 to adult primary care physicians in practices affiliated with the Massachusetts General Hospital (MGH). We evaluated survey respondent demographics, personal health habits, obesity training, knowledge of bariatric surgery care, perceptions, attitudes, and beliefs regarding the etiology of obesity and treatment strategies. Results. Younger primary care physicians (age 20-39) were more likely to have received some obesity training than those aged 40-49 (OR: 0.08, 95% CI: 0.008-0.822) or those 50+ (OR: 0.03, 95% CI: 0.004-0.321). Physicians who were young, had obesity, or received obesity education in medical school or postgraduate training were more likely to answer bariatric surgery knowledge questions correctly. Conclusions. There is a need for educational programs to improve physician knowledge and competency in treating patients with obesity. Obesity is a complex chronic disease, and it is important for clinicians to be equipped with the knowledge of the multiple treatment modalities that may be considered to help their patients achieve a healthy weight.

Weight loss, saline loading, and the natriuretic peptide system

Background

In epidemiologic studies, obesity has been associated with reduced natriuretic peptide (NP) concentrations. Reduced NP production could impair the ability of obese individuals to respond to salt loads, increasing the risk of hypertension and other disorders. We hypothesized that weight loss enhances NP production before and after salt loading.

Methods and Results

We enrolled 15 obese individuals (mean BMI 45±5.4 kg/m²) undergoing gastric bypass surgery. Before and 6 months after surgery, subjects were admitted to the clinical research center and administered a large‐volume intravenous saline challenge. Echocardiography and serial blood sampling were performed. From the pre‐operative visit to 6 months after surgery, subjects had a mean BMI decrease of 27%. At the 6‐month visit, N‐terminal pro‐atrial NP (Nt‐proANP) levels were 40% higher before, during, and after the saline infusion, compared with levels measured at the same time points during the pre‐operative visit (P<0.001). The rise in Nt‐pro‐ANP induced by the saline infusion (≈50%) was similar both before and after surgery (saline, P<0.001; interaction, P=0.2). Similar results were obtained for BNP and Nt‐proBNP; resting concentrations increased by 50% and 31%, respectively, after gastric bypass surgery. The increase in NP concentrations after surgery was accompanied by significant decreases in mean arterial pressure (P=0.004) and heart rate (P<0.001), and an increase in mitral annular diastolic velocity (P=0.02).

Conclusion

In obese individuals, weight loss is associated with a substantial increase in the “setpoint” of circulating NP concentrations. Higher NP concentrations could contribute to an enhanced ability to handle salt loads after weight loss.

Role of the microbiome in energy regulation and metabolism

Intestinal microbes regulate metabolic function and energy balance; an altered microbial ecology is believed to contribute to the development of several metabolic diseases. Relative species abundance and metabolic characteristics of the intestinal microbiota change substantially in those who are obese or have other metabolic disorders and in response to ingested nutrients or therapeutic agents. The mechanisms through which the intestinal microbiota and its metabolites affect host homeostasis are just beginning to be understood. We review the relationships between the intestinal microbiota and host metabolism, including energy intake, use, and expenditure, in relation to glucose and lipid metabolism. These associations, along with interactions among the intestinal microbiota, mucus layer, bile acids, and mucosal immune responses, reveal potential mechanisms by which the microbiota affect metabolism. We discuss how controlled studies involving direct perturbations of microbial communities in human and animal models are required to identify effective therapeutic targets in the microbiota.

Bone loss after bariatric surgery: discordant results between DXA and QCT bone density

Several studies, using dual-energy X-ray absorptiometry (DXA), have reported substantial bone loss after bariatric surgery. However, profound weight loss may cause artifactual changes in DXA areal bone mineral density (aBMD) results. Assessment of volumetric bone mineral density (vBMD) by quantitative computed tomography (QCT) may be less susceptible to such artifacts. We assessed changes in BMD of the lumbar spine and proximal femur prospectively for 1 year using DXA and QCT in 30 morbidly obese adults undergoing Roux-en-Y gastric bypass surgery and 20 obese nonsurgical controls. At 1 year, subjects who underwent gastric bypass surgery lost 37 ± 2 kg compared with 3 ± 2 kg lost in the nonsurgical controls (p < 0.0001). Spine BMD declined more in the surgical group than in the nonsurgical group whether assessed by DXA (-3.3 versus -1.1%, p = 0.034) or by QCT (-3.4 versus 0.2%, p = 0.010). Total hip and femoral neck aBMD declined significantly in the surgical group when assessed by DXA (-8.9 versus -1.1%, p < 0.0001 for the total hip and -6.1 versus -2.0%, p = 0.002 for the femoral neck), but no changes in hip vBMD were noted using QCT. Within the surgical group, serum P1NP and CTX levels increased by 82% ± 10% and by 220% ± 22%, respectively, by 6 months and remained elevated over 12 months (p < 0.0001 for all). Serum calcium, vitamin D, and PTH levels remained stable in both groups. We conclude that moderate vertebral bone loss occurs in the first year after gastric bypass surgery. However, striking declines in DXA aBMD at the proximal femur were not confirmed with QCT vBMD measurements. These discordant results suggest that artifacts induced by large changes in body weight after bariatric surgery affect DXA and/or QCT measurements of bone, particularly at the hip.

Obesity and liver disease: the epidemic of the twenty-first century

Obesity is a rapidly growing health problem that is associated with more than 65 comorbidities and results in substantially increased all-cause mortality. The increase of obesity has played an important role in the increasing prevalence of nonalcoholic fatty liver disease (NAFLD), the most common cause of liver disease in the United States. Understanding the prevalence, comorbidities, and pathogenesis of obesity provides an essential foundation for clinicians who care for individuals with NAFLD.

Conserved shifts in the gut microbiota due to gastric bypass reduce host weight and adiposity

Roux-en-Y gastric bypass (RYGB) results in rapid weight loss, reduced adiposity, and improved glucose metabolism. These effects are not simply attributable to decreased caloric intake or absorption, but the mechanisms linking rearrangement of the gastrointestinal tract to these metabolic outcomes are largely unknown. Studies in humans and rats have shown that RYGB restructures the gut microbiota, prompting the hypothesis that some of the effects of RYGB are caused by altered host-microbial interactions. To test this hypothesis, we used a mouse model of RYGB that recapitulates many of the metabolic outcomes in humans. 16S ribosomal RNA gene sequencing of murine fecal samples collected after RYGB surgery, sham surgery, or sham surgery coupled to caloric restriction revealed that alterations to the gut microbiota after RYGB are conserved among humans, rats, and mice, resulting in a rapid and sustained increase in the relative abundance of Gammaproteobacteria (Escherichia) and Verrucomicrobia (Akkermansia). These changes were independent of weight change and caloric restriction, were detectable throughout the length of the gastrointestinal tract, and were most evident in the distal gut, downstream of the surgical manipulation site. Transfer of the gut microbiota from RYGB-treated mice to nonoperated, germ-free mice resulted in weight loss and decreased fat mass in the recipient animals relative to recipients of microbiota induced by sham surgery, potentially due to altered microbial production of short-chain fatty acids. These findings provide the first empirical support for the claim that changes in the gut microbiota contribute to reduced host weight and adiposity after RYGB surgery.

Advantages of percent weight loss as a method of reporting weight loss after Roux-en-Y gastric bypass

OBJECTIVE

Although Roux-en-Y gastric bypass (RYGB) is an effective treatment for severe obesity, weight loss (WL) after this operation is highly variable. Accurate predictors of outcome would thus be useful in identifying those patients who would most benefit from this invasive therapy. WL has been characterized using several different metrics, including the number of BMI units lost (ΔBMI), percent baseline WL (%WL), and percent excess body WL (%EBWL). To identify clinically relevant predictors most sensitively, it is necessary to avoid confounding by other factors, including preoperative BMI (pBMI), the strongest known predictor of RYGB-induced WL.

DESIGN AND METHODS

To determine the WL measure least associated with pBMI, outcomes of 846 patients undergoing RYGB were analyzed.

RESULTS

Patients in this cohort had an average pBMI of 50.0 kg/m(2) at baseline. At weight nadir, they lost an average 19.4 kg/m(2), 38.7% WL, and 81.2% EBWL. pBMI was strongly and positively associated with ΔBMI at both 1 year (r = 0.56, P = 4.7 × 10(-51)) and nadir (r = 0.58, P = 2.8 × 10(-77)) and strongly but negatively associated with %EBWL at 1 year (r = -0.52, P = 3.8 × 10(-44)) and nadir (r = -0.45, P = 7.2×10(-43)). In contrast, pBMI was not significantly associated with %WL at 1 year (r = 0.04, P = 0.33) and only weakly associated at nadir (r = 0.13, P = 0.0002).

CONCLUSIONS

Of the metrics examined, %WL is the parameter describing WL after RYGB least influenced by pBMI. It thus improves comparison of WL outcomes across studies of patients undergoing surgery and facilitates the most sensitive identification of novel predictors of surgery-induced WL. We therefore is recommend that %WL be adopted more broadly in reporting weight loss after RYGB.

Endoscopic suturing for transoral outlet reduction increases weight loss after Roux-en-Y gastric bypass surgery

BACKGROUND & AIMS

Weight regain or insufficient loss after Roux-en-Y gastric bypass (RYGB) is common. This is partially attributable to dilatation of the gastrojejunostomy (GJ), which diminishes the restrictive capacity of RYGB. Endoluminal interventions for GJ reduction are being explored as alternatives to revision surgery. We performed a randomized, blinded, sham-controlled trial to evaluate weight loss after sutured transoral outlet reduction (TORe).

METHODS

Patients with weight regain or inadequate loss after RYGB and GJ diameter greater than 2 cm were assigned randomly to groups that underwent TORe (n = 50) or a sham procedure (controls, n = 27). Intraoperative performance, safety, weight loss, and clinical outcomes were assessed.

RESULTS

Subjects who received TORe had a significantly greater mean percentage weight loss from baseline (3.5%; 95% confidence interval, 1.8%-5.3%) than controls (0.4%; 95% confidence interval, 2.3% weight gain to 3.0% weight loss) (P = .021), using a last observation carried forward intent-to-treat analysis. As-treated analysis also showed greater mean percentage weight loss in the TORe group than controls (3.9% and 0.2%, respectively; P = .014). Weight loss or stabilization was achieved in 96% subjects receiving TORe and 78% of controls (P = .019). The TORe group had reduced systolic and diastolic blood pressure (P < .001) and a trend toward improved metabolic indices. In addition, 85% of the TORe group reported compliance with the healthy lifestyle eating program, compared with 53.8% of controls; 83% of TORe subjects said they would undergo the procedure again, and 78% said they would recommend the procedure to a friend. The groups had similar frequencies of adverse events.

CONCLUSIONS

A multicenter randomized trial provides Level I evidence that TORe reduces weight regain after RYGB. These results were achieved using a superficial suction-based device; greater levels of weight loss could be achieved with newer, full-thickness suturing devices. TORe is one approach to avoid weight regain; a longitudinal multidisciplinary approach with dietary counseling and behavioral changes are required for long-term results. ClinicalTrials.gov identifier: NCT00394212.

Weight loss after gastric bypass is associated with a variant at 15q26.1

The amount of weight loss attained after Roux-en-Y gastric bypass (RYGB) surgery follows a wide and normal distribution, and recent evidence indicates that this weight loss is due to physiological, rather than mechanical, mechanisms. To identify potential genetic factors associated with weight loss after RYGB, we performed a genome-wide association study (GWAS) of 693 individuals undergoing RYGB and then replicated this analysis in an independent population of 327 individuals undergoing RYGB. We found that a 15q26.1 locus near ST8SIA2 and SLCO3A1 was significantly associated with weight loss after RYGB. Expression of ST8SIA2 in omental fat of these individuals at baseline was significantly associated with weight loss after RYGB. Gene expression analysis in RYGB and weight-matched, sham-operated (WMS) mice revealed that expression of St8sia2 and Slco3a1 was significantly altered in metabolically active tissues in RYGB-treated compared to WMS mice. These findings provide strong evidence for specific genetic influences on weight loss after RYGB and underscore the biological nature of the response to RYGB.

Inverse regulation of inflammation and mitochondrial function in adipose tissue defines extreme insulin sensitivity in morbidly obese patients

Obesity is associated with insulin resistance, a major risk factor for type 2 diabetes and cardiovascular disease. However, not all obese individuals are insulin resistant, which confounds our understanding of the mechanistic link between these conditions. We conducted transcriptome analyses on 835 obese subjects with mean BMI of 48.8, on which we have previously reported genetic associations of gene expression. Here, we selected ~320 nondiabetic (HbA(1c) <7.0) subjects and further stratified the cohort into insulin-resistant versus insulin-sensitive subgroups based on homeostasis model assessment-insulin resistance. An unsupervised informatics analysis revealed that immune response and inflammation-related genes were significantly downregulated in the omental adipose tissue of obese individuals with extreme insulin sensitivity and, to a much lesser extent, in subcutaneous adipose tissue. In contrast, genes related to β-oxidation and the citric acid cycle were relatively overexpressed in adipose of insulin-sensitive patients. These observations were verified by querying an independent cohort of our published dataset of 37 subjects whose subcutaneous adipose tissue was sampled before and after treatment with thiazolidinediones. Whereas the immune response and inflammation pathway genes were downregulated by thiazolidinedione treatment, β-oxidation and citric acid cycle genes were upregulated. This work highlights the critical role that omental adipose inflammatory pathways might play in the pathophysiology of insulin resistance, independent of body weight.

Isolated duodenal exclusion increases energy expenditure and improves glucose homeostasis in diet-induced obese rats

Roux-en-Y gastric bypass (RYGB) in rodent models reduces food intake (FI), increases resting energy expenditure (EE), and improves glycemic control. We have shown that mimicking the duodenal component of RYGB by implantation of a 10-cm endoluminal sleeve device (ELS-10) induces weight loss and improves glycemic control in diet-induced obese (DIO) rats. We sought to determine the mechanisms and structural requirements of these effects. We examined the effects of ELS-10 devices implanted in male DIO rats on body weight, food intake (FI), meal patterns, total and resting EE, and multiple parameters of glucose homeostasis, comparing them with sham-operated (SO) rats and with SO rats weight matched to the ELS-10-treated group. To determine the extent of duodenal exclusion required to influence metabolic outcomes, we compared the effects of implanting 10-, 4-, or 1-cm ELS devices. ELS-10 rats exhibited 13% higher total and 9% higher resting EE than SO controls. ELS-10 rats also exhibited enhanced postprandial GLP-1 secretion and improved glucose tolerance and insulin sensitivity out of proportion to the effects of weight loss alone. Implantation of 4- or 1-cm ELS devices had no effect on EE and limited effects on glucose homeostasis. Complete duodenal exclusion with ELS-10 induces weight loss by decreasing FI and increasing EE and improves glycemic control through weight loss-independent mechanisms. Thus signals originating in the proximal small intestine appear to exert a direct influence on the physiological regulation of EE and glucose homeostasis. Their selective manipulation could provide effective new therapies for obesity and diabetes that mimic the benefits of RYGB.

Coding and Reimbursement for Weight Loss Surgery: Best Practice Recommendations

OBJECTIVE

To review the use and usefulness of billing codes for services related to weight loss surgery (WLS) and to examine third party reimbursement policies for these services.

RESEARCH METHODS AND PROCEDURES

The Task Group carried out a systematic search of MEDLINE, the Internet, and the trade press for publications on WLS, coding, reimbursement, and coding and reimbursement policy. Twenty-eight articles were each reviewed and graded using a system based on established evidence-based models. The Massachusetts Dietetics Association provided reimbursement data for nutrition services. Three suppliers of laparoscopic WLS equipment provided summaries of coding and reimbursement information. WLS program directors were surveyed for information on use of procedure codes related to WLS.

RESULTS

Recommendations focused on correcting or improving on the current lack of congruity among coding practices, reimbursement policies, and accepted clinical practice; lack of uniform coding and reimbursement data across institutions; inconsistent and/or inaccurate diagnostic and billing codes; inconsistent insurance reimbursement criteria; and inability to leverage reimbursement and coding data to track outcomes, identify best practices, and perform accurate risk-benefit analyses.

DISCUSSION

Rapid changes in the prevalence of obesity, our understanding of its clinical impact, and the technologies for surgical treatment have yet to be adequately reflected in coding, coverage, and reimbursement policies. Issues identified as key to effective change include improved characterization of the risks, benefits, and costs of WLS; anticipation and monitoring of technological advances; encouragement of consistent patterns of insurance coverage; and promotion of billing codes for WLS procedures that facilitate accurate tracking of clinical use and outcomes.

Melanocortin-4 receptor signaling is required for weight loss after gastric bypass surgery

CONTEXT

Roux-en-Y gastric bypass (RYGB) is one of the most effective long-term therapies for the treatment of severe obesity. Recent evidence indicates that RYGB effects weight loss through multiple physiological mechanisms, including changes in energy expenditure, food intake, food preference, and reward pathways.

OBJECTIVE

Because central melanocortin signaling plays an important role in the regulation of energy homeostasis, we investigated whether genetic disruption of the melanocortin-4 receptor (MC4R) in rodents and humans affects weight loss after RYGB.

METHODS AND RESULTS

Here we report that MC4R(-/-) mice lost substantially less weight after surgery than wild-type animals, indicating that MC4R signaling is necessary for the weight loss effects of RYGB in this model. Mice heterozygous for MC4R remain fully responsive to gastric bypass. To determine whether mutations affect surgically induced weight loss in humans, we sequenced the MC4R gene in 972 patients undergoing RYGB. Patients heterozygous for MC4R mutations exhibited the same magnitude and distribution of postoperative weight loss as patients without such mutations, suggesting that although two normal copies of the MC4R gene are necessary for normal weight regulation, a single normal copy of the MC4R gene is sufficient to mediate the weight loss effects of RYGB.

CONCLUSIONS

MC4R is the first gene identified that is required for the sustained effects of bariatric surgery. The need for MC4R signaling for the weight loss effects of RYGB in mice underscores the physiological mechanisms of action of this procedure and demonstrates that RYGB both influences and is dependent on the normal pathways that regulate energy balance.

Obesity epidemic: overview, pathophysiology, and the intensive care unit conundrum

Obesity is one of the leading causes of preventable death in the United States, second only to smoking. The annual number of deaths attributed to obesity is estimated to be as high as 400,000. Nearly 70% of the adult U.S. population is overweight or obese. The historical viewpoint toward obesity has deemed it to be a lifestyle choice or characterological flaw. However, given the emerging research into the development of obesity and its related complications, our perspective is changing. It is now clear that obesity is a heterogeneous disease with many different subtypes, which involves an interplay between genetic and environmental factors. The current epidemic of obesity is the result of an obesogenic environment (which includes energy-dense foods and a lack of physical activity) in individuals who have a genetic susceptibility for developing obesity. The pathophysiology associated with weight gain is much more complex than originally thought. The heterogeneous nature of the disease makes the development of treatment strategies for obesity difficult. Obesity in general is associated with increased all-cause mortality and cause-specific mortality (from cardiovascular, diabetic, hepatic, and neoplastic causes). Yet despite increased overall mortality rates, current evidence suggests that when these same patients are admitted to the intensive care unit (ICU), the obesity provides some protection against mortality. At present, there is no clear explanation for this obesity conundrum in critical illness.

Calcium and vitamin D supplementation is associated with decreased abdominal visceral adipose tissue in overweight and obese adults

BACKGROUND

Several studies suggest that calcium and vitamin D (CaD) may play a role in the regulation of abdominal fat mass.

OBJECTIVE

This study investigated the effect of CaD-supplemented orange juice (OJ) on weight loss and reduction of visceral adipose tissue (VAT) in overweight and obese adults (mean ± SD age: 40.0 ± 12.9 y).

DESIGN

Two parallel, double-blind, placebo-controlled trials were conducted with either regular or reduced-energy (lite) orange juice. For each 16-wk trial, 171 participants were randomly assigned to 1 of 2 groups. The treatment groups consumed three 240-mL glasses of OJ (regular or lite) fortified with 350 mg Ca and 100 IU vitamin D per serving, and the control groups consumed either unfortified regular or lite OJ. Computed tomography scans of VAT and subcutaneous adipose tissue were performed by imaging a single cut at the lumbar 4 level.

RESULTS

After 16 wk, the average weight loss (∼2.45 kg) did not differ significantly between groups. In the regular OJ trial, the reduction of VAT was significantly greater (P = 0.024) in the CaD group (-12.7 ± 25.0 cm(2)) than in the control group (-1.3 ± 13.6 cm(2)). In the lite OJ trial, the reduction of VAT was significantly greater (P = 0.039) in the CaD group (-13.1 ± 18.4 cm(2)) than in the control group (-6.4 ± 17.5 cm(2)) after control for baseline VAT. The effect of calcium and vitamin D on VAT remained highly significant when the results of the 2 trials were combined (P = 0.007).

CONCLUSIONS

The findings suggest that calcium and/or vitamin D supplementation contributes to a beneficial reduction of VAT. This trial is registered at clinicaltrial.gov as NCT00386672, NCT01363115.