Combination therapy with naltrexone and bupropion for obesity reduces total and visceral adiposity

The effect of obesity pharmacotherapy on body composition, including muscle mass

Obesity pharmacotherapy represents a promising approach to treating obesity and may provide benefits beyond weight loss alone. Maintaining or even increasing muscle mass during weight loss is important to overall health, metabolic function and weight loss maintenance. Drugs such as liraglutide, semaglutide, tirzepatide, and naltrexone/bupropion have shown significant weight loss effects, and emerging evidence suggests they may also have effects on body composition, particularly a positive influence on muscle mass. However, further research is needed to fully understand the mechanism of action of these drugs and their effects on muscle mass. Clinicians should consider these factors when developing an obesity treatment plan for an individual patient.

Changes in lipid profile and glucose metabolism following administration of bupropion alone or in combination with naltrexone: A systematic review and meta-regression analysis

BACKGROUND

Considering the conflicting effects of bupropion on parameters related to metabolic syndrome including glucose metabolism and lipid profile, in this meta-analysis study, we investigated the effects of this drug alone or in combination with naltrexone on glucose metabolism and lipid profile.

METHODS

Scopus, PubMed/Medline, Web of Science and Embase databases were searched using standard keywords to identify all controlled trials investigating effects of bupropion alone and combined with naltrexone on the glucose and lipid profile. Pooled weighted mean difference and 95% confidence intervals were achieved by random-effects model.

RESULTS

Twelve studies with 5152 participants' were included in this article. The pooled findings showed that bupropion alone or in combination with naltrexone would significantly reduce glucose (weighted mean difference (WMD): -2.25 mg/dL, 95% confidence interval (CI): -4.10, -0.40), insulin (WMD: -4.06 μU/mL, 95% CI: -6.09, -2.03), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD: -0.58, 95% CI: -0.98, -0.19), triglyceride (TG) (WMD: -11.78 mg/dL, 95% CI: -14.48 to -9.08) and increase high-density lipoprotein (HDL) (WMD: 2.68 mg/dL, 95% CI: 2.13 to 3.24). A Greater reduction in glucose levels was observed with duration >26 weeks. Dose of bupropion intake ≤360 mg and intervention for more than 26 weeks decreased insulin level significantly. With regard to lipid profile, reduction of triglycerides is more significant with dose of bupropion greater than 360 mg and a shorter intervention length equal to 26 weeks.

CONCLUSIONS

The addition of combination therapies such as bupropion and naltrexone to lifestyle modification can significantly improve glucose metabolism and some lipid parameters.

Comparison of the Efficacy of Anti-Obesity Medications in Real-World Practice

Purpose

Anti-obesity medications (AOMs), along with lifestyle interventions, are effective means of inducing and maintaining weight loss in patients with obesity. Although the efficacy of AOMs has been reported, there have been no direct comparisons of these drugs. Therefore, in the present study, we aimed to compare the efficacy of all the AOMs available in Korea in a real-world setting.

Patients and Methods

The body weight and composition of 205 adults treated with phentermine, phentermine/topiramate, liraglutide, naltrexone/bupropion, lorcaserin, or orlistat for at least 6 months were analyzed at 2 month intervals. The prevalence of the achievement of a ≥5% weight loss and the changes in body composition were compared between participants using each AOM at each visit.

Results

A total of 132 (64.4%) participants achieved ≥5% weight loss within 6 months (prevalence of ≥5% weight loss after 6 months: phentermine, 87.2%; phentermine/topiramate, 67.7%; liraglutide, 58.1%; naltrexone/bupropion, 35.3%; lorcaserin, 75%; orlistat, 50%). At each visit, after adjustment for age, sex, and baseline body weight, phentermine use was associated with a significantly higher prevalence of ≥5% weight loss than the use of the other AOMs, except for liraglutide. There were significant differences in the body weight, body mass index and body fat mass among the AOM groups by visit (P for interaction <0.05), but not in their waist circumference, skeletal muscle mass, percentage body fat, or visceral fat area.

Conclusion

All the AOMs were effective at inducing and maintaining weight loss, in the absence of significant changes in muscle mass, over a 6 month period, and the short-term use of phentermine and the long-term use of phentermine/topiramate or liraglutide would be practical choices for the treatment of obesity. However, further, large-scale studies are necessary to confirm these findings.

Adipose Tissue, Non-Communicable Diseases, and Physical Exercise: An Imperfect Triangle

The study of adipose tissue has received considerable attention due to its importance not just in maintaining body energy homeostasis but also in playing a role in a number of other physiological processes. Beyond storing energy, adipose tissue is important in endocrine, immunological, and neuromodulatory functions, secreting hormones that participate in the regulation of energy homeostasis. An imbalance of these functions will generate structural and functional changes in the adipose tissue, favoring the secretion of deleterious adipocytokines that induce a pro-inflammatory state, allowing the development of metabolic and cardiovascular diseases and even some types of cancer. A common theme worldwide has been the development of professional guidelines for the control and treatment of obesity, with emphasis on hypocaloric diets and exercise. The aim of this review is to examine the pathophysiological mechanisms of obesity, considering the relationship among adipose tissue and two aspects that contribute positively or negatively to keeping a healthy body homeostasis, namely, exercise and noninfectious diseases. We conclude that the relationship of these aspects does not have homogeneous effects among individuals. Nevertheless, it is possible to establish some common mechanisms, like a decrease in pro-inflammatory markers in the case of exercise, and an increase in chronic inflammation in non-communicable diseases. An accurate diagnosis might consider the particular variables of a patient, namely their molecular profile and how it affects its metabolism, routines, and lifestyle; their underling health conditions; and probably even the constitution of their microbiome. We foresee that the development and accessibility of omics approaches and precision medicine will greatly improve the diagnosis, treatment, and successful outcomes for obese patients.

Visceral adipose tissue and residual cardiovascular risk: a pathological link and new therapeutic options

Obesity is a heterogeneous disease that affects almost one-third of the global population. A clear association has been established between obesity and cardiovascular disease (CVD). However, CVD risk is known to be related more to the local distribution of fat than to total body fat. Visceral adipose tissue (VAT) in particular has a high impact on CVD risk. This manuscript reviews the role of VAT in residual CV risk and the available therapeutic strategies for decreasing residual CV risk related to VAT accumulation. Among the many pathways involved in residual CV risk, obesity and particularly VAT accumulation play a major role by generating low-grade systemic inflammation, which in turn has a high prognostic impact on all-cause mortality and myocardial infarction. In recent years, many therapeutic approaches have been developed to reduce body weight. Orlistat was shown to reduce both weight and VAT but has low tolerability and many drug-drug interactions. Naltrexone-bupropion combination lowers body weight but has frequent side effects and is contraindicated in patients with uncontrolled hypertension. Liraglutide and semaglutide, glucagon-like peptide 1 (GLP-1) agonists, are the latest drugs approved for the treatment of obesity, and both have been shown to induce significant body weight loss. Liraglutide, semaglutide and other GLP-1 agonists also showed a positive effect on CV outcomes in diabetic patients. In addition, liraglutide showed to specifically reduce VAT and inflammatory biomarkers in obese patients without diabetes. GLP-1 agonists are promising compounds to limit inflammation in human visceral adipocytes.

Pharmacologic treatment of obesity

Background: Obesity and obesity-related comorbidities are increasingly being recognized as significant threats to global health. Pharmacological treatments are required in patients in whom lifestyle modifications fail to achieve an individual’s target body weight.Current Concepts: Currently available short-term anti-obesity drugs, including phentermine, diethylpropion, and mazindol (all sympathetic nerve agents) serve as appetite suppressants. Prescription anti-obesity drugs currently approved for long-term use in Korea include orlistat, phentermine/topiramate, naltrexone/bupropion, and liraglutide. Semaglutide (2.4 mg) has recently been authorized by the United States Food and Drug Administration for treatment of obesity. Research is underway to introduce novel drugs that are likely to revolutionize the global anti-obesity drug market. Representative examples include tirzepatide, a dual agonist of glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide and cagrilintide, an amylin analogue. These drugs have shown excellent weight-loss effects with tolerable adverse effects in phase II or III clinical trials, with significantly greater effectiveness than that of currently available medications.Discussion and Conclusion: Despite the introduction of a variety of anti-obesity drugs, these agents are not currently widely used in all patients with obesity owing to high costs, adverse effects, and unsatisfactory effectiveness. Further research is warranted to determine the effects and adverse effects of combinations of available drugs, including tirzepatide and cagrilintide, along with the development of newer agents that may show a different mechanism of action.

Mesolimbic opioid-dopamine interaction is disrupted in obesity but recovered by weight loss following bariatric surgery

Obesity is a growing burden to health and the economy worldwide. Obesity is associated with central µ-opioid receptor (MOR) downregulation and disruption of the interaction between MOR and dopamine D₂ receptor (D₂R) system in the ventral striatum. Weight loss recovers MOR function, but it remains unknown whether it also recovers aberrant opioid-dopamine interaction. Here we addressed this issue by studying 20 healthy non-obese and 25 morbidly obese women (mean BMI 41) eligible for bariatric surgery. Brain MOR and D₂R availability were measured using positron emission tomography (PET) with [¹¹C]carfentanil and [¹¹C]raclopride, respectively. Either Roux-en-Y gastric bypass or sleeve gastrectomy was performed on obese subjects according to standard clinical treatment. 21 obese subjects participated in the postoperative PET scanning six months after bariatric surgery. In the control subjects, MOR and D₂R availabilities were associated in the ventral striatum (r = .62) and dorsal caudate (r = .61). Preoperatively, the obese subjects had disrupted association in the ventral striatum (r = .12) but the unaltered association in dorsal caudate (r = .43). The association between MOR and D₂R availabilities in the ventral striatum was recovered (r = .62) among obese subjects following the surgery-induced weight loss. Bariatric surgery and concomitant weight loss recover the interaction between MOR and D₂R in the ventral striatum in the morbidly obese. Consequently, the dysfunctional opioid-dopamine interaction in the ventral striatum is likely associated with an obese phenotype and may mediate excessive energy uptake. Striatal opioid-dopamine interaction provides a feasible target for pharmacological and behavioral interventions for treating obesity.

An open-label trial on the efficacy and tolerability of naltrexone/bupropion SR for treating altered eating behaviours and weight loss in binge eating disorder

PURPOSE

Binge eating disorder (BED) has a considerable clinical relevance by virtue of its high numerous psychiatric and medical comorbidities; among the latter, the most frequent is obesity. Available treatments for BED have shown frequent relapse of binges or weight regain in the long term. The new combination of naltrexone and bupropion sustained release (NB) has proved to be effective for weight loss among obese patients. As NB acts on hypothalamic and reward circuits, that seem involved in the pathogenesis and maintenance of BED symptoms, this study aims to evaluate the efficacy of NB in improving pathological eating behavior and losing weight in BED patients.

METHODS

In this preliminary study, 23 obese-BED patients and a control group of 20 obese non-BED patients (respectively, Groups 1 and 2) who had previously undergone at least 5 unsuccessful weight-loss programs were treated with NB in addition to modified life style. Evaluation at t0 and after 16 weeks of treatment (t1) included anthropometric measurement, eating behavior assessment and psychopathological questionnaires (EDE-Q, BES, YFAS, BDI and STAI).

RESULTS

A significant and similar weight loss (ΔBMI% ≈ 8%) was evident for both groups. Pathological eating behavior (i.e., binge, grazing, emotional eating, craving for carbohydrates, and post-dinner eating), BES score and YFAS severity significantly improved, especially among BED. NB was well tolerated and drop-out rate was low.

CONCLUSION

Treatment with NB, in addition to a reduced-calorie diet and increased physical activity, seems an effective and well-tolerated option for improving pathological eating behavior and losing weight in obese-BED patients.

LEVEL OF EVIDENCE

Level III case-control study.

Safety and efficacy of naltrexone for weight loss in adult patients - a systematic review

INTRODUCTION

This is a report of a systematic review of the safety and efficacy of naltrexone or naltrexone/bupropion on weight loss.

MATERIAL AND METHODS

The databases Medline, PubMed, and Embase as well as the Cochrane Controlled Trials Register for randomized controlled trials were searched for studies published from January 1966 to January 2018. A meta-analysis, randomised controlled trials, controlled trials, uncontrolled trials, cohort studies and open-label studies were analysed.

RESULTS

Of 191 articles, 14 fulfilled the inclusion criteria: 1 meta-analysis, 10 randomized controlled trials, and 3 studies without randomization were found. In these studies, the efficacy and safety of naltrexone/bupropion in obesity were analysed. In the majority of these studies, patients with at least 5% or 10% weight loss, as a primary outcome, were investigated. Generally, naltrexone/bupropion treatment can be a promising therapy for obese patients, including when combined with mental health treatment.

CONCLUSIONS

Based on these studies, it can be said that naltrexone/bupropion treatment is effective in the weight loss of overweight subjects. The naltrexone/bupropion treatment was well tolerated by the patients, and side effects were rarely reported.

Comprehensive Review of Current and Upcoming Anti-Obesity Drugs

Obesity is among the leading causes of morbidity and mortality worldwide and its prevalence continues to increase globally. Because obesity is a chronic, complex, and heterogeneous disease influenced by genetic, developmental, biological, and environmental factors, it is necessary to approach obesity with an integrated and comprehensive treatment strategy. As it is difficult to achieve and sustain successful long-term weight loss in most patients with obesity through lifestyle modifications (e.g., diet, exercise, and behavioral therapy), pharmacological approaches to the treatment of obesity should be considered as an adjunct therapy. Currently, four drugs (orlistat, naltrexone extended-release [ER]/bupropion ER, phentermine/topiramate controlled-release, and liraglutide) can be used long-term (>12 weeks) to promote weight loss by suppressing appetite or decreasing fat absorption. Pharmacotherapy for obesity should be conducted according to a proper assessment of the clinical evidence and customized to individual patients considering the characteristics of each drug and comorbidities associated with obesity. In this review, we discuss the mechanisms of action, efficacy, and safety of these available long-term anti-obesity drugs and introduce other potential agents under investigation. Furthermore, we discuss the need for research on personalized obesity medicine.

Naltrexone + Bupropion Combination for the Treatment of Binge-eating Disorder with Obesity: A Randomized, Controlled Pilot Study

PURPOSE

Binge-eating disorder (BED), the most prevalent eating disorder, is associated strongly with obesity and functional impairments. Few evidence-based treatments for BED exist; a pharmacotherapy effective in reducing both binge eating and weight needs to be identified. This placebo-controlled double-blind pilot RCT evaluated the acute effects of naltrexone + bupropion (NB) on BED with obesity and examined the longer-term effects through 6-month follow-up after the discontinuation of medication.

METHODS

Twenty-two adult patients with BED were randomized to receive 12 weeks of double-blind treatment with fixed-dose NB (naltrexone + bupropion XL 50/300 mg) or placebo. Independent (blinded) researcher-clinicians evaluated patients at major outcome time points (baseline, posttreatment, and 6-month follow-up after the treatment period); patients were also evaluated for the tracking of course/tolerability throughout treatments and at 3-month follow-up. Primary outcomes were changes from baseline in binge-eating frequency and percentage weight. Secondary outcomes were changes in eating-disorder psychopathology and depression.

FINDINGS

A total of 22 patients were enrolled (86.4% women; mean age, 50.4 years), with 77.3% of patients completing treatments; completion rates (NB, 83.3%; placebo, 70.0%) and adverse events did not differ significantly between NB and placebo. Analyses revealed significant reductions from baseline in binge-eating, eating-disorder psychopathology, depression, and weight during treatment, but these changes with NB did not differ significantly from those with placebo. The percentage of patients who attained 3% weight loss was significantly greater with NB than with placebo (45.5% vs 0%); weight-loss and binge-eating reductions were significantly correlated in the group that received NB. At 6-month follow-up, outcomes remained improved relative to baseline, with no significant differences between NB and placebo.

IMPLICATIONS

The findings from this pilot RCT suggest that NB was well-tolerated in these patients with BED and comorbid obesity. Most outcomes were not statistically different between NB and placebo. A larger-scale, adequately powered RCT is needed for determining the efficacy of NB in the treatment of BED. ClinicalTrials.gov identifier: NCT02317744.

Diabesity: the combined burden of obesity and diabetes on heart disease and the role of imaging

Diabesity is a term used to describe the combined adverse health effects of obesity and diabetes mellitus. The worldwide dual epidemic of obesity and type 2 diabetes is an important public health issue. Projections estimate a sixfold increase in the number of adults with obesity in 40 years and an increase in the number of individuals with diabetes to 642 million by 2040. Increased adiposity is the strongest risk factor for developing diabetes. Early detection of the effects of diabesity on the cardiovascular system would enable the optimal implementation of effective therapies that prevent atherosclerosis progression, cardiac remodelling, and the resulting ischaemic heart disease and heart failure. Beyond conventional imaging techniques, such as echocardiography, CT and cardiac magnetic resonance, novel post-processing tools and techniques provide information on the biological processes that underlie metabolic heart disease. In this Review, we summarize the effects of obesity and diabetes on myocardial structure and function and illustrate the use of state-of-the-art multimodality cardiac imaging to elucidate the pathophysiology of myocardial dysfunction, prognosticate long-term clinical outcomes and potentially guide treatment strategies.

Current Long-Term Pharmacotherapies for the Management of Obesity

Obesity is a serious and growing worldwide health challenge associated with type 2 diabetes mellitus, cardiovascular disease, osteoarthritis, some cancers, sleep apnea, asthma, and nonalcoholic fatty liver. The Korean Society for the Study of Obesity recommends that pharmacotherapy should be considered when intensive lifestyle modifications fail to achieve a weight reduction in obese patients with a body mass index ≥25 kg/m². Long-term medications for obesity have traditionally fallen into two major categories: centrally acting anorexiant medications and peripherally acting medications, such as orlistat. In this paper, we provide an overview of the anti-obesity medications currently available for the long-term and individualized treatment of obesity.

Sarcopenic obesity in older adults: aetiology, epidemiology and treatment strategies

The prevalence of obesity in combination with sarcopenia (the age-related loss of muscle mass and strength or physical function) is increasing in adults aged 65 years and older. A major subset of adults over the age of 65 is now classified as having sarcopenic obesity, a high-risk geriatric syndrome predominantly observed in an ageing population that is at risk of synergistic complications from both sarcopenia and obesity. This Review discusses pathways and mechanisms leading to muscle impairment in older adults with obesity. We explore sex-specific hormonal changes, inflammatory pathways and myocellular mechanisms leading to the development of sarcopenic obesity. We discuss the evolution, controversies and challenges in defining sarcopenic obesity and present current body composition modalities used to assess this condition. Epidemiological surveys form the basis of defining its prevalence and consequences beyond comorbidity and mortality. Current treatment strategies, and the evidence supporting them, are outlined, with a focus on calorie restriction, protein supplementation and aerobic and resistance exercises. We also describe weight loss-induced complications in patients with sarcopenic obesity that are relevant to clinical management. Finally, we review novel and potential future therapies including testosterone, selective androgen receptor modulators, myostatin inhibitors, ghrelin analogues, vitamin K and mesenchymal stem cell therapy.

Centrally Acting Agents for Obesity: Past, Present, and Future

For many years, obesity was believed to be a condition of overeating that could be resolved through counseling and short-term drug treatment. Obesity was not recognized as a chronic disease until 1985 by the scientific community, and 2013 by the medical community. Pharmacotherapy for obesity has advanced remarkably since the first class of drugs, amphetamines, were approved for short-term use. Most amphetamines were removed from the obesity market due to adverse events and potential for addiction, and it became apparent that obesity pharmacotherapies were needed that could safely be administered over the long term. This review of central nervous system (CNS) acting anti-obesity drugs evaluates current therapies such as phentermine/topiramate, which act through multiple neurotransmitter pathways to reduce appetite. In the synergistic mechanism of bupropion/naltrexone, naltrexone blocks the feed-back inhibitory circuit of bupropion to give greater weight loss. Lorcaserin, a selective agonist of a serotonin receptor that regulates food intake, and the glucagon-like-peptide-1 (GLP-1) receptor agonist liraglutide are reviewed. Future drugs include tesofensine, a potent triple reuptake inhibitor in Phase III trials for obesity, and semaglutide, an oral GLP-1 analog approved for diabetes and currently in trials for obesity. Another potential new pharmacotherapy, setmelanotide, is a melanocortin-4 receptor agonist, which is still in an early stage of development. As our understanding of the communication between the CNS, gut, adipose tissue, and other organs evolves, it is anticipated that obesity drug development will move toward new centrally acting combinations and then to drugs acting on peripheral target tissues.

Bariatric Surgery Resistance: Using Preoperative Lifestyle Medicine and/or Pharmacology for Metabolic Responsiveness

Bariatric surgery is an effective and durable treatment for individuals with obesity and its associated comorbidities. However, not all patients meet weight loss and/or cardiometabolic goals following bariatric surgery, suggesting that some people are bariatric surgery resistant. The reason for this resistance is unclear, but potential factors, such as adiposity-derived inflammation, insulin resistance, hyperglycemia, and aerobic fitness prior to surgery, have been related to blunted surgery responsiveness. Exercise, diet, and/or pharmacology are effective at reducing inflammation and improving insulin action as well as physical function. Herein, we present data that supports the novel hypothesis that intervening prior to surgery can enhance disease resolution in people who are resistant to bariatric surgery.

Drugs Involved in Dyslipidemia and Obesity Treatment: Focus on Adipose Tissue

Metabolic syndrome can be defined as a state of disturbed metabolic homeostasis characterized by visceral obesity, atherogenic dyslipidemia, arterial hypertension, and insulin resistance. The growing prevalence of metabolic syndrome will certainly contribute to the burden of cardiovascular disease. Obesity and dyslipidemia are main features of metabolic syndrome, and both can present with adipose tissue dysfunction, involved in the pathogenic mechanisms underlying this syndrome. We revised the effects, and underlying mechanisms, of the current approved drugs for dyslipidemia and obesity (fibrates, statins, niacin, resins, ezetimibe, and orlistat; sibutramine; and diethylpropion, phentermine/topiramate, bupropion and naltrexone, and liraglutide) on adipose tissue. Specifically, we explored how these drugs can modulate the complex pathways involved in metabolism, inflammation, atherogenesis, insulin sensitivity, and adipogenesis. The clinical outcomes of adipose tissue modulation by these drugs, as well as differences of major importance for clinical practice between drugs of the same class, were identified. Whether solutions to these issues will be found in further adjustments and combinations between drugs already in use or necessarily in new advances in pharmacology is not known. To better understand the effect of drugs used in dyslipidemia and obesity on adipose tissue not only is challenging for physicians but could also be the next step to tackle cardiovascular disease.

Phenotypes of Obesity: How it Impacts Management

PURPOSE OF REVIEW

The worldwide prevalence of obesity is increasing. Obesity is strongly associated with many chronic health conditions that have been shown to improve with weight loss. However, counseling patients on weight loss can be challenging. Identifying specific aspects of weight management may personalize the conversation about weight loss and better address the individual patient's health goals and perceived barriers to change.

RECENT FINDINGS

Physical and behavioral phenotypes are being identified to better tailor treatment recommendations, given lack of efficacy of currently available interventions. The current review provides a summary of the evidence behind the management of several recognized clinical phenotypes, to include body fat distribution (e.g., central obesity), muscle mass (e.g., sarcopenic obesity of the elderly), and problematic eating behaviors (e.g., cravings). Identifying specific aspects of weight management may personalize the conversation about weight loss and better address the individual patient's health goals and perceived barriers to change.

Regulation of visceral and epicardial adipose tissue for preventing cardiovascular injuries associated to obesity and diabetes

Nowadays, obesity is seriously increasing in most of the populations all over the world, and is associated with the development and progression of high-mortality diseases such as type-2 diabetes mellitus (T2DM) and its subsequent cardiovascular pathologies. Recent data suggest that both body fat distribution and adipocyte phenotype, can be more determinant for fatal outcomes in obese patients than increased general adiposity. In particular, visceral adiposity is significantly linked to long term alterations on different cardiac structures, and in developed forms of myocardial diseases such as hypertensive and ischaemic heart diseases, and diabetic cardiomyopathy. Interestingly, this depot may be also related to epicardial fat accumulation through secretion of lipids, adipokines, and pro-inflammatory and oxidative factors from adipocytes. Thus, visceral adiposity and its white single-lipid-like adipocytes, are risk factors for different forms of heart disease and heart failure, mainly in higher degree obese subjects. However, under specific stimuli, some of these adipocytes can transdifferentiate to brown multi-mitochondrial-like adipocytes with anti-inflammatory and anti-apoptotic proprieties. Accordingly, in order to improve potential cardiovascular abnormalities in obese and T2DM patients, several therapeutic strategies have been addressed to modulate the visceral and epicardial fat volume and phenotypes. In addition to lifestyle modifications, specific genetic manipulations in adipose tissue and administration of PPARγ agonists or statins, have improved fat volume and phenotype, and cardiovascular failures. Furthermore, incretin stimulation reduced visceral and epicardial fat thickness whereas increased formation of brown adipocytes, alleviating insulin resistance and associated cardiovascular pathologies.

Effects of lorcaserin on fat and lean mass loss in obese and overweight patients without and with type 2 diabetes mellitus: the BLOSSOM and BLOOM-DM studies

Body composition was determined using dual-energy X-ray absorptiometry (DXA) in a subset of patients without (BLOSSOM) and with (BLOOM-DM) type 2 diabetes who received diet and exercise counselling along with either lorcaserin 10 mg twice daily or placebo. DXA scans were performed on study day 1 (baseline), week 24 and week 52. Baseline demographics of the subpopulations (without diabetes, n = 189; with diabetes, n = 63) were similar between studies and representative of their study populations. At week 52, patients without diabetes on lorcaserin lost significantly more fat mass relative to those on placebo (-12.06% vs -5.93%; p = 0.008). In patients with diabetes, fat mass was also decreased with lorcaserin relative to placebo (-9.87% vs -1.65%; p < 0.05). More fat mass was lost in the trunk region with lorcaserin compared with placebo (without diabetes: -3.31% vs -2.05%; with diabetes: -3.65% vs -0.36%). Weight loss with lorcaserin was associated with a greater degree of fat mass loss than lean mass loss, and most of the fat mass lost for patients without and with diabetes was from the central region of the body.

Type 2 Diabetes Treatment in the Patient with Obesity

Lifestyle modification is the cornerstone treatment of type 2 diabetes in the obese patient, and is highly effective at promoting glucose regulation. However, many individuals struggle over time to maintain optimal glycemic control and/or body weight with lifestyle modification. Therefore, additional therapeutic approaches are needed. Pharmacologic interventions have shown promising results for obesity-related diabetes complications. Not surprisingly though lifestyle modification and pharmacology may become ineffective for treating diabetes over time. Bariatric surgery is considered by some, but not all, to be the most effective and durable treatment for combating obesity. In fact many patients with type 2 diabetes have normalized glucose concentrations within days postoperation. Taken together, treatment of obesity in the patient with type 2 diabetes requires a multi-faceted approach.

Evolution of pharmacological obesity treatments: focus on adverse side-effect profiles

Pharmacotherapy directed toward reducing body weight may provide benefits for both curbing obesity and lowering the risk of obesity-associated comorbidities; however, many weight loss medications have been withdrawn from the market because of serious adverse effects. Examples include pulmonary hypertension (aminorex), cardiovascular toxicity, e.g. flenfluramine-induced valvopathy, stroke [phenylpropanolamine (PPA)], excess non-fatal cardiovascular events (sibutramine), and neuro-psychiatric issues (rimonabant; approved in Europe, but not in the USA). This negative experience has helped mould the current drug development and approval process for new anti-obesity drugs. Differences between the US Food and Drug Administration (FDA) and the European Medicines Agency, however, in perceptions of risk-benefit considerations for individual drugs have resulted in discrepancies in approval and/or withdrawal of weight-reducing medications. Thus, two drugs recently approved by the FDA, i.e. lorcaserin and phentermine + topiramate extended release, are not available in Europe. In contrast, naltrexone sustained release (SR)/bupropion SR received FDA approval, and liraglutide 3.0 mg was recently approved in both the USA and Europe. Regulatory strategies adopted by the FDA to manage the potential for uncommon but potentially serious post-marketing toxicity include: (i) risk evaluation and mitigation strategy programmes; (ii) stipulating post-marketing safety trials; (iii) considering responder rates and limiting cumulative exposure by discontinuation if weight loss is not attained within a reasonable timeframe; and (iv) requiring large cardiovascular outcome trials before or after approval. We chronicle the adverse effects of anti-obesity pharmacotherapy and consider how the history of high-profile toxicity issues has shaped the current regulatory landscape for new and future weight-reducing drugs.

Effects of additional exercise training on epicardial, intra-abdominal and subcutaneous adipose tissue in major depressive disorder: A randomized pilot study

OBJECTIVE

Major depressive disorder (MDD) is associated with increased amounts of intra-abdominal and epicardial adipose tissue, risk factors for the development of cardio-metabolic disorders. Exercise has been shown to reduce intra-abdominal fat in different conditions such as obesity and diabetes mellitus, thereby reducing cardio-metabolic risks. Therefore we examined the effects of exercise on adipose tissue compartments in patients with MDD.

METHODS

Of thirty depressed patients included, twenty received supervised exercise training, and ten received no specific training. Volumes of subcutaneous, intra-abdominal and epicardial adipose tissue were measured using magnetic resonance imaging, and factors constituting the metabolic syndrome were determined.

RESULTS

Significant effects of the training condition were observed on the amount of epicardial adipose tissue (P=0.017), subcutaneous adipose tissue (P=0.023), weight (P=0.047), body-mass index (P=0.04), high density lipoproteins (P=0.021) and the number of metabolic syndrome factors (P=0.018). The amount of intra-abdominal adipose tissue decreased slightly, although not significantly, in the exercise group.

CONCLUSION

Exercise training reduces the amount of visceral, in particular epicardial adipose tissue, in patients with MDD, and ameliorates factors constituting the metabolic syndrome. Given the high prevalence of cardio-metabolic disorders in major depression, exercise training may be recommended as an additional treatment component.

Current and emerging medications for overweight or obesity in people with comorbidities

Recently, the recognition of obesity as a complex disease that requires chronic management has become more widespread. There has also been a movement away from a focus on body mass index alone, and toward the management of obesity-related comorbidities as well as excess weight. This article examines the current and emerging pharmacological options for weight management in people with overweight or obesity who have, or are at a high risk of, weight-related comorbidities. In the USA, the current options for pharmacological weight management are phentermine (indicated for short-term use only), orlistat, combined phentermine/topiramate extended release, lorcaserin, naltrexone/bupropion and liraglutide 3.0 mg. Currently, orlistat, naltrexone/bupropion and liraglutide 3.0 mg are approved in Europe. All of the above-mentioned medications have shown weight-loss efficacy versus placebo. Those approved for long-term weight management have also been associated with improvements in weight-related comorbidities, such as hypertension, prediabetes, diabetes or dyslipidaemia, or related biomarkers. As with all drugs, the safety and tolerability profiles of medications for weight management should be considered alongside their efficacy to ensure correct use. Additional medications for weight management that are in clinical development include bupropion/zonisamide and beloranib. The field of obesity treatment is advancing with a number of medications being recently approved, and with other pharmacological options emerging.

Clinical Management of Type 2 Diabetes Mellitus after Bariatric Surgery

Bariatric surgery has emerged as an effective treatment for type 2 diabetes in the setting of obesity, with recent clinical trials demonstrating biochemical remission (i.e., euglycemia) in up to 40 % of subjects at 3 years post-surgery. Conversely, these trials also highlight that a significant proportion of individuals undergoing bariatric surgery experience residual diabetes (i.e., they do not achieve remission or experience diabetes recurrence). The management of residual diabetes following surgery requires personalized attention, yet limited evidence exists on which to base clinical decisions. Hence, we aim to review the evidence that does exist and propose clinical management strategies in patients with persistent hyperglycemia following bariatric surgery.

Efficacy comparison of medications approved for chronic weight management

For the first time, patients who are obese are able to benefit from 5 different FDA approved pharmacologic agents for chronic weight management. Although weight loss from all of these medications was limited to 5% to 10% of total body weight loss in the Phase III clinical trials, patients are capable of losing more weight when a cumulative approach of diet, exercise, and multiple medications are used. A pilot study of adding phentermine to lorcaserin yielded double the weight loss than lorcaserin alone. A higher percentage of total body weight is lost with use of combination phentermine/topiramate compared to orlistat, lorcaserin, and bupropion/naltrexone but there are more contraindications to its use and potential cardiovascular adverse effects due to adrenergic agonism. Lorcaserin and bupropion/naltrexone yielded similar weight loss but carry different adverse effect profiles and interactions with other psychiatric medications may preclude use of one over the other. When choosing a medication for obesity, several factors need to be considered, such as comorbidities, medication interactions, and risk of potential adverse effects.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Combating the dual burden: therapeutic targeting of common pathways in obesity and type 2 diabetes

The increasing prevalence of obesity is contributing substantially to the ongoing epidemic of type 2 diabetes. Abdominal adiposity, a feature of ectopic fat syndrome, is associated with silent inflammation, abnormal hormone secretion, and various metabolic disturbances that contribute to insulin resistance and insulin secretory defects, resulting in type 2 diabetes, and induce a toxic pattern that leads to cardiovascular disease, liver pathologies, and cancer. Despite the importance of weight control strategies in the prevention and management of type 2 diabetes, long-term results from lifestyle or drug interventions are generally disappointing. Furthermore, most of the classic glucose-lowering drugs have a side-effect of weight gain, which renders the management of most overweight or obese people with type 2 diabetes even more challenging. Many anti-obesity pharmacological drugs targeting central control of appetite were withdrawn from the market because of safety concerns. The gastrointestinal lipase inhibitor orlistat was the only anti-obesity drug available until the recent US, but not European, launch of phentermine-controlled-release topiramate and lorcaserin. Improved knowledge about bodyweight regulation opens new prospects for the potential use of peptides derived from the gut or the adipose tissue. Combination therapy will probably be necessary to avoid compensatory mechanisms and potentiate initial weight loss while avoiding weight regain. New glucose-lowering treatments, especially glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter-2 inhibitors, offer advantages over traditional antidiabetic drugs by promoting weight loss while improving glucose control. In this Review, we explore the overlapping pathophysiology and also how various treatments can, alone or in combination, combat the dual burden of obesity and type 2 diabetes.

Naltrexone sustained-release/bupropion sustained-release for the management of obesity: review of the data to date

Obesity is an emerging disease worldwide. Changes in living habits, especially with increased consumption of high-calorie foods and decreased levels of physical activity, lead to an energy imbalance that brings weight gain. Overweight and obesity are major risk factors for several chronic diseases (including cardiovascular diseases, diabetes, and cancer), reduce quality of life, and are associated with higher mortality. For all these reasons, it is of the utmost importance that the trend be reversed and obese people enabled to lose weight. It is known that eating a healthy diet and exercising regularly can help prevent obesity, but data show that in many cases these steps are not enough. This is the reason why, over the last few decades, several antiobesity drugs have been developed. However, the disappointing results demonstrated for the vast majority of them have not discouraged the pharmaceutical industry from continuing to look for an effective drug or combination of drugs. The systematic review presented here focuses on naltrexone sustained-release/bupropion sustained-release combination (Contrave^®). We conclude from the current published reports that its effectiveness in the treatment of obesity can be estimated as a placebo-subtracted weight loss of around 4.5%. This weight reduction is moderate but similar to other antiobesity drugs. The safety profile of this combination is acceptable, despite additional data regarding cardiovascular disease being needed.

Targeting central melanocortin receptors: a promising novel approach for treating alcohol abuse disorders

The melanocortin (MC) peptides are produced centrally by propiomelanocortin (POMC) neurons within the arcuate nucleus of the hypothalamus and act through five seven-transmembrane G-protein coupled melanocortin receptor (MCR) subtypes. The MC3R and MC4R subtypes, the most abundant central MCRs, are widely expressed in brain regions known to modulate neurobiological responses to ethanol, including regions of the hypothalamus and extended amygdala. Agouti-related protein (AgRP), also produced in the arcuate nucleus, is secreted in terminals expressing MCRs and functions as an endogenous MCR antagonist. This review highlights recent genetic and pharmacological findings that have implicated roles for the MC and AgRP systems in modulating ethanol consumption. Ethanol consumption is associated with significant alterations in the expression levels of various MC peptides/protein, which suggests that ethanol-induced perturbations of MC/AgRP signaling may modulate excessive ethanol intake. Consistently, MCR agonists decrease, and AgRP increases, ethanol consumption in mice. MCR agonists fail to blunt ethanol intake in mutant mice lacking the MC4R, suggesting that the protective effects of MCR agonists are modulated by the MC4R. Interestingly, recent evidence reveals that MCR agonists are more effective at blunting binge-like ethanol intake in mutant mice lacking the MC3R, suggesting that the MC3R has opposing effects on the MC4R. Finally, mutant mice lacking AgRP exhibit blunted voluntary and binge-like ethanol drinking, consistent with pharmacological studies. Collectively, these preclinical observations provide compelling evidence that compounds that target the MC system may provide therapeutic value for treating alcohol abuse disorders and that the utilization of currently available MC-targeting compounds- such as those being used to treat eating disorders- may be used as effective treatments to this end.

Naltrexone/bupropion for obesity: an investigational combination pharmacotherapy for weight loss

The mechanism of action of the combination therapy, naltrexone/bupropion (NB), for obesity has not been fully described to date. Weight loss attempts rarely result in long-term success. This is likely a result of complex interactions among multiple peripheral and CNS systems that defend against weight loss, and may explain the overwhelming lack of effective obesity treatments. NB is an investigational combination therapy for obesity that was developed based on evidence that obesity involves alterations in the hypothalamic melanocortin system as well as brain reward systems that influence food craving and mood. Naltrexone and bupropion both have actions in these brain regions that may cause them to influence food intake, food craving, and other aspects of eating behavior that affect body weight. We review the individual actions of naltrexone and bupropion in brain hypothalamic and reward systems, and describe the current in vitro, in vivo, and clinical evidence for how NB influences food intake and produces weight loss.

Effects of naltrexone sustained-release/bupropion sustained-release combination therapy on body weight and glycemic parameters in overweight and obese patients with type 2 diabetes

OBJECTIVE

To assess the efficacy and safety of 32 mg naltrexone sustained-release (SR)/360 mg bupropion SR (NB) in overweight/obese individuals with type 2 diabetes with or without background oral antidiabetes drugs.

RESEARCH DESIGN AND METHODS

This was a 56-week, double-blind, placebo-controlled study in which 505 patients received standardized lifestyle intervention and were randomized 2:1 to NB or placebo. Coprimary end points were percent weight change and achievement of ≥5% weight loss. Secondary end points included achievement of HbA1c <7% (53 mmol/mol), achievement of weight loss ≥10%, and change in HbA1c, waist circumference, fasting blood glucose, and lipids.

RESULTS

In the modified intent-to-treat population (54% female, 80% Caucasian, and mean age 54 years, weight 106 kg, BMI 37 kg/m(2), and HbA1c 8.0% [64 mmol/mol]), NB resulted in significantly greater weight reduction (-5.0 vs. -1.8%; P < 0.001) and proportion of patients achieving ≥5% weight loss (44.5 vs. 18.9%, P < 0.001) compared with placebo. NB also resulted in significantly greater HbA1c reduction (-0.6 vs. -0.1% [6.6 vs. 1.1 mmol/mol]; P < 0.001), percent of patients achieving HbA1c <7% (53 mmol/mol) (44.1 vs. 26.3%; P < 0.001), and improvement in triglycerides and HDL cholesterol compared with placebo. NB was associated with higher incidence of nausea (42.3 vs. 7.1%), constipation (17.7 vs. 7.1%), and vomiting (18.3 vs. 3.6%). No difference was observed between groups in the incidence of depression, suicidal ideation, or hypoglycemia.

CONCLUSIONS

NB therapy in overweight/obese patients with type 2 diabetes induced weight loss, which was associated with improvements in glycemic control and select cardiovascular risk factors and was generally well tolerated with a safety profile similar to that in patients without diabetes.