A one-year randomized trial of lorcaserin for weight loss in obese and overweight adults: the BLOSSOM trial

Exploratory Literature Meta-Analysis to Characterize the Relationship Between Early and Longer Term Body Weight Loss for Antiobesity Compounds

The presented analysis was performed to characterize the relationship between treatment-related early (week 4) and longer term (3-6 months) weight loss to understand the potential utility of 4-week proof-of-mechanism studies in the early decision-making process during clinical development of new antiobesity compounds. A regression-based meta-analysis was performed leveraging publically available clinical outcomes data to (1) characterize the within-trial relationship between treatment-related early and longer term body weight loss and (2) identify and quantify key covariate effects on this relationship. Data from 89 randomized clinical trials with 209 treatment arms, representing observations from 54 461 patients and 9 treatments, were available for the meta-analysis. Results indicated that (1) there is a correlation between treatment-related early and longer term body weight loss (r > 0.9), (2) baseline body weight influences the relationship between early and longer term weight loss, whereas comorbidity such as type 2 diabetes mellitus, class of drugs including GLP-1 analogues and the antiobesity compounds lorcaserin or phentermine/topiramate showed no significant effects on this relationship. The model was externally evaluated with data from the investigational compound beloranib, for which longer term weight loss could be successfully predicted based on early response data. Based on these results, the identified strong relationship between treatment-related early and longer term weight loss appears to be independent of mechanism of action. Thus, findings from this analysis can optimize design of clinical studies and facilitate development of new anti-obesity compounds.

Lorcaserin Use in the Management of Morbid Obesity in a Pre-Liver Transplant Patient

Management of obesity and decompensated cirrhosis in those requiring liver transplantation (LT) is a challenging dilemma. Because of concerns for perioperative complications, many centers avoid transplant in those with a body mass index (BMI) greater than 40 kg/m(2) . Bariatric surgery is associated with increased risk attributable to complications of portal hypertension, including variceal rupture. Therefore, weight loss and LT options are limited. Several new classes of weight loss drugs are commercially available, including the anoretic, lorcaserin. This case illustrates the successful use of lorcaserin in a morbidly obese individual with decompensated cirrhosis evaluated for LT listing. (Hepatology 2016;64:301-302).

Lorcaserin and CP-809101 reduce motor impulsivity and reinstatement of food seeking behavior in male rats: Implications for understanding the anti-obesity property of 5-HT2C receptor agonists

RATIONALE

The 5-HT2C receptor agonist lorcaserin (Belviq®) has been approved by the FDA for the treatment of obesity. Impulsivity is a contributory feature of some eating disorders.

OBJECTIVE

Experiments investigated the effect of lorcaserin and the highly selective 5-HT2C agonist CP-809101 on measures of impulsivity and on reinstatement of food-seeking behaviour, a model of dietary relapse. The effect of both drugs on 22-h deprivation-induced feeding was also examined, as was the effect of prefeeding in each impulsivity test.

RESULTS

Lorcaserin (0.3-0.6 mg/kg SC) and CP-809101 (0.6-1 mg/kg SC) reduced premature responding in rats trained on the 5-CSRTT and improved accuracy in a Go-NoGo task by reducing false alarms. At equivalent doses, both drugs also reduced reinstatement for food-seeking behaviour. Neither drug altered impulsive choice measured in a delay-discounting task. Lorcaserin (1-3 mg/kg SC) and CP-809101 (3-6 mg/kg SC) reduced deprivation-induced feeding but only at higher doses.

CONCLUSIONS

These results suggest that in addition to previously reported effects on satiety and reward, altered impulse control may represent a contributory factor to the anti-obesity property of 5-HT2C receptor agonists. Lorcaserin may promote weight loss by improving adherence to dietary regimens in individuals otherwise prone to relapse and may be beneficial in cases where obesity is associated with eating disorders tied to impulsive traits, such as binge eating disorder.

Association of Pharmacological Treatments for Obesity With Weight Loss and Adverse Events: A Systematic Review and Meta-analysis

IMPORTANCE

Five medications have been approved for the management of obesity, but data on comparative effectiveness are limited.

OBJECTIVE

To compare weight loss and adverse events among drug treatments for obesity using a systematic review and network meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, Scopus, and Cochrane Central from inception to March 23, 2016; clinical trial registries.

STUDY SELECTION

Randomized clinical trials conducted among overweight and obese adults treated with US Food and Drug Administration-approved long-term weight loss agents (orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, or liraglutide) for at least 1 year compared with another active agent or placebo.

DATA EXTRACTION AND SYNTHESIS

Two investigators identified studies and independently abstracted data using a predefined protocol. A Bayesian network meta-analysis was performed and relative ranking of agents was assessed using surface under the cumulative ranking (SUCRA) probabilities. Quality of evidence was assessed using GRADE criteria.

MAIN OUTCOMES AND MEASURES

Proportions of patients with at least 5% weight loss and at least 10% weight loss, magnitude of decrease in weight, and discontinuation of therapy because of adverse events at 1 year.

RESULTS

Twenty-eight randomized clinical trials with 29 018 patients (median age, 46 years; 74% women; median baseline body weight, 100.5 kg; median baseline body mass index, 36.1) were included. A median 23% of placebo participants had at least 5% weight loss vs 75% of participants taking phentermine-topiramate (odds ratio [OR], 9.22; 95% credible interval [CrI], 6.63-12.85; SUCRA, 0.95), 63% of participants taking liraglutide (OR, 5.54; 95% CrI, 4.16-7.78; SUCRA, 0.83), 55% taking naltrexone-bupropion (OR, 3.96; 95% CrI, 3.03-5.11; SUCRA, 0.60), 49% taking lorcaserin (OR, 3.10; 95% CrI, 2.38-4.05; SUCRA, 0.39), and 44% taking orlistat (OR, 2.70; 95% CrI, 2.34-3.09; SUCRA, 0.22). All active agents were associated with significant excess weight loss compared with placebo at 1 year-phentermine-topiramate, 8.8 kg (95% CrI, -10.20 to -7.42 kg); liraglutide, 5.3 kg (95% CrI, -6.06 to -4.52 kg); naltrexone-bupropion, 5.0 kg (95% CrI, -5.94 to -3.96 kg); lorcaserin, 3.2 kg (95% CrI, -3.97 to -2.46 kg); and orlistat, 2.6 kg (95% CrI, -3.04 to -2.16 kg). Compared with placebo, liraglutide (OR, 2.95; 95% CrI, 2.11-4.23) and naltrexone-bupropion (OR, 2.64; 95% CrI, 2.10-3.35) were associated with the highest odds of adverse event-related treatment discontinuation. High attrition rates (30%-45% in all trials) were associated with lower confidence in estimates.

CONCLUSIONS AND RELEVANCE

Among overweight or obese adults, orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, and liraglutide, compared with placebo, were each associated with achieving at least 5% weight loss at 52 weeks. Phentermine-topiramate and liraglutide were associated with the highest odds of achieving at least 5% weight loss.

Prevention of type 2 Diabetes Mellitus: Potential of pharmacological agents

People with impaired glucose tolerance or impaired fasting glucose, or "pre-diabetes", are at high risk for progression to type 2 diabetes, as are those with metabolic syndrome or a history of gestational diabetes. Both glucose-lowering and anti-obesity pharmacotherapies have been studied to determine if the onset of type 2 diabetes can be delayed or prevented. Here we review the available data in the field. The most common theme is the reduction in insulin resistance, such as with weight loss, decreasing demands on the beta cell to improve insulin secretion and prolong its function. Overall, therapies which decrease diabetes incidence in high-risk populations delay the onset of diabetes but do not correct the underlying beta cell defect.

Management of obesity

A modern approach to obesity acknowledges the multifactorial determinants of weight gain and the health benefits to be derived from weight loss. Foundational to any weight loss effort is lifestyle change, diet, and increased physical activity. The approach should be a high quality diet to which patients will adhere accompanied by an exercise prescription describing frequency, intensity, type, and time with a minimum of 150 min moderate weekly activity. For patients who struggle with weight loss and who would receive health benefit from weight loss, management of medications that are contributing to weight gain and use of approved medications for chronic weight management along with lifestyle changes are appropriate. Medications approved in the USA or European Union are orlistat, naltrexone/bupropion, and liraglutide; in the USA, lorcaserin and phentermine/topiramate are also available. Surgical management (gastric banding, sleeve gastrectomy, and Roux-en Y gastric bypass) can produce remarkable health improvement and reduce mortality for patients with severe obesity.

Bariatric Left Gastric Artery Embolization for the Treatment of Obesity: A Review of Gut Hormone Involvement in Energy Homeostasis

OBJECTIVE

The global population is becoming more overweight and obese, leading to increases in associated morbidity and mortality rates. Advances in catheter-directed embolotherapy offer the potential for the interventional radiologist to make a contribution to weight loss. Left gastric artery embolization reduces the supply of blood to the gastric fundus and decreases serum levels of ghrelin. Early evidence suggests that this alteration in gut hormone balance leads to changes in energy homeostasis and weight reduction. The pathophysiologic findings and current evidence associated with the use of left gastric artery embolization are reviewed.

CONCLUSION

The prevalence of obesity continues to increase at an alarming rate, and, thus far, advances in medical management have been relatively ineffective in slowing this trend. Lifestyle modifications such as diet and exercise are effective initially, but most patients regain the weight in the long term. Bariatric surgery is the most effective strategy for achieving long-term weight loss; however, as with all surgical procedures, it has potential complications.

The New Era of Drug Therapy for Obesity: The Evidence and the Expectations

There is an urgent need for effective pharmacological therapies to help tackle the growing obesity epidemic and the healthcare crisis it poses. The past 3 years have seen approval of a number of novel anti-obesity drugs. The majority of these influence hypothalamic appetite pathways via dopaminergic or serotoninergic signalling. Some are combination therapies, allowing lower doses to minimize the potential for off-target effects. An alternative approach is to mimic endogenous satiety signals using long-lasting forms of peripheral appetite-suppressing hormones. There is also considerable interest in targeting thermogenesis by brown adipose tissue to increase resting energy expenditure. Obesity pharmacotherapy has seen several false dawns, but improved understanding of the pathways regulating energy balance, and better-designed trials, give many greater confidence that recently approved agents will be both efficacious and safe. Nevertheless, a number of issues from preclinical and clinical development continue to attract debate, and additional large-scale trials are still required to address areas of uncertainty.

Mechanistic relationship between the vagal afferent pathway, central nervous system and peripheral organs in appetite regulation

The hypothalamus is a center of food intake and energy metabolism regulation. Information signals from peripheral organs are mediated through the circulation or the vagal afferent pathway and input into the hypothalamus, where signals are integrated to determine various behaviors, such as eating. Numerous appetite-regulating peptides are expressed in the central nervous system and the peripheral organs, and interact in a complex manner. Of such peptides, gut peptides are known to bind to receptors at the vagal afferent pathway terminal that extend into the mucosal layer of the digestive tract, modulate the electrical activity of the vagus nerve, and subsequently send signals to the solitary nucleus and furthermore to the hypothalamus. All peripheral peptides other than ghrelin suppress appetite, and they synergistically suppress appetite through the vagus nerve. In contrast, the appetite-enhancing peptide, ghrelin, antagonizes the actions of appetite-suppressing peptides through the vagus nerve, and appetite-suppressing peptides have attenuated effects in obesity as a result of inflammation in the vagus nerve. With greater understanding of the mechanism for food intake and energy metabolism regulation, medications that apply the effects of appetite-regulating peptides or implantable devices that electrically stimulate the vagus nerve are being investigated as novel treatments for obesity in basic and clinical studies.

Effectiveness, tolerability and practical application of the newer generation anti-obesity medications

OBJECTIVE

Comparison of the efficacy and tolerability of five newer anti-obesity medications to guide clinical decision making, examining bupropion-naltrexone combination, liraglutide, lorcaserin, orlistat, and phentermine-topiramate combination.

METHODS

A brief literature review and internet search for high-powered, randomized and placebo-controlled drug trials was conducted. Drug trial information was established for five currently approved anti-obesity medications. Secondarily, a statistical comparison of medications through Number Needed to Treat (NNT) and Number Needed to Harm (NNH) analyses were attempted as a way to provide a clinical analysis across these varied medications. Finally, a commentary about clinical application is issued for each agent accounting for typical side-effects, serious side-effects, mechanism of action and ease of use.

RESULTS

All five agents are currently approved oral medications to lower weight. The NNT range was 3-12, and NNH range was 4-17. The agent with the best NNT is phentermine-topiramate combination (NNT=3) and the agent with the best NNH is bupropion-naltrexone combination (NNH=17).

CONCLUSION

When considering each patient's clinical presentation, knowledge of each drug's mechanism of action, side-effect profile, efficacy, and NNT and NNH values can help in selecting an anti-obesity medication to augment his or her weight loss efforts.

Aster spathulifolius Maxim extract reduces body weight and fat mass in obese humans

Aster spathulifolius Maxim (AS), a perennial herb of the genus Aster within the family Asteraceae, induced weight loss in a rat model of diet-induced obesity. We hypothesized that AS could also reduce body weight in obese humans. Therefore, we performed a randomized, double-blind, placebo-controlled clinical trial in Korea to evaluate the effect of AS extract (ASE) on body weight and fat mass and its safety in obese humans. Forty-four obese participants (body mass index [BMI], 25-30 kg/m(2)) aged ≥20 years were randomly assigned to the placebo or ASE group (700 mg/d of ASE) and were instructed to take a once-daily pill for 12 weeks. Weight, BMI, waist circumference, fat mass (measured using bioimpedance, dual-energy X-ray absorptiometry, and computed tomography), and laboratory tests were assessed at baseline and at 12 weeks. Body weight significantly decreased after 12 weeks of treatment in the ASE group (placebo vs ASE: -0.08 ± 2.11 kg vs -3.30 ± 3.15 kg, P < .05), and so did body fat mass (placebo vs ASE; bioimpedance method: -0.51 ± 1.89 kg vs -2.38 ± 2.30 kg, P < .05; dual-energy X-ray absorptiometry: 0.38 ± 1.59 kg vs -2.26 ± 2.37 kg, P < .05). Changes in lipid profiles, fasting plasma glucose, and hemoglobin A1c did not differ between the 2 groups. No drug-related adverse events were observed during the study. In conclusion, ASE significantly decreases body weight and fat mass in obese humans, suggesting that ASE may be a potential therapeutic candidate for reducing obesity.

Long-term effects of weight-reducing drugs in people with hypertension

BACKGROUND

All major guidelines on antihypertensive therapy recommend weight loss; anti-obesity drugs may be able to help in this respect.

PRIMARY OBJECTIVES

To assess the long-term effects of pharmacologically induced reduction in body weight in adults with essential hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events).

SECONDARY OBJECTIVES

To assess the long-term effects of pharmacologically induced reduction in body weight in adults with essential hypertension on change from baseline in systolic blood pressure, change from baseline in diastolic blood pressure, and body weight reduction.

SEARCH METHODS

We obtained studies using computerised searches of the Cochrane Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid EMBASE, the clinical trials registry ClinicalTrials.gov, and from handsearches in reference lists and systematic reviews (status as of 13 April 2015).

SELECTION CRITERIA

Randomised controlled trials in hypertensive adults of at least 24 weeks' duration that compared long-term pharmacologic interventions for weight loss with placebo. 

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias, and extracted data. Where appropriate and in the absence of significant heterogeneity between studies (P > 0.1), we pooled studies using fixed-effect meta-analysis. When heterogeneity was present, we used the random-effects method and investigated the cause of heterogeneity.

MAIN RESULTS

After updating the literature search, which was extended to include four new weight-reducing drugs, we identified one additional study of phentermine/topiramate, bringing the total number of studies to nine that compare orlistat, sibutramine, or phentermine/topiramate to placebo and thus fulfil our inclusion criteria. We identified no relevant studies investigating rimonabant, liraglutide, lorcaserin, or naltrexone/bupropion. No study included mortality and cardiovascular morbidity as predefined outcomes. Incidence of gastrointestinal side effects was consistently higher in those participants treated with orlistat versus those treated with placebo. The most frequent side effects were dry mouth, constipation, and headache with sibutramine, and dry mouth and paresthaesia with phentermine/topiramate. In participants assigned to orlistat, sibutramine, or phentermine/topiramate body weight was reduced more effectively than in participants in the usual-care/placebo groups. Orlistat reduced systolic blood pressure as compared to placebo by -2.5 mm Hg (mean difference (MD); 95% confidence interval (CI): -4.0 to -0.9 mm Hg) and diastolic blood pressure by -1.9 mm Hg (MD; 95% CI: -3.0 to -0.9 mm Hg). Sibutramine increased diastolic blood pressure compared to placebo by +3.2 mm Hg (MD; 95% CI: +1.4 to +4.9 mm Hg). The one trial that investigated phentermine/topiramate suggested it lowered blood pressure.

AUTHORS' CONCLUSIONS

In people with elevated blood pressure, orlistat and sibutramine reduced body weight to a similar degree, while phentermine/topiramate reduced body weight to a greater extent. In the same trials, orlistat and phentermine/topiramate reduced blood pressure, while sibutramine increased it. We could include no trials investigating rimonabant, liraglutide, lorcaserin, or naltrexone/bupropion in people with elevated blood pressure. Long-term trials assessing the effect of orlistat, liraglutide, lorcaserin, phentermine/topiramate, or naltrexone/bupropion on mortality and morbidity are unavailable and needed. Rimonabant and sibutramine have been withdrawn from the market, after long-term trials on mortality and morbidity have confirmed concerns about the potential severe side effects of these two drugs. The European Medicines Agency refused marketing authorisation for phentermine/topiramate due to safety concerns, while the application for European marketing authorisation for lorcaserin was withdrawn by the manufacturer after the Committee for Medicinal Products for Human Use judged the overall benefit/risk balance to be negative.

Weight management in obesity - past and present

AIMS

To describe the treatment of obesity from ancient times to present day.

METHODS

Articles reporting the development of anti-obesity therapies were identified through a search for 'anti-obesity' AND 'pharmacotherapy' AND 'development' within the title or abstract on PubMed and 'obesity' in ClinicalTrials.gov. Relevant articles and related literature were selected for inclusion.

RESULTS

Stone-age miniature obese female statuettes indicate the existence and cultural significance of obesity as long as 30,000 years ago. Records from Ancient Egyptian and Biblical eras through Greco-Roman to Medieval times indicate that obesity was present throughout the major periods of history, although peoples of previous centuries would probably have experienced overweight and obesity as exceptional rather than normal. Health risks of obesity were noted by the Greek physician Hippocrates (460-377 BCE) when the earliest anti-obesity recommendations on diet, exercise, lifestyle and use of emetics and cathartics were born. These recommendations remained largely unchanged until the early 20th century, when spreading urbanisation, increasingly sedentary jobs and greater availability of processed foods produced a sharp rise in obesity. This led to the need for new, more effective, ways to lose weight, to address comorbidities associated with obesity, and to attain the current cultural ideal of slimness. Drug companies of the 1940s and 1950s produced a series of anti-obesity pharmacotherapies in short succession, based largely on amphetamines. Increased regulation of drug development in the 1960s and new efficacy requirements for weight-loss drugs led to rapid reduction in anti-obesity therapies available by the early 1990s.

CONCLUSION

In the last two decades, several new and emerging therapies have been approved or are in development to provide safe, long-term pharmacological agents for the treatment of obesity.

Naltrexone/bupropion for the treatment of obesity and obesity with Type 2 diabetes

Contrave® is a combination of naltrexone hydrochloride extended release and bupropion hydrochloride extended release for the treatment of obesity, and is used with lifestyle modification. Its safety and efficacy were assessed in four randomized, double-blind, placebo-controlled, 56-week Phase III clinical trials in 4536 adult subjects: COR-1, COR-II, COR-BMOD and COR-DM. All four studies demonstrated statistically significant and clinically meaningful weight loss following up to 52 weeks of treatment with naltrexone/bupropion compared with placebo. The average weight loss from baseline across the four studies was approximately 11–22 lbs (5–9 kg). Results show the efficacy of Contrave for weight loss, as well as significant improvements in cardiometabolic markers. This review focuses on the four studies, their outcomes and the mechanism of action of Contrave.

A Comparison of New Pharmacological Agents for the Treatment of Obesity

Objective: To review and compare the phase 3 clinical trial evidence on the 4 new pharmacological agents approved for the management of overweight and obesity. Data Sources: Searches were performed (from 1966 through January 2016) in PubMed/MEDLINE, Scientific Citation Index, and product package inserts to identify key phase 3 clinical trials that were used in the approval of each agent. Study Selection and Data Extraction: Phase 3 clinical trials that listed end points of ≥5% and ≥10% weight loss benchmarks from baseline as well as total percentage of weight loss by participants were selected for the review. Data Synthesis: No head-to-head trials have been identified between these agents at this point, which limits comparisons across agents. Phentermine/topiramate ER appeared to have the best overall average weight loss from baseline as well as highest percentages of patients achieving both ≥5% and ≥10% weight loss benchmarks, followed second by naltrexone/bupropion, and then liraglutide, with lorcaserin showing the lowest rates. Phentermine/topiramate ER completion rates were highest for both treatment and placebo groups, followed by liraglutide, with lorcaserin and naltrexone/bupropion showing similar completion rates, below that of the other 2 agents. Common side effects reported differed between agents, although the most common adverse events reported were gastrointestinal in nature, with liraglutide demonstrating the highest reported rates and lorcaserin demonstrating the lowest. Conclusion: These 4 new pharmacological agents represent new options for the clinician to utilize when trying to manage the problem of obesity. No clear first-line agent has emerged, so treatment decisions should be based on patient-specific factors.

Amylin: Pharmacology, Physiology, and Clinical Potential

Amylin is a pancreatic β-cell hormone that produces effects in several different organ systems. Here, we review the literature in rodents and in humans on amylin research since its discovery as a hormone about 25 years ago. Amylin is a 37-amino-acid peptide that activates its specific receptors, which are multisubunit G protein-coupled receptors resulting from the coexpression of a core receptor protein with receptor activity-modifying proteins, resulting in multiple receptor subtypes. Amylin's major role is as a glucoregulatory hormone, and it is an important regulator of energy metabolism in health and disease. Other amylin actions have also been reported, such as on the cardiovascular system or on bone. Amylin acts principally in the circumventricular organs of the central nervous system and functionally interacts with other metabolically active hormones such as cholecystokinin, leptin, and estradiol. The amylin-based peptide, pramlintide, is used clinically to treat type 1 and type 2 diabetes. Clinical studies in obesity have shown that amylin agonists could also be useful for weight loss, especially in combination with other agents.

Review of Pharmacologic Weight Loss Medications in a Patient-Centered Medical Home

Background: Per the Centers for Disease Control, 78 million adults were classified as obese in the United States in 2009 to 2010. Lifestyle modifications and pharmacologic treatment are appropriate options to combat obesity. Objectives: The primary objective of the study was to assess change in body weight after 12 weeks in patients seen at a family medicine patient-centered medical home (PCMH) who were prescribed Food and Drug Administration-approved weight loss medications. Methods: A retrospective medical record review was used to evaluate weight loss in adult patients with office visits at the PCMH. Adult patients were eligible for inclusion in the study if prescribed a Food and Drug Administration approved weight loss medication between July 1, 2013, and March 31, 2014, and had at least one weight documented during a follow-up visit 12 weeks after the initial prescription. Results: Of the 27 patients identified for study inclusion, 22 (81.5%) were prescribed phentermine. The remaining 5 (18.5%) patients were prescribed phentermine/topiramate ER. After 12 weeks of pharmacologic therapy, the median change in body weight was -3.7 kg (range = -16.8 to 5.5 kg) regardless of medication taken. This correlates to a -1.4 kg/m² (range = -15.7 to 4.2 kg/m²) median change in body mass index. Twelve patients (44.4%) lost at least 5% of their body weight during the study period. Conclusions: In our study population, we observed a median weight loss of 3.7 kg over 12 weeks while utilizing weight loss medications. Unfortunately, other lifestyle-modification services offered through the PCMH were not consistently utilized.

Next generation of weight management medications: implications for diabetes and CVD risk

Since the 1980s, the prevalence of obesity has almost doubled worldwide. Treatments for obesity include lifestyle modification, medications and surgery. Newer anti-obesity medications have been shown to be effective at inducing initial weight management in addition to successful long-term weight maintenance. Historically, weight management medications have been associated with public safety concerns that have resulted in the majority being withdrawn from the market or never receiving medicinal authorization. Recently, several countries have approved some newer generation weight management medications which may be beneficial to combat obesity. These medications have varying effects on cardiometabolic parameters, both positive and potentially negative. This review will outline the mechanisms of action of these medications and their implications for both diabetes and cardiovascular risks.

Role of Bupropion Plus Naltrexone for the Management of Obesity

Objective. The pharmacology, pharmacokinetics, efficacy, and safety of bupropion plus naltrexone for weight loss were reviewed. Data Sources. A MEDLINE search (1970 to November 2015) was conducted for English-language articles using specific MESH terms. Study Selection and Data Extraction. Published Phase 3 clinical trials with primary endpoints related to weight loss were included and critiqued in this review. Study Selection and Data Extraction. Five trials were retrieved and reviewed regarding the efficacy and safety of bupropion plus naltrexone among obese and overweight patients. Data Synthesis. Bupropion is a dopamine/norepinephrine reuptake inhibitor, and naltrexone is an opioid receptor antagonist. The combination of these agents has led to increased weight loss, compared to placebo, among overweight and obese patients with a body mass index (BMI) at or above 30 or BMI at or above 27 with a comorbid condition. The combination of bupropion and naltrexone can produce an average placebo-subtracted weight loss of 4.25% over 56 weeks. Gastrointestinal (ie, nausea, vomiting, constipation) and central nervous system adverse events (ie, headache, dizziness) were commonly reported, and there was a high dropout rate among participants. Conclusions. Bupropion plus naltrexone has demonstrated effective weight loss, in conjunction with lifestyle modifications, among overweight and obese patients with and without comorbidities. Bupropion plus naltrexone has not been studied among special patient populations, such as those with sleep apnea, osteoarthritis, or extreme BMIs. Additional clinical trials and postmarketing data will provide a better understanding of this medication for weight loss.

Weight maintenance: challenges, tools and strategies for primary care physicians

Obesity is recognized as a chronic disease and one of the major healthcare challenges facing us today. Weight loss can be achieved via lifestyle, pharmacological and surgical interventions, but weight maintenance remains a lifetime challenge for individuals with obesity. Guidelines for the management of obesity have highlighted the role of primary care providers (PCPs). This review examines the long-term outcomes of clinical trials to identify effective weight maintenance strategies that can be utilized by PCPs. Because of the broad nature of the topic, a structured PubMed search was conducted to identify relevant research articles, peer-reviewed reviews, guidelines and articles published by regulatory bodies. Trials have demonstrated the benefit of sustained weight loss in managing obesity and its comorbidities. Maintaining 5-10% weight loss for ≥1 year is known to ameliorate many comorbidities. Weight maintenance with lifestyle modification - although challenging - is possible but requires long-term support to reinforce diet, physical activity and behavioural changes. The addition of pharmacotherapy to lifestyle interventions promotes greater and more sustained weight loss. Clinical evidence and recently approved pharmacotherapy has given PCPs improved strategies to support their patients with maintenance of weight loss. Further studies are needed to assess the translation of these strategies into clinical practice.

The 5-HT₂C receptor agonist, lorcaserin, and the 5-HT₆ receptor antagonist, SB-742457, promote satiety; a microstructural analysis of feeding behaviour

RATIONALE

Whilst the FDA-approved anorectic, lorcaserin and various 5-hydroxytryptamine (5-HT)6 receptor antagonists reduce feeding, a direct assessment of their impact upon feeding behaviour is less clear. We therefore examined the action of lorcaserin and the clinical-stage developmental candidate 5-HT6 receptor antagonist, SB-742457, upon microstructural analysis of licking behaviour. Such analysis provides a rich source of information about the mechanisms controlling food intake.

OBJECTIVES

The objective of the present study was to gain insight into the influence upon feeding behaviour of the 5-HT2C receptor agonist, lorcaserin and the developmental 5-HT6 receptor antagonist, SB-742457.

METHODS

The impact of lorcaserin and SB-742457 upon licking behaviour of non-deprived rats for a glucose solution was assessed using microstructural analysis.

RESULTS

Lorcaserin (0.1-3.0 mg/kg) displayed a dose-dependent ability to reduce glucose consumption via reduction in the number of bouts of licking. A similar action was evident with SB-742457, but only at the lowest dose tested (3.0 mg/kg).

CONCLUSIONS

The behavioural actions of both lorcaserin and SB-742457 demonstrate they directly promote satiety.

The GLP-1 agonist, liraglutide, as a pharmacotherapy for obesity

There is a global obesity epidemic that will continue to be a financial burden on healthcare systems around the world. Tackling obesity through diet and exercise should always be the first intervention, but this has not proved to be effective for a large number of patients. Pharmacotherapeutic options have been limited and many previously available drugs have been withdrawn due to safety concerns. Currently, only bariatric surgery has the capability to induce both substantial and durable weight loss. This article briefly reviews the history of pharmacotherapy for obesity before focusing on the clinical trial evidence for the use of the GLP-1 agonist liraglutide as a weight loss agent and comparing its efficacy with other emerging drug therapies for obesity.

Regulation of appetite, satiation, and body weight by enteroendocrine cells. Part 1: characteristics of enteroendocrine cells and their capability of weight regulation

The gastrointestinal tract is the gateway for food in our body. Food ingestion and the ensuing digestive processes depend on the composition and amount of ingested nutrients. This complex process of nutrient digestion and absorption is effectively regulated by the enteroendocrine system. Enteroendocrine cells (EECs) reside scattered throughout the intestinal epithelium. They express nutrient receptors that face the lumen and secrete peptide hormones in response to food. Besides regulating digestion, gastrointestinal endocrine cells are involved in the regulation of appetite and satiety. The first part of this review describes the anatomical and biological characteristics of EECs and discusses the capability of their hormones to influence appetite, satiety, and body weight. In the second part, we then discuss the therapeutic potential of EECs in the treatment of obesity.

Pharmacotherapy for the treatment of obesity

The recognition of the complex counter-regulatory hormonal, metabolic and neurochemical mechanisms that promote weight regain following weight loss and the conceptualisation of obesity as a chronic disease requiring long-term management has led to increasing focus on the role of adjunctive therapies for obesity, particularly pharmacotherapy. Currently available pharmacotherapy achieves a weight loss intermediate between that commonly attained by lifestyle intervention and bariatric surgery, however its accessibility, compared to bariatric surgery increases its appeal. Despite the poor history of obesity pharmacotherapy, novel agents that are in development appear to have several advantages over predecessors. They are generally more selective in their mechanism of action, thereby potentially minimising adverse sequelae and improving the risk-benefit ratio of pharmacotherapy. Another approach has been to use combined pharmacotherapy to better counteract the multiple counter-regulatory neuroendocrine mechanisms which promote weight regain, as well as allowing lower constituent doses of the combined monotherapy agents, which improves the safety and tolerability of these agents that are usually required long-term for chronic weight maintenance. This review will provide an overview of past, present and future pharmacotherapy for obesity. The efficacy and safety profile of currently available pharmacotherapy will be discussed in the setting of stringent regulatory review processes now in place given the fraught history of pharmacological interventions for obesity. Potential novel therapies that seek to better target the multiple complex counter-regulatory mechanisms promoting weight regain while improving the efficacy/safety profile, will also be examined.

Treating morbid obesity in cirrhosis: A quest of holy grail

The problem of obesity is increasing worldwide in epidemic proportions; the situation is similarly becoming more common in patients with cirrhosis which negatively affect the prognosis of disease and also makes liver transplantation difficult especially in the living donor liver transplantation setting where low graft to recipient weight ratio negatively affects survival. Treatment of obesity is difficult in cirrhosis due to difficulty in implementation of lifestyle measures, limited data on safety of anti-obesity drugs and high risk of surgery. Currently approved anti-obesity drugs have limited data in patients with cirrhosis. Bariatric surgery remains an option in selected compensated cirrhotic patients. Endoscopic interventions for obesity are emerging and are quite promising in patients with cirrhosis as these are minimally invasive. In present review, we briefly discuss various modalities of weight reduction in obese patients and their applicability in patients with cirrhosis.

European Guidelines for Obesity Management in Adults

Obesity is a chronic metabolic disease characterised by an increase of body fat stores. It is a gateway to ill health, and it has become one of the leading causes of disability and death, affecting not only adults but also children and adolescents worldwide. In clinical practice, the body fatness is estimated by BMI, and the accumulation of intra-abdominal fat (marker for higher metabolic and cardiovascular disease risk) can be assessed by waist circumference. Complex interactions between biological, behavioural, social and environmental factors are involved in regulation of energy balance and fat stores. A comprehensive history, physical examination and laboratory assessment relevant to the patient's obesity should be obtained. Appropriate goals of weight management emphasise realistic weight loss to achieve a reduction in health risks and should include promotion of weight loss, maintenance and prevention of weight regain. Management of co-morbidities and improving quality of life of obese patients are also included in treatment aims. Balanced hypocaloric diets result in clinically meaningful weight loss regardless of which macronutrients they emphasise. Aerobic training is the optimal mode of exercise for reducing fat mass while a programme including resistance training is needed for increasing lean mass in middle-aged and overweight/obese individuals. Cognitive behavioural therapy directly addresses behaviours that require change for successful weight loss and weight loss maintenance. Pharmacotherapy can help patients to maintain compliance and ameliorate obesity-related health risks. Surgery is the most effective treatment for morbid obesity in terms of long-term weight loss. A comprehensive obesity management can only be accomplished by a multidisciplinary obesity management team. We conclude that physicians have a responsibility to recognise obesity as a disease and help obese patients with appropriate prevention and treatment. Treatment should be based on good clinical care, and evidence-based interventions; should focus on realistic goals and lifelong multidisciplinary management.

Anti-obesity drugs

PURPOSE OF REVIEW

The prevalence of obesity across the world continues to climb, bringing with it otherwise preventable obesity-related comorbidities including type 2 diabetes, hypertension and cardiovascular disease. Weight loss is difficult to achieve and maintain through lifestyle interventions alone, leading to intense efforts to develop adjunctive pharmacological approaches. Herein, we examine recent advances in this field and limitations of currently available and emerging agents.

RECENT FINDINGS

Liraglutide, lorcaserin and combination of phentermine-topiramate and bupropion-naltrexone have all been the subject of recent studies examining their efficacy as weight-loss agents. Although each effectively induces weight loss over and above placebo, significant concerns exist regarding side-effect profiles and safety, along with their ability to achieve sustained effects. Dropout rates in all examined studies were up to 50% or more, usually a result of intolerable side-effects. Recruitment of a high proportion of women of European descent also casts doubt on the generalizability of trial data.

SUMMARY

Pharmacological interventions for weight loss remain limited, with side-effects often outweighing efficacy. Interestingly, substantial early weight loss was associated with sustained loss, suggesting a responsive phenotype and future trials might best be targeted in identifying responsive subpopulations.

Treatment of obesity in 2015

Obesity is a major health priority in the United States, as well as globally. It is associated with multiple comorbidities and reduced life expectancy. Effective management of obesity involves producing an intervention plan tailored to the individual patient. Potential contributory factors to weight gain, including dietary habits, physical inactivity, associated medical conditions, and medications, should be identified and addressed. Lifestyle interventions comprising diet modification, physical activity, and behavior therapy are foundational to the management of obesity. Caloric restriction is the most important component in achieving weight loss through negative energy balance, whereas sustained physical activity is important in maintaining the weight loss. Adjunctive therapies in the form of pharmacotherapy and bariatric surgery are required in patients who do not achieve targeted weight loss and health goals with lifestyle interventions. Currently there are 3 drugs approved for long-term management of obesity, orlistat, phentermine/topiramate extended release, and lorcaserin, and there are 2 on the horizon, bupropion/naltrexone and liraglutide. Bariatric surgery is an effective strategy recognized to produce durable weight loss with amelioration of obesity-related comorbidities and should be considered a treatment option in eligible patients.

Weight Loss Pharmacotherapy: Brief Summary of the Clinical Literature and Comments on Racial Differences

The disparity in obesity rates between White, Black, and Hispanic individuals, especially women, is striking. Moreover, at any given body mass index or abdominal girth, incident diabetes is greater in Black, Hispanic and other racial-ethnic minorities than Whites. In addition to the growing health burden, the total costs of obesity in 2030 could exceed $500 billion (USD). Weight loss of 5%-15% from baseline can be attained with anti-obesity pharmacotherapy approved for long-term use in combination with lifestyle change. Weight loss of ≥ 5% is associated with medical benefits including reduction of incident diabetes and cardiovascular risk. While medical weight loss after one year or more in the US population is better than previously seen in many clinical trials, >60% of adults fail to sustain a 5% weight loss. Drug therapies approved for long-term weight loss may permit even more subjects to sustain healthful weight reduction.

Pharmacotherapy for the management of obesity

In the last 30 years, obesity has rapidly increased and obesity-related comorbidities have surged. Once considered to be a problem only in developed nations, obesity has become a global epidemic. Consequently, the costs associated with managing overweight and obesity worldwide are astronomical. The objective of this mini-review is to provide an overview of current options available for obesity management, with a focus on anti-obesity pharmacotherapies. The impact of weight loss on improving obesity-related comorbidities and risk factors has been well documented. Although established clinical guidelines suggest comprehensive lifestyle modification to induce weight loss, many patients do not respond to lifestyle interventions and may not qualify for bariatric surgery. For these patients, pharmacotherapy may serve as a therapeutic option. Several anti-obesity pharmacotherapies, such as phentermine, are indicated for short-term use and are not required to demonstrate clinically meaningful weight loss (i.e., ≥5%). For long-term weight management, the FDA has approved 5 agents so far-orlistat, lorcaserin, phentermine/topiramate, naltrexone/bupropion, and liraglutide. These drugs have shown efficacy in enabling patients to achieve clinically meaningful weight loss and improving cardiometabolic parameters. Healthcare practitioners can help alleviate the obesity epidemic by tailoring these pharmacotherapies based on individual needs, comorbidities, and associated drug safety concerns.

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.

Current Perspectives on Long-term Obesity Pharmacotherapy

Approximately 1 in 4 adult Canadians are obese and, thus, are at an elevated risk for developing type 2 diabetes, cardiovascular disease and other conditions. Current treatment guidelines recommend that obese individuals lose 5% to 10% of their starting weights to minimize the risk factors for cardiovascular disease and reduce the risk for developing type 2 diabetes or hypertension. All obesity-management strategies involve lifestyle management, but few patients will lose a significant amount of weight and manage to keep it off over the long term using just this strategy. Bariatric surgery is associated with significant long-term weight loss but is restricted to subjects with very high body mass indices, who often wait many years to undergo the procedure. Recent breakthroughs in understanding the mechanisms underlying the development and maintenance of elevated body fat have led to the arrival of new obesity pharmacotherapies. These novel antiobesity therapies, which work by reducing energy intake or through increasing satiety, decreasing hunger, or reducing absorption of calories, may be used indefinitely once patients have demonstrated significant responses (usually defined as ≥5% weight loss) over the first 12 weeks of treatment. To date, 2 long-term obesity pharmacotherapies have been approved and are available in Canada: liraglutide and orlistat. Here, I summarize the mechanisms and clinical features of medications for long-term obesity management that are available in Canada, as well as those available in other jurisdictions or are currently in development.

Lorcaserin Hcl for the treatment of obesity

INTRODUCTION

Obesity is a major health priority necessitating safe and effective strategies to address the obesity epidemic. Lorcaserin is a serotonergic agonist specific to the 5HT- 2C receptor approved for chronic management of obesity in patients with a BMI ≥ 30 kg/m(2) or a BMI ≥ 27 kg/m(2) with comorbidities related to obesity.

AREAS COVERED

In this paper, the pharmacodynamic and pharmacokinetic properties of lorcaserin are reviewed followed by a discussion of efficacy and safety data from major clinical trials.

EXPERT OPINION

Lorcaserin is a unique highly selective serotonergic agonist designed to mitigate the risks associated with previous agents in this class. At therapeutic doses, it is well tolerated and produces modest but clinically meaningful weight loss with significant improvement in cardiometabolic parameters. Therapeutic efficacy should be assessed at 12 weeks (≥ 5% weight loss) to identify responders who will derive maximum weight loss and metabolic benefit from long-term therapy. The results of the ongoing cardiovascular outcomes trial (CAMELLIA TIMI 61) will determine the role of lorcaserin in primary prevention of diabetes in overweight/obese individuals and its use in the high-risk population of patients with established cardiovascular disease or multiple cardiovascular risk factors.

Obesity Education Strategies for Cancer Prevention in Women's Health

Obesity is the cause of up to one-third of all cancers affecting women today, most notably endometrial, colon and breast cancer. Women's health providers are poised to advise women on obesity's link to cancer development, but often lack resources or training to provide appropriate counseling. Here, we review obesity's role in increasing the risk of several common reproductive system conditions faced by women, including polycystic ovarian syndrome, infertility, gynecologic surgical complications, and pregnancy complications. These events can be used as teachable moments to help frame the discussion of weight management and promote cancer prevention. We also review national guidelines and existing tangible weight-loss strategies that can be employed within the outpatient women's health setting to help women achieve weight loss goals and affect cancer prevention.

Identification of educational needs in the management of overweight and obesity: results of an international survey of attitudes and practice

Despite the availability of a growing range of interventions to assist control of body weight for people with excess weight or obesity, only a small proportion of people achieve their weight loss goals and are able to maintain body weight reductions in the long term. Negative attitudes and beliefs are often found among physicians and others involved in treating obesity and may adversely impact the effectiveness of management. In this international study, healthcare professionals were invited to complete an online survey of their attitudes and practice in the management of excess body weight. A total of 335 clinicians completed the survey of whom approximately half were based in Europe. A key finding from the survey is that, while participants are generally confident in their ability to manage overweight and obesity effectively, they also report that most of their patients are not successful in achieving their weight loss goals. At the same time, participants tended to overestimate the effectiveness of current medical management in maintaining reductions in body weight. Educational initiatives addressing the real-life effectiveness of different weight control interventions may help to close the gap between clinicians' perceptions and reality in the management of excess body weight.

Obesity medications: what does the future look like?

PURPOSE OF REVIEW

Lifestyle modification remains the mainstay of treatment for obesity despite the lack of substantial long-term efficacy. For many who do not respond to lifestyle therapy and are not candidates for weight loss surgery, pharmacotherapy is a viable treatment option. Advances in understanding mechanisms of appetite control, nutrient sensing, and energy expenditure have not only helped shape current drug development but have also changed the way in which antiobesity medications are prescribed. Current antiobesity medications and pharmacological strategies will be reviewed.

RECENT FINDINGS

Two new antiobesity drugs - naltrexone/bupropion (Contrave) and liraglutide (Saxenda) - were approved by the US Food and Drug Administration in 2014 and join four other approved obesity medications, including phentermine/topiramate XR (Qsymia) and lorcaserin (Belviq), to form the largest number of medications available for the treatment of obesity. In addition, investigational drugs, like belnoranib, show promise in early clinical trials, brightening the outlook on drug development.

SUMMARY

To combat the complex physiological system of energy regulation and the known variation of treatment response, combinatory therapies for obesity, including pharmacotherapy, are needed. Now six US Food and Drug Administration-approved antiobesity medications, including two combination medications, will allow providers to tailor obesity treatment in combination with lifestyle modification for a great number of individuals with obesity.

Advances in the Science, Treatment, and Prevention of the Disease of Obesity: Reflections From a Diabetes Care Editors' Expert Forum

As obesity rates increase, so too do the risks of type 2 diabetes, cardiovascular disease, and numerous other detrimental conditions. The prevalence of obesity in U.S. adults more than doubled between 1980 and 2010, from 15.0 to 36.1%. Although this trend may be leveling off, obesity and its individual, societal, and economic costs remain of grave concern. In June 2014, a Diabetes Care Editors' Expert Forum convened to review the state of obesity research and discuss the latest prevention initiatives and behavioral, medical, and surgical therapies. This article, an outgrowth of the forum, offers an expansive view of the obesity epidemic, beginning with a discussion of its root causes. Recent insights into the genetic and physiological factors that influence body weight are reviewed, as are the pathophysiology of obesity-related metabolic dysfunction and the concept of metabolically healthy obesity. The authors address the crucial question of how much weight loss is necessary to yield meaningful benefits. They describe the challenges of behavioral modification and predictors of its success. The effects of diabetes pharmacotherapies on body weight are reviewed, including potential weight-neutral combination therapies. The authors also summarize the evidence for safety and efficacy of pharmacotherapeutic and surgical obesity treatments. The article concludes with an impassioned call for researchers, clinicians, governmental agencies, health policymakers, and health-related industries to collectively embrace the urgent mandate to improve prevention and treatment and for society at large to acknowledge and manage obesity as a serious disease.

The Serotonin 2C Receptor Agonist Lorcaserin Attenuates Intracranial Self-Stimulation and Blocks the Reward-Enhancing Effects of Nicotine

Lorcaserin, a serotonin (5-hydroxytryptamine, 5-HT) 2C receptor agonist, was recently approved for the treatment of obesity. We previously suggested that 5-HT2C receptor agonists affect reward processes and reduce the rewarding effects of drugs of abuse. Here, we determined whether lorcaserin (1) decreases responding for brain stimulation reward (BSR) and (2) prevents nicotine from enhancing the efficacy of BSR. Rats were trained on the intracranial self-stimulation (ICSS) paradigm to nosepoke for BSR of either the dorsal raphé nucleus or left medial forebrain bundle. In Experiment 1, lorcaserin (0.3-1.0 mg/kg) dose-dependently reduced the efficacy of BSR. This effect was blocked by prior administration of the 5-HT2C receptor antagonist SB242084. In Experiment 2, separate groups of rats received saline or nicotine (0.4 mg/kg) for eight sessions prior to testing. Although thresholds were unaltered in saline-treated rats, nicotine reduced reward thresholds. An injection of lorcaserin (0.3 mg/kg) prior to nicotine prevented the reward-enhancing effect of nicotine across multiple test sessions. These results demonstrated that lorcaserin reduces the rewarding value of BSR and also prevents nicotine from facilitating ICSS. Hence, lorcaserin may be effective in treating psychiatric disorders, including obesity and nicotine addiction, by reducing the value of food or drug rewards.

Therapeutic Potential of 5-HT2C Receptor Agonists for Addictive Disorders

The neurotransmitter 5-hydroxytryptamine (5-HT; serotonin) has long been associated with the control of a variety of motivated behaviors, including feeding. Much of the evidence linking 5-HT and feeding behavior was obtained from studies of the effects of the 5-HT releaser (dex)fenfluramine in laboratory animals and humans. Recently, the selective 5-HT2C receptor agonist lorcaserin received FDA approval for the treatment of obesity. This review examines evidence to support the use of selective 5-HT2C receptor agonists as treatments for conditions beyond obesity, including substance abuse (particularly nicotine, psychostimulant, and alcohol dependence), obsessive compulsive, and excessive gambling disorder. Following a brief survey of the early literature supporting a role for 5-HT in modulating food and drug reinforcement, we propose that intrinsic differences between SSRI and serotonin releasers may have underestimated the value of serotonin-based pharmacotherapeutics to treat clinical forms of addictive behavior beyond obesity. We then highlight the critical involvement of the 5-HT2C receptor in mediating the effect of (dex)fenfluramine on feeding and body weight gain and the evidence that 5-HT2C receptor agonists reduce measures of drug reward and impulsivity. A recent report of lorcaserin efficacy in a smoking cessation trial further strengthens the idea that 5-HT2C receptor agonists may have potential as a treatment for addiction. This review was prepared as a contribution to the proceedings of the 11th International Society for Serotonin Research Meeting held in Hermanus, South Africa, July 9-12, 2014.

Serotonin, a possible intermediate between disturbed circadian rhythms and metabolic disease

It is evident that eating in misalignment with the biological clock (such as in shift work, eating late at night and skipping breakfast) is associated with increased risk for obesity and diabetes. The biological clock located in the suprachiasmatic nucleus dictates energy balance including feeding behavior and glucose metabolism. Besides eating and sleeping patterns, glucose metabolism also exhibits clear diurnal variations with higher blood glucose concentrations, glucose tolerance and insulin sensitivity prior to waking up. The daily variation in plasma glucose concentrations in rats, is independent of the rhythm in feeding behavior. On the other hand, feeding itself has profound effects on glucose metabolism, but differential effects occur depending on the time of the day. We here review data showing that a disturbed diurnal eating pattern results in alterations in glucose metabolism induced by a disrupted circadian clock. We first describe the role of central serotonin on feeding behavior and glucose metabolism and subsequently describe the effects of central serotonin on the circadian system. We next explore the interaction between the serotonergic system and the circadian clock in conditions of disrupted diurnal rhythms in feeding and how this might be involved in the metabolic dysregulation that occurs with chronodisruption.

5-hydroxytryptamine medications for the treatment of obesity

The central 5-hydroxytryptamine (5-HT; serotonin) system represents a fundamental component of the brain's control of energy homeostasis. Medications targeting the 5-HT pathway have been at the forefront of obesity treatment for the past 15 years. Pharmacological agents targeting 5-HT receptors (5-HTR), in combination with genetic models of 5-HTR manipulation, have uncovered a role for specific 5-HTRs in energy balance and reveal the 5-HT2 C R as the principal 5-HTR mediating this homeostatic process. Capitalising on this neurophysiological machinery, 5-HT2 C R agonists improve obesity and glycaemic control in patient populations. The underlying therapeutic mechanism has been probed using model systems and appears to be achieved primarily through 5-HT2 C R modulation of the brain melanocortin circuit via activation of pro-opiomelanocortin neurones signalling at melanocortin4 receptors. Thus, 5-HT2 C R agonists offer a means to improve obesity and type 2 diabetes, which are conditions that now represent global challenges to human health.

Liraglutide: an injectable option for the management of obesity

OBJECTIVE

To review the efficacy and safety of liraglutide, marketed as Saxenda, a glucagon-like peptide-1 analog for obesity management.

DATA SOURCES

A MEDLINE search (1970 to March 2015) was conducted for English-language articles using the terms glucagon-like peptide 1, liraglutide, and obesity.

STUDY SELECTION AND DATA EXTRACTION

Published articles pertinent to the efficacy and safety of liraglutide for short- and long-term obesity management among overweight or obese patients and special populations were reviewed and summarized.

DATA SYNTHESIS

Based on randomized placebo-controlled and active-comparator studies, liraglutide can increase weight loss among overweight and obese patients in a dose-dependent manner with once-daily doses of 1.2 to 3.0 mg. It has been shown that a higher proportion of patients experienced 5% and 10% weight loss from baseline compared with placebo and orlistat. Data support the potential benefit of liraglutide among overweight and obese patients with prediabetes, as well as women with polycystic ovary syndrome (PCOS) with an inadequate response to metformin. Larger and more robust studies are needed to determine the clinical significance of liraglutide among other agents for obesity in diverse populations.

CONCLUSIONS

Liraglutide is an adjunct to lifestyle modifications to improve success rates among overweight or obese individuals without diabetes. It may have a potential role in special populations, such as in those with prediabetes and women with PCOS. Based on its clinical evidence, liraglutide can result in more weight loss from baseline compared with orlistat and placebo. Adverse events associated with liraglutide are primarily gastrointestinal and usually dose dependent.

Managing overweight and obesity in adults to reduce cardiovascular disease risk

Obesity is a leading preventable cause of death and disability worldwide. Obesity increases the risk for clinically identifiable risk factors for cardiovascular disease (CVD) as well as a host of other metabolic, sleep, and orthopedic disorders. Coordinated and systematic interventions are needed to manage obesity and reduce these risks. The Obesity 2 Expert Panel updated the previous guidelines and produced the "Guideline for the Management of Overweight and Obesity in Adults." The Panel used data from publications from years 1999 to 2011 to address five critical questions, provide evidence statements, and recommend creation of a treatment algorithm to guide decision making about clinical care. The current review discusses the evidence statements pertaining to CVD risk in the assessment and management of patients who are overweight and obese. We summarize the FDA-approved medications for the treatment of overweight and obesity and their impact on CVD risk and risk factors, as well as ongoing clinical trials which will further inform clinical practice.

Meta-chlorophenylpiperazine enhances leptin sensitivity in diet-induced obese mice

BACKGROUND AND PURPOSE

Most forms of human obesity are characterized by impaired leptin sensitivity and, therefore, the effectiveness of anti-obesity leptin therapy in these leptin-resistant obese patients is marginal. Hence, the development of strategies to increase leptin sensitivity is of high priority in the field of obesity research.

EXPERIMENTAL APPROACH

We first examined the effects of co-administration of leptin and meta-chlorophenylpiperazine (mCPP), an agonist of 5-HT2C and 5-HT1B receptors, on energy balance in leptin-resistant diet-induced obese (DIO) mice. We further assessed leptin-induced phosphorylation of the STAT-3 (pSTAT3) in various brain regions of DIO mice pretreated with mCPP or in mice genetically lacking 5-HT2C receptors.

RESULTS

Co-administration of mCPP with leptin had an additive effect on reducing body weight in DIO mice. Furthermore, mCPP pretreatment in DIO mice enhanced leptin-induced pSTAT3 in the arcuate nucleus, the ventromedial hypothalamic nucleus, and the ventral premammillary nucleus. Finally, deletion of 5-HT2C receptors significantly blunted leptin-induced pSTAT3 in these same hypothalamic regions.

CONCLUSIONS AND IMPLICATIONS

Our study provides evidence that drugs, which activate 5-HT2C receptors, could function as leptin sensitizers and be used in combination with leptin to provide additional weight loss in DIO.