Efficacy and safety of lorcaserin in obese adults: a meta-analysis of 1-year randomized controlled trials (RCTs) and narrative review on short-term RCTs

Surgical management of obesity in patients with morbid obesity and nonalcoholic fatty liver disease

Most patients with severe complex obesity presenting for bariatric-metabolic surgery have nonalcoholic fatty liver disease (NAFLD). NAFLD is associated with central obesity, insulin resistance, type 2 diabetes, hypertension, and obesity-related dyslipidemia. Weight loss should be a primary therapy for NAFLD. However, evidence supporting intentional weight loss as a therapy for NAFLD is limited. Bariatric-metabolic surgery provides the most reliable method of achieving substantial sustained weight loss and the most commonly used procedures are associated with reduced steatosis and lobular inflammatory changes, but there are mixed reports regarding fibrosis. Surgery should complement treatment of obesity-related comorbidity, but not replace established therapy.

Nutritional management of type 2 diabetes mellitus and obesity and pharmacologic therapies to facilitate weight loss

Diet plays an integral role in the treatment of type 2 diabetes mellitus (T2DM). Unfortunately, many patients with T2DM do not have access to a registered dietitian or certified diabetes educator, and rates of physician counseling about diet remain low. This article provides an overview of the current recommendations for the nutritional management of T2DM, which are endorsed by the American Diabetes Association (ADA). Medical nutrition therapy, which provides a flexible and individualized approach to diet, emphasizes the total number (rather than the type) of carbohydrate consumed. Because fat intake also affects glycemia and cardiovascular risk, a reduction in daily mono- and polyunsaturated fat intake is recommended for most patients with T2DM. Weight loss plays an important adjunct role in treating patients with T2DM, because the majority of individuals with T2DM are overweight or obese. Patient lifestyle modification, which encompasses diet, physical activity, and behavioral therapy, can be used to facilitate weight loss in conjunction with several different dietary approaches. These include low-carbohydrate, low-fat, low-glycemic index, and Mediterranean diets. Studies have demonstrated that modest weight loss (5%-10% of body weight) is associated with significant improvements in patient measures of glycemic control, lipids, blood pressure, and other cardiovascular risk factors. Furthermore, a modest weight loss of as little as 4.5 kg can result in reducing the glycated hemoglobin level by approximately 0.5%. Pharmacologic agents, when combined with these approaches, may further augment weight loss. Familiarity with these principles can help physicians provide dietary counseling to their patients with T2DM and obesity.

Long-term drug treatment for obesity: a systematic and clinical review

IMPORTANCE

Thirty-six percent of US adults are obese, and many cannot lose sufficient weight to improve health with lifestyle interventions alone.

OBJECTIVE

To conduct a systematic review of medications currently approved in the United States for obesity treatment in adults. We also discuss off-label use of medications studied for obesity and provide considerations for obesity medication use in clinical practice.

EVIDENCE REVIEW

A PubMed search from inception through September 2013 was performed to find meta-analyses, systematic reviews, and randomized, placebo-controlled trials for currently approved obesity medications lasting at least 1 year that had a primary or secondary outcome of body weight change, included at least 50 participants per group, reported at least 50% retention, and reported results on an intention-to-treat basis. Studies of medications approved for other purposes but tested for obesity treatment were also reviewed.

FINDINGS

Obesity medications approved for long-term use, when prescribed with lifestyle interventions, produce additional weight loss relative to placebo ranging from approximately 3% of initial weight for orlistat and lorcaserin to 9% for top-dose (15/92 mg) phentermine plus topiramate-extended release at 1 year. The proportion of patients achieving clinically meaningful (at least 5%) weight loss ranges from 37% to 47% for lorcaserin, 35% to 73% for orlistat, and 67% to 70% for top-dose phentermine plus topiramate-extended release. All 3 medications produce greater improvements in many cardiometabolic risk factors than placebo, but no obesity medication has been shown to reduce cardiovascular morbidity or mortality. Most prescriptions are for noradrenergic medications, despite their approval only for short-term use and limited data for their long-term safety and efficacy.

CONCLUSIONS AND RELEVANCE

Medications approved for long-term obesity treatment, when used as an adjunct to lifestyle intervention, lead to greater mean weight loss and an increased likelihood of achieving clinically meaningful 1-year weight loss relative to placebo. By discontinuing medication in patients who do not respond with weight loss of at least 5%, clinicians can decrease their patients' exposure to the risks and costs of drug treatment when there is little prospect of long-term benefit.

An integrated serotonin and octopamine neuronal circuit directs the release of an endocrine signal to control C. elegans body fat

Serotonin (5-hydroxytryptamine, 5-HT) is an ancient and conserved neuromodulator of energy balance. Despite its importance, the neural circuits and molecular mechanisms underlying 5-HT-mediated control of body fat remain poorly understood. Here, we decipher the serotonergic neural circuit for body fat loss in C. elegans and show that the effects of 5-HT require signaling from octopamine, the invertebrate analog of adrenaline, to sustain body fat loss. Our results provide a potential molecular explanation for the long-observed potent effects of combined serotonergic and adrenergic weight loss drugs. In metabolic tissues, we find that the conserved regulatory adipocyte triglyceride lipase ATGL-1 drives serotonergic fat loss. We show that the serotonergic chloride channel MOD-1 relays a long-range endocrine signal from C. elegans body cavity neurons to control distal ATGL-1 function, via the nuclear receptor NHR-76. Our findings establish a conserved neuroendocrine axis operated by neural serotonergic and adrenergic-like signaling to regulate body fat.

From obesity to substance abuse: therapeutic opportunities for 5-HT2C receptor agonists

The recent US Food and Drug Administration (FDA) approval of the serotonin (5-hydroxytryptamine, 5-HT) 5-HT2C receptor agonist lorcaserin for the treatment of obesity represents a new therapeutic drug class available to the clinic. Preclinical evidence supports the potential for this drug class to treat other related conditions such as substance abuse. In the present article we review this evidence and further suggest that overlapping neurobiological systems may contribute to an anti-addictive and anti-obesity profile. The availability of selective 5-HT2C agonists provides an opportunity to evaluate their potential as treatments for nicotine dependence or psychostimulant abuse, conditions for which there is significant medical need but only limited available treatment options.

Drug treatment of obesity in the cardiovascular patient

PURPOSE OF REVIEW

The incidence of obesity and its associated comorbidities have significantly increased over the years with adverse health and financial consequences for society. Lifestyle changes are essential for the prevention and treatment of obesity but their benefit appears limited as inadequate and nonsustained weight loss results have been reported. Pharmacotherapy is frequently advocated as part of a weight loss strategy. In this review, we will discuss the antiobesity drugs with Food and Drug Administration approval and their cardiovascular implications.

RECENT FINDINGS

Orlistat (Xenical) remains the single monotherapy that has approval in Europe. Topiramate (Topamax) and phentermine have long been approved in the United States, whereas lorcaserin and the extended release combination of phentermine with topiramate have recently gained approval. The development of single peptides targeting gut hormones or other host signals related to obesity may represent promising therapeutic options.

SUMMARY

Despite the recent failures of a number of antiobesity drugs, the pharmacotherapy of obesity is progressing rapidly. Treating the obese cardiovascular patient has proven challenging. Efficacy, safety and the sustainability of weight loss are key areas of focus in drug development strategies.