Current updates in the medical management of obesity

Adipose tissue inflammation linked to obesity: A review of current understanding, therapies and relevance of phyto-therapeutics

Obesity is a current global challenge affecting all ages and is characterized by the up-regulated secretion of bioactive factors/pathways which result in adipose tissue inflammation (ATI). Current obesity therapies are mainly focused on lifestyle (diet/nutrition) changes. This is because many chemosynthetic anti-obesogenic medications cause adverse effects like diarrhoea, dyspepsia, and faecal incontinence, among others. As such, it is necessary to appraise the efficacies and mechanisms of action of safer, natural alternatives like plant-sourced compounds, extracts [extractable phenol (EP) and macromolecular antioxidant (MA) extracts], and anti-inflammatory peptides, among others, with a view to providing a unique approach to obesity care. These natural alternatives may constitute potent therapies for ATI linked to obesity. The potential of MA compounds (analysed for the first time in this review) and extracts in ATI and obesity management is elucidated upon, while also highlighting research gaps and future prospects. Furthermore, immune cells, signalling pathways, genes, and adipocyte cytokines play key roles in ATI responses and are targeted in certain therapies. As a result, this review gives an in-depth appraisal of ATI linked to obesity, its causes, mechanisms, and effects of past, present, and future therapies for reversal and alleviation of ATI. Achieving a significant decrease in morbidity and mortality rates attributed to ATI linked to obesity and related comorbidities is possible as research improves our understanding over time.

Swertiamarin decreases lipid accumulation dependent on 3-ketoacyl-coA thiolase

Natural compounds are important resources for drug discovery. Using Caenorhabditis elegans (C. elegans) models, we screened active natural compounds with lipid lowering effects. Swertiamarin was found as a potent candidate to reduce lipid content in C. elegans. Using RNAi screening, we were able to demonstrate that kat-1 (ketoacyl thiolase-1) is necessary for the lipid lowering effect of swertiamarin. Furthermore, the activity of swertiamarin was verified in high fat diet induced obese mice. Consistent with the results in C. elegans, swertiamarin ameliorated high fat diet induced lipid deposition and hyperlipidemia. These results indicate that swertiamarin exerts lipid-lowering effects through kat-1 regulation and could serve as a possible therapeutic option to improve hyperlipidemia induced comorbidities.

Correlation of body composition parameters using different methods among Brazilian obese adults

Abstract Data comparing anthropometric measurements, bioelectrical impedance analysis (BIA) and dual-energy X-ray absortiometry (DXA) parameters are somehow limited and conflicting. The objective of this study was to correlate anthropometric, BIA and DXA parameters among obese Brazilian adults with focus on the comparison with visceral adipose tissue (VAT) obtained from DXA and in the value of antropometric measurements. Fifty voluntary participants were enrolled. The Spearman correlation test was used to assess the correlation of VAT with anthropometric measurements, BIA and other DXA parameters. The intra-class correlation coefficient (ICC) was used to evaluate concordance between lean mass (LM), fat mass (FM), %body fat (%BF) and %upper body fat (%UBF) obtained from BIA and DXA. Most were female (80%) and had an average body index mass (BMI) of 39.0 (± 6.4) kg/m2. The only anthropometric measurements showing a strong correlation with VAT were abdominal circumference (AC) and waist-to-height ratio (WHtR), but just in females. There was a very good correlation for LM [ICC = 0.951 (CI = 0.913 - 0.972)], FM [ICC = 0.987 (CI = 0.977 – 0.993)], %BF [ICC = 0.961 (CI = 0.931-0.978)], and %UBF [ICC = 0.873 (CI = 0.776 – 0.928)], between data collected through BIA and DXA. Among the anthropometric measurements assessed, only AC and WHtR seems to estimate patients with abdominal fat distribution and higher VAT in females. DXA and BIA proved similar for the evaluation of LM, FM, %BF and %UBF, although DXA has the advantage of estimating VAT.

Engineering Mammalian Designer Cells for the Treatment of Metabolic Diseases

Synthetic biology applies engineering principles to biological systems and has significantly advanced the design of synthetic gene circuits that can reprogram cell activities to perform new functions. The ability to engineer mammalian designer cells with robust therapeutic behaviors has brought new opportunities for treating metabolic diseases. In this review, the authors highlight the most recent advances in the development of synthetic designer cells uploaded with open- or closed-loop gene circuits for the treatment of metabolic disorders including diabetes, hypertension, hyperuricemia, and obesity, and discuss the current technologies and future perspectives in applying these designer cells for clinical applications. In the future, more and more rationally designed cells will be constructed and revolutionized to treat a number of metabolic disorders in an intelligent manner.

Differential Role of Adipose Tissues in Obesity and Related Metabolic and Vascular Complications

This review focuses on the contribution of white, brown, and perivascular adipose tissues to the pathophysiology of obesity and its associated metabolic and vascular complications. Weight gain in obesity generates excess of fat, usually visceral fat, and activates the inflammatory response in the adipocytes and then in other tissues such as liver. Therefore, low systemic inflammation responsible for insulin resistance contributes to atherosclerotic process. Furthermore, an inverse relationship between body mass index and brown adipose tissue activity has been described. For these reasons, in recent years, in order to combat obesity and its related complications, as a complement to conventional treatments, a new insight is focusing on the role of the thermogenic function of brown and perivascular adipose tissues as a promising therapy in humans. These lines of knowledge are focused on the design of new drugs, or other approaches, in order to increase the mass and/or activity of brown adipose tissue or the browning process of beige cells from white adipose tissue. These new treatments may contribute not only to reduce obesity but also to prevent highly prevalent complications such as type 2 diabetes and other vascular alterations, such as hypertension or atherosclerosis.

Fatty acid metabolism and the basis of brown adipose tissue function

Obesity has reached epidemic proportions, leading to severe associated pathologies such as insulin resistance, cardiovascular disease, cancer and type 2 diabetes. Adipose tissue has become crucial due to its involvement in the pathogenesis of obesity-induced insulin resistance, and traditionally white adipose tissue has captured the most attention. However in the last decade the presence and activity of heat-generating brown adipose tissue (BAT) in adult humans has been rediscovered. BAT decreases with age and in obese and diabetic patients. It has thus attracted strong scientific interest, and any strategy to increase its mass or activity might lead to new therapeutic approaches to obesity and associated metabolic diseases. In this review we highlight the mechanisms of fatty acid uptake, trafficking and oxidation in brown fat thermogenesis. We focus on BAT's morphological and functional characteristics and fatty acid synthesis, storage, oxidation and use as a source of energy.

Quality of life and psychological well-being in obesity management: improving the odds of success by managing distress

BACKGROUND

Obesity is increasing in prevalence and placing an ever-greater burden on individuals and healthcare resources alike. Obesity management is complex and, for many, elusive.

AIMS AND METHODS

This paper reviews the major factors that influence psychological well-being in individuals with obesity and describes the means by which their impact on distress and other aspects of quality of life (QoL) can be quantified. The goal is to enable healthcare providers to set reasonable, achievable, maintainable weight loss targets that will improve the psychological well-being and QoL of individuals living with obesity. PubMed and Web of Science searches were conducted to identify literature that addresses the key question: How can distress over obesity be measured and taken into account when tailoring weight loss interventions for a particular patient?

DISCUSSION AND CONCLUSIONS

'Distress over obesity' is a key parameter that illustrates the psychological consequences of excess weight. Healthcare providers can draw on a range of obesity-specific and non-specific assessment tools to quantify distress as well as the other contributions of obesity to QoL and mental/emotional health. When physicians consider the psychological/QoL aspects of obesity and how these change with successful weight loss, it becomes possible to set achievable, realistic weight loss goals and develop a manageable plan to achieve them. Any future developments that make it easier to achieve these goals should be made widely available to all patients in need, in order to help them turn a vicious cycle of failure into a virtuous cycle of success.

Phentermine-topiramate: First combination drug for obesity

Obesity is spreading globally at an alarming speed. The management of obesity is multifaceted and includes lifestyle modifications as the cornerstone. Until only orlistat was approved for long term use in obesity. The US Food and Drug Administration granted approval to a fixed dose mid 2012 combination of phentermine immediate release and topiramate extended release in 2012 for treatment of obese patients or overweight patients with comorbid conditions. The new drug has shown significant weight loss compared with placebo for a period up to 2 years.

Active ingredients from natural botanicals in the treatment of obesity

Obesity is considered as a chronic disease that can induce a series of comorbidities and complications. Chinese medicine has long clinical experiences in the treatment of obesity. This review summarizes the natural products from traditional Chinese medicine (TCM) that are reported to have anti-obesity effects in the past two decades. Botanic TCM comprises 90% of total Chinese crude drugs, and generally contains various active ingredients, in which the effective anti-obesity ingredients identified can be divided into saponins, polysaccharides, alkaloids, polyphenols and others. Astragaloside IV, glycyrrhizin, macrostemonoside A, berberine, betaine, capsaicin, matrine, methyl piperate, piperine, rutaecarpine, asimilobine, epigallocatechingallate, magnolol, resveratrol, soybean-isoflavone, α-linolenic acid, emodin, geniposide, phillyrin, salidroside and ursolic acid are specified in this review, and their sources, models, efficacy are described. It is concluded that the mechanisms of these components for the treatment of obesity include: (i) suppression of appetite, increase of satiety, reduction of energy intake; (ii) reduction in the digestion and absorption of exogenous lipid; (iii) attenuation of the synthesis of endogenous lipid; (iv) promotion of the oxidation and expenditure of lipid and (v) improvement of lipid metabolism disorder. Authors believe that the effective compounds from TCM will provide an alternative and hopeful way for the treatment of obesity.

A closed-loop synthetic gene circuit for the treatment of diet-induced obesity in mice

Diet-induced obesity is a lifestyle-associated medical condition that increases the risk of developing cardiovascular disease, type 2 diabetes and certain types of cancer. Here we report the design of a closed-loop genetic circuit that constantly monitors blood fatty acid levels in the setting of diet-associated hyperlipidemia and coordinates reversible and adjustable expression of the clinically licensed appetite-suppressing peptide hormone pramlintide. Grafting of the peroxisome proliferator-activated receptor-α onto the phloretin-responsive repressor TtgR produces a synthetic intracellular lipid-sensing receptor (LSR) that reversibly induces chimeric TtgR-specific promoters in a fatty acid-adjustable manner. Mice with diet-induced obesity in which microencapsulated cells engineered for LSR-driven expression of pramlintide are implanted show significant reduction in food consumption, blood lipid levels and body weight when put on a high-fat diet. Therapeutic designer circuits that monitor levels of pathologic metabolites and link these with the tailored expression of protein pharmaceuticals may provide new opportunities for the treatment of metabolic disorders.

Mitochondrial fatty acid oxidation in obesity

SIGNIFICANCE

Current lifestyles with high-energy diets and little exercise are triggering an alarming growth in obesity. Excess of adiposity is leading to severe increases in associated pathologies, such as insulin resistance, type 2 diabetes, atherosclerosis, cancer, arthritis, asthma, and hypertension. This, together with the lack of efficient obesity drugs, is the driving force behind much research.

RECENT ADVANCES

Traditional anti-obesity strategies focused on reducing food intake and increasing physical activity. However, recent results suggest that enhancing cellular energy expenditure may be an attractive alternative therapy.

CRITICAL ISSUES

This review evaluates recent discoveries regarding mitochondrial fatty acid oxidation (FAO) and its potential as a therapy for obesity. We focus on the still controversial beneficial effects of increased FAO in liver and muscle, recent studies on how to potentiate adipose tissue energy expenditure, and the different hypotheses involving FAO and the reactive oxygen species production in the hypothalamic control of food intake.

FUTURE DIRECTIONS

The present review aims to provide an overview of novel anti-obesity strategies that target mitochondrial FAO and that will definitively be of high interest in the future research to fight against obesity-related disorders.

Clinical utility of insulin and insulin analogs

Diabetes is a pandemic disease characterized by autoimmune, genetic and metabolic abnormalities. While insulin deficiency manifested as hyperglycemia is a common sequel of both Type-1 and Type-2 diabetes (T1DM and T2DM), it does not result from a single genetic defect--rather insulin deficiency results from the functional loss of pancreatic β cells due to multifactorial mechanisms. Since pancreatic β cells of patients with T1DM are destroyed by autoimmune reaction, these patients require daily insulin injections. Insulin resistance followed by β cell dysfunction and β cell loss is the characteristics of T2DM. Therefore, most patients with T2DM will require insulin treatment due to eventual loss of insulin secretion. Despite the evidence of early insulin treatment lowering macrovascular (coronary artery disease, peripheral arterial disease and stroke) and microvascular (diabetic nephropathy, neuropathy and retinopathy) complications of T2DM, controversy exists among physicians on how to initiate and intensify insulin therapy. The slow acting nature of regular human insulin makes its use ineffective in counteracting postprandial hyperglycemia. Instead, recombinant insulin analogs have been generated with a variable degree of specificity and action. Due to the metabolic variability among individuals, optimum blood glucose management is a formidable task to accomplish despite the presence of novel insulin analogs. In this article, we present a recent update on insulin analog structure and function with an overview of the evidence on the various insulin regimens clinically used to treat diabetes.

Phentermine and topiramate for the management of obesity: a review

Obesity is now a major public health concern worldwide with increasing prevalence and a growing list of comorbidities and complications. The morbidity, mortality and reduced productivity associated with obesity and its complications result in a major burden to health care costs. Obesity is a complex chronic medical syndrome often with multiple different etiologic factors in individual patients. The long term successful management of obesity remains particularly challenging and invariably requires a multifaceted approach including lifestyle and behavioral modification, increased physical activity, and adjunctive pharmacotherapy. Bariatric surgery remains a last resort though at present it has the best results for achieving sustained robust weight loss. Obesity pharmacotherapy has been very limited in its role for long term obesity management because of the past history of several failed agents as well as the fact that presently available agents are few, and generally utilized as monotherapy. The recent FDA approval of the fixed drug combination of phentermine and extended release topiramate (topiramate-ER) (trade name Qsymia™) marks the first FDA approved combination pharmacotherapeutic agent for obesity since the Phen-Fen combination of the 1990s. This review details the history and clinical trial basis for the use of both phentermine and topiramate in obesity therapeutics as well as the results of clinical trials of their combination for obesity treatment in humans. The initial clinical approval trials offer evidence that this fixed drug combination offers synergistic potential for effective, robust and sustained weight loss with mean weight loss of at least 10% of baseline achieved and sustained for up to 2 years in over 50% of subjects treated. It is anticipated that this agent will be the first in a new trend of multi-agent combination therapy for the chronic adjunctive management of obesity.