Behavioral and pharmacologic therapies for obesity

Peripheral reduction of FGFR4 with antisense oligonucleotides increases metabolic rate and lowers adiposity in diet-induced obese mice

Obesity is a primary risk factor for multiple metabolic disorders. Many drugs for the treatment of obesity, which mainly act through CNS as appetite suppressants, have failed during development or been removed from the market due to unacceptable adverse effects. Thus, there are very few efficacious drugs available and remains a great unmet medical need for anti-obesity drugs that increase energy expenditure by acting on peripheral tissues without severe side effects. Here, we report a novel approach involving antisense inhibition of fibroblast growth factor receptor 4 (FGFR4) in peripheral tissues. Treatment of diet-induce obese (DIO) mice with FGFR4 antisense oligonucleotides (ASO) specifically reduced liver FGFR4 expression that not only resulted in decrease in body weight (BW) and adiposity in free-feeding conditions, but also lowered BW and adiposity under caloric restriction. In addition, combination treatment with FGFR4 ASO and rimonabant showed additive reduction in BW and adiposity. FGFR4 ASO treatment increased basal metabolic rate during free-feeding conditions and, more importantly, prevented adaptive decreases of metabolic rate induced by caloric restriction. The treatment increased fatty acid oxidation while decreased lipogenesis in both liver and fat. Mechanistic studies indicated that anti-obesity effect of FGFR4 ASO was mediated at least in part through an induction of plasma FGF15 level resulted from reduction of hepatic FGFR4 expression. The anti-obesity effect was accompanied by improvement in plasma glycemia, whole body insulin sensitivity, plasma lipid levels and liver steatosis. Therefore, FGFR4 could be a potential novel target and antisense reduction of hepatic FGFR4 expression could be an efficacious therapy as an adjunct to diet restriction or to an appetite suppressant for the treatment of obesity and related metabolic disorders.

Substituting dietary monounsaturated fat for saturated fat is associated with increased daily physical activity and resting energy expenditure and with changes in mood

BACKGROUND

The Western diet increases risk of metabolic disease.

OBJECTIVE

We determined whether lowering the ratio of saturated fatty acids to monounsaturated fatty acids in the Western diet would affect physical activity and energy expenditure.

DESIGN

With the use of a balanced design, 2 cohorts of 18 and 14 young adults were enrolled in separate randomized, double-masked, crossover trials that compared a 3-wk high-palmitic acid diet (HPA; similar to the Western diet fat composition) to a low-palmitic acid and high-oleic acid diet (HOA; similar to the Mediterranean diet fat composition). All foods were provided by the investigators, and the palmitic acid (PA):oleic acid (OA) ratio was manipulated by adding different oil blends to the same foods. In both cohorts, we assessed physical activity (monitored continuously by using accelerometry) and resting energy expenditure (REE). To gain insight into a possible mood disturbance that might explain changes in physical activity, the Profile of Mood States (POMS) was administered in cohort 2.

RESULTS

Physical activity was higher during the HOA than during the HPA in 15 of 17 subjects in cohort 1 (P = 0.008) (mean: 12% higher; P = 0.003) and in 12 of 12 subjects in the second, confirmatory cohort (P = 0.005) (mean: 15% higher; P = 0.003). When the HOA was compared with the HPA, REE measured during the fed state was 3% higher for cohort 1 (P < 0.01), and REE was 4.5% higher in the fasted state for cohort 2 (P = 0.04). POMS testing showed that the anger-hostility score was significantly higher during the HPA (P = 0.007).

CONCLUSIONS

The replacement of dietary PA with OA was associated with increased physical activity and REE and less anger. Besides presumed effects on mitochondrial function (increased REE), the dietary PA:OA ratio appears to affect behavior. The second cohort was derived from a study that was registered at clinicaltrials.gov as R01DK082803.

Mass spectrometry-based metabolomics towards understanding of gene functions with a diversity of biological contexts

Currently, mass spectrometry-based metabolomics studies extend beyond conventional chemical categorization and metabolic phenotype analysis to understanding gene function in various biological contexts (e.g., mammalian, plant, and microbial). These novel utilities have led to many innovative discoveries in the following areas: disease pathogenesis, therapeutic pathway or target identification, the biochemistry of animal and plant physiological and pathological activities in response to diverse stimuli, and molecular signatures of host-pathogen interactions during microbial infection. In this review, we critically evaluate the representative applications of mass spectrometry-based metabolomics to better understand gene function in diverse biological contexts, with special emphasis on working principles, study protocols, and possible future development of this technique. Collectively, this review raises awareness within the biomedical community of the scientific value and applicability of mass spectrometry-based metabolomics strategies to better understand gene function, thus advancing this application's utility in a broad range of biological fields.

Orlistat with behavioral weight loss for obesity with versus without binge eating disorder: randomized placebo-controlled trial at a community mental health center serving educationally and economically disadvantaged Latino/as

OBJECTIVE

This study was a randomized placebo-controlled trial testing the addition of orlistat to behavioral weight loss for obesity in Spanish-speaking-only Latino/as with versus without binge eating disorder (BED) performed at a community mental health center serving educationally- and economically-disadvantaged patients. Latino/as have high rates of obesity but are under-represented in obesity treatment studies and despite comparable-to-or-higher rates of BED than Whites, Latino/as are under-represented in BED treatment studies. BED is associated with obesity but whether it predicts/moderates treatment outcomes remains uncertain. Thus, this study also tested whether BED prospectively predicts/moderates outcomes.

METHODS

Seventy-nine obese Spanish-speaking-only Latino/as with BED (N=40) versus without BED (N=39) at a community mental health center were randomly assigned to four-months of orlistat-plus-BWL or placebo-plus-BWL. BWL was culturally-enhanced modification of Diabetes-Prevention-Program delivered in weekly sessions in Spanish. Orlistat (120 mg tid) and matching-placebo delivered with standard clinical-management. Participants were assessed independently throughout treatment, post-treatment, and six-month follow-up.

RESULTS

78% completed treatments; completion rates did not differ significantly by medication or BED. Intent-to-treat mixed-models analyses revealed significant improvements in binge eating, eating-psychopathology, and depression, and significant--albeit modest--weight-loss. Overall, the addition of orlistat to BWL was not associated with greater improvements; however, BED moderated weight-loss: orlistat-plus-BWL produced significantly greater weight-loss in non-BED group but not in BED. Improvements were maintained through 6-month follow-up; BED significantly predicted/moderated increases in eating concerns and depression following treatment. Within BED-group, binge-eating remission rates were 65% (post-treatment) and 50% (follow-up).

CONCLUSIONS

In this controlled trial performed at community mental health center serving educationally- and economically-disadvantaged Spanish-speaking-only Latino/as with co-morbid psychiatric needs, we observed outcomes for the BWL plus orlistat/placebo medication that approximate or are slightly dampened relative to the literature for efficacy trials with much more restrictive obese and BED samples. In this complex patient group, adding orlistat to BWL produced greater weight-loss than adding placebo among obese patients without BED but not among those with BED. Although 50% of BED patients maintained abstinence from binge-eating following these specific obesity treatments (BWL plus orlistat/placebo), BED was a negative prognostic indicator for some outcome variables.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00516919.

Inhibitory Activities of Cudrania tricuspidata Leaves on Pancreatic Lipase In Vitro and Lipolysis In Vivo

To identify effective herb to treat obesity, we screened 115 herbal extracts for inhibition of porcine pancreatic lipase (triacylg-ycerol acylhydrolase, EC 3.1.1.3) activity in vitro. Of the extracts tested, Cudrania tricuspidata leaves exhibited the most pronounced inhibitory effect on lipase activity with an IC₅₀ value of 9.91 μg/mL. Antilipid absorption effects of C. tricuspidata leaves were examined in rats after oral administration of lipid emulsions containing 50 or 250 mg  C. tricuspidata/kg body weight. Plasma triacylglycerol levels 2 h after the oral administration of emulsions containing C. tricuspidata were significantly reduced compared to the untreated group (P < 0.05). These results suggest that C. tricuspidata leaves may be useful for the treatment of obesity.

The vagus nerve and the inflammatory reflex--linking immunity and metabolism

The vagus nerve has an important role in regulation of metabolic homeostasis, and efferent vagus nerve-mediated cholinergic signalling controls immune function and proinflammatory responses via the inflammatory reflex. Dysregulation of metabolism and immune function in obesity are associated with chronic inflammation, a critical step in the pathogenesis of insulin resistance and type 2 diabetes mellitus. Cholinergic mechanisms within the inflammatory reflex have, in the past 2 years, been implicated in attenuating obesity-related inflammation and metabolic complications. This knowledge has led to the exploration of novel therapeutic approaches in the treatment of obesity-related disorders.

Inhibition of fatty acid metabolism reduces human myeloma cells proliferation

Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40–70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma.

Health promotion lifestyle interventions for weight management in psychosis: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Psychiatric patients have more physical health problems and much shorter life expectancies compared to the general population, due primarily to premature cardiovascular disease. A multi-causal model which includes a higher prevalence of risk factors has provided a valid explanation. It takes into consideration not only risks such as gender, age, and family history that are inherently non-modifiable, but also those such as obesity, smoking, diabetes, hypertension, and dyslipidemia that are modifiable through behavioural changes and improved care. Thus, it is crucial to focus on factors that increase cardiovascular risk. Obesity in particular has been associated with both the lifestyle habits and the side effects of antipsychotic medications. The present systematic review and meta-analysis aims at collecting and updating available evidence on the efficacy of non-pharmacological health promotion programmes for psychotic patients in randomised clinical trials.

METHODS

We systematically reviewed the randomised controlled trials from 1990 onward, in which psychoeducational and/or cognitive-behavioural interventions aimed at weight loss or prevention of weight gain in patients with psychosis had been compared to treatment as usual. We carried out a meta-analysis and pooled the results of the studies with Body Mass Index as primary outcome.

RESULTS

The results of the meta-analysis show an effect toward the experimental group. At the end of the intervention phase there is a -0.98 kg/m(2) reduction in the mean Body Mass Index of psychotic subjects. Notably, prevention studies with individual psychoeducational programmes that include diet and/or physical activity seem to have the highest impact.

CONCLUSIONS

When compared with treatment as usual in psychotic patients, preventive and individual lifestyle interventions that include diet and physical activity generally prove to be effective in reducing weight. Physical screening and monitoring programmes are well accepted by patients and can be implemented in a variety of settings. A weight loss of 0.98 points in the Body Mass Index corresponds to a loss of 3.12% of the initial weight. This percentage is below the 5% to 10% weight loss deemed sufficient to improve weight-related complications such as hypertension, type II diabetes, and dyslipidemia. However, it is reported that outcomes associated with metabolic risk factors may have greater health implications than weight changes alone. Therefore, in addition to weight reduction, the assessment of metabolic parameters to monitor other independent risk factors should also be integrated into physical health promotion and management in people with mental disorders.

Role of the gut in lipid homeostasis

Intestinal lipid transport plays a central role in fat homeostasis. Here we review the pathways regulating intestinal absorption and delivery of dietary and biliary lipid substrates, principally long-chain fatty acid, cholesterol, and other sterols. We discuss the regulation and functions of CD36 in fatty acid absorption, NPC1L1 in cholesterol absorption, as well as other lipid transporters including FATP4 and SRB1. We discuss the pathways of intestinal sterol efflux via ABCG5/G8 and ABCA1 as well as the role of the small intestine in high-density lipoprotein (HDL) biogenesis and reverse cholesterol transport. We review the pathways and genetic regulation of chylomicron assembly, the role of dominant restriction points such as microsomal triglyceride transfer protein and apolipoprotein B, and the role of CD36, l-FABP, and other proteins in formation of the prechylomicron complex. We will summarize current concepts of regulated lipoprotein secretion (including HDL and chylomicron pathways) and include lessons learned from families with genetic mutations in dominant pathways (i.e., abetalipoproteinemia, chylomicron retention disease, and familial hypobetalipoproteinemia). Finally, we will provide an integrative view of intestinal lipid homeostasis through recent findings on the role of lipid flux and fatty acid signaling via diverse receptor pathways in regulating absorption and production of satiety factors.

Intragastric balloon in association with lifestyle and/or pharmacotherapy in the long-term management of obesity

BACKGROUND

Intragastric balloon (BioEnterics Intragastric Balloon, BIB®) or pharmacotherapy are possible options for the treatment of obese patients when traditional approaches have failed. The aim of our study was to compare in obese patients the effect on weight loss and metabolic changes of lifestyle modifications associated with either BIB or pharmacotherapy or the two treatments in sequence as a maintenance strategy for weight loss.

METHODS

Fifty obese patients were recruited and randomly assigned to lifestyle modifications combined with either BIB for 6 months (n = 30) or sibutramine (pharmacotherapy group) for 1 year (n = 20). After BIB removal, patients were randomly assigned to either correct lifestyle (BIB/lifestyle) or lifestyle plus pharmacotherapy (BIB/pharmacotherapy).

RESULTS

At 6 months, patients treated with BIB lost significantly (P < 0.05) more weight (percent of initial weight lost, %IWL = 14.5 ± 1.2; percent of excess BMI lost, %EBL = 37.7 ± 3.2) than patients who received pharmacological treatment (%IWL = 9.1 ± 1.5, %EBL = 25.3 ± 4.1). At 1 year, the weight lost was significantly (P < 0.05) greater in patients treated with either BIB/pharmacotherapy (%IWL = 15.8 ± 2.3%, %EBL = 41.3 ± 6.7%) or BIB/lifestyle (%IWL = 14.3 ± 2.7, %EBL = 34.9 ± 6.5%) in respect to pharmacotherapy group (%IWL = 8.0 ± 1.4%, %EBL = 22.1 ± 3.9%). Moreover, patients treated sequentially with BIB/lifestyle or BIB/pharmacotherapy showed a significant (P < 0.05) improvement in insulin sensitivity and triglycerides levels.

CONCLUSIONS

BIB represents an efficacious long-term obesity treatment when supplemental strategies, as lifestyle modifications or pharmacotherapy, are established for weight maintenance after its removal.

Effects of glucagon-like peptide-1 receptor agonists on body weight: a meta-analysis

Glucagon-Like Peptide-1 receptor agonists (GLP-1RAs), approved as glucose-lowering drugs for the treatment of type 2 diabetes, have also been shown to reduce body weight. An extensive Medline, Cochrane database, and Embase search for “exenatide,” “liraglutide,” “albiglutide,” “semaglutide,” and “lixisenatide” was performed, collecting all randomized clinical trials on humans up to December 15, 2011, with a duration of at least 24 weeks, comparing GLP-1 receptor agonists with either placebo or active drugs. Twenty two (7,859 patients) and 7 (2,416 patients) trials with available results on body weight at 6 and 12 months, respectively, were included. When compared with placebo, GLP-1RAs determine a reduction of BMI at 6 months of −1.0 [−1.3; −0.6] kg/m². Considering the average BMI at baseline (32.4 kg/m²) these data means a weight reduction of about 3% at 6 months. This result could seem modest from a clinical standpoint; however, it could be affected by many factors contributing to an underestimation of the effect of GLP-1RA on body weight, such as non adequate doses, inclusion criteria, efficacy of GLP-1RA on reducing glycosuria, and association to non-pharmacological interventions not specifically aimed to weight reduction.

Metabolic rate regulation by the renin-angiotensin system: brain vs. body

Substantial evidence supports a role for the renin-angiotensin system (RAS) in the regulation of metabolic function, but an apparent paradox exists where genetic or pharmacological inhibition of the RAS occasionally has similar physiological effects as chronic angiotensin infusion. Similarly, while RAS targeting in animal models has robust metabolic consequences, effects in humans are more subtle. Here, we review the data supporting a role for the RAS in metabolic rate regulation and propose a model where the local brain RAS works in opposition to the peripheral RAS, thus helping to explain the paradoxically similar effects of RAS supplementation and inhibition. Selectively modulating the peripheral RAS or brain RAS may thus provide a more effective treatment paradigm for obesity and obesity-related disorders.

A pilot study investigating the efficacy of postoperative dietary counseling to improve outcomes after bariatric surgery

BACKGROUND

Bariatric surgery is a powerful treatment of severe obesity. During the past several years, a greater appreciation for the need for multidisciplinary care to optimize outcomes has developed, and a number of studies have been started to examine the role of postoperative interventions used in combination with surgery. The purpose of the present study was to investigate the hypothesis that the provision of postoperative dietary counseling, delivered by a registered dietitian, would lead to greater weight loss and more positive improvements in dietary intake and eating behavior compared with standard postoperative care. The study was performed at an academic medical center.

METHODS

Eighty-four individuals who underwent bariatric surgery were randomly assigned to receive either dietary counseling or standard postoperative care for the first 4 months after surgery. The participants completed measures of macronutrient intake and eating behavior at baseline and 2, 4, 6, 12, 18, and 24 months after surgery.

RESULTS

The patients who received dietary counseling achieved greater weight loss than those who received standard postoperative care that did not involve this counseling, although this difference did not reach statistical significance. Patients in the dietary counseling arm did report significant changes in several eating behaviors believed to be important to successful long-term weight maintenance.

CONCLUSION

The results of our pilot study provide some support for the efficacy of early postoperative dietary counseling to improve outcomes after bariatric surgery.

Identification of new genes involved in human adipogenesis and fat storage

Since the worldwide increase in obesity represents a growing challenge for health care systems, new approaches are needed to effectively treat obesity and its associated diseases. One prerequisite for advances in this field is the identification of genes involved in adipogenesis and/or lipid storage. To provide a systematic analysis of genes that regulate adipose tissue biology and to establish a target-oriented compound screening, we performed a high throughput siRNA screen with primary (pre)adipocytes, using a druggable siRNA library targeting 7,784 human genes. The primary screen showed that 459 genes affected adipogenesis and/or lipid accumulation after knock-down. Out of these hits, 333 could be validated in a secondary screen using independent siRNAs and 110 genes were further regulated on the gene expression level during adipogenesis. Assuming that these genes are involved in neutral lipid storage and/or adipocyte differentiation, we performed InCell-Western analysis for the most striking hits to distinguish between the two phenotypes. Beside well known regulators of adipogenesis and neutral lipid storage (i.e. PPARγ, RXR, Perilipin A) the screening revealed a large number of genes which have not been previously described in the context of fatty tissue biology such as axonemal dyneins. Five out of ten axonemal dyneins were identified in our screen and quantitative RT-PCR-analysis revealed that these genes are expressed in preadipocytes and/or maturing adipocytes. Finally, to show that the genes identified in our screen are per se druggable we performed a proof of principle experiment using an antagonist for HTR2B. The results showed a very similar phenotype compared to knock-down experiments proofing the “druggability”. Thus, we identified new adipogenesis-associated genes and those involved in neutral lipid storage. Moreover, by using a druggable siRNA library the screen data provides a very attractive starting point to identify anti-obesity compounds targeting the adipose tissue.

Neuronal and intracellular signaling pathways mediating GLP-1 energy balance and glycemic effects

The glucagon-like peptide-1 (GLP-1) system is physiologically involved in the control of energy balance and blood glucose homeostasis. Thus, GLP-1-based pharmaceuticals are emerging as a potent treatment for not only type II diabetes mellitus (T2DM), but potentially for obesity as well. Despite the plethora of investigations over the last two decades examining the physiological, endocrine, and behavioral responses mediated by the GLP-1 receptor (GLP-1R), the field is only recently embracing the perspective that GLP-1-mediated control of food intake and glycemia involves action on GLP-1R that are distributed throughout the periphery (e.g. pancreatic β-cells, vagus nerve), as well as action on many GLP-1R-expressing nuclei within the central nervous system (CNS). This review highlights peripheral, as well as central GLP-1R populations that mediate GLP-1's food intake inhibitory and glycemic effects. In addition, focus is devoted to recent studies that examine the GLP-1R-mediated intracellular signaling pathways that are required for GLP-1's glycemic and feeding responses.

Additive feeding inhibitory and aversive effects of naltrexone and exendin-4 combinations

Objective

One developing strategy for obesity treatment has been to use combinations of differently acting pharmacotherapies to improve weight loss with fewer adverse effects. The purpose of this study was to determine whether the combination of naltrexone, an opioid antagonist acting on the reward system, and exendin-4, a glucagon-like peptide 1 (GLP-1) agonist, acting on satiety signaling, would produce larger reductions in food intake than either alone in rats. Because the anorectic potencies of both compounds have been associated with nausea and malaise, the influence of these drug combinations on the acquisition of a conditioned taste aversion (CTA) was also determined.

Methods

In Experiment 1, the acute anorectic effects of naltrexone (0.32–3.2 mg/kg; IP) and exendin-4 (1–10 µg/kg; IP) were assessed alone or in combination. Combinational doses were further investigated by the repeated daily administration of 1 mg/kg naltrexone + 3.2 µg/kg exendin-4 for 4 days. In Experiment 2, both compounds alone or in combination were used as unconditioned stimuli in a series of CTA tests.

Results

Naltrexone and exendin-4, alone or in combination, suppressed food intake in a dose dependent fashion, and the interaction on food intake between naltrexone and exendin-4 was additive. In the CTA paradigm, naltrexone (1 mg/Kg) alone did not support acquisition, whereas a CTA was evident with doses of Ex-4 (1 or 3.2 µg/Kg). Combinations of naltrexone and exendin-4 also resulted in a more rapid and robust acquisition of a CTA.

Conclusion

Given that the Nal and Ex-4 combination produces additive effects on not only food intake reduction but also food aversion learning, this specific drug combination does not have the benefit of minimizing the adverse effects associated with each individual drug. These data suggest that it is necessary to evaluate both the positive and adverse effects at early stages of combinational drug development.

Anti-Obesity Drugs: A Review about Their Effects and Safety

The current recommendations for the treatment of obese people include increased physical activity and reduced calories intake. When the behavioral approach is not sufficient, a pharmacologic treatment is recommended. In past years, numerous drugs have been approved for the treatment of obesity; however, most of them have been withdrawn from the market because of their adverse effects. In fact, amphetamine, rimonabant and sibutramine licenses have been withdrawn due to an increased risk of psychiatric disorders and non-fatal myocardial infarction or stroke. Even if orlistat is not as effective as other drugs in reducing body weight, orlistat is presently the only available choice for the treatment of obesity because of its safety for cardiovascular events and positive effects on diabetic control. Hopefully, more effective and better tolerated anti-obesity drugs will be developed through an improved understanding of the multiple mechanisms and complex physiological systems targeting appetite.

Hindbrain leptin and glucagon-like-peptide-1 receptor signaling interact to suppress food intake in an additive manner

Background

The physiological control of feeding behavior involves modulation of the intake inhibitory effects of gastrointestinal satiation signaling via endogenous hindbrain leptin receptor (LepR) and glucagon-like-peptide-1 receptor (GLP-1R) activation.

Design and Results

Using a variety of dose-combinations of hindbrain delivered (4^th icv) leptin and the GLP-1R agonist exendin-4, experiments demonstrate that hindbrain LepR and GLP-1R signaling interact to control food intake and body weight in an additive fashion. In addition, the maximum intake suppressive response that could be achieved by 4^th icv leptin alone in non-obese rats (~33%) was shown to be further suppressed when exendin-4 was co-administered. Importantly, it was determined that the interaction between hindbrain LepR signaling and GLP-1R signaling is relevant to endogenous food intake control, as hindbrain GLP-1R blockade by the selective antagonist exendin-(9–39) attenuated the intake inhibitory effects of hindbrain leptin delivery.

Conclusions

Collectively, the findings reported here show that hindbrain LepR and GLP-1R activation interact in at least an additive fashion to control food intake and body weight. As evidence is accumulating that combination pharmacotherapies offer greater sustained food intake and body weight suppression in obese individuals when compared to mono-drug therapies or lifestyle modifications alone, these findings highlight the need for further examination of combined CNS GLP-1R and LepR signaling as a potential drug target for obesity treatment.

Early resolution of type 2 diabetes seen after Roux-en-Y gastric bypass and vertical sleeve gastrectomy

BACKGROUND

Type 2 diabetes (T2D) accounts for the majority of diagnosed cases of diabetes in adults in the United States. Many of these individuals are also morbidly obese and choose to undergo bariatric surgery to lose weight and gain glycemic control. The Roux-en-Y gastric bypass (RYGB) has been shown to resolve diabetes before substantial weight loss occurs. Several studies suggest that the vertical sleeve gastrectomy (VSG), a newer bariatric operation, may result in comparable weight loss and rapid diabetes control.

METHODS

We conducted a retrospective chart review of 262 patients diagnosed with diabetes who underwent either the RYGB or the VSG between 2002 and 2010. Medication usage before and after surgery was recorded. Patients who discontinued all medications postoperatively were considered "resolved" of T2D, and those who reduced the number of medications were considered as "showing improvement" in their T2D. Peri- and postoperative complications were also recorded for each operation.

RESULTS

At 8 weeks postoperatively, follow-up data were available for 38 RYGB patients and 71 VSG patients. Approximately 79% of RYGB patients and 83% of VSG patients remained off their diabetes medication. VSG patients experienced a significantly lower incidence of major and minor complications both peri- and postoperatively compared with RYGB patients.

CONCLUSIONS

Both operations appear to equally resolve T2D in an obese, adult population; however, the incidence of both major and minor complications is much lower in the VSG patient group. Therefore, the VSG should also be considered as a treatment option for obese individuals with T2D.

High-resolution mapping of a novel genetic locus regulating voluntary physical activity in mice

Both human beings and animals exhibit substantial inter-individual variation in voluntary physical activity, and evidence indicates that a significant component of this variation is because of genetic factors. However, little is known of the genetic basis underlying central regulation of voluntary physical activity in mammals. In this study, using an F(2) intercross population and interval-specific congenic strains (ISCS) derived from the C57BL/6J strain and a chromosome 13 substitution strain, C57BL/6J-Chr13A/J/NA/J, we identified a 3.76-Mb interval on chromosome 13 containing 25 genes with a significant impact on daily voluntary wheel running activity in mice. Brain expression and polymorphisms between the C57BL/6J and A/J strains were examined to prioritize candidate genes. As the dopaminergic pathway regulates motor movement and motivational behaviors, we tested its function by examining cocaine-induced locomotor responses in ISCS with different levels of activity. The low-activity ISCS exhibited a significantly higher response to acute cocaine administration than the high-activity ISCS. Expression analysis of key dopamine-related genes (dopamine transporter and D1, D2, D3, D4 and D5 receptors) revealed that expression of D1 receptor was higher in the low-activity ISCS than in the high-activity ISCS in both the dorsal striatum and nucleus accumbens. Pathway analysis implicated Tcfap2a, a gene found within the 3.76-Mb interval, involved in the D1 receptor pathway. Using a luciferase reporter assay, we confirmed that the transcriptional factor, Tcfap2a, regulates the promoter activity of the D1 receptor gene. Thus, Tcfap2a is proposed as a candidate genetic regulator of the level of voluntary physical activity through its influence on a dopaminergic pathway.

Improving pregnancy outcome in obese women

The global pandemic of maternal obesity presents a major challenge for healthcare providers, and has significant short- and long-term implications for both maternal and fetal health. Currently, the evidence-base underpinning many of the interventions either currently in use or recommended to improve pregnancy outcome in obese women is limited. The nature and timing of these interventions vary widely, ranging from simple advice to more intensive dietary and exercise programmes, cognitive behavioural therapy and drug trials. In addition, a growing number of very severely obese women now enter pregnancy having had surgical interventions. Although surgical interventions such as gastric bypass or banding may be associated with improved pregnancy outcomes, these women have particular nutritional requirements, which need to be addressed to optimise pregnancy outcome. Until the outcomes of ongoing current trials are reported and provide a firm evidence base on which to base future intervention strategies and guide evidence based care for obese pregnant women, pregnancy outcome is best optimised by high-risk antenatal care delivered by healthcare providers who are experienced in supporting these high-risk women.

Investigation of Mendelian forms of obesity holds out the prospect of personalized medicine

Mendelian forms of obesity are already known to account for approximately 5% of the severely obese but are currently underinvestigated. In contrast, there has been much recent concentration on genome-wide single nucleotide polymorphism (SNP) associations in obesity, with particular emphasis given to the role of the fat mass and obesity associated (FTO) gene. Unfortunately, despite the enormous resources devoted to this work, none of the SNP markers in the ∼30 genes discovered to have associations with common obesity have meaningful predictive power. This is very different from the situation for Mendelian obesity, where mutations have very clear effects on phenotype. Study of Mendelian obesity has also added significantly to our understanding of mechanisms of appetite regulation, with all known causative genes being active in the brain and most forming part of the leptin-melanocortin signaling pathway. Investigation of genomic structural variation has also recently revealed deletions causing obesity, sometimes with concomitant neurocognitive dysfunction. Advances in next-generation sequencing are expected to uncover additional highly penetrant causes of obesity. Screening for Mendelian forms of obesity is rarely carried out but holds considerable promise for improved clinical care of these high-risk patients.

Lifestyle modification in the management of the metabolic syndrome: achievements and challenges

Lifestyle modification based on behavior therapy is the most important and effective strategy to manage the metabolic syndrome. Modern lifestyle modification therapy combines specific recommendations on diet and exercise with behavioral and cognitive strategies. The intervention may be delivered face-to-face or in groups, or in groups combined with individual sessions. The main challenge of treatment is helping patients maintain healthy behavior changes in the long term. In the last few years, several strategies have been evaluated to improve the long-term effect of lifestyle modification. Promising results have been achieved by combining lifestyle modification with pharmacotherapy, using meals replacement, setting higher physical activity goals, and long-term care. The key role of cognitive processes in the success/failure of weight loss and maintenance suggests that new cognitive procedures and strategies should be included in the traditional lifestyle modification interventions, in order to help patients build a mind-set favoring long-term lifestyle changes. These new strategies raise optimistic expectations for an effective treatment of metabolic syndrome with lifestyle modifications, provided public health programs to change the environment where patients live support them.