The Fight Against Obesity Escalates: New Drugs on the Horizon and Metabolic Implications

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

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

Obesity and Leukemia: Biological Mechanisms, Perspectives, and Challenges

PURPOSE OF REVIEW

To examine the epidemiological data on obesity and leukemia; evaluate the effect of obesity on leukemia outcomes in childhood acute lymphoblastic leukemia (ALL) survivors; assess the potential mechanisms through which obesity may increase the risk of leukemia; and provide the effects of obesity management on leukemia. Preventive (diet, physical exercise, obesity pharmacotherapy, bariatric surgery) measures, repurposing drugs, candidate therapeutic agents targeting oncogenic pathways of obesity and insulin resistance in leukemia as well as challenges of the COVID-19 pandemic are also discussed.

RECENT FINDINGS

Obesity has been implicated in the development of 13 cancers, such as breast, endometrial, colon, renal, esophageal cancers, and multiple myeloma. Leukemia is estimated to account for approximately 2.5% and 3.1% of all new cancer incidence and mortality, respectively, while it represents the most frequent cancer in children younger than 5 years. Current evidence indicates that obesity may have an impact on the risk of leukemia. Increased birthweight may be associated with the development of childhood leukemia. Obesity is also associated with worse outcomes and increased mortality in leukemic patients. However, there are several limitations and challenges in meta-analyses and epidemiological studies. In addition, weight gain may occur in a substantial number of childhood ALL survivors while the majority of studies have documented an increased risk of relapse and mortality among patients with childhood ALL and obesity. The main pathophysiological pathways linking obesity to leukemia include bone marrow adipose tissue; hormones such as insulin and the insulin-like growth factor system as well as sex hormones; pro-inflammatory cytokines, such as IL-6 and TNF-α; adipocytokines, such as adiponectin, leptin, resistin, and visfatin; dyslipidemia and lipid signaling; chronic low-grade inflammation and oxidative stress; and other emerging mechanisms. Obesity represents a risk factor for leukemia, being among the only known risk factors that could be prevented or modified through weight loss, healthy diet, and physical exercise. Pharmacological interventions, repurposing drugs used for cardiometabolic comorbidities, and bariatric surgery may be recommended for leukemia and obesity-related cancer prevention.

Short-Chain Fatty Acids-A Product of the Microbiome and Its Participation in Two-Way Communication on the Microbiome-Host Mammal Line

PURPOSE OF REVIEW

The review aims to describe short-chain fatty acids (SCFAs) as metabolites of bacteria, their complex influence on whole-body metabolism, and alterations in the SCFA profile in obesity and after bariatric surgery (BS).

RECENT FINDINGS

The fecal profile of SCFAs in obese patients differs from that of lean patients, as well as their gut microbiota composition. In obese patients, a lower diversity of bacteria is observed, as well as higher concentrations of SCFAs in stool samples. Obesity is now considered a global epidemic and bariatric surgery (BS) is an effective treatment for severe obesity. BS affects the structure and functioning of the digestive system, and also alters gut microbiota and the concentration of fecal SCFAs. Generally, after BS, SCFA levels are lower but levels of branched short-chain fatty acids (BSCFAs) are elevated, the effect of which is not fully understood. Moreover, changes in the profile of circulating SCFAs are little known and this is an area for further research. Obesity seems to be inherently associated with changes in the SCFA profile. It is necessary to better understand the impact of BS on microbiota and the metabolome in both feces and blood as only a small percentage of SCFAs are excreted. Further research may allow the development of a personalized therapeutic approach to the BS patient in terms of diet and prebiotic intervention.

The Role of Next-Generation Probiotics in Obesity and Obesity-Associated Disorders: Current Knowledge and Future Perspectives

Obesity and obesity-associated disorders pose a major public health issue worldwide. Apart from conventional weight loss drugs, next-generation probiotics (NGPs) seem to be very promising as potential preventive and therapeutic agents against obesity. Candidate NGPs such as Akkermansia muciniphila, Faecalibacterium prausnitzii, Anaerobutyricum hallii, Bacteroides uniformis, Bacteroides coprocola, Parabacteroides distasonis, Parabacteroides goldsteinii, Hafnia alvei, Odoribacter laneus and Christensenella minuta have shown promise in preclinical models of obesity and obesity-associated disorders. Proposed mechanisms include the modulation of gut flora and amelioration of intestinal dysbiosis, improvement of intestinal barrier function, reduction in chronic low-grade inflammation and modulation of gut peptide secretion. Akkermansia muciniphila and Hafnia alvei have already been administered in overweight/obese patients with encouraging results. However, safety issues and strict regulations should be constantly implemented and updated. In this review, we aim to explore (1) current knowledge regarding NGPs; (2) their utility in obesity and obesity-associated disorders; (3) their safety profile; and (4) their therapeutic potential in individuals with overweight/obesity. More large-scale, multicentric and longitudinal studies are mandatory to explore their preventive and therapeutic potential against obesity and its related disorders.

Obesity and main urologic cancers: Current systematic evidence, novel biological mechanisms, perspectives and challenges

Urologic cancers (UC) account for 13.1% of all new cancer cases and 7.9% of all cancer-related deaths. A growing body of evidence has indicated a potential causal link between obesity and UC. The aim of the present review is to appraise in a critical and integrative manner evidence from meta-analyses and mechanistic studies on the role of obesity in four prevalent UC (kidney-KC, prostate-PC, urinary bladder-UBC, and testicular cancer-TC). Special emphasis is given on Mendelian Randomization Studies (MRS) corroborating a genetic causal association between obesity and UC, as well as on the role of classical and novel adipocytokines. Furthermore, the molecular pathways that link obesity to the development and progression of these cancers are reviewed. Available evidence indicates that obesity confers increased risk for KC, UBC, and advanced PC (20-82%, 10-19%, and 6-14%, respectively), whereas for TC adult height (5-cm increase) may increase the risk by 13%. Obese females tend to be more susceptible to UBC and KC than obese males. MRS have shown that a higher genetic-predicted BMI may be causally linked to KC and UBC but not PC and TC. Biological mechanisms that are involved in the association between excess body weight and UC include the Insulin-like Growth Factor axis, altered availability of sex hormones, chronic inflammation and oxidative stress, abnormal secretion of adipocytokines, ectopic fat deposition, dysbiosis of the gastrointestinal and urinary tract microbiomes and circadian rhythm dysregulation. Anti-hyperglycemic and non-steroidal anti-inflammatory drugs, statins, and adipokine receptor agonists/antagonists show potential as adjuvant cancer therapies. Identifying obesity as a modifiable risk factor for UC may have significant public health implications, allowing clinicians to tailor individualized prevention strategies for patients with excess body weight.

Metabolically Healthy Obesity: Are Interventions Useful?

PURPOSE OF REVIEW

This review aims to detail the current global research state of metabolically healthy obesogenesis with regard to metabolic factors, disease prevalence, comparisons to unhealthy obesity, and targeted interventions to reverse or delay progression from metabolically healthy to unhealthy obesity.

RECENT FINDINGS

As a long-term condition with increased risk of cardiovascular, metabolic, and all-cause mortality risks, obesity threatens public health on a national level. The recent discovery of metabolically healthy obesity (MHO), a transitional condition during which obese persons carry comparatively lower health risks, has added to confusion about the true effect of visceral fat and subsequent long-term health risks. In this context, the evaluation of fat loss interventions, such as bariatric surgery, lifestyle changes (diet/exercise), and hormonal therapies require re-evaluation in light of evidence that progression to high-risk stages of obesity relies on metabolic status and that strategies to protect the metabolism may be useful in the prevention of metabolically unhealthy obesity. Typical calorie-based exercise and diet interventions have failed to reduce the prevalence of unhealthy obesity. Holistic lifestyle, psychological, hormonal, and pharmacological interventions for MHO, on the other hand, may at least prevent progression to metabolically unhealthy obesity.

Glucagon-like peptide-1 (GLP-1) receptor agonists and neuroinflammation: Implications for neurodegenerative disease treatment

Chronic, excessive neuroinflammation is a key feature of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). However, neuroinflammatory pathways have yet to be effectively targeted in clinical treatments for such diseases. Interestingly, increased inflammation and neurodegenerative disease risk have been associated with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), suggesting that treatments that mitigate T2DM pathology may be successful in treating neuroinflammatory and neurodegenerative pathology as well. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that promotes healthy insulin signaling, regulates blood sugar levels, and suppresses appetite. Consequently, numerous GLP-1 receptor (GLP-1R) stimulating drugs have been developed and approved by the US Food and Drug Administration (FDA) and related global regulatory authorities for the treatment of T2DM. Furthermore, GLP-1R stimulating drugs have been associated with anti-inflammatory, neurotrophic, and neuroprotective properties in neurodegenerative disorder preclinical models, and hence hold promise for repurposing as a treatment for neurodegenerative diseases. In this review, we discuss incretin signaling, neuroinflammatory pathways, and the intersections between neuroinflammation, brain IR, and neurodegenerative diseases, with a focus on AD and PD. We additionally overview current FDA-approved incretin receptor stimulating drugs and agents in development, including unimolecular single, dual, and triple receptor agonists, and highlight those in clinical trials for neurodegenerative disease treatment. We propose that repurposing already-approved GLP-1R agonists for the treatment of neurodegenerative diseases may be a safe, efficacious, and cost-effective strategy for ameliorating AD and PD pathology by quelling neuroinflammation.

Nutritional Deficiencies Before and After Bariatric Surgery: Prevention and Treatment

PURPOSE OF REVIEW

Bariatric surgery has the unique ability to drive substantial and sustainable weight loss in people living with obesity. Non-reversibility of these surgical techniques provides lifelong benefits but entails the need for continuous medical follow-up. The purpose of the current paper is to review and summarize current data on nutritional deficiencies in patients before and after bariatric surgery.

RECENT FINDINGS

The cornerstone of preventing the emergence of disorders related to nutritional deficiencies is preoperative screening and correct supplementation since they may be exacerbated postoperatively. Following guidelines in conjunction to a lifelong personalized medical approach is of high importance. Bariatric surgery is a well-studied successful and durable means of weight loss that may lead to nutritional deficiencies. There is, thus, a medical need for careful monitoring and treatment of micro- and macronutrient deficiencies by an experienced multidisciplinary team.

[Obesity treatment-legal and illegal drugs and the future]

Obesity and its comorbidities represent a worldwide growing health challenge. In Germany, at least 15 million people are suffering from this disease. To date, lifestyle modification is the most frequently used treatment modality, but offers only limited success concerning both the extent and the sustainability of weight loss, while surgical interventions are restricted to people with severe obesity (body mass index ≥40 kg/m²). For this reason, there are huge efforts to develop pharmacological options for better and clinically meaningful weight management. At present, only a few compounds (orlistat, liraglutide, amfepramon) are available for adjunct drug treatment of obesity in Germany. However, new principles and compounds that could revolutionize obesity management in the years to come are on the horizon. For alternative "slimming drugs", mainly dietary supplements, scientific evidence is lacking on efficacy or clinically meaningful weight loss.

The Role of Mitochondrial Adaptation and Metabolic Flexibility in the Pathophysiology of Obesity and Insulin Resistance: an Updated Overview

PURPOSE OF REVIEW

The term "metabolic flexibility" denotes the dynamic responses of the cellular oxidative machinery in order to adapt to changes in energy substrate availability. A progressive loss of this adaptive capacity has been implicated in the development of obesity-related comorbidities. Mitochondria are dynamic intracellular organelles which play a fundamental role in energy metabolism, and the mitochondrial adaptation to environmental challenges may be viewed as the functional component of metabolic flexibility. Herein, we attempt to comprehensively review the available evidence regarding the role of mitochondrial adaptation and metabolic flexibility in the pathogenesis of obesity and related morbidities, namely insulin resistance states and non-alcoholic fatty liver disease (NAFLD).

RECENT FINDINGS

Overall, there is a concrete body of evidence to support the presence of impaired mitochondrial adaptation as a principal component of systemic metabolic inflexibility in conditions related to obesity. There are still many unresolved questions regarding the relationship between the gradual loss of mitochondrial adaptability and the progression of obesity-related complications, such as causality issues, the timely appearance and reversibility of the described disturbances, and the generalizability of the findings to the mitochondrial content of every affected tissue or organ. The evidence regarding the causality between the observed associations remains inconclusive, although most of the available data points towards a bidirectional, potentially mutually amplifying relationship. The spectrum of NAFLD is of particular interest, since functional and pathological changes in the course of its development closely mirror the progression of dysmetabolism, if not constituting a dynamic component of the latter.

Effects of weight loss medications on mortality and cardiovascular events: A systematic review of randomized controlled trials in adults with overweight and obesity

AIMS

Adults affected by obesity are at higher risk of premature mortality. Medications can help to lose weight and to maintain weight loss. Aim of this meta-analysis was to assess whether anti-obesity medications affect all-cause mortality, mortality due to cardiovascular events, cardiovascular risk factors and body weight.

DATA SYNTHESIS

A Medline search was performed to identify randomized controlled trials (RCTs) of anti-obesity medications in adults with overweight or obesity reporting data on all-cause mortality, cardiovascular mortality or non-fatal cardiovascular events, with a follow-up of at least 6 months. We identified 28 RCTs with 50,106 participants. The median follow-up was 52 weeks. Evidence did not show superiority of anti-obesity medications over placebo in reducing all-cause mortality (risk ratio 1.03, 95%Confidence Interval [CI] 0.87 to 1.21) or cardiovascular mortality (risk ratio 0.92, 95%CI 0.72 to 1.18). All-cause mortality rate was positively associated with weight loss (β = 0.0007; p = 0.045); hence, for each kg of body weight lost there was a 0.07% decrease of all-cause mortality. The pharmacological treatment reduced total-cholesterol (7.15 mg/dl; 95%CI 1.46-12.85), LDL-cholesterol (5.06 mg/dl; 95%CI 1.12-9.00), and triglycerides levels (9.88 mg/dl; 95%CI 5.02-14.75), while it increased HDL-cholesterol (1.37 mg/dl; 95%CI 0.17-2.57). Systolic blood pressure decreased (0.90 mmHg; 95%CI 0.15-1.64).

CONCLUSIONS

Although we were unable to demonstrate a superiority of anti-obesity medications over placebo on mortality, metaregression showed that even a small weight reduction tends to reduce all-cause mortality in obesity. Our data support public health measures to reduce the obesity burden by including the use of anti-obesity medications.

REGISTRATION NUMBER (PROSPERO)

CRD42020210329.

The psychological impact of COVID-19 pandemic on patients included in a bariatric surgery program

PURPOSE

The COVID-19 pandemic has radically impacted the world lifestyle. Epidemics are well-known to cause mental distress, and patients with a current or past history of obesity are at increased risk for the common presence of psychological comorbidities. This study investigates the psychological impact of the current pandemic in patients participating in a bariatric surgery program.

METHODS

Patients were consecutively enrolled during the Italian lockdown among those waiting for bariatric surgery or attending a post-bariatric follow-up, and were asked to complete through an online platform the Depression Anxiety Stress Scales-21 and a self-assessment questionnaire of 22 items evaluating the resilience, change in eating behavior and emotional responses referring to the ongoing pandemic.

RESULTS

59% of the 434 enrolled subjects reported of being worried about the pandemic, and 63% specifically reported of being worried about their or their relatives' health. 37% and 56% felt lonelier and more bored, respectively. 66% was hungrier with increased frequency of snacking (55%) and 39% reported more impulse to eat. Noteworthy, 49% felt unable to follow a recommended diet. No difference in terms of psychological profile was recorded among pre and post-bariatric subjects. Logistic regression analysis on post-bariatric patients showed a relationship between snacking, hunger, eating impulsivity, and anxiety, stress, and/or depression symptoms.

CONCLUSION

The pandemic led to increased psychological distress in patients with a current or past history of obesity, reducing quality of life and affecting dietary compliance. Targeted psychological support is warranted in times of increased stress for fragile subjects such as pre- and post-bariatric patients.

LEVEL OF EVIDENCE

Level V: cross-sectional descriptive study.

Long Noncoding RNAs: Novel Important Players in Adipocyte Lipid Metabolism and Derivative Diseases

Obesity, a global public health issue, is characterized by excessive adiposity and is strongly related to some chronic diseases including cardiovascular diseases and diabetes. Extra energy intake-induced adipogenesis involves various transcription factors and long noncoding RNAs (lncRNAs) that control lipogenic mRNA expression. Currently, lncRNAs draw much attention for their contribution to adipogenesis and adipose tissue function. Increasing evidence also manifests the pivotal role of lncRNAs in modulating white, brown, and beige adipose tissue development and affecting the progression of the diseases induced by adipose dysfunction. The aim of this review is to summarize the roles of lncRNAs in adipose tissue development and obesity-caused diseases to provide novel drug targets for the treatment of obesity and metabolic diseases.

Cardiovascular disease in patients with severe mental illness

Individuals diagnosed with schizophrenia or bipolar disorder have a life expectancy 15-20 years shorter than that in the general population. The rate of unnatural deaths, such as suicide and accidents, is high for these patients. Despite this increased proportion of unnatural deaths, physical conditions account for approximately 70% of deaths in patients with either schizophrenia or bipolar disorder, with cardiovascular disease contributing 17.4% and 22.0% to the reduction in overall life expectancy in men and women, respectively. Risk factors for cardiovascular disease, such as smoking, unhealthy diet and lack of exercise, are common in these patients, and lifestyle interventions have been shown to have small effects. Pharmacological interventions to reduce risk factors for cardiovascular disease have been proven to be effective. Treatment with antipsychotic drugs is associated with reduced mortality but also with an increased risk of weight gain, dyslipidaemia and diabetes mellitus. These patients have higher risks of both myocardial infarction and stroke but a lower risk of undergoing interventional procedures compared with the general population. Data indicate a negative attitude from clinicians working outside the mental health fields towards patients with severe mental illness. Education might be a possible method to decrease the negative attitudes towards these patients, thereby improving their rates of diagnosis and treatment.