Leptin, Obesity, and Leptin Resistance: Where Are We 25 Years Later?

The flowers extracts of Citrus aurantium regulates fat metabolism in obese C57BL/6J mice by improving intestinal microbiota disorders

BACKGROUND

Obesity can lead to many diseases such as diabetes, hypertension, cancer and cardiovascular diseases, which seriously affect people's quality of life and health.

AIMS OF THE STUDY

To investigate the main components and potential of n-butanol extract from Citrus aurantium L. var. amara Engl to reduce lipid accumulation and to explore its modulatory effects on the gut microbiota.

METHODS

The main components of n-butanol extract were analyzed using liquid chromatography quadrupole trap mass spectrometry (LC-QTRAP-MS) and a high-fat diet-induced obese mouse model was established to analyze its effects on the determination of gene expression levels and intestinal microbiota using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and 16S rRNA gene sequence method.

RESULTS

The n-butanol extract mainly consists of 15 components, and it could significantly inhibit weight gain, reduce liver coefficient and improve oxidative damage. By regulating the expression of related genes, it inhibited hepatic steatosis and hypertrophy of epididymal tissue. The n-butanol extract increased the diversity of intestinal microbiota, improved the composition and structure of the flora, and reversed the high-fat diet-induced disturbance of intestinal microbiota in mice.

CONCLUSION

These results indicated that the n-butanol extract of C. aurantium could inhibit lipid accumulation and provide a more comprehensive basis for the development and utilization of C. aurantium in anti-obesity activity. © 2025 Society of Chemical Industry.

Low-grade systemic inflammation biomarkers in sedentary young healthy adults are not significantly affected by a 24-week concurrent training intervention

In this study, we measured the dose-response effect of a 24-week concurrent training (CT) intervention on low-grade systemic inflammation biomarkers in sedentary young healthy adults. A total of 100 untrained participants were randomized to (1) no exercise (control group, n = 35), (2) aerobic + resistance exercise (CT) at moderate intensity (exercise-moderate group; n = 33), or (3) CT at vigorous intensity (exercise-vigorous group, n = 32). Serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), IL-7, IL-8, and IL-10, interferon-gamma (IFN-γ), tumor necrosis factor-α, leptin, and adiponectin were determined and compared among the three groups. The exercise-vigorous group members had lower differences in IL-7 levels among them, compared to the exercise-moderate group members (Δ = ‒7.97% vs. 1.90%; p = 0.030; 95% CI [‒0.90, ‒0.04]). The exercise-vigorous group members showed higher differences in CRP values (Δ = 20.1%; F = 3.339; p = 0.046) compared to both the control (Δ = ‒1.91%) and the exercise-moderate (Δ = ‒23.3%) group members, whereas the control group exhibited higher differences in IFN-γ levels compared to the exercise-vigorous group (Δ = 15.3% vs. 2.62%; p = 0.048; 95% CI [‒0.68, ‒0.01]). For individuals in the three groups, body composition and physical fitness correlated overall with leptin. The data show, and we concluded, that the training intervention had no significant effect on low-grade systemic inflammation biomarkers.

Chromium and formoterol therapy for obesity-induced asthma in rats

The development of asthma is impacted by fat. Asthma is more common in obese persons. The purpose of the experimental study is to determine how chromium, formoterol, and their combination can improve the quality of life for obese people with lung anomalies. Thirty-six male Wistar rats were divided into six groups: control (C), obesity (CO), obese-asthma (COA), and obese-asthma groups treated with formoterol (OAF), chromium (OACR), or both (OACRF). Except for group C, all groups received a high-fat diet for 4 weeks. Subsequently, ovalbumin (OVA) was administered subcutaneously (s.c.) to all groups except C and CO to induce sensitization. Asthma was triggered via 1% OVA aerosol challenges on days 26-28. Over 5 days, OAF and OACRF received daily formoterol inhalations (50 μg/kg), while OACR and OACRF were given chromium (400 μg/kg). Treatments were timed to align with asthma induction protocols. Lipid profile and inflammatory indicators were examined at the end of the trial-Immunohistochemical analysis of lung tissue, Histopathological and lung tissue stained with Hematoxylin and Eosin. The combination therapy (OACRF) significantly reduced body weight (p < 0.05), lowered LDL and triglycerides, increased HDL, and normalized lung tissue architecture compared to controls. Immunohistochemistry revealed reduced IL-1β and IL-17α expression. The (OACRF) group demonstrated superior asthma control by reducing body weight, improving inflammatory indicators, and restoring lung tissue to its normal state by administering chromium and formoterol therapy. The most effective strategy for treating both obesity and asthma is to address their two connected conditions. These findings demonstrate that combined chromium and formoterol therapy effectively addresses metabolic and inflammatory components of obesity-induced asthma, offering a promising dual-target therapeutic strategy.

Does BMI matter when treating depression with esketamine? A retrospective analysis of real-world data

OBJECTIVE

Intranasal (IN) esketamine was approved as a therapy for treatment-resistant depression in March 2019. There continues to be interest in the field to better understand factors associated with response to treatment. The aim of the current study is to assess the association between BMI and response to esketamine.

METHODS

A retrospective analysis was conducted on all patients treated with intranasal esketamine at the Yale Interventional Psychiatry Service between January 2015 and May 2023. The primary outcome was the association between BMI (ctegorized as obese vs. non-obese) and response to treatment (≥50 % improvement) by Montgomery-Åsberg Depression Rating Scale (MADRS). Statistical models, including generalized linear mixed-effects models were employed.

RESULTS

A total of 190 patients met criteria for inclusion in the study, out of which 34.2 % were categorized as obese. Patients with obesity were significantly more likely to respond to esketamine treatment (RR = 1.63; p = 0.033) compared to non-obese patients. No linear association between BMI and treatment response was observed when BMI was treated as a continuous variable (RR = 1.02, p = 0.163).

CONCLUSION

Obesity appears to be associated with a higher response rate to intranasal esketamine treatment for depression. Although the underlying mechanisms of this association are still unknown, increased body fat may prolong the presence of lipid-soluble compounds such as ketamine/esketamine or their active metabolites.

Effect of interdisciplinary obesity care on metabolic markers and body weight in people with type 2 diabetes in a rural setting: A randomised controlled trial

Management of type 2 diabetes includes medications that can unintentionally increase obesity and insulin resistance. This unblinded, single-centre, randomised controlled trial focused on rural Australian adults with type 2 diabetes (aged 18-75 and body mass index [BMI] >30 kg/m2), measuring the effectiveness of a tailored interdisciplinary obesity care approach compared with usual diabetes care. Led by a nurse practitioner with allied health support (dietitian ± psychologist and physiotherapist), the bariatric treatment involved reducing weight-gaining medications, a 500-calories/day deficit, an unsupervised exercise program emphasising movement/strength and psychotherapy, 3-monthly to 24-months with support phone calls at weeks 2, 4, 8 and 10. Outcomes from the 224 (113 intervention/111 control) participants were differences in biomedical and physical markers within- and between-groups estimated using multivariate mixed-effects linear regression between recruitment and 6-monthly follow-ups. Greater change occurred in intervention compared with control groups at 12 and 24 months in mean: body weight (-5.9 kg [95% confidence interval, CI: -8.53, -3.23] and -9.0 kg [95% CI: -13.2, -4.77]); BMI (-2.03 kg/m2 [95% CI: -2.92, -1.15] and -3.51 kg/m2 [95% CI: -4.93, -2.08]); and glycated haemoglobin (-0.26% [95% CI: -0.69%, 0.18%] and -0.63% [95% CI: -1.17%, 0.08%]). The control group showed a significant increase in mean leptin level, resulting in a between-group difference (-27.1 [95% CI: -42.7, -11.5]). Lipids and blood pressure differences were inconclusive, while exploratory analysis showed greater decline in estimated glomerular filtration rate in the control group. The interdisciplinary obesity approach, compared with usual diabetes care, resulted in sustained weight loss and improved diabetes control over 2 years. Trial registration number: ACTRN12622000240741.

The potential role of targeting the leptin receptor as a treatment for breast cancer in the context of hyperleptinemia: a literature review

Since cancer is becoming a leading cause of death worldwide, efforts should be concentrated on understanding its underlying biological alterations that would be utilized in disease management, especially prevention strategies. Within this context, multiple bodies of evidence have highlighted leptin's practical and promising role, a peptide hormone extracted from adipose and fatty tissues with other adipokines, in promoting the proliferation, migration, and metastatic invasion of breast carcinoma cells. Excessive blood leptin levels and hyperleptinemia increase body fat content and stimulate appetite. Also, high leptin level is believed to be associated with several conditions, including overeating, emotional stress, inflammation, obesity, and gestational diabetes. It has been noted that when leptin has impaired signaling in CNS, causing the lack of its normal function in energy balance, it results in leptin resistance, leading to a rise in its concentration in peripheral tissues. Our research paper will shed highlighting on potentially targeting the leptin receptor and its cellular signaling in suppressing breast cancer progression.

Role of Microneedles for Improved Treatment of Obesity: Progress and Challenges

Obesity is a global metabolic health epidemic characterized by excessive lipid and fat accumulation, leading to severe conditions such as diabetes, cancer, and cardiovascular disease. Immediate attention and management of obesity-related health risks are most warranted. The imbalance between fat absorption, metabolic rate, and environmental and genetic factors is responsible for obesity. Treatment typically involves lifestyle modifications, pharmacotherapy, and surgery. While lifestyle changes are crucial, effective treatment often necessitates medication as a preferred adjunct strategy. However, medications commonly used, such as oral pharmacotherapy, often show side effects due to systemic exposure and, thus, may not effectively target the intended areas, leading to drug loss. On the other hand, transdermal administration of drugs with microneedle (MN)-based technologies, a painless drug delivery approach with patient compliance, is gaining interest as an alternative obesity treatment, as it directly targets adipose tissue via local delivery, minimizing system exposure and dose reduction. This Review addresses the pathophysiology of obesity, current treatment strategies, challenges in the treatment of obesity using conventional formulations, the importance of the use of nano-based medications through transdermal delivery, and the use of MNs as a promising platform for the effective delivery of nanoparticle-based anti-obesity medications. The potential of combining MNs with stimuli-responsive and non-responsive adjuvant therapies to enhance treatment efficacy and patient outcomes is explored. In addition, the limitations and future perspectives related to the use of MNs for obesity are addressed to highlight the transformative potential of this technology for obesity management. MNs hold promise in precisely delivering anti-obesity drugs while requiring lower dosages and minimizing side effects compared to conventional oral or injectable therapies and ultimately improving the quality of life for individuals struggling with obesity and its associated comorbidities.

Combined Administration of Metformin and Propionate Reduces the Degree of Oxidative/Nitrosative Damage of Hypothalamic Neurons in Rat Model of Type 2 Diabetes Mellitus

Many complications associated with type 2 diabetes mellitus (T2DM) are closely linked with the generation of reactive species or free radicals leading to oxidative/nitrosative stress. The aim of this study was to investigate the effect of combined administration of metformin with propionate on the degree of oxidative/nitrosative damage in the brain of rats with an experimental model of T2DM. Male Wistar rats were divided into control (healthy rats); rats with T2DM and no further therapy; rats with T2DM that received: metformin, propionate, propionate + metformin. Ventromedial hypothalamus samples were analyzed by transmission electron microscopy, gas-liquid chromatography, Western blotting, RT-PCR and electron paramagnetic resonance. Combined treatment resulted in normalization of the neuronal NOS levels and reduction of mRNA level of induced nitric oxide synthase (NOS) and superoxide radicals compared to untreated T2DM rats. A decrease was also observed in the level of 8-oxyguanine with normalization of fatty acids distribution. The combined treatment partially mitigated ultrastructural alterations resulting from oxidative/nitrosative damage in neurons' mitochondria in T2DM. Thus, we demonstrated a positive effect of the combined use of metformin and propionate on all indicators of oxidative/nitrosative stress in T2DM.

Poor maternal nutrition during gestation in sheep alters key hormonal systems involved in energy homeostasis and appetite in the offspring

Disturbances in maternal nutrient availability through increased or decreased abundance of specific or total nutrients during pre-natal development can have negative impacts on offspring growth. These changes are likely mediated, at least in part, by hormonal systems that control energy homeostasis and appetite. Regulation of insulin signaling is critical to ensuring appropriate glucose homeostasis. Poor maternal nutrition during gestation impacts circulating glucose and insulin concentration in both the dam and offspring, reducing circulating insulin and glucose in offspring of restricted-fed dams and increased circulating insulin and glucose in the offspring of over-fed dams. Leptin and ghrelin are key regulators of appetite and feed intake. Offspring of over-fed ewes often exhibit leptin resistance, which may lead to changes in adiposity. Leptin responses in offspring of restricted-fed ewes are not well defined, although restricted-fed ewes themselves exhibit decreased circulating leptin concentrations. Little is known about the effects of poor maternal nutrition on offspring ghrelin. Glucocorticoids and thyroid hormones are required for appropriate fetal development. Poor maternal nutrition during gestation alters the development of the hypothalamic-pituitary-adrenal and thyroid axes in the offspring, although the effects vary according to the type, duration, timing, and severity of the nutritional insult. The relationships between insulin, leptin, ghrelin, glucocorticoids, and thyroid hormones can result in synergistic effects, exacerbating negative outcomes for the offspring. The impacts of poor maternal nutrition are multi-faceted, and the resulting alterations in body composition can continue to impact hormone regulation beyond the initial insult caused by poor maternal nutrition during gestation.

An Introduction to the Complete Blood Count for Clinical Chemists: White Blood Cells

BACKGROUND

The most frequently ordered laboratory test worldwide is the complete blood count (CBC). As clinical chemists are increasingly assigned to assist or direct laboratories outside of the traditional clinical chemistry sections, such as the automated hematology section, expertise must be established. This review article is a dedication to that ongoing effort.

CONTENT

In this primer, the white blood cell (WBC) test components of the CBC are introduced, followed by a discussion of the laboratory evaluation of leukopenia and leukocytosis.

SUMMARY

The laboratorian's approach to consult cases should be guided by the patient's clinical history and presentation while being able to provide key laboratory-based insights to assist in resolving result discrepancies that may otherwise go unnoticed.

Anti-obesity peptides from food: Production, evaluation, sources, and commercialization

The global obesity epidemic has heightened interest in natural solutions, with anti-obesity peptides emerging as promising candidates. Derived from food sources such as plants, algae, marine organisms, and products like milk and eggs, these peptides combat obesity through various mechanisms but face challenges in production and scalability. The aim of this review is to explore their sources, mechanisms, measurement, and synthesis methods, including innovative approaches such as de novo synthesis, proteomics, and bioinformatics. Its unique contribution lies in critically analyzing the current state of research while highlighting novel synthesis techniques and their practical relevance in addressing commercialization challenges, offering valuable insights for advancing anti-obesity peptide development. Diverse methods for assessing the anti-obesity properties of these peptides are discussed, encompassing both in vitro and in vivo experimental approaches, as well as emerging alternatives. The review also explores the integration of cutting-edge technologies in peptide synthesis with the potential to revolutionize scalability and cost-effectiveness. Key findings assert that despite the great potential of peptides from various food sources to fight against obesity and advances in their identification and analysis, challenges like scalability, regulatory hurdles, bioavailability issues, high production costs, and consumer appeal persist. Future research should explore the use of bioinformatics tools and advanced peptide screening technologies to identify and design peptides with enhanced efficacy and bioavailability, efficient and cost-effective extraction and purification methods, sustainable practices such as utilizing byproducts from the food industry, and the efficacy of products containing isolated anti-obesity peptides versus whole materials in clinical settings.

Sarcopenic obesity and brain health: A critical appraisal of the current evidence

Sarcopenic obesity (SO) is a body composition phenotype derived from the simultaneous presence in the same individual of an increase in fat mass and a decrease in skeletal muscle mass and/or function. Several protocols for the diagnosis of SO have been proposed in the last two decades making prevalence and disease risk estimates of SO heterogeneous and challenging to interpret. Dementia is a complex neurological disorder that significantly impacts patients, carers and healthcare systems. The identification of risk factors for early cognitive impairment and dementia is key to mitigating the forecasted trends of a 2-fold increase in dementia case numbers over the next two decades worldwide. Excess adiposity and sarcopenia have both been independently associated with risk of cognitive impairment and dementia. Whether SO is associated with a greater risk of cognitive impairment and dementia is currently uncertain. This review critically appraises the current evidence on the association between SO with cognitive outcomes and dementia risk. It also discusses some of the putative biological mechanisms that may link the SO phenotype with alteration of brain functions.

Roles of thyroid and leptin hormones and their crosstalk in male reproductive functions: an updated review

PURPOSE

This review aims to provide updated information regarding the role of thyroid and leptin hormones and their crosstalk in affecting the male reproductive function in hypothyroid and obesity conditions.

METHOD

A wide literature search was made using online search engines on published articles using keywords including thyroid hormone, hypothyroidism, leptin hormone, hyperleptinemia, obesity, the relationship between thyroid and leptin hormones and male reproduction, and hypothyroidism, obesity, and male reproduction.

RESULTS

All information pertaining thyroid and leptin hormone effects on male reproduction, hypothyroidism, hyperleptinemia, and obesity effect on male fertility as well as the related molecular mechanisms are obtained.

CONCLUSION

Thyroid and leptin hormones individually play a significant role in male reproduction. Alterations of these hormones' levels could adversely affect the male reproductive functions. PI3K/AKT signaling was found to be the major signaling pathway involved in mediating the effect of both hormones on male reproduction. Impaired crosstalk between the two hormones may occur in hypothyroidism with obesity which would contribute towards male reproductive dysfunction.

Glucagon-Like Peptide 1 Receptor (Glp1r) Deficiency Does Not Appreciably Alter Airway Inflammation or Gut-Lung Microbiome Axis in a Mouse Model of Obese Allergic Airways Disease and Bariatric Surgery

Purpose

High body mass index (≥30 kg/m2) is associated with asthma severity, and nearly 40% of asthma patients exhibit obesity. Furthermore, over 40% of patients with obesity and asthma that receive bariatric surgery no longer require asthma medication. Increased levels of glucagon-like peptide 1 (GLP-1) occur after bariatric surgery, and recent studies suggest that GLP-1 receptor (GLP-1R) signaling may regulate the gut microbiome and have anti-inflammatory properties in the lung. Thus, we hypothesized that increased GLP-1R signaling following metabolic surgery in obese and allergen-challenged mice leads to gut/lung microbiome alterations, which together contribute to improved features of allergic airways disease.

Methods

Male and female Glp1r-deficient (Glp1r-/- ) and replete (Glp1r+/+) mice were administered high fat diet (HFD) to induce obesity with simultaneous intranasal challenge with house dust mite (HDM) allergen to model allergic airway disease with appropriate controls. Mice on HFD received either no surgery, sham surgery, or vertical sleeve gastrectomy (VSG) on week 10 and were sacrificed on week 13. Data were collected with regard to fecal and lung tissue microbiome, lung histology, metabolic markers, and respiratory inflammation.

Results

HFD led to metabolic imbalance characterized by lower GLP-1 and higher leptin levels, increased glucose intolerance, and alterations in gut microbiome composition. Prevalence of bacteria associated with short chain fatty acid (SCFA) production, namely Bifidobacterium, Lachnospiraceae UCG-001, and Parasutterella, was reduced in mice fed HFD and positively associated with serum GLP-1 levels. Intranasal HDM exposure induced airway inflammation. While Glp1r-/- genotype affected fecal microbiome beta diversity metrics, its effect was limited.

Conclusion

Herein, GLP-1R deficiency had surprisingly little effect on host gut and lung microbiomes and health, despite recent studies suggesting that GLP-1 receptor agonists are protective against lung inflammation.

Leptin, NK cells, and the weight of immunity: Insights into obesity

Obesity is a chronic inflammatory disease that affects more than 1 billion people worldwide and is associated with various metabolic and physiological dysfunctions, directly impacting the dynamics of the immune response, partly due to elevated leptin levels. Leptin is an important peptide hormone that regulates neuroendocrine function and energy homeostasis, with its blood levels reflecting energy reserves, fat mass, or energy deprivation. This hormone also plays a fundamental role in regulating immune function, including the activity of NK cells, which are essential components in antiviral and antitumor activity. In obese individuals, leptin resistance is commonly established, however, NK cells and other immune components remain responsive to this hormone. So far, leptin has demonstrated paradoxical activities of these cells, often associated with a dysfunctional profile when associated with obesity. The excessive fat is usually related to metabolic remodeling in NK cells, resulting in compromised antitumor responses due to reduced cytotoxic capacity and decreased expression of cytokines important for these defense mechanisms, such as IFN-γ. Therefore, this review approaches a better understanding of the immunoendocrine interactions between leptin and NK cells in the context of obesity.

Recent Advances in the Anti-Obesity Benefits of Phytoconstituents: From Phytochemistry to Targeting Novel-Systems

Obesity is a metabolic disorder that has become a global health concern. The existing pharmaceutical drugs for treating obesity have some side effects. Compounds from natural sources are prospective substitutes for treating chronic diseases such as obesity, with the added advantages of being safe and cost-effective. However, due to factors such as poor solubility, low bioavailability, and instability in the physiological environment, the therapeutic efficacy of phytoconstituents is limited. Nowadays, developing nanoscaled systems has emerged as a vital strategy for enhancing the delivery and therapeutic effect of phytoconstituents. The present study discusses and categorizes phytoconstituents with anti-obesity effects and concludes the main mechanisms underlying their effects. Importantly, strategies used to develop phytoconstituent-based nano-drug delivery systems (NDDS) for obesity treatment that show improved efficacy relative to traditional administration routes are reviewed. Finally, the progress of research on phytoconstituent-based NDDS for obesity treatment is summarized to provide a reference for the development of safe and effective treatment strategies for obesity.

Natural Products From Plants Targeting Leptin Resistance for the Future Development of Anti-Obesity Agents

Obesity is a serious health threat, which has affected 16% of adults globally in 2022 and shows a trend toward youthfulness. Leptin, as a regulator of body weight, can suppress appetite and promote energy expenditure, making it potential in obesity treatment. Nevertheless, with the progress of relevant research, it is worth noting that monotherapy with leptin is not an effective strategy since most obese individuals are hyperleptinemic and resistant to leptin, where high levels of leptin fail to exert its weight-loss effects. Therefore, the potential to unlock the weight-loss properties of leptin using pharmacology to improve resistance has provided a new direction for this field. However, most synthetic medicines have retreated from the market due to their undesirable side effects, while natural products are increasingly sought after for drug development due to their minimal side effects. Indeed, natural products are ideal alternatives to oral synthetic agents since a growing body of research has demonstrated their desirable effects on improving leptin resistance through potential therapeutic targets like the JAK2/STAT3 signaling pathway, protein tyrosine phosphatase 1B, the exchange proteins directly activated by cAMP/Ras-related protein 1 signaling pathway, endoplasmic reticulum stress, pro-opiomelanocortin gene, and leptin levels. This review outlines natural products that can improve leptin resistance by inhibiting or activating these targets and evaluates their efficacy in experiments and human clinical trials, offering insights for the development of anti-obesity agents. However, more high-quality clinical research is necessary to validate these findings, as current clinical evidence is constrained by heterogeneity and small sample sizes.

Optimised Skeletal Muscle Mass as a Key Strategy for Obesity Management

The 'Body Mass Index' (BMI) is an anachronistic and outdated ratio that is used as an internationally accepted diagnostic criterion for obesity, and to prioritise, stratify, and outcome-assess its management options. On an individual level, the BMI has the potential to mislead, including inaccuracies in cardiovascular risk assessment. Furthermore, the BMI places excessive emphasis on a reduction in overall body weight (rather than optimised body composition) and contributes towards a misunderstanding of the quiddity of obesity and a dispassionate societal perspective and response to the global obesity problem. The overall objective of this review is to provide an overview of obesity that transitions away from the BMI and towards a novel vista: viewing obesity from the perspective of the skeletal muscle (SM). We resurrect the SM as a tissue hidden in plain sight and provide an overview of the key role that the SM plays in influencing metabolic health and efficiency. We discuss the complex interlinks between the SM and the adipose tissue (AT) through key myokines and adipokines, and argue that rather than two separate tissues, the SM and AT should be considered as a single entity: the 'Adipo-Muscle Axis'. We discuss the vicious circle of sarcopenic obesity, in which aging- and obesity-related decline in SM mass contributes to a worsened metabolic status and insulin resistance, which in turn further compounds SM mass and function. We provide an overview of the approaches that can mitigate against the decline in SM mass in the context of negative energy balance, including the optimisation of dietary protein intake and resistance physical exercises, and of novel molecules in development that target the SM, which will play an important role in the future management of obesity. Finally, we argue that the Adipo-Muscle Ratio (AMR) would provide a more clinically meaningful descriptor and definition of obesity than the BMI and would help to shift our focus regarding its effective management away from merely inducing weight loss and towards optimising the AMR with proper attention to the maintenance and augmentation of SM mass and function.

Revisiting the role of IL-27 in obesity-related metabolic diseases: safeguard or perturbation?

The prevalence of metabolic diseases, such as obesity, has been steadily increasing in recent years, posing a significant threat to public health. Therefore, early identification and intervention play a crucial role. With the deepening understanding of the etiology of metabolic diseases, novel therapeutic targets are emerging for the treatment of obesity, lipid metabolism disorders, cardiovascular and cerebrovascular diseases, glucose metabolism disorders, and other related metabolic conditions. IL-27, as a multi-potent cytokine, holds great promise as a potential candidate target in this regard. This article provides a comprehensive review of the latest findings on IL-27 expression and signal transduction in the regulation of immune inflammatory cells, as well as its implications in obesity and other related metabolic diseases. Furthermore, it explores the potential of IL-27 as a novel therapeutic target for the treatment of obesity and metabolic disorders. Finally, an overview is presented on both the opportunities and challenges associated with targeting IL-27 for therapeutic interventions.

TAS1R2 rs35874116 Associations with Taste, Diet, and Health in an Italian Population

BACKGROUND/OBJECTIVES

The TAS1R2 SNP rs35874116 has previously been associated with sweet taste, diet, and health status, although never comprehensively in a single study. Also, associations between TAS1R2 and sweet taste might be body mass index (BMI)-dependent. Therefore, this study aimed to conduct a comprehensive investigation of rs35874116 and sweet taste intensity and liking, food liking, and diet and health status whilst considering BMI.

METHODS

Five-hundred and fifty-four participants were recruited. Linear regression models were used to explore rs35874116 associations with sweet taste intensity and liking, food liking, and diet and health status. A secondary analysis stratified participants by BMI <25/≥25 kg/m2.

RESULTS

The rs35874116 wildtype was associated with increased sweet taste intensity (p = 0.0345, B 1.29, SE 0.61) and liking (p = 0.021, B 0.25, SE 0.11). However, these associations only remained in BMI ≥25 individuals (intensity: p = 0.037, B 1.29, SE 0.61, liking: p = 0.008, B 0.46, SE 0.17). It was also associated with decreased diet quality (p = 0.03, B -0.27, SE 0.13) and reduced free sugar consumption but increased saturated fat consumption in BMI ≥25 individuals (free sugars: p = 0.0416, B -0.8, SE 0.38, saturated fat: p = 0.031, B 1.38, SE 0.62). There was no association with the mean liking score for sweet foods, although there were some associations with individual foods, which require further investigation. There were no associations with health status.

CONCLUSIONS

This study revealed an association between the rs35874116 wildtype and an increased intensity and liking of the sweet taste and a corresponding worse overall dietary quality. This study adds to previous evidence regarding how associations between TAS1R2 and sweet taste are BMI-dependent.

A New Strategy for Obesity Treatment: Revealing the Frontiers of Anti-obesity Medications

Obesity dramatically increases the risk of type 2 diabetes, fatty liver, hypertension, cardiovascular disease, and cancer, causing both declines in quality of life and life expectancy, which is a serious worldwide epidemic. At present, more and more patients with obesity are choosing drug therapy. However, given the high failure rate, high cost, and long design and testing process for discovering and developing new anti-obesity drugs, drug repurposing could be an innovative method and opportunity to broaden and improve pharmacological tools in this context. Because different diseases share molecular pathways and targets in the cells, anti-obesity drugs discovered in other fields are a viable option for treating obesity. Recently, some drugs initially developed for other diseases, such as treating diabetes, tumors, depression, alcoholism, erectile dysfunction, and Parkinson's disease, have been found to exert potential anti-obesity effects, which provides another treatment prospect. In this review, we will discuss the potential benefits and barriers associated with these drugs being used as obesity medications by focusing on their mechanisms of action when treating obesity. This could be a viable strategy for treating obesity as a significant advance in human health.

Adenylate kinase 5 deficiency impairs epididymal white adipose tissue homeostasis and decreases fat mass

IMPORTANCE

The brain and adipose tissue interact metabolically, and if there is a problem with the energy metabolism of the brain, it cannot maintain the energy balance with the adipose tissue. Therefore, when adenylate kinase 5 (AK5), which regulates energy metabolism in the brain, is knocked out, problems with lipid metabolism may occur.

OBJECTIVE

We aimed to elucidate the metabolic function and phenotype of AK5, a gene with an unknown function in metabolism.

METHODS

We generated AK5 knockout (KO) mice and administered high-fat and fasting diets to the mice to confirm their physiological phenotype and metabolic differences.

RESULTS

In the high-fat diet (HFD) test, no differences in body weight, epididymal white adipose tissue (eWAT), or fat mass of AK5 KO mice were observed. In indirect calorimetry, the respiratory exchange ratio and activity counts increased in normal chow diet mice, but there was no difference between the HFD groups. At the mRNA level, there were no significant differences in the expression of lipid metabolism markers between wild-type and AK5 KO mice. Still, the glucose signal of adipocytes increased in AK5 KO mice. In the fasting test, the eWAT of AK5 KO mice was significantly reduced, as was the expression of lipid metabolism and inflammation-related immune markers. Thus, the apoptosis of adipocytes increased, and an imbalance in energy metabolism occurred.

CONCLUSIONS AND RELEVANCE

When AK5 KO mice are energy deficient, it becomes difficult to use eWAT for energy storage, imbalance occurs, and apoptosis of adipocytes in eWAT increases.

The Anti-Obesity Effect of Fish Oil in Diet-Induced Obese Mice Occurs via Both Decreased Food Intake and the Induction of Heat Production Genes in Brown but Not White Adipose Tissue

Omega-3 (ω-3) polyunsaturated fatty acids in fish oil have been shown to prevent diet-induced obesity in lean mice and to promote heat production in adipose tissue. However, the effects of fish oil on obese animals remain unclear. This study investigated the effects of fish oil in obese mice. C57BL/6J mice were fed a lard-based high-fat diet (LD) for 8 weeks and then assigned to either a fish oil-based high-fat diet (FOD) or continued the LD for additional 8 weeks. A control group was fed a standard diet for 16 weeks. Mice fed the FOD showed weight loss, reduced adipose tissue mass, and lower plasma insulin and leptin levels compared to those fed the LD. Rectal temperatures were higher in the FOD and LD groups compared to the control group. Energy intake was lower in the FOD group than the LD group but similar to the control group. The FOD and LD groups exhibited increased expression of heat-producing genes such as Ppargc1a, Ucp1, Adrb3, and Ppara in brown adipose tissue but not in white adipose tissue. The FOD reduced food consumption and increased rectal temperature and heat-producing genes in brown adipose tissue. Fish oil may therefore be a potential therapeutic approach to obesity.

Research Progress on the Relationship Between Artificial Sweeteners and Breast Cancer

Artificial sweeteners, as low-calorie sugar substitutes, have attracted much attention in recent years, especially in terms of their potential health effects. Although they add almost no calories, studies have shown that artificial sweeteners may affect metabolism by stimulating insulin secretion and changing the intestinal microbiota, increasing the risk of metabolic syndrome and type 2 diabetes. Breast cancer, as the most common cancer in the world, is related to multiple factors such as genetics and hormone levels. The results of studies on artificial sweeteners and breast cancer risk are conflicting, with some showing a positive correlation between the two and others failing to confirm it. Differences in study design, participant characteristics, and the types of sweeteners have led to this ambiguity. Although some studies have focused on mechanisms such as hormone disorders, insulin response, and changes in the intestinal microbiota, further exploration is needed to establish a causal relationship. Our review aims to comprehensively analyze the potential association between artificial sweeteners and breast cancer and its mechanisms, as well as encourage future studies to reveal its long-term health effects.

Obesogens and Energy Homeostasis: Definition, Mechanisms of Action, Exposure, and Adverse Effects on Human Health

BACKGROUND

Obesity is a major risk factor for noncommunicable diseases and is associated with a reduced life expectancy of up to 20 years, as well as with other consequences such as unemployment and increased economic burden for society. It is a multifactorial disease, and physiopathology of obesity involves dysregulated calorie utilization and energy balance, disrupted homeostasis of appetite and satiety, lifestyle factors including sedentary lifestyle, lower socioeconomic status, genetic predisposition, epigenetics, and environmental factors. Some endocrine-disrupting chemicals (EDCs) have been proposed as "obesogens" that stimulate adipogenesis leading to obesity. In this review, definition of obesogens, their adverse effects, underlying mechanisms, and metabolic implications will be updated and discussed.

SUMMARY

Disruption of lipid homeostasis by EDCs involves multiple mechanisms including increase in the number and size of adipocytes, disruption of endocrine-regulated adiposity and metabolism, alteration of hypothalamic regulation of appetite, satiety, food preference and energy balance, and modification of insulin sensitivity in the liver, skeletal muscle, pancreas, gastrointestinal system, and the brain. At a cellular level, obesogens can exert their endocrine disruptive effects by interfering with peroxisome proliferator-activated receptors and steroid receptors. Human exposure to chemical obesogens mainly occurs by ingestion and, to some extent, by inhalation and dermal uptake, usually in an unconscious manner. Persistent pollutants are lipophilic features; thus, they bioaccumulate in adipose tissue.

KEY MESSAGES

Although there are an increasing number of reports studying the effects of obesogens, their mechanisms of action remain to be elucidated. In addition, epidemiological studies are needed in order to evaluate human exposure to obesogens.

Alterations in Adipose Tissue and Adipokines in Heterozygous APE1/Ref-1 Deficient Mice

BACKGRUOUND

The role of apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) in adipose tissue remains poorly understood. This study investigates adipose tissue dysfunction in heterozygous APE1/Ref-1 deficiency (APE1/Ref-1+/-) mice, focusing on changes in adipocyte physiology, oxidative stress, adipokine regulation, and adipose tissue distribution.

METHODS

APE1/Ref-1 mRNA and protein levels in white adipose tissue (WAT) were measured in APE1/Ref-1+/- mice, compared to their wild-type (APE1/Ref-1+/+) controls. Oxidative stress was assessed by evaluating reactive oxygen species (ROS) levels. Histological and immunohistochemical analyses were conducted to observe adipocyte size and macrophage infiltration of WAT. Adipokine expression was measured, and micro-magnetic resonance imaging (MRI) was used to quantify abdominal fat volumes.

RESULTS

APE1/Ref-1+/- mice exhibited significant reductions in APE1/Ref-1 mRNA and protein levels in WAT and liver tissue. These mice also showed elevated ROS levels, suggesting a regulatory role for APE1/Ref-1 in oxidative stress in WAT and liver. Histological and immunohistochemical analyses revealed hypertrophic adipocytes and macrophage infiltration in WAT, while Oil Red O staining demonstrated enhanced ectopic fat deposition in the liver of APE1/Ref-1+/- mice. These mice also displayed altered adipokine expression, with decreased adiponectin and increased leptin levels in the WAT, along with corresponding alterations in plasma levels. Despite no significant changes in overall body weight, microMRI assessments demonstrated a significant increase in visceral and subcutaneous abdominal fat volumes in APE1/Ref-1+/- mice.

CONCLUSION

APE1/Ref-1 is crucial in adipokine regulation and mitigating oxidative stress. These findings suggest its involvement in adipose tissue dysfunction, highlighting its potential impact on abdominal fat distribution and its implications for obesity and oxidative stress-related conditions.

The effect of ketogenic diet on adipokines levels: a systematic review and meta-analysis of randomized-controlled trials

BACKGROUND

Considering the impact of adipokines on metabolic syndrome-related disorders and even chronic illnesses, it would appear vital to look for efficient treatments for these variables. The goal of this study was to thoroughly examine how the ketogenic diet (KD) affects adipokines.

METHODS

Using standard keywords, the databases Scopus, PubMed/Medline, Web of Science, Cochrane, and Embase were searched to find all controlled trials looking into how KD affected adipokines (leptin, adiponectin, and ghrelin). By using a random-effects model analysis, pooled weighted mean difference and 95% confidence intervals were obtained.

RESULTS

This article featured twenty-two studies. The combined results demonstrated that, as compared to the control group, leptin levels in all populations are significantly lower when KD is adhered to (WMD: - 0.14 ng/ml, 95% CI: - 8.66, - 3.61, P < 0.001). On the other hand, no discernible impact of this diet on ghrelin and adiponectin concentrations was noted. The subgroup analysis results demonstrated that the drop in leptin levels was considerably higher in persons with BMI > 30 kg/m2 and in trials that followed the KD for ≤ 8 weeks than in the other groups.

CONCLUSIONS

Generally speaking, this diet can be utilized as a potentially helpful supplementary therapy to improve this adipokine, given the significance that leptin plays on numerous metabolic illnesses.

Inflammation and Physical Performance in Overweight and Obese Schoolchildren

Obesity represents a critical public health concern, often linked to low-grade chronic inflammation starting in childhood. This study aimed to evaluate the impact of a 12-week kinesiotherapy program on physical performance and levels of leptin and C-reactive protein (CRP) in overweight and obese children.

METHODS

Conducted at the Filantropia Municipal Clinical Hospital, 160 children aged 6 to 15 were randomly assigned to a study group (SG, n = 80) and a control group (CG, n = 80). The SG engaged in a tailored kinesiotherapy program, while the CG maintained their usual activities. All children and their families learned five key principles for preventing and managing obesity.

RESULTS

Results indicated significant improvements in the SG, with enhancements in the 6 min walking distance, Timed Up and Go test, and walking cadence (all p-values < 0.001). Notably, leptin and CRP levels (23.02 ± 7.17 to 16.62 ± 7.83, 4.13 ± 1.00 to 3.90 ± 0.95 mg/l, respectively) decreased significantly in the SG, contrasting with no significant changes in the CG. Regression analysis revealed a positive correlation between leptin levels and physical activity in the SG (coefficient: 0.5642, R-squared: 0.266).

CONCLUSIONS

These findings suggest that targeted exercise programs can effectively enhance physical performance and reduce inflammation markers in overweight children, highlighting the importance of tailored interventions in managing obesity.

Adipokines and Cardiometabolic Heart Failure with Preserved Ejection Fraction: A State-of-the-Art Review

BACKGROUND

Cardiometabolic heart failure with preserved ejection fraction (HFpEF) is largely driven by obesity-related factors, including adipokines and bioactive peptides primarily secreted by the adipose tissue, such as leptin, adiponectin, and resistin. These molecules link metabolic dysregulation to cardiovascular dysfunction, influencing HFpEF progression and patient outcomes Methods: A comprehensive literature search was conducted in PubMed up to 20 November 2024, using keywords and MeSH terms, such as "HFpEF", "adipokines", "leptin", "adiponectin", and "resistin", yielding 723 results. Boolean operators refined the search, and reference lists of key studies were reviewed. After screening for duplicates and irrelevant studies, 103 articles were included, providing data on adipokines' roles in HFpEF pathophysiology, biomarkers, and therapeutic implications.

RESULTS

Both preclinical and clinical studies have demonstrated that adipokines play a role in modulating cardiovascular function, thereby contributing to the development of cardiometabolic HFpEF. Leptin promotes myocardial hypertrophy, fibrosis, endothelial dysfunction, and inflammation, though contradictory evidence suggests potential cardioprotective roles in subgroups like obese African American women. Adiponectin generally offers protective effects but presents a paradox, where elevated levels may correlate with worse outcomes, which may reflect either a compensatory response to cardiac dysfunction or a maladaptive state characterized by adiponectin resistance. Resistin is associated with increased cardiovascular risk through pro-inflammatory and pro-fibrotic effects, though its role in HFpEF requires further clarification. Other adipokines, like retinol-binding protein 4 and omentin-1, have emerged as potential contributors. Despite growing insights, clinical translation remains limited, underscoring a significant gap between experimental evidence and therapeutic application.

CONCLUSIONS

Future research should focus on targeted interventions that modulate adipokine pathways to potentially improve HFpEF outcomes. Innovative treatment strategies addressing underlying metabolic disturbances and adipokine dysregulation are essential for advancing the management of this challenging condition.

Intestinal gluconeogenesis controls the neonatal development of hypothalamic feeding circuits

OBJECTIVE

Intestinal gluconeogenesis (IGN) regulates adult energy homeostasis in part by controlling the same hypothalamic targets as leptin. In neonates, leptin exhibits a neonatal surge controlling axonal outgrowth between the different hypothalamic nuclei involved in feeding circuits and autonomic innervation of peripheral tissues involved in energy and glucose homeostasis. Interestingly, IGN is induced during this specific time-window. We hypothesized that the neonatal pic of IGN also regulates the development of hypothalamic feeding circuits and sympathetic innervation of adipose tissues.

METHODS

We genetically induced neonatal IGN by overexpressing G6pc1 the catalytic subunit of glucose-6-phosphatase (the mandatory enzyme of IGN) at birth or at twelve days after birth. The neonatal development of hypothalamic feeding circuits was studied by measuring Agouti-related protein (AgRP) and Pro-opiomelanocortin (POMC) fiber density in hypothalamic nuclei of 20-day-old pups. The effect of the neonatal induction of intestinal G6pc1 on sympathetic innervation of the adipose tissues was studied via tyrosine hydroxylase (TH) quantification. The metabolic consequences of the neonatal induction of intestinal G6pc1 were studied in adult mice challenged with a high-fat/high-sucrose (HFHS) diet for 2 months.

RESULTS

Induction of intestinal G6pc1 at birth caused a neonatal reorganization of AgRP and POMC fiber density in the paraventricular nucleus of the hypothalamus, increased brown adipose tissue tyrosine hydroxylase levels, and protected against high-fat feeding-induced metabolic disorders. In contrast, inducing intestinal G6pc1 12 days after birth did not impact AgRP/POMC fiber densities, adipose tissue innervation or adult metabolism.

CONCLUSION

These findings reveal that IGN at birth but not later during postnatal life controls the development of hypothalamic feeding circuits and sympathetic innervation of adipose tissues, promoting a better management of metabolism in adulthood.

Leptin is a potential biomarker of childhood obesity and an indicator of the effectiveness of weight-loss interventions

Childhood obesity represents a significant public health concern, imposing a substantial burden on the healthcare system. Furthermore, weight-loss programs often exhibit reduced effectiveness in adults who have a history of childhood obesity. Therefore, early intervention against childhood obesity is imperative. Presently, the primary method for diagnosing childhood obesity relies on body mass index (BMI), yet this approach has inherent limitations. Leptin, a satiety hormone produced by adipocytes, holds promise as a superior tool for predicting both childhood and subsequent adulthood obesity. In this review, we elucidate the tools employed for assessing obesity in children, delve into the biological functions of leptin, and examine the factors governing its expression. Additionally, we discuss maternal and infantile leptin levels as predictors of childhood obesity. By exploring the relationship between leptin levels and weight loss, we present leptin as a potential indicator of the effectiveness of obesity interventions.

Myeloid-Derived Suppressor Cells (MDSCs) and Obesity-Induced Inflammation in Type 2 Diabetes

Type 2 diabetes mellitus is a complex metabolic disorder characterized by insulin resistance and, subsequently, decreased insulin secretion. This condition is closely linked to obesity, a major risk factor that boosts the development of chronic systemic inflammation, which, in turn, is recognized for its crucial role in the onset of insulin resistance. Under conditions of obesity, adipose tissue, particularly visceral fat, becomes an active endocrine organ that releases a wide range of pro-inflammatory mediators, including cytokines, chemokines, and adipokines. These mediators, along with cluster of differentiation (CD) markers, contribute to the maintenance of systemic low-grade inflammation, promote cellular signaling and facilitate the infiltration of inflammatory cells into tissues. Emerging studies have indicated the accumulation of a new cell population in the adipose tissue in these conditions, known as myeloid-derived suppressor cells (MDSCs). These cells possess the ability to suppress the immune system, impacting obesity-related chronic inflammation. Given the limited literature addressing the role of MDSCs in the context of type 2 diabetes, this article aims to explore the complex interaction between inflammation, obesity, and MDSC activity. Identifying and understanding the role of these immature cells is essential not only for improving the management of type 2 diabetes but also for the potential development of targeted therapeutic strategies aimed at both glycemic control and the reduction in associated inflammation.

Impaired olfactory system in metabolic imbalance-related neuropathology

Olfactory dysfunction, influenced by factors such as aging and environmental stress, is linked to various neurological disorders. The olfactory bulb's connections to brain areas like the hypothalamus, piriform cortex, entorhinal cortex, and limbic system make olfactory dysfunction a contributor to a range of neuropathological conditions. Recent research has underscored that olfactory deficits are prevalent in individuals with both metabolic syndrome and dementia. These systemic metabolic alterations correlate with olfactory impairments, potentially affecting brain regions associated with the olfactory bulb. In cases of metabolic syndrome, phenomena such as insulin resistance and disrupted glucose metabolism may result in compromised olfactory function, leading to multiple neurological issues. This review synthesizes key findings on the interplay between metabolic-induced olfactory dysfunction and neuropathology. It emphasizes the critical role of olfactory assessment in diagnosing and managing neurological diseases related to metabolic syndrome.

Recent advances on cyanidin-3-O-glucoside in preventing obesity-related metabolic disorders: A comprehensive review

Anthocyanins, found in various pigmented plants as secondary metabolites, represent a class of dietary polyphenols known for their bioactive properties, demonstrating health-promoting effects against several chronic diseases. Among these, cyanidin-3-O-glucoside (C3G) is one of the most prevalent types of anthocyanins. Upon consumption, C3G undergoes phases I and II metabolism by oral epithelial cells, absorption in the gastric epithelium, and gut transformation (phase II & microbial metabolism), with limited amounts reaching the bloodstream. Obesity, characterized by excessive body fat accumulation, is a global health concern associated with heightened risks of disability, illness, and mortality. This comprehensive review delves into the biodegradation and absorption dynamics of C3G within the gastrointestinal tract. It meticulously examines the latest research findings, drawn from in vitro and in vivo models, presenting evidence underlining C3G's bioactivity. Notably, C3G has demonstrated significant efficacy in combating obesity, by regulating lipid metabolism, specifically decreasing lipid synthesis, increasing fatty acid oxidation, and reducing lipid accumulation. Additionally, C3G enhances energy homeostasis by boosting energy expenditure, promoting the activity of brown adipose tissue, and stimulating mitochondrial biogenesis. Furthermore, C3G shows potential in managing various prevalent obesity-related conditions. These include cardiovascular diseases (CVD) and hypertension through the suppression of reactive oxygen species (ROS) production, enhancement of endogenous antioxidant enzyme levels, and inhibition of the nuclear factor-kappa B (NF-κB) signaling pathway and by exercising its cardioprotective and vascular effects by decreasing pulmonary artery thickness and systolic pressure which enhances vascular relaxation and angiogenesis. Type 2 diabetes mellitus (T2DM) and insulin resistance (IR) are also managed by reducing gluconeogenesis via AMPK pathway activation, promoting autophagy, protecting pancreatic β-cells from oxidative stress and enhancing glucose-stimulated insulin secretion. Additionally, C3G improves insulin sensitivity by upregulating GLUT-1 and GLUT-4 expression and regulating the PI3K/Akt pathway. C3G exhibits anti-inflammatory properties by inhibiting the NF-κB pathway, reducing pro-inflammatory cytokines, and shifting macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. C3G demonstrates antioxidative effects by enhancing the expression of antioxidant enzymes, reducing ROS production, and activating the Nrf2/AMPK signaling pathway. Moreover, these mechanisms also contribute to attenuating inflammatory bowel disease and regulating gut microbiota by decreasing Firmicutes and increasing Bacteroidetes abundance, restoring colon length, and reducing levels of inflammatory cytokines. The therapeutic potential of C3G extends beyond metabolic disorders; it has also been found effective in managing specific cancer types and neurodegenerative disorders. The findings of this research can provide an important reference for future investigations that seek to improve human health through the use of naturally occurring bioactive compounds.

Biomarkers of insulin sensitivity/resistance

In recent years, remarkable advancements in elucidating the intricate molecular underpinnings of type 2 diabetes mellitus (T2D) have been achieved. Insulin resistance (IR) has been unequivocally acknowledged as the driving pathogenetic mechanism of T2D, preceding disease onset by several years. Nonetheless, diagnostic tools for ascertaining IR are lacking in current clinical practice, representing a critical unmet need; use of the hyperinsulinemic-euglycemic glucose clamp, widely accepted as the gold standard method for evaluating IR at present, is cumbersome in a clinical setting. Thus, the development of well-validated, reliable, and affordable biomarkers of IR has attracted considerable attention from the research community. The biomarkers under investigation can be divided into two major categories: (1) indices or ratios, comprising parameters obtained from a basic or comprehensive metabolic panel and/or derived from anthropometric measurements, and (2) circulating molecules implicated in pathophysiological processes associated with IR. Furthermore, numerous novel biomarkers, including markers of β-cell dysfunction, radiographic quantification of excess visceral adipose tissue, T2D prediction models, certain microRNAs and metabolomic biomarkers, have also provided promising preliminary results. This narrative review aims to present current evidence pertaining to the most notable and exciting biomarkers of IR that are under rigorous evaluation.

GLP-1, GIP, and Glucagon Agonists for Obesity Treatment: A Hunger Perspective

For centuries, increasingly sophisticated methods and approaches have been brought to bear to promote weight loss. Second only to the Holy Grail of research on aging, the idea of finding a single and simple way to lose weight has long preoccupied the minds of laymen and scientists alike. The effects of obesity are far-reaching and not to be minimized; the need for more effective treatments is obvious. Is there a single silver bullet that addresses this issue without effort on the part of the individual? The answer to this question has been one of the most elusive and sought-after in modern history. Now and then, a miraculous discovery propagates the illusion that a simple solution is possible. Now there are designer drugs that seem to accomplish the task: we can lose weight without effort using mono, dual, and triple agonists of receptors for glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and glucagon. There are, however, fundamental biological principles that raise intriguing questions about these therapies beyond the currently reported side-effects. This perspective reflects upon these issues from the angle of complex goal-oriented behaviors, and systemic and cellular metabolism associated with satiety and hunger.

The association between macrosomia and glucose, lipids and hormones levels in maternal and cord serum: a case-control study

BACKGROUND

The formation of macrosomia is associated with excessive nutrition and/or unable to regulate effectively. This case-control study aims to explore the relationship between macrosomia and glucose, lipids and hormones levels in maternal and cord serum.

METHODS

In the case-control study, 78 pairs of mothers and newborns were recruited who received care at one hospital of Hebei, China between 2016 and 2019. According to the birth weight (BW) of newborns, participants were divided into macrosomia group (BW ≥ 4000 g, n = 39) and control group (BW between 2500 g and 3999 g, n = 39). Maternal vein blood and cord vein blood were collected and assayed. All data were compared between the two groups. Unconditional logistics regression analysis was used to test the relationship between macrosomia and glucose, lipids and hormones in maternal and cord serum.

RESULTS

In maternal and cord serum, the levels of leptin, leptin/adiponectin ratio (LAR), glucose and triglyceride (TG) in macrosomia group were higher than those in control group, and the levels of high-density lipoprotein cholesterol (HDL-C) were lower. The percentage of maternal glucose and lipids transfer to cord blood did not differ between the two groups. High levels of TG in maternal serum were positively correlated with macrosomia, and high levels of LAR, TG and glucose in cord serum were positively correlated with macrosomia.

CONCLUSION

In conclusion, the results of the current study, suggest that the nutrients and metabolism-related hormones in maternal and umbilical cord are closely related to macrosomia. During pregnancy, the nutritional status of pregnant women should be paid attention to and to obtain a good birth outcome.

Day and Night Reversed Feeding Aggravates High-Fat Diet-Induced Abnormalities in Intestinal Flora and Lipid Metabolism in Adipose Tissue of Mice

BACKGROUND

The incongruity between dietary patterns and the circadian clock poses an elevated risk for metabolic health issues, particularly obesity and associated metabolic disorders. The intestinal microflora engages in regulating various physiological functions of the host through its metabolites.

OBJECTIVES

This study aimed to investigate the impact of reversed feeding schedules during the day and night on intestinal flora and lipid metabolism in high-fat diet-induced obese mice.

METHODS

Mice aged 8-10 wk were subjected to either daytime or nighttime feeding and were administered a control or high-fat diet for 18 wk. At the end of the experiment, various assessments were conducted, including analysis of serum biochemic indices, histologic examination, evaluation of gene and protein expression in adipose tissue, and scrutiny of changes in intestinal microbial composition.

RESULTS

The results showed that day-night reversed feeding caused an increase in fasting blood glucose and exacerbated the high-fat diet-induced weight gain and lipid abnormalities. The mRNA expression levels of Leptin and Dgat1 were increased by day-night reversed feeding, which also reduced the expression level of adiponectin under the high-fat diet. Additionally, there was a significant increase in the protein concentrations of PPARγ, SREBP1c, and CD36. Inverted feeding schedules led to a reduction in intestinal microbial diversity, an increase in the abundance of inflammation-related bacteria, such as Coriobacteriaceae_UCG-002, and a suppression of beneficial bacteria, including Akkermansia, Candidatus_Saccharimonas, Anaeroplasma, Bifidobacterium, Carnobacterium, and Odoribacter. Acinetobacter exhibited a significant negative correlation with Leptin and Fasn, suggesting potential involvement in the regulation of lipid metabolism.

CONCLUSIONS

The results elucidated the abnormalities of lipid metabolism and intestinal flora caused by day-night reversed feeding, which exacerbates the adverse effects of a high-fat diet on lipid metabolism and intestinal microflora. This reversal in feeding patterns may disrupt both intestinal and lipid metabolism homeostasis by altering the composition and abundance of intestinal microflora in mice.

Association Between Osteoporosis and Adiposity Index Reveals Nonlinearity Among Postmenopausal Women and Linearity Among Men Aged over 50 Years

PURPOSE

Previous research shows conflicting views on the relationship between obesity and osteoporosis, partly due to variations in obesity classification and the nonlinear nature of these relationships. This study investigated the association between adiposity indices and osteoporosis, diagnosed using dual-energy X-ray absorptiometry (DXA), employing nonlinear models and offering optimal thresholds to prevent further bone mineral density decline.

METHODS

In 2019, a prospective study enrolled males over 50 years and postmenopausal women. Anthropometric measurements, blood biochemistry, and osteoporosis measured by DXA were collected. Associations between adiposity indices and osteoporosis were analyzed using a generalized additive model and segmented regression model.

RESULTS

The study included 872 women and 1321 men. Indices such as abdominal volume index (AVI), visceral adiposity index (VAI), waist circumference (WC), hip circumference, body mass index (BMI), waist-to-hip ratio, and waist-to-height ratio (WHtR) were inversely associated with osteoporosis. In women, the relationship between the risk of osteoporosis and the adiposity indices was U-shaped, with thresholds of WC = 94 cm, AVI = 17.67 cm2, BMI = 25.74 kg/m2, VAI = 4.29, and WHtR = 0.61, considering changes in bone mineral density. Conversely, men exhibited a linear patterns for the inverse association.

CONCLUSION

The impact of obesity and adiposity on osteoporosis varies significantly between women and men. In postmenopausal women, the relationship is nonlinear (U-shaped), with both very low and very high adiposity linked to higher osteoporosis risk. In men over 50, the relationship is linear, with higher adiposity associated with lower osteoporosis risk. The study suggests that maintaining specific levels of adiposity could help prevent osteoporosis in postmenopausal women.

Bone development in fetuses with intrauterine growth restriction caused by maternal endocrine-metabolic dysfunctions

Intrauterine growth restriction (IUGR) affects a large proportion of infants, particularly in underdeveloped countries. Among the main causes of IUGR, maternal endocrine-metabolic dysfunction is highlighted, either due to its high incidence or due to the severity of the immediate and mediated changes that these dysfunctions cause in the fetus and the mother. Although the effects of endocrine and metabolic disorders have been widely researched, there are still no reviews that bring together and summarize the effects of these conditions on bone development in cases of IUGR. Therefore, the present literature review was conducted with the aim of discussing bone changes observed in fetuses with IUGR caused by maternal endocrine-metabolic dysfunction. The main endocrine dysfunctions that occur with IUGR include maternal hyperthyroidism, hypothyroidism, and hypoparathyroidism. Diabetes mellitus, hypertensive disorders, and obesity are the most important maternal metabolic dysfunctions that compromise fetal growth. The bone changes reported in the fetus are, for the most part, due to damage to cell proliferation and differentiation, as well as failures in the synthesis and mineralization of the extracellular matrix, which results in shortening and fragility of the bones. Some maternal dysfunctions, such as hyperthyroidism, have been widely studied, whereas conditions such as hypoparathyroidism and gestational hypertensive disorders require further study regarding the mechanisms underlying the development of bone changes. Similarly, there is a gap in the literature regarding changes related to intramembranous ossification, as most published articles only describe changes in endochondral bone formation associated with IUGR. Furthermore, there is a need for more research aimed at elucidating the late postnatal changes that occur in the skeletons of individuals affected by IUGR and their possible relationships with adult diseases, such as osteoarthritis and osteoporosis.

Plasma levels of adipokines and insulin are associated with markers of brain atrophy and cognitive decline in the spectrum of Alzheimer's Disease

The discovery that metabolic alterations often coexist with neurodegenerative conditions has sparked interest in the examination of metabolic regulatory factors as potential modulators of brain health. Here, we examined the role of adipokines (leptin, adiponectin, resistin, and IL6) and insulin on different markers of brain atrophy in participants on the spectrum of Alzheimer's Disease. We included 566 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset with 1063 follow-up time points (average follow-up: one year); and examined the association between metabolic regulatory factors and volumetric MRI values, white matter hyperintensities, and measures of cognitive impairment. Higher leptin, resistin, IL6, and insulin were associated with markers of cerebral atrophy, such as lower total brain volume, or higher ventricular volume. Higher leptin and resistin were also associated with greater impairment in daily life activities. Higher adiponectin was associated with lower ventricle volume. There was no association between adipokines or insulin with white matter hyperintensities. Our findings indicate a co-occurrence between alterations in metabolic regulatory factors and in brain volume along the preclinical to clinical spectrum of Alzheimer's Disease. These results suggest that strategies aimed at promoting metabolic health may positively impact brain health.

Marked Point Process Secretory Events Statistically Characterize Leptin Pulsatile Dynamics

Recent studies have highlighted leptin, a key hormone that regulates energy intake and induces satiety, due to the worldwide prevalence of obesity. In this study, we analyzed plasma leptin measurements from 18 women with premenopausal obesity before and after bromocriptine treatment. By using underlying pulses recovered through deconvolution, we modeled the leptin secretory pulses as marked point processes and applied statistical distributions to evaluate the dynamics of leptin, including the interpulse intervals and amplitudes of the secretion. We fit the generalized inverse Gaussian and lognormal distributions to the intervals and the Gaussian, lognormal, and gamma distributions to the amplitudes of pulses. We evaluated the models' goodness of fit using statistical metrics including Akaike's information criterion, Kolmogorov-Smirnov plots, and quantile-quantile plots. Our evaluation results revealed the effectiveness of these statistical distributions in modeling leptin secretion. Although the lognormal and gamma distributions performed the best based on the metrics, we found all distributions capable of accurately modeling the timing of secretory events, leading us to a better understanding of the physiology of leptin secretion and providing a basis for leptin monitoring. In terms of pulse amplitude, the evaluation metrics indicated the gamma distribution as the most accurate statistical representation. We found no statistically significant effect of bromocriptine intake on the model parameters except for one distribution model.

Use of Guazuma ulmifolia Lam. Stem Bark Extracts to Prevent High-Fat Diet Induced Metabolic Disorders in Mice

This study aimed to evaluate the effects of supplementation with ethanolic and aqueous extracts from the bark of the stem of Guazuma ulmifolia in mice submitted to a high-fat diet as well as to evaluate the chemical composition of these extracts. The chemical composition and antioxidant potential was evaluated in aqueous and ethanolic extracts of the stem bark. The in vivo test consisted of evaluating the effects of the aqueous and ethanolic extracts of the stem bark on C57BL/6 mice receiving a high-fat diet. The animals were evaluated for weight gain, feed consumption, visceral adiposity, serum, and inflammatory and hormonal parameters. The results of the chemical analyses corroborate those obtained by the literature, which reported gallocatechin, epigallocatechin and epigallocatechin gallate. Compared with the ethanolic extract, the aqueous extract showed greater antioxidant capacity. Both extracts resulted in lower feed consumption in the animals, but they did not influence weight gain or visceral adiposity and resulted in varied changes in the lipid profile. In addition, they did not influence glucose tolerance, insulin sensitivity, or fasting blood glucose. Furthermore, the leptin levels increased, which may have contributed to satiety, but this was shown to have a negative impact on other inflammatory and hormonal parameters. Therefore, under the conditions of this study, the biologically active compounds present in the plant species Guazuma ulmifolia were not able to contribute to the treatment of metabolic changes related to the consumption of a high-fat diet.

The impact of obesity on reproductive health and metabolism in reproductive-age females

Obesity is a highly prevalent chronic disease that impacts >40% of reproductive-aged females. The pathophysiology of obesity is complex and can be understood simply as a chronic energy imbalance whereby caloric intake exceeds caloric expenditure with an energy surplus stored in adipose tissue. Obesity may be categorized into degrees of severity as well as different phenotypes on the basis of metabolic health and underlying pathophysiology. Obesity and excess adiposity have a significant impact on fertility and reproductive health, with direct effects on the hypothalamic-pituitary-ovarian axis, the ovary and oocyte, and the endometrium. There are significant adverse pregnancy outcomes related to obesity, and excess weight gain before, during, and after pregnancy that can alter the lifelong risk for metabolically unhealthy obesity. Given the high prevalence and pervasive impact of obesity on reproductive health, there is a need for better and individualized care for reproductive-aged females that considers obesity phenotype, underlying pathophysiology, and effective and sustainable interventions to treat obesity and manage weight gain before, during, and after pregnancy.

Isoliquiritigenin in combination with visceral adipose tissue and related markers as a predictive tool for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease in the world. New non-invasive diagnostic tools are needed to promptly treat this disease and avoid its complications. This study aimed to find key metabolites and related variables that could be used to predict and diagnose NAFLD. Ninety-eight subjects with NAFLD and 45 controls from the Fatty Liver in Obesity (FLiO) Study (NCT03183193) were analyzed. NAFLD was diagnosed and graded by ultrasound and classified into two groups: 0 (controls) and ≥ 1 (NAFLD). Hepatic status was additionally assessed through magnetic resonance imaging (MRI), elastography, and determination of transaminases. Anthropometry, body composition (DXA), biochemical parameters, and lifestyle factors were evaluated as well. Non-targeted metabolomics of serum was performed with high-performance liquid chromatography coupled to time-of-flight mass spectrometry (HPLC-TOF-MS). Isoliquiritigenin (ISO) had the strongest association with NAFLD out of the determinant metabolites. Individuals with higher concentrations of ISO had healthier metabolic and hepatic status and were less likely to have NAFLD (OR 0.13). Receiver operating characteristic (ROC) curves demonstrated the predictive power of ISO in panel combination with other NAFLD and IR-related variables, such as visceral adipose tissue (VAT) (AUROC 0.972), adiponectin (AUROC 0.917), plasmatic glucose (AUROC 0.817), and CK18-M30 (AUROC 0.810). Individuals with lower levels of ISO have from 71 to 82% more risk of presenting NAFLD compared to individuals with higher levels. Metabolites such as ISO, in combination with visceral adipose tissue, IR, and related markers, constitute a potential non-invasive tool to predict and diagnose NAFLD.

Impact of Resistance and Endurance Training on Ghrelin and Plasma Leptin Levels in Overweight and Obese Subjects

Exercise training is a valuable tool for improving body weight and composition in overweight or obese adults, which leads to a negative energy balance. It is relevant to consider whether exercise can help people lose weight or prevent weight gain because any energy expended in exercise increases the severity of hunger and promotes food consumption. Over the past decade, the identification of the circulating peptide ghrelin, which alerts the brain to the body's nutritional state, has significantly expanded our understanding of this homeostatic mechanism that controls appetite and body weight. To shed more light on this issue, we decided to investigate the effects of resistance and endurance training on plasma ghrelin and leptin levels. In addition, we sought to understand the mechanisms by which acute and chronic exercise can regulate hunger. This review analyzes studies published in the last fifteen years that focused on changes suffered by ghrelin, leptin, or both after physical exercise in overweight or obese individuals. Most studies have shown a decrease in leptin levels and an increase in ghrelin levels in these cases. Exercise regimens that support weight maintenance need further investigation.

Impact of Serotonin Transporter Absence on Brain Insulin Receptor Expression, Plasma Metabolome Changes, and ADHD-like Behavior in Mice fed a Western Diet

The impaired function of the serotonin transporter (SERT) in humans has been linked to a higher risk of obesity and type 2 diabetes, especially as people age. Consuming a "Western diet" (WD), which is high in saturated fats, cholesterol, and sugars, can induce metabolic syndrome. Previous research indicated that mice carrying a targeted inactivation of the Sert gene (knockout, KO) and fed a WD display significant metabolic disturbances and behaviors reminiscent of ADHD. These abnormalities might be mediated via a dysfunction in insulin receptor (IR) signaling, which is also associated with adult ADHD. However, the impact of Sert deficiency on IR signaling and systemic metabolic changes has not been thoroughly explored. In this study, we conducted a detailed analysis of locomotor behavior in wild-type (WT) and KO mice fed a WD or control diet. We investigated changes in the blood metabolome and examined, via PCR, the expression of insulin receptor A and B isoforms and key regulators of their function in the brain. Twelve-month-old KO mice and their WT littermates were fed a WD for three weeks. Nuclear magnetic resonance spectroscopy analysis of plasma samples showed that KO mice on a WD had higher levels of lipids and lipoproteins and lower levels of glucose, lactate, alanine, valine, and isoleucine compared to other groups. SERT-KO mice on the control diet exhibited increased brain levels of both IR A and B isoforms, accompanied by a modest increase in the negative regulator ENPP. The KO mice also displayed anxiety-like behavior and reduced exploratory activity in an open field test. However, when the KO animals were fed a WD, the aberrant expression levels of IR isoforms in the KO mice and locomotor behavior were ameliorated indicating a complex interaction between genetic and dietary factors that might contribute to ADHD-like symptoms. Overall, our findings suggest that the lack of Sert leads to a unique metabolic phenotype in aged mice, characterized by dysregulated IR-related pathways. These changes are exacerbated by WD in the blood metabolome and are associated with behavioral abnormalities.

Discovery of a Novel Dual Targeting Peptide for Human Glioma: From In Silico Simulation to Acting as Targeting Ligand

Purpose

Receptor-mediated transcytosis (RMT) is a more specific, highly efficient, and reliable approach to crossing the blood-brain-barrier (BBB) and releasing the therapeutic cargos into the brain parenchyma.

Methods

Here, we introduced and characterized a human/mouse-specific novel leptin-derived peptide using in silico, in vitro and in vivo experiments.

Results

Based on the bioinformatics analysis and molecular dynamics (MD) simulation, a 14 amino acid peptide sequence (LDP 14) was introduced and its interaction with leptin-receptor (ObR) was analyzed in comparison with an well known leptin-derived peptide, Lep 30. MD simulation data revealed a significant stable interaction between ligand binding domains (LBD) of ObR with LDP 14. Analyses demonstrated suitable cellular uptake of LDP 14 alone and its derivatives (LDP 14-modified G4 PAMAM dendrimer and LDP 14-modified G4 PAMAM/pEGFP-N1 plasmid complexes) via ObR, energy and species dependent manner (preferred uptake by human/mouse cell lines compared to rat cell line). Importantly, our findings illustrated that the entry of LDP 14-modified dendrimers in hBCEC-D3 cells not only is not affected by protein corona (PC) formation, as the main reason for diminishing the cellular uptake, but also PC per se can enhance uptake rate. Finally, fluorescein labeled LDP 14-modified G4 PAMAM dendrimers efficiently accumulated in the mice brain with lower biodistribution in other organs, in our in vivo study.

Conclusion

LDP 14 introduced as a novel and highly efficient ligand, which can be used for drugs/genes delivery to brain tissue in different central nervous system (CNS) disorders.

Implication of the endocannabidiome and metabolic pathways in fragile X syndrome pathophysiology

Fragile X Syndrome (FXS) results from the silencing of the FMR1 gene and is the most prevalent inherited cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorder. It is well established that Fragile X individuals are subjected to a wide array of comorbidities, ranging from cognitive, behavioural, and medical origin. Furthermore, recent studies have also described metabolic impairments in FXS individuals. However, the molecular mechanisms linking FMRP deficiency to improper metabolism are still misunderstood. The endocannabinoidome (eCBome) is a lipid-based signalling system that regulates several functions across the body, ranging from cognition, behaviour and metabolism. Alterations in the eCBome have been described in FXS animal models and linked to neuronal hyperexcitability, a core deficit of the disease. However, the potential link between dysregulation of the eCBome and altered metabolism observed in FXS remains unexplored. As such, this review aims to overcome this issue by describing the most recent finding related to eCBome and metabolic dysfunctions in the context of FXS. A better comprehension of this association will help deepen our understanding of FXS pathophysiology and pave the way for future therapeutic interventions.

Inflammatory markers as diagnostic and precision nutrition tools for metabolic dysfunction-associated steatotic liver disease: Results from the Fatty Liver in Obesity trial

BACKGROUND & AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing public health concern. The disease is silent, and its diagnosis is often delayed. Inflammatory markers constitute an interesting tool to act as subrogate, non-invasive markers. This study aimed to evaluate the changes of inflammatory markers throughout a two-year dietary intervention in subjects presenting MASLD, to determine which of the markers are suitable to predict the disease, and act as a customizing tool for MASLD's dietary treatment.

METHODS

Ninety-eight subjects with MASLD and forty-five controls from the Fatty Liver in Obesity (FLiO) Study were analyzed. MASLD was diagnosed and graded by ultrasound. The MASLD subjects were randomly assigned to two different dietary strategies, the American Heart Association (AHA diet) or a dietary strategy based on the Mediterranean pattern, which was specially designed for the study (FLiO diet), and then followed for two years. Hepatic status was additionally assessed through Magnetic Resonance Imaging (MRI), elastography, and determination of transaminases.

RESULTS & DISCUSSION

Inflammatory markers improved throughout the intervention in the MASLD subjects and managed to reach similar levels to controls, especially at 6 and 12 months. Additionally, leptin, adiponectin, M30, and LECT2 managed to significantly diagnose the disease at all time marks of the intervention, making them candidates for subrogate non-invasive markers of the disease. Moreover, baseline chemerin, leptin, LECT2, and M65 were used to build a predictive score to achieve greater weight loss, and therefore, which strategy could be more useful for MASLD 's treatment. The predictive score was significantly able assign a specific diet to 55% of the study participants, meaning that the remaining 45% could achieve the same amount of weight loss following either diet equally.

CONCLUSION

Inflammatory markers constitute a potential non-invasive tool to be used in MASLD screening and could also constitute an interesting tool for MASLD's treatment customization, being able to predict the effectiveness of a dietary strategy based on the initial inflammatory state of each subject.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov (NCT03183193).