The role of glucagon-like peptide-1 impairment in obesity and potential therapeutic implications

Dynamical modeling the effect of glucagon-like peptide on glucose-insulin regulatory system based on mice experimental observation

As an emerging global epidemic, type 2 diabetes mellitus (T2DM) represents one of the leading causes of morbidity and mortality worldwide. Existing evidences demonstrated that glucagon-like peptide-1 (GLP-1) modulate the glucose regulatory system by enhancing the β-cell function. However, the detailed process of GLP-1 in glycaemic regulator for T2DM remains to be clarified. Thus, in this study, we propose an Institute of Cancer Research (ICR) mice high fat and cholesterol dietary experimental data-driven mathematical model to investigate the secretory effect of GLP-1 on the dynamics of glucose-insulin regulatory system. Specifically, we develop a mathematical model of GLP-1 dynamics as part of the interaction model of β-cell, insulin, and glucose dynamics. The parameter estimation and data fitting are in agreement with the data in mice experiments In addition, uncertainty quantification is performed to explore the possible factors that influence the pathways leading to the pathological state. Model analyses reveal that the high fat or high cholesterol diet stimulated GLP-1 plays an important role in the dynamics of glucose, insulin and β cells in short-term. These results show that enhanced GLP-1 may mitigate the dysregulation of glucose-insulin regulatory system via promoting the β cells function and stimulating secretion of insulin, which offers an in-depth insights into the mechanistic of hyperglycemia from dynamical approach and provide the theoretical basis for GLP-1 served as a potential clinical targeted drug for treatment of T2DM.

Neprilysin activity is increased in metabolic dysfunction-associated steatotic liver disease and normalizes after bariatric surgery or GLP-1 therapy

Inhibitors of neprilysin improve glycemia in patients with heart failure and type 2 diabetes (T2D). The effect of weight loss by diet, surgery, or pharmacotherapy on neprilysin activity (NEPa) is unknown. We investigated circulating NEPa and neprilysin protein concentrations in obesity, T2D, metabolic dysfunction-associated steatotic liver disease (MASLD), and following bariatric surgery, or GLP-1-receptor-agonist therapy. NEPa, but not neprilysin protein, was enhanced in obesity, T2D, and MASLD. Notably, MASLD associated with NEPa independently of BMI and HbA1c. NEPa decreased after bariatric surgery with a concurrent increase in OGTT-stimulated GLP-1. Diet-induced weight loss did not affect NEPa, but individuals randomized to 52-week weight maintenance with liraglutide (1.2 mg/day) decreased NEPa, consistent with another study following 6-week liraglutide (3 mg/day). A 90-min GLP-1 infusion did not alter NEPa. Thus, MASLD may drive exaggerated NEPa, and lowered NEPa following bariatric surgery or liraglutide therapy may contribute to the reported improved cardiometabolic effects.

Enhanced Physical Capacity and Gastrointestinal Symptom Improvement in Southern Italian IBS Patients following Three Months of Moderate Aerobic Exercise

Moderate-intensity aerobic exercise improves gastrointestinal (GI) health and alleviates irritable bowel syndrome (IBS) symptoms. This study explored its effects on physical capacity (PC) and IBS symptoms in 40 patients from Southern Italy (11 males, 29 females; 52.10 ± 7.72 years). The exercise program involved moderate-intensity aerobic exercise (60/75% of HRmax) for at least 180 min per week. Before and after the intervention, participants completed the IBS-SSS questionnaire to assess IBS symptoms, reported their physical activity levels, and underwent field tests to evaluate PC. PC was quantified as the Global Physical Capacity Score (GPCS). A total of 38 subjects (21 males, 17 females; 53.71 ± 7.27 years) without lower GI symptoms served as a No IBS group. No significant differences were found between IBS patients and No IBS subjects, except for the symptom score, as expected. After the exercise, all participants experienced significant improvements in both IBS symptoms and PC. Higher PC levels correlated with greater benefits in IBS symptomatology, especially with GPCS reaching above-average values. Engaging in moderate-intensity aerobic exercise for at least 180 min per week positively impacts IBS symptoms and PC. Monitoring GPCS in IBS patients provides insights into the connection between physical activity and symptom severity, aiding healthcare professionals in tailoring effective treatment plans.

Breaking down silos: the multifaceted nature of obesity and the future of weight management

The continued global increase in the prevalence of obesity prompted a meeting at the Royal Society of London investigating causal mechanisms of the disease, 'Causes of obesity: theories, conjectures, and evidence' in October 2022. Evidence presented indicates areas of obesity science where there have been advancements, including an increased understanding of biological and physiological processes of weight gain and maintenance, yet it is clear there is still debate on the relative contribution of plausible causes of the modern obesity epidemic. Consensus was reached that obesity is not a reflection of diminished willpower, but rather the confluence of multiple, complex factors. As such, addressing obesity requires multifactorial prevention and treatment strategies. The accumulated evidence suggests that a continued focus primarily on individual-level contributors will be suboptimal in promoting weight management at the population level. Here, we consider individual biological and physiological processes within the broader context of sociodemographic and sociocultural exposures as well as environmental changes to optimize research priorities and public health efforts. This requires a consideration of a systems-level approach that efficiently addresses both systemic and group-specific environmental determinants, including psychosocial factors, that often serve as a barrier to otherwise efficacious prevention and treatment options. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.

Circulating levels of all proglucagon-derived peptides are differentially regulated postprandially by obesity status and in response to high-fat meals vs. high-carbohydrate meals

BACKGROUND & AIMS

We measured all proglucagon-derived peptides (PGDPs) levels in response to administration of three mixed meal tolerance tests (MMTs), examining differences in postprandial PGDP responses in subjects with leanness and obesity or between high-fat vs. high carbohydrate meals.

METHODS

We designed three physiology interventional studies, administering MMTs over a 180-min period to individuals without diabetes after an overnight fast. In Study 1, a 450 kcal MMT was administered to n = 4 normal weight and n = 9 individuals with obesity. In Study 2, a 600 kcal high-fat MMT was administered to n = 15 normal-weight and n = 15 individuals with obesity. In Study 3, n = 32 participants with obesity were assigned to receive a 600-kcal high-fat (n = 15) or an isocaloric high-carbohydrate MMT (n = 17). Fasting and postprandial levels of c-peptide and PGDPs (proglucagon, GLP-1, GLP-2, glicentin, oxyntomodulin, glucagon, major proglucagon fragment [MPGF]) were assessed.

RESULTS

In study 1, individuals with normal weight displayed elevated glicentin postprandial secretion compared with people with obesity (p = 0.002). Following a high-fat MMT with 33% higher energy content in study 2, all postprandial PGDPs levels were elevated (p-time<0.001), irrespective of weight status. In study 3, a prolonged postprandial upregulation of PGDPs during the high-fat MMT was observed in contrast with the acute, short-term (max 60 min) PGDP responses to a high-carbohydrate MMT (p-time∗meal<0.001). Across both studies 2 and 3, the postprandial responses of glucagon and MPGF were higher in subjects with male sex whereas glicentin was higher in subjects with female sex.

CONCLUSIONS

Fat and carbohydrate content of a meal can substantially affect the postprandial levels of PGDPs. Circulating levels of PGDPs are influenced by the energy content of the meal, and additionally, the presence of leanness or obesity affects circulating levels of select PGDPs. These results, which are to be confirmed by additional studies, expand our understanding of PGDP physiology in leanness and obesity.

CLINICALTRIALS

GOV REGISTRATION NUMBERS: (NCT04170010, NCT04430946, NCT04575194).

The glucagon-like peptide-1 (GLP-1) analogue semaglutide reduces alcohol drinking and modulates central GABA neurotransmission

Growing evidence indicates that the glucagon-like peptide-1 (GLP-1) system is involved in the neurobiology of addictive behaviors, and GLP-1 analogues may be used for the treatment of alcohol use disorder (AUD). Here, we examined the effects of semaglutide, a long-acting GLP-1 analogue, on biobehavioral correlates of alcohol use in rodents. A drinking-in-the-dark procedure was used to test the effects of semaglutide on binge-like drinking in male and female mice. We also tested the effects of semaglutide on binge-like and dependence-induced alcohol drinking in male and female rats, as well as acute effects of semaglutide on spontaneous inhibitory postsynaptic currents (sIPSCs) from central amygdala (CeA) and infralimbic cortex (ILC) neurons. Semaglutide dose-dependently reduced binge-like alcohol drinking in mice; a similar effect was observed on the intake of other caloric/noncaloric solutions. Semaglutide also reduced binge-like and dependence-induced alcohol drinking in rats. Semaglutide increased sIPSC frequency in CeA and ILC neurons from alcohol-naive rats, suggesting enhanced GABA release, but had no overall effect on GABA transmission in alcohol-dependent rats. In conclusion, the GLP-1 analogue semaglutide decreased alcohol intake across different drinking models and species and modulated central GABA neurotransmission, providing support for clinical testing of semaglutide as a potentially novel pharmacotherapy for AUD.

Potential contributors to variation in weight-loss response to liraglutide

Obesity treatment requires a chronic state of negative energy balance. Obesity medications can help with this, increasing long-term dietary compliance by promoting satiety or reducing hunger. However, efficacy and safety of obesity medications vary for individuals. Early identification of non-responders to obesity medications may limit drug exposure while optimizing benefits for responders. This review summarizes factors that impact weight-loss response to liraglutide. Factors linked to greater weight loss on liraglutide include being female, not having diabetes, having relatively high baseline weight, and losing at least 4% of initial weight after 16 weeks of treatment. Other covariates that may predict treatment response but require further confirmation include central effects, nausea, gastric emptying of solids, and genotype. Baseline body mass index, race, and age seem less relevant for predicting weight-loss response to liraglutide. Lesser known and harder-to-measure factors such as cerebral blood flow, food cue reactivity, gut hormone levels, and dietary adherence possibly impact variability of response to liraglutide. This information should assist healthcare providers with establishing realistic weight-loss probability for individual patients. Future research should improve the ability to identify responders to liraglutide. Importantly, this review may provide a framework to identify responders to other obesity medications.

Inulin: properties and health benefits

Inulin, a soluble dietary fiber, is widely found in more than 36 000 plant species as a reserve polysaccharide. The primary sources of inulin, include Jerusalem artichoke, chicory, onion, garlic, barley, and dahlia, among which Jerusalem artichoke tubers and chicory roots are often used as raw materials for inulin production in the food industry. It is universally acknowledged that inulin as a prebiotic has an outstanding effect on the regulation of intestinal microbiota via stimulating the growth of beneficial bacteria. In addition, inulin also exhibits excellent health benefits in regulating lipid metabolism, weight loss, lowering blood sugar, inhibiting the expression of inflammatory factors, reducing the risk of colon cancer, enhancing mineral absorption, improving constipation, and relieving depression. In this review paper, we attempt to present an exhaustive overview of the function and health benefits of inulin.

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.

Concentration of Selected Adipokines and Factors Regulating Carbohydrate Metabolism in Patients with Head and Neck Cancer in Respect to Their Body Mass Index

Head and neck cancers (HNCs) are a group of tumors not common in European populations. So far, not much is known about the role of obesity, adipokines, glucose metabolism, and inflammation in the pathogenesis of HNC. The aim of the study was to determine the concentrations of ghrelin, omentin-1, adipsin, adiponectin, leptin, resistin, visfatin, glucagon, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), plasminogen activator inhibitor-1 (PAI-1), and gastric inhibitory peptide (GIP) in the blood serum of HNC patients depending on their body mass index (BMI). The study included 46 patients divided into two groups according to their BMI values: the normal BMI group (nBMI) included 23 patients with BMI < 25 kg/m² and the increased BMI group (iBMI) included patients with BMI ≥ 25 kg/m². A control group (CG) included 23 healthy people (BMI < 25 kg/m²). Statistically significant differences in the levels of adipsin, ghrelin, glucagon, PAI-1, and visfatin were shown between nBMI and CG. In the case of nBMI and iBMI, statistically significant differences were observed in the concentrations of adiponectin, C-peptide, ghrelin, GLP-1, insulin, leptin, omentin-1, PAI-1, resistin, and visfatin. The obtained results indicate a disruption of endocrine function of adipose tissue and impaired glucose metabolism in HNC. Obesity, which is not a typical risk factor for HNC, may aggravate the negative metabolic changes associated with this type of neoplasm. Ghrelin, visfatin, PAI-1, adipsin, and glucagon might be related to head and neck carcinogenesis. They seem to be promising directions for further research.

Deep Sea Water Inhibited Pancreatic β-Cell Apoptosis and Regulated Glucose Homeostasis by Affecting Lipid Metabolism in Db/Db Mice

PURPOSE

Deep sea water (DSW) is a natural resource rich in minerals, which participates in biological processes such as energy metabolism, regulates serum glucose and lipids levels, and has a certain protective effect on endocrine and metabolism-related diseases. Studies have shown that the improvement of glucose tolerance in diabetic mice by DSW may be associated with the protective effect on the structure and function of pancreatic islets, and the specific mechanism is still unclear. Other studies have shown that long-term exposure to high concentrations of fatty acids can lead to apoptosis and dysfunction of pancreatic β-cell, increasing the risk of type 2 diabetes mellitus (T2DM). Down-regulation of plasma fatty acid levels may reduce pancreatic β-cell dysfunction, thereby improving glucose homeostasis. Understanding the specific mechanism of DSW regulating blood glucose is of great significance for its clinical application.

METHODS

In the present study we used db/db mice as a T2DM model and treated mice with deep ocean mineral concentration (DOMC, a commercial product of DSW) for 4 and 12 weeks. Basic information, serum biochemical indicators, and pathological tissues were gathered for exploration.

RESULTS

The db/db mice treated with 4 weeks' DOMC (db/db+DOMC) showed decreased plasma cholesterol and triglyceride levels. Tests implied that in adipose tissues, the db/db+DOMC group's lipolysis process was inhibited, and the β-fatty acid oxidation process was promoted. Besides, DOMC reduced lipogenesis and encouraged β-oxidation in the liver, as a result, improved fatty liver in db/db mice. Further measurements showed DOMC improved glucose homeostasis slightly in db/db animals after a 12-week treatment by preventing pancreatic β-cell apoptosis.

CONCLUSION

DOMC inhibited pancreatic β-cell apoptosis and regulated glucose homeostasis in db/db mice by lowering the lipid levels via regulation of fatty acid β-oxidation, lipolysis, and lipogenesis processes.

Role of Glucagon-like Peptide-1 (GLP-1) Agonists in the Management of Diabetic Patients with or without COVID-19

Glucagon-like peptide 1 (GLP-1) is a gut-derived hormone released after a meal, which alleviates hyperglycemia, increases β-cell survival, reduces body weight, and reduces inflammation. These thrilling effects motivated clinical studies to discover the potential use of GLP-1 receptor agonists (GLP-1 RAs) in the management of T2D. GLP-1 RAs are potential anti-diabetic agents that can reduce blood pressure, glucose levels, HbA1c and, weight loss without hypoglycemia risk. This manuscript reviews the importance of GLP-1 RAs‎ and their role in the management of T2D with or without COVID-19 infection. Hence, this manuscript can help physicians and researchers to choose the most appropriate drugs for the individualized treatment of subjects.

The physiological dissimilarities of Holstein dairy cows with different milk yields

BACKGROUND

Even if breed, parity, dietary and environmental management are same, dairy cows still have notable differences in milk yield that may be underpinned by physiologic differences.

OBJECTIVES

This study aimed to investigate the physiological dissimilarities of dairy cows with different milk yields.

METHODS

Thirty cows were sorted into high milk-yielding cows (group H: 58.93±2.31 kg/day), moderate milk-yielding cows (group M: 44.99±0.54 kg/day), and low milk-yielding cows (group L: 24.99±6.83 kg/day) according to milk yield. Blood was collected and serum parameters were assessed. Rumen fluid was collected for the evaluation of rumen fermentation parameters (RFPs) and bacterial community composition (BCC).

RESULTS

Serum prolactin, growth hormone, glutathione peroxidase, immunoglobulin A and non-esterified fatty acid had a significantly positive correlation with milk yield (p < 0.05), whereas serum glucagon and total antioxidant capacity had a significantly negative correlation with milk yield (p < 0.05). The concentration of valeric acid and the ratio of acetic acid to propionic acid in the rumen fluid in group H was significantly lower than that in group L (p < 0.05). The concentration of acetic acid and butyric acid in group H was significantly lower than that in groups M and L (p < 0.05). The relative abundances of Ruminococcaceae_NK4A214_group, Prevotella_1, Rikenellaceae_RC9_gut_group, Christensenellaceae_R-7_group, Muribaculaceae, and Ruminococcus_2 were negatively correlated with milk yield, whereas the relative abundance of Succinivibrionaceae_UCG-001, Lachnospiraceae_NK3A20_group, Shuttleworthia and Dialister were positively correlated with milk yield (p < 0.05).

CONCLUSIONS

This study indicates that dairy cows with different milk yields have clear divergence in serum indicators, RFPs, BCC and rumen microbial metabolism.

α/Sulfono-γ-AA peptide hybrids agonist of GLP-1R with prolonged action both in vitro and in vivo

Peptides are increasingly important resources for biological and therapeutic development, however, their intrinsic susceptibility to proteolytic degradation represents a big hurdle. As a natural agonist for GLP-1R, glucagon-like peptide 1 (GLP-1) is of significant clinical interest for the treatment of type-2 diabetes mellitus, but its in vivo instability and short half-life have largely prevented its therapeutic application. Here, we describe the rational design of a series of α/sulfono-γ-AA peptide hybrid analogues of GLP-1 as the GLP-1R agonists. Certain GLP-1 hybrid analogues exhibited enhanced stability (t _1/2 > 14 days) compared to t _1/2 (<1 day) of GLP-1 in the blood plasma and in vivo. These newly developed peptide hybrids may be viable alternative of semaglutide for type-2 diabetes treatment. Additionally, our findings suggest that sulfono-γ-AA residues could be adopted to substitute canonical amino acids residues to improve the pharmacological activity of peptide-based drugs.

Consumption of probiotic yogurt and vitamin D-fortified yogurt increases fasting level of GLP-1 in obese adults undergoing low-calorie diet: A double-blind randomized controlled trial

Energy restriction and manipulation of macronutrient composition of the diet are the main approaches that are used by people who aim to lose weight. When such strategies are employed, appetite and endocrine regulators of satiety, such as gut peptides, all are deeply affected. The gut microbiota-brain axis controls energy homeostasis in humans by affecting central satiety and gut peptides. The purpose of this study was to evaluate if the synergistic effect of probiotics and vitamin D in yogurt matrix can modulate this effect. In the double-blind, randomized, placebo-controlled trial, 140 obese adults were randomly allocated into four groups: 1) regular yogurt plus low-calorie diet; 2) PY plus low-calorie diet; 3) vitamin D-fortified yogurt plus low-calorie diet, and 4) probiotic and vitamin D co-fortified yogurt plus low-calorie diet. All groups were encouraged to increase their physical activity. Glucagon-like peptide-1 (GLP-1), peptide Tyrosin-Tysrosin (PYY), ghrelin, anthropometric variables, insulin, fasting blood sugar (FBS), insulin resistance/sensitivity, 1,25(OH)2 D3, dietary intake, and physical activity were measured before and after 10 weeks. The difference between groups for GLP-1 after 10 weeks was significant after adjusting for baseline GLP-1 and protein intake as confounders. PY showed the largest effect size (ES) on GLP-1 (p = 14.2) and FBS (p = 14) compared with others. Pairwise comparison of yogurts effect sizes on GLP-1 showed a significant difference in group 1 vs. group 2 (p = .001), group 1 vs. group 3 (p = .003), and group 1 vs. group 4 (p = .048). Vitamin D-fortified yogurt had the largest effect size on the serum level of vitamin D and it showed a significant difference with RY (p = .018) and PY (p = .002). Consumption of vitamin D-fortified yogurt and PY could be regarded as a promising approach during calorie restriction.

Methanolic fruit extract of Myrica nagi protects the hypothalamus and attenuates inflammation associated with gold thioglucose- and high-fat diet-induced obesity via various adipokines

BACKGROUND

Myrica nagi is popular in unani and ayurveda. Chemical constituents like myricetin isolated from its fruit has been shown to exert beneficial effects against cardiovascular disease, cancer, inflammatory conditions, and metabolic disorders.

OBJECTIVES

This study aimed to elucidate the anti-obesity effect of the methanolic extract of M. nagi (MEMN) using in vivo animal models of obesity induced by gold thioglucose or a high-fat diet.

MATERIALS AND METHODS

The obese mice were treated or untreated with MEMN for 8 weeks. Thereafter, feed intake, Lee index, and body mass index (BMI); biochemical parameters such as lipid profile, liver enzymes and specific biomarkers of obesity, including insulin, leptin, adiponectin, free fatty acids (FFA), monocyte chemoattractant protein (MCP)-1, and resistin, were recorded. The weight and histopathology of organs and fat tissue were examined to validate the effectiveness of the extract.

RESULTS

MEMN administration at various doses significantly reduced the induced weight gain, feed intake, BMI, and Lee index. Adipose tissue decreased as the MEMN dose increased. MEMN attenuated liver enzyme activity, decreased lipid, leptin, MCP-1, resistin, and FFA levels, and increased adiponectin levels. It also increased protection of liver cells and decreased accumulation of mesenteric fat.

CONCLUSIONS

MEMN supplementation decreased weight and improved obesity serum/plasma lipid biomarker, insulin, leptin, adiponectin, MCP-1, and resistin levels. The weight-reducing activity of MEMN may be mediated by decreased gastrointestinal fat absorption and modulation of inflammation associated signaling pathways, leading to reduced adipose inflammation associated with energy expenditure.

Binge eating disorder, frequency of depression, and systemic inflammatory state in individuals with obesity - A cross sectional study

Introduction

Binge eating disorder (BED) is the most prevalent eating disorder in individuals with obesity. Its association with factors that control hunger and satiety has not yet been elucidated. We evaluated whether levels of inflammatory markers, frequency of psychiatric comorbidities, and appetite-related hormones levels differ between individuals with obesity with and without BED.

Subjects and methods

The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-5 - Clinician Version (SCID-5-CV), Binge Eating Scale, and Hospital Anxiety and Depression Scale were evaluated in 39 individuals with obesity. Plasma levels of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), leptin, ghrelin, and glucagon-like peptide-1 (GLP-1) were measured.

Results

Individuals of the BED group exhibited significantly higher percentages of altered eating patterns (hyperphagia, bingeing, post-dinner eating, feeling "stuffed", and emotional eating), higher depressive symptom scores and levels of leptin, CRP, and TNF-α, compared to those from the non-BED group. Logistic regression showed that BED was independently associated with depressive symptoms and CRP levels.

Conclusion

Individuals with obesity and BED showed greater psychiatric comorbidity, worse eating patterns and worse inflammatory profile than those without BED. BED should be assessed as an indicator of clinical severity in patients with obesity.

Objective ambulatory pH monitoring and subjective symptom assessment of gastroesophageal reflux disease show type of carbohydrate and type of fat matter

Background

Rising prevalence of gastroesophageal reflux disease (GERD) in US Veterans is concurrent with increasing excess body weight.

Objective

The objective of this cross-sectional study is to examine relationships between dietary macronutrients, gastrointestinal hormones, and GERD status.

Methods

Ninety-eight veterans with overweight/obesity and empiric proton pump inhibitor (PPI) treatment were enrolled from the Tennessee Valley Healthcare System. Subjects had esophageal manometry and 24-h pH monitoring. Subjective symptoms were assessed with Gastroesophageal Reflux Disease Questionnaire (GERDQ) and Symptom Assessment Scale (GSAS). The primary outcomes, total acid exposure time (AET) and number of reflux episodes, enabled categorizing subjects as either pathologic GERD or inconclusive GERD. Data analysis included independent T-tests, Spearman Rho correlations, and multivariable linear regression modeling.

Results

Higher intake of sugar-sweetened beverages (sugar-sweetened tea, soda, and fruit juice) associated with higher AET. Higher saturated-to-unsaturated fat intake is associated with higher AET and number of reflux episodes. Overall, sugar-sweetened beverage intake, saturated-to-unsaturated fat ratio, tomato-based food items, glucagon-like polypeptide 1 (GLP-1) level, time of first meal, and education status accounted for a significant amount of the variability in AET. Pathologic GERD subjects reported more heartburn (p = 0.006), regurgitation (p = 0.01), acid taste (0.001), and nausea severity (p = 0.04). GERDQ score associated with AET (r = 0.31, p = 0.005), but GSAS did not (r = 0.12, p = 0.28).

Conclusion

Of the many foods and nutrients tested, the type (not amount) of carbohydrate (simple sugars) and the type (not amount) of fat (saturated vs unsaturated fat) consumed associated with objective and/or subjective GERD testing. These novel findings contribute to the evidence base guiding specific dietary recommendations in the clinical management of GERD.

Efficacy and Safety of Nutrient Supplements for Glycaemic Control and Insulin Resistance in Type 2 Diabetes: An Umbrella Review and Hierarchical Evidence Synthesis

Background: Nutrient supplements are widely used for type 2 diabetes (T2D), yet evidence-based guidance for clinicians is lacking. Methods: We searched the four electronic databases from November 2015−December 2021. The most recent, most comprehensive, high-ranked systematic reviews, meta-analyses, and/or umbrella reviews of randomised controlled trials in adults with T2D were included. Data were extracted on study characteristics, aggregate outcome measures per group (glycaemic control, measures of insulin sensitivity and secretion), adverse events, and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessments. Quality was assessed using A Measurement Tool to Assess Systematic Reviews Version 2.0 (AMSTAR 2). Results: Twelve meta-analyses and one umbrella review were included. There was very low certainty evidence that chromium, Vitamin C, and omega-3 polyunsaturated fatty acids (Ω-3 PUFAs) were superior to placebo for the primary outcome of glycated hemoglobin (HbA1c) (Mean Difference/MD −0.54, −0.54 and ES −0.27, respectively). Probiotics were superior to placebo for HbA1c (Weighted Mean Difference/WMD −0.43%). There was very low certainty evidence that Vitamin D was superior to placebo for lowering HbA1c in trials of <6 months (MD −0.17%). Magnesium, zinc, Vitamin C, probiotics, and polyphenols were superior to placebo for FBG. Vitamin D was superior to placebo for insulin resistance. Data on safety was limited. Conclusions: Future research should identify who may benefit from nutrient supplementation, safety, and optimal regimens and formulations.

Glucagon-like Peptide-1 Receptor Analogues for the Treatment of Obesity

There is an increasing prevalence of obesity worldwide, associated with significant morbidity and mortality, which frequently reduces quality of life and life expectancy. Consequently, there is a substantial and growing personal and economic burden necessitating the development of more effective therapies for obesity. Glucagon-like peptide-1 receptor analogues (GLP-1RAs) are licensed for the treatment of type 2 diabetes (T2D), and there is substantial evidence that these drugs not only improve cardiovascular outcomes but also promote weight loss. More recent evidence supports the use of the GLP-1RAs liraglutide and semaglutide in people with obesity without T2D. This article discusses the results of the major cardiovascular outcome trials for GLP-1RAs in people with T2D, the SCALE Obesity and Prediabetes study (Effect of liraglutide on body weight in non-diabetic obese subjects or overweight subjects with co-morbidities: SCALE™ - Obesity and Pre-diabetes; ClinicalTrials.gov identifier: NCT01272219; investigating liraglutide) and the STEP studies (Semaglutide treatment effect in people with obesity; assorted studies; investigating subcutaneous semaglutide). We also highlight the importance of a cost-effective approach to obesity pharmacotherapy. Clinicians should consider the use of GLP-1RAs in people with obesity, especially those with T2D or other obesity-related diseases, such as hypertension and dyslipidaemia. Ongoing trials, as well as clinical and cost-effectiveness appraisals, are anticipated over the next 12 months, and their findings may change the current landscape of obesity pharmacotherapy.

Genome-wide analyses of multiple obesity-related cytokines and hormones informs biology of cardiometabolic traits

BACKGROUND

A complex set of perturbations occur in cytokines and hormones in the etiopathogenesis of obesity and related cardiometabolic conditions such as type 2 diabetes (T2D). Evidence for the genetic regulation of these cytokines and hormones is limited, particularly in African-ancestry populations. In order to improve our understanding of the biology of cardiometabolic traits, we investigated the genetic architecture of a large panel of obesity- related cytokines and hormones among Africans with replication analyses in African Americans.

METHODS

We performed genome-wide association studies (GWAS) in 4432 continental Africans, enrolled from Ghana, Kenya, and Nigeria as part of the Africa America Diabetes Mellitus (AADM) study, for 13 obesity-related cytokines and hormones, including adipsin, glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), interleukin-1 receptor antagonist (IL1-RA), interleukin-6 (IL-6), interleukin-10 (IL-10), leptin, plasminogen activator inhibitor-1 (PAI-1), resistin, visfatin, insulin, glucagon, and ghrelin. Exact and local replication analyses were conducted in African Americans (n = 7990). The effects of sex, body mass index (BMI), and T2D on results were investigated through stratified analyses.

RESULTS

GWAS identified 39 significant (P value < 5 × 10-8) loci across all 13 traits. Notably, 14 loci were African-ancestry specific. In this first GWAS for adipsin and ghrelin, we detected 13 and 4 genome-wide significant loci respectively. Stratified analyses by sex, BMI, and T2D showed a strong effect of these variables on detected loci. Eight novel loci were successfully replicated: adipsin (3), GIP (1), GLP-1 (1), and insulin (3). Annotation of these loci revealed promising links between these adipocytokines and cardiometabolic outcomes as illustrated by rs201751833 for adipsin and blood pressure and locus rs759790 for insulin level and T2D in lean individuals.

CONCLUSIONS

Our study identified genetic variants underlying variation in multiple adipocytokines, including the first loci for adipsin and ghrelin. We identified population differences in variants associated with adipocytokines and highlight the importance of stratification for discovery of loci. The high number of African-specific loci detected emphasizes the need for GWAS in African-ancestry populations, as these loci could not have been detected in other populations. Overall, our work contributes to the understanding of the biology linking adipocytokines to cardiometabolic traits.

Factors Related to Weight Loss Maintenance in the Medium-Long Term after Bariatric Surgery: A Review

Despite bariatric surgery being the most effective treatment for obesity, some individuals do not respond adequately, especially in the long term. Identifying the predictors of correct weight maintenance in the medium (from 1 to 3 years after surgery) and long term (from 3 years and above) is of vital importance to reduce failure after bariatric surgery; therefore, we summarize the evidence about certain factors, among which we highlight surgical technique, psychological factors, physical activity, adherence to diet, gastrointestinal hormones or neurological factors related to appetite control. We conducted a search in PubMed focused on the last five years (2015–2021). Main findings are as follows: despite Roux-en-Y gastric bypass being more effective in the long term, sleeve gastrectomy shows a more beneficial effectiveness–complications balance; pre-surgical psychological and behavioral evaluation along with post-surgical treatment improve long-term surgical outcomes; physical activity programs after bariatric surgery, in addition to continuous and comprehensive care interventions regarding diet habits, improve weight loss maintenance, but it is necessary to improve adherence; the impact of bariatric surgery on the gut–brain axis seems to influence weight maintenance. In conclusion, although interesting findings exist, the evidence is contradictory in some places, and long-term clinical trials are necessary to draw more robust conclusions.

The potential role of incretin-based therapies for polycystic ovary syndrome: a narrative review of the current evidence

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects women of reproductive age. Metabolic consequences associated with PCOS include, but are not limited to, insulin resistance (IR), type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). This narrative review aims to provide a comprehensive overview of the potential therapeutic roles of the incretin-based therapies in the management of PCOS.

METHODS

We performed a systematic search of databases including PubMed, MEDLINE and EMBASE up to 1 October 2020. We developed a search string of medical subject headings (MeSH) including the terms PCOS, incretin mimetics, glucagon-like peptide-1 (GLP-1), glucagon-like peptide-1 receptor antagonists (GLP-1 RAs), liraglutide, exenatide, semaglutide, dipeptidyl peptidase-4 (DPP-4) inhibitors, combined with IR, testosterone and sex hormone-binding globulin (SHBG).

RESULTS

We identified 854 relevant articles and, after the initial screening, eight interventional animal studies, one observational animal study, 14 interventional human studies, two case-control studies and one systematic review were included. These studies showed the potential significant roles of GLP-1 RAs and DPP-4 inhibitors in the management of PCOS, with significant improvements in the metabolic parameters, including substantial weight reduction and improved insulin sensitivity. These agents also improved the hormonal parameters through decreased free androgen and increased SHBG. Moreover, they improved menstrual regularity, increased fertility with enhanced ovulation and pregnancy in obese women with PCOS.

CONCLUSION

GLP-1 RAs and DPP-4 inhibitors have a promising therapeutic role in PCOS; however, larger clinical trials are needed to establish the role of incretin-based therapies in the management of PCOS.

GLP-1 receptors are involved in the GLP-1 (7-36) amide-induced modulation of glucose homoeostasis, emesis and feeding in Suncus murinus (house musk shrew)

GLP-1 receptor agonists are used for the treatment of type 2 diabetes but they may reduce appetite and cause nausea and emesis. We investigated if GLP-1 (7-36) amide can modulate glucose homoeostasis, emesis and feeding via an exendin (9-39)-sensitive mechanism in Suncus murinus. The effect of GLP-1 (7-36) amide on glucose homeostasis was examined using an intraperitoneal glucose tolerance test. In conscious fasted animals, food and water consumption and behavior were measured for 1 h following drug administration. c-Fos expression in the brain was measured using immunohistochemistry. GLP-1 (7-36) amide reduced blood glucose levels dose-dependently. Exendin (9-39) did not modify blood glucose levels but suppressed the glucose-lowering effect of GLP-1 (7-36) amide. GLP-1 (7-36) amide inhibited food and water intake, induced emesis and elevated c-Fos expression in the brainstem and hypothalamic nuclei in the brain. Exendin (9-39) antagonised the inhibition of food and water intake and emesis induced by GLP-1 (7-36) amide and the effects on c-Fos expression in the hypothalamus and brainstem, excepting for the bed nucleus of the stria terminalis. These data suggest that the action of GLP-1 (7-36) amide to modulate blood glucose, suppress food and water intake and induce emesis involve GLP-1 receptors in the hypothalamus and brainstem.

Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity (SELECT) rationale and design

Cardiovascular disease (CVD) is a major cause of morbidity and mortality. Although it has been widely appreciated that obesity is a major risk factor for CVD, treatments that produce effective, durable weight loss and the impact of weight reduction in reducing cardiovascular risk have been elusive. Instead, progress in CVD risk reduction has been achieved through medications indicated for controlling lipids, hyperglycemia, blood pressure, heart failure, inflammation, and/or thrombosis. Obesity has been implicated as promoting all these issues, suggesting that sustained, effective weight loss may have independent cardiovascular benefit. GLP-1 receptor agonists (RAs) reduce weight, improve glycemia, decrease cardiovascular events in those with diabetes, and may have additional cardioprotective effects. The GLP-1 RA semaglutide is in phase 3 studies as a medication for obesity treatment at a dose of 2.4 mg subcutaneously (s.c.) once weekly. Semaglutide Effects on Heart Disease and Stroke in Patients with Overweight or Obesity (SELECT) is a randomized, double-blind, parallel-group trial testing if semaglutide 2.4 mg subcutaneously once weekly is superior to placebo when added to standard of care for preventing major adverse cardiovascular events in patients with established CVD and overweight or obesity but without diabetes. SELECT is the first cardiovascular outcomes trial to evaluate superiority in major adverse cardiovascular events reduction for an antiobesity medication in such a population. As such, SELECT has the potential for advancing new approaches to CVD risk reduction while targeting obesity.

Glucagon-Like Peptide-1 (GLP-1) in the Integration of Neural and Endocrine Responses to Stress

Glucagon like-peptide 1 (GLP-1) within the brain is produced by a population of preproglucagon neurons located in the caudal nucleus of the solitary tract. These neurons project to the hypothalamus and another forebrain, hindbrain, and mesolimbic brain areas control the autonomic function, feeding, and the motivation to feed or regulate the stress response and the hypothalamic-pituitary-adrenal axis. GLP-1 receptor (GLP-1R) controls both food intake and feeding behavior (hunger-driven feeding, the hedonic value of food, and food motivation). The activation of GLP-1 receptors involves second messenger pathways and ionic events in the autonomic nervous system, which are very relevant to explain the essential central actions of GLP-1 as neuromodulator coordinating food intake in response to a physiological and stress-related stimulus to maintain homeostasis. Alterations in GLP-1 signaling associated with obesity or chronic stress induce the dysregulation of eating behavior. This review summarized the experimental shreds of evidence from studies using GLP-1R agonists to describe the neural and endocrine integration of stress responses and feeding behavior.

The Protective Role of Hydrogen Sulfide Against Obesity-Associated Cellular Stress in Blood Glucose Regulation

Circulating palmitic acid (PA) is increased in obesity and causes metabolic stress, leading to diabetes. This includes the impairment of the glucoregulatory hormone glucagon-like peptide-1 (GLP-1) secreted from intestinal L-cells. Recently, the anti-inflammatory gasotransmitter hydrogen sulfide (H₂S) has been implicated in the enhancement of GLP-1 secretion. We hypothesized that H₂S can reduce the oxidative stress caused by palmitate and play a protective role in L-cell function. This study was conducted on both human and mouse L-cells and a mouse model of Western diet (WD)-induced obesity. PA-induced L-cell stress was assessed using DCF-DA. H₂S was delivered using the donor GYY4137. C57BL/6 mice were fed either chow diet or PA-enriched WD for 20 weeks with ongoing measurements of glycemia and GLP-1 secretion. In both L-cell models, we demonstrated that PA caused an increase in reactive oxygen species (ROS). This ROS induction was partially blocked by the H₂S administration. In mice, the WD elevated body weight in both sexes and elevated fasting blood glucose and lipid peroxidation in males. Additionally, a single GYY4137 injection improved oral glucose tolerance in WD-fed male mice and also enhanced glucose-stimulated GLP-1 release. To conclude, H₂S reduces oxidative stress in GLP-1 cells and can improve glucose clearance in mice.

The Implication of Gut Hormones in the Regulation of Energy Homeostasis and Their Role in the Pathophysiology of Obesity

PURPOSE OF REVIEW

This review provides an update on the role of gut hormones and their interactions in the regulation of energy homeostasis, describes gut hormone adaptations in obesity and in response to weight loss, and summarizes the current evidence on the role of gut hormone-based therapies for obesity treatment.

RECENT FINDINGS

Gut hormones play a key role in regulating eating behaviour, energy and glucose homeostasis. Dysregulated gut hormone responses have been proposed to be pathogenetically involved in the development and perpetuation of obesity. Summarizing the major gut hormone changes in obesity, obese individuals are characterized by blunted postprandial ghrelin suppression, loss of premeal ghrelin peaks, impaired diurnal ghrelin variability and reduced fasting and postprandial levels of anorexigenic peptides. Adaptive alterations of gut hormone levels are implicated in weight regain, thus complicating hypocaloric dietary interventions, and can further explain the profound weight loss and metabolic improvement following bariatric surgery. A plethora of compounds mimicking gut hormone changes after bariatric surgery are currently under investigation, introducing a new era in the pharmacotherapy of obesity. The current trend is to combine different gut hormone receptor agonists and target multiple systems simultaneously, in order to replicate as closely as possible the gut hormone milieu after bariatric surgery and circumvent the counter-regulatory adaptive changes associated with dietary energy restriction. An increasing number of preclinical and early-phase clinical trials reveal the additive benefits obtained with dual or triple gut peptide receptor agonists in reducing body weight and improving glycaemia. Gut hormones act as potent regulators of energy and glucose homeostasis. Therapeutic strategies targeting their levels or receptors emerge as a promising approach to treat patients with obesity and hyperglycaemia.

Bariatric surgery reveals a gut-restricted TGR5 agonist with anti-diabetic effects

Bariatric surgery, the most effective treatment for obesity and type 2 diabetes, is associated with increased levels of the incretin hormone GLP-1 and changes in levels of circulating bile acids. The levels of individual bile acids in the GI tract following surgery, however, have remained largely unstudied. Using UPLC-MS-based quantification, we observed an increase in an endogenous bile acid, cholic acid-7-sulfate (CA7S), in the GI tract of both mice and humans after sleeve gastrectomy. We show that CA7S is a TGR5 agonist that increases Tgr5 expression and induces GLP-1 secretion. Further, CA7S administration increases glucose tolerance in insulin-resistant mice in a TGR5-dependent manner. CA7S remains gut-restricted, minimizing off-target effects previously observed for TGR5 agonists absorbed into circulation. By studying changes in individual metabolites following surgery, this study has revealed a naturally occurring TGR5 agonist that exerts systemic glucoregulatory effects while remaining confined to the gut.

Fermented Dairy Products, Probiotic Supplementation, and Cardiometabolic Diseases: A Systematic Review and Meta-analysis

Fermented dairy foods (FDFs) and probiotics are promising tools for the prevention and management of cardiometabolic diseases (CMDs), respectively. The relation between the regular consumption of FDFs and CMD risk factors was assessed by prospective cohort studies (PCSs), and the effect of probiotic supplementation added into a dairy matrix on CMD parameters was evaluated by randomized controlled trials (RCTs). Moreover, the effects of probiotic supplementation added into a dairy matrix were compared with those administered in capsule/powder form. Twenty PCSs and 52 RCTs met the inclusion criteria for the systematic review and meta-analysis. In PCSs, fermented milk was associated with a 4% reduction in risk of stroke, ischemic heart disease, and cardiovascular mortality [RR (95% CI); 0.96 (0.94, 0.98)]; yogurt intake was associated with a risk reduction of 27% [RR (95% CI); 0.73 (0.70, 0.76)] for type 2 diabetes (T2D) and 20% [RR (95% CI); 0.80 (0.74, 0.87)] for metabolic syndrome development. In RCTs, probiotic supplementation added into dairy matrices produced a greater reduction in lipid biomarkers than when added into capsules/powder in hypercholesterolemic subjects, and probiotic supplementation by capsules/powder produced a greater reduction in T2D biomarkers than when added into dairy matrices in diabetic subjects. Both treatments (dairy matrix and capsules/powder) resulted in a significant reduction in anthropometric parameters in obese subjects. In summary, fermented milk consumption is associated with reduced cardiovascular risk, while yogurt intake is associated with a reduced risk of T2D and metabolic syndrome development in the general population. Furthermore, probiotic supplementation added into dairy matrices could be considered beneficial for lowering lipid concentrations and reducing anthropometric parameters. Additionally, probiotic capsule/powder supplementation could contribute to T2D management and reduce anthropometric parameters. However, these results should be interpreted with caution due to the heterogeneity of the studies and the different probiotic strains used in the studies. This trial is registered with PROSPERO (CRD42018091791) and the protocol can be accessed at http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018091791.

An MRM-Based Multiplexed Quantification Assay for Human Adipokines and Apolipoproteins

Adipokines and apolipoproteins are key regulators and potential biomarkers in obesity and associated diseases and their quantitative assessment is crucial for functional analyses to understand disease mechanisms. Compared to routinely used ELISAs, multiple reaction monitoring (MRM)-based mass spectrometry allows multiplexing and detection of proteins for which antibodies are not available. Thus, we established an MRM method to quantify 9 adipokines and 10 apolipoproteins in human serum. We optimized sample preparation by depleting the two most abundant serum proteins for improved detectability of low abundant proteins. Intra-day and inter-day imprecision were below 16.5%, demonstrating a high accuracy. In 50 serum samples from participants with either normal weight or obesity, we quantified 8 adipokines and 10 apolipoproteins. Significantly different abundances were observed for five adipokines (adipsin, adiponectin, chemerin, leptin, vaspin) and four apolipoproteins (apo-B100/-C2/-C4/-D) between the body mass index (BMI) groups. Additionally, we applied our MRM assay to serum samples from normal weight children and human adipocyte cell culture supernatants to proof the feasibility for large cohort studies and distinct biological matrices. In summary, this multiplexed assay facilitated the investigation of relationships between adipokines or apolipoproteins and phenotypes or clinical parameters in large cohorts, which may contribute to disease prediction approaches in the future.

Inter-organ communication: a gatekeeper for metabolic health

Multidirectional interactions between metabolic organs in the periphery and the central nervous system have evolved concomitantly with multicellular organisms to maintain whole-body energy homeostasis and ensure the organism's adaptation to external cues. These interactions are altered in pathological conditions such as obesity and type 2 diabetes. Bioactive peptides and proteins, such as hormones and cytokines, produced by both peripheral organs and the central nervous system, are key messengers in this inter-organ communication. Despite the early discovery of the first hormones more than 100 years ago, recent studies taking advantage of novel technologies have shed light on the multiple ways used by cells in the body to communicate and maintain energy balance. This review briefly summarizes well-established concepts and focuses on recent advances describing how specific proteins and peptides mediate the crosstalk between gut, brain, and other peripheral metabolic organs in order to maintain energy homeostasis. Additionally, this review outlines how the improved knowledge about these inter-organ networks is helping us to redefine therapeutic strategies in an effort to promote healthy living and fight metabolic disorders and other diseases.

Obesity and cardiovascular risk: a call for action from the European Society of Hypertension Working Group of Obesity, Diabetes and the High-risk Patient and European Association for the Study of Obesity: part A: mechanisms of obesity induced hypertension, diabetes and dyslipidemia and practice guidelines for treatment

: Obesity is a key factor for cardiovascular diseases and complications. Obesity is associated with hypertension, dyslipidemia and type II diabetes, which are the major predictors of cardiovascular disease in the future. It predisposes for atrial fibrillation, heart failure, sudden cardiac death, renal disease and ischemic stroke that are the main causes of cardiovascular hospitalization and mortality. As obesity and the cardiovascular effects on the vessels and the heart start early in life, even from childhood, it is important for health policies to prevent obesity very early before the disease manifestation emerge. Key roles in the prevention are strategies to increase physical exercise, reduce body weight and to prevent or treat hypertension, lipids disorders and diabetes earlier and efficiently to prevent cardiovascular complications.Epidemiology and mechanisms of obesity-induced hypertension, diabetes and dyslipidemia will be reviewed and the role of lifestyle modification and treatment strategies in obesity will be updated and analyzed. The best treatment options for people with obesity, hypertension, diabetes and dyslipidemia will discussed.

Liraglutide induces beige fat development and promotes mitochondrial function in diet induced obesity mice partially through AMPK-SIRT-1-PGC1-α cell signaling pathway

PURPOSE

Glucagon like peptide-1 (GLP-1) is produced to induce postprandial insulin secretion. Liraglutide, a full agonist of the GLP-1 receptor, has a protective effect on weight gain in obese subjects. Brown adipose tissue plays a major role in the control of energy balance and is known to be involved in the weight loss regulated by liraglutide. The putative anti-obesity properties of liraglutide and the cell signaling pathways involved were examined.

METHODS

Four groups of C57/BL6 mice fed with chow or HFHS diet were injected with either liraglutide or vehicle for four weeks. Western blotting was used to analyze protein expression.

RESULTS

Liraglutide significantly attenuated the weight gain in mice fed with HFHS diet and was associated with significant reductions of epididymal fat and inguinal fat mass. Furthermore, liraglutide significantly upregulated the expression of brown adipose-specific markers in perigonadal fat in association with upregulation of AMPK-SIRT-1-PGC1-α cell signaling. However, elevation of brown fat markers in skeletal muscle was only observed in HFHS diet fed mice after liraglutide treatment, and AMPK-SIRT-1 cell signaling is not involved in this process.

CONCLUSIONS

the anti-obesity effect of liraglutide occurs through adaptive thermogenesis and may act through different cell signaling pathways in fat and skeletal muscle tissue. Liraglutide induces beige fat development partially through the AMPK-SIRT-1-PGC1-α cell signaling pathway. Therefore, liraglutide is a potential medication for obesity prevention and in targeting pre-diabetics.

A carbohydrate-reduced high-protein diet acutely decreases postprandial and diurnal glucose excursions in type 2 diabetes patients

The aim of the study was to assess whether a simple substitution of carbohydrate in the conventionally recommended diet with protein and fat would result in a clinically meaningful reduction in postprandial hyperglycaemia in subjects with type 2 diabetes mellitus (T2DM). In all, sixteen subjects with T2DM treated with metformin only, fourteen male, with a median age of 65 (43-70) years, HbA1c of 6·5 % (47 mmol/l) (5·5-8·3 % (37-67 mmol/l)) and a BMI of 30 (sd 4·4) kg/m2 participated in the randomised, cross-over study. A carbohydrate-reduced high-protein (CRHP) diet was compared with an iso-energetic conventional diabetes (CD) diet. Macronutrient contents of the CRHP/CD diets consisted of 31/54 % energy from carbohydrate, 29/16 % energy from protein and 40/30 % energy from fat, respectively. Each diet was consumed on 2 consecutive days in a randomised order. Postprandial glycaemia, pancreatic and gut hormones, as well as satiety, were evaluated at breakfast and lunch. Compared with the CD diet, the CRHP diet reduced postprandial AUC of glucose by 14 %, insulin by 22 % and glucose-dependent insulinotropic polypeptide by 17 % (all P<0·001), respectively. Correspondingly, glucagon AUC increased by 33 % (P<0·001), cholecystokinin by 24 % (P=0·004) and satiety scores by 7 % (P=0·035), respectively. A moderate reduction in carbohydrate with an increase in fat and protein in the diet, compared with an energy-matched CD diet, greatly reduced postprandial glucose excursions and resulted in increased satiety in patients with well-controlled T2DM.

Peptide-oligourea hybrids analogue of GLP-1 with improved action in vivo

Peptides have gained so much attention in the last decade that they are now part of the main strategies, with small molecules and biologics, for developing new medicines. Despite substantial progress, the successful development of peptides as drugs still requires a number of limitations to be addressed, including short in vivo half-lives and poor membrane permeability. Here, we describe the use of oligourea foldamers as tool to improve the pharmaceutical properties of GLP-1, a 31 amino acid peptide hormone involved in metabolism and glycemic control. Our strategy consists in replacing four consecutive amino acids of GLP-1 by three consecutive ureido residues by capitalizing on the structural resemblance of oligourea and α-peptide helices. The efficacy of the approach is demonstrated with three GLP-1-oligourea hybrids showing prolonged activity in vivo. Our findings should enable the use of oligoureas in other peptides to improve their pharmaceutical properties and may provide new therapeutic applications.

Relationship between the insulin resistance and circulating predictive biochemical markers in metabolic syndrome among young adults in western Algeria

AIM

The metabolic syndrome (MetS) becomes increasingly obvious from an early age. The current study aimed at exploring the relationship between insulin resistance and the main biomarkers of MetS in young adult algerian patients.

METHODS

Glucose, HbA1C, total cholesterol (TC), hjgh bensity lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), insulinemia and C-peptide, adipokins (leptin, adiponectin), inflammatory cytokines (IL-6 and TNF-a), us-CRP and GLP-1 were measured by suitable methods. Homeostasis model assessment (HOMA) was used to detect the degree of insulin resistance.

RESULTS

The MetS patients displayed higher glucose, insulin, HbA1c values and impaired lipid profile as judged by increasing TC, TG, LDL-C levels and lower HDL-C. Furthermore, adipokines, HDL-C and CRP contents were significantly higher whilst TG and LDL-C were much lower in MetS female group as compared to male patients suggesting most pronounced metabolic perturbation in the latter group. The probability of a significant correlation between HOMA and studied variables was often higher in female than male subjects. Such was the case for total cholesterol, HDL-cholesterol, triglycerides, adiponectin, interleukin-6, TNF-α and hs-CRP.

CONCLUSION

The high rate of metabolic syndrome among young obese adults is alarming, this requiring extensive investigations in prone subjects.

Diabetes and obesity. The role of agonists glucagon-like peptide-1 of in the treatment of type 2 diabetes

Significant number of patients with type 2 diabetes mellitus are obese. It is known that even glucose intolerance, as well as diabetes, can lead to vascular complications. At the same time, weight loss can reduce the risk of type 2 diabetes in obese and pre-diabetic patients. According to available data, a significant decrease in the incretin effect is observed in patients with type 2 diabetes and obese individuals. Thus, a decrease in the incretin effect leads to a violation of the insulin response to the intake of carbohydrates, and, consequently, an increase in the level of glucose in the blood. It was also found that the decrease in the incretin effect in patients with type 2 diabetes can be associated with a lower secretion of glucagon-like peptide-1. The interest is represented by groups of antidiabetic drugs capable of regulating glycemia by affecting the secretion of insulin and glucagon, depending on its level. Such drugs include glucagon-like peptide-1 receptor agonists. The article shows the advantage of prolonged action in patients with type 2 diabetes and obesity of the glucagon-like peptide 1 receptor agonists (albiglutide, dulaglutide, exenatide with slow release) dosing 1 time a week.

Acute Effects of Dietary Carbohydrate Restriction on Glycemia, Lipemia and Appetite Regulating Hormones in Normal-Weight to Obese Subjects

Postprandial responses to food are highly dependent on the macronutrient composition of the diet. We investigated the acute effects of transition from the recommended moderately high carbohydrate (HC) diet towards a carbohydrate-reduced high-protein (CRHP) diet on postprandial glycemia, insulinemia, lipemia, and appetite-regulating hormones in non-diabetic adults. Fourteen subjects, including five males (Mean ± SD: age 62 ± 6.5; BMI 32 ± 7.6 kg/m²; hemoglobin A_1c (HbA_1c) 40 ± 3.0 mmol/mol; HOMA2-IR 2.1 ± 0.9) were included in this randomized, cross-over study. Iso-caloric diets were consumed for two consecutive days with a median wash-out period of 21 days (range 2–8 weeks) between diets (macronutrient energy composition: CRHP/HC; 31%/54% carbohydrate, 29%/16% protein, 40%/30% fat). Postprandial glucose, insulin secretion rate (ISR), triglycerides (TGs), non-esterified fatty acids (NEFAs), and satiety ratings were assessed after ingestion of breakfast (Br) and lunch (Lu), and gut hormones and glucagon were assessed after ingestion of Br. Compared with the HC diet, the CRHP diet reduced peak glucose concentrations (Br 11%, p = 0.024; Lu 11%, p < 0.001), glucose excursions (Br 80%, p = 0.20; Lu 85%, p < 0.001), and ISR (Br 31%; Lu 64%, both p < 0.001) whereas CRHP, as compared with HC, increased glucagon-like peptide-1 (Br 27%, p = 0.015) and glucagon values (Br 249%, p < 0.001). NEFA and TG levels increased in the CRHP diet as compared with the HC diet after Br, but no difference was found after Lu (NEFA Br 22%, p < 0.01; TG Br 42%, p = 0.012). Beta-cell glucose sensitivity, insulin clearance, cholecystokinin values, and subjective satiety ratings were unaffected. It is possible to achieve a reduction in postprandial glycemia and insulin without a deleterious effect on beta-cell glucose sensitivity by substituting part of dietary carbohydrate with iso-caloric protein and fat in subjects without type 2 diabetes mellitus (T2DM). The metabolic effects are more pronounced after the second meal.

Enteroendocrine and adipokine associations with type 2 diabetes: Phenotypic risk scoring approaches

BACKGROUND AND AIM

The contribution of gut-derived factors to the mechanisms linking obesity and metabolic disease remains under-investigated. The aim of the current study was to examine the associations between glucagon and enteroendocrine signaling and type 2 diabetes (T2D) using a derived risk score approach. To compare the relative importance of the enteroendocrine system, associations between adipokine measures and T2D were also investigated.

METHODS

A total of 130 individuals with T2D and 161 individuals without T2D were included in the study. Circulating concentrations of enteroendocrine (glucagon, ghrelin, glucagon-like peptide-1, and gastric inhibitory peptide) and adipokine mediators (adiponectin, leptin, resistin, visfatin, and adipsin) were measured. Standard scores (Z-scores) were determined for each measure and enteroendocrine risk scores (ERS) and adipokine risk scores (ARS) calculated based on summation of the component measures. Associations between both the ERS and ARS and T2D status were assessed using logistic regression models.

RESULTS

The ERS was significantly associated with T2D status in an adjusted model (odds ratio: 1.36; 95% confidence interval [CI]: 1.08-1.72; P = 0.009). Associations between the ARS and T2D status were not independent of age, sex, and body mass index (odds ratio: 1.21; 95%CI: 0.99-1.47; P = 0.06). Quantification of risk across ERS tertiles revealed that individuals with an ERS in the upper tertile were 10 times more likely (CI: 3.23-32.73; P < 0.001) to have T2D.

CONCLUSIONS

These data support an association between enteroendocrine signaling and T2D. Use of the ERS as a potential tool for classifying individuals with metabolic syndrome as high or low risk for T2D development is being considered.

COMPARISON OF THE LEVELS OF C-REACTIVE PROTEIN, GLP-1 AND GLP-2 AMONG INDIVIDUALS WITH DIABETES, MORBID OBESITY AND HEALTHY CONTROLS: AN EXPLORATORY STUDY

BACKGROUND

The glucagon-like peptides 1 and 2 (GLP-1/GLP-2) are gut hormones that may directly affect the glucose homeostasis and their activity seems to be significantly affected by chronic inflammation.

OBJECTIVE

To evaluate the postprandial levels of glucagon-like peptides 1 and 2 (GLP-1/GLP-2), C-reactive protein (CRP), and the postprandial glucose and insulin levels among individuals with obesity, type 2 diabetes, and healthy controls.

METHODS

An exploratory cross-sectional study, which involved individuals awaiting for bariatric/metabolic surgery and healthy controls. Postprandial levels of GLP-1, GLP-2, glucose, and insulin were obtained after a standard meal tolerance test. Inflammation was assessed by means of CRP.

RESULTS

There were 30 individuals enrolled in the study, divided into three groups: non-diabetic with morbid obesity (NDO; n=11 individuals), diabetic with mild obesity (T2D; n=12 individuals), and healthy controls (C; n=7 individuals). The mean CRP levels were significantly higher in the NDO group (6.6±4.7 mg/dL) than in the T2D (3.3±2.2 mg/dL) and C groups (2.5±3.2 mg/dL) (P=0.038). The GLP-1 levels following standard meal tolerance test and the area under the curve of GLP-1 did not differ among the three groups. The GLP-2 levels were significantly lower in the NDO and T2D than in the C group following standard meal tolerance test at all the times evaluated. The area under the curve of the GLP-2 was significantly lower in the NDO and T2D groups than in the C group (P=0.05 and P=0.01, respectively).

CONCLUSION

GLP-2 levels were impaired in the individuals with obesity and diabetes. This mechanism seems to be enrolled in preventing the worsening of the glucose homeostasis in these individuals.

Treatment of clozapine-associated obesity and diabetes with exenatide in adults with schizophrenia: A randomized controlled trial (CODEX)

Clozapine causes obesity and type 2 diabetes (T2DM). Glucagon-like peptide-1 (GLP-1) receptor agonists (e.g. exenatide) can counter clozapine-associated GLP-1 dysregulation in animals, and may be beneficial in people on clozapine. This randomized, controlled, open-label, pilot trial evaluated weekly exenatide for weight loss among clozapine-treated obese adults with schizophrenia, with or without T2DM. A total of 28 outpatients were randomized to once-weekly extended-release subcutaneous exenatide or usual care for 24 weeks. The primary outcome was proportion of participants with >5% weight loss. All 28 participants completed the study; 3/14 in the exenatide group and 2/14 in the usual care group had T2DM. Six people on exenatide achieved >5% weight loss vs one receiving usual care (P = .029). Compared with usual care, participants on exenatide had greater mean weight loss (-5.29 vs -1.12 kg; P = .015) and body mass index reduction (-1.78 vs -0.39 kg/m² ; P = .019), and reduced fasting glucose (-0.34 vs 0.39 mmol/L; P = .036) and glycated haemoglobin levels (-0.21% vs 0.03%; P = .004). There were no significant differences in other metabolic syndrome components. Exenatide may be a promising therapeutic agent for glycaemic control and weight loss in clozapine-treated people with obesity, and could assist in reducing clozapine-associated cardio-metabolic morbidity and mortality.

Does endogenous GLP-1 affect resting energy expenditure and fuel selection in overweight and obese adults?

PURPOSE

To investigate the association between fasting glucagon-like peptide 1 (GLP-1) levels and resting energy expenditure (REE), and respiratory quotient (RQ) in overweight and obese adults.

METHOD

Study participants were enrolled at the Dietetic and Metabolic Unit, University of Pavia, Italy. Inclusion criteria were age ≥ 25 and ≤ 45 years, and body mass index (BMI) ≥ 25 and ≤ 35 kg/m². Diabetic subjects were excluded. Body composition was measured by dual-energy X-ray absorptiometry. REE was evaluated using indirect calorimetry, and RQ was calculated from respiratory gas exchanges. Fasting GLP-1, glucose, insulin and free fatty acid (FFA) levels, and 24-h norepinephrine urinary excretion were measured. Homeostasis model assessments of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β) were calculated.

RESULTS

Thirty-seven participants were included (age 43.4 ± 1.6 years; BMI 30.6 ± 0.5 kg/m²). REE was not associated with fasting GLP-1 levels (p = 0.98) after adjustment for age, sex, fat-free mass (FFM), and fat mass (FM). Similarly, no association was observed between RQ and GLP-1 levels (p = 0.95), after adjustment for age, sex, and body fat.

CONCLUSION

In adults subjects with increased adiposity fasting, GLP-1 levels do not seem to play a role in the regulation of energy metabolism and in fuel selection.

Weight Loss and Appetite Control in Women

PURPOSE OF REVIEW

The aim of this review is to describe and discuss weight loss-induced variations in appetite in women and factors responsible for these changes.

RECENT FINDINGS

Studies have shown postweight loss increases in fasting and postprandial appetite in individuals engaged in weight loss trials, especially in women. Similarly, appetite-related peptides associated to the homeostatic control of feeding, such as leptin, ghrelin and peptide YY, were also found to be altered in way that promotes increased appetite after weight loss interventions. Sustained caloric deficits also drive increases in the frequency and strength of food cravings, food reward and seem to enhance oro-sensory sensations in women who lost weight. The menstrual cycle has also been to shown to influence caloric intake in women, more specifically food cravings. On the other hand, caloric restriction seems to increase cognitive restraint, decrease habitual disinhibition and susceptibility to hunger among women engaged in weight loss trials. Neural analysis corroborates these results, showing increased activation in brain areas involved in food reward and self-control processing. In conclusion, evidence supports that weight loss increases appetite sensations, and promotes changes in homeostatic and non-homeostatic control of feeding, which collectively seem to upregulate appetite in women.

Comprehensive Care for Bariatric Surgery Patients

Obesity is a worldwide epidemic, and those suffering from obesity have increased morbidity and mortality rates. There are various causes of obesity and many treatment options for patients suffering from obesity, including nonsurgical treatments. However, bariatric surgery is often the best choice for optimal weight loss and the attenuation of comorbidities. Currently, laparoscopic sleeve gastrectomy is the most common type of bariatric surgery in the United States due to its technical simplicity, feasibility, and overall positive outcomes. This article discusses bariatric surgical criteria and selection, expected perioperative course, potential complications after surgery, and nursing implications for the care of bariatric patients. A case report is used to exemplify stages of surgical care and follow-up treatment for patients who undergo laparoscopic sleeve gastrectomy.