Metabolic complications of obesity

Immunometabolic Signatures of Circulating Monocytes in Humans With Obesity and Insulin Resistance

Obesity is associated with chronic inflammation and metabolic complications, including insulin resistance (IR). Immune cells drive inflammation through the rewiring of intracellular metabolism. However, the impact of obesity-related IR on the metabolism and functionality of circulating immune cells, like monocytes, remains poorly understood. To increase insight into the interindividual variation of immunometabolic signatures among individuals and their role in the development of IR, we assessed systemic and tissue-specific IR and circulating immune markers, and we characterized metabolic signatures and cytokine secretion of circulating monocytes from 194 individuals with a BMI ≥25 kg/m2. Monocyte metabolic signatures were defined using extracellular acidification rates (ECARs) to estimate glycolysis and oxygen consumption rates (OCRs) for oxidative metabolism. Although monocyte metabolic signatures and function based on cytokine secretion varied greatly among study participants, they were strongly associated with each other. The ECAR-to-OCR ratio, representing the balance between glycolysis and oxidative metabolism, was negatively associated with fasting insulin levels, systemic IR, and liver-specific IR. These results indicate that monocytes from individuals with IR were relatively more dependent on oxidative metabolism, whereas monocytes from more insulin-sensitive individuals were more dependent on glycolysis. Additionally, circulating CXCL11 was negatively associated with the degree of systemic IR and positively with the ECAR-to-OCR ratio in monocytes, suggesting that individuals with high IR and a monocyte metabolic dependence on oxidative metabolism also have lower levels of circulating CXCL11. Our findings suggest that monocyte metabolism is related to obesity-associated IR progression and deepen insights into the interplay between innate immune cell metabolism and IR development in humans.

ARTICLE HIGHLIGHTS

County-level socio-environmental factors and obesity prevalence in the United States

AIMS

To investigate high-risk sociodemographic and environmental determinants of health (SEDH) potentially associated with adult obesity in counties in the United States using machine-learning techniques.

MATERIALS AND METHODS

We performed a cross-sectional analysis of county-level adult obesity prevalence (body mass index ≥30 kg/m2) in the United States using data from the Diabetes Surveillance System 2017. We harvested 49 county-level SEDH factors that were used in a classification and regression trees (CART) model to identify county-level clusters. The CART model was validated using a 'hold-out' set of counties and variable importance was evaluated using Random Forest.

RESULTS

Overall, we analysed 2752 counties in the United States, identifying a national median (interquartile range) obesity prevalence of 34.1% (30.2%, 37.7%). The CART method identified 11 clusters with a 60.8% relative increase in prevalence across the spectrum. Additionally, seven key SEDH variables were identified by CART to guide the categorization of clusters, including Physically Inactive (%), Diabetes (%), Severe Housing Problems (%), Food Insecurity (%), Uninsured (%), Population over 65 years (%) and Non-Hispanic Black (%).

CONCLUSION

There is significant county-level geographical variation in obesity prevalence in the United States, which can in part be explained by complex SEDH factors. The use of machine-learning techniques to analyse these factors can provide valuable insights into the importance of these upstream determinants of obesity and, therefore, aid in the development of geo-specific strategic interventions and optimize resource allocation to help battle the obesity pandemic.

High-intensity interval training attenuates impairment in regulatory protein machinery of mitochondrial quality control in skeletal muscle of diet-induced obese mice

Mitochondrial quality control processes are essential in governing mitochondrial integrity and function. The purpose of the study was to examine the effects of 10 weeks of high-intensity interval training (HIIT) on the regulatory protein machinery of skeletal muscle mitochondrial quality control and whole-body glucose homeostasis in diet-induced obese mice. Male C57BL/6 mice were assigned to low-fat diet (LFD) or high-fat diet (HFD) group. After 10 weeks, HFD-fed mice were divided into sedentary and HIIT (HFD + HIIT) groups for another 10 weeks (n = 9/group). Graded exercise test, glucose and insulin tolerance tests, mitochondrial respiration, and protein markers of mitochondrial quality control processes were determined. HFD-fed mice exhibited lower ADP-stimulated mitochondrial respiration (p < 0.05). However, 10 weeks of HIIT prevented this impairment (p < 0.05). Importantly, the ratio of Drp1(Ser616) over Drp1(Ser637) phosphorylation, an indicator of mitochondrial fission, was significantly higher in HFD-fed mice (p < 0.05), but such increase was attenuated in HFD-HIIT compared to HFD (-35.7%, p < 0.05). Regarding autophagy, skeletal muscle p62 content was lower in the HFD group than the LFD group (-35.1%, p < 0.05); however, such reduction was disappeared in the HFD + HIIT group. In addition, LC3B II/I ratio was higher in the HFD group than the LFD group (15.5%, p < 0.05) but was ameliorated in the HFD + HIIT group (-29.9%, p < 0.05). Overall, our study demonstrated that 10 weeks of HIIT was effective in improving skeletal muscle mitochondrial respiration and the regulatory protein machinery of mitochondrial quality control in diet-induced obese mice through the alterations of mitochondrial fission protein Drp1 phosphorylations and p62/LC3B-mediated regulatory machinery of autophagy.

Nutrition support in the pediatric total pancreatectomy with islet autotransplantation recipient

For children with diminished quality of life and chronic pain caused by acute recurrent or chronic pancreatitis who are undergoing total pancreatectomy with islet autotransplantation, postoperative nutrition support has several unique characteristics. Surgical complications may lead to delays in nutrition support initiation or require modifications to the regimen. Early postoperative dysmotility requires the use of temporary enteral nutrition until this improves. The resultant complete exocrine pancreatic insufficiency necessitates lifelong pancreatic enzyme replacement therapy and fat-soluble vitamin supplementation. A low-oxalate diet is recommended to prevent kidney stones. Carbohydrate counting is needed for the provision of short-term insulin dosing and possibly long-term as well, depending on the transplanted islet yield. Children should have careful nutrition assessment and monitoring at several follow-up visits during the first year, then annually, and at any time with concerns.

In vivo corneal confocal microscopy as a non-invasive test to assess obesity induced small fibre nerve damage and inflammation

PURPOSE

To investigate small nerve fibre damage and inflammation at the level of the sub-basal nerve plexus (SNP) of severe obese patients and compare the results with those of healthy subjects.

METHODS

This cross-sectional, observational study investigated the data of 28 patients (14 out of 28 prediabetic or diabetic) with severe obesity (Body Mass Index; BMI ≥ 40) and 20 healthy subjects. Corneal nerve fibre density (CNFD), branch density (CNBD), fibre length (CNFL), nerve fibre area (CNFA), nerve fibre width (CNFW), and nerve fractal dimension (CNFrD) and dendritic cell (DC) density were evaluated using in vivo confocal microscopy (IVCM, Heidelberg Retinal Tomograph III Rostock Cornea Module). Automatic CCMetrics software (University of Manchester, UK) was used for quantitative analysis of SNP.

RESULTS

Mean age was 48.4±7.4 and 45.1 ± 5.8 in the control and obese group, respectively (p = 0.09). Mean BMI were 49.1 ± 7.8 vs. 23.3 ± 1.4 in obese vs. control group, respectively (p < 0.001). Mean CNFD, CNBD, CNFL, CNFA, CNFW were significantly reduced in obese group compared with those in the control group (always p < 0.05, respectively). There were no significant differences in any ACCMetrics parameters between prediabetic/diabetic and non-diabetic obese patients. Increased DC densities were detected in obese group compared with those in control group (p < 0.0001). There were significant correlations between BMI scores and SNP parameters.

CONCLUSION

Imaging with IVCM is a feasible, non-invasive method to detect and quantify occult corneal nerve damage and increased inflammation in patients with obesity. This study suggests that obesity may be a separate risk factor for peripheral neuropathy regardless of DM.

High-Intensity Interval Training Attenuates Impairment in Regulatory Protein Machinery of Mitochondrial Quality Control in Skeletal Muscle of Diet-Induced Obese Mice

Mitochondrial quality control processes are essential in governing mitochondrial integrity and function. The purpose of the study was to examine the effects of 10 weeks of HIIT on the regulatory protein machinery of skeletal muscle mitochondrial quality control and whole-body glucose homeostasis in diet-induced obese mice. Male C57BL/6 mice were randomly assigned to a low-fat diet (LFD) or high-fat diet (HFD) group. After 10 weeks, HFD-fed mice were divided into sedentary and HIIT (HFD+HIIT) groups and remained on HFD for another 10 weeks (n=9/group). Graded exercise test, glucose and insulin tolerance tests, mitochondrial respiration and regulatory protein markers of mitochondrial quality control processes were determined by immunoblots. Ten weeks of HIIT enhanced ADP-stimulated mitochondrial respiration in diet-induced obese mice (P < 0.05) but did not improve whole-body insulin sensitivity. Importantly, the ratio of Drp1(Ser 616 ) over Drp1(Ser 637 ) phosphorylation, an indicator of mitochondrial fission, was attenuated in HFD-HIIT compared to HFD (-35.7%, P < 0.05). Regarding autophagy, skeletal muscle p62 content was lower in HFD group than LFD group (-35.1%, P < 0.05), however, such reduction was disappeared in HFD+HIIT group. In addition, LC3B II/I ratio was higher in HFD than LFD group (15.5%, P < 0.05) but was ameliorated in HFD+HIIT group (-29.9%, P < 0.05). Overall, our study demonstrated that 10 weeks of HIIT was effective in improving skeletal muscle mitochondrial respiration and the regulatory protein machinery of mitochondrial quality control in diet-induced obese mice through the alterations of mitochondrial fission protein Drp1 activity and p62/LC3B-mediated regulatory machinery of autophagy.

Identification of five genetic variants with differential effects on obesity-related traits based on age

Obesity is a major public health concern, and its prevalence generally increases with age. As the number of elderly people is increasing in the aging population, the age-dependent increase in obesity has raised interest in the underlying mechanism. To understand the genetic basis of age-related increase in obesity, we identified genetic variants showing age-dependent differential effects on obesity. We conducted stratified analyses between young and old groups using genome-wide association studies of 355,335 United Kingom Biobank participants for five obesity-related phenotypes, including body mass index, body fat percentage, waist-hip ratio, waist circumference, and hip circumference. Using t-statistic, we identified five significant lead single nucleotide polymorphisms: rs2258461 with body mass index, rs9861311 and rs429358 with body fat percentage, rs2870099 with waist-hip ratio, and rs145500243 with waist circumference. Among these single nucleotide polymorphisms, rs429358, located in APOE gene was associated with diverse age-related diseases, such as Alzheimer’s disease, coronary artery disease, age-related degenerative macular diseases, and cognitive decline. The C allele of rs429358 gradually decreases body fat percentage as one grows older in the range of 40–69 years. In conclusion, we identified five genetic variants with differential effects on obesity-related phenotypes based on age using a stratified analysis between young and old groups, which may help to elucidate the mechanisms by which age influences the development of obesity.

A Botanical Mixture Consisting of Inula japonica and Potentilla chinensis Relieves Obesity via the AMPK Signaling Pathway in 3T3-L1 Adipocytes and HFD-Fed Obese Mice

Excessive lipid accumulation in white adipose tissue (WAT) is the major cause of obesity. Herein, we investigated the anti-obesity effect and molecular mechanism of a botanical mixture of 30% EtOH extract from the leaves of Inula japonica and Potentilla chinensis (EEIP) in 3T3-L1 preadipocytes and high-fat diet (HFD)-fed obese mice. In vitro, EEIP prevented lipid accumulation by downregulating the expression of lipogenesis-related transcription factors such as CCAAT/enhancer binding protein (C/EBP)α, peroxisome proliferator-activated receptor (PPAR)γ, and sterol regulatory element binding protein (SREBP)-1 via AMP-activated protein kinase (AMPK) activation and G0/G1 cell cycle arrest by regulating the Akt-mTOR pathways without inducing cytotoxicity. In vivo, EEIP significantly reduced body weight gain and body fat mass in the group administered concurrently with HFD (pre-) or administered during the maintenance of HFD (post-) including subcutaneous, gonadal, renal, and mesenteric fats, and improved blood lipid profiles and metabolic hormones. EEIP pre-administration also alleviated WAT hypertrophy and liver lipid accumulation by reducing C/EBPα, PPARγ, and SREBP-1 expression via AMPK activation. In the brown adipose tissue, EEIP pre-administration upregulated the expression of thermogenic factors. Furthermore, EEIP improved the HFD-induced altered gut microbiota in mice. Taken together, our data indicated that EEIP improves HFD-induced obesity through adipogenesis inhibition in the WAT and liver and is a promising dietary natural material for improving obesity.

Voxel-Mirrored Homotopic Connectivity Is Altered in Meibomian Gland Dysfunction Patients That Are Morbidly Obese

Purpose: To investigate the altered functional connectivity (FC) of the cerebral hemispheres in patients with morbid obesity (MO) with meibomian gland dysfunction (MGD) by voxel-mirrored homotopic connectivity (VMHC). Methods: Patients and matched healthy controls (HCs) were recruited, and all subjects underwent functional resonance magnetic imaging (fMRI), and VMHC results were processed statistically to assess the differences in FC in different brain regions between the two groups. We further used ROC curves to evaluate the diagnostic value of these differences. We also used Pearson’s correlation analysis to explore the relationship between changes in VMHC values in specific brain regions, visual acuity, and Mini-Mental State Examination (MMSE) score. Conclusions: Patients with morbid obesity and MGD had abnormal FC in the cerebral hemispheres in several specific brain areas, which were mainly concentrated in pathways related to vision and perception and may correlate to some extent with the clinical presentations of the patients.

Therapeutic Potential of Semaglutide, a Newer GLP-1 Receptor Agonist, in Abating Obesity, Non-Alcoholic Steatohepatitis and Neurodegenerative diseases: A Narrative Review

INTRODUCTION

Semaglutide, a peptidic GLP-1 receptor agonist, has been clinically approved for treatment of type 2 diabetes mellitus and is available in subcutaneous and oral dosage form. Diabetes, insulin resistance, and obesity are responsible for the pathological manifestations of non-alcoholic steatohepatitis (NASH). Similarly, insulin resistance in brain is also responsible for neurodegeneration and impaired cognitive functions.

BACKGROUND

Observations from phase-3 clinical trials like SUSTAIN and PIONEER indicated anti-obesity potential of semaglutide, which was established in STEP trials. Various pre-clinical and phase-2 studies have indicated the therapeutic potential of semaglutide in non-alcoholic steatohepatitis and neurodegenerative disorders like Parkinson's and Alzheimer's disease.

DISCUSSION

Significant weight reduction ability of semaglutide has been demonstrated in various phase-3 clinical trials, for which recently semaglutide became the first long-acting GLP-1 receptor agonist to be approved by the United States Food and Drug Administration for management of obesity. Various pre-clinical and clinical studies have revealed the hepatoprotective effect of semaglutide in NASH and neuroprotective effect in Parkinson's and Alzheimer's disease.

CONCLUSION

Many GLP-1 receptor agonists have shown hepatoprotective and neuroprotective activity in animal and human trials. As semaglutide is an already clinically approved drug, successful human trials would hasten its inclusion into therapeutic treatment of NASH and neurodegenerative diseases. Semaglutide improves insulin resistance, insulin signalling pathway, and reduce body weight which are responsible for prevention or progression of NASH and neurodegenerative diseases.

Evaluation of the alteration in retinal features following bariatric surgery in patients with morbid obesity

Aim: The aim of the study is to evaluate the effect of bariatric surgery on the retina and choroid in non-diabetic and non-hypertensive patients with morbid obesity using optic coherence tomography (OCT) retrospectively. Material and Method: Seventy-four eyes of seventy-four patients who have been underwent sleeve gasterectomy for morbid obesity in Balıkesir University Medicine Faculty & February 2019 and November 2020 were evaluated. All participants has a detailed ophthalmologic examination including best-corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp biomicroscopy, retinal examination through non-dilated pupil via 90 D fundus lens, the retinal thickness (central, perifoveal, and parafoveal superior/nasal/inferior/temporal quadrants), and choroidal thickness through optic coherence tomography (RTVue XR Avanti, Optovue) in immediate preoperative and postoperative sixth-month. All values were compared. Results: The macular thickness was increased significantly in all quadrants in postoperative visits (p0.05). The correlation between preoperative BMI and preoperative choroidal thickness was significant (R: 0.416, p

MED12 Regulates Human Adipose-Derived Stem Cell Adipogenesis and Mediator Kinase Subunit Expression in Murine Adipose Depots

The mediator kinase module plays a critical role in the regulation of transcription during metabolic processes. Here we demonstrate that in human adipose-derived stem cells (hASCs), kinase module subunits have distinct mRNA and protein expression profiles during different stages of adipogenesis. In addition, siRNA-mediated loss of MED12 results in decreased adipogenesis as evident through decreased lipid accumulation and decreased expression of PPARγ, a master regulator of adipogenesis. Moreover, the decrease in adipogenesis and reduced PPARγ expression are observed only during the early stages of MED12 knockdown. At later stages, knockdown of MED12 did not have any significant effects on adipogenesis or PPARγ expression. We also observed that MED12 was present in a protein complex with PPARγ and C/EBPα during all stages of adipogenesis in hASCs. In 3T3-L1 preadipocytes and adipocytes, MED12 is present in protein complexes with PPARγ1, C/EBPα, and STAT5A. CDK8, another member of the kinase module, was only found to interact with C/EBPα. We found that the expression of all kinase module subunits decreased in inguinal, gonadal, and retroperitoneal white adipose tissue (WAT) depots in the fed state after an overnight fast, whereas the expression of kinase module subunits remained consistent in mesenteric WAT (mWAT) and brown adipose tissue. These data demonstrate that the kinase module undergoes physiologic regulation during fasting and feeding in specific mouse adipose tissue depots, and that MED12 likely plays a specific role in initiating and maintaining adipogenesis.

Circulating HDL and Non-HDL Associated Apolipoproteins and Breast Cancer Severity

Plasma lipids are carried within lipoproteins with various apolipoprotein content. This study evaluates the interest of measuring the apolipoproteins of circulating lipoproteins in breast cancer. Patients with early-stage breast cancer (n = 140) were included. Tumors differed by the expression of estrogen and progesterone receptor (HR- and HR+ for negative and positive expression) and the proliferation marker Ki-67 (≤20% or ≥30%). Apolipoprotein concentrations were determined in plasma, HDL and non-HDL fractions, and results are given in mg/dL, median (25th-75th). Patients did not differ in their plasma and lipoprotein lipid concentrations. HDL apoC-I and non-HDL apoC-II were reduced (1.34 (1.02-1.80) vs. 1.61 (1.32-2.04), p = 0.04; 0.31 (0.18-0.65) vs. 0.63 (0.39-1.02), p = 0.01; respectively), in RH-/high Ki-67 patients in comparison to RH-/low Ki-67 patients, while plasma apoD and HDL apoD were higher (3.24 (2.99-4.16) vs. 3.07 (2.39-3.51), p = 0.04; 2.74 (2.36-3.35) vs. 2.45 (2.01-2.99), p = 0.04; respectively). When RH+/high Ki-67 patients were compared with RH+/low Ki-67 patients, HDL apoC-I and HDL apoC-III were higher (1.56 (1.20-1.95) vs. 1.35 (1.10-1.62), p = 0.02; 2.80 (2.42-3.64) vs. 2.38 (1.69-2.96), p = 0.02; respectively). The distribution of exchangeable apolipoproteins, such as apoC-I, apoC-II, apoC-III, apoD, between lipoproteins is linked to the severity of breast cancer.

Preconception weight loss improves fertility and maternal outcomes in obese mice

Women with obesity have higher incidences of infertility, with longer time to conception and increased risk of pregnancy complications compared to women with normal body weight. There is a lack of evidence demonstrating the benefit of preconception maternal weight loss on fertility and pregnancy outcomes. We aimed to determine if preconception weight loss, either with diet modification or glucose-like peptide 1 receptor agonist liraglutide, improves maternal weight, fertility, and pregnancy outcomes. C57BL/6 female mice were fed either a high-fat diet (HFD) or chow for 8 weeks. HFD-fed dams were administered liraglutide (0.3 mg/kg, s.c., for 4 weeks) or switched to chow to induce weight loss. Prior to mating, liraglutide was ceased and mice continued on HFD. Mice in the 'diet switch' group continued on chow. Pregnancy rates were recorded. Maternal anthropometry and glucose tolerance were measured before and after the intervention and at late gestation. Offspring outcomes were assessed. Liraglutide or diet switch led to weight reduction, improved insulin resistance (P< 0.001), and enhanced fertility, particularly in the liraglutide group (P< 0.005). Liraglutide-treated mice had significantly higher gestational weight gain (GWG) compared to the diet switch group (P< 0.05), with similar weight and glucose tolerance in late gestation to HFD mice. In contrast, diet switch maintained similar weight and glucose tolerance in late gestation to control mice. Pre-pregnancy weight intervention with liraglutide was effective at restoring fertility. Diet modification also improved fertility and avoided catch up weight gain in pregnancy. Liraglutide may be a therapeutic strategy for weight loss to prepare for pregnancy. However, our study provides caution about the potential for excessive GWG without diet intervention in pregnancy.

Hypothalamic Overexpression of Neurosecretory Protein GL Leads to Obesity in Male C57BL/6J Mice

INTRODUCTION

The mechanisms underlying obesity are not fully understood, necessitating the creation of novel animal models for the investigation of metabolic disorders. We have previously found that neurosecretory protein GL (NPGL), a newly identified hypothalamic neuropeptide, is involved in feeding behavior and fat accumulation in rats. However, the impact of NPGL on obesity remains unclear in any animal model. The present investigation sought to elucidate whether NPGL causes obesity in the obesity-prone mouse strain C57BL/6J.

METHODS

We overexpressed the NPGL-precursor gene (Npgl) in the hypothalamus using adeno-associated virus in male C57BL/6J mice fed normal chow (NC) or a high-calorie diet (HCD). After 9 weeks of Npgl overexpression, we measured adipose tissues, muscle, and several organ masses in addition to food intake and body mass. To assess the effects of Npgl overexpression on peripheral tissues, we analyzed mRNA expression of lipid metabolism-related genes by quantitative RT-PCR. Whole body energy consumption was assessed using an O2/CO2 metabolism measurement before an apparent increase in body mass.

RESULTS

Npgl overexpression increased food intake, body mass, adipose tissues and liver masses, and food efficiency under both NC and HCD, resulting in obesity observable within 8 weeks. Furthermore, we observed fat accumulation in adipose tissues and liver. Additionally, mRNA expression of lipid metabolism-related factors was increased in white adipose tissue and the liver after Npgl overexpression. Npgl overexpression inhibited energy expenditure during a dark period.

CONCLUSION

Taken together, the present study suggests that NPGL can act as an obesogenic factor that acts within a short period of time in mice. As a result, this Npgl overexpression-induced obesity can be widely applied to study the etiology of obesity from genes to behavior.

Is there any connection between choroidal thickness and obesity?

Obesity is a health-threatening and epidemic medical condition that can affect individuals of different ages and is potentially associated with an increased risk of systemic and ocular disorders. Despite the well-documented adverse effects of obesity on different parts of the body vasculature, less published data are available concerning obesity-related consequences on the ocular vasculature. As the human choroid is a highly vascularized tissue, its morphology and function might be altered in obese individuals. The micro-structural changes within the choroid could also trigger development of subsequent functional abnormalities of the eye. Previous population-based studies have asserted an association between obesity and choroidal thickness; however, they reported conflicting patterns of association between obesity and changes in choroidal thickness. Therefore, to enhance our understanding of the changes in choroidal morphology secondary to obesity, we reviewed studies describing the micro-structural consequences of obesity on the choroidal thickness profile and its underlying physiological and anatomical basis. This review includes all original publications related to the association between choroidal thickness and obesity published until mid-2021 that were indexed in PubMed, Google Scholar, ScienceDirect, or Scopus.

Circulating extracellular DNA is in association with continuous metabolic syndrome score in healthy adolescents

Obesity is associated with chronic low-grade inflammation that eventually leads to metabolic complications. Extracellular DNA (ecDNA) is a damage-associated molecular pattern. Extracellular mitochondrial DNA can activate innate immunity. We hypothesized that ecDNA, especially of mitochondrial origin, could be associated with components of the metabolic syndrome in young healthy probands. In a cross-sectional study, healthy adolescents (n = 1,249) provided blood samples. Anthropometric data, blood pressure, and blood counts were assessed. In addition, biochemical analysis of sera or plasma was conducted, including the quantification of advanced oxidation protein products (AOPPs) as a marker of oxidative stress induced by neutrophil or monocyte activation. Plasma ecDNA was isolated and measured by fluorometry. Nuclear and mitochondrial DNA were quantified by real-time PCR. Males had higher total plasma ecDNA [15 (11-21) vs. 11 (8-17) ng/mL; median (interquartile range)], nuclear [1,760 (956-3,273) vs. 1,153 (600-2,292) genome equivalents (GE)/mL], and mitochondrial [37,181 (14,836-90,896) vs. 30,089 (12,587-72,286) GE/mL] DNA. ecDNA correlated positively with the continuous metabolic syndrome score (r = 0.158 for males and r = 0.134 for females). Stronger correlations were found between ecDNA of mitochondrial origin and AOPP (r = 0.202 and 0.186 for males and females, respectively). Multivariate regression analysis revealed associations of nuclear DNA with leukocyte and erythrocyte counts. The results of this study of healthy adolescents show that circulating ecDNA is associated with the risk of metabolic syndrome, not with obesity per se. The association between mitochondrial ecDNA and AOPP requires further attention as it supports a potential role of mitochondria-induced sterile inflammation in the pathogenesis of the metabolic syndrome.

Nicotinamide Protects Against Diet-Induced Body Weight Gain, Increases Energy Expenditure, and Induces White Adipose Tissue Beiging

SCOPE

Interventions that boost NAD+ availability are of potential therapeutic interest for obesity treatment. The potential of nicotinamide (NAM), the amide form of vitamin B3 and a physiological precursor of nicotinamide adenine dinucleotide (NAD)+ , in preventing weight gain has not previously been studied in vivo. Other NAD+ precursors have been shown to decrease weight gain; however, their impact on adipose tissue is not addressed.

METHODS AND RESULTS

Two doses of NAM (high dose: 1% and low dose: 0.25%) are given by drinking water to C57BL/6J male mice, starting at the same time as the high-fat diet feeding. NAM supplementation protects against diet-induced obesity by augmenting global body energy expenditure in C57BL/6J male mice. The manipulation markedly alters adipose morphology and metabolism, particularly in inguinal (i) white adipose tissue (iWAT). An increased number of brown and beige adipocyte clusters, protein abundance of uncoupling protein 1 (UCP1), mitochondrial activity, adipose NAD+ , and phosphorylated AMP-activated protein kinase (P-AMPK) levels are observed in the iWAT of treated mice. Notably, a significant improvement in hepatic steatosis, inflammation, and glucose tolerance is also observed in NAM high-dose treated mice.

CONCLUSION

NAM influences whole-body energy expenditure by driving changes in the adipose phenotype. Thus, NAM is an attractive potential treatment for preventing obesity and associated complications.

Standardized hot water extract from the leaves of Hydrangea serrata (Thunb.) Ser. alleviates obesity via the AMPK pathway and modulation of the gut microbiota composition in high fat diet-induced obese mice

Obesity is an increasing health problem worldwide as it is the major risk factor for metabolic diseases. In the present study, we investigated the anti-obesity effects of WHS by examining its effects on high fat diet (HFD)-induced obese mice. Male C57BL/6 mice were fed either a normal diet (ND) or a high fat diet (HFD) with or without WHS. At the end of the experiment, we observed the changes in their body weight and white adipose tissue (WAT) weight and lipid profiles in plasma. We performed western blot and histological analyses of WAT and liver to elucidate the molecular mechanisms of action. We also conducted fecal 16S rRNA analysis for investigating the gut microbiota. Our results indicated that pre- and post-oral administration of WHS significantly prevented body weight gain and reduced body fat weight in HFD-induced obese mice. In addition, WHS was found to improve adipocyte hypertrophy and liver fat accumulation by regulating the AMPK and AKT/mTOR pathways. WHS ameliorated hyperlipidemia by reducing total cholesterol and low-density lipoprotein (LDL) and decreased the energy metabolism-related hormones, leptin and insulin, in mouse plasma. Furthermore, we found that WHS modulated gut dysbiosis by normalizing HFD-induced changes. Taken together, our in vivo data implicate that WHS can be considered as a potential dietary supplement for alleviating obesity.

Body Composition is Associated With Islet Function After Pancreatectomy and Islet Autotransplantation for Pancreatitis

CONTEXT

Body composition in total pancreatectomy with islet autotransplantation (TPIAT) has never been studied.

OBJECTIVE

Determine whether presurgical body composition is associated with islet function and insulin sensitivity after TPIAT.

METHODS

In 88 adults undergoing TPIAT (median age 41.0 years, IQR 32.8-48.0), beta-cell function and insulin sensitivity were assessed using mixed meal tolerance test and frequent sample intravenous glucose tolerance test before surgery and 12 and 18 months afterward. Body composition was measured by dual x-ray absorptiometry. Analyses used linear and logistic regression.

RESULTS

Before surgery, 8 individuals (9.1%) were underweight, 40 (45.5%) normal weight, 20 (22.7%) overweight, and 20 (22.7%) obese. Overweight/obese patients had higher area under the curve C-peptide and lower insulin sensitivity index. Baseline body weight was positively associated with first-phase insulin secretion (AIRg) at 12 months (average 38.5 [SE 17.1] mU/L/min higher per extra kg; P = 0.03) and 18 months (38.3 [18.5]; P = 0.04), while baseline lean mass was inversely associated with AIRg at 12 months (-0.05 [0.02] per extra kg; P = 0.01) and 18 months (-0.05 [0.02]; P = 0.03). Percent gynoid fat was inversely associated with disposition index at 18 months (-206.0 [97.2] per extra percent; P = 0.04). Percent body fat and percent gynoid fat were associated with glucose effectiveness index at 18 months (1.9 × 10-3 [0.9 × 10-3] per extra percent; P = 0.04 and -1.96 × 10-3 [0.8 × 10-3]; P = 0.02, respectively). Insulin independence was not significantly associated with body weight or composition.

CONCLUSIONS

Half of these chronic pancreatitis patients were overweight/obese; underweight was uncommon. Preoperative body weight and composition were associated with islet function but not insulin independence after TPIAT.

Ginger (Zingiber officinale) Attenuates Obesity and Adipose Tissue Remodeling in High-Fat Diet-Fed C57BL/6 Mice

Obesity is characterized by excessive fat accumulation in adipose tissue, which is an active endocrine organ regulating energy metabolism. Ginger (Zingiber officinale) is known to have antioxidant, anti-inflammatory, and antiobesity effects, but the role of ginger in modulating adipocyte metabolism is largely unknown. In this study, we hypothesized that ginger supplementation inhibits high-fat (HF)-diet-mediated obesity. C57BL/6 male mice were randomly assigned to three diets for 7 weeks: low fat (LF, 16% kcal from fat), HF (HF, 60% kcal from fat), or HF with 5% ginger powder in diet (HF + G). The HF diet increased body weight (BW) and BW gain, as well as fasting glucose, total cholesterol, and hepatic lipid levels, compared to the LF diet-fed group. Ginger supplementation significantly improved HF-diet-induced BW gain, hyperglycemia, hypercholesterolemia, and hepatic steatosis without altering food intake. Next, we investigated whether ginger modulates adipocyte remodeling. HF-mediated adipocyte hypertrophy with increased lipogenic levels was significantly improved by ginger supplementation. Furthermore, the HF+G group showed high levels of the fatty-acid oxidation gene, carnitine palmitoyltransferase 1 (CPT1), which was accompanied by a reduction in adipocyte inflammatory gene expression. Taken together, our work demonstrated that ginger supplementation attenuated HF-diet-mediated obesity and adipocyte remodeling in C57BL/6 mice.

Overweight and Obesity Are Associated With Acute Kidney Injury and Acute Respiratory Distress Syndrome, but Not With Increased Mortality in Hospitalized COVID-19 Patients: A Retrospective Cohort Study

OBJECTIVE

To evaluate the association between overweight and obesity on the clinical course and outcomes in patients hospitalized with COVID-19.

DESIGN

Retrospective, observational cohort study.

METHODS

We performed a multicenter, retrospective, observational cohort study of hospitalized COVID-19 patients to evaluate the associations between overweight and obesity on the clinical course and outcomes.

RESULTS

Out of 1634 hospitalized COVID-19 patients, 473 (28.9%) had normal weight, 669 (40.9%) were overweight, and 492 (30.1%) were obese. Patients who were overweight or had obesity were younger, and there were more women in the obese group. Normal-weight patients more often had pre-existing conditions such as malignancy, or were organ recipients. During admission, patients who were overweight or had obesity had an increased probability of acute respiratory distress syndrome [OR 1.70 (1.26-2.30) and 1.40 (1.01-1.96)], respectively and acute kidney failure [OR 2.29 (1.28-3.76) and 1.92 (1.06-3.48)], respectively. Length of hospital stay was similar between groups. The overall in-hospital mortality rate was 27.7%, and multivariate logistic regression analyses showed that overweight and obesity were not associated with increased mortality compared to normal-weight patients.

CONCLUSION

In this study, overweight and obesity were associated with acute respiratory distress syndrome and acute kidney injury, but not with in-hospital mortality nor length of hospital stay.

Mangiferin induces the expression of a thermogenic signature via AMPK signaling during brown-adipocyte differentiation

Mangiferin (MF) from Mangifera indica has been serendipitously found to ameliorate obesity and is used as an antioxidant, anti-inflammatory, antimicrobial, and anticancer agent. Nonetheless, the mechanism of MF-induced brown-adipose-tissue activation has not been studied. Therefore, we investigated the effect of MF on thermogenic features during brown-adipocyte differentiation. Treatment with MF improved the expression of a brown-fat signature and of mitochondrial-mass-related genes, thus resulting in UCP1 induction. MF also raised the expression of other thermogenic regulators, including peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α), PR domain-containing protein 16 (PRDM16), and peroxisome proliferator-activated receptors alpha and gamma (PPAR-α and -γ). MF promoted mitochondrial biogenesis, judging by increased expression of cell death-inducing DNA fragmentation factor α-like effector A (CIDEA), mitochondrial transcription factor A (TFAM), iodothyronine deiodinase 2 (DIO2), cytochrome c oxidase subunit 7A (COX7A), cyclooxygenase 2 (COX2), sirtuin 1 (SIRT1), and nuclear respiratory factor 1 (NRF1). MF treatment increased the mitochondrial DNA amount and improved mitochondrial respiratory function by increasing the oxygen consumption rate during brown-adipocyte differentiation. A gene knockdown assay involving small interfering RNA and competitive inhibition with dorsomorphin revealed that MF may promote thermogenesis in brown preadipocytes via activation of AMPK signaling. Collectively, our findings suggest that MF may be a novel pharmaceutical agent that can ameliorate obesity via activation of brown adipose tissue.

Transcriptome analysis-identified long noncoding RNA CRNDE in maintaining endothelial cell proliferation, migration, and tube formation

Obesity is a leading risk factor for type-2 diabetes. Diabetes often leads to the dysregulation of angiogenesis, although the mechanism is not fully understood. Previously, long noncoding RNAs (lncRNAs) have been found to modulate angiogenesis. In this study, we asked how the expression levels of lncRNAs change in endothelial cells in response to excessive palmitic acid treatment, an obesity-like condition. Bioinformatics analysis revealed that 305 protein-coding transcripts were upregulated and 70 were downregulated, while 64 lncRNAs were upregulated and 46 were downregulated. Gene ontology and pathway analysis identified endoplasmic reticulum stress, HIF-1 signaling, and Toll-like receptor signaling as enriched after palmitic acid treatment. Moreover, we newly report enrichment of AGE-RAGE signaling pathway in diabetic complications, IL-17 signaling, and cysteine and methionine metabolism by palmitic acid. One lncRNA, Colorectal Neoplasia Differentially Expressed (CRNDE), was selected for further investigation. Palmitic acid induces CRNDE expression by 1.9-fold. We observed that CRNDE knockdown decreases endothelial cell proliferation, migration, and capillary tube formation. These decreases are synergistic under palmitic acid stress. These data demonstrated that lncRNA CRNDE is a regulator of endothelial cell proliferation, migration, and tube formation in response to palmitic acid, and a potential target for therapies treating the complications of obesity-induced diabetes.

HDL and LDL: Potential New Players in Breast Cancer Development

Breast cancer is the most prevalent cancer and primary cause of cancer-related mortality in women. The identification of risk factors can improve prevention of cancer, and obesity and hypercholesterolemia represent potentially modifiable breast cancer risk factors. In the present work, we review the progress to date in research on the potential role of the main cholesterol transporters, low-density and high-density lipoproteins (LDL and HDL), on breast cancer development. Although some studies have failed to find associations between lipoproteins and breast cancer, some large clinical studies have demonstrated a direct association between LDL cholesterol levels and breast cancer risk and an inverse association between HDL cholesterol and breast cancer risk. Research in breast cancer cells and experimental mouse models of breast cancer have demonstrated an important role for cholesterol and its transporters in breast cancer development. Instead of cholesterol, the cholesterol metabolite 27-hydroxycholesterol induces the proliferation of estrogen receptor-positive breast cancer cells and facilitates metastasis. Oxidative modification of the lipoproteins and HDL glycation activate different inflammation-related pathways, thereby enhancing cell proliferation and migration and inhibiting apoptosis. Cholesterol-lowering drugs and apolipoprotein A-I mimetics have emerged as potential therapeutic agents to prevent the deleterious effects of high cholesterol in breast cancer.

The pathogenesis of obesity

Body fat mass increases when energy intake exceeds energy expenditure. In the long term, a positive energy balance will result in obesity. The worldwide prevalence of obesity has increased dramatically, posing a serious threat to human health. Therefore, insight in the pathogenesis of obesity is important to identify novel prevention and treatment strategies. This review describes the physiology of energy expenditure and energy intake in the context of body weight gain in humans. We focus on the components of energy expenditure and the regulation of energy intake. Finally, we describe rare monogenetic causes leading to an impairment in central regulation of food intake and obesity.

Comprehensive identification of pleiotropic loci for body fat distribution using the NHGRI-EBI Catalog of published genome-wide association studies

We conducted a hypothesis-free cross-trait analysis for waist-to-hip ratio adjusted for body mass index (WHR_adjBMI ) loci derived through genome-wide association studies (GWAS). Summary statistics from published GWAS were used to capture all WHR_adjBMI single-nucleotide polymorphisms (SNPs), and their proxy SNPs were identified. These SNPs were used to extract cross-trait associations between WHR_adjBMI SNPs and other traits through the NHGRI-EBI GWAS Catalog. Pathway analysis was conducted for pleiotropic WHR_adjBMI SNPs. We found 160 WHR_adjBMI SNPs and 3675 proxy SNPs. Cross-trait analysis identified 239 associations, of which 100 were for obesity traits. The remaining 139 associations were filtered down to 101 unique linkage disequilibrium block associations, which were grouped into 13 categories: lipids, red blood cell traits, white blood cell counts, inflammatory markers and autoimmune diseases, type 2 diabetes-related traits, adiponectin, cancers, blood pressure, height, neuropsychiatric disorders, electrocardiography changes, urea measurement, and others. The highest number of cross-trait associations were found for triglycerides (n = 10), high-density lipoprotein cholesterol (n = 9), and reticulocyte counts (n = 8). Pathway analysis for WHR_adjBMI pleiotropic SNPs found immune function pathways as the top canonical pathways. Results from our original methodology indicate a novel genetic association between WHR_adjBMI and reticulocyte counts and highlight the pleiotropy between abdominal obesity, immune pathways, and other traits.

Statins: a role in breast cancer therapy?

Statin drugs have been used for more than two decades to treat hypercholesterolemia and as cardio-preventive drugs, resulting in a marked decrease in cardiovascular morbidity and mortality worldwide. Statins halt hepatic cholesterol biosynthesis by inhibiting the rate-limiting enzyme in the mevalonate pathway, hydroxymethylglutaryl-coenzyme A reductase (HMGCR). The mevalonate pathway regulates a host of biochemical processes in addition to cholesterol production. Attenuation of these pathways is likely responsible for the myriad benefits of statin therapy beyond cholesterol reduction - the so-called pleiotropic effects of statins. Chief amongst these purported effects is anti-cancer activity. A considerable body of preclinical, epidemiologic and clinical evidence shows that statins impair proliferation of breast cancer cells and reduce the risk of breast cancer recurrence. Potential mechanisms for this effect have been explored in laboratory models, but remain poorly understood and require further investigation. The number of clinical trials assessing the putative clinical benefit of statins in breast cancer is increasing. Currently, a total of 30 breast cancer/statin trials are listed at the global trial identifier website clinicaltrials.gov. Given the compelling evidence from performed trials in a variety of clinical settings, there have been calls for a clinical trial of statins in the adjuvant breast cancer setting. It would be imperative for such a trial to incorporate tumour biomarkers predictive of statin response in its design and analysis plan. Ongoing translational clinical trials aimed at biomarker discovery will help identify, which breast cancer patients are most likely to benefit from adjuvant statin therapy, and will add valuable clinical knowledge to the field.

Flavonoids, Potential Bioactive Compounds, and Non-Shivering Thermogenesis

Obesity results from the body having either high energy intake or low energy expenditure. Based on this energy equation, scientists have focused on increasing energy expenditure to prevent abnormal fat accumulation. Activating the human thermogenic system that regulates body temperature, particularly non-shivering thermogenesis in either brown or white adipose tissue, has been suggested as a promising solution to increase energy expenditure. Together with the increasing interest in understanding the mechanism by which plant-derived dietary compounds prevent obesity, flavonoids were recently shown to have the potential to regulate non-shivering thermogenesis. In this article, we review the latest research on flavonoid derivatives that increase energy expenditure through non-shivering thermogenesis.

The role of central dopamine and serotonin in human obesity: lessons learned from molecular neuroimaging studies

Obesity results from an imbalance between energy intake and expenditure, and many studies have aimed to determine why obese individuals continue to (over)consume food under conditions of caloric excess. The two major "neurotransmitter hypotheses" of obesity state that increased food intake is partially driven by decreased dopamine-mediated reward and decreased serotonin-mediated homeostatic feedback in response to food intake. Using molecular neuroimaging studies to visualize and quantify aspects of the central dopamine and serotonin systems in vivo, recent PET and SPECT studies have also implicated alterations in these systems in human obesity. The interpretation of these data, however, is more complex than it may appear. Here, we discuss important characteristics and limitations of current radiotracer methods and use this framework to comprehensively review the available human data on central dopamine and serotonin in obesity. On the basis of the available evidence, we conclude that obesity is associated with decreased central dopaminergic and serotonergic signaling and that future research, especially in long-term follow-up and interventional settings, is needed to advance our understanding of the neuronal pathophysiology of obesity in humans.

Reduction of intraocular pressure after bariatric surgery

PURPOSE

To investigate the effects of bariatric surgery on intraocular pressure (IOP).

METHODS

We prospectively enroled consecutive obese patients who underwent a laparoscopic sleeve gastrectomy procedure. We measured IOP prior to and 3-6 months following surgery and recorded medical and demographical parameters.

RESULTS

Thirty-two patients completed all evaluations. Mean age was 40.5 ± 12 and 24 (75%) were men. Following surgery, mean body-mass index (BMI) decreased from 42 ± 6 to 31 ± 8 (p < 0.001). The mean IOP decreased from 16.9 ± 4 mmHg to 14.1 ± 3 mmHg (p < 0.001). The extent of IOP reduction was correlated with the baseline IOP (Pearson r = 0.737, p < 0.001) and central corneal thickness (Pearson r = 0.453, p = 0.010).

CONCLUSION

In a cohort of obese individuals undergoing sleeve gastrectomy, there was a significant decrease in IOP measured 3-6 months after the procedure. Our results suggest that significant weight loss could have beneficial effects on IOP in obese individuals with ocular hypertension which might enable avoidance of antiglaucoma medications. The high likelihood of a reduction in IOP should be taken into account when considering bariatric surgery in such patients.

Associations of Physical Activity and Obesity With the Risk of Developing the Metabolic Syndrome in Law Enforcement Officers

OBJECTIVE

The aim of this study was to examine the associations of physical activity and body mass index (BMI) with the metabolic syndrome (MetS) in police officers.

METHODS

Self-reported physical activity, MetS, and a modified MetS (MMetS, excluding obesity) were assessed in 448 officers.

RESULTS

Of the officers, 27.5% had MetS, 48.7% were overweight, and 31.7% were obese. Being overweight and obese increased the MetS risk by 6.8- and 10.9-fold, respectively, independent of physical activity level. Moderate and low levels of physical activity were associated with a 1.9- and 2.5-fold increased risk for MetS, but not after adjusting for BMI. However, within BMI categories, the risk for MMetS was lower as physical activity increased.

CONCLUSION

In police, a higher BMI is more critical than reduced physical activity for MetS risk; however, physical activity can attenuate some of the risk associated with a higher BMI.

Hepatic Diacylglycerol-Associated Protein Kinase Cε Translocation Links Hepatic Steatosis to Hepatic Insulin Resistance in Humans

Hepatic lipid accumulation has been implicated in the development of insulin resistance, but translational evidence in humans is limited. We investigated the relationship between liver fat and tissue-specific insulin sensitivity in 133 obese subjects. Although the presence of hepatic steatosis in obese subjects was associated with hepatic, adipose tissue, and peripheral insulin resistance, we found that intrahepatic triglycerides were not strictly sufficient or essential for hepatic insulin resistance. Thus, to examine the molecular mechanisms that link hepatic steatosis to hepatic insulin resistance, we comprehensively analyzed liver biopsies from a subset of 29 subjects. Here, hepatic cytosolic diacylglycerol content, but not hepatic ceramide content, was increased in subjects with hepatic insulin resistance. Moreover, cytosolic diacylglycerols were strongly associated with hepatic PKCε activation, as reflected by PKCε translocation to the plasma membrane. These results demonstrate the relevance of hepatic diacylglycerol-induced PKCε activation in the pathogenesis of NAFLD-associated hepatic insulin resistance in humans.

•

The presence of hepatic steatosis is associated with insulin resistance

•

Intrahepatic triglycerides are not sufficient for hepatic insulin resistance

•

Diacylglycerol in hepatic cytosol predicts insulin inhibition of glucose production

•

Diacylglycerol-associated insulin resistance is characterized by PKCε translocation

Novel thyroid hormone analogues, enzyme inhibitors and mimetics, and their action

Thyroid hormones (THs) play key roles in modulating the overall metabolism of the body, protein synthesis, fat metabolism, neuronal and bone growth, and cardiovascular as well as renal functions. In this review, we discuss on the thyroid hormone synthesis and activation, thyroid hormone receptors (TRs) and mechanism of action, applications of thyroid hormone analogues, particularly the compounds that are selective ligands for TRβ receptors, or enzyme inhibitors for the treatment of thyroidal disorders with a specific focus on thyroid peroxidase and iodothyronine deiodinases. We also discuss on the development of small-molecule deiodinase mimetics and their mechanism of deiodination, as these compounds have the potential to regulate the thyroid hormone levels.

GC-1: A Thyromimetic With Multiple Therapeutic Applications in Liver Disease

Thyroid hormones (THs), namely, 3,5,3'-triiodo-l-thyronine (T3) and 3,5,3',5'-tetraiodo-l-thyronine (thyroxine or T4), influence a variety of physiological processes that have important implications in fetal development, metabolism, cell growth, and proliferation. While THs elicit several beneficial effects on lipid metabolism and improve myocardial contractility, these therapeutically desirable effects are associated to a thyrotoxic state that severely limits the possible use of THs as therapeutic agents. Therefore, several efforts have been made to develop T3 analogs that could retain the beneficial actions (triglyceride, cholesterol, obesity, and body mass lowering) without the adverse TH-dependent side effects. This goal was achieved by the synthesis of TRβ-selective agonists. In this review, we summarize the current knowledge on the effects of one of the best characterized TH analogs, the TRβ1-selective thyromimetic, GC-1. In particular, we review some of the effects of GC-1 on different liver disorders, with reference to its possible clinical application. A brief comment on the possible therapeutic use of GC-1 in extrahepatic disorders is also included.

LXR-dependent regulation of macrophage-specific reverse cholesterol transport is impaired in a model of genetic diabesity

Diabesity and fatty liver have been associated with low levels of high-density lipoprotein cholesterol, and thus could impair macrophage-specific reverse cholesterol transport (m-RCT). Liver X receptor (LXR) plays a critical role in m-RCT. Abcg5/g8 sterol transporters, which are involved in cholesterol trafficking into bile, as well as other LXR targets, could be compromised in the livers of obese individuals. We aimed to determine m-RCT dynamics in a mouse model of diabesity, the db/db mice. These obese mice displayed a significant retention of macrophage-derived cholesterol in the liver and reduced fecal cholesterol elimination compared with nonobese mice. This was associated with a significant downregulation of the hepatic LXR targets, including Abcg5/g8. Pharmacologic induction of LXR promoted the delivery of total tracer output into feces in db/db mice, partly due to increased liver and small intestine Abcg5/Abcg8 gene expression. Notably, a favorable upregulation of the hepatic levels of ABCG5/G8 and NR1H3 was also observed postoperatively in morbidly obese patients, suggesting a similar LXR impairment in these patients. In conclusion, our data show that downregulation of the LXR axis impairs cholesterol transfer from macrophages to feces in db/db mice, whereas the induction of the LXR axis partly restores impaired m-RCT by elevating the liver and small intestine expressions of Abcg5/g8.

The effect of bariatric surgery on the retrobulbar flow hemodynamic parameters in patients with obesity: color Doppler evaluation

PURPOSE

To evaluate the effect of weight loss on the retrobulbar hemodynamics in patients who had undergone bariatric surgery for obesity using color Doppler ultrasound (CDU) and to evaluate correlations with intraocular pressure (IOP) changes measured using Goldman applanation tonometry.

METHODS

Thirty-two patients were included in this prospective study. Body mass index (BMI), IOP measurements, and retrobulbar CDU examination were performed on all individuals 6 months before and after bariatric surgery.

RESULTS

The preoperative mean BMI value was 48.8 ± 2.27 kg/m², and mean IOP value was 18.2 ± 2.06 mmHg. At 6 months postoperatively, mean BMI and IOP were 36.28 ± 5.41 kg/m² and 16.1 ± 1.81 mmHg which was statistically significantly lower than the preoperative measurements (p < 0.001). In the comparison of pre- and postoperative orbital CDU value, the preoperative OA PSV (30.16 ± 5.31 cm/s) and OA EDV (10.93 ± 3.04) values were significantly lower than the postoperative OA PSV (36.21 ± 5.56) and OA EDV (12.84 ± 3.38) values (p < 0.001 and p < 0.05, respectively). A significant correlation was determined between BMI and IOP (r = -0.443; p < 0.05).

CONCLUSIONS

Decrease in body weight resulting from bariatric surgery performed on morbid obese patients causes alterations in both IOP and retrobulbar hemodynamics. Morbidly obese patients who undergo bariatric surgery have statistically significantly lower IOP values and increase in OA Doppler parameters (PSV, EDV) than in the preoperative period, which reflects a better retrobulbar and ocular blood flow.

Glibenclamide treatment blocks metabolic dysfunctions and improves vagal activity in monosodium glutamate-obese male rats

BACKGROUND/AIMS

Autonomic nervous system imbalance is associated with metabolic diseases, including diabetes. Glibenclamide is an antidiabetic drug that acts by stimulating insulin secretion from pancreatic beta cells and is widely used in the treatment of type 2 diabetes. Since there is scarce data concerning autonomic nervous system activity and diabetes, the aim of this work was to test whether glibenclamide can improve autonomic nervous system activity and muscarinic acetylcholine receptor function in pre-diabetic obese male rats.

METHODS

Pre-diabetes was induced by treatment with monosodium L-glutamate in neonatal rats. The monosodium L-glutamate group was treated with glibenclamide (2 mg/kg body weight /day) from weaning to 100 days of age, and the control group was treated with water. Body weight, food intake, Lee index, fasting glucose, insulin levels, homeostasis model assessment of insulin resistance, omeostasis model assessment of β-cell function, and fat tissue accumulation were measured. The vagus and sympathetic nerve electrical activity were recorded. Insulin secretion was measured in isolated islets challenged with glucose, acetylcholine, and the selective muscarinic acetylcholine receptor antagonists by radioimmunoassay technique.

RESULTS

Glibenclamide treatment prevented the onset of obesity and diminished the retroperitoneal (18%) and epididymal (25%) fat pad tissues. In addition, the glibenclamide treatment also reduced the parasympathetic activity by 28% and glycemia by 20% in monosodium L-glutamate-treated rats. The insulinotropic effect and unaltered cholinergic actions in islets from monosodium L-glutamate groups were increased.

CONCLUSION

Early glibenclamide treatment prevents monosodium L-glutamate-induced obesity onset by balancing autonomic nervous system activity.

A comparison of RS4-type resistant starch to RS2-type resistant starch in suppressing oxidative stress in high-fat-diet-induced obese rats

The anti-obesity effects of two types of resistant starch (RS) in high-fat-diet-induced obese rats were investigated.

Urinary chromium is associated with changes in leukocyte miRNA expression in obese subjects

BACKGROUND/OBJECTIVES

Epidemiological studies suggest a link between chromium (Cr) status and cardiovascular disease. Increased urinary excretion of Cr was reported in subjects with diabetes compared with non-diabetic controls and those with non-diabetic insulin resistance. Epigenetic alterations have been linked to the presence of Cr, and microRNA (miRNA) expression has been implicated in the pathogenesis of metabolic diseases and cardiovascular diseases (CVDs). We investigated the association between Cr excretion and miRNA expression in leukocytes from obese subjects. We also examined the relationship between altered miRNA expression and selected clinical parameters to further investigate mechanisms linking Cr to metabolic diseases and CVDs.

SUBJECTS/METHODS

We analyzed urinary Cr in 90 Italian subjects using inductively coupled plasma-mass spectrometry. Peripheral blood miRNA levels were screened with TaqMan Low-Density Array Human MicroRNA A. Cr level-associated expression of miRNAs was detected with multivariate regression analyses, and the top 10 candidate miRNAs were selected for validation. We also used multivariate regression analyses to assess possible associations between validated miRNAs and glycated hemoglobin (A1c) and blood pressure (BP). The validated miRNAs were further investigated by functional analysis with Ingenuity Pathway Analysis software.

RESULTS

Urinary Cr levels (mean: 0.35 μg/l; s.d.=0.24) ranged from 0.05 to 1.27 μg/l. In the screening phase, 43 miRNAs were negatively associated with Cr. Of the top 10 miRNAs selected for validation, nine (miR-451, miR-301, miR-15b, miR-21, miR-26a, miR-362-3p, miR-182, miR-183 and miR-486-3p) were downregulated in association with Cr (P-false discovery rate (FDR)<0.10). miR-451 expression was associated with A1c (β=-0.06; P=0.0416), whereas miR-486-3p expression was associated both with diastolic (β=2.1; P=0.004) and systolic BP (β=3.3; P=0.003).

CONCLUSIONS

These results indicate that miR-451 and miR-486-3p are involved in the link between Cr levels and metabolic diseases and CVDs.

Siah2 Protein Mediates Early Events in Commitment to an Adipogenic Pathway

Adipose tissue expansion occurs by increasing the size of existing adipocytes or by increasing the number of adipocytes via adipogenesis. Adipose tissue dysfunction in obesity is associated with adipocyte hypertrophy and impaired adipogenesis. We recently demonstrated that deletion of the ubiquitin ligase Siah2 is associated with enlarged adipocytes in lean or obese mice. In this study, we find that adipogenesis is impaired in 3T3-L1 preadipocytes stably transfected with Siah2 shRNA and that overexpression of Siah2 in non-precursor fibroblasts promotes adipogenesis. In the 3T3-L1 model, loss of Siah2 is associated with sustained β-catenin expression post-induction, but depletion of β-catenin only partially restores PPARγ expression and adipocyte formation. Using wild-type and Siah2^-/- adipose tissue and adipose stromal vascular cells, we observe that Siah2 influences the expression of several factors that control adipogenesis, including Wnt pathway genes, β-catenin, Zfp432, and Bmp-4 Consistent with increased β-catenin levels in shSiah2 preadipocytes, Wnt10b is elevated in Siah2^-/- adipose tissue and remains elevated in Siah2^-/- primary stromal cells after addition of the induction mixture. However, addition of BMP-4 to Siah2^-/- stromal cells reduces Wnt10b expression, reduces Zfp521 protein levels, and increases expression of Zfp423, a transcriptional regulator of peroxisome proliferator-activated receptor γ expression that controls commitment to adipogenesis and is repressed by Zfp521. These results indicate that Siah2 acts upstream of BMP-4 to regulate factors that control the commitment of adipocyte progenitors to an adipogenic pathway. Our findings reveal an essential role for Siah2 in the early events that signal undifferentiated progenitor cells to become mature adipocytes.

Body Size, Metabolic Factors, and Risk of Endometrial Cancer in Black Women

Total and abdominal obesity, as well as metabolic factors such as type 2 diabetes, have been associated with a higher risk of endometrial cancer in white women. It remains unclear to what extent these factors influence the risk of endometrial cancer in black women. We followed 47,557 participants from the Black Women's Health Study for incident endometrial cancer from 1995 through 2013 (n = 274). We used Cox regression models to estimate incidence rate ratios and 95% confidence intervals while accounting for potential confounders. Incidence rate ratios for body mass indices (weight (kg)/height (m)(2)) of 25.0-29.9, 30.0-34.9, 35.0-39.9, and ≥40.0 versus those <25.0 were 1.00 (95% confidence interval (CI): 0.67, 1.48), 1.49 (95% CI: 0.97, 2.30), 2.16 (95% CI: 1.34, 3.49), and 3.60 (95% CI: 2.24, 5.78), respectively (Ptrend <0.0001). A high weight-to-height ratio was also associated with a higher risk (for the highest quartile vs. the lowest, incidence rate ratio = 2.83, 95% CI: 1.77, 4.53), as was type 2 diabetes mellitus (incidence rate ratio = 1.52, 95% CI: 1.04, 2.21). Positive associations with measures of central adiposity (waist circumference, waist-to-hip ratio, and waist-to-height ratio) and hypertension were attenuated after we controlled for body mass index. Total adiposity was an independent risk factor for endometrial cancer among black women and appeared to explain most of the associations seen with other adiposity measures and metabolic factors.

Apolipoproteins, lipids and risk of cancer

The epidemiological evidence for an obesity-cancer association is solid, whereas the association between obesity-associated lipoprotein levels and cancer is less evident. We investigated circulating levels of Apolipoprotein A1 (ApoA1), Apolipoprotein B (ApoB), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) and association to risk of overall cancer and common cancer forms. The Malmö Diet and Cancer Study, a population-based prospective cohort study, enrolled 17,035 women and 11,063 men (1991-1996). Incident cancer cases were ascertained by record linkage with the Swedish Cancer Registry until end of follow-up, January 1, 2012. Baseline serum levels of ApoA1 and ApoB were analyzed for the entire cohort and HDL-C and LDL-C levels in 5,281 participants. Hazard ratios, with 95% confidence interval, were calculated using Cox's proportional hazards analysis. In the entire cohort, none of the exposures were related to overall cancer risk (HRadj ApoA1 = 0.98, 95%CI: 0.95,1.01; HRadj ApoB = 1.01, 95%CI: 0.98-1.04). Among men, ApoB was positively associated with cancer risk (HRadj ApoB = 1.06, 95%CI: 1.01,1.10). Female breast cancer risk was inversely associated with ApoB (HRadj = 0.92, 95%CI: 0.86,0.99). Among both genders, ApoA1 was inversely associated with lung cancer risk (HRadj = 0.88, 95%CI: 0.80,0.97), whereas high ApoB increased lung cancer risk (HRadj = 1.08, 95%CI: 0.99,1.18). Colorectal cancer risk was increased with high ApoB (HRadj = 1.08, 95%CI: 1.01,1.16) among both genders. Apolipoprotein levels were not associated with prostate cancer incidence. Circulating levels of apolipoproteins are associated with overall cancer risk in men and across both genders with breast, lung and colorectal cancer risk. Validation of these findings may facilitate future primary prevention strategies for cancer.

Evaluation of Anterior Segment Parameters in Obesity

PURPOSE

To investigate anterior segment parameters in obese patients in comparison to healthy individuals.

METHODS

Thirty-four obese subjects and 34 age-sex-matched healthy subjects were enrolled in this prospective cross-sectional study. Ophthalmological examinations including intraocular pressure (IOP), central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), and axial length (AL) measurements were performed on each subject. Height and weight of all subjects were recorded and body mass index (BMI) was calculated.

RESULTS

IOP was significantly higher in the obese group (p = 0.003). The mean ACD in obese subjects was significantly lower than that in control subjects (p = 0.036). AL, ACV, ACA and CCT were not significantly different between the groups. There was a positive correlation between BMI and IOP (r = 0.404, p < 0.001). ACD and ACA were negatively correlated with BMI.

CONCLUSIONS

IOP was significantly higher and ACD was significantly lower in obese subjects. AL, ACV, ACA and CCT were not significantly different between the groups. The impact of obesity on anterior chamber parameters should be further investigated.

Angiogenesis in diabetes and obesity

The prevalence of diabetes mellitus and obesity continues to increase globally. Diabetic vascular complications are the main chronic diabetic complications and associated with mortality and disability. Angiogenesis is a key pathological characteristic of diabetic microvascular complications. However, there are two tissue-specific paradoxical changes in the angiogenesis in diabetic microvascular complications: an excessive uncontrolled formation of premature blood vessels in some tissues, such as the retina, and a deficiency in the formation of small blood vessels in peripheral tissues, such as the skin. This review will discuss the paradoxical phenomena of angiogenesis and its underlying mechanism in obesity, diabetes and diabetic complications.

Pathway-selective insulin resistance and metabolic disease: the importance of nutrient flux

Hepatic glucose and lipid metabolism are altered in metabolic disease (e.g. obesity, metabolic syndrome, and Type 2 diabetes). Insulin-dependent regulation of glucose metabolism is impaired. In contrast, lipogenesis, hypertriglyceridemia, and hepatic steatosis are increased. Because insulin promotes lipogenesis and liver fat accumulation, to explain the elevation in plasma and tissue lipids, investigators have suggested the presence of pathway-selective insulin resistance. In this model, insulin signaling to glucose metabolism is impaired, but insulin signaling to lipid metabolism is intact. We discuss the evidence for the differential regulation of hepatic lipid and glucose metabolism. We suggest that the primary phenotypic driver is altered substrate delivery to the liver, as well as the repartitioning of hepatic nutrient handling. Specific alterations in insulin signaling serve to amplify the alterations in hepatic substrate metabolism. Thus, hyperinsulinemia and its resultant increased signaling may facilitate lipogenesis, but are not the major drivers of the phenotype of pathway-selective insulin resistance.

Mature adipocyte proteome reveals differentially altered protein abundances between lean, overweight and morbidly obese human subjects

Overweight (OW) and obese individuals are considered to be graded parts of the scale having increasing weight as a common feature. They may not, however, be part of the same continuum and may differ metabolically. In this study we applied an untargeted proteomic approach to compare protein abundances in mature adipocytes derived from the subcutaneous adipose tissue of overweight and morbidly obese female subjects to those of lean age matched controls. Mature adipocytes were isolated from liposuction samples of abdominal subcutaneous adipose tissue collected from both lean (L; n = 7, 23.3 ± 0.4 kg/m(2); mean BMI ± SD), overweight (OW; n = 8, 27.9 ± 0.6 kg/m(2); mean BMI ± SD) and morbidly obese (MOB; n = 7, 44.8 ± 3.8 kg/m(2); mean BMI ± SD) individuals. Total protein extracts were then compared by two-dimensional difference in gel electrophoresis (2D DIGE). One hundred and ten differentially expressed protein spots (i.e., fitting the statistical criteria ANOVA test, p < 0.05; fold-change ≥1.5) were detected, and of these, 89 were identified by MALDI-TOF mass spectrometry. Of these, 66 protein spots were common to both groups whereas 23 were unique to the MOB group. Significant differences were evident in the abundances of key proteins involved in glucose and lipid metabolism, energy regulation, cytoskeletal structure and redox control signaling pathways. Differences in the abundance of some chaperones were also evident. The differentially abundant proteins were investigated using Ingenuity Pathway Analysis (IPA) to establish their associations with known biological functions. The network identified in the OW group with the highest score relates to-: cell-to-cell signaling and interaction; in contrast, in the MOB group the major interacting pathways are associated with lipid metabolism, small molecule biochemistry and cancer. The differences in abundance of the differentially regulated proteins were validated by immunoblotting. These findings provide insights into metabolic differences in OW and MOB individuals.

Sense of coherence is significantly associated with both metabolic syndrome and lifestyle in Japanese computer software office workers

OBJECTIVES

Sense of coherence (SOC) is an individual characteristic related to a positive life orientation, leading to effective coping. Little is known about the relationship between SOC and metabolic syndrome (MetS). This cross-sectional study aimed at testing the hypothesis that workers with a strong SOC have fewer atherosclerotic risk factors, including MetS, and healthier lifestyle behaviors.

MATERIAL AND METHODS

One hundred and sixty-seven computer software workers aged 20-64 years underwent a periodical health examination including assessment of body mass index, waist circumference, blood pressure, blood lipid levels, fasting blood sugar (FBS) levels and lifestyle behaviors (walking duration, smoking status, nutrition, alcohol consumption, and sleep duration). During this period, the participants also completed a 29-item questionnaire of SOC and the Brief Job Stress Questionnaire to assess job stressors such as job strain and workplace social support.

RESULTS

Our results showed that the participants with a stronger SOC were likely to walk for at least 1 h a day, to eat slowly or at a moderate speed, and to sleep for at least 6 h. Compared with the participants with the weakest SOC, those with the strongest SOC had a significantly lower odds ratio (OR) for being overweight (OR = 0.31; 95% confidence interval (CI): 0.11-0.81), and having higher FBS levels (OR = 0.11; 95% CI: 0.02-0.54), dyslipidemia (OR = 0.29; 95% CI: 0.09-0.84), and MetS (OR = 0.12; 95% CI: 0.02-0.63), even after adjusting for age, gender and job stressors.

CONCLUSIONS

High SOC is associated with a healthy lifestyle and fewer atherosclerotic risk factors, including MetS.