Obese Nondiabetic Individuals Research Articles

Unexpected cardiovascular risks of glucagon-like peptide-1 receptor agonist and aspirin co-administration in individuals with obesity, with and without type 2 diabetes: A propensity score matched cohort study.

To examine the cardiovascular safety of combining glucagon-like peptide-1 receptor agonists (GLP-1 RAs) with aspirin in individuals with obesity, both with and without type 2 diabetes (T2D). This propensity score matched cohort study analysed data from 2 946 579 individuals with obesity, with and without T2D, using the TriNetX US and Global dataset. Participants were categorized into four matched groups: those receiving GLP-1 RA plus aspirin versus those receiving GLP-1 RA alone, for both diabetic and non-diabetic individuals. Cardiovascular outcomes and adverse events were evaluated over 5 years using Cox proportional hazards models. Individuals with obesity treated with GLP-1 RAs plus aspirin showed significantly higher risks of various cardiovascular events compared to those on GLP-1 RAs alone. In non-diabetic obese individuals, the combination therapy increased risks of hypertensive heart diseases (HR 1.40, 95% CI 1.15-1.60), ischaemic heart disease (HR 2.39, 95% CI 1.92-2.97) and heart failure (HR 1.97, 95% CI 1.54-2.53). Similar patterns were observed in individuals with T2D. Atrial fibrillation and cardiac arrhythmias showed increasing hazard ratios over time. The combination therapy also led to more frequent adverse events, including gastrointestinal bleeding. The combination of GLP-1 RAs with aspirin in individuals with obesity, both with and without T2D, was associated with increased cardiovascular risks compared to GLP-1 RA monotherapy. These findings suggest that there may be risks associated with the combined use of these treatments and highlight the need for further research into this possible complication with regard to treatment.

Value of serum osteoprotegerin in the assessment of endothelial dysfunction in obesity

ObjectiveOsteoprotegerin is a member of the tumor necrosis factor receptor superfamily. The study aimed to assess serum osteoprotegerin and endothelial dysfunction relationship in obese non-diabetic subjects. Elucidating the association linking serum osteoprotegerin level to obesity and insulin resistance.Materials and methodsSixty obese non-diabetic subjects attending the outpatient endocrine clinic were compared with 20 controls. All subjects went through history taking, clinical examination, and anthropometric measuring. Laboratory tests included fasting blood glucose, HbA1c, HOMA-IR, lipid profile, and serum osteoprotegerin level—assessment of endothelial dysfunction measured by carotid intimal thickening and flow meter dilatation.ResultsObese subjects had significantly higher rates of insulin resistance and dyslipidemia compared with controls (P = 0.017 and 0.002, respectively). Serum osteoprotegerin levels were significantly lower in obese subjects compared with controls (P = 0.011). In obese subjects, there was a significant positive correlation between osteoprotegerin and HOMA-IR (r = 0.272; P = 0.035), whereas there was no significant correlation between OPG and endothelial dysfunction.ConclusionThe study showed that osteoprotegerin significantly decreased in obese non-diabetic individuals in comparison with control subjects. A significant positive correlation between osteoprotegerin and HOMA-IR has been reported in obese non-diabetic subjects. OPG can be considered a serum biomarker to predict insulin resistance in obese individuals.

The relation between plasma apelin 36 and insulin resistance in obese type 2 diabetic Egyptian population

ABSTRACT Background Obesity causes changes in the production of adipose tissue secreted factors, which are responsible for metabolism modulation. One of these factors is Apelin, a small peptide that interacts with a specific cell-surface receptor to modulate various cells signaling processes. Apelin is regarded as a new player because of its powerful role in energy metabolism and improvement of insulin sensitivity. Aim of the Work This study investigates the plasma apelin 36 role and to what extent it can impact the insulin resistance in obese Egyptians diagnosed with type 2 diabetes (T2DM). Subjects and Methods The study involved 90 participants, with 30 assigned to each of the three study involved categories: obese individuals with diabetes, obese individuals without diabetes, and healthy controls (n = 30 for each group). Measurements of skin fold thickness, body mass index (BMI), waist/hip ratio, and body fat % were obtained along with a comprehensive clinical examination and history. The following were investigated: plasma insulin, Hb A1c, lipid profile, plasma apelin (ELISA), plasma leptin (ELISA), and plasma adiponectin (ELISA). Results The median value of serum leptin in obese subjects (groups I and II) was higher significantly than healthy control group (group III) (p = <0.001). A significant decrease in serum adiponectin could be detected in obese subjects (groups I and II) compared to control subjects (Group III) (p = 0.004). When compared to the healthy control group (group III), the mean serum apelin level was significantly higher in the obese participants (groups I and II) and much higher among obese diabetic group (p = <0.001). A statistically significant correlation (p = 0.001) was observed between fasting serum insulin and both HOMA-IR and serum apelin among the non-diabetic obese participants involved in the study. Conclusions Obese people have raised serum apelin levels; those with T2DM have significantly greater serum apelin levels. While it showed a positive correlation with insulin level and HOMA-IR among the obese non-diabetic individuals.

Comparison of triglyceride-glucose index and anthropometric obesity indices in predicting severe grades of hepatic steatosis in nonalcoholic fatty liver disease among non-diabetic obese individuals.

The triglyceride glucose index (TyG) has been proposed as a promising indicator of both insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD). However, the efficacy of the TyG index in predicting NAFLD has not been adequately studied, particularly in obese individuals. We analyzed 190 morbidly obese individuals. The TyG index, anthropometric obesity indices, homeostatic model assessment (HOMA-IR), and biochemical parameters were compared. NAFLD was diagnosed by hepatic ultrasonography and classified into four grades (0, 1, 2, and 3). Individuals in grades 2 and 3 are considered to have severe steatosis, while those in grades 0 and 1 do not. The area under the curve (AUC) values of the TyG index, body mass index, neck circumferences, waist-to-hip ratio, and HOMA-IR did not differ significantly in predicting severe steatosis (0.640, 0.742, 0.725, 0.620, and 0.624 respectively). However, the AUC values of waist circumference and alanine aminotransferase provided better predictions than the TyG index (0.782, 0.744, and 0.640 respectively). The TyG index is highly effective in predicting both the presence and severity of NAFLD. However, it did not outperform simple obesity indices in predicting NAFLD and its severity in obese patients.

Efficacy and safety of semaglutide 2.4 mg for weight loss in overweight or obese adults without diabetes: An updated systematic review and meta-analysis including the 2-year STEP 5 trial.

To explore the safety and efficacy of subcutaneous semaglutide 2.4 mg, administered once a week in non-diabetic overweight or obese individuals. A thorough search was performed of various databases including PubMed, Embase, the Cochrane Library, Web of Science, clinicaltrials.gov, CNKI and Wanfang from their inception up to April 11, 2023. Our aim was to identify randomized controlled trials (RCTs) that compared the efficacy of semaglutide administered once weekly with placebo in overweight or obese adults. Through a review of the literature, data were extracted from relevant studies and assessed for quality, and a meta-analysis was conducted using RevMan 5.4.1 software. Six RCTs comprising 3962 overweight or obese individuals were identified. The findings indicated that, in comparison to the placebo group, semaglutide caused a significant and sustainable reduction in the percentage of body weight (BW; mean difference [MD]: -11.80% [95% confidence interval {CI} -12.93, -10.68]; P < 0.00001) as well as a decrease in absolute BW (MD: -12.2 kg [95% CI -13.3, -11.1]; P < 0.00001), body mass index (MD: -4.5 kg/m2 [95% CI -4.9, -4.1]; P < 0.00001) and waist circumference (MD:-9.4 cm [95% CI -10.1, -8.8]; P < 0.00001). Moreover, it achieved a higher proportion of patients who experienced weight loss exceeding 5%, 10%, 15% and 20%. Furthermore, semaglutide showed significant efficacy in controlling blood pressure, blood sugar levels, C-reactive protein levels, and lipid profiles. In terms of safety, the most common adverse effects following semaglutide treatment were gastrointestinal adverse reactions (risk ratio: 1.49 [95% CI 1.38, 1.60]; P < 0.00001), which were generally mild to moderate in severity and temporary. In overweight or obese non-diabetic individuals, semaglutide had a remarkable and sustained weight loss effect that was well tolerated and safe.

1505-P: CD44 Knockdown in Human Adipocytes—Effect on Adipocyte Proliferation and Differentiation

Introduction: eGWAS implicates the immune-cell receptor CD44 as the top candidate gene in the molecular pathogenesis of T2D1. We have shown that in human adipose tissue, CD44 expression is associated with inflammatory gene expression, M1 macrophage phenotype, and systemic insulin resistance2. Here we sought to determine whether CD44 directly impairs adipocyte function via siRNA knockdown in human preadipocytes with quantification of proliferation, differentiation, and gene expression. Methods: Abdominal subcutaneous adipose tissue was harvested from five healthy nondiabetic obese individuals during bariatric surgery. Preadipocytes were isolated via collagenase digestion and seeded at 1×10^4 cells/well and treated with siRNA-CD44 or mock condition (control) using siRNA Maxi Transfection Reagents (Invitrogen). Cell proliferation was assayed by MTS (Promega) on Days 1, 2, 3 post transfection. Differentiation was induced at confluence (as described3), and cells were harvested at days 3, 6, 12 after confluence for gene expression and at day 12 for oil red O staining (total lipid uptake) and immunofluorescence microscopy (% differentiation = bodipy/dapi*100). Results: CD44 knockdown decreased preadipocyte proliferation and increased adipocyte differentiation and lipid uptake. Conclusion: CD44 may contribute to human insulin resistance by impairing adipocyte differentiation and fat storage. Disclosure H.Chen: None. N.R.Saini: None. E.M.Ayhan: None. T.Mclaughlin: Board Member; January, Inc., Research Support; Merck &amp; Co., Inc., Stock/Shareholder; Eiger Bio. Funding National Institutes of Health (1R21AI159024-01A1)

A Liquid Biopsy-Based Approach to Isolate and Characterize Adipose Tissue-Derived Extracellular Vesicles from Blood.

Obesity is a major risk factor for multiple chronic diseases. Anthropometric and imaging approaches are primarily used to assess adiposity, and there is a dearth of techniques to determine the changes in adipose tissue (AT) at the molecular level. Extracellular vesicles (EVs) have emerged as a novel and less invasive source of biomarkers for various pathologies. Furthermore, the possibility of enriching cell or tissue-specific EVs from the biofluids based on their unique surface markers has led to classifying these vesicles as "liquid biopsies", offering valuable molecular information on hard-to-access tissues. Here, we isolated small EVs from AT (sEVAT) of lean and diet-induced obese (DIO) mice, identified unique surface proteins on sEVAT by surface shaving followed by mass spectrometry, and developed a signature of five unique proteins. Using this signature, we pulled out sEVAT from the blood of mice and validated the specificity of isolated sEVAT by measuring the expression of adiponectin, 38 adipokines on an array, and several adipose tissue-related miRNAs. Furthermore, we provided evidence of sEV applicability in disease prediction by characterizing sEVAT from the blood of lean and DIO mice. Interestingly, sEVAT-DIO cargo showed a stronger pro-inflammatory effect on THP1 monocytes compared to sEVAT-Lean and a significant increase in obesity-associated miRNA expression. Equally important, sEVAT cargo revealed an obesity-associated aberrant amino acid metabolism that was subsequently validated in the corresponding AT. Lastly, we show a significant increase in inflammation-related molecules in sEVAT isolated from the blood of nondiabetic obese (>30 kg/m2) individuals. Overall, the present study offers a less-invasive approach to characterize AT.

Myocardial Tissue-Level Characteristics of Adults With Metabolically Healthy Obesity

BackgroundIt remains unclear whether adults with metabolically healthy obesity (MHO) have altered myocardial tissue-level characteristics. ObjectivesThis study aims to assess the subclinical myocardial tissue-level characteristics of adults with MHO. MethodsThe EARLY-MYO-OBESITY (EARLY Assessment of MYOcardial Tissue Characteristics in OBESITY; NCT05277779) registry was a prospective, 3-center, cardiac imaging study of obese nondiabetic individuals without cardiac symptoms who underwent cardiac magnetic resonance. Myocardial tissue-level characteristics, including extracellular volume fraction (ECV) and native T2 values, were measured as indicators of myocardial fibrosis and edema. Global longitudinal peak systolic strain and early diastolic longitudinal strain rate were assessed by tissue tracking analysis to detect subclinical systolic and diastolic dysfunction. ResultsA total of 120 participants were included: MHO (n = 32; mean age, 38 years; 41% men), metabolically healthy controls without obesity (n = 32; mean age: 37 years; 41% men), and metabolically unhealthy obesity (MUHO) (n = 56; mean age: 37 years; 55% men). The MHO group had higher ECV and native T2 values than healthy controls (both P < 0.001); furthermore, the ECV was higher in the MUHO group than in the MHO group (P = 0.002). The prevalence of myocardial fibrosis was 44% (14 of 32) in the MHO group and 71% (40 of 56) in the MUHO group. Although there was no intergroup difference in left ventricular ejection fraction, the MHO group had reduced global longitudinal peak systolic and early diastolic longitudinal strain rates, indicating subclinical systolic and diastolic dysfunction. Multivariate regression analysis identified increased body mass index to be an independent risk factor for myocardial fibrosis (OR: 6.28 [95% CI: 3.17-12.47]; P < 0.001). ConclusionsThis study provides the first evidence of subclinical myocardial tissue-level remodeling in adults with obesity, regardless of metabolic health. Early identification of cardiac impairment may facilitate preventive strategies against heart failure in the MHO population. (EARLY Assessment of MYOcardial Tissue Characteristics in OBESITY [EARLY-MYO-OBESITY]; NCT05277779)

Abstract 12480: Changes in Tmao Levels Following Bariatric Surgery Vary by Procedure Type

Introduction: Trimethylamine-N-oxide (TMAO), a metabolite generated by the gut microbiota from dietary phosphatidylcholine and carnitine, is linked to atherosclerosis and thrombosis. Although bariatric surgery improves CV outcomes, several studies in both animals and humans have shown increased TMAO levels after bariatric surgery. We tested the impact of the two most common bariatric procedures on plasma TMAO. Methods: This study included 93 severely obese non-diabetic individuals who did not take diabetes or lipid-lowering medications and underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Plasma TMAO was measured before and ≥ six months after bariatric surgery. Results: Mean age of the subjects was 31.4 ± 7.2 years and 90% were female. At baseline, average weight and BMI were 117.1 ± 24.4 kg and 43.4 ± 8.0 kg/m 2 respectively. Average baseline plasma TMAO level was 2.2 ± 1.4 μM. 29 patients underwent RYGB and 64 patients underwent SG. There were no significant differences in baseline weight, BMI, or TMAO between procedures. RYGB patients lost significantly more weight than SG patients (37.5 ± 8.6 kg for RYGB vs 32.8 ± 9.0 kg for SG, p = 0.03). TMAO levels did not change following SG, whereas they increased after RYGB ( Figure ). Changes in TMAO were not associated with changes in other clinical measures, for example, body weight and BMI ( Figure ) for either RYGB or SG patients. Conclusions: We found contrasting responses in circulating TMAO following bariatric surgical procedures employing dissimilar anatomical alterations. Given TMAO-associated CVD risk, these differences may lead to contrasting CV outcomes in the future. Additional research to understand changes in TMAO and the microbiota after bariatric surgery, and their clinical relevance, are warranted.

Circulating 1,5-Anhydroglucitol as a Biomarker of ß-cell Mass Independent of a Diabetes Phenotype in Human Subjects.

During an asymptomatic prediabetic state, the functional ß-cell mass decreases to a critical threshold, triggering diabetes and related symptoms. To date, there are no reliable readouts able to capture in vivo a potential drop of the ß-cell mass. Beside its use as a short-term marker of glycemic control, the deoxyhexose 1,5-anhydroglucitol was identified in rodents as a circulating biomarker of the functional ß-cell mass already in the asymptomatic prediabetic stage. The present study investigated the putative corresponding relevance of circulating 1,5-anhydroglucitol in different human cohorts. We analyzed clinical and blood parameters in patients with established type 2 diabetes and subjects considered at high risk of developing diabetes, as well as patients with no history of diabetes scheduled for pancreaticoduodenectomy. Circulating 1,5-anhydroglucitol was reduced in type 2 diabetic patients, negatively correlating with fasting plasma glucose (P < 0.0001) and hemoglobin A1c (P < 0.0001). In healthy subjects, 1,5-AG levels positively correlated with body mass index (P = 0.004) and Homeostatic Model Assessment of Insulin Resistance %S (P < 0.03) and was particularly high in nondiabetic obese individuals, potentially accounting for compensatory ß-cell expansion. Patients with no history of diabetes undergoing pancreaticoduodenectomy exhibited a 50% reduction of circulating 1,5-anhydroglucitol levels following surgery leading to an acute loss of their ß-cell mass (P = 0.002), regardless their glucose tolerance status. In summary, plasma concentration of 1,5-anhydroglucitol follows the ß-cell mass and its noninvasive monitoring may alert about the loss of ß cells in subjects at risk for diabetes, an event that cannot be captured by other clinical parameters of glycemic control.

Compensatory intestinal antibody response against pro-inflammatory microbiota after bariatric surgery

ABSTRACT Obesity and type 2 diabetes (T2D) are growing burdens for individuals and the health-care system. Bariatric surgery is an efficient, but drastic treatment to reduce body weight, normalize glucose values, and reduce low-grade inflammation. The gut microbiome, which is in part controlled by intestinal antibodies, such as IgA, is involved in the development of both conditions. Knowledge of the effect of bariatric surgery on systemic and intestinal antibody response is limited. Here, we determined the fecal antibody and gut microbiome response in 40 T2D and non-diabetic (ND) obese individuals that underwent bariatric surgery (N = 40). Body weight, fasting glucose concentrations and inflammatory parameters decreased after bariatric surgery, whereas pro-inflammatory bacterial species such as lipopolysaccharide (LPS), and flagellin increased in the feces. Simultaneously, concentrations of LPS- and flagellin-specific intestinal IgA levels increased with the majority of pro-inflammatory bacteria coated with IgA after surgery. Finally, serum antibodies decreased in both groups, along with a lower inflammatory tone. We conclude that intestinal rearrangement by bariatric surgery leads to expansion of typical pro-inflammatory bacteria, which may be compensated by an improved antibody response. Although further evidence and mechanistic insights are needed, we postulate that this apparent compensatory antibody response might help to reduce systemic inflammation by neutralizing intestinal immunogenic components and thereby enhance intestinal barrier function after bariatric surgery.

Association between Depression and Risk Factors as Obesity and Type 2 Diabetes Mellitus

Background: the prevalence of mood and anxiety disorders is higher among persons living with diabetes compared to those without diabetes. Numerous studies have demonstrated that both obesity and metabolic disorders are associated with depression. This study aimed to confirm the association between depression and risk factors as obesity and type 2 diabetes mellitus.Subjects and methods: This comparative cross-sectional study was carried out on 90 adults attending to the Diabetes outpatient clinic in Internal Medicine Department, Faculty of Medicine, Zagazig University Hospitals. They were divided into three groups, 30 patients with type 2 diabetes mellitus with normal body mass index (BMI), 30 obese non-diabetic individuals and 30 obese type 2 diabetic patients. Full medical history, clinical examination, laboratory investigation and assessment of depression were performed. Result: Age was 51.60±14.28, 42.26±12.21 and 51.93±9.89 respectively and Group B it was significantly younger than other two groups with no significant difference between them. No significant difference was found between groups regarding disease duration or diabetes mellitus (DM) treatment and also complication but regarding comorbidity Group C was significantly associated with comorbidity. Group A was significantly lower regarding Beck Depression Inventory and overall depression was significantly associated with group B and Group C as it was 30.0% and 46.7% respectively. Grade and overall depression were significantly associated with BMI >35 group. Conclusion: Type 2 diabetes mellitus and morbid obesity (BMI > 35) were associated with high prevalence of depression. It is evident that several modifiable and non-modifiable risk factors play an important role in the pathogenesis of diabetes and depression among population.

180-OR: Single-Cell RNA Sequencing Reveals a Role for ROS Signaling in Nutrient-Induced ß-Cell Proliferation

In nondiabetic obese individuals, β-cell mass accretion maintains glucose homeostasis by balancing levels of circulating insulin and insulin resistance. Type 2 diabetes appears when these compensatory mechanisms fail. Deciphering the pathways controlling β-cell proliferation may help to identify therapeutic targets to expand β-cell mass and prevent or delay the onset of diabetes. Previously we demonstrated that the monounsaturated fatty-acid oleate potentiates glucose-induced rat β-cell proliferation. Aim: To identify the transcriptional mechanisms underlying oleate-induced rat β-cell proliferation. Methods: Rat islets were exposed to 16.7mM glucose (Glu) with or without 0.5 mM oleate (Glu+Ol) or palmitate (Glu+Pal) for 48h. Proliferation was assessed by flow cytometry (C-peptide staining and EdU incorporation). Single-cell cDNA libraries were generated using 10X Genomics technology and sequenced on the Illumina platform. Bioinformatic analyses were performed using Seurat package. Results: β-cell proliferation was potentiated by Ol, but not Pal. Following single-cell RNA sequencing, UMAP plots revealed several β-cell sub-populations, including proliferating β-cells. A number of differences in gene expression were identified between groups in non-proliferating sub-populations. Among these, gene sets involved in ER-stress and β-cell differentiation were significantly up- and down-regulated, respectively, in response to Pal, but not Ol. Gene set enrichment analyses comparing proliferative vs. non-proliferative β-cells revealed an up-regulation of reactive oxygen species (ROS) and oxidoreductase activity-related pathways in both Glu and Glu+Ol groups. The antioxidant N-acetyl cysteine or the peroxiredoxin inhibitor Conoidin A inhibited Glu+Ol-induced β-cell proliferation. Conclusion: Our results suggest the involvement of ROS signaling through a redox relay via peroxiredoxin activation in nutrient-induced β-cell proliferation. Disclosure A. Vivoli: None. J. Ghislain: None. A. Castell: None. A. Filali: None. R. M. Sladek: None. V. Poitout: None.

Liraglutide for overweight and obesity

Liraglutide for overweight and obesity

The metabesity factor HMG20A potentiates astrocyte survival and reactive astrogliosis preserving neuronal integrity.

Rationale: We recently demonstrated that the 'Metabesity' factor HMG20A regulates islet beta-cell functional maturity and adaptation to physiological stress such as pregnancy and pre-diabetes. HMG20A also dictates central nervous system (CNS) development via inhibition of the LSD1-CoREST complex but its expression pattern and function in adult brain remains unknown. Herein we sought to determine whether HMG20A is expressed in the adult CNS, specifically in hypothalamic astrocytes that are key in glucose homeostasis and whether similar to islets, HMG20A potentiates astrocyte function in response to environmental cues.Methods: HMG20A expression profile was assessed by quantitative PCR (QT-PCR), Western blotting and/or immunofluorescence in: 1) the hypothalamus of mice exposed or not to either a high-fat diet or a high-fat high-sucrose regimen, 2) human blood leukocytes and adipose tissue obtained from healthy or diabetic individuals and 3) primary mouse hypothalamic astrocytes exposed to either high glucose or palmitate. RNA-seq and cell metabolic parameters were performed on astrocytes treated or not with a siHMG20A. Astrocyte-mediated neuronal survival was evaluated using conditioned media from siHMG20A-treated astrocytes. The impact of ORY1001, an inhibitor of the LSD1-CoREST complex, on HMG20A expression, reactive astrogliosis and glucose metabolism was evaluated in vitro and in vivo in high-fat high-sucrose fed mice.Results: We show that Hmg20a is predominantly expressed in hypothalamic astrocytes, the main nutrient-sensing cell type of the brain. HMG20A expression was upregulated in diet-induced obesity and glucose intolerant mice, correlating with increased transcript levels of Gfap and Il1b indicative of inflammation and reactive astrogliosis. Hmg20a transcript levels were also increased in adipose tissue of obese non-diabetic individuals as compared to obese diabetic patients. HMG20A silencing in astrocytes resulted in repression of inflammatory, cholesterol biogenesis and epithelial-to-mesenchymal transition pathways which are hallmarks of reactive astrogliosis. Accordingly, HMG20A depleted astrocytes exhibited reduced mitochondrial bioenergetics and increased susceptibility to apoptosis. Neuron viability was also hindered in HMG20A-depleted astrocyte-derived conditioned media. ORY1001 treatment rescued expression of reactive astrogliosis-linked genes in HMG20A ablated astrocytes while enhancing cell surface area, GFAP intensity and STAT3 expression in healthy astrocytes, mimicking the effect of HMG20A. Furthermore, ORY1001 treatment protected against obesity-associated glucose intolerance in mice correlating with a regression of hypothalamic HMG20A expression, indicative of reactive astrogliosis attenuation with improved health status.Conclusion: HMG20A coordinates the astrocyte polarization state. Under physiological pressure such as obesity and insulin resistance that induces low grade inflammation, HMG20A expression is increased to induce reactive astrogliosis in an attempt to preserve the neuronal network and re-establish glucose homeostasis. Nonetheless, a chronic metabesity state or functional mutations will result in lower levels of HMG20A, failure to promote reactive astrogliosis and increase susceptibility of neurons to stress-induced apoptosis. Such effects could be reversed by ORY1001 treatment both in vitro and in vivo, paving the way for a new therapeutic approach for Type 2 Diabetes Mellitus.

Effect of Treatment of Periodontitis on Incretin Axis in Obese and Nonobese Individuals: A Cohort Study.

Periodontitis confers an increased risk of developing type 2 diabetes and, in patients with obesity, it might interfere with the incretin axis. The effect of periodontal treatment on glucoregulatory hormones remains unknown. To evaluate the effect of periodontal treatment on incretin axis in obese and lean nondiabetic individuals. King's College Dental Hospital and Institute, London, UK. The metabolic profile of obese and normal-body-mass-index individuals affected by periodontitis was studied at baseline, 2, and 6 months after intensive periodontal treatment, by measuring plasma insulin, glucagon, glucagon-like peptide-1(GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) and markers of systemic inflammation and oxidative stress. Circulating levels of incretins and inflammatory markers. At baseline, periodontal parameters were worse for obese than nonobese; this was accompanied by higher levels of circulating high-sensitivity C-reactive protein (hs-CRP), insulin, and GLP-1. The response to periodontal treatment was less favorable in the obese group, without significant variations of hs-CRP or malondialdehyde. Glucoregulatory hormones changed differently after treatment: while insulin and glucagon did not vary at 2 and 6 months, GLP-1 and GIP significantly increased at 6 months in both groups. In particular, GLP-1 increased more rapidly in obese participants, while the increase of GIP followed similar trends across visits in both groups. Nonsurgical treatment of periodontitis is associated with increased GLP-1 and GIP levels in nonobese and obese patients; changes in GLP-1 were more rapid in obese participants. This might have positive implications for the metabolic risk of these individuals.

Multi-layered epigenetic regulation of IRS2 expression in the liver of obese individuals with type 2 diabetes

Aims/hypothesisIRS2 is an important molecular switch that mediates insulin signalling in the liver. IRS2 dysregulation is responsible for the phenomenon of selective insulin resistance that is observed in type 2 diabetes. We hypothesise that epigenetic mechanisms are involved in the regulation of IRS2 in the liver of obese and type 2 diabetic individuals.MethodsDNA methylation of seven CpG sites was studied by bisulphite pyrosequencing and mRNA and microRNA (miRNA) expression was assessed by quantitative real-time PCR in liver biopsies of 50 obese non-diabetic and 31 obese type 2 diabetic participants, in a cross-sectional setting. Methylation-sensitive luciferase assays and electrophoretic mobility shift assays were performed. Furthermore, HepG2 cells were treated with insulin and high glucose concentrations to induce miRNA expression and IRS2 downregulation.ResultsWe found a significant downregulation of IRS2 expression in the liver of obese individuals with type 2 diabetes (0.84 ± 0.08-fold change; p = 0.0833; adjusted p value [pa] = 0.0417; n = 31) in comparison with non-diabetic obese participants (n = 50). This downregulation correlated with hepatic IRS2 DNA methylation at CpG5. Additionally, CpG6, which is located in intron 1 of IRS2, was hypomethylated in type 2 diabetes; this site spans the sterol regulatory element binding transcription factor 1 (SREBF1) recognition motif, which likely acts as transcriptional repressor. The adjacent polymorphism rs4547213 (G>A) was significantly associated with DNA methylation at a specificity-protein-1 (SP1) binding site (CpG3). Moreover, DNA methylation of cg25924746, a CpG site located in the shore region of the IRS2 promoter-associated CpG island, was increased in the liver of individuals with type 2 diabetes, as compared with those without diabetes. A second epigenetic mechanism, upregulation of hepatic miRNA hsa-let-7e-5p (let-7e-5p) in obese individuals with type 2 diabetes (n = 29) vs non-diabetic obese individuals (n = 49) (1.2 ± 0.08-fold change; p = 0.0332; pa = 0.0450), is likely to act synergistically with altered IRS2 DNA methylation to decrease IRS2 expression. Mechanistic in vitro experiments demonstrated an acute upregulation of let-7e-5p expression and simultaneous IRS2 downregulation in a liver (HepG2) cell line upon hyperinsulinaemic and hyperglycaemic conditions.Conclusions/interpretationOur study highlights a new multi-layered epigenetic network that could be involved in subtle dysregulation of IRS2 in the liver of individuals with type 2 diabetes. This might lead to fine-tuning of IRS2 expression and is likely to be supplementary to the already known factors regulating IRS2 expression. Thereby, our findings could support the discovery of new diagnostic and therapeutic strategies for type 2 diabetes.Graphical abstract

2098-P: Transcriptomic Changes Associated with Oleate-Induced ß-Cell Proliferation in Rat Islets

Background: In nondiabetic obese individuals, β-cell mass accretion maintains glucose homeostasis by balancing levels of circulating insulin and insulin resistance. Type 2 diabetes appears when these compensatory mechanisms fail. Deciphering the pathways controlling β-cell proliferation has thus become a major research goal in the hope to identify therapeutic targets to expand β-cell mass and prevent or delay the onset of diabetes. Previously we demonstrated that fatty acids potentiate glucose induced β-cell proliferation in response to nutrient surfeit in rats. In recent studies we identified the mono-unsaturated fatty-acid oleate as a major fatty acid driving β-cell proliferation in rat islets ex vivo. Aim: To identify the transcriptional mechanisms underlying oleate-induced β-cell proliferation in rats. Method: Rat islets were exposed to 16.7mM glucose +/- oleate (0.5mM) for 48h. Proliferation was assessed by flow cytometry using c-peptide antibodies and EdU. Single cell cDNA libraries were generated using 10X Genomics technology and sequenced on the Illumina platform. Bioinformatic analyses were performed using the Cell Ranger pipeline, Seurat and Monocle. Results: Oleate induced a 3.1+/-0.4 fold increase (p&amp;lt;0.01; n=4) in β-cell proliferation. Following single-cell RNA sequencing, t-SNE plots revealed several β-cell sub-populations, including proliferating β-cells. Comparison between proliferative and non-proliferative β-cells identified more than 300 differentially expressed genes. Gene ontology suggested an increase in mitochondrial activity and reactive oxygen species (ROS) in proliferating β-cells. Pseudotime ordering of β cells revealed that ER-stress related genes are up-regulated prior to proliferation in response to oleate. Conclusion: Our study suggests an involvement of ROS and ER-stress in oleate-induced β-cells proliferation. Further functional analyses will substantiate the importance of these stress responses. Disclosure A. Vivoli: None. A. Castell: None. A. Pacis: None. R.M. Sladek: None. J. Ghislain: None. V. Poitout: None.

MON-382 Bone Quality and Strength in Obese Men with Type 2 Diabetes Mellitus Are Impaired and Negatively Influenced by Adiposity

Background: Obesity and type 2 diabetes mellitus (T2DM) are both associated with normal to above average bone mineral density (BMD) but increased risk of fragility fractures. The impact of T2DM on bone mechanical and microarchitectural features in the obese population is unknown. We hypothesize that obese diabetics have lower bone quality compared to obese nondiabetic individuals. In this study, we investigated the microarchitectural features and mechanical properties of bone of obese men with and without T2DM along with the independent predictors of bone strength. Methods: Ninety-seven obese men (BMI >30) aged 35-65 years-old of which 38 had T2DM were included in the analysis. BMD and body composition were evaluated by DXA and bone microarchitecture of the tibia by high-resolution peripheral quantitative computed tomography. Bone strength was assessed by micro finite element analysis-derived parameters as failure load (f. load) and stiffness. Serum testosterone and estradiol were measured by LC-MS. Serum SHBG, osteocalcin (OCN), C-telopeptide (CTx) and sclerostin (SCL) were measured by ELISA. Results: OCN is lower in obese men with T2DM compared to those without T2DM (4.8 ± 2.8 vs 6.2 ± 2.6 ng/mL p=0.03, respectively), with also a trend for reduced CTx and SCL in the former. BMD at all sites was reduced in obese men with T2DM, but there were no differences in body composition. Obese diabetics also had lower tibial total volumetric BMD (vBMD) (p=0.04) and trabecular vBMD (p=0.01) with greater trabecular spacing (p=0.005). F. load (13.3 ± 2.1 vs 14.5 ± 2.3 kN, p= 0.02) and stiffness (24.7± 4.2 vs 27 ± 4.6 kN/mm, p=0.02) were reduced in men with T2DM relative to men without T2DM, respectively. F. load and stiffness were positively correlated with BMD at all sites, fat free mass (FFM), lean mass, free testosterone, free estradiol and SCL, but negatively correlated with % total body fat and visceral adipose tissue (VAT). FFM, BMD of the total hip, femoral neck and lumbar spine and free testosterone were significant independent predictors of bone strength in the entire group (model: R2: 65.01 p< 0.0001 for f. load and model: R2:63.21 p < 0.0001 for stiffness), whereas age and lumbar spine BMD were found to be independent predictors of bone strength in the non-diabetic group (model R2: 54.6 p< 0.0001 for both f. load and stiffness). Analysis limited to the diabetic subgroup showed that BMD at the femoral neck and total hip, % total body fat, VAT volume, SCL and free estradiol were independent predictors of bone strength (model: R2: 88.4 and p< 0.0001 for f. load and model: R2: 85.3 and p<0.0001 for stiffness). Interleukin-6 was comparable between groups. Conclusions: Obese men with T2DM have lower bone formation and impaired bone quality and strength compared to those without T2DM. In addition to BMD and gonadal hormones, adiposity is an important predictor of bone strength in obese men with T2DM.

The Map3k12 (Dlk)/JNK3 signaling pathway is required for pancreatic beta-cell proliferation during postnatal development.

Unveiling the key pathways underlying postnatal beta-cell proliferation can be instrumental to decipher the mechanisms of beta-cell mass plasticity to increased physiological demand of insulin during weight gain and pregnancy. Using transcriptome and global Serine Threonine Kinase activity (STK) analyses of islets from newborn (10days old) and adult rats, we found that highly proliferative neonatal rat islet cells display a substantially elevated activity of the mitogen activated protein 3 kinase 12, also called dual leucine zipper-bearing kinase (Dlk). As a key upstream component of the c-Jun amino terminal kinase (Jnk) pathway, Dlk overexpression was associated with increased Jnk3 activity and was mainly localized in the beta-cell cytoplasm. We provide the evidence that Dlk associates with and activates Jnk3, and that this cascade stimulates the expression of Ccnd1 and Ccnd2, two essential cyclins controlling postnatal beta-cell replication. Silencing of Dlk or of Jnk3 in neonatal islet cells dramatically hampered primary beta-cell replication and the expression of the two cyclins. Moreover, the expression of Dlk, Jnk3, Ccnd1 and Ccnd2 was induced in high replicative islet beta cells from ob/ob mice during weight gain, and from pregnant female rats. In human islets from non-diabetic obese individuals, DLK expression was also cytoplasmic and the rise of the mRNA level was associated with an increase of JNK3, CCND1 and CCND2 mRNA levels, when compared to islets from lean and obese patients with diabetes. In conclusion, we find that activation of Jnk3 signalling by Dlk could be a key mechanism for adapting islet beta-cell mass during postnatal development and weight gain.