Lean Volunteers Research Articles

Relation of R-Spondin 3 Gene expression android obesity and Susceptibility to Cardiovascular disease in Sudanese Patients in Khartoum State.

Background: Obesity is a major risk factor for the development of cardiovascular disease. A growing database of clinical evidence implicates intra-abdominal adiposity as a powerful driving force for elevated cardiometabolic risk. Addressing intra-abdominal adiposity should play a central role in future strategies aimed at improving cardiovascular outcomes in patients with abdominal obesity and its associated cardiometabolic risk in Sudan. Several studies aimed to identify some factors controlling the size and function of different areas of fat. Our research is focusing on a particular gene called R-SPONDIN3,
 Objectives: It is to find the amount of R-Spondin3 Gene expression in Abdominal obesity and Susceptibility to Cardiovascular disease in Sudanese Patients in Khartoum State
 Material and methods: - The study was including 300 participants (156 males and 144 females) classified into three groups. The first group was including one hundred participants with abdominal obesity (obese), the second group was including one hundred participants already diagnosed with CVD entangled with obesity (Heart Group as positive control group), while the third group was include one hundred healthy lean volunteers (negative control group)
 Results: - The findings of this study showed Conventional PCR results were significantly different (P <0.001) in Heart group subjects as compared to healthy controls and obese group. Among heart group mutation was detected in some subjects (19%) and the rest without mutation (81%) but in obese group no mutation was detected. Comparison between the different studied groups according to gene expression showed significant differences (P <0.001) mean value of gene expression in healthy group subjects was 1.0 ± 0.0, Obesity group was 2.44 ± 0.50 and heart group subjects was 4.54 ± 0.87 respectively. 
 Conclusion: The amount of R-SPONDIN3 gene expression among the obese and CVD patients is show up significant different and the amount of gene expressing among the CVD patients is higher than obese which is suggested that the amount of gene expressed in obese patients with heart disease more than obese patients without cardiovascular complications

Laparoscopic sleeve gastrectomy induces molecular changes in peripheral white blood cells

Peripheral white blood cells (PWBC) may allow for the development of obesity biomarkers. We aimed to investigate the existence of gene expression and DNA methylation changes in PWBC after a very low calorie diet (VLCD) followed by a laparoscopic sleeve gastrectomy (LSG), and its correlation with surgical outcomes. From July 2013 to June 2014, 35 consecutive bariatric patients and 33 healthy lean volunteers were recruited. Molecular data was obtained once on the control group and at 3 different times on the LSG group: 1) at baseline; 2) after 2 weeks of VLCD, right before LSG; and 3) 6 months after LSG. The expression of 12 genes in PWBC was analyzed by quantitative real-time polymerase chain reaction: ghrelin (GHRL), visfatin (NAMPT), insulin receptor substrate 1 (IRS1), fat mass and obesity-related gene (FTO), leptin (LEP), peroxisome proliferator-activated receptor gamma (PPARG), adiponectin (ADIPOQ), fatty acid synthase (FASN), melanocortin 4 receptor (MC4R), fas cell surface death receptor (FAS), tumor necrosis factor alpha (TNF) and chemokine (C-C motif) ligand 2 (CCL2). Moreover, DNA methylation of GHRL, NAMPT and FAS promoters was analyzed in PWBC by bisulfite pyrosequencing. Seven genes (GHRL, NAMPT, IRS1, FTO, FAS, TNF and CCL2) had detectable expression in PWBC. FTO expression at baseline was lower in patients than in controls (p=0.042), equalizing after LSG. In patients, FAS expression decreased after VLCD (p=0.01) and stayed low after LSG (p=0.015). Also, CCL2 expression decreased 50% after LSG compared to pre-surgical levels (p=0.016). All studied CpG sites in the GHRL gene promoter followed a consistent pattern of DNA methylation/demethylation. No direct correlation between these molecular changes and surgical outcomes was found at 1-year follow-up. FTO expression increased and FAS and CCL2 expression decreased in PWBC after LSG. Molecular changes did not correlate with surgical outcomes.

Role of Roof plate-specific SPONDIN3 Mutation in the Determination of Obesity Phenotypes/Fat Distribution and Susceptibility to Cardiovascular disease in Sudanese Patients in Khartoum State

Background: Obesity is a major risk factor for the development of cardiovascular disease. A growing database of clinical evidence implicates intra-abdominal adiposity as a powerful driving force for elevated cardiometabolic risk (1). Addressing intra-abdominal adiposity should play a central role in future strategies aimed at improving cardiovascular outcomes in patients with abdominal obesity and its associated cardiometabolic risk in Sudan.
 Objectives: It is to find the mutation in R-SPONDIN3gene and its association to both of fat deposition around the abdomen and susceptibility to cardiovascular disease in Sudanese patients in Khartoum State.
 Material and methods: Conventional PCR was done to detect R- SPONDIN3 in 300 participants (males and females) classified into three groups. The first group will include one hundred participants with abdominal obesity, the second group will include one hundred participants already diagnosed with CVD entangled with obesity (positive control group), while the third group will include one hundred healthy lean volunteers (negative control group). Data was analyzed using SPSS Version 22 software. P value < 0.05 was considered as statistically significant.
 Results: In this study, the results of Conventional PCR were significantly different in (P <0.001) in Heart group subjects as compared to healthy controls and obese group. Comparison between the different studied groups according to gene expression showed significant differences (P <0.001) mean value of gene expression in healthy group subjects was 1.0 ± 0.0, Obesity group was 2.44 ± 0.50 and heart group subjects was 4.54 ± 0.87 respectively .
 Conclusion: clinically, detect R- SPONDIN3 mutation in patients with diagnosed with CVD entangled with obesity and amount of the gene expressed cleared different between obese and CVD subjects entangled with obesity.
 Keywords: R-SPONDIN3 gene, abdominal Obesity, CVD.

Impact of Rye Kernel-Based Evening Meal on Microbiota Composition of Young Healthy Lean Volunteers With an Emphasis on Their Hormonal and Appetite Regulations, and Blood Levels of Brain-Derived Neurotrophic Factor.

Rye kernel bread (RKB) evening meals improve glucose tolerance, enhance appetite regulation and increase satiety in healthy volunteers. These beneficial effects on metabolic responses have been shown to be associated with increased gut fermentation. The present study aimed to elucidate if RKB evening meals may cause rapid alterations in microbiota composition that might be linked to metabolic-, immune-, and appetite- parameters. Gut-brain axis interaction was also studied by relating microbiota composition to amount of brain-derived neurotrophic factor (BDNF) in blood plasma. Nineteen healthy volunteers, ten women and nine men aged 22–29 years, BMI < 25 (NCT02093481) participated in the study performed in a crossover design. Each person was assigned to either white wheat bread (WWB) or RKB intake as a single evening meal or three consecutive evenings. Stool and blood samples as well as subjective appetite ratings were obtained the subsequent morning after each test occasion, resulting in four independent collections per participant (n = 76). DNA was extracted from the fecal samples and V4 hypervariable region of the bacterial 16S rRNA genes was sequenced using next generation sequencing technology. Higher abundance of Prevotella and Faecalibacterium with simultaneous reduction of Bacteroides spp. were observed after RKB meals compared to WWB. The associations between metabolic test variables and microbiota composition showed a positive correlation between Bacteroides and adiponectin levels, whereas only Prevotella genus was found to have positive association with plasma levels of BDNF. These novel findings in gut-brain interactions might be of importance, since decreased levels of BDNF, that plays an essential role in brain function, contribute to the pathogenesis of several major neurodisorders, including Alzheimer's. Thus, daily consumption of Faecalibacterium- and/or Prevotella-favoring meals should be investigated further for their potential to prevent neurodegenerative processes in the brain.

Influences of Dietary Added Sugar Consumption on Striatal Food-Cue Reactivity and Postprandial GLP-1 Response.

Sugar consumption in the United States exceeds recommendations from the American Heart Association. Overconsumption of sugar is linked to risk for obesity and metabolic disease. Animal studies suggest that high-sugar diets alter functions in brain regions associated with reward processing, including the dorsal and ventral striatum. Human neuroimaging studies have shown that these regions are responsive to food cues, and that the gut-derived satiety hormones, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY), suppress striatal food-cue responsivity. We aimed to determine the associations between dietary added sugar intake, striatal responsivity to food cues, and postprandial GLP-1 and PYY levels. Twenty-two lean volunteers underwent a functional magnetic resonance imaging (fMRI) scan during which they viewed pictures of food and non-food items after a 12-h fast. Before scanning, participants consumed a glucose drink. A subset of 19 participants underwent an additional fMRI session in which they consumed water as a control condition. Blood was sampled for GLP-1, and PYY levels and hunger ratings were assessed before and ~75 min after drink consumption. In-person 24-h dietary recalls were collected from each participant on three to six separate occasions over a 2-month period. Average percent calories from added sugar were calculated using information from 24-h dietary recalls. A region-of-interest analysis was performed to compare the blood oxygen level-dependent (BOLD) response to food vs. non-food cues in the bilateral dorsal striatum (caudate/putamen) and ventral striatum (nucleus accumbens). The relationships between added sugar, striatal responses, and hormone changes after drink consumption were assessed using Spearman’s correlations. We observed a positive correlation between added sugar intake and BOLD response to food cues in the dorsal striatum and a similar trend in the nucleus accumbens after glucose, but not water, consumption. Added sugar intake was negatively associated with GLP-1 response to glucose. Post hoc analysis revealed a negative correlation between GLP-1 response to glucose and BOLD response to food cues in the dorsal striatum. Our findings suggest that habitual added sugar intake is related to increased striatal response to food cues and decreased GLP-1 release following glucose intake, which could contribute to susceptibility to overeating.

Intragastric administration of leucine or isoleucine lowers the blood glucose response to a mixed-nutrient drink by different mechanisms in healthy, lean volunteers

The branched-chain amino acids leucine and isoleucine lower blood glucose after oral glucose ingestion, and the intraduodenal infusion of leucine decreases energy intake in healthy, lean men. We investigated the effects of the intragastric administration of leucine and isoleucine on the gastric emptying of, and blood glucose responses to, a physiologic mixed-macronutrient drink and subsequent energy intake. In 2 separate studies, 12 healthy, lean subjects received on 3 separate occasions an intragastric infusion of 5 g leucine (leucine-5g) or an intragastric infusion of 10 g leucine (leucine-10g), an intragastric infusion of 5 g isoleucine (isoleucine-5g) or an intragastric infusion of 10 g isoleucine (isoleucine-10g), or a control. Fifteen minutes later, subjects consumed a mixed-nutrient drink (400 kcal, 56 g carbohydrates, 15 g protein, and 12 g fat), and gastric emptying (13C-acetate breath test) and blood glucose, plasma insulin, C-peptide, glucagon, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and cholecystokinin (leucine study only) were measured for 60 min. Immediately afterward, energy intake from a cold, buffet-style meal was assessed. Compared with the control, leucine-10g decreased the blood glucose area under the curve (AUC) (P < 0.05) and tended to reduce peak blood glucose (P = 0.07), whereas effects of leucine-5g were NS. Leucine-10g, but not leucine-5g, increased plasma insulin and C-peptide AUCs (P < 0.01 for both), but neither dose affected glucagon, GLP-1, GIP, cholecystokinin, gastric emptying, or energy intake. Compared with the control, isoleucine-10g reduced the blood glucose AUC and peak blood glucose (P < 0.01), whereas effects of isoleucine-5g were NS. Neither load affected insulin, C-peptide, glucagon, GLP-1, or GIP. Isoleucine-10g, but not isoleucine-5g, slowed gastric emptying (P < 0.05), but gastric emptying was not correlated with the blood glucose AUC. Isoleucine did not affect energy intake. In healthy subjects, both leucine and isoleucine reduced blood glucose in response to a mixed-nutrient drink but did not affect subsequent energy intake. The mechanisms underlying glucose lowering appear to differ; leucine stimulated insulin, whereas isoleucine acted insulin independently. These trials were registered at www.anzctr.org.au as 12613000899741 and 12614000837628.

Effect of Meal Size on Postprandial Lipid Profile and Endothelial Changes in Healthy Subjects

Background: A well balanced diet is important for normal function of endothelial cells. Diets high in fat and/or calories can lead to hypertriglyceridemia and postprandial lipidemia and thus are considered a risk factor for the development of atherosclerosis. Big meals may result in chronic elevations in the level of atherogenic lipoproteins as well as evoking chronic inflammatory response. Both may lead to pathological changes on the arterial vessel wall and myocardium. Objective(s): To study the effect of the size of a well-balanced meal on the lipid profile in the post prandial state and its effect on the endothelial function, ventricular filling and diastolic function. Methods: one group pretest-posttest study was carried out on 40 young healthy lean volunteers aged 30 to 39 years who after overnight fast were invited to eat a big breakfast meal. Postprandial blood samples were then drawn after 3-4 hours to determine changes induced by the big meal in the blood. On the following day, the same procedure was adopted but with a breakfast meal which contains only one third of the size of the big meal (small meal). The items of comparison between the two meals included: The changes induced by both types of meals on the lipid profile of the blood by assessing the postprandial levels of TG, TC, LDL-C, HDL-C and FFAs; assessment of the inflammatory response by assessing postprandial levels of CRP; The changes induced on endothelial cell functions by assessing the postprandial levels of ET1 and NO; and the changes induced by the two types of meals on the left ventricular function as determined by echo Doppler as well as tissue Doppler imaging (TDI). Results: The big meal was associated with elevations in TG, TC, LDL-C, CRP, ET1 and NO (P=0.001, 0.021, 0.057, 0.110, 0.002, 0.001respectively). The small meal showed significant increase in levels of HDL-C (P=0.001) and FFAs (P=0.048). The diastolic function of the left ventricle showed significant reduction after the ingestion of the big meal versus the small meal. Conclusions: The study concluded that big meal size negatively impact lipid homeostasis and endothelial function and the recognition of this possible danger of big meals can lead to the possibility of prevention of atherosclerosis through controlling of the meal size. Keywords : Meal size, postprandial, Lipid profile, CRP, endothelin 1, nitric oxide, diastolic function, ventricular filling

Increased Interleukin-32 Levels in Obesity Promote Adipose Tissue Inflammation and Extracellular Matrix Remodeling: Effect of Weight Loss.

Interleukin (IL)-32 is a recently described cytokine involved in the regulation of inflammation. We aimed to explore whether IL-32 could function as an inflammatory and angiogenic factor in human obesity and obesity-associated type 2 diabetes. Samples obtained from 90 subjects were used in the study. Obese patients exhibited higher expression levels of IL-32 in visceral adipose tissue (AT) as well as in subcutaneous AT and peripheral blood mononuclear cells. IL32 was mainly expressed by stromovascular fraction cells, and its expression was significantly enhanced by inflammatory stimuli and hypoxia, whereas no changes were found after the incubation with anti-inflammatory cytokines. The addition of exogenous IL-32 induced the expression of inflammation and extracellular matrix-related genes in human adipocyte cultures, and IL32-silenced adipocytes showed a downregulation of inflammatory genes. Furthermore, adipocyte-conditioned media obtained from obese patients increased IL32 gene expression in human monocyte cultures, whereas the adipocyte-conditioned media from lean volunteers had no effect on IL32 mRNA levels. These findings provide evidence, for the first time, about the inflammatory and remodeling properties of IL-32 in AT, implicating this cytokine in obesity-associated comorbidities.

Weight loss reduces anti-ADAMTS13 autoantibodies and improves inflammatory and coagulative parameters in obese patients.

Obese patients have been described at increased risk of thrombotic thrombocytopenic purpura, a disease caused by anti-ADAMTS13 autoantibodies. ADAMTS13 has a structure homology with the adipokine thrombospondin-1. We previously demonstrated an increased presence of anti-ADAMTS13 antibodies in obese patients. We aimed to study the changes induced by weight loss after bariatric surgery on some inflammatory and coagulative parameters and their link with anti-ADAMTS13 autoantibodies. We studied 100 obese patients before and after weight loss induced by bariatric surgery and 79 lean volunteers as controls. We measured anthropometric, metabolic and inflammatory parameters, thrombospondin-1, ADAMTS13 activity, anti-ADAMTS13 autoantibodies, Von Willebrand factor. At baseline, 13 % of patients was positive for anti-ADAMTS13 autoantibodies, while all controls were negative. Thrombospondin-1 levels were higher in obese subjects with than without antibodies, with a positive correlation between the two parameters. In multiple logistic regression analysis only thrombospondin-1 levels predicted positivity for anti-ADAMTS13 antibodies. After weight loss both anti-ADAMTS13 antibodies and thrombospondin-1 reduced significantly. Weight loss in obesity improves the inflammatory and coagulative profile, and in particular anti-ADAMTS13 autoantibodies, ADAMTS13 activity and thrombospondin-1.

Comparison of the gut microbial community between obese and lean peoples using 16S gene sequencing in a Japanese population.

Altered gut microbial ecology contributes to the development of metabolic diseases including obesity. In this study, we performed 16S rRNA sequence analysis of the gut microbiota profiles of obese and lean Japanese populations. The V3–V4 hypervariable regions of 16S rRNA of fecal samples from 10 obese and 10 lean volunteers were sequenced using the Illumina MiSeqTMII system. The average body mass index of the obese and lean group were 38.1 and 16.6 kg/m2, respectively (p<0.01). The Shannon diversity index was significantly higher in the lean group than in the obese group (p<0.01). The phyla Firmicutes and Fusobacteria were significantly more abundant in obese people than in lean people. The abundance of the phylum Bacteroidetes and the Bacteroidetes/Firmicutes ratio were not different between the obese and lean groups. The genera Alistipes, Anaerococcus, Corpococcus, Fusobacterium and Parvimonas increased significantly in obese people, and the genera Bacteroides, Desulfovibrio, Faecalibacterium, Lachnoanaerobaculum and Olsenella increased significantly in lean people. Bacteria species possessing anti-inflammatory properties, such as Faecalibacterium prausnitzii, increased significantly in lean people, but bacteria species possessing pro-inflammatory properties increased in obese people. Obesity-associated gut microbiota in the Japanese population was different from that in Western people.

Peripheral mononuclear blood cells contribute to the obesity-associated inflammatory state independently of glycemic status: involvement of the novel proinflammatory adipokines chemerin, chitinase-3-like protein 1, lipocalin-2 and osteopontin.

Inflammation is a critical contributor to the pathogenesis of metabolic disorders with adipose tissue being crucial in the inflammatory response by releasing multiple adipokines with either pro- or anti-inflammatory activities with potential functions as metabolic regulators. Peripheral blood mononuclear cells (PBMC) have been proposed as representative of the inflammatory status in obesity. The aim of the present study was to evaluate the contribution of PBMC to the obesity-associated chronic inflammation analyzing the expression of novel adipokines. Samples obtained from 69 subjects were used in the study. Real-time PCR determinations were performed to quantify gene expression levels in PBMC of novel adipokines including chemerin, chitinase-3-like protein 1 (YKL-40), lipocalin-2 (LCN-2) and osteopontin (OPN), and their circulating concentrations were also determined by ELISA. We show, for the first time, that PBMC gene expression levels of chemerin (P<0.0001), chitinase-3-like protein 1 (P=0.010), lipocalin-2 (P<0.0001) and osteopontin (P<0.0001) were strongly upregulated in obesity independently of the glycemic state. Circulating concentrations of these adipokines followed the same trend being significantly higher (P<0.05) in obese normoglycemic and type 2 diabetic patients compared to lean volunteers and also associated (P<0.05) with their corresponding mRNA levels in PBMC. These results provide evidence that alterations in inflammation-related adipokines are manifest in PBMC, which might contribute to the low-grade chronic inflammation that characterizes obesity.

Bariatric surgery in morbidly obese insulin resistant humans normalises insulin signalling but not insulin-stimulated glucose disposal.

AimsWeight-loss after bariatric surgery improves insulin sensitivity, but the underlying molecular mechanism is not clear. To ascertain the effect of bariatric surgery on insulin signalling, we examined glucose disposal and Akt activation in morbidly obese volunteers before and after Roux-en-Y gastric bypass surgery (RYGB), and compared this to lean volunteers.Materials and MethodsThe hyperinsulinaemic euglycaemic clamp, at five infusion rates, was used to determine glucose disposal rates (GDR) in eight morbidly obese (body mass index, BMI=47.3±2.2 kg/m2) patients, before and after RYGB, and in eight lean volunteers (BMI=20.7±0.7 kg/m2). Biopsies of brachioradialis muscle, taken at fasting and insulin concentrations that induced half-maximal (GDR50) and maximal (GDR100) GDR in each subject, were used to examine the phosphorylation of Akt-Thr308, Akt-473, and pras40, in vivo biomarkers for Akt activity.ResultsPre-operatively, insulin-stimulated GDR was lower in the obese compared to the lean individuals (P<0.001). Weight-loss of 29.9±4 kg after surgery significantly improved GDR50 (P=0.004) but not GDR100 (P=0.3). These subjects still remained significantly more insulin resistant than the lean individuals (p<0.001). Weight loss increased insulin-stimulated skeletal muscle Akt-Thr308 and Akt-Ser473 phosphorylation, P=0.02 and P=0.03 respectively (MANCOVA), and Akt activity towards the substrate PRAS40 (P=0.003, MANCOVA), and in contrast to GDR, were fully normalised after the surgery (obese vs lean, P=0.6, P=0.35, P=0.46, respectively).ConclusionsOur data show that although Akt activity substantially improved after surgery, it did not lead to a full restoration of insulin-stimulated glucose disposal. This suggests that a major defect downstream of, or parallel to, Akt signalling remains after significant weight-loss.

86 Obese Patients Have Significantly Higher Motilin Plasma Levels Which Decrease After Roux-en-Y Gastric Bypass Surgery

Objective: Changes in gut hormones are suggested to play an important role in the metabolic reprogramming that occurs after Roux-en-Y gastric bypass (RYGB) surgery. We have recently shown that gastric phases III of the migrating motor complex (MMC) are associated with hunger peaks in healthy lean volunteers and that both can be induced through the administration of erythromycin, a motilin receptor agonist. The aim of this study was to evaluate the role of motilin and phase III as hunger-inducing factors in obese patients and to study the effect of RYGB surgery on plasma motilin levels. Design: Blood samples for motilin and ghrelin (total and octanoylated) were taken during a complete MMC cycle in healthy lean controls (n=15, 28±2y, 22±0.5kg/m2) and obese patients (n=16, 40±3y, 41±0.8kg/m2) before surgery and 6 months (n=8, 39±4y, 29±1.3kg/m2) or 1 year after surgery (n=7, 40±4y, 25±1.1kg/m2). Gastrointestinal motility was measured using high-resolution manometry after a 12 hour overnight fast. Hunger was scored every 5 min on a visual analogue scale of 10 cm. An i.v. infusion of 40 mg erythromycin was given 20 min after the end of the second phase III in obese patients to evaluate the effect on hunger. Hedonic hunger was measured using the Power of Food scale in obese patients prior to, 6 months and 1 year after surgery. Results: A positive correlation was found between BMI and motilin (r=0.53; p=0.005) and a negative correlation between BMI and ghrelin (total (r=-0.52; p=0.007) and octanoylated (r=-0.43; p=0.02). Obese patients had significantly higher motilin plasma levels compared to lean controls (fig 1, p=0.0005) during the MMC cycle but tended to lack the motilin (-3±6% vs 15±6%; p=0.052) plasma peak prior to phase III. The obese patients had significantly less phases III that started in the antrum for both the first (44% vs 60%; p= 0.03) and second (22% vs 40%; p=0.0091) phase III compared to lean controls. Hunger scores during phase III were significantly lower in obese patients (p=0.0022) compared to lean controls, but could be increased through the administration of erythromycin (p=0.97) which induced a premature gastric phase III in all patients. After RYGB surgery the AUC of motilin plasma levels was significantly reduced (fig 2, p=0.018). Although hunger scores during phase III were not affected by RYGB (p=0.9), hedonic hunger was significantly decreased (p=0.0009). Conclusion: Our study is the first to describe a positive correlation between motilin plasma levels and BMI which could indicate that motilin plays an important role in the pathogenesis of obesity, moreover we have shown that motilin levels decrease after RYGB. The switch in origin of phase III contractions, due to the absence of a peak in plasma motilin levels, could represent a counter regulatory mechanism to decrease hunger in obese patients.

Clearance approach in hyperinsulinemic–euglycemic clamp evaluation in lean and obese subjects

Purpose/Aim: The main aim of this study was to propose a method to express whole body insulin sensitivity as estimated by a hyperinsulinemic–euglycemic clamp (HEC) as a dimensionless parameter. Materials and methods: Two groups of subjects were examined: The first group was comprised of seven healthy lean volunteers with BMI <25 kg/m2 and a second group comprised of four obese subjects with BMI ≥30 kg/m2. The dependence between the M/I index expressing the whole body insulin sensitivity, and the dimensionless whole human body effect E as a ratio of the clearance of glucose and the clearance of insulin after their exogenous administration during the last 40 min of the HEC test, was expressed by regression analysis. Unlike an expression of insulin sensitivity/resistance as a function of M taking into account the space corrections or the M/I index, our whole human body effect represents the insulin sensitivity/resistance as a dimensionless number. Results: A linear dependence between the M/I index and the dimensionless effect E with zero intercept and slope at 2.2623 ± 0.157, r = 0.914, and between the M/I index and the effect E recalculated per kg of human body weight with zero intercept and slope at 0.03164 ± 0.00127, r = 0.978, were observed. Conclusions: The high correlation between the M/I index and new effect E in lean and obese volunteers confirms our proposal that the HEC test could be evaluated by a dimensionless parameter which eliminates potential unit mismatches in the expression of clamp results.

Influence of acute hyperlipidemia to adipocyte-derived hormones in lean normotensive and subjects with metabolic syndrome.

BackgroundAdipocyte-derived factors and regulators likely contribute to the metabolic syndrome (MetS) in patients with central obesity. This study was undertaken to assess the contribution of leptin, adiponectin, and acylation stimulating protein (ASP-C3ades/ARG) to hemodynamic (blood pressure [BP]) and metabolic (insulin, glucose, lipids) features of MetS.MethodsIn this study, leptin, adiponectin, and C3ades/ARG were measured at baseline and in response to an infusion of Intralipid® and heparin in 12 lean healthy controls and 12 patients with MetS.ResultsBaseline plasma leptin (27.6 ± 6.2 vs. 10.9 ± 3.8 ng/mL, p < 0.01) and plasma C3ades/ARG (273 ± 79 vs 198 ± 57 mg/dL, p < 0.05) were higher in the MetS than control group, whereas baseline plasma adiponectin was higher in the control than MetS group (9.9 ± 1.9 vs. 5.4 ± 0.6 g/mL). Plasma leptin correlated with body mass index (BMI), systolic and diastolic BP (r = 0.53-0.77, p < 0.01). Conversely, adiponectin correlated inversely with insulin, glucose, waist circumference, and insulin sensitivity (r = 0.48-0.51, p ≤ 0.02). Plasma triglycerides increased similarly in MetS and control groups after 4-hours of Intralipid and heparin. C3ades/ARG increased only in lean volunteers. The decrease in triglycerides 1-hour post-infusion was lower in the MetS than control group (-116 ± 33 vs. -282 ± 81 mg/dL, p = 0.01) and correlated inversely with the change in C3ades/ARG.ConclusionThese data suggest that leptin is more closely associated with hemodynamic (BP) aspects of MetS, whereas adiponectin and C3ades/ARG are more closely associated with metabolic components.

Glucagon regulates orexin A secretion in humans and rodents.

Orexin A (OXA) modulates food intake, energy expenditure, and lipid and glucose metabolism. OXA regulates the secretion of insulin and glucagon, while glucose regulates OXA release. Here, we evaluate the role of glucagon in regulating OXA release both in vivo and in vitro. In a double-blind crossover study, healthy volunteers and type 1 diabetic patients received either intramuscular glucagon or placebo. Patients newly diagnosed with type 2 diabetes underwent hyperinsulinaemic-euglycaemic clamp experiments, and insulin-hypoglycaemia tests were performed on healthy volunteers. The primary endpoint was a change in OXA levels after intramuscular glucagon or placebo administration in healthy participants and patients with type 1 diabetes. Secondary endpoints included changes in OXA in healthy participants during insulin tolerance tests and in patients with type 2 diabetes under hyperinsulinaemic-euglycaemic conditions. Participants and staff conducting examinations and taking measurements were blinded to group assignment. OXA secretion in response to glucagon treatment was assessed in healthy and obese mice, the streptozotocin-induced mouse model of type 1 diabetes, and isolated rat pancreatic islets. Plasma OXA levels declined in lean volunteers and in type 1 diabetic patients injected with glucagon. OXA levels increased during hyperinsulinaemic hypoglycaemia testing in healthy volunteers and during hyperinsulinaemic euglycaemic conditions in type 2 diabetic patients. Plasma OXA concentrations in healthy lean and obese mice and in a mouse model of type 1 diabetes were lower after glucagon treatment, compared with vehicle control. Glucagon decreased OXA secretion from isolated rat pancreatic islets at both low and high glucose levels. OXA secretion declined in pancreatic islets exposed to diazoxide at high and low glucose levels, and after exposure to an anti-insulin antibody. Glucagon further reduced OXA secretion in islets pretreated with diazoxide or an anti-insulin antibody. Glucagon inhibits OXA secretion in humans and animals, irrespective of changes in glucose or insulin levels. Through modifying OXA secretion, glucagon may influence energy expenditure, body weight, food intake and glucose metabolism.

New evidence for an association between liver enzymes and pancreatic islet β-cell dysfunction in young obese patients

To explore the relationship between serum liver enzymes and both the glucose tolerance status and insulin secretion in young obese patients. A total of 734 young obese patients (BMI ≥ 25 kg m(-2)) and 231 lean healthy volunteers matched in age (BMI < 23 kg m(-2)) were enrolled in this cross-sectional observational study. The 734 obese patients were subdivided to three groups (OB-NGR, OB-IGR, and OB-DM) according to their glucose tolerance status. FSIVGTT was performed to assess the degree of insulin sensitivity (SI) and islet secretion function (AIRg). The disposition index (DI; product of SI and AIRg) was calculated as an integrated measurement of insulin secretion and insulin action after compensating for insulin resistance. The extent and distribution of hepatic fat infiltration was assessed using the liver/spleen ratio (L/S ratio) with CT scan. ALT and GGT levels in OB-NGR, OB-IGR, and OB-DM groups were significantly increased compared to the normal controls, and were incrementally increased in turn in the three groups, whereas DI decreased at the same time. One standard deviation increment in ALT and GGT increased the risk of β-cell dysfunction after controlling for potential confounders such as sex, age, BMI, waist-hip ratio, and blood pressure. Even after the adjustment of the serum lipid profile and L/S ratio, the odds ratio of ALT remained statistically significant (OR, 1.603; 95 % CI, 1.225-2.096). Serum levels of liver enzymes showed an independent close relationship with insulin secretion capacity. Excluding the impact of a fatty liver, increased ALT and GGT levels indicated a significant association with the attenuation of pancreatic β-cell function. This study provides the possibility that elevated liver enzymes might be treated as simple biomarkers of early insulin secretion deficit in type 2 diabetes, especially in young obese patients.

Short-term regional meal fat storage in nonobese humans is not a predictor of long-term regional fat gain

Although body fat distribution strongly predicts metabolic health outcomes related to excess weight, little is known about the factors an individual might exhibit that predict a particular fat distribution pattern. We utilized the meal fatty acid tracer-adipose biopsy technique to assess upper and lower body subcutaneous (UBSQ and LBSQ, respectively) meal fat storage in lean volunteers who then were overfed to gain weight. Meal fatty acid storage in UBSQ and LBSQ adipose tissue, as well as daytime substrate oxidation (indirect calorimetry), was measured in 28 nonobese volunteers [n = 15 men, body mass index = 22.1 ± 2.5 (SD)] before and after an ∼8-wk period of supervised overfeeding (weight gain = 4.6 ± 2.2 kg, fat gain = 3.8 ± 1.7 kg). Meal fat storage (mg/g adipose tissue lipid) in UBSQ (visit 1: 0.78 ± 0.34 and 1.04 ± 0.71 for women and men, respectively, P = 0.22; visit 2: 0.71 ± 0.24 and 0.90 ± 0.37 for women and men, respectively, P = 0.08) and LBSQ (visit 1: 0.60 ± 0.23 and 0.48 ± 0.29 for women and men, respectively, P = 0.25; visit 2: 0.62 ± 0.24 and 0.65 ± 0.23 for women and men, respectively, P = 0.67) adipose tissue did not differ between men and women at either visit. Fractional meal fatty acid storage in UBSQ (0.31 ± 0.15) or LBSQ (0.19 ± 0.13) adipose tissue at visit 1 did not predict the percent change in regional body fat in response to overfeeding. These data indicate that meal fat uptake trafficking in the short term (24 h) is not predictive of body fat distribution patterns. In general, UBSQ adipose tissue appears to be a favored depot for meal fat deposition in both sexes, and redistribution of meal fatty acids likely takes place at later time periods.

Effect of meal timing and glycaemic index on glucose control and insulin secretion in healthy volunteers

Shiftworkers have a higher risk of CHD and type 2 diabetes. They consume a large proportion of their daily energy and carbohydrate intake in the late evening or night-time, a factor which could be linked to their increase in disease risk. We compared the metabolic effects of varying both dietary glycaemic index (GI) and the time at which most daily energy intake was consumed. We hypothesised that glucose control would be optimal with a low-GI diet, consumed predominantly early in the day. A total of six healthy lean volunteers consumed isoenergetic meals on four occasions, comprising either high- or low-GI foods, with 60 % energy consumed predominantly early (breakfast) or late (supper). Interstitial glucose was measured continuously for 20 h. Insulin, TAG and non-esterified fatty acids were measured for 2 h following every meal. Highest glucose values were observed when large 5021 kJ (1200 kcal) high-GI suppers were consumed. Glucose levels were also significantly higher in predominantly late high- v. low-GI meals (P<0·01). Using an estimate of postprandial insulin sensitivity throughout the day, we demonstrate that this follows the same trend, with insulin sensitivity being significantly worse in high energy consumed in the evening meal pattern. Both meal timing and GI affected glucose tolerance and insulin secretion. Avoidance of large, high-GI meals in the evening may be particularly beneficial in improving postprandial glucose profiles and may play a role in reducing the risk of type 2 diabetes; however, longer-term studies are needed to confirm this.

Increased Levels of Calprotectin in Obesity Are Related to Macrophage Content: Impact on Inflammation and Effect of Weight Loss

Calprotectin has been recently described as a novel marker of obesity. The aim of this study was to determine the circulating concentrations and expression levels of calprotectin subunits (S100A8 and S100A9) in visceral adipose tissue (VAT), exploring its impact on insulin resistance and inflammation and the effect of weight loss. We included 53 subjects in the study. Gene expression levels of the S100A8/A9 complex were analyzed in VAT as well as in both adipocytes and stromovascular fraction cells (SVFCs). In addition, circulating calprotectin and soluble receptor for the advanced glycation end product (sRAGE) concentrations were measured before and after weight loss achieved by Roux-en-Y gastric bypass (RYGB) (n = 26). Circulating concentrations and VAT expression of S100A8/A9 complex were increased in normoglycemic and type 2 diabetic obese patients (P < 0.01) and associated with markers of inflammation (P < 0.01). Oppositely, concentrations of sRAGE were significantly lower (P < 0.001) in both obese groups compared to lean volunteers. Elevated calprotectin levels in obese patients decreased (P < 0.00001) after RYGB, whereas sRAGE concentrations tended to increase. Calprotectin was mainly expressed by SVFCs, and its expression was significantly correlated (P < 0.01) with mRNA levels of the monocyte-macrophage-related molecules macrophage-specific antigen CD68 (CD68), monocyte chemotactic protein 1 (MCP1), integrin α-M (CD11B), and NADPH oxidase 2 (NOX2). Tumor necrosis factor-α treatment significantly enhanced (P < 0.05) the mRNA levels of S100 calcium-binding protein A8 (S100A8) of human visceral adipocytes. The increased levels of calprotectin in obesity and obesity-associated type 2 diabetes, its positive association with inflammation as well as the higher expression levels in the SVFCs in VAT suggests a potential role of this protein as a chemotactic factor in the recruitment of macrophages to VAT, increasing inflammation and the development of obesity-associated comorbidities.