Science.gov

Sample records for abnormal glucose homeostasis

  1. Alternative indices of glucose homeostasis as biochemical diagnostic tests for abnormal glucose tolerance in an African setting.

    PubMed

    Kengne, Andre Pascal; Erasmus, Rajiv T; Levitt, Naomi S; Matsha, Tandi E

    2017-04-01

    Accurate diabetes diagnosis is important in Africa, where rates are increasing, and the disease largely undiagnosed. The cumbersome oral glucose tolerance test (OGTT) remains the reference standard, while alternative diagnostic methods are not yet established in Africans. We assessed the ability of fasting plasma glucose (FPG), HbA1c and fructosamine, to diagnose OGTT-based abnormal glucose tolerance in mixed-ancestry South Africans. Mixed-ancestry adults, residing in Cape Town were examined between February and November 2015. OGTT values were used to classify glucose tolerance status as: screen-detected diabetes, prediabetes, dysglycaemia (combination of diabetes and prediabetes) and normal glucose tolerance. Of the 793 participants included, 65 (8.2%) had screen-detected diabetes, 157 (19.8%) prediabetes and 571 (72.0%) normal glucose tolerance. Correlations of FPG and 2-h glucose with HbA1c (r=0.51 and 0.52) were higher than those with fructosamine (0.34 and 0.30), both p<0.0001. The highest c-statistic for the prediction of abnormal glucose tolerance was recorded with 2-h glucose [c-statistic=0.997 (screen-detected diabetes), 0.979 (prediabetes) and 0.984 (dysglycaemia)] and the lowest with fructosamine (0.865, 0.596 and 0.677). At recommended or data-specific optimal cut-offs, no combination of FPG, HbA1c and fructosamine did better than 2-h glucose, while FPG was better than HbA1c and fructosamine on a range of performance measures. Abnormal glucose tolerance in this population is overwhelmingly expressed through 2-h glucose's abnormalities; and no combination of FPG, HbA1c and fructosamine was effective at accurately discriminating OGTT-defined abnormal glucose tolerance. Tested non-glucose based strategies are unreliable alternatives to OGTT for dysglycaemia diagnosis in this population. Copyright © 2017 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

  2. High prevalence of abnormal glucose homeostasis secondary to decreased insulin secretion in individuals with hereditary haemochromatosis.

    PubMed

    McClain, D A; Abraham, D; Rogers, J; Brady, R; Gault, P; Ajioka, R; Kushner, J P

    2006-07-01

    The prevalence and mechanisms of diabetes in hereditary haemochromatosis are not known. We therefore measured glucose tolerance, insulin secretory capacity and insulin sensitivity in adults with haemochromatosis. Subjects recruited from referrals to a haemochromatosis clinic underwent OGTT and frequently sampled IVGTT. A chart review of former clinic patients was also performed. The prevalence of diabetes (23%) and IGT (30%) was increased in haemochromatosis compared with matched control subjects (0% diabetes and 14% IGT). Subjects with haemochromatosis and diabetes were overweight (14%) or obese (86%). The prevalence of diabetes, as determined by chart review of fasting glucose values, in subjects who had haemochromatosis and were in the 40-79 years age range was 26%. Overall, patients with haemochromatosis and control subjects had similar values for acute insulin response to glucose and insulin sensitivity. However, patients with haemochromatosis and IGT had a 68% decrease in acute insulin response to glucose (p<0.02) compared with those with NGT. They were not insulin-resistant, exhibiting instead a 62% increase in insulin sensitivity (NS). Haemochromatosis subjects with diabetes exhibited further declines in acute insulin response to glucose, insulin resistance, or both. Diabetes and IGT are common in haemochromatosis, justifying screening for diabetes and therapeutic phlebotomy. The major abnormality associated with IGT is decreased insulin secretory capacity. Diabetes is usually associated with obesity and concomitant insulin resistance.

  3. The effects of abnormalities of glucose homeostasis on the expression and binding of muscarinic receptors in cerebral cortex of rats.

    PubMed

    Sherin, Antony; Peeyush, Kumar T; Naijil, George; Nandhu, Mohan Sobhana; Jayanarayanan, Sadanandan; Jes, Paul; Paulose, Cheramadathikudiyil Skaria

    2011-01-25

    Glucose homeostasis in humans is an important factor for the functioning of nervous system. Both hypo and hyperglycemia contributes to neuronal functional deficit. In the present study, effect of insulin induced hypoglycemia and streptozotocin induced diabetes on muscarinic receptor binding, cholinergic enzymes; AChE, ChAT expression and GLUT3 in the cerebral cortex of experimental rats were analysed. Total muscarinic, muscarinic M(1) receptor showed a significant decrease and muscarinic M(3) receptor subtype showed a significant increased binding in the cerebral cortex of hypoglycemic rats compared to diabetic and control. Real-Time PCR analysis of muscarinic M(1), M(3) receptor subtypes confirmed the receptor binding studies. Immunohistochemistry of muscarinic M(1), M(3) receptors using specific antibodies were also carried out. AChE and GLUT3 expression up regulated and ChAT expression down regulated in hypoglycemic rats compared to diabetic and control rats. Our results showed that hypo/hyperglycemia caused impaired glucose transport in neuronal cells as shown by altered expression of GLUT3. Increased AChE and decreased ChAT expression is suggested to alter cortical acetylcholine metabolism in experimental rats along with altered muscarinic receptor binding in hypo/hyperglycemic rats, impair cholinergic transmission, which subsequently lead to cholinergic dysfunction thereby causing learning and memory deficits. We observed a prominent cholinergic functional disturbance in hypoglycemic condition than in hyperglycemia. Hypoglycemia exacerbated the neurochemical changes in cerebral cortex induced by hyperglycemia. These findings have implications for both therapy and identification of causes contributing to neuronal dysfunction in diabetes. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Anchored phosphatases modulate glucose homeostasis

    PubMed Central

    Hinke, Simon A; Navedo, Manuel F; Ulman, Allison; Whiting, Jennifer L; Nygren, Patrick J; Tian, Geng; Jimenez-Caliani, Antonio J; Langeberg, Lorene K; Cirulli, Vincenzo; Tengholm, Anders; Dell'Acqua, Mark L; Santana, L Fernando; Scott, John D

    2012-01-01

    Endocrine release of insulin principally controls glucose homeostasis. Nutrient-induced exocytosis of insulin granules from pancreatic β-cells involves ion channels and mobilization of Ca2+ and cyclic AMP (cAMP) signalling pathways. Whole-animal physiology, islet studies and live-β-cell imaging approaches reveal that ablation of the kinase/phosphatase anchoring protein AKAP150 impairs insulin secretion in mice. Loss of AKAP150 impacts L-type Ca2+ currents, and attenuates cytoplasmic accumulation of Ca2+ and cAMP in β-cells. Yet surprisingly AKAP150 null animals display improved glucose handling and heightened insulin sensitivity in skeletal muscle. More refined analyses of AKAP150 knock-in mice unable to anchor protein kinase A or protein phosphatase 2B uncover an unexpected observation that tethering of phosphatases to a seven-residue sequence of the anchoring protein is the predominant molecular event underlying these metabolic phenotypes. Thus anchored signalling events that facilitate insulin secretion and glucose homeostasis may be set by AKAP150 associated phosphatase activity. PMID:22940692

  5. The SH2B1 obesity locus and abnormal glucose homeostasis: lack of evidence for association from a meta-analysis in individuals of European ancestry.

    PubMed

    Prudente, S; Copetti, M; Morini, E; Mendonca, C; Andreozzi, F; Chandalia, M; Baratta, R; Pellegrini, F; Mercuri, L; Bailetti, D; Abate, N; Frittitta, L; Sesti, G; Florez, J C; Doria, A; Trischitta, V

    2013-11-01

    The development of type 2 diabetes (T2D) is influenced both by environmental and by genetic determinants. Obesity is an important risk factor for T2D, mostly mediated by obesity-related insulin resistance. Obesity and insulin resistance are also modulated by the genetic milieu; thus, genes affecting risk of obesity and insulin resistance might also modulate risk of T2D. Recently, 32 loci have been associated with body mass index (BMI) by genome-wide studies, including one locus on chromosome 16p11 containing the SH2B1 gene. Animal studies have suggested that SH2B1 is a physiological enhancer of the insulin receptor and humans with rare deletions or mutations at SH2B1 are obese with a disproportionately high insulin resistance. Thus, the role of SH2B1 in both obesity and insulin resistance makes it a strong candidate for T2D. However, published data on the role of SH2B1 variability on the risk for T2D are conflicting, ranging from no effect at all to a robust association. The SH2B1 tag SNP rs4788102 (SNP, single nucleotide polymorphism) was genotyped in 6978 individuals from six studies for abnormal glucose homeostasis (AGH), including impaired fasting glucose, impaired glucose tolerance or T2D, from the GENetics of Type 2 Diabetes in Italy and the United States (GENIUS T2D) consortium. Data from these studies were then meta-analyzed, in a Bayesian fashion, with those from DIAGRAM+ (n = 47,117) and four other published studies (n = 39,448). Variability at the SH2B1 obesity locus was not associated with AGH either in the GENIUS consortium (overall odds ratio (OR) = 0.96; 0.89-1.04) or in the meta-analysis (OR = 1.01; 0.98-1.05). Our data exclude a role for the SH2B1 obesity locus in the modulation of AGH. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Pancreatic regulation of glucose homeostasis

    PubMed Central

    Röder, Pia V; Wu, Bingbing; Liu, Yixian; Han, Weiping

    2016-01-01

    In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed. PMID:26964835

  7. Brain glucose sensing, counterregulation, and energy homeostasis.

    PubMed

    Marty, Nell; Dallaporta, Michel; Thorens, Bernard

    2007-08-01

    Neuronal circuits in the central nervous system play a critical role in orchestrating the control of glucose and energy homeostasis. Glucose, beside being a nutrient, is also a signal detected by several glucose-sensing units that are located at different anatomical sites and converge to the hypothalamus to cooperate with leptin and insulin in controlling the melanocortin pathway.

  8. Atypical antipsychotics and glucose homeostasis.

    PubMed

    Bergman, Richard N; Ader, Marilyn

    2005-04-01

    Persistent reports have linked atypical antipsychotics with diabetes, yet causative mechanisms responsible for this linkage are unclear. Goals of this review are to outline the pathogenesis of nonimmune diabetes and to survey the available literature related to why antipsychotics may lead to this disease. We accessed the literature regarding atypical antipsychotics and glucose homeostasis using PubMed. The search included English-language publications from 1990 through October 2004. Keywords used included atypical antipsychotics plus one of the following: glucose, insulin, glucose tolerance, obesity, or diabetes. In addition, we culled information from published abstracts from several national and international scientific meetings for the years 2001 through 2004, including the American Diabetes Association, the International Congress on Schizophrenia Research, and the American College of Neuropsychopharmacology. The latter search was necessary because of the paucity of well-controlled prospective studies. We examined publications with significant new data or publications that contributed to the overall comprehension of the impact of atypical antipsychotics on glucose metabolism. We favored original peer-reviewed articles and were less likely to cite single case studies and/or anecdotal information. Approximately 75% of the fewer than 150 identified articles were examined and included in this review. Validity of data was evaluated using the existence of peer-review status as well as our own experience with methodology described in the specific articles. The metabolic profile caused by atypical antipsychotic treatment resembles type 2 diabetes. These agents cause weight gain in treated subjects and may induce obesity in both visceral and subcutaneous depots, as occurs in diabetes. Insulin resistance, usually associated with obesity, occurs to varying degrees with different antipsychotics, although more comparative studies with direct assessment of resistance are

  9. Hypothalamic neurones governing glucose homeostasis.

    PubMed

    Coppari, R

    2015-06-01

    The notion that the brain directly controls the level of glucose in the blood (glycaemia) independent of its known action on food intake and body weight has been known ever since 1849. That year, the French physiologist Dr Claude Bernard reported that physical puncture of the floor of the fourth cerebral ventricle rapidly leads to an increased level of sugar in the blood (and urine) in rabbits. Despite this important discovery, it took approximately 150 years before significant efforts aimed at understanding the underlying mechanism of brain-mediated control of glucose metabolism were made. Technological developments allowing for genetically-mediated manipulation of selected molecular pathways in a neurone-type-specific fashion unravelled the importance of specific molecules in specific neuronal populations. These neuronal pathways govern glucose metabolism in the presence and even in the absence of insulin. Also, a peculiarity of these pathways is that certain biochemically-defined neurones govern glucose metabolism in a tissue-specific fashion. © 2015 British Society for Neuroendocrinology.

  10. Impact of intermittent fasting on glucose homeostasis.

    PubMed

    Varady, Krista A

    2016-07-01

    This article provides an overview of the most recent human trials that have examined the impact of intermittent fasting on glucose homeostasis. Our literature search retrieved one human trial of alternate day fasting, and three trials of Ramadan fasting published in the past 12 months. Current evidence suggests that 8 weeks of alternate day fasting that produces mild weight loss (4% from baseline) has no effect on glucose homeostasis. As for Ramadan fasting, decreases in fasting glucose, insulin, and insulin resistance have been noted after 4 weeks in healthy normal weight individuals with mild weight loss (1-2% from baseline). However, Ramadan fasting may have little impact on glucoregulatory parameters in women with polycystic ovarian syndrome who failed to observe weight loss. Whether intermittent fasting is an effective means of regulating glucose homeostasis remains unclear because of the scarcity of studies in this area. Large-scale, longer-term randomized controlled trials will be required before the use of fasting can be recommended for the prevention and treatment of metabolic diseases.

  11. Impaired embryonic development in glucose-6-phosphate dehydrogenase-deficient Caenorhabditis elegans due to abnormal redox homeostasis induced activation of calcium-independent phospholipase and alteration of glycerophospholipid metabolism.

    PubMed

    Chen, Tzu-Ling; Yang, Hung-Chi; Hung, Cheng-Yu; Ou, Meng-Hsin; Pan, Yi-Yun; Cheng, Mei-Ling; Stern, Arnold; Lo, Szecheng J; Chiu, Daniel Tsun-Yee

    2017-01-12

    Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a commonly pervasive inherited disease in many parts of the world. The complete lack of G6PD activity in a mouse model causes embryonic lethality. The G6PD-deficient Caenorhabditis elegans model also shows embryonic death as indicated by a severe hatching defect. Although increased oxidative stress has been implicated in both cases as the underlying cause, the exact mechanism has not been clearly delineated. In this study with C. elegans, membrane-associated defects, including enhanced permeability, defective polarity and cytokinesis, were found in G6PD-deficient embryos. The membrane-associated abnormalities were accompanied by impaired eggshell structure as evidenced by a transmission electron microscopic study. Such loss of membrane structural integrity was associated with abnormal lipid composition as lipidomic analysis revealed that lysoglycerophospholipids were significantly increased in G6PD-deficient embryos. Abnormal glycerophospholipid metabolism leading to defective embryonic development could be attributed to the increased activity of calcium-independent phospholipase A 2 (iPLA) in G6PD-deficient embryos. This notion is further supported by the fact that the suppression of multiple iPLAs by genetic manipulation partially rescued the embryonic defects in G6PD-deficient embryos. In addition, G6PD deficiency induced disruption of redox balance as manifested by diminished NADPH and elevated lipid peroxidation in embryos. Taken together, disrupted lipid metabolism due to abnormal redox homeostasis is a major factor contributing to abnormal embryonic development in G6PD-deficient C. elegans.

  12. Regulation of Glucose Homeostasis by GLP-1

    PubMed Central

    Nadkarni, Prashant; Chepurny, Oleg G.; Holz, George G.

    2014-01-01

    Glucagon-like peptide-1(7–36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeo-stasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics. PMID:24373234

  13. [Glucose homeostasis and gut-brain connection].

    PubMed

    De Vadder, Filipe; Mithieux, Gilles

    2015-02-01

    Since the XIX(th) century, the brain has been known for its role in regulating food intake (via the control of hunger sensation) and glucose homeostasis. Further interest has come from the discovery of gut hormones, which established a clear link between the gut and the brain in regulating glucose and energy homeostasis. The brain has two particular structures, the hypothalamus and the brainstem, which are sensitive to information coming either from peripheral organs or from the gut (via circulating hormones or nutrients) about the nutritional status of the organism. However, the efforts for a better understanding of these mechanisms have allowed to unveil a new gut-brain neural axis as a key regulator of the metabolic status of the organism. Certain nutrients control the hypothalamic homeostatic function via this axis. In this review, we describe how the gut is connected to the brain via different neural pathways, and how the interplay between these two organs drives the energy balance. © 2015 médecine/sciences – Inserm.

  14. Monogenic syndromes of abnormal glucose homeostasis: clinical review and relevance to the understanding of the pathology of insulin resistance and ß cell failure

    PubMed Central

    Porter, J; Barrett, T

    2005-01-01

    Type 2 diabetes mellitus is caused by a combination of insulin resistance and ß cell failure. The polygenic nature of type 2 diabetes has made it difficult to study. Although many candidate genes for this condition have been suggested, in most cases association studies have been equivocal. Monogenic forms of diabetes have now been studied extensively, and the genetic basis of many of these syndromes has been elucidated, leading to greater understanding of the functions of the genes involved. Common variations in the genes causing monogenic disorders have been associated with susceptibility to type 2 diabetes in several populations and explain some of the linkage seen in genome-wide scans. Monogenic disorders are also helpful in understanding both normal and disordered glucose and insulin metabolism. Three main areas of defect contribute to diabetes: defects in insulin signalling leading to insulin resistance; defects of insulin secretion leading to hypoinsulinaemia; and apoptosis leading to decreased ß cell mass. These three pathological pathways are reviewed, focusing on rare genetic syndromes which have diabetes as a prominent feature. Apoptosis seems to be a final common pathway in both type 1 and type 2 diabetes. Study of rare forms of diabetes may help ion determining new therapeutic targets to preserve or increase ß cell mass and function. PMID:15772126

  15. Genetically determined schizophrenia is not associated with impaired glucose homeostasis.

    PubMed

    Polimanti, Renato; Gelernter, Joel; Stein, Dan J

    2018-05-01

    Here, we used data from large genome-wide association studies to test the presence of causal relationships, conducting a Mendelian randomization analysis; and shared molecular mechanisms, calculating the genetic correlation, among schizophrenia, type 2 diabetes (T2D), and impaired glucose homeostasis. Although our Mendelian randomization analysis was well-powered, no causal relationship was observed between schizophrenia and T2D, or traits related to glucose impaired homeostasis. Similarly, we did not observe any global genetic overlap among these traits. These findings indicate that there is no causal relationships or shared mechanisms between schizophrenia and impaired glucose homeostasis. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Energy Homeostasis and Abnormal RNA Metabolism in Amyotrophic Lateral Sclerosis

    PubMed Central

    Liu, Yu-Ju; Tsai, Po-Yi; Chern, Yijuang

    2017-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease that is clinically characterized by progressive muscle weakness and impaired voluntary movement due to the loss of motor neurons in the brain, brain stem and spinal cord. To date, no effective treatment is available. Ample evidence suggests that impaired RNA homeostasis and abnormal energy status are two major pathogenesis pathways in ALS. In the present review article, we focus on recent studies that report molecular insights of both pathways, and discuss the possibility that energy dysfunction might negatively regulate RNA homeostasis via the impairment of cytoplasmic-nuclear shuttling in motor neurons and subsequently contribute to the development of ALS. PMID:28522961

  17. Preoperative octreotide therapy and surgery in acromegaly: associations between glucose homeostasis and treatment response.

    PubMed

    Helseth, R; Carlsen, S M; Bollerslev, J; Svartberg, J; Øksnes, M; Skeie, S; Fougner, S L

    2016-02-01

    In acromegaly, high GH/IGF-1 levels associate with abnormal glucose metabolism. Somatostatin analogs (SSAs) reduce GH and IGF-1 but inhibit insulin secretion. We studied glucose homeostasis in de novo patients with acromegaly and changes in glucose metabolism after treatment with SSA and surgery. In this post hoc analysis from a randomized controlled trial, 55 de novo patients with acromegaly, not using antidiabetic medication, were included. Before surgery, 26 patients received SSAs for 6 months. HbA1c, fasting glucose, and oral glucose tolerance test were performed at baseline, after SSA pretreatment and at 3 months postoperative. Area under curve of glucose (AUC-G) was calculated. Glucose homeostasis was compared to baseline levels of GH and IGF-1, change after SSA pretreatment, and remission both after SSA pretreatment and 3 months postoperative. In de novo patients, IGF-1/GH levels did not associate with baseline glucose parameters. After SSA pretreatment, changes in GH/IGF-1 correlated positively to change in HbA1c levels (both p < 0.03). HbA1c, fasting glucose, and AUC-G increased significantly during SSA pretreatment in patients not achieving hormonal control (all p < 0.05) but did not change significantly in patients with normalized hormone levels. At 3 months postoperative, HbA1c, fasting glucose, and AUC-G were significantly reduced in both cured and not cured patients (all p < 0.05). To conclude, in de novo patients with acromegaly, disease activity did not correlate with glucose homeostasis. Surgical treatment of acromegaly improved glucose metabolism in both cured and not cured patients, while SSA pretreatment led to deterioration in glucose homeostasis in patients not achieving biochemical control.

  18. Association of SSTR2 Polymorphisms and Glucose Homeostasis Phenotypes

    PubMed Central

    Sutton, Beth S.; Palmer, Nicholette D.; Langefeld, Carl D.; Xue, Bingzhong; Proctor, Alexandria; Ziegler, Julie T.; Haffner, Steven M.; Norris, Jill M.; Bowden, Donald W.

    2009-01-01

    OBJECTIVE This study evaluated the influence of somatostatin receptor type 2 (SSTR2) polymorphisms on measures of glucose homeostasis in the Insulin Resistance Atherosclerosis Family Study (IRASFS). SSTR2 is a G-protein–coupled receptor that, in response to somatostatin, mediates inhibition of insulin, glucagon, and growth hormone release and thus may affect glucose homeostasis. RESEARCH DESIGN AND METHODS Ten single nucleotide polymorphisms (SNPs) spanning the gene were chosen using a SNP density selection algorithm and genotyped on 1,425 Hispanic-American individuals from 90 families in the IRASFS. These families comprised two samples (set 1 and set 2), which were analyzed individually and as a combined set. Single SNP tests of association were performed for four glucose homeostasis measures—insulin sensitivity (SI), acute insulin response (AIR), disposition index (DI), and fasting blood glucose (FBG)—using generalized estimating equations. RESULTS The SSTR2 locus was encompassed by a single linkage disequilibrium (LD) block (D′ = 0.91–1.00; r2 = 0.09–0.97) that contained four of the ten SNPs evaluated. Within the SSTR2-containing LD block, evidence of association was observed in each of the two sets and in a combined analysis with decreased SI(βhomozygous = −0.16; Pmeta-analysis = 0.0024–0.0030), decreased DI (βhomozygous = −0.35 to −5.16; Pmeta-analysis = 0.0075–0.027), and increased FBG (βhomozygous = 2.30; Pmeta-analysis = 0.045). SNPs outside the SSTR2-containing LD block were not associated with measures of glucose homeostasis. CONCLUSIONS We observed evidence for association of SSTR2 polymorphisms with measures of glucose homeostasis. Thus, variants in SSTR2 may influence pathways of SIto modulate glucose homeostasis. PMID:19324939

  19. Cooperation between brain and islet in glucose homeostasis and diabetes

    PubMed Central

    Schwartz, Michael W.; Seeley, Randy J.; Tschöp, Matthias H.; Woods, Stephen C.; Morton, Gregory J.; Myers, Martin G.; D'Alessio, David

    2014-01-01

    Although a prominent role for the brain in glucose homeostasis was proposed by scientists in the nineteenth century, research throughout most of the twentieth century focused on evidence that the function of pancreatic islets is both necessary and sufficient to explain glucose homeostasis, and that diabetes results from defects of insulin secretion, action or both. However, insulin-independent mechanisms, referred to as ‘glucose effectiveness’, account for roughly 50% of overall glucose disposal, and reduced glucose effectiveness also contributes importantly to diabetes pathogenesis. Although mechanisms underlying glucose effectiveness are poorly understood, growing evidence suggests that the brain can dynamically regulate this process in ways that improve or even normalize glycaemia in rodent models of diabetes. Here we present evidence of a brain-centred glucoregulatory system (BCGS) that can lower blood glucose levels via both insulin-dependent and -independent mechanisms, and propose a model in which complex and highly coordinated interactions between the BCGS and pancreatic islets promote normal glucose homeostasis. Because activation of either regulatory system can compensate for failure of the other, defects in both may be required for diabetes to develop. Consequently, therapies that target the BCGS in addition to conventional approaches based on enhancing insulin effects may have the potential to induce diabetes remission, whereas targeting just one typically does not. PMID:24201279

  20. Dietary fructose and glucose differentially affect lipid and glucose homeostasis.

    PubMed

    Schaefer, Ernst J; Gleason, Joi A; Dansinger, Michael L

    2009-06-01

    Absorbed glucose and fructose differ in that glucose largely escapes first-pass removal by the liver, whereas fructose does not, resulting in different metabolic effects of these 2 monosaccharides. In short-term controlled feeding studies, dietary fructose significantly increases postprandial triglyceride (TG) levels and has little effect on serum glucose concentrations, whereas dietary glucose has the opposite effects. When dietary glucose and fructose have been directly compared at approximately 20-25% of energy over a 4- to 6-wk period, dietary fructose caused significant increases in fasting TG and LDL cholesterol concentrations, whereas dietary glucose did not, but dietary glucose did increase serum glucose and insulin concentrations in the postprandial state whereas dietary fructose did not. When fructose at 30-60 g ( approximately 4-12% of energy) was added to the diet in the free-living state, there were no significant effects on lipid or glucose biomarkers. Sucrose and high-fructose corn syrup (HFCS) contain approximately equal amounts of fructose and glucose and no metabolic differences between them have been noted. Controlled feeding studies at more physiologic dietary intakes of fructose and glucose need to be conducted. In our view, to decrease the current high prevalence of obesity, dyslipidemia, insulin resistance, and diabetes, the focus should be on restricting the intake of excess energy, sucrose, HFCS, and animal and trans fats and increasing exercise and the intake of vegetables, vegetable oils, fish, fruit, whole grains, and fiber.

  1. Glucocorticoid receptor polymorphism in obesity and glucose homeostasis.

    PubMed

    Majer-Łobodzińska, Agnieszka; Adamiec-Mroczek, Joanna

    2017-01-01

    Glucocorticoid receptor (GR) activity plays a significant role in the etiology of obesity and is essential for glucose homeostasis, the development of hyperinsulinaemia and subsequent increased fat deposition. Several polymorphisms in the GR gene have been described, and at least three of them seem to be associated with altered glucocorticoid sensitivity and changes in glucose homeostasis, and other metabolic parameters. The N363S polymorphism has been associated with increased sensitivity to glucocorticoides, increased insulin response to dexamethasone and increased plasma glucose level. BclI polymorphism is associated with increased abdominal obesity, hyperinsulinaemia and increased insulin resistance. Another polymorphism, ER22/23EK, in contrast to the others, is associated with relative resistance to glucocoricides actions and more beneficial metabolic profile-lower insulin resistance level, decreased lower cardiovascular risk and subseuent prolongation of life time. More research is still needed to understand the mechanisms behind these associations at the molecular level.

  2. CNS-targets in control of energy and glucose homeostasis.

    PubMed

    Kleinridders, André; Könner, A Christine; Brüning, Jens C

    2009-12-01

    The exceeding efforts in understanding the signals initiated by nutrients and hormones in the central nervous system (CNS) to regulate glucose and energy homeostasis have largely revolutionized our understanding of the neurocircuitry in control of peripheral metabolism. The ability of neurons to sense nutrients and hormones and to adopt a coordinated response to these signals is of crucial importance in controlling food intake, energy expenditure, glucose and lipid metabolism. Anatomical lesion experiments, pharmacological inhibition of signaling pathways, and, more recently, the analysis of conditional mouse mutants with modifications of hormone and nutrient signaling in defined neuronal populations have broadened our understanding of these complex neurocircuits. This review summarizes recent findings regarding the role of the CNS in sensing and transmitting nutritional and hormonal signals to control energy and glucose homeostasis and aims to define them as potential novel drug targets for the treatment of obesity and type 2 diabetes mellitus.

  3. Upper intestinal lipids regulate energy and glucose homeostasis.

    PubMed

    Cheung, Grace W C; Kokorovic, Andrea; Lam, Tony K T

    2009-09-01

    Upon the entry of nutrients into the small intestine, nutrient sensing mechanisms are activated to allow the body to adapt appropriately to the incoming nutrients. To date, mounting evidence points to the existence of an upper intestinal lipid-induced gut-brain neuronal axis to regulate energy homeostasis. Moreover, a recent discovery has also revealed an upper intestinal lipid-induced gut-brain-liver neuronal axis involved in the regulation of glucose homeostasis. In this mini-review, we will focus on the mechanisms underlying the activation of these respective neuronal axes by upper intestinal lipids.

  4. Hypothalamic Vitamin D Improves Glucose Homeostasis and Reduces Weight.

    PubMed

    Sisley, Stephanie R; Arble, Deanna M; Chambers, Adam P; Gutierrez-Aguilar, Ruth; He, Yanlin; Xu, Yong; Gardner, David; Moore, David D; Seeley, Randy J; Sandoval, Darleen A

    2016-09-01

    Despite clear associations between vitamin D deficiency and obesity and/or type 2 diabetes, a causal relationship is not established. Vitamin D receptors (VDRs) are found within multiple tissues, including the brain. Given the importance of the brain in controlling both glucose levels and body weight, we hypothesized that activation of central VDR links vitamin D to the regulation of glucose and energy homeostasis. Indeed, we found that small doses of active vitamin D, 1α,25-dihydroxyvitamin D3 (1,25D3) (calcitriol), into the third ventricle of the brain improved glucose tolerance and markedly increased hepatic insulin sensitivity, an effect that is dependent upon VDR within the paraventricular nucleus of the hypothalamus. In addition, chronic central administration of 1,25D3 dramatically decreased body weight by lowering food intake in obese rodents. Our data indicate that 1,25D3-mediated changes in food intake occur through action within the arcuate nucleus. We found that VDR colocalized with and activated key appetite-regulating neurons in the arcuate, namely proopiomelanocortin neurons. Together, these findings define a novel pathway for vitamin D regulation of metabolism with unique and divergent roles for central nervous system VDR signaling. Specifically, our data suggest that vitamin D regulates glucose homeostasis via the paraventricular nuclei and energy homeostasis via the arcuate nuclei. © 2016 by the American Diabetes Association.

  5. Proposed mechanisms of the effects of proanthocyanidins on glucose homeostasis.

    PubMed

    Yang, Kaiyuan; Chan, Catherine B

    2017-08-01

    Proanthocyanidins are a major group of flavonoids in the human diet, known for their strong antioxidant properties. Emerging evidence from clinical studies indicates a role of proanthocyanidins in modulating glucose homeostasis, and higher proanthocyanidin intake has been associated with reduced risk of diabetes. On the other hand, recent studies report limited bioavailability of proanthocyanidins. At relatively low concentrations in the systemic circulation, proanthocyanidins may act as cell-signaling molecules to modulate glucose homeostasis. For example, they affect hepatic glucose production via adenosine monophosphate-activated protein kinase and/or insulin-signaling pathways. There is also evidence for a direct role of proanthocyanidins in modulating several pancreatic β-cell functions: prevention of oxidative stress, enhancement of insulin secretion, and promotion of β-cell survival. Therefore, greater understanding of the potentially beneficial effects of proanthocyanidins on cell-signaling pathways implicated in glucose homeostasis is needed. In addition, further investigation to address the in vivo metabolism of proanthocyanidins and the comparative effectiveness of proanthocyanidin-derived metabolites is warranted. The dosage and the experimental model should be given special attention when results from mechanistic studies using proanthocyanidins are interpreted. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Hypothalamic Vitamin D Improves Glucose Homeostasis and Reduces Weight

    PubMed Central

    Arble, Deanna M.; Chambers, Adam P.; Gutierrez-Aguilar, Ruth; He, Yanlin; Xu, Yong; Gardner, David; Moore, David D.; Seeley, Randy J.; Sandoval, Darleen A.

    2016-01-01

    Despite clear associations between vitamin D deficiency and obesity and/or type 2 diabetes, a causal relationship is not established. Vitamin D receptors (VDRs) are found within multiple tissues, including the brain. Given the importance of the brain in controlling both glucose levels and body weight, we hypothesized that activation of central VDR links vitamin D to the regulation of glucose and energy homeostasis. Indeed, we found that small doses of active vitamin D, 1α,25-dihydroxyvitamin D3 (1,25D3) (calcitriol), into the third ventricle of the brain improved glucose tolerance and markedly increased hepatic insulin sensitivity, an effect that is dependent upon VDR within the paraventricular nucleus of the hypothalamus. In addition, chronic central administration of 1,25D3 dramatically decreased body weight by lowering food intake in obese rodents. Our data indicate that 1,25D3-mediated changes in food intake occur through action within the arcuate nucleus. We found that VDR colocalized with and activated key appetite-regulating neurons in the arcuate, namely proopiomelanocortin neurons. Together, these findings define a novel pathway for vitamin D regulation of metabolism with unique and divergent roles for central nervous system VDR signaling. Specifically, our data suggest that vitamin D regulates glucose homeostasis via the paraventricular nuclei and energy homeostasis via the arcuate nuclei. PMID:27217488

  7. Gut-Brain Glucose Signaling in Energy Homeostasis.

    PubMed

    Soty, Maud; Gautier-Stein, Amandine; Rajas, Fabienne; Mithieux, Gilles

    2017-06-06

    Intestinal gluconeogenesis is a recently identified function influencing energy homeostasis. Intestinal gluconeogenesis induced by specific nutrients releases glucose, which is sensed by the nervous system surrounding the portal vein. This initiates a signal positively influencing parameters involved in glucose control and energy management controlled by the brain. This knowledge has extended our vision of the gut-brain axis, classically ascribed to gastrointestinal hormones. Our work raises several questions relating to the conditions under which intestinal gluconeogenesis proceeds and may provide its metabolic benefits. It also leads to questions on the advantage conferred by its conservation through a process of natural selection. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Intermittent Hypoxia Impairs Glucose Homeostasis in C57BL6/J Mice: Partial Improvement with Cessation of the Exposure

    PubMed Central

    Polak, Jan; Shimoda, Larissa A.; Drager, Luciano F.; Undem, Clark; McHugh, Holly; Polotsky, Vsevolod Y.; Punjabi, Naresh M.

    2013-01-01

    Objectives: Obstructive sleep apnea is associated with insulin resistance, glucose intolerance, and type 2 diabetes mellitus. Although several studies have suggested that intermittent hypoxia in obstructive sleep apnea may induce abnormalities in glucose homeostasis, it remains to be determined whether these abnormalities improve after discontinuation of the exposure. The objective of this study was to delineate the effects of intermittent hypoxia on glucose homeostasis, beta cell function, and liver glucose metabolism and to investigate whether the impairments improve after the hypoxic exposure is discontinued. Interventions: C57BL6/J mice were exposed to 14 days of intermittent hypoxia, 14 days of intermittent air, or 7 days of intermittent hypoxia followed by 7 days of intermittent air (recovery paradigm). Glucose and insulin tolerance tests were performed to estimate whole-body insulin sensitivity and calculate measures of beta cell function. Oxidative stress in pancreatic tissue and glucose output from isolated hepatocytes were also assessed. Results: Intermittent hypoxia increased fasting glucose levels and worsened glucose tolerance by 67% and 27%, respectively. Furthermore, intermittent hypoxia exposure was associated with impairments in insulin sensitivity and beta cell function, an increase in liver glycogen, higher hepatocyte glucose output, and an increase in oxidative stress in the pancreas. While fasting glucose levels and hepatic glucose output normalized after discontinuation of the hypoxic exposure, glucose intolerance, insulin resistance, and impairments in beta cell function persisted. Conclusions: Intermittent hypoxia induces insulin resistance, impairs beta cell function, enhances hepatocyte glucose output, and increases oxidative stress in the pancreas. Cessation of the hypoxic exposure does not fully reverse the observed changes in glucose metabolism. Citation: Polak J; Shimoda LA; Drager LF; Undem C; McHugh H; Polotsky VY; Punjabi NM

  9. Role of Galectin-3 in Obesity and Impaired Glucose Homeostasis

    PubMed Central

    Menini, Stefano; Iacobini, Carla; Blasetti Fantauzzi, Claudia; Pesce, Carlo M.; Pugliese, Giuseppe

    2016-01-01

    Galectin-3 is an important modulator of several biological functions. It has been implicated in numerous disease conditions, particularly in the long-term complications of diabetes because of its ability to bind the advanced glycation/lipoxidation end products that accumulate in target organs and exert their toxic effects by triggering proinflammatory and prooxidant pathways. Recent evidence suggests that galectin-3 may also participate in the development of obesity and type 2 diabetes. It has been shown that galectin-3 levels are higher in obese and diabetic individuals and parallel deterioration of glucose homeostasis. Two studies in galectin-3 knockout mice fed a high-fat diet (HFD) have shown increased adiposity and adipose tissue and systemic inflammation associated with altered glucose homeostasis, suggesting that galectin-3 negatively modulates the responsiveness of innate and adaptive immunity to overnutrition. However, these studies have also shown that impaired glucose homeostasis occurs in galectin-3 knockout animals independently of obesity. Moreover, another study reported decreased weight and fat mass in HFD-fed galectin-3 knockout mice. In vitro, galectin-3 was found to stimulate differentiation of preadipocytes into mature adipocytes. Altogether, these data indicate that galectin-3 deserves further attention in order to clarify its role as a potential player and therapeutic target in obesity and type 2 diabetes. PMID:26770660

  10. Physical activity, fitness, glucose homeostasis, and brain morphology in twins.

    PubMed

    Rottensteiner, Mirva; Leskinen, Tuija; Niskanen, Eini; Aaltonen, Sari; Mutikainen, Sara; Wikgren, Jan; Heikkilä, Kauko; Kovanen, Vuokko; Kainulainen, Heikki; Kaprio, Jaakko; Tarkka, Ina M; Kujala, Urho M

    2015-03-01

    The main aim of the present study (FITFATTWIN) was to investigate how physical activity level is associated with body composition, glucose homeostasis, and brain morphology in young adult male monozygotic twin pairs discordant for physical activity. From a population-based twin cohort, we systematically selected 10 young adult male monozygotic twin pairs (age range, 32-36 yr) discordant for leisure time physical activity during the past 3 yr. On the basis of interviews, we calculated a mean sum index for leisure time and commuting activity during the past 3 yr (3-yr LTMET index expressed as MET-hours per day). We conducted extensive measurements on body composition (including fat percentage measured by dual-energy x-ray absorptiometry), glucose homeostasis including homeostatic model assessment index and insulin sensitivity index (Matsuda index, calculated from glucose and insulin values from an oral glucose tolerance test), and whole brain magnetic resonance imaging for regional volumetric analyses. According to pairwise analysis, the active twins had lower body fat percentage (P = 0.029) and homeostatic model assessment index (P = 0.031) and higher Matsuda index (P = 0.021) compared with their inactive co-twins. Striatal and prefrontal cortex (subgyral and inferior frontal gyrus) brain gray matter volumes were larger in the nondominant hemisphere in active twins compared with those in inactive co-twins, with a statistical threshold of P < 0.001. Among healthy adult male twins in their mid-30s, a greater level of physical activity is associated with improved glucose homeostasis and modulation of striatum and prefrontal cortex gray matter volume, independent of genetic background. The findings may contribute to later reduced risk of type 2 diabetes and mobility limitations.

  11. Mathematical model of glucose-insulin homeostasis in healthy rats.

    PubMed

    Lombarte, Mercedes; Lupo, Maela; Campetelli, German; Basualdo, Marta; Rigalli, Alfredo

    2013-10-01

    According to the World Health Organization there are over 220 million people in the world with diabetes and 3.4 million people died in 2004 as a consequence of this pathology. Development of an artificial pancreas would allow to restore control of blood glucose by coupling an infusion pump to a continuous glucose sensor in the blood. The design of such a device requires the development and application of mathematical models which represent the gluco-regulatory system. Models developed by other research groups describe very well the gluco-regulatory system but have a large number of mathematical equations and require complex methodologies for the estimation of its parameters. In this work we propose a mathematical model to study the homeostasis of glucose and insulin in healthy rats. The proposed model consists of three differential equations and 8 parameters that describe the variation of: blood glucose concentration, blood insulin concentration and amount of glucose in the intestine. All parameters were obtained by setting functions to the values of glucose and insulin in blood obtained after oral glucose administration. In vivo and in silico validations were performed. Additionally, a qualitative analysis has been done to verify the aforementioned model. We have shown that this model has a single, biologically consistent equilibrium point. This model is a first step in the development of a mathematical model for the type I diabetic rat. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Physiology and role of irisin in glucose homeostasis

    PubMed Central

    Perakakis, Nikolaos; Triantafyllou, Georgios A.; Fernández-Real, José Manuel; Huh, Joo Young; Park, Kyung Hee; Seufert, Jochen; Mantzoros, Christos S.

    2018-01-01

    Irisin is a myokine that leads to increased energy expenditure by stimulating the ‘browning’ of white adipose tissue. In the first description of this hormone, increased levels of circulating irisin, which is cleaved from its precursor fibronectin type III domain-containing protein 5, were associated with improved glucose homeostasis by reducing insulin resistance. Consequently, several studies attempted to characterize the role of irisin in glucose regulation, but contradictory results have been reported, and even the existence of this hormone has been questioned. In this Review, we present the current knowledge on the physiology of irisin and its role in glucose homeostasis. We describe the mechanisms involved in the synthesis, secretion, circulation and regulation of irisin, and the controversies regarding the measurement of irisin. We also discuss the direct effects of irisin on glucose regulatory mechanisms in different organs, the indirect effects and interactions with other hormones, and the important open questions with regard to irisin in those organs. Finally, we present the results from animal interventional studies and from human clinical studies investigating the association of irisin with obesity, insulin resistance, type 2 diabetes mellitus and the metabolic syndrome. PMID:28211512

  13. Prion protein modulates glucose homeostasis by altering intracellular iron.

    PubMed

    Ashok, Ajay; Singh, Neena

    2018-04-26

    The prion protein (PrP C ), a mainly neuronal protein, is known to modulate glucose homeostasis in mouse models. We explored the underlying mechanism in mouse models and the human pancreatic β-cell line 1.1B4. We report expression of PrP C on mouse pancreatic β-cells, where it promoted uptake of iron through divalent-metal-transporters. Accordingly, pancreatic iron stores in PrP knockout mice (PrP -/- ) were significantly lower than wild type (PrP +/+ ) controls. Silencing of PrP C in 1.1B4 cells resulted in significant depletion of intracellular (IC) iron, and remarkably, upregulation of glucose transporter GLUT2 and insulin. Iron overloading, on the other hand, resulted in downregulation of GLUT2 and insulin in a PrP C -dependent manner. Similar observations were noted in the brain, liver, and neuroretina of iron overloaded PrP +/+ but not PrP -/- mice, indicating PrP C -mediated modulation of insulin and glucose homeostasis through iron. Peripheral challenge with glucose and insulin revealed blunting of the response in iron-overloaded PrP +/+ relative to PrP -/- mice, suggesting that PrP C -mediated modulation of IC iron influences both secretion and sensitivity of peripheral organs to insulin. These observations have implications for Alzheimer's disease and diabetic retinopathy, known complications of type-2-diabetes associated with brain and ocular iron-dyshomeostasis.

  14. Sleep Architecture and Glucose and Insulin Homeostasis in Obese Adolescents

    PubMed Central

    Koren, Dorit; Levitt Katz, Lorraine E.; Brar, Preneet C.; Gallagher, Paul R.; Berkowitz, Robert I.; Brooks, Lee J.

    2011-01-01

    OBJECTIVE Sleep deprivation is associated with increased risk of adult type 2 diabetes mellitus (T2DM). It is uncertain whether sleep deprivation and/or altered sleep architecture affects glycemic regulation or insulin sensitivity or secretion. We hypothesized that in obese adolescents, sleep disturbances would associate with altered glucose and insulin homeostasis. RESEARCH DESIGN AND METHODS This cross-sectional observational study of 62 obese adolescents took place at the Clinical and Translational Research Center and Sleep Laboratory in a tertiary care children’s hospital. Subjects underwent oral glucose tolerance test (OGTT), anthropometric measurements, overnight polysomnography, and frequently sampled intravenous glucose tolerance test (FSIGT). Hemoglobin A1c (HbA1c) and serial insulin and glucose levels were obtained, indices of insulin sensitivity and secretion were calculated, and sleep architecture was assessed. Correlation and regression analyses were performed to assess the association of total sleep and sleep stages with measures of insulin and glucose homeostasis, adjusted for confounding variables. RESULTS We found significant U-shaped (quadratic) associations between sleep duration and both HbA1c and serial glucose levels on OGTT and positive associations between slow-wave sleep (N3) duration and insulin secretory measures, independent of degree of obesity, pubertal stage, sex, and obstructive sleep apnea measures. CONCLUSIONS Insufficient and excessive sleep was associated with short-term and long-term hyperglycemia in our obese adolescents. Decreased N3 was associated with decreased insulin secretion. These effects may be related, with reduced insulin secretory capacity leading to hyperglycemia. We speculate that optimizing sleep may stave off the development of T2DM in obese adolescents. PMID:21933909

  15. Rapamycin impairs HPD-induced beneficial effects on glucose homeostasis

    PubMed Central

    Chang, Geng-Ruei; Chiu, Yi-Shin; Wu, Ying-Ying; Lin, Yu-Chi; Hou, Po-Hsun; Mao, Frank Chiahung

    2015-01-01

    Background and Purpose Rapamycin, which is used clinically to treat graft rejection, has also been proposed to have an effect on metabolic syndrome; however, very little information is available on its effects in lean animals/humans. The purpose of this study was to characterize further the effects of the continuous use of rapamycin on glucose homeostasis in lean C57BL6/J mice. Experimental Approach Mice were fed a high-protein diet (HPD) for 12 weeks to develop a lean model and then were treated daily with rapamycin for 5 weeks while remaining on a HPD. Metabolic parameters, endocrine profiles, glucose tolerance tests, insulin sensitivity index, the expression of the glucose transporter GLUT4 and chromium distribution were measured in vivo. Key Results Lower body weight gain as well as a decreased caloric intake, fat pads, fatty liver scores, adipocyte size and glucose tolerance test values were observed in HPD-fed mice compared with mice fed a high-fat or standard diet. Despite these beneficial effects, rapamycin-treated lean mice showed greater glucose intolerance, reduced insulin sensitivity, lower muscle GLUT4 expression and changes in chromium levels in tissues even with high insulin levels. Conclusion and Implications Our findings demonstrate that continuous rapamycin administration may lead to the development of diabetes syndrome, as it was found to induce hyperglycaemia and glucose intolerance in a lean animal model. PMID:25884889

  16. The importance of sensitive screening for abnormal glucose metabolism in patients with IgA nephropathy.

    PubMed

    Jia, Xiaoyuan; Pan, Xiaoxia; Xie, Jingyuan; Shen, Pingyan; Wang, Zhaohui; Li, Ya; Wang, Weiming; Chen, Nan

    2016-01-01

    To investigate the prevalence of abnormal glucose metabolism, insulin resistance (IR) and the related risk factors in IgA nephropathy (IgAN) patients. We analyzed oral glucose tolerance test (OGTT) and clinical data of 107 IgAN patients and 106 healthy controls. Glucose metabolism, homeostasis model assessment of insulin resistance (HOMA-IR) and the insulin sensitivity index (ISI) of both groups were evaluated. The prevalence of abnormal glucose metabolism was significantly higher in the IgAN group than in the control group (41.12% vs. 9.43%, p < 0.001), while the prevalence of IR between the two groups was not significantly different. IgAN patients have significantly higher fasting blood glucose, fasting insulin, OGTT 2-hour blood glucose, OGTT 2-hour insulin, HOMA-IR, and lower ISI than healthy controls. Triglyceride (OR = 2.55), 24-hour urine protein excretion (OR = 1.39), and age (OR = 1.06) were independent risk factors for abnormal glucose metabolism in IgAN patients. BMI, eGFR, 24-hour urine protein excretion, triglyceride, fasting blood glucose, fasting insulin, OGTT 2-hour blood glucose, and OGTT 2-hour insulin were significantly higher in IgAN patients with IR than in IgAN patients without IR, while HDL and ISI were significantly lower. BMI, serum albumin, and 24-hour urine protein excretion were correlated factors of IR in IgAN patients. Our study highlighted that abnormal glucose metabolism was common in IgAN patients. Triglyceride and 24-hour urine protein excretion were significant risk factors for abnormal glucose metabolism. Therefore, sensitive screening for glucose metabolism status and timely intervention should be carried out in clinical work.

  17. Central insulin action in energy and glucose homeostasis.

    PubMed

    Plum, Leona; Belgardt, Bengt F; Brüning, Jens C

    2006-07-01

    Insulin has pleiotropic biological effects in virtually all tissues. However, the relevance of insulin signaling in peripheral tissues has been studied far more extensively than its role in the brain. An evolving body of evidence indicates that in the brain, insulin is involved in multiple regulatory mechanisms including neuronal survival, learning, and memory, as well as in regulation of energy homeostasis and reproductive endocrinology. Here we review insulin's role as a central homeostatic signal with regard to energy and glucose homeostasis and discuss the mechanisms by which insulin communicates information about the body's energy status to the brain. Particular emphasis is placed on the controversial current debate about the similarities and differences between hypothalamic insulin and leptin signaling at the molecular level.

  18. Effects of Taurine Supplementation on Neuronal Excitability and Glucose Homeostasis.

    PubMed

    El Idrissi, Abdeslem; El Hilali, Fatiha; Rotondo, Salvatore; Sidime, Francoise

    2017-01-01

    In this study we examined the role of chronic taurine supplementation on plasma glucose homeostasis and brain excitability through activation of the insulin receptor. FVB/NJ male mice were supplemented with taurine in drinking water (0.05% w/v) for 4 weeks and subjected to a glucose tolerance test (7.5 mg/kg BW) after 12 h fasting. We found that taurine-fed mice were slightly hypoglycemic prior to glucose injection and showed significantly reduced plasma glucose at 30 and 60 min post-glucose injection when compared to control mice. Previously, we reported that taurine supplementation induces biochemical changes that target the GABAergic system. Those studies show that taurine-fed mice are hyperexcitable, have reduced GABA A receptors expression and increased GAD and somatostatin expression in the brain. In this study, we found that taurine-fed mice had a significant increase in insulin receptor (IR) immuno-reactivity in the pancreas and all brain regions examined. At the mRNA level, we found that the IR showed differential regional expression. Surprisingly, we found that neurons express the gene for insulin and that taurine had a significant role in regulating insulin gene expression. We propose that increased insulin production and secretion in taurine-fed mice cause an increase activation of the central IR and may be partially responsible for the increased neuronal excitability observed in taurine supplemented mice. Furthermore, the high levels of neuronal insulin expression and its regulation by taurine implicates taurine in the regulation of metabolic homeostasis.

  19. Glucose Homeostasis and Effect of Chelation on β Cell Function in Children With β-Thalassemia Major.

    PubMed

    Gomber, Sunil; Dabas, Aashima; Bagmar, Shilpa; Madhu, Sri Venkata

    2018-01-01

    To assess the prevalence of impaired glucose tolerance in β-thalassemia major and correlate it with chelation therapy. Sixty-seven subjects with β-thalassemia major, aged 1 to 20 years, were enrolled in our prospective cohort. Clinical details were recorded. Baseline oral glucose tolerance test, serum insulin, C peptide, and insulin resistance were measured. The biochemical profile was repeated after 6 months. The mean age of subjects was 7.43±4.48 years. Eight (11.9%) subjects had impaired fasting glucose, 7 (10.4%) had impaired glucose tolerance, and 1 (1.4%) subject had diabetes at baseline. Subjects with abnormal glucose profile had longer disease duration (95% confidence interval [CI] of difference=-6.64 to -0.68; P=0.019) and higher fasting blood glucose (95% CI of difference=-32.1 to -10.5; P=0.001) and serum ferritin (95% CI of difference=-219.8 to -3.4; P=0.001) than normoglycemic subjects. Insulin resistance and serum ferritin showed significant increase at 6 months (P<0.001 and P=0.001, respectively). Patients on deferiprone alone significantly improved glucose homeostasis on follow-up than those on desferrioxamine or combination therapy of desferrioxamine and deferiprone (P<0.05). Prolonged disease duration and higher serum ferritin adversely affects glucose homeostasis in thalassemic children. Deferiprone was the most effective chelator to improve glucose homeostasis in chronically transfused thalassemics.

  20. The Role of Pancreatic Preproglucagon in Glucose Homeostasis in Mice.

    PubMed

    Chambers, Adam P; Sorrell, Joyce E; Haller, April; Roelofs, Karen; Hutch, Chelsea R; Kim, Ki-Suk; Gutierrez-Aguilar, Ruth; Li, Bailing; Drucker, Daniel J; D'Alessio, David A; Seeley, Randy J; Sandoval, Darleen A

    2017-04-04

    Glucagon-like peptide 1 (GLP-1) is necessary for normal gluco-regulation, and it has been widely presumed that this function reflects the actions of GLP-1 released from enteroendocrine L cells. To test the relative importance of intestinal versus pancreatic sources of GLP-1 for physiological regulation of glucose, we administered a GLP-1R antagonist, exendin-[9-39] (Ex9), to mice with tissue-specific reactivation of the preproglucagon gene (Gcg). Ex9 impaired glucose tolerance in wild-type mice but had no impact on Gcg-null or GLP-1R KO mice, suggesting that Ex9 is a true and specific GLP-1R antagonist. Unexpectedly, Ex-9 had no effect on blood glucose in mice with restoration of intestinal Gcg. In contrast, pancreatic reactivation of Gcg fully restored the effect of Ex9 to impair both oral and i.p. glucose tolerance. These findings suggest an alternative model whereby islet GLP-1 also plays an important role in regulating glucose homeostasis. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Calcium homeostasis during oral glucose load in healthy women.

    PubMed

    D'Erasmo, E; Pisani, D; Ragno, A; Raejntroph, N; Vecci, E; Acca, M

    1999-04-01

    It has been demonstrated that in healthy subjects during oral glucose tolerance test, serum calcium declines, while urinary calcium excretion increases, even if there is not a general agreement in this regard. The study was carried out in order to evaluate the effects of glucose oral load on calcium homeostasis in eight healthy adult women, also considering ionized calcium, plasma insulin and parathyroid hormone changes. The results showed a decline of total and ionized serum calcium (p < 0.05 and p < 0.01, respectively; maximum of the decrease at time 120'), in parallel with the increase of urinary calcium/ creatinine ratio (p < 0.05). Serum glucose and insulin increase (p < 0.0001 and p < 0.0005 respectively; maximum value at time 60'), while the parathyroid hormone level decreases (maximum decline at time 120', p < 0.01). No changes were observed in fasting control subjects for all parameters considered. The changes of these parameters with time suggest that the effects of glucose oral load on calcium metabolism in healthy adult women may be the consequence of parathyroid hormone suppression induced by acute hyperglycemia/hyperinsulinemia. The results confirm in vivo the PTH behaviour in vitro, on cultured bovine parathyroid cells, with high glucose concentration.

  2. Ventromedial hypothalamic glucose sensing and glucose homeostasis vary throughout the estrous cycle

    PubMed Central

    Santiago, Ammy M.; Clegg, Deborah J.; Routh, Vanessa H.

    2016-01-01

    Objective 17β-Estradiol (17βE) regulates glucose homeostasis in part by centrally mediated mechanisms. In female rodents, the influence of the ovarian cycle on hypoglycemia counterregulation and glucose tolerance is unclear. We found previously that in prepubertal females, 17βE modulates glucose sensing in nonadapting glucose-inhibited (GI) and adapting GI (AdGI) neurons within the ventrolateral portion of the ventromedial nucleus (VL-VMN). Nonadapting GI neurons persistently decrease their activity as glucose increases while AdGI neurons transiently respond to a glucose increase. To begin to understand if endogenous fluctuations in estrogen levels across the estrous cycle impact hypothalamic glucose sensing and glucose homeostasis, we assessed whether hypoglycemia counterregulation and glucose tolerance differed across the phases of the estrous cycle. We hypothesized that the response to insulin-induced hypoglycemia (IIH) and/or glucose tolerance would vary throughout the estrous cycle according to changes in 17βE availability. Moreover, that these changes would correlate with estrous-dependent changes in the glucose sensitivity of VL-VMN glucose-sensing neurons (GSNs). Methods These hypotheses were tested in female mice by measuring the response to IIH, glucose tolerance and the glucose sensitivity of VL-VMN GSNs during each phase of the estrous cycle. Furthermore, a physiological brain concentration of 17βE seen during proestrus was acutely applied to brain slices isolated on the day of diestrous and the response to low glucose in VL-VMN GSNs was assayed. Results The response to IIH was strongest during diestrous. The response of nonadapting GI and AdGI neurons to a glucose decrease from 2.5 to 0.5mM also peaked during diestrous; an effect which was blunted by the addition of 17βE. In contrast, the glucose sensitivity of the subpopulation of GSNs which are excited by glucose (GE) was not affected by estrous phase or exogenous 17βE application. Conclusion

  3. Ventromedial hypothalamic glucose sensing and glucose homeostasis vary throughout the estrous cycle.

    PubMed

    Santiago, Ammy M; Clegg, Deborah J; Routh, Vanessa H

    2016-12-01

    17β-Estradiol (17βE) regulates glucose homeostasis in part by centrally mediated mechanisms. In female rodents, the influence of the ovarian cycle on hypoglycemia counterregulation and glucose tolerance is unclear. We found previously that in prepubertal females, 17βE modulates glucose sensing in nonadapting glucose-inhibited (GI) and adapting GI (AdGI) neurons within the ventrolateral portion of the ventromedial nucleus (VL-VMN). Nonadapting GI neurons persistently decrease their activity as glucose increases while AdGI neurons transiently respond to a glucose increase. To begin to understand if endogenous fluctuations in estrogen levels across the estrous cycle impact hypothalamic glucose sensing and glucose homeostasis, we assessed whether hypoglycemia counterregulation and glucose tolerance differed across the phases of the estrous cycle. We hypothesized that the response to insulin-induced hypoglycemia (IIH) and/or glucose tolerance would vary throughout the estrous cycle according to changes in 17βE availability. Moreover, that these changes would correlate with estrous-dependent changes in the glucose sensitivity of VL-VMN glucose-sensing neurons (GSNs). These hypotheses were tested in female mice by measuring the response to IIH, glucose tolerance and the glucose sensitivity of VL-VMN GSNs during each phase of the estrous cycle. Furthermore, a physiological brain concentration of 17βE seen during proestrus was acutely applied to brain slices isolated on the day of diestrous and the response to low glucose in VL-VMN GSNs was assayed. The response to IIH was strongest during diestrous. The response of nonadapting GI and AdGI neurons to a glucose decrease from 2.5 to 0.5mM also peaked during diestrous; an effect which was blunted by the addition of 17βE. In contrast, the glucose sensitivity of the subpopulation of GSNs which are excited by glucose (GE) was not affected by estrous phase or exogenous 17βE application. These data suggest that physiological

  4. Perinatal exercise improves glucose homeostasis in adult offspring

    PubMed Central

    Carter, Lindsay G.; Lewis, Kaitlyn N.; Wilkerson, Donald C.; Tobia, Christine M.; Ngo Tenlep, Sara Y.; Shridas, Preetha; Garcia-Cazarin, Mary L.; Wolff, Gretchen; Andrade, Francisco H.; Charnigo, Richard J.; Esser, Karyn A.; Egan, Josephine M.; de Cabo, Rafael

    2012-01-01

    Emerging research has shown that subtle factors during pregnancy and gestation can influence long-term health in offspring. In an attempt to be proactive, we set out to explore whether a nonpharmacological intervention, perinatal exercise, might improve offspring health. Female mice were separated into sedentary or exercise cohorts, with the exercise cohort having voluntary access to a running wheel prior to mating and during pregnancy and nursing. Offspring were weaned, and analyses were performed on the mature offspring that did not have access to running wheels during any portion of their lives. Perinatal exercise caused improved glucose disposal following an oral glucose challenge in both female and male adult offspring (P < 0.05 for both). Blood glucose concentrations were reduced to lower values in response to an intraperitoneal insulin tolerance test for both female and male adult offspring of parents with access to running wheels (P < 0.05 and P < 0.01, respectively). Male offspring from exercised dams showed increased percent lean mass and decreased fat mass percent compared with male offspring from sedentary dams (P < 0.01 for both), but these parameters were unchanged in female offspring. These data suggest that short-term maternal voluntary exercise prior to and during healthy pregnancy and nursing can enhance long-term glucose homeostasis in offspring. PMID:22932781

  5. The GLP-1 response to glucose does not mediate beta and alpha cell dysfunction in Hispanics with abnormal glucose metabolism.

    PubMed

    Adams, Elizabeth; Genter, Pauline; Keefe, Emma; Sandow, Kevin; Gray, Virginia; Rotter, Jerome I; Chen, Yii-Der Ida; Ipp, Eli

    2018-01-01

    Glucagon-like peptide-1 (GLP-1) contributes to insulin secretion after meals. Though Hispanics have increased risk for type 2 diabetes mellitus, it is unknown if impaired GLP-1 secretion contributes to this risk. We therefore studied plasma GLP-1 secretion and action in Hispanic adults. Hispanic (H; n = 31) and non-Hispanic (nH; n = 15) participants underwent an oral glucose tolerance test (OGTT). All participants were categorized by glucose tolerance into four groups: normal glucose tolerant non-Hispanic (NGT-nH; n = 15), normal glucose tolerant Hispanic (NGT-H; n = 12), impaired glucose tolerant Hispanic (IGT-H; n = 11), or newly diagnosed type 2 diabetes mellitus, Hispanic (T2D-H; n = 8). Glucose-induced increments in plasma GLP-1 (Δ-GLP-1) were not different in NGT-H and NGT-nH (p = .38), nor amongst Hispanic subgroups with varying degrees of glucose homeostasis (p = .6). In contrast, the insulinogenic index in T2D-H group was lower than the other groups (p = .016). Subjects with abnormal glucose homeostasis (AGH), i.e., T2D-H plus IGT-H, had a diminished glucagon suppression index compared to patients with normal glucose homeostasis (NGT-H plus NGT-nH) (p = .035). GLP-1 responses to glucose were similar in Hispanic and Non-Hispanic NGT. Despite similar glucose-induced Δ-GLP-1, insulin and glucagon responses were abnormal in T2D-H and AGH, respectively. Thus, impaired GLP-1 secretion is unlikely to play a role in islet dysfunction in T2D. Although GLP-1 therapeutics enhance insulin secretion and glucagon suppression, it is likely due to pharmacological amplification of the GLP-1 pathways rather than treatment of hormonal deficiency. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Sleep duration and sleep quality are associated differently with alterations of glucose homeostasis.

    PubMed

    Byberg, S; Hansen, A-L S; Christensen, D L; Vistisen, D; Aadahl, M; Linneberg, A; Witte, D R

    2012-09-01

    Studies suggest that inadequate sleep duration and poor sleep quality increase the risk of impaired glucose regulation and diabetes. However, associations with specific markers of glucose homeostasis are less well explained. The objective of this study was to explore possible associations of sleep duration and sleep quality with markers of glucose homeostasis and glucose tolerance status in a healthy population-based study sample. The study comprised 771 participants from the Danish, population-based cross-sectional 'Health2008' study. Sleep duration and sleep quality were measured by self-report. Markers of glucose homeostasis were derived from a 3-point oral glucose tolerance test and included fasting plasma glucose, 2-h plasma glucose, HbA(1c), two measures of insulin sensitivity (the insulin sensitivity index(0,120) and homeostasis model assessment of insulin sensitivity), the homeostasis model assessment of β-cell function and glucose tolerance status. Associations of sleep duration and sleep quality with markers of glucose homeostasis and tolerance were analysed by multiple linear and logistic regression. A 1-h increment in sleep duration was associated with a 0.3 mmol/mol (0.3%) decrement in HbA(1c) and a 25% reduction in the risk of having impaired glucose regulation. Further, a 1-point increment in sleep quality was associated with a 2% increase in both the insulin sensitivity index(0,120) and homeostasis model assessment of insulin sensitivity, as well as a 1% decrease in homeostasis model assessment of β-cell function. In the present study, shorter sleep duration was mainly associated with later alterations in glucose homeostasis, whereas poorer sleep quality was mainly associated with earlier alterations in glucose homeostasis. Thus, adopting healthy sleep habits may benefit glucose metabolism in healthy populations. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

  7. Deletion of Rab GAP AS160 modifies glucose uptake and GLUT4 translocation in primary skeletal muscles and adipocytes and impairs glucose homeostasis.

    PubMed

    Lansey, Melissa N; Walker, Natalie N; Hargett, Stefan R; Stevens, Joseph R; Keller, Susanna R

    2012-11-15

    Tight control of glucose uptake in skeletal muscles and adipocytes is crucial to glucose homeostasis and is mediated by regulating glucose transporter GLUT4 subcellular distribution. In cultured cells, Rab GAP AS160 controls GLUT4 intracellular retention and release to the cell surface and consequently regulates glucose uptake into cells. To determine AS160 function in GLUT4 trafficking in primary skeletal muscles and adipocytes and investigate its role in glucose homeostasis, we characterized AS160 knockout (AS160(-/-)) mice. We observed increased and normal basal glucose uptake in isolated AS160(-/-) adipocytes and soleus, respectively, while insulin-stimulated glucose uptake was impaired and GLUT4 expression decreased in both. No such abnormalities were found in isolated AS160(-/-) extensor digitorum longus muscles. In plasma membranes isolated from AS160(-/-) adipose tissue and gastrocnemius/quadriceps, relative GLUT4 levels were increased under basal conditions and remained the same after insulin treatment. Concomitantly, relative levels of cell surface-exposed GLUT4, determined with a glucose transporter photoaffinity label, were increased in AS160(-/-) adipocytes and normal in AS160(-/-) soleus under basal conditions. Insulin augmented cell surface-exposed GLUT4 in both. These observations suggest that AS160 is essential for GLUT4 intracellular retention and regulation of glucose uptake in adipocytes and skeletal muscles in which it is normally expressed. In vivo studies revealed impaired insulin tolerance in the presence of normal (male) and impaired (female) glucose tolerance. Concurrently, insulin-elicited increases in glucose disposal were abolished in all AS160(-/-) skeletal muscles and liver but not in AS160(-/-) adipose tissues. This suggests AS160 as a target for differential manipulation of glucose homeostasis.

  8. Revisiting "Vegetables" to combat modern epidemic of imbalanced glucose homeostasis.

    PubMed

    Tiwari, Ashok Kumar

    2014-04-01

    Vegetables have been part of human food since prehistoric times and are considered nutritionally necessary and good for health. Vegetables are rich natural resource of biological antioxidants and possess capabilities of maintaining glucose homeostasis. When taken before starch-rich diet, juice also of vegetables such as ridge gourd, bottle gourd, ash gourd, chayote and juice of leaves of vegetables such as radish, Indian Dill, ajwain, tropical green amaranth, and bladder dock are reported to arrest significantly the rise in postprandial blood glucose level. Juice of vegetables such as ash gourd, squash gourd, and tropical green amaranth leaves are observed to tone-down sweet-beverages such as sucrose, fructose, and glucose-induced postprandial glycemic excursion. On the other hand, juice of egg-plant and juice of leaves of Ceylon spinach, Joyweed, and palak are reported to augment starch-induced postprandial glycemic excursion; and juice of leaves of Ceylon spinach, Joyweed, and radish supplement to the glucose-induced postprandial glycemia. Vegetables possess multifaceted antihyperglycemic activities such as inhibition of pancreatic α-amylase and intestinal α-glucosidase, inhibition of protein-tyrosine phosphatase 1β in liver and skeletal muscles, and insulin mimetic and secretagogue activities. Furthermore, they are also reported to influence polyol pathway in favor of reducing development of oxidative stress, and consequently the development of diabetic complications. In the wake of emergence of modern maladaptive diet-induced hyperglycemic epidemic therefore, vegetables may offer cost-effective dietary regimen to control diet-induced glycemic over load and future development of diabetes mellitus. However, for vegetables have been reported to do both, mitigate as well as supplement to the diet-induced postprandial glycemic load, care is required in selection of vegetables when considered as medicament.

  9. Loss of CTRP1 disrupts glucose and lipid homeostasis

    PubMed Central

    Rodriguez, Susana; Lei, Xia; Petersen, Pia S.; Tan, Stefanie Y.; Little, Hannah C.

    2016-01-01

    C1q/TNF-related protein 1 (CTRP1) is a conserved plasma protein of the C1q family with notable metabolic and cardiovascular functions. We have previously shown that CTRP1 infusion lowers blood glucose and that transgenic mice with elevated circulating CTRP1 are protected from diet-induced obesity and insulin resistance. Here, we used a genetic loss-of-function mouse model to address the requirement of CTRP1 for metabolic homeostasis. Despite similar body weight, food intake, and energy expenditure, Ctrp1 knockout (KO) mice fed a low-fat diet developed insulin resistance and hepatic steatosis. Impaired glucose metabolism in Ctrp1 KO mice was associated with increased hepatic gluconeogenic gene expression and decreased skeletal muscle glucose transporter glucose transporter 4 levels and AMP-activated protein kinase activation. Loss of CTRP1 enhanced the clearance of orally administered lipids but did not affect intestinal lipid absorption, hepatic VLDL-triglyceride export, or lipoprotein lipase activity. In contrast to triglycerides, hepatic cholesterol levels were reduced in Ctrp1 KO mice, paralleling the reduced expression of cholesterol synthesis genes. Contrary to expectations, when challenged with a high-fat diet to induce obesity, Ctrp1 KO mice had increased physical activity and reduced body weight, adiposity, and expression of lipid synthesis and fibrotic genes in adipose tissue; these phenotypes were linked to elevated FGF-21 levels. Due in part to increased hepatic AMP-activated protein kinase activation and reduced expression of lipid synthesis genes, Ctrp1 KO mice fed a high-fat diet also had reduced liver and serum triglyceride and cholesterol levels. Taken together, these results provide genetic evidence to establish the significance of CTRP1 to systemic energy metabolism in different metabolic and dietary contexts. PMID:27555298

  10. Nervous glucose sensing regulates postnatal β cell proliferation and glucose homeostasis

    PubMed Central

    Tarussio, David; Metref, Salima; Seyer, Pascal; Mounien, Lourdes; Vallois, David; Magnan, Christophe; Foretz, Marc; Thorens, Bernard

    2013-01-01

    How glucose sensing by the nervous system impacts the regulation of β cell mass and function during postnatal development and throughout adulthood is incompletely understood. Here, we studied mice with inactivation of glucose transporter 2 (Glut2) in the nervous system (NG2KO mice). These mice displayed normal energy homeostasis but developed late-onset glucose intolerance due to reduced insulin secretion, which was precipitated by high-fat diet feeding. The β cell mass of adult NG2KO mice was reduced compared with that of WT mice due to lower β cell proliferation rates in NG2KO mice during the early postnatal period. The difference in proliferation between NG2KO and control islets was abolished by ganglionic blockade or by weaning the mice on a carbohydrate-free diet. In adult NG2KO mice, first-phase insulin secretion was lost, and these glucose-intolerant mice developed impaired glucagon secretion when fed a high-fat diet. Electrophysiological recordings showed reduced parasympathetic nerve activity in the basal state and no stimulation by glucose. Furthermore, sympathetic activity was also insensitive to glucose. Collectively, our data show that GLUT2-dependent control of parasympathetic activity defines a nervous system/endocrine pancreas axis that is critical for β cell mass establishment in the postnatal period and for long-term maintenance of β cell function. PMID:24334455

  11. Exenatide Regulates Cerebral Glucose Metabolism in Brain Areas Associated With Glucose Homeostasis and Reward System.

    PubMed

    Daniele, Giuseppe; Iozzo, Patricia; Molina-Carrion, Marjorie; Lancaster, Jack; Ciociaro, Demetrio; Cersosimo, Eugenio; Tripathy, Devjit; Triplitt, Curtis; Fox, Peter; Musi, Nicolas; DeFronzo, Ralph; Gastaldelli, Amalia

    2015-10-01

    Glucagon-like peptide 1 receptors (GLP-1Rs) have been found in the brain, but whether GLP-1R agonists (GLP-1RAs) influence brain glucose metabolism is currently unknown. The study aim was to evaluate the effects of a single injection of the GLP-1RA exenatide on cerebral and peripheral glucose metabolism in response to a glucose load. In 15 male subjects with HbA1c of 5.7 ± 0.1%, fasting glucose of 114 ± 3 mg/dL, and 2-h glucose of 177 ± 11 mg/dL, exenatide (5 μg) or placebo was injected in double-blind, randomized fashion subcutaneously 30 min before an oral glucose tolerance test (OGTT). The cerebral glucose metabolic rate (CMRglu) was measured by positron emission tomography after an injection of [(18)F]2-fluoro-2-deoxy-d-glucose before the OGTT, and the rate of glucose absorption (RaO) and disposal was assessed using stable isotope tracers. Exenatide reduced RaO0-60 min (4.6 ± 1.4 vs. 13.1 ± 1.7 μmol/min ⋅ kg) and decreased the rise in mean glucose0-60 min (107 ± 6 vs. 138 ± 8 mg/dL) and insulin0-60 min (17.3 ± 3.1 vs. 24.7 ± 3.8 mU/L). Exenatide increased CMRglu in areas of the brain related to glucose homeostasis, appetite, and food reward, despite lower plasma insulin concentrations, but reduced glucose uptake in the hypothalamus. Decreased RaO0-60 min after exenatide was inversely correlated to CMRglu. In conclusion, these results demonstrate, for the first time in man, a major effect of a GLP-1RA on regulation of brain glucose metabolism in the absorptive state. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  12. Setting sail for glucose homeostasis with the AKAP150-PP2B-anchor.

    PubMed

    Teo, Adrian Kee Keong; Kulkarni, Rohit N

    2012-10-17

    Glucose-stimulated insulin secretion, controlled by multiple protein phosphorylation events, is critical for the regulation of glucose homeostasis. Protein kinase A (PKA) is known to play a role in β cell physiology, but the role of its anchoring protein is not fully understood. Hinke et al (2012) illustrate the significance of A-kinase anchoring protein 150 in tethering protein phosphatase 2B to mediate nutrient-stimulated insulin secretion and thus modulate glucose homeostasis.

  13. Effects of celiac superior mesenteric ganglionectomy on glucose homeostasis and hormonal changes during oral glucose tolerance testing in rats.

    PubMed

    Kumakura, Atsushi; Shikuma, Junpei; Ogihara, Norikazu; Eiki, Jun-ichi; Kanazawa, Masao; Notoya, Yōko; Kikuchi, Masatoshi; Odawara, Masato

    2013-01-01

    The liver plays an important role in maintaining glucose homeostasis in the body. In the prandial state, some of the glucose which is absorbed by the gastrointestinal tract is converted into glycogen and stored in the liver. In contrast, the liver produces glucose by glycogenolysis and gluconeogenesis while fasting. Thus, the liver contributes to maintaining blood glucose level within normoglycemic range. Glycogenesis and glycogenolysis are regulated by various mechanisms including hormones, the sympathetic and parasympathetic nervous systems and the hepatic glucose content. In this study, we examined a rat model in which the celiac superior mesenteric ganglion (CSMG) was resected. We attempted to elucidate how the celiac sympathetic nervous system is involved in regulating glucose homeostasis by assessing the effects of CSMG resection on glucose excursion during an oral glucose tolerance test, and by examining hepatic glycogen content and hepatic glycogen phosphorylase (GP) activity. On the oral glucose tolerance test, CSMG-resected rats demonstrated improved glucose tolerance and significantly increased GP activity compared with sham-operated rats, whereas there were no significant differences in insulin, glucagon or catecholamine levels between the 2 groups. These results suggest that the celiac sympathetic nervous system is involved in regulating the rate of glycogen consumption through GP activity. In conclusion, the examined rat model showed that the celiac sympathetic nervous system regulates hepatic glucose metabolism in conjunction with vagal nerve innervations and is a critical component in the maintenance of blood glucose homeostasis.

  14. Mechanisms and significance of brain glucose signaling in energy balance, glucose homeostasis, and food-induced reward.

    PubMed

    Devarakonda, Kavya; Mobbs, Charles V

    2016-12-15

    The concept that hypothalamic glucose signaling plays an important role in regulating energy balance, e.g., as instantiated in the so-called "glucostat" hypothesis, is one of the oldest in the field of metabolism. However the mechanisms by which neurons in the hypothalamus sense glucose, and the function of glucose signaling in the brain, has been difficult to establish. Nevertheless recent studies probing mechanisms of glucose signaling have also strongly supported a role for glucose signaling in regulating energy balance, glucose homeostasis, and food-induced reward. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Quantifying the Contribution of the Liver to Glucose Homeostasis: A Detailed Kinetic Model of Human Hepatic Glucose Metabolism

    PubMed Central

    König, Matthias; Bulik, Sascha; Holzhütter, Hermann-Georg

    2012-01-01

    Despite the crucial role of the liver in glucose homeostasis, a detailed mathematical model of human hepatic glucose metabolism is lacking so far. Here we present a detailed kinetic model of glycolysis, gluconeogenesis and glycogen metabolism in human hepatocytes integrated with the hormonal control of these pathways by insulin, glucagon and epinephrine. Model simulations are in good agreement with experimental data on (i) the quantitative contributions of glycolysis, gluconeogenesis, and glycogen metabolism to hepatic glucose production and hepatic glucose utilization under varying physiological states. (ii) the time courses of postprandial glycogen storage as well as glycogen depletion in overnight fasting and short term fasting (iii) the switch from net hepatic glucose production under hypoglycemia to net hepatic glucose utilization under hyperglycemia essential for glucose homeostasis (iv) hormone perturbations of hepatic glucose metabolism. Response analysis reveals an extra high capacity of the liver to counteract changes of plasma glucose level below 5 mM (hypoglycemia) and above 7.5 mM (hyperglycemia). Our model may serve as an important module of a whole-body model of human glucose metabolism and as a valuable tool for understanding the role of the liver in glucose homeostasis under normal conditions and in diseases like diabetes or glycogen storage diseases. PMID:22761565

  16. Abnormal vascularization in mouse retina with dysregulated retinal cholesterol homeostasis

    PubMed Central

    Omarova, Saida; Charvet, Casey D.; Reem, Rachel E.; Mast, Natalia; Zheng, Wenchao; Huang, Suber; Peachey, Neal S.; Pikuleva, Irina A.

    2012-01-01

    Several lines of evidence suggest a link between age-related macular degeneration and retinal cholesterol maintenance. Cytochrome P450 27A1 (CYP27A1) is a ubiquitously expressed mitochondrial sterol 27-hydroxylase that plays an important role in the metabolism of cholesterol and cholesterol-related compounds. We conducted a comprehensive ophthalmic evaluation of mice lacking CYP27A1. We found that the loss of CYP27A1 led to dysregulation of retinal cholesterol homeostasis, including unexpected upregulation of retinal cholesterol biosynthesis. Cyp27a1–/– mice developed retinal lesions characterized by cholesterol deposition beneath the retinal pigment epithelium. Further, Cyp27a1-null mice showed pathological neovascularization, which likely arose from both the retina and the choroid, that led to the formation of retinal-choroidal anastomosis. Blood flow alterations and blood vessel leakage were noted in the areas of pathology. The Cyp27a1–/– retina was hypoxic and had activated Müller cells. We suggest a mechanism whereby abolished sterol 27-hydroxylase activity leads to vascular changes and identify Cyp27a1–/– mice as a model for one of the variants of type 3 retinal neovascularization occurring in some patients with age-related macular degeneration. PMID:22820291

  17. The lipid accumulation product as a useful index for identifying abnormal glucose regulation in young Korean women.

    PubMed

    Oh, J-Y; Sung, Y-A; Lee, H J

    2013-04-01

    The lipid accumulation product, a combination of waist circumference and triglycerides concentration, has been suggested as a better marker for abnormal glucose regulation than BMI. We aimed to compare the lipid accumulation product and BMI as useful markers for abnormal glucose regulation in young Korean women. The lipid accumulation product was calculated using the formula [waist circumference (cm) - 58] × triglycerides (mmol/l). Glucose tolerance status was determined using a 75-g oral glucose tolerance test in 2810 Korean women aged 18-39 years from the general population. The prevalence of abnormal glucose regulation was 6.8% (isolated impaired fasting glucose 1.8%, isolated impaired glucose tolerance 4.0%; impaired fasting glucose + impaired glucose tolerance 0.4% and diabetes mellitus 0.6%). According to the quintile distributions of the lipid accumulation product and BMI, women with a lipid accumulation product quintile greater than their BMI quintile exhibited significantly greater areas under the curve and higher levels of 2-h post-load glucose, insulin, homeostasis model analysis of insulin resistance and lipid profiles than did women with a BMI quintile greater than their lipid accumulation product quintile. Multiple logistic regression revealed that the lipid accumulation product exhibited a higher odds ratio for abnormal glucose regulation than did BMI after adjusting for age, systolic blood pressure, HDL cholesterol, previous history of gestational diabetes and family history of diabetes (odds ratios 3.5 and 2.6 of the highest vs. the lowest quintiles of lipid accumulation product and BMI, respectively). The lipid accumulation product could be useful for identifying the young Korean women with abnormal glucose regulation. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

  18. Glucose abnormalities in Asian patients with chronic hepatitis C.

    PubMed

    Bo, Qingyan; Orsenigo, Roberto; Wang, Junyi; Griffel, Louis; Brass, Clifford

    2015-01-01

    Many studies have demonstrated a potential association between type 2 diabetes (T2D) and hepatitis C virus infection in Western countries, while similar evidence is limited in Asia. We compared the prevalence of glucose abnormalities (impaired fasting glucose [IFG] and T2D) and their risk factors between Asian and non-Asian chronic hepatitis C (CHC) patients, and evaluated whether glucose abnormalities impacted the viral responses to peginterferon plus ribavirin treatment (current standard of care in most Asian countries). This study retrospectively analyzed data of 1,887 CHC patients from three Phase II/III studies with alisporivir (DEB025) as treatment for CHC. The chi-square test was used to compare the prevalence of IFG/T2D between Asian and non-Asian CHC patients, and logistic regression was used to adjust for sex, age, and cirrhosis status. Risk factors for IFG/T2D were evaluated using univariate and multivariate analysis. Our results indicated that the prevalence of IFG/T2D was high in both Asian and non-Asian CHC patients (23.0% vs 20.9%), and no significant difference was found between these two populations (adjusted odds ratio: 1.3, 95% confidence interval: 0.97, 1.7; P=0.08). Age, sex, and cirrhosis status were risk factors for IFG/T2D in both populations, while body mass index was positively associated with IFG/T2D in non-Asian but not in Asian participants. No significant differences in sustained virological response rates were seen between patients with normal fasting glucose and patients with IFG/T2D for both populations. These results demonstrate that the prevalence of glucose abnormalities in Asian CHC patients was similar to that in non-Asians, and glucose abnormalities had no impact on viral response to peginterferon plus ribavirin.

  19. Glucose abnormalities in Asian patients with chronic hepatitis C

    PubMed Central

    Bo, Qingyan; Orsenigo, Roberto; Wang, Junyi; Griffel, Louis; Brass, Clifford

    2015-01-01

    Many studies have demonstrated a potential association between type 2 diabetes (T2D) and hepatitis C virus infection in Western countries, while similar evidence is limited in Asia. We compared the prevalence of glucose abnormalities (impaired fasting glucose [IFG] and T2D) and their risk factors between Asian and non-Asian chronic hepatitis C (CHC) patients, and evaluated whether glucose abnormalities impacted the viral responses to peginterferon plus ribavirin treatment (current standard of care in most Asian countries). This study retrospectively analyzed data of 1,887 CHC patients from three Phase II/III studies with alisporivir (DEB025) as treatment for CHC. The chi-square test was used to compare the prevalence of IFG/T2D between Asian and non-Asian CHC patients, and logistic regression was used to adjust for sex, age, and cirrhosis status. Risk factors for IFG/T2D were evaluated using univariate and multivariate analysis. Our results indicated that the prevalence of IFG/T2D was high in both Asian and non-Asian CHC patients (23.0% vs 20.9%), and no significant difference was found between these two populations (adjusted odds ratio: 1.3, 95% confidence interval: 0.97, 1.7; P=0.08). Age, sex, and cirrhosis status were risk factors for IFG/T2D in both populations, while body mass index was positively associated with IFG/T2D in non-Asian but not in Asian participants. No significant differences in sustained virological response rates were seen between patients with normal fasting glucose and patients with IFG/T2D for both populations. These results demonstrate that the prevalence of glucose abnormalities in Asian CHC patients was similar to that in non-Asians, and glucose abnormalities had no impact on viral response to peginterferon plus ribavirin. PMID:26609222

  20. The ICET-A Recommendations for the Diagnosis and Management of Disturbances of Glucose Homeostasis in Thalassemia Major Patients

    PubMed Central

    De Sanctis, Vincenzo; Soliman, Ashraf T.; Elsedfy, Heba; Yaarubi, Saif AL; Skordis, Nicos; Khater, Doaa; El Kholy, Mohamed; Stoeva, Iva; Fiscina, Bernadette; Angastiniotis, Michael; Daar, Shahina; Kattamis, Christos

    2016-01-01

    Iron overload in patients with thalassemia major (TM) affects glucose regulation and is mediated by several mechanisms. The pathogenesis of glycaemic abnormalities in TM is complex and multifactorial. It has been predominantly attributed to a combination of reduced insulin secretory capacity and insulin resistance. The exact mechanisms responsible for progression from norm glycaemia to overt diabetes in these patients are still poorly understood but are attributed mainly to insulin deficiency resulting from the toxic effects of iron deposited in the pancreas and insulin resistance. A group of endocrinologists, haematologists and paediatricians, members of the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescence Medicine (ICET-A) convened to formulate recommendations for the diagnosis and management of abnormalities of glucose homeostasis in thalassemia major patients on the basis of available evidence from clinical and laboratory data and consensus practice. The results of their work and discussions are described in this article. PMID:27872738

  1. Importance of Abnormal Chloride Homeostasis in Stable Chronic Heart Failure.

    PubMed

    Grodin, Justin L; Verbrugge, Frederik H; Ellis, Stephen G; Mullens, Wilfried; Testani, Jeffrey M; Tang, W H Wilson

    2016-01-01

    The aim of this analysis was to determine the long-term prognostic value of lower serum chloride in patients with stable chronic heart failure. Electrolyte abnormalities are prevalent in patients with chronic heart failure. Little is known regarding the prognostic implications of lower serum chloride. Serum chloride was measured in 1673 consecutively consented stable patients with a history of heart failure undergoing elective diagnostic coronary angiography. All patients were followed for 5-year all-cause mortality, and survival models were adjusted for variables that confounded the chloride-risk relationship. The average chloride level was 102 ± 4 mEq/L. Over 6772 person-years of follow-up, there were 547 deaths. Lower chloride (per standard deviation decrease) was associated with a higher adjusted risk of mortality (hazard ratio 1.29, 95% confidence interval 1.12-1.49; P < 0.001). Chloride levels net-reclassified risk in 10.4% (P = 0.03) when added to a multivariable model (with a resultant C-statistic of 0.70), in which sodium levels were not prognostic (P = 0.30). In comparison to those with above first quartile chloride (≥ 101 mEq/L) and sodium (≥ 138 meq/L), subjects with first quartile chloride had a higher adjusted mortality risk, whether they had first quartile sodium (hazard ratio 1.35, 95% confidence interval 1.08-1.69; P = 0.008) or higher (hazard ratio 1.43, 95% confidence interval 1.12-1.85; P = 0.005). However, subjects with first quartile sodium but above first quartile chloride had no association with mortality (P = 0.67). Lower serum chloride levels are independently and incrementally associated with increased mortality risk in patients with chronic heart failure. A better understanding of the biological role of serum chloride is warranted. © 2015 American Heart Association, Inc.

  2. Abnormal oral glucose tolerance and glucose malabsorption after vagotomy and pyloroplasty. A tracer method for measuring glucose absorption rates

    SciTech Connect

    Radziuk, J.; Bondy, D.C.

    1982-11-01

    The mechanisms underlying the abnormal glucose tolerance in patients who had undergone vagotomy and pyloroplasty were investigated by measuring the rates of absorption of ingested glucose and the clearance rate of glucose using tracer methods. These methods are based on labeling a 100-g oral glucose load with (1-/sup 14/C)glucose and measuring glucose clearance using plasma levels of infused (3-/sup 3/H)glucose. The rate of appearance of both ingested and total glucose is then calculated continuously using a two-compartment model of glucose kinetics. It was found that about 30% of the ingested glucose (100 g) failed to appear in the systemic circulation.more » That this was due to malabsorption was confirmed using breath-hydrogen analysis. The absorption period is short (101 +/- 11 min) compared with normal values but the clearance of glucose is identical to that in control subjects, and it peaks 132 +/- 7 min after glucose loading. The peak plasma insulin values were more than four times higher in patients than in normal subjects, and this may afford an explanation of rates of glucose clearance that are inappropriate for the short absorption period. The combination of glucose malabsorption and this clearance pattern could yield the hypoglycemia that may be observed in patients after gastric surgery.« less

  3. Brown Adipose Tissue Improves Whole-Body Glucose Homeostasis and Insulin Sensitivity in Humans

    PubMed Central

    Chondronikola, Maria; Volpi, Elena; Børsheim, Elisabet; Porter, Craig; Annamalai, Palam; Enerbäck, Sven; Lidell, Martin E.; Saraf, Manish K.; Labbe, Sebastien M.; Hurren, Nicholas M.; Yfanti, Christina; Chao, Tony; Andersen, Clark R.; Cesani, Fernando; Hawkins, Hal

    2014-01-01

    Brown adipose tissue (BAT) has attracted scientific interest as an antidiabetic tissue owing to its ability to dissipate energy as heat. Despite a plethora of data concerning the role of BAT in glucose metabolism in rodents, the role of BAT (if any) in glucose metabolism in humans remains unclear. To investigate whether BAT activation alters whole-body glucose homeostasis and insulin sensitivity in humans, we studied seven BAT-positive (BAT+) men and five BAT-negative (BAT−) men under thermoneutral conditions and after prolonged (5–8 h) cold exposure (CE). The two groups were similar in age, BMI, and adiposity. CE significantly increased resting energy expenditure, whole-body glucose disposal, plasma glucose oxidation, and insulin sensitivity in the BAT+ group only. These results demonstrate a physiologically significant role of BAT in whole-body energy expenditure, glucose homeostasis, and insulin sensitivity in humans, and support the notion that BAT may function as an antidiabetic tissue in humans. PMID:25056438

  4. Contribution of galactose and fructose to glucose homeostasis

    USDA-ARS?s Scientific Manuscript database

    To determine the contributions of galactose and fructose to glucose formation, 6 subjects (26 +/- 2 years old; body mass index, 22.4 +/-0.2 kg/m2) (mean +/- SE) were studied during fasting conditions. Three subjects received a primed constant intravenous infusion of[6,6-2H2] glucose for 3 hours foll...

  5. Wired on sugar: the role of the CNS in the regulation of glucose homeostasis

    PubMed Central

    Grayson, Bernadette E.; Seeley, Randy J.; Sandoval, Darleen A.

    2014-01-01

    Obesity and type 2 diabetes mellitus (T2DM) — disorders of energy homeostasis and glucose homeostasis, respectively — are tightly linked and the incidences of both conditions are increasing in parallel. The CNS integrates information regarding peripheral nutrient and hormonal changes and processes this information to regulate energy homeostasis. Recent findings indicate that some of the neural circuits and mechanisms underlying energy balance are also essential for the regulation of glucose homeostasis. We propose that disruption of these overlapping pathways links the metabolic disturbances associated with obesity and T2DM. A better understanding of these converging mechanisms may lead to therapeutic strategies that target both T2DM and obesity. PMID:23232606

  6. CREBH Maintains Circadian Glucose Homeostasis by Regulating Hepatic Glycogenolysis and Gluconeogenesis.

    PubMed

    Kim, Hyunbae; Zheng, Ze; Walker, Paul D; Kapatos, Gregory; Zhang, Kezhong

    2017-07-15

    Cyclic AMP-responsive element binding protein, hepatocyte specific (CREBH), is a liver-enriched, endoplasmic reticulum-tethered transcription factor known to regulate the hepatic acute-phase response and lipid homeostasis. In this study, we demonstrate that CREBH functions as a circadian transcriptional regulator that plays major roles in maintaining glucose homeostasis. The proteolytic cleavage and posttranslational acetylation modification of CREBH are regulated by the circadian clock. Functionally, CREBH is required in order to maintain circadian homeostasis of hepatic glycogen storage and blood glucose levels. CREBH regulates the rhythmic expression of the genes encoding the rate-limiting enzymes for glycogenolysis and gluconeogenesis, including liver glycogen phosphorylase (PYGL), phosphoenolpyruvate carboxykinase 1 (PCK1), and the glucose-6-phosphatase catalytic subunit (G6PC). CREBH interacts with peroxisome proliferator-activated receptor α (PPARα) to synergize its transcriptional activities in hepatic gluconeogenesis. The acetylation of CREBH at lysine residue 294 controls CREBH-PPARα interaction and synergy in regulating hepatic glucose metabolism in mice. CREBH deficiency leads to reduced blood glucose levels but increases hepatic glycogen levels during the daytime or upon fasting. In summary, our studies revealed that CREBH functions as a key metabolic regulator that controls glucose homeostasis across the circadian cycle or under metabolic stress. Copyright © 2017 American Society for Microbiology.

  7. CREBH Maintains Circadian Glucose Homeostasis by Regulating Hepatic Glycogenolysis and Gluconeogenesis

    PubMed Central

    Kim, Hyunbae; Zheng, Ze; Walker, Paul D.; Kapatos, Gregory

    2017-01-01

    ABSTRACT Cyclic AMP-responsive element binding protein, hepatocyte specific (CREBH), is a liver-enriched, endoplasmic reticulum-tethered transcription factor known to regulate the hepatic acute-phase response and lipid homeostasis. In this study, we demonstrate that CREBH functions as a circadian transcriptional regulator that plays major roles in maintaining glucose homeostasis. The proteolytic cleavage and posttranslational acetylation modification of CREBH are regulated by the circadian clock. Functionally, CREBH is required in order to maintain circadian homeostasis of hepatic glycogen storage and blood glucose levels. CREBH regulates the rhythmic expression of the genes encoding the rate-limiting enzymes for glycogenolysis and gluconeogenesis, including liver glycogen phosphorylase (PYGL), phosphoenolpyruvate carboxykinase 1 (PCK1), and the glucose-6-phosphatase catalytic subunit (G6PC). CREBH interacts with peroxisome proliferator-activated receptor α (PPARα) to synergize its transcriptional activities in hepatic gluconeogenesis. The acetylation of CREBH at lysine residue 294 controls CREBH-PPARα interaction and synergy in regulating hepatic glucose metabolism in mice. CREBH deficiency leads to reduced blood glucose levels but increases hepatic glycogen levels during the daytime or upon fasting. In summary, our studies revealed that CREBH functions as a key metabolic regulator that controls glucose homeostasis across the circadian cycle or under metabolic stress. PMID:28461393

  8. Influence of Amino Acids in Dairy Products on Glucose Homeostasis: The Clinical Evidence.

    PubMed

    Chartrand, Dominic; Da Silva, Marine S; Julien, Pierre; Rudkowska, Iwona

    2017-06-01

    Dairy products have been hypothesized to protect against type 2 diabetes because of their high content of whey proteins, rich in branched-chain amino acids (BCAAs) - leucine, isoleucine and valine - and lysine, which may decrease postprandial glucose responses and stimulate insulin secretion. Paradoxically, epidemiologic studies also show that higher levels of plasma BCAAs have been linked to insulin resistance and type 2 diabetes. Therefore, the objective was to review the recent clinical evidence concerning the intake of amino acids found in dairy proteins so as to determine their impact on glucose homeostasis in healthy persons and in those with prediabetes and type 2 diabetes. Clinical studies have reported that the major dairy amino acids, namely, leucine, isoleucine, glutamine, phenylalanine, proline and lysine, have beneficial effects on glucose homeostasis. Yet the reported doses of amino acids investigated are too elevated to be reached through adequate dairy product intake. The minor dairy amino acids, arginine and glycine, may improve glucose homeostasis by improving other risk factors for type 2 diabetes. Further, the combination of amino acids may also improve glucose-related outcomes, suggesting additive or synergistic effects. Nevertheless, additional long-term studies in individuals with prediabetes and type 2 diabetes are needed to ascertain the benefits for glucose homeostasis of amino acids found in dairy foods. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  9. Gastrointestinal Transit Time, Glucose Homeostasis and Metabolic Health: Modulation by Dietary Fibers

    PubMed Central

    Müller, Mattea; Canfora, Emanuel E.; Blaak, Ellen E.

    2018-01-01

    Gastrointestinal transit time may be an important determinant of glucose homeostasis and metabolic health through effects on nutrient absorption and microbial composition, among other mechanisms. Modulation of gastrointestinal transit may be one of the mechanisms underlying the beneficial health effects of dietary fibers. These effects include improved glucose homeostasis and a reduced risk of developing metabolic diseases such as obesity and type 2 diabetes mellitus. In this review, we first discuss the regulation of gastric emptying rate, small intestinal transit and colonic transit as well as their relation to glucose homeostasis and metabolic health. Subsequently, we briefly address the reported health effects of different dietary fibers and discuss to what extent the fiber-induced health benefits may be mediated through modulation of gastrointestinal transit. PMID:29495569

  10. Glyceollin-containing fermented soybeans improve glucose homeostasis in diabetic mice.

    PubMed

    Park, Sunmin; Kim, Da Sol; Kim, Jeong Hwan; Kim, Jong Sang; Kim, Hyo Jung

    2012-02-01

    Our previous in vitro study demonstrated that glyceollins help normalize glucose homeostasis by potentiating β-cell function and survival in insulinoma cells as well as improving glucose utilization in adipocytes. Here, we investigated whether fermented soybeans containing glyceollins had an antidiabetic action in type 2 diabetic animals. The diabetic mice, their diabetes induced by intraperitoneal injections of streptozotocin (20 mg/kg bw), were administered a high fat diet with no soybeans (control), 10% unfermented soybeans and 10% fermented soybeans containing glyceollins, respectively, (FSG) for 8 weeks. As positive controls, rosiglitazone (20 mg/kg/bw) was given to diabetic mice fed a no soybean diet and non-diabetic mice were also placed on the same diet. Among the diabetic mice, FSG-treated mice exhibited the lowest peak for blood glucose levels with an elevation of serum insulin levels during the first part of oral glucose tolerance testing. FSG also made blood glucose levels drop quickly after the peak and it decreased blood glucose levels more than the control during insulin tolerance testing. This improvement was associated with increased hepatic glycogen accumulation and decreased triglyceride storage. The phosphorylation of Akt, AMP-kinase, and acetyl-CoA carboxylase in the liver was potentiated by FSG, whereas phosphoenolpyruvate carboxykinase expression decreased. The enhancement of glucose homeostasis was comparable to the effect induced by rosiglitazone, a commercial peroxisome proliferator-activated receptor-γ agonist, but it did not match the level of glucose homeostasis in the non-diabetic mice. Glyceollin-containing FSG improves glucose homeostasis, partly by enhancing hepatic insulin sensitivity in type 2 diabetic mice. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Acute activation of GLP-1-expressing neurons promotes glucose homeostasis and insulin sensitivity.

    PubMed

    Shi, Xuemei; Chacko, Shaji; Li, Feng; Li, Depei; Burrin, Douglas; Chan, Lawrence; Guan, Xinfu

    2017-11-01

    Glucagon-like peptides are co-released from enteroendocrine L cells in the gut and preproglucagon (PPG) neurons in the brainstem. PPG-derived GLP-1/2 are probably key neuroendocrine signals for the control of energy balance and glucose homeostasis. The objective of this study was to determine whether activation of PPG neurons per se modulates glucose homeostasis and insulin sensitivity in vivo. We generated glucagon (Gcg) promoter-driven Cre transgenic mice and injected excitatory hM3Dq-mCherry AAV into their brainstem NTS. We characterized the metabolic impact of PPG neuron activation on glucose homeostasis and insulin sensitivity using stable isotopic tracers coupled with hyperinsulinemic euglycemic clamp. We showed that after ip injection of clozapine N-oxide, Gcg-Cre lean mice transduced with hM3Dq in the brainstem NTS downregulated basal endogenous glucose production and enhanced glucose tolerance following ip glucose tolerance test. Moreover, acute activation of PPG neurons NTS enhanced whole-body insulin sensitivity as indicated by increased glucose infusion rate as well as augmented insulin-suppression of endogenous glucose production and gluconeogenesis. In contrast, insulin-stimulation of glucose disposal was not altered significantly. We conclude that acute activation of PPG neurons in the brainstem reduces basal glucose production, enhances intraperitoneal glucose tolerance, and augments hepatic insulin sensitivity, suggesting an important physiological role of PPG neurons-mediated circuitry in promoting glycemic control and insulin sensitivity. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  12. Glucose Homeostasis Variables in Pregnancy versus Maternal and Infant Body Composition

    PubMed Central

    Henriksson, Pontus; Löf, Marie; Forsum, Elisabet

    2015-01-01

    Intrauterine factors influence infant size and body composition but the mechanisms involved are to a large extent unknown. We studied relationships between the body composition of pregnant women and variables related to their glucose homeostasis, i.e., glucose, HOMA-IR (homeostasis model assessment-insulin resistance), hemoglobin A1c and IGFBP-1 (insulin-like growth factor binding protein-1), and related these variables to the body composition of their infants. Body composition of 209 women in gestational week 32 and of their healthy, singleton and full-term one-week-old infants was measured using air displacement plethysmography. Glucose homeostasis variables were assessed in gestational week 32. HOMA-IR was positively related to fat mass index and fat mass (r2 = 0.32, p < 0.001) of the women. Maternal glucose and HOMA-IR values were positively (p ≤ 0.006) associated, while IGFBP-1was negatively (p = 0.001) associated, with infant fat mass. HOMA-IR was positively associated with fat mass of daughters (p < 0.001), but not of sons (p = 0.65) (Sex-interaction: p = 0.042). In conclusion, glucose homeostasis variables of pregnant women are related to their own body composition and to that of their infants. The results suggest that a previously identified relationship between fat mass of mothers and daughters is mediated by maternal insulin resistance. PMID:26184296

  13. Lysophosphatidic acid impairs glucose homeostasis and inhibits insulin secretion in high-fat diet obese mice.

    PubMed

    Rancoule, C; Attané, C; Grès, S; Fournel, A; Dusaulcy, R; Bertrand, C; Vinel, C; Tréguer, K; Prentki, M; Valet, P; Saulnier-Blache, J S

    2013-06-01

    Lysophosphatidic acid (LPA) is a lipid mediator produced by adipocytes that acts via specific G-protein-coupled receptors; its synthesis is modulated in obesity. We previously reported that reducing adipocyte LPA production in high-fat diet (HFD)-fed obese mice is associated with improved glucose tolerance, suggesting a negative impact of LPA on glucose homeostasis. Here, our aim was to test this hypothesis. First, glucose tolerance and plasma insulin were assessed after acute (30 min) injection of LPA (50 mg/kg) or of the LPA1/LPA3 receptor antagonist Ki16425 (5 mg kg(-1) day(-1), i.p.) in non-obese mice fed a normal diet (ND) and in obese/prediabetic (defined as glucose-intolerant) HFD mice. Glucose and insulin tolerance, pancreas morphology, glycogen storage, glucose oxidation and glucose transport were then studied after chronic treatment (3 weeks) of HFD mice with Ki16425. In ND and HFD mice, LPA acutely impaired glucose tolerance by inhibiting glucose-induced insulin secretion. These effects were blocked by pre-injection of Ki16425 (5 mg/kg, i.p.). Inhibition of glucose-induced insulin secretion by LPA also occurred in isolated mouse islets. Plasma LPA was higher in HFD mice than in ND mice and Ki16425 transiently improved glucose tolerance. The beneficial effect of Ki16425 became permanent after chronic treatment and was associated with increased pancreatic islet mass and higher fasting insulinaemia. Chronic treatment with Ki16425 also improved insulin tolerance and increased liver glycogen storage and basal glucose use in skeletal muscle. Exogenous and endogenous LPA exerts a deleterious effect on glucose disposal through a reduction of plasma insulin; pharmacological blockade of LPA receptors improves glucose homeostasis in obese/prediabetic mice.

  14. Central insulin and leptin-mediated autonomic control of glucose homeostasis

    PubMed Central

    Marino, Joseph S.; Xu, Yong; Hill, Jennifer W.

    2016-01-01

    Largely as a result of rising obesity rates, the incidence of type 2 diabetes is escalating rapidly. Type 2 diabetes results from multi-organ dysfunctional glucose metabolism. Recent publications have highlighted hypothalamic insulin- and adipokine-sensing as a major determinant of peripheral glucose and insulin responsiveness. The preponderance of evidence indicates that the brain is the master regulator of glucose homeostasis, and that hypothalamic insulin and leptin signaling in particular play a crucial role in the development of insulin resistance. This review discusses the neuronal crosstalk between the hypothalamus, autonomic nervous system, and tissues associated with the pathogenesis of type 2 diabetes, and how hypothalamic insulin and leptin signaling are integral to maintaining normal glucose homeostasis. PMID:21489811

  15. Central insulin and leptin-mediated autonomic control of glucose homeostasis.

    PubMed

    Marino, Joseph S; Xu, Yong; Hill, Jennifer W

    2011-07-01

    Largely as a result of rising obesity rates, the incidence of type 2 diabetes is escalating rapidly. Type 2 diabetes results from multi-organ dysfunctional glucose metabolism. Recent publications have highlighted hypothalamic insulin- and adipokine-sensing as a major determinant of peripheral glucose and insulin responsiveness. The preponderance of evidence indicates that the brain is the master regulator of glucose homeostasis, and that hypothalamic insulin and leptin signaling in particular play a crucial role in the development of insulin resistance. This review discusses the neuronal crosstalk between the hypothalamus, autonomic nervous system, and tissues associated with the pathogenesis of type 2 diabetes, and how hypothalamic insulin and leptin signaling are integral to maintaining normal glucose homeostasis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Hypothalamic vitamin D improves glucose homeostasis and reduces weight

    USDA-ARS?s Scientific Manuscript database

    Despite clear associations between vitamin D deficiency and obesity and/or type 2 diabetes, a causal relationship is not established. Vitamin D receptors (VDRs) are found within multiple tissues, including the brain. Given the importance of the brain in controlling both glucose levels and body weigh...

  17. Deletion of Lkb1 in Pro-Opiomelanocortin Neurons Impairs Peripheral Glucose Homeostasis in Mice

    PubMed Central

    Claret, Marc; Smith, Mark A.; Knauf, Claude; Al-Qassab, Hind; Woods, Angela; Heslegrave, Amanda; Piipari, Kaisa; Emmanuel, Julian J.; Colom, André; Valet, Philippe; Cani, Patrice D.; Begum, Ghazala; White, Anne; Mucket, Phillip; Peters, Marco; Mizuno, Keiko; Batterham, Rachel L.; Giese, K. Peter; Ashworth, Alan; Burcelin, Remy; Ashford, Michael L.; Carling, David; Withers, Dominic J.

    2011-01-01

    OBJECTIVE AMP-activated protein kinase (AMPK) signaling acts as a sensor of nutrients and hormones in the hypothalamus, thereby regulating whole-body energy homeostasis. Deletion of Ampkα2 in pro-opiomelanocortin (POMC) neurons causes obesity and defective neuronal glucose sensing. LKB1, the Peutz-Jeghers syndrome gene product, and Ca2+-calmodulin–dependent protein kinase kinase β (CaMKKβ) are key upstream activators of AMPK. This study aimed to determine their role in POMC neurons upon energy and glucose homeostasis regulation. RESEARCH DESIGN AND METHODS Mice lacking either Camkkβ or Lkb1 in POMC neurons were generated, and physiological, electrophysiological, and molecular biology studies were performed. RESULTS Deletion of Camkkβ in POMC neurons does not alter energy homeostasis or glucose metabolism. In contrast, female mice lacking Lkb1 in POMC neurons (PomcLkb1KO) display glucose intolerance, insulin resistance, impaired suppression of hepatic glucose production, and altered expression of hepatic metabolic genes. The underlying cellular defect in PomcLkb1KO mice involves a reduction in melanocortin tone caused by decreased α-melanocyte–stimulating hormone secretion. However, Lkb1-deficient POMC neurons showed normal glucose sensing, and body weight was unchanged in PomcLkb1KO mice. CONCLUSIONS Our findings demonstrate that LKB1 in hypothalamic POMC neurons plays a key role in the central regulation of peripheral glucose metabolism but not body-weight control. This phenotype contrasts with that seen in mice lacking AMPK in POMC neurons with defects in body-weight regulation but not glucose homeostasis, which suggests that LKB1 plays additional functions distinct from activating AMPK in POMC neurons. PMID:21266325

  18. Deletion of Lkb1 in pro-opiomelanocortin neurons impairs peripheral glucose homeostasis in mice.

    PubMed

    Claret, Marc; Smith, Mark A; Knauf, Claude; Al-Qassab, Hind; Woods, Angela; Heslegrave, Amanda; Piipari, Kaisa; Emmanuel, Julian J; Colom, André; Valet, Philippe; Cani, Patrice D; Begum, Ghazala; White, Anne; Mucket, Phillip; Peters, Marco; Mizuno, Keiko; Batterham, Rachel L; Giese, K Peter; Ashworth, Alan; Burcelin, Remy; Ashford, Michael L; Carling, David; Withers, Dominic J

    2011-03-01

    AMP-activated protein kinase (AMPK) signaling acts as a sensor of nutrients and hormones in the hypothalamus, thereby regulating whole-body energy homeostasis. Deletion of Ampkα2 in pro-opiomelanocortin (POMC) neurons causes obesity and defective neuronal glucose sensing. LKB1, the Peutz-Jeghers syndrome gene product, and Ca(2+)-calmodulin-dependent protein kinase kinase β (CaMKKβ) are key upstream activators of AMPK. This study aimed to determine their role in POMC neurons upon energy and glucose homeostasis regulation. Mice lacking either Camkkβ or Lkb1 in POMC neurons were generated, and physiological, electrophysiological, and molecular biology studies were performed. Deletion of Camkkβ in POMC neurons does not alter energy homeostasis or glucose metabolism. In contrast, female mice lacking Lkb1 in POMC neurons (PomcLkb1KO) display glucose intolerance, insulin resistance, impaired suppression of hepatic glucose production, and altered expression of hepatic metabolic genes. The underlying cellular defect in PomcLkb1KO mice involves a reduction in melanocortin tone caused by decreased α-melanocyte-stimulating hormone secretion. However, Lkb1-deficient POMC neurons showed normal glucose sensing, and body weight was unchanged in PomcLkb1KO mice. Our findings demonstrate that LKB1 in hypothalamic POMC neurons plays a key role in the central regulation of peripheral glucose metabolism but not body-weight control. This phenotype contrasts with that seen in mice lacking AMPK in POMC neurons with defects in body-weight regulation but not glucose homeostasis, which suggests that LKB1 plays additional functions distinct from activating AMPK in POMC neurons.

  19. The Role of Incretins in Glucose Homeostasis and Diabetes Treatment

    PubMed Central

    Kim, Wook; Egan, Josephine M.

    2009-01-01

    Incretins are gut hormones that are secreted from enteroendocrine cells into the blood within minutes after eating. One of their many physiological roles is to regulate the amount of insulin that is secreted after eating. In this manner, as well as others to be described in this review, their final common raison d’être is to aid in disposal of the products of digestion. There are two incretins, known as glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1), that share many common actions in the pancreas but have distinct actions outside of the pancreas. Both incretins are rapidly deactivated by an enzyme called dipeptidyl peptidase 4 (DPP4). A lack of secretion of incretins or an increase in their clearance are not pathogenic factors in diabetes. However, in type 2 diabetes (T2DM), GIP no longer modulates glucose-dependent insulin secretion, even at supraphysiological (pharmacological) plasma levels, and therefore GIP incompetence is detrimental to β-cell function, especially after eating. GLP-1, on the other hand, is still insulinotropic in T2DM, and this has led to the development of compounds that activate the GLP-1 receptor with a view to improving insulin secretion. Since 2005, two new classes of drugs based on incretin action have been approved for lowering blood glucose levels in T2DM: an incretin mimetic (exenatide, which is a potent long-acting agonist of the GLP-1 receptor) and an incretin enhancer (sitagliptin, which is a DPP4 inhibitor). Exenatide is injected subcutaneously twice daily and its use leads to lower blood glucose and higher insulin levels, especially in the fed state. There is glucose-dependency to its insulin secretory capacity, making it unlikely to cause low blood sugars (hypoglycemia). DPP4 inhibitors are orally active and they increase endogenous blood levels of active incretins, thus leading to prolonged incretin action. The elevated levels of GLP-1 are thought to be the mechanism underlying their

  20. Rictor/mTORC2 facilitates central regulation of energy and glucose homeostasis.

    PubMed

    Kocalis, Heidi E; Hagan, Scott L; George, Leena; Turney, Maxine K; Siuta, Michael A; Laryea, Gloria N; Morris, Lindsey C; Muglia, Louis J; Printz, Richard L; Stanwood, Gregg D; Niswender, Kevin D

    2014-07-01

    Insulin signaling in the central nervous system (CNS) regulates energy balance and peripheral glucose homeostasis. Rictor is a key regulatory/structural subunit of the mTORC2 complex and is required for hydrophobic motif site phosphorylation of Akt at serine 473. To examine the contribution of neuronal Rictor/mTORC2 signaling to CNS regulation of energy and glucose homeostasis, we utilized Cre-LoxP technology to generate mice lacking Rictor in all neurons, or in either POMC or AgRP expressing neurons. Rictor deletion in all neurons led to increased fat mass and adiposity, glucose intolerance and behavioral leptin resistance. Disrupting Rictor in POMC neurons also caused obesity and hyperphagia, fasting hyperglycemia and pronounced glucose intolerance. AgRP neuron specific deletion did not impact energy balance but led to mild glucose intolerance. Collectively, we show that Rictor/mTORC2 signaling, especially in POMC-expressing neurons, is important for central regulation of energy and glucose homeostasis.

  1. A brain-liver circuit regulates glucose homeostasis.

    PubMed

    Pocai, Alessandro; Obici, Silvana; Schwartz, Gary J; Rossetti, Luciano

    2005-01-01

    Increased glucose production (GP) is the major determinant of fasting hyperglycemia in diabetes mellitus. Previous studies suggested that lipid metabolism within specific hypothalamic nuclei is a biochemical sensor for nutrient availability that exerts negative feedback on GP. Here we show that central inhibition of fat oxidation leads to selective activation of brainstem neurons within the nucleus of the solitary tract and the dorsal motor nucleus of the vagus and markedly decreases liver gluconeogenesis, expression of gluconeogenic enzymes, and GP. These effects require central activation of ATP-dependent potassium channels (K(ATP)) and descending fibers within the hepatic branch of the vagus nerve. Thus, hypothalamic lipid sensing potently modulates glucose metabolism via neural circuitry that requires the activation of K(ATP) and selective brainstem neurons and intact vagal input to the liver. This crosstalk between brain and liver couples central nutrient sensing to peripheral nutrient production and its disruption may lead to hyperglycemia.

  2. Psychosocial stress predicts abnormal glucose metabolism: the Australian Diabetes, Obesity and Lifestyle (AusDiab) study.

    PubMed

    Williams, Emily D; Magliano, Dianna J; Tapp, Robyn J; Oldenburg, Brian F; Shaw, Jonathan E

    2013-08-01

    The evidence supporting a relationship between stress and diabetes has been inconsistent. This study examined the effects of stress on abnormal glucose metabolism, using a population-based sample of 3,759, with normoglycemia at baseline, from the Australian Diabetes, Obesity and Lifestyle study. Perceived stress and stressful life events were measured at baseline, with health behavior and anthropometric information also collected. Oral glucose tolerance tests were undertaken at baseline and 5-year follow-up. The primary outcome was the development of abnormal glucose metabolism (impaired fasting glucose, impaired glucose tolerance, and type 2 diabetes), according to WHO 1999 criteria. Perceived stress predicted incident abnormal glucose metabolism in women but not men, after multivariate adjustment. Life events showed an inconsistent relationship with abnormal glucose metabolism. Perceived stress predicted abnormal glucose metabolism in women. Healthcare professionals should consider psychosocial adversity when assessing risk factor profiles for the development of diabetes.

  3. Serotonin 2c receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis

    USDA-ARS?s Scientific Manuscript database

    Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor a...

  4. Serotonin 2C receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis.

    PubMed

    Berglund, Eric D; Liu, Chen; Sohn, Jong-Woo; Liu, Tiemin; Kim, Mi Hwa; Lee, Charlotte E; Vianna, Claudia R; Williams, Kevin W; Xu, Yong; Elmquist, Joel K

    2013-12-01

    Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor agonists on energy and glucose homeostasis are unknown. Here, we show that mice lacking serotonin 2C receptors (Htr2c) specifically in pro-opiomelanocortin (POMC) neurons had normal body weight but developed glucoregulatory defects including hyperinsulinemia, hyperglucagonemia, hyperglycemia, and insulin resistance. Moreover, these mice did not show anorectic responses to serotonergic agents that suppress appetite and developed hyperphagia and obesity when they were fed a high-fat/high-sugar diet. A requirement of serotonin 2C receptors in POMC neurons for the maintenance of normal energy and glucose homeostasis was further demonstrated when Htr2c loss was induced in POMC neurons in adult mice using a tamoxifen-inducible POMC-cre system. These data demonstrate that serotonin 2C receptor-expressing POMC neurons are required to control energy and glucose homeostasis and implicate POMC neurons as the target for the effect of serotonin 2C receptor agonists on weight-loss induction and improved glycemic control.

  5. Acute activation of GLP-1-expressing neurons promotes glucose homeostasis and insulin sensitivity

    USDA-ARS?s Scientific Manuscript database

    Glucagon-like peptides are co-released from enteroendocrine L cells in the gut and preproglucagon (PPG) neurons in the Brainstem. PPG-derived GLP-1/2 are probably key neuroendocrine signals for the control of energy balance and glucose Homeostasis. The objective of this study was to determine whethe...

  6. Pulmonary Ozone Exposure Alters Essential Metabolic Pathways involved in Glucose Homeostasis in the Liver

    EPA Science Inventory

    Pulmonary Ozone Exposure Alters Essential Metabolic Pathways involved in Glucose Homeostasis in the Liver D.B. Johnson, 1 W.O. Ward, 2 V.L. Bass, 2 M.C.J. Schladweiler, 2A.D. Ledbetter, 2 D. Andrews, and U.P. Kodavanti 2 1 Curriculum in Toxicology, UNC School of Medicine, Cha...

  7. Central Effects of Leptin on Glucose Homeostasis are Modified during Pregnancy in the Rat.

    PubMed

    Ladyman, S R; Grattan, D R

    2016-10-01

    Despite increased leptin concentrations during pregnancy, fat mass and food intake are increased. The satiety response to central leptin is suppressed, indicating a state of leptin insensitivity in the hypothalamus. Although the regulation of food intake is a major function of leptin, this hormone also influences a wide range of functions within the body. These actions include the regulation of glucose homeostasis, which undergoes major adaptation in the maternal body to generate optimal conditions for foetal development and growth. The present study aimed to investigate the effects of central leptin treatment on glucose homeostasis in pregnant rats to determine whether pregnancy-induced leptin insensitivity is functionally specific, and to further investigate changes in glucose homeostasis during pregnancy. After an overnight fast, nonpregnant and day 14 pregnant rats received an i.c.v. injection of leptin (100 ng or 4 μg) or vehicle then underwent a glucose tolerance test (GTT). Further groups of nonpregnant and day 14 pregnant rats were killed 30 min after leptin (doses ranging from 40 ng-4 μg) or vehicle i.c.v. injections for western blot analysis of phospho-signal transducer and activator of transcription 3 (STAT3) and phospho-Akt in various hypothalamic nuclei. Central leptin injection prior to a GTT lead to lowered basal insulin concentrations and impaired glucose tolerance in nonpregnant female rats, whereas the same doses of leptin had no significant effect on glucose tolerance in day 14 pregnant rats, indicating that, similar to the satiety actions of leptin, the effects of leptin on glucose homeostasis are suppressed during pregnancy. Furthermore, in the arcuate nucleus and ventromedial and dorsomedial nuclei of the hypothalamus, comprising three leptin-sensitive areas, there was no evidence that leptin induced Akt phosphorylation despite significant increases in phospho-STAT3, suggesting that leptin does not act through phospho-Akt in these areas

  8. Increased prevalence of abnormal glucose tolerance among obese siblings of children with type 2 diabetes.

    PubMed

    Magge, Sheela N; Stettler, Nicolas; Jawad, Abbas F; Levitt Katz, Lorraine E

    2009-04-01

    To test the hypothesis that overweight siblings of children with type 2 diabetes mellitus (T2DM) have a higher prevalence of abnormal glucose tolerance (AGT) compared with other overweight children. This was a cross-sectional study of overweight (body mass index [BMI] >or= 95(th) percentile) subjects, age 8 to 17 years, with at least 1 sibling age >or= 12 years. The primary outcome was AGT, as assessed by the oral glucose tolerance test (2-hour glucose >or= 140 mg/dL). The secondary outcome was insulin resistance by homeostasis model assessment (HOMA). The sibling (n=20) and control (n=42) groups were similar in terms of age, sex, racial distribution (largely African American), pubertal status, and BMI. The prevalence of AGT in the sibling group was 40.0% (n=8), compared with 14.3% (n=6) in controls (P= .048, Fisher exact test; unadjusted odds ratio=4.0; 95% confidence interval=1.2 to 13.5). Univariate analysis did not identify confounders for either outcome. There were no significant differences in HOMA or hemoglobin A1c between the 2 groups. Overweight siblings of children with T2DM had 4 times greater odds of having AGT compared with other overweight children. This group may represent a particularly high-risk population to target for screening and pediatric T2DM prevention.

  9. ATM Regulates Adipocyte Differentiation and Contributes to Glucose Homeostasis.

    PubMed

    Takagi, Masatoshi; Uno, Hatsume; Nishi, Rina; Sugimoto, Masataka; Hasegawa, Setsuko; Piao, Jinhua; Ihara, Norimasa; Kanai, Sayaka; Kakei, Saori; Tamura, Yoshifumi; Suganami, Takayoshi; Kamei, Yasutomi; Shimizu, Toshiaki; Yasuda, Akio; Ogawa, Yoshihiro; Mizutani, Shuki

    2015-02-11

    Ataxia-telangiectasia (A-T) patients occasionally develop diabetes mellitus. However, only limited attempts have been made to gain insight into the molecular mechanism of diabetes mellitus development in A-T patients. We found that Atm -/- mice were insulin resistant and possessed less subcutaneous adipose tissue as well as a lower level of serum adiponectin than Atm +/+ mice. Furthermore, in vitro studies revealed impaired adipocyte differentiation in Atm -/- cells caused by the lack of induction of C/EBPα and PPARγ, crucial transcription factors involved in adipocyte differentiation. Interestingly, ATM was activated by stimuli that induced differentiation, and the binding of ATM to C/EBPβ and p300 was involved in the transcriptional regulation of C/EBPα and adipocyte differentiation. Thus, our study sheds light on the poorly understood role of ATM in the pathogenesis of glucose intolerance in A-T patients and provides insight into the role of ATM in glucose metabolism. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Hormones and the autonomic nervous system are involved in suprachiasmatic nucleus modulation of glucose homeostasis.

    PubMed

    Ruiter, Marieke; Buijs, Ruud M; Kalsbeek, Andries

    2006-05-01

    Glucose is one of the most important energy sources for the body in general, and the brain in particular. It is essential for survival to keep glucose levels within strict boundaries. Acute disturbances of glucose homeostasis are rapidly corrected by hormonal and neuronal mechanisms. Furthermore, changes in energy expenditure associated with the light-dark cycle induce variations in the plasma glucose concentration that are more gradual. Organisms take advantage of adapting their internal physiology to the predictable daily changes in energy expenditure, because it enables them to anticipate these changes and to prevent unnecessary disturbance of homeostasis. The hypothalamic biological clock, located in the suprachiasmatic nucleus (SCN), receives light information from the eyes and transmits this information to the rest of the body to synchronize physiology to the environment. Here we review several studies providing evidence for biological clock control of the daily variation in several aspects of glucose metabolism. Although both hormones and the autonomic nervous system can stimulate glucose uptake or production by organs in the periphery, we have shown that the biological clock control of glucose metabolism mostly occurs through the autonomic nervous system. The critical involvement of the biological clock is also indicated by several studies, indicating that disturbance of the biological clock is often associated with metabolic diseases, such as obesity, diabetes mellitus and hypertension.

  11. SRC-2 orchestrates polygenic inputs for fine-tuning glucose homeostasis

    PubMed Central

    Fleet, Tiffany; Zhang, Bin; Lin, Fumin; Zhu, Bokai; Dasgupta, Subhamoy; Stashi, Erin; Tackett, Bryan; Thevananther, Sundararajah; Rajapakshe, Kimal I.; Gonzales, Naomi; Dean, Adam; Mao, Jianqiang; Timchenko, Nikolai; Malovannaya, Anna; Qin, Jun; Coarfa, Cristian; DeMayo, Francesco; Dacso, Clifford C.; Foulds, Charles E.; O’Malley, Bert W.; York, Brian

    2015-01-01

    Despite extensive efforts to understand the monogenic contributions to perturbed glucose homeostasis, the complexity of genetic events that fractionally contribute to the spectrum of this pathology remain poorly understood. Proper maintenance of glucose homeostasis is the central feature of a constellation of comorbidities that define the metabolic syndrome. The ability of the liver to balance carbohydrate uptake and release during the feeding-to-fasting transition is essential to the regulation of peripheral glucose availability. The liver coordinates the expression of gene programs that control glucose absorption, storage, and secretion. Herein, we demonstrate that Steroid Receptor Coactivator 2 (SRC-2) orchestrates a hierarchy of nutritionally responsive transcriptional complexes to precisely modulate plasma glucose availability. Using DNA pull-down technology coupled with mass spectrometry, we have identified SRC-2 as an indispensable integrator of transcriptional complexes that control the rate-limiting steps of hepatic glucose release and accretion. Collectively, these findings position SRC-2 as a major regulator of polygenic inputs to metabolic gene regulation and perhaps identify a previously unappreciated model that helps to explain the clinical spectrum of glucose dysregulation. PMID:26487680

  12. Deletion of the Rab GAP Tbc1d1 modifies glucose, lipid, and energy homeostasis in mice.

    PubMed

    Hargett, Stefan R; Walker, Natalie N; Hussain, Syed S; Hoehn, Kyle L; Keller, Susanna R

    2015-08-01

    Tbc1d1 is a Rab GTPase-activating protein (GAP) implicated in regulating intracellular retention and cell surface localization of the glucose transporter GLUT4 and thus glucose uptake in a phosphorylation-dependent manner. Tbc1d1 is most abundant in skeletal muscle but is expressed at varying levels among different skeletal muscles. Previous studies with male Tbc1d1-deficient (Tbc1d1(-/-)) mice on standard and high-fat diets established a role for Tbc1d1 in glucose, lipid, and energy homeostasis. Here we describe similar, but also additional abnormalities in male and female Tbc1d1(-/-) mice. We corroborate that Tbc1d1 loss leads to skeletal muscle-specific and skeletal muscle type-dependent abnormalities in GLUT4 expression and glucose uptake in female and male mice. Using subcellular fractionation, we show that Tbc1d1 controls basal intracellular GLUT4 retention in large skeletal muscles. However, cell surface labeling of extensor digitorum longus muscle indicates that Tbc1d1 does not regulate basal GLUT4 cell surface exposure as previously suggested. Consistent with earlier observations, female and male Tbc1d1(-/-) mice demonstrate increased energy expenditure and skeletal muscle fatty acid oxidation. Interestingly, we observe sex-dependent differences in in vivo phenotypes. Female, but not male, Tbc1d1(-/-) mice have decreased body weight and impaired glucose and insulin tolerance, but only male Tbc1d1(-/-) mice show increased lipid clearance after oil gavage. We surmise that similar changes at the tissue level cause differences in whole-body metabolism between male and female Tbc1d1(-/-) mice and between male Tbc1d1(-/-) mice in different studies due to variations in body composition and nutrient handling. Copyright © 2015 the American Physiological Society.

  13. NPY modulates PYY function in the regulation of energy balance and glucose homeostasis.

    PubMed

    Zhang, L; Nguyen, A D; Lee, I-C J; Yulyaningsih, E; Riepler, S J; Stehrer, B; Enriquez, R F; Lin, S; Shi, Y-C; Baldock, P A; Sainsbury, A; Herzog, H

    2012-08-01

    Both the neuronal-derived neuropeptide Y (NPY) and the gut hormone peptide YY (PYY) have been implicated in the regulation of energy balance and glucose homeostasis. However, despite similar affinities for the same Y receptors, the co-ordinated actions of these two peptides in energy and glucose homeostasis remain largely unknown. To investigate the mechanisms and possible interactions between PYY with NPY in the regulation of these processes, we utilized NPY/PYY single and double mutant mouse models and examined parameters of energy balance and glucose homeostasis. PYY(-/-) mice exhibited increased fasting-induced food intake, enhanced fasting and oral glucose-induced serum insulin levels, and an impaired insulin tolerance, - changes not observed in NPY(-/-) mice. Interestingly, whereas PYY deficiency-induced impairment in insulin tolerance remained in NPY(-/-) PYY(-/-) mice, effects of PYY deficiency on fasting-induced food intake and serum insulin concentrations at baseline and after the oral glucose bolus were absent in NPY(-/-) PYY(-/-) mice, suggesting that NPY signalling may be required for PYY's action on insulin secretion and fasting-induced hyperphagia. Moreover, NPY(-/-) PYY(-/-) , but not NPY(-/-) or PYY(-/-) mice had significantly decreased daily food intake, indicating interactive control by NPY and PYY on spontaneous food intake. Furthermore, both NPY(-/-) and PYY(-/-) mice showed significantly reduced respiratory exchange ratio during the light phase, with no additive effects observed in NPY(-/-) PYY(-/-) mice, indicating that NPY and PYY may regulate oxidative fuel selection via partly shared mechanisms. Overall, physical activity and energy expenditure, however, are not significantly altered by NPY and PYY single or double deficiencies. These findings show significant and diverse interactions between NPY and PYY signalling in the regulation of different aspects of energy balance and glucose homeostasis. © 2012 Blackwell Publishing Ltd.

  14. Importance of the gut-brain axis in the control of glucose homeostasis.

    PubMed

    Migrenne, Stéphanie; Marsollier, Nicolas; Cruciani-Guglielmacci, Céline; Magnan, Christophe

    2006-12-01

    Adult mammals finely match glucose production to glucose utilization, thus allowing glycaemia to be maintained in a physiological range of 0.8-1.2mg/dl whatever the energetic status of the mammal (i.e. fed or fasted, rested or exercised). To accomplish this, peripheral signals originating from the gut 'inform' the central nervous system, which in turn is able to monitor the status of both peripheral glucose stores and ongoing fuel availability. Indeed, both secretion and action of hormones regulating endogenous glucose production and utilization are regulated by the autonomic nervous system. These gut signals are either hormonal (e.g. glucagon-like peptide-1, ghrelin and cholecystokinine) or neuronal (e.g. afferent vagus nerve fibres). Recent data, combined with the development of incretin analogues for treatment of diabetes, highlight the importance of the gut-brain axis, especially glucagon-like peptide-1 and ghrelin, in the control of glucose homeostasis.

  15. Astrocytes in the nucleus of the solitary tract are activated by low glucose or glucoprivation: evidence for glial involvement in glucose homeostasis.

    PubMed

    McDougal, David H; Hermann, Gerlinda E; Rogers, Richard C

    2013-01-01

    Glucose homeostasis is maintained through interplay between central and peripheral control mechanisms which are aimed at storing excess glucose following meals and mobilizing these same stores during periods of fasting. The nucleus of the solitary tract (NST) in the dorsal medulla has long been associated with the central detection of glucose availability and the control of glucose homeostasis. Recent evidence has emerged which supports the involvement of astrocytes in glucose homeostasis. The aim of the present study was to investigate whether NST-astrocytes respond to physiologically relevant decreases in glucose availability, in vitro, as well as to the presence of the glucoprivic compound 2-deoxy-D-Glucose. This report demonstrates that some NST-astrocytes are capable of responding to low glucose or glucoprivation by increasing cytoplasmic calcium; a change that reverses with restoration of normal glucose availability. While some NST-neurons also demonstrate an increase in calcium signaling during low glucose availability, this effect is smaller and somewhat delayed compared to those observed in adjacent astrocytes. TTX did not abolish these hypoglycemia mediated responses of astrocytes, suggesting that NST-astrocytes may be directly sensing low glucose levels as opposed to responding to neuronal detection of hypoglycemia. Thus, chemodetection of low glucose by NST-astrocytes may play an important role in the autonomic regulation of glucose homeostasis.

  16. A closed-loop multi-level model of glucose homeostasis

    PubMed Central

    Uluseker, Cansu; Simoni, Giulia; Dauriz, Marco; Matone, Alice

    2018-01-01

    Background The pathophysiologic processes underlying the regulation of glucose homeostasis are considerably complex at both cellular and systemic level. A comprehensive and structured specification for the several layers of abstraction of glucose metabolism is often elusive, an issue currently solvable with the hierarchical description provided by multi-level models. In this study we propose a multi-level closed-loop model of whole-body glucose homeostasis, coupled with the molecular specifications of the insulin signaling cascade in adipocytes, under the experimental conditions of normal glucose regulation and type 2 diabetes. Methodology/Principal findings The ordinary differential equations of the model, describing the dynamics of glucose and key regulatory hormones and their reciprocal interactions among gut, liver, muscle and adipose tissue, were designed for being embedded in a modular, hierarchical structure. The closed-loop model structure allowed self-sustained simulations to represent an ideal in silico subject that adjusts its own metabolism to the fasting and feeding states, depending on the hormonal context and invariant to circadian fluctuations. The cellular level of the model provided a seamless dynamic description of the molecular mechanisms downstream the insulin receptor in the adipocytes by accounting for variations in the surrounding metabolic context. Conclusions/Significance The combination of a multi-level and closed-loop modeling approach provided a fair dynamic description of the core determinants of glucose homeostasis at both cellular and systemic scales. This model architecture is intrinsically open to incorporate supplementary layers of specifications describing further individual components influencing glucose metabolism. PMID:29420588

  17. Childhood cardiorespiratory fitness, muscular fitness and adult measures of glucose homeostasis.

    PubMed

    Fraser, Brooklyn J; Blizzard, Leigh; Schmidt, Michael D; Juonala, Markus; Dwyer, Terence; Venn, Alison J; Magnussen, Costan G

    2018-02-14

    To assess whether childhood cardiorespiratory fitness (CRF) and muscular fitness phenotypes (strength, power, endurance) predict adult glucose homeostasis measures. Prospective longitudinal study. Study examining participants who had physical fitness measured in childhood (aged 7-15 years) and who attended follow-up clinics approximately 20 years later and provided a fasting blood sample which was tested for glucose and insulin. Physical fitness measurements included muscular strength (right and left grip, shoulder flexion, shoulder and leg extension), power (standing long jump distance) and endurance (number of push-ups in 30s), and CRF (1.6km run duration). In adulthood, fasting glucose and insulin levels were used to derive glucose homeostasis measures of insulin resistance (HOMA2-IR) and beta cell function (HOMA2-β). A standard deviation increase in childhood CRF or muscular strength (males) was associated with fasting glucose (CRF: β=-0.06mmol/L), fasting insulin (CRF: β=-0.73mU/L; strength: β=-0.40mU/L), HOMA2-IR (CRF: β=-0.06; strength: β=-0.05) and HOMA2-β (CRF: β=-3.06%; strength: β=-2.62%) in adulthood, independent of the alternative fitness phenotype (all p<0.01). Adjustment for childhood waist circumference reduced the effect by 17-35% for CRF and 0-15% for muscular strength (males) and statistical significance remained for all associations expect between CRF, fasting glucose and HOMA2-β (p>0.06). CRF and muscular fitness in childhood were inversely associated with measures of fasting insulin, insulin resistance and beta cell function in adulthood. Childhood CRF and muscular fitness could both be potential independent targets for strategies to help reduce the development of adverse glucose homeostasis. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. Effects of prenatal caffeine exposure on glucose homeostasis of adult offspring rats

    NASA Astrophysics Data System (ADS)

    Kou, Hao; Wang, Gui-hua; Pei, Lin-guo; Zhang, Li; Shi, Chai; Guo, Yu; Wu, Dong-fang; Wang, Hui

    2017-12-01

    Epidemiological evidences show that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR). The IUGR offspring also present glucose intolerance and type 2 diabetes mellitus after maturity. We have previously demonstrated that PCE induced IUGR and increased susceptibility to adult metabolic syndrome in rats. This study aimed to further investigate the effects of PCE on glucose homeostasis in adult offspring rats. Pregnant rats were administered caffeine (120 mg/kg/day, intragastrically) from gestational days 11 to 20. PCE offspring presented partial catch-up growth pattern after birth, characterizing by the increased body weight gain rates. Meanwhile, PCE had no significant influences on the basal blood glucose and insulin phenotypes of adult offspring but increased the glucose tolerance, glucose-stimulated insulin section and β cell sensitivity to glucose in female progeny. The insulin sensitivity of both male and female PCE offspring were enhanced accompanied with reduced β cell fraction and mass. Western blotting results revealed that significant augmentation in protein expression of hepatic insulin signaling elements of PCE females, including insulin receptor (INSR), insulin receptor substrate 1 (IRS-1) and the phosphorylation of serine-threonine protein kinase (Akt), was also potentiated. In conclusion, we demonstrated that PCE reduced the pancreatic β mass but increased the glucose tolerance in adult offspring rats, especially for females. The adaptive compensatory enhancement of β cell responsiveness to glucose and elevated insulin sensitivity mainly mediated by upregulated hepatic insulin signaling might coordinately contribute to the increased glucose tolerance.

  19. Leptin Rapidly Improves Glucose Homeostasis in Obese Mice by Increasing Hypothalamic Insulin Sensitivity

    PubMed Central

    Koch, Christiane; Augustine, Rachael A.; Steger, Juliane; Ganjam, Goutham K.; Benzler, Jonas; Pracht, Corinna; Lowe, Chrishanthi; Schwartz, Michael W.; Shepherd, Peter R.; Anderson, Greg M.; Grattan, David R.; Tups, Alexander

    2013-01-01

    Obesity is associated with resistance to the actions of both leptin and insulin via mechanisms that remain incompletely understood. To investigate whether leptin resistance per se contributes to insulin resistance and impaired glucose homeostasis, we investigated the effect of acute leptin administration on glucose homeostasis in normal as well as leptin- or leptin receptor-deficient mice. In hyperglycemic, leptin-deficient Lepob/ob mice, leptin acutely and potently improved glucose metabolism, before any change of body fat mass, via a mechanism involving the p110α and β isoforms of phosphatidylinositol-3-kinase (PI3K). Unlike insulin, however, the anti-diabetic effect of leptin occurred independently of phospho-AKT, a major downstream target of PI3K, and instead involved enhanced sensitivity of the hypothalamus to insulin action upstream of PI3K, through modulation of IRS1 (insulin receptor substrate 1) phosphorylation. These data suggest that leptin resistance, as occurs in obesity, reduces the hypothalamic response to insulin and thereby impairs peripheral glucose homeostasis, contributing to the development of type 2 diabetes. PMID:21123564

  20. Leptin rapidly improves glucose homeostasis in obese mice by increasing hypothalamic insulin sensitivity.

    PubMed

    Koch, Christiane; Augustine, Rachael A; Steger, Juliane; Ganjam, Goutham K; Benzler, Jonas; Pracht, Corinna; Lowe, Chrishanthi; Schwartz, Michael W; Shepherd, Peter R; Anderson, Greg M; Grattan, David R; Tups, Alexander

    2010-12-01

    Obesity is associated with resistance to the actions of both leptin and insulin via mechanisms that remain incompletely understood. To investigate whether leptin resistance per se contributes to insulin resistance and impaired glucose homeostasis, we investigated the effect of acute leptin administration on glucose homeostasis in normal as well as leptin- or leptin receptor-deficient mice. In hyperglycemic, leptin-deficient Lep(ob/ob) mice, leptin acutely and potently improved glucose metabolism, before any change of body fat mass, via a mechanism involving the p110α and β isoforms of phosphatidylinositol-3-kinase (PI3K). Unlike insulin, however, the anti-diabetic effect of leptin occurred independently of phospho-AKT, a major downstream target of PI3K, and instead involved enhanced sensitivity of the hypothalamus to insulin action upstream of PI3K, through modulation of IRS1 (insulin receptor substrate 1) phosphorylation. These data suggest that leptin resistance, as occurs in obesity, reduces the hypothalamic response to insulin and thereby impairs peripheral glucose homeostasis, contributing to the development of type 2 diabetes.

  1. Evaluating the mechanisms of improved glucose homeostasis after bariatric surgery in Ossabaw miniature swine.

    PubMed

    Sham, Jonathan G; Simianu, Vlad V; Wright, Andrew S; Stewart, Skye D; Alloosh, Mouhamad; Sturek, Michael; Cummings, David E; Flum, David R

    2014-01-01

    Roux-en-Y gastric bypass (RYGB) is the most common bariatric operation; however, the mechanism underlying the profound weight-independent effects on glucose homeostasis remains unclear. Large animal models of naturally occurring insulin resistance (IR), which have been lacking, would provide opportunities to elucidate such mechanisms. Ossabaw miniature swine naturally exhibit many features that may be useful in evaluating the anti diabetic effects of bariatric surgery. Glucose homeostasis was studied in 53 Ossabaw swine. Thirty-two received an obesogenic diet and were randomized to RYGB, gastrojejunostomy (GJ), gastrojejunostomy with duodenal exclusion (GJD), or Sham operations. Intravenous glucose tolerance tests and standardized meal tolerance tests were performed prior to, 1, 2, and 8 weeks after surgery and at a single time-point for regular diet control pigs. High-calorie-fed Ossabaws weighed more and had greater IR than regular diet controls, though only 70% developed IR. All operations caused weight-loss-independent improvement in IR, though only in pigs with high baseline IR. Only RYGB induced weight loss and decreased IR in the majority of pigs, as well as increasing AUCinsulin/AUCglucose. Similar to humans, Ossabaw swine exhibit both obesity-dependent and obesity-independent IR. RYGB promoted weight loss, IR improvement, and increased AUCinsulin/AUCglucose, compared to the smaller changes following GJ and GJD, suggesting a combination of upper and lower gut mechanisms in improving glucose homeostasis.

  2. Maintenance of Gastrointestinal Glucose Homeostasis by the Gut-Brain Axis.

    PubMed

    Chen, Xiyue; Eslamfam, Shabnam; Fang, Luoyun; Qiao, Shiyan; Ma, Xi

    2017-01-01

    Gastrointestinal homeostasis is a dynamic balance under the interaction between the host, GI tract, nutrition and energy metabolism. Glucose is the main energy source in living cells. Thus, glucose metabolic disorders can impair normal cellular function and endanger organisms' health. Diseases that are associated with glucose metabolic disorders such as obesity, diabetes, hypertension, and other metabolic syndromes are in fact life threatening. Digestive system is responsible for food digestion and nutrient absorption. It is also involved in neuronal, immune, and endocrine pathways. In addition, the gut microbiota plays an essential role in initiating signal transduction, and communication between the enteric and central nervous system. Gut-brain axis is composed of enteric neural system, central neural system, and all the efferent and afferent neurons that are involved in signal transduction between the brain and gut-brain. Gut-brain axis is influenced by the gut-microbiota as well as numerous neurotransmitters. Properly regulated gut-brain axis ensures normal digestion, absorption, energy production, and subsequently maintenance of glucose homeostasis. Understanding the underlying regulatory mechanisms of gut-brain axis involved in gluose homeostasis would enable us develop more efficient means of prevention and management of metabolic disease such as diabetic, obesity, and hypertension. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Phosphatidyl inositol 3-kinase signaling in hypothalamic proopiomelanocortin neurons contributes to the regulation of glucose homeostasis.

    PubMed

    Hill, Jennifer W; Xu, Yong; Preitner, Frederic; Fukuda, Makota; Cho, You-Ree; Luo, Ji; Balthasar, Nina; Coppari, Roberto; Cantley, Lewis C; Kahn, Barbara B; Zhao, Jean J; Elmquist, Joel K

    2009-11-01

    Recent studies demonstrated a role for hypothalamic insulin and leptin action in the regulation of glucose homeostasis. This regulation involves proopiomelanocortin (POMC) neurons because suppression of phosphatidyl inositol 3-kinase (PI3K) signaling in these neurons blunts the acute effects of insulin and leptin on POMC neuronal activity. In the current study, we investigated whether disruption of PI3K signaling in POMC neurons alters normal glucose homeostasis using mouse models designed to both increase and decrease PI3K-mediated signaling in these neurons. We found that deleting p85alpha alone induced resistance to diet-induced obesity. In contrast, deletion of the p110alpha catalytic subunit of PI3K led to increased weight gain and adipose tissue along with reduced energy expenditure. Independent of these effects, increased PI3K activity in POMC neurons improved insulin sensitivity, whereas decreased PI3K signaling resulted in impaired glucose regulation. These studies show that activity of the PI3K pathway in POMC neurons is involved in not only normal energy regulation but also glucose homeostasis.

  4. Pro-inflammatory mediators disrupt glucose homeostasis in airway surface liquid ‡

    PubMed Central

    Garnett, James P.; Nguyen, Trang T.; Moffatt, James D.; Pelham, Elizabeth R.; Kalsi, Kameljit K.; Baker, Emma H.; Baines, Deborah L.

    2012-01-01

    The glucose concentration of the airway surface liquid (ASL) is much lower than blood and is tightly regulated by the airway epithelium. ASL glucose is elevated in patients with viral colds, cystic fibrosis, chronic obstructive pulmonary disease (COPD) and asthma. Elevated ASL glucose is also associated with increased incidence of respiratory infection. However, the mechanism by which ASL glucose increases under inflammatory conditions is unknown. The aim of this study was to investigate the effect of pro-inflammatory mediators (PIMs) on the mechanisms governing airway glucose homeostasis in polarised monolayers of human airway (H441) and primary human bronchial epithelial (HBE) cells. Monolayers were treated with TNF-α, IFN-γ and LPS over 72 hours. PIM treatment led to increase in ASL glucose concentration and significantly reduced H441 and HBE transepithelial resistance (RT). This decline in RT was associated with an increase in paracellular permeability of glucose. Similar enhanced rates of paracellular glucose flux were also observed across excised trachea from LPS-treated mice. Interestingly, PIMs enhanced glucose uptake across the apical, but not the basolateral, membrane of H441 and HBE monolayers. This increase was predominantly via phloretin-sensitive GLUT-mediated uptake, which coincided with an increase in GLUT2 and GLUT10 abundance. In conclusion, exposure of airway epithelial monolayers to PIMs results in increased paracellular glucose flux, and apical GLUT-mediated glucose uptake. However uptake was insufficient to limit glucose accumulation in ASL. These data provide for the first time, a mechanism to support clinical findings that ASL glucose concentration is increased in patients with airway inflammation. PMID:22623330

  5. Effects of Ramadan fasting on glucose homeostasis and adiponectin levels in healthy adult males.

    PubMed

    Gnanou, Justin V; Caszo, Brinnell A; Khalil, Khalifah M; Abdullah, Shahidah L; Knight, Victor F; Bidin, Mohd Z

    2015-01-01

    Adiponectin is a hormone secreted by adipocytes during the fasting phase of the fast-fed cycle. Ramadan fasting involves prolonged fasting for up to twelve hours and thus could lead to increased secretion of adiponectin by adipocytes. However, studies on the role of adiponectin on glucose and body weight homeostasis during Ramadan fasting is still a matter of controversy. Thus the specific aim of this study was to assess the effect of fasting during Ramadan on the adiponectin levels, body weight and glucose homeostasis in healthy male Malaysian subjects. Twenty healthy male (19-23 years) Muslim subjects were followed up during the fasting month of Ramadan. Anthropometry and blood samples were taken one week before and during the fourth week of fasting. Plasma glucose, insulin and adiponectin were estimated and insulin sensitivity indices were estimated using the Homeostasis Model Assessment. Subjects experienced a significant decrease in body weight (2.4 %, p < 0.001) and body mass index (5.5 %, p < 0.01). There was also a significant decrease of 12.3 %, 52.8 % and 45.6 % of plasma glucose, insulin and adiponectin respectively (p < 0.01). The drop in adiponectin was positively correlated with the decrease in body weight (r = 0.45, p < 0.05). There was also a significant increase in insulin sensitivity and a decrease in insulin resistance (p < 0.01). These results indicate that Ramadan fasting in young healthy individuals has a positive impact on the maintenance of glucose homeostasis. It also shows that adiponectin levels dropped along with significant loss in weight. We feel caloric restriction during the Ramadan fasting is in itself sufficient to improve insulin sensitivity in healthy individuals.

  6. Molecular aspects of glucose homeostasis in skeletal muscle--A focus on the molecular mechanisms of insulin resistance.

    PubMed

    Carnagarin, Revathy; Dharmarajan, Arun M; Dass, Crispin R

    2015-12-05

    Among all the varied actions of insulin, regulation of glucose homeostasis is the most critical and intensively studied. With the availability of glucose from nutrient metabolism, insulin action in muscle results in increased glucose disposal via uptake from the circulation and storage of excess, thereby maintaining euglycemia. This major action of insulin is executed by redistribution of the glucose transporter protein, GLUT4 from intracellular storage sites to the plasma membrane and storage of glucose in the form of glycogen which also involves modulation of actin dynamics that govern trafficking of all the signal proteins of insulin signal transduction. The cellular mechanisms responsible for these trafficking events and the defects associated with insulin resistance are largely enigmatic, and this review provides a consolidated overview of the various molecular mechanisms involved in insulin-dependent glucose homeostasis in skeletal muscle, as insulin resistance at this major peripheral site impacts whole body glucose homeostasis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Glucose is necessary to maintain neurotransmitter homeostasis during synaptic activity in cultured glutamatergic neurons.

    PubMed

    Bak, Lasse K; Schousboe, Arne; Sonnewald, Ursula; Waagepetersen, Helle S

    2006-10-01

    Glucose is the primary energy substrate for the adult mammalian brain. However, lactate produced within the brain might be able to serve this purpose in neurons. In the present study, the relative significance of glucose and lactate as substrates to maintain neurotransmitter homeostasis was investigated. Cultured cerebellar (primarily glutamatergic) neurons were superfused in medium containing [U-13C]glucose (2.5 mmol/L) and lactate (1 or 5 mmol/L) or glucose (2.5 mmol/L) and [U-13C]lactate (1 mmol/L), and exposed to pulses of N-methyl-D-aspartate (300 micromol/L), leading to synaptic activity including vesicular release. The incorporation of 13C label into intracellular lactate, alanine, succinate, glutamate, and aspartate was determined by mass spectrometry. The metabolism of [U-13C]lactate under non-depolarizing conditions was high compared with that of [U-13C]glucose; however, it decreased significantly during induced depolarization. In contrast, at both concentrations of extracellular lactate, the metabolism of [U-13C]glucose was increased during neuronal depolarization. The role of glucose and lactate as energy substrates during vesicular release as well as transporter-mediated influx and efflux of glutamate was examined using preloaded D-[3H]aspartate as a glutamate tracer and DL-threo-beta-benzyloxyaspartate to inhibit glutamate transporters. The results suggest that glucose is essential to prevent depolarization-induced reversal of the transporter (efflux), whereas vesicular release was unaffected by the choice of substrate. In conclusion, the present study shows that glucose is a necessary substrate to maintain neurotransmitter homeostasis during synaptic activity and that synaptic activity does not induce an upregulation of lactate metabolism in glutamatergic neurons.

  8. Compartmentalized acyl-CoA metabolism in skeletal muscle regulates systemic glucose homeostasis.

    PubMed

    Li, Lei O; Grevengoed, Trisha J; Paul, David S; Ilkayeva, Olga; Koves, Timothy R; Pascual, Florencia; Newgard, Christopher B; Muoio, Deborah M; Coleman, Rosalind A

    2015-01-01

    The impaired capacity of skeletal muscle to switch between the oxidation of fatty acid (FA) and glucose is linked to disordered metabolic homeostasis. To understand how muscle FA oxidation affects systemic glucose, we studied mice with a skeletal muscle-specific deficiency of long-chain acyl-CoA synthetase (ACSL)1. ACSL1 deficiency caused a 91% loss of ACSL-specific activity and a 60-85% decrease in muscle FA oxidation. Acsl1(M-/-) mice were more insulin sensitive, and, during an overnight fast, their respiratory exchange ratio was higher, indicating greater glucose use. During endurance exercise, Acsl1(M-/-) mice ran only 48% as far as controls. At the time that Acsl1(M-/-) mice were exhausted but control mice continued to run, liver and muscle glycogen and triacylglycerol stores were similar in both genotypes; however, plasma glucose concentrations in Acsl1(M-/-) mice were ∼40 mg/dL, whereas glucose concentrations in controls were ∼90 mg/dL. Excess use of glucose and the likely use of amino acids for fuel within muscle depleted glucose reserves and diminished substrate availability for hepatic gluconeogenesis. Surprisingly, the content of muscle acyl-CoA at exhaustion was markedly elevated, indicating that acyl-CoAs synthesized by other ACSL isoforms were not available for β-oxidation. This compartmentalization of acyl-CoAs resulted in both an excessive glucose requirement and severely compromised systemic glucose homeostasis. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  9. Bisphenol S exposure impairs glucose homeostasis in male zebrafish (Danio rerio).

    PubMed

    Zhao, Fei; Jiang, Guobin; Wei, Penghao; Wang, Hongfang; Ru, Shaoguo

    2018-01-01

    Bisphenol S (BPS) is a substitute of the plastic additive bisphenol A (BPA). Its concentrations detected in surface waters and urine samples are on the same order of magnitude as BPA. Human exposure to BPA has been implicated in the development of diabetes mellitus; however, whether BPS can disrupt glucose homeostasis and increase blood glucose concentration remains unclear. We extensively investigated the effects of environmentally relevant concentrations of BPS on glucose metabolism in male zebrafish (Danio rerio) and the underlying mechanisms of these effects. Male zebrafish were exposed to 1, 10, or 100μg/L of BPS for 28 d. Fasting blood glucose (FBG) levels, glycogen levels in the liver and muscle, and mRNA levels of key glucose metabolic enzymes and the activities of the encoded proteins in tissues were evaluated to assess the effect of BPS on glucose metabolism. Plasma insulin levels and expression of preproinsulin and glucagon genes in the visceral tissue were also evaluated. Compared with the control group, exposure to 1 and 10μg/L of BPS significantly increased FBG levels but decreased insulin levels. Gluconeogenesis and glycogenolysis in the liver were promoted, and glycogen synthesis in the liver and muscle and glycolysis in the muscle were inhibited. Exposure to 100μg/L of BPS did not significantly alter plasma insulin and blood glucose levels, but nonetheless pronouncedly interfered with gluconeogenesis, glycogenolysis, glycolysis, and glycogen synthesis. Our data indicates that BPS at environmentally relevant concentrations impairs glucose homeostasis of male zebrafish possibly by hampering the physiological effect of insulin; higher BPS doses also pronouncedly interfered with glucose metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Role of the M3 muscarinic acetylcholine receptor in beta-cell function and glucose homeostasis.

    PubMed

    Gautam, D; Han, S-J; Duttaroy, A; Mears, D; Hamdan, F F; Li, J H; Cui, Y; Jeon, J; Wess, J

    2007-11-01

    The release of insufficient amounts of insulin in the presence of elevated blood glucose levels is one of the key features of type 2 diabetes. Various lines of evidence indicate that acetylcholine (ACh), the major neurotransmitter of the parasympathetic nervous system, can enhance glucose-stimulated insulin secretion from pancreatic beta-cells. Studies with isolated islets prepared from whole body M(3) muscarinic ACh receptor knockout mice showed that cholinergic amplification of glucose-dependent insulin secretion is exclusively mediated by the M(3) muscarinic receptor subtype. To investigate the physiological relevance of this muscarinic pathway, we used Cre/loxP technology to generate mutant mice that lack M(3) receptors only in pancreatic beta-cells. These mutant mice displayed impaired glucose tolerance and significantly reduced insulin secretion. In contrast, transgenic mice overexpressing M(3) receptors in pancreatic beta-cells showed a pronounced increase in glucose tolerance and insulin secretion and were resistant to diet-induced glucose intolerance and hyperglycaemia. These findings indicate that beta-cell M(3) muscarinic receptors are essential for maintaining proper insulin secretion and glucose homeostasis. Moreover, our data suggest that enhancing signalling through beta-cell M(3) muscarinic receptors may represent a new avenue in the treatment of glucose intolerance and type 2 diabetes.

  11. Hypothalamic Neuropeptide 26RFa Acts as an Incretin to Regulate Glucose Homeostasis.

    PubMed

    Prévost, Gaëtan; Jeandel, Lydie; Arabo, Arnaud; Coëffier, Moïse; El Ouahli, Mariama; Picot, Marie; Alexandre, David; Gobet, Françoise; Leprince, Jérôme; Berrahmoune, Hind; Déchelotte, Pierre; Malagon, Maria; Bonner, Caroline; Kerr-Conte, Julie; Chigr, Fatiha; Lefebvre, Hervé; Anouar, Youssef; Chartrel, Nicolas

    2015-08-01

    26RFa is a hypothalamic neuropeptide that promotes food intake. 26RFa is upregulated in obese animal models, and its orexigenic activity is accentuated in rodents fed a high-fat diet, suggesting that this neuropeptide might play a role in the development and maintenance of the obese status. As obesity is frequently associated with type 2 diabetes, we investigated whether 26RFa may be involved in the regulation of glucose homeostasis. In the current study, we show a moderate positive correlation between plasma 26RFa levels and plasma insulin in patients with diabetes. Plasma 26RFa concentration also increases in response to an oral glucose tolerance test. In addition, we found that 26RFa and its receptor GPR103 are present in human pancreatic β-cells as well as in the gut. In mice, 26RFa attenuates the hyperglycemia induced by a glucose load, potentiates insulin sensitivity, and increases plasma insulin concentrations. Consistent with these data, 26RFa stimulates insulin production by MIN6 insulinoma cells. Finally, we show, using in vivo and in vitro approaches, that a glucose load induces a massive secretion of 26RFa by the small intestine. Altogether, the present data indicate that 26RFa acts as an incretin to regulate glucose homeostasis. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  12. Role of orexins in the central and peripheral regulation of glucose homeostasis: Evidences & mechanisms.

    PubMed

    Rani, Monika; Kumar, Raghuvansh; Krishan, Pawan

    2018-04-01

    Orexins (A & B), neuropeptides of hypothalamic origin, act through G-protein coupled receptors, orexin 1 receptor (OX 1 R) and orexin 2 receptor (OX 2 R). The wide projection of orexin neurons in the hypothalamic region allows them to interact with the other neurons and regulate food intake, emotional status, sleep wake cycle and energy metabolism. The autonomic nervous system plays an important regulatory role in the energy metabolism as well as glucose homeostasis. Orexin neurons are also under the control of GABAergic neurons. Emerging preclinical as well as clinical research has reported the role of orexins in the glucose homeostasis since orexins are involved in hypothalamic metabolism circuitry and also rely on sensing peripheral metabolic signals such as gut, adipose derived and pancreatic peptides. Apart from the hypothalamic origin, integration and control in various physiological functions, peripheral origin in wide organs, raises the possibility of use of orexins as a therapeutic biomarker in the management of metabolic disorders. The present review focuses the central as well as peripheral roles of orexins in the glucose homeostasis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Perk Gene Dosage Regulates Glucose Homeostasis by Modulating Pancreatic β-Cell Functions

    PubMed Central

    Wang, Rong; Munoz, Elyse E.; Zhu, Siying; McGrath, Barbara C.; Cavener, Douglas R.

    2014-01-01

    Background Insulin synthesis and cell proliferation are under tight regulation in pancreatic β-cells to maintain glucose homeostasis. Dysfunction in either aspect leads to development of diabetes. PERK (EIF2AK3) loss of function mutations in humans and mice exhibit permanent neonatal diabetes that is characterized by insufficient β-cell mass and reduced proinsulin trafficking and insulin secretion. Unexpectedly, we found that Perk heterozygous mice displayed lower blood glucose levels. Methodology Longitudinal studies were conducted to assess serum glucose and insulin, intracellular insulin synthesis and storage, insulin secretion, and β-cell proliferation in Perk heterozygous mice. In addition, modulation of Perk dosage specifically in β-cells showed that the glucose homeostasis phenotype of Perk heterozygous mice is determined by reduced expression of PERK in the β-cells. Principal Findings We found that Perk heterozygous mice first exhibited enhanced insulin synthesis and secretion during neonatal and juvenile development followed by enhanced β-cell proliferation and a substantial increase in β-cell mass at the adult stage. These differences are not likely to entail the well-known function of PERK to regulate the ER stress response in cultured cells as several markers for ER stress were not differentially expressed in Perk heterozygous mice. Conclusions In addition to the essential functions of PERK in β-cells as revealed by severely diabetic phenotype in humans and mice completely deficient for PERK, reducing Perk gene expression by half showed that intermediate levels of PERK have a profound impact on β-cell functions and glucose homeostasis. These results suggest that an optimal level of PERK expression is necessary to balance several parameters of β-cell function and growth in order to achieve normoglycemia. PMID:24915520

  14. Leptin Is Required for Glucose Homeostasis after Roux-en-Y Gastric Bypass in Mice.

    PubMed

    Mokadem, Mohamad; Zechner, Juliet F; Uchida, Aki; Aguirre, Vincent

    2015-01-01

    Leptin, the protein product of the ob gene, increases energy expenditure and reduces food intake, thereby promoting weight reduction. Leptin also regulates glucose homeostasis and hepatic insulin sensitivity via hypothalamic proopiomelanocortin neurons in mice. Roux-en-Y gastric bypass (RYGB) induces weight loss that is substantial and sustained despite reducing plasma leptin levels. In addition, patients who fail to undergo diabetes remission after RYGB are hypoletinemic compared to those who do and to lean controls. We have previously demonstrated that the beneficial effects of RYGB in mice require the melanocortin-4 receptor, a downstream effector of leptin action. Based on these observations, we hypothesized that leptin is required for sustained weight reduction and improved glucose homeostasis observed after RYGB. To investigate this hypothesis, we performed RYGB or sham operations on leptin-deficient ob/ob mice maintained on regular chow. To investigate whether leptin is involved in post-RYGB weight maintenance, we challenged post-surgical mice with high fat diet. RYGB reduced total body weight, fat and lean mass and caused reduction in calorie intake in ob/ob mice. However, it failed to improve glucose tolerance, glucose-stimulated plasma insulin, insulin tolerance, and fasting plasma insulin. High fat diet eliminated the reduction in calorie intake observed after RYGB in ob/ob mice and promoted weight regain, although not to the same extent as in sham-operated mice. We conclude that leptin is required for the effects of RYGB on glucose homeostasis but not body weight or composition in mice. Our data also suggest that leptin may play a role in post-RYGB weight maintenance.

  15. Effect of chromium supplementation on the glucose homeostasis and anthropometry of type 2 diabetic patients: Double blind, randomized clinical trial: Chromium, glucose homeostasis and anthropometry.

    PubMed

    Guimarães, Marília Mendonça; Carvalho, Ana Clara Martins Silva; Silva, Maria Sebastiana

    2016-07-01

    To evaluate the effect of chromium supplementation on the glucose homeostasis and anthropometry of type 2 diabetic patients. Fifty-six individuals with type 2 Diabetes were randomized on a double blind clinical trial into three groups: placebo (NC0), 50μg (NC50) and 200μg (NC200) of chromium nicotinate. Glucose homeostasis, anthropometry and physical activity intensity were evaluated at the beginning, at day 45 and at day 90. Energy intake was evaluated at the beginning, between the beginning and 45 days, and between days 45 and 90 of the study. There were no differences within or between groups for HOMA-IR, waist circumference, body fat percentage, lean body mass percentage and total energy intake during the trial. There was an increase of the HOMA-β in group NC0 (p=0.0349) and a decrease of 1.08kg in group NC50 (p=0.0048) at 90 days. The relation between body mass index, body fat percentage and insulin sensitivity did not change in the placebo and supplemented groups (p>0.05). In the effect of the intervention, for each 1cm increase in waist circumference there was an increase of 1.90±0.63 in HOMA-IR (p=0.0087) and 16.31±5.27% in HOMA-β (p=0.0073) in group NC200. No difference was seen in the intensity of physical activity within the groups and in the comparison between the supplemented groups (NC50 and NC200) and placebo (NC0) at 90 days. There was an increase in energy expenditure in physical activity at 90days (p=0.0371) of intervention in the group subjects NC50. As for total energy intake, there were no differences within or between the groups during the study. 50μg and 200μg supplementation with chromium nicotinate for 90days did not promote improvements in glucose homeostasis and anthropometry in individuals with type 2 diabetes mellitus. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Glucose Homeostasis During Short-term and Prolonged Exposure to High Altitudes

    PubMed Central

    Ader, Marilyn; Bergman, Richard N.

    2015-01-01

    Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis. PMID:25675133

  17. Hepatic F-Box Protein FBXW7 Maintains Glucose Homeostasis Through Degradation of Fetuin-A.

    PubMed

    Zhao, Jiejie; Xiong, Xuelian; Li, Yao; Liu, Xing; Wang, Tao; Zhang, Hong; Jiao, Yang; Jiang, Jingjing; Zhang, Huijie; Tang, Qiqun; Gao, Xin; Li, Xuejun; Lu, Yan; Liu, Bin; Hu, Cheng; Li, Xiaoying

    2018-05-01

    Type 2 diabetes mellitus (T2DM) has become one of the most serious and long-term threats to human health. However, the molecular mechanism that links obesity to insulin resistance remains largely unknown. Here, we show that F-box and WD repeat domain-containing 7 (FBXW7), an E3 ubiquitin protein ligase, is markedly downregulated in the liver of two obese mouse models and obese human subjects. We further identify a functional low-frequency human FBXW7 coding variant (p.Ala204Thr) in the Chinese population, which is associated with elevated blood glucose and T2DM risk. Notably, mice with liver-specific knockout of FBXW7 develop hyperglycemia, glucose intolerance, and insulin resistance even on a normal chow diet. Conversely, overexpression of FBXW7 in the liver not only prevents the development of high-fat diet-induced insulin resistance but also attenuates the disease signature of obese mice. Mechanistically, FBXW7 directly binds to hepatokine fetuin-A to induce its ubiquitination and subsequent proteasomal degradation, comprising an important mechanism maintaining glucose homeostasis. Thus, we provide evidence showing a beneficial role of FBXW7 in glucose homeostasis. © 2018 by the American Diabetes Association.

  18. PEDF attenuates insulin-dependent molecular pathways of glucose homeostasis in skeletal myocytes.

    PubMed

    Carnagarin, Revathy; Dharmarajan, Arun M; Dass, Crispin R

    2016-02-15

    Pigment epithelium-derived factor (PEDF) is an anti-angiogenic serpin associated with insulin resistance in metabolic disorders such as diabetes, metabolic syndrome, obesity and polycystic ovarian syndrome. While the mechanism of PEDF induced-insulin resistance of metabolic disorders has been attributed to its inflammatory and lipolytic effects, little evidence exists to support a direct role of PEDF in mediating insulin resistance. Here, we seminally provide evidence that PEDF can inhibit insulin signal transduction governing glucose homeostasis from the receptor to the effector phosphorylation through Akt/PKB-dependent and -independent pathways in mouse and human skeletal muscle cell lines. PEDF attenuates the insulin-dependent molecular axes of glucose metabolism. Exposure of skeletal myocytes to PEDF attenuates insulin-dependent insulin receptor autophosphorylation, tyrosine phosphorylation of insulin receptor substrate 1, and dual loop phosphorylation-activation of Akt. PEDF significantly inhibits the downstream effector - glycogen synthase kinase (and thereby the glycogenic axis of insulin signalling). PEDF turned off both the molecular switches of GLUT4 translocation: IRS-Akt/PKB-AS160 mediated and IR-pCbl-dependent GLUT4 translocation (the molecular axis of glucose uptake). These findings implicate a direct effect of PEDF on multiple insulin-dependent molecular mechanisms of glucose homeostasis in skeletal muscle cells, thereby enabling it to contribute to peripheral insulin resistance at the cellular level. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. CD14 Deficiency Impacts Glucose Homeostasis in Mice through Altered Adrenal Tone

    PubMed Central

    Young, James L.; Mora, Alfonso; Cerny, Anna; Czech, Michael P.; Woda, Bruce; Kurt-Jones, Evelyn A.; Finberg, Robert W.; Corvera, Silvia

    2012-01-01

    The toll-like receptors comprise one of the most conserved components of the innate immune system, signaling the presence of molecules of microbial origin. It has been proposed that signaling through TLR4, which requires CD14 to recognize bacterial lipopolysaccharide (LPS), may generate low-grade inflammation and thereby affect insulin sensitivity and glucose metabolism. To examine the long-term influence of partial innate immune signaling disruption on glucose homeostasis, we analyzed knockout mice deficient in CD14 backcrossed into the diabetes-prone C57BL6 background at 6 or 12 months of age. CD14-ko mice, fed either normal or high-fat diets, displayed significant glucose intolerance compared to wild type controls. They also displayed elevated norepinephrine urinary excretion and increased adrenal medullary volume, as well as an enhanced norepinephrine secretory response to insulin-induced hypoglycemia. These results point out a previously unappreciated crosstalk between innate immune- and sympathoadrenal- systems, which exerts a major long-term effect on glucose homeostasis. PMID:22253759

  20. Requirement of the ATM/p53 tumor suppressor pathway for glucose homeostasis.

    PubMed

    Armata, Heather L; Golebiowski, Diane; Jung, Dae Young; Ko, Hwi Jin; Kim, Jason K; Sluss, Hayla K

    2010-12-01

    Ataxia telangiectasia (A-T) patients can develop multiple clinical pathologies, including neuronal degeneration, an elevated risk of cancer, telangiectasias, and growth retardation. Patients with A-T can also exhibit an increased risk of insulin resistance and type 2 diabetes. The ATM protein kinase, the product of the gene mutated in A-T patients (Atm), has been implicated in metabolic disease, which is characterized by insulin resistance and increased cholesterol and lipid levels, blood pressure, and atherosclerosis. ATM phosphorylates the p53 tumor suppressor on a site (Ser15) that regulates transcription activity. To test whether the ATM pathway that regulates insulin resistance is mediated by p53 phosphorylation, we examined insulin sensitivity in mice with a germ line mutation that replaces the p53 phosphorylation site with alanine. The loss of p53 Ser18 (murine Ser15) led to increased metabolic stress, including severe defects in glucose homeostasis. The mice developed glucose intolerance and insulin resistance. The insulin resistance correlated with the loss of antioxidant gene expression and decreased insulin signaling. N-Acetyl cysteine (NAC) treatment restored insulin signaling in late-passage primary fibroblasts. The addition of an antioxidant in the diet rendered the p53 Ser18-deficient mice glucose tolerant. This analysis demonstrates that p53 phosphorylation on an ATM site is an important mechanism in the physiological regulation of glucose homeostasis.

  1. Acute low-dose endotoxin treatment results in improved whole-body glucose homeostasis in mice.

    PubMed

    Stevens, Joseph R; McMillan, Ryan P; Resendes, Justin T; Lloyd, Shannon K; Ali, Mostafa M; Frisard, Madlyn I; Hargett, Stefan; Keller, Susanna R; Hulver, Matthew W

    2017-03-01

    Obese individuals present with an increased inflammatory tone as compared to healthy, normal-weight individuals, which is associated with insulin resistance. One factor hypothesized to contribute to increased inflammation in obese and diabetic states is elevated blood endotoxin levels, a condition known as metabolic endotoxemia. In non-obese and insulin sensitive individuals, circulating endotoxin concentrations fluctuate over the course of the day with elevations in the post-prandial state that return to baseline levels in the post-absorptive state. Evidence suggests that high-fat feeding alters these fluctuations causing endotoxin levels to remain high throughout the day. The effects of alterations in endotoxin levels on glucose metabolism are not clearly understood. The goal of this study was to determine the effects of both short-term and long-term increases in endotoxin (lipopolysaccharide, LPS) of a low magnitude on the glucose tolerance and insulin signaling in a human primary cell line as well as the effects of short-term endotoxin treatments on glucose homeostasis in a C57/Bl6 mouse model. First, we tested the hypothesis that short-term low-dose endotoxin treatments would augment insulin signaling and glycogen synthesis while long-term treatments would be disruptive in the cell culture model. Second, we examined if these short-term low dose treatments of endotoxin would contribute to similar improvements in whole-body glucose homeostasis in a mouse model. Contrary to our initial hypothesis, short-term endotoxin treatment had no effect on insulin signaling or glycogen synthesis, however long-term treatment indeed decreased glycogen synthesis (P<.05). Interestingly, short-term endotoxin treatment resulted in significant improvements in glucose homeostasis in the mouse model (P<.01); which is believed to be at least partly attributed to an inhibitory action of LPS on liver glucose production. This research shows that low-magnitude, short-term changes in LPS

  2. Acute Low-Dose Endotoxin Treatment Results in Improved Whole-Body Glucose Homeostasis in Mice

    PubMed Central

    Stevens, Joseph R.; McMillan, Ryan P.; Resendes, Justin T.; Lloyd, Shannon K.; Ali, Mostafa M.; Frisard, Madlyn I.; Hargett, Stefan; Keller, Susanna R.; Hulver, Matthew W.

    2017-01-01

    Background Obese individuals present with an increased inflammatory tone as compared to healthy, normal-weight individuals, which is associated with insulin resistance. One factor hypothesized to contribute to increased inflammation in obese and diabetic states is elevated blood endotoxin levels, a condition known as metabolic endotoxemia. In non-obese and insulin sensitive individuals, circulating endotoxin concentrations fluctuate over the course of the day with elevations in the post-prandial state that return to baseline levels in the post-absorptive state. Evidence suggests that high-fat feeding alters these fluctuations causing endotoxin levels to remain high throughout the day. The effects of alterations in endotoxin levels on glucose metabolism are not clearly understood. Purpose/Procedures The goal of this study was to determine the effects of both short-term and long-term increases in endotoxin (lipopolysaccharide, LPS) of a low magnitude on the glucose tolerance and insulin signaling in a human primary cell line as well as the effects of short-term endotoxin treatments on glucose homeostasis in a C57/Bl6 mouse model. First, we tested the hypothesis that short-term low-dose endotoxin treatments would augment insulin signaling and glycogen synthesis while long-term treatments would be disruptive in the cell culture model. Second, we examined if these short-term low dose treatments of endotoxin would contribute to similar improvements in whole-body glucose homeostasis in a mouse model. Main Findings Contrary to our initial hypothesis, short-term endotoxin treatment had no effect on insulin signaling or glycogen synthesis, however long-term treatment indeed decreased glycogen synthesis (P<.05). Interestingly, short-term endotoxin treatment resulted in significant improvements in glucose homeostasis in the mouse model (P<.01); which is believed to be at least partly attributed to an inhibitory action of LPS on liver glucose production. Conclusions This

  3. Intermittent hypoxia training in prediabetes patients: Beneficial effects on glucose homeostasis, hypoxia tolerance and gene expression.

    PubMed

    Serebrovska, Tetiana V; Portnychenko, Alla G; Drevytska, Tetiana I; Portnichenko, Vladimir I; Xi, Lei; Egorov, Egor; Gavalko, Anna V; Naskalova, Svitlana; Chizhova, Valentina; Shatylo, Valeriy B

    2017-09-01

    The present study aimed at examining beneficial effects of intermittent hypoxia training (IHT) under prediabetic conditions. We investigate the effects of three-week IHT on blood glucose level, tolerance to acute hypoxia, and leukocyte mRNA expression of hypoxia inducible factor 1α (HIF-1α) and its target genes, i.e. insulin receptor, facilitated glucose transporter-solute carrier family-2, and potassium voltage-gated channel subfamily J. Seven healthy and 11 prediabetic men and women (44-70 years of age) were examined before, next day and one month after three-week IHT (3 sessions per week, each session consisting 4 cycles of 5-min 12% O 2 and 5-min room air breathing). We found that IHT afforded beneficial effects on glucose homeostasis in patients with prediabetes reducing fasting glucose and during standard oral glucose tolerance test. The most pronounced positive effects were observed at one month after IHT termination. IHT also significantly increased the tolerance to acute hypoxia (i.e. SaO 2 level at 20th min of breathing with 12% O 2 ) and improved functional parameters of respiratory and cardiovascular systems. IHT stimulated HIF-1α mRNA expression in blood leukocytes in healthy and prediabetic subjects, but in prediabetes patients the maximum increase was lagged. The greatest changes in mRNA expression of HIF-1α target genes occurred a month after IHT and coincided with the largest decrease in blood glucose levels. The higher expression of HIF-1α was positively associated with higher tolerance to hypoxia and better glucose homeostasis. In conclusion, our results suggest that IHT may be useful for preventing the development of type 2 diabetes. Impact statement The present study investigated the beneficial effects of intermittent hypoxia training (IHT) in humans under prediabetic conditions. We found that three-week moderate IHT induced higher HIF-1α mRNA expressions as well as its target genes, which were positively correlated with higher tolerance

  4. Approach to Assessing Determinants of Glucose Homeostasis in the Conscious Mouse

    PubMed Central

    Hughey, Curtis C.; Wasserman, David H.; Lee-Young, Robert S.; Lantier, Louise

    2014-01-01

    Obesity and type 2 diabetes lessen the quality of life of those afflicted and place considerable burden on the healthcare system. Furthermore, the detrimental impact of these pathologies is expected to persist or even worsen. Diabetes is characterized by impaired insulin action and glucose homeostasis. This has led to a rapid increase in the number of mouse models of metabolic disease being used in the basic sciences to assist in facilitating a greater understanding of the metabolic dysregulation associated with obesity and diabetes, the identification of therapeutic targets, and the discovery of effective treatments. This review briefly describes the most frequently utilized models of metabolic disease. A presentation of standard methods and technologies on the horizon for assessing metabolic phenotypes in mice, with particular emphasis on glucose handling and energy balance, is provided. The article also addresses issues related to study design, selection and execution of metabolic tests of glucose metabolism, the presentation of data, and interpretation of results. PMID:25074441

  5. Transepithelial glucose transport and Na+/K+ homeostasis in enterocytes: an integrative model

    PubMed Central

    Drengstig, Tormod; Ruoff, Peter

    2014-01-01

    The uptake of glucose and the nutrient coupled transcellular sodium traffic across epithelial cells in the small intestine has been an ongoing topic in physiological research for over half a century. Driving the uptake of nutrients like glucose, enterocytes must have regulatory mechanisms that respond to the considerable changes in the inflow of sodium during absorption. The Na-K-ATPase membrane protein plays a major role in this regulation. We propose the hypothesis that the amount of active Na-K-ATPase in enterocytes is directly regulated by the concentration of intracellular Na+ and that this regulation together with a regulation of basolateral K permeability by intracellular ATP gives the enterocyte the ability to maintain ionic Na+/K+ homeostasis. To explore these regulatory mechanisms, we present a mathematical model of the sodium coupled uptake of glucose in epithelial enterocytes. Our model integrates knowledge about individual transporter proteins including apical SGLT1, basolateral Na-K-ATPase, and GLUT2, together with diffusion and membrane potentials. The intracellular concentrations of glucose, sodium, potassium, and chloride are modeled by nonlinear differential equations, and molecular flows are calculated based on experimental kinetic data from the literature, including substrate saturation, product inhibition, and modulation by membrane potential. Simulation results of the model without the addition of regulatory mechanisms fit well with published short-term observations, including cell depolarization and increased concentration of intracellular glucose and sodium during increased concentration of luminal glucose/sodium. Adding regulatory mechanisms for regulation of Na-K-ATPase and K permeability to the model show that our hypothesis predicts observed long-term ionic homeostasis. PMID:24898586

  6. The impact of transsphenoidal surgery on glucose homeostasis and insulin resistance in acromegaly.

    PubMed

    Stelmachowska-Banaś, Maria; Zieliński, Grzegorz; Zdunowski, Piotr; Podgórski, Jan; Zgliczyński, Wocjiech

    2011-01-01

    Impaired glucose tolerance and overt diabetes mellitus are frequently associated with acro-megaly. The aim of this study was to find out whether these alterations could be reversed after transsphenoidal surgery. Two hundred and thirty-nine acromegalic patients were studied before and 6-12 months after transsphenoidal surgery. Diagnosis of active acromegaly was established on the basis of widely recognized criteria. In each patient, glucose and insulin concentrations were assessed during the 75 γ oral glucose tolerance test (OGTT). To estimate insulin resistance, we used homeostasis model assessment (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI). At the moment of diagnosis, diabetes mellitus was present in 25% of the acromegalic patients. After surgery, the pre-valence of diabetes mellitus normalized to the level present in the general Polish population. We found a statistically significant reduction after surgery in plasma glucose levels both fasting (89.45 ± 13.92 mg/dL vs. 99.12 ± 17.33 mg/dL, p < 0.001) and during OGTT. Similarly, a prominent reduction in insulin secretion was found after surgery compared to the moment of diagnosis (15.44 ± 8.80 mIU/mL vs. 23.40 ± 10.24 mIU/mL, p < 0.001). After transsphenoidal surgery, there was a significant reduction in HOMA-IR (3.08 vs. 6.76, p < 0.0001) and a significant increase in QUICKI (0.32 vs. 0.29, p < 0.001). There were no statistically significant differences after surgery in fasting glucose and insulin levels between patients with controlled and in-adequately controlled disease. We conclude that in acromegalic patients glucose homeostasis alterations and insulin sensitivity can be normalized after transsphenoidal surgery, even if strict biochemical cure criteria are not fulfilled.

  7. The Contribution of Intestinal Gluconeogenesis to Glucose Homeostasis Is Low in 2-Day-Old Pigs.

    PubMed

    Cherbuy, Claire; Vaugelade, Pierre; Labarthe, Simon; Honvo-Houeto, Edith; Darcy-Vrillon, Béatrice; Watford, Malcolm; Duée, Pierre-Henri

    2017-03-01

    -old piglets. Conclusion: Our results indicate that there is a low contribution to glucose homeostasis from intestinal gluconeogenesis in 2-d-old piglets. © 2017 American Society for Nutrition.

  8. Helicobacter pylori colonization ameliorates glucose homeostasis in mice through a PPAR γ-dependent mechanism.

    PubMed

    Bassaganya-Riera, Josep; Dominguez-Bello, Maria Gloria; Kronsteiner, Barbara; Carbo, Adria; Lu, Pinyi; Viladomiu, Monica; Pedragosa, Mireia; Zhang, Xiaoying; Sobral, Bruno W; Mane, Shrinivasrao P; Mohapatra, Saroj K; Horne, William T; Guri, Amir J; Groeschl, Michael; Lopez-Velasco, Gabriela; Hontecillas, Raquel

    2012-01-01

    There is an inverse secular trend between the incidence of obesity and gastric colonization with Helicobacter pylori, a bacterium that can affect the secretion of gastric hormones that relate to energy homeostasis. H. pylori strains that carry the cag pathogenicity island (PAI) interact more intimately with gastric epithelial cells and trigger more extensive host responses than cag(-) strains. We hypothesized that gastric colonization with H. pylori strains differing in cag PAI status exert distinct effects on metabolic and inflammatory phenotypes. To test this hypothesis, we examined metabolic and inflammatory markers in db/db mice and mice with diet-induced obesity experimentally infected with isogenic forms of H. pylori strain 26695: the cag PAI wild-type and its cag PAI mutant strain 99-305. H. pylori colonization decreased fasting blood glucose levels, increased levels of leptin, improved glucose tolerance, and suppressed weight gain. A response found in both wild-type and mutant H. pylori strain-infected mice included decreased white adipose tissue macrophages (ATM) and increased adipose tissue regulatory T cells (Treg) cells. Gene expression analyses demonstrated upregulation of gastric PPAR γ-responsive genes (i.e., CD36 and FABP4) in H. pylori-infected mice. The loss of PPAR γ in immune and epithelial cells in mice impaired the ability of H. pylori to favorably modulate glucose homeostasis and ATM infiltration during high fat feeding. Gastric infection with some commensal strains of H. pylori ameliorates glucose homeostasis in mice through a PPAR γ-dependent mechanism and modulates macrophage and Treg cell infiltration into the abdominal white adipose tissue.

  9. Helicobacter pylori Colonization Ameliorates Glucose Homeostasis in Mice through a PPAR γ-Dependent Mechanism

    PubMed Central

    Bassaganya-Riera, Josep; Dominguez-Bello, Maria Gloria; Kronsteiner, Barbara; Carbo, Adria; Lu, Pinyi; Viladomiu, Monica; Pedragosa, Mireia; Zhang, Xiaoying; Sobral, Bruno W.; Mane, Shrinivasrao P.; Mohapatra, Saroj K.; Horne, William T.; Guri, Amir J.; Groeschl, Michael; Lopez-Velasco, Gabriela; Hontecillas, Raquel

    2012-01-01

    Background There is an inverse secular trend between the incidence of obesity and gastric colonization with Helicobacter pylori, a bacterium that can affect the secretion of gastric hormones that relate to energy homeostasis. H. pylori strains that carry the cag pathogenicity island (PAI) interact more intimately with gastric epithelial cells and trigger more extensive host responses than cag− strains. We hypothesized that gastric colonization with H. pylori strains differing in cag PAI status exert distinct effects on metabolic and inflammatory phenotypes. Methodology/Principal Findings To test this hypothesis, we examined metabolic and inflammatory markers in db/db mice and mice with diet-induced obesity experimentally infected with isogenic forms of H. pylori strain 26695: the cag PAI wild-type and its cag PAI mutant strain 99–305. H. pylori colonization decreased fasting blood glucose levels, increased levels of leptin, improved glucose tolerance, and suppressed weight gain. A response found in both wild-type and mutant H. pylori strain-infected mice included decreased white adipose tissue macrophages (ATM) and increased adipose tissue regulatory T cells (Treg) cells. Gene expression analyses demonstrated upregulation of gastric PPAR γ-responsive genes (i.e., CD36 and FABP4) in H. pylori-infected mice. The loss of PPAR γ in immune and epithelial cells in mice impaired the ability of H. pylori to favorably modulate glucose homeostasis and ATM infiltration during high fat feeding. Conclusions/Significance Gastric infection with some commensal strains of H. pylori ameliorates glucose homeostasis in mice through a PPAR γ-dependent mechanism and modulates macrophage and Treg cell infiltration into the abdominal white adipose tissue. PMID:23166823

  10. Testosterone supplementation improves glucose homeostasis despite increasing hepatic insulin resistance in male mouse model of type 2 diabetes mellitus.

    PubMed

    Pal, M; Gupta, S

    2016-12-12

    Clinical studies have revealed that testosterone supplementation had a positive effect on glucose homeostasis in type 2 diabetes mellitus (T2DM), but did not address how testosterone supplementation affected insulin responsiveness in the liver, a key glucose homeostatic organ. In this study, we aimed to study the effect of testosterone supplementation on hepatic insulin responsiveness and glucose homeostasis through liver in male high-fat diet-induced T2DM mice. Testosterone treatment to T2DM animals showed reduced hepatic glucose output. Testosterone inhibited the insulin signaling in liver, thus increased insulin resistance. However, testosterone treatment inactivated GSK3α independent of PI3K/AKT pathway and inhibited FOXO1 By interaction of androgen receptor to FOXO1 and downregulated PEPCK, causing repression of gluconeogenic pathway, which is otherwise upregulated in T2DM, resulted in better glucose homeostasis.

  11. Association of Dyslipidemia and Glucose Abnormalities with Antiretroviral Treatment in a Cohort of HIV-infected Latin American Children

    PubMed Central

    Paganella, MP; Cohen, RA; Harris, DR; Kuchenbecker, RS; Sperhacke, RD; Kato, SK; Silva, CLO; Sturzbecher, FT; Oliveira, RHS; Pavía Ruz, N; Hazra, R

    2016-01-01

    Objective(s) To estimate the incidence of lipid and glucose abnormalities and assess their association with exposure to antiretroviral (ARV) regimens among perinatally HIV-infected Latin American children. Design Longitudinal cohort study. Methods Data were analyzed from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) International Site Development Initiative (NISDI) Pediatric Latin American Countries Epidemiologic Study (PLACES). The incidence of dyslipidemia (total cholesterol>200mg/dL, HDL<35mg/dL, LDL≥130mg/dL, triglycerides>110mg/dL [age<10 years] or >150mg/dL [≥10 years]) and fasting glucose abnormalities (homeostasis model assessment of insulin resistance >2.5 [Tanner Stage 1] or >4.0 [Tanner Stage>1]; impaired glucose: 110 to <126mg/dL; diabetes: ≥126 mg/dL) was estimated. Proportional hazards regression was used to evaluate the risk of abnormalities associated with ARV regimen, adjusted for covariates. Results There were 385 children eligible for analysis (mean age 6.6 years). Incident cholesterol abnormalities were reported in 18.1% of participants (95% confidence interval [CI] 14.1–22.8%), HDL and LDL cholesterol abnormalities in 19.6% (15.1–24.7%) and 15.0% (11.3–19.5%), respectively, and triglyceride abnormalities in 44.2% (37.7–50.8%). In multivariable analysis, ARV regimen was only associated with triglyceride abnormalities; participants receiving a protease inhibitor-containing (PI) regimen were 3.6 times as likely to experience a triglyceride abnormality as those receiving no ARVs (95% CI: 1.3–10.5; p=0.0167). The cumulative incidence of insulin resistance was 3.8% (1.8–7.1%); there were no incident cases of diabetes and only two of impaired fasting glucose. Conclusions Children receiving PI-containing regimens were at increased risk of developing triglyceride abnormalities. Continued monitoring of lipid levels in children receiving PI-containing regimens appears warranted. PMID:27570910

  12. p21-Activated protein kinases and their emerging roles in glucose homeostasis.

    PubMed

    Chiang, Yu-ting Alex; Jin, Tianru

    2014-04-01

    p21-Activated protein kinases (PAKs) are centrally involved in a plethora of cellular processes and functions. Their function as effectors of small GTPases Rac1 and Cdc42 has been extensively studied during the past two decades, particularly in the realms of cell proliferation, apoptosis, and hence tumorigenesis, as well as cytoskeletal remodeling and related cellular events in health and disease. In recent years, a large number of studies have shed light onto the fundamental role of group I PAKs, most notably PAK1, in metabolic homeostasis. In skeletal muscle, PAK1 was shown to mediate the function of insulin on stimulating GLUT4 translocation and glucose uptake, while in pancreatic β-cells, PAK1 participates in insulin granule localization and vesicle release. Furthermore, we demonstrated that PAK1 mediates the cross talk between insulin and Wnt/β-catenin signaling pathways and hence regulates gut proglucagon gene expression and the production of the incretin hormone glucagon-like peptide-1 (GLP-1). The utilization of chemical inhibitors of PAK and the characterization of Pak1(-/-) mice enabled us to gain mechanistic insights as well as to assess the overall contribution of PAKs in metabolic homeostasis. This review summarizes our current understanding of PAKs, with an emphasis on the emerging roles of PAK1 in glucose homeostasis.

  13. MicroRNA-451 Negatively Regulates Hepatic Glucose Production and Glucose Homeostasis by Targeting Glycerol Kinase-Mediated Gluconeogenesis.

    PubMed

    Zhuo, Shu; Yang, Mengmei; Zhao, Yanan; Chen, Xiaofang; Zhang, Feifei; Li, Na; Yao, Pengle; Zhu, Tengfei; Mei, Hong; Wang, Shanshan; Li, Yu; Chen, Shiting; Le, Yingying

    2016-11-01

    MicroRNAs (miRNAs) are a new class of regulatory molecules implicated in type 2 diabetes, which is characterized by insulin resistance and hepatic glucose overproduction. We show that miRNA-451 (miR-451) is elevated in the liver tissues of dietary and genetic mouse models of diabetes. Through an adenovirus-mediated gain- and loss-of-function study, we found that miR-451 negatively regulates hepatic gluconeogenesis and blood glucose levels in normal mice and identified glycerol kinase (Gyk) as a direct target of miR-451. We demonstrate that miR-451 and Gyk regulate hepatic glucose production, the glycerol gluconeogenesis axis, and the AKT-FOXO1-PEPCK/G6Pase pathway in an opposite manner; Gyk could reverse the effect of miR-451 on hepatic gluconeogenesis and AKT-FOXO1-PEPCK/G6Pase pathway. Moreover, overexpression of miR-451 or knockdown of Gyk in diabetic mice significantly inhibited hepatic gluconeogenesis, alleviated hyperglycemia, and improved glucose tolerance. Further studies showed that miR-451 is upregulated by glucose and insulin in hepatocytes; the elevation of hepatic miR-451 in diabetic mice may contribute to inhibiting Gyk expression. This study provides the first evidence that miR-451 and Gyk regulate the AKT-FOXO1-PEPCK/G6Pase pathway and play critical roles in hepatic gluconeogenesis and glucose homeostasis and identifies miR-451 and Gyk as potential therapeutic targets against hyperglycemia in diabetes. © 2016 by the American Diabetes Association.

  14. The Role of Estrogens in Control of Energy Balance and Glucose Homeostasis

    PubMed Central

    Clegg, Deborah J.; Hevener, Andrea L.

    2013-01-01

    Estrogens play a fundamental role in the physiology of the reproductive, cardiovascular, skeletal, and central nervous systems. In this report, we review the literature in both rodents and humans on the role of estrogens and their receptors in the control of energy homeostasis and glucose metabolism in health and metabolic diseases. Estrogen actions in hypothalamic nuclei differentially control food intake, energy expenditure, and white adipose tissue distribution. Estrogen actions in skeletal muscle, liver, adipose tissue, and immune cells are involved in insulin sensitivity as well as prevention of lipid accumulation and inflammation. Estrogen actions in pancreatic islet β-cells also regulate insulin secretion, nutrient homeostasis, and survival. Estrogen deficiency promotes metabolic dysfunction predisposing to obesity, the metabolic syndrome, and type 2 diabetes. We also discuss the effect of selective estrogen receptor modulators on metabolic disorders. PMID:23460719

  15. Reciprocal regulation of insulin and plasma 5'-AMP in glucose homeostasis in mice.

    PubMed

    Xia, Lin; Wang, Zhongqiu; Zhang, Ying; Yang, Xiao; Zhan, Yibei; Cheng, Rui; Wang, Shiming; Zhang, Jianfa

    2015-03-01

    A previous investigation has demonstrated that plasma 5'-AMP (pAMP) exacerbates and causes hyperglycemia in diabetic mice. However, the crosstalk between pAMP and insulin signaling to regulate glucose homeostasis has not been investigated in depth. In this study, we showed that the blood glucose level was more dependent on the ratio of insulin to pAMP than on the absolute level of these two factors. Administration of 5'-AMP significantly attenuated the insulin-stimulated insulin receptor (IR) autophosphorylation in the liver and muscle tissues, resulting in the inhibition of downstream AKT phosphorylation. A docking analysis indicated that adenosine was a potential inhibitor of IR tyrosine kinase. Moreover, the 5'-AMP treatment elevated the ATP level in the pancreas and in the isolated islets, stimulating insulin secretion and increasing the plasma level of insulin. The insulin administration decreased the 5'-AMP-induced hyper-adenosine level by the up-regulation of adenosine kinase activities. Our results indicate that blood glucose homeostasis is reciprocally regulated by pAMP and insulin. © 2015 Society for Endocrinology.

  16. Perinatal Bisphenol A Exposure and Adult Glucose Homeostasis: Identifying Critical Windows of Exposure

    PubMed Central

    Liu, Jingli; Yu, Pan; Qian, Wenyi; Li, Yan; Zhao, Jingjing; Huan, Fei; Wang, Jun; Xiao, Hang

    2013-01-01

    Bisphenol A (BPA) is a widespread endocrine-disrupting chemical used as the building block for polycarbonate plastics. Epidemiological evidence has correlated BPA exposure with higher risk of heart disease and type 2 diabetes. However, it remains unknown whether there are critical windows of susceptibility to BPA exposure on the development of dysglycemia. This study was an attempt to investigate the critical windows and the long-term consequences of perinatal exposure to BPA on glucose homeostasis. Pregnant mice were given either vehicle or BPA (100 µg/kg/day) at different time of perinatal stage: 1) on days 1–6 of pregnancy (P1–P6, preimplantation exposure); 2) from day 6 of pregnancy until postnatal day (PND) 0 (P6–PND0, fetal exposure); 3) from lactation until weaning (PND0–PND21, neonatal exposure); and 4) from day 6 of gestation until weaning (P6–PND21, fetal and neonatal exposure). At 3, 6 and 8 months of age, offspring in each group were challenged with glucose and insulin tolerance tests. Then islet morphometry and β-cell function were measured. The glucose homeostasis was impaired in P6-PND0 mice from 3 to 6 months of age, and this continued to 8 months in males, but not females. While in PND0-PND21 and P6-PND21 BPA-treated groups, only the 3-month-old male offspring developed glucose intolerance. Moreover, at the age of 3 months, perinatal exposure to BPA resulted in the increase of β-cell mass mainly due to the coordinate changes in cell replication, neogenesis, and apoptosis. The alterations of insulin secretion and insulin sensitivity, rather than β-cell mass, were consistent with the development of glucose intolerance. Our findings suggest that BPA may contribute to metabolic disorders relevant to glucose homeostasis and the effects of BPA were dose, sex, and time-dependent. Fetal development stage may be the critical window of susceptibility to BPA exposure. PMID:23675523

  17. Cortical delta-opioid receptors potentiate K+ homeostasis during anoxia and oxygen-glucose deprivation.

    PubMed

    Chao, Dongman; Donnelly, David F; Feng, Yin; Bazzy-Asaad, Alia; Xia, Ying

    2007-02-01

    Central neurons are extremely vulnerable to hypoxic/ischemic insult, which is a major cause of neurologic morbidity and mortality as a consequence of neuronal dysfunction and death. Our recent work has shown that delta-opioid receptor (DOR) is neuroprotective against hypoxic and excitotoxic stress, although the underlying mechanisms remain unclear. Because hypoxia/ischemia disrupts ionic homeostasis with an increase in extracellular K(+), which plays a role in neuronal death, we asked whether DOR activation preserves K(+) homeostasis during hypoxic/ischemic stress. To test this hypothesis, extracellular recordings with K(+)-sensitive microelectrodes were performed in mouse cortical slices under anoxia or oxygen-glucose deprivation (OGD). The main findings in this study are that (1) DOR activation with [D-Ala(2), D-Leu(5)]-enkephalinamide attenuated the anoxia- and OGD-induced increase in extracellular K(+) and decrease in DC potential in cortical slices; (2) DOR inhibition with naltrindole, a DOR antagonist, completely abolished the DOR-mediated prevention of increase in extracellular K(+) and decrease in DC potential; (3) inhibition of protein kinase A (PKA) with N-(2-[p-bromocinnamylamino]-ethyl)-5-isoquinolinesulfonamide dihydrochloride had no effect on the DOR protection; and (4) inhibition of protein kinase C (PKC) with chelerythrine chloride reduced the DOR protection, whereas the PKC activator (phorbol 12-myristate 13-acetate) mimicked the effect of DOR activation on K(+) homeostasis. These data suggest that activation of DOR protects the cortex against anoxia- or ODG-induced derangement of potassium homeostasis, and this protection occurs via a PKC-dependent and PKA-independent pathway. We conclude that an important aspect of DOR-mediated neuroprotection is its early action against derangement of K(+) homeostasis during anoxia or ischemia.

  18. Ambient air pollution, adipokines, and glucose homeostasis: The Framingham Heart Study.

    PubMed

    Li, Wenyuan; Dorans, Kirsten S; Wilker, Elissa H; Rice, Mary B; Kloog, Itai; Schwartz, Joel D; Koutrakis, Petros; Coull, Brent A; Gold, Diane R; Meigs, James B; Fox, Caroline S; Mittleman, Murray A

    2018-02-01

    To examine associations of proximity to major roadways, sustained exposure to fine particulate matter (PM 2.5 ), and acute exposure to ambient air pollutants with adipokines and measures of glucose homeostasis among participants living in the northeastern United States. We included 5958 participants from the Framingham Offspring cohort examination cycle 7 (1998-2001) and 8 (2005-2008) and Third Generation cohort examination cycle 1 (2002-2005) and 2 (2008-2011), who did not have type 2 diabetes at the time of examination visit. We calculated 2003 annual average PM 2.5 at participants' home address, residential distance to the nearest major roadway, and daily PM 2.5 , black carbon (BC), sulfate, nitrogen oxides (NO x ), and ozone concentrations. We used linear mixed effects models for fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) which were measured up to twice, and used linear regression models for adiponectin, resistin, leptin, and hemoglobin A1c (HbA1c) which were measured only once, adjusting for demographics, socioeconomic position, lifestyle, time, and seasonality. The mean age was 51years and 55% were women. Participants who lived 64m (25th percentile) from a major roadway had 0.28% (95% CI: 0.05%, 0.51%) higher fasting plasma glucose than participants who lived 413m (75th percentile) away, and the association appeared to be driven by participants who lived within 50m from a major roadway. Higher exposures to 3- to 7-day moving averages of BC and NO x were associated with higher glucose whereas the associations for ozone were negative. The associations otherwise were generally null and did not differ by median age, sex, educational attainment, obesity status, or prediabetes status. Living closer to a major roadway or acute exposure to traffic-related air pollutants were associated with dysregulated glucose homeostasis but not with adipokines among participants from the Framingham Offspring and Third Generation

  19. Transient Receptor Potential Canonical 3 (TRPC3) Channels Are Required for Hypothalamic Glucose Detection and Energy Homeostasis.

    PubMed

    Chrétien, Chloé; Fenech, Claire; Liénard, Fabienne; Grall, Sylvie; Chevalier, Charlène; Chaudy, Sylvie; Brenachot, Xavier; Berges, Raymond; Louche, Katie; Stark, Romana; Nédélec, Emmanuelle; Laderrière, Amélie; Andrews, Zane B; Benani, Alexandre; Flockerzi, Veit; Gascuel, Jean; Hartmann, Jana; Moro, Cédric; Birnbaumer, Lutz; Leloup, Corinne; Pénicaud, Luc; Fioramonti, Xavier

    2017-02-01

    The mediobasal hypothalamus (MBH) contains neurons capable of directly detecting metabolic signals such as glucose to control energy homeostasis. Among them, glucose-excited (GE) neurons increase their electrical activity when glucose rises. In view of previous work, we hypothesized that transient receptor potential canonical type 3 (TRPC3) channels are involved in hypothalamic glucose detection and the control of energy homeostasis. To investigate the role of TRPC3, we used constitutive and conditional TRPC3-deficient mouse models. Hypothalamic glucose detection was studied in vivo by measuring food intake and insulin secretion in response to increased brain glucose level. The role of TRPC3 in GE neuron response to glucose was studied by using in vitro calcium imaging on freshly dissociated MBH neurons. We found that whole-body and MBH TRPC3-deficient mice have increased body weight and food intake. The anorectic effect of intracerebroventricular glucose and the insulin secretory response to intracarotid glucose injection are blunted in TRPC3-deficient mice. TRPC3 loss of function or pharmacological inhibition blunts calcium responses to glucose in MBH neurons in vitro. Together, the results demonstrate that TRPC3 channels are required for the response to glucose of MBH GE neurons and the central effect of glucose on insulin secretion and food intake. © 2017 by the American Diabetes Association.

  20. Variation in Glucose Homeostasis Traits Associated With P2RX7 Polymorphisms in Mice and Humans

    PubMed Central

    Todd, Jennifer N.; Poon, Wenny; Lyssenko, Valeriya; Groop, Leif; Nichols, Brendan; Wilmot, Michael; Robson, Simon; Enjyoji, Keiichi; Herman, Mark A.; Hu, Cheng; Zhang, Rong; Jia, Weiping; Ma, Ronald

    2015-01-01

    Context: Extracellular nucleotide receptors are expressed in pancreatic B-cells. Purinergic signaling via these receptors may regulate pancreatic B-cell function. Objective: We hypothesized that purinergic signaling might influence glucose regulation and sought evidence in human studies of glycemic variation and a mouse model of purinergic signaling dysfunction. Design: In humans, we mined genome-wide meta-analysis data sets to examine purinergic signaling genes for association with glycemic traits and type 2 diabetes. We performed additional testing in two genomic regions (P2RX4/P2RX7 and P2RY1) in a cohort from the Prevalence, Prediction, and Prevention of Diabetes in Botnia (n = 3504), which includes more refined measures of glucose homeostasis. In mice, we generated a congenic model of purinergic signaling dysfunction by crossing the naturally hypomorphic C57BL6 P2rx7 allele onto the 129SvJ background. Results: Variants in five genes were associated with glycemic traits and in three genes with diabetes risk. In the Prevalence, Prediction, and Prevention of Diabetes in Botnia study, the minor allele in the missense functional variant rs1718119 (A348T) in P2RX7 was associated with increased insulin sensitivity and secretion, consistent with its known effect on increased pore function. Both male and female P2x7-C57 mice demonstrated impaired glucose tolerance compared with matched P2x7-129 mice. Insulin tolerance testing showed that P2x7-C57 mice were also less responsive to insulin than P2x7-129 mice. Conclusions: We show association of the purinergic signaling pathway in general and hypofunctioning P2X7 variants in particular with impaired glucose homeostasis in both mice and humans. PMID:25719930

  1. The mitochondrial isoform of phosphoenolpyruvate carboxykinase (PEPCK-M) and glucose homeostasis: has it been overlooked?

    PubMed Central

    Stark, Romana; Kibbey, Richard G.

    2013-01-01

    Background Plasma glucose levels are tightly regulated within a narrow physiologic range. Insulin-mediated glucose uptake by tissues must be balanced by the appearance of glucose from nutritional sources, glycogen stores, or gluconeogenesis. In this regard, a common pathway regulating both glucose clearance and appearance has not been described. The metabolism of glucose to produce ATP is generally considered to be the primary stimulus for insulin release from beta-cells. Similarly, gluconeogenesis from phosphoenolpyruvate (PEP) is believed to be the primarily pathway via the cytosolic isoform of phosphoenolpyruvate carboxykinase (PEPCK-C). These models cannot adequately explain the regulation of insulin secretion or gluconeogenesis. Scope of review A metabolic sensing pathway involving mitochondrial GTP (mtGTP) and PEP synthesis by the mitochondrial isoform of PEPCK (PEPCK-M) is associated with glucose-stimulated insulin secretion from pancreatic beta-cells. Here we examine whether there is evidence for a similar mtGTP-dependent pathway involved in gluconeogenesis. In both islets and the liver, mtGTP is produced at the substrate level by the enzyme succinyl CoA synthetase (SCS-GTP) with a rate proportional to the TCA cycle. In the beta-cell PEPCK-M then hydrolyzes mtGTP in the production of PEP that, unlike mtGTP, can escape the mitochondria to generate a signal for insulin release. Similarly, PEPCK-M and mtGTP might also provide a significant source of PEP in gluconeogenic tissues for the production of glucose. This review will focus on the possibility that PEPCK-M, as a sensor for TCA cycle flux, is a key mechanism to regulate both insulin secretion and gluconeogenesis suggesting conservation of this biochemical mechanism in regulating multiple aspects of glucose homeostasis. Moreover, we propose that this mechanism may be more important for regulating insulin secretion and gluconeogenesis compared to canonical nutrient sensing pathways. Major conclusions PEPCK

  2. Glucose Homeostasis, Pancreatic Endocrine Function, and Outcomes in Advanced Heart Failure.

    PubMed

    Melenovsky, Vojtech; Benes, Jan; Franekova, Janka; Kovar, Jan; Borlaug, Barry A; Segetova, Marketa; Tura, Andrea; Pelikanova, Tereza

    2017-08-07

    The mechanisms and relevance of impaired glucose homeostasis in advanced heart failure (HF) are poorly understood. The study goals were to examine glucose regulation, pancreatic endocrine function, and metabolic factors related to prognosis in patients with nondiabetic advanced HF. In total, 140 advanced HF patients without known diabetes mellitus and 21 sex-, age-, and body mass index-matched controls underwent body composition assessment, oral glucose tolerance testing, and measurement of glucose-regulating hormones to model pancreatic β-cell secretory response. Compared with controls, HF patients had similar fasting glucose and insulin levels but higher levels after oral glucose tolerance testing. Insulin secretion was not impaired, but with increasing HF severity, there was a reduction in glucose, insulin, and insulin/glucagon ratio-a signature of starvation. The insulin/C-peptide ratio was decreased in HF, indicating enhanced insulin clearance, and this was correlated with lower cardiac output, hepatic insufficiency, right ventricular dysfunction, and body wasting. After a median of 449 days, 41% of patients experienced an adverse event (death, urgent transplant, or assist device). Increased glucagon and, paradoxically, low fasting plasma glucose displayed the strongest relations to outcome ( P =0.01). Patients in the lowest quartile of fasting plasma glucose (3.8-5.1 mmol·L -1 , 68-101 mg·dL -1 ) had 3-times higher event risk than in the top quartile (6.0-7.9 mmol·L -1 , 108-142 mg·dL -1 ; relative risk: 3.05 [95% confidence interval, 1.46-6.77]; P =0.002). Low fasting plasma glucose and increased glucagon are robust metabolic predictors of adverse events in advanced HF. Pancreatic insulin secretion is preserved in advanced HF, but levels decrease with increasing HF severity due to enhanced insulin clearance that is coupled with right heart failure and cardiac cachexia. © 2017 The Authors. Published on behalf of the American Heart Association, Inc

  3. Perfluorooctanoic acid exposure for 28 days affects glucose homeostasis and induces insulin hypersensitivity in mice

    NASA Astrophysics Data System (ADS)

    Yan, Shengmin; Zhang, Hongxia; Zheng, Fei; Sheng, Nan; Guo, Xuejiang; Dai, Jiayin

    2015-06-01

    Perfluoroalkyl acids (PFAAs) are widely used in many applications due to their unique physical and chemical characteristics. Because of the increasing prevalence of metabolic syndromes, including obesity, dyslipidemia and insulin resistance, concern has arisen about the roles of environmental pollutants in such diseases. Earlier epidemiologic studies showed a potential association between perfluorooctanoic acid (PFOA) and glucose metabolism, but how PFOA influences glucose homeostasis is still unknown. Here, we report on the modulation of the phosphatidylinositol 3-kinase-serine/threonine protein kinase (PI3K-AKT) signaling pathway in the livers of mice after 28 d of exposure to PFOA. Compared with normal mice, PFOA exposure significantly decreased the expression of the phosphatase and tensin homologue (PTEN) protein and affected the PI3K-AKT signaling pathway in the liver. Tolerance tests further indicated that PFOA exposure induced higher insulin sensitivity and glucose tolerance in mice. Biochemical analysis revealed that PFOA exposure reduced hepatic glycogen synthesis, which might be attributed to gluconeogenesis inhibition. The levels of several circulating proteins were altered after PFOA exposure, including proteins potentially related to diabetes and liver disease. Our results suggest that PFOA affected glucose metabolism and induced insulin hypersensitivity in mice.

  4. Abnormal glucose levels found in transportation accidents : final report.

    DOT National Transportation Integrated Search

    2000-06-01

    Purpose. The Federal Aviation Administration's Office of Aviation Medicine (OAM) is responsible for the certification of pilots with diabetic conditions. Therefore, it is essential for OAM to monitor pilots involved in fatal accidents for abnormal gl...

  5. Effects of sodium benzoate, a widely used food preservative, on glucose homeostasis and metabolic profiles in humans.

    PubMed

    Lennerz, Belinda S; Vafai, Scott B; Delaney, Nigel F; Clish, Clary B; Deik, Amy A; Pierce, Kerry A; Ludwig, David S; Mootha, Vamsi K

    2015-01-01

    Sodium benzoate is a widely used preservative found in many foods and soft drinks. It is metabolized within mitochondria to produce hippurate, which is then cleared by the kidneys. We previously reported that ingestion of sodium benzoate at the generally regarded as safe (GRAS) dose leads to a robust excursion in the plasma hippurate level [1]. Since previous reports demonstrated adverse effects of benzoate and hippurate on glucose homeostasis in cells and in animal models, we hypothesized that benzoate might represent a widespread and underappreciated diabetogenic dietary exposure in humans. Here, we evaluated whether acute exposure to GRAS levels of sodium benzoate alters insulin and glucose homeostasis through a randomized, controlled, cross-over study of 14 overweight subjects. Serial blood samples were collected following an oral glucose challenge, in the presence or absence of sodium benzoate. Outcome measurements included glucose, insulin, glucagon, as well as temporal mass spectrometry-based metabolic profiles. We did not find a statistically significant effect of an acute oral exposure to sodium benzoate on glucose homeostasis. Of the 146 metabolites targeted, four changed significantly in response to benzoate, including the expected rise in benzoate and hippurate. In addition, anthranilic acid, a tryptophan metabolite, exhibited a robust rise, while acetylglycine dropped. Although our study shows that GRAS doses of benzoate do not have an acute, adverse effect on glucose homeostasis, future studies will be necessary to explore the metabolic impact of chronic benzoate exposure. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Effects of sodium benzoate, a widely used food preservative, on glucose homeostasis and metabolic profiles in humans

    PubMed Central

    Lennerz, Belinda; Vafai, Scott B.; Delaney, Nigel F.; Clish, Clary B.; Deik, Amy A.; Pierce, Kerry A.; Ludwig, David S.; Mootha, Vamsi K.

    2014-01-01

    Sodium benzoate is a widely used preservative found in many foods and soft drinks. It is metabolized within mitochondria to produce hippurate, which is then cleared by the kidneys. We previously reported that ingestion of sodium benzoate at the generally regarded as safe (GRAS) dose leads to a robust excursion in the plasma hippurate level [1]. Since previous reports demonstrated adverse effects of benzoate and hippurate on glucose homeostasis in cells and in animal models, we hypothesized that benzoate might represent a widespread and underappreciated diabetogenic dietary exposure in humans. Here, we evaluated whether acute exposure to GRAS levels of sodium benzoate alters insulin and glucose homeostasis through a randomized, controlled, cross-over study of 14 overweight subjects. Serial blood samples were collected following an oral glucose challenge, in the presence or absence of sodium benzoate. Outcome measurements included glucose, insulin, glucagon, as well as temporal mass spectrometry-based metabolic profiles. We did not find a statistically significant effect of an acute oral exposure to sodium benzoate on glucose homeostasis. Of the 146 metabolites targeted, four changed significantly in response to benzoate, including the expected rise in benzoate and hippurate. In addition, anthranilic acid, a tryptophan metabolite, exhibited a robust rise, while acetylglycine dropped. Although our study shows that GRAS doses of benzoate do not have an acute, adverse effect on glucose homeostasis, future studies will be necessary to explore the metabolic impact of chronic benzoate exposure. PMID:25497115

  7. The impact of ethnicity on glucose homeostasis after gestational diabetes mellitus.

    PubMed

    Ignell, Claes; Shaat, Nael; Ekelund, Magnus; Berntorp, Kerstin

    2013-12-01

    The objective of this study was to examine measures of insulin resistance and beta cell function in relation to ethnicity and the development of diabetes after gestational diabetes mellitus (GDM). Glucose homeostasis was assessed during a 75 g oral glucose tolerance test 1-2 years after delivery in 456 women with previous GDM (362 European, 94 non-European; including 41 Arab and 43 Asian women) and 133 control women. Insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR). The insulinogenic index (I/G30) and the disposition index [(I/G30)/HOMA-IR] were used to quantify insulin secretion. Women developing diabetes after GDM were characterized by increased HOMA-IR [p = 0.010, adjusted for body mass index (BMI)], whereas the disposition index was decreased in all women with previous GDM irrespective of glucose tolerance, most pronounced in the presence of diabetes (BMI-adjusted p = 1 × 10(-5)). Non-European origin was associated with increased HOMA-IR (p = 0.001 vs. European), strengthened by adjustment for BMI in Asian women (p = 0.046 vs. p = 0.016), but eradicated among Arab women (p = 0.004 vs. p = 0.65). Non-European women exhibited an increased frequency of diabetes after GDM (17 % vs. European 4 %, p = 2 × 10(-5)). In addition to BMI, non-European and Asian origin was associated with the development of diabetes after GDM in a multivariate logistic regression analysis, whereas Arab origin was not. Our results highlight the importance of preventive measures to ensure a healthy lifestyle in women with GDM, particularly in high-risk ethnic groups.

  8. Sex-Related Differences in the Effects of the Mediterranean Diet on Glucose and Insulin Homeostasis

    PubMed Central

    Bédard, Alexandra; Corneau, Louise; Lamarche, Benoît; Dodin, Sylvie; Lemieux, Simone

    2014-01-01

    Objective. To document sex differences in the impact of the Mediterranean diet (MedDiet) on glucose/insulin homeostasis and to verify whether these sex-related effects were associated with changes in nonesterified fatty acids (NEFA). Methods. All foods were provided to 38 men and 32 premenopausal women (24–53 y) during 4 weeks. Variables were measured during a 180 min OGTT before and after the MedDiet. Results. A sex-by-time interaction for plasma insulin iAUC was found (men: −17.8%, P = 0.02; women: +9.4%, P = 0.63; P for sex-by-time interaction = 0.005). A sex-by-time interaction was also observed for insulin sensitivity (Cederholm index, P = 0.03), for which only men experienced improvements (men: +8.1%, P = 0.047; women: −5.9%, P = 0.94). No sex difference was observed for glucose and C-peptide responses. Trends toward a decrease in NEFA AUC (P = 0.06) and an increase in NEFA suppression rate (P = 0.06) were noted, with no sex difference. Changes in NEFA were not associated with change in insulin sensitivity. Conclusions. Results suggest that the more favorable changes in glucose/insulin homeostasis observed in men compared to women in response to the MedDiet are not explained by sex differences in NEFA response. This clinical trial is registered with clinicaltrials.gov NCT01293344. PMID:25371817

  9. Enhanced leptin sensitivity and improved glucose homeostasis in mice lacking suppressor of cytokine signaling-3 in POMC-expressing cells.

    PubMed

    Kievit, Paul; Howard, Jane K; Badman, Michael K; Balthasar, Nina; Coppari, Roberto; Mori, Hiroyuki; Lee, Charlotte E; Elmquist, Joel K; Yoshimura, Akihiko; Flier, Jeffrey S

    2006-08-01

    Suppressor of cytokine signaling-3 (Socs-3) negatively regulates the action of various cytokines, as well as the metabolic hormones leptin and insulin. Mice with haploinsufficiency of Socs-3, or those with neuronal deletion of Socs-3, are lean and more leptin and insulin sensitive. To examine the role of Socs-3 within specific neurons critical to energy balance, we created mice with selective deletion of Socs-3 within pro-opiomelanocortin (POMC)-expressing cells. These mice had enhanced leptin sensitivity, measured by weight loss and food intake after leptin infusion. On chow diet, glucose homeostasis was improved despite normal weight gain. On a high-fat diet, the rate of weight gain was reduced, due to increased energy expenditure rather than decreased food intake; glucose homeostasis and insulin sensitivity were substantially improved. These studies demonstrate that Socs-3 within POMC neurons regulates leptin sensitivity and glucose homeostasis, and plays a key role in linking high-fat diet to disordered metabolism.

  10. Impact of streptozotocin on altering normal glucose homeostasis during insulin testing in diabetic rats compared to normoglycemic rats

    PubMed Central

    Qinna, Nidal A; Badwan, Adnan A

    2015-01-01

    Streptozotocin (STZ) is currently the most used diabetogenic agent in testing insulin and new antidiabetic drugs in animals. Due to the toxic and disruptive nature of STZ on organs, apart from pancreas, involved in preserving the body’s normal glucose homeostasis, this study aims to reassess the action of STZ in inducing different glucose response states in diabetic rats while testing insulin. Diabetic Sprague-Dawley rats induced with STZ were classified according to their initial blood glucose levels into stages. The effect of randomizing rats in such a manner was investigated for the severity of interrupting normal liver, pancreas, and kidney functions. Pharmacokinetic and pharmacodynamic actions of subcutaneously injected insulin in diabetic and nondiabetic rats were compared. Interruption of glucose homeostasis by STZ was challenged by single and repeated administrations of injected insulin and oral glucose to diabetic rats. In diabetic rats with high glucose (451–750 mg/dL), noticeable changes were seen in the liver and kidney functions compared to rats with lower basal glucose levels. Increased serum levels of recombinant human insulin were clearly indicated by a significant increase in the calculated maximum serum concentration and area under the concentration–time curve. Reversion of serum glucose levels to normal levels pre- and postinsulin and oral glucose administrations to STZ diabetic rats were found to be variable. In conclusion, diabetic animals were more responsive to insulin than nondiabetic animals. STZ was capable of inducing different levels of normal glucose homeostasis disruption in rats. Both pharmacokinetic and pharmacodynamic actions of insulin were altered when different initial blood glucose levels of STZ diabetic rats were selected for testing. Such findings emphasize the importance of selecting predefined and unified glucose levels when using STZ as a diabetogenic agent in experimental protocols evaluating new antidiabetic agents

  11. Disrupting mitochondrial Ca2+ homeostasis causes tumor-selective TRAIL sensitization through mitochondrial network abnormalities.

    PubMed

    Ohshima, Yohei; Takata, Natsuhiko; Suzuki-Karasaki, Miki; Yoshida, Yukihiro; Tokuhashi, Yasuaki; Suzuki-Karasaki, Yoshihiro

    2017-10-01

    The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has emerged as a promising anticancer agent with high tumor-selective cytotoxicity. The congenital and acquired resistance of some cancer types including malignant melanoma and osteosarcoma impede the current TRAIL therapy of these cancers. Since fine tuning of the intracellular Ca2+ level is essential for cell function and survival, Ca2+ dynamics could be a promising target for cancer treatment. Recently, we demonstrated that mitochondrial Ca2+ removal increased TRAIL efficacy toward malignant melanoma and osteosarcoma cells. Here we report that mitochondrial Ca2+ overload leads to tumor-selective sensitization to TRAIL cytotoxicity. Treatment with the mitochondrial Na+/Ca2+ exchanger inhibitor CGP-37157 and oxidative phosphorylation inhibitor antimycin A and FCCP resulted in a rapid and persistent mitochondrial Ca2+ rise. These agents also increased TRAIL sensitivity in a tumor-selective manner with a switching from apoptosis to a nonapoptotic cell death. Moreover, we found that mitochondrial Ca2+ overload led to increased mitochondrial fragmentation, while mitochondrial Ca2+ removal resulted in mitochondrial hyperfusion. Regardless of their reciprocal actions on the mitochondrial dynamics, both interventions commonly exacerbated TRAIL-induced mitochondrial network abnormalities. These results expand our previous study and suggest that an appropriate level of mitochondrial Ca2+ is essential for maintaining the mitochondrial dynamics and the survival of these cells. Thus, disturbing mitochondrial Ca2+ homeostasis may serve as a promising approach to overcome the TRAIL resistance of these cancers with minimally compromising the tumor-selectivity.

  12. Association of variants in gastric inhibitory polypeptide receptor gene with impaired glucose homeostasis in obese children and adolescents from Berlin.

    PubMed

    Sauber, Jeannine; Grothe, Jessica; Behm, Maria; Scherag, André; Grallert, Harald; Illig, Thomas; Hinney, Anke; Hebebrand, Johannes; Wiegand, Susanna; Grüters, Annette; Krude, Heiko; Biebermann, Heike

    2010-08-01

    In the past 20 years, obesity has become a major health problem due to associated diseases like type 2 diabetes mellitus. The gastric inhibitory polypeptide receptor (GIPR) modulates body weight and glucose homeostasis and, therefore, represents an interesting candidate gene for obesity and the comorbidity impaired glucose homeostasis. Recently, a GIPR variation was found to be associated with impaired insulin response in humans. In this study, we screened the GIPR gene for mutations and examined the association between three single-nucleotide polymorphisms (SNPs; rs8111428, rs2302382, rs1800437) and childhood obesity, as well as impaired glucose homeostasis. The coding region of the GIPR was screened for mutations by direct sequencing. We genotyped three known SNPs in 2280 healthy normal weight (1696) and obese (584) children and adolescents. Genotyping was performed using the SNaPshot protocol, the iplex, and matrix-assisted laser desorption ionization time-of-flight spectrometry technique. Obesity was defined by a body mass index SDS above 2; homeostatic model assessment was calculated. No evidence for an association was found between the SNPs and the obesity phenotype. Significant association was found between the minor allele C of the SNP rs1800437 and elevated homeostasis model of insulin resistance values (P=0.001). No further sequence variations in the GIPR were found to be associated with childhood obesity. Variations of the GIPR sequence are not associated with childhood obesity. This study points to a potential role for rs1800437 in glucose homeostasis. Further studies are necessary to confirm these results.

  13. Fasting glucose measurement as a potential first step screening for glucose metabolism abnormalities in women with anovulatory polycystic ovary syndrome.

    PubMed

    Veltman-Verhulst, Susanne M; Goverde, Angelique J; van Haeften, Timon W; Fauser, Bart C J M

    2013-08-01

    Is routine screening by oral glucose tolerance test (OGTT) needed for all women with polycystic ovary syndrome (PCOS)? Screening for glucose metabolism abnormalities of PCOS patients by an OGTT could potentially be limited to patients who present with a fasting glucose concentration between 6.1 and 7.0 mmol/l only. Women with PCOS are at increased risk of developing diabetes. This study proposes a stepwise screening strategy for (pre)diabetes for PCOS patients based on risk stratification by fasting plasma glucose. A cross-sectional study of 226 women diagnosed with anovulatory PCOS. A consecutive series of 226 patients, diagnosed with PCOS at the University Medical Centre Utrecht, the Netherlands, were screened for glucose metabolism abnormalities by OGTT (75 g glucose load). The majority of the 226 women (mean age: 29.6 ± 4.3 years; BMI: 27.3 ± 6.7 kg/m(2); 81% Caucasian) presented with a normal OGTT (169 women (75%)). Of the 57 (25%) women presenting with mild to moderate glucose abnormalities, 53 (93%) could be identified by fasting glucose concentrations only. Diabetes was diagnosed in a total of eight women (3.5%). In six women, the diagnosis was based on fasting glucose >7.0 mmol/l. The other two cases of diabetes initially presented with fasting glucose between 6.1 and 7.0 mmol/l and were diagnosed by OGTT assessment. No women diagnosed with diabetes presented with fasting glucose levels below 6.1 mmol/l. We therefore conclude that all diabetes patients could potentially be found by initial fasting glucose assessment followed by OGTT only in patients with fasting glucose between 6.1 and 7.0 mmol/l. Before general implementation can be advised, this screening algorithm should be validated in a prospective study of a similar or greater number of PCOS women. Our study comprised of a mostly Caucasian (81%) population, therefore generalization to other ethnic populations should be done with caution. No external finance was involved in this study. B

  14. Melanocortin-4-receptors Expressed by Cholinergic Neurons Regulate Energy Balance and Glucose Homeostasis

    PubMed Central

    Rossi, Jari; Balthasar, Nina; Olson, David; Scott, Michael; Berglund, Eric; Lee, Charlotte E.; Choi, Michelle J.; Lauzon, Danielle; Lowell, Bradford B.; Elmquist, Joel K.

    2011-01-01

    Summary Melanocortin-4-receptor (MC4R) mutations cause dysregulation of energy balance and hyperinsulinemia. We have used mouse models to study the physiological roles of extrahypothalamic MC4Rs. Re-expression of MC4Rs in cholinergic neurons (ChAT-Cre, loxTB MC4R mice) modestly reduced body weight gain without altering food intake and was sufficient to normalize energy expenditure and attenuate hyperglycemia and hyperinsulinemia. In contrast, restoration of MC4R expression in brainstem neurons including those in the dorsal motor nucleus of the vagus (Phox2b-Cre, loxTB MC4R mice) was sufficient to attenuate hyperinsulinemia, while the hyperglycemia and energy balance were not normalized. Additionally, hepatic insulin action and insulin mediated-suppression of hepatic glucose production were improved in ChAT-Cre, loxTB MC4R mice. These findings suggest that MC4Rs expressed by cholinergic neurons regulate energy expenditure and hepatic glucose production. Our results also provide further evidence of the dissociation in pathways mediating the effects of melanocortins on energy balance and glucose homeostasis. PMID:21284986

  15. Imidacloprid insecticide exposure induces stress and disrupts glucose homeostasis in male rats.

    PubMed

    Khalil, Samah R; Awad, Ashraf; Mohammed, Hesham H; Nassan, Mohamed Abdo

    2017-10-01

    In the present study, we evaluated the stress response in adult rats who were administered imidacloprid (IMI) orally in two doses (0.5 and 1.0mg/kg bw for 60days). It led to an alteration in the levels of cortisone and catecholamines and induced behavioral deficits, particularly in the animals exposed to the dose of 1.0mg/kg. IMI was further analyzed for the effect on glucose homeostasis in developing and adult rats at a dose of 1.0mg/kg bw where it elicited a hyperglycemic effect. Moreover, we observed an alteration in the mRNA levels of glucose transporters. Histopathological and immunohistochemical data displayed structural perturbations in pancreatic tissue with a decline in the expression of insulin and GLUT4, particularly in the developing rats. Collectively, IMI treatment resulted in stress represented by behavioral and biochemical changes, particularly at a dose of 1.0mg/kg bw. Moreover, IMI perturbed the glucose regulation through hyperglycemic activity in both developing and adult rats, an observation clearly evident in the developing rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Association between site-specific bone mineral density and glucose homeostasis and anthropometric traits in healthy men and women.

    PubMed

    Kim, Se-Min; Cui, Jinrui; Rhyu, Jane; Guo, Xiuqing; Chen, Yii-Der I; Hsueh, Willa A; Rotter, Jerome I; Goodarzi, Mark O

    2018-06-01

    Patients with type 2 diabetes mellitus have an increased risk of fracture despite normal or increased bone mineral density (BMD). Studies on the relationship of glucose homeostasis with BMD phenotypes have been inconclusive because distinguishing the roles of insulin resistance and hyperglycaemia in bone remodelling is challenging. In this study, we sought to define the relationship of site-specific BMD with glucose homeostasis traits and anthropometric traits. In a cross-sectional study, we examined 787 subjects from the Mexican-American Coronary Artery Disease (MACAD) cohort who had undergone euglycaemic-hyperinsulinaemic clamps, oral glucose tolerance testing and dual X-ray absorptiometry. Glucose homeostasis traits included insulinogenic index (IGI30), insulin sensitivity (M value), insulin clearance (MCRI), fasting insulin, fasting glucose and 2-hour glucose. Univariate and multivariate analyses were performed to assess the association of glucose homeostasis and anthropometric traits with site-specific BMD. Two-hour glucose was negatively associated with arm BMD in women, which remained significant in multivariate analysis (β = -.15, P = .0015). Positive correlations between fasting insulin and BMD at weight-bearing sites, including pelvis (β = .22, P < .0001) and legs (β = .17, P = .001) in women and pelvis (β = .33, P < .0001) in men, lost significance after multivariate adjustment. Lean mass exhibited strong independent positive associations with BMD at multiple sites in both sexes. Our findings suggest that (i) anabolic effects of insulin might work via mechanical loading from lean mass; (ii) a direct negative effect of increasing glucose might be more prominent at cortical-bone-rich sites in women; and (iii) lean mass is a strong positive predictor of bone mass. © 2018 John Wiley & Sons Ltd.

  17. Experience with the high-intensity sweetener saccharin impairs glucose homeostasis and GLP-1 release in rats

    PubMed Central

    Swithers, Susan E.; Laboy, Alycia F.; Clark, Kiely; Cooper, Stephanie; Davidson, T.L.

    2012-01-01

    Previous work from our lab has demonstrated that experience with high-intensity sweeteners in rats leads to increased food intake, body weight gain and adiposity, along with diminished caloric compensation and decreased thermic effect of food. These changes may occur as a result of interfering with learned relations between the sweet taste of food and the caloric or nutritive consequences of consuming those foods. The present experiments determined whether experience with the high-intensity sweetener saccharin versus the caloric sweetener glucose affected blood glucose homeostasis. The results demonstrated that during oral glucose tolerance tests, blood glucose levels were more elevated in animals that had previously consumed the saccharin-sweetened supplements. In contrast, during glucose tolerance tests when a glucose solution was delivered directly into the stomach, no differences in blood glucose levels between the groups were observed. Differences in oral glucose tolerance responses were not accompanied by differences in insulin release; insulin release was similar in animals previously exposed to saccharin and those previously exposed to glucose. However, release of GLP-1 in response to an oral glucose tolerance test, but not to glucose tolerance tests delivered by gavage, was significantly lower in saccharin-exposed animals compared to glucose-exposed animals. Differences in both blood glucose and GLP-1 release in saccharin animals were rapid and transient, and suggest that one mechanism by which exposure to high-intensity sweeteners that interfere with a predictive relation between sweet tastes and calories may impair energy balance is by suppressing GLP-1 release, which could alter glucose homeostasis and reduce satiety. PMID:22561130

  18. Dimethyl amiloride improves glucose homeostasis in mouse models of type 2 diabetes.

    PubMed

    Gunawardana, Subhadra C; Head, W Steven; Piston, David W

    2008-06-01

    Dimethyl amiloride (DMA) enhances insulin secretion in the pancreatic beta-cell. DMA also enhances time-dependent potentiation (TDP) and enables TDP to occur in situations where it is normally absent. As we have demonstrated before, these effects are mediated in part through inhibition of neuronal nitric oxide synthase (nNOS), resulting in increased availability of arginine. Thus both DMA and arginine have the potential to correct the secretory defect in diabetes by enabling or enhancing TDP. In the current study we have demonstrated the ability of these agents to improve blood glucose homeostasis in three mouse models of type 2 diabetes. The pattern of TDP under different conditions indicates that inhibition of NOS is not the only mechanism through which DMA exerts its positive effects. Thus we also have explored another possible mechanism through which DMA enables/enhances TDP, via the activation of mitochondrial alpha-ketoglutarate dehydrogenase.

  19. Gene-Environment Interactions Controlling Energy and Glucose Homeostasis and the Developmental Origins of Obesity

    PubMed Central

    Bouret, Sebastien; Levin, Barry E.; Ozanne, Susan E.

    2015-01-01

    Obesity and type 2 diabetes mellitus (T2DM) often occur together and affect a growing number of individuals in both the developed and developing worlds. Both are associated with a number of other serious illnesses that lead to increased rates of mortality. There is likely a polygenic mode of inheritance underlying both disorders, but it has become increasingly clear that the pre- and postnatal environments play critical roles in pushing predisposed individuals over the edge into a disease state. This review focuses on the many genetic and environmental variables that interact to cause predisposed individuals to become obese and diabetic. The brain and its interactions with the external and internal environment are a major focus given the prominent role these interactions play in the regulation of energy and glucose homeostasis in health and disease. PMID:25540138

  20. Central control of glucose homeostasis: the brain--endocrine pancreas axis.

    PubMed

    Thorens, B

    2010-10-01

    A large body of data gathered over the last decades has delineated the neuronal pathways that link the central nervous system with the autonomic innervation of the endocrine pancreas, which controls alpha- and beta-cell secretion activity and mass. These are important regulatory functions that are certainly keys for preserving the capacity of the endocrine pancreas to control glucose homeostasis over a lifetime. Identifying the cells involved in controlling the autonomic innervation of the endocrine pancreas, in response to nutrient, hormonal and environmental cues and how these cues are detected to activate neuronal activity are important goals of current research. Elucidation of these questions may possibly lead to new means for preserving or restoring defects in insulin and glucagon secretion associated with type 2 diabetes. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  1. Gene-environment interactions controlling energy and glucose homeostasis and the developmental origins of obesity.

    PubMed

    Bouret, Sebastien; Levin, Barry E; Ozanne, Susan E

    2015-01-01

    Obesity and type 2 diabetes mellitus (T2DM) often occur together and affect a growing number of individuals in both the developed and developing worlds. Both are associated with a number of other serious illnesses that lead to increased rates of mortality. There is likely a polygenic mode of inheritance underlying both disorders, but it has become increasingly clear that the pre- and postnatal environments play critical roles in pushing predisposed individuals over the edge into a disease state. This review focuses on the many genetic and environmental variables that interact to cause predisposed individuals to become obese and diabetic. The brain and its interactions with the external and internal environment are a major focus given the prominent role these interactions play in the regulation of energy and glucose homeostasis in health and disease. Copyright © 2015 the American Physiological Society.

  2. Sensing the fuels: glucose and lipid signaling in the CNS controlling energy homeostasis.

    PubMed

    Jordan, Sabine D; Könner, A Christine; Brüning, Jens C

    2010-10-01

    The central nervous system (CNS) is capable of gathering information on the body's nutritional state and it implements appropriate behavioral and metabolic responses to changes in fuel availability. This feedback signaling of peripheral tissues ensures the maintenance of energy homeostasis. The hypothalamus is a primary site of convergence and integration for these nutrient-related feedback signals, which include central and peripheral neuronal inputs as well as hormonal signals. Increasing evidence indicates that glucose and lipids are detected by specialized fuel-sensing neurons that are integrated in these hypothalamic neuronal circuits. The purpose of this review is to outline the current understanding of fuel-sensing mechanisms in the hypothalamus, to integrate the recent findings in this field, and to address the potential role of dysregulation in these pathways in the development of obesity and type 2 diabetes mellitus.

  3. Revisiting “Vegetables” to combat modern epidemic of imbalanced glucose homeostasis

    PubMed Central

    Tiwari, Ashok Kumar

    2014-01-01

    Vegetables have been part of human food since prehistoric times and are considered nutritionally necessary and good for health. Vegetables are rich natural resource of biological antioxidants and possess capabilities of maintaining glucose homeostasis. When taken before starch-rich diet, juice also of vegetables such as ridge gourd, bottle gourd, ash gourd, chayote and juice of leaves of vegetables such as radish, Indian Dill, ajwain, tropical green amaranth, and bladder dock are reported to arrest significantly the rise in postprandial blood glucose level. Juice of vegetables such as ash gourd, squash gourd, and tropical green amaranth leaves are observed to tone-down sweet-beverages such as sucrose, fructose, and glucose-induced postprandial glycemic excursion. On the other hand, juice of egg-plant and juice of leaves of Ceylon spinach, Joyweed, and palak are reported to augment starch-induced postprandial glycemic excursion; and juice of leaves of Ceylon spinach, Joyweed, and radish supplement to the glucose-induced postprandial glycemia. Vegetables possess multifaceted antihyperglycemic activities such as inhibition of pancreatic α-amylase and intestinal α-glucosidase, inhibition of protein-tyrosine phosphatase 1β in liver and skeletal muscles, and insulin mimetic and secretagogue activities. Furthermore, they are also reported to influence polyol pathway in favor of reducing development of oxidative stress, and consequently the development of diabetic complications. In the wake of emergence of modern maladaptive diet-induced hyperglycemic epidemic therefore, vegetables may offer cost-effective dietary regimen to control diet-induced glycemic over load and future development of diabetes mellitus. However, for vegetables have been reported to do both, mitigate as well as supplement to the diet-induced postprandial glycemic load, care is required in selection of vegetables when considered as medicament. PMID:24991093

  4. Hepatic OATP Transporter and Thyroid Hormone Receptor Interplay Determines Cholesterol and Glucose Homeostasis

    PubMed Central

    Meyer zu Schwabedissen, Henriette E.; Ware, Joseph A.; Finkelstein, David; Chaudhry, Amarjit S.; Lemay, Sara; Leon-Ponte, Matilde; Strom, Stephen C.; Zaher, Hani; Schwarz, Ute I.; Freeman, David J.; Schuetz, Erin G.; Tirona, Rommel G.; Kim, Richard B.

    2011-01-01

    The role of Organic Anion Transporting Polypeptides (OATPs), particularly the members of OATP1B-subfamily, in hepatocellular handling of endogenous and exogenous compounds is an important and emerging area of research. Using a mouse model lacking Slco1b2, the murine ortholog of the OATP1B-subfamily, we previously demonstrated that genetic ablation causes reduced hepatic clearance capacity for substrates. In this report we focused on the physiological function of the hepatic OATP1B transporters. First we studied the influence of the Oatp1b2 deletion on bile acid metabolism showing that lack of the transporter results in a significantly reduced expression of Cyp7a1 the key enzyme of bile acid synthesis, resulting in elevated cholesterol levels after high dietary fat challenge. Furthermore, Slco1b2−/− mice exhibited delayed clearance after oral glucose challenge resulting from reduced hepatic glucose uptake. In addition to increased hepatic glycogen content, Slco1b2−/−exhibited reduced glucose output after pyruvate challenge. This is in accordance with reduced hepatic expression of PEPCK in knockout mice. We show this phenotype is due to the loss of liver-specific Oatp1b2-mediated hepatocellular thyroid hormone entry, which then leads to reduced transcriptional activation of target genes of hepatic thyroid hormone receptor (TR) including the prior mentioned Cyp7a1 and Pepck, but also Dio1 and Glut2. Importantly, we assessed human relevance using a cohort of archived human livers where OATP1B1 expression was noted to be highly associated with TR target genes, especially for GLUT2. Furthermore, GLUT2 expression was significantly decreased in livers harboring a common genetic polymorphism in SLCO1B1. Conclusion Our findings reveal that OATP1B-mediated hepatic thyroid hormone entry is a key determinant of cholesterol and glucose homeostasis. PMID:21538436

  5. The CNS glucagon-like peptide-2 receptor in the control of energy balance and glucose homeostasis

    PubMed Central

    2014-01-01

    The gut-brain axis plays a key role in the control of energy balance and glucose homeostasis. In response to luminal stimulation of macronutrients and microbiota-derived metabolites (secondary bile acids and short chain fatty acids), glucagon-like peptides (GLP-1 and -2) are cosecreted from endocrine L cells in the gut and coreleased from preproglucagonergic neurons in the brain stem. Glucagon-like peptides are proposed as key mediators for bariatric surgery-improved glycemic control and energy balance. Little is known about the GLP-2 receptor (Glp2r)-mediated physiological roles in the control of food intake and glucose homeostasis, yet Glp1r has been studied extensively. This review will highlight the physiological relevance of the central nervous system (CNS) Glp2r in the control of energy balance and glucose homeostasis and focuses on cellular mechanisms underlying the CNS Glp2r-mediated neural circuitry and intracellular PI3K signaling pathway. New evidence (obtained from Glp2r tissue-specific KO mice) indicates that the Glp2r in POMC neurons is essential for suppressing feeding behavior, gastrointestinal motility, and hepatic glucose production. Mice with Glp2r deletion selectively in POMC neurons exhibit hyperphagic behavior, accelerated gastric emptying, glucose intolerance, and hepatic insulin resistance. GLP-2 differentially modulates postsynaptic membrane excitability of hypothalamic POMC neurons in Glp2r- and PI3K-dependent manners. GLP-2 activates the PI3K-Akt-FoxO1 signaling pathway in POMC neurons by Glp2r-p85α interaction. Intracerebroventricular GLP-2 augments glucose tolerance, suppresses glucose production, and enhances insulin sensitivity, which require PI3K (p110α) activation in POMC neurons. Thus, the CNS Glp2r plays a physiological role in the control of food intake and glucose homeostasis. This review will also discuss key questions for future studies. PMID:24990862

  6. Glucose-6-phosphate transporter gene therapy corrects metabolic and myeloid abnormalities in glycogen storage disease type Ib mice

    PubMed Central

    Yiu, Wai Han; Pan, Chi-Jiunn; Allamarvdasht, Mohammad; Kim, So Youn; Chou, Janice Y.

    2008-01-01

    Glycogen storage disease type Ib (GSD-Ib) is caused by a deficiency in the glucose-6-phosphate transporter (G6PT), an endoplasmic reticulum-associated transmembrane protein that is ubiquitously expressed. GSD-Ib patients suffer from disturbed glucose homeostasis and myeloid dysfunctions. To evaluate the feasibility of gene replacement therapy for GSD-Ib, we have infused adenoviral (Ad) vector containing human G6PT (Ad-hG6PT) into G6PT-deficient (G6PT-/-) mice that manifest symptoms characteristics of the human disorder. Ad-hG6PT-infusion restores significant levels of G6PT mRNA expression in the liver, bone marrow, and spleen and corrects metabolic as well as myeloid abnormalities in G6PT-/- mice. The G6PT-/- mice receiving gene therapy exhibit improved growth; normalized serum profiles for glucose, cholesterol, triglyceride, uric acid, and lactic acid; and reduced hepatic glycogen deposition. The therapy also corrects neutropenia and lowers the elevated serum levels of granulocyte colony stimulating factor. The development of bone and spleen in the infused G6PT-/- mice is improved and accompanied by increased cellularity and normalized myeloid progenitor cell frequencies in both tissues. This effective use of gene therapy to correct metabolic imbalances and myeloid dysfunctions in GSD-Ib mice holds promise for the future of gene therapy in humans. PMID:17006547

  7. Abnormal oxygen homeostasis in the nucleus tractus solitarii of the spontaneously hypertensive rat.

    PubMed

    Hosford, Patrick S; Millar, Julian; Ramage, Andrew G; Marina, Nephtali

    2017-04-01

    What is the central question of this study? Arterial hypertension is associated with impaired neurovascular coupling in the somatosensory cortex. Abnormalities in activity-dependent oxygen consumption in brainstem regions involved in the control of cardiovascular reflexes have not been explored previously. What is the main finding and its importance? Using fast-cyclic voltammetry, we found that changes in local tissue PO2 in the nucleus tractus solitarii induced by electrical stimulation of the vagus nerve are significantly impaired in spontaneously hypertensive rats. This is consistent with previous observations showing that brainstem hypoxia plays an important role in the pathogenesis of arterial hypertension. The effects of arterial hypertension on cerebral blood flow remain poorly understood. Haemodynamic responses within the somatosensory cortex have been shown to be impaired in the spontaneously hypertensive rat (SHR) model. However, it is unknown whether arterial hypertension affects oxygen homeostasis in vital brainstem areas that control cardiovascular reflexes. In this study, we assessed vagus nerve stimulation-induced changes in local tissue PO2 (PtO2) in the caudal nucleus tractus solitarii (cNTS) of SHRs and normotensive Wistar rats. Measurements of PtO2 were performed using a novel application of fast-cyclic voltammetry, which allows higher temporal resolution of O 2 changes than traditional optical fluorescence techniques. Electrical stimulation of the central cut end of the vagus nerve (ESVN) caused profound reductions in arterial blood pressure along with biphasic changes in PtO2 in the cNTS, characterized by a rapid decrease in PtO2 ('initial dip') followed by a post-stimulus overshoot above baseline. The initial dip was found to be significantly smaller in SHRs compared with normotensive Wistar rats even after ganglionic blockade. The post-ESVN overshoot was similar in both groups but was reduced in Wistar rats after ganglionic blockade. In

  8. Assessment of glucose homeostasis in crossbred steer progeny sired by Brahman bulls that experienced prenatal transportation stress

    USDA-ARS?s Scientific Manuscript database

    The objective of this experiment was to assess glucose homeostasis of crossbred male progeny whose Brahman sires experienced prenatal transportation stress (PS) in utero. Sixteen steers (PNS group) sired by 3 PS bulls gestating dams were transported for 2 h at 60, 80, 100, 120, and 140 ± 5 d of gest...

  9. The CNS glucagon-like peptide-2 receptor in the control of energy balance and glucose homeostasis

    USDA-ARS?s Scientific Manuscript database

    The gut-brain axis plays a key role in the control of energy balance and glucose homeostasis. In response to luminal stimulation of macronutrients and microbiotaderived metabolites (secondary bile acids and short chain fatty acids), glucagon-like peptides (GLP-1 and -2) are cosecreted from endocrine...

  10. Ovarian SAHA syndrome is associated with a more insulin-resistant profile and represents an independent risk factor for glucose abnormalities in women with polycystic ovary syndrome: a prospective controlled study.

    PubMed

    Dalamaga, Maria; Papadavid, Evangelia; Basios, Georgios; Vaggopoulos, Vassilios; Rigopoulos, Dimitrios; Kassanos, Dimitrios; Trakakis, Eftihios

    2013-12-01

    SAHA syndrome is characterized by the tetrad: seborrhea, acne, hirsutism, and androgenetic alopecia. No previous study has examined the prevalence of glucose abnormalities in ovarian SAHA and explored whether it may be an independent risk factor for glucose abnormalities. In a prospective controlled study, we investigated the spectrum of glucose abnormalities in ovarian SAHA and explored whether it is associated with a more insulin-resistant profile. In all, 316 patients with a diagnosis of polycystic ovary syndrome (PCOS) (56 with SAHA) and 102 age-matched healthy women were examined and underwent a 2-hour oral glucose tolerance test. Serum glucose homeostasis parameters, hormones, and adipokines were determined. SAHA prevalence was 17.7% in patients with PCOS and predominance of the severe PCOS phenotype. Ovarian SAHA was independently associated with a more insulin-resistant profile (higher homeostatic model assessment of insulin resistance score, lower quantitative insulin sensitivity check index [QUICKI] and MATSUDA indices, and relative hypoadiponectinemia), and represented an independent risk factor for glucose abnormalities regardless of anthropometric features, age, and PCOS phenotype. There was no performance of skin biopsies. The prompt recognition of SAHA syndrome in women with PCOS permits an earlier diagnosis and surveillance of metabolic abnormalities, especially in Mediterranean PCOS population exhibiting a lower prevalence of glucose abnormalities. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  11. T cell protein tyrosine phosphatase (TCPTP) deficiency in muscle does not alter insulin signalling and glucose homeostasis in mice.

    PubMed

    Loh, K; Merry, T L; Galic, S; Wu, B J; Watt, M J; Zhang, S; Zhang, Z-Y; Neel, B G; Tiganis, T

    2012-02-01

    Insulin activates insulin receptor protein tyrosine kinase and downstream phosphatidylinositol-3-kinase (PI3K)/Akt signalling in muscle to promote glucose uptake. The insulin receptor can serve as a substrate for the protein tyrosine phosphatase (PTP) 1B and T cell protein tyrosine phosphatase (TCPTP), which share a striking 74% sequence identity in their catalytic domains. PTP1B is a validated therapeutic target for the alleviation of insulin resistance in type 2 diabetes. PTP1B dephosphorylates the insulin receptor in liver and muscle to regulate glucose homeostasis, whereas TCPTP regulates insulin receptor signalling and gluconeogenesis in the liver. In this study we assessed for the first time the role of TCPTP in the regulation of insulin receptor signalling in muscle. We generated muscle-specific TCPTP-deficient (Mck-Cre;Ptpn2(lox/lox)) mice (Mck, also known as Ckm) and assessed the impact on glucose homeostasis and muscle insulin receptor signalling in chow-fed versus high-fat-fed mice. Blood glucose and insulin levels, insulin and glucose tolerance, and insulin-induced muscle insulin receptor activation and downstream PI3K/Akt signalling remained unaltered in chow-fed Mck-Cre;Ptpn2(lox/lox) versus Ptpn2(lox/lox) mice. In addition, body weight, adiposity, energy expenditure, insulin sensitivity and glucose homeostasis were not altered in high-fat-fed Mck-Cre;Ptpn2(lox/lox) versus Ptpn2(lox/lox) mice. These results indicate that TCPTP deficiency in muscle has no effect on insulin signalling and glucose homeostasis, and does not prevent high-fat diet-induced insulin resistance. Thus, despite their high degree of sequence identity, PTP1B and TCPTP contribute differentially to insulin receptor regulation in muscle. Our results are consistent with the notion that these two highly related PTPs make distinct contributions to insulin receptor regulation in different tissues.

  12. Butyrylcholinesterase regulates central ghrelin signaling and has an impact on food intake and glucose homeostasis.

    PubMed

    Chen, V P; Gao, Y; Geng, L; Brimijoin, S

    2017-09-01

    Ghrelin is the only orexigenic hormone known to stimulate food intake and promote obesity and insulin resistance. We recently showed that plasma ghrelin is controlled by butyrylcholinesterase (BChE), which has a strong impact on feeding and weight gain. BChE knockout (KO) mice are prone to obesity on high-fat diet, but hepatic BChE gene transfer rescues normal food intake and obesity resistance. However, these mice lack brain BChE and still develop hyperinsulinemia and insulin resistance, suggesting essential interactions between BChE and ghrelin within the brain. To test the hypothesis we used four experimental groups: (1) untreated wild-type mice, (2) BChE KO mice with LUC delivered by adeno-associated virus (AAV) in combined intravenous (i.v.) and intracerebral (i.c.) injections, (3) KO mice given AAV for mouse BChE (i.v. only) and (4) KO mice given the same vector both i.v. and i.c. All mice ate a 45% calorie high-fat diet from the age of 1 month. Body weight, body composition, daily caloric intake and serum parameters were monitored throughout, and glucose tolerance and insulin tolerance tests were performed at intervals. Circulating ghrelin levels dropped substantially in the KO mice after i.v. AAV-BChE delivery, which led to normal food intake and healthy body weight. BChE KO mice that received AAV-BChE through i.v. and i.c. combined treatments not only resisted weight gain on high-fat diet but also retained normal glucose and insulin tolerance. These data indicate a central role for BChE in regulating both insulin and glucose homeostasis. BChE gene transfer could be a useful therapy for complications linked to diet-induced obesity and insulin resistance.

  13. Personality traits and abnormal glucose regulation in middle-aged Swedish men and women.

    PubMed

    Eriksson, Anna-Karin; Gustavsson, J Petter; Hilding, Agneta; Granath, Fredrik; Ekbom, Anders; Ostenson, Claes-Göran

    2012-01-01

    To examine associations between personality and abnormal glucose regulation. This cross-sectional study comprised 2152 men and 3143 women (43-66 years). Oral glucose tolerance test identified 316 men and 213 women with previously unknown impaired fasting glucose (IFG), impaired glucose tolerance (IGT), IFG+IGT, or type 2 diabetes. Personality traits antagonism (low agreeableness), impulsivity (low conscientiousness), hedonic capacity (high extraversion), negative affectivity (high neuroticism) and alexithymia (low openness) were measured by a self-report inventory. Based on distribution of scores, responses were divided into "low" (<1 SD), "middle" (±1 SD) and "high" (>1 SD). Middle groups were considered reference groups. Prevalence odds ratios (ORs) and 95% confidence intervals (CIs) were estimated. In men, OR for low antagonism was 0.3 (CI 0.2-0.6) (age- and multi-adjusted models) while in women, neither high nor low antagonism was associated to abnormal glucose regulation. Men and women with high hedonic capacity had ORs 0.5 (0.3-0.9) and 0.6 (0.4-1.0), respectively (age- and multi-adjusted models). The other scales illustrated no significant associations. No elevated risk of abnormal glucose regulation was observed for deviating scores on personality scales. Instead, reduced risks were indicated in men with low antagonism, and in men and women with high hedonic capacity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Targeted delivery of HGF to the skeletal muscle improves glucose homeostasis in diet-induced obese mice.

    PubMed

    Sanchez-Encinales, Viviana; Cozar-Castellano, Irene; Garcia-Ocaña, Adolfo; Perdomo, Germán

    2015-12-01

    Hepatocyte growth factor (HGF) is a cytokine that increases glucose transport ex vivo in skeletal muscle. The aim of this work was to decipher the impact of whether conditional overexpression of HGF in vivo could improve glucose homeostasis and insulin sensitivity in mouse skeletal muscle. Following tetracyclin administration, muscle HGF levels were augmented threefold in transgenic mice (SK-HGF) compared to control mice without altering plasma HGF levels. In conditions of normal diet, SK-HGF mice showed no differences in body weight, plasma triglycerides, blood glucose, plasma insulin and glucose tolerance compared to control mice. Importantly, obese SK-HGF mice exhibited improved whole-body glucose tolerance independently of changes in body weight or plasma triglyceride levels compared to control mice. This effect on glucose homeostasis was associated with significantly higher (∼80%) levels of phosphorylated protein kinase B in muscles from SK-HGF mice compared to control mice. In conclusion, muscle expression of HGF counteracts obesity-mediated muscle insulin resistance and improves glucose tolerance in mice.

  15. Predictors of Abnormal Glucose Tolerance in the Early Postpartum Period in Patients with Gestational Diabetes.

    PubMed

    Inoue, Shigeru; Shinagawa, Takaaki; Horinouchi, Takashi; Kozuma, Yutaka; Yonemoto, Koji; Hori, Daizo; Ushijima, Kimio

    2016-01-01

    This study was designed to investigate the clinical predictors of abnormal glucose tolerance 5-7 weeks after delivery. Subjects were 155 women diagnosed with gestational diabetes mellitus (GDM) between October 2005 and September 2013 whose pregnancy and delivery were managed at our center. Subjects were divided into a normal glucose tolerance group (NGT; n = 113), or abnormal glucose tolerance group (AGT; n = 42) with borderline or overt diabetes mellitus, based on 75-g oral glucose tolerance test (75 gOGTT) results 5-7 weeks after delivery. We extracted profiles by which abnormal glucose tolerance levels 5-7 weeks after delivery were predicted using a classification and regression tree (CART) from parameters measured at the time of GDM diagnosis. Logistic regression analysis was used to determine prediction accuracy. Subjects with fasting plasma glucose (FPG) ≥92 mg/dL and immuno-reactive insulin level <100 μU/mL 60 min after load (IRI60min) at time of diagnosis showed a significantly higher risk of developing abnormal glucose tolerance 5-7 weeks after delivery than subjects with FPG <92 mg/dL (p < 0.0001). Subjects with FPG ≥92 mg/dL and IRI60min ≥ 100 μU/mL had the same risk as those with FPG of <92 mg/dL. Patients with gestational diabetes who met the criteria specified above at diagnosis were at a higher risk of developing diabetes mellitus in the future. By explaining this issue to patients, we expect to improve the rate of postpartum follow-up. This should facilitate early detection of diabetes, and help prevent associated complications.

  16. Nature and prognostic importance of abnormal glucose tolerance and diabetes in acute heart failure.

    PubMed

    Berry, C; Brett, M; Stevenson, K; McMurray, J J V; Norrie, J

    2008-03-01

    To investigate the nature and importance of blood glucose abnormalities in an unselected heart failure (HF) population. Cohort study. Urban University hospital. All index emergency HF admissions to one University hospital during the year 2000 were studied. 454 consecutive index admissions had blood chemistry, diabetic status and follow-up information recorded. 390 (86%) patients had an echocardiogram, of whom 117 (30%) had preserved left ventricular systolic function and 110 (24%) had diabetes. Sixty (13%) patients had abnormal glucose tolerance (8.0-10.99 mmol/l), and 284 (63%) patients had a normal admission blood glucose (<8 mmol/l). 51 (11.2%) patients died in hospital. After adjustment for other prognostic attributes, abnormal glucose tolerance (Cox hazard ratio HR, 95% CI: 5.920, 1.03 to 34.00; p = 0.046) but not diabetes (HR 3.46, 0.75 to 16.02; p = 0.112) predicted in-hospital mortality. During follow-up (median 812 (range 632-978) days), 104 (36.6%), 30 (50.0%) and 55 (50%) patients with a normal admission blood glucose concentration, abnormal glucose tolerance and diabetes, respectively, died (log rank test p = 0.0037, adjusted p = 0.075). Compared with patients with normal admission blood glucose, abnormal glucose tolerance (adjusted HR: 1.41 (0.92 to 2.16); p = 0.12) and diabetes (adjusted HR: 2.02 (1.41 to 2.88); p = 0.0001) predicted mortality. Considering glucose on admission as a continuous covariate, a 2 mmol/l increase was associated with a HR of 1.08 (1.03 to 1.13), p = 0.0010, which after adjustment for the above covariates became 1.08 (1.03 to 1.13), p = 0.0023. Admission blood glucose concentration and diabetes are prognostically important in HF and could help target some patients for more intensive therapy.

  17. Role of proximal gut exclusion from food on glucose homeostasis in patients with Type 2 diabetes.

    PubMed

    Cohen, R; le Roux, C W; Papamargaritis, D; Salles, J E; Petry, T; Correa, J L; Pournaras, D J; Galvao Neto, M; Martins, B; Sakai, P; Schiavon, C A; Sorli, C

    2013-12-01

    To report Type 2 diabetes-related outcomes after the implantation of a duodenal-jejunal bypass liner device and to investigate the role of proximal gut exclusion from food in glucose homeostasis using the model of this device. Sixteen patients with Type 2 diabetes and BMI <36 kg/m(2) were evaluated before and 1, 12 and 52 weeks after duodenal-jejunal bypass liner implantation and 26 weeks after explantation. Mixed-meal tolerance tests were conducted over a period of 120 min and glucose, insulin and C-peptide levels were measured. The Matsuda index and the homeostatic model of assessment of insulin resistance were used for the estimation of insulin sensitivity and insulin resistance. The insulin secretion rate was calculated using deconvolution of C-peptide levels. Body weight decreased by 1.3 kg after 1 week and by 2.4 kg after 52 weeks (P < 0.001). One year after duodenal-jejunal bypass liner implantation, the mean (sem) HbA(1c) level decreased from 71.3 (2.4) mmol/mol (8.6[0.2]%) to 58.1 (4.4) mmol/mol (7.5 [0.4]%) and mean (sem) fasting glucose levels decreased from 203.3 (13.5) mg/dl to 155.1 (13.1) mg/dl (both P < 0.001). Insulin sensitivity improved by >50% as early as 1 week after implantation as measured by the Matsuda index and the homeostatic model of assessment of insulin resistance (P < 0.001), but there was a trend towards deterioration in all the above-mentioned variables 26 weeks after explantation. Fasting insulin levels, insulin area under the curve, fasting C-peptide, C-peptide area under the curve, fasting insulin and total insulin secretion rates did not change during the duodenal-jejunal bypass liner implantation period or after explantation. The duodenal-jejunal bypass liner improves glycaemia in overweight and obese patients with Type 2 diabetes by rapidly improving insulin sensitivity. A reduction in hepatic glucose output is the most likely explanation for this improvement. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.

  18. Simultaneous coffee caffeine intake and sleep deprivation alter glucose homeostasis in Iranian men: a randomized crossover trial.

    PubMed

    Rasaei, Behrouz; Talib, Ruzita Abd; Noor, Mohd Ismail; Karandish, Majid; Karim, Norimah A

    2016-12-01

    Sleep deprivation and coffee caffeine consumption have been shown to affect glucose homeostasis separately, but the combined effects of these two variables are unknown. Forty-two healthy Iranian men, aged 20-40 years old, were assigned to three groups in a randomised crossover trial involving three treatments with two-week washout periods. Subjects were moderate coffee consumers (<=3 cups/day), and had a Pittsburgh Sleep Quality Index <=5. Each treatment involved three nights of deprived sleep (4 hrs. in bed) plus 3×150 cc/cup of boiled water (BW treatment), decaffeinated coffee (DC treatment, without sugar, 99.9% caffeine-free), and caffeinated coffee (CC treatment, without sugar, 65 mg caffeine/ cup). DC and CC treatments were blinded. At the end of each treatment, fasting serum glucose (using enzyme assays) and insulin (using electrochemiluminescence immunoassay) were measured and, again, two hours after an oral glucose tolerance test (OGTT). Insulin resistance was quantified with the homeostasis model. Repeated measures ANOVA indicated no significant difference between the treatments in fasting serum glucose (p=0.248) or insulin resistance (p=0.079). However, ANOVA demonstrated differences between treatments in fasting serum insulin (p=0.004) and glucose, as well as insulin after OGTT (p<0.001). Pairwise comparisons test (within subjects) showed that the CC treatment yielded higher serum glucose and insulin after OGTT (p<0.001), higher fasting serum insulin (p=0.001), and increased insulin resistance (p=0.039) as compared to the DC treatment. Thus caffeinated coffee was more adverse for glucose homeostasis compared to decaffeinated coffee in individuals who were simultaneously sleep deprived.

  19. The short-chain fatty acid receptor, FFA2, contributes to gestational glucose homeostasis.

    PubMed

    Fuller, Miles; Priyadarshini, Medha; Gibbons, Sean M; Angueira, Anthony R; Brodsky, Michael; Hayes, M Geoffrey; Kovatcheva-Datchary, Petia; Bäckhed, Fredrik; Gilbert, Jack A; Lowe, William L; Layden, Brian T

    2015-11-15

    The structure of the human gastrointestinal microbiota can change during pregnancy, which may influence gestational metabolism; however, a mechanism of action remains unclear. Here we observed that in wild-type (WT) mice the relative abundance of Actinobacteria and Bacteroidetes increased during pregnancy. Along with these changes, short-chain fatty acids (SCFAs), which are mainly produced through gut microbiota fermentation, significantly changed in both the cecum and peripheral blood throughout gestation in these mice. SCFAs are recognized by G protein-coupled receptors (GPCRs) such as free fatty acid receptor-2 (FFA2), and we have previously demonstrated that the fatty acid receptor-2 gene (Ffar2) expression is higher in pancreatic islets during pregnancy. Using female Ffar2-/- mice, we explored the physiological relevance of signaling through this GPCR and found that Ffar2-deficient female mice developed fasting hyperglycemia and impaired glucose tolerance in the setting of impaired insulin secretion compared with WT mice during, but not before, pregnancy. Insulin tolerance tests were similar in Ffar2-/- and WT mice before and during pregnancy. Next, we examined the role of FFA2 in gestational β-cell mass, observing that Ffar2-/- mice had diminished gestational expansion of β-cells during pregnancy. Interestingly, mouse genotype had no significant impact on the composition of the gut microbiome, but did affect the observed SCFA profiles, suggesting a functional difference in the microbiota. Together, these results suggest a potential link between increased Ffar2 expression in islets and the alteration of circulating SCFA levels, possibly explaining how changes in the gut microbiome contribute to gestational glucose homeostasis.

  20. The short chain fatty acid receptor, FFA2, contributes to gestational glucose homeostasis

    DOE PAGES

    Fuller, Miles; Priyadarshini, Medha; Gibbons, Sean M.; ...

    2015-09-22

    The structure of the human gastrointestinal microbiota can change during pregnancy, which may influence gestational metabolism; however, a mechanism of action remains unclear. Here we observed that in wild-type (WT) mice the relative abundance of Actinobacteria and Bacteroidetes increased during pregnancy. Along with these changes, short-chain fatty acids (SCFAs), which are mainly produced through gut microbiota fermentation, significantly changed in both the cecum and peripheral blood throughout gestation in these mice. SCFAs are recognized by G protein-coupled receptors (GPCRs) such as free fatty acid receptor-2 (FFA2), and we have previously demonstrated that the fatty acid receptor-2 gene ( Ffar2) expressionmore » is higher in pancreatic islets during pregnancy. Using female Ffar2-/- mice, we explored the physiological relevance of signaling through this GPCR and found that Ffar2-deficient female mice developed fasting hyperglycemia and impaired glucose tolerance in the setting of impaired insulin secretion compared with WT mice during, but not before, pregnancy. Insulin tolerance tests were similar in Ffar2-/- and WT mice before and during pregnancy. Next, we examined the role of FFA2 in gestational β-cell mass, observing that Ffar2-/- mice had diminished gestational expansion of β-cells during pregnancy. Interestingly, mouse genotype had no significant impact on the composition of the gut microbiome, but did affect the observed SCFA profiles, suggesting a functional difference in the microbiota. Altogether, these results suggest a potential link between increased Ffar2 expression in islets and the alteration of circulating SCFA levels, possibly explaining how changes in the gut microbiome contribute to gestational glucose homeostasis.« less

  1. The short chain fatty acid receptor, FFA2, contributes to gestational glucose homeostasis

    SciTech Connect

    Fuller, Miles; Priyadarshini, Medha; Gibbons, Sean M.

    The structure of the human gastrointestinal microbiota can change during pregnancy, which may influence gestational metabolism; however, a mechanism of action remains unclear. Here we observed that in wild-type (WT) mice the relative abundance of Actinobacteria and Bacteroidetes increased during pregnancy. Along with these changes, short-chain fatty acids (SCFAs), which are mainly produced through gut microbiota fermentation, significantly changed in both the cecum and peripheral blood throughout gestation in these mice. SCFAs are recognized by G protein-coupled receptors (GPCRs) such as free fatty acid receptor-2 (FFA2), and we have previously demonstrated that the fatty acid receptor-2 gene ( Ffar2) expressionmore » is higher in pancreatic islets during pregnancy. Using female Ffar2-/- mice, we explored the physiological relevance of signaling through this GPCR and found that Ffar2-deficient female mice developed fasting hyperglycemia and impaired glucose tolerance in the setting of impaired insulin secretion compared with WT mice during, but not before, pregnancy. Insulin tolerance tests were similar in Ffar2-/- and WT mice before and during pregnancy. Next, we examined the role of FFA2 in gestational β-cell mass, observing that Ffar2-/- mice had diminished gestational expansion of β-cells during pregnancy. Interestingly, mouse genotype had no significant impact on the composition of the gut microbiome, but did affect the observed SCFA profiles, suggesting a functional difference in the microbiota. Altogether, these results suggest a potential link between increased Ffar2 expression in islets and the alteration of circulating SCFA levels, possibly explaining how changes in the gut microbiome contribute to gestational glucose homeostasis.« less

  2. Serine racemase is expressed in islets and contributes to the regulation of glucose homeostasis.

    PubMed

    Lockridge, Amber D; Baumann, Daniel C; Akhaphong, Brian; Abrenica, Alleah; Miller, Robert F; Alejandro, Emilyn U

    2016-11-01

    NMDA receptors (NMDARs) have recently been discovered as functional regulators of pancreatic β-cell insulin secretion. While these excitatory receptor channels have been extensively studied in the brain for their role in synaptic plasticity and development, little is known about how they work in β-cells. In neuronal cells, NMDAR activation requires the simultaneous binding of glutamate and a rate-limiting co-agonist, such as D-serine. D-serine levels and availability in most of the brain rely on endogenous synthesis by the enzyme serine racemase (Srr). Srr transcripts have been reported in human and mouse islets but it is not clear whether Srr is functionally expressed in β-cells or what its role in the pancreas might be. In this investigation, we reveal that Srr protein is highly expressed in primary human and mouse β-cells. Mice with whole body deletion of Srr (Srr KO) show improved glucose tolerance through enhanced insulin secretory capacity, possibly through Srr-mediated alterations in islet NMDAR expression and function. We observed elevated insulin sensitivity in some animals, suggesting Srr metabolic regulation in other peripheral organs as well. Srr expression in neonatal and embryonic islets, and adult deficits in Srr KO pancreas weight and islet insulin content, point toward a potential role for Srr in pancreatic development. These data reveal the first evidence that Srr may regulate glucose homeostasis in peripheral tissues and provide circumstantial evidence that D-serine may be an endogenous islet NMDAR co-agonist in β-cells.

  3. Neuronal SH2B1 is essential for controlling energy and glucose homeostasis.

    PubMed

    Ren, Decheng; Zhou, Yingjiang; Morris, David; Li, Minghua; Li, Zhiqin; Rui, Liangyou

    2007-02-01

    SH2B1 (previously named SH2-B), a cytoplasmic adaptor protein, binds via its Src homology 2 (SH2) domain to a variety of protein tyrosine kinases, including JAK2 and the insulin receptor. SH2B1-deficient mice are obese and diabetic. Here we demonstrated that multiple isoforms of SH2B1 (alpha, beta, gamma, and/or delta) were expressed in numerous tissues, including the brain, hypothalamus, liver, muscle, adipose tissue, heart, and pancreas. Rat SH2B1beta was specifically expressed in neural tissue in SH2B1-transgenic (SH2B1(Tg)) mice. SH2B1(Tg) mice were crossed with SH2B1-knockout (SH2B1(KO)) mice to generate SH2B1(TgKO) mice expressing SH2B1 only in neural tissue but not in other tissues. Systemic deletion of the SH2B1 gene resulted in metabolic disorders in SH2B1(KO) mice, including hyperlipidemia, leptin resistance, hyperphagia, obesity, hyperglycemia, insulin resistance, and glucose intolerance. Neuron-specific restoration of SH2B1beta not only corrected the metabolic disorders in SH2B1(TgKO) mice, but also improved JAK2-mediated leptin signaling and leptin regulation of orexigenic neuropeptide expression in the hypothalamus. Moreover, neuron-specific overexpression of SH2B1 dose-dependently protected against high-fat diet-induced leptin resistance and obesity. These observations suggest that neuronal SH2B1 regulates energy balance, body weight, peripheral insulin sensitivity, and glucose homeostasis at least in part by enhancing hypothalamic leptin sensitivity.

  4. [Role of peripheral serotonin in the insulin secretion and glucose homeostasis].

    PubMed

    Cataldo, Luis Rodrigo; Cortés, Víctor Antonio; Galgani, José Eduardo; Olmos, Pablo Roberto; Santos, José Luis

    2014-09-01

    The most studied roles of serotonin (5-hydroxytryptamine, 5HT) have been related to its action in the Central Nervous System (CNS). However, most of 5HT is produced outside the CNS, mainly in the enterochromaffin cells of the gut. Additionally, other tissues such as the endocrine pancreas, particularly β-cells, have its own serotonin system able to synthesize, secrete and respond to extracellular 5HT through cell surface receptors subtypes that have been grouped in 7 families (HTR1-7). Interestingly, 5HT is stored in granules and released together with insulin from β-cells and its biological significance is likely a combination of intra and extracellular actions. The expression of enzymes involved in 5HT synthesis and their receptors varied markedly in β-pancreatic cells during pregnancy, in parallel with an increase in their insulin secretion potential (probably through the action of Htr3a) and an increase in β-cell mass (through the action of Htr2b and Htr1d). In addition, it has been suggested that gut-derived 5HT may promote hepatic gluconeogenesis during prolonged fasting through Htr2b receptor. Taken together, these findings suggest that peripheral 5HT plays an important role in the regulation of glucose homeostasis through the differential expression and activation of 5-HT membrane receptors on the surface of hepatocytes, adipocytes and pancreatic β-cells. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  5. Activating transcription factor 3 is a target molecule linking hepatic steatosis to impaired glucose homeostasis.

    PubMed

    Kim, Ji Yeon; Park, Keon Jae; Hwang, Joo-Yeon; Kim, Gyu Hee; Lee, DaeYeon; Lee, Yoo Jeong; Song, Eun Hyun; Yoo, Min-Gyu; Kim, Bong-Jo; Suh, Young Ho; Roh, Gu Seob; Gao, Bin; Kim, Won; Kim, Won-Ho

    2017-08-01

    predicting the progression of NAFLD and the development of T2D. Furthermore, given the significant association between hepatic ATF3 expression and both hepatic steatosis and impaired glucose homeostasis, in vivo ATF3 silencing may be a potential central strategy for preventing and managing NAFLD and T2D. Copyright © 2017 European Association for the Study of the Liver. All rights reserved.

  6. Leptin and insulin pathways in POMC and AgRP neurons that modulate energy balance and glucose homeostasis.

    PubMed

    Varela, Luis; Horvath, Tamas L

    2012-12-01

    With the steady rise in the prevalence of obesity and its associated diseases, research aimed at understanding the mechanisms that regulate and control whole body energy homeostasis has gained new interest. Leptin and insulin, two anorectic hormones, have key roles in the regulation of body weight and energy homeostasis, as highlighted by the fact that several obese patients develop resistance to these hormones. Within the brain, the hypothalamic proopiomelanocortin and agouti-related protein neurons have been identified as major targets of leptin and insulin action. Many studies have attempted to discern the individual contributions of various components of the principal pathways that mediate the central effects of leptin and insulin. The aim of this review is to discuss the latest findings that might shed light on, and lead to a better understanding of, energy balance and glucose homeostasis. In addition, recently discovered targets and mechanisms that mediate hormonal action in the brain are highlighted.

  7. Leptin and insulin pathways in POMC and AgRP neurons that modulate energy balance and glucose homeostasis

    PubMed Central

    Varela, Luis; Horvath, Tamas L

    2012-01-01

    With the steady rise in the prevalence of obesity and its associated diseases, research aimed at understanding the mechanisms that regulate and control whole body energy homeostasis has gained new interest. Leptin and insulin, two anorectic hormones, have key roles in the regulation of body weight and energy homeostasis, as highlighted by the fact that several obese patients develop resistance to these hormones. Within the brain, the hypothalamic proopiomelanocortin and agouti-related protein neurons have been identified as major targets of leptin and insulin action. Many studies have attempted to discern the individual contributions of various components of the principal pathways that mediate the central effects of leptin and insulin. The aim of this review is to discuss the latest findings that might shed light on, and lead to a better understanding of, energy balance and glucose homeostasis. In addition, recently discovered targets and mechanisms that mediate hormonal action in the brain are highlighted. PMID:23146889

  8. Partial ablation of adult Drosophila insulin-producing neurons modulates glucose homeostasis and extends life span without insulin resistance.

    PubMed

    Haselton, Aaron; Sharmin, Effat; Schrader, Janel; Sah, Megha; Poon, Peter; Fridell, Yih-Woei C

    2010-08-01

    In Drosophila melanogaster (D. melanogaster), neurosecretory insulin-like peptide-producing cells (IPCs), analogous to mammalian pancreatic beta cells are involved in glucose homeostasis. Extending those findings, we have developed in the adult fly an oral glucose tolerance test and demonstrated that IPCs indeed are responsible for executing an acute glucose clearance response. To further develop D. melanogaster as a relevant system for studying age-associated metabolic disorders, we set out to determine the impact of adult-specific partial ablation of IPCs (IPC knockdown) on insulin-like peptide (ILP) action, metabolic outcomes and longevity. Interestingly, while IPC knockdown flies are hyperglycemic and glucose intolerant, these flies remain insulin sensitive as measured by peripheral glucose disposal upon insulin injection and serine phosphorylation of a key insulin-signaling molecule, Akt. Significant increases in stored glycogen and triglyceride levels as well as an elevated level of circulating lipid measured in adult IPC knockdown flies suggest profound modulation in energy metabolism. Additional physiological outcomes measured in those flies include increased resistance to starvation and impaired female fecundity. Finally, increased life span and decreased mortality rates measured in IPC knockdown flies demonstrate that it is possible to modulate ILP action in adult flies to achieve life span extension without insulin resistance. Taken together, we have established and validated an invertebrate genetic system to further investigate insulin action, metabolic homeostasis and regulation of aging regulated by adult IPCs.

  9. Increasing ICA512 autoantibody titers predict development of abnormal oral glucose tolerance tests.

    PubMed

    Sanda, Srinath

    2018-03-01

    Determine if autoantibody titer magnitude and variability predict glucose abnormalities in subjects at risk for type 1 diabetes. Demographic information, longitudinal autoantibody titers, and oral glucose tolerance test (OGTT) data were obtained from the TrialNet Pathway to Prevention study. Subjects (first and second degree relatives of individuals with type 1 diabetes) with at least 2 diabetes autoantibodies were selected for analysis. Autoantibody titer means were calculated for each subject for the duration of study participation and the relationship between titer tertiles and glucose value tertiles from OGTTs (normal, impaired, and diabetes) was assessed with a proportional odds ordinal regression model. A matched pairs analysis was used to examine the relationship between changes in individual autoantibody titers and 120-minute glucose values. Titer variability was quantified using cumulative titer standard deviations. We studied 778 subjects recruited in the TrialNet Pathway to Prevention study between 2006 and 2014. Increased cumulative mean titer values for both ICA512 and GAD65 (estimated increase in proportional odds = 1.61, 95% CI = 1.39, 1.87, P < 1 × 10 -9 and 1.17, 95% CI = 1.03, 1.32, P = .016, respectively) were associated with peak 120-minute glucose values. While fluctuating titer levels were observed in some subjects, no significant relationship between titer standard deviation and glucose values was observed. ICA512 autoantibody titers associate with progressive abnormalities in glucose metabolism in subjects at risk for type 1 diabetes. Fluctuations in autoantibody titers do not correlate with lower rates of progression to clinical disease. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Chromium picolinate positively influences the glucose transporter system via affecting cholesterol homeostasis in adipocytes cultured under hyperglycemic diabetic conditions

    PubMed Central

    Pattar, Guruprasad R.; Tackett, Lixuan; Liu, Ping; Elmendorf, Jeffrey S.

    2008-01-01

    Since trivalent chromium (Cr3+) enhances glucose metabolism, interest in the use of Cr3+as a therapy for type 2 diabetes has grown in the mainstream medical community. Moreover, accumulating evidence suggests that Cr3+ may also benefit cardiovascular disease (CVD) and atypical depression. We have found that cholesterol, a lipid implicated in both CVD and neurodegenerative disorders, also influences cellular glucose uptake. A recent study in our laboratory shows that exposure of 3T3-L1 adipocytes to chromium picolinate (CrPic, 10 nM) induces a loss of plasma membrane cholesterol. Concomitantly, accumulation of intracellularly sequestered glucose transporter GLUT4 at the plasma membrane was dependent on the CrPic-induced cholesterol loss. Since CrPic supplementation has the greatest benefit on glucose metabolism in hyperglycemic insulin-resistant individuals, we asked here if the CrPic effect on cells was glucose-dependent. We found that GLUT4 redistribution in cells treated with CrPic occurs only in cells cultured under high glucose (25 mM) conditions that resemble the diabetic-state, and not in cells cultured under non-diabetic (5.5 mM glucose) conditions. Examination of the effect of CrPic on proteins involved in cholesterol homeostasis revealed that the activity of sterol regulatory element-binding protein (SREBP), a membrane-bound transcription factor ultimately responsible for controlling cellular cholesterol balance, was upregulated by CrPic. In addition, ABCA1, a major player in mediating cholesterol efflux was decreased, consistent with SREBP transcriptional repression of the ABCA1 gene. Although the exact mechanism of Cr3+-induced cholesterol loss remains to be determined, these cellular responses highlight a novel and significant effect of chromium on cholesterol homeostasis. Furthermore, these findings provide an important clue to our understanding of how chromium supplementation might benefit hypercholesterolemia-associated disorders. PMID:16870493

  11. Chromium picolinate positively influences the glucose transporter system via affecting cholesterol homeostasis in adipocytes cultured under hyperglycemic diabetic conditions.

    PubMed

    Pattar, Guruprasad R; Tackett, Lixuan; Liu, Ping; Elmendorf, Jeffrey S

    2006-11-07

    Since trivalent chromium (Cr(3+)) enhances glucose metabolism, interest in the use of Cr(3+)as a therapy for type 2 diabetes has grown in the mainstream medical community. Moreover, accumulating evidence suggests that Cr(3+) may also benefit cardiovascular disease (CVD) and atypical depression. We have found that cholesterol, a lipid implicated in both CVD and neurodegenerative disorders, also influences cellular glucose uptake. A recent study in our laboratory shows that exposure of 3T3-L1 adipocytes to chromium picolinate (CrPic, 10 nM) induces a loss of plasma membrane cholesterol. Concomitantly, accumulation of intracellularly sequestered glucose transporter GLUT4 at the plasma membrane was dependent on the CrPic-induced cholesterol loss. Since CrPic supplementation has the greatest benefit on glucose metabolism in hyperglycemic insulin-resistant individuals, we asked here if the CrPic effect on cells was glucose-dependent. We found that GLUT4 redistribution in cells treated with CrPic occurs only in cells cultured under high glucose (25 mM) conditions that resemble the diabetic-state, and not in cells cultured under non-diabetic (5.5 mM glucose) conditions. Examination of the effect of CrPic on proteins involved in cholesterol homeostasis revealed that the activity of sterol regulatory element-binding protein (SREBP), a membrane-bound transcription factor ultimately responsible for controlling cellular cholesterol balance, was upregulated by CrPic. In addition, ABCA1, a major player in mediating cholesterol efflux was decreased, consistent with SREBP transcriptional repression of the ABCA1 gene. Although the exact mechanism of Cr(3+)-induced cholesterol loss remains to be determined, these cellular responses highlight a novel and significant effect of chromium on cholesterol homeostasis. Furthermore, these findings provide an important clue to our understanding of how chromium supplementation might benefit hypercholesterolemia-associated disorders.

  12. Inositol 1,4,5-trisphosphate receptor 1 mutation perturbs glucose homeostasis and enhances susceptibility to diet-induced diabetes.

    PubMed

    Ye, Risheng; Ni, Min; Wang, Miao; Luo, Shengzhan; Zhu, Genyuan; Chow, Robert H; Lee, Amy S

    2011-08-01

    The inositol 1,4,5-trisphosphate receptors (IP3Rs) as ligand-gated Ca(2)(+) channels are key modulators of cellular processes. Despite advances in understanding their critical role in regulating neuronal function and cell death, how this family of proteins impact cell metabolism is just emerging. Unexpectedly, a transgenic mouse line (D2D) exhibited progressive glucose intolerance as a result of transgene insertion. Inverse PCR was used to identify the gene disruption in the D2D mice. This led to the discovery that Itpr1 is among the ten loci disrupted in chromosome 6. Itpr1 encodes for IP3R1, the most abundant IP3R isoform in mouse brain and also highly expressed in pancreatic β-cells. To study IP3R1 function in glucose metabolism, we used the Itpr1 heterozygous mutant mice, opt/+. Glucose homeostasis in male mice cohorts was examined by multiple approaches of metabolic phenotyping. Under regular diet, the opt/+ mice developed glucose intolerance but no insulin resistance. Decrease in second-phase glucose-stimulated blood insulin level was observed in opt/+ mice, accompanied by reduced β-cell mass and insulin content. Strikingly, when fed with high-fat diet, the opt/+ mice were more susceptible to the development of hyperglycemia, glucose intolerance, and insulin resistance. Collectively, our studies identify the gene Itpr1 being interrupted in the D2D mice and uncover a novel role of IP3R1 in regulation of in vivo glucose homeostasis and development of diet-induced diabetes.

  13. Mucosal Maltase-Glucoamylase Plays a Crucial Role in Starch Digestion and Prandial Glucose Homeostasis of Mice1–3

    PubMed Central

    Nichols, Buford L.; Quezada-Calvillo, Roberto; Robayo-Torres, Claudia C.; Ao, Zihua; Hamaker, Bruce R.; Butte, Nancy F.; Marini, Juan; Jahoor, Farook; Sterchi, Erwin E.

    2009-01-01

    Starch is the major source of food glucose and its digestion requires small intestinal α-glucosidic activities provided by the 2 soluble amylases and 4 enzymes bound to the mucosal surface of enterocytes. Two of these mucosal activities are associated with sucrase-isomaltase complex, while another 2 are named maltase-glucoamylase (Mgam) in mice. Because the role of Mgam in α-glucogenic digestion of starch is not well understood, the Mgam gene was ablated in mice to determine its role in the digestion of diets with a high content of normal corn starch (CS) and resulting glucose homeostasis. Four days of unrestricted ingestion of CS increased intestinal α-glucosidic activities in wild-type (WT) mice but did not affect the activities of Mgam-null mice. The blood glucose responses to CS ingestion did not differ between null and WT mice; however, insulinemic responses elicited in WT mice by CS consumption were undetectable in null mice. Studies of the metabolic route followed by glucose derived from intestinal digestion of 13C-labeled and amylase-predigested algal starch performed by gastric infusion showed that, in null mice, the capacity for starch digestion and its contribution to blood glucose was reduced by 40% compared with WT mice. The reduced α-glucogenesis of null mice was most probably compensated for by increased hepatic gluconeogenesis, maintaining prandial glucose concentration and total flux at levels comparable to those of WT mice. In conclusion, mucosal α-glucogenic activity of Mgam plays a crucial role in the regulation of prandial glucose homeostasis. PMID:19193815

  14. Diagnostic Accuracies of Glycated Hemoglobin, Fructosamine, and Homeostasis Model Assessment of Insulin Resistance in Predicting Impaired Fasting Glucose, Impaired Glucose Tolerance, or New Onset Diabetes After Transplantation.

    PubMed

    Rosettenstein, Kerri; Viecelli, Andrea; Yong, Kenneth; Nguyen, Hung Do; Chakera, Aron; Chan, Doris; Dogra, Gursharan; Lim, Ee Mun; Wong, Germaine; Lim, Wai H

    2016-07-01

    New onset diabetes after transplantation (NODAT) is associated with a 3-fold greater risk of cardiovascular disease events, with early identification and treatment potentially attenuating this risk. The optimal screening test to identify those with NODAT remains unclear, and the aim of this study was to examine the diagnostic accuracies of 4 screening tests in identifying impaired fasting glucose, impaired glucose tolerance (IGT), and NODAT. This is a single-center prospective cohort study of 83 nondiabetic kidney transplant recipients between 2008 and 2011. Oral glucose tolerance test was considered the gold standard in identifying IFG/IGT or NODAT. Diagnostic accuracies of random blood glucose, glycated hemoglobin (HBA1c), fructosamine, and Homeostasis Model Assessment-Insulin Resistance in predicting IFG/IGT or NODAT were assessed using the area under the receiver operating characteristic curve. Forty (48%) recipients had IFG/IGT or NODAT. Compared with HBA1c with adjusted area under the curve (AUC) of 0.88 (95% confidence interval [95% CI], 0.77-0.93), fructosamine was the most accurate test with adjusted AUC of 0.92 (95% CI, 0.83-0.96). The adjusted AUCs of random blood glucose and Homeostasis Model Assessment-Insulin Resistance in identifying IFG/IGT were between 0.81 and 0.85. Restricting to identifying IGT/NODAT using 2-hour oral glucose tolerance test (n = 66), fructosamine was the most accurate diagnostic test with adjusted AUC of 0.93 (95% CI, 0.84-0.99), but not statistically different to HBA1c with adjusted AUC of 0.88 (95% CI, 0.76-0.96). Although HBA1c is an acceptable and widely used screening test in detecting IFG/IGT or NODAT, fructosamine may be a more accurate diagnostic test but this needs to be further examined in larger cohorts.

  15. Lipoprotein lipase in hypothalamus is a key regulator of body weight gain and glucose homeostasis in mice.

    PubMed

    Laperrousaz, Elise; Moullé, Valentine S; Denis, Raphaël G; Kassis, Nadim; Berland, Chloé; Colsch, Benoit; Fioramonti, Xavier; Philippe, Erwann; Lacombe, Amélie; Vanacker, Charlotte; Butin, Noémie; Bruce, Kimberley D; Wang, Hong; Wang, Yongping; Gao, Yuanqing; Garcia-Caceres, Cristina; Prévot, Vincent; Tschöp, Matthias H; Eckel, Robert H; Le Stunff, Hervé; Luquet, Serge; Magnan, Christophe; Cruciani-Guglielmacci, Céline

    2017-07-01

    Regulation of energy balance involves the participation of many factors, including nutrients, among which are circulating lipids, acting as peripheral signals informing the central nervous system of the energy status of the organism. It has been shown that neuronal lipoprotein lipase (LPL) participates in the control of energy balance by hydrolysing lipid particles enriched in triacylglycerols. Here, we tested the hypothesis that LPL in the mediobasal hypothalamus (MBH), a well-known nucleus implicated in the regulation of metabolic homeostasis, could also contribute to the regulation of body weight and glucose homeostasis. We injected an adeno-associated virus (AAV) expressing Cre-green fluorescent protein into the MBH of Lpl-floxed mice (and wild-type mice) to specifically decrease LPL activity in the MBH. In parallel, we injected an AAV overexpressing Lpl into the MBH of wild-type mice. We then studied energy homeostasis and hypothalamic ceramide content. The partial deletion of Lpl in the MBH in mice led to an increase in body weight compared with controls (37.72 ± 0.7 g vs 28.46 ± 0.12, p < 0.001) associated with a decrease in locomotor activity. These mice developed hyperinsulinaemia and glucose intolerance. This phenotype also displayed reduced expression of Cers1 in the hypothalamus as well as decreased concentration of several C18 species of ceramides and a 3-fold decrease in total ceramide intensity. Conversely, overexpression of Lpl specifically in the MBH induced a decrease in body weight. Our study shows that LPL in the MBH is an important regulator of body weight and glucose homeostasis.

  16. [Joint effect of birth weight and obesity measures on abnormal glucose metabolism at adulthood].

    PubMed

    Xi, Bo; Cheng, Hong; Chen, Fangfang; Zhao, Xiaoyuan; Mi, Jie

    2016-01-01

    To investigate the joint effect of birth weight and each of obesity measures (body mass index (BMI) and waist circumference (WC)) on abnormal glucose metabolism (including diabetes) at adulthood. Using the historical cohort study design and the convenience sampling method, 1 921 infants who were born in Beijing Union Medical College Hospital from June 1948 to December 1954 were selected to do the follow-up in 1995 and 2001 respectively. Through Beijing Household Registration and Management System, they were invited to participate in this study. A total of 972 subjects (627 were followed up in 1995 and 345 were followed up in 2001) with complete information on genders, age, birth weight, family history of diabetes, BMI, WC, fasting plasma glucose (FPG) and 2-hour plasma glucose (2 h PG) met the study inclusion criteria at the follow-up visits. In the data analysis, they were divided into low, normal, and high birth weight, respectively. The ANOVA and Chi-squared tests were used to compare the differences in their characteristics by birth weight group. In addition, multiple binary Logistic regression model was used to investigate the single effect of birth weight, BMI, and waist circumference on abnormal glucose metabolism at adulthood. Stratification analysis was used to investigate the joint effect of birth weight and each of obesity measures (BMI and WC) on abnormal glucose metabolism. There were 972 subjects (males: 50.7%, mean age: (46.0±2.2) years) included in the final data analysis. The 2 h PG in low birth weight group was (7.6±3.2) mmol/L , which was higher than that in normal birth weight group (6.9±2.1) mmol/L and high birth weight group (6.4±1.3) mmol/L (F=3.88, P=0.021). After adjustment for genders, age, body length, gestation age, family history of diabetes, physical activity, smoking and alcohol consumption, and duration of follow-up, subjects with overweight and obesity at adulthood had 2.73 (95% confidence interval (CI) =2.06- 3.62) times risk

  17. A low-protein diet combined with low-dose endotoxin leads to changes in glucose homeostasis in weanling rats.

    PubMed

    Bandsma, Robert H J; Ackerley, Cameron; Koulajian, Khajag; Zhang, Ling; van Zutphen, Tim; van Dijk, Theo H; Xiao, Changting; Giacca, Adria; Lewis, Gary F

    2015-09-01

    Severe malnutrition is a leading cause of global childhood mortality, and infection and hypoglycemia or hyperglycemia are commonly present. The etiology behind the changes in glucose homeostasis is poorly understood. Here, we generated an animal model of severe malnutrition with and without low-grade inflammation to investigate the effects on glucose homeostasis. Immediately after weaning, rats were fed diets containing 5 [low-protein diet (LP)] or 20% protein [control diet (CTRL)], with or without repeated low-dose intraperitoneal lipopolysaccharide (LPS; 2 mg/kg), to mimic inflammation resulting from infections. After 4 wk on the diets, hyperglycemic clamps or euglycemic hyperinsulinemic clamps were performed with infusion of [U-(13)C6]glucose and [2-(13)C]glycerol to assess insulin secretion, action, and hepatic glucose metabolism. In separate studies, pancreatic islets were isolated for further analyses of insulin secretion and islet morphometry. Glucose clearance was reduced significantly by LP feeding alone (16%) and by LP feeding with LPS administration (43.8%) compared with control during the hyperglycemic clamps. This was associated with a strongly reduced insulin secretion in LP-fed rats in vivo as well as ex vivo in islets but signficantly enhanced whole body insulin sensitivity. Gluconeogenesis rates were unaffected by LP feeding, but glycogenolysis was higher after LP feeding. A protein-deficient diet in young rats leads to a susceptibility to low-dose endotoxin-induced impairment in glucose clearance with a decrease in the islet insulin secretory pathway. A protein-deficient diet is associated with enhanced peripheral insulin sensitivity but impaired insulin-mediated suppression of hepatic glycogenolysis. Copyright © 2015 the American Physiological Society.

  18. Exacerbated immune stress response during experimental magnesium deficiency results from abnormal cell calcium homeostasis.

    PubMed

    Malpuech-Brugère, C; Rock, E; Astier, C; Nowacki, W; Mazur, A; Rayssiguier, Y

    1998-01-01

    The aim of this study was to assess the potential mechanism underlying the enhanced inflammatory processes during magnesium deficit. In this study, exacerbated response to live bacteria and platelet activating factors was shown in rats fed a magnesium-deficient diet. Peritoneal cells from these animals also showed enhanced superoxide anion production and calcium mobilising potency following in vitro stimulation. The latter effect occurred very early in the course of magnesium deficiency. These studies first showed that an abnormal calcium handling induced by extracellular magnesium depression in vivo may be at the origin of exacerbated inflammatory response.

  19. AMPK is essential for energy homeostasis regulation and glucose sensing by POMC and AgRP neurons.

    PubMed

    Claret, Marc; Smith, Mark A; Batterham, Rachel L; Selman, Colin; Choudhury, Agharul I; Fryer, Lee G D; Clements, Melanie; Al-Qassab, Hind; Heffron, Helen; Xu, Allison W; Speakman, John R; Barsh, Gregory S; Viollet, Benoit; Vaulont, Sophie; Ashford, Michael L J; Carling, David; Withers, Dominic J

    2007-08-01

    Hypothalamic AMP-activated protein kinase (AMPK) has been suggested to act as a key sensing mechanism, responding to hormones and nutrients in the regulation of energy homeostasis. However, the precise neuronal populations and cellular mechanisms involved are unclear. The effects of long-term manipulation of hypothalamic AMPK on energy balance are also unknown. To directly address such issues, we generated POMC alpha 2KO and AgRP alpha 2KO mice lacking AMPK alpha2 in proopiomelanocortin- (POMC-) and agouti-related protein-expressing (AgRP-expressing) neurons, key regulators of energy homeostasis. POMC alpha 2KO mice developed obesity due to reduced energy expenditure and dysregulated food intake but remained sensitive to leptin. In contrast, AgRP alpha 2KO mice developed an age-dependent lean phenotype with increased sensitivity to a melanocortin agonist. Electrophysiological studies in AMPK alpha2-deficient POMC or AgRP neurons revealed normal leptin or insulin action but absent responses to alterations in extracellular glucose levels, showing that glucose-sensing signaling mechanisms in these neurons are distinct from those pathways utilized by leptin or insulin. Taken together with the divergent phenotypes of POMC alpha 2KO and AgRP alpha 2KO mice, our findings suggest that while AMPK plays a key role in hypothalamic function, it does not act as a general sensor and integrator of energy homeostasis in the mediobasal hypothalamus.

  20. Sindbis virus glycoproteins are abnormally glycosylated in Chinese hamster ovary cells deprived of glucose.

    PubMed

    Davidson, S K; Hunt, L A

    1985-07-01

    We have previously demonstrated that Sindbis virus infection of Chinese hamster ovary (CHO) cells altered the protein glycosylation machinery of the cell, so that both normal, full-size (nine mannose-containing) oligosaccharides and abnormal, "truncated' (five mannose-containing) oligosaccharides are transferred from lipid-linked precursors to newly synthesized viral membrane glycoproteins. In the present studies, we have examined the precursor oligosaccharides on viral glycoproteins that were pulse-labelled with [3H]mannose in the presence or absence of glucose, since glucose starvation of uninfected CHO cells has been reported to induce synthesis of truncated precursor oligosaccharides. Pulse-labelling in the absence of glucose led to a greater than 10-fold increase in the relative amount of the truncated precursor oligosaccharides being transferred to the newly synthesized viral glycoproteins and to an apparent underglycosylation of some precursor viral polypeptides, with some asparaginyl sites not acquiring covalently linked oligosaccharides. The mature virion glycoproteins from CHO cells which were pulse-labelled in the absence of glucose and then 'chased' in the presence of glucose contained proportionately more unusual Man3GlcNAc2-size oligosaccharides. These small neutral-type oligosaccharides were apparently not as good a substrate for further processing into complex acidic-type oligosaccharides as the normal Man5GlcNAc2 intermediate that results from the full-size precursor oligosaccharides.

  1. The Essential Role of Mbd5 in the Regulation of Somatic Growth and Glucose Homeostasis in Mice

    PubMed Central

    Du, Yarui; Liu, Bo; Guo, Fan; Xu, Guifang; Ding, Yuqiang; Liu, Yong; Sun, Xin; Xu, Guoliang

    2012-01-01

    Methyl-CpG binding domain protein 5 (MBD5) belongs to the MBD family proteins, which play central roles in transcriptional regulation and development. The significance of MBD5 function is highlighted by recent studies implicating it as a candidate gene involved in human 2q23.1 microdeletion syndrome. To investigate the physiological role of Mbd5, we generated knockout mice. The Mbd5-deficient mice showed growth retardation, wasting and pre-weaning lethality. The observed growth retardation was associated with the impairment of GH/IGF-1 axis in Mbd5-null pups. Conditional knockout of Mbd5 in the brain resulted in the similar phenotypes as whole body deletion, indicating that Mbd5 functions in the nervous system to regulate postnatal growth. Moreover, the mutant mice also displayed enhanced glucose tolerance and elevated insulin sensitivity as a result of increased insulin signaling, ultimately resulting in disturbed glucose homeostasis and hypoglycemia. These results indicate Mbd5 as an essential factor for mouse postnatal growth and maintenance of glucose homeostasis. PMID:23077600

  2. The essential role of Mbd5 in the regulation of somatic growth and glucose homeostasis in mice.

    PubMed

    Du, Yarui; Liu, Bo; Guo, Fan; Xu, Guifang; Ding, Yuqiang; Liu, Yong; Sun, Xin; Xu, Guoliang

    2012-01-01

    Methyl-CpG binding domain protein 5 (MBD5) belongs to the MBD family proteins, which play central roles in transcriptional regulation and development. The significance of MBD5 function is highlighted by recent studies implicating it as a candidate gene involved in human 2q23.1 microdeletion syndrome. To investigate the physiological role of Mbd5, we generated knockout mice. The Mbd5-deficient mice showed growth retardation, wasting and pre-weaning lethality. The observed growth retardation was associated with the impairment of GH/IGF-1 axis in Mbd5-null pups. Conditional knockout of Mbd5 in the brain resulted in the similar phenotypes as whole body deletion, indicating that Mbd5 functions in the nervous system to regulate postnatal growth. Moreover, the mutant mice also displayed enhanced glucose tolerance and elevated insulin sensitivity as a result of increased insulin signaling, ultimately resulting in disturbed glucose homeostasis and hypoglycemia. These results indicate Mbd5 as an essential factor for mouse postnatal growth and maintenance of glucose homeostasis.

  3. Genetic models rule out a major role of beta cell glycogen in the control of glucose homeostasis.

    PubMed

    Mir-Coll, Joan; Duran, Jordi; Slebe, Felipe; García-Rocha, Mar; Gomis, Ramon; Gasa, Rosa; Guinovart, Joan J

    2016-05-01

    Glycogen accumulation occurs in beta cells of diabetic patients and has been proposed to partly mediate glucotoxicity-induced beta cell dysfunction. However, the role of glycogen metabolism in beta cell function and its contribution to diabetes pathophysiology remain poorly understood. We investigated the function of beta cell glycogen by studying glucose homeostasis in mice with (1) defective glycogen synthesis in the pancreas; and (2) excessive glycogen accumulation in beta cells. Conditional deletion of the Gys1 gene and overexpression of protein targeting to glycogen (PTG) was accomplished by Cre-lox recombination using pancreas-specific Cre lines. Glucose homeostasis was assessed by determining fasting glycaemia, insulinaemia and glucose tolerance. Beta cell mass was determined by morphometry. Glycogen was detected histologically by periodic acid-Schiff's reagent staining. Isolated islets were used for the determination of glycogen and insulin content, insulin secretion, immunoblots and gene expression assays. Gys1 knockout (Gys1 (KO)) mice did not exhibit differences in glucose tolerance or basal glycaemia and insulinaemia relative to controls. Insulin secretion and gene expression in isolated islets was also indistinguishable between Gys1 (KO) and controls. Conversely, despite effective glycogen overaccumulation in islets, mice with PTG overexpression (PTG(OE)) presented similar glucose tolerance to controls. However, under fasting conditions they exhibited lower glycaemia and higher insulinaemia. Importantly, neither young nor aged PTG(OE) mice showed differences in beta cell mass relative to age-matched controls. Finally, a high-fat diet did not reveal a beta cell-autonomous phenotype in either model. Glycogen metabolism is not required for the maintenance of beta cell function. Glycogen accumulation in beta cells alone is not sufficient to trigger the dysfunction or loss of these cells, or progression to diabetes.

  4. Cucurbitane Triterpenoids from the Fruits of Momordica Charantia Improve Insulin Sensitivity and Glucose Homeostasis in Streptozotocin-Induced Diabetic Mice.

    PubMed

    Han, Joo-Hui; Tuan, Nguyen Quoc; Park, Min-Ho; Quan, Khong Trong; Oh, Joonseok; Heo, Kyung-Sun; Na, MinKyun; Myung, Chang-Seon

    2018-04-01

    Momordica charantia (M. charantia) has antidiabetic effects, and cucurbitane-type triterpenoid is one of the compounds of M. charantia. This study aims to investigate whether the new cucurbitane-type triterpenoids affect insulin sensitivity both in vitro and in vivo, and the underlying mechanisms. Four compounds (C1-C4) isolated from the ethanol extract of M. charantia enhance glucose uptake in C2C12 myotubes via insulin receptor substrate-1 (IRS-1) rather than via adenosine monophosphate-activated protein kinase. The most potent, compound 2 (C2), significantly increases the activation of IRS-1 and downstream signaling pathways, resulting in glucose transporter 4 translocation. Furthermore, these C2-induced in vitro effects are blocked by specific signal inhibitors. We further evaluate the antidiabetic effect of C2 using a streptozotocin (STZ)-induced diabetic mouse model. Consistent with in vitro data, treatment with C2 (1.68 mg kg -1 ) significantly decreases blood glucose level and enhances glycogen storage in STZ-injected mice. These effects appear to be mediated by the IRS-1 signaling pathway in skeletal muscle, not in adipose and liver tissues, suggesting that C2 improves hyperglycemia by increasing glucose uptake into skeletal muscle. Our findings demonstrate that the new cucurbitane-type triterpenoids have potential for prevention and management of diabetes by improving insulin sensitivity and glucose homeostasis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The Action of Antidiabetic Plants of the Canadian James Bay Cree Traditional Pharmacopeia on Key Enzymes of Hepatic Glucose Homeostasis

    PubMed Central

    Nachar, Abir; Vallerand, Diane; Musallam, Lina; Lavoie, Louis; Arnason, John; Haddad, Pierre S.

    2013-01-01

    We determined the capacity of putative antidiabetic plants used by the Eastern James Bay Cree (Canada) to modulate key enzymes of gluconeogenesis and glycogen synthesis and key regulating kinases. Glucose-6-phosphatase (G6Pase) and glycogen synthase (GS) activities were assessed in cultured hepatocytes treated with crude extracts of seventeen plant species. Phosphorylation of AMP-dependent protein kinase (AMPK), Akt, and Glycogen synthase kinase-3 (GSK-3) were probed by Western blot. Seven of the seventeen plant extracts significantly decreased G6Pase activity, Abies balsamea and Picea glauca, exerting an effect similar to insulin. This action involved both Akt and AMPK phosphorylation. On the other hand, several plant extracts activated GS, Larix laricina and A. balsamea, far exceeding the action of insulin. We also found a significant correlation between GS stimulation and GSK-3 phosphorylation induced by plant extract treatments. In summary, three Cree plants stand out for marked effects on hepatic glucose homeostasis. P. glauca affects glucose production whereas L. laricina rather acts on glucose storage. However, A. balsamea has the most promising profile, simultaneously and powerfully reducing G6Pase and stimulating GS. Our studies thus confirm that the reduction of hepatic glucose production likely contributes to the therapeutic potential of several antidiabetic Cree traditional medicines. PMID:23864882

  6. [Glucose-monitoring neurons of the medial ventrolateral prefrontal (orbitofrontal) cortex are involved in the maintenance of homeostasis].

    PubMed

    Szabó, István; Hormay, Edina; Csetényi, Bettina; Nagy, Bernadett; Karádi, Zoltán

    2017-05-01

    The medial orbitofrontal cortex is involved in the regulation of feeding and metabolism. Little is known, however, about the role of local glucose-monitoring neurons in these processes, and our knowledge is also poor about characteristics of these cells. The functional significance of these chemosensory neurons was to be elucidated. Electrophysiology, by the multibarreled microelectrophoretic technique, and metabolic investigations, after streptozotocin induced selective destruction of the chemosensory neurons, were employed. Fifteen percent of the neurons responded to glucose, and these chemosensory cells displayed differential neurotransmitter and taste sensitivities. In acute glucose tolerance test, at the 30th and 60th minutes, blood glucose level in the streptozotocin-treated rats was significantly higher than that in the controls. The plasma triglyceride concentrations were also higher in the streptozotocin-treated group. Glucose-monitoring neurons of the medial orbitofrontal cortex integrate internal and external environmental signals, and monitor metabolic processes, thus, are indispensable to maintain the healthy homeostasis. Orv Hetil. 2017; 158(18): 692-700.

  7. Liver Plays a Major Role in FGF-21 Mediated Glucose Homeostasis.

    PubMed

    Liu, Mingyao; Cao, Hongwei; Hou, Yuting; Sun, Guopeng; Li, Deshan; Wang, Wenfei

    2018-01-01

    The liver is a vital organ in vertebrates and has a wide range of functions, including glucose absorption, glycogen storage and glucose production. Fibroblast growth factor (FGF)-21 is a metabolic regulator that is primarily produced by the liver. In this paper, we studied the effect of FGF-21 on glucose metabolism in the liver. The glucose uptake of cells was detected by 2-Deoxy-d-[3H] glucose; the synergy between insulin and FGF-21 was evaluated. The mRNA expression of GLUT1-4, G6Pase and PEPCK was detected by real-time PCR. Glycogen synthesis was examined by the anthrone method. Blood samples to monitor glucose in db/db diabetic mice were obtained by tail snip. Glucose metabolism in the liver and adipose tissues was observed by fluorescence microscopy. In this study, FGF-21 stimulated glucose uptake by liver cells in both a dose and time-dependent manner, and at the same time, FGF-21 specifically stimulated GLUT1 expression in the liver cells. Furthermore, FGF-21 demonstrated a synergistic effect with insulin on glucose absorption, which is in accordance with enhanced GLUT-1 and -4 expression. Treatment with FGF-21 increased glycogen storage in liver cells. Consistent with in vitro results, FGF-21 lowered the plasma glucose level and stimulated GLUT1 expression and glycogen synthesis in db/db diabetic mice. Simultaneously, FGF-21 inhibited the gene expression of G6Pase and PEPCK. Our results suggest that FGF-21 clears up plasma glucose by stimulating glucose absorption in the liver of diabetic animals and decreases glucose release from the liver by inhibiting gluconeogenesis. Overall, these data indicate that the liver is an important target organ of FGF-21 to regulate glucose metabolism. © 2018 The Author(s). Published by S. Karger AG, Basel.

  8. Vitamin D and prebiotics may benefit the intestinal microbacteria and improve glucose homeostasis in prediabetes and type 2 diabetes.

    PubMed

    Barengolts, Elena

    2013-01-01

    To review the role of human large bowel microbacteria (microbiota) in the glucose homeostasis, to address vitamin D (VD) and prebiotics interactions with microbiota, and to summarize recent randomized clinical trials (RCTs) of VD and prebiotics supplementation in prediabetes (PreDM) and type 2 diabetes mellitus (T2DM). Primary literature was reviewed in the following areas: composition and activity of human microbiota associated with PreDM and T2DM, interactions between microbiota and glucose homeostasis, the interaction of microbiota with VD/prebiotics, and RCTs of VD/prebiotics in subjects with PreDM or T2DM. The human microbiota is comprised of 100 trillion bacteria with an aggregate genome that is 150-fold larger than the human genome. Data from the animal models and human studies reveal that an "obesogenic" diet results into the initial event of microbiota transformation from symbiosis to dysbiosis. The microbial antigens, such as Gram(-) bacteria and lipopolysaccharide (LPS), translocate to the host interior and trigger increased energy harvesting and Toll-like receptor (TLR) activation with subsequent inflammatory pathways signaling. The "double hit" of steatosis (ectopic fat accumulation) and "-itis" (inflammation) and contribution of "corisks" (e.g., vitamin D deficiency [VDD]) are required to activate molecular signaling, including impaired insulin signaling and secretion, that ends with T2DM and associated diseases. Dietary changes (e.g., prebiotics, VD supplementation) may ameliorate this process if initiated prior to the process becoming irreversible. Emerging evidence suggests an important role of microbiota in glucose homeostasis. VD supplementation and prebiotics may be useful in managing PreDM and T2DM.

  9. The relationship between sleep and glucagon-like peptide 1 in patients with abnormal glucose tolerance.

    PubMed

    Reutrakul, Sirimon; Sumritsopak, Rungtip; Saetung, Sunee; Chanprasertyothin, Suwannee; Anothaisintawee, Thunyarat

    2017-12-01

    Glucagon-like peptide 1 plays a role in glucose regulation. Sleep disturbances (obstructive sleep apnea, insufficient or poor sleep quality) have been shown to adversely affect glucose metabolism. This study aimed to explore the relationship between sleep and glucagon-like peptide 1 regulation in patients with abnormal glucose tolerance. Seventy-one adults with haemoglobin A1c levels between 5.7% and < 6.5% and no history of diabetes participated. Habitual sleep duration and efficiency were obtained from 7-day actigraphy recordings. Obstructive sleep apnea was assessed using an overnight home monitor. Glucagon-like peptide 1 levels were measured during a 75-g glucose tolerance. The area under the curve of glucagon-like peptide 1 was calculated. The mean age (SD) was 55.1 (8.3) years and median (interquartile range) haemoglobin A1c was 5.97% (5.86, 6.23). There was no relationship between sleep duration or efficiency and fasting or area under the curve glucagon-like peptide 1. Glucagon-like peptide 1 levels did not differ among those sleeping ≤ 5.75, > 5.75-< 6.5 or ≥ 6.5 h per night. Increasing apnea-hypopnea index, an indicator of obstructive sleep apnea severity, correlated with lower area under the curve glucagon-like peptide 1 (B -0.242, P = 0.045), but not with fasting glucagon-like peptide 1 (B -0.213, P = 0.079). After adjusting for sex, haemoglobin A1c and body mass index, increasing apnea-hypopnea index was negatively associated with having area under the curve glucagon-like peptide 1 in the highest quartile (odds ratio 0.581, P = 0.028, 95% CI 0.359, 0.942). This study demonstrated that increasing obstructive sleep apnea severity was associated with lower glucagon-like peptide 1 response to glucose challenge. This could possibly be an additional mechanism by which obstructive sleep apnea affects glucose metabolism. Whether raising glucagon-like peptide 1 levels in patients with abnormal glucose tolerance with more severe obstructive sleep

  10. Catalpic acid decreases abdominal fat deposition, improves glucose homeostasis and upregulates PPAR alpha expression in adipose tissue.

    PubMed

    Hontecillas, Raquel; Diguardo, Maggie; Duran, Elisa; Orpi, Marcel; Bassaganya-Riera, Josep

    2008-10-01

    Catalpic acid (CAT) is a conjugated linolenic acid (CLN) isomer containing trans-9, trans-11, cis-13 double bonds in an 18-carbon chain and it is found primarily in the seed oil of ornamental and medicinal trees and shrubs of the family Bignoniaceae. The objective of this study was to investigate whether CAT decreases obesity and ameliorates insulin sensitivity and glucose tolerance in mice fed high-fat diets. To test the efficacy of CAT in decreasing obesity and diabetes we used both a model of diet-induced obesity (DIO) and a genetic model of obesity (i.e., mice lacking the leptin receptor). Blood was collected on days 0, 7, 14, 21 and 28 for determining fasting glucose and insulin concentrations in plasma. In addition, a glucose tolerance test was administered on day 28. We found that dietary CAT (1g/100g) decreased fasting plasma glucose and insulin concentrations, ameliorated the glucose normalizing ability following glucose challenge and decreased abdominal white adipose tissue accumulation. In white adipose tissue (WAT), CAT upregulated peroxisome proliferator-activated receptor (PPAR) alpha and its responsive genes [i.e., stearoyl-coenzyme A desaturase (SCD1) and enoyl-coenzyme A hydratase (ECH)], increased concentrations of high-density lipoprotein (HDL) cholesterol and decreased plasma triglyceride (TG) levels. CAT decreased abdominal fat deposition, increased HDL cholesterol, decreased TG concentrations, decreased glucose and insulin homeostasis and modulated WAT gene expression in a manner reminiscent of the actions of the PPAR alpha-activating fibrate class of lipid-lowering drugs.

  11. The Importance of Abnormal Chloride Homeostasis in Stable Chronic Heart Failure

    PubMed Central

    Grodin, Justin L.; Verbrugge, Frederik H.; Ellis, Stephen G.; Mullens, Wilfried; Testani, Jeffrey M.; Wilson Tang MD, W. H.

    2015-01-01

    Background The aim of this analysis was to determine the long-term prognostic value of lower serum chloride in patients with stable chronic heart failure. Electrolyte abnormalities are prevalent in patients with chronic heart failure. Little is known regarding the prognostic implications of lower serum chloride. Methods and Results Serum chloride was measured in 1,673 consecutively consented stable patients with a history of heart failure undergoing elective diagnostic coronary angiography. All patients were followed for 5-year all-cause mortality, and survival models were adjusted for variables that confounded the chloride-risk relationship. The average chloride level was 102±4 mEq/L. Over 6,772 person-years of follow-up, there were 547 deaths. Lower chloride (per standard deviation decrease) was associated with a higher adjusted risk of mortality (HR 1.29, 95%CI 1.12–1.49, P<0.001). Chloride levels net-reclassified risk in 10.4% (P=0.03) when added to a multivariable model (with a resultant C-statistic of 0.70), in which sodium levels were not prognostic (P=0.30). In comparison to those with above first quartile chloride (≥101 mEq/L) and sodium (≥138 meq/L), subjects with first quartile chloride had a higher adjusted mortality risk, whether they had first quartile sodium (HR 1.35, 95%CI 1.08–1.69, P=0.008) or higher (HR 1.43, 95%CI 1.12–1.85, P=0.005). However, subjects with first quartile sodium but above first quartile chloride had no association with mortality (P=0.67). Conclusions Lower serum chloride levels are independently and incrementally associated with increased mortality risk in patients with chronic heart failure. A better understanding of the biological role of serum chloride is warranted. PMID:26721916

  12. Association between ADIPOQ SNPs with plasma adiponectin and glucose homeostasis and adiposity phenotypes in the IRAS Family Study.

    PubMed

    An, S Sandy; Hanley, Anthony J G; Ziegler, Julie T; Brown, W Mark; Haffner, Steven M; Norris, Jill M; Rotter, Jerome I; Guo, Xiuqing; Chen, Y-D Ida; Wagenknecht, Lynne E; Langefeld, Carl D; Bowden, Donald W; Palmer, Nicholette D

    2012-12-01

    Adiponectin is an adipocytokine associated with a variety of metabolic traits. These associations in human studies, in conjunction with functional studies in model systems, have implicated adiponectin in multiple metabolic processes. We hypothesize that genetic variants associated with plasma adiponectin would also be associated with glucose homeostasis and adiposity phenotypes. The Insulin Resistance Atherosclerosis Family Study was designed to identify the genetic and environmental basis of insulin resistance and adiposity in the Hispanic- (n=1,424) and African-American (n=604) population. High quality metabolic phenotypes, e.g. insulin sensitivity (S(I)), acute insulin response (AIR), disposition index (DI), fasting glucose, body mass index (BMI), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and waist circumference, were explored. Based on association analysis of more than 40 genetic polymorphisms in the adiponectin gene (ADIPOQ), we found no consistent association of ADIPOQ variants with plasma adiponectin levels and adiposity phenotypes. However, there were two promoter variants, rs17300539 and rs822387, associated with plasma adiponectin levels (P=0.0079 and 0.021, respectively) in the Hispanic-American cohort that were also associated with S(I) (P=0.0067 and 0.013, respectively). In contrast, there was only a single promoter SNP, rs17300539, associated with plasma adiponectin levels (P=0.0018) and fasting glucose (P=0.042) in the African-American cohort. Strikingly, high impact coding variants did not show evidence of association. The lack of consistent patterns of association between variants, adiponectin levels, glucose homeostasis, and adiposity phenotypes suggests a reassessment of the influence of adiponectin in these pathways. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Quantitative approaches to energy and glucose homeostasis: machine learning and modelling for precision understanding and prediction

    PubMed Central

    Murphy, Kevin G.; Jones, Nick S.

    2018-01-01

    Obesity is a major global public health problem. Understanding how energy homeostasis is regulated, and can become dysregulated, is crucial for developing new treatments for obesity. Detailed recording of individual behaviour and new imaging modalities offer the prospect of medically relevant models of energy homeostasis that are both understandable and individually predictive. The profusion of data from these sources has led to an interest in applying machine learning techniques to gain insight from these large, relatively unstructured datasets. We review both physiological models and machine learning results across a diverse range of applications in energy homeostasis, and highlight how modelling and machine learning can work together to improve predictive ability. We collect quantitative details in a comprehensive mathematical supplement. We also discuss the prospects of forecasting homeostatic behaviour and stress the importance of characterizing stochasticity within and between individuals in order to provide practical, tailored forecasts and guidance to combat the spread of obesity. PMID:29367240

  14. Morphological and Glucose Metabolism Abnormalities in Alcoholic Korsakoff's Syndrome: Group Comparisons and Individual Analyses

    PubMed Central

    Pitel, Anne-Lise; Aupée, Anne-Marie; Chételat, Gaël; Mézenge, Florence; Beaunieux, Hélène; de la Sayette, Vincent; Viader, Fausto; Baron, Jean-Claude; Eustache, Francis; Desgranges, Béatrice

    2009-01-01

    Background Gray matter volume studies have been limited to few brain regions of interest, and white matter and glucose metabolism have received limited research attention in Korsakoff's syndrome (KS). Because of the lack of brain biomarkers, KS was found to be underdiagnosed in postmortem studies. Methodology/Principal Findings Nine consecutively selected patients with KS and 22 matched controls underwent both structural magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography examinations. Using a whole-brain analysis, the between-group comparisons of gray matter and white matter density and relative glucose uptake between patients with KS and controls showed the involvement of both the frontocerebellar and the Papez circuits, including morphological abnormalities in their nodes and connection tracts and probably resulting hypometabolism. The direct comparison of the regional distribution and degree of gray matter hypodensity and hypometabolism within the KS group indicated very consistent gray matter distribution of both abnormalities, with a single area of significant difference in the middle cingulate cortex showing greater hypometabolism than hypodensity. Finally, the analysis of the variability in the individual patterns of brain abnormalities within our sample of KS patients revealed that the middle cingulate cortex was the only brain region showing significant GM hypodensity and hypometabolism in each of our 9 KS patients. Conclusions/Significance These results indicate widespread brain abnormalities in KS including both gray and white matter damage mainly involving two brain networks, namely, the fronto-cerebellar circuit and the Papez circuit. Furthermore, our findings suggest that the middle cingulate cortex may play a key role in the pathophysiology of KS and could be considered as a potential in vivo brain biomarker. PMID:19936229

  15. Salsalate (Salicylate) Uncouples Mitochondria, Improves Glucose Homeostasis, and Reduces Liver Lipids Independent of AMPK-β1

    PubMed Central

    Smith, Brennan K.; Ford, Rebecca J.; Desjardins, Eric M.; Green, Alex E.; Hughes, Meghan C.; Houde, Vanessa P.; Day, Emily A.; Marcinko, Katarina; Crane, Justin D.; Mottillo, Emilio P.; Perry, Christopher G.R.; Kemp, Bruce E.; Tarnopolsky, Mark A.; Steinberg, Gregory R.

    2017-01-01

    Salsalate is a prodrug of salicylate that lowers blood glucose in patients with type 2 diabetes (T2D) and reduces nonalcoholic fatty liver disease (NAFLD) in animal models; however, the mechanism mediating these effects is unclear. Salicylate directly activates AMPK via the β1 subunit, but whether salsalate requires AMPK-β1 to improve T2D and NAFLD has not been examined. Therefore, wild-type (WT) and AMPK-β1–knockout (AMPK-β1KO) mice were treated with a salsalate dose resulting in clinically relevant serum salicylate concentrations (~1 mmol/L). Salsalate treatment increased VO2, lowered fasting glucose, improved glucose tolerance, and led to an ~55% reduction in liver lipid content. These effects were observed in both WT and AMPK-β1KO mice. To explain these AMPK-independent effects, we found that salicylate increases oligomycin-insensitive respiration (state 4o) and directly increases mitochondrial proton conductance at clinical concentrations. This uncoupling effect is tightly correlated with the suppression of de novo lipogenesis. Salicylate is also able to stimulate brown adipose tissue respiration independent of uncoupling protein 1. These data indicate that the primary mechanism by which salsalate improves glucose homeostasis and NAFLD is via salicylate-driven mitochondrial uncoupling. PMID:27554471

  16. Oxygen Glucose Deprivation in Rat Hippocampal Slice Cultures Results in Alterations in Carnitine Homeostasis and Mitochondrial Dysfunction

    PubMed Central

    Rau, Thomas F.; Lu, Qing; Sharma, Shruti; Sun, Xutong; Leary, Gregory; Beckman, Matthew L.; Hou, Yali; Wainwright, Mark S.; Kavanaugh, Michael; Poulsen, David J.; Black, Stephen M.

    2012-01-01

    Mitochondrial dysfunction characterized by depolarization of mitochondrial membranes and the initiation of mitochondrial-mediated apoptosis are pathological responses to hypoxia-ischemia (HI) in the neonatal brain. Carnitine metabolism directly supports mitochondrial metabolism by shuttling long chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Our previous studies have shown that HI disrupts carnitine homeostasis in neonatal rats and that L-carnitine can be neuroprotective. Thus, this study was undertaken to elucidate the molecular mechanisms by which HI alters carnitine metabolism and to begin to elucidate the mechanism underlying the neuroprotective effect of L-carnitine (LCAR) supplementation. Utilizing neonatal rat hippocampal slice cultures we found that oxygen glucose deprivation (OGD) decreased the levels of free carnitines (FC) and increased the acylcarnitine (AC): FC ratio. These changes in carnitine homeostasis correlated with decreases in the protein levels of carnitine palmitoyl transferase (CPT) 1 and 2. LCAR supplementation prevented the decrease in CPT1 and CPT2, enhanced both FC and the AC∶FC ratio and increased slice culture metabolic viability, the mitochondrial membrane potential prior to OGD and prevented the subsequent loss of neurons during later stages of reperfusion through a reduction in apoptotic cell death. Finally, we found that LCAR supplementation preserved the structural integrity and synaptic transmission within the hippocampus after OGD. Thus, we conclude that LCAR supplementation preserves the key enzymes responsible for maintaining carnitine homeostasis and preserves both cell viability and synaptic transmission after OGD. PMID:22984394

  17. Brown adipose tissue improves whole-body glucose homeostasis and insulin sensitivity in humans

    USDA-ARS?s Scientific Manuscript database

    Brown adipose tissue (BAT) has attracted scientific interest as an antidiabetic tissue owing to its ability to dissipate energy as heat. Despite a plethora of data concerning the role of BAT in glucose metabolism in rodents, the role of BAT (if any) in glucose metabolism in humans remains unclear. T...

  18. The Effect of Selenium Supplementation on Glucose Homeostasis and the Expression of Genes Related to Glucose Metabolism.

    PubMed

    Jablonska, Ewa; Reszka, Edyta; Gromadzinska, Jolanta; Wieczorek, Edyta; Krol, Magdalena B; Raimondi, Sara; Socha, Katarzyna; Borawska, Maria H; Wasowicz, Wojciech

    2016-12-13

    The aim of the study was to evaluate the effect of selenium supplementation on the expression of genes associated with glucose metabolism in humans, in order to explain the unclear relationship between selenium and the risk of diabetes. For gene expression analysis we used archival samples of cDNA from 76 non-diabetic subjects supplemented with selenium in the previous study. The supplementation period was six weeks and the daily dose of selenium was 200 µg (as selenium yeast). Blood for mRNA isolation was collected at four time points: before supplementation, after two and four weeks of supplementation, and after four weeks of washout. The analysis included 15 genes encoding selected proteins involved in insulin signaling and glucose metabolism. In addition, HbA1c and fasting plasma glucose were measured at three and four time points, respectively. Selenium supplementation was associated with a significantly decreased level of HbA1c but not fasting plasma glucose (FPG) and significant down-regulation of seven genes: INSR , ADIPOR1 , LDHA , PDHA , PDHB , MYC , and HIF1AN . These results suggest that selenium may affect glycemic control at different levels of regulation, linked to insulin signaling, glycolysis, and pyruvate metabolism. Further research is needed to investigate mechanisms of such transcriptional regulation and its potential implication in direct metabolic effects.

  19. Abnormal Glucose Metabolism and High-Energy Expenditure in Idiopathic Pulmonary Arterial Hypertension

    PubMed Central

    Malin, Steven K.; Barnes, Jarrod W.; Tian, Liping; Kirwan, John P.; Dweik, Raed A.

    2017-01-01

    Rationale: Insulin resistance has emerged as a potential mechanism related to the pathogenesis of idiopathic pulmonary arterial hypertension (IPAH). However, direct measurements of insulin and glucose metabolism have not been performed in patients with IPAH to date. Objectives: To perform comprehensive metabolic phenotyping of humans with IPAH. Methods: We assessed plasma insulin and glucose, using an oral glucose tolerance test and estimated insulin resistance, and β-cell function in 14 patients with IPAH and 14 control subjects matched for age, sex, blood pressure, and body mass index. Body composition (dual-energy X-ray absorptiometry), inflammation (CXC chemokine ligand 10, endothelin-1), physical fitness (6-min walk test), and energy expenditure (indirect calorimetry) were also assessed. Measurements and Main Results: Patients with IPAH had a higher rate of impaired glucose tolerance (57 vs. 14%; P < 0.05) and reduced glucose-stimulated insulin secretion compared with matched control subjects (IPAH: 1.31 ± 0.76 μU/ml⋅mg/dl vs. control subjects: 2.21 ± 1.27 μU/ml⋅mg/dl; P < 0.05). Pancreatic β-cell function was associated with circulating endothelin-1 (r = –0.71, P < 0.01) and CXC chemokine ligand 10 (r = –0.56, P < 0.05). Resting energy expenditure was elevated in IPAH (IPAH: 32 ± 3.4 vs. control subjects: 28.8 ± 2.9 kcal/d/kg fat-free mass; P < 0.05) and correlated with the plasma glucose response (r = 0.51, P < 0.01). Greater insulin resistance was associated with reduced 6-minute walk distance (r = 0.55, P < 0.05). Conclusions: Independent of age, sex, blood pressure, and body mass index, patients with IPAH have glucose intolerance, decreased insulin secretion in response to glucose, and elevated resting energy expenditure. These abnormalities are associated with circulating markers of inflammation and vascular dysfunction. PMID:27922752

  20. Dietary Betaine Supplementation Increases Fgf21 Levels to Improve Glucose Homeostasis and Reduce Hepatic Lipid Accumulation in Mice

    PubMed Central

    Ejaz, Asma; Martinez-Guino, Laura; Goldfine, Allison B.; Ribas-Aulinas, Francesc; De Nigris, Valeria; Ribó, Sílvia; Gonzalez-Franquesa, Alba; Garcia-Roves, Pablo M.; Li, Elizabeth; Dreyfuss, Jonathan M.; Gall, Walt; Kim, Jason K.; Bottiglieri, Teodoro; Villarroya, Francesc; Gerszten, Robert E.

    2016-01-01

    Identifying markers of human insulin resistance may permit development of new approaches for treatment and prevention of type 2 diabetes. To this end, we analyzed the fasting plasma metabolome in metabolically characterized human volunteers across a spectrum of insulin resistance. We demonstrate that plasma betaine levels are reduced in insulin-resistant humans and correlate closely with insulin sensitivity. Moreover, betaine administration to mice with diet-induced obesity prevents the development of impaired glucose homeostasis, reduces hepatic lipid accumulation, increases white adipose oxidative capacity, and enhances whole-body energy expenditure. In parallel with these beneficial metabolic effects, betaine supplementation robustly increased hepatic and circulating fibroblast growth factor (Fgf)21 levels. Betaine administration failed to improve glucose homeostasis and liver fat content in Fgf21−/− mice, demonstrating that Fgf21 is necessary for betaine’s beneficial effects. Together, these data indicate that dietary betaine increases Fgf21 levels to improve metabolic health in mice and suggest that betaine supplementation merits further investigation as a supplement for treatment or prevention of type 2 diabetes in humans. PMID:26858359

  1. Reviewing the Effects of l-Leucine Supplementation in the Regulation of Food Intake, Energy Balance, and Glucose Homeostasis

    PubMed Central

    Pedroso, João A.B.; Zampieri, Thais T.; Donato, Jose

    2015-01-01

    Leucine is a well-known activator of the mammalian target of rapamycin (mTOR). Because mTOR signaling regulates several aspects of metabolism, the potential of leucine as a dietary supplement for treating obesity and diabetes mellitus has been investigated. The objective of the present review was to summarize and discuss the available evidence regarding the mechanisms and the effects of leucine supplementation on the regulation of food intake, energy balance, and glucose homeostasis. Based on the available evidence, we conclude that although central leucine injection decreases food intake, this effect is not well reproduced when leucine is provided as a dietary supplement. Consequently, no robust evidence indicates that oral leucine supplementation significantly affects food intake, although several studies have shown that leucine supplementation may help to decrease body adiposity in specific conditions. However, more studies are necessary to assess the effects of leucine supplementation in already-obese subjects. Finally, although several studies have found that leucine supplementation improves glucose homeostasis, the underlying mechanisms involved in these potential beneficial effects remain unknown and may be partially dependent on weight loss. PMID:26007339

  2. Dietary Betaine Supplementation Increases Fgf21 Levels to Improve Glucose Homeostasis and Reduce Hepatic Lipid Accumulation in Mice.

    PubMed

    Ejaz, Asma; Martinez-Guino, Laura; Goldfine, Allison B; Ribas-Aulinas, Francesc; De Nigris, Valeria; Ribó, Sílvia; Gonzalez-Franquesa, Alba; Garcia-Roves, Pablo M; Li, Elizabeth; Dreyfuss, Jonathan M; Gall, Walt; Kim, Jason K; Bottiglieri, Teodoro; Villarroya, Francesc; Gerszten, Robert E; Patti, Mary-Elizabeth; Lerin, Carles

    2016-04-01

    Identifying markers of human insulin resistance may permit development of new approaches for treatment and prevention of type 2 diabetes. To this end, we analyzed the fasting plasma metabolome in metabolically characterized human volunteers across a spectrum of insulin resistance. We demonstrate that plasma betaine levels are reduced in insulin-resistant humans and correlate closely with insulin sensitivity. Moreover, betaine administration to mice with diet-induced obesity prevents the development of impaired glucose homeostasis, reduces hepatic lipid accumulation, increases white adipose oxidative capacity, and enhances whole-body energy expenditure. In parallel with these beneficial metabolic effects, betaine supplementation robustly increased hepatic and circulating fibroblast growth factor (Fgf)21 levels. Betaine administration failed to improve glucose homeostasis and liver fat content in Fgf21(-/-) mice, demonstrating that Fgf21 is necessary for betaine's beneficial effects. Together, these data indicate that dietary betaine increases Fgf21 levels to improve metabolic health in mice and suggest that betaine supplementation merits further investigation as a supplement for treatment or prevention of type 2 diabetes in humans. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  3. Selective Reversible Inhibition of Liver Carnitine Palmitoyl-Transferase 1 by Teglicar Reduces Gluconeogenesis and Improves Glucose Homeostasis

    PubMed Central

    Conti, Roberto; Mannucci, Edoardo; Pessotto, Pompeo; Tassoni, Emanuela; Carminati, Paolo; Giannessi, Fabio; Arduini, Arduino

    2011-01-01

    OBJECTIVE We have developed a new antihyperglycemic agent (teglicar) through the selective and reversible inhibition of the liver isoform of carnitine palmitoyl-transferase 1 (L-CPT1). RESEARCH DESIGN AND METHODS Glucose production was investigated in isolated hepatocytes and during pancreatic clamps in healthy rats. Chronic treatments on C57BL/6J, db/db, high-fat fed mice, and rats were performed to understand glucose metabolism and insulin sensitivity. RESULTS In isolated hepatocytes, teglicar concentration dependently reduced ketone bodies and glucose production up to 72 and 50%, respectively. In rats, teglicar reduced the endogenous glucose production (−62%) without affecting peripheral glucose utilization. Heart 2-[3H]deoxyglucose uptake in mice was also not affected, confirming in vivo the drug selectivity toward L-CPT1. Chronic treatment in db/db mice (50 mg/kg/bid; 45 days) reduced postabsorptive glycemia (−38%), water consumption (−31%), and fructosamine (−30%). Such antidiabetic activity was associated with an improved insulin sensitivity assessed by the insulin tolerance test. A significant 50% increase in hepatic triglyceride content (HTGC) was found, although plasma alanineaminotransferase was not altered. In addition, long-term teglicar administration to high-fat fed C57BL/6J mice normalized glycemia (−19%) and insulinemia (−53%). Long-term teglicar administration (30 days, 80 mg/kg) in healthy overnight-fasted rats slightly reduced basal glycemia (−20%, ns), reduced basal insulin levels by 60%, doubled triglycerides, and increased free-fatty acids (+53%). HTGC was markedly increased, but liver and peripheral insulin sensitivity assessed by hyperinsulinemiceuglycemic clamp were not affected. CONCLUSIONS Teglicar, in vitro and in animal models, reduces gluconeogenesis and improves glucose homeostasis, refreshing the interest in selective and reversible L-CPT1 inhibition as a potential antihyperglycemic approach. PMID:21270274

  4. Clinical assessment of blood glucose homeostasis in horses: comparison of a continuous glucose monitoring system with a combined intravenous glucose and insulin test protocol.

    PubMed

    Johnson, P J; Wiedmeyer, C E; LaCarrubba, A; Messer, N T; Dingfelder, H A; Cogswell, A M; Amorim, J R R; Ganjam, V K

    2011-01-01

    The combined glucose-insulin test (CGIT) is helpful for evaluating insulin sensitivity. A continuous glucose monitoring system (CGMS) reports changes in interstitial glucose concentrations as they occur in the blood. Use of the CGMS minimizes animal contact and may be useful when performing a CGIT. Results obtained using a CGMS are useful for the evaluation of glucose responses during the evaluation of insulin sensitivity in equids. Seven mature, obese ponies. Ponies were equipped with CGMS for determination of interstitial glucose concentrations. Glucose (150 mg/kg, i.v.) and insulin (0.1 U/kg, i.v.) were administered and blood glucose concentrations determined at (minutes after time zero) 1, 5, 15, 25, 35, 45, 60, 75, 90, 105, and 120 with a hand-held glucometer. Blood chemistry results were compared with simultaneously obtained results using CGMS. Concordance coefficients determined for comparison of blood glucose concentrations determined by a hand-held glucometer and those determined by CGMS after the zero time point were 0.623, 0.764, 0.834, 0.854, and 0.818 (for delays of 0, 5, 10, 15, and 20 minutes, respectively). Interstitial glucose concentrations obtained by the CGMS compared favorably to blood glucose concentrations. CGMS may be useful for assessment of glucose dynamics in the CGIT. Copyright © 2010 by the American College of Veterinary Internal Medicine.

  5. Impaired glucose homeostasis in non-diabetic Greek hypertensives with diabetes family history. Effect of the obesity status.

    PubMed

    Vyssoulis, Gregory P; Liakos, Charalampos I; Karpanou, Eva A; Triantafyllou, Athanasios I; Michaelides, Andreas P; Tzamou, Vanessa E; Markou, Maria I; Stefanadis, Christodoulos I

    2013-01-01

    Arterial hypertension (AH) and diabetes mellitus (DM) are established cardiovascular risk factors. Impaired glucose homeostasis (IGH; impaired fasting glucose or/and impaired glucose tolerance) or pre-diabetes, obesity, and DM family history identify individuals at risk for type 2 DM in whom preventive interventions are necessary. The aim of this study was to determine the glycemic profile in non-diabetic Greek adult hypertensive men and women according to DM family history and the obesity status. Diabetes family history, obesity markers (waist-to-hip ratio, WHR; body mass index, BMI), glycemic parameters (fasting and 2-hour post-load plasma glucose, if necessary; glycated hemoglobin, HbA1c; fasting insulin), insulin resistance indices (homeostasis model assessment, HOMA; quantitative insulin sensitivity check index, QUICKI; Bennett; McAuley), and IGH prevalence were determined in a large cohort of 11,540 Greek hypertensives referred to our institutions. Positive DM family history was associated with elevated fasting glucose (98.6 ± 13.1 vs 96.5 ± 12.3 mg/dL), HbA1c (5.58% ± 0.49% vs 5.50% ± 0.46%), fasting insulin (9.74 ± 4.20 vs 9.21 ± 3.63 μU/mL) and HOMA (2.43 ± 1.19 vs 2.24 ± 1.01) values, lower QUICKI (0.342 ± 0.025 vs 0.345 ± 0.023), Bennett (0.285 ± 0.081 vs 0.292 ± 0.078) and McAuley (6.73 ± 3.43 vs 6.95 ± 3.44) values, and higher IGH prevalence (45.3% vs 38.7%); P < .01 for all comparisons. The difference in the prevalence of IGH according to DM family history was significant (P < .01) in both genders and every WHR and BMI subgroup (except for women with BMI <20 kg/m(2)). Non-diabetic hypertensives with positive DM family history present with higher IGH prevalence and worse glycemic indices levels compared with those with negative family history, especially in the higher WHR/BMI subgroups. Copyright © 2013 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  6. Area-Level Socioeconomic Status and Incidence of Abnormal Glucose Metabolism

    PubMed Central

    Williams, Emily D.; Magliano, Dianna J.; Zimmet, Paul Z.; Kavanagh, Anne M.; Stevenson, Christopher E.; Oldenburg, Brian F.; Shaw, Jonathan E.

    2012-01-01

    OBJECTIVE To examine the role of area-level socioeconomic status (SES) on the development of abnormal glucose metabolism (AGM) using national, population-based data. RESEARCH DESIGN AND METHODS The Australian Diabetes, Obesity and Lifestyle (AusDiab) study is a national, population-based, longitudinal study of adults aged ≥25 years. A sample of 4,572 people provided complete baseline (1999 to 2000) and 5-year follow-up (2004 to 2005) data relevant for these analyses. Incident AGM was assessed using fasting plasma glucose and 2-h plasma glucose from oral glucose tolerance tests, and demographic, socioeconomic, and behavioral data were collected by interview and questionnaire. Area SES was defined using the Index of Relative Socioeconomic Disadvantage. Generalized linear mixed models were used to examine the relationship between area SES and incident AGM, with adjustment for covariates and correction for cluster design effects. RESULTS Area SES predicted the development of AGM, after adjustment for age, sex, and individual SES. People living in areas with the most disadvantage were significantly more likely to develop AGM, compared with those living in the least deprived areas (odds ratio 1.53; 95% CI 1.07–2.18). Health behaviors (in particular, physical activity) and central adiposity appeared to partially mediate this relationship. CONCLUSIONS Our findings suggest that characteristics of the physical, social, and economic aspects of local areas influence diabetes risk. Future research should focus on identifying the aspects of local environment that are associated with diabetes risk and how they might be modified. PMID:22619081

  7. Central serotonergic neurons activate and recruit thermogenic brown and beige fat and regulate glucose and lipid homeostasis.

    PubMed

    McGlashon, Jacob M; Gorecki, Michelle C; Kozlowski, Amanda E; Thirnbeck, Caitlin K; Markan, Kathleen R; Leslie, Kirstie L; Kotas, Maya E; Potthoff, Matthew J; Richerson, George B; Gillum, Matthew P

    2015-05-05

    Thermogenic brown and beige adipocytes convert chemical energy to heat by metabolizing glucose and lipids. Serotonin (5-HT) neurons in the CNS are essential for thermoregulation and accordingly may control metabolic activity of thermogenic fat. To test this, we generated mice in which the human diphtheria toxin receptor (DTR) was selectively expressed in central 5-HT neurons. Treatment with diphtheria toxin (DT) eliminated 5-HT neurons and caused loss of thermoregulation, brown adipose tissue (BAT) steatosis, and a >50% decrease in uncoupling protein 1 (Ucp1) expression in BAT and inguinal white adipose tissue (WAT). In parallel, blood glucose increased 3.5-fold, free fatty acids 13.4-fold, and triglycerides 6.5-fold. Similar BAT and beige fat defects occurred in Lmx1b(f/f)ePet1(Cre) mice in which 5-HT neurons fail to develop in utero. We conclude 5-HT neurons play a major role in regulating glucose and lipid homeostasis, in part through recruitment and metabolic activation of brown and beige adipocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Neonatal hypothyroidism affects testicular glucose homeostasis through increased oxidative stress in prepubertal mice: effects on GLUT3, GLUT8 and Cx43.

    PubMed

    Sarkar, D; Singh, S K

    2017-07-01

    Thyroid hormones (THs) play an important role in maintaining the link between metabolism and reproduction and the altered THs status is associated with induction of oxidative stress in various organs like brain, heart, liver and testis. Further, reactive oxygen species play a pivotal role in regulation of glucose homeostasis in several organs, and glucose utilization by Leydig cells is essential for testosterone biosynthesis and thus is largely dependent on glucose transporter 8 (GLUT8). Glucose uptake by Sertoli cells is mediated through glucose transporter 3 (GLUT3) under the influence of THs to meet energy requirement of developing germ cells. THs also modulate level of gap junctional protein such as connexin 43 (Cx43), a potential regulator of cell proliferation and apoptosis in the seminiferous epithelium. Although the role of transient neonatal hypothyroidism in adult testis in terms of testosterone production is well documented, the effect of THs deficiency in early developmental period and its role in testicular glucose homeostasis and oxidative stress with reference to Cx43 in immature mice remain unknown. Therefore, the present study was conducted to evaluate the effect of neonatal hypothyroidism on testicular glucose homeostasis and oxidative stress at postnatal days (PND) 21 and 28 in relation to GLUT3, GLUT8 and Cx43. Hypothyroidism induced by 6-propyl-2-thiouracil (PTU) markedly decreased testicular glucose level with considerable reduction in expression level of GLUT3 and GLUT8. Likewise, lactate dehydrogenase (LDH) activity and intratesticular concentration of lactate were also decreased in hypothyroid mice. There was also a rise in germ cell apoptosis with increased expression of caspase-3 in PTU-treated mice. Further, neonatal hypothyroidism affected germ cell proliferation with decreased expression of proliferating cell nuclear antigen (PCNA) and Cx43. In conclusion, our results suggest that neonatal hypothyroidism alters testicular glucose

  9. Control of glucose homeostasis and insulin sensitivity by the Let-7 family of microRNAs

    PubMed Central

    Frost, Robert J. A.; Olson, Eric N.

    2011-01-01

    Diabetes mellitus is the most common metabolic disorder worldwide and a major risk factor for cardiovascular disease. MicroRNAs are negative regulators of gene expression that have been implicated in many biological processes, including metabolism. Here we show that the Let-7 family of microRNAs regulates glucose metabolism in multiple organs. Global and pancreas-specific overexpression of Let-7 in mice resulted in impaired glucose tolerance and reduced glucose-induced pancreatic insulin secretion. Mice overexpressing Let-7 also had decreased fat mass and body weight, as well as reduced body size. Global knockdown of the Let-7 family with an antimiR was sufficient to prevent and treat impaired glucose tolerance in mice with diet-induced obesity, at least in part by improving insulin sensitivity in liver and muscle. AntimiR treatment of mice on a high-fat diet also resulted in increased lean and muscle mass, but not increased fat mass, and prevented ectopic fat deposition in the liver. These findings demonstrate that Let-7 regulates multiple aspects of glucose metabolism and suggest antimiR-induced Let-7 knockdown as a potential treatment for type 2 diabetes mellitus. Furthermore, our Cre-inducible Let-7-transgenic mice provide a unique model for studying tissue-specific aspects of body growth and type 2 diabetes. PMID:22160727

  10. Effects of Bisphenol A on glucose homeostasis and brain insulin signaling pathways in male mice.

    PubMed

    Fang, Fangfang; Chen, Donglong; Yu, Pan; Qian, Wenyi; Zhou, Jing; Liu, Jingli; Gao, Rong; Wang, Jun; Xiao, Hang

    2015-02-01

    The potential effects of Bisphenol A (BPA) on peripheral insulin resistance have recently gained more attention, however, its functions on brain insulin resistance are still unknown. The aim of the present study was to investigate the effects of BPA on insulin signaling and glucose transport in mouse brain. The male mice were administrated of 100 μg/kg/day BPA or vehicle for 15 days then challenged with glucose and insulin tolerance tests. The insulin levels were detected with radioimmunoassay (RIA), and the insulin signaling pathways were investigated by Western blot. Our results revealed that BPA significantly increased peripheral plasma insulin levels, and decreased the insulin signals including phosphorylated insulin receptor (p-IR), phosphorylated insulin receptor substrate 1 (p-IRS1), phosphorylated protein kinase B (p-AKT), phosphorylated glycogen synthase kinase 3β (p-GSK3β) and phosphorylated extracellular regulated protein kinases (p-ERK1/2) in the brain, though insulin expression in both hippocampus and profrontal cortex was increased. In parallel, BPA exposure might contribute to glucose transport disturbance in the brain since the expression of glucose transporters were markedly decreased. In conclusion, BPA exposure perturbs the insulin signaling and glucose transport in the brain, therefore, it might be a risk factor for brain insulin resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. A 12-week randomized clinical trial investigating the potential for sucralose to affect glucose homeostasis.

    PubMed

    Grotz, V Lee; Pi-Sunyer, Xavier; Porte, Daniel; Roberts, Ashley; Richard Trout, J

    2017-08-01

    The discovery of gut sweet taste receptors has led to speculations that non-nutritive sweeteners, including sucralose, may affect glucose control. A double-blind, parallel, randomized clinical trial, reported here and previously submitted to regulatory agencies, helps to clarify the role of sucralose in this regard. This was primarily an out-patient study, with 4-week screening, 12-week test, and 4-week follow-up phases. Normoglycemic male volunteers (47) consumed ∼333.3 mg encapsulated sucralose or placebo 3x/day at mealtimes. HbA1c, fasting glucose, insulin, and C-peptide were measured weekly. OGTTs were conducted in-clinic overnight, following overnight fasting twice during screening phase, twice during test phase, and once at follow-up. Throughout the study, glucose, insulin, C-peptide and HbA1c levels were within normal range. No statistically significant differences between sucralose and placebo groups in change from baseline for fasting glucose, insulin, C-peptide and HbA1c, no clinically meaningful differences in time to peak levels or return towards basal levels in OGTTs, and no treatment group differences in mean glucose, insulin, or C-peptide AUC change from baseline were observed. The results of other relevant clinical trials and studies of gastrointestinal sweet taste receptors are compared to these findings. The collective evidence supports that sucralose has no effect on glycemic control. Copyright © 2017 Heartland Food Products Group. Published by Elsevier Inc. All rights reserved.

  12. Regulatory role of mucosal maltase-glucoamylase in starch digestion and glucose homeostasis

    USDA-ARS?s Scientific Manuscript database

    Slower rates of starch digestion by sucrase-isomaltase (Si) in Mgam null mice may fail to regulate gluconeogenesis (GNG). Mgam nulls have 40% reduction of glucose production from starch. The aim of this study was to measure glycemic index and rate of gluconeogenesis (fGNG) as fraction of total gluc...

  13. Central insulin and leptin-mediated autonomic control of glucose homeostasis

    USDA-ARS?s Scientific Manuscript database

    Largely as a result of rising obesity rates, the incidence of type 2 diabetes is escalating rapidly. Type 2 diabetes results from multi-organ dysfunctional glucose metabolism. Recent publications have highlighted hypothalamic insulin- and adipokine-sensing as a major determinant of peripheral glucos...

  14. The effects of an amino acid supplement on glucose homeostasis, inflammatory markers, and incretins after laparoscopic gastric bypass.

    PubMed

    Breitman, Igal; Saraf, Neha; Kakade, Manasi; Yellumahanthi, Kishore; White, Merritt; Hackett, Jo Ann; Clements, Ronald H

    2011-04-01

    Protein supplements are routinely used after a laparoscopic gastric bypass (LGB). The aim of this study was to evaluate the impact of an amino acid supplement on glucose homeostasis and hormonal and inflammatory markers after LGB. Thirty patients undergoing LGB were randomized to receive or not 24 g of an oral supplement containing a leucine metabolite, glutamine, and arginine twice daily. Changes in weight, glucose, insulin, C-peptide, insulin sensitivity, interleukin (IL) 6, C-reactive protein (CRP), leptin, insulin-like growth factor (IGF) 1, ghrelin, and incretins were assessed preoperatively and 2 weeks and 8 weeks postoperatively. Thirty patients (96.7% female, age 46.9 ± 8.4 years, body mass index 43.3 ± 4.1 kg/m(2)) were randomized. The experimental (n = 14) and control (n = 16) groups were not significantly different at baseline. Weight loss was similar for the 2 groups. Fasting glucose decreased significantly at 2 and 8 weeks compared with base line (p < 0.0001) with no difference between the experimental and control groups (p = 0.8), but insulin and calculated insulin sensitivity, which were similar at baseline, became significantly worse in the experimental group 8 weeks after surgery (p = 0.02 for insulin; p = 0.04 for the homeostasis model assessment of insulin resistance). CRP and IL-6, which were similar at baseline, were found to be significantly higher at 8 weeks in the experimental group (p = 0.018 and p = 0.05, respectively). Leptin and IGF-1 levels decreased significantly from baseline at 2 and 8 weeks (p < 0.0001), but there was no difference between the 2 groups. No significant changes in GLP-1, ghrelin, or gastric inhibitory polypeptide were noticed after 8 weeks. An amino acid supplement had no effect on the early postoperative incretins after LGB. It may have a negative influence on glucose kinetics and degree of inflammation. Future studies are needed to clarify these effects. Copyright © 2011 American College of Surgeons. Published by

  15. Neuronal calcium sensor synaptotagmin-9 is not involved in the regulation of glucose homeostasis or insulin secretion.

    PubMed

    Gustavsson, Natalia; Wang, Xiaorui; Wang, Yue; Seah, Tingting; Xu, Jun; Radda, George K; Südhof, Thomas C; Han, Weiping

    2010-11-09

    Insulin secretion is a complex and highly regulated process. It is well established that cytoplasmic calcium is a key regulator of insulin secretion, but how elevated intracellular calcium triggers insulin granule exocytosis remains unclear, and we have only begun to define the identities of proteins that are responsible for sensing calcium changes and for transmitting the calcium signal to release machineries. Synaptotagmins are primarily expressed in brain and endocrine cells and exhibit diverse calcium binding properties. Synaptotagmin-1, -2 and -9 are calcium sensors for fast neurotransmitter release in respective brain regions, while synaptotagmin-7 is a positive regulator of calcium-dependent insulin release. Unlike the three neuronal calcium sensors, whose deletion abolished fast neurotransmitter release, synaptotagmin-7 deletion resulted in only partial loss of calcium-dependent insulin secretion, thus suggesting that other calcium-sensors must participate in the regulation of insulin secretion. Of the other synaptotagmin isoforms that are present in pancreatic islets, the neuronal calcium sensor synaptotagmin-9 is expressed at the highest level after synaptotagmin-7. In this study we tested whether synaptotagmin-9 participates in the regulation of glucose-stimulated insulin release by using pancreas-specific synaptotagmin-9 knockout (p-S9X) mice. Deletion of synaptotagmin-9 in the pancreas resulted in no changes in glucose homeostasis or body weight. Glucose tolerance, and insulin secretion in vivo and from isolated islets were not affected in the p-S9X mice. Single-cell capacitance measurements showed no difference in insulin granule exocytosis between p-S9X and control mice. Thus, synaptotagmin-9, although a major calcium sensor in the brain, is not involved in the regulation of glucose-stimulated insulin release from pancreatic β-cells.

  16. Role of FAT/CD36 in fatty acid sensing, energy, and glucose homeostasis regulation in DIO and DR rats.

    PubMed

    Le Foll, Christelle; Dunn-Meynell, Ambrose A; Levin, Barry E

    2015-02-01

    Hypothalamic fatty acid (FA) sensing neurons alter their activity utilizing the FA translocator/receptor, FAT/CD36. Depletion of ventromedial hypothalamus (VMH) CD36 with adeno-associated viral vector expressing CD36 shRNA (AAV CD36 shRNA) leads to redistribution of adipose stores and insulin resistance in outbred rats. This study assessed the requirement of VMH CD36-mediated FA sensing for the regulation of energy and glucose homeostasis in postnatal day 5 (P5) and P21 selectively bred diet-induced obese (DIO) and diet-resistant (DR) rats using VMH AAV CD36 shRNA injections. P5 CD36 depletion altered VMH neuronal FA sensing predominantly in DIO rats. After 10 wk on a 45% fat diet, DIO rats injected with VMH AAV CD36 shRNA at P21 ate more and gained more weight than DIO AAV controls, while DR AAV CD36 shRNA-injected rats gained less weight than DR AAV controls. VMH CD36 depletion increased inguinal fat pad weights and leptin levels in DIO and DR rats. Although DR AAV CD36 shRNA-injected rats became as obese as DIO AAV controls, only DIO control and CD36 depleted rats became insulin-resistant on a 45% fat diet. VMH CD36 depletion stunted linear growth in DIO and DR rats. DIO rats injected with AAV CD36 shRNA at P5 had increased fat mass, mostly due to a 45% increase in subcutaneous fat. They were also insulin-resistant with an associated 71% increase of liver triglycerides. These results demonstrate that VMH CD36-mediated FA sensing is a critical factor in the regulation of energy and glucose homeostasis and fat deposition in DIO and DR rats.

  17. Abnormal Glucose Metabolism in Alzheimer’s Disease: Relation to Autophagy/Mitophagy and Therapeutic Approaches

    PubMed Central

    Banerjee, Kalpita; Munshi, Soumyabrata; Frank, David E.; Gibson, Gary E.

    2015-01-01

    Diminished glucose metabolism accompanies many neurodegenerative diseases including Alzheimer’s disease. An understanding of the relation of these metabolic changes to the disease will enable development of novel therapeutic strategies. Following a metabolic challenge, cells generally conserve energy to preserve viability. This requires activation of many cellular repair/regenerative processes such as mitophagy/autophagy and fusion/fission. These responses may diminish cell function in the long term. Prolonged fission induces mitophagy/autophagy which promotes repair but if prolonged progresses to mitochondrial degradation. Abnormal glucose metabolism alters protein signaling including the release of proteins from the mitochondria or migration of proteins from the cytosol to the mitochondria or nucleus. This overview provides an insight into the different mechanisms of autophagy/mitophagy and mitochondrial dynamics in response to the diminished metabolism that occurs with diseases, especially neurodegenerative diseases such as Alzheimer's disease. The review discusses multiple aspects of mitochondrial responses including different signaling proteins and pathways of mitophagy and mitochondrial biogenesis. Improving cellular bioenergetics and mitochondrial dynamics will alter protein signaling and improve cellular/mitochondrial repair and regeneration. An understanding of these changes will suggest new therapeutic strategies. PMID:26077923

  18. Are barriers to physical activity similar for adults with and without abnormal glucose metabolism?

    PubMed

    Hume, Clare; Dunstan, David; Salmon, Jo; Healy, Genevieve; Andrianopoulos, Nick; Owen, Neville

    2010-01-01

    The purpose of this study was to examine perceived barriers to physical activity among adults with and without abnormal glucose metabolism (AGM), and whether barriers varied according to physical activity status. The 1999 to 2000 Australian Diabetes, Obesity, and Lifestyle Study (AusDiab) was a population-based cross-sectional study among adults aged > or =25 years. AGM was identified through an oral glucose tolerance test. The previous week's physical activity and individual, social, and environmental barriers to physical activity were self-reported. Logistic regression analyses examined differences in barriers to physical activity between those with and without AGM, and for those with and without AGM who did and did not meet the minimum recommendation of 150 minutes/week of moderate-to-vigorous intensity physical activity. Of the 7088 participants (47.5 +/- 12.7 years; 46% male), 18.5% had AGM. Approximately 47.5% of those with AGM met the physical activity recommendation, compared to 54.7% of those without AGM (P < .001). Key barriers to physical activity included lack of time, other priorities, and being tired. Following adjustment for sociodemographic and behavioral factors, there were few differences in barriers to physical activity between those with and without AGM, even after stratifying according to physical activity. Adults with AGM report similar barriers to physical activity, as do those without AGM. Programs for those with AGM can therefore focus on the known generic adult-reported barriers to physical activity.

  19. Progesterone receptor knockout mice have an improved glucose homeostasis secondary to -cell proliferation

    NASA Astrophysics Data System (ADS)

    Picard, Frédéric; Wanatabe, Mitsuhiro; Schoonjans, Kristina; Lydon, John; O'Malley, Bert W.; Auwerx, Johan

    2002-11-01

    Gestational diabetes coincides with elevated circulating progesterone levels. We show that progesterone accelerates the progression of diabetes in female db/db mice. In contrast, RU486, an antagonist of the progesterone receptor (PR), reduces blood glucose levels in both female WT and db/db mice. Furthermore, female, but not male, PR-/- mice had lower fasting glycemia than PR+/+ mice and showed higher insulin levels on glucose injection. Pancreatic islets from female PR-/- mice were larger and secreted more insulin consequent to an increase in -cell mass due to an increase in -cell proliferation. These findings demonstrate an important role of progesterone signaling in insulin release and pancreatic function and suggest that it affects the susceptibility to diabetes.

  20. Air Pollution Exposure and Abnormal Glucose Tolerance during Pregnancy: The Project Viva Cohort

    PubMed Central

    Gold, Diane R.; Rifas-Shiman, Sheryl L.; Koutrakis, Petros; Schwartz, Joel D.; Kloog, Itai; Melly, Steven; Coull, Brent A.; Zanobetti, Antonella; Gillman, Matthew W.; Oken, Emily

    2014-01-01

    Background: Exposure to fine particulate matter (PM with diameter ≤ 2.5 μm; PM2.5) has been linked to type 2 diabetes mellitus, but associations with hyperglycemia in pregnancy have not been well studied. Methods: We studied Boston, Massachusetts–area pregnant women without known diabetes. We identified impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) during pregnancy from clinical glucose tolerance tests at median 28.1 weeks gestation. We used residential addresses to estimate second-trimester PM2.5 and black carbon exposure via a central monitoring site and spatiotemporal models. We estimated residential traffic density and roadway proximity as surrogates for exposure to traffic-related air pollution. We performed multinomial logistic regression analyses adjusted for sociodemographic covariates, and used multiple imputation to account for missing data. Results: Of 2,093 women, 65 (3%) had IGT and 118 (6%) had GDM. Second-trimester spatiotemporal exposures ranged from 8.5 to 15.9 μg/m3 for PM2.5 and from 0.1 to 1.7 μg/m3 for black carbon. Traffic density was 0–30,860 vehicles/day × length of road (kilometers) within 100 m; 281 (13%) women lived ≤ 200 m from a major road. The prevalence of IGT was elevated in the highest (vs. lowest) quartile of exposure to spatiotemporal PM2.5 [odds ratio (OR) = 2.63; 95% CI: 1.15, 6.01] and traffic density (OR = 2.66; 95% CI: 1.24, 5.71). IGT also was positively associated with other exposure measures, although associations were not statistically significant. No pollutant exposures were positively associated with GDM. Conclusions: Greater exposure to PM2.5 and other traffic-related pollutants during pregnancy was associated with IGT but not GDM. Air pollution may contribute to abnormal glycemia in pregnancy. Citation: Fleisch AF, Gold DR, Rifas-Shiman SL, Koutrakis P, Schwartz JD, Kloog I, Melly S, Coull BA, Zanobetti A, Gillman MW, Oken E. 2014. Air pollution exposure and abnormal glucose

  1. Alternative rapamycin treatment regimens mitigate the impact of rapamycin on glucose homeostasis and the immune system.

    PubMed

    Arriola Apelo, Sebastian I; Neuman, Joshua C; Baar, Emma L; Syed, Faizan A; Cummings, Nicole E; Brar, Harpreet K; Pumper, Cassidy P; Kimple, Michelle E; Lamming, Dudley W

    2016-02-01

    Inhibition of the mechanistic target of rapamycin (mTOR) signaling pathway by the FDA-approved drug rapamycin has been shown to promote lifespan and delay age-related diseases in model organisms including mice. Unfortunately, rapamycin has potentially serious side effects in humans, including glucose intolerance and immunosuppression, which may preclude the long-term prophylactic use of rapamycin as a therapy for age-related diseases. While the beneficial effects of rapamycin are largely mediated by the inhibition of mTOR complex 1 (mTORC1), which is acutely sensitive to rapamycin, many of the negative side effects are mediated by the inhibition of a second mTOR-containing complex, mTORC2, which is much less sensitive to rapamycin. We hypothesized that different rapamycin dosing schedules or the use of FDA-approved rapamycin analogs with different pharmacokinetics might expand the therapeutic window of rapamycin by more specifically targeting mTORC1. Here, we identified an intermittent rapamycin dosing schedule with minimal effects on glucose tolerance, and we find that this schedule has a reduced impact on pyruvate tolerance, fasting glucose and insulin levels, beta cell function, and the immune system compared to daily rapamycin treatment. Further, we find that the FDA-approved rapamycin analogs everolimus and temsirolimus efficiently inhibit mTORC1 while having a reduced impact on glucose and pyruvate tolerance. Our results suggest that many of the negative side effects of rapamycin treatment can be mitigated through intermittent dosing or the use of rapamycin analogs. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  2. Ambient Air Pollutants Have Adverse Effects on Insulin and Glucose Homeostasis in Mexican Americans

    PubMed Central

    Chen, Zhanghua; Salam, Muhammad T.; Toledo-Corral, Claudia; Watanabe, Richard M.; Xiang, Anny H.; Buchanan, Thomas A.; Habre, Rima; Bastain, Theresa M.; Lurmann, Fred; Wilson, John P.; Trigo, Enrique

    2016-01-01

    OBJECTIVE Recent studies suggest that air pollution plays a role in type 2 diabetes (T2D) incidence and mortality. The underlying physiological mechanisms have yet to be established. We hypothesized that air pollution adversely affects insulin sensitivity and secretion and serum lipid levels. RESEARCH DESIGN AND METHODS Participants were selected from BetaGene (n = 1,023), a study of insulin resistance and pancreatic β-cell function in Mexican Americans. All participants underwent DXA and oral and intravenous glucose tolerance tests and completed dietary and physical activity questionnaires. Ambient air pollutant concentrations (NO2, O3, and PM2.5) for short- and long-term periods were assigned by spatial interpolation (maximum interpolation radius of 50 km) of data from air quality monitors. Traffic-related air pollution from freeways (TRAP) was estimated using the dispersion model as NOx. Variance component models were used to analyze individual and multiple air pollutant associations with metabolic traits. RESULTS Short-term (up to 58 days cumulative lagged averages) exposure to PM2.5 was associated with lower insulin sensitivity and HDL-to-LDL cholesterol ratio and higher fasting glucose and insulin, HOMA-IR, total cholesterol, and LDL cholesterol (LDL-C) (all P ≤ 0.036). Annual average PM2.5 was associated with higher fasting glucose, HOMA-IR, and LDL-C (P ≤ 0.043). The effects of short-term PM2.5 exposure on insulin sensitivity were largest among obese participants. No statistically significant associations were found between TRAP and metabolic outcomes. CONCLUSIONS Exposure to ambient air pollutants adversely affects glucose tolerance, insulin sensitivity, and blood lipid concentrations. Our findings suggest that ambient air pollutants may contribute to the pathophysiology in the development of T2D and related sequelae. PMID:26868440

  3. New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk

    PubMed Central

    Dupuis, Josée; Langenberg, Claudia; Prokopenko, Inga; Saxena, Richa; Soranzo, Nicole; Jackson, Anne U; Wheeler, Eleanor; Glazer, Nicole L; Bouatia-Naji, Nabila; Gloyn, Anna L; Lindgren, Cecilia M; Mägi, Reedik; Morris, Andrew P; Randall, Joshua; Johnson, Toby; Elliott, Paul; Rybin, Denis; Thorleifsson, Gudmar; Steinthorsdottir, Valgerdur; Henneman, Peter; Grallert, Harald; Dehghan, Abbas; Hottenga, Jouke Jan; Franklin, Christopher S; Navarro, Pau; Song, Kijoung; Goel, Anuj; Perry, John R B; Egan, Josephine M; Lajunen, Taina; Grarup, Niels; Sparsø, Thomas; Doney, Alex; Voight, Benjamin F; Stringham, Heather M; Li, Man; Kanoni, Stavroula; Shrader, Peter; Cavalcanti-Proença, Christine; Kumari, Meena; Qi, Lu; Timpson, Nicholas J; Gieger, Christian; Zabena, Carina; Rocheleau, Ghislain; Ingelsson, Erik; An, Ping; O’Connell, Jeffrey; Luan, Jian'an; Elliott, Amanda; McCarroll, Steven A; Payne, Felicity; Roccasecca, Rosa Maria; Pattou, François; Sethupathy, Praveen; Ardlie, Kristin; Ariyurek, Yavuz; Balkau, Beverley; Barter, Philip; Beilby, John P; Ben-Shlomo, Yoav; Benediktsson, Rafn; Bennett, Amanda J; Bergmann, Sven; Bochud, Murielle; Boerwinkle, Eric; Bonnefond, Amélie; Bonnycastle, Lori L; Borch-Johnsen, Knut; Böttcher, Yvonne; Brunner, Eric; Bumpstead, Suzannah J; Charpentier, Guillaume; Chen, Yii-Der Ida; Chines, Peter; Clarke, Robert; Coin, Lachlan J M; Cooper, Matthew N; Cornelis, Marilyn; Crawford, Gabe; Crisponi, Laura; Day, Ian N M; de Geus, Eco; Delplanque, Jerome; Dina, Christian; Erdos, Michael R; Fedson, Annette C; Fischer-Rosinsky, Antje; Forouhi, Nita G; Fox, Caroline S; Frants, Rune; Franzosi, Maria Grazia; Galan, Pilar; Goodarzi, Mark O; Graessler, Jürgen; Groves, Christopher J; Grundy, Scott; Gwilliam, Rhian; Gyllensten, Ulf; Hadjadj, Samy; Hallmans, Göran; Hammond, Naomi; Han, Xijing; Hartikainen, Anna-Liisa; Hassanali, Neelam; Hayward, Caroline; Heath, Simon C; Hercberg, Serge; Herder, Christian; Hicks, Andrew A; Hillman, David R; Hingorani, Aroon D; Hofman, Albert; Hui, Jennie; Hung, Joe; Isomaa, Bo; Johnson, Paul R V; Jørgensen, Torben; Jula, Antti; Kaakinen, Marika; Kaprio, Jaakko; Kesaniemi, Y Antero; Kivimaki, Mika; Knight, Beatrice; Koskinen, Seppo; Kovacs, Peter; Kyvik, Kirsten Ohm; Lathrop, G Mark; Lawlor, Debbie A; Le Bacquer, Olivier; Lecoeur, Cécile; Li, Yun; Lyssenko, Valeriya; Mahley, Robert; Mangino, Massimo; Manning, Alisa K; Martínez-Larrad, María Teresa; McAteer, Jarred B; McCulloch, Laura J; McPherson, Ruth; Meisinger, Christa; Melzer, David; Meyre, David; Mitchell, Braxton D; Morken, Mario A; Mukherjee, Sutapa; Naitza, Silvia; Narisu, Narisu; Neville, Matthew J; Oostra, Ben A; Orrù, Marco; Pakyz, Ruth; Palmer, Colin N A; Paolisso, Giuseppe; Pattaro, Cristian; Pearson, Daniel; Peden, John F; Pedersen, Nancy L.; Perola, Markus; Pfeiffer, Andreas F H; Pichler, Irene; Polasek, Ozren; Posthuma, Danielle; Potter, Simon C; Pouta, Anneli; Province, Michael A; Psaty, Bruce M; Rathmann, Wolfgang; Rayner, Nigel W; Rice, Kenneth; Ripatti, Samuli; Rivadeneira, Fernando; Roden, Michael; Rolandsson, Olov; Sandbaek, Annelli; Sandhu, Manjinder; Sanna, Serena; Sayer, Avan Aihie; Scheet, Paul; Scott, Laura J; Seedorf, Udo; Sharp, Stephen J; Shields, Beverley; Sigurðsson, Gunnar; Sijbrands, Erik J G; Silveira, Angela; Simpson, Laila; Singleton, Andrew; Smith, Nicholas L; Sovio, Ulla; Swift, Amy; Syddall, Holly; Syvänen, Ann-Christine; Tanaka, Toshiko; Thorand, Barbara; Tichet, Jean; Tönjes, Anke; Tuomi, Tiinamaija; Uitterlinden, André G; van Dijk, Ko Willems; van Hoek, Mandy; Varma, Dhiraj; Visvikis-Siest, Sophie; Vitart, Veronique; Vogelzangs, Nicole; Waeber, Gérard; Wagner, Peter J; Walley, Andrew; Walters, G Bragi; Ward, Kim L; Watkins, Hugh; Weedon, Michael N; Wild, Sarah H; Willemsen, Gonneke; Witteman, Jaqueline C M; Yarnell, John W G; Zeggini, Eleftheria; Zelenika, Diana; Zethelius, Björn; Zhai, Guangju; Zhao, Jing Hua; Zillikens, M Carola; Borecki, Ingrid B; Loos, Ruth J F; Meneton, Pierre; Magnusson, Patrik K E; Nathan, David M; Williams, Gordon H; Hattersley, Andrew T; Silander, Kaisa; Salomaa, Veikko; Smith, George Davey; Bornstein, Stefan R; Schwarz, Peter; Spranger, Joachim; Karpe, Fredrik; Shuldiner, Alan R; Cooper, Cyrus; Dedoussis, George V; Serrano-Ríos, Manuel; Morris, Andrew D; Lind, Lars; Palmer, Lyle J; Hu, Frank B.; Franks, Paul W; Ebrahim, Shah; Marmot, Michael; Kao, W H Linda; Pankow, James S; Sampson, Michael J; Kuusisto, Johanna; Laakso, Markku; Hansen, Torben; Pedersen, Oluf; Pramstaller, Peter Paul; Wichmann, H Erich; Illig, Thomas; Rudan, Igor; Wright, Alan F; Stumvoll, Michael; Campbell, Harry; Wilson, James F; Hamsten, Anders; Bergman, Richard N; Buchanan, Thomas A; Collins, Francis S; Mohlke, Karen L; Tuomilehto, Jaakko; Valle, Timo T; Altshuler, David; Rotter, Jerome I; Siscovick, David S; Penninx, Brenda W J H; Boomsma, Dorret; Deloukas, Panos; Spector, Timothy D; Frayling, Timothy M; Ferrucci, Luigi; Kong, Augustine; Thorsteinsdottir, Unnur; Stefansson, Kari; van Duijn, Cornelia M; Aulchenko, Yurii S; Cao, Antonio; Scuteri, Angelo; Schlessinger, David; Uda, Manuela; Ruokonen, Aimo; Jarvelin, Marjo-Riitta; Waterworth, Dawn M; Vollenweider, Peter; Peltonen, Leena; Mooser, Vincent; Abecasis, Goncalo R; Wareham, Nicholas J; Sladek, Robert; Froguel, Philippe; Watanabe, Richard M; Meigs, James B; Groop, Leif; Boehnke, Michael; McCarthy, Mark I; Florez, Jose C; Barroso, Inês

    2010-01-01

    Circulating glucose levels are tightly regulated. To identify novel glycemic loci, we performed meta-analyses of 21 genome-wide associations studies informative for fasting glucose (FG), fasting insulin (FI) and indices of β-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 non-diabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with FG/HOMA-B and two associated with FI/HOMA-IR. These include nine new FG loci (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and FAM148B) and one influencing FI/HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB/TMEM195 with type 2 diabetes (T2D). Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify T2D risk loci, as well as loci that elevate FG modestly, but do not cause overt diabetes. PMID:20081858

  4. Evidence for brain glucose dysregulation in Alzheimer's disease.

    PubMed

    An, Yang; Varma, Vijay R; Varma, Sudhir; Casanova, Ramon; Dammer, Eric; Pletnikova, Olga; Chia, Chee W; Egan, Josephine M; Ferrucci, Luigi; Troncoso, Juan; Levey, Allan I; Lah, James; Seyfried, Nicholas T; Legido-Quigley, Cristina; O'Brien, Richard; Thambisetty, Madhav

    2018-03-01

    It is unclear whether abnormalities in brain glucose homeostasis are associated with Alzheimer's disease (AD) pathogenesis. Within the autopsy cohort of the Baltimore Longitudinal Study of Aging, we measured brain glucose concentration and assessed the ratios of the glycolytic amino acids, serine, glycine, and alanine to glucose. We also quantified protein levels of the neuronal (GLUT3) and astrocytic (GLUT1) glucose transporters. Finally, we assessed the relationships between plasma glucose measured before death and brain tissue glucose. Higher brain tissue glucose concentration, reduced glycolytic flux, and lower GLUT3 are related to severity of AD pathology and the expression of AD symptoms. Longitudinal increases in fasting plasma glucose levels are associated with higher brain tissue glucose concentrations. Impaired glucose metabolism due to reduced glycolytic flux may be intrinsic to AD pathogenesis. Abnormalities in brain glucose homeostasis may begin several years before the onset of clinical symptoms. Copyright © 2017 the Alzheimer's Association. All rights reserved.

  5. Effects of saxagliptin on glucose homeostasis and body composition of obese patients with newly diagnosed pre-diabetes.

    PubMed

    Wang, Zixuan; Xu, Dengcheng; Huang, Lanhui; Zhang, Tiantian; Wang, Junqiao; Chen, Qing; Kong, Lei; Zhou, Xinli

    2017-08-01

    To assess the effect of saxagliptin monotherapy on blood glucose and islet β-cell function in obese patients with newly diagnosed pre-diabetes and abnormal fat metabolism. A 24-week, randomized controlled trial was conducted involving 25 obese subjects with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) (mean age 45years) to receive lifestyle intervention only (control group) or combined with saxagliptin 2.5mg or 5mg daily (S2.5 or S5 group), metformin 1500mg daily (Met group). Anthropometrics, body fat and biochemical parameters were measured before and after 4, 12 and 24weeks intervention. S5 group and Met group showed a significant decrease in fasting plasma glucose (FPG) and HbA1c compared with the control group (all P<0.05) after 24-week intervention. However, the decrease in 2h postprandial plasma glucose levels (2hPPG) in S5 group were greater compared with control group (P<0.01). Insulin resistance (HOMA-IR) was reduced in S5 group, Met group and control group (P<0.05), and the β-cell function (HOMA-β) was improved in all groups (P<0.05). However, the changes in obesity-related indicators including waist circumference, hip circumference, weight, BMI, body fat, percentage of body fat and waist-to-hip fat ratio were greate in Met group (all P<0.05) compared with other groups (P>0.05). Saxagliptin monotherapy may prevent or delay the progression of IGT or IFG to type 2 diabetes mellitus in obese patients with newly diagnosed pre-diabetes. ClinicalTrials.gov: NCT01960205. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice

    PubMed Central

    Smith, Mark A.; Katsouri, Loukia; Irvine, Elaine E.; Hankir, Mohammed K.; Pedroni, Silvia M.A.; Voshol, Peter J.; Gordon, Matthew W.; Choudhury, Agharul I.; Woods, Angela; Vidal-Puig, Antonio; Carling, David; Withers, Dominic J.

    2015-01-01

    Summary Hypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons. PMID:25865886

  7. Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice.

    PubMed

    Smith, Mark A; Katsouri, Loukia; Irvine, Elaine E; Hankir, Mohammed K; Pedroni, Silvia M A; Voshol, Peter J; Gordon, Matthew W; Choudhury, Agharul I; Woods, Angela; Vidal-Puig, Antonio; Carling, David; Withers, Dominic J

    2015-04-21

    Hypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  8. FGF21 improves glucose homeostasis in an obese diabetes-prone mouse model independent of body fat changes.

    PubMed

    Laeger, Thomas; Baumeier, Christian; Wilhelmi, Ilka; Würfel, Josefine; Kamitz, Anne; Schürmann, Annette

    2017-11-01

    Fibroblast growth factor 21 (FGF21) is considered to be a promising therapeutic candidate for the treatment of type 2 diabetes. However, as FGF21 levels are elevated in obese and diabetic conditions we aimed to test if exogenous FGF21 is sufficient to prevent diabetes and beta cell loss in New Zealand obese (NZO) mice, a model for polygenetic obesity and type 2 diabetes. Male NZO mice were treated with a specific dietary regimen that leads to the onset of diabetes within 1 week. Mice were treated subcutaneously with PBS or FGF21 to assess changes in glucose homeostasis, energy expenditure, food intake and other metabolic endpoints. FGF21 treatment prevented islet destruction and the onset of hyperglycaemia, and improved glucose clearance. FGF21 increased energy expenditure by inducing browning in subcutaneous white adipose tissue. However, as a result of a compensatory increased food intake, body fat did not decrease in response to FGF21 treatment, but exhibited elevated Glut4 expression. FGF21 prevents the onset of diet-induced diabetes, without changing body fat mass. Beneficial effects are mediated via white adipose tissue browning and elevated thermogenesis. Furthermore, these data indicate that obesity does not induce FGF21 resistance in NZO mice.

  9. Nuclear and Membrane Actions of Estrogen Receptor Alpha: Contribution to the Regulation of Energy and Glucose Homeostasis.

    PubMed

    Guillaume, Maeva; Montagner, Alexandra; Fontaine, Coralie; Lenfant, Françoise; Arnal, Jean-François; Gourdy, Pierre

    2017-01-01

    Estrogen receptor alpha (ERα) has been demonstrated to play a key role in reproduction but also to exert numerous functions in nonreproductive tissues. Accordingly, ERα is now recognized as a key regulator of energy homeostasis and glucose metabolism and mediates the protective effects of estrogens against obesity and type 2 diabetes. This chapter attempts to summarize our current understanding of the mechanisms of ERα activation and their involvement in the modulation of energy balance and glucose metabolism. We first focus on the experimental studies that constitute the basis of the understanding of ERα as a nuclear receptor and more specifically on the key roles played by its two activation functions (AFs). We depict the consequences of the selective inactivation of these AFs in mouse models, which further underline the prominent role of nuclear ERα in the prevention of obesity and diabetes, as on the reproductive tract and the vascular system. Besides these nuclear actions, a fraction of ERα is associated with the plasma membrane and activates nonnuclear signaling from this site. Such rapid effects, called membrane-initiated steroid signals (MISS), have been characterized in a variety of cell lines and in particular in endothelial cells. The development of selective pharmacological tools that specifically activate MISS as well as the generation of mice expressing an ERα protein impeded for membrane localization has just begun to unravel the physiological role of MISS in vivo and their contribution to ERα-mediated metabolic protection. Finally, we discuss novel perspectives for the design of tissue-selective ER modulators.

  10. Hibiscus rosa sinensis Linn. Petals Modulates Glycogen Metabolism and Glucose Homeostasis Signalling Pathway in Streptozotocin-Induced Experimental Diabetes.

    PubMed

    Pillai, Sneha S; Mini, S

    2016-03-01

    The prevalence of diabetes mellitus is becoming more and more serious and reaches epidemic proportions worldwide. Scientific research is constantly looking for new agents that could be used as dietary functional ingredients in the fight against diabetes. The objective of the present study was to evaluate the effect of ethyl acetate fraction of Hibiscus rosa sinensis Linn. petals on experimental diabetes at a dose of 25 mg/kg body weight and it was compared with standard anti-diabetic drug metformin. The elevated levels of serum glucose (398.56 ± 35.78) and glycated haemoglobin (12.89 ± 1.89) in diabetic rats were significantly decreased (156.89 ± 14.45 and 6.12 ± 0.49, respectively) by Hibiscus rosa sinensis petals (EHRS) administration. Hepatotoxicity marker enzyme levels in serum were normalized. The fraction supplementation restored the glycogen content by regulating the activities of glycogen metabolizing enzymes. It significantly modulated the expressions of marker genes involved in glucose homeostasis signalling pathway. Histopathological analysis of liver and pancreas supported our findings. The overall effect was comparable with metformin. Hence, our study reveals the role of hibiscus petals for alleviation of diabetes complications, thus it can be propagated as a nutraceutical agent.

  11. Effects of the new dual PPAR α/δ agonist GFT505 on lipid and glucose homeostasis in abdominally obese patients with combined dyslipidemia or impaired glucose metabolism.

    PubMed

    Cariou, Bertrand; Zaïr, Yassine; Staels, Bart; Bruckert, Eric

    2011-09-01

    We evaluated the metabolic effects and tolerability of GFT505, a novel dual peroxisome proliferator-activated receptor α/δ agonist, in abdominally obese patients with either combined dyslipidemia or prediabetes. The S1 study was conducted in 94 patients with combined dyslipidemia while the S2 study was conducted in 47 patients with prediabetes. Participants were randomly assigned in a double-blind manner to GFT505 at 80 mg/day or placebo for 28 (S1) or 35 (S2) days. Primary efficacy end points were changes from baseline at week 4 in both fasting plasma triglycerides and HDL cholesterol in the S1 group and 2-h glucose upon oral glucose tolerance test in the S2 group. In comparison with placebo, GFT505 significantly reduced fasting plasma triglycerides (S1: least squares means -16.7% [95% one-sided CI -∞ to -5.3], P = 0.005; S2: -24.8% [-∞ to -10.5], P = 0.0003) and increased HDL cholesterol (S1: 7.8% [3.0 to ∞], P = 0.004; S2: 9.3% [1.7 to ∞], P = 0.009) in both studies, whereas LDL cholesterol only decreased in S2 (-11.0% [ -∞ to -3.5], P = 0.002). In S2, GFT505 did not reduce 2-h glucose (-0.52 mmol/L [-∞ to 0.61], P = 0.18) but led to a significant decrease of homeostasis model assessment of insulin resistance (-31.4% [-∞ to 12.5], P = 0.001), fasting plasma glucose (-0.37 mmol/L [-∞ to -0.10], P = 0.01) and fructosamine (-3.6% [-∞ to -0.20], P = 0.02). GFT505 also reduced γ glutamyl transferase levels in both studies (S1: -19.9% [-∞ to -12.8], P < 0.0001; S2: -15.1% [-∞ to -1.1], P = 0.004). No specific adverse safety signals were reported during the studies. GFT505 may be considered a new drug candidate for the treatment of lipid and glucose disorders associated with the metabolic syndrome.

  12. Effects of the New Dual PPARα/δ Agonist GFT505 on Lipid and Glucose Homeostasis in Abdominally Obese Patients With Combined Dyslipidemia or Impaired Glucose Metabolism

    PubMed Central

    Cariou, Bertrand; Zaïr, Yassine; Staels, Bart; Bruckert, Eric

    2011-01-01

    OBJECTIVE We evaluated the metabolic effects and tolerability of GFT505, a novel dual peroxisome proliferator–activated receptor α/δ agonist, in abdominally obese patients with either combined dyslipidemia or prediabetes. RESEARCH DESIGN AND METHODS The S1 study was conducted in 94 patients with combined dyslipidemia while the S2 study was conducted in 47 patients with prediabetes. Participants were randomly assigned in a double-blind manner to GFT505 at 80 mg/day or placebo for 28 (S1) or 35 (S2) days. Primary efficacy end points were changes from baseline at week 4 in both fasting plasma triglycerides and HDL cholesterol in the S1 group and 2-h glucose upon oral glucose tolerance test in the S2 group. RESULTS In comparison with placebo, GFT505 significantly reduced fasting plasma triglycerides (S1: least squares means −16.7% [95% one-sided CI −∞ to −5.3], P = 0.005; S2: −24.8% [−∞ to −10.5], P = 0.0003) and increased HDL cholesterol (S1: 7.8% [3.0 to ∞], P = 0.004; S2: 9.3% [1.7 to ∞], P = 0.009) in both studies, whereas LDL cholesterol only decreased in S2 (−11.0% [ −∞ to −3.5], P = 0.002). In S2, GFT505 did not reduce 2-h glucose (−0.52 mmol/L [−∞ to 0.61], P = 0.18) but led to a significant decrease of homeostasis model assessment of insulin resistance (−31.4% [−∞ to 12.5], P = 0.001), fasting plasma glucose (−0.37 mmol/L [−∞ to −0.10], P = 0.01) and fructosamine (−3.6% [−∞ to −0.20], P = 0.02). GFT505 also reduced γ glutamyl transferase levels in both studies (S1: −19.9% [−∞ to −12.8], P < 0.0001; S2: −15.1% [−∞ to −1.1], P = 0.004). No specific adverse safety signals were reported during the studies. CONCLUSIONS GFT505 may be considered a new drug candidate for the treatment of lipid and glucose disorders associated with the metabolic syndrome. PMID:21816979

  13. The Effects of an Amino Acid Supplement on Glucose Homeostasis, Inflammatory Markers, and Incretins after Laparoscopic Gastric Bypass

    PubMed Central

    Breitman, Igal; Saraf, Neha; Kakade, Manasi; Yellumahanthi, Kishore; White, Merritt; Hackett, Jo Ann; Clements, Ronald H.

    2011-01-01

    Background Protein supplements are routinely used after a laparoscopic gastric bypass (LGB). The aim of this study is to evaluate the impact of an amino acid supplement on glucose homeostasis, hormonal and inflammatory markers after LGB. Methods 30 patients undergoing LGB were randomized to receive or not to receive 24g of an oral supplement containing a leucine metabolite, glutamine and arginine twice daily for 8 weeks. Changes in weight, BMI, ghrelin, GLP-1, GIP, glucose, insulin, C-peptide, insulin sensitivity, IL-6, CRP, leptin and IGF-1 were assessed preoperatively, 2 weeks and 8-weeks postoperatively. Results 30 patients (96.7% females, 46.9 ± 8.4 years, 113.4 ± 11.6 kg and BMI 43.3 ± 4.1 kg/m2) were randomized. The experimental (N=14) and control groups (N=16) were not significantly different at baseline. Weight and BMI were decreased significantly at two weeks and at eight weeks (p<0.0001 for each variable), but no statistical significance was observed between the two groups. Fasting glucose decreased significantly at 2 & 8 weeks as compared to base line (p<0.0001) with no difference between experimental and control groups (p=0.8), but insulin and calculated insulin sensitivity, that were similar at baseline, become significantly worse in the experimental group 8 weeks after surgery ( p=0.02 for insulin, p=0.04 for the homeostasis model assessment (HOMA) index). CRP, which was similar at baseline, was found to be significantly lower at 8 weeks in control vs. experimental group, (P=0.018). IL-6 decreased significantly from baseline at 2 weeks and rebounded at 8 weeks in both groups, there was a trend of higher IL-6 in the experimental group that becomes significant at 8 weeks (p=0.05). Leptin and IGF-1 levels decreased significantly from baseline at 2 & 8 weeks (p<0.0001) but there was no difference between the two groups. No significant change in GLP-1, ghrelin or GIP were noticed after 8 weeks. Conclusion An amino acid supplement had no effect on the

  14. Phloretin promotes adipocyte differentiation in vitro and improves glucose homeostasis in vivo.

    PubMed

    Shu, Gang; Lu, Nai-Sheng; Zhu, Xiao-Tong; Xu, Yong; Du, Min-Qing; Xie, Qiu-Ping; Zhu, Can-Jun; Xu, Qi; Wang, Song-Bo; Wang, Li-Na; Gao, Ping; Xi, Qian-Yun; Zhang, Yong-Liang; Jiang, Qing-Yan

    2014-12-01

    Adipocyte dysfunction is associated with many metabolic diseases such as obesity, insulin resistance and diabetes. Previous studies found that phloretin promotes 3T3-L1 cells differentiation, but the underlying mechanisms for phloretin's effects on adipogenesis remain unclear. In this study, we demonstrated that phloretin enhanced the lipid accumulation in porcine primary adipocytes in a time-dependent manner. Furthermore, phloretin increased the utilization of glucose and nonesterified fatty acid, while it decreased the lactate output. Microarray analysis revealed that genes associated with peroxisome proliferator-activated receptor-γ (PPARγ), mitogen-activated protein kinase and insulin signaling pathways were altered in response to phloretin. We further confirmed that phloretin enhanced expression of PPARγ, CAAT enhancer binding protein-α (C/EBPα) and adipose-related genes, such as fatty acids translocase and fatty acid synthase. In addition, phloretin activated the Akt (Thr308) and extracellular signal-regulated kinase, and therefore, inactivated Akt targets protein. Wortmannin effectively blocked the effect of phloretin on Akt activity and the protein levels of PPARγ, C/EBPα and fatty acid binding protein-4 (FABP4/aP2). Oral administration of 5 or 10 mg/kg phloretin to C57BL BKS-DB mice significantly decreased the serum glucose level and improved glucose tolerance. In conclusion, phloretin promotes the adipogenesis of porcine primary preadipocytes through Akt-associated signaling pathway. These findings suggested that phloretin might be able to increase insulin sensitivity and alleviate the metabolic diseases. Copyright © 2014. Published by Elsevier Inc.

  15. Effect of high-dose pitavastatin on glucose homeostasis in patients at elevated risk of new-onset diabetes: insights from the CAPITAIN and PREVAIL-US studies.

    PubMed

    Chapman, M J; Orsoni, A; Robillard, P; Hounslow, N; Sponseller, C A; Giral, P

    2014-05-01

    Statin treatment may impair glucose homeostasis and increase the risk of new-onset diabetes mellitus, although this may depend on the statin, dose and patient population. We evaluated the effects of pitavastatin 4 mg/day on glucose homeostasis in patients with metabolic syndrome in the CAPITAIN trial. Findings were validated in a subset of patients enrolled in PREVAIL-US. Participants with a well defined metabolic syndrome phenotype were recruited to CAPITAIN to reduce the influence of confounding factors. Validation and comparison datasets were selected comprising phenotypically similar subsets of individuals enrolled in PREVAIL-US and treated with pitavastatin or pravastatin, respectively. Mean change from baseline in parameters of glucose homeostasis (fasting plasma glucose [FPG], glycated hemoglobin [HbA1c], insulin, quantitative insulin-sensitivity check index [QUICKI] and homeostasis model of assessment-insulin resistance [HOMA-IR]) and plasma lipid profile were assessed at 6 months (CAPITAIN) and 3 months (PREVAIL-US) after initiating treatment. In CAPITAIN (n = 12), no significant differences from baseline in HbA1c, insulin, HOMA-IR and QUICKI were observed at day 180 in patients treated with pitavastatin. A small (4%) increase in FPG from baseline to day 180 (P < 0.05), was observed. In the validation dataset (n = 9), no significant differences from baseline in glycemic parameters were observed at day 84 (all comparisons P > 0.05). Similar results were observed for pravastatin in the comparison dataset (n = 14). Other than a small change in FPG in the CAPITAIN study, neutral effects of pitavastatin on glucose homeostasis were observed in two cohorts of patients with metabolic syndrome, independent of its efficacy in reducing levels of atherogenic lipoproteins. The small number of patients and relatively short follow-up period represent limitations of the study. Nevertheless, these data suggest that statin-induced diabetogenesis may

  16. Osteopontin-a Alters Glucose Homeostasis in Anchorage-Independent Breast Cancer Cells*

    PubMed Central

    Wang, Bo; Kennedy, Michael A.; Weber, Georg F.

    2013-01-01

    Invasive breast tumor cells generate three splice variants of the metastasis gene osteopontin, while non-invasive breast cells express only the unspliced form or no osteopontin at all. One role for osteopontin in tumor progression is the support of anchorage-independence. Here we show that the full-length gene product, osteopontin-a, induces a gene expression profile that is associated with tissue remodeling and directed movement/sprouting. This occurs via signals through STAT1 and STAT3 to snglycero-3-phosphocholine. Osteopontin-a upregulates the levels of glucose in breast cancer cells, likely through STAT3 and its transcriptional targets apolipoprotein D and IGFBP5. The splice variants osteopontin-a and osteopontin-c may synergize, with each form activating signal transduction pathways that are distinct from the other. The elevated glucose is used by osteopontin-c dependent signals to generate chemical energy (Shi et al. manuscript submitted). The splice variant-specific metabolic effects of osteopontin add a novel aspect to the pro-metastatic functions of this molecule. PMID:24157812

  17. Diglycosyl diselenides alter redox homeostasis and glucose consumption of infective African trypanosomes.

    PubMed

    Franco, Jaime; Sardi, Florencia; Szilágyi, László; Kövér, Katalin E; Fehér, Krisztina; Comini, Marcelo A

    2017-12-01

    With the aim to develop compounds able to target multiple metabolic pathways and, thus, to lower the chances of drug resistance, we investigated the anti-trypanosomal activity and selectivity of a series of symmetric diglycosyl diselenides and disulfides. Of 18 compounds tested the fully acetylated forms of di-β-D-glucopyranosyl and di-β-D-galactopyranosyl diselenides (13 and 15, respectively) displayed strong growth inhibition against the bloodstream stage of African trypanosomes (EC 50 0.54 μM for 13 and 1.49 μM for 15) although with rather low selectivity (SI < 10 assayed with murine macrophages). Nonacetylated versions of the same sugar diselenides proved to be, however, much less efficient or completely inactive to suppress trypanosome growth. Significantly, the galactosyl (15), and to a minor extent the glucosyl (13), derivative inhibited glucose catabolism but not its uptake. Both compounds induced redox unbalance in the pathogen. In vitro NMR analysis indicated that diglycosyl diselenides react with glutathione, under physiological conditions, via formation of selenenylsulfide bonds. Our results suggest that non-specific cellular targets as well as actors of the glucose and the redox metabolism of the parasite may be affected. These molecules are therefore promising leads for the development of novel multitarget antitrypanosomal agents. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Exercise-induced BCL2-regulated autophagy is required for muscle glucose homeostasis.

    PubMed

    He, Congcong; Bassik, Michael C; Moresi, Viviana; Sun, Kai; Wei, Yongjie; Zou, Zhongju; An, Zhenyi; Loh, Joy; Fisher, Jill; Sun, Qihua; Korsmeyer, Stanley; Packer, Milton; May, Herman I; Hill, Joseph A; Virgin, Herbert W; Gilpin, Christopher; Xiao, Guanghua; Bassel-Duby, Rhonda; Scherer, Philipp E; Levine, Beth

    2012-01-18

    Exercise has beneficial effects on human health, including protection against metabolic disorders such as diabetes. However, the cellular mechanisms underlying these effects are incompletely understood. The lysosomal degradation pathway, autophagy, is an intracellular recycling system that functions during basal conditions in organelle and protein quality control. During stress, increased levels of autophagy permit cells to adapt to changing nutritional and energy demands through protein catabolism. Moreover, in animal models, autophagy protects against diseases such as cancer, neurodegenerative disorders, infections, inflammatory diseases, ageing and insulin resistance. Here we show that acute exercise induces autophagy in skeletal and cardiac muscle of fed mice. To investigate the role of exercise-mediated autophagy in vivo, we generated mutant mice that show normal levels of basal autophagy but are deficient in stimulus (exercise- or starvation)-induced autophagy. These mice (termed BCL2 AAA mice) contain knock-in mutations in BCL2 phosphorylation sites (Thr69Ala, Ser70Ala and Ser84Ala) that prevent stimulus-induced disruption of the BCL2-beclin-1 complex and autophagy activation. BCL2 AAA mice show decreased endurance and altered glucose metabolism during acute exercise, as well as impaired chronic exercise-mediated protection against high-fat-diet-induced glucose intolerance. Thus, exercise induces autophagy, BCL2 is a crucial regulator of exercise- (and starvation)-induced autophagy in vivo, and autophagy induction may contribute to the beneficial metabolic effects of exercise.

  19. Impaired glucose homeostasis in transgenic mice expressing the human transient neonatal diabetes mellitus locus, TNDM

    PubMed Central

    Ma, Dan; Shield, Julian P.H.; Dean, Wendy; Leclerc, Isabelle; Knauf, Claude; Burcelin, Rémy; Rutter, Guy A.; Kelsey, Gavin

    2004-01-01

    Transient neonatal diabetes mellitus (TNDM) is a rare inherited diabetic syndrome apparent in the first weeks of life and again during early adulthood. The relative contributions of reduced islet β cell number and impaired β cell function to the observed hypoinsulinemia are unclear. The inheritance pattern of this imprinted disorder implicates overexpression of one or both genes within the TNDM locus: ZAC, which encodes a proapoptotic zinc finger protein, and HYMAI, which encodes an untranslated mRNA. To investigate the consequences for pancreatic function, we have developed a high-copy transgenic mouse line, TNDM29, carrying the human TNDM locus. TNDM29 neonates display hyperglycemia, and older adults, impaired glucose tolerance. Neonatal hyperglycemia occurs only on paternal transmission, analogous to paternal dependence of TNDM in humans. Embryonic pancreata of TNDM29 mice showed reductions in expression of endocrine differentiation factors and numbers of insulin-staining structures. By contrast, β cell mass was normal or elevated at all postnatal stages, whereas pancreatic insulin content in neonates and peak serum insulin levels after glucose infusion in adults were reduced. Expression of human ZAC and HYMAI in these transgenic mice thus recapitulates key features of TNDM and implicates impaired development of the endocrine pancreas and β cell function in disease pathogenesis. PMID:15286800

  20. Can HbA1c be Used to Screen for Glucose Abnormalities Among Adults with Severe Mental Illness?

    PubMed

    Romain, A J; Letendre, E; Akrass, Z; Avignon, A; Karelis, A D; Sultan, A; Abdel-Baki, A

    2017-04-01

    Aim: Prediabetes and type 2 diabetes are highly prevalent among individuals with serious mental illness and increased by antipsychotic medication. Although widely recommended, many obstacles prevent these patients from obtaining a proper screening for dysglycemia. Currently, glycated hemoglobin (HbA1c), fasting glucose, and 2-hour glucose levels from the oral glucose tolerance test are used for screening prediabetes and type 2 diabetes. The objective of this study was to investigate if HbA1c could be used as the only screening test among individuals with serious mental illness. Methods: Cross sectional study comparing the sensitivity of HbA1c, fasting glucose, and 2-h oral glucose tolerance test to detect dysglycemias in serious mental illness participants referred for metabolic complications. Results: A total of 84 participants (43 female; aged: 38.5±12.8 years; BMI: 35.0±6.8 kg/m²) was included. Regarding prediabetes, 44, 44 and 76% were identified by HbA1c, fasting glucose, and 2 h- oral glucose tolerance test respectively and for type 2 diabetes, 60, 53 and 66% were identified by HbA1c, fasting glucose and 2 h-oral glucose tolerance test. The overlap between the 3 markers was low (8% of participants for prediabetes and 26% for Type 2 diabetes). Sensitivity of HbA1c were moderate (range 40-62.5%), while its specificity was excellent (92-93%). Conclusion: The present study indicates a low agreement between HbA1c, fasting glucose and 2-h oral glucose tolerance test. It appears that these markers do not identify the same participants. Thus, HbA1c may not be used alone to detect all glucose abnormalities among individuals with serious mental illness. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Association between lung capacity and abnormal glucose metabolism: findings from China and Australia.

    PubMed

    Yu, Dahai; Chen, Tao; Qin, Rui; Cai, Yamei; Jiang, Zhixin; Zhao, Zhanzheng; Simmons, David

    2016-07-01

    Restricted pulmonary function is found among people with diabetes. This study aimed to investigate the dose-response relationship between pulmonary function measurements [forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)] and risk of metabolic syndrome (MS)/type 2 diabetes. A total of 1454 adults in rural Victoria, Australia, and 5824 adults in Nanjing, China, from randomly selected households provided clinical history, oral glucose tolerance test, lipids, anthropometric, blood pressure and spirometric measurements. MS was defined by International Diabetes Federation criteria. Adjusted odds ratios for MS and type 2 diabetes with lung capacity measurements were estimated using logistic regression. Dose-response relationships were explored using the restricted cubic spline models. There was a nonlinear relationship between FEV1 and the risk of type 2 diabetes and MS (both P < 0·0001) in both the Australian and Chinese populations. The FEV1 associated with the lowest risk of type 2 diabetes and MS was above 2·70 l (95%CI: 2·68 to 2·72 l and 2·65 to 2·76 l in Chinese and Australian populations, respectively). The discrimination of the model could be significantly improved using the FEV1 threshold in both the Australian and Chinese populations. In both the Australian and Chinese populations, the risk of type 2 diabetes and MS is lowest with a FEV1 of 2·65-2·76 l. This might be used in clinical practice in different countries as a prompt to screen for type 2 diabetes and MS in patients with obstructive lung disease and to ensure there was no abnormal glucose metabolism before the commencement of steroids if indicated. © 2015 John Wiley & Sons Ltd.

  2. A composite computational model of liver glucose homeostasis. I. Building the composite model.

    PubMed

    Hetherington, J; Sumner, T; Seymour, R M; Li, L; Rey, M Varela; Yamaji, S; Saffrey, P; Margoninski, O; Bogle, I D L; Finkelstein, A; Warner, A

    2012-04-07

    A computational model of the glucagon/insulin-driven liver glucohomeostasis function, focusing on the buffering of glucose into glycogen, has been developed. The model exemplifies an 'engineering' approach to modelling in systems biology, and was produced by linking together seven component models of separate aspects of the physiology. The component models use a variety of modelling paradigms and degrees of simplification. Model parameters were determined by an iterative hybrid of fitting to high-scale physiological data, and determination from small-scale in vitro experiments or molecular biological techniques. The component models were not originally designed for inclusion within such a composite model, but were integrated, with modification, using our published modelling software and computational frameworks. This approach facilitates the development of large and complex composite models, although, inevitably, some compromises must be made when composing the individual models. Composite models of this form have not previously been demonstrated.

  3. Expression of peroxisome proliferator-activated receptor-gamma in key neuronal subsets regulating glucose metabolism and energy homeostasis.

    PubMed

    Sarruf, David A; Yu, Fang; Nguyen, Hong T; Williams, Diana L; Printz, Richard L; Niswender, Kevin D; Schwartz, Michael W

    2009-02-01

    In addition to increasing insulin sensitivity and adipogenesis, peroxisome proliferator-activated receptor (PPAR)-gamma agonists cause weight gain and hyperphagia. Given the central role of the brain in the control of energy homeostasis, we sought to determine whether PPARgamma is expressed in key brain areas involved in metabolic regulation. Using immunohistochemistry, PPARgamma distribution and its colocalization with neuron-specific protein markers were investigated in rat and mouse brain sections spanning the hypothalamus, the ventral tegmental area, and the nucleus tractus solitarius. In several brain areas, nuclear PPARgamma immunoreactivity was detected in cells that costained for neuronal nuclei, a neuronal marker. In the hypothalamus, PPARgamma immunoreactivity was observed in a majority of neurons in the arcuate (including both agouti related protein and alpha-MSH containing cells) and ventromedial hypothalamic nuclei and was also present in the hypothalamic paraventricular nucleus, the lateral hypothalamic area, and tyrosine hydroxylase-containing neurons in the ventral tegmental area but was not expressed in the nucleus tractus solitarius. To validate and extend these histochemical findings, we generated mice with neuron-specific PPARgamma deletion using nestin cre-LoxP technology. Compared with littermate controls, neuron-specific PPARgamma knockout mice exhibited dramatic reductions of both hypothalamic PPARgamma mRNA levels and PPARgamma immunoreactivity but showed no differences in food intake or body weight over a 4-wk study period. We conclude that: 1) PPARgamma mRNA and protein are expressed in the hypothalamus, 2) neurons are the predominant source of PPARgamma in the central nervous system, although it is likely expressed by nonneuronal cell types as well, and 3) arcuate nucleus neurons that control energy homeostasis and glucose metabolism are among those in which PPARgamma is expressed.

  4. A critical role for beta cell M3 muscarinic acetylcholine receptors in regulating insulin release and blood glucose homeostasis in vivo.

    PubMed

    Gautam, Dinesh; Han, Sung-Jun; Hamdan, Fadi F; Jeon, Jongrye; Li, Bo; Li, Jian Hua; Cui, Yinghong; Mears, David; Lu, Huiyan; Deng, Chuxia; Heard, Thomas; Wess, Jürgen

    2006-06-01

    One of the hallmarks of type 2 diabetes is that pancreatic beta cells fail to release sufficient amounts of insulin in the presence of elevated blood glucose levels. Insulin secretion is modulated by many hormones and neurotransmitters including acetylcholine, the major neurotransmitter of the peripheral parasympathetic nervous system. The physiological role of muscarinic acetylcholine receptors expressed by pancreatic beta cells remains unclear at present. Here, we demonstrate that mutant mice selectively lacking the M3 muscarinic acetylcholine receptor subtype in pancreatic beta cells display impaired glucose tolerance and greatly reduced insulin release. In contrast, transgenic mice selectively overexpressing M3 receptors in pancreatic beta cells show a profound increase in glucose tolerance and insulin release. Moreover, these mutant mice are resistant to diet-induced glucose intolerance and hyperglycemia. These findings indicate that beta cell M3 muscarinic receptors play a key role in maintaining proper insulin release and glucose homeostasis.

  5. Rauwolfia serpentina improves altered glucose and lipid homeostasis in fructose-induced type 2 diabetic mice.

    PubMed

    Azmi, Muhammad Bilal; Qureshi, Shamim A

    2016-09-01

    Rauwolfia serpentina is well-reported in traditional medicines for the treatment of hypertensive and neurological disorders. However, its antidiabetic potential has been currently described in both alloxan-treated and normoglycemic mice. Present effort was carried out to investigate the effect of methanol root extract (MREt) of R.serpentina in fructose-induced type 2 diabetic mice. Experimental mice were grouped into normal control (distilled water 1ml/kg) and fructose-induced type 2 diabetic groups (10% fructose 1 ml/kg).The second group sub-divided into negative (0.05% DMSO 1ml/kg) control, positive (pioglitazone 15mg/kg) control and three test groups (MREt 10, 30 & 60 mg/kg). Each treatment was given orally for 14 days consecutively then mice were sacrificed in order to collect serum and liver samples to analyze physical, biochemical as well as hematological markers. MREt significantly improved percent body weight and glycemic change along with serum insulin, total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-c), very low-density lipoprotein (VLDL-c), high-density lipoprotein-cholesterols (HDL-c), total hemoglobin, glycosylated hemoglobin, hepatic glycogen, coronary risk and fasting insulin resistance indices while suppressed down the activity of 3-hydroxy-3-methylglutaryl Coenzyme A reductase enzyme in test groups when compared with diabetic controls. The present findings conclude that MREt of R. serpentina can effectively betters the carbohydrate and lipid homeostasis by either inhibiting fructose absorption in intestine or decreasing insulin resistance in fructose-induced type 2 diabetic mice.

  6. Early Pregnancy Cravings, Dietary Intake, and Development of Abnormal Glucose Tolerance.

    PubMed

    Farland, Leslie V; Rifas-Shiman, Sheryl L; Gillman, Matthew W

    2015-12-01

    Little is known about the relationships between pregnancy cravings, maternal diet, and development of abnormal glucose tolerance. We examined relationships of pregnancy cravings with dietary intake and risk of developing isolated hyperglycemia (IH), impaired glucose tolerance (IGT), or gestational diabetes (GDM) later in pregnancy. Among 2,022 mothers in Project Viva, a prospective birth cohort recruited from medical practices in eastern Massachusetts between 1999 and 2002, we assessed type of pregnancy craving based on self-report at mean gestation of 10.9 weeks. The outcomes were cross-sectional dietary intake from a food frequency questionnaire and incident IH, IGT, or GDM determined by glucose tolerance screening at 26 to 28 weeks. We used linear regression to analyze the cross-sectional relationships between pregnancy cravings and dietary intake and multinomial logistic regression to analyze the prospective relationships among pregnancy cravings and development of IH, IGT, or GDM. During the first trimester, 443 (22%) women craved sweets, 225 (11%) craved salty foods, 261 (13%) craved savory foods, and 100 (4.9%) craved starchy foods. Sweet cravings were associated with increased intake of sucrose (1.9 g/day; 95% CI 0.1 to 3.7), total fat (1.5 g/day; 95% CI 0.1 to 2.9), and saturated fat (0.8 g/day; 95% CI 0.2 to 1.4); salty cravings were associated with increased fiber (0.7 servings/day; 95% CI -0.1 to 1.6); savory cravings were associated with increased n-3 fatty acids (0.10 g/day; 95% CI 0.02 to 0.17); and starchy cravings were associated with increased carbohydrates (8.0 g/day; 95% CI 0.3 to 15.7) and decreased total fat (-2.6 g/day; 95% CI -5.2 to -0.1). Salty cravings were associated with lower risk of GDM (adjusted odds ratio 0.34, 95% CI 0.12-0.97). New cravings in the first trimester of pregnancy were associated with dietary intake. Craving salty foods may predict reduced risk of developing GDM, whereas craving sweet food does not appear to alter one

  7. Mitochondrial Sirtuin 4 Resolves Immune Tolerance in Monocytes by Rebalancing Glycolysis and Glucose Oxidation Homeostasis

    PubMed Central

    Tao, Jie; Zhang, Jingpu; Ling, Yun; McCall, Charles E.; Liu, Tie Fu

    2018-01-01

    The goal of this investigation was to define the molecular mechanism underlying physiologic conversion of immune tolerance to resolution of the acute inflammatory response, which is unknown. An example of this knowledge gap and its clinical importance is the broad-based energy deficit and immunometabolic paralysis in blood monocytes from non-survivors of human and mouse sepsis that precludes sepsis resolution. This immunometabolic dysregulation is biomarked by ex vivo endotoxin tolerance to increased glycolysis and TNF-α expression. To investigate how tolerance switches to resolution, we adapted our previously documented models associated with acute inflammatory, immune, and metabolic reprogramming that induces endotoxin tolerance as a model of sepsis in human monocytes. We report here that mitochondrial sirtuin 4 (SIRT4) physiologically breaks tolerance and resolves acute inflammation in human monocytes by coordinately reprogramming of metabolism and bioenergetics. We find that increased SIRT4 mRNA and protein expression during immune tolerance counters the increase in pyruvate dehydrogenase kinase 1 (PDK1) and SIRT1 that promote tolerance by switching glucose-dependent support of immune resistance to fatty acid oxidation support of immune tolerance. By decreasing PDK1, pyruvate dehydrogenase complex reactivation rebalances mitochondrial respiration, and by decreasing SIRT1, SIRT4 represses fatty acid oxidation. The precise mechanism for the mitochondrial SIRT4 nuclear feedback is unclear. Our findings are consistent with a new concept in which mitochondrial SIRT4 directs the axis that controls anabolic and catabolic energy sources. PMID:29593712

  8. Neuronal Rap1 Regulates Energy Balance, Glucose Homeostasis, and Leptin Actions.

    PubMed

    Kaneko, Kentaro; Xu, Pingwen; Cordonier, Elizabeth L; Chen, Siyu S; Ng, Amy; Xu, Yong; Morozov, Alexei; Fukuda, Makoto

    2016-09-13

    The CNS contributes to obesity and metabolic disease; however, the underlying neurobiological pathways remain to be fully established. Here, we show that the small GTPase Rap1 is expressed in multiple hypothalamic nuclei that control whole-body metabolism and is activated in high-fat diet (HFD)-induced obesity. Genetic ablation of CNS Rap1 protects mice from dietary obesity, glucose imbalance, and insulin resistance in the periphery and from HFD-induced neuropathological changes in the hypothalamus, including diminished cellular leptin sensitivity and increased endoplasmic reticulum (ER) stress and inflammation. Furthermore, pharmacological inhibition of CNS Rap1 signaling normalizes hypothalamic ER stress and inflammation, improves cellular leptin sensitivity, and reduces body weight in mice with dietary obesity. We also demonstrate that Rap1 mediates leptin resistance via interplay with ER stress. Thus, neuronal Rap1 critically regulates leptin sensitivity and mediates HFD-induced obesity and hypothalamic pathology and may represent a potential therapeutic target for obesity treatment. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Class IIa histone deacetylases are hormone-activated regulators of FOXO and mammalian glucose homeostasis.

    PubMed

    Mihaylova, Maria M; Vasquez, Debbie S; Ravnskjaer, Kim; Denechaud, Pierre-Damien; Yu, Ruth T; Alvarez, Jacqueline G; Downes, Michael; Evans, Ronald M; Montminy, Marc; Shaw, Reuben J

    2011-05-13

    Class IIa histone deacetylases (HDACs) are signal-dependent modulators of transcription with established roles in muscle differentiation and neuronal survival. We show here that in liver, class IIa HDACs (HDAC4, 5, and 7) are phosphorylated and excluded from the nucleus by AMPK family kinases. In response to the fasting hormone glucagon, class IIa HDACs are rapidly dephosphorylated and translocated to the nucleus where they associate with the promoters of gluconeogenic enzymes such as G6Pase. In turn, HDAC4/5 recruit HDAC3, which results in the acute transcriptional induction of these genes via deacetylation and activation of FOXO family transcription factors. Loss of class IIa HDACs in murine liver results in inhibition of FOXO target genes and lowers blood glucose, resulting in increased glycogen storage. Finally, suppression of class IIa HDACs in mouse models of type 2 diabetes ameliorates hyperglycemia, suggesting that inhibitors of class I/II HDACs may be potential therapeutics for metabolic syndrome. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Xbp1s in Pomc neurons connects ER stress with energy balance and glucose homeostasis.

    PubMed

    Williams, Kevin W; Liu, Tiemin; Kong, Xingxing; Fukuda, Makoto; Deng, Yingfeng; Berglund, Eric D; Deng, Zhuo; Gao, Yong; Liu, Tianya; Sohn, Jong-Woo; Jia, Lin; Fujikawa, Teppei; Kohno, Daisuke; Scott, Michael M; Lee, Syann; Lee, Charlotte E; Sun, Kai; Chang, Yongsheng; Scherer, Philipp E; Elmquist, Joel K

    2014-09-02

    The molecular mechanisms underlying neuronal leptin and insulin resistance in obesity and diabetes remain unclear. Here we show that induction of the unfolded protein response transcription factor spliced X-box binding protein 1 (Xbp1s) in pro-opiomelanocortin (Pomc) neurons alone is sufficient to protect against diet-induced obesity as well as improve leptin and insulin sensitivity, even in the presence of strong activators of ER stress. We also demonstrate that constitutive expression of Xbp1s in Pomc neurons contributes to improved hepatic insulin sensitivity and suppression of endogenous glucose production. Notably, elevated Xbp1s levels in Pomc neurons also resulted in activation of the Xbp1s axis in the liver via a cell-nonautonomous mechanism. Together our results identify critical molecular mechanisms linking ER stress in arcuate Pomc neurons to acute leptin and insulin resistance as well as liver metabolism in diet-induced obesity and diabetes. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Orally Administered Baker's Yeast β-Glucan Promotes Glucose and Lipid Homeostasis in the Livers of Obesity and Diabetes Model Mice.

    PubMed

    Cao, Yan; Sun, Ying; Zou, Siwei; Li, Mengxia; Xu, Xiaojuan

    2017-11-08

    Baker's yeast glucan (BYG) has been reported to be an anti-diabetic agent. In the work described herein, further study on the effect of orally administered BYG on glucose and lipid homeostasis in the livers of ob/ob mice was performed. It was found that BYG decreased the blood glucose and the hepatic glucose and lipid disorders. Western blotting analysis revealed that BYG up-regulated p-AKT and p-AMPK, and down-regulated p-Acc in the liver. Furthermore, RNA-Seq analysis indicated that BYG down-regulated genes responsible for gluconeogenesis (G6pase and Got1), fatty acid biosynthesis (Acly, Acc, Fas, etc.), glycerolipid synthesis (Gpam and Lipin1/2), and cholesterol synthesis (Hmgcr, Fdps, etc.). Additionally, BYG decreased glucose transporters SGLT1 and GLUT2, fat emulsification, and adipogenic genes/proteins in the intestine to decrease glucose and lipid absorption. All these findings demonstrated that BYG is beneficial for regulating glucose and lipid homeostasis in diabetic mice, and thus has potential applications in anti-diabetic foods or drugs.

  12. FGF21 maintains glucose homeostasis by mediating the cross talk between liver and brain during prolonged fasting.

    PubMed

    Liang, Qingning; Zhong, Ling; Zhang, Jialiang; Wang, Yu; Bornstein, Stefan R; Triggle, Chris R; Ding, Hong; Lam, Karen S L; Xu, Aimin

    2014-12-01

    Hepatic gluconeogenesis is a main source of blood glucose during prolonged fasting and is orchestrated by endocrine and neural pathways. Here we show that the hepatocyte-secreted hormone fibroblast growth factor 21 (FGF21) induces fasting gluconeogenesis via the brain-liver axis. Prolonged fasting induces activation of the transcription factor peroxisome proliferator-activated receptor α (PPARα) in the liver and subsequent hepatic production of FGF21, which enters into the brain to activate the hypothalamic-pituitary-adrenal (HPA) axis for release of corticosterone, thereby stimulating hepatic gluconeogenesis. Fasted FGF21 knockout (KO) mice exhibit severe hypoglycemia and defective hepatic gluconeogenesis due to impaired activation of the HPA axis and blunted release of corticosterone, a phenotype similar to that observed in PPARα KO mice. By contrast, intracerebroventricular injection of FGF21 reverses fasting hypoglycemia and impairment in hepatic gluconeogenesis by restoring corticosterone production in both FGF21 KO and PPARα KO mice, whereas all these central effects of FGF21 were abrogated by blockage of hypothalamic FGF receptor-1. FGF21 acts directly on the hypothalamic neurons to activate the mitogen-activated protein kinase extracellular signal-related kinase 1/2 (ERK1/2), thereby stimulating the expression of corticotropin-releasing hormone by activation of the transcription factor cAMP response element binding protein. Therefore, FGF21 maintains glucose homeostasis during prolonged fasting by fine tuning the interorgan cross talk between liver and brain. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  13. Cardiac-Specific Disruption of GH Receptor Alters Glucose Homeostasis While Maintaining Normal Cardiac Performance in Adult Male Mice.

    PubMed

    Jara, Adam; Liu, Xingbo; Sim, Don; Benner, Chance M; Duran-Ortiz, Silvana; Qian, Yanrong; List, Edward O; Berryman, Darlene E; Kim, Jason K; Kopchick, John J

    2016-05-01

    GH is considered necessary for the proper development and maintenance of several tissues, including the heart. Studies conducted in both GH receptor null and bovine GH transgenic mice have demonstrated specific cardiac structural and functional changes. In each of these mouse lines, however, GH-induced signaling is altered systemically, being decreased in GH receptor null mice and increased in bovine GH transgenic mice. Therefore, to clarify the direct effects GH has on cardiac tissue, we developed a tamoxifen-inducible, cardiac-specific GHR disrupted (iC-GHRKO) mouse line. Cardiac GH receptor was disrupted in 4-month-old iC-GHRKO mice to avoid developmental effects due to perinatal GHR gene disruption. Surprisingly, iC-GHRKO mice showed no difference vs controls in baseline or postdobutamine stress test echocardiography measurements, nor did iC-GHRKO mice show differences in longitudinal systolic blood pressure measurements. Interestingly, iC-GHRKO mice had decreased fat mass and improved insulin sensitivity at 6.5 months of age. By 12.5 months of age, however, iC-GHRKO mice no longer had significant decreases in fat mass and had developed glucose intolerance and insulin resistance. Furthermore, investigation via immunoblot analysis demonstrated that iC-GHRKO mice had appreciably decreased insulin stimulated Akt phosphorylation, specifically in heart and liver, but not in epididymal white adipose tissue. These changes were accompanied by a decrease in circulating IGF-1 levels in 12.5-month-old iC-GHRKO mice. These data indicate that whereas the disruption of cardiomyocyte GH-induced signaling in adult mice does not affect cardiac function, it does play a role in systemic glucose homeostasis, in part through modulation of circulating IGF-1.

  14. Effect of one time high dose "stoss therapy" of vitamin D on glucose homeostasis in high risk obese adolescents.

    PubMed

    Brar, Preneet Cheema; Contreras, Maria; Fan, Xiaozhou; Visavachaipan, Nipapat

    2018-04-05

    To study the effect of using a one time high dose "stoss therapy" of vitamin D2 (ergocalciferol: VD2) on indices of insulin sensitivity {whole body sensitivity index: WBISI} and secretion {insulinogenic index: IGI} measured during an oral glucose tolerance test (OGTT) in obese adolescents with VDD (25 OHD; serum metabolite of vit D: < 30 ng/dL). In a randomized placebo controlled cross over design 20 obese adolescents with vitamin D deficiency (VDD) had baseline OGTT. Arm A received one time high dose 300,000 IU of ergocalciferol and Arm B received placebo. After 6 weeks the adolescents were reassigned to Arm A if they were in Arm B and vice versa. 25OHD, calcium, parathyroid hormone, comprehensive metabolic panel, urine calcium creatinine ratio were measured at each study visit. OGTTs to assess indices of sensitivity and secretion were done at baseline, 6 weeks and 12 weeks respectively. Adolescents were obese and insulin resistant (mean ± SD: mean age = 15.1 ± 1.9 years; BMI: 32.7 ± 9.8; homeostatic model of insulin resistance: HOMA-IR: 4.2 ± 2.8). Stoss therapy with VD2 increased 25OHD from baseline (16.7 ± 2.9 to 19.5 ± 4.5; p = 0.0029) when compared to the placebo. WBISI (2.8 ± 1.9) showed a trend towards improvement in Rx group (p = 0.0577) after adjustment for covariates. IGI (3 ± 2.2) showed an improvement in both Rx and placebo groups. Our study demonstrated that using a high dose of VD2 (300,000 IU) did not have any beneficial effect on insulin sensitivity (whole body sensitivity index {WBISI}) and secretory indices (insulinogenic index {IGI}) in obese adolescents. High dose "stoss therapy" of VD2 did not appear to have any beneficial effect on glucose homeostasis on obese adolescents.

  15. Resequencing of IRS2 reveals rare variants for obesity but not fasting glucose homeostasis in Hispanic children.

    PubMed

    Butte, Nancy F; Voruganti, V Saroja; Cole, Shelley A; Haack, Karin; Comuzzie, Anthony G; Muzny, Donna M; Wheeler, David A; Chang, Kyle; Hawes, Alicia; Gibbs, Richard A

    2011-09-22

    Our objective was to resequence insulin receptor substrate 2 (IRS2) to identify variants associated with obesity- and diabetes-related traits in Hispanic children. Exonic and intronic segments, 5' and 3' flanking regions of IRS2 (∼14.5 kb), were bidirectionally sequenced for single nucleotide polymorphism (SNP) discovery in 934 Hispanic children using 3730XL DNA Sequencers. Additionally, 15 SNPs derived from Illumina HumanOmni1-Quad BeadChips were analyzed. Measured genotype analysis tested associations between SNPs and obesity and diabetes-related traits. Bayesian quantitative trait nucleotide analysis was used to statistically infer the most likely functional polymorphisms. A total of 140 SNPs were identified with minor allele frequencies (MAF) ranging from 0.001 to 0.47. Forty-two of the 70 coding SNPs result in nonsynonymous amino acid substitutions relative to the consensus sequence; 28 SNPs were detected in the promoter, 12 in introns, 28 in the 3'-UTR, and 2 in the 5'-UTR. Two insertion/deletions (indels) were detected. Ten independent rare SNPs (MAF = 0.001-0.009) were associated with obesity-related traits (P = 0.01-0.00002). SNP 10510452_139 in the promoter region was shown to have a high posterior probability (P = 0.77-0.86) of influencing BMI, fat mass, and waist circumference in Hispanic children. SNP 10510452_139 contributed between 2 and 4% of the population variance in body weight and composition. None of the SNPs or indels were associated with diabetes-related traits or accounted for a previously identified quantitative trait locus on chromosome 13 for fasting serum glucose. Rare but not common IRS2 variants may play a role in the regulation of body weight but not an essential role in fasting glucose homeostasis in Hispanic children.

  16. Resequencing of IRS2 reveals rare variants for obesity but not fasting glucose homeostasis in Hispanic children

    PubMed Central

    Voruganti, V. Saroja; Cole, Shelley A.; Haack, Karin; Comuzzie, Anthony G.; Muzny, Donna M.; Wheeler, David A.; Chang, Kyle; Hawes, Alicia; Gibbs, Richard A.

    2011-01-01

    Our objective was to resequence insulin receptor substrate 2 (IRS2) to identify variants associated with obesity- and diabetes-related traits in Hispanic children. Exonic and intronic segments, 5′ and 3′ flanking regions of IRS2 (∼14.5 kb), were bidirectionally sequenced for single nucleotide polymorphism (SNP) discovery in 934 Hispanic children using 3730XL DNA Sequencers. Additionally, 15 SNPs derived from Illumina HumanOmni1-Quad BeadChips were analyzed. Measured genotype analysis tested associations between SNPs and obesity and diabetes-related traits. Bayesian quantitative trait nucleotide analysis was used to statistically infer the most likely functional polymorphisms. A total of 140 SNPs were identified with minor allele frequencies (MAF) ranging from 0.001 to 0.47. Forty-two of the 70 coding SNPs result in nonsynonymous amino acid substitutions relative to the consensus sequence; 28 SNPs were detected in the promoter, 12 in introns, 28 in the 3′-UTR, and 2 in the 5′-UTR. Two insertion/deletions (indels) were detected. Ten independent rare SNPs (MAF = 0.001–0.009) were associated with obesity-related traits (P = 0.01–0.00002). SNP 10510452_139 in the promoter region was shown to have a high posterior probability (P = 0.77–0.86) of influencing BMI, fat mass, and waist circumference in Hispanic children. SNP 10510452_139 contributed between 2 and 4% of the population variance in body weight and composition. None of the SNPs or indels were associated with diabetes-related traits or accounted for a previously identified quantitative trait locus on chromosome 13 for fasting serum glucose. Rare but not common IRS2 variants may play a role in the regulation of body weight but not an essential role in fasting glucose homeostasis in Hispanic children. PMID:21771880

  17. Sex Differences in the Association of Urinary Bisphenol-A Concentration with Selected Indices of Glucose Homeostasis among U.S. adults

    PubMed Central

    Beydoun, Hind A.; Khanal, Suraj; Zonderman, Alan B.; Beydoun, May A.

    2013-01-01

    Purpose Emerging evidence suggests that exposure to endocrine disruptors may initiate or exacerbate adiposity and associated health problems. This study examined sex differences in the association of urinary level of bisphenol-A (BPA) with selected indices of glucose homeostasis among U.S. adults. Methods Data analyses were performed using a sample of 1,586 participants from the 2005–2008 National Health and Nutrition Examination Surveys. BPA level and the ratio of BPA-to-creatinine level were defined as log-transformed variables and in quartiles. Selected indices of glucose homeostasis were defined using fasting glucose and insulin data. Multivariate linear and logistic regression models for the hypothesized relationships were constructed after controlling for age, sex, race, education, marital status, smoking status, physical activity, total dietary intake and urinary creatinine concentration. Results Taking 1st quartile as a referent, 3rd quartile of BPA level was positively associated with log-transformed level of insulin and β-cell function (HOMA-β) as well as insulin resistance (log-transformed HOMA-IR; HOMA-IR≥2.5), with significant BPA-by-sex interaction; these associations were stronger among males than among females. Irrespective of sex, the ratio of BPA-to-creatinine level was not predictive of indices of glucose homeostasis. Conclusions A complex association may exist between BPA and hyperinsulinemia among adult U.S. men. Prospective cohort studies are needed to further elucidate endocrine disruptors as determinants of adiposity-related disturbances. PMID:23954568

  18. Gallic Acid Ameliorated Impaired Glucose and Lipid Homeostasis in High Fat Diet-Induced NAFLD Mice

    PubMed Central

    Chao, Jung; Huo, Teh-Ia; Cheng, Hao-Yuan; Tsai, Jen-Chieh; Liao, Jiunn-Wang; Lee, Meng-Shiou; Qin, Xue-Mei; Hsieh, Ming-Tsuen; Pao, Li-Heng; Peng, Wen-Huang

    2014-01-01

    Gallic acid (GA), a naturally abundant plant phenolic compound in vegetables and fruits, has been shown to have potent anti-oxidative and anti-obesity activity. However, the effects of GA on nonalcoholic fatty liver disease (NAFLD) are poorly understood. In this study, we investigated the beneficial effects of GA administration on nutritional hepatosteatosis model by a more “holistic view” approach, namely 1H NMR-based metabolomics, in order to prove efficacy and to obtain information that might lead to a better understanding of the mode of action of GA. Male C57BL/6 mice were placed for 16 weeks on either a normal chow diet, a high fat diet (HFD, 60%), or a high fat diet supplemented with GA (50 and 100 mg/kg/day, orally). Liver histopathology and serum biochemical examinations indicated that the daily administration of GA protects against hepatic steatosis, obesity, hypercholesterolemia, and insulin resistance among the HFD-induced NAFLD mice. In addition, partial least squares discriminant analysis scores plots demonstrated that the cluster of HFD fed mice is clearly separated from the normal group mice plots, indicating that the metabolic characteristics of these two groups are distinctively different. Specifically, the GA-treated mice are located closer to the normal group of mice, indicating that the HFD-induced disturbances to the metabolic profile were partially reversed by GA treatment. Our results show that the hepatoprotective effect of GA occurs in part through a reversing of the HFD caused disturbances to a range of metabolic pathways, including lipid metabolism, glucose metabolism (glycolysis and gluconeogenesis), amino acids metabolism, choline metabolism and gut-microbiota-associated metabolism. Taken together, this study suggested that a 1H NMR-based metabolomics approach is a useful platform for natural product functional evaluation. The selected metabolites are potentially useful as preventive action biomarkers and could also be used to help

  19. Irs2 and Irs4 synergize in non-LepRb neurons to control energy balance and glucose homeostasis.

    PubMed

    Sadagurski, Marianna; Dong, X Charlie; Myers, Martin G; White, Morris F

    2014-02-01

    Insulin receptor substrates (Irs1, 2, 3 and Irs4) mediate the actions of insulin/IGF1 signaling. They have similar structure, but distinctly regulate development, growth, and metabolic homeostasis. Irs2 contributes to central metabolic sensing, partially by acting in leptin receptor (LepRb)-expressing neurons. Although Irs4 is largely restricted to the hypothalamus, its contribution to metabolic regulation is unclear because Irs4-null mice barely distinguishable from controls. We postulated that Irs2 and Irs4 synergize and complement each other in the brain. To examine this possibility, we investigated the metabolism of whole body Irs4(-/y) mice that lacked Irs2 in the CNS (bIrs2(-/-)·Irs4(-/y)) or only in LepRb-neurons (Lepr (∆Irs2) ·Irs4 (-/y) ). bIrs2(-/-)·Irs4(-/y) mice developed severe obesity and decreased energy expenditure, along with hyperglycemia and insulin resistance. Unexpectedly, the body weight and fed blood glucose levels of Lepr (∆Irs2) ·Irs4 (-/y) mice were not different from Lepr (∆Irs2) mice, suggesting that the functions of Irs2 and Irs4 converge upon neurons that are distinct from those expressing LepRb.

  20. Interferon beta overexpression attenuates adipose tissue inflammation and high-fat diet-induced obesity and maintains glucose homeostasis.

    PubMed

    Alsaggar, M; Mills, M; Liu, D

    2017-01-01

    The worldwide prevalence of obesity is increasing, raising health concerns regarding obesity-related complications. Chronic inflammation has been characterized as a major contributor to the development of obesity and obesity-associated metabolic disorders. The purpose of the current study is to assess whether the overexpression of interferon beta (IFNβ1), an immune-modulating cytokine, will attenuate high-fat diet-induced adipose inflammation and protect animals against obesity development. Using hydrodynamic gene transfer to elevate and sustain blood concentration of IFNβ1 in mice fed a high-fat diet, we showed that the overexpression of Ifnβ1 gene markedly suppressed immune cell infiltration into adipose tissue, and attenuated production of pro-inflammatory cytokines. Systemically, IFNβ1 blocked adipose tissue expansion and body weight gain, independent of food intake. Possible browning of white adipose tissue might also contribute to blockade of weight gain. More importantly, IFNβ1 improved insulin sensitivity and glucose homeostasis. These results suggest that targeting inflammation represents a practical strategy to block the development of obesity and its related pathologies. In addition, IFNβ1-based therapies have promising potential for clinical applications for the prevention and treatment of various inflammation-driven pathologies.

  1. Abnormal Chloride Homeostasis in the Substancia Nigra Pars Reticulata Contributes to Locomotor Deficiency in a Model of Acute Liver Injury

    PubMed Central

    Wei, Yan-Yan; Chen, Jing; Dou, Ke-Feng; Wang, Ya-Yun

    2013-01-01

    Background Altered chloride homeostasis has been thought to be a risk factor for several brain disorders, while less attention has been paid to its role in liver disease. We aimed to analyze the involvement and possible mechanisms of altered chloride homeostasis of GABAergic neurons within the substantia nigra pars reticulata (SNr) in the motor deficit observed in a model of encephalopathy caused by acute liver failure, by using glutamic acid decarboxylase 67 - green fluorescent protein knock-in transgenic mice. Methods Alterations in intracellular chloride concentration in GABAergic neurons within the SNr and changes in the expression of two dominant chloride homeostasis-regulating genes, KCC2 and NKCC1, were evaluated in mice with hypolocomotion due to hepatic encephalopathy (HE). The effects of pharmacological blockade and/or activation of KCC2 and NKCC1 functions with their specific inhibitors and/or activators on the motor activity were assessed. Results In our mouse model of acute liver injury, chloride imaging indicated an increase in local intracellular chloride concentration in SNr GABAergic neurons. In addition, the mRNA and protein levels of KCC2 were reduced, particularly on neuronal cell membranes; in contrast, NKCC1 expression remained unaffected. Furthermore, blockage of KCC2 reduced motor activity in the normal mice and led to a further deteriorated hypolocomotion in HE mice. Blockade of NKCC1 was not able to normalize motor activity in mice with liver failure. Conclusion Our data suggest that altered chloride homeostasis is likely involved in the pathophysiology of hypolocomotion following HE. Drugs aimed at restoring normal chloride homeostasis would be a potential treatment for hepatic failure. PMID:23741482

  2. Fibroblast growth factor 21 is not required for glucose homeostasis, ketosis and tumour suppression associated to ketogenic diets in mice

    PubMed Central

    Stemmer, Kerstin; Zani, Fabio; Habegger, Kirk M.; Neff, Christina; Kotzbeck, Petra; Bauer, Michaela; Yalamanchilli, Suma; Azad, Ali; Lehti, Maarit; Martins, Paulo J.F.; Müller, Timo D.; Pfluger, Paul T.; Seeley, Randy J.

    2016-01-01

    AIMS/HYPOTHESIS Ketogenic diets (KDs) increasingly gained attention as effective means for weight loss and potential adjunctive treatment of cancer. Metabolic benefits of KDs are regularly ascribed towards enhanced hepatic secretion of fibroblast growth factor (FGF) 21, and its systemic effects on fatty acid oxidation, energy expenditure and body weight. Ambiguous data from Fgf21 knockout strains and low FGF21 concentrations reported for humans in ketosis have nevertheless cast doubt regarding the endogenous function of FGF21. We here aimed to elucidate the causal role of FGF21 in mediating therapeutic benefits of KDs on metabolism and cancer. METHODS We established a dietary model of increased vs. decreased FGF21 by feeding C57BL/6J mice with KDs, either depleted or enriched with protein, respectively. We furthermore used wild type and Fgf21 knockout mice that were subjected to the respective diets, and monitored energy and glucose homeostasis as well as tumor growth after transplantation of Lewis-Lung-Carcinoma cells. RESULTS Hepatic and circulating but not adipose tissue FGF21 levels were profoundly increased by protein starvation and independent of the state of ketosis. We demonstrate that endogenous FGF21 is not essential for the maintenance of normoglycemia upon protein and carbohydrate starvation and is dispensable for the effects of KDs on energy expenditure. Furthermore, the tumor-suppressing effects of KDs were independent from FGF21, and rather driven by concomitant protein and carbohydrate starvation. CONCLUSION/INTERPRETATION Our data indicate that multiple systemic effects of KDs exposure in mice that were previously ascribed towards increased FGF21 secretion are rather a consequence of protein malnutrition. PMID:26099854

  3. FGF21 is not required for glucose homeostasis, ketosis or tumour suppression associated with ketogenic diets in mice.

    PubMed

    Stemmer, Kerstin; Zani, Fabio; Habegger, Kirk M; Neff, Christina; Kotzbeck, Petra; Bauer, Michaela; Yalamanchilli, Suma; Azad, Ali; Lehti, Maarit; Martins, Paulo J F; Müller, Timo D; Pfluger, Paul T; Seeley, Randy J

    2015-10-01

    Ketogenic diets (KDs) have increasingly gained attention as effective means for weight loss and potential adjunctive treatment of cancer. The metabolic benefits of KDs are regularly ascribed to enhanced hepatic secretion of fibroblast growth factor 21 (FGF21) and its systemic effects on fatty-acid oxidation, energy expenditure (EE) and body weight. Ambiguous data from Fgf21-knockout animal strains and low FGF21 concentrations reported in humans with ketosis have nevertheless cast doubt regarding the endogenous function of FGF21. We here aimed to elucidate the causal role of FGF21 in mediating the therapeutic benefits of KDs on metabolism and cancer. We established a dietary model of increased vs decreased FGF21 by feeding C57BL/6J mice with KDs, either depleted of protein or enriched with protein. We furthermore used wild-type and Fgf21-knockout mice that were subjected to the respective diets, and monitored energy and glucose homeostasis as well as tumour growth after transplantation of Lewis lung carcinoma cells. Hepatic and circulating, but not adipose tissue, FGF21 levels were profoundly increased by protein starvation, independent of the state of ketosis. We demonstrate that endogenous FGF21 is not essential for the maintenance of normoglycaemia upon protein and carbohydrate starvation and is therefore not needed for the effects of KDs on EE. Furthermore, the tumour-suppressing effects of KDs were independent of FGF21 and, rather, driven by concomitant protein and carbohydrate starvation. Our data indicate that the multiple systemic effects of KD exposure in mice, previously ascribed to increased FGF21 secretion, are rather a consequence of protein malnutrition.

  4. Association of glucose homeostasis measures with heart rate variability among Hispanic/Latino adults without diabetes: the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

    PubMed

    Meyer, Michelle L; Gotman, Nathan M; Soliman, Elsayed Z; Whitsel, Eric A; Arens, Raanan; Cai, Jianwen; Daviglus, Martha L; Denes, Pablo; González, Hector M; Moreiras, Juan; Talavera, Gregory A; Heiss, Gerardo

    2016-03-16

    Reduced heart rate variability (HRV), a measure of cardiac autonomic function, is associated with an increased risk of cardiovascular disease (CVD) and mortality. Glucose homeostasis measures are associated with reduced cardiac autonomic function among those with diabetes, but inconsistent associations have been reported among those without diabetes. This study aimed to examine the association of glucose homeostasis measures with cardiac autonomic function among diverse Hispanic/Latino adults without diabetes. The Hispanic community Health Study/Study of Latinos (HCHS/SOL; 2008-2011) used two-stage area probability sampling of households to enroll 16,415 self-identified Hispanics/Latinos aged 18-74 years from four USA communities. Resting, standard 12-lead electrocardiogram recordings were used to estimate the following ultrashort-term measures of HRV: RR interval (RR), standard deviation of all normal to normal RR (SDNN) and root mean square of successive differences in RR intervals (RMSSD). Multivariable regression analysis was used to estimate associations between glucose homeostasis measures with HRV using data from 11,994 adults without diabetes (mean age 39 years; 52 % women). Higher fasting glucose was associated with lower RR, SDNN, and RMSSD. Fasting insulin and the homeostasis model assessment of insulin resistance was negatively associated with RR, SDNN, and RMSSD, and the association was stronger among men compared with women. RMSSD was, on average, 26 % lower in men with higher fasting insulin and 29 % lower in men with lower insulin resistance; for women, the corresponding estimates were smaller at 4 and 9 %, respectively. Higher glycated hemoglobin was associated with lower RR, SDNN, and RMSSD in those with abdominal adiposity, defined by sex-specific cut-points for waist circumference, after adjusting for demographics and medication use. There were no associations between glycated hemoglobin and HRV measures among those without abdominal adiposity

  5. Leptin and leptin receptor gene polymorphisms and changes in glucose homeostasis in response to regular exercise in nondiabetic individuals: the HERITAGE family study.

    PubMed

    Lakka, Timo A; Rankinen, Tuomo; Weisnagel, S John; Chagnon, Yvon C; Lakka, Hanna-Maaria; Ukkola, Olavi; Boulé, Normand; Rice, Treva; Leon, Arthur S; Skinner, James S; Wilmore, Jack H; Rao, D C; Bergman, Richard; Bouchard, Claude

    2004-06-01

    We recently reported that a genomic region close to the leptin locus was linked to fasting insulin response to exercise training in nondiabetic white subjects. We tested the hypothesis that common exonic variants in the leptin (LEP) and leptin receptor (LEPR) genes modify the effects of regular physical activity on glucose homeostasis in nondiabetic whites (n = 397) and blacks (n = 143). In whites, exercise increased insulin sensitivity index (P = 0.041) and disposition index (P = 0.046) in the LEPR 109R allele carriers but not in the K109K homozygotes, increased glucose disappearance index more in the R109R homozygotes than in the K109 allele carriers (P = 0.039), and decreased fasting glucose only in the 109R allele carriers (P = 0.018). We also found an interaction between the LEP A19G and LEPR K109R polymorphisms on the change in fasting insulin in whites (P = 0.010). The association between the LEP A19G polymorphism and the change in insulin was evident only in the LEPR 109R carriers (P = 0.019). The decrease in insulin was strongest in the LEP A19A homozygotes who carried the LEPR 109R allele. Similar interaction was observed in blacks (P = 0.046). Variations in the LEP and LEPR genes are associated with the magnitude of the effects of regular exercise on glucose homeostasis in nondiabetic individuals.

  6. Coffee Consumption, Newly Diagnosed Diabetes, and Other Alterations in Glucose Homeostasis: A Cross-Sectional Analysis of the Longitudinal Study of Adult Health (ELSA-Brasil)

    PubMed Central

    Yarmolinsky, James; Mueller, Noel T.; Duncan, Bruce B.; Bisi Molina, Maria del Carmen; Goulart, Alessandra C.; Schmidt, Maria Inês

    2015-01-01

    Introduction Observational studies have reported fairly consistent inverse associations between coffee consumption and risk of type 2 diabetes, but this association has been little investigated with regard to lesser degrees of hyperglycemia and other alterations in glucose homeostasis. Additionally, the association between coffee consumption and diabetes has been rarely investigated in South American populations. We examined the cross-sectional relationships of coffee intake with newly diagnosed diabetes and measures of glucose homeostasis, insulin sensitivity, and insulin secretion, in a large Brazilian cohort of middle-aged and elderly individuals. Methods We used baseline data from 12,586 participants of the Longitudinal Study of Adult Health (ELSA-Brasil). Logistic regression analyses were performed to examine associations between coffee consumption and newly diagnosed diabetes. Analysis of covariance was used to assess coffee intake in relation to two-hour glucose from an oral glucose tolerance test, fasting glucose, glycated hemoglobin, fasting and –2-hour postload insulin and measures of insulin sensitivity. Results We found an inverse association between coffee consumption and newly diagnosed diabetes, after adjusting for multiple covariates [23% and 26% lower odds of diabetes for those consuming coffee 2–3 and >3 times per day, respectively, compared to those reporting never or almost never consuming coffee, (p = .02)]. An inverse association was also found for 2-hour postload glucose [Never/almost never: 7.57 mmol/L, ≤1 time/day: 7.48 mmol/L, 2-3 times/day: 7.22 mmol/L, >3 times/day: 7.12 mol/L, p<0.0001] but not with fasting glucose concentrations (p = 0.07). Coffee was additionally associated with 2-hour postload insulin [Never/almost never: 287.2 pmol/L, ≤1 time/day: 280.1 pmol/L, 2–3 times/day: 275.3 pmol/L, >3 times/day: 262.2 pmol/L, p = 0.0005) but not with fasting insulin concentrations (p = .58). Conclusion Our present study provides

  7. Evidence of a link between resting energy expenditure and bone remodelling, glucose homeostasis and adipokine variations in adolescent girls with anorexia nervosa.

    PubMed

    Maïmoun, L; Guillaume, S; Lefebvre, P; Philibert, P; Bertet, H; Picot, M-C; Gaspari, L; Paris, F; Seneque, M; Dupuys, A-M; Courtet, P; Thomas, E; Mariano-Goulart, D; Bringer, J; Renard, E; Sultan, C

    2016-01-01

    Low bone mass is a consequence of anorexia nervosa (AN). This study assessed the effects of energy deficiency on various bone and hormonal parameters. The interrelationships between energy deficiency and bone remodelling, glucose homeostasis and adipokines underscore the importance of preventing energy deficiency to limit demineralisation and hormonal alterations in AN patients. Low areal bone mineral density (aBMD) is a well-known consequence of AN. However, the impact of reduced energy expenditure on bone metabolism is unknown. This study assessed the effects of energy deficiency on bone remodelling and its potential interactions with glucose homeostasis and adipose tissue-derived hormones in AN, a clinical model for reduced energy expenditure. Fifty women with AN and 50 age-matched controls (mean age 18.1 ± 2.7 and 18.0 ± 2.1 years, respectively) were enrolled. aBMD was determined with DXA. Resting energy expenditure (REEm), a marker of energy status, was indirectly assessed by calorimetry. Bone turnover markers, undercarboxylated osteocalcin (ucOC), parameters of glucose homeostasis, adipokines and growth factors were concomitantly evaluated. AN patients presented low aBMD at all bone sites. REEm, bone formation markers, ucOC, glucose, insulin, HOMA-IR, leptin and IGF-1 were significantly reduced, whereas the bone resorption marker, leptin receptor (sOB-R) and adiponectin were elevated in AN compared with CON. In AN patients, REEm was positively correlated with weight, BMI, whole body (WB) fat mass, WB fat-free soft tissue, markers of bone formation, glucose, insulin, HOMA-IR, leptin and IGF-1 and negatively correlated with the bone resorption marker and sOB-R. Biological parameters, aBMD excepted, appeared more affected by the weight variation in the last 6 months than by the disease duration. The strong interrelationships between REEm and bone remodelling, glucose homeostasis and adipokines underscore the importance of preventing energy deficiency

  8. Normal adiponectin levels despite abnormal glucose tolerance (or diabetes) and inflammation in adult patients with cystic fibrosis.

    PubMed

    Hammana, I; Malet, A; Costa, M; Brochiero, E; Berthiaume, Y; Potvin, S; Chiasson, J-L; Coderre, L; Rabasa-Lhoret, R

    2007-06-01

    Circulating adiponectin levels are negatively associated with glucose intolerance, inflammation and central adiposity. Since these conditions are common in cystic fibrosis (CF), we examined whether adiponectin values are altered in these patients. To determine if CF patients have altered adiponectin levels and if these levels correlate with glucose tolerance categories (normal, impaired glucose tolerance (IGT) and cystic fibrosis-related diabetes (CFRD)), insulin resistance or inflammatory markers such as fibrinogen and C-reactive protein (CRP). Oral glucose tolerance tests (OGTTs) were performed and adiponectin levels were measured in 90 CF patients not known to be diabetic and 15 healthy controls matched for age, sex and body mass index (BMI). Inflammatory markers, serum albumin concentrations and the clinical status of CF patients (i.e. pulmonary function) were also examined. CF pathology was characterized by a high prevalence (43.5%) of glucose tolerance abnormalities: 26.5% of IGT and 17.0% of newly diagnosed CFRD. CF patients also presented systemic inflammation as revealed by a significant increase of fibrinogen (P=0.029) in all patients and higher CRP levels in CFRD patients compared to the controls (P<0.05). On the other hand, CF and control subjects had similar albumin serum concentration. While CF patients and controls had similar serum adiponectin values, women had significantly higher hormone levels than men (P<0.001). Adiponectin levels did not correlate with glucose tolerance, inflammatory markers or insulin resistance. On the other hand, they correlated positively with both total and HDL-cholesterol (P<0.001). CF patients did not show any alterations in adiponectin levels despite insulin resistance, glucose intolerance and sub clinical chronic inflammation. Thus, CF appears to be one of the rare conditions in which discordance between adiponectin values and insulin resistance or inflammation is evident.

  9. Exposure to low level of arsenic and lead in drinking water from Antofagasta city induces gender differences in glucose homeostasis in rats.

    PubMed

    Palacios, Javier; Roman, Domingo; Cifuentes, Fredi

    2012-08-01

    Populations chronically exposed to arsenic in drinking water often have increased prevalence of diabetes mellitus. The purpose of this study was to compare the glucose homeostasis of male and female rats exposed to low levels of heavy metals in drinking water. Treated groups were Sprague-Dawley male and female rats exposed to drinking water from Antofagasta city, with total arsenic of 30 ppb and lead of 53 ppb for 3 months; control groups were exposed to purified water by reverse osmosis. The two treated groups in both males and females showed arsenic and lead in the hair of rats. The δ-aminolevulinic acid dehydratase was used as a sensitive biomarker of arsenic toxicity and lead. The activity of δ-aminolevulinic acid dehydratase was reduced only in treated male rats, compared to the control group. Treated males showed a significantly sustained increase in blood glucose and plasma insulin levels during oral glucose tolerance test compared to control group. The oral glucose tolerance test and the homeostasis model assessment of insulin resistance demonstrated that male rats were insulin resistant, and females remained sensitive to insulin after treatment. The total cholesterol and LDL cholesterol increased in treated male rats vs. the control, and triglyceride increased in treated female rats vs. the control. The activity of intestinal Na+/glucose cotransporter in male rats increased compared to female rats, suggesting a significant increase in intestinal glucose absorption. The findings indicate that exposure to low levels of arsenic and lead in drinking water could cause gender differences in insulin resistance.

  10. Use of a Connected Glucose Meter and Certified Diabetes Educator Coaching to Decrease the Likelihood of Abnormal Blood Glucose Excursions: The Livongo for Diabetes Program.

    PubMed

    Downing, Janelle; Bollyky, Jenna; Schneider, Jennifer

    2017-07-11

    The Livongo for Diabetes Program offers members (1) a cellular technology-enabled, two-way messaging device that measures blood glucose (BG), centrally stores the glucose data, and delivers messages back to the individual in real time; (2) unlimited BG test strips; and (3) access to a diabetes coaching team for questions, goal setting, and automated support for abnormal glucose excursions. The program is sponsored by at-risk self-insured employers, health plans and provider organizations where it is free to members with diabetes or it is available directly to the person with diabetes where they cover the cost. The objective of our study was to evaluate BG data from 4544 individuals with diabetes who were enrolled in the Livongo program from October 2014 through December 2015. Members used the Livongo glucose meter to measure their BG levels an average of 1.8 times per day. We estimated the probability of having a day with a BG reading outside of the normal range (70-180 mg/dL, or 3.9-10.0 mmol/L) in months 2 to 12 compared with month 1 of the program, using individual fixed effects to control for individual characteristics. Livongo members experienced an average 18.4% decrease in the likelihood of having a day with hypoglycemia (BG <70 mg/dL) and an average 16.4% decrease in hyperglycemia (BG >180 mg/dL) in months 2-12 compared with month 1 as the baseline. The biggest impact was seen on hyperglycemia for nonusers of insulin. We do not know all of the contributing factors such as medication or other treatment changes during the study period. These findings suggest that access to a connected glucose meter and certified diabetes educator coaching is associated with a decrease in the likelihood of abnormal glucose excursions, which can lead to diabetes-related health care savings. ©Janelle Downing, Jenna Bollyky, Jennifer Schneider. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 11.07.2017.

  11. Nigella sativa improves glucose homeostasis and serum lipids in type 2 diabetes: A systematic review and meta-analysis.

    PubMed

    Daryabeygi-Khotbehsara, Reza; Golzarand, Mahdieh; Ghaffari, Mohammad Payam; Djafarian, Kurosh

    2017-12-01

    Global prevalence of type 2 diabetes (T2D) is very high and is currently growing alarmingly. With respect to recent researchers' attention to the potential role of herbal medicine in disease prevention and management, the present meta-analysis review investigates the effectiveness of Nigella sativa (N. sativa), a popular herb, in T2D. Literature search was conducted covering PubMed/Medline, Scopus, and Cochrane Registry of Clinical Trials up to February 2017 to obtain the relevant published intervention studies. Study selection, quality rating and data extraction of studies were investigated by two independent reviewers. Heterogeneity was assessed using I-squared (I 2 ) statistics test. Subgroup analysis was done to assess type of N. sativa supplement as source of heterogeneity. Effect sizes of eligible studies were pooled using STATA software version 12 (STATA corp, College Station, TX, USA). Seven trials were included in the meta-analysis of glycemic and serum lipid profile end points. Supplementation with N. sativa significantly improved fasting blood sugar (FBS) [-17.84mg/dl, 95% CI: -21.19 to -14.49, p<0.001], HbA1c [-0.71%, 95% CI: -1.04 to -0.39, p<0.001], total-cholesterol (TC) [WMD: -22.99mg/dl, 95% CI: -32.16 to -13.83, p<0.001] and LDL-cholesterol (LDL-c) [-22.38mg/dl, 95% CI: -33.60 to -11.15, p<0.001]. The overall effects for triglyceride (TG) [-6.80mg/dl, 95% CI: -33.59 to 19.99, p=0.61] and HDL-cholesterol (HDL-c) [0.37mg/dl, 95% CI: -1.59 to 2.33, p=0.71] were insignificant. Subgroup analysis revealed significant reduction on TG with N. sativa seed oil [-14.8mg/dl, 95% CI: -23.1 to -6.5, p<0.001], while TG was increased with seed powder [29.4mg/dl, 95% CI: 16.9-42.0, p<0.001]. All measures, but HbA1c, showed no evidence of publication bias. Although, the meta-analysis conducted included a few number of studies, but has shown promising results on the effectiveness of N. sativa on glucose homeostasis and serum lipids. Current findings suggest N

  12. p53-upregulated-modulator-of-apoptosis (PUMA) deficiency affects food intake but does not impact on body weight or glucose homeostasis in diet-induced obesity.

    PubMed

    Litwak, Sara A; Loh, Kim; Stanley, William J; Pappas, Evan G; Wali, Jibran A; Selck, Claudia; Strasser, Andreas; Thomas, Helen E; Gurzov, Esteban N

    2016-04-01

    BCL-2 proteins have been implicated in the control of glucose homeostasis and metabolism in different cell types. Thus, the aim of this study was to determine the role of the pro-apoptotic BH3-only protein, p53-upregulated-modulator-of-apoptosis (PUMA), in metabolic changes mediated by diet-induced obesity, using PUMA deficient mice. At 10 weeks of age, knockout and wild type mice either continued consuming a low fat chow diet (6% fat), or were fed with a high fat diet (23% fat) for 14-17 weeks. We measured body composition, glucose and insulin tolerance, insulin response in peripheral tissues, energy expenditure, oxygen consumption, and respiratory exchange ratio in vivo. All these parameters were indistinguishable between wild type and knockout mice on chow diet and were modified equally by diet-induced obesity. Interestingly, we observed decreased food intake and ambulatory capacity of PUMA knockout mice on high fat diet. This was associated with increased adipocyte size and fasted leptin concentration in the blood. Our findings suggest that although PUMA is dispensable for glucose homeostasis in lean and obese mice, it can affect leptin levels and food intake during obesity.

  13. Lactobacillus gasseri in the Upper Small Intestine Impacts an ACSL3-Dependent Fatty Acid-Sensing Pathway Regulating Whole-Body Glucose Homeostasis.

    PubMed

    Bauer, Paige V; Duca, Frank A; Waise, T M Zaved; Dranse, Helen J; Rasmussen, Brittany A; Puri, Akshita; Rasti, Mozhgan; O'Brien, Catherine A; Lam, Tony K T

    2018-03-06

    Long-chain acyl-CoA synthetase (ACSL)-dependent upper small intestinal lipid metabolism activates pre-absorptive pathways to regulate metabolic homeostasis, but whether changes in the upper small intestinal microbiota alter specific fatty acid-dependent pathways to impact glucose homeostasis remains unknown. We here first find that upper small intestinal infusion of Intralipid, oleic acid, or linoleic acid pre-absorptively increases glucose tolerance and lowers glucose production in rodents. High-fat feeding impairs pre-absorptive fatty acid sensing and reduces upper small intestinal Lactobacillus gasseri levels and ACSL3 expression. Transplantation of healthy upper small intestinal microbiota to high-fat-fed rodents restores L. gasseri levels and fatty acid sensing via increased ACSL3 expression, while L. gasseri probiotic administration to non-transplanted high-fat-fed rodents is sufficient to restore upper small intestinal ACSL3 expression and fatty acid sensing. In summary, we unveil a glucoregulatory role of upper small intestinal L. gasseri that impacts an ACSL3-dependent glucoregulatory fatty acid-sensing pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. p53-upregulated-modulator-of-apoptosis (PUMA) deficiency affects food intake but does not impact on body weight or glucose homeostasis in diet-induced obesity.

    PubMed Central

    Litwak, Sara A.; Loh, Kim; Stanley, William J.; Pappas, Evan G.; Wali, Jibran A.; Selck, Claudia; Strasser, Andreas; Thomas, Helen E.; Gurzov, Esteban N.

    2016-01-01

    BCL-2 proteins have been implicated in the control of glucose homeostasis and metabolism in different cell types. Thus, the aim of this study was to determine the role of the pro-apoptotic BH3-only protein, p53-upregulated-modulator-of-apoptosis (PUMA), in metabolic changes mediated by diet-induced obesity, using PUMA deficient mice. At 10 weeks of age, knockout and wild type mice either continued consuming a low fat chow diet (6% fat), or were fed with a high fat diet (23% fat) for 14–17 weeks. We measured body composition, glucose and insulin tolerance, insulin response in peripheral tissues, energy expenditure, oxygen consumption, and respiratory exchange ratio in vivo. All these parameters were indistinguishable between wild type and knockout mice on chow diet and were modified equally by diet-induced obesity. Interestingly, we observed decreased food intake and ambulatory capacity of PUMA knockout mice on high fat diet. This was associated with increased adipocyte size and fasted leptin concentration in the blood. Our findings suggest that although PUMA is dispensable for glucose homeostasis in lean and obese mice, it can affect leptin levels and food intake during obesity. PMID:27033313

  15. The Exercise-Induced Irisin Is Associated with Improved Levels of Glucose Homeostasis Markers in Pregnant Women Participating in 8-Week Prenatal Group Fitness Program: A Pilot Study.

    PubMed

    Szumilewicz, Anna; Worska, Aneta; Piernicka, Magdalena; Kuchta, Agnieszka; Kortas, Jakub; Jastrzębski, Zbigniew; Radzimiński, Łukasz; Jaworska, Joanna; Micielska, Katarzyna; Ziemann, Ewa

    2017-01-01

    Both exercise and pregnancy influence serum irisin concentration. To determine how the interaction of pregnancy and exercise affects irisin level and whether various patterns of exercise adherence had different effect on irisin concentration. It was a one-group pretest-posttest study among 9 Caucasian nulliparous healthy women in normal pregnancy (age 23 ± 3 years, 21 ± 2 weeks of gestation; mean ± SD) who participated in 8-week group fitness program. Before and after exercise intervention, we determined serum concentrations of irisin and selected parameters of lipid profile and glucose homeostasis markers. In active women, irisin slightly decreased with the development of pregnancy. After 8 weeks of exercising, irisin correlated negatively with fasting glucose ( R = -0.922; p = 0.001), glycated hemoglobin ( R = -0.784; p = 0.012), and insulin concentrations ( R = -0.845; p = 0.004). In women exercising below recommended level, we observed a significant drop in irisin concentration, whereas in women exercising at least three times a week this myokine slightly increased (31% difference; 90% confidence limits ±28; a large, clear effect). Irisin stimulated by prenatal exercise may improve glucose homeostasis markers in healthy women and compensate for metabolic changes induced by pregnancy. Moreover, the frequency of exercise may regulate the changes in exercise-induced irisin concentration.

  16. The Exercise-Induced Irisin Is Associated with Improved Levels of Glucose Homeostasis Markers in Pregnant Women Participating in 8-Week Prenatal Group Fitness Program: A Pilot Study

    PubMed Central

    Worska, Aneta; Piernicka, Magdalena; Kortas, Jakub; Jastrzębski, Zbigniew; Radzimiński, Łukasz; Jaworska, Joanna; Micielska, Katarzyna

    2017-01-01

    Background Both exercise and pregnancy influence serum irisin concentration. Aim To determine how the interaction of pregnancy and exercise affects irisin level and whether various patterns of exercise adherence had different effect on irisin concentration. Methods It was a one-group pretest-posttest study among 9 Caucasian nulliparous healthy women in normal pregnancy (age 23 ± 3 years, 21 ± 2 weeks of gestation; mean ± SD) who participated in 8-week group fitness program. Before and after exercise intervention, we determined serum concentrations of irisin and selected parameters of lipid profile and glucose homeostasis markers. Results In active women, irisin slightly decreased with the development of pregnancy. After 8 weeks of exercising, irisin correlated negatively with fasting glucose (R = −0.922; p = 0.001), glycated hemoglobin (R = −0.784; p = 0.012), and insulin concentrations (R = −0.845; p = 0.004). In women exercising below recommended level, we observed a significant drop in irisin concentration, whereas in women exercising at least three times a week this myokine slightly increased (31% difference; 90% confidence limits ±28; a large, clear effect). Conclusions Irisin stimulated by prenatal exercise may improve glucose homeostasis markers in healthy women and compensate for metabolic changes induced by pregnancy. Moreover, the frequency of exercise may regulate the changes in exercise-induced irisin concentration. PMID:29226153

  17. Glucose Metabolism during Resting State Reveals Abnormal Brain Networks Organization in the Alzheimer’s Disease and Mild Cognitive Impairment

    PubMed Central

    Martínez-Montes, Eduardo

    2013-01-01

    This paper aims to study the abnormal patterns of brain glucose metabolism co-variations in Alzheimer disease (AD) and Mild Cognitive Impairment (MCI) patients compared to Normal healthy controls (NC) using the Alzheimer Disease Neuroimaging Initiative (ADNI) database. The local cerebral metabolic rate for glucose (CMRgl) in a set of 90 structures belonging to the AAL atlas was obtained from Fluro-Deoxyglucose Positron Emission Tomography data in resting state. It is assumed that brain regions whose CMRgl values are significantly correlated are functionally associated; therefore, when metabolism is altered in a single region, the alteration will affect the metabolism of other brain areas with which it interrelates. The glucose metabolism network (represented by the matrix of the CMRgl co-variations among all pairs of structures) was studied using the graph theory framework. The highest concurrent fluctuations in CMRgl were basically identified between homologous cortical regions in all groups. Significant differences in CMRgl co-variations in AD and MCI groups as compared to NC were found. The AD and MCI patients showed aberrant patterns in comparison to NC subjects, as detected by global and local network properties (global and local efficiency, clustering index, and others). MCI network’s attributes showed an intermediate position between NC and AD, corroborating it as a transitional stage from normal aging to Alzheimer disease. Our study is an attempt at exploring the complex association between glucose metabolism, CMRgl covariations and the attributes of the brain network organization in AD and MCI. PMID:23894356

  18. Gsα Deficiency in the Ventromedial Hypothalamus Enhances Leptin Sensitivity and Improves Glucose Homeostasis in Mice on a High-Fat Diet.

    PubMed

    Berger, Alta; Kablan, Ahmed; Yao, Catherine; Ho, Thuy; Podyma, Brandon; Weinstein, Lee S; Chen, Min

    2016-02-01

    In both mice and patients with Albright hereditary osteodystrophy, heterozygous inactivating mutations of Gsα, a ubiquitously expressed G protein that mediates receptor-stimulated intracellular cAMP production, lead to obesity and insulin resistance but only when the mutation is present on the maternal allele. This parent-of-origin effect in mice was shown to be due to Gsα imprinting in one or more brain regions. The ventromedial hypothalamus (VMH) is involved in the regulation of energy and glucose homeostasis, but the role of Gsα in VMH on metabolic regulation is unknown. To examine this, we created VMH-specific Gsα-deficient mice by mating Gsα-floxed mice with SF1-cre mice. Heterozygotes with Gsα mutation on either the maternal or paternal allele had a normal metabolic phenotype, and there was no molecular evidence of Gsα imprinting, indicating that the parent-of-origin metabolic effects associated with Gsα mutations is not due to Gsα deficiency in VMH SF1 neurons. Homozygous VMH Gsα knockout mice (VMHGsKO) showed no changes in body weight on either a regular or high-fat diet. However, glucose metabolism (fasting glucose, glucose tolerance, insulin sensitivity) was significantly improved in male VMHGsKO mice, with the difference more dramatic on the high-fat diet. In addition, male VMHGsKO mice on the high-fat diet showed a greater anorexigenic effect and increased VMH signal transducer and activator of transcription-3 phosphorylation in response to leptin. These results indicate that VMH Gsα/cyclic AMP signaling regulates glucose homeostasis and alters leptin sensitivity in mice, particularly in the setting of excess caloric intake.

  19. Brain-derived neurotrophic factor in the nucleus tractus solitarii modulates glucose homeostasis after carotid chemoreceptor stimulation in rats.

    PubMed

    Montero, Sergio; Cuéllar, Ricardo; Lemus, Mónica; Avalos, Reyes; Ramírez, Gladys; de Álvarez-Buylla, Elena Roces

    2012-01-01

    Neuronal systems, which regulate energy intake, energy expenditure and endogenous glucose production, sense and respond to input from hormonal related signals that convey information from body energy availability. Carotid chemoreceptors (CChr) function as sensors for circulating glucose levels and contribute to glycemic counterregulatory responses. Brain-derived neurotrophic factor (BDNF) that plays an important role in the endocrine system to regulate glucose metabolism could play a role in hyperglycemic glucose reflex with brain glucose retention (BGR) evoked by anoxic CChr stimulation. Infusing BDNF into the nucleus tractus solitarii (NTS) before CChr stimulation, showed that this neurotrophin increased arterial glucose and BGR. In contrast, BDNF receptor (TrkB) antagonist (K252a) infusions in NTS resulted in a decrease in both glucose variables.

  20. Effect of nitrate supplementation on hepatic blood flow and glucose homeostasis: a double-blind, placebo-controlled, randomized control trial

    PubMed Central

    Wilkerson, Daryl P.; Fulford, Jon; Winyard, Paul G.; Benjamin, Nigel; Shore, Angela C.

    2016-01-01

    Nitric oxide alters gastric blood flow, improves vascular function, and mediates glucose uptake within the intestines and skeletal muscle. Dietary nitrate, acting as a source of nitric oxide, appears to be a potential low-cost therapy that may help maintain glucose homeostasis. In a randomized, double-blind, placebo-controlled crossover study, 31 young and older adult participants had a standardized breakfast, supplemented with either nitrate-rich beetroot juice (11.91 mmol nitrate) or nitrate-depleted beetroot juice as placebo (0.01 mmol nitrate). MRI was used to assess apparent diffusion coefficient (ADC), portal vein flux, and velocity. Plasma glucose, incretin, and C-peptide concentrations and blood pressure were assessed. Outcome variables were measured at baseline and hourly for 3 h. Compared with a placebo, beetroot juice resulted in a significant elevation in plasma nitrate and plasma nitrite concentration. No differences were seen for the young or older adult cohorts between placebo and beetroot juice for ADC, or portal vein flux. There was an interaction effect in the young adults between visits for portal vein velocity. Nitrate supplementation did not reduce plasma glucose, active GLP-1, total GLP-1, or plasma C-peptide concentrations for the young or older adult cohorts. Despite a significant elevation in plasma nitrite concentration following an acute dose of (11.91 mmol) nitrate, there was no effect on hepatic blood flow, plasma glucose, C-peptide, or incretin concentration in healthy adults. PMID:27418682

  1. Effect of nitrate supplementation on hepatic blood flow and glucose homeostasis: a double-blind, placebo-controlled, randomized control trial.

    PubMed

    Shepherd, Anthony I; Wilkerson, Daryl P; Fulford, Jon; Winyard, Paul G; Benjamin, Nigel; Shore, Angela C; Gilchrist, Mark

    2016-09-01

    Nitric oxide alters gastric blood flow, improves vascular function, and mediates glucose uptake within the intestines and skeletal muscle. Dietary nitrate, acting as a source of nitric oxide, appears to be a potential low-cost therapy that may help maintain glucose homeostasis. In a randomized, double-blind, placebo-controlled crossover study, 31 young and older adult participants had a standardized breakfast, supplemented with either nitrate-rich beetroot juice (11.91 mmol nitrate) or nitrate-depleted beetroot juice as placebo (0.01 mmol nitrate). MRI was used to assess apparent diffusion coefficient (ADC), portal vein flux, and velocity. Plasma glucose, incretin, and C-peptide concentrations and blood pressure were assessed. Outcome variables were measured at baseline and hourly for 3 h. Compared with a placebo, beetroot juice resulted in a significant elevation in plasma nitrate and plasma nitrite concentration. No differences were seen for the young or older adult cohorts between placebo and beetroot juice for ADC, or portal vein flux. There was an interaction effect in the young adults between visits for portal vein velocity. Nitrate supplementation did not reduce plasma glucose, active GLP-1, total GLP-1, or plasma C-peptide concentrations for the young or older adult cohorts. Despite a significant elevation in plasma nitrite concentration following an acute dose of (11.91 mmol) nitrate, there was no effect on hepatic blood flow, plasma glucose, C-peptide, or incretin concentration in healthy adults. Copyright © 2016 the American Physiological Society.

  2. An aqueous extract of Curcuma longa (turmeric) rhizomes stimulates insulin release and mimics insulin action on tissues involved in glucose homeostasis in vitro.

    PubMed

    Mohankumar, Sureshkumar; McFarlane, James R

    2011-03-01

    Curcuma longa (turmeric) has been used widely as a spice, particularly in Asian countries. It is also used in the Ayurvedic system of medicine as an antiinflammatory and antimicrobial agent and for numerous other curative properties. The aim of this study was to investigate the effects of an aqueous extract of Curcuma longa (AEC) on tissues involved in glucose homeostasis. The extract was prepared by soaking 100 g of ground turmeric in 1 L of water, which was filtered and stored at -20°C prior to use. Pancreas and muscle tissues of adult mice were cultured in DMEM with 5 or 12 mmol/L glucose and varying doses of extract. The AEC stimulated insulin secretion from mouse pancreatic tissues under both basal and hyperglycaemic conditions, although the maximum effect was only 68% of that of tolbutamide. The AEC induced stepwise stimulation of glucose uptake from abdominal muscle tissues in the presence and absence of insulin, and the combination of AEC and insulin significantly potentiated the glucose uptake into abdominal muscle tissue. However, this effect was attenuated by wortmannin, suggesting that AEC possibly acts via the insulin-mediated glucose uptake pathway. In summary, water soluble compounds of turmeric exhibit insulin releasing and mimicking actions within in vitro tissue culture conditions. Copyright © 2010 John Wiley & Sons, Ltd.

  3. Consumption of added sugars from liquid but not solid sources predicts impaired glucose homeostasis and insulin resistance among youth at risk of obesity.

    PubMed

    Wang, Jiawei; Light, Kelly; Henderson, Mélanie; O'Loughlin, Jennifer; Mathieu, Marie-Eve; Paradis, Gilles; Gray-Donald, Katherine

    2014-01-01

    Little is known about longitudinal associations between added sugar consumption (solid and liquid sources) and glucose-insulin homeostasis among youth. Caucasian children (8-10 y) with at least one obese biological parent were recruited in the QUébec Adipose and Lifestyle InvesTigation in Youth (QUALITY) cohort (n = 630) and followed-up 2 y later (n = 564). Added sugars were assessed by 3 24-h dietary recalls at baseline. Two-year changes were examined in multivariate linear regression models, adjusting for baseline level, age, sex, Tanner stage, energy intake, fat mass (dual-energy X-ray absorptiometry), and physical activity (7 d accelerometer). Added sugar intake in either liquid or solid sources was not related to changes in adiposity measures (fat mass, body mass index, or waist circumference). However, a higher consumption (10 g/d) of added sugars from liquid sources was associated with 0.04 mmol/L higher fasting glucose, 2.3 pmol/L higher fasting insulin, 0.1 unit higher homeostasis model assessment of insulin resistance (HOMA-IR), and 0.4 unit lower Matsuda-insulin sensitivity index (Matsuda-ISI) in all participants (P < 0.01). No associations were observed with consumption of added sugars from solid sources. Overweight/obese children at baseline had greater increases in adiposity indicators, fasting insulin, and HOMA-IR and decreases in Matsuda-ISI during those 2 y than normal-weight children. Consumption of added sugars from liquid or solid sources was not associated with changes in adiposity, but liquid added sugars were a risk factor for the development of impaired glucose homeostasis and insulin resistance over 2 y among youth at risk of obesity.

  4. Prevalence of abnormal glucose tolerance and risk factors in urban and rural Malaysia.

    PubMed

    Mustafa, Norlaila; Kamarudin, Nor Azmi; Ismail, Ab Aziz; Khir, Amir Sharifuddin; Ismail, Ikram Shah; Musa, Kamarul Imran; Kadir, Khalid Abdul; Yaacob, Nor Azwany; Ali, Osman; Isa, Siti Harnida Md; Wan Bebakar, Wan Mohamad; wan Mohamud, Wan Nazaimoon

    2011-06-01

    To determine the prevalence of prediabetes and diabetes among rural and urban Malaysians. This cross-sectional survey was conducted among 3,879 Malaysian adults (1,335 men and 2,544 women). All subjects underwent the 75-g oral glucose tolerance test (OGTT). The overall prevalence of prediabetes was 22.1% (30.2% in men and 69.8% in women). Isolated impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were found in 3.4 and 16.1% of the study population, respectively, whereas 2.6% of the subjects had both IFG and IGT. Based on an OGTT, the prevalence of newly diagnosed type 2 diabetes was 12.6% (31.0% in men and 69.0% in women). The prediabetic subjects also had an increased prevalence of cardiovascular disease risk factors. The large proportion of undiagnosed cases of prediabetes and diabetes reflects the lack of public awareness of the disease.

  5. Abnormal glucose tolerance post-gestational diabetes mellitus as defined by the International Association of Diabetes and Pregnancy Study Groups criteria.

    PubMed

    Noctor, Eoin; Crowe, Catherine; Carmody, Louise A; Saunders, Jean A; Kirwan, Breda; O'Dea, Angela; Gillespie, Paddy; Glynn, Liam G; McGuire, Brian E; O'Neill, Ciarán; O'Shea, P M; Dunne, F P

    2016-10-01

    An increase in gestational diabetes mellitus (GDM) prevalence has been demonstrated across many countries with adoption of the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) diagnostic criteria. Here, we determine the cumulative incidence of abnormal glucose tolerance among women with previous GDM, and identify clinical risk factors predicting this. Two hundred and seventy women with previous IADPSG-defined GDM were prospectively followed up for 5years (mean 2.6) post-index pregnancy, and compared with 388 women with normal glucose tolerance (NGT) in pregnancy. Cumulative incidence of abnormal glucose tolerance (using American Diabetes Association criteria for impaired fasting glucose, impaired glucose tolerance and diabetes) was determined using the Kaplan-Meier method of survival analysis. Cox regression models were constructed to test for factors predicting abnormal glucose tolerance. Twenty-six percent of women with previous GDM had abnormal glucose tolerance vs 4% with NGT, with the log-rank test demonstrating significantly different survival curves (P<0.001). Women meeting IADPSG, but not the World Health Organization (WHO) 1999 criteria, had a lower cumulative incidence than women meeting both sets of criteria, both in the early post-partum period (4.2% vs 21.7%, P<0.001) and at longer-term follow-up (13.7% vs 32.6%, P<0.001). Predictive factors were glucose levels on the pregnancy oral glucose tolerance test, family history of diabetes, gestational week at testing, and BMI at follow-up. The proportion of women developing abnormal glucose tolerance remains high among those with IADPSG-defined GDM. This demonstrates the need for continued close follow-up, although the optimal frequency and method needs further study. © 2016 European Society of Endocrinology.

  6. Peripheral Insulin Resistance and Impaired Insulin Signaling Contribute to Abnormal Glucose Metabolism in Preterm Baboons

    PubMed Central

    McGill-Vargas, Lisa L.; Gastaldelli, Amalia; Seidner, Steven R.; McCurnin, Donald C.; Leland, Michelle M.; Anzueto, Diana G.; Johnson, Marney C.; Liang, Hanyu; DeFronzo, Ralph A.; Musi, Nicolas

    2015-01-01

    Premature infants develop hyperglycemia shortly after birth, increasing their morbidity and death. Surviving infants have increased incidence of diabetes as young adults. Our understanding of the biological basis for the insulin resistance of prematurity and developmental regulation of glucose production remains fragmentary. The objective of this study was to examine maturational differences in insulin sensitivity and the insulin-signaling pathway in skeletal muscle and adipose tissue of 30 neonatal baboons using the euglycemic hyperinsulinemic clamp. Preterm baboons (67% gestation) had reduced peripheral insulin sensitivity shortly after birth (M value 12.5 ± 1.5 vs 21.8 ± 4.4 mg/kg · min in term baboons) and at 2 weeks of age (M value 12.8 ± 2.6 vs 16.3 ± 4.2, respectively). Insulin increased Akt phosphorylation, but these responses were significantly lower in preterm baboons during the first week of life (3.2-fold vs 9.8-fold). Preterm baboons had lower glucose transporter-1 protein content throughout the first 2 weeks of life (8%-12% of term). In preterm baboons, serum free fatty acids (FFAs) did not decrease in response to insulin, whereas FFAs decreased by greater than 80% in term baboons; the impaired suppression of FFAs in the preterm animals was paired with a decreased glucose transporter-4 protein content in adipose tissue. In conclusion, peripheral insulin resistance and impaired non-insulin-dependent glucose uptake play an important role in hyperglycemia of prematurity. Impaired insulin signaling (reduced Akt) contributes to the defect in insulin-stimulated glucose disposal. Counterregulatory hormones are not major contributors. PMID:25560831

  7. Peripheral insulin resistance and impaired insulin signaling contribute to abnormal glucose metabolism in preterm baboons.

    PubMed

    Blanco, Cynthia L; McGill-Vargas, Lisa L; Gastaldelli, Amalia; Seidner, Steven R; McCurnin, Donald C; Leland, Michelle M; Anzueto, Diana G; Johnson, Marney C; Liang, Hanyu; DeFronzo, Ralph A; Musi, Nicolas

    2015-03-01

    Premature infants develop hyperglycemia shortly after birth, increasing their morbidity and death. Surviving infants have increased incidence of diabetes as young adults. Our understanding of the biological basis for the insulin resistance of prematurity and developmental regulation of glucose production remains fragmentary. The objective of this study was to examine maturational differences in insulin sensitivity and the insulin-signaling pathway in skeletal muscle and adipose tissue of 30 neonatal baboons using the euglycemic hyperinsulinemic clamp. Preterm baboons (67% gestation) had reduced peripheral insulin sensitivity shortly after birth (M value 12.5 ± 1.5 vs 21.8 ± 4.4 mg/kg · min in term baboons) and at 2 weeks of age (M value 12.8 ± 2.6 vs 16.3 ± 4.2, respectively). Insulin increased Akt phosphorylation, but these responses were significantly lower in preterm baboons during the first week of life (3.2-fold vs 9.8-fold). Preterm baboons had lower glucose transporter-1 protein content throughout the first 2 weeks of life (8%-12% of term). In preterm baboons, serum free fatty acids (FFAs) did not decrease in response to insulin, whereas FFAs decreased by greater than 80% in term baboons; the impaired suppression of FFAs in the preterm animals was paired with a decreased glucose transporter-4 protein content in adipose tissue. In conclusion, peripheral insulin resistance and impaired non-insulin-dependent glucose uptake play an important role in hyperglycemia of prematurity. Impaired insulin signaling (reduced Akt) contributes to the defect in insulin-stimulated glucose disposal. Counterregulatory hormones are not major contributors.

  8. Skeletal muscle neuronal nitric oxide synthase micro protein is reduced in people with impaired glucose homeostasis and is not normalized by exercise training.

    PubMed

    Bradley, Scott J; Kingwell, Bronwyn A; Canny, Benedict J; McConell, Glenn K

    2007-10-01

    Skeletal muscle inducible nitric oxide synthase (NOS) protein is greatly elevated in people with type 2 diabetes mellitus, whereas endothelial NOS is at normal levels. Diabetic rat studies suggest that skeletal muscle neuronal NOS (nNOS) micro protein expression may be reduced in human insulin resistance. The aim of this study was to determine whether skeletal muscle nNOSmicro protein expression is reduced in people with impaired glucose homeostasis and whether exercise training increases nNOSmicro protein expression in these individuals because exercise training increases skeletal muscle nNOSmicro protein in rats. Seven people with type 2 diabetes mellitus or prediabetes (impaired fasting glucose and/or impaired glucose tolerance) and 7 matched (sex, age, fitness, body mass index, blood pressure, lipid profile) healthy controls aged 36 to 60 years participated in this study. Vastus lateralis muscle biopsies for nNOSmicro protein determination were obtained, aerobic fitness was measured (peak pulmonary oxygen uptake [Vo(2) peak]), and glucose tolerance and insulin homeostasis were assessed before and after 1 and 4 weeks of cycling exercise training (60% Vo(2) peak, 50 minutes x 5 d wk(-1)). Skeletal muscle nNOSmicro protein was significantly lower (by 32%) in subjects with type 2 diabetes mellitus or prediabetes compared with that in controls before training (17.7 +/- 1.2 vs 26.2 +/- 3.4 arbitrary units, P < .05). The Vo(2) peak and indicators of insulin sensitivity improved with exercise training in both groups (P < .05), but there was no effect of exercise training on skeletal muscle nNOSmicro protein in either group. In conclusion, individuals with impaired glucose homeostasis have reduced skeletal muscle nNOSmicro protein content. However, because exercise training improves insulin sensitivity without influencing skeletal muscle nNOSmicro protein expression, it seems that changes in skeletal muscle nNOSmicro protein are not central to the control of insulin

  9. The influence of parenteral glutamine supplementation on glucose homeostasis in critically ill polytrauma patients--A randomized-controlled clinical study.

    PubMed

    Grintescu, Ioana Marina; Luca Vasiliu, Irina; Cucereanu Badica, Ioana; Mirea, Liliana; Pavelescu, Daniela; Balanescu, Andreea; Grintescu, Ioana Cristina

    2015-06-01

    Rapid onset of resistance to insulin is a prominent component of stress metabolism in multiple trauma patients. Recent studies have clarified the role of amino acids (especially glutamine) in glucose transportation and the benefits of parenteral alanyl-glutamine supplementation (0.3-0.6 g/kg/day) in glucose homeostasis. The aims of this study are to evaluate the incidence of hyperglycemic episodes and the need for exogenous insulin to maintain stable glucose levels in critically ill polytrauma patients supplemented with parenteral glutamine dipeptide (Dipeptiven(®)) versus standard nutritional support. This was an open-label randomized-controlled trial of 82 polytrauma patients aged 20-60 years old, randomly assigned into two equal groups independent of sex, age and Injury Severity Score. We excluded patients with diabetes mellitus, or renal or hepatic failure. One group received parenteral Dipeptiven(®) supplementation of 0.5 g/kg/day and the other received standard isocaloric isoproteinic nutritional support. We found that 63% of patients in the glutamine-supplemented group had no hyperglycemic episodes; only 37% required exogenous insulin (mean daily requirement of 44 units/day). In the control group, 51% of patients required insulin (mean daily requirement 63 unit/day; p = 0.0407). The effect of glutamine supplementation on glucose homeostasis is associated with a lower incidence of hyperglycemia among critically ill polytrauma patients, and leads to a lower mean daily dose of insulin. Controlled-trials.com Identifier: ISRCTN71592366 (http://www.controlled-trials.com/ISRCTN71592366/ISRCTN71592366). Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  10. BI 885578, a Novel IGF1R/INSR Tyrosine Kinase Inhibitor with Pharmacokinetic Properties That Dissociate Antitumor Efficacy and Perturbation of Glucose Homeostasis.

    PubMed

    Sanderson, Michael P; Apgar, Joshua; Garin-Chesa, Pilar; Hofmann, Marco H; Kessler, Dirk; Quant, Jens; Savchenko, Alexander; Schaaf, Otmar; Treu, Matthias; Tye, Heather; Zahn, Stephan K; Zoephel, Andreas; Haaksma, Eric; Adolf, Günther R; Kraut, Norbert

    2015-12-01

    Inhibition of the IGF1R, INSRA, and INSRB receptor tyrosine kinases represents an attractive approach of pharmacologic intervention in cancer, owing to the roles of the IGF1R and INSRA in promoting cell proliferation and survival. However, the central role of the INSRB isoform in glucose homeostasis suggests that prolonged inhibition of this kinase could result in metabolic toxicity. We describe here the profile of the novel compound BI 885578, a potent and selective ATP-competitive IGF1R/INSR tyrosine kinase inhibitor distinguished by rapid intestinal absorption and a short in vivo half-life as a result of rapid metabolic clearance. BI 885578, administered daily per os, displayed an acceptable tolerability profile in mice at doses that significantly reduced the growth of xenografted human GEO and CL-14 colon carcinoma tumors. We found that treatment with BI 885578 is accompanied by increases in circulating glucose and insulin levels, which in turn leads to compensatory hyperphosphorylation of muscle INSRs and subsequent normalization of blood glucose within a few hours. In contrast, the normalization of IGF1R and INSR phosphorylation in GEO tumors occurs at a much slower rate. In accordance with this, BI 885578 led to a prolonged inhibition of cell proliferation and induction of apoptosis in GEO tumors. We propose that the remarkable therapeutic window observed for BI 885578 is achieved by virtue of the distinctive pharmacokinetic properties of the compound, capitalizing on the physiologic mechanisms of glucose homeostasis and differential levels of IGF1R and INSR expression in tumors and normal tissues. ©2015 American Association for Cancer Research.

  11. Cognitive Performance: A Cross-Sectional Study on Serum Vitamin D and Its Interplay With Glucose Homeostasis in Dutch Older Adults.

    PubMed

    Brouwer-Brolsma, Elske M; Dhonukshe-Rutten, Rosalie A M; van Wijngaarden, Janneke P; van de Zwaluw, Nikita L; in 't Veld, Paulette H; Wins, Sophie; Swart, Karin M A; Enneman, Anke W; Ham, Annelies C; van Dijk, Suzanne C; van Schoor, Natasja M; van der Velde, Nathalie; Uitterlinden, Andre G; Lips, Paul; Kessels, Roy P C; Steegenga, Wilma T; Feskens, Edith J M; de Groot, Lisette C P G M

    2015-07-01

    First, the association between serum 25-hydroxyvitamin D (25[OH]D) and cognitive performance was examined. Second, we assessed whether there was evidence for an interplay between 25(OH)D and glucose homeostasis in the association with cognitive performance. Associations were studied using cross-sectional data of 776 (3 domains) up to 2722 (1 domain) Dutch community-dwelling older adults, aged 65 years or older. Serum 25(OH)D, plasma glucose, and insulin concentrations were obtained. Cognitive performance was assessed with an extensive cognitive test battery. Prevalence ratios (PRs) were calculated to quantify the association between 25(OH)D and cognition; poor performance was defined as the worst 10% of the distribution of the cognitive scores. The overall median MMSE score was 29 (IQR 28-30). Higher serum 25(OH)D was associated with better attention and working memory, PR 0.50 (95% CI 0.29-0.84) for the third serum 25(OH)D tertile, indicating a 50% lower probability of being a poor performer than participants in the lowest tertile. Beneficial trends were shown for 25(OH)D with executive function and episodic memory. Serum 25(OH)D was not associated with plasma glucose or insulin. Plasma insulin only modified the association between serum 25(OH)D and executive function (P for interaction: .001), suggesting that the improvement in executive function with high 25(OH)D concentrations is stronger in participants with high plasma insulin concentrations compared with those with low plasma insulin concentrations. Higher 25(OH)D concentrations significantly associated with better attention and working memory performance. This study does not demonstrate an interplay between serum 25(OH)D and glucose homeostasis in the association with cognitive performance. Copyright © 2015 AMDA - The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  12. Dietary Fatty Acids Differentially Associate with Fasting Versus 2-Hour Glucose Homeostasis: Implications for The Management of Subtypes of Prediabetes

    PubMed Central

    Guess, Nicola; Perreault, Leigh; Kerege, Anna; Strauss, Allison; Bergman, Bryan C.

    2016-01-01

    Over-nutrition has fuelled the global epidemic of type 2 diabetes, but the role of individual macronutrients to the diabetogenic process is not well delineated. We aimed to examine the impact of dietary fatty acid intake on fasting and 2-hour plasma glucose concentrations, as well as tissue-specific insulin action governing each. Normoglycemic controls (n = 15), athletes (n = 14), and obese (n = 23), as well as people with prediabetes (n = 10) and type 2 diabetes (n = 11), were queried about their habitual diet using a Food Frequency Questionnaire. All subjects were screened by an oral glucose tolerance test (OGTT) and studied using the hyperinsulinemic/euglycemic clamp with infusion of 6,62H2-glucose. Multiple regression was performed to examine relationships between dietary fat intake and 1) fasting plasma glucose, 2) % suppression of endogenous glucose production, 3) 2-hour post-OGTT plasma glucose, and 4) skeletal muscle insulin sensitivity (glucose rate of disappearance (Rd) and non-oxidative glucose disposal (NOGD)). The %kcal from saturated fat (SFA) was positively associated with fasting (β = 0.303, P = 0.018) and 2-hour plasma glucose (β = 0.415, P<0.001), and negatively related to % suppression of hepatic glucose production (β = -0.245, P = 0.049), clamp Rd (β = -0.256, P = 0.001) and NOGD (β = -0.257, P = 0.001). The %kcal from trans fat was also negatively related to clamp Rd (β = -0.209, P = 0.008) and NOGD (β = -0.210, P = 0.008). In contrast, the %kcal from polyunsaturated fat (PUFA) was negatively associated with 2-hour glucose levels (β = -0.383, P = 0.001), and positively related to Rd (β = 0.253, P = 0.007) and NOGD (β = 0.246, P = 0.008). Dietary advice to prevent diabetes should consider the underlying pathophysiology of the prediabetic state. PMID:26999667

  13. Reevaluation of the non-lesional dry skin in atopic dermatitis by acute barrier disruption: an abnormal permeability barrier homeostasis with defective processing to generate ceramide.

    PubMed

    Sugiura, Ayumi; Nomura, Tsuyoshi; Mizuno, Atsuko; Imokawa, Genji

    2014-07-01

    Atopic dermatitis is characterized by disruption of the cutaneous barrier due to reduced ceramide levels even in non-lesional dry skin. Following further acute barrier disruption by repeated tape strippings, we re-characterized the non-lesional dry skin of subjects with atopic dermatitis, which shows significantly reduced levels of barrier function and ceramide but not of beta-glucocerebrosidase activity. For the first time, we report an abnormal trans-epidermal water loss homeostasis in which delayed recovery kinetics of trans-epidermal water loss occurred on the first day during the 4 days after acute barrier disruption compared with healthy control skin. Interestingly, whereas the higher ceramide level in the stratum corneum of healthy control skin was further significantly up-regulated at 4 days post-tape stripping, the lower ceramide level in the stratum corneum of subjects with atopic dermatitis was not significantly changed. In a parallel study, whereas beta-glucocerebrosidase activity at 4 days post-tape stripping was significantly up-regulated in healthy control skin compared with before tape stripping, the level of that activity remained substantially unchanged in atopic dermatitis. These findings indicate that subjects with atopic dermatitis have a defect in sphingolipid-metabolic processing that generates ceramide in the interface between the stratum corneum and the epidermis. The results also support the notion that the continued disruption of barrier function in atopic dermatitis non-lesional skin is associated with the impaired homeostasis of a ceramide-generating process, which underscores an atopy-specific inflammation-triggered ceramide deficiency that is distinct from other types of dermatitis.

  14. Effects of Saturated Fat, Polyunsaturated Fat, Monounsaturated Fat, and Carbohydrate on Glucose-Insulin Homeostasis: A Systematic Review and Meta-analysis of Randomised Controlled Feeding Trials

    PubMed Central

    Micha, Renata; Wu, Jason H. Y.; de Oliveira Otto, Marcia C.; Mozaffarian, Dariush

    2016-01-01

    Background Effects of major dietary macronutrients on glucose-insulin homeostasis remain controversial and may vary by the clinical measures examined. We aimed to assess how saturated fat (SFA), monounsaturated fat (MUFA), polyunsaturated fat (PUFA), and carbohydrate affect key metrics of glucose-insulin homeostasis. Methods and Findings We systematically searched multiple databases (PubMed, EMBASE, OVID, BIOSIS, Web-of-Knowledge, CAB, CINAHL, Cochrane Library, SIGLE, Faculty1000) for randomised controlled feeding trials published by 26 Nov 2015 that tested effects of macronutrient intake on blood glucose, insulin, HbA1c, insulin sensitivity, and insulin secretion in adults aged ≥18 years. We excluded trials with non-isocaloric comparisons and trials providing dietary advice or supplements rather than meals. Studies were reviewed and data extracted independently in duplicate. Among 6,124 abstracts, 102 trials, including 239 diet arms and 4,220 adults, met eligibility requirements. Using multiple-treatment meta-regression, we estimated dose-response effects of isocaloric replacements between SFA, MUFA, PUFA, and carbohydrate, adjusted for protein, trans fat, and dietary fibre. Replacing 5% energy from carbohydrate with SFA had no significant effect on fasting glucose (+0.02 mmol/L, 95% CI = -0.01, +0.04; n trials = 99), but lowered fasting insulin (-1.1 pmol/L; -1.7, -0.5; n = 90). Replacing carbohydrate with MUFA lowered HbA1c (-0.09%; -0.12, -0.05; n = 23), 2 h post-challenge insulin (-20.3 pmol/L; -32.2, -8.4; n = 11), and homeostasis model assessment for insulin resistance (HOMA-IR) (-2.4%; -4.6, -0.3; n = 30). Replacing carbohydrate with PUFA significantly lowered HbA1c (-0.11%; -0.17, -0.05) and fasting insulin (-1.6 pmol/L; -2.8, -0.4). Replacing SFA with PUFA significantly lowered glucose, HbA1c, C-peptide, and HOMA. Based on gold-standard acute insulin response in ten trials, PUFA significantly improved insulin secretion capacity (+0.5 pmol/L/min; 0.2, 0

  15. Palmitic acid in the sn-2 position of dietary triacylglycerols does not affect insulin secretion or glucose homeostasis in healthy men and women

    PubMed Central

    Filippou, A; Teng, K-T; Berry, S E; Sanders, T A B

    2014-01-01

    Background/objectives: Dietary triacylglycerols containing palmitic acid in the sn-2 position might impair insulin release and increase plasma glucose. Subjects/Methods: We used a cross-over designed feeding trial in 53 healthy Asian men and women (20–50 years) to test this hypothesis by exchanging 20% energy of palm olein (PO; control) with randomly interesterified PO (IPO) or high oleic acid sunflower oil (HOS). After a 2-week run-in period on PO, participants were fed PO, IPO and HOS for 6 week consecutively in randomly allocated sequences. Fasting (midpoint and endpoint) and postprandial blood at the endpoint following a test meal (3.54 MJ, 14 g protein, 85 g carbohydrate and 50 g fat as PO) were collected for the measurement of C-peptide, insulin, glucose, plasma glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1, lipids and apolipoproteins; pre-specified primary and secondary outcomes were postprandial changes in C-peptide and plasma glucose. Results: Low density lipoprotein cholesterol was 0.3 mmol/l (95% confidence interval (95% CI)) 0.1, 0.5; P<0.001) lower on HOS than on PO or IPO as predicted, indicating good compliance to the dietary intervention. There were no significant differences (P=0.58) between diets among the 10 male and 31 female completers in the incremental area under the curve (0–2 h) for C-peptide in nmol.120 min/l: GM (95% CI) were PO 220 (196, 245), IPO 212 (190, 235) and HOS 224 (204, 244). Plasma glucose was 8% lower at 2 h on IPO vs PO and HOS (both P<0.05). Conclusion: Palmitic acid in the sn-2 position does not adversely impair insulin secretion and glucose homeostasis. PMID:25052227

  16. Palmitic acid in the sn-2 position of dietary triacylglycerols does not affect insulin secretion or glucose homeostasis in healthy men and women.

    PubMed

    Filippou, A; Teng, K-T; Berry, S E; Sanders, T A B

    2014-09-01

    Dietary triacylglycerols containing palmitic acid in the sn-2 position might impair insulin release and increase plasma glucose. We used a cross-over designed feeding trial in 53 healthy Asian men and women (20-50 years) to test this hypothesis by exchanging 20% energy of palm olein (PO; control) with randomly interesterified PO (IPO) or high oleic acid sunflower oil (HOS). After a 2-week run-in period on PO, participants were fed PO, IPO and HOS for 6 week consecutively in randomly allocated sequences. Fasting (midpoint and endpoint) and postprandial blood at the endpoint following a test meal (3.54 MJ, 14 g protein, 85 g carbohydrate and 50 g fat as PO) were collected for the measurement of C-peptide, insulin, glucose, plasma glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1, lipids and apolipoproteins; pre-specified primary and secondary outcomes were postprandial changes in C-peptide and plasma glucose. Low density lipoprotein cholesterol was 0.3 mmol/l (95% confidence interval (95% CI)) 0.1, 0.5; P<0.001) lower on HOS than on PO or IPO as predicted, indicating good compliance to the dietary intervention. There were no significant differences (P=0.58) between diets among the 10 male and 31 female completers in the incremental area under the curve (0-2 h) for C-peptide in nmol.120 min/l: GM (95% CI) were PO 220 (196, 245), IPO 212 (190, 235) and HOS 224 (204, 244). Plasma glucose was 8% lower at 2 h on IPO vs PO and HOS (both P<0.05). Palmitic acid in the sn-2 position does not adversely impair insulin secretion and glucose homeostasis.

  17. Plasma metabolomic profiles reflective of glucose homeostasis in non-diabetic and Type 2 diabetic obese African-American women

    USDA-ARS?s Scientific Manuscript database

    Insulin resistance progressing to type 2 diabetes mellitus (T2DM) is marked by a broad perturbation of macronutrient intermediary metabolism. Understanding the biochemical networks that underlie metabolic homeostasis and how they associate with insulin action will help unravel diabetes etiology and...

  18. Improvements in glucose homeostasis in response to regular exercise are influenced by the PPARG Pro12Ala variant: results from the HERITAGE Family Study.

    PubMed

    Ruchat, S-M; Rankinen, T; Weisnagel, S J; Rice, T; Rao, D C; Bergman, R N; Bouchard, C; Pérusse, L

    2010-04-01

    Exercise training improves glucose homeostasis, but large inter-individual differences are reported, suggesting a role of genetic factors. We investigated whether variants either confirmed or newly identified as diabetes susceptibility variants through genome-wide association studies (GWAS) modulate changes in phenotypes derived from an IVGTT in response to an endurance training programme. We analysed eight polymorphisms in seven type 2 diabetes genes (CDKAL1 rs7756992; CDKN2A and CDKN2B rs10811661 and rs564398; HHEX rs7923837; IGF2BP2 rs4402960; KCNJ11 rs5215; PPARG rs1801282; and TCF7L2 rs7903146) in a maximum of 481 sedentary, non-diabetic white individuals, who participated in a 20-week endurance training programme. Associations were tested between the variants and changes in IVGTT-derived phenotypes. The only evidence of association with training response was found with PPARG rs1801282 (Pro12Ala). We observed that Ala carriers experienced greater increase in overall glucose tolerance (Deltaglucose disappearance index Ala/Ala 0.22 +/- 0.22, Pro/Ala 0.14 +/- 0.06, Pro/Pro 0.004 +/- 0.03; p = 0.0008), glucose effectiveness (Ala/Ala 0.28 +/- 0.41, Pro/Ala 0.44 +/- 0.14, Pro/Pro 0.09 +/- 0.06; p = 0.004), acute insulin response to glucose (Ala/Ala 64.21 +/- 37.73, Pro/Ala -11.92 +/- 40.30, Pro/Pro -46.30 +/- 14.70; p = 0.03) and disposition index (Ala/Ala 551.8 +/- 448.5, Pro/Ala 534.6 +/- 218.3, Pro/Pro -7.44 +/- 88.18; p = 0.003). Compared with Pro/Pro individuals, PPARG Ala carriers experienced greater improvements in glucose and insulin metabolism in response to regular endurance training. However, we did not find evidence of association between type 2 diabetes susceptibility variants recently identified through GWAS and glucose homeostasis response to exercise. Our results extend those of previous studies showing that Ala carriers appear to be more responsive to beneficial health effects of lifestyle interventions.

  19. Risk factors associated with abnormal glucose tolerance in the early postpartum period among Japanese women with gestational diabetes.

    PubMed

    Kugishima, Yukari; Yasuhi, Ichiro; Yamashita, Hiroshi; Fukuda, Masashi; Kuzume, Akiko; Sugimi, So; Umezaki, Yasushi; Suga, Sachie; Kusuda, Nobuko

    2015-04-01

    To identify the risk factors associated with abnormal glucose tolerance (AGT) on the first postpartum oral glucose tolerance test (OGTT) among Japanese women with gestational diabetes (GDM). In a retrospective study, data were analyzed from women with GDM who underwent their first postpartum OGTT 6-8weeks post partum at a center in Omura, Japan, between January 1, 2007, and December 31, 2011. Women with diabetes or impaired glucose tolerance were deemed to have postpartum AGT. The association between postpartum AGT and various risk factors was analyzed. Among 169 women who underwent a postpartum OGTT, 58 (34.3%) had AGT. The significant risk factors associated with postpartum AGT in univariate analysis were pre-pregnancy body mass index (P=0.096), 1-hour plasma glucose (P=0.006), hemoglobin A1c (P<0.001), insulinogenic index (P=0.05), an insulinogenic index of less than 0.4 (P=0.006), and insulin therapy during pregnancy (P<0.001). Independent risk factors identified by multivariate logistic regression models were insulinogenic index (odds ratio [OR] 0.10, 95% confidence interval [CI] 0.01-0.74; P=0.002), an insulinogenic index of less than 0.4 (OR 5.70, 95% CI 1.69-21.66; P=0.005), and insulin therapy during pregnancy (OR 3.43, 95% CI 1.03-12.55; P=0.044). Among Japanese women with GDM, a lower insulinogenic index and use of insulin therapy during pregnancy are associated with early postpartum AGT. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  20. Impact of long-term potassium supplementation on thiazide diuretic-induced abnormalities of glucose and uric acid metabolisms.

    PubMed

    Zhang, Jian-Liang; Yu, Hui; Hou, Ying-Wei; Wang, Ke; Bi, Wen-Shan; Zhang, Liang; Wang, Qian; Li, Pan; Yu, Man-Li; Zhao, Xian-Xian

    2018-04-01

    Treatment of hypertension with thiazide diuretics may trigger hypokalemia, hyperglycemia, and hyperuricemia. Some studies suggest simultaneous potassium supplementation in hypertensive patients using thiazide diuretics. However, few clinical studies have reported the impact of long-term potassium supplementation on thiazide diuretic-induced abnormalities in blood glucose and uric acid (UA) metabolisms. One hundred hypertensive patients meeting the inclusion criteria were equally randomized to two groups: IND group receiving indapamide (1.25-2.5 mg daily) alone, and IND/KCI group receiving IND (1.25-2.5 mg daily) plus potassium chloride (40 mmol daily), both for 24 weeks. At the end of 24-week follow-up, serum K + level in IND group decreased from 4.27 ± 0.28 to 3.98 ± 0.46 mmol/L (P < 0.001), and fasting plasma glucose (FPG) and UA increased from 5.11 ± 0.52 to 5.31 ± 0.57 mmol/L (P < 0.05), and from 0.404 ± 0.078 to 0.433 ± 0.072 mmol/L (P < 0.05), respectively. Serum K + level in IND/KCl group decreased from 4.27 ± 0.36 to 3.89 ± 0.28 mmol/L (P < 0.001), and FPB and UA increased from 5.10 ± 0.41 to 5.35 ± 0.55 mmol/L (P < 0.01), and from 0.391 ± 0.073 to 0.457 ± 0.128 mmol/L (P < 0.001), respectively. The difference value between the serum K + level and FPG before and after treatment was not statistically significant between the two groups. However, the difference value in UA in IND/KCl group was significantly higher than that in IND group (0.066 (95% confidence interval (CI): 0.041-0.090)  mmol/L vs. 0.029 (95% CI: 0.006-0.058) mmol/L, P < 0.05). The results showed that long-term routine potassium supplementation could not prevent or attenuate thiazide diuretic-induced abnormalities of glucose metabolism in hypertensive patients; rather, it may aggravate the UA metabolic abnormality.

  1. Extrastriatal dopaminergic abnormalities of DA homeostasis in Parkinson’s patients with medication-induced pathological gambling: A [11C] FLB-457 and PET study

    PubMed Central

    Ray, Nicola J.; Miyasaki, Janis M.; Zurowski, Mateusz; Ko, Ji Hyun; Cho, Sang Soo; Pellecchia, Giovanna; Antonelli, Francesca; Houle, Sylvain; Lang, Anthony E.; Strafella, Antonio P.

    2012-01-01

    Impulse control disorders such as pathological gambling (PG) are a serious and common adverse effect of dopamine (DA) replacement medication in Parkinson’s disease (PD). Patients with PG have increased impulsivity and abnormalities in striatal DA, in common with behavioural and substance addictions in the non-PD population. To date, no studies have investigated the role of extrastriatal dopaminergic abnormalities in PD patients with PG. We used the PET radiotracer, [11C] FLB-457, with high-affinity for extrastriatal DA D2/3 receptors. 14 PD patients on DA agonists were imaged while they performed a gambling task involving real monetary reward and a control task. Trait impulsivity was measured with the Barratt Impulsivity Scale (BIS). Seven of the patients had a history of PG that developed subsequent to DA agonist medication. Change in [11C] FLB-457 binding potential (BP) during gambling was reduced in PD with PG patients in the midbrain, where D2/D3 receptors are dominated by autoreceptors. The degree of change in [11C] FLB-457 binding in this region correlated with impulsivity. In the cortex, [11C] FLB-457 BP was significantly greater in the anterior cingulate cortex (ACC) in PD patients with PG during the control task, and binding in this region was also correlated with impulsivity. Our findings provide the first evidence that PD patients with PG have dysfunctional activation of DA autoreceptors in the midbrain and low DA tone in the ACC. Thus, altered striatal and cortical DA homeostasis may incur vulnerability for the development of PG in PD, linked with the impulsive personality trait. PMID:22766031

  2. BH3-Only protein bmf is required for the maintenance of glucose homeostasis in an in vivo model of HNF1α-MODY diabetes.

    PubMed

    Pfeiffer, S; Halang, L; Düssmann, H; Byrne, M M; Prehn, Jhm

    2015-01-01

    Heterozygous loss-of-function mutations in the hepatocyte nuclear factor 1α (HNF-1α) gene can lead to diminished amounts of functional HNF-1α, resulting in the onset of a particularly severe form of maturity-onset diabetes of the young (MODY). We have previously shown that induction of a dominant-negative mutant of HNF-1α (DNHNF-1α) results in the activation of the bioenergetic stress sensor AMP-activated protein kinase (AMPK), preceding the onset of apoptosis and the induction of pro-apoptotic Bcl-2 homology domain-3-only protein Bmf (Bcl-2-modifying factor) as a mediator of DNHNF-1α-induced apoptosis. Through the knockout of bmf in a transgenic mouse model with DNHNF-1α suppression of HNF-1α function in pancreatic beta-cells, this study aimed to examine the effect of loss-of-function of this BH3-only protein on the disease pathology and progression, and further elucidate the role of Bmf in mediating DNHNF-1α-induced beta-cell loss. Morphological analysis revealed an attenuation in beta-cell loss in bmf-deficient diabetic male mice and preserved insulin content. Surprisingly, bmf deficiency was found to exacerbate hyperglycemia in both diabetic male and hyperglycemic female mice, and ultimately resulted in a decreased glucose-stimulated insulin response, implicating a role for Bmf in glucose homeostasis regulation independent of an effect on beta-cell loss. Collectively, our data demonstrate that Bmf contributes to the decline in beta-cells in a mouse model of HNF1A-MODY but is also required for the maintenance of glucose homeostasis in vivo.

  3. BH3-Only protein bmf is required for the maintenance of glucose homeostasis in an in vivo model of HNF1α-MODY diabetes

    PubMed Central

    Pfeiffer, S; Halang, L; Düssmann, H; Byrne, MM; Prehn, JHM

    2015-01-01

    Heterozygous loss-of-function mutations in the hepatocyte nuclear factor 1α (HNF-1α) gene can lead to diminished amounts of functional HNF-1α, resulting in the onset of a particularly severe form of maturity-onset diabetes of the young (MODY). We have previously shown that induction of a dominant-negative mutant of HNF-1α (DNHNF-1α) results in the activation of the bioenergetic stress sensor AMP-activated protein kinase (AMPK), preceding the onset of apoptosis and the induction of pro-apoptotic Bcl-2 homology domain-3-only protein Bmf (Bcl-2-modifying factor) as a mediator of DNHNF-1α-induced apoptosis. Through the knockout of bmf in a transgenic mouse model with DNHNF-1α suppression of HNF-1α function in pancreatic beta-cells, this study aimed to examine the effect of loss-of-function of this BH3-only protein on the disease pathology and progression, and further elucidate the role of Bmf in mediating DNHNF-1α-induced beta-cell loss. Morphological analysis revealed an attenuation in beta-cell loss in bmf-deficient diabetic male mice and preserved insulin content. Surprisingly, bmf deficiency was found to exacerbate hyperglycemia in both diabetic male and hyperglycemic female mice, and ultimately resulted in a decreased glucose-stimulated insulin response, implicating a role for Bmf in glucose homeostasis regulation independent of an effect on beta-cell loss. Collectively, our data demonstrate that Bmf contributes to the decline in beta-cells in a mouse model of HNF1A-MODY but is also required for the maintenance of glucose homeostasis in vivo. PMID:27551471

  4. Eating carbohydrate mostly at lunch and protein mostly at dinner within a covert hypocaloric diet influences morning glucose homeostasis in overweight/obese men.

    PubMed

    Alves, Raquel Duarte Moreira; de Oliveira, Fernanda Cristina Esteves; Hermsdorff, Helen Hermana Miranda; Abete, Itziar; Zulet, María Angeles; Martínez, José Alfredo; Bressan, Josefina

    2014-02-01

    To evaluate the effects of two dietary patterns in which carbohydrates and proteins were eaten mostly at lunch or dinner on body weight and composition, energy metabolism, and biochemical markers in overweight/obese men. Fifty-eight men (30.0 ± 7.4 years; 30.8 ± 2.4 kg/m(2)) followed a covert hypocaloric balanced diet (-10 % of daily energy requirements) during 8 weeks. Subjects were randomly assigned to three groups: control diet (CT); diurnal carbohydrate/nocturnal protein (DCNP); and nocturnal carbohydrate/diurnal protein (NCDP). Main analyzed outcomes were weight loss, body composition, diet-induced thermogenesis (DIT), and glucose/lipid profile. In all groups, a significant decrease in body weight, BMI, and fat mass (kg and %) was verified, without differences between groups. Interestingly, within group analyses showed that the fat-free mass (kg) significantly decreased in NCDP and in CT after 8-week intervention, but not in DCNP. A detrimental increase in fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMAIR) was verified only in DCNP, while NCDP and CT groups presented a non-significant reduction. Moreover, significant differences between DCNP and the other groups were detected for fasting insulin and HOMAIR. After the adjustments, NCDP presented a significantly higher DIT and energy expenditure after lunch, compared with DCNP, but after dinner, there were no differences among groups. Eating carbohydrates mostly at dinner and protein mostly at lunch within a hypocaloric balanced diet had similar effect on body composition and biochemical markers, but higher effect on DIT compared with control diet. Moreover, eating carbohydrates mostly at lunch and protein mostly at dinner had a deleterious impact on glucose homeostasis.

  5. AP4M1 is abnormally expressed in oxygen-glucose deprived hippocampal neurons.

    PubMed

    Zhang, J; Cheng, X Y; Sheng, G Y

    2014-03-20

    AP4M1 mutations have been suggested to be associated with autosomal recessive cerebral palsy syndrome. But the pathogenic mechanism remains uncertain. The purpose of this study is to investigate whether and how AP4M1 expression is changed in injured neurons. Primary cultured hippocampal neurons were prepared for this experiment. They were subjected to oxygen-glucose deprivation (OGD) leading to apoptosis, mimicking brain ischemia. Neuron-specific enolase (NSE) was labeled immunofluorescently to confirm that the purity of neuron was higher than 90%. Real-time PCR and western blotting were performed to measure the gene expression. AP4M1 was labeled with MAP2 or Tau-1 to observe the distribution. We found that the AP4M1 protein levels immediately after the procedure were similar between the OGD group and the sham group. However, down-regulation was observed 12h after the reperfusion, and became more notable at 24h. The real-time PCR showed similar results, except that the down-regulation of mRNA was able to be detected immediately after the OGD. Immunofluorescent labeling revealed AP4M1 distributed in the dendrites of normal neurons, but it redistributed to the axons after the OGD procedure. In conclusion, AP4M1 is not only down-regulated at both the mRNA and protein levels, but also redistributed from dendrites to axons in oxygen-glucose deprived hippocampal neurons. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Chickens from lines artificially selected for juvenile low and high body weight differ in glucose homeostasis and pancreas physiology.

    PubMed

    Sumners, L H; Zhang, W; Zhao, X; Honaker, C F; Zhang, S; Cline, M A; Siegel, P B; Gilbert, E R

    2014-06-01

    Artificial selection of White Plymouth Rock chickens for juvenile (day 56) body weight resulted in two divergent genetic lines: hypophagic low weight (LWS) chickens and hyperphagic obese high weight (HWS) chickens, with the latter more than 10-fold heavier than the former at selection age. A study was designed to investigate glucose regulation and pancreas physiology at selection age in LWS chickens and HWS chickens. Oral glucose tolerance and insulin sensitivity tests revealed differences in threshold sensitivity to insulin and glucose clearance rate between the lines. Results from real-time PCR showed greater pancreatic mRNA expression of four glucose regulatory genes (preproinsulin, PPI; preproglucagon, PPG; glucose transporter 2, GLUT2; and pancreatic duodenal homeobox 1, Pdx1) in LWS chickens, than HWS chickens. Histological analysis of the pancreas revealed that HWS chickens have larger pancreatic islets, less pancreatic islet mass, and more pancreatic inflammation than LWS chickens, all of which presumably contribute to impaired glucose metabolism. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. The Resist Diabetes trial: Rationale, design, and methods of a hybrid efficacy/effectiveness intervention trial for resistance training maintenance to improve glucose homeostasis in older prediabetic adults

    PubMed Central

    Marinik, Elaina L.; Kelleher, Sarah; Savla, Jyoti; Winett, Richard A.; Davy, Brenda M.

    2014-01-01

    Advancing age is associated with reduced levels of physical activity, increased body weight and fat, decreased lean body mass, and a high prevalence of type 2 diabetes (T2D). Resistance training (RT) increases muscle strength and lean body mass, and reduces risk of T2D among older adults. The Resist Diabetes trial will determine if a social cognitive theory (SCT)-based intervention improves RT maintenance in older, prediabetic adults, using a hybrid efficacy/effectiveness approach. Sedentary, overweight/obese (BMI 25-39.9 kg/m2) adults aged 50-69 (N=170) with prediabetes (impaired fasting glucose and/or impaired glucose tolerance) completed a supervised 3-month RT (2x/wk) Initiation Phase and were then randomly assigned (n=159; 94% retention) to one of two 6-month maintenance conditions: SCT or Standard care. The SCT intervention consisted of faded contacts compared to Standard care. Participants continue RT at an approved, self-selected community facility during maintenance. A subsequent 6-month period involves no contact for both conditions. Assessments occur at baseline and months 3 (post-initiation), 9 (post-intervention), and 15 (six months after no contact). Primary outcomes are prediabetes indices (i.e., impaired fasting and 2-hour glucose concentration) and strength. Secondary measures include insulin sensitivity, beta-cell responsiveness, and disposition index (oral glucose and C-peptide minimal model); adherence; body composition; and SCT measures. Resist Diabetes is the first trial to examine the effectiveness of a high fidelity SCT-based intervention for maintaining RT in older adults with prediabetes to improve glucose homeostasis. Successful application of SCT constructs for RT maintenance may support translation of our RT program for diabetes prevention into community settings. PMID:24252311

  8. Maternal and post-weaning high-fat, high-sucrose diet modulates glucose homeostasis and hypothalamic POMC promoter methylation in mouse offspring.

    PubMed

    Zheng, Jia; Xiao, Xinhua; Zhang, Qian; Yu, Miao; Xu, Jianping; Wang, Zhixin; Qi, Cuijuan; Wang, Tong

    2015-10-01

    Substantial evidence demonstrated that maternal dietary nutrients can significantly determine the susceptibility to developing metabolic disorders in the offspring. Therefore, we aimed to investigate the later-life effects of maternal and postweaning diets interaction on epigenetic modification of the central nervous system in the offspring. We examined the effects of dams fed a high-fat, high-sucrose (FS) diet during pregnancy and lactation and weaned to FS diet continuously until 32 weeks of age. Then, DNA methylation and gene expressions of hypothalamic proopiomelanocortin (POMC) and melanocortin receptor 4 (MC4R) were determined in the offspring. Offspring of FS diet had heavier body weight, impaired glucose tolerance, decreased insulin sensitivity and higher serum leptin level at 32-week age (p < 0.05). The expression of POMC and MC4R genes were significantly increased in offspring exposed to FS diet during gestation, lactation and into 32-week age (p < 0.05). Consistently, hypomethylation of POMC promoter in the hypothalamus occurred in the FS diet offspring (p < 0.05), compared with the C group. However, no methylation was detected of MC4R promoter in both the two groups. Furthermore, POMC-specific methylation (%) was negatively associated with glucose response to a glucose load (r = -0.273, p = 0.039). Maternal and post-weaning high-fat diet predisposes the offspring for obesity, glucose intolerance and insulin resistance in later life. Our findings can advance our thinking around the DNA methylation status of the promoter of the POMC and MC4R genes between long-term high-fat, high-sucrose diet and glucose homeostasis in mouse.

  9. Double blockade of angiotensin II (AT1)-receptors and ACE does not improve weight gain and glucose homeostasis better than single-drug treatments in obese rats

    PubMed Central

    Miesel, Anja; Müller-Fielitz, Helge; Jöhren, Olaf; Vogt, Florian M; Raasch, Walter

    2012-01-01

    BACKGROUND AND PURPOSE Combination therapies are becoming increasingly important for the treatment of high blood pressure. Little is known about whether double blockade of angiotensin II (AT1) receptors and angiotensin-converting enzyme (ACE) exert synergistic metabolic effects. EXPERIMENTAL APPROACH Spontaneously hypertensive rats were allowed to choose between palatable chocolate bars and standard chow and were simultaneously treated with the AT1 blocker telmisartan (8 mg·kgbw−1·day−1), the ACE inhibitor ramipril (4 mg·kgbw−1·day−1) or a combination of the two (8 + 4 mg·kgbw−1·day−1) for 12 weeks. KEY RESULTS Although food-dependent energy intake was increased by telmisartan and telmisartan + ramipril compared with ramipril or controls, body weight gain, abundance of fat and plasma leptin levels were decreased. Increased insulin levels in response to an oral glucose tolerance test were comparably attenuated by telmisartan and telmisartan + ramipril, but not by ramipril. During an insulin tolerance test, glucose utilization was equally as effectively improved by telmisartan and telmisartan + ramipril. In response to a stress test, ACTH, corticosterone and glucose increased in controls. These stress reactions were attenuated by telmisartan and telmisartan + ramipril. CONCLUSIONS AND IMPLICATIONS The combination of telmisartan + ramipril was no more efficacious in regulating body weight and glucose homeostasis than telmisartan alone. However, telmisartan was more effective than ramipril in improving metabolic parameters and in reducing body weight. The association between the decrease in stress responses and the diminished glucose levels after stress supports our hypothesis that the ability of telmisartan, as an AT1 receptor blocker, to alleviate stress reactions may contribute to its hypoglycaemic actions. PMID:22014027

  10. The resist diabetes trial: Rationale, design, and methods of a hybrid efficacy/effectiveness intervention trial for resistance training maintenance to improve glucose homeostasis in older prediabetic adults.

    PubMed

    Marinik, Elaina L; Kelleher, Sarah; Savla, Jyoti; Winett, Richard A; Davy, Brenda M

    2014-01-01

    Advancing age is associated with reduced levels of physical activity, increased body weight and fat, decreased lean body mass, and a high prevalence of type 2 diabetes (T2D). Resistance training (RT) increases muscle strength and lean body mass, and reduces risk of T2D among older adults. The Resist Diabetes trial will determine if a social cognitive theory (SCT)-based intervention improves RT maintenance in older, prediabetic adults, using a hybrid efficacy/effectiveness approach. Sedentary, overweight/obese (BMI: 25-39.9 kg/m(2)) adults aged 50-69 (N = 170) with prediabetes (impaired fasting glucose and/or impaired glucose tolerance) completed a supervised 3-month RT (2×/wk) initiation phase and were then randomly assigned (N = 159; 94% retention) to one of two 6-month maintenance conditions: SCT or standard care. The SCT intervention consisted of faded contacts compared to standard care. Participants continue RT at an approved, self-selected community facility during maintenance. A subsequent 6-month period involves no contact for both conditions. Assessments occur at baseline and months 3 (post-initiation), 9 (post-intervention), and 15 (six months after no contact). Primary outcomes are prediabetes indices (i.e., impaired fasting and 2-hour glucose concentration) and strength. Secondary measures include insulin sensitivity, beta-cell responsiveness, and disposition index (oral glucose and C-peptide minimal model); adherence; body composition; and SCT measures. Resist Diabetes is the first trial to examine the effectiveness of a high fidelity SCT-based intervention for maintaining RT in older adults with prediabetes to improve glucose homeostasis. Successful application of SCT constructs for RT maintenance may support translation of our RT program for diabetes prevention into community settings. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Study on the relationship between the expression of IGF-1 in umbilical cord blood and abnormal glucose metabolism during pregnancy.

    PubMed

    Liu, K; Wu, H-Y; Xu, Y-H

    2017-02-01

    To explore the relationship between the expression of insulin-like growth factor-1 (IGF-1) in neonatal umbilical cord blood and abnormal glucose metabolism during pregnancy. We have selected 63 cases of delivery randomly, term birth and maternal from January 2015 to January 2016 in our hospital, gestational diabetes mellitus for Group A, abnormal gestational glucose tolerance for Group B and normal for Group C with 21 cases in each group. The venous blood samples were collected from all the pregnant females 2 weeks before delivery, and the levels of HbA1c in serum were detected by Elisa method. During the delivery, the umbilical cord blood was collected and the levels of IGF-1 were measured by double site immune enzyme analysis. The neonatal weight was recorded and the correlation analysis was made in respect of the measurement results. The level of HbA1c in Group A was significantly higher than that in Group C (p < 0.05); IGF-1 level and neonatal weight of Group B were significantly higher than that of Group C (p < 0.05), IGF-1 has a significant correlation with neonatal weight in Group C, and HbA1c and IGF-1 were positively correlated (p < 0.05); IGF-1 was positively correlated with neonatal weight in Group A and Group B (p < 0.05). There was a significant positive correlation between the IGF-1 level of neonatal umbilical cord blood and the neonatal weight (p < 0.05). Also, the level of HbA1c was positively correlated with the level of IGF-1 in neonatal umbilical cord blood at the end of pregnancy (p < 0.05). The expression level of IGF-1 in the final stage of pregnant females can be detected to predict the expression level of IGF-1 in newborn infants and then the growth status of the fetus can be obtained.

  12. Soy Leaf Extract Containing Kaempferol Glycosides and Pheophorbides Improves Glucose Homeostasis by Enhancing Pancreatic β-Cell Function and Suppressing Hepatic Lipid Accumulation in db/db Mice.

    PubMed

    Li, Hua; Ji, Hyeon-Seon; Kang, Ji-Hyun; Shin, Dong-Ha; Park, Ho-Yong; Choi, Myung-Sook; Lee, Chul-Ho; Lee, In-Kyung; Yun, Bong-Sik; Jeong, Tae-Sook

    2015-08-19

    This study investigated the molecular mechanisms underlying the antidiabetic effect of an ethanol extract of soy leaves (ESL) in db/db mice. Control groups (db/+ and db/db) were fed a normal diet (ND), whereas the db/db-ESL group was fed ND with 1% ESL for 8 weeks. Dietary ESL improved glucose tolerance and lowered plasma glucose, glycated hemoglobin, HOMA-IR, and triglyceride levels. The pancreatic insulin content of the db/db-ESL group was significantly greater than that of the db/db group. ESL supplementation altered pancreatic IRS1, IRS2, Pdx1, Ngn3, Pax4, Ins1, Ins2, and FoxO1 expression. Furthermore, ESL suppressed lipid accumulation and increased glucokinase activity in the liver. ESL primarily contained kaempferol glycosides and pheophorbides. Kaempferol, an aglycone of kaempferol glycosides, improved β-cell proliferation through IRS2-related FoxO1 signaling, whereas pheophorbide a, a product of chlorophyll breakdown, improved insulin secretion and β-cell proliferation through IRS1-related signaling with protein kinase A in MIN6 cells. ESL effectively regulates glucose homeostasis by enhancing IRS-mediated β-cell insulin signaling and suppressing SREBP-1-mediated hepatic lipid accumulation in db/db mice.

  13. Gestational glucocorticoid exposure disrupts glucose homeostasis that is accompanied by increased endoglin and DPP-4 activity instead of GSK-3 in rats.

    PubMed

    Badmus, Olufunto O; Michael, Olugbenga S; Rabiu, Saheed; Olatunji, Lawrence A

    2018-04-13

    Gestational glucocorticoid (GC) treatment has been associated with cardiometabolic disorder (CMD) in offspring's in later life. Elevated dipeptidyl peptidase-4 (DPP-4) activity, endoglin and glycogen synthase kinase-3 (GSK-3) has also been implicated in the development of insulin resistance (IR) and/or vascular inflammation. We aimed to investigate the impact of GC exposure on glucose metabolism and the circulating levels of inflammatory biomarkers, DPP-4 activity and GSK-3 in pregnant rats. Pregnant Wistar rats received either vehicle or dexamethasone (DEX; 0.2 mg/kg; po) between gestational days 14 and 19. Gestational GC exposure resulted in impaired glucose homeostasis that is accompanied with elevated circulating levels of inflammatory biomarkers (endoglin, uric acid, and platelet/lymphocyte ratio), oxidative stress (malondialdehyde), blood viscosity, reduced NO level and increased DPP-4 activity. However, these effects were associated with atherogenic dyslipidemia and reduced GSK-3.We conclude that plasma endoglin, a marker of vascular inflammation, and plasma DPP-4 activity are increased in pregnant rats treated with GC during late gestation. Therefore, glucose deregulation associated with gestational GC exposure is through endoglin-/DPP-4-dependent but GSK-3-independent pathway. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Alpha2delta-1 in SF1+ Neurons of the Ventromedial Hypothalamus Is an Essential Regulator of Glucose and Lipid Homeostasis.

    PubMed

    Felsted, Jennifer A; Chien, Cheng-Hao; Wang, Dongqing; Panessiti, Micaella; Ameroso, Dominique; Greenberg, Andrew; Feng, Guoping; Kong, Dong; Rios, Maribel

    2017-12-05

    The central mechanisms controlling glucose and lipid homeostasis are inadequately understood. We show that α2δ-1 is an essential regulator of glucose and lipid balance, acting in steroidogenic factor-1 (SF1) neurons of the ventromedial hypothalamus (VMH). These effects are body weight independent and involve regulation of SF1 + neuronal activity and sympathetic output to metabolic tissues. Accordingly, mice with α2δ-1 deletion in SF1 neurons exhibit glucose intolerance, altered lipolysis, and decreased cholesterol content in adipose tissue despite normal energy balance regulation. Profound reductions in the firing rate of SF1 neurons, decreased sympathetic output, and elevated circulating levels of serotonin are associated with these alterations. Normal calcium currents but reduced excitatory postsynaptic currents in mutant SF1 neurons implicate α2δ-1 in the promotion of excitatory synaptogenesis separate from its canonical role as a calcium channel subunit. Collectively, these findings identify an essential mechanism that regulates VMH neuronal activity and glycemic and lipid control and may be a target for tackling metabolic disease. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  15. A preliminary trial of the effect of recombinant human growth hormone on short-term linear growth and glucose homeostasis in children with Crohn's disease.

    PubMed

    Wong, S C; Kumar, P; Galloway, P J; Blair, J C; Didi, M; Dalzell, A M; Hassan, K; McGrogan, P; Ahmed, S Faisal

    2011-05-01

    It is unclear whether recombinant human growth hormone (rhGH) improves linear growth in children with Crohn's disease (CD). To investigate the effects of rhGH on height velocity (HV) and glucose homeostasis over a 6-month period. Randomized controlled trial in two tertiary children's hospitals in 22 children with inflammatory bowel disease amongst whom 21 had CD. Duration of disease from diagnosis and number of acute relapses requiring either exclusive enteral nutrition or therapeutic dose of oral prednisolone were similar in the treatment and control groups. Either rhGH (0·067 mg/kg per day) as daily subcutaneous injections (rhGH group; n, 11) or no rhGH, (Ctrl; n, 11) for 6 months. Percentage change in HV after 6 months in the two groups. Auxology, puberty, skeletal age, disease factors, treatment and glucose homeostasis were also assessed. Median HV increased from 4·5 (range, 0·6, 8·9) at baseline to 10·8 (6·1, 15·0) cm/year at 6 month (P = 0·003) in the rhGH group, whereas in the Ctrl group, it was 3·8 (1·4, 6·7) and 3·5 cm/year (2·0, 9·6), respectively (P = 0·58). Median percentage increase in HV after 6 months in the rhGH group was 140% (16·7, 916·7) compared with 17·4% (-42·1%, 97·7%) in the Ctrl group (P < 0·001). There were no significant differences in disease activity and proinflammatory cytokines at baseline and 6 months in both groups and change in bone age for chronological age was also similar in the two groups. In the rhGH group, fasting insulin increased from 4·0 (2·0, 11·0) to 7·0 mU/l (2·0, 16·0) (P = 0·02), whereas in the Ctrl group, it was 3·0 (1·2, 12·7) and 3·8 mU/l (2·1, 7·0) (P = 0·72), respectively. Although this pilot trial shows that rhGH can improve short-term linear growth in children with CD, the clinical efficacy of this therapy needs to be further studied in longer-term studies of growth, glucose homeostasis and disease status. © 2011 Blackwell Publishing Ltd.

  16. Regional cerebral glucose metabolic abnormality in Prader-Willi syndrome: A 18F-FDG PET study under sedation.

    PubMed

    Kim, Sang Eun; Jin, Dong-Kyu; Cho, Sang Soo; Kim, Ji-Hae; Hong, Sungdo David; Paik, Kyung Hoon; Oh, Yoo Joung; Kim, An Hee; Kwon, Eun Kyung; Choe, Yon Ho

    2006-07-01

    Prader-Willi syndrome (PWS) is a genetic disorder caused by the nonexpression of paternal genes in the PWS region of chromosome 15q11-13 and is the most common cause of human syndromic obesity. We investigated regional brain metabolic impairment in children with PWS by 18F-FDG PET. Sixteen children with PWS (9 males, 7 females; mean age +/- SD, 4.2 +/- 1.1 y) and 7 healthy children (4 males, 3 females; mean age +/- SD, 4.0 +/- 1.7 y) underwent brain 18F-FDG PET in the resting state. The images of PWS children were compared using statistical parametric mapping analysis with those of healthy children in a voxelwise manner. Group comparison showed that children with PWS had decreased glucose metabolism in the right superior temporal gyrus and left cerebellar vermis, regions that are associated with taste perception/food reward and cognitive and emotional function, respectively. Metabolism was increased in the right orbitofrontal, bilateral middle frontal, right inferior frontal, left superior frontal, and bilateral anterior cingulate gyri, right temporal pole, and left uncus, regions that are involved in cognitive functions related to eating or obsessive-compulsive behavior. Interestingly, no significant metabolic abnormality was found in the hypothalamus, the brain region believed to be most involved in energy intake and expenditure. This study describes the neural substrate underlying the abnormal eating behavior and psychobehavioral problems of PWS.

  17. Meta-analysis investigating associations between healthy diet and fasting glucose and insulin levels and modification by loci associated with glucose homeostasis in data from 15 cohorts

    USDA-ARS?s Scientific Manuscript database

    Whether loci that influence fasting glucose (FG) and fasting insulin (FI) levels, as identified by genome-wide association studies, modify associations of diet with FG or FI is unknown. We utilized data from 15 US and European cohort studies comprising 51,289 persons without diabetes to test whether...

  18. Obesity and abnormal glucose tolerance in offspring of diabetic mothers: A systematic review and meta-analysis.

    PubMed

    Kawasaki, Maki; Arata, Naoko; Miyazaki, Celine; Mori, Rintaro; Kikuchi, Toru; Ogawa, Yoshihiro; Ota, Erika

    2018-01-01

    Rising prevalence of childhood obesity and type 2 diabetes mellitus (T2DM) is an emerging public health issue. To investigate the association of maternal hyperglycemia exposure during pregnancy with obesity and abnormal glucose tolerance in offspring, and the age at occurrence. We searched MEDLINE and EMBASE for observational studies on obesity and diabetes in offspring of diabetic mothers (gestational diabetes mellitus (GDM), type 1 diabetes mellitus (T1DM) and T2DM), and those on non-diabetic mothers. We performed fixed effect meta-analysis for all studies except when heterogeneity was detected. The quality of studies was evaluated using the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS). Twenty observational studies were included involving a total of 26,509 children. Offspring of GDM mother had higher BMI z-score in childhood (pooled MD: 0.14, 95%CI: 0.04-0.24, seven studies, 21,691children, low quality of evidence). Offspring of T1DM mothers had higher BMI z-score from prepubertal to adolescent (pooled MD: 0.35, 95% CI: 0.13-0.58, three studies, 844 children, low quality of evidence) compared with control. After adjustment for maternal pre-pregnancy BMI, this association remained in offspring of T1DM, but disappeared in those of GDM mothers. Offspring of GDM mother had higher 2-hour plasma glucose from prepubertal to early adulthood (pooled MD: 0.43 mmol/L, 95% CI: 0.18-0.69, five studies, 890 children), while those of T1DM mothers had higher rate of T2DM in 2-5 years old to early adulthood (pooled odds ratio [OR], 6.10: 95% CI: 1.23-30.37, two studies, 448 children, very low quality of evidence) compared with control. As there was only one study with offspring of T2DM mothers, evidence is sparse. Only observational studies were included, with a few adequately adjusted for covariables. Exposure to maternal hyperglycemia was associated with offspring obesity and abnormal glucose tolerance especially in offspring of T1DM mothers, but the evidence

  19. Obesity and abnormal glucose tolerance in offspring of diabetic mothers: A systematic review and meta-analysis

    PubMed Central

    Kawasaki, Maki; Miyazaki, Celine; Mori, Rintaro; Kikuchi, Toru; Ogawa, Yoshihiro; Ota, Erika

    2018-01-01

    Background Rising prevalence of childhood obesity and type 2 diabetes mellitus (T2DM) is an emerging public health issue. Objectives To investigate the association of maternal hyperglycemia exposure during pregnancy with obesity and abnormal glucose tolerance in offspring, and the age at occurrence. Methods We searched MEDLINE and EMBASE for observational studies on obesity and diabetes in offspring of diabetic mothers (gestational diabetes mellitus (GDM), type 1 diabetes mellitus (T1DM) and T2DM), and those on non-diabetic mothers. We performed fixed effect meta-analysis for all studies except when heterogeneity was detected. The quality of studies was evaluated using the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS) Results Twenty observational studies were included involving a total of 26,509 children. Offspring of GDM mother had higher BMI z-score in childhood (pooled MD: 0.14, 95%CI: 0.04–0.24, seven studies, 21,691children, low quality of evidence). Offspring of T1DM mothers had higher BMI z-score from prepubertal to adolescent (pooled MD: 0.35, 95% CI: 0.13–0.58, three studies, 844 children, low quality of evidence) compared with control. After adjustment for maternal pre-pregnancy BMI, this association remained in offspring of T1DM, but disappeared in those of GDM mothers. Offspring of GDM mother had higher 2-hour plasma glucose from prepubertal to early adulthood (pooled MD: 0.43 mmol/L, 95% CI: 0.18–0.69, five studies, 890 children), while those of T1DM mothers had higher rate of T2DM in 2–5 years old to early adulthood (pooled odds ratio [OR], 6.10: 95% CI: 1.23–30.37, two studies, 448 children, very low quality of evidence) compared with control. As there was only one study with offspring of T2DM mothers, evidence is sparse. Limitations Only observational studies were included, with a few adequately adjusted for covariables. Conclusions Exposure to maternal hyperglycemia was associated with offspring obesity and abnormal

  20. Mucosal maltase-glucoamylase plays a crucial role in starch digestion and prandial glucose homeostasis of mice

    USDA-ARS?s Scientific Manuscript database

    Starch is the major source of food glucose, and its digestion requires small intestinal alpha-glucosidic activities provided by the 2 soluble amylases and 4 enzymes bound to the mucosal surface of enterocytes. Two of these mucosal activities are associated with sucrase-isomaltase complex, while anot...

  1. The yeast protein kinase Sch9 adjusts V-ATPase assembly/disassembly to control pH homeostasis and longevity in response to glucose availability.

    PubMed

    Wilms, Tobias; Swinnen, Erwin; Eskes, Elja; Dolz-Edo, Laura; Uwineza, Alice; Van Essche, Ruben; Rosseels, Joëlle; Zabrocki, Piotr; Cameroni, Elisabetta; Franssens, Vanessa; De Virgilio, Claudio; Smits, Gertien J; Winderickx, Joris

    2017-06-01

    The conserved protein kinase Sch9 is a central player in the nutrient-induced signaling network in yeast, although only few of its direct substrates are known. We now provide evidence that Sch9 controls the vacuolar proton pump (V-ATPase) to maintain cellular pH homeostasis and ageing. A synthetic sick phenotype arises when deletion of SCH9 is combined with a dysfunctional V-ATPase, and the lack of Sch9 has a significant impact on cytosolic pH (pHc) homeostasis. Sch9 physically interacts with, and influences glucose-dependent assembly/disassembly of the V-ATPase, thereby integrating input from TORC1. Moreover, we show that the role of Sch9 in regulating ageing is tightly connected with V-ATPase activity and vacuolar acidity. As both Sch9 and the V-ATPase are highly conserved in higher eukaryotes, it will be interesting to further clarify their cooperative action on the cellular processes that influence growth and ageing.

  2. [A prospective study of risk factors in pregnant women with abnormal glucose metabolism].

    PubMed

    Yang, Hui-xia; Zhang, Mei-hua; Sun, Wei-jie; Zhao, Yi

    2005-11-01

    To evaluate the risk factors for gestational diabetes mellitus (GDM) and gestational impaired glucose tolerance (GIGT). A prospective case-control study was performed in 85 women with GDM, 63 cases with GIGT and 125 cases as control recruited from Feb 2004 to Aug 2004 in Peking University First Hospital. Univariate analysis and multivariate logistic regression were used to identify risk factors of GDM and GIGT. (1) The mean age, and body mass index (BMI) before pregnancy and larger maternal weight gains during pregnancy were significantly different between GDM/GIGT and control group (P < 0.05). (2) More intakes of fruits and carbohydrate per day increased the incidence of GDM and GIGT (P < 0.05). (3) There was a higher proportion of women with family history of diabetes among the GDM (42.2%) and GIGT (36.5%) compared with control group (19.2%). Irregular menses (16.5%, 23.8%), and polycystic ovary syndrome (PCOS) (5.9%, 3.2%) were more prevalent in the GDM, GIGT groups versus control subjects (6.4%, 0). The incidence of vulvovaginal candidiasis (VVC) was significantly higher in pregnant women with GDM and GIGT (15.3% and 17.4%) than in control group (7.2%). (4) Multivariate logistic regression showed that age, irregular menses, BMI before pregnancy, history of spontaneous abortion, educational level and VVC all were independent factors for GDM or GIGT. Maternal age, irregular menses, obesity before gestation, rapid weight gains during pregnancy, history of spontaneous abortion as well as VVC are independent risk factors for GDM or GIGT. PCOS and family history of diabetes increase the incidence of GDM and GIGT but these are not independent risk factors for GDM and GIGT.

  3. Effects of exercise training alone vs a combined exercise and nutritional lifestyle intervention on glucose homeostasis in prediabetic individuals: a randomised controlled trial.

    PubMed

    Slentz, Cris A; Bateman, Lori A; Willis, Leslie H; Granville, Esther O; Piner, Lucy W; Samsa, Gregory P; Setji, Tracy L; Muehlbauer, Michael J; Huffman, Kim M; Bales, Connie W; Kraus, William E

    2016-10-01

    Although the Diabetes Prevention Program (DPP) established lifestyle changes (diet, exercise and weight loss) as the 'gold standard' preventive therapy for diabetes, the relative contribution of exercise alone to the overall utility of the combined diet and exercise effect of DPP is unknown; furthermore, the optimal intensity of exercise for preventing progression to diabetes remains very controversial. To establish clinical efficacy, we undertook a study (2009 to 2013) to determine: how much of the effect on measures of glucose homeostasis of a 6 month programme modelled after the first 6 months of the DPP is due to exercise alone; whether moderate- or vigorous-intensity exercise is better for improving glucose homeostasis; and to what extent amount of exercise is a contributor to improving glucose control. The primary outcome was improvement in fasting plasma glucose, with improvement in plasma glucose AUC response to an OGTT as the major secondary outcome. The trial was a parallel clinical trial. Sedentary, non-smokers who were 45-75 year old adults (n = 237) with elevated fasting glucose (5.28-6.94 mmol/l) but without cardiovascular disease, uncontrolled hypertension, or diabetes, from the Durham area, were studied at Duke University. They were randomised into one of four 6 month interventions: (1) low amount (42 kJ kg body weight(-1) week(-1) [KKW])/moderate intensity: equivalent of expending 42 KKW (e.g. walking ∼16 km [8.6 miles] per week) with moderate-intensity (50% [Formula: see text]) exercise; (2) high amount (67 KKW)/moderate intensity: equivalent of expending 67 KKW (∼22.3 km [13.8 miles] per week) with moderate-intensity exercise; (3) high amount (67 KKW)/vigorous intensity: equivalent to group 2, but with vigorous-intensity exercise (75% [Formula: see text]); and (4) diet + 42 KKW moderate intensity: same as group 1 but with diet and weight loss (7%) to mimic the first 6 months of the DPP. Computer-generated randomisation lists

  4. Dietary restriction slightly affects glucose homeostasis and delays plasma cholesterol removal in rabbits with dietary lipid lowering.

    PubMed

    Yu, Qi; Liu, Ruihan; Han, Lijuan; Zhang, Guangwei; Guan, Hua; Pan, Qi; Wang, Siwang; Liu, Enqi

    2018-04-15

    Dietary restriction (DR) has been reported to promote the beneficial effects on atherosclerotic progression, lipid and glucose metabolism, but little is known about these effects can be enhanced or weakened by dietary lipid lowering. After 12 weeks of the high-cholesterol diet (HCD) feeding, hypercholesterolemic rabbits were fed with either a chow diet ad libitum (AL) or a chow diet with DR for 16 weeks of dietary lipid lowering. Here, we found the DR group exhibited a loss in body weight, small internal organs and the reduced fat mass, but the AL group accumulated more subcutaneous fat than the baseline group. DR treatment slightly worsened glucose tolerance but enhanced insulin sensitivity, and a slight effect of DR on insulin secretion was also observed. After diet cholesterol withdrawal, rabbits showed persistently lowering of total cholesterol and triglyceride in plasma. The DR group had significantly higher plasma total cholesterol than the AL group at the most time points during 7 to 16 weeks of lipid lowering. Although both AL and DR groups developed more severe atherosclerosis than baseline group, DR did not improve atherosclerotic progression and the accumulation of macrophages and smooth muscle cells as well. We concluded that DR affected glucose and lipid metabolism but did not ameliorate atherosclerosis in rabbits when associated with lipid lowering by the dietary cholesterol withdrawal.

  5. Pak3 promotes cell cycle exit and differentiation of β-cells in the embryonic pancreas and is necessary to maintain glucose homeostasis in adult mice.

    PubMed

    Piccand, Julie; Meunier, Aline; Merle, Carole; Jia, Zhengping; Barnier, Jean-Vianney; Gradwohl, Gérard

    2014-01-01

    The transcription factor neurogenin3 (Ngn3) triggers islet cell differentiation in the developing pancreas. However, little is known about the molecular mechanisms coupling cell cycle exit and differentiation in Ngn3(+) islet progenitors. We identified a novel effector of Ngn3 endocrinogenic function, the p21 protein-activated kinase Pak3, known to control neuronal differentiation and implicated in X-linked intellectual disability in humans. We show that Pak3 expression is initiated in Ngn3(+) endocrine progenitor cells and next maintained in maturing hormone-expressing cells during pancreas development as well as in adult islet cells. In Pak3-deficient embryos, the proliferation of Ngn3(+) progenitors and β-cells is transiently increased concomitantly with an upregulation of Ccnd1. β-Cell differentiation is impaired at E15.5 but resumes at later stages. Pak3-deficient mice do not develop overt diabetes but are glucose intolerant under high-fat diet (HFD). In the intestine, Pak3 is expressed in enteroendocrine cells but is not necessary for their differentiation. Our results indicate that Pak3 is a novel regulator of β-cell differentiation and function. Pak3 acts downstream of Ngn3 to promote cell cycle exit and differentiation in the embryo by a mechanism that might involve repression of Ccnd1. In the adult, Pak3 is required for the proper control of glucose homeostasis under challenging HFD.

  6. Exposure to Bisphenol-A during Pregnancy Partially Mimics the Effects of a High-Fat Diet Altering Glucose Homeostasis and Gene Expression in Adult Male Mice

    PubMed Central

    García-Arevalo, Marta; Alonso-Magdalena, Paloma; Rebelo Dos Santos, Junia; Quesada, Ivan; Carneiro, Everardo M.; Nadal, Angel

    2014-01-01

    Bisphenol-A (BPA) is one of the most widespread EDCs used as a base compound in the manufacture of polycarbonate plastics. The aim of our research has been to study how the exposure to BPA during pregnancy affects weight, glucose homeostasis, pancreatic β-cell function and gene expression in the major peripheral organs that control energy flux: white adipose tissue (WAT), the liver and skeletal muscle, in male offspring 17 and 28 weeks old. Pregnant mice were treated with a subcutaneous injection of 10 µg/kg/day of BPA or a vehicle from day 9 to 16 of pregnancy. One month old offspring were divided into four different groups: vehicle treated mice that ate a normal chow diet (Control group); BPA treated mice that also ate a normal chow diet (BPA); vehicle treated animals that had a high fat diet (HFD) and BPA treated animals that were fed HFD (HFD-BPA). The BPA group started to gain weight at 18 weeks old and caught up to the HFD group before week 28. The BPA group as well as the HFD and HFD-BPA ones presented fasting hyperglycemia, glucose intolerance and high levels of non-esterified fatty acids (NEFA) in plasma compared with the Control one. Glucose stimulated insulin release was disrupted, particularly in the HFD-BPA group. In WAT, the mRNA expression of the genes involved in fatty acid metabolism, Srebpc1, Pparα and Cpt1β was decreased by BPA to the same extent as with the HFD treatment. BPA treatment upregulated Pparγ and Prkaa1 genes in the liver; yet it diminished the expression of Cd36. Hepatic triglyceride levels were increased in all groups compared to control. In conclusion, male offspring from BPA-treated mothers presented symptoms of diabesity. This term refers to a form of diabetes which typically develops in later life and is associated with obesity. PMID:24959901

  7. Effects of the Soluble Fiber Complex PolyGlycopleX® on Glucose Homeostasis and Body Weight in Young Zucker Diabetic Rats

    PubMed Central

    Grover, Gary James; Koetzner, Lee; Wicks, Joan; Gahler, Roland J.; Lyon, Michael R.; Reimer, Raylene A.; Wood, Simon

    2011-01-01

    Dietary fiber can reduce insulin resistance, body weight, and hyperlipidemia depending on fiber type, water solubility, and viscosity. PolyGlycopleX® (PGX®) is a natural, novel water soluble, non-starch polysaccharide complex that with water forms a highly viscous gel compared to other naturally occurring dietary fiber. We determined the effect of dietary PGX® vs. cellulose and inulin on the early development of insulin resistance, body weight, hyperlipidemia, and glycemia-induced tissue damage in young Zucker diabetic rats (ZDFs) in fasted and non-fasted states. ZDFs (5 weeks old) were fed a diet containing 5% (wgt/wgt) cellulose, inulin, or PGX® for 8 weeks. Body weight, lipids, insulin, and glucose levels were determined throughout the study and homeostasis model assessment (HOMA) was used to measure insulin sensitivity throughout the study in fasted animals. At study termination, insulin sensitivity (oral glucose tolerance test, OGTT) and kidney, liver, and pancreatic histopathology were determined. Body weight and food intake were significantly reduced by PGX® vs. inulin and cellulose. Serum insulin in fasted and non-fasted states was significantly reduced by PGX® as was non-fasted blood glucose. Insulin resistance, measured as a HOMA score, was significantly reduced by PGX® in weeks 5 through 8 as well as terminal OGTT scores in fed and fasted states. Serum total cholesterol was also significantly reduced by PGX®. PGX® significantly reduced histological kidney and hepatic damage in addition to reduced hepatic steatosis and cholestasis. A greater mass of pancreatic β-cells was found in the PGX® group. PGX® therefore may be a useful dietary additive in the control of the development of the early development of the metabolic syndrome. PMID:21922008

  8. Novel association between the nonsynonymous A803G polymorphism of the N-acetyltransferase 2 gene and impaired glucose homeostasis in obese children and adolescents.

    PubMed

    Marzuillo, Pierluigi; Di Sessa, Anna; Umano, Giuseppina Rosaria; Nunziata, Luigia; Cirillo, Grazia; Perrone, Laura; Miraglia Del Giudice, Emanuele; Grandone, Anna

    2017-09-01

    The N-acetyltransferase 2 ( NAT2 ) A803G polymorphism has been associated with decreased insulin sensitivity in a large adult population with the A allele associated with insulin-resistance-related traits. Evaluate the association of this polymorphism with anthropometric and metabolic parameters in obese children and adolescents. A total of 748 obese children and adolescents were enrolled. Anthropometric and laboratory data were collected. During oral glucose tolerance test, the presence of a possible exaggerated plasma glucose excursion at 1 h (1HPG) or impaired glucose tolerance (IGT) was considered. Homeostasis model assessment, oral disposition index (oDI) and insulinogenic index (IDI) were calculated. Patients were genotyped for the NAT2 A803G polymorphism. The prevalence of both IGT and elevated-1HPG was higher in children carrying the A803 allele (P = .02 and P = .03). Moreover, this allele was associated with both oDI and IGI reduction (P = .01). No differences among the NAT2 A803G genotypes for the other parameters were shown. Children homozygous for the A allele presented an odds ratio (OR), to show IGT of 4.9 (P = .01). Children both homozygous and heterozygous for the A allele had higher risk to show elevated-1HPG (OR of 2.7, P = .005; and OR = 2.3, P = .005) compared with patients homozygous for the NAT2 803G allele. NAT2 A803 allele seems to play a role in worsening the destiny of obese children carrying it, predisposing them to elevated-1HPG and IGT and then to a possible future type 2 diabetes mellitus throughout an impairment of pancreatic β-cellular insulin secretion as suggested by oDI and IGI reduction. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Exposure to bisphenol-A during pregnancy partially mimics the effects of a high-fat diet altering glucose homeostasis and gene expression in adult male mice.

    PubMed

    García-Arevalo, Marta; Alonso-Magdalena, Paloma; Rebelo Dos Santos, Junia; Quesada, Ivan; Carneiro, Everardo M; Nadal, Angel

    2014-01-01

    Bisphenol-A (BPA) is one of the most widespread EDCs used as a base compound in the manufacture of polycarbonate plastics. The aim of our research has been to study how the exposure to BPA during pregnancy affects weight, glucose homeostasis, pancreatic β-cell function and gene expression in the major peripheral organs that control energy flux: white adipose tissue (WAT), the liver and skeletal muscle, in male offspring 17 and 28 weeks old. Pregnant mice were treated with a subcutaneous injection of 10 µg/kg/day of BPA or a vehicle from day 9 to 16 of pregnancy. One month old offspring were divided into four different groups: vehicle treated mice that ate a normal chow diet (Control group); BPA treated mice that also ate a normal chow diet (BPA); vehicle treated animals that had a high fat diet (HFD) and BPA treated animals that were fed HFD (HFD-BPA). The BPA group started to gain weight at 18 weeks old and caught up to the HFD group before week 28. The BPA group as well as the HFD and HFD-BPA ones presented fasting hyperglycemia, glucose intolerance and high levels of non-esterified fatty acids (NEFA) in plasma compared with the Control one. Glucose stimulated insulin release was disrupted, particularly in the HFD-BPA group. In WAT, the mRNA expression of the genes involved in fatty acid metabolism, Srebpc1, Pparα and Cpt1β was decreased by BPA to the same extent as with the HFD treatment. BPA treatment upregulated Pparγ and Prkaa1 genes in the liver; yet it diminished the expression of Cd36. Hepatic triglyceride levels were increased in all groups compared to control. In conclusion, male offspring from BPA-treated mothers presented symptoms of diabesity. This term refers to a form of diabetes which typically develops in later life and is associated with obesity.

  10. Effects of the Soluble Fiber Complex PolyGlycopleX on Glucose Homeostasis and Body Weight in Young Zucker Diabetic Rats.

    PubMed

    Grover, Gary James; Koetzner, Lee; Wicks, Joan; Gahler, Roland J; Lyon, Michael R; Reimer, Raylene A; Wood, Simon

    2011-01-01

    Dietary fiber can reduce insulin resistance, body weight, and hyperlipidemia depending on fiber type, water solubility, and viscosity. PolyGlycopleX(®) (PGX(®)) is a natural, novel water soluble, non-starch polysaccharide complex that with water forms a highly viscous gel compared to other naturally occurring dietary fiber. We determined the effect of dietary PGX(®) vs. cellulose and inulin on the early development of insulin resistance, body weight, hyperlipidemia, and glycemia-induced tissue damage in young Zucker diabetic rats (ZDFs) in fasted and non-fasted states. ZDFs (5 weeks old) were fed a diet containing 5% (wgt/wgt) cellulose, inulin, or PGX(®) for 8 weeks. Body weight, lipids, insulin, and glucose levels were determined throughout the study and homeostasis model assessment (HOMA) was used to measure insulin sensitivity throughout the study in fasted animals. At study termination, insulin sensitivity (oral glucose tolerance test, OGTT) and kidney, liver, and pancreatic histopathology were determined. Body weight and food intake were significantly reduced by PGX(®) vs. inulin and cellulose. Serum insulin in fasted and non-fasted states was significantly reduced by PGX(®) as was non-fasted blood glucose. Insulin resistance, measured as a HOMA score, was significantly reduced by PGX(®) in weeks 5 through 8 as well as terminal OGTT scores in fed and fasted states. Serum total cholesterol was also significantly reduced by PGX(®). PGX(®) significantly reduced histological kidney and hepatic damage in addition to reduced hepatic steatosis and cholestasis. A greater mass of pancreatic β-cells was found in the PGX(®) group. PGX(®) therefore may be a useful dietary additive in the control of the development of the early development of the metabolic syndrome.

  11. Reduction of Syndecan Transcript Levels in the Insulin-Producing Cells Affects Glucose Homeostasis in Adult Drosophila melanogaster.

    PubMed

    Warren, Jonathan L; Hoxha, Eneida; Jumbo-Lucioni, Patricia; De Luca, Maria

    2017-11-01

    Signaling by direct cell-matrix interactions has been shown to impact the transcription, secretion, and storage of insulin in mammalian β cells. However, more research is still needed in this area. Syndecans are transmembrane heparan sulfate proteoglycans that function independently and in synergy with integrin-mediated signaling to mediate cell adhesion to the extracellular matrix. In this study, we used the model organism Drosophila melanogaster to determine whether knockdown of the Syndecan (Sdc) gene expression specifically in the insulin-producing cells (IPCs) might affect insulin-like peptide (ILP) production and secretion. IPCs of adult flies produce three ILPs (ILP2, ILP3, and ILP5), which have significant homology to mammalian insulin. We report that flies with reduced Sdc expression in the IPCs did not show any difference in the expression of ilp genes compared to controls. However, they had significantly reduced levels of the circulating ILP2 protein, higher circulating carbohydrates, and were less glucose tolerant than control flies. Finally, we found that IPCs-specific Sdc knockdown led to reduced levels of head Glucose transporter1 gene expression, extracellular signal-regulated kinase phosphorylation, and reactive oxygen species. Taken together, our findings suggest a cell autonomous role for Sdc in insulin release in D. melanogaster.

  12. Randomised controlled trial of effect of terbutaline before elective caesarean section on postnatal respiration and glucose homeostasis

    PubMed Central

    Eisler, G.; Hjertberg, R.; Lagercrantz, H.

    1999-01-01

    AIM—To determine if terbutaline given to mothers before elective caesarean section facilitates neonatal respiration and metabolism.
METHODS—A randomised controlled trial of 25 full term infants delivered by elective caesarean section was conducted. The mothers received a continuous infusion of terbutaline or saline 120-0 minutes before birth. Umbilical artery blood was collected at birth and analysed for blood gases and catecholamines. The lung function of each infant was assessed two hours after birth, and blood pressure, heart rate, blood glucose and body temperature were monitored until 24 hours of age.
RESULTS—The infants of the treated mothers (n=13) had significantly higher dynamic lung compliance (p<0.001), lower airway resistance (p<0.001), and respiratory frequency than control infants (n=12). Blood glucose and adrenaline concentrations were significantly higher in the treated group (p=0.0014 and p<0.01). None of these infants had any clinical respiratory difficulties; there were two cases of transient tachypnoea in the control group. No negative side effects due to the terbutaline treatment were seen among the infants. The mothers felt no discomfort caused by the terbutaline infusion, although they bled more during surgery (p=0.03).
CONCLUSION—Stimulation of the β adrenoceptors in utero with terbutaline infusion to the mothers promotes neonatal respiratory and metabolic adaptation after elective caesarean section.

 PMID:10325782

  13. Experimental study on effect of hydroalcoholic extract of Emblica officinalis fruits on glucose homeostasis and metabolic parameters

    PubMed Central

    Patel, Snehal S.; Goyal, Ramesh K.; Shah, Rajendra S.; Tirgar, Pravin R.; Jadav, Pinakin D.

    2013-01-01

    Polyphenols from natural source are potential therapeutics that act alone or supplement anti-diabetic drugs in the prevention and treatment of diabetes. The present investigation was undertaken to study the effect of hydroalcoholic extract (HE) of fruits of Emblica officinalis on type 1 diabetic rats. Diabetes was induced by streptozotocin (STZ) (45 mg/kg i.v.). HE (100 mg/kg, p.o.) was administered for 4 weeks and at the end of treatment, blood samples were collected and analyzed for various biochemical parameters. STZ produced a diabetic state exhibiting all the cardinal symptoms such as loss of body weight, polydipsia, polyuria, glucosuria, polyphagia, hypoinsulinemia, and hyperglycemia associated with hypercholesterolemia and hypertriglyceridemia. Treatment with HE prevented cardinal symptoms and caused significant decrease in fasting serum glucose, AUCglucose, cholesterol, triglyceride, low-density lipoprotein (LDL) and very LDL in diabetic rats. However, insulin, AUCinsulin, and serum high-density lipoprotein level were not significantly altered by treatment. Treatment also reduced lipid peroxidation and increased anti-oxidant parameters in the liver homogenates of diabetic rats. Polyphenol enriched fraction of HE significantly improved disarranged carbohydrate and lipid metabolism of chemically induced diabetes in rats. The mechanism of its anti-diabetic activity appears to be either improvement in peripheral glucose utilization, increased insulin sensitivity, or anti-oxidant property. PMID:24696584

  14. Specific Sirt1 Activator-mediated Improvement in Glucose Homeostasis Requires Sirt1-Independent Activation of AMPK.

    PubMed

    Park, Sung-Jun; Ahmad, Faiyaz; Um, Jee-Hyun; Brown, Alexandra L; Xu, Xihui; Kang, Hyeog; Ke, Hengming; Feng, Xuesong; Ryall, James; Philp, Andrew; Schenk, Simon; Kim, Myung K; Sartorelli, Vittorio; Chung, Jay H

    2017-04-01

    The specific Sirt1 activator SRT1720 increases mitochondrial function in skeletal muscle, presumably by activating Sirt1. However, Sirt1 gain of function does not increase mitochondrial function, which raises a question about the central role of Sirt1 in SRT1720 action. Moreover, it is believed that the metabolic effects of SRT1720 occur independently of AMP-activated protein kinase (AMPK), an important metabolic regulator that increases mitochondrial function. Here, we show that SRT1720 activates AMPK in a Sirt1-independent manner and SRT1720 activates AMPK by inhibiting a cAMP degrading phosphodiesterase (PDE) in a competitive manner. Inhibiting the cAMP effector protein Epac prevents SRT1720 from activating AMPK or Sirt1 in myotubes. Moreover, SRT1720 does not increase mitochondrial function or improve glucose tolerance in AMPKα2 knockout mice. Interestingly, weight loss induced by SRT1720 is not sufficient to improve glucose tolerance. Therefore, contrary to current belief, the metabolic effects produced by SRT1720 require AMPK, which can be activated independently of Sirt1. Published by Elsevier B.V.

  15. TAS2R38 and Its Influence on Smoking Behavior and Glucose Homeostasis in the German Sorbs

    PubMed Central

    Keller, Maria; Liu, Xuanshi; Wohland, Tobias; Rohde, Kerstin; Gast, Marie-Therese; Stumvoll, Michael; Kovacs, Peter; Tönjes, Anke; Böttcher, Yvonne

    2013-01-01

    Background Genetic variants within the bitter taste receptor gene TAS2R38 are associated with sensitivity to bitter taste and are related to eating behavior in the Amish population. Sensitivity to bitter taste is further related to anthropometric traits in an genetically isolated Italian population. We tested whether the TAS2R38 variants (rs713598; rs1726866 and rs10246939) may be related to eating behavior, anthropometric parameters, metabolic traits and consumer goods intake in the German Sorbs. Materials and Methods The three SNPs were genotyped in a total cohort of 1007 individuals (male/female: 405/602). The German version of the three-factor eating questionnaire was completed by 548 individuals. Genetic association analyses for smoking behavior, alcohol and coffee intake, eating behavior factors (restraint, disinhibition and hunger) and other metabolic traits were analyzed. Further, by combining the three SNPs we applied comparative haplotype analyses categorizing PAV (proline-alanine-valine) carriers (tasters) vs. homozygous AVI (alanin-valine-isoleucine) carriers (non-tasters). Results Significant associations of genetic variants within TAS2R38 were identified with percentage of body fat, which were driven by associations in women. In men, we observed significant associations with 30 min plasma glucose, and area under the curve for plasma glucose (0–120 min) (all adjusted P≤0.05). Further, we found that carriers of at least one PAV allele show significantly lower cigarette smoking per day (P = 0.002) as well as, albeit non-significant, lower alcohol intake. We did not confirm previously reported associations between genetic variants of TAS2R38 and eating behavior. Conclusion Our data suggest that genetic variation in TAS2R38 is related to individual body composition measures and may further influence consumer goods intake in the Sorbs possibly via individual sensitivity to bitter taste. PMID:24312479

  16. Effects of postnatal growth restriction and subsequent catch-up growth on neurodevelopment and glucose homeostasis in rats.

    PubMed

    Alexeev, Erica E; Lönnerdal, Bo; Griffin, Ian J

    2015-06-05

    There is increasing evidence that poor growth of preterm infants is a risk factor for poor long-term development, while the effects of early postnatal growth restriction are not well known. We utilized a rat model to examine the consequences of different patterns of postnatal growth and hypothesized that early growth failure leads to impaired development and insulin resistance. Rat pups were separated at birth into normal (N, n = 10) or restricted intake (R, n = 16) litters. At d11, R pups were re-randomized into litters of 6 (R-6), 10 (R-10) or 16 (R-16) pups/dam. N pups remained in litters of 10 pups/dam (N-10). Memory and learning were examined through T-maze test. Insulin sensitivity was measured by i.p. insulin tolerance test and glucose tolerance test. By d10, N pups weighed 20% more than R pups (p < 0.001). By d15, the R-6 group caught up to the N-10 group in weight, the R-10 group showed partial catch-up growth and the R-16 group showed no catch-up growth. All R groups showed poorer scores in developmental testing when compared with the N-10 group during T-Maze test (p < 0.05). Although R-16 were more insulin sensitive than R-6 and R-10, all R groups were more glucose tolerant than N-10. In rats, differences in postnatal growth restriction leads to changes in development and in insulin sensitivity. These results may contribute to better elucidating the causes of poor developmental outcomes in human preterm infants.

  17. Sodium Orthovanadate and Trigonella Foenum Graecum Prevents Neuronal Parameters Decline and Impaired Glucose Homeostasis in Alloxan Diabetic Rats.

    PubMed

    Kumar, Pardeep; Taha, Asia; Kumar, Nitin; Kumar, Vinod; Baquer, Najma Zaheer

    2015-01-01

    Hyperglycemia is the most important contributor in the onset and progress of diabetic complications mainly by producing oxidative stress. The present study was carried out to observe, the antihyperglycemic effect of sodium orthovanadate (SOV) and Trigonella foenum graecum seed powder (TSP) administration on blood glucose and insulin levels, membrane linked enzymes (monoamine oxidase, acetylcholinesterase, Ca2+ATPase), intracellular calcium (Ca2+) levels, lipid peroxidation, membrane fluidity and neurolipofuscin accumulation in brain of the alloxan induced diabetic rats and to see whether the treatment with SOV and TSP was capable of reversing the diabetic effects. Diabetes was induced by administration of alloxan monohydrate (15 mg/100 g body weight) and rats were treated with 2 IU insulin, 0.6 mg/ml SOV, 5% TSP in the diet and a combination of 0.2 mg/ml SOV and 5% TSP separately for three weeks. Diabetic rats showed hyperglycemia with almost four fold high blood glucose levels. Activities of acetylcholinesterase and Ca2+ATPase decreased in diabetic rat brain. Diabetic rats exhibited an increased level of intracellular Ca2+ levels, lipid peroxidation, neurolipofuscin accumulations and monoamine oxidase activity. Treatment of diabetic rats with insulin, TSP, SOV and a combined therapy of lower dose of SOV with TSP revived normoglycemia and restored the altered level of membrane bound enzymes, lipid peroxidation and neurolipofuscin accumulation. Our results showed that lower doses of SOV (0.2 mg/ml) could be used in combination with TSP in normalization of altered metabolic parameters and membrane linked enzymes without any harmful side effect.

  18. A Thyroid Hormone Challenge in Hypothyroid Rats Identifies T3 Regulated Genes in the Hypothalamus and in Models with Altered Energy Balance and Glucose Homeostasis

    PubMed Central

    Herwig, Annika; Campbell, Gill; Mayer, Claus-Dieter; Boelen, Anita; Anderson, Richard A.; Ross, Alexander W.; Mercer, Julian G.

    2014-01-01

    Background: The thyroid hormone triiodothyronine (T3) is known to affect energy balance. Recent evidence points to an action of T3 in the hypothalamus, a key area of the brain involved in energy homeostasis, but the components and mechanisms are far from understood. The aim of this study was to identify components in the hypothalamus that may be involved in the action of T3 on energy balance regulatory mechanisms. Methods: Sprague Dawley rats were made hypothyroid by giving 0.025% methimazole (MMI) in their drinking water for 22 days. On day 21, half the MMI-treated rats received a saline injection, whereas the others were injected with T3. Food intake and body weight measurements were taken daily. Body composition was determined by magnetic resonance imaging, gene expression was analyzed by in situ hybridization, and T3-induced gene expression was determined by microarray analysis of MMI-treated compared to MMI-T3-injected hypothalamic RNA. Results: Post mortem serum thyroid hormone levels showed that MMI treatment decreased circulating thyroid hormones and increased thyrotropin (TSH). MMI treatment decreased food intake and body weight. Body composition analysis revealed reduced lean and fat mass in thyroidectomized rats from day 14 of the experiment. MMI treatment caused a decrease in circulating triglyceride concentrations, an increase in nonesterified fatty acids, and decreased insulin levels. A glucose tolerance test showed impaired glucose clearance in the thyroidectomized animals. In the brain, in situ hybridization revealed marked changes in gene expression, including genes such as Mct8, a thyroid hormone transporter, and Agrp, a key component in energy balance regulation. Microarray analysis revealed 110 genes to be up- or downregulated with T3 treatment (±1.3-fold change, p<0.05). Three genes chosen from the differentially expressed genes were verified by in situ hybridization to be activated by T3 in cells located at or close to the hypothalamic

  19. Hepatic Mitochondrial Pyruvate Carrier 1 Is Required for Efficient Regulation of Gluconeogenesis and Whole-Body Glucose Homeostasis.

    PubMed

    Gray, Lawrence R; Sultana, Mst Rasheda; Rauckhorst, Adam J; Oonthonpan, Lalita; Tompkins, Sean C; Sharma, Arpit; Fu, Xiaorong; Miao, Ren; Pewa, Alvin D; Brown, Kathryn S; Lane, Erin E; Dohlman, Ashley; Zepeda-Orozco, Diana; Xie, Jianxin; Rutter, Jared; Norris, Andrew W; Cox, James E; Burgess, Shawn C; Potthoff, Matthew J; Taylor, Eric B

    2015-10-06

    Gluconeogenesis is critical for maintenance of euglycemia during fasting. Elevated gluconeogenesis during type 2 diabetes (T2D) contributes to chronic hyperglycemia. Pyruvate is a major gluconeogenic substrate and requires import into the mitochondrial matrix for channeling into gluconeogenesis. Here, we demonstrate that the mitochondrial pyruvate carrier (MPC) comprising the Mpc1 and Mpc2 proteins is required for efficient regulation of hepatic gluconeogenesis. Liver-specific deletion of Mpc1 abolished hepatic MPC activity and markedly decreased pyruvate-driven gluconeogenesis and TCA cycle flux. Loss of MPC activity induced adaptive utilization of glutamine and increased urea cycle activity. Diet-induced obesity increased hepatic MPC expression and activity. Constitutive Mpc1 deletion attenuated the development of hyperglycemia induced by a high-fat diet. Acute, virally mediated Mpc1 deletion after diet-induced obesity decreased hyperglycemia and improved glucose tolerance. We conclude that the MPC is required for efficient regulation of gluconeogenesis and that the MPC contributes to the elevated gluconeogenesis and hyperglycemia in T2D. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Lifetime Exposure to a Constant Environment Amplifies the Impact of a Fructose-Rich Diet on Glucose Homeostasis during Pregnancy.

    PubMed

    Song, Aleida; Astbury, Stuart; Hoedl, Abha; Nielsen, Brent; Symonds, Michael E; Bell, Rhonda C

    2017-03-25

    The need to refine rodent models of human-related disease is now being recognized, in particular the rearing environment that can profoundly modulate metabolic regulation. Most studies on pregnancy and fetal development purchase and transport young females into the research facility, which after a short period of acclimation are investigated (Gen0). We demonstrate that female offspring (Gen1) show an exaggerated hyperinsulinemic response to pregnancy when fed a standard diet and with high fructose intake, which continues throughout pregnancy. Markers of maternal hepatic metabolism were differentially influenced, as the gene expression of acetyl-CoA-carboxylase was raised in Gen1 given fructose and controls, whereas glucose transporter 5 and fatty acid synthase expression were only raised with fructose. Gen1 rats weighed more than Gen0 throughout the study, although fructose feeding raised the percent body fat but not body weight. We show that long-term habituation to the living environment has a profound impact on the animal's metabolic responses to nutritional intervention and pregnancy. This has important implications for interpreting many studies investigating the influence of maternal consumption of fructose on pregnancy outcomes and offspring to date.

  1. Markers of insulin resistance and carotid atherosclerosis. A comparison of the homeostasis model assessment and triglyceride glucose index.

    PubMed

    Irace, C; Carallo, C; Scavelli, F B; De Franceschi, M S; Esposito, T; Tripolino, C; Gnasso, A

    2013-07-01

    The present investigation was designed to test the association between carotid atherosclerosis and two simple markers of insulin resistance, i.e. HOMA-Index and TyG-Index. The study was performed in two different cohorts. In the first cohort, 330 individuals were enrolled. Blood pressure, lipids, glucose, waist and cigarette smoking were evaluated. HOMA-IR and TyG-Index were calculated as markers of prevalent hepatic and muscular insulin resistance respectively. Carotid atherosclerosis was assessed by Doppler ultrasonography. The association between cardiovascular risk factors, markers of insulin resistance and carotid atherosclerosis was assessed by multiple logistic regression analyses. In the second cohort, limited to the evaluation of TyG-Index, 1432 subjects were studied. In the first cohort, TyG-Index was significantly associated with carotid atherosclerosis in a model including age, sex, diabetes, cigarette smoking and LDL cholesterol, while HOMA-IR was not. When components of metabolic syndrome were added to the model as dichotomous variables (absent/present), TyG-Index retained its predictive power. The same result was obtained when the metabolic syndrome was added to the model (absence/presence). The association between TyG-Index and carotid atherosclerosis was confirmed in the second cohort. The present findings suggest that TyG-Index is better associated with carotid atherosclerosis than HOMA-IR. © 2013 John Wiley & Sons Ltd.

  2. Effect of Vanadyl Rosiglitazone, a New Insulin-Mimetic Vanadium Complexes, on Glucose Homeostasis of Diabetic Mice.

    PubMed

    Jiang, Pingzhe; Dong, Zhen; Ma, Baicheng; Ni, Zaizhong; Duan, Huikun; Li, Xiaodan; Wang, Bin; Ma, Xiaofeng; Wei, Qian; Ji, Xiangzhen; Li, Minggang

    2016-11-01

    Diabetes has been cited as the most challenging health problem in the twenty-first century. Accordingly, it is urgent to develop a new type of efficient and low-toxic antidiabetic medication. Since vanadium compounds have insulin-mimetic and potential hypoglycemic activities for type 1 and type 2 diabetes, a new trend has been developed using vanadium and organic ligands to form a new compound in order to increase the intestinal absorption and reduce the toxicity of vanadium compound. In the current investigation, a new organic vanadium compounds, vanadyl rosiglitazone, was synthesized and determined by infrared spectra. Vanadyl rosiglitazone and three other organic vanadium compounds were administered to the diabetic mice through oral administration for 5 weeks. The results of mouse model test indicated that vanadyl rosiglitazone could regulate the blood glucose level and relieve the symptoms of polydipsia, polyphagia, polyuria, and weight loss without side effects and was more effective than the other three organic vanadium compounds including vanadyl trehalose, vanadyl metformin, and vanadyl quercetin. The study indicated that vanadyl rosiglitazone presents insulin-mimetic activities, and it will be a good potential candidate for the development of a new type of oral drug for type 2 diabetes.

  3. IL-6 Improves Energy and Glucose Homeostasis in Obesity via Enhanced Central IL-6 trans-Signaling.

    PubMed

    Timper, Katharina; Denson, Jesse Lee; Steculorum, Sophie Marie; Heilinger, Christian; Engström-Ruud, Linda; Wunderlich, Claudia Maria; Rose-John, Stefan; Wunderlich, F Thomas; Brüning, Jens Claus

    2017-04-11

    Interleukin (IL)-6 engages similar signaling mechanisms to leptin. Here, we find that central application of IL-6 in mice suppresses feeding and improves glucose tolerance. In contrast to leptin, whose action is attenuated in obesity, the ability of IL-6 to suppress feeding is enhanced in obese mice. IL-6 suppresses feeding in the absence of neuronal IL-6-receptor (IL-6R) expression in hypothalamic or all forebrain neurons of mice. Conversely, obese mice exhibit increased soluble IL-6R levels in the cerebrospinal fluid. Blocking IL-6 trans-signaling in the CNS abrogates the ability of IL-6 to suppress feeding. Furthermore, gp130 expression is enhanced in the paraventricular nucleus of the hypothalamus (PVH) of obese mice, and deletion of gp130 in the PVH attenuates the beneficial central IL-6 effects on metabolism. Collectively, these experiments indicate that IL-6 trans-signaling is enhanced in the CNS of obese mice, allowing IL-6 to exert its beneficial metabolic effects even under conditions of leptin resistance. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Antioxidants Complement the Requirement for Protein Chaperone Function to Maintain β-Cell Function and Glucose Homeostasis

    PubMed Central

    Han, Jaeseok; Song, Benbo; Kim, Jiun; Kodali, Vamsi K.; Pottekat, Anita; Wang, Miao; Hassler, Justin; Wang, Shiyu; Pennathur, Subramaniam; Back, Sung Hoon; Katze, Michael G.

    2015-01-01

    Proinsulin misfolding in the endoplasmic reticulum (ER) initiates a cell death response, although the mechanism(s) remains unknown. To provide insight into how protein misfolding may cause β-cell failure, we analyzed mice with the deletion of P58IPK/DnajC3, an ER luminal co-chaperone. P58IPK−/− mice become diabetic as a result of decreased β-cell function and mass accompanied by induction of oxidative stress and cell death. Treatment with a chemical chaperone, as well as deletion of Chop, improved β-cell function and ameliorated the diabetic phenotype in P58IPK−/− mice, suggesting P58IPK deletion causes β-cell death through ER stress. Significantly, a diet of chow supplemented with antioxidant dramatically and rapidly restored β-cell function in P58IPK−/− mice and corrected abnormal localization of MafA, a critical transcription factor for β-cell function. Antioxidant feeding also preserved β-cell function in Akita mice that express mutant misfolded proinsulin. Therefore defective protein folding in the β-cell causes oxidative stress as an essential proximal signal required for apoptosis in response to ER stress. Remarkably, these findings demonstrate that antioxidant feeding restores cell function upon deletion of an ER molecular chaperone. Therefore antioxidant or chemical chaperone treatment may be a promising therapeutic approach for type 2 diabetes. PMID:25795214

  5. Factors associated with screening for glucose abnormalities after gestational diabetes mellitus: baseline cohort of the interventional IMPACT study.

    PubMed

    Bihan, H; Cosson, E; Khiter, C; Vittaz, L; Faghfouri, F; Leboeuf, D; Carbillon, L; Dauphin, H; Reach, G; Valensi, P

    2014-04-01

    Although it is important to screen women who have had gestational diabetes mellitus (GDM) for abnormal post-partum glucose levels, such testing is rarely performed. The aim of this study was to use data from the first observational phase of the IMPACT study to determine rates of screening within 6 months of delivery in a multiethnic cohort, focusing in particular on the effects of social deprivation and the risk of future diabetes. To investigate the frequency of post-partum screening, charts were analyzed, and all women attending four centres located in a deprived area who had had GDM between January 2009 and December 2010 were contacted by phone. The Evaluation of Precarity and Inequalities in Health Examination Centres (EPICES) deprivation index and Finnish Diabetes Risk Score (FINDRISK) questionnaire were also evaluated. Data were evaluable for 589 of the 719 women contacted (mean age: 33.4 ± 5.2 years; mean body mass index: 27.6 ± 5.4 kg/m(2)), and 196 (33.3%) reported having been screened. On multivariate analysis, factors associated with a lack of screening were smoking [odds ratio (OR): 0.42 (0.20-0.90), P<0.05], low consumption of fruit and vegetables [OR: 0.58 (0.39-0.82), P<0.01] and heavier offspring birth weight (P<0.05), although there were no differences in FINDRISK and EPICES scores between screened and unscreened women. One-third of women who had had GDM reported having been screened for dysglycaemia at 6 months post-partum. However, it is expected that the interventional phase of the IMPACT study will increase screening rates, especially in women with the risk factors associated with lower screening rates during this observational phase. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. HbA1c in the diagnosis of diabetes and abnormal glucose tolerance in patients with Graves' hyperthyroidism.

    PubMed

    Yang, Liyong; Shen, Ximei; Yan, Sunjie; Yuan, Xin; Lu, Juanjuan; Wei, Wenfeng

    2013-07-01

    To assess the suitability of HbA1c as a criterion for the diagnosis of diabetes in patients with Graves' disease. This study enrolled 310 patients with untreated newly diagnosed Graves' disease, 208 patients with euthyroid goiter and 329 age-matched (control) subjects without thyroid disease from Fuzhou, China. The performance of HbA1c against the OGTT for diagnosing diabetes was determined. The Framingham risk score was used to assess general cardiovascular disease (CVD) risk. The percentage of patients with abnormal glucose metabolism as classified by HbA1c levels was lower than by OGTT criteria in patients with Graves' disease-33.2% vs. 41.3% for pre-diabetes and 4.5% vs. 11.3% for diabetes, respectively. The sensitivity of HbA1c for diagnosing diabetes in patients with Graves' disease was lower than in patients with euthyroid goiter and subjects without thyroid disease (34.9%, 63.2% and 60.6% respectively), while the specificity was similar (99.3%, 98.6%, 97.4%). Approximately 7.4% of patients with Graves' disease diagnosed with diabetes according to OGTT criteria were misdiagnosed as not having the disease by HbA1c, much higher than that for the other two groups. Patients with Graves' disease with diabetes not diagnosed with the disease by HbA1c showed a high risk for CVD. The low sensitivity of the HbA1c criterion underestimated the percentage of diabetes in patients with Graves' disease. Patients with diabetes who were misdiagnosed as not having the disease by HbA1c were at high risk for CVD. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Prevalence of plasma lipid abnormalities and its association with glucose metabolism in Spain: the di@bet.es study.

    PubMed

    Martinez-Hervas, Sergio; Carmena, Rafael; Ascaso, Juan F; Real, Jose T; Masana, Luis; Catalá, Miguel; Vendrell, Joan; Vázquez, José Antonio; Valdés, Sergio; Urrutia, Inés; Soriguer, Federico; Serrano-Rios, Manuel; Rojo-Martínez, Gemma; Pascual-Manich, Gemma; Ortega, Emilio; Mora-Peces, Inmaculada; Menéndez, Edelmiro; Martínez-Larrad, Maria T; López-Alba, Alfonso; Gomis, Ramón; Goday, Albert; Girbés, Juan; Gaztambide, Sonia; Franch, Josep; Delgado, Elías; Castell, Conxa; Castaño, Luis; Casamitjana, Roser; Calle-Pascual, Alfonso; Bordiú, Elena

    2014-01-01

    Dyslipidemia is a significant contributor to the elevated CVD risk observed in type 2 diabetes mellitus. We assessed the prevalence of dyslipidemia and its association with glucose metabolism status in a representative sample of the adult population in Spain and the percentage of subjects at guideline-recommended LDL-C goals. The di@bet.es study is a national, cross-sectional population-based survey of 5728 adults. A total of 4776 subjects were studied. Dyslipidemia was diagnosed in 56.8% of subjects; only 13.2% of subjects were treated with lipid lowering drugs. Lipid abnormalities were found in 56.8% of Spanish adults: 23.3% with high LDL-C, 21.5% high TG, 35.8% high non-HDL-C, and 17.2% low HDL-C. Most normal subjects showed an LDL-C ≤ 3.36 mmol/l. Pre-diabetics presented similar proportion when considering a goal of 3.36 mmol/l, but only 35% of them reached an LDL-C goal ≤ 2.6 mmol/l. Finally, 45.3% of diabetics had an LDL-C ≤ 2.6 mmol/l, and only 11.3% achieved an LDL-C ≤ 1.8 mmol/l. Our study demonstrates a high prevalence of dyslipidemia in the adult Spanish population, and a low use of lipid-lowering drugs. Moreover, the number of subjects achieving their corresponding LDL-C goal is small, particularly in subjects at high cardiovascular risk, such as diabetics. Copyright © 2013 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  8. Androgen receptor deficiency in monocytes/macrophages does not alter adiposity or glucose homeostasis in male mice.

    PubMed

    Rubinow, Katya B; Houston, Barbara; Wang, Shari; Goodspeed, Leela; Ogimoto, Kayoko; Morton, Gregory J; McCarty, Christopher; Braun, Robert E; Page, Stephanie T

    2018-01-01

    Androgen deprivation in men leads to increased adiposity, but the mechanisms underlying androgen regulation of fat mass have not been fully defined. Androgen receptor (AR) is expressed in monocytes/macrophages, which are resident in key metabolic tissues and influence energy metabolism in surrounding cells. Male mice bearing a cell-specific knockout of the AR in monocytes/macrophages (M-ARKO) were generated to determine whether selective loss of androgen signaling in these cells would lead to altered body composition. Wild-type (WT) and M-ARKO mice (12-22 weeks of age, n = 12 per group) were maintained on a regular chow diet for 8 weeks and then switched to a high-fat diet for 8 additional weeks. At baseline and on both the regular chow and high-fat diets, no differences in lean mass or fat mass were observed between groups. Consistent with the absence of differential body weight or adiposity, no differences in food intake (3.0 ± 0.5 g per day for WT mice vs 2.8 ± 0.4 g per day for M-ARKO mice) or total energy expenditure (0.6 ± 0.1 Kcal h -1 for WT mice vs 0.5 ± 0.1 Kcal h -1 for M-ARKO mice) were evident between groups during high-fat feeding. Liver weight was greater in M-ARKO than that in WT mice (1.5 ± 0.1 g vs 1.3 ± 0.0 g, respectively, P = 0.02). Finally, M-ARKO mice did not exhibit impairments in glucose tolerance or insulin sensitivity relative to WT mice at any study time point. In aggregate, these findings suggest that AR signaling specifically in monocytes/macrophages does not contribute to the regulation of systemic energy balance, adiposity, or insulin sensitivity in male mice.

  9. A Novel Arabidopsis Vacuolar Glucose Exporter Is Involved in Cellular Sugar Homeostasis and Affects the Composition of Seed Storage Compounds1[W][OA

    PubMed Central

    Poschet, Gernot; Hannich, Barbara; Raab, Sabine; Jungkunz, Isabel; Klemens, Patrick A.W.; Krueger, Stephan; Wic, Stefan; Neuhaus, H. Ekkehard; Büttner, Michael

    2011-01-01

    Subcellular sugar partitioning in plants is strongly regulated in response to developmental cues and changes in external conditions. Besides transitory starch, the vacuolar sugars represent a highly dynamic pool of instantly accessible metabolites that serve as energy source and osmoprotectant. Here, we present the molecular identification and functional characterization of the vacuolar glucose (Glc) exporter Arabidopsis (Arabidopsis thaliana) Early Responsive to Dehydration-Like6 (AtERDL6). We demonstrate tonoplast localization of AtERDL6 in plants. In Arabidopsis, AtERDL6 expression is induced in response to factors that activate vacuolar Glc pools, like darkness, heat stress, and wounding. On the other hand, AtERDL6 transcript levels drop during conditions that trigger Glc accumulation in the vacuole, like cold stress and external sugar supply. Accordingly, sugar analyses revealed that Aterdl6 mutants have elevated vacuolar Glc levels and that Glc flux across the tonoplast is impaired under stress conditions. Interestingly, overexpressor lines indicated a very similar function for the ERDL6 ortholog Integral Membrane Protein from sugar beet (Beta vulgaris). Aterdl6 mutant plants display increased sensitivity against external Glc, and mutant seeds exhibit a 10% increase in seed weight due to enhanced levels of seed sugars, proteins, and lipids. Our findings underline the importance of vacuolar Glc export during the regulation of cellular Glc homeostasis and the composition of seed reserves. PMID:21984725

  10. Minireview: Toward the Establishment of a Link between Melatonin and Glucose Homeostasis: Association of Melatonin MT2 Receptor Variants with Type 2 Diabetes

    PubMed Central

    Karamitri, Angeliki; Renault, Nicolas; Clement, Nathalie; Guillaume, Jean-Luc

    2013-01-01

    The existence of interindividual variations in G protein-coupled receptor sequences has been recognized early on. Recent advances in large-scale exon sequencing techniques are expected to dramatically increase the number of variants identified in G protein-coupled receptors, giving rise to new challenges regarding their functional characterization. The current minireview will illustrate these challenges based on the MTNR1B gene, which encodes the melatonin MT2 receptor, for which exon sequencing revealed 40 rare nonsynonymous variants in the general population and in type 2 diabetes (T2D) cohorts. Functional characterization of these MT2 mutants revealed 14 mutants with loss of Gi protein activation that associate with increased risk of T2D development. This repertoire of disease-associated mutants is a rich source for structure-activity studies and will help to define the still poorly understood role of melatonin in glucose homeostasis and T2D development in humans. Defining the functional defects in carriers of rare MT2 mutations will help to provide personalized therapies to these patients in the future. PMID:23798576

  11. Serum miRNA levels are related to glucose homeostasis and islet autoantibodies in children with high risk for type 1 diabetes.

    PubMed

    Åkerman, Linda; Casas, Rosaura; Ludvigsson, Johnny; Tavira, Beatriz; Skoglund, Camilla

    2018-01-01

    Micro RNAs (miRNAs) are promising disease biomarkers due to their high stability. Their expression in serum is altered in type 1 diabetes, but whether deviations exist in individuals with high risk for type 1 diabetes remains unexplored. We therefore assessed serum miRNAs in high-risk individuals (n = 21) positive for multiple islet autoantibodies, age-matched healthy children (n = 17) and recent-onset type 1 diabetes patients (n = 8), using Serum/Plasma Focus microRNA PCR Panels from Exiqon. The miRNA levels in the high-risk group were similar to healthy controls, and no specific miRNA profile was identified for the high-risk group. However, serum miRNAs appeared to reflect glycemic status and ongoing islet autoimmunity in high-risk individuals, since several miRNAs were associated to glucose homeostasis and autoantibody titers. High-risk individuals progressing to clinical disease after the sampling could not be clearly distinguished from non-progressors, while miRNA expression in the type 1 diabetes group deviated significantly from high-risk individuals and healthy controls, perhaps explained by major metabolic disturbances around the time of diagnosis.

  12. Insulin Storage and Glucose Homeostasis in Mice Null for the Granule Zinc Transporter ZnT8 and Studies of the Type 2 Diabetes–Associated Variants

    PubMed Central

    Nicolson, Tamara J.; Bellomo, Elisa A.; Wijesekara, Nadeeja; Loder, Merewyn K.; Baldwin, Jocelyn M.; Gyulkhandanyan, Armen V.; Koshkin, Vasilij; Tarasov, Andrei I.; Carzaniga, Raffaella; Kronenberger, Katrin; Taneja, Tarvinder K.; da Silva Xavier, Gabriela; Libert, Sarah; Froguel, Philippe; Scharfmann, Raphael; Stetsyuk, Volodymir; Ravassard, Philippe; Parker, Helen; Gribble, Fiona M.; Reimann, Frank; Sladek, Robert; Hughes, Stephen J.; Johnson, Paul R.V.; Masseboeuf, Myriam; Burcelin, Remy; Baldwin, Stephen A.; Liu, Ming; Lara-Lemus, Roberto; Arvan, Peter; Schuit, Frans C.; Wheeler, Michael B.; Chimienti, Fabrice; Rutter, Guy A.

    2009-01-01

    OBJECTIVE Zinc ions are essential for the formation of hexameric insulin and hormone crystallization. A nonsynonymous single nucleotide polymorphism rs13266634 in the SLC30A8 gene, encoding the secretory granule zinc transporter ZnT8, is associated with type 2 diabetes. We describe the effects of deleting the ZnT8 gene in mice and explore the action of the at-risk allele. RESEARCH DESIGN AND METHODS Slc30a8 null mice were generated and backcrossed at least twice onto a C57BL/6J background. Glucose and insulin tolerance were measured by intraperitoneal injection or euglycemic clamp, respectively. Insulin secretion, electrophysiology, imaging, and the generation of adenoviruses encoding the low- (W325) or elevated- (R325) risk ZnT8 alleles were undertaken using standard protocols. RESULTS ZnT8−/− mice displayed age-, sex-, and diet-dependent abnormalities in glucose tolerance, insulin secretion, and body weight. Islets isolated from null mice had reduced granule zinc content and showed age-dependent changes in granule morphology, with markedly fewer dense cores but more rod-like crystals. Glucose-stimulated insulin secretion, granule fusion, and insulin crystal dissolution, assessed by total internal reflection fluorescence microscopy, were unchanged or enhanced in ZnT8−/− islets. Insulin processing was normal. Molecular modeling revealed that residue-325 was located at the interface between ZnT8 monomers. Correspondingly, the R325 variant displayed lower apparent Zn2+ transport activity than W325 ZnT8 by fluorescence-based assay. CONCLUSIONS ZnT8 is required for normal insulin crystallization and insulin release in vivo but not, remarkably, in vitro. Defects in the former processes in carriers of the R allele may increase type 2 diabetes risks. PMID:19542200

  13. Influence of High Aspect Ratio Vessel Cell Culture on TNF-Alpha, Insulin Secretion and Glucose Homeostasis in Pancreatic Islets of Langerhans from Wistar Furth Rats

    NASA Technical Reports Server (NTRS)

    Tobin, Brian W.a; Leeper-Woodford, Sandra K.

    1999-01-01

    The present studies were carried out to determine the influence of a ground based microgravity paradigm, utilizing the High Aspect Ratio Vessel (HARV) cell culture upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF-alpha) production of pancreatic islets of Langerhans. An additional aim was to elucidate alterations in insulin secretion and glucose utilization using the HARV low shear, gravity averaged vector, cell culture technique. Islets were isolated (1726 +/- 117, 150 micron islet equivalent units) from Wistar Furth rats and assigned to four treatment groups: 1) HARV, 2) HARV plus LPS, 3) static culture, 4) static culture plus LPS. Following 48 hours of culture, insulin concentration was increased in both HARV and static cultures (p<0.05). Islet medium from HARV and static cultures were assayed for TNF-alpha (L929 cytotoxicity assay) and was measured at selected time points for 48 hours. TNF-alpha was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (p<0.05). This is a novel observation and indicates that TNF producing cells are present in islets and that LPS stimulates TNF secretion in isolated islets. A decrease in insulin concentration was demonstrated in the islet medium of the LPS stimulated HARV culture (p<0.05). That TNF-alpha is associated with a decreased insulin secretion is intriguing, both as it relates to in-flight investigations, and as it may provide insight into the pathophysiology of Type I and Type 11 diabetes. Glucose concentration in islet medium was lesser throughout the experiment in static cultures, suggesting a decreased reliance upon glucose as a metabolic substrate in the islets cultured in HARVS. In conclusion, the present studies demonstrate alterations in LPS induced TNF-alpha production of pancreatic islets of Langerhans, favoring a lesser TNF production in the microgravity HARV paradigm. Additionally, alterations in fuel

  14. Subchronic effects of inhaled ambient particulate matter on glucose homeostasis and target organ damage in a type 1 diabetic rat model

    SciTech Connect

    Yan, Yuan-Horng; Department of Medical Research, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan; Charles, Chou C.-K.

    Epidemiological studies have reported associations between particulate matter (PM) and cardiovascular effects, and diabetes mellitus (DM) patients might be susceptible to these effects. The chief chronic injuries resulting from DM are small vascular injuries (micro-vascular complications) or large blood vessel injuries (macro-vascular complications). However, toxicological data regarding the effects of PM on DM-related cardiovascular complications is limited. Our objective was to investigate whether subchronic PM exposure alters glucose homeostasis and causes cardiovascular complications in a type 1 DM rat model. We constructed a real world PM{sub 2.5} exposure system, the Taipei Air Pollution Exposure System for Health Effects (TAPES), tomore » continuously deliver non-concentrated PM for subchronic exposure. A type 1 DM rat model was induced using streptozotocin. Between December 22, 2009 and April 9, 2010, DM rats were exposed to PM or to filtered air (FA) using TAPES in Taipei, Taiwan, 24 h/day, 7 days/week, for a total of 16 weeks. The average concentrations (mean [SD]) of PM{sub 2.5} in the exposure and control chambers of the TAPES were 13.30 [8.65] and 0.13 [0.05] μg/m{sup 3}, respectively. Glycated hemoglobin A1c (HbA1c) was significantly elevated after exposure to PM compared with exposure to FA (mean [SD], 7.7% [3.1%] vs. 4.7% [1.0%], P < 0.05). Interleukin 6 and fibrinogen levels were significantly increased after PM exposure. PM caused focal myocarditis, aortic medial thickness, advanced glomerulosclerosis, and accentuation of tubular damage of the kidney (tubular damage index: 1.76 [0.77] vs. 1.15 [0.36], P < 0.001). PM exposure might induce the macro- and micro-vascular complications in DM through chronic hyperglycemia and systemic inflammation. - Highlights: • The study demonstrated cardiovascular and renal effects of PM in a rat model of DM. • TAPES is a continuous, real world, long-term PM exposure system. • HbA1c, a marker of glycemic

  15. Oral glucose tolerance test significantly impacts the prevalence of abnormal glucose tolerance among Indian women with polycystic ovary syndrome: lessons from a large database of two tertiary care centers on the Indian subcontinent.

    PubMed

    Ganie, Mohd Ashraf; Dhingra, Atul; Nisar, Sobia; Sreenivas, Vishnubhatla; Shah, Zaffar Amin; Rashid, Aafia; Masoodi, Shariq; Gupta, Nandita

    2016-01-01

    To estimate the prevalence of abnormal glucose tolerance (AGT) among Indian women with polycystic ovary syndrome (PCOS) and analyze the role of oral glucose tolerance (OGTT) test on its estimation. Cross-sectional clinical study. Tertiary care center. A total of 2,014 women with PCOS diagnosed on the basis of the Rotterdam 2003 criteria were enrolled, and the data of 1,746 subjects were analyzed. In addition to recording clinical, biochemical, and hormone parameters, a 75 g OGTT was administered. Prevalence of AGT and impact of age, body mass index (BMI), family history, and OGTT on its prevalence. The mean age of subjects was 23.8 ± 5.3 years, with a mean BMI of 24.9 ± 4.4 kg/m(2). The overall prevalence of AGT was 36.3% (6.3% diabetes and 30% impaired fasting plasma glucose/impaired glucose tolerance) using American Diabetes Association criteria. The glucose intolerance showed a rising trend with advancing age (30.3%, 35.4%, 51%, and 58.8% in the second, third, fourth, and fifth decades, respectively) and increasing BMI. Family history of diabetes mellitus was present in 54.6% (953/1,746) subjects, and it did not correlate with any of the studied parameters except waist circumference and BMI. Sensitivity was better with 2-hour post-OGTT glucose values as compared with fasting plasma glucose, since using fasting plasma glucose alone would have missed the diagnosis in 107 (6.1%) subjects. We conclude that AGT is high among young Indian women with PCOS and that it is not predicted by family history of type 2 DM. OGTT significantly improves the detection rate of AGT among Indian women with PCOS. Copyright © 2016. Published by Elsevier Inc.

  16. Effects of selenium supplementation on glucose homeostasis, inflammation, and oxidative stress in gestational diabetes: Randomized, double-blind, placebo-controlled trial.

    PubMed

    Asemi, Zatollah; Jamilian, Mehri; Mesdaghinia, Elaheh; Esmaillzadeh, Ahmad

    2015-10-01

    To our knowledge, no reports are available indicating the effects of selenium supplementation on metabolic parameters, inflammatory factors, and oxidative stress in gestational diabetes mellitus (GDM). The aim of this study was to assess the effects of selenium supplementation on metabolic status in pregnant women with GDM who were not on oral hypoglycemic agents. This randomized, double-blind, placebo-controlled clinical trial was performed with 70 women with GDM. Patients were randomly assigned to receive either 200 μg selenium supplements as tablet (n = 35) or placebo (n = 35) for 6 wk from weeks 24 to 28 of gestation. Fasting plasma samples were taken at study baseline and after 6 wk of intervention to quantify related variables. Selenium supplementation, compared with placebo, resulted in a significant reduction in fasting plasma glucose (-10.5 ± 11.9 versus +4.5 ± 12.9 mg/dL; P < 0.001), serum insulin levels (-1.98 ± 11.25 versus +5.26 ± 9.33 μIU/mL; P = 0.005), homeostasis model of assessment (HOMA)-insulin resistance (-0.84 ± 2.76 versus +1.47 ± 2.46; P < 0.001) and a significant increase in quantitative insulin sensitivity check index (+0.008 ± 0.03 versus -0.01 ± 0.01; P = 0.009). Additionally, a significant decrease in serum high-sensitivity C-reactive protein (hs-CRP) levels (-791.8 ± 2271.8 versus +500.5 ± 2563.3 ng/mL; P = 0.02) was seen after the administration of selenium supplements compared with placebo. Additionally, we observed a significant elevation in plasma glutathione (+52.14 ± 58.31 versus -39.93 ± 153.52 μmol/L; P = 0.002) and a significant reduction in plasma malondialdehyde levels (-0.01 ± 0.36 versus +0.67 ± 1.90 μmol/L; P = 0.04) after consumption of selenium supplements compared with placebo. We did not find any significant effect of taking selenium supplements on HOMA β-cell function, lipid profiles, plasma nitric oxide, or total antioxidant capacity concentrations. Selenium supplementation in pregnant women with

  17. The expression of dominant negative TCF7L2 in pancreatic beta cells during the embryonic stage causes impaired glucose homeostasis.

    PubMed

    Shao, Weijuan; Xiong, Xiaoquan; Ip, Wilfred; Xu, Fenghao; Song, Zhuolun; Zeng, Kejing; Hernandez, Marcela; Liang, Tao; Weng, Jianping; Gaisano, Herbert; Nostro, M Cristina; Jin, Tianru

    2015-04-01

    Disruption of TCF7L2 in mouse pancreatic β-cells has generated different outcomes in several investigations. Here we aim to clarify role of β-cell TCF7L2 and Wnt signaling using a functional-knockdown approach. Adenovirus-mediated dominant negative TCF7L2 (TCF7L2DN) expression was conducted in Ins-1 cells. The fusion gene in which TCF7L2DN expression is driven by P TRE3G was utilized to generate the transgenic mouse line TCF7L2DN Tet . The double transgenic line was created by mating TCF7L2DN Tet with Ins2-rtTA, designated as βTCFDN. β-cell specific TCF7L2DN expression was induced in βTCFDN by doxycycline feeding. TCF7L2DN expression in Ins-1 cells reduced GSIS, cell proliferation and expression of a battery of genes including incretin receptors and β-cell transcription factors. Inducing TCF7L2DN expression in βTCFDN during adulthood or immediately after weaning generated no or very modest metabolic defect, while its expression during embryonic development by doxycycline feeding in pregnant mothers resulted in significant glucose intolerance associated with altered β-cell gene expression and reduced β-cell mass. Our observations support a cell autonomous role for TCF7L2 in pancreatic β-cells suggested by most, though not all, investigations. βTCFDN is a novel model for further exploring the role of TCF7L2 in β-cell genesis and metabolic homeostasis.

  18. A randomised trial of salsalate for insulin resistance and cardiovascular risk factors in persons with abnormal glucose tolerance

    PubMed Central

    Goldfine, A. B.; Conlin, P. R.; Halperin, F.; Koska, J.; Permana, P.; Schwenke, D.; Shoelson, S. E.

    2016-01-01

    Aims/hypothesis Chronic sub-acute inflammation contributes to the pathogenesis of type 2 diabetes mellitus and cardiovascular disease. High doses of salicylate reduce inflammation, glucose and triacylglycerols, and may improve insulin sensitivity, suggesting therapeutic potential in impaired fasting glucose and/or impaired glucose tolerance. This trial aimed to evaluate the effect of salsalate vs placebo on insulin resistance and glycaemia in impaired fasting glucose and/or impaired glucose tolerance. Methods We conducted a 12 week, two-centre, randomised, placebo-controlled study to evaluate the effect of salsalate (up to 4 g/day) vs placebo on systemic glucose disposal. Secondary objectives included treatment effects on glycaemia, inflammation and cardiovascular risk factors. Seventy-eight participants with impaired fasting glucose and/or impaired glucose tolerance from two VA healthcare systems were enrolled. Randomisation assignment was provided by the coordinating center directly to site pharmacists, and participants and research staff were blinded to treatment assignment. Results Seventy-one individuals were randomised to placebo (n = 36) or salsalate (n = 35). Glucose disposal did not change in either group (salsalate 1% [95% CI −39%, 56%]; placebo 6% [95% CI −20%, 61%], p = 0.3 for placebo vs salsalate). Fasting glucose was reduced by 6% during the study by salsalate (p = 0.006) but did not change with placebo. Declines in glucose were accompanied by declines in fasting C-peptide with salsalate. Insulin clearance was reduced with salsalate. In the salsalate group, triacylglycerol levels were lower by 25% (p = 0.01) and adiponectin increased by 53% (p = 0.02) at the end of the study. Blood pressure, endothelial function and other inflammation markers did not differ between groups. Adipose tissue nuclear factor κB (NF-κB) activity declined in the salsalate group compared with placebo (−16% vs 42%, p = 0.005), but was not correlated with metabolic

  19. Atlantic DIP: high prevalence of abnormal glucose tolerance post partum is reduced by breast-feeding in women with prior gestational diabetes mellitus.

    PubMed

    O'Reilly, Michael W; Avalos, Gloria; Dennedy, Michael C; O'Sullivan, Eoin P; Dunne, Fidelma

    2011-12-01

    Gestational diabetes (GDM) is associated with adverse fetal and maternal outcomes, and identifies women at risk of future type 2 diabetes mellitus (T2DM). Breast-feeding may improve post partum maternal glucose tolerance. Our objective was to identify the prevalence of post partum dysglycemia after GDM, to delineate associated factors and to examine the effect of lactation on post partum glucose tolerance. We compared post partum 75 g oral glucose tolerance test (OGTT) results from 300 women with GDM and 220 controls with normal gestational glucose tolerance (NGT) in five regional centers. Breast-feeding data was collected at time of OGTT. Methods Post partum OGTT results were classified as normal (fasting plasma glucose (FPG) <5.6 mmol/l, 2 h <7.8 mmol/l) and abnormal (impaired fasting glucose (IFG), FPG 5.6-6.9 mmol/l; impaired glucose tolerance (IGT), 2 h glucose 7.8-11 mmol/l; IFG+IGT; T2DM, FPG ≥7 mmol/l±2 h glucose ≥11.1 mmol/l). Binary logistic regression was used to identify factors predictive of persistent hyperglycemia. Five hundred and twenty women were tested; six (2.7%) with NGT in pregnancy had post partum dysglycemia compared with 57 (19%) with GDM in index pregnancy (P<0.001). Non-European ethnicity (odds ratio (OR) 3.40; 95% confidence interval (CI) 1.45-8.02, P=0.005), family history of T2DM (OR 2.14; 95% CI 1.06-4.32, P=0.034), and gestational insulin use (OR 2.62; 95% CI 1.17-5.87, P=0.019) were associated with persistent dysglycemia. The prevalence of persistent hyperglycemia was significantly lower in women who breast-fed vs bottle-fed post partum (8.2 vs 18.4%, P<0.001). Non-European ethnicity, gestational insulin use, family history of T2DM, and elevated body mass index were associated with persistent dysglycemia after GDM. Breast-feeding may confer beneficial metabolic effects after GDM and should be encouraged.

  20. POLYMORPHISMS NEAR SOCS3 ARE ASSOCIATED WITH OBESITY AND GLUCOSE HOMEOSTASIS TRAITS IN HISPANIC AMERICANS FROM THE INSULIN RESISTANCE ATHEROSCLEROSIS FAMILY STUDY

    PubMed Central

    Talbert, Matthew E; Langefeld, Carl D; Ziegler, Julie; Mychaleckyj, Josyf C; Haffner, Steven M; Norris, Jill M; Bowden, Donald W

    2009-01-01

    The SOCS3 gene product participates in the feedback inhibition of a range of cytokine signals. Most notably, SOCS3 inhibits the functioning of leptin and downstream steps in insulin signaling after being expressed by terminal transcription factors, such as STAT3 and c-fos. The SOCS3 gene is located in the chromosome region 17q24–17q25, previously linked to body mass index (BMI), visceral adipose tissue (VAT), and waist circumference (WAIST) in Hispanic families in the Insulin Resistance Atherosclerosis Family Study (IRASFS). A high density map of 1536 single nucleotide polymorphisms (SNPs) was constructed to cover a portion of the 17q linkage interval in DNA samples from 1425 Hispanic subjects from 90 extended families in IRASFS. Analysis of this dense SNP map data revealed evidence of association of rs9914220 (located 10 kb 5’ of the SOCS3 gene) with BMI, VAT, and WAIST (P-value ranging from 0 003 to 0.017). Using a tagging SNP approach, rs9914220 and 22 additional SOCS3 SNPs were genotyped for genetic association analysis with measures of adiposity and glucose homeostasis. The adiposity phenotypes utilized in association analyses included BMI, WAIST, waist to hip ratio (WHR), subcutaneous adipose tissue (SAT), VAT, and visceral to subcutaneous ratio (VSR). Linkage disequilibrium (LD) calculations revealed three haplotype blocks near SOCS3. Haplotype Block 1 (5’ of SOCS3) contained SNPs consistently associated with BMI, WAIST, WHR, and VAT (P-values ranging from 2.00x10−4 to .036). Haplotype Block 3 contained single-SNPs that were associated with most adiposity traits except for VSR (P-values ranging from 0.002 to 0.047). When trait associated SNPs were included in linkage analyses as covariates, a reduction of VAT LOD score from 1.26 to .76 above the SOCS3 locus (110 cM) was observed. Multi-SNP haplotype testing using the quantitative pedigree disequilibrium test (QPDT) was broadly consistent with the single-SNP associations. In conclusion, these results

  1. comparative study of glucose homeostasis, lipids and lipoproteins, HDL functionality, and cardiometabolic parameters in modestly severely obese African Americans and White Americans with prediabetes: implications for the metabolic paradoxes.

    PubMed

    Healy, Sara J; Osei, Kwame; Gaillard, Trudy

    2015-02-01

    To determine whether modestly severe obesity modifies glucose homeostasis, levels of cardiometabolic markers, and HDL function in African Americans (AAs) and white Americans (WAs) with prediabetes. We studied 145 subjects with prediabetes (N = 61 WAs, N = 84 AAs, mean age 46.5 ± 11.2 years, mean BMI 37.8 ± 6.3 kg/m(2)). We measured fasting levels of lipids, lipoproteins, and an inflammatory marker (C-reactive protein [CRP]); HDL functionality (i.e., levels of paraoxonase 1 [PON1]); and levels of oxidized LDL, adiponectin, and interleukin-6 (IL-6). We measured serum levels of glucose, insulin, and C-peptide during an oral glucose tolerance test. Values for insulin sensitivity index (Si), glucose effectiveness index (Sg), glucose effectiveness at zero insulin (GEZI), and acute insulin response to glucose (AIRg) were derived using a frequently sampled intravenous glucose tolerance test (using MINMOD software). Mean levels of fasting and incremental serum glucose, insulin, and C-peptide tended to be higher in WAs versus AAs. The mean Si was not different in WAs versus AAs (2.6 ± 2.3 vs. 2.9 ± 3.0 × 10(-4) × min(-1) [μU/mL](-1)). Mean values for AIRg and disposition index as well as Sg and GEZI were lower in WAs than AAs. WAs had higher serum triglyceride levels than AAs (116.1 ± 55.5 vs. 82.7 ± 44.2 mg/dL, P = 0.0002). Mean levels of apolipoprotein (apo) A1, HDL cholesterol, PON1, oxidized LDL, CRP, adiponectin, and IL-6 were not significantly different in obese AAs versus WAs with prediabetes. Modestly severe obesity attenuated the ethnic differences in Si, but not in Sg and triglyceride levels in WAs and AAs with prediabetes. Despite the lower Si and PON1 values, AAs preserved paradoxical relationships between the Si and HDL/apoA1/triglyceride ratios. We conclude that modestly severe obesity has differential effects on the pathogenic mechanisms underlying glucose homeostasis and atherogenesis in obese AAs and WAs with prediabetes. © 2015 by the American

  2. Comparative Study of Glucose Homeostasis, Lipids and Lipoproteins, HDL Functionality, and Cardiometabolic Parameters in Modestly Severely Obese African Americans and White Americans With Prediabetes: Implications for the Metabolic Paradoxes

    PubMed Central

    Healy, Sara J.; Osei, Kwame

    2015-01-01

    OBJECTIVE To determine whether modestly severe obesity modifies glucose homeostasis, levels of cardiometabolic markers, and HDL function in African Americans (AAs) and white Americans (WAs) with prediabetes. RESEARCH DESIGN AND METHODS We studied 145 subjects with prediabetes (N = 61 WAs, N = 84 AAs, mean age 46.5 ± 11.2 years, mean BMI 37.8 ± 6.3 kg/m2). We measured fasting levels of lipids, lipoproteins, and an inflammatory marker (C-reactive protein [CRP]); HDL functionality (i.e., levels of paraoxonase 1 [PON1]); and levels of oxidized LDL, adiponectin, and interleukin-6 (IL-6). We measured serum levels of glucose, insulin, and C-peptide during an oral glucose tolerance test. Values for insulin sensitivity index (Si), glucose effectiveness index (Sg), glucose effectiveness at zero insulin (GEZI), and acute insulin response to glucose (AIRg) were derived using a frequently sampled intravenous glucose tolerance test (using MINMOD software). RESULTS Mean levels of fasting and incremental serum glucose, insulin, and C-peptide tended to be higher in WAs versus AAs. The mean Si was not different in WAs versus AAs (2.6 ± 2.3 vs. 2.9 ± 3.0 × 10−4 × min−1 [μU/mL]−1). Mean values for AIRg and disposition index as well as Sg and GEZI were lower in WAs than AAs. WAs had higher serum triglyceride levels than AAs (116.1 ± 55.5 vs. 82.7 ± 44.2 mg/dL, P = 0.0002). Mean levels of apolipoprotein (apo) A1, HDL cholesterol, PON1, oxidized LDL, CRP, adiponectin, and IL-6 were not significantly different in obese AAs versus WAs with prediabetes. CONCLUSIONS Modestly severe obesity attenuated the ethnic differences in Si, but not in Sg and triglyceride levels in WAs and AAs with prediabetes. Despite the lower Si and PON1 values, AAs preserved paradoxical relationships between the Si and HDL/apoA1/triglyceride ratios. We conclude that modestly severe obesity has differential effects on the pathogenic mechanisms underlying glucose homeostasis and atherogenesis in obese

  3. Effects of Roux-en-Y gastric bypass on energy and glucose homeostasis are preserved in two mouse models of functional glucagon-like peptide-1 deficiency☆ab

    PubMed Central

    Mokadem, Mohamad; Zechner, Juliet F.; Margolskee, Robert F.; Drucker, Daniel J.; Aguirre, Vincent

    2013-01-01

    Glucagon-like peptide-1 (GLP-1) secretion is greatly enhanced after Roux-en-Y gastric bypass (RYGB). While intact GLP-1exerts its metabolic effects via the classical GLP-1 receptor (GLP-1R), proteolytic processing of circulating GLP-1 yields metabolites such as GLP-1(9–36)amide/GLP-1(28–36)amide, that exert similar effects independent of the classical GLP-1R. We investigated the hypothesis that GLP-1, acting via these metabolites or through its known receptor, is required for the beneficial effects of RYGB using two models of functional GLP-1 deficiency – α-gustducin-deficient (α-Gust−/−) mice, which exhibit attenuated nutrient-stimulated GLP-1 secretion, and GLP-1R-deficient mice. We show that the effect of RYGB to enhance glucose-stimulated GLP-1 secretion was greatly attenuated in α-Gust−/− mice. In both genetic models, RYGB reduced body weight and improved glucose homeostasis to levels observed in lean control mice. Therefore, GLP-1, acting through its classical GLP-1R or its bioactive metabolites, does not seem to be involved in the effects of RYGB on body weight and glucose homeostasis. PMID:24634822

  4. Acarbose, the α-glucosidase inhibitor, attenuates the blood pressure and splanchnic blood flow responses to meal in elderly patients with postprandial hypotension concomitant with abnormal glucose metabolism.

    PubMed

    Qiao, Wei; Li, Jing; Li, Ying; Qian, Duan; Chen, Lei; Wei, Xiansen; Jin, Jiangli; Wang, Yong

    2016-02-01

    Postprandial hypotension (PPH) is a unique clinical phenomenon in the elderly, but its underlying pathogenesis has not been completely elucidated, and drug treatment is still in clinical exploratory stage. The aim of the study was to evaluate the relationship between the fall in postprandial blood pressure and splanchnic blood flow, and to provide a theoretical basis for the treatment of PPH by taking acarbose. The study included 20 elderly inpatients diagnosed with PPH concomitant with abnormal glucose metabolism at stable condition. They were treated with 50 mg acarbose with their meal to observe the changes in blood pressure, heart rate, and blood glucose level, and to monitor the hemodynamics of the superior mesenteric artery (SMA) before and after treatment. Without acarbose treatment, patients after a meal had significantly decreased systolic and diastolic blood pressure, faster postprandial heart rate, higher postprandial glucose level at each period, and increased postprandial SMA blood flow compared with that at fasting state (P<0.05). Acarbose treatment significantly attenuated the decrease of postprandial systolic blood pressures from 35.50±12.66 to 22.25±6.90 mmHg (P=0.000), the increase of heart rate from 9.67±5.94 to 5.33±3.20 beats/min (P=0.016), the increase of postprandial blood glucose from 3.55±1.69 to 2.28±1.61 mmol/l (P=0.000), the increase of postprandial SMA blood flow from 496.80±147.15 to 374.55±97.89 ml/min (P=0.031), and the incidence of PPH, syncope, falls, dizziness, weakness, and angina pectoris (P<0.05). The maximal decrease of postprandial systolic blood pressure was positively associated with the maximal increase in postprandial SMA blood flow (r=0.351, P=0.026). Acarbose treatment showed no significant side effects. The increase in postprandial splanchnic perfusion is one of the reasons for PPH formation. Acarbose may exert its role in PPH treatment by reducing postprandial gastrointestinal blood perfusion. Giving

  5. SUGAR: spotting undiagnosed glucose abnormal results--a new protocol to increase postpartum testing among women with gestational diabetes mellitus.

    PubMed

    Carson, Michael P; Morgan, Benjamin; Gussman, Debra; Brown, Monica; Rothenberg, Karen; Wisner, Theresa A

    2015-02-01

    Over 70% of women with gestational diabetes mellitus (GDM) will develop diabetes mellitus (DM), but only 30% follow through with the recommended postpartum oral glucose tolerance testing (OGTT). HbA1c is approved to diagnose DM, and combined with a fasting plasma glucose it can identify 93% of patients with dysglycemia. We tested the hypothesis that a single blood draw to assess for dysglycemia at the postpartum visit could improve testing rates compared with those required to obtain an OGTT at an outside laboratory. Prospective cohort study of all women with GDM who delivered between July 2010 and December 2011. When insurance status required testing at an outside laboratory an OGTT was ordered, when insurance allowed testing at our center a random sugar and HbA1c were drawn at the postpartum visit (SUGAR Protocol). Of the 40 women, 36 attended a postpartum visit. In the SUGAR arm, 19 of 19 (100%) were tested versus 9 of 17 (53%) in the OGTT arm; relative risk of testing was 1.9 (95% confidence interval, 1.2-3.0). 36% were glucose intolerant. This pilot study found that an in-office testing model doubled the rate of postpartum testing in this clinic population, and was reasonably sensitive at detecting dysglycemia. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  6. Long-term exposure to abnormal glucose levels alters drug metabolism pathways and insulin sensitivity in primary human hepatocytes

    NASA Astrophysics Data System (ADS)

    Davidson, Matthew D.; Ballinger, Kimberly R.; Khetani, Salman R.

    2016-06-01

    Hyperglycemia in type 2 diabetes mellitus has been linked to non-alcoholic fatty liver disease, which can progress to inflammation, fibrosis/cirrhosis, and hepatocellular carcinoma. Understanding how chronic hyperglycemia affects primary human hepatocytes (PHHs) can facilitate the development of therapeutics for these diseases. Conversely, elucidating the effects of hypoglycemia on PHHs may provide insights into how the liver adapts to fasting, adverse diabetes drug reactions, and cancer. In contrast to declining PHH monocultures, micropatterned co-cultures (MPCCs) of PHHs and 3T3-J2 murine embryonic fibroblasts maintain insulin-sensitive glucose metabolism for several weeks. Here, we exposed MPCCs to hypo-, normo- and hyperglycemic culture media for ~3 weeks. While albumin and urea secretion were not affected by glucose level, hypoglycemic MPCCs upregulated CYP3A4 enzyme activity as compared to other glycemic states. In contrast, hyperglycemic MPCCs displayed significant hepatic lipid accumulation in the presence of insulin, while also showing decreased sensitivity to insulin-mediated inhibition of glucose output relative to a normoglycemic control. In conclusion, we show for the first time that PHHs exposed to hypo- and hyperglycemia can remain highly functional, but display increased CYP3A4 activity and selective insulin resistance, respectively. In the future, MPCCs under glycemic states can aid in novel drug discovery and mechanistic investigations.

  7. CSF glucose test

    MedlinePlus

    Glucose test - CSF; Cerebrospinal fluid glucose test ... The glucose level in the CSF should be 50 to 80 mg/100 mL (or greater than 2/3 ... Abnormal results include higher and lower glucose levels. Abnormal ... or fungus) Inflammation of the central nervous system Tumor

  8. Could post-weaning dietary chia seed mitigate the development of dyslipidemia, liver steatosis and altered glucose homeostasis in offspring exposed to a sucrose-rich diet from utero to adulthood?

    PubMed

    Fortino, M A; Oliva, M E; Rodriguez, S; Lombardo, Y B; Chicco, A

    2017-01-01

    The present work analyzes the effects of dietary chia seeds during postnatal life in offspring exposed to a sucrose-rich diet (SRD) from utero to adulthood. At weaning, chia seed (rich in α-linolenic acid) replaced corn oil (rich in linoleic acid) in the SRD. At 150 days of offspring life, anthropometrical parameters, blood pressure, plasma metabolites, hepatic lipid metabolism and glucose homeostasis were analyzed. Results showed that chia was able to prevent the development of hypertension, liver steatosis, hypertriglyceridemia and hypercholesterolemia. Normal triacylglycerol secretion and triacylglycerol clearance were accompanied by an improvement of de novo hepatic lipogenic and carnitine-palmitoyl transferase-1 enzymatic activities, associated with an accretion of n-3 polyunsaturated fatty acids in the total composition of liver homogenate. Glucose homeostasis and plasma free fatty acid levels were improved while visceral adiposity was slightly decreased. These results confirm that the incorporation of chia seed in the diet in postnatal life may provide a viable therapeutic option for preventing/mitigating adverse outcomes induced by an SRD from utero to adulthood. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Neuronal regulation of homeostasis by nutrient sensing.

    PubMed

    Lam, Tony K T

    2010-04-01

    In type 2 diabetes and obesity, the homeostatic control of glucose and energy balance is impaired, leading to hyperglycemia and hyperphagia. Recent studies indicate that nutrient-sensing mechanisms in the body activate negative-feedback systems to regulate energy and glucose homeostasis through a neuronal network. Direct metabolic signaling within the intestine activates gut-brain and gut-brain-liver axes to regulate energy and glucose homeostasis, respectively. In parallel, direct metabolism of nutrients within the hypothalamus regulates food intake and blood glucose levels. These findings highlight the importance of the central nervous system in mediating the ability of nutrient sensing to maintain homeostasis. Futhermore, they provide a physiological and neuronal framework by which enhancing or restoring nutrient sensing in the intestine and the brain could normalize energy and glucose homeostasis in diabetes and obesity.

  10. Differences of prevalence of dyslipidemia and risk factors related to LDL-c in the patients with abnormal fasting glucose between Uygur and Han in Xinjiang.

    PubMed

    Quan, Li; Hu, Lin; Zhang, Li; Jiang, Sheng

    2015-01-01

    To evaluate the incidence of dyslipidemia among Uygur and Han patients with impaired fasting glucose (IFG). To investigate the influence factors on LDL-c in this population. This cross-sectional study included a total of 4709 participants, consisting of Uygurs patients (n=2053) and Han patients (n=2656) from Xinjiang province, who were screened for diabetes mellitus. A stratified multistage sampling design was used to collect the participants. The influence factors on LDL-c were analyzed by Logistic regression analysis. Among the IFG patients (n=1757), Uighur IFG group had a higher prevalence of dyslipidemia than that of Han IFG group, 99.8% vs. 63.7%, P<0.05. Similar trends were existed in the prevalence of hypercholesteremia, hypertriglyceridemia, high LDL-c and low HDL-c (all P<0.05). Among the Uighur groups, IFG group had higher dyslipidemia rate than that of euglycemia group (74%). However, there was no such difference in the Han groups. Logistic regression analysis revealed that risk factors associated with LDL-c were age, total cholesterol and 2 h postprandial blood glucose for the Uighur IFG patients. However, gender and total cholesterol were risk factors for Han IFG patients. Uighur IFG patients had higher incidence of dyslipidemia than that of Han IFG patients. For Uyghur IFG patients, closing follow-up of total cholesterol and 2 h postprandial blood glucose were necessary. As to the Han IFG patients, we should pay more attention to male and total cholesterol in order to lower LDL-c levels. So, appropriately preventive and therapeutic measures should be chosen based on the characteristics of abnormal lipid profiles in different nationality.

  11. Renal glucose metabolism in normal physiological conditions and in diabetes.

    PubMed

    Alsahli, Mazen; Gerich, John E

    2017-11-01

    The kidney plays an important role in glucose homeostasis via gluconeogenesis, glucose utilization, and glucose reabsorption from the renal glomerular filtrate. After an overnight fast, 20-25% of glucose released into the circulation originates from the kidneys through gluconeogenesis. In this post-absorptive state, the kidneys utilize about 10% of all glucose utilized by the body. After glucose ingestion, renal gluconeogenesis increases and accounts for approximately 60% of endogenous glucose release in the postprandial period. Each day, the kidneys filter approximately 180g of glucose and virtually all of this is reabsorbed into the circulation. Hormones (most importantly insulin and catecholamines), substrates, enzymes, and glucose transporters are some of the various factors influencing the kidney's role. Patients with type 2 diabetes have an increased renal glucose uptake and release in the fasting and the post-prandial states. Additionally, glucosuria in these patients does not occur at plasma glucose levels that would normally produce glucosuria in healthy individuals. The major abnormality of renal glucose metabolism in type 1 diabetes appears to be impaired renal glucose release during hypoglycemia. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evaluation of the Genetic and Nutritional Control of Obesity and Type 2 Diabetes in a Novel Mouse Model on Chromosome 7: An Insight into Insulin Signaling and Glucose Homeostasis

    SciTech Connect

    Nelson, S.; Dhar, M.

    Obesity is the main cause of type 2 diabetes, accounting for 90-95% of all diabetes cases in the US. Human obesity is a complex trait and can be studied using appropriate mouse models. A novel polygenic mouse model for studying the genetic and environmental contributions to and the physiological ramifications of obesity and related phenotypes is found in specific lines of mice bred and maintained at Oak Ridge National Laboratory. Heterozygous mice with a maternally inherited copy of two radiation-induced deletions in the p region of mouse chromosome 7, p23DFioD and p30PUb, have significantly greater body fat and show hyperinsulinemiamore » compared to the wild-type. A single gene, Atp10c, maps to this critical region and codes for a putative aminophospholipid translocase. Biochemical and molecular studies were initiated to gain insight into obesity and glucose homeostasis in these animals and to study the biological role of Atp10c in creating these phenotypes. Glucose and insulin tolerance tests were standardized for the heterozygous p23DFioD and control mice on a custom-made diet containing 20% protein, 70% carbohydrate, and 10% fat (kcal). Atp10c expression profiles were also generated using Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR). Heterozygous p23DFioD animals showed insulin resistance after receiving a dose of either 0.375 or 0.75 U/kg Illetin R insulin. RT-PCR data also shows differences in Atp10c expression in the mutants versus control mice. Using these standardized biochemical assays, future studies will further the understanding of genetic and nutritional controls of glucose homeostasis and obesity in animal models and subsequently in human populations.« less

  13. Haptoglobin, alpha-thalassaemia and glucose-6-phosphate dehydrogenase polymorphisms and risk of abnormal transcranial Doppler among patients with sickle cell anaemia in Tanzania.

    PubMed

    Cox, Sharon E; Makani, Julie; Soka, Deogratias; L'Esperence, Veline S; Kija, Edward; Dominguez-Salas, Paula; Newton, Charles R J; Birch, Anthony A; Prentice, Andrew M; Kirkham, Fenella J

    2014-06-01

    Transcranial Doppler ultrasonography measures cerebral blood flow velocity (CBFv) of basal intracranial vessels and is used clinically to detect stroke risk in children with sickle cell anaemia (SCA). Co-inheritance in SCA of alpha-thalassaemia and glucose-6-phosphate dehydrogenase (G6PD) polymorphisms is reported to associate with high CBFv and/or risk of stroke. The effect of a common functional polymorphism of haptoglobin (HP) is unknown. We investigated the effect of co-inheritance of these polymorphisms on CBFv in 601 stroke-free Tanzanian SCA patients aged <24 years. Homozygosity for alpha-thalassaemia 3·7 deletion was significantly associated with reduced mean CBFv compared to wild-type (β-coefficient -16·1 cm/s, P = 0·002) adjusted for age and survey year. Inheritance of 1 or 2 alpha-thalassaemia deletions was associated with decreased risk of abnormally high CBFv, compared to published data from Kenyan healthy control children (Relative risk ratio [RRR] = 0·53 [95% confidence interval (CI):0·35-0·8] & RRR = 0·43 [95% CI:0·23-0·78]), and reduced risk of abnormally low CBFv for 1 deletion only (RRR = 0·38 [95% CI:0·17-0·83]). No effects were observed for G6PD or HP polymorphisms. This is the first report of the effects of co-inheritance of common polymorphisms, including the HP polymorphism, on CBFv in SCA patients resident in Africa and confirms the importance of alpha-thalassaemia in reducing risk of abnormal CBFv. © 2014 The Authors. British Journal of Haematology Published by John Wiley & Sons Ltd.

  14. Characterization of the Impaired Glucose Homeostasis Produced in C57BL/6 Mice by Chronic Exposure to Arsenic and High-Fat Diet

    PubMed Central

    Paul, David S.; Walton, Felecia S.; Saunders, R. Jesse

    2011-01-01

    Background: Type 2 diabetes is characterized by glucose intolerance and insulin resistance. Obesity is the leading cause of type 2 diabetes. Growing evidence suggests that chronic exposure to inorganic arsenic (iAs) also produces symptoms consistent with diabetes. Thus, iAs exposure may further increase the risk of diabetes in obese individuals. Objectives: Our goal was to characterize diabetogenic effects of iAs exposure and high-fat diet (HFD) in weaned C57BL/6 mice. Methods: Mice were fed HFD or low-fat diet (LFD) while exposed to iAs in drinking water (25 or 50 ppm As) for 20 weeks; control HFD and LFD mice drank deionized water. Body mass and adiposity were monitored throughout the study. We measured glucose and insulin levels in fasting blood and in blood collected during oral glucose tolerance tests (OGTT) to evaluate the diabetogenic effects of the treatment. Results: Control mice fed HFD accumulated more fat, had higher fasting blood glucose, and were more insulin resistant than were control LFD mice. However, these diabetes indicators decreased with iAs intake in a dose-dependent manner. OGTT showed impaired glucose tolerance for both control and iAs-treated HFD mice compared with respective LFD mice. Notably, glucose intolerance was more pronounced in HFD mice treated with iAs despite a significant decrease in adiposity, fasting blood glucose, and insulin resistance. Conclusions: Our data suggest that iAs exposure acts synergistically with HFD-induced obesity in producing glucose intolerance. However, mechanisms of the diabetogenic effects of iAs exposure may differ from the mechanisms associated with the obesity-induced type 2 diabetes. PMID:21592922

  15. Preservation of blood glucose homeostasis in slow-senescing somatotrophism-deficient mice subjected to intermittent fasting begun at middle or old age.

    PubMed

    Arum, Oge; Saleh, Jamal K; Boparai, Ravneet K; Kopchick, John J; Khardori, Romesh K; Bartke, Andrzej

    2014-06-01

    Poor blood glucose homeostatic regulation is common, consequential, and costly for older and elderly populations, resulting in pleiotrophically adverse clinical outcomes. Somatotrophic signaling deficiency and dietary restriction have each been shown to delay the rate of senescence, resulting in salubrious phenotypes such as increased survivorship. Using two growth hormone (GH) signaling-related, slow-aging mouse mutants we tested, via longitudinal analyses, whether genetic perturbations that increase survivorship also improve blood glucose homeostatic regulation in senescing mammals. Furthermore, we institute a dietary restriction paradigm that also decelerates aging, an intermittent fasting (IF) feeding schedule, as either a short-term or a sustained intervention beginning at either middle or old age, and assess its effects on blood glucose control. We find that either of the two genetic alterations in GH signaling ameliorates fasting hyperglycemia; additionally, both longevity-inducing somatotrophic mutations improve insulin sensitivity into old age. Strikingly, we observe major and broad improvements in blood glucose homeostatic control by IF: IF improves ad libitum-fed hyperglycemia, glucose tolerance, and insulin sensitivity, and reduces hepatic gluconeogenesis, in aging mutant and normal mice. These results on correction of aging-resultant blood glucose dysregulation have potentially important clinical and public health implications for our ever-graying global population, and are consistent with the Longevity Dividend concept.

  16. Three-component homeostasis control

    NASA Astrophysics Data System (ADS)

    Xu, Jin; Hong, Hyunsuk; Jo, Junghyo

    2014-03-01

    Two reciprocal components seem to be sufficient to maintain a control variable constant. However, pancreatic islets adapt three components to control glucose homeostasis. They are α (secreting glucagon), β (insulin), and δ (somatostatin) cells. Glucagon and insulin are the reciprocal hormones for increasing and decreasing blood glucose levels, while the role of somatostatin is unknown. However, it has been known how each hormone affects other cell types. Based on the pulsatile hormone secretion and the cellular interactions, this system can be described as coupled oscillators. In particular, we used the Landau-Stuart model to consider both amplitudes and phases of hormone oscillations. We found that the presence of the third component, δ cell, was effective to resist under glucose perturbations, and to quickly return to the normal glucose level once perturbed. Our analysis suggested that three components are necessary for advanced homeostasis control.

  17. Cytosolic NADPH Homeostasis in Glucose-starved Procyclic Trypanosoma brucei Relies on Malic Enzyme and the Pentose Phosphate Pathway Fed by Gluconeogenic Flux*

    PubMed Central

    Allmann, Stefan; Morand, Pauline; Ebikeme, Charles; Gales, Lara; Biran, Marc; Hubert, Jane; Brennand, Ana; Mazet, Muriel; Franconi, Jean-Michel; Michels, Paul A. M.; Portais, Jean-Charles; Boshart, Michael; Bringaud, Frédéric

    2013-01-01

    All living organisms depend on NADPH production to feed essential biosyntheses and for oxidative stress defense. Protozoan parasites such as the sleeping sickness pathogen Trypanosoma brucei adapt to different host environments, carbon sources, and oxidative stresses during their infectious life cycle. The procyclic stage develops in the midgut of the tsetse insect vector, where they rely on proline as carbon source, although they prefer glucose when grown in rich media. Here, we investigate the flexible and carbon source-dependent use of NADPH synthesis pathways in the cytosol of the procyclic stage. The T. brucei genome encodes two cytosolic NADPH-producing pathways, the pentose phosphate pathway (PPP) and the NADP-dependent malic enzyme (MEc). Reverse genetic blocking of those pathways and a specific inhibitor (dehydroepiandrosterone) of glucose-6-phosphate dehydrogenase together established redundancy with respect to H2O2 stress management and parasite growth. Blocking both pathways resulted in ∼10-fold increase of susceptibility to H2O2 stress and cell death. Unexpectedly, the same pathway redundancy was observed in glucose-rich and glucose-depleted conditions, suggesting that gluconeogenesis can feed the PPP to provide NADPH. This was confirmed by (i) a lethal phenotype of RNAi-mediated depletion of glucose-6-phosphate isomerase (PGI) in the glucose-depleted Δmec/Δmec null background, (ii) an ∼10-fold increase of susceptibility to H2O2 stress observed for the Δmec/Δmec/RNAiPGI double mutant when compared with the single mutants, and (iii) the 13C enrichment of glycolytic and PPP intermediates from cells incubated with [U-13C]proline, in the absence of glucose. Gluconeogenesis-supported NADPH supply may also be important for nucleotide and glycoconjugate syntheses in the insect host. PMID:23665470

  18. Hematological parameters and red blood cell morphological abnormality of Glucose-6-Phosphate dehydrogenase deficiency co-inherited with thalassemia.

    PubMed

    Pengon, Jutharat; Svasti, Saovaros; Kamchonwongpaisan, Sumalee; Vattanaviboon, Phantip

    2018-03-01

    Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and thalassemia are genetically independent hemolytic disorders. Co-inheritance of both disorders may affect red blood cell pathology to a greater extent than normally seen in either disorder alone. This study determines the prevalence and evaluates hematological changes of G-6-PD deficiency and thalassemia co-inheritance. G-6-PD deficiency was screened from 200 male thalassemia blood samples using a fluorescent spot test. Hematological parameters and red blood cell morphology were evaluated among G-6-PD deficiency/thalassemia co-inheritance, G-6-PD deficiency alone, thalassemia alone, and normal individuals. G-6-PD deficiency was detected together with hemoglobin (Hb) E heterozygote, Hb E homozygote, β-thalassemia trait, and β-thalassemia/Hb E, α-thalassemia-2 trait, and Hb H disease. Hb level, hematocrit, mean cell volume, and mean cell Hb of G-6-PD deficiency co-inherited with asymptomatic thalassemia carriers show significantly lower mean values compared to carriers with only the same thalassemia genotypes. Higher mean red blood cell distribution width was observed in G-6-PD deficiency co-inherited with Hb E heterozygote, as with numbers of hemighost cells in G-6-PD deficiency/thalassemia co-inheritance compared to those with either disorder. Apart from Hb level, hematological parameters of co-inheritance disorders were not different from individuals with a single thalassemia disease. G-6-PD deficiency co-inherited with thalassemia in males was present in 10% of the participants, resulting in worsening of red blood cell pathology compared with inheritance of thalassemia alone. Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

  19. Hepatic glucose sensing is required to preserve β cell glucose competence

    PubMed Central

    Seyer, Pascal; Vallois, David; Poitry-Yamate, Carole; Schütz, Frédéric; Metref, Salima; Tarussio, David; Maechler, Pierre; Staels, Bart; Lanz, Bernard; Grueter, Rolf; Decaris, Julie; Turner, Scott; da Costa, Anabela; Preitner, Frédéric; Minehira, Kaori; Foretz, Marc; Thorens, Bernard

    2013-01-01

    Liver glucose metabolism plays a central role in glucose homeostasis and may also regulate feeding and energy expenditure. Here we assessed the impact of glucose transporter 2 (Glut2) gene inactivation in adult mouse liver (LG2KO mice). Loss of Glut2 suppressed hepatic glucose uptake but not glucose output. In the fasted state, expression of carbohydrate-responsive element-binding protein (ChREBP) and its glycolytic and lipogenic target genes was abnormally elevated. Feeding, energy expenditure, and insulin sensitivity were identical in LG2KO and control mice. Glucose tolerance was initially normal after Glut2 inactivation, but LG2KO mice exhibited progressive impairment of glucose-stimulated insulin secretion even though β cell mass and insulin content remained normal. Liver transcript profiling revealed a coordinated downregulation of cholesterol biosynthesis genes in LG2KO mice that was associated with reduced hepatic cholesterol in fasted mice and reduced bile acids (BAs) in feces, with a similar trend in plasma. We showed that chronic BAs or farnesoid X receptor (FXR) agonist treatment of primary islets increases glucose-stimulated insulin secretion, an effect not seen in islets from Fxr–/– mice. Collectively, our data show that glucose sensing by the liver controls β cell glucose competence and suggest BAs as a potential mechanistic link. PMID:23549084

  20. Effects of Low-Molecular-Weight Fucoidan and High Stability Fucoxanthin on Glucose Homeostasis, Lipid Metabolism, and Liver Function in a Mouse Model of Type II Diabetes.

    PubMed

    Lin, Hong-Ting Victor; Tsou, Yu-Chi; Chen, Yu-Ting; Lu, Wen-Jung; Hwang, Pai-An

    2017-04-07

    The combined effects of low-molecular-weight fucoidan (LMF) and fucoxanthin (Fx) in terms of antihyperglycemic, antihyperlipidemic, and hepatoprotective activities were investigated in a mouse model of type II diabetes. The intake of LMF, Fx, and LMF + Fx lowered the blood sugar and fasting blood sugar levels, and increased serum adiponectin levels. The significant decrease in urinary sugar was only observed in LMF + Fx supplementation. LMF and Fx had ameliorating effects on the hepatic tissue of db/db mice by increasing hepatic glycogen and antioxidative enzymes, and LMF was more effective than Fx at improving hepatic glucose metabolism. As for glucose and lipid metabolism in the adipose tissue, the expression of insulin receptor substrate (IRS)-1, glucose transporter (GLUT), peroxisome proliferator-activated receptor gamma (PPARγ), and uncoupling protein (UCP)-1 mRNAs in the adipose tissue of diabetic mice was significantly upregulated by Fx and LMF + Fx, and levels of inflammatory adipocytokines, such as adiponectin, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6), were significantly modulated only by LMF + Fx supplementation. The efficacy of LMF + Fx supplementation on the decrease in urinary sugar and on glucose and lipid metabolism in the white adipose tissue of db/db mice was better than that of Fx or LMF alone, indicating the occurrence of a synergistic effect of LMF and Fx.

  1. Insulin Resistance and Prognosis of Nondiabetic Patients With Ischemic Stroke: The ACROSS-China Study (Abnormal Glucose Regulation in Patients With Acute Stroke Across China).

    PubMed

    Jing, Jing; Pan, Yuesong; Zhao, Xingquan; Zheng, Huaguang; Jia, Qian; Mi, Donghua; Chen, Weiqi; Li, Hao; Liu, Liping; Wang, Chunxue; He, Yan; Wang, David; Wang, Yilong; Wang, Yongjun

    2017-04-01

    Insulin resistance was common in patients with stroke. This study investigated the association between insulin resistance and outcomes in nondiabetic patients with first-ever acute ischemic stroke. Patients with ischemic stroke without history of diabetes mellitus in the ACROSS-China registry (Abnormal Glucose Regulation in Patients With Acute Stroke Across China) were included. Insulin resistance was defined as a homeostatis model assessment-insulin resistance (HOMA-IR) index in the top quartile (Q4). HOMA-IR was calculated as fasting insulin (μU/mL)×fasting glucose (mmol/L)/22.5. Multivariable logistic regression or Cox regression was performed to estimate the association between HOMA-IR and 1-year prognosis (mortality, stroke recurrence, poor functional outcome [modified Rankin scale score 3-6], and dependence [modified Rankin scale score 3-5]). Among the 1245 patients with acute ischemic stroke enrolled in this study, the median HOMA-IR was 1.9 (interquartile range, 1.1-3.1). Patients with insulin resistance were associated with a higher mortality risk than those without (adjusted hazard ratio, 1.68; 95% confidence interval, 1.12-2.53; P =0.01), stroke recurrence (adjusted hazard ratio, 1.57, 95% confidence interval, 1.12-2.19; P =0.008), and poor outcome (adjusted odds ratio, 1.42; 95% confidence interval, 1.03-1.95; P =0.03) but not dependence after adjustment for potential confounders. Higher HOMA-IR quartile categories were associated with a higher risk of 1-year death, stroke recurrence, and poor outcome ( P for trend =0.005, 0.005, and 0.001, respectively). Insulin resistance was associated with an increased risk of death, stroke recurrence, and poor outcome but not dependence in nondiabetic patients with acute ischemic stroke. © 2017 American Heart Association, Inc.

  2. Osmotic Homeostasis

    PubMed Central

    Zeidel, Mark L.

    2015-01-01

    Alterations in water homeostasis can disturb cell size and function. Although most cells can internally regulate cell volume in response to osmolar stress, neurons are particularly at risk given a combination of complex cell function and space restriction within the calvarium. Thus, regulating water balance is fundamental to survival. Through specialized neuronal “osmoreceptors” that sense changes in plasma osmolality, vasopressin release and thirst are titrated in order to achieve water balance. Fine-tuning of water absorption occurs along the collecting duct, and depends on unique structural modifications of renal tubular epithelium that confer a wide range of water permeability. In this article, we review the mechanisms that ensure water homeostasis as well as the fundamentals of disorders of water balance. PMID:25078421

  3. Genetic Variants Associated With Quantitative Glucose Homeostasis Traits Translate to Type 2 Diabetes in Mexican Americans: The GUARDIAN (Genetics Underlying Diabetes in Hispanics) Consortium.

    PubMed

    Palmer, Nicholette D; Goodarzi, Mark O; Langefeld, Carl D; Wang, Nan; Guo, Xiuqing; Taylor, Kent D; Fingerlin, Tasha E; Norris, Jill M; Buchanan, Thomas A; Xiang, Anny H; Haritunians, Talin; Ziegler, Julie T; Williams, Adrienne H; Stefanovski, Darko; Cui, Jinrui; Mackay, Adrienne W; Henkin, Leora F; Bergman, Richard N; Gao, Xiaoyi; Gauderman, James; Varma, Rohit; Hanis, Craig L; Cox, Nancy J; Highland, Heather M; Below, Jennifer E; Williams, Amy L; Burtt, Noel P; Aguilar-Salinas, Carlos A; Huerta-Chagoya, Alicia; Gonzalez-Villalpando, Clicerio; Orozco, Lorena; Haiman, Christopher A; Tsai, Michael Y; Johnson, W Craig; Yao, Jie; Rasmussen-Torvik, Laura; Pankow, James; Snively, Beverly; Jackson, Rebecca D; Liu, Simin; Nadler, Jerry L; Kandeel, Fouad; Chen, Yii-Der I; Bowden, Donald W; Rich, Stephen S; Raffel, Leslie J; Rotter, Jerome I; Watanabe, Richard M; Wagenknecht, Lynne E

    2015-05-01

    Insulin sensitivity, insulin secretion, insulin clearance, and glucose effectiveness exhibit strong genetic components, although few studies have examined their genetic architecture or influence on type 2 diabetes (T2D) risk. We hypothesized that loci affecting variation in these quantitative traits influence T2D. We completed a multicohort genome-wide association study to search for loci influencing T2D-related quantitative traits in 4,176 Mexican Americans. Quantitative traits were measured by the frequently sampled intravenous glucose tolerance test (four cohorts) or euglycemic clamp (three cohorts), and random-effects models were used to test the association between loci and quantitative traits, adjusting for age, sex, and admixture proportions (Discovery). Analysis revealed a significant (P < 5.00 × 10(-8)) association at 11q14.3 (MTNR1B) with acute insulin response. Loci with P < 0.0001 among the quantitative traits were examined for translation to T2D risk in 6,463 T2D case and 9,232 control subjects of Mexican ancestry (Translation). Nonparametric meta-analysis of the Discovery and Translation cohorts identified significant associations at 6p24 (SLC35B3/TFAP2A) with glucose effectiveness/T2D, 11p15 (KCNQ1) with disposition index/T2D, and 6p22 (CDKAL1) and 11q14 (MTNR1B) with acute insulin response/T2D. These results suggest that T2D and insulin secretion and sensitivity have both shared and distinct genetic factors, potentially delineating genomic components of these quantitative traits that drive the risk for T2D. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  4. Examination of the Effects of Arsenic on Glucose Homeostasis in Cell Culture and Animal Studies: Development of a Mouse Model for Arsenic-Induced Diabetes

    PubMed Central

    Paul, David S.; Hernández-Zavala, Araceli; Walton, Felecia S.; Adair, Blakely M.; dina, Jiří D; Matoušek, Tomáš; Stýblo, Miroslav

    2009-01-01

    Previous epidemiologic studies found increased prevalences of type 2 diabetes mellitus in populations exposed to high levels of inorganic arsenic (iAs) in drinking water. Although results of epidemiologic studies in low-exposure areas or occupational settings have been inconclusive, laboratory research has shown that exposures to iAs can produce effects that are consistent with type 2 diabetes. The current paper reviews the results of laboratory studies that examined the effects of iAs on glucose metabolism and describes new experiments in which the diabetogenic effects of iAs exposure were reproduced in a mouse model. Here, weanling male C57BL/6 mice drank deionized water with or without the addition of arsenite (25 or 50 ppm As) for 8 weeks. Intraperitoneal glucose tolerance tests revealed impaired glucose tolerance in mice exposed to 50 ppm As, but not to 25 ppm As. Exposure to 25 and 50 ppm As in drinking-water resulted in proportional increases in the concentration of iAs and its metabolites in the liver and in organs targeted by type 2 diabetes, including pancreas, skeletal muscle and adipose tissue. Dimethylarsenic was the predominant form of As in the tissues of mice in both 25 and 50 ppm groups. Notably, the average concentration of total speciated arsenic in livers from mice in the 50 ppm group was comparable to the highest concentration of total arsenic reported in the livers of Bangladeshi residents who had consumed water with an order of magnitude lower level of iAs. These data suggest that mice are less susceptible than humans to the diabetogenic effects of chronic exposure to iAs due to a more efficient clearance of iAs or its metabolites from target tissues. PMID:17336358

  5. Green tea and vitamin E enhance exercise-induced benefits in body composition, glucose homeostasis, and antioxidant status in elderly men and women.

    PubMed

    Narotzki, Baruch; Reznick, Abraham Z; Navot-Mintzer, Dalya; Dagan, Bracha; Levy, Yishai

    2013-01-01

    To investigate the effects of green tea plus vitamin E in addition to exercise on body composition and metabolic and antioxidant parameters in healthy elderly individuals. Interventional randomized controlled prospective trial. For 12 weeks, 22 elderly men and women (age: 71.1 ± 1.2 years; body mass index: 28.3 ± 0.5 kg/m(2) [mean ± SE]) undertook 30 minutes of moderately intense walking 6 d/wk. They were randomly assigned to ingest either green tea plus vitamin E (GTVE; 3 cups and 400 IU, respectively; n = 11) or placebo (n = 11). Data on anthropometrics, fasting insulin and glucose levels, physical fitness, dietary intake, safety parameters, and biomarkers of oxidation status were recorded and analyzed at the start and end of the study. Though dietary intake was unchanged, improved exercise capacity was followed by a significant reduction in body weight and fasting insulin levels in all participants. Additional consumption of GTVE resulted in a twofold increase in serum vitamin E (from 20.4 to 40.6 μmol/L, p < 0.001) and a decrease of men's and women's waist circumferences (from 100.8 and 95.7 to 96.9 and 85.0 cm, p < 0.05 and p < 0.01, respectively) and fasting glucose levels (from 5.30 to 4.98 mmol/L, p < 0.01). Plasma protein carbonyls dropped (from 0.93 to 0.77 nmol/mg protein, p < 0.05), whereas erythrocyte catalase activities increased (from 26.7 to 29.7 U/g hemoglobin, p < 0.05) in the GTVE group only. Oral peroxidase activities were increased in both groups. A daily dose of GTVE in healthy elderly men and women may improve exercise-induced benefits in body composition and glucose tolerance and may also lower oxidative burden.

  6. The renin-angiotensin system: a target of and contributor to dyslipidemias, altered glucose homeostasis, and hypertension of the metabolic syndrome

    PubMed Central

    Putnam, Kelly; Shoemaker, Robin; Yiannikouris, Frederique

    2012-01-01

    The renin-angiotensin system (RAS) is an important therapeutic target in the treatment of hypertension. Obesity has emerged as a primary contributor to essential hypertension in the United States and clusters with other metabolic disorders (hyperglycemia, hypertension, high triglycerides, low HDL cholesterol) defined within the metabolic syndrome. In addition to hypertension, RAS blockade may also serve as an effective treatment strategy to control impaired glucose and insulin tolerance and dyslipidemias in patients with the metabolic syndrome. Hyperglycemia, insulin resistance, and/or specific cholesterol metabolites have been demonstrated to activate components required for the synthesis [angiotensinogen, renin, angiotensin-converting enzyme (ACE)], degradation (ACE2), or responsiveness (angiotensin II type 1 receptors, Mas receptors) to angiotensin peptides in cell types (e.g., pancreatic islet cells, adipocytes, macrophages) that mediate specific disorders of the metabolic syndrome. An activated local RAS in these cell types may contribute to dysregulated function by promoting oxidative stress, apoptosis, and inflammation. This review will discuss data demonstrating the regulation of components of the RAS by cholesterol and its metabolites, glucose, and/or insulin in cell types implicated in disorders of the metabolic syndrome. In addition, we discuss data supporting a role for an activated local RAS in dyslipidemias and glucose intolerance/insulin resistance and the development of hypertension in the metabolic syndrome. Identification of an activated RAS as a common thread contributing to several disorders of the metabolic syndrome makes the use of angiotensin receptor blockers and ACE inhibitors an intriguing and novel option for multisymptom treatment. PMID:22227126

  7. Combination of the sodium-glucose cotransporter-2 inhibitor empagliflozin with orlistat or sibutramine further improves the body-weight reduction and glucose homeostasis of obese rats fed a cafeteria diet.

    PubMed

    Vickers, Steven P; Cheetham, Sharon C; Headland, Katie R; Dickinson, Keith; Grempler, Rolf; Mayoux, Eric; Mark, Michael; Klein, Thomas

    2014-01-01

    The present study assessed the potential of the sodium glucose-linked transporter (SGLT)-2 inhibitor empagliflozin to decrease body weight when administered alone or in combination with the clinically effective weight-loss agents orlistat and sibutramine in obese rats fed a cafeteria diet. Female Wistar rats were exposed to a cafeteria diet to induce obesity. Empagliflozin was dosed once daily (10, 30, and 60 mg/kg) for 28 days. Combination studies were subsequently performed using a submaximal empagliflozin dose (10 mg/kg) with either sibutramine or orlistat. Body weight, food, and water intake were recorded daily. The effect of drug treatment on glucose tolerance, relevant plasma parameters, and carcass composition was determined. Empagliflozin dose-dependently reduced body weight, plasma leptin, and body fat though increased urinary glucose excretion. The combination of empagliflozin and orlistat significantly reduced body weight compared to animals treated with either drug alone, and significantly improved glucose tolerance, plasma insulin, and leptin compared to vehicle-treated controls. The effect of sibutramine to improve glycemic control in an oral glucose-tolerance test was also significantly increased, with empagliflozin and combination treatment leading to a reduction in carcass fat greater than that observed with either drug alone. These data demonstrate that empagliflozin reduces body weight in cafeteria-fed obese rats. In combination studies, empagliflozin further improved the body-weight or body-fat loss of animals in comparison to orlistat or sibutramine alone. Such studies may indicate improved strategies for the treatment of obese patients with prediabetes or type 2 diabetes.

  8. Tetrahydro iso-alpha acids from hops improve glucose homeostasis and reduce body weight gain and metabolic endotoxemia in high-fat diet-fed mice.

    PubMed

    Everard, Amandine; Geurts, Lucie; Van Roye, Marie; Delzenne, Nathalie M; Cani, Patrice D

    2012-01-01

    Obesity and related metabolic disorders such as insulin resistance and type 2 diabetes are associated with a low-grade inflammatory state possibly through changes in gut microbiota composition and the development of higher plasma lipopolysaccharide (LPS) levels, i.e. metabolic endotoxemia. Various phytochemical compounds have been investigated as potential tools to regulate these metabolic features. Humulus lupulus L. (hops) contains several classes of compounds with anti-inflammatory potential. Recent evidence suggests that hops-derived compounds positively impact adipocyte metabolism and glucose tolerance in obese and diabetic rodents via undefined mechanisms. In this study, we found that administration of tetrahydro iso-alpha acids (termed META060) to high-fat diet (HFD)-fed obese and diabetic mice for 8 weeks reduced body weight gain, the development of fat mass, glucose intolerance, and fasted hyperinsulinemia, and normalized insulin sensitivity markers. This was associated with reduced portal plasma LPS levels, gut permeability, and higher intestinal tight junction proteins Zonula occludens-1 and occludin. Moreover, META060 treatment increased the plasma level of the anti-inflammatory cytokine interleukin-10 and decreased the plasma level of the pro-inflammatory cytokine granulocyte colony-stimulating factor. In conclusion, this research allows us to decipher a novel mechanism contributing to the positive effects of META060 treatment, and supports the need to investigate such compounds in obese and type 2 diabetic patients.

  9. Chronic administration of Angelica sinensis polysaccharide effectively improves fatty liver and glucose homeostasis in high-fat diet-fed mice.

    PubMed

    Wang, Kaiping; Cao, Peng; Wang, Hanxiang; Tang, Zhuohong; Wang, Na; Wang, Jinglin; Zhang, Yu

    2016-05-18

    This study aimed to investigate the therapeutic effects of Angelica sinensis polysaccharide (ASP), an active component derived from a water extract of Angelica sinensis, in high-fat diet (HFD)-fed BALB/c mice. The potential mechanisms underlying the activity of this compound were also considered. Specifically, serum and hepatic biochemical parameters were evaluated, and key proteins involved in the lipid/glucose metabolism were analyzed. Long-term feeding with a HFD induced severe fatty liver and hyperglycemia. Histological examination clearly showed that ASP reduced lipid accumulation in the liver and attenuated hepatic steatosis in HFD-fed mice. In addition, ASP markedly alleviated serum and liver lipid disorders and fatty liver via the upregulation of PPARγ expression and the activation of adiponectin-SIRT1-AMPK signaling. Furthermore, ASP also significantly relieved severe oxidative stress, demonstrating that ASP might attenuate nonalcoholic fatty liver disease via a "two-hit" mechanism. In addition, ASP reduced blood glucose levels and ameliorated insulin resistance via the regulation of related metabolic enzymes and by activating the PI3K/Akt pathway in HFD-fed mice. Our findings revealed that ASP might be used as an alternative dietary supplement or health care product to ameliorate metabolic syndrome in populations that consistently consume HFDs.

  10. Effects of abnormal 75 g oral glucose tolerance test at different time points on neonatal complications and neurobehavioral development in the pregnant women with gestational diabetes mellitus (a STROBE-compliant article).

    PubMed

    Zhou, Jian-Li; Xing, Jun; Liu, Cong-Hui; Wen, Jie; Zhao, Nan-Nan; Kang, Yuan-Yuan; Shao, Ting

    2018-05-01

    With the improvement of living standard, gestational diabetes mellitus (GDM) incidence is increasing every year. We observed the effects of abnormal 75 g oral glucose tolerance test (OGTT) at different time points on neonatal complications and neurobehavioral development in GDM.A total of 144 newborns whose mothers were diagnosed with GDM and received prenatal examination and childbirth in our hospital from October 2015 to April 2016, were observed in this study. Pregnant women underwent 75 g OGTT and the blood glucose level was recorded on an empty stomach, as well as postprandial 1 and 2 hours, respectively. Based on the frequency of 75 g OGTT-abnormal time points, the pregnant women were divided into group 1 (OGTT abnormality at 1 time point), group 2 (OGTT abnormality at 2 time points), and group 3 (OGTT abnormality at 3 time points). Neonatal behavioral neurological assessment (NBNA) was performed on the 3 groups, respectively.In the total score of NBNA, there was a significant difference among the 3 groups (F = 17.120, P = .000), and there were significant differences between the 3 groups (all P < .05). The incidence of neonatal hypoglycemia was significantly lower in groups 1 and 2 than in group 3, and the incidence of macrosomia was significantly lower in groups 1 than in groups 2 and 3 (all P < .05). In the 144 newborns, NBNA scoring was significantly lower in the newborns with hypoglycemia than in the newborns with normal blood glucose level, and in macrosomia than in the newborns with normal body weight (all P < .01).With the increase of OGTT-abnormal time points in the pregnant women with GDM, the incidences of neonatal hypoglycemia and macrosomia rise and neonatal NBNA score decreases. Therefore, reasonable measures should be adopted as early as possible to prevent poor prognosis in the pregnant women with