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Sasaki N, Maeda R, Ozono R, Yoshimura K, Nakano Y, Higashi Y. Early-Phase Changes in Serum Free Fatty Acid Levels After Glucose Intake Are Associated With Type 2 Diabetes Incidence: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases. Diabetes Care 2022; 45:2309-2315. [PMID: 35944240 DOI: 10.2337/dc21-2554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 06/27/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Experimental studies suggest that excess serum free fatty acid (FFA) levels result in impaired glucose metabolism. This study investigated the relationship between changes in serum FFA levels after glucose intake and type 2 diabetes risk. RESEARCH DESIGN AND METHODS This observational study included 6,800 individuals without diabetes who underwent a 75-g oral glucose tolerance test. Serum FFA levels were measured before and 30 and 60 min after glucose intake. The percentages of changes in serum FFA levels from 0 to 30 and from 30 to 60 min were compared, and a low rate of change in FFA levels was determined using the receiver operating characteristic curve analysis. RESULTS Over a mean 5.3-year follow-up period, 485 participants developed type 2 diabetes. After adjusting for plasma glucose levels and indices of insulin resistance and β-cell function, low rates of change in FFA levels at 0-30 min (adjusted odds ratio [aOR] 1.91; 95% CI 1.54-2.37) and 30-60 min (aOR 1.48; 95% CI 1.15-1.90) were associated with the incidence of type 2 diabetes. Stratified analysis revealed that the low rate of change in FFA levels at 30-60 min (aOR 1.97; 95% CI 1.05-3.69) was associated with the incidence of type 2 diabetes even in participants with normal fasting glucose levels or glucose tolerance. CONCLUSIONS Changes in serum FFA levels within the 1st h after glucose intake could be a primary predictor of type 2 diabetes. This change may occur prior to the onset of impaired glucose metabolism.
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Affiliation(s)
- Nobuo Sasaki
- Health Management and Promotion Center, Hiroshima Atomic Bomb Casualty Council, Hiroshima, Japan
| | - Ryo Maeda
- Health Management and Promotion Center, Hiroshima Atomic Bomb Casualty Council, Hiroshima, Japan
| | - Ryoji Ozono
- Department of General Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Kenichi Yoshimura
- Department of Biostatistics, Medical Center for Translational and Clinical Research, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Yukiko Nakano
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Yukihito Higashi
- Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
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2
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Shitole SG, Biggs ML, Ix JH, Fretts AM, Tracy RP, Siscovick DS, Djoussé L, Mukamal KJ, Kizer JR. Fasting and Postload Nonesterified Fatty Acids and Glucose Dysregulation in Older Adults. Am J Epidemiol 2022; 191:1235-1247. [PMID: 35247051 PMCID: PMC9989335 DOI: 10.1093/aje/kwac044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 02/07/2022] [Accepted: 03/01/2022] [Indexed: 02/04/2023] Open
Abstract
To evaluate the association of nonesterified fatty acids (NEFA) with dysglycemia in older adults, NEFA levels were measured among participants in the Cardiovascular Health Study (United States; enrolled 1989-1993). Associations with insulin sensitivity and pancreatic β-cell function, and with incident type 2 diabetes mellitus (DM), were examined. The sample comprised 2,144 participants (aged 77.9 (standard deviation, 4.5) years). Participant data from the Cardiovascular Health Study visit in 1996-1997 was used with prospective follow-up through 2010. Fasting and postload NEFA showed significant associations with lower insulin sensitivity and pancreatic β-cell function, individually and on concurrent adjustment. Over median follow-up of 9.7 years, 236 cases of DM occurred. Postload NEFA were associated with risk of DM (per standard deviation, hazard ratio = 1.18, 95% confidence interval: 1.08, 1.29), but fasting NEFA were not (hazard ratio = 1.12, 95% confidence interval: 0.97, 1.29). The association for postload NEFA persisted after adjustment for putative intermediates, and after adjustment for fasting NEFA. Sex and body mass index modified these associations, which were stronger for fasting NEFA with DM in men but were accentuated for postload NEFA in women and among leaner individuals. Fasting and postload NEFA were related to lower insulin sensitivity and pancreatic β-cell function, but only postload NEFA were associated with increased DM. Additional study into NEFA metabolism could uncover novel potential targets for diabetes prevention in elders.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Jorge R Kizer
- Correspondence to Dr. Jorge R. Kizer, 4150 Clement Street, San Francisco, CA 94121 (e-mail: )
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3
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Shibib L, Al-Qaisi M, Ahmed A, Miras AD, Nott D, Pelling M, Greenwald SE, Guess N. Reversal and Remission of T2DM - An Update for Practitioners. Vasc Health Risk Manag 2022; 18:417-443. [PMID: 35726218 PMCID: PMC9206440 DOI: 10.2147/vhrm.s345810] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 05/10/2022] [Indexed: 01/04/2023] Open
Abstract
Over the past 50 years, many countries around the world have faced an unchecked pandemic of obesity and type 2 diabetes (T2DM). As best practice treatment of T2DM has done very little to check its growth, the pandemic of diabesity now threatens to make health-care systems economically more difficult for governments and individuals to manage within their budgets. The conventional view has been that T2DM is irreversible and progressive. However, in 2016, the World Health Organization (WHO) global report on diabetes added for the first time a section on diabetes reversal and acknowledged that it could be achieved through a number of therapeutic approaches. Many studies indicate that diabetes reversal, and possibly even long-term remission, is achievable, belying the conventional view. However, T2DM reversal is not yet a standardized area of practice and some questions remain about long-term outcomes. Diabetes reversal through diet is not articulated or discussed as a first-line target (or even goal) of treatment by any internationally recognized guidelines, which are mostly silent on the topic beyond encouraging lifestyle interventions in general. This review paper examines all the sustainable, practical, and scalable approaches to T2DM reversal, highlighting the evidence base, and serves as an interim update for practitioners looking to fill the practical knowledge gap on this topic in conventional diabetes guidelines.
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Affiliation(s)
- Lina Shibib
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Mo Al-Qaisi
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Ahmed Ahmed
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Alexander D Miras
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - David Nott
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Marc Pelling
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Stephen E Greenwald
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Nicola Guess
- School of Life Sciences, Westminster University, London, UK
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4
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Chueire VB, Muscelli E. Effect of free fatty acids on insulin secretion, insulin sensitivity and incretin effect - a narrative review. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2021; 65:24-31. [PMID: 33320449 PMCID: PMC10528699 DOI: 10.20945/2359-3997000000313] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 09/26/2020] [Indexed: 11/23/2022]
Abstract
Deleterious effects of free fatty acids, FFAs, on insulin sensitivity are observed in vivo studies in humans. Mechanisms include impaired insulin signaling, oxidative stress, inflammation, and mitochondrial dysfunction, but the effects on insulin secretion are less well known. Our aim was to review the relationship of increased FFAs with insulin resistance, secretion and mainly with the incretin effect in humans. Narrative review. Increased endogenous or administered FFAs induce insulin resistance. FFAs effects on insulin secretion are debatable; inhibition and stimulation have been reported, depending on the type and duration of lipids exposition and the study subjects. Chronically elevated FFAs seem to decrease insulin biosynthesis, glucose-stimulated insulin secretion and β-cell glucose sensitivity. Lipids infusion decreases the response to incretins with unchanged incretin levels in volunteers with normal glucose tolerance. In contrast, FFAs reduction by acipimox did not restore the incretin effect in type-2 diabetes, probably due to the dysfunctional β-cell. Possible mechanisms of FFAs excess on incretin effect include reduction of the expression and levels of GLP-1 (glucagon like peptide-1) receptor, reduction of connexin-36 expression thus the coordinated secretory activity in response to GLP-1, and GIP (glucose-dependent insulinotropic polypeptide) receptors downregulation in islets cells. Increased circulating FFAs impair insulin sensitivity. Effects on insulin secretion are complex and controversial. Deleterious effects on the incretin-induced potentiation of insulin secretion were reported. More investigation is needed to better understand the extent and mechanisms of β-cell impairment and insulin resistance induced by increased FFAs and how to prevent them.
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Affiliation(s)
- Valeria Bahdur Chueire
- Departamento de Endocrinologia, Hospital da Pontifícia Universidade Católica de Campinas, Campinas, SP, Brasil,
| | - Elza Muscelli
- Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brasil
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5
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Benito-Vicente A, Jebari-Benslaiman S, Galicia-Garcia U, Larrea-Sebal A, Uribe KB, Martin C. Molecular mechanisms of lipotoxicity-induced pancreatic β-cell dysfunction. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 359:357-402. [PMID: 33832653 DOI: 10.1016/bs.ircmb.2021.02.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type 2 diabetes (T2D), a heterogeneous disorder derived from metabolic dysfunctions, leads to a glucose overflow in the circulation due to both defective insulin secretion and peripheral insulin resistance. One of the critical risk factor for T2D is obesity, which represents a global epidemic that has nearly tripled since 1975. Obesity is characterized by chronically elevated free fatty acid (FFA) levels, which cause deleterious effects on glucose homeostasis referred to as lipotoxicity. Here, we review the physiological FFA roles onto glucose-stimulated insulin secretion (GSIS) and the pathological ones affecting many steps of the mechanisms and modulation of GSIS. We also describe in vitro and in vivo experimental evidences addressing lipotoxicity in β-cells and the role of saturation and chain length of FFA on the potency of GSIS stimulation. The molecular mechanisms underpinning lipotoxic-β-cell dysfunction are also reviewed. Among them, endoplasmic reticulum stress, oxidative stress and mitochondrial dysfunction, inflammation, impaired autophagy and β-cell dedifferentiation. Finally therapeutic strategies for the β-cells dysfunctions such as the use of metformin, glucagon-like peptide 1, thiazolidinediones, anti-inflammatory drugs, chemical chaperones and weight are discussed.
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Affiliation(s)
- Asier Benito-Vicente
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Shifa Jebari-Benslaiman
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Unai Galicia-Garcia
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Molecular Biophysics, Fundación Biofísica Bizkaia, Leioa, Spain
| | - Asier Larrea-Sebal
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Molecular Biophysics, Fundación Biofísica Bizkaia, Leioa, Spain
| | - Kepa B Uribe
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Donostia San Sebastián, Spain
| | - Cesar Martin
- Department of Molecular Biophysics, Biofisika Institute (University of Basque Country and Consejo Superior de Investigaciones Científicas (UPV/EHU, CSIC)), Leioa, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain.
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6
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Lytrivi M, Ghaddar K, Lopes M, Rosengren V, Piron A, Yi X, Johansson H, Lehtiö J, Igoillo-Esteve M, Cunha DA, Marselli L, Marchetti P, Ortsäter H, Eizirik DL, Cnop M. Combined transcriptome and proteome profiling of the pancreatic β-cell response to palmitate unveils key pathways of β-cell lipotoxicity. BMC Genomics 2020; 21:590. [PMID: 32847508 PMCID: PMC7448506 DOI: 10.1186/s12864-020-07003-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/19/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Prolonged exposure to elevated free fatty acids induces β-cell failure (lipotoxicity) and contributes to the pathogenesis of type 2 diabetes. In vitro exposure of β-cells to the saturated free fatty acid palmitate is a valuable model of lipotoxicity, reproducing features of β-cell failure observed in type 2 diabetes. In order to map the β-cell response to lipotoxicity, we combined RNA-sequencing of palmitate-treated human islets with iTRAQ proteomics of insulin-secreting INS-1E cells following a time course exposure to palmitate. RESULTS Crossing transcriptome and proteome of palmitate-treated β-cells revealed 85 upregulated and 122 downregulated genes at both transcript and protein level. Pathway analysis identified lipid metabolism, oxidative stress, amino-acid metabolism and cell cycle pathways among the most enriched palmitate-modified pathways. Palmitate induced gene expression changes compatible with increased free fatty acid mitochondrial import and β-oxidation, decreased lipogenesis and modified cholesterol transport. Palmitate modified genes regulating endoplasmic reticulum (ER) function, ER-to-Golgi transport and ER stress pathways. Furthermore, palmitate modulated cAMP/protein kinase A (PKA) signaling, inhibiting expression of PKA anchoring proteins and downregulating the GLP-1 receptor. SLC7 family amino-acid transporters were upregulated in response to palmitate but this induction did not contribute to β-cell demise. To unravel critical mediators of lipotoxicity upstream of the palmitate-modified genes, we identified overrepresented transcription factor binding sites and performed network inference analysis. These identified LXR, PPARα, FOXO1 and BACH1 as key transcription factors orchestrating the metabolic and oxidative stress responses to palmitate. CONCLUSIONS This is the first study to combine transcriptomic and sensitive time course proteomic profiling of palmitate-exposed β-cells. Our results provide comprehensive insight into gene and protein expression changes, corroborating and expanding beyond previous findings. The identification of critical drivers and pathways of the β-cell lipotoxic response points to novel therapeutic targets for type 2 diabetes.
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Affiliation(s)
- Maria Lytrivi
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium.,Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Kassem Ghaddar
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Miguel Lopes
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Victoria Rosengren
- Diabetes Research Unit, Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institutet, Stockholm, Sweden
| | - Anthony Piron
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Xiaoyan Yi
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Henrik Johansson
- Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology, Karolinska Institutet, Science for Life Laboratory, 171 21, Solna, Sweden
| | - Janne Lehtiö
- Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology, Karolinska Institutet, Science for Life Laboratory, 171 21, Solna, Sweden
| | - Mariana Igoillo-Esteve
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Daniel A Cunha
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Henrik Ortsäter
- Diabetes Research Unit, Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institutet, Stockholm, Sweden
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium
| | - Miriam Cnop
- ULB Center for Diabetes Research, Université Libre de Bruxelles, CP-618, Route de Lennik 808, 1070, Brussels, Belgium. .,Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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7
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López-Palau NE, Olais-Govea JM. Mathematical model of blood glucose dynamics by emulating the pathophysiology of glucose metabolism in type 2 diabetes mellitus. Sci Rep 2020; 10:12697. [PMID: 32728136 PMCID: PMC7391357 DOI: 10.1038/s41598-020-69629-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 07/10/2020] [Indexed: 11/09/2022] Open
Abstract
Mathematical modelling has established itself as a theoretical tool to understand fundamental aspects of a variety of medical-biological phenomena. The predictive power of mathematical models on some chronic conditions has been helpful in its proper prevention, diagnosis, and treatment. Such is the case of the modelling of glycaemic dynamics in type 2 diabetes mellitus (T2DM), whose physiology-based mathematical models have captured the metabolic abnormalities of this disease. Through a physiology-based pharmacokinetic-pharmacodynamic approach, this work addresses a mathematical model whose structure starts from a model of blood glucose dynamics in healthy humans. This proposal is capable of emulating the pathophysiology of T2DM metabolism, including the effect of gastric emptying and insulin enhancing effect due to incretin hormones. The incorporation of these effects lies in the implemented methodology since the mathematical functions that represent metabolic rates, with a relevant contribution to hyperglycaemia, are adjusting individually to the clinical data of patients with T2DM. Numerically, the resulting model successfully simulates a scheduled graded intravenous glucose test and oral glucose tolerance tests at different doses. The comparison between simulations and clinical data shows an acceptable description of the blood glucose dynamics in T2DM. It opens the possibility of using this model to develop model-based controllers for the regulation of blood glucose in T2DM.
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Affiliation(s)
- Nelida Elizabeth López-Palau
- División de Matemáticas Aplicadas, IPICyT, Camino a la Presa San José No. 2055, Lomas Cuarta Sección, 78216, San Luis Potosí, SLP, Mexico.,Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Av. Eugenio Garza Sada 300, 78211, San Luis Potosí, SLP, Mexico
| | - José Manuel Olais-Govea
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Av. Eugenio Garza Sada 300, 78211, San Luis Potosí, SLP, Mexico. .,Tecnologico de Monterrey, Writing Lab, TecLab, Vicerrectoría de Investigación y Transferencia de Tecnología, 64849, Monterrey, NL, Mexico.
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8
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Ezeh U, Chen IYD, Chen YH, Azziz R. Adipocyte Insulin Resistance in PCOS: Relationship With GLUT-4 Expression and Whole-Body Glucose Disposal and β-Cell Function. J Clin Endocrinol Metab 2020; 105:5834379. [PMID: 32382742 PMCID: PMC7274487 DOI: 10.1210/clinem/dgaa235] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/29/2020] [Indexed: 01/16/2023]
Abstract
CONTEXT Impaired sensitivity to the antilipolytic action of insulin in adipose tissue (AT) may play a role in determining metabolic dysfunction in polycystic ovary syndrome (PCOS). OBJECTIVES To test the hypothesis that insulin resistance (IR) in AT is associated with whole-body insulin sensitivity and β-cell function in PCOS. RESEARCH DESIGN AND SETTING Prospective cross-sectional study. METHODS Eighteen participants with PCOS and 18-matched control participants underwent a modified frequently sampled intravenous glucose tolerance test (mFSIVGTT); subgroups underwent single-slice computed tomography scans determining AT distribution and adipocyte glucose transporter type 4 (GLUT-4) expression. MAIN OUTCOME MEASURES IR in AT in basal (by the adipose insulin resistance index [Adipo-IR]) and dynamic (mFSIVGTT-derived indices of insulin-mediated nonesterified fatty acids [NEFA] suppression [NEFAnadir, TIMEnadir, and %NEFAsupp]) states; whole-body insulin-mediated glucose uptake and insulin secretion in basal (by homeostatic model assessment [HOMA]-IR and HOMA-β%) and dynamic (mFSIVGTT-derived insulin sensitivity index [Si], acute insulin response to glucose [AIRg], and disposition index [Di]) states. RESULTS Participants with PCOS had higher HOMA-IR and HOMA-β%, lower Si and Di, higher longer TIMEnadir, higher Adipo-IR and NEFAnadir, and a trend toward lower GLUT-4, than the control group participants. Adipo-IR was associated with dynamic state IR in AT (NEFAnadir TIMEnadir, and %NEFAsupp), but only in PCOS, and with HOMA-IR and HOMA-β% in both groups. NEFAnadir and TIMEnadir were negatively and %NEFAsupp positively associated with Si only in PCOS, but not with AIRg and Di, or GLUT-4 expression. CONCLUSION Women with PCOS demonstrated increased IR in AT, which is closely associated with whole-body IR but not with dynamic state β-cell function or adipocyte GLUT-4 gene expression.
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Affiliation(s)
- Uche Ezeh
- Department of Obstetrics and Gynecology, Stanford Healthcare-ValleyCare Hospital, Pleasanton, California
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ida Y-D Chen
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
| | - Yen-Hao Chen
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Obstetrics & Gynecology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Ricardo Azziz
- Department of Obstetrics & Gynecology and Center for Androgen-Related Disorders, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Obstetrics & Gynecology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
- Department of Health Policy, Management and Behavior, School of Public Health, University at Albany, SUNY, Albany, New York
- Department of Obstetrics & Gynecology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Correspondence and Reprint Requests: Ricardo Azziz, American Society for Reproductive Medicine, 1209 Montgomery Hwy, Birmingham, AL. E-mail:
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9
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Anti-Inflammatory Strategies Targeting Metaflammation in Type 2 Diabetes. Molecules 2020; 25:molecules25092224. [PMID: 32397353 PMCID: PMC7249034 DOI: 10.3390/molecules25092224] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/28/2020] [Accepted: 05/02/2020] [Indexed: 02/06/2023] Open
Abstract
One of the concepts explaining the coincidence of obesity and type 2 diabetes (T2D) is the metaflammation theory. This chronic, low-grade inflammatory state originating from metabolic cells in response to excess nutrients, contributes to the development of T2D by increasing insulin resistance in peripheral tissues (mainly in the liver, muscles, and adipose tissue) and by targeting pancreatic islets and in this way impairing insulin secretion. Given the role of this not related to infection inflammation in the development of both: insulin resistance and insulitis, anti-inflammatory strategies could be helpful not only to control T2D symptoms but also to treat its causes. This review presents current concepts regarding the role of metaflammation in the development of T2D in obese individuals as well as data concerning possible application of different anti-inflammatory strategies (including lifestyle interventions, the extra-glycemic potential of classical antidiabetic compounds, nonsteroidal anti-inflammatory drugs, immunomodulatory therapies, and bariatric surgery) in the management of T2D.
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10
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Weir GC. Glucolipotoxicity, β-Cells, and Diabetes: The Emperor Has No Clothes. Diabetes 2020; 69:273-278. [PMID: 31519699 PMCID: PMC7034184 DOI: 10.2337/db19-0138] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 04/08/2019] [Indexed: 12/21/2022]
Abstract
Reduction of β-cell mass and function is central to the pathogenesis of type 2 diabetes. The terms glucotoxicity, lipotoxicity, and glucolipotoxicity are used to describe potentially responsible processes. The premise is that chronically elevated glucose levels are toxic to β-cells, that elevated lipid levels in the form of circulating free fatty acids (FFA) also have toxic effects, and that the combination of the two, glucolipotoxicity, is particularly harmful. Much work has shown that high concentrations of FFA can be very damaging to β-cells when used for in vitro experiments, and when infused in large amounts in humans and rodents they produce suppression of insulin secretion. The purpose of this Perspective is to raise doubts about whether the FFA levels found in real-life situations are ever high enough to cause problems. Evidence supporting the importance of glucotoxicity is strong because there is such a tight correlation between defective insulin secretion and rising glucose levels. However, there is virtually no convincing evidence that the alterations in FFA levels occurring during progression to diabetes are pathogenic. Thus, the terms lipotoxicity and glucolipotoxicity should be used with great caution, if at all, because evidence supporting their importance has not yet emerged.
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Affiliation(s)
- Gordon C Weir
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
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11
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Prentki M, Peyot ML, Masiello P, Madiraju SRM. Nutrient-Induced Metabolic Stress, Adaptation, Detoxification, and Toxicity in the Pancreatic β-Cell. Diabetes 2020; 69:279-290. [PMID: 32079704 DOI: 10.2337/dbi19-0014] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/20/2019] [Indexed: 11/13/2022]
Abstract
Paraphrasing the Swiss physician and father of toxicology Paracelsus (1493-1541) on chemical agents used as therapeutics, "the dose makes the poison," it is now realized that this aptly applies to the calorigenic nutrients. The case here is the pancreatic islet β-cell presented with excessive levels of nutrients such as glucose, lipids, and amino acids. The short-term effects these nutrients exert on the β-cell are enhanced insulin biosynthesis and secretion and changes in glucose sensitivity. However, chronic fuel surfeit triggers additional compensatory and adaptive mechanisms by β-cells to cope with the increased insulin demand or to protect itself. When these mechanisms fail, toxicity due to the nutrient surplus ensues, leading to β-cell dysfunction, dedifferentiation, and apoptosis. The terms glucotoxicity, lipotoxicity, and glucolipotoxicity have been widely used, but there is some confusion as to what they mean precisely and which is most appropriate for a given situation. Here we address the gluco-, lipo-, and glucolipo-toxicities in β-cells by assessing the evidence both for and against each of them. We also discuss potential mechanisms and defend the view that many of the identified "toxic" effects of nutrient excess, which may also include amino acids, are in fact beneficial adaptive processes. In addition, candidate fuel-excess detoxification pathways are evaluated. Finally, we propose that a more general term should be used for the in vivo situation of overweight-associated type 2 diabetes reflecting both the adaptive and toxic processes to mixed calorigenic nutrients excess: "nutrient-induced metabolic stress" or, in brief, "nutri-stress."
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Affiliation(s)
- Marc Prentki
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| | - Marie-Line Peyot
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| | - Pellegrino Masiello
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - S R Murthy Madiraju
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
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12
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Lytrivi M, Castell AL, Poitout V, Cnop M. Recent Insights Into Mechanisms of β-Cell Lipo- and Glucolipotoxicity in Type 2 Diabetes. J Mol Biol 2019; 432:1514-1534. [PMID: 31628942 DOI: 10.1016/j.jmb.2019.09.016] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/15/2019] [Accepted: 09/16/2019] [Indexed: 12/24/2022]
Abstract
The deleterious effects of chronically elevated free fatty acid (FFA) levels on glucose homeostasis are referred to as lipotoxicity, and the concurrent exposure to high glucose may cause synergistic glucolipotoxicity. Lipo- and glucolipotoxicity have been studied for over 25 years. Here, we review the current evidence supporting the role of pancreatic β-cell lipo- and glucolipotoxicity in type 2 diabetes (T2D), including lipid-based interventions in humans, prospective epidemiological studies, and human genetic findings. In addition to total FFA quantity, the quality of FFAs (saturation and chain length) is a key determinant of lipotoxicity. We discuss in vitro and in vivo experimental models to investigate lipo- and glucolipotoxicity in β-cells and describe experimental pitfalls. Lipo- and glucolipotoxicity adversely affect many steps of the insulin production and secretion process. The molecular mechanisms underpinning lipo- and glucolipotoxic β-cell dysfunction and death comprise endoplasmic reticulum stress, oxidative stress and mitochondrial dysfunction, impaired autophagy, and inflammation. Crosstalk between these stress pathways exists at multiple levels and may aggravate β-cell lipo- and glucolipotoxicity. Lipo- and glucolipotoxicity are therapeutic targets as several drugs impact the underlying stress responses in β-cells, potentially contributing to their glucose-lowering effects in T2D.
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Affiliation(s)
- Maria Lytrivi
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Anne-Laure Castell
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Vincent Poitout
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada.
| | - Miriam Cnop
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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13
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Li Z, Zhou M, Cai Z, Liu H, Zhong W, Hao Q, Cheng D, Hu X, Hou J, Xu P, Xue Y, Zhou Y, Xu T. RNA-binding protein DDX1 is responsible for fatty acid-mediated repression of insulin translation. Nucleic Acids Res 2019; 46:12052-12066. [PMID: 30295850 PMCID: PMC6294501 DOI: 10.1093/nar/gky867] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 09/14/2018] [Indexed: 01/13/2023] Open
Abstract
The molecular mechanism in pancreatic β cells underlying hyperlipidemia and insulin insufficiency remains unclear. Here, we find that the fatty acid-induced decrease in insulin levels occurs due to a decrease in insulin translation. Since regulation at the translational level is generally mediated through RNA-binding proteins, using RNA antisense purification coupled with mass spectrometry, we identify a novel insulin mRNA-binding protein, namely, DDX1, that is sensitive to palmitate treatment. Notably, the knockdown or overexpression of DDX1 affects insulin translation, and the knockdown of DDX1 eliminates the palmitate-induced repression of insulin translation. Molecular mechanism studies show that palmitate treatment causes DDX1 phosphorylation at S295 and dissociates DDX1 from insulin mRNA, thereby leading to the suppression of insulin translation. In addition, DDX1 may interact with the translation initiation factors eIF3A and eIF4B to regulate translation. In high-fat diet mice, the inhibition of insulin translation happens at an early prediabetic stage before the elevation of glucose levels. We speculate that the DDX1-mediated repression of insulin translation worsens the situation of insulin resistance and contributes to the elevation of blood glucose levels in obese animals.
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Affiliation(s)
- Zonghong Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China.,Jilin Province Key Laboratory on Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Maoge Zhou
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhaokui Cai
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongyang Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Wen Zhong
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiang Hao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Dongwan Cheng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Xihao Hu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Junjie Hou
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Pingyong Xu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuanchao Xue
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yifa Zhou
- Jilin Province Key Laboratory on Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Tao Xu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
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Hagman E, Besor O, Hershkop K, Santoro N, Pierpont B, Mata M, Caprio S, Weiss R. Relation of the degree of obesity in childhood to adipose tissue insulin resistance. Acta Diabetol 2019; 56:219-226. [PMID: 30637483 PMCID: PMC6373259 DOI: 10.1007/s00592-018-01285-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 12/29/2018] [Indexed: 02/07/2023]
Abstract
AIMS In this study, we investigated whether adipose tissue insulin resistance (IR) is affected by the degree of obesity during the fasting and post-prandial state, independent of glucose tolerance among obese children and adolescents. We also tested whether systemic subclinical inflammation is associated with adipose tissue IR. METHODS Subjects were recruited to the Yale Pathophysiology of Type 2 Diabetes in Youth Study (NCT01967849). An oral glucose-tolerance test was performed to establish glucose-tolerance status and blood samples were drawn for measurement of free fatty acids (FFAs), to calculate the area under the curve (AUC) of FFA. Adipose tissue insulin resistance was calculated as the product of insulin and FFA concentrations. RESULTS In total, 671 children and adolescents (58.6% females) were included with a mean age of 13.3(2.7) years and BMI Z score of 2.45(0.31). The degree of obesity emerged as an independent predictor of both fasting and post-prandial adipose IR, p < 0.0001. Higher degree of obesity was associated with greater AUC FFA (lower suppression) compared to lower degree of obesity, p = 0.01. Furthermore, higher levels of IL-6 were positively associated with post-prandial adipose tissue IR, p = 0.02. CONCLUSIONS The degree of obesity in childhood and adolescence is strongly associated with adipose tissue IR independent of glucose tolerance. This is reflected not only in calculated indices of adipose IR but also in lower suppression of FFAs during the OGTT regardless of glucose tolerance or fasting adipose tissue IR. Furthermore, markers of subclinical inflammation such as IL-6 are associated with adipose tissue IR, independent of other factors.
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Affiliation(s)
- Emilia Hagman
- Department of Human Metabolism and Nutrition, Braun School of Public Health, Hebrew University, Jerusalem, Israel.
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Blickagången 6A, 141 57, Stockholm, Sweden.
| | - Omri Besor
- Department of Pediatrics, Ruth Rappaport Children's Hospital, Rambam Medical Center, Haifa, Israel
| | - Karen Hershkop
- Department of Human Metabolism and Nutrition, Braun School of Public Health, Hebrew University, Jerusalem, Israel
| | - Nicola Santoro
- Department of Pediatrics, Yale University, New Haven, CT, USA
| | | | - Mariana Mata
- Department of Pediatrics, Yale University, New Haven, CT, USA
| | - Sonia Caprio
- Department of Pediatrics, Yale University, New Haven, CT, USA
| | - Ram Weiss
- Department of Pediatrics, Ruth Rappaport Children's Hospital, Rambam Medical Center, Haifa, Israel
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15
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Blaslov K, Naranđa FS, Kruljac I, Renar IP. Treatment approach to type 2 diabetes: Past, present and future. World J Diabetes 2018; 9:209-219. [PMID: 30588282 PMCID: PMC6304295 DOI: 10.4239/wjd.v9.i12.209] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/20/2018] [Accepted: 11/26/2018] [Indexed: 02/05/2023] Open
Abstract
Type 2 diabetes mellitus (DM) is a lifelong metabolic disease, characterized by hyperglycaemia which gradually leads to the development and progression of vascular complications. It is recognized as a global burden disease, with substantial consequences on human health (fatality) as well as on health-care system costs. This review focuses on the topic of historical discovery and understanding the complexity of the disease in the field of pathophysiology, as well as development of the pharmacotherapy beyond insulin. The complex interplay of insulin secretion and insulin resistance developed from previously known "ominous triumvirate" to "ominous octet" indicate the implication of multiple organs in glucose metabolism. The pharmacological approach has progressed from biguanides to a wide spectrum of medications that seem to provide a beneficial effect on the cardiovascular system. Despite this, we are still not achieving the target treatment goals. Thus, the future should bring novel antidiabetic drug classes capable of acting on several levels simultaneously. In conclusion, given the raising burden of type 2 DM, the best present strategy that could contribute the most to the reduction of morbidity and mortality should be focused on primary prevention.
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Affiliation(s)
- Kristina Blaslov
- Department of Endocrinology, Diabetes and Metabolic Diseases Mladen Sekso, University Hospital Center Sestre Milosrdnice, Zagreb 10000, Croatia
| | | | - Ivan Kruljac
- Department of Endocrinology, Diabetes and Metabolic Diseases Mladen Sekso, University Hospital Center Sestre Milosrdnice, Zagreb 10000, Croatia
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16
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Nowotny B, Kahl S, Klüppelholz B, Hoffmann B, Giani G, Livingstone R, Nowotny PJ, Stamm V, Herder C, Tura A, Pacini G, Hwang JH, Roden M. Circulating triacylglycerols but not pancreatic fat associate with insulin secretion in healthy humans. Metabolism 2018; 81:113-125. [PMID: 29273469 DOI: 10.1016/j.metabol.2017.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 11/08/2017] [Accepted: 12/13/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND Loss of adequate insulin secretion for the prevailing insulin resistance is critical for the development of type 2 diabetes and has been suggested to result from circulating lipids (triacylglycerols [TG] or free fatty acids) and/or adipocytokines or from ectopic lipid storage in the pancreas. This study aimed to address whether circulating lipids, adipocytokines or pancreatic fat primarily associates with lower insulin secretion. SUBJECTS/METHODS Nondiabetic persons (n=73), recruited from the general population, underwent clinical examinations, fasting blood drawing to measure TG and adipocytokines and oral glucose tolerance testing (OGTT) to assess basal and dynamic insulin secretion and sensitivity indices. Magnetic resonance imaging and 1H-magnetic resonance spectroscopy were used to measure body fat distribution and ectopic fat content in liver and pancreas. RESULTS In age-, sex- and BMI-adjusted analyses, total and high-molecular-weight adiponectin were the strongest negative predictors of fasting beta-cell function (BCF; β=-0.403, p=0.0003 and β=-0.237, p=0.01, respectively) and adaptation index (AI; β=-0.210, p=0.006 and β=-0.133, p=0.02, respectively). Circulating TG, but not pancreatic fat content, related positively to BCF (β=0.375, p<0.0001) and AI (β=0.192, p=0.003). Similar results were obtained for the disposition index (DI). CONCLUSIONS The association of serum lipids and adiponectin with beta-cell function may represent a compensatory response to adapt for lower insulin sensitivity in nondiabetic humans.
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Affiliation(s)
- Bettina Nowotny
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; Division of Endocrinology and Diabetology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany
| | - Sabine Kahl
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; Division of Endocrinology and Diabetology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany
| | - Birgit Klüppelholz
- German Center for Diabetes Research, München-Neuherberg, Germany; Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany
| | - Barbara Hoffmann
- IUF - Leibniz Research Institute for Environmental Medicine, Institute for Occupational, Social and Environmental Medicine, Heinrich-Heine University, Düsseldorf, Germany
| | - Guido Giani
- German Center for Diabetes Research, München-Neuherberg, Germany; Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany
| | - Roshan Livingstone
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany
| | - Peter J Nowotny
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany
| | - Valerie Stamm
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany
| | - Christian Herder
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany
| | - Andrea Tura
- Metabolic Unit, Institute of Neuroscience, CNR, Padova, Italy
| | - Giovanni Pacini
- Metabolic Unit, Institute of Neuroscience, CNR, Padova, Italy
| | - Jong-Hee Hwang
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany; Division of Endocrinology and Diabetology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany.
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17
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Fowler M, Champagne C, Crocker D. Adiposity and fat metabolism during combined fasting and lactation in elephant seals. J Exp Biol 2018. [DOI: 10.1242/jeb.161554] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
ABSTRACT
Animals that fast depend on mobilizing lipid stores to power metabolism. Northern elephant seals (Mirounga angustirostris) incorporate extended fasting into several life-history stages: development, molting, breeding and lactation. The physiological processes enabling fasting and lactation are important in the context of the ecology and life history of elephant seals. The rare combination of fasting and lactation depends on the efficient mobilization of lipid from adipose stores and its direction into milk production. The mother elephant seal must ration her finite body stores to power maintenance metabolism, as well as to produce large quantities of lipid and protein-rich milk. Lipid from body stores must first be mobilized; the action of lipolytic enzymes and hormones stimulate the release of fatty acids into the bloodstream. Biochemical processes affect the release of specific fatty acids in a predictable manner, and the pattern of release from lipid stores is closely reflected in the fatty acid content of the milk lipid. The content of the milk may have substantial developmental, thermoregulatory and metabolic consequences for the pup. The lactation and developmental patterns found in elephant seals are similar in some respects to those of other mammals; however, even within the limited number of mammals that simultaneously fast and lactate, there are important differences in the mechanisms that regulate lipid mobilization and milk lipid content. Although ungulates and humans do not fast during lactation, there are interesting comparisons to these groups regarding lipid mobilization and milk lipid content patterns.
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18
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Tricò D, Trifirò S, Mengozzi A, Morgantini C, Baldi S, Mari A, Natali A. Reducing Cholesterol and Fat Intake Improves Glucose Tolerance by Enhancing β Cell Function in Nondiabetic Subjects. J Clin Endocrinol Metab 2018; 103:622-631. [PMID: 29095990 DOI: 10.1210/jc.2017-02089] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 10/23/2017] [Indexed: 12/22/2022]
Abstract
CONTEXT A diet low in cholesterol and fat is commonly recommended to prevent metabolic and cardiovascular diseases; however, its effect on glucose tolerance is largely unknown. OBJECTIVE We examined whether and by which mechanisms a chronic reduction of cholesterol and fat intake affects glucose tolerance in nondiabetic individuals, independently of weight changes. DESIGN AND PARTICIPANTS In this crossover, randomized clinical trial, 30 healthy subjects, including 15 with family history of type 2 diabetes (T2D) (T2D offspring), underwent a 75-g oral glucose tolerance test (OGTT) after two 14-day isocaloric high-cholesterol, high-fat (HChF) or low-cholesterol, and low-fat (LChF) diets. MAIN OUTCOME MEASURES We evaluated changes in glucose tolerance, β cell function, insulin clearance, and insulin sensitivity by modeling plasma glucose, insulin, and C-peptide levels during the OGTT. RESULTS The shift from the HChF to the LChF diet was neutral on body weight but increased glucose tolerance (mean glucose -5%, P = 0.01) and three components of β cell function: glucose sensitivity (+17%, P = 0.01), insulin secretion at fasting glucose (+20%, P = 0.02), and potentiation (+19%, P = 0.03). The LChF diet improved insulin sensitivity (+7%, P = 0.048) only in T2D offspring, who tended to be more susceptible to the positive effect of the diet on glucose tolerance. CONCLUSIONS A chronic and isocaloric decrease in dietary cholesterol and fat intake improves glucose tolerance by diffusely ameliorating β cell function in nondiabetic subjects. Individuals genetically predisposed to develop T2D tend to be more susceptible to the positive effect of this dietary intervention on glucose tolerance and insulin sensitivity.
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Affiliation(s)
- Domenico Tricò
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy
| | - Silvia Trifirò
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Alessandro Mengozzi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Cecilia Morgantini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Simona Baldi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Andrea Mari
- Institute of Neuroscience, National Research Council, Padua, Italy
| | - Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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Connolly A, Leblanc S, Baillargeon JP. Role of Lipotoxicity and Contribution of the Renin-Angiotensin System in the Development of Polycystic Ovary Syndrome. Int J Endocrinol 2018; 2018:4315413. [PMID: 29971102 PMCID: PMC6008888 DOI: 10.1155/2018/4315413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 05/03/2018] [Indexed: 12/15/2022] Open
Abstract
Polycystic ovary syndrome (PCOS) is a common and significant condition associated with hyperandrogenism, infertility, low quality of life, and metabolic comorbidities. One possible explanation of PCOS development is cellular dysfunction induced by nonesterified fatty acids (NEFAs), that is, lipotoxicity, which could explain both the hyperandrogenemia and insulin resistance that characterize women with PCOS. The literature suggests that androgen biosynthesis may be induced by overexposure of androgen-secreting tissues to NEFA and/or defective NEFA metabolism, leading to lipotoxic effects. Indeed, lipotoxicity could trigger androgenic hyperresponsiveness to insulin, LH, and ACTH. In most PCOS women, lipotoxicity also causes insulin resistance, inducing compensatory hyperinsulinemia, and may thus further increase hyperandrogenemia. Many approaches aimed at insulin sensitization also reduce lipotoxicity and have been shown to treat PCOS hyperandrogenemia. Furthermore, our group and others found that angiotensin II type 2 receptor (AT2R) activation is able to improve lipotoxicity. We provided evidence, using C21/M24, that AT2R activation improves adipocytes' size and insulin sensitivity in an insulin-resistant rat model, as well as androgen levels in a PCOS obese rat model. Taken together, these findings point toward the important role of lipotoxicity in PCOS development and of the RAS system as a new target for the treatment of PCOS.
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Affiliation(s)
- Alexandre Connolly
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, 3001 12e Avenue Nord, Université de Sherbrooke, Sherbrooke, QC, Canada J1H 5N4
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, 3001 12e Avenue Nord, Université de Sherbrooke, Sherbrooke, QC, Canada J1H 5N4
| | - Samuel Leblanc
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, 3001 12e Avenue Nord, Université de Sherbrooke, Sherbrooke, QC, Canada J1H 5N4
| | - Jean-Patrice Baillargeon
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, 3001 12e Avenue Nord, Université de Sherbrooke, Sherbrooke, QC, Canada J1H 5N4
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Previti E, Salinari S, Bertuzzi A, Capristo E, Bornstein S, Mingrone G. Glycemic control after metabolic surgery: a Granger causality and graph analysis. Am J Physiol Endocrinol Metab 2017; 313:E622-E630. [PMID: 28698280 DOI: 10.1152/ajpendo.00042.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 07/10/2017] [Accepted: 07/10/2017] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to examine the contribution of nonesterified fatty acids (NEFA) and incretin to insulin resistance and diabetes amelioration after malabsorptive metabolic surgery that induces steatorrhea. In fact, NEFA infusion reduces glucose-stimulated insulin secretion, and high-fat diets predict diabetes development. Six healthy controls, 11 obese subjects, and 10 type 2 diabetic (T2D) subjects were studied before and 1 mo after biliopancreatic diversion (BPD). Twenty-four-hour plasma glucose, NEFA, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), and gastric inhibitory polypeptide (GIP) time courses were obtained and analyzed by Granger causality and graph analyses. Insulin sensitivity and secretion were computed by the oral glucose minimal model. Before metabolic surgery, NEFA levels had the strongest influence on the other variables in both obese and T2D subjects. After surgery, GLP-1 and C-peptide levels controlled the system in obese and T2D subjects. Twenty-four-hour GIP levels were markedly reduced after BPD. Finally, not only did GLP-1 levels play a central role, but also insulin and C-peptide levels had a comparable relevance in the network of healthy controls. After BPD, insulin sensitivity was completely normalized in both obese and T2D individuals. Increased 24-h GLP-1 circulating levels positively influenced glucose homeostasis in both obese and T2D subjects who underwent a malabsorptive bariatric operation. In the latter, the reduction of plasma GIP levels also contributed to the improvement of glucose metabolism. It is possible that the combination of a pharmaceutical treatment reducing GIP and increasing GLP-1 plasma levels will contribute to better glycemic control in T2D. The application of Granger causality and graph analyses sheds new light on the pathophysiology of metabolic surgery.
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Affiliation(s)
- Elena Previti
- Department of Computer, Control, and Management Engineering "Antonio Ruberti," Sapienza University of Rome, Rome, Italy
| | - Serenella Salinari
- Department of Computer, Control, and Management Engineering "Antonio Ruberti," Sapienza University of Rome, Rome, Italy
| | - Alessandro Bertuzzi
- Institute for System Analysis and Computer Science "Antonio Ruberti," Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Esmeralda Capristo
- Department of Internal Medicine, Catholic University of the Sacred Heart, Rome, Italy
| | - Stephan Bornstein
- Department of Medicine III, Universitätsklinikum Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany; and
- Diabetes and Nutritional Sciences, King's College London, London, United Kingdom
| | - Geltrude Mingrone
- Department of Internal Medicine, Catholic University of the Sacred Heart, Rome, Italy;
- Diabetes and Nutritional Sciences, King's College London, London, United Kingdom
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21
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Abstract
Enlarged fat cells in obese adipose tissue diminish capacity to store fat and are resistant to the anti-lipolytic effect of insulin. Insulin resistance (IR)-associated S-nitrosylation of insulin-signaling proteins increases in obesity. In accordance with the inhibition of insulin-mediated anti-lipolytic action, plasma free fatty acid (FFA) levels increase. Additionally, endoplasmic reticulum stress stimuli induce lipolysis by activating cyclic adenosine monophosphate/Protein kinase A (cAMP/PKA) and extracellular signal-regulated kinase ½ (ERK1/2) signaling in adipocytes. Failure of packaging of excess lipid into lipid droplets causes chronic elevation of circulating fatty acids, which can reach to toxic levels within non-adipose tissues. Deleterious effects of lipid accumulation in non-adipose tissues are known as lipotoxicity. In fact, triglycerides may also serve a storage function for long-chain non-esterified fatty acids and their products such as ceramides and diacylglycerols (DAGs). Thus, excess DAG, ceramide and saturated fatty acids in obesity can induce chronic inflammation and have harmful effect on multiple organs and systems. In this context, chronic adipose tissue inflammation, mitochondrial dysfunction and IR have been discussed within the scope of lipotoxicity.
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22
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Doliba NM, Liu Q, Li C, Chen P, Liu C, Naji A, Matschinsky FM. Inhibition of cholinergic potentiation of insulin secretion from pancreatic islets by chronic elevation of glucose and fatty acids: Protection by casein kinase 2 inhibitor. Mol Metab 2017; 6:1240-1253. [PMID: 29031723 PMCID: PMC5641685 DOI: 10.1016/j.molmet.2017.07.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/24/2017] [Accepted: 07/31/2017] [Indexed: 01/24/2023] Open
Abstract
Objectives Chronic hyperlipidemia and hyperglycemia are characteristic features of type 2 diabetes (T2DM) that are thought to cause or contribute to β-cell dysfunction by “glucolipotoxicity.” Previously we have shown that acute treatment of pancreatic islets with fatty acids (FA) decreases acetylcholine-potentiated insulin secretion. This acetylcholine response is mediated by M3 muscarinic receptors, which play a key role in regulating β-cell function. Here we examine whether chronic FA exposure also inhibits acetylcholine-potentiated insulin secretion using mouse and human islets. Methods Islets were cultured for 3 or 4 days at different glucose concentration with 0.5 mM palmitic acid (PA) or a 2:1 mixture of PA and oleic acid (OA) at 1% albumin (PA/BSA molar ratio 3.3). Afterwards, the response to glucose and acetylcholine were studied in perifusion experiments. Results FA-induced impairment of insulin secretion and Ca2+ signaling depended strongly on the glucose concentrations of the culture medium. PA and OA in combination reduced acetylcholine potentiation of insulin secretion more than PA alone, both in mouse and human islets, with no evidence of a protective role of OA. In contrast, lipotoxicity was not observed with islets cultured for 3 days in medium containing less than 1 mM glucose and a mixture of glutamine and leucine (7 mM each). High glucose and FAs reduced endoplasmic reticulum (ER) Ca2+ storage capacity; however, preserving ER Ca2+ by blocking the IP3 receptor with xestospongin C did not protect islets from glucolipotoxic effects on insulin secretion. In contrast, an inhibitor of casein kinase 2 (CK2) protected the glucose dependent acetylcholine potentiation of insulin secretion in mouse and human islets against glucolipotoxicity. Conclusions These results show that chronic FA treatment decreases acetylcholine potentiation of insulin secretion and that this effect is strictly glucose dependent and might involve CK2 phosphorylation of β-cell M3 muscarinic receptors. Glucolipotoxicity impairs acetylcholine-potentiation of insulin secretion. Glucose amplification of insulin secretion rather than triggering is damaged by FA. Inhibitor of casein kinase 2 preserved islet function against glucolipotoxicity.
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Affiliation(s)
- Nicolai M Doliba
- Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA.
| | - Qin Liu
- Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Changhong Li
- Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Pan Chen
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Chengyang Liu
- Department of Surgery, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Ali Naji
- Department of Surgery, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Franz M Matschinsky
- Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
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Natali A, Baldi S, Bonnet F, Petrie J, Trifirò S, Tricò D, Mari A. Plasma HDL-cholesterol and triglycerides, but not LDL-cholesterol, are associated with insulin secretion in non-diabetic subjects. Metabolism 2017; 69:33-42. [PMID: 28285650 DOI: 10.1016/j.metabol.2017.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 12/15/2016] [Accepted: 01/03/2017] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Experimental data support the notion that lipoproteins might directly affect beta cell function, however clinical data are sparse and inconsistent. We aimed at verifying whether, independently of major confounders, serum lipids are associated with alterations in insulin secretion or clearance non-diabetic subjects. METHODS Cross sectional and observational prospective (3.5yrs), multicentre study in which 1016 non-diabetic volunteers aged 30-60yrs. and with a wide range of BMI (20.0-39.9kg/m2) were recruited in a setting of University hospital ambulatory care (RISC study). MAIN OUTCOME MEASURES baseline fasting lipids, fasting and OGTT-induced insulin secretion and clearance (measured by glucose and C-peptide modeling), peripheral insulin sensitivity (by the euglycemic clamp). Lipids and OGTT were repeated in 980 subjects after 3.5years. RESULTS LDL-cholesterol did not show independent associations with fasting or stimulated insulin secretion or clearance. After accounting for potential confounders, HDL-cholesterol displayed negative and triglycerides positive independent associations with fasting and OGTT insulin secretion; neither with insulin clearance. Low HDL-cholesterol and high triglycerides were associated with an increase in glucose-dependent and a decrease in non-glucose-dependent insulin secretion. Over 3.5years both an HDL-cholesterol decline and a triglycerides rise were associated with an increase in fasting insulin secretion independent of changes in body weight or plasma glucose. CONCLUSIONS LDL-cholesterol does not seem to influence any major determinant of insulin bioavailability while low HDL-cholesterol and high triglycerides might contribute to sustain the abnormalities in insulin secretion that characterize the pre-diabetic state.
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Affiliation(s)
- Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Italy.
| | - Simona Baldi
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - Fabrice Bonnet
- Service Endocrinologie-Diabétologie, Centre Hospitalo-Universitaire (CHU), University Rennes 1, Rennes, France
| | - John Petrie
- Institute of Cardiovascular and Medical Sciences BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - Silvia Trifirò
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - Domenico Tricò
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - Andrea Mari
- CNR Institute of Neuroscience, Padova, Italy
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Lane-Cordova AD, Witmer JR, Dubishar K, DuBose LE, Chenard CA, Siefers KJ, Myers JE, Points LJ, Pierce GL. High trans but not saturated fat beverage causes an acute reduction in postprandial vascular endothelial function but not arterial stiffness in humans. Vasc Med 2016; 21:429-436. [PMID: 27558396 DOI: 10.1177/1358863x16656063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A diet high in trans-fatty acids (TFAs) is associated with a higher risk of cardiovascular disease (CVD) than a diet high in saturated fatty acids (SFAs), but the mechanisms remain unclear. We hypothesized that a beverage high in TFAs would cause a larger reduction in postprandial endothelial function and an increase in arterial stiffness, in part from greater reductions in insulin sensitivity, compared with a beverage high in SFAs. Eleven healthy adults (aged 47±5 years) ingested a warm test beverage (520 kcal, 56 g total fat, 5 g carbohydrate, 1 g protein) high in either TFAs or SFAs in a randomized cross-over study. Ingestion of the beverage high in TFAs (p<0.01) but not high in SFAs (p=0.49) decreased endothelial function (brachial artery flow-mediated dilation, mmΔ) at 3-4 hours (p<0.01 for time; p=0.034 for interaction), but did not alter aortic stiffness or carotid β-stiffness. The homeostasis model of insulin resistance (interaction p=0.062) tended to decrease after SFAs but not TFAs. A beverage high in TFAs but not SFAs results in a postprandial reduction in endothelial function and a trend for decreased insulin sensitivity, potentially explaining the higher risk of CVD with a diet high in TFAs.
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Affiliation(s)
- Abbi D Lane-Cordova
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Jordan R Witmer
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Kaitlyn Dubishar
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Lyndsey E DuBose
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Catherine A Chenard
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Kyle J Siefers
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Janie E Myers
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Lauren J Points
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA
| | - Gary L Pierce
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, USA .,Fraternal Order of Eagles Diabetes Research Center, The University of Iowa, Iowa City, IA, USA.,Center for Hypertension Research, The University of Iowa, Iowa City, IA, USA.,Abboud Cardiovascular Research Center, The University of Iowa, Iowa City, IA, USA
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25
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Hershkop K, Besor O, Santoro N, Pierpont B, Caprio S, Weiss R. Adipose Insulin Resistance in Obese Adolescents Across the Spectrum of Glucose Tolerance. J Clin Endocrinol Metab 2016; 101:2423-31. [PMID: 27054297 PMCID: PMC4891802 DOI: 10.1210/jc.2016-1376] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
CONTEXT Adipocytes represent an important insulin-responsive tissue taking an active part in glucose metabolism. OBJECTIVE This study sought to assess adipose tissue insulin resistance (IR) across the spectrum of glucose tolerance and to test its relation with free fatty acid (FFA) suppression during an oral glucose tolerance test (OGTT). DESIGN AND SETTING A cross-sectional analysis of a pediatric clinic-derived cohort of obese adolescents. PATIENTS OR OTHER PARTICIPANTS Participants age 7-20 y with a body mass index that exceeded the 95th percentile for their age and sex. INTERVENTION(S) A standard oral glucose tolerance test. MAIN OUTCOME MEASURES The adipose tissue insulin resistance index (calculated as the product of fasting insulin and FFA concentrations) (Adipose IR) and the area under curve of FFAs during the OGTT were compared between glucose tolerance categories. RESULTS A total of 962 obese children and adolescents participated in this study. Adipose IR significantly increased across glucose tolerance categories (P for trend < .001). Within the normal glucose tolerance participants, an increase in adipose IR was observed related to an increase in 2-hr glucose levels. In a subsample of participants who underwent abdominal imaging for determination of lipid partitioning (n = 115), a tight relation of visceral fat (r = 0.34; P < .001) and the visceral/sc fat ratio (r = 0.55; P < .001) with the Adipose IR index was evident. Greater area under the curve FFAs (lower FFA suppression) during the OGTT was evident with worsening glucose tolerance (P for trend < .001). Glucose tolerance category, degree of obesity (body mass index-z score), IL-6, and low adiponectin emerged as significant predictors of the Adipose IR. CONCLUSIONS Adipose IR is associated with reduced suppression of FFAs during the OGTT and with an altered adipocytokine profile. The negative relation with insulin secretion deserves further longitudinal investigation in the context of deteriorating glucose tolerance.
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Affiliation(s)
- Karen Hershkop
- Department of Human Metabolism and Nutrition (K.H., O.B., R.W.), Braun School of Public Health, Hebrew University, Jerusalem 91120, Israel; and the Department of Pediatrics (N.S., B.P., S.C.), Yale School of Medicine, New Haven, Connecticut 06510
| | - Omri Besor
- Department of Human Metabolism and Nutrition (K.H., O.B., R.W.), Braun School of Public Health, Hebrew University, Jerusalem 91120, Israel; and the Department of Pediatrics (N.S., B.P., S.C.), Yale School of Medicine, New Haven, Connecticut 06510
| | - Nicola Santoro
- Department of Human Metabolism and Nutrition (K.H., O.B., R.W.), Braun School of Public Health, Hebrew University, Jerusalem 91120, Israel; and the Department of Pediatrics (N.S., B.P., S.C.), Yale School of Medicine, New Haven, Connecticut 06510
| | - Bridget Pierpont
- Department of Human Metabolism and Nutrition (K.H., O.B., R.W.), Braun School of Public Health, Hebrew University, Jerusalem 91120, Israel; and the Department of Pediatrics (N.S., B.P., S.C.), Yale School of Medicine, New Haven, Connecticut 06510
| | - Sonia Caprio
- Department of Human Metabolism and Nutrition (K.H., O.B., R.W.), Braun School of Public Health, Hebrew University, Jerusalem 91120, Israel; and the Department of Pediatrics (N.S., B.P., S.C.), Yale School of Medicine, New Haven, Connecticut 06510
| | - Ram Weiss
- Department of Human Metabolism and Nutrition (K.H., O.B., R.W.), Braun School of Public Health, Hebrew University, Jerusalem 91120, Israel; and the Department of Pediatrics (N.S., B.P., S.C.), Yale School of Medicine, New Haven, Connecticut 06510
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Faubert J, Battista MC, Baillargeon JP. PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM: Insulin action and lipotoxicity in the development of polycystic ovary syndrome: A review1. J Anim Sci 2016; 94:1803-11. [DOI: 10.2527/jas.2015-0089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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27
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Dong HY, Jiang XM, Niu CB, Du L, Feng JY, Jia FY. Cerebrolysin improves sciatic nerve dysfunction in a mouse model of diabetic peripheral neuropathy. Neural Regen Res 2016; 11:156-62. [PMID: 26981106 PMCID: PMC4774211 DOI: 10.4103/1673-5374.175063] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
To examine the effects of Cerebrolysin on the treatment of diabetic peripheral neuropathy, we first established a mouse model of type 2 diabetes mellitus by administering a high-glucose, high-fat diet and a single intraperitoneal injection of streptozotocin. Mice defined as diabetic in this model were then treated with 1.80, 5.39 or 8.98 mL/kg of Cerebrolysin via intraperitoneal injections for 10 consecutive days. Our results demonstrated that the number, diameter and area of myelinated nerve fibers increased in the sciatic nerves of these mice after administration of Cerebrolysin. The results of several behavioral tests showed that Cerebrolysin dose-dependently increased the slope angle in the inclined plane test (indicating an improved ability to maintain body position), prolonged tail-flick latency and foot-licking time (indicating enhanced sensitivity to thermal and chemical pain, respectively, and reduced pain thresholds), and increased an index of sciatic nerve function in diabetic mice compared with those behavioral results in untreated diabetic mice. Taken together, the anatomical and functional results suggest that Cerebrolysin ameliorated peripheral neuropathy in a mouse model of type 2 diabetes mellitus.
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Affiliation(s)
- Han-Yu Dong
- Department of Pediatric Neurology and Rehabilitation, First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Xin-Mei Jiang
- Institute of Jilin Neurological Research, First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Chun-Bo Niu
- Department of Pathology, China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, China
| | - Lin Du
- Department of Pediatric Neurology and Rehabilitation, First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Jun-Yan Feng
- Department of Pediatric Neurology and Rehabilitation, First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Fei-Yong Jia
- Department of Pediatric Neurology and Rehabilitation, First Hospital of Jilin University, Changchun, Jilin Province, China; Institute of Jilin Neurological Research, First Hospital of Jilin University, Changchun, Jilin Province, China
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28
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Consumption of dairy foods in relation to impaired glucose metabolism and type 2 diabetes mellitus: the Maastricht Study. Br J Nutr 2016; 115:1453-61. [DOI: 10.1017/s0007114516000313] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AbstractObservational studies suggest an inverse association between total dairy product intake and diabetes risk. However, there is a lack of information on the relationship of specific dairy products with impaired glucose metabolism (IGM) and type 2 diabetes mellitus (T2DM). Individuals aged 40–75 years were recruited for the Maastricht Study. All the participants filled out a 253-food item FFQ, covering fifty specific dairy items that captured differences between full-fat, semi-skimmed and skimmed products, as well as fermented and non-fermented products. Glucose metabolism status was assessed by an oral glucose tolerance test, and participants were informed on their glucose metabolism status after returning the FFQ. Data of 2391 individuals were available to estimate OR (95 % CI) for IGM (n 470) and newly diagnosed (ND) T2DM (n 125), with adjustment for age, sex, BMI, physical activity, smoking status, education, energy intake and intakes of vegetables, fruits, meat and fish. For IGM, fully adjusted analyses revealed inverse associations, with OR comparing the highest with the lowest tertile of intake of 0·73 (95 % CI 0·55, 0·96) for skimmed products and 0·74 (95 % CI 0·54, 0·99) for fermented products. These dairy products were not associated with ND T2DM. In contrast, full-fat products were positively associated with ND T2DM (OR 2·01; 95 % CI 1·16, 3·47), whereas total dairy product intake was inversely associated with ND T2DM (OR 0·50; 95 % CI 0·26, 0·93). In conclusion, individuals with a high consumption of skimmed and fermented products had lower odds of having IGM, and individuals with a high consumption of total dairy products had lower odds of having ND T2DM. High intake of full-fat products was not related to IGM but was positively related to ND T2DM.
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29
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Frohnert BI, Rewers MJ. Metabolomics in childhood diabetes. Pediatr Diabetes 2016; 17:3-14. [PMID: 26420304 PMCID: PMC4703499 DOI: 10.1111/pedi.12323] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 12/30/2022] Open
Abstract
Recent increases in the incidence of both type 1 (T1D) and type 2 diabetes (T2D) in children and adolescents point to the importance of environmental factors in the development of these diseases. Metabolomic analysis explores the integrated response of the organism to environmental changes. Metabolic profiling can identify biomarkers that are predictive of disease incidence and development, potentially providing insight into disease pathogenesis. This review provides an overview of the role of metabolomic analysis in diabetes research and summarizes recent research relating to the development of T1D and T2D in children.
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Affiliation(s)
- Brigitte I Frohnert
- Barbara Davis Center for Childhood Diabetes; University of Colorado; Aurora CO 80045 USA
| | - Marian J Rewers
- Barbara Davis Center for Childhood Diabetes; University of Colorado; Aurora CO 80045 USA
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30
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Hasnain SZ, Prins JB, McGuckin MA. Oxidative and endoplasmic reticulum stress in β-cell dysfunction in diabetes. J Mol Endocrinol 2016; 56:R33-54. [PMID: 26576641 DOI: 10.1530/jme-15-0232] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/17/2015] [Indexed: 12/12/2022]
Abstract
The inability of pancreatic β-cells to make sufficient insulin to control blood sugar is a central feature of the aetiology of most forms of diabetes. In this review we focus on the deleterious effects of oxidative stress and endoplasmic reticulum (ER) stress on β-cell insulin biosynthesis and secretion and on inflammatory signalling and apoptosis with a particular emphasis on type 2 diabetes (T2D). We argue that oxidative stress and ER stress are closely entwined phenomena fundamentally involved in β-cell dysfunction by direct effects on insulin biosynthesis and due to consequences of the ER stress-induced unfolded protein response. We summarise evidence that, although these phenomenon can be driven by intrinsic β-cell defects in rare forms of diabetes, in T2D β-cell stress is driven by a range of local environmental factors including increased drivers of insulin biosynthesis, glucolipotoxicity and inflammatory cytokines. We describe our recent findings that a range of inflammatory cytokines contribute to β-cell stress in diabetes and our discovery that interleukin 22 protects β-cells from oxidative stress regardless of the environmental triggers and can correct much of diabetes pathophysiology in animal models. Finally we summarise evidence that β-cell dysfunction is reversible in T2D and discuss therapeutic opportunities for relieving oxidative and ER stress and restoring glycaemic control.
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Affiliation(s)
- Sumaira Z Hasnain
- ImmunityInfection and Inflammation Program, Mater Research Institute, Translational Research Institute, University of Queensland, 37 Kent Street, Woolloongabba, Brisbane, Queensland 4102, AustraliaMetabolic Diseases ProgramMater Research Institute, The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Johannes B Prins
- ImmunityInfection and Inflammation Program, Mater Research Institute, Translational Research Institute, University of Queensland, 37 Kent Street, Woolloongabba, Brisbane, Queensland 4102, AustraliaMetabolic Diseases ProgramMater Research Institute, The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Michael A McGuckin
- ImmunityInfection and Inflammation Program, Mater Research Institute, Translational Research Institute, University of Queensland, 37 Kent Street, Woolloongabba, Brisbane, Queensland 4102, AustraliaMetabolic Diseases ProgramMater Research Institute, The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, Brisbane, Queensland 4102, Australia
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31
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Palmitate-induced impairment of glucose-stimulated insulin secretion precedes mitochondrial dysfunction in mouse pancreatic islets. Biochem J 2015; 473:487-96. [PMID: 26621874 DOI: 10.1042/bj20151080] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 11/30/2015] [Indexed: 01/08/2023]
Abstract
It has been well established that excessive levels of glucose and palmitate lower glucose-stimulated insulin secretion (GSIS) by pancreatic β-cells. This β-cell 'glucolipotoxicity' is possibly mediated by mitochondrial dysfunction, but involvement of bioenergetic failure in the pathological mechanism is the subject of ongoing debate. We show in the present study that increased palmitate levels impair GSIS before altering mitochondrial function. We demonstrate that GSIS defects arise from increased insulin release under basal conditions in addition to decreased insulin secretion under glucose-stimulatory conditions. Real-time respiratory analysis of intact mouse pancreatic islets reveals that mitochondrial ATP synthesis is not involved in the mechanism by which basal insulin is elevated. Equally, mitochondrial lipid oxidation and production of reactive oxygen species (ROS) do not contribute to increased basal insulin secretion. Palmitate does not affect KCl-induced insulin release at a basal or stimulatory glucose level, but elevated basal insulin release is attenuated by palmitoleate and associates with increased intracellular calcium. These findings deepen our understanding of β-cell glucolipotoxicity and reveal that palmitate-induced GSIS impairment is disconnected from mitochondrial dysfunction, a notion that is important when targeting β-cells for the treatment of diabetes and when assessing islet function in human transplants.
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Rebelos E, Seghieri M, Natali A, Balkau B, Golay A, Piatti PM, Lalic NM, Laakso M, Mari A, Ferrannini E. Influence of endogenous NEFA on beta cell function in humans. Diabetologia 2015; 58:2344-51. [PMID: 26160433 DOI: 10.1007/s00125-015-3685-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 06/15/2015] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS It is a commonly held view that chronically elevated NEFA levels adversely affect insulin secretion and insulin action (lipotoxicity). However, the effect of NEFA on beta cell function has only been explored using acute NEFA elevations. Our aim was to analyse the relationship between endogenous NEFA levels and beta cell function. METHODS In 1,267 individuals followed-up for 3 years, we measured insulin sensitivity (by clamp) and beta cell function (by C-peptide modelling during OGTT and as the acute insulin response [AIR] to IVGTT). RESULTS At baseline, both fasting and insulin-suppressed NEFA levels were higher across glucose tolerance groups, while insulin sensitivity was lower, insulin output was higher, and beta cell glucose sensitivity and AIR were lower (all p < 0.0001). In multiple logistic analyses adjusting for age, BMI, WHR and glucose tolerance, both fasting and insulin-suppressed NEFA levels were inversely related to insulin sensitivity, as expected (both p < 0.0001). Furthermore, after adjusting for insulin sensitivity, insulin-suppressed NEFA were positively associated with total insulin output (p = 0.0042). In contrast, neither fasting nor insulin-suppressed NEFA were related to beta cell glucose sensitivity or AIR. At follow-up, worsening of glucose tolerance (n = 126) was predicted by lower insulin and beta cell glucose sensitivity. In this model, baseline NEFA were not significant predictors of progression. CONCLUSIONS/INTERPRETATION In the non-diabetic state and in subjects with impaired glucose tolerance, circulating endogenous NEFA are not independently associated measures of beta cell function, and do not predict deterioration of glucose tolerance. Thus, in the Relationship Between Insulin Sensitivity and Cardiovascular Disease (RISC) cohort there is no evidence for beta cell lipotoxicity of endogenous total NEFA concentrations.
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Affiliation(s)
- Eleni Rebelos
- Department of Clinical & Experimental Medicine, University of Pisa, Via Roma, 67, 56126, Pisa, Italy
| | - Marta Seghieri
- Department of Clinical & Experimental Medicine, University of Pisa, Via Roma, 67, 56126, Pisa, Italy
| | - Andrea Natali
- Department of Clinical & Experimental Medicine, University of Pisa, Via Roma, 67, 56126, Pisa, Italy
| | | | - Alain Golay
- Division of Therapeutical Teaching for Chronic Diseases, University Hospital, Geneva, Switzerland
| | - Pier Marco Piatti
- Cardio-Metabolism and Clinical Trials Unit, Department of Internal Medicine, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Nebojsa M Lalic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, CCS, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Markku Laakso
- Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Andrea Mari
- CNR Institute of Neuroscience, Padova, Italy
| | - Ele Ferrannini
- Department of Clinical & Experimental Medicine, University of Pisa, Via Roma, 67, 56126, Pisa, Italy.
- CNR Institute of Clinical Physiology, Pisa, Italy.
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Gervais A, Battista MC, Carranza-Mamane B, Lavoie HB, Baillargeon JP. Follicular fluid concentrations of lipids and their metabolites are associated with intraovarian gonadotropin-stimulated androgen production in women undergoing in vitro fertilization. J Clin Endocrinol Metab 2015; 100:1845-54. [PMID: 25695883 DOI: 10.1210/jc.2014-3649] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
CONTEXT Although growing evidence points toward a role of lipotoxicity in the development of hyperandrogenesis, the main feature of polycystic ovary syndrome, few studies directly assessed this association in vivo in humans, and none targeted the ovarian milieu. OBJECTIVE The main objective of this study was to correlate follicular fluid (FF) T levels with lipids, lipid metabolites, and inflammation markers. DESIGN This was a cross-sectional study. SETTING Recruitment was performed in two fertility clinics at one private and one academic center. PARTICIPANTS Eighty women requiring in vitro fertilization were recruited during one of their scheduled visit at the fertility clinic. All women aged between 18 and 40 years with a body mass index between 18 and 40 kg/m(2) were invited to participate. INTERVENTION(S) There were no interventions. MAIN OUTCOME MEASURE(S) At the time of oocyte aspiration, FF was collected and analyzed for total T, lipids [nonesterified fatty acids (NEFAs) plus triglycerides], NEFA metabolites (acylcarnitines; markers of ineffective NEFAs β-oxidation), and inflammatory marker composition. The hypothesis being tested was formulated before the data collection. RESULTS FF T levels were significantly correlated with FF levels of lipids (r = 0.381, P = .001; independently of IL-6), acylcarnitines (r ≥ 0.255, all P = .008; not independently of lipids), and IL-6 (r = 0.300, P = .009, independently of lipids). Additionally, FF lipid levels were significantly and strongly correlated with acylcarnitines (r ≥ 0.594; all P < .001). CONCLUSIONS These results suggest that ovarian androgen production is related to intraovarian exposure to lipids, independently of inflammation and mainly through ineffective NEFA β-oxidation (as shown by higher acylcarnitine levels). Inflammation is also associated with intraovarian androgenesis, independently of lipids.
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Affiliation(s)
- A Gervais
- Division of Endocrinology (A.G., M.-C.B., J.-P.B.), Department of Medicine, and Department of Obstetrics and Gynecology (B.C.-M.), Université de Sherbrooke, and Centre de Recherche Clinique Étienne-LeBel (B.C.-M., J.-P.B.), Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4; and PROCREA Cliniques (B.C.-M.), Mt Royal, Québec, Canada H3P 2W3
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Cornell S. Continual evolution of type 2 diabetes: an update on pathophysiology and emerging treatment options. Ther Clin Risk Manag 2015; 11:621-32. [PMID: 25931824 PMCID: PMC4404882 DOI: 10.2147/tcrm.s67387] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Diabetes is a complex and progressive disease that has a major societal and economic impact. The most common form of diabetes, type 2 diabetes mellitus (T2DM), is a multifactorial disease, the pathophysiology of which involves not only the pancreas but also the liver, skeletal muscle, adipose tissue, gastrointestinal tract, brain, and kidney. Novel therapies with mechanisms of action that are different from most existing drugs are emerging. One such class consists of compounds that inhibit renal sodium-glucose cotransporter 2, which is responsible for the bulk of glucose reabsorption by the kidneys. This new class of compounds improves glycemic control independently of insulin and promotes weight reduction, providing an additional tool to treat patients with T2DM. This review discusses the underlying pathophysiology of T2DM, clinical guidelines, and available and emerging treatment options, with particular emphasis on sodium-glucose cotransporter 2 inhibitors.
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Affiliation(s)
- Susan Cornell
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, USA
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Torres JM, Gamazon ER, Parra EJ, Below JE, Valladares-Salgado A, Wacher N, Cruz M, Hanis CL, Cox NJ. Cross-tissue and tissue-specific eQTLs: partitioning the heritability of a complex trait. Am J Hum Genet 2014; 95:521-34. [PMID: 25439722 PMCID: PMC4225593 DOI: 10.1016/j.ajhg.2014.10.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 10/01/2014] [Indexed: 01/10/2023] Open
Abstract
Top signals from genome-wide association studies (GWASs) of type 2 diabetes (T2D) are enriched with expression quantitative trait loci (eQTLs) identified in skeletal muscle and adipose tissue. We therefore hypothesized that such eQTLs might account for a disproportionate share of the heritability estimated from all SNPs interrogated through GWASs. To test this hypothesis, we applied linear mixed models to the Wellcome Trust Case Control Consortium (WTCCC) T2D data set and to data sets representing Mexican Americans from Starr County, TX, and Mexicans from Mexico City. We estimated the proportion of phenotypic variance attributable to the additive effect of all variants interrogated in these GWASs, as well as a much smaller set of variants identified as eQTLs in human adipose tissue, skeletal muscle, and lymphoblastoid cell lines. The narrow-sense heritability explained by all interrogated SNPs in each of these data sets was substantially greater than the heritability accounted for by genome-wide-significant SNPs (∼10%); GWAS SNPs explained over 50% of phenotypic variance in the WTCCC, Starr County, and Mexico City data sets. The estimate of heritability attributable to cross-tissue eQTLs was greater in the WTCCC data set and among lean Hispanics, whereas adipose eQTLs significantly explained heritability among Hispanics with a body mass index ≥ 30. These results support an important role for regulatory variants in the genetic component of T2D susceptibility, particularly for eQTLs that elicit effects across insulin-responsive peripheral tissues.
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Affiliation(s)
- Jason M Torres
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, IL 60637, USA
| | - Eric R Gamazon
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Esteban J Parra
- Department of Anthropology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Jennifer E Below
- Human Genetics Center, University of Texas Health Science Center at Houston, Houston, TX 77225, USA
| | - Adan Valladares-Salgado
- Unidades de Investigacion Medica en Bioquimica y Unidad de Epidemiologia Clinica, Hospital de Especialidades, Centro Medico Nacional "Siglo XXI," Instituto Mexicano del Seguro Social, Mexico City, CP 06720, Mexico
| | - Niels Wacher
- Unidades de Investigacion Medica en Bioquimica y Unidad de Epidemiologia Clinica, Hospital de Especialidades, Centro Medico Nacional "Siglo XXI," Instituto Mexicano del Seguro Social, Mexico City, CP 06720, Mexico
| | - Miguel Cruz
- Unidades de Investigacion Medica en Bioquimica y Unidad de Epidemiologia Clinica, Hospital de Especialidades, Centro Medico Nacional "Siglo XXI," Instituto Mexicano del Seguro Social, Mexico City, CP 06720, Mexico
| | - Craig L Hanis
- Human Genetics Center, University of Texas Health Science Center at Houston, Houston, TX 77225, USA
| | - Nancy J Cox
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA.
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Pereira S, Park E, Mori Y, Haber CA, Han P, Uchida T, Stavar L, Oprescu AI, Koulajian K, Ivovic A, Yu Z, Li D, Bowman TA, Dewald J, El-Benna J, Brindley DN, Gutierrez-Juarez R, Lam TKT, Najjar SM, McKay RA, Bhanot S, Fantus IG, Giacca A. FFA-induced hepatic insulin resistance in vivo is mediated by PKCδ, NADPH oxidase, and oxidative stress. Am J Physiol Endocrinol Metab 2014; 307:E34-46. [PMID: 24824652 PMCID: PMC4080148 DOI: 10.1152/ajpendo.00436.2013] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Fat-induced hepatic insulin resistance plays a key role in the pathogenesis of type 2 diabetes in obese individuals. Although PKC and inflammatory pathways have been implicated in fat-induced hepatic insulin resistance, the sequence of events leading to impaired insulin signaling is unknown. We used Wistar rats to investigate whether PKCδ and oxidative stress play causal roles in this process and whether this occurs via IKKβ- and JNK-dependent pathways. Rats received a 7-h infusion of Intralipid plus heparin (IH) to elevate circulating free fatty acids (FFA). During the last 2 h of the infusion, a hyperinsulinemic-euglycemic clamp with tracer was performed to assess hepatic and peripheral insulin sensitivity. An antioxidant, N-acetyl-L-cysteine (NAC), prevented IH-induced hepatic insulin resistance in parallel with prevention of decreased IκBα content, increased JNK phosphorylation (markers of IKKβ and JNK activation, respectively), increased serine phosphorylation of IRS-1 and IRS-2, and impaired insulin signaling in the liver without affecting IH-induced hepatic PKCδ activation. Furthermore, an antisense oligonucleotide against PKCδ prevented IH-induced phosphorylation of p47(phox) (marker of NADPH oxidase activation) and hepatic insulin resistance. Apocynin, an NADPH oxidase inhibitor, prevented IH-induced hepatic and peripheral insulin resistance similarly to NAC. These results demonstrate that PKCδ, NADPH oxidase, and oxidative stress play a causal role in FFA-induced hepatic insulin resistance in vivo and suggest that the pathway of FFA-induced hepatic insulin resistance is FFA → PKCδ → NADPH oxidase and oxidative stress → IKKβ/JNK → impaired hepatic insulin signaling.
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Affiliation(s)
- Sandra Pereira
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Edward Park
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Yusaku Mori
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - C Andrew Haber
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Ping Han
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Toyoyoshi Uchida
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Laura Stavar
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and
| | - Andrei I Oprescu
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Khajag Koulajian
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Alexander Ivovic
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Zhiwen Yu
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and
| | - Deling Li
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and
| | - Thomas A Bowman
- Center for Diabetes and Endocrine Research and the Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio; and
| | - Jay Dewald
- Metabolic and Cardiovascular Diseases Laboratory, Alberta Institute for Human Nutrition, University of Alberta, Edmonton, Alberta, Canada
| | - Jamel El-Benna
- Inserm, U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France; Laboratoire d'Excellence Inflamex, Faculté de Médecine, Université Paris Diderot, Sorbonne Paris Cité, Site Xavier Bichat, Paris, France
| | - David N Brindley
- Metabolic and Cardiovascular Diseases Laboratory, Alberta Institute for Human Nutrition, University of Alberta, Edmonton, Alberta, Canada
| | - Roger Gutierrez-Juarez
- Department of Medicine, Diabetes Research Center, Albert Einstein College of Medicine, Bronx, New York
| | - Tony K T Lam
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Sonia M Najjar
- Center for Diabetes and Endocrine Research and the Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio; and
| | | | | | - I George Fantus
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and
| | - Adria Giacca
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada;
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Abstract
Pancreatic β-cell function is of critical importance in the regulation of fuel homoeostasis, and metabolic dysregulation is a hallmark of diabetes mellitus (DM). The β-cell is an intricately designed cell type that couples metabolism of dietary sources of carbohydrates, amino acids and lipids to insulin secretory mechanisms, such that insulin release occurs at appropriate times to ensure efficient nutrient uptake and storage by target tissues. However, chronic exposure to high nutrient concentrations results in altered metabolism that impacts negatively on insulin exocytosis, insulin action and may ultimately lead to development of DM. Reduced action of insulin in target tissues is associated with impairment of insulin signalling and contributes to insulin resistance (IR), a condition often associated with obesity and a major risk factor for DM. The altered metabolism of nutrients by insulin-sensitive target tissues (muscle, adipose tissue and liver) can result in high circulating levels of glucose and various lipids, which further impact on pancreatic β-cell function, IR and progression of the metabolic syndrome. Here, we have considered the role played by the major nutrient groups, carbohydrates, amino acids and lipids, in mediating β-cell insulin secretion, while also exploring the interplay between amino acids and insulin action in muscle. We also focus on the effects of altered lipid metabolism in adipose tissue and liver resulting from activation of inflammatory processes commonly observed in DM pathophysiology. The aim of this review is to describe commonalities and differences in metabolism related to insulin secretion and action, pertinent to the development of DM.
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Affiliation(s)
- Philip Newsholme
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Vinicius Cruzat
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Frank Arfuso
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Kevin Keane
- School of Biomedical SciencesCHIRI Biosciences Research Precinct, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
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38
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Moreno MF, de Souza GIDMH, Hachul ACL, Dos Santos B, Okuda MH, Neto NIP, Boldarine VT, Esposito E, Ribeiro EB, do Nascimento CMDPO, Ganen ADP, Oyama LM. Coacervate whey protein improves inflammatory milieu in mice fed with high-fat diet. Nutr Metab (Lond) 2014; 11:15. [PMID: 24673809 PMCID: PMC3996175 DOI: 10.1186/1743-7075-11-15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 03/22/2014] [Indexed: 02/06/2023] Open
Abstract
Background Functional foods with bioactive properties may help in treat obesity, as they can lead to a decreased risks of inflammatory diseases. The aim of this study was to investigate the effects of chitosan coacervate whey protein on the proinflammatory processes in mice fed with high-fat diet. Methods Mice were divided into two groups receiving either a normolipidic or high-fat diet; the animals in each of the two diet groups were given a diet supplement of either coacervate (gavage, 36 mg protein/kg of body weight) or tap water for four weeks [groups: normolipidic diet plus water (C); normolipidic diet and coacervate (CC); high-fat diet and water (H); and high-fat diet and coacervate (HC)]. Results The high-fat diet promoted inflammation, possibly by decreased adiponectin/sum of adipose tissues ratio and increased phosphorylation of NF-κB p50. In HC we observed a positive correlation between IL-10 and TNF-α in mesenteric adipose tissue, retroperitoneal adipose tissue and liver tissue. We also observed a positive correlation between lipopolisaccharide with IL-10 in the liver tissue. Conclusions High-fat diet treatment promoted metabolic alterations and inflammation, and chitosan coacervate whey protein modulated inflammatory milieu.
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Affiliation(s)
- Mayara Franzoi Moreno
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | | | - Ana Claudia Losinskas Hachul
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Bruno Dos Santos
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Marcos Hiromu Okuda
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Nelson Inácio Pinto Neto
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Valter Tadeu Boldarine
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Elisa Esposito
- Instituto de Ciências e Tecnologia da Universidade Federal de São Paulo, São José dos Campos, SP, Brazil
| | - Eliane Beraldi Ribeiro
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | | | - Aline de Piano Ganen
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Lila Missae Oyama
- Departamento de Fisiologia, Disciplina de Fisiologia da Nutrição, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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Abstract
Regulation of metabolic fuel homeostasis is a critical function of β-cells, which are located in the islets of Langerhans of the animal pancreas. Impairment of this β-cell function is a hallmark of pancreatic β-cell failure and may lead to development of type 2 diabetes mellitus. β-Cells are essentially "fuel sensors" that monitor and react to elevated nutrient load by releasing insulin. This response involves metabolic activation and generation of metabolic coupling factors (MCFs) that relay the nutrient signal throughout the cell and induce insulin biosynthesis and secretion. Glucose is the most important insulin secretagogue as it is the primary fuel source in food. Glucose metabolism is central to generation of MCFs that lead to insulin release, most notably ATP. In addition, other classes of nutrients are able to augment insulin secretion and these include members of the lipid and amino acid family of nutrients. Therefore, it is important to investigate the interplay between glucose, lipid, and amino acid metabolism, as it is this mixed nutrient sensing that generate the MCFs required for insulin exocytosis. The mechanisms by which these nutrients are metabolized to generate MCFs, and how they impact on β-cell insulin release and function, are discussed in detail in this article.
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Affiliation(s)
- Kevin Keane
- School of Biomedical Sciences, CHIRI Biosciences Research Precinct, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Philip Newsholme
- School of Biomedical Sciences, CHIRI Biosciences Research Precinct, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia.
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Frohnert BI, Jacobs DR, Steinberger J, Moran A, Steffen LM, Sinaiko AR. Relation between serum free fatty acids and adiposity, insulin resistance, and cardiovascular risk factors from adolescence to adulthood. Diabetes 2013; 62:3163-9. [PMID: 23670973 PMCID: PMC3749355 DOI: 10.2337/db12-1122] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The objective of this study was to describe longitudinal relations of serum total free fatty acids (FFAs) to insulin resistance (IR) and cardiovascular (CV) risk factors from adolescence into adulthood. The cohort included participants in a longitudinal study of obesity and IR with complete data, including anthropometric measures, FFAs, IR measured by euglycemic clamp, blood pressure, fasting serum lipids, and insulin at mean 15 and 22 years of age (n = 207) and their parents (n = 272). FFAs and IR were not significantly related at mean 15 years of age but were significantly related at mean age 22 years. FFA did not relate to BMI at either age. FFA at 15 years of age estimated IR at 22 years of age. In parents (mean age 51 years), FFA was significantly correlated with BMI, percent body fat, systolic blood pressure, LDL, and IR. Associations with all risk factors except IR in parents were attenuated by adjustment for BMI. Most 22 years of age correlations with parents were higher than corresponding 15 years of age correlations. This study finds that FFA is associated with IR starting in young adulthood. The relation between FFA and CV risk factors does not become significant until later adulthood. The results support a significant impact of early metabolic dysfunction on later CV risk.
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Affiliation(s)
- Brigitte I Frohnert
- Department of Pediatrics, Medical School, University of Minnesota, Minneapolis, Minnesota, USA.
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Asrih M, Jornayvaz FR. Inflammation as a potential link between nonalcoholic fatty liver disease and insulin resistance. J Endocrinol 2013; 218:R25-36. [PMID: 23833274 DOI: 10.1530/joe-13-0201] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) has become a major health problem in developed countries. It has affected more than 30% of the general population and is commonly associated with insulin resistance, which is a major risk factor for the development of type 2 diabetes and a central feature of the metabolic syndrome. Furthermore, accumulating evidences reveal that NAFLD as well as insulin resistance is strongly related to inflammation. Cytokines and adipokines play a pivotal role in inflammatory processes. In addition, these inflammatory mediators regulate various functions including metabolic energy balance, inflammation, and immune response. However, their role in modulating ectopic lipids involved in the development of insulin resistance, such as diacylglycerols and ceramides, remains unknown. The aim of this review is first to describe the pathophysiology of insulin resistance in NAFLD. In particular, we discuss the role of ectopic lipid accumulation in the liver. Secondly, we also summarize recent findings emphasizing the role of main inflammatory markers in both NAFLD and insulin resistance and their potential role in modulating hepatic fat content in NAFLD and associated hepatic insulin resistance.
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Affiliation(s)
- Mohamed Asrih
- Service of Endocrinology, Diabetes, Hypertension and Nutrition, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211 Genève 14, Switzerland
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Michaliszyn SF, Bonadonna RC, Sjaarda LA, Lee S, Farchoukh L, Arslanian SA. β-Cell lipotoxicity in response to free fatty acid elevation in prepubertal youth: African American versus Caucasian contrast. Diabetes 2013; 62:2917-22. [PMID: 23557704 PMCID: PMC3717834 DOI: 10.2337/db12-1664] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Prepubertal African American (AA) youth compared with their Caucasian (C) peers have higher insulin secretion, which correlates positively with free fatty acid (FFA) concentration. In our continued efforts to explain the racial disparity in insulinemia, and because FFAs modulate insulin secretion, we hypothesized that AA youth would have a greater response to FFA-induced β-cell insulin secretion than C youth. We compared the short-term effects of FFA elevation on fasting and glucose-stimulated C-peptide-modeled insulin secretion in prepubertal normal-weight AA versus C peers during a 2-h hyperglycemic clamp (12.5 mmol/L) on two occasions: 1) infusion of normal saline and 2) infusion of 20% intralipid (IL). During IL infusion, insulin sensitivity (IS) declined comparably in AA and C youth. Glucose sensitivity of first- and second-phase insulin secretion showed a significant condition × race interaction being higher in AA youth. Disposition index, β-cell function relative to IS, declined with IL infusion in AA and C youth, with a significantly greater decrease in Cs compared with AAs. In conclusion, AA and C prepubertal youth both demonstrated a decline in β-cell function relative to IS during IL infusion, indicative of acute lipotoxicity. The greater decline in C youth compared with AAs may suggest that C youth are more susceptible to β-cell lipotoxicity than AA youth, or alternatively, that AA youth are hypersensitive to FFA stimulation of β-cell insulin secretion, consistent with our theory.
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Affiliation(s)
- Sara F. Michaliszyn
- Division of Weight Management, Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Riccardo C. Bonadonna
- Division of Endocrinology and Metabolic Disease, University of Verona School of Medicine, and Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Lindsey A. Sjaarda
- Eunice Kennedy Shriver National Institute of Child Health & Human Development, National Institutes of Health, Bethesda, Maryland
| | - SoJung Lee
- Division of Weight Management, Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Lama Farchoukh
- Division of Weight Management, Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Silva A. Arslanian
- Division of Weight Management, Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
- Division of Pediatric Endocrinology, Metabolism & Diabetes Mellitus, Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Silva A. Arslanian,
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Lebovitz HE, Ludvik B, Yaniv I, Haddad W, Schwartz T, Aviv R. Fasting plasma triglycerides predict the glycaemic response to treatment of type 2 diabetes by gastric electrical stimulation. A novel lipotoxicity paradigm. Diabet Med 2013; 30:687-93. [PMID: 23323566 PMCID: PMC3709131 DOI: 10.1111/dme.12132] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 11/12/2012] [Accepted: 01/10/2013] [Indexed: 12/31/2022]
Abstract
BACKGROUND Non-stimulatory, meal-mediated electrical stimulation of the stomach (TANTALUS-DIAMOND) improves glycaemic control and causes modest weight loss in patients with Type 2 diabetes who are inadequately controlled on oral anti-diabetic medications. The magnitude of the glycaemic response in clinical studies has been variable. A preliminary analysis of data from patients who had completed 6 months of treatment indicated that the glycaemic response to the electrical stimulation was inversely related to the baseline fasting plasma triglyceride level. METHOD An analysis of 40 patients who had had detailed longitudinal studies for 12 months. RESULTS Twenty-two patients with fasting plasma triglycerides ≤ 1.7 mmol/l had mean decreases in HbA1c after 3, 6 and 12 months of gastric contraction modulation treatment of -15 ± 2.1 mmol/mol (-1.39 ± 0.20%), -16 ± 2.2 mmol/mol (-1.48 ± 0.20%) and -14 ± 3.0 mmol/mol (-1.31 ± 0.26%), respectively. In contrast, 18 patients with fasting plasma triglyceride > 1.7 mmol/l had mean decreases in HbA1c of -7 ± 1.7 mmol/mol (-0.66 ± 0.16%), -5 ± 1.6 mmol/mol (-0.44 ± 0.18%) and -5 ± 1.7 mmol/mol (-0.42 ± 0.16%), respectively. Pearson's correlation coefficient between fasting plasma triglyceride and decreases in HbA1c at 12 months of treatment was 0.34 (P < 0.05). Homeostasis model assessment of insulin resistance was unchanged during 12 months of treatment in patients with high baseline fasting triglycerides, while it progressively improved in patients with low fasting plasma triglycerides. Patients with low fasting plasma triglycerides had a tendency to lose more weight than those with high fasting plasma triglycerides, but this did not achieve statistical significance. CONCLUSIONS The data presented suggest the existence of a triglyceride lipotoxic mechanism that interferes with gastric/neural mediated pathways that can regulate glycaemic control in patients with type 2 diabetes. The data suggest the existence of a triglyceride lipotoxic pathway that interferes with gastric/neural mediated pathways that can regulate glycaemic control.
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Affiliation(s)
- H E Lebovitz
- Department of Medicine, State University of New York Health Science Center at Brooklyn, Brooklyn, NY, USA.
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Wagner R, Kaiser G, Gerst F, Christiansen E, Due-Hansen ME, Grundmann M, Machicao F, Peter A, Kostenis E, Ulven T, Fritsche A, Häring HU, Ullrich S. Reevaluation of fatty acid receptor 1 as a drug target for the stimulation of insulin secretion in humans. Diabetes 2013; 62:2106-11. [PMID: 23378609 PMCID: PMC3661642 DOI: 10.2337/db12-1249] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The role of free fatty acid receptor 1 (FFAR1/GPR40) in glucose homeostasis is still incompletely understood. Small receptor agonists stimulating insulin secretion are undergoing investigation for the treatment of type 2 diabetes. Surprisingly, genome-wide association studies did not discover diabetes risk variants in FFAR1. We reevaluated the role of FFAR1 in insulin secretion using a specific agonist, FFAR1-knockout mice and human islets. Nondiabetic individuals were metabolically phenotyped and genotyped. In vitro experiments indicated that palmitate and a specific FFAR1 agonist, TUG-469, stimulate glucose-induced insulin secretion through FFAR1. The proapoptotic effect of chronic exposure of β-cells to palmitate was independent of FFAR1. TUG-469 was protective, whereas inhibition of FFAR1 promoted apoptosis. In accordance with the proapoptotic effect of palmitate, in vivo cross-sectional observations demonstrated a negative association between fasting free fatty acids (NEFAs) and insulin secretion. Because NEFAs stimulate secretion through FFAR1, we examined the interaction of genetic variation in FFAR1 with NEFA and insulin secretion. The inverse association of NEFA and secretion was modulated by rs1573611 and became steeper for carriers of the minor allele. In conclusion, FFAR1 agonists support β-cell function, but variation in FFAR1 influences NEFA effects on insulin secretion and therefore could affect therapeutic efficacy of FFAR1 agonists.
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Affiliation(s)
- Robert Wagner
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholz Centre Munich at the University of Tübingen, Partner in the German Center for Diabetes Research, Tübingen, Germany
| | - Gabriele Kaiser
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
| | - Felicia Gerst
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholz Centre Munich at the University of Tübingen, Partner in the German Center for Diabetes Research, Tübingen, Germany
| | - Elisabeth Christiansen
- University of Southern Denmark, Department of Physics, Chemistry and Pharmacy, Odense M, Denmark
| | - Maria E. Due-Hansen
- University of Southern Denmark, Department of Physics, Chemistry and Pharmacy, Odense M, Denmark
| | - Manuel Grundmann
- University of Bonn, Institute for Pharmaceutical Biology, Bonn, Germany
| | - Fausto Machicao
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholz Centre Munich at the University of Tübingen, Partner in the German Center for Diabetes Research, Tübingen, Germany
| | - Andreas Peter
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholz Centre Munich at the University of Tübingen, Partner in the German Center for Diabetes Research, Tübingen, Germany
| | - Evi Kostenis
- University of Bonn, Institute for Pharmaceutical Biology, Bonn, Germany
| | - Trond Ulven
- University of Southern Denmark, Department of Physics, Chemistry and Pharmacy, Odense M, Denmark
| | - Andreas Fritsche
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholz Centre Munich at the University of Tübingen, Partner in the German Center for Diabetes Research, Tübingen, Germany
| | - Hans-Ulrich Häring
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholz Centre Munich at the University of Tübingen, Partner in the German Center for Diabetes Research, Tübingen, Germany
| | - Susanne Ullrich
- University of Tübingen, Department of Internal Medicine IV, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholz Centre Munich at the University of Tübingen, Partner in the German Center for Diabetes Research, Tübingen, Germany
- Corresponding author: Susanne Ullrich,
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Hughan KS, Bonadonna RC, Lee S, Michaliszyn SF, Arslanian SA. β-Cell lipotoxicity after an overnight intravenous lipid challenge and free fatty acid elevation in African American versus American white overweight/obese adolescents. J Clin Endocrinol Metab 2013; 98:2062-9. [PMID: 23526462 PMCID: PMC3644601 DOI: 10.1210/jc.2012-3492] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Overweight/obese (OW/OB) African American (AA) adolescents have a more diabetogenic insulin secretion/sensitivity pattern compared with their American white (AW) peers. The present study investigated β-cell lipotoxicity to test whether increased free fatty acid (FFA) levels result in greater β-cell dysfunction in AA vs AW OW/OB adolescents. RESEARCH DESIGN AND METHODS Glucose-stimulated insulin secretion was modeled, from glucose and C-peptide concentrations during a 2-hour hyperglycemic (225 mg/dL) clamp in 22 AA and 24 AW OW/OB adolescents, on 2 occasions after a 12-hour overnight infusion of either normal saline or intralipid (IL) in a random sequence. β-Cell function relative to insulin sensitivity, the disposition index (DI), was examined during normal saline and IL conditions. Substrate oxidation was evaluated with indirect calorimetry and body composition and abdominal adiposity with dual-energy X-ray absorptiometry and magnetic resonance imaging at L4-L5, respectively. RESULTS Age, sex, body mass index, total and sc adiposity were similar between racial groups, but visceral adiposity was significantly lower in AAs. During IL infusion, FFAs and fat oxidation increased and insulin sensitivity decreased similarly in AAs and AWs. β-Cell glucose sensitivity of first- and second-phase insulin secretion did not change significantly during IL infusion in either group, but DI in each phase decreased significantly and similarly in AAs and AWs. CONCLUSIONS Overweight/obese AA and AW adolescents respond to an overnight fat infusion with significant declines in insulin sensitivity, DI, and β-cell function relative to insulin sensitivity, suggestive of β-cell lipotoxicity. However, contrary to our hypothesis, there does not seem to be a race differential in β-cell lipotoxicity. Longer durations of FFA elevation may unravel such race-related contrasts.
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Affiliation(s)
- Kara S Hughan
- Division of Weight Management and Wellness, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15224, USA
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Anti-diabetic effect of amorphastilbol through PPARα/γ dual activation in db/db mice. Biochem Biophys Res Commun 2013; 432:73-9. [DOI: 10.1016/j.bbrc.2013.01.083] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 01/16/2013] [Indexed: 01/31/2023]
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Estadella D, da Penha Oller do Nascimento CM, Oyama LM, Ribeiro EB, Dâmaso AR, de Piano A. Lipotoxicity: effects of dietary saturated and transfatty acids. Mediators Inflamm 2013; 2013:137579. [PMID: 23509418 PMCID: PMC3572653 DOI: 10.1155/2013/137579] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 12/19/2012] [Accepted: 12/19/2012] [Indexed: 01/18/2023] Open
Abstract
The ingestion of excessive amounts of saturated fatty acids (SFAs) and transfatty acids (TFAs) is considered to be a risk factor for cardiovascular diseases, insulin resistance, dyslipidemia, and obesity. The focus of this paper was to elucidate the influence of dietary SFA and TFA intake on the promotion of lipotoxicity to the liver and cardiovascular, endothelial, and gut microbiota systems, as well as on insulin resistance and endoplasmic reticulum stress. The saturated and transfatty acids favor a proinflammatory state leading to insulin resistance. These fatty acids can be involved in several inflammatory pathways, contributing to disease progression in chronic inflammation, autoimmunity, allergy, cancer, atherosclerosis, hypertension, and heart hypertrophy as well as other metabolic and degenerative diseases. As a consequence, lipotoxicity may occur in several target organs by direct effects, represented by inflammation pathways, and through indirect effects, including an important alteration in the gut microbiota associated with endotoxemia. Interactions between these pathways may perpetuate a feedback process that exacerbates an inflammatory state. The importance of lifestyle modification, including an improved diet, is recommended as a strategy for treatment of these diseases.
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Affiliation(s)
- Débora Estadella
- Programa de Pós-Graduação em Nutrição, Disciplina de Fisiologia da Nutrição, EPM, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu, 862 Edifício de Ciências Biomédicas, 2 andar, Vila Clementino, 04023-060 São Paulo, SP, Brazil
| | - Claudia M. da Penha Oller do Nascimento
- Programa de Pós-Graduação em Nutrição, Disciplina de Fisiologia da Nutrição, EPM, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu, 862 Edifício de Ciências Biomédicas, 2 andar, Vila Clementino, 04023-060 São Paulo, SP, Brazil
| | - Lila M. Oyama
- Programa de Pós-Graduação em Nutrição, Disciplina de Fisiologia da Nutrição, EPM, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu, 862 Edifício de Ciências Biomédicas, 2 andar, Vila Clementino, 04023-060 São Paulo, SP, Brazil
| | - Eliane B. Ribeiro
- Programa de Pós-Graduação em Nutrição, Disciplina de Fisiologia da Nutrição, EPM, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu, 862 Edifício de Ciências Biomédicas, 2 andar, Vila Clementino, 04023-060 São Paulo, SP, Brazil
| | - Ana R. Dâmaso
- Departamento de Biociências, UNIFESP, Campus Baixada Santista, 11060-001 Santos, SP, Brazil
| | - Aline de Piano
- Programa de Pós-Graduação em Nutrição, Disciplina de Fisiologia da Nutrição, EPM, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu, 862 Edifício de Ciências Biomédicas, 2 andar, Vila Clementino, 04023-060 São Paulo, SP, Brazil
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49
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Tang C, Naassan AE, Chamson-Reig A, Koulajian K, Goh TT, Yoon F, Oprescu AI, Ghanim H, Lewis GF, Dandona P, Donath MY, Ehses JA, Arany E, Giacca A. Susceptibility to fatty acid-induced β-cell dysfunction is enhanced in prediabetic diabetes-prone biobreeding rats: a potential link between β-cell lipotoxicity and islet inflammation. Endocrinology 2013; 154:89-101. [PMID: 23150493 DOI: 10.1210/en.2012-1720] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
β-Cell lipotoxicity is thought to play an important role in the development of type 2 diabetes. However, no study has examined its role in type 1 diabetes, which could be clinically relevant for slow-onset type 1 diabetes. Reports of enhanced cytokine toxicity in fat-laden islets are consistent with the hypothesis that lipid and cytokine toxicity may be synergistic. Thus, β-cell lipotoxicity could be enhanced in models of autoimmune diabetes. To determine this, we examined the effects of prolonged free fatty acids elevation on β-cell secretory function in the prediabetic diabetes-prone BioBreeding (dp-BB) rat, its diabetes-resistant BioBreeding (dr-BB) control, and normal Wistar-Furth (WF) rats. Rats received a 48-h iv infusion of saline or Intralipid plus heparin (IH) (to elevate free fatty acid levels ~2-fold) followed by hyperglycemic clamp or islet secretion studies ex vivo. IH significantly decreased β-cell function, assessed both by the disposition index (insulin secretion corrected for IH-induced insulin resistance) and in isolated islets, in dp-BB, but not in dr-BB or WF, rats, and the effect of IH was inhibited by the antioxidant N-acetylcysteine. Furthermore, IH significantly increased islet cytokine mRNA and plasma cytokine levels (monocyte chemoattractant protein-1 and IL-10) in dp-BB, but not in dr-BB or WF, rats. All dp-BB rats had mononuclear infiltration of islets, which was absent in dr-BB and WF rats. In conclusion, the presence of insulitis was permissive for IH-induced β-cell dysfunction in the BB rat, which suggests a link between β-cell lipotoxicity and islet inflammation.
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Affiliation(s)
- Christine Tang
- Department of Physiology, University of Toronto, Room 3336, Medical Sciences Building, Toronto, Ontario, Canada M5S 1A8
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50
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Dobson CC, Mongillo DL, Brien DC, Stepita R, Poklewska-Koziell M, Winterborn A, Holloway AC, Brien JF, Reynolds JN. Chronic prenatal ethanol exposure increases adiposity and disrupts pancreatic morphology in adult guinea pig offspring. Nutr Diabetes 2012; 2:e57. [PMID: 23247731 PMCID: PMC3542435 DOI: 10.1038/nutd.2012.31] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: Ethanol consumption during pregnancy can lead to a range of adverse developmental outcomes in children, termed fetal alcohol spectrum disorder (FASD). Central nervous system injury is a debilitating and widely studied manifestation of chronic prenatal ethanol exposure (CPEE). However, CPEE can also cause structural and functional deficits in metabolic pathways in offspring. Objectives and Methods: This study tested the hypothesis that CPEE increases whole-body adiposity and disrupts pancreatic structure in guinea pig offspring. Pregnant guinea pigs received ethanol (4 g kg−1 maternal body weight per day) or isocaloric-sucrose/pair-feeding (control) for 5 days per week throughout gestation. Results: Male and female CPEE offspring demonstrated growth restriction at birth, followed by a rapid period of catch-up growth before weaning (postnatal day (PD) 1–7). Whole-body magnetic resonance imaging (MRI) in young adult offspring (PD100–140) revealed increased visceral and subcutaneous adiposity produced by CPEE. At the time of killing (PD150–200), CPEE offspring also had increased pancreatic adipocyte area and decreased β-cell insulin-like immunopositive area, suggesting reduced insulin production and/or secretion from pancreatic islets. Conclusion: CPEE causes increased adiposity and pancreatic dysmorphology in offspring, which may signify increased risk for the development of metabolic syndrome and type 2 diabetes mellitus.
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Affiliation(s)
- C C Dobson
- Department of Biomedical and Molecular Sciences, Pharmacology and Toxicology Graduate Program, Queen's University, Kingston, Ontario, Canada
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