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Zhang Y, Tsai TH, Ezrokhi M, Stoelzel C, Cincotta AH. Tyrosine Hydroxylase Knockdown at the Hypothalamic Supramammillary Nucleus Area Induces Obesity and Glucose Intolerance. Neuroendocrinology 2023; 114:483-510. [PMID: 38128505 PMCID: PMC11098027 DOI: 10.1159/000535944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 12/14/2023] [Indexed: 12/23/2023]
Abstract
INTRODUCTION The supramammillary nucleus (SuMN) exerts influences on a wide range of brain functions including feeding and feeding-independent fuel metabolism. However, which specific neuronal type(s) within the SuMN manifest this influence has not been delineated. This study investigated the effect of SuMN tyrosine hydroxylase (TH) (rate-limiting enzyme in dopamine synthesis) knockdown (THx) on peripheral fuel metabolism. METHODS SuMN-THx was accomplished using a virus-mediated shRNA to locally knockdown TH gene expression at the SuMN. The impact of SuMN-THx was examined over 35-72 days in rats least prone to developing metabolic syndrome (MS) - female Sprague-Dawley rats resistant to the obesogenic effect of high fat diet (HFDr) and fed regular chow (RC) - upon body weight/fat, feeding, glucose tolerance, and insulin sensitivity. The influence of HFD, gender, and long-term response of SuMN-THx was subsequently investigated in female HFDr rats fed HFD, male HFDr rats fed RC, and female HFD-sensitive rats fed RC over 1 year, respectively. RESULTS SuMN-THx induced obesity and glucose intolerance, elevated plasma leptin and triglycerides, increased hepatic mRNA levels of gluconeogenic, lipogenic, and pro-inflammatory genes, reduced white adipose fatty acid oxidation rate, and altered plasma corticosterone level and hepatic circadian gene expression. Moreover, SuMN-THx increased feeding during the natural resting/fasting period and altered ghrelin feeding response suggesting ghrelin resistance. This MS-inducing effect was enhanced by HFD feeding, similarly observed in male rats and persisted over 1 year. DISCUSSION/CONCLUSION SuMN-THx induced long-term, gender-nonspecific, multiple pathophysiological changes leading to MS suggesting SuMN dopaminergic circuits communicating with other brain metabolism and behavior control centers modulate peripheral fuel metabolism.
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Cincotta AH. Brain Dopamine-Clock Interactions Regulate Cardiometabolic Physiology: Mechanisms of the Observed Cardioprotective Effects of Circadian-Timed Bromocriptine-QR Therapy in Type 2 Diabetes Subjects. Int J Mol Sci 2023; 24:13255. [PMID: 37686060 PMCID: PMC10487918 DOI: 10.3390/ijms241713255] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 09/10/2023] Open
Abstract
Despite enormous global efforts within clinical research and medical practice to reduce cardiovascular disease(s) (CVD), it still remains the leading cause of death worldwide. While genetic factors clearly contribute to CVD etiology, the preponderance of epidemiological data indicate that a major common denominator among diverse ethnic populations from around the world contributing to CVD is the composite of Western lifestyle cofactors, particularly Western diets (high saturated fat/simple sugar [particularly high fructose and sucrose and to a lesser extent glucose] diets), psychosocial stress, depression, and altered sleep/wake architecture. Such Western lifestyle cofactors are potent drivers for the increased risk of metabolic syndrome and its attendant downstream CVD. The central nervous system (CNS) evolved to respond to and anticipate changes in the external (and internal) environment to adapt survival mechanisms to perceived stresses (challenges to normal biological function), including the aforementioned Western lifestyle cofactors. Within the CNS of vertebrates in the wild, the biological clock circuitry surveils the environment and has evolved mechanisms for the induction of the obese, insulin-resistant state as a survival mechanism against an anticipated ensuing season of low/no food availability. The peripheral tissues utilize fat as an energy source under muscle insulin resistance, while increased hepatic insulin resistance more readily supplies glucose to the brain. This neural clock function also orchestrates the reversal of the obese, insulin-resistant condition when the low food availability season ends. The circadian neural network that produces these seasonal shifts in metabolism is also responsive to Western lifestyle stressors that drive the CNS clock into survival mode. A major component of this natural or Western lifestyle stressor-induced CNS clock neurophysiological shift potentiating the obese, insulin-resistant state is a diminution of the circadian peak of dopaminergic input activity to the pacemaker clock center, suprachiasmatic nucleus. Pharmacologically preventing this loss of circadian peak dopaminergic activity both prevents and reverses existing metabolic syndrome in a wide variety of animal models of the disorder, including high fat-fed animals. Clinically, across a variety of different study designs, circadian-timed bromocriptine-QR (quick release) (a unique formulation of micronized bromocriptine-a dopamine D2 receptor agonist) therapy of type 2 diabetes subjects improved hyperglycemia, hyperlipidemia, hypertension, immune sterile inflammation, and/or adverse cardiovascular event rate. The present review details the seminal circadian science investigations delineating important roles for CNS circadian peak dopaminergic activity in the regulation of peripheral fuel metabolism and cardiovascular biology and also summarizes the clinical study findings of bromocriptine-QR therapy on cardiometabolic outcomes in type 2 diabetes subjects.
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Civelek E, Ozturk Civelek D, Akyel YK, Kaleli Durman D, Okyar A. Circadian Dysfunction in Adipose Tissue: Chronotherapy in Metabolic Diseases. BIOLOGY 2023; 12:1077. [PMID: 37626963 PMCID: PMC10452180 DOI: 10.3390/biology12081077] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023]
Abstract
Essential for survival and reproduction, the circadian timing system (CTS) regulates adaptation to cyclical changes such as the light/dark cycle, temperature change, and food availability. The regulation of energy homeostasis possesses rhythmic properties that correspond to constantly fluctuating needs for energy production and consumption. Adipose tissue is mainly responsible for energy storage and, thus, operates as one of the principal components of energy homeostasis regulation. In accordance with its roles in energy homeostasis, alterations in adipose tissue's physiological processes are associated with numerous pathologies, such as obesity and type 2 diabetes. These alterations also include changes in circadian rhythm. In the current review, we aim to summarize the current knowledge regarding the circadian rhythmicity of adipogenesis, lipolysis, adipokine secretion, browning, and non-shivering thermogenesis in adipose tissue and to evaluate possible links between those alterations and metabolic diseases. Based on this evaluation, potential therapeutic approaches, as well as clock genes as potential therapeutic targets, are also discussed in the context of chronotherapy.
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Affiliation(s)
- Erkan Civelek
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, 34116 Istanbul, Turkey; (E.C.); (D.K.D.)
| | - Dilek Ozturk Civelek
- Department of Pharmacology, Faculty of Pharmacy, Bezmialem Vakıf University, 34093 Istanbul, Turkey;
| | - Yasemin Kubra Akyel
- Department of Medical Pharmacology, School of Medicine, Istanbul Medipol University, 34815 Istanbul, Turkey;
| | - Deniz Kaleli Durman
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, 34116 Istanbul, Turkey; (E.C.); (D.K.D.)
| | - Alper Okyar
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, 34116 Istanbul, Turkey; (E.C.); (D.K.D.)
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Birhan MT, Ayele TM, Abebe FW, Dgnew FN. Effect of bromocriptine on glycemic control, risk of cardiovascular diseases and weight in patients with type 2 diabetes: a systematic review. Diabetol Metab Syndr 2023; 15:151. [PMID: 37415177 DOI: 10.1186/s13098-023-01073-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/29/2023] [Indexed: 07/08/2023] Open
Abstract
BACKGROUND Type 2 diabetes (T2DM) patients, including those in good glycemic control, have an increased risk of cardiovascular disease (CVD). Maintaining good glycemic control with drugs may reduce long-term CVD risk. Bromocriptine has been in clinical use for over 30 years, but the utility of bromocriptine in the treatment of diabetes patients has been proposed more recently. OBJECTIVE To summarize the available data regarding the effect of bromocriptine in T2DM management. METHOD A systematic literature search was conducted in the electronic databases, including Google Scholar, PubMed, Medline, and Science Direct, to locate studies that meet the objectives of this systematic review. Additional articles were included by conducting direct Google searches of the references cited by eligible articles located by the database search. The following search terms were used on PubMed "bromocriptine OR dopamine agonist AND diabetes mellitus OR hyperglycemia OR obese". RESULT Eight studies were included in the final analysis. 6210 of the 9391 study participants received bromocriptine treatment, while 3183 received a placebo. The studies demonstrated that patients who took bromocriptine treatment had significantly reduced blood glucose and BMI, which is the main cardiovascular risk factor in T2DM patients. CONCLUSION Based on this systematic review, bromocriptine may be used for T2DM treatment for its cardiovascular risk reduction effect, especially body weight reduction. However, advanced study designs might be warranted.
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Affiliation(s)
- Mulualem Tesfaye Birhan
- Department of Pharmacy, College of Health Science, Debre Tabor University, P.O.Box:272, Debre Tabor, 6300, Ethiopia
| | - Teklie Mengie Ayele
- Department of Pharmacy, College of Health Science, Debre Tabor University, P.O.Box:272, Debre Tabor, 6300, Ethiopia.
| | - Fikire Wondimu Abebe
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of health sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Fiseha Nigussie Dgnew
- Department of Pharmacy, College of Health Science, Debre Tabor University, P.O.Box:272, Debre Tabor, 6300, Ethiopia
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Hariri A, Mirian M, Zarrabi A, Kohandel M, Amini-Pozveh M, Aref AR, Tabatabaee A, Prabhakar PK, Sivakumar PM. The circadian rhythm: an influential soundtrack in the diabetes story. Front Endocrinol (Lausanne) 2023; 14:1156757. [PMID: 37441501 PMCID: PMC10333930 DOI: 10.3389/fendo.2023.1156757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/03/2023] [Indexed: 07/15/2023] Open
Abstract
Type 2 Diabetes Mellitus (T2DM) has been the main category of metabolic diseases in recent years due to changes in lifestyle and environmental conditions such as diet and physical activity. On the other hand, the circadian rhythm is one of the most significant biological pathways in humans and other mammals, which is affected by light, sleep, and human activity. However, this cycle is controlled via complicated cellular pathways with feedback loops. It is widely known that changes in the circadian rhythm can alter some metabolic pathways of body cells and could affect the treatment process, particularly for metabolic diseases like T2DM. The aim of this study is to explore the importance of the circadian rhythm in the occurrence of T2DM via reviewing the metabolic pathways involved, their relationship with the circadian rhythm from two perspectives, lifestyle and molecular pathways, and their effect on T2DM pathophysiology. These impacts have been demonstrated in a variety of studies and led to the development of approaches such as time-restricted feeding, chronotherapy (time-specific therapies), and circadian molecule stabilizers.
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Affiliation(s)
- Amirali Hariri
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mina Mirian
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ali Zarrabi
- Department of Biomedical Engineering, Faculty of Engineering and Natural Sciences, Istinye University, Istanbul, Türkiye
| | - Mohammad Kohandel
- Department of Applied Mathematics, Faculty of Mathematics, University of Waterloo, Waterloo, ON, Canada
| | - Maryam Amini-Pozveh
- Department of Prosthodontics Dentistry, Dental Materials Research Center, Dental Research Institute, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Amir Reza Aref
- Belfer Center for Applied Cancer Science, Dana Farber Cancer Institute, Boston, MA, United States
- Translational Sciences, Xsphera Biosciences Inc., Boston, MA, United States
| | - Aliye Tabatabaee
- School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Pranav Kumar Prabhakar
- Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Lovely Professional University, Phagwara, Punjab, India
- Division of Research and Development, Lovely Professional University, Phagwara Punjab, India
| | - Ponnurengam Malliappan Sivakumar
- Institute of Research and Development, Duy Tan University, Da Nang, Vietnam
- School of Medicine and Pharmacy, Duy Tan University, Da Nang, Vietnam
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Derkach KV, Sorokoumov VN, Bakhtyukov AA, Bondareva VM, Shpakov AO. Insulin and Leptin Levels in Blood and Brain Structures of Rats with Diet-Induced Obesity and the Effect of Various Drugs on Them. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022060187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Aslanoglou D, Bertera S, Friggeri L, Sánchez-Soto M, Lee J, Xue X, Logan RW, Lane JR, Yechoor VK, McCormick PJ, Meiler J, Free RB, Sibley DR, Bottino R, Freyberg Z. Dual pancreatic adrenergic and dopaminergic signaling as a therapeutic target of bromocriptine. iScience 2022; 25:104771. [PMID: 35982797 PMCID: PMC9379584 DOI: 10.1016/j.isci.2022.104771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/10/2022] [Accepted: 07/11/2022] [Indexed: 11/23/2022] Open
Abstract
Bromocriptine is approved as a diabetes therapy, yet its therapeutic mechanisms remain unclear. Though bromocriptine's actions have been mainly attributed to the stimulation of brain dopamine D2 receptors (D2R), bromocriptine also targets the pancreas. Here, we employ bromocriptine as a tool to elucidate the roles of catecholamine signaling in regulating pancreatic hormone secretion. In β-cells, bromocriptine acts on D2R and α2A-adrenergic receptor (α2A-AR) to reduce glucose-stimulated insulin secretion (GSIS). Moreover, in α-cells, bromocriptine acts via D2R to reduce glucagon secretion. α2A-AR activation by bromocriptine recruits an ensemble of G proteins with no β-arrestin2 recruitment. In contrast, D2R recruits G proteins and β-arrestin2 upon bromocriptine stimulation, demonstrating receptor-specific signaling. Docking studies reveal distinct bromocriptine binding to α2A-AR versus D2R, providing a structural basis for bromocriptine's dual actions on β-cell α2A-AR and D2R. Together, joint dopaminergic and adrenergic receptor actions on α-cell and β-cell hormone release provide a new therapeutic mechanism to improve dysglycemia.
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Affiliation(s)
- Despoina Aslanoglou
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Suzanne Bertera
- Institute of Cellular Therapeutics, Allegheny Health Network Research Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Laura Friggeri
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Marta Sánchez-Soto
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Jeongkyung Lee
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiangning Xue
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ryan W. Logan
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - J. Robert Lane
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, UK
- Centre of Membrane Protein and Receptors, Universities of Birmingham and Nottingham, Nottingham, UK
| | - Vijay K. Yechoor
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter J. McCormick
- Centre for Endocrinology, William Harvey Research Institute, Bart’s and the London School of Medicine and Dentistry, Queen Mary, University of London, London, UK
| | - Jens Meiler
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - R. Benjamin Free
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - David R. Sibley
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Rita Bottino
- Institute of Cellular Therapeutics, Allegheny Health Network Research Institute, Allegheny Health Network, Pittsburgh, PA, USA
- Imagine Pharma, Pittsburgh, PA, USA
| | - Zachary Freyberg
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, PA, USA
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Cincotta AH, Cersosimo E, Alatrach M, Ezrokhi M, Agyin C, Adams J, Chilton R, Triplitt C, Chamarthi B, Cominos N, DeFronzo RA. Bromocriptine-QR Therapy Reduces Sympathetic Tone and Ameliorates a Pro-Oxidative/Pro-Inflammatory Phenotype in Peripheral Blood Mononuclear Cells and Plasma of Type 2 Diabetes Subjects. Int J Mol Sci 2022; 23:ijms23168851. [PMID: 36012132 PMCID: PMC9407769 DOI: 10.3390/ijms23168851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
Bromocriptine-QR is a sympatholytic dopamine D2 agonist for the treatment of type 2 diabetes that has demonstrated rapid (within 1 year) substantial reductions in adverse cardiovascular events in this population by as yet incompletely delineated mechanisms. However, a chronic state of elevated sympathetic nervous system activity and central hypodopaminergic function has been demonstrated to potentiate an immune system pro-oxidative/pro-inflammatory condition and this immune phenotype is known to contribute significantly to the advancement of cardiovascular disease (CVD). Therefore, the possibility exists that bromocriptine-QR therapy may reduce adverse cardiovascular events in type 2 diabetes subjects via attenuation of this underlying chronic pro-oxidative/pro-inflammatory state. The present study was undertaken to assess the impact of bromocriptine-QR on a wide range of immune pro-oxidative/pro-inflammatory biochemical pathways and genes known to be operative in the genesis and progression of CVD. Inflammatory peripheral blood mononuclear cell biology is both a significant contributor to cardiovascular disease and also a marker of the body’s systemic pro-inflammatory status. Therefore, this study investigated the effects of 4-month circadian-timed (within 2 h of waking in the morning) bromocriptine-QR therapy (3.2 mg/day) in type 2 diabetes subjects whose glycemia was not optimally controlled on the glucagon-like peptide 1 receptor agonist on (i) gene expression status (via qPCR) of a wide array of mononuclear cell pro-oxidative/pro-inflammatory genes known to participate in the genesis and progression of CVD (OXR1, NRF2, NQO1, SOD1, SOD2, CAT, GSR, GPX1, GPX4, GCH1, HMOX1, BiP, EIF2α, ATF4, PERK, XBP1, ATF6, CHOP, GSK3β, NFkB, TXNIP, PIN1, BECN1, TLR2, TLR4, TLR10, MAPK8, NLRP3, CCR2, GCR, L-selectin, VCAM1, ICAM1) and (ii) humoral measures of sympathetic tone (norepinephrine and normetanephrine), whole-body oxidative stress (nitrotyrosine, TBARS), and pro-inflammatory factors (IL-1β, IL-6, IL-18, MCP-1, prolactin, C-reactive protein [CRP]). Relative to pre-treatment status, 4 months of bromocriptine-QR therapy resulted in significant reductions of mRNA levels in PBMC endoplasmic reticulum stress-unfolded protein response effectors [GRP78/BiP (34%), EIF2α (32%), ATF4 (29%), XBP1 (25%), PIN1 (14%), BECN1 (23%)], oxidative stress response proteins [OXR1 (31%), NRF2 (32%), NQO1 (39%), SOD1 (52%), CAT (26%), GPX1 (33%), GPX4 (31%), GCH1 (30%), HMOX1 (40%)], mRNA levels of TLR pro-inflammatory pathway proteins [TLR2 (46%), TLR4 (20%), GSK3β (19%), NFkB (33%), TXNIP (18%), NLRP3 (32%), CCR2 (24%), GCR (28%)], mRNA levels of pro-inflammatory cellular receptor proteins CCR2 and GCR by 24% and 28%, and adhesion molecule proteins L-selectin (35%) and VCAM1 (24%). Relative to baseline, bromocriptine-QR therapy also significantly reduced plasma levels of norepinephrine and normetanephrine by 33% and 22%, respectively, plasma pro-oxidative markers nitrotyrosine and TBARS by 13% and 10%, respectively, and pro-inflammatory factors IL-18, MCP1, IL-1β, prolactin, and CRP by 21%,13%, 12%, 42%, and 45%, respectively. These findings suggest a unique role for circadian-timed bromocriptine-QR sympatholytic dopamine agonist therapy in reducing systemic low-grade sterile inflammation to thereby reduce cardiovascular disease risk.
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Affiliation(s)
- Anthony H. Cincotta
- VeroScience LLC, Tiverton, RI 02878, USA
- Correspondence: ; Tel.: +1-401-816-0525
| | - Eugenio Cersosimo
- Texas Diabetes Institute, University Health System, San Antonio, TX 78207, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Mariam Alatrach
- Texas Diabetes Institute, University Health System, San Antonio, TX 78207, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | | | - Christina Agyin
- Texas Diabetes Institute, University Health System, San Antonio, TX 78207, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - John Adams
- Texas Diabetes Institute, University Health System, San Antonio, TX 78207, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Robert Chilton
- Texas Diabetes Institute, University Health System, San Antonio, TX 78207, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Curtis Triplitt
- Texas Diabetes Institute, University Health System, San Antonio, TX 78207, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | | | | | - Ralph A. DeFronzo
- Texas Diabetes Institute, University Health System, San Antonio, TX 78207, USA
- Division of Diabetes, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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Naz F, Malik A, Riaz M, Mahmood Q, Mehmood MH, Rasool G, Mahmood Z, Abbas M. Bromocriptine Therapy: Review of mechanism of action, safety and tolerability. Clin Exp Pharmacol Physiol 2022; 49:903-922. [DOI: 10.1111/1440-1681.13678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Faiza Naz
- Punjab University College of Pharmacy University of the Punjab Lahore Pakistan
| | - Abdul Malik
- College of Pharmacy University of Sargodha Sargodha Pakistan
| | - Muhammad Riaz
- Department of Allied Health Sciences University of Sargodha Sargodha Pakistan
| | - Qaisar Mahmood
- College of Pharmacy University of Sargodha Sargodha Pakistan
| | - Malik Hassan Mehmood
- Department of Pharmacology, Faculty of Pharmaceutical Sciences Government College University Faisalabad Pakistan
| | - Ghulam Rasool
- Department of Allied Health Sciences University of Sargodha Sargodha Pakistan
| | - Zahed Mahmood
- Department of Biochemistry Government College University Faisalabad Pakistan
| | - Mazhar Abbas
- Department of Biochemistry College of Veterinary and Animal Sciences, University of Veterinary and Animal Sciences (Jhang Campus) Lahore Pakistan
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Ezrokhi M, Zhang Y, Luo S, Cincotta AH. Time-of-Day-Dependent Effects of Bromocriptine to Ameliorate Vascular Pathology and Metabolic Syndrome in SHR Rats Held on High Fat Diet. Int J Mol Sci 2021; 22:ijms22116142. [PMID: 34200262 PMCID: PMC8201259 DOI: 10.3390/ijms22116142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 12/31/2022] Open
Abstract
The treatment of type 2 diabetes patients with bromocriptine-QR, a unique, quick release micronized formulation of bromocriptine, improves glycemic control and reduces adverse cardiovascular events. While the improvement of glycemic control is largely the result of improved postprandial hepatic glucose metabolism and insulin action, the mechanisms underlying the drug's cardioprotective effects are less well defined. Bromocriptine is a sympatholytic dopamine agonist and reduces the elevated sympathetic tone, characteristic of metabolic syndrome and type 2 diabetes, which potentiates elevations of vascular oxidative/nitrosative stress, known to precipitate cardiovascular disease. Therefore, this study investigated the impact of bromocriptine treatment upon biomarkers of vascular oxidative/nitrosative stress (including the pro-oxidative/nitrosative stress enzymes of NADPH oxidase 4, inducible nitric oxide (iNOS), uncoupled endothelial nitric oxide synthase (eNOS), the pro-inflammatory/pro-oxidative marker GTP cyclohydrolase 1 (GTPCH 1), and the pro-vascular health enzyme, soluble guanylate cyclase (sGC) as well as the plasma level of thiobarbituric acid reactive substances (TBARS), a circulating marker of systemic oxidative stress), in hypertensive SHR rats held on a high fat diet to induce metabolic syndrome. Inasmuch as the central nervous system (CNS) dopaminergic activities both regulate and are regulated by CNS circadian pacemaker circuitry, this study also investigated the time-of-day-dependent effects of bromocriptine treatment (10 mg/kg/day at either 13 or 19 h after the onset of light (at the natural waking time or late during the activity period, respectively) among animals held on 14 h daily photoperiods for 16 days upon such vascular biomarkers of vascular redox state, several metabolic syndrome parameters, and mediobasal hypothalamic (MBH) mRNA expression levels of neuropeptides neuropeptide Y (NPY) and agouti-related protein (AgRP) which regulate the peripheral fuel metabolism and of mRNA expression of other MBH glial and neuronal cell genes that support such metabolism regulating neurons in this model system. Such bromocriptine treatment at ZT 13 improved (reduced) biomarkers of vascular oxidative/nitrosative stress including plasma TBARS level, aortic NADPH oxidase 4, iNOS and GTPCH 1 levels, and improved other markers of coupled eNOS function, including increased sGC protein level, relative to controls. However, bromocriptine treatment at ZT 19 produced no improvement in either coupled eNOS function or sGC protein level. Moreover, such ZT 13 bromocriptine treatment reduced several metabolic syndrome parameters including fasting insulin and leptin levels, as well as elevated systolic and diastolic blood pressure, insulin resistance, body fat store levels and liver fat content, however, such effects of ZT 19 bromocriptine treatment were largely absent versus control. Finally, ZT 13 bromocriptine treatment reduced MBH NPY and AgRP mRNA levels and mRNA levels of several MBH glial cell/neuronal genes that code for neuronal support/plasticity proteins (suggesting a shift in neuronal structure/function to a new metabolic control state) while ZT 19 treatment reduced only AgRP, not NPY, and was with very little effect on such MBH glial cell genes expression. These findings indicate that circadian-timed bromocriptine administration at the natural circadian peak of CNS dopaminergic activity (that is diminished in insulin resistant states), but not outside this daily time window when such CNS dopaminergic activity is naturally low, produces widespread improvements in biomarkers of vascular oxidative stress that are associated with the amelioration of metabolic syndrome and reductions in MBH neuropeptides and gene expressions known to facilitate metabolic syndrome. These results of such circadian-timed bromocriptine treatment upon vascular pathology provide potential mechanisms for the observed marked reductions in adverse cardiovascular events with circadian-timed bromocriptine-QR therapy (similarly timed to the onset of daily waking as in this study) of type 2 diabetes subjects and warrant further investigations into related mechanisms and the potential application of such intervention to prediabetes and metabolic syndrome patients as well.
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Luo S, Ezrokhi M, Cominos N, Tsai TH, Stoelzel CR, Trubitsyna Y, Cincotta AH. Experimental dopaminergic neuron lesion at the area of the biological clock pacemaker, suprachiasmatic nuclei (SCN) induces metabolic syndrome in rats. Diabetol Metab Syndr 2021; 13:11. [PMID: 33485386 PMCID: PMC7825247 DOI: 10.1186/s13098-021-00630-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The daily peak in dopaminergic neuronal activity at the area of the biological clock (hypothalamic suprachiasmatic nuclei [SCN]) is diminished in obese/insulin resistant vs lean/insulin sensitive animals. The impact of targeted lesioning of dopamine (DA) neurons specifically at the area surrounding (and that communicate with) the SCN (but not within the SCN itself) upon glucose metabolism, adipose and liver lipid gene expression, and cardiovascular biology in normal laboratory animals has not been investigated and was the focus of this study. METHODS Female Sprague-Dawley rats received either DA neuron neurotoxic lesion by bilateral intra-cannula injection of 6-hydroxydopamine (2-4 μg/side) or vehicle treatment at the area surrounding the SCN at 20 min post protriptyline ip injection (20 mg/kg) to protect against damage to noradrenergic and serotonergic neurons. RESULTS At 16 weeks post-lesion relative to vehicle treatment, peri-SCN area DA neuron lesioning increased weight gain (34.8%, P < 0.005), parametrial and retroperitoneal fat weight (45% and 90% respectively, P < 0.05), fasting plasma insulin, leptin and norepinephrine levels (180%, 71%, and 40% respectively, P < 0.05), glucose tolerance test area under the curve (AUC) insulin (112.5%, P < 0.05), and insulin resistance (44%-Matsuda Index, P < 0.05) without altering food consumption during the test period. Such lesion also induced the expression of several lipid synthesis genes in adipose and liver and the adipose lipolytic gene, hormone sensitive lipase in adipose (P < 0.05 for all). Liver monocyte chemoattractant protein 1 (a proinflammatory protein associated with metabolic syndrome) gene expression was also significantly elevated in peri-SCN area dopaminergic lesioned rats. Peri-SCN area dopaminergic neuron lesioned rats were also hypertensive (systolic BP rose from 157 ± 5 to 175 ± 5 mmHg, P < 0.01; diastolic BP rose from 109 ± 4 to 120 ± 3 mmHg, P < 0.05 and heart rate increase from 368 ± 12 to 406 ± 12 BPM, P < 0.05) and had elevated plasma norepinephrine levels (40% increased, P < 0.05) relative to controls. CONCLUSIONS These findings indicate that reduced dopaminergic neuronal activity in neurons at the area of and communicating with the SCN contributes significantly to increased sympathetic tone and the development of metabolic syndrome, without effect on feeding.
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Affiliation(s)
- Shuqin Luo
- VeroScience LLC, 1334 Main Road, Tiverton, RI, 02878, USA
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12
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Stoelzel CR, Zhang Y, Cincotta AH. Circadian-timed dopamine agonist treatment reverses high-fat diet-induced diabetogenic shift in ventromedial hypothalamic glucose sensing. Endocrinol Diabetes Metab 2020; 3:e00139. [PMID: 32704560 PMCID: PMC7375120 DOI: 10.1002/edm2.139] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/28/2020] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION Within the ventromedial hypothalamus (VMH), glucose inhibitory (GI) neurons sense hypoglycaemia while glucose excitatory (GE) neurons sense hyperglycaemia to initiate counter control mechanisms under normal conditions. However, potential electrophysiological alterations of these two neuronal types in vivo in insulin-resistant states have never been simultaneously fully documented. Further, the anti-diabetic effect of dopamine agonism on this VMH system under insulin resistance has not been studied. METHODS This study examined the impact of a high-fat diet (HFD) on in vivo electrophysiological recordings from VMH GE and GI neurons and the ability of circadian-timed dopamine agonist therapy to reverse any adverse effect of the HFD on such VMH activities and peripheral glucose metabolism. RESULTS HFD significantly inhibited VMH GE neuronal electrophysiological response to local hyperglycaemia (36.3%) and augmented GI neuronal excitation response to local hypoglycaemia (47.0%). Bromocriptine (dopamine agonist) administration at onset of daily activity (but not during the daily sleep phase) completely reversed both VMH GE and GI neuronal aberrations induced by HFD. Such timed treatment also normalized glucose intolerance and insulin resistance. These VMH and peripheral glucose metabolism effects of circadian-timed bromocriptine may involve its known effect to reduce elevated VMH noradrenergic activity in insulin-resistant states as local VMH administration of norepinephrine was observed to significantly inhibit VMH GE neuronal sensing of local hyperglycaemia in insulin-sensitive animals on regular chow diet (52.4%). CONCLUSIONS HFD alters VMH glucose sensing in a manner that potentiates hyperglycaemia and this effect on the VMH can be reversed by appropriately circadian-timed dopamine agonist administration.
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13
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Chamarthi B, Vinik A, Ezrokhi M, Cincotta AH. Circadian-timed quick-release bromocriptine lowers elevated resting heart rate in patients with type 2 diabetes mellitus. Endocrinol Diabetes Metab 2020; 3:e00101. [PMID: 31922028 PMCID: PMC6947713 DOI: 10.1002/edm2.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/09/2019] [Accepted: 10/20/2019] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Sympathetic nervous system (SNS) overactivity is a risk factor for insulin resistance and cardiovascular disease (CVD). We evaluated the impact of bromocriptine-QR, a dopamine-agonist antidiabetes medication, on elevated resting heart rate (RHR) (a marker of SNS overactivity in metabolic syndrome), blood pressure (BP) and the relationship between bromocriptine-QR's effects on RHR and HbA1c in type 2 diabetes subjects. DESIGN AND SUBJECTS RHR and BP changes were evaluated in this post hoc analysis of data from a randomized controlled trial in 1014 type 2 diabetes subjects randomized to bromocriptine-QR vs placebo added to standard therapy (diet ± ≤2 oral antidiabetes medications) for 24 weeks without concomitant antihypertensive or antidiabetes medication changes, stratified by baseline RHR (bRHR). RESULTS In subjects with bRHR ≥70 beats/min, bromocriptine-QR vs placebo reduced RHR by -3.4 beats/min and reduced BP (baseline 130/79; systolic, diastolic, mean arterial BP reductions [mm Hg]: -3.6 [P = .02], -1.9 [P = .05], -2.5 [P = .02]). RHR reductions increased with higher baseline HbA1c (bHbA1c) (-2.7 [P = .03], -5 [P = .002], -6.1 [P = .002] with bHbA1c ≤7, >7, ≥7.5%, respectively] in the bRHR ≥70 group and more so with bRHR ≥80 (-4.5 [P = .07], -7.8 [P = .015], -9.9 [P = .005]). Subjects with bRHR <70 had no significant change in RHR or BP. With bHbA1c ≥7.5%, %HbA1c reductions with bromocriptine-QR vs placebo were -0.50 (P = .04), -0.73 (P = .005) and -1.22 (P = .008) with bRHR <70, ≥70 and ≥80, respectively. With bRHR ≥70, the magnitude of bromocriptine-QR-induced RHR reduction was an independent predictor of bromocriptine-QR's HbA1c lowering effect. CONCLUSION Bromocriptine-QR lowers elevated RHR with concurrent decrease in BP and hyperglycaemia. These findings suggest a potential sympatholytic mechanism contributing to bromocriptine-QR's antidiabetes effect and potentially its previously demonstrated effect to reduce CVD events.
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Affiliation(s)
| | - Aaron Vinik
- Eastern Virginia Medical School Strelitz Diabetes CenterNorfolkVirginia
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14
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Vinik AI, Casellini C, Parson HK, Colberg SR, Nevoret ML. Cardiac Autonomic Neuropathy in Diabetes: A Predictor of Cardiometabolic Events. Front Neurosci 2018; 12:591. [PMID: 30210276 PMCID: PMC6119724 DOI: 10.3389/fnins.2018.00591] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 08/06/2018] [Indexed: 12/15/2022] Open
Abstract
Autonomic nervous system (ANS) imbalance manifesting as cardiac autonomic neuropathy in the diabetic population is an important predictor of cardiovascular events. Symptoms and signs of ANS dysfunction, such as resting heart rate elevations, diminished blood pressure responses to standing, and altered time and frequency domain measures of heart rate variability in response to deep breathing, standing, and the Valsalva maneuver, should be elicited from all patients with diabetes and prediabetes. With the recognition of the presence of ANS imbalance or for its prevention, a rigorous regime should be implemented with lifestyle modification, physical activity, and cautious use of medications that lower blood glucose. Rather than intensifying diabetes control, a regimen tailored to the individual risk of autonomic imbalance should be implemented. New agents that may improve autonomic function, such as SGLT2 inhibitors, should be considered and the use of incretins monitored. One of the central mechanisms of dysfunction is disturbance of the hypothalamic cardiac clock, a consequence of dopamine deficiency that leads to sympathetic dominance, insulin resistance, and features of the metabolic syndrome. An improvement in ANS balance may be critical to reducing cardiovascular events, cardiac failure, and early mortality in the diabetic population.
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Affiliation(s)
- Aaron I Vinik
- Division of Endocrinology and Metabolism, Strelitz Diabetes Center and Neuroendocrine Unit, Department of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Carolina Casellini
- Division of Endocrinology and Metabolism, Strelitz Diabetes Center and Neuroendocrine Unit, Department of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Henri K Parson
- Division of Endocrinology and Metabolism, Strelitz Diabetes Center and Neuroendocrine Unit, Department of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Sheri R Colberg
- Department of Human Movement Sciences, Old Dominion University, Norfolk, VA, United States
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Michael Besser G, Pfeiffer RF, Thorner MO. ANNIVERSARY REVIEW: 50 years since the discovery of bromocriptine. Eur J Endocrinol 2018; 179:R69-R75. [PMID: 29752299 DOI: 10.1530/eje-18-0378] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 05/11/2018] [Indexed: 11/08/2022]
Abstract
Ergotism is the long-term ergot poisoning by ingestion of rye or other grains infected with the fungus Claviceps purpurea and more recently by excessive intake of ergot drugs. It has either neuropsychiatric or vascular manifestations. In the Middle Ages, the gangrenous poisoning was known as St. Anthony's fire, after the order of the Monks of St. Anthony who were particularly skilled at treating the condition. In 1917, Prof. Arthur Stoll returned home to Switzerland from Germany, to lead the development of a new pharmaceutical department at Sandoz Chemical Company. Stoll, using the special methods of extraction learned from his work with his mentor Willstetter, started his industrial research work with ergot. He succeeded in isolating, from the ergot of rye, ergotamine as an active principle of an old popular remedy for excessive post-partum bleeding. The success of this discovery occurred in 1918 and was translated into a pharmaceutical product in 1921 under the trade name Gynergen. In subsequent work, Stoll and his team were leaders in identifying the structure of the many other alkaloids and amines produced by Claviceps purpurea This was the cultural background and scientific foundation on which bromocriptine was discovered.
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Affiliation(s)
| | - Ronald F Pfeiffer
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
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Scaroni C, Zilio M, Foti M, Boscaro M. Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management. Endocr Rev 2017; 38:189-219. [PMID: 28368467 DOI: 10.1210/er.2016-1105] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 03/15/2017] [Indexed: 12/13/2022]
Abstract
An impaired glucose metabolism, which often leads to the onset of diabetes mellitus (DM), is a common complication of chronic exposure to exogenous and endogenous glucocorticoid (GC) excess and plays an important part in contributing to morbidity and mortality in patients with Cushing syndrome (CS). This article reviews the pathogenesis, epidemiology, diagnosis, and management of changes in glucose metabolism associated with hypercortisolism, addressing both the pathophysiological aspects and the clinical and therapeutic implications. Chronic hypercortisolism may have pleiotropic effects on all major peripheral tissues governing glucose homeostasis. Adding further complexity, both genomic and nongenomic mechanisms are directly induced by GCs in a context-specific and cell-/organ-dependent manner. In this paper, the discussion focuses on established and potential pathologic molecular mechanisms that are induced by chronically excessive circulating levels of GCs and affect glucose homeostasis in various tissues. The management of patients with CS and DM includes treating their hyperglycemia and correcting their GC excess. The effects on glycemic control of various medical therapies for CS are reviewed in this paper. The association between DM and subclinical CS and the role of screening for CS in diabetic patients are also discussed.
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Affiliation(s)
- Carla Scaroni
- Endocrinology Unit, Department of Medicine, DIMED, University of Padova, Via Ospedale 105, 35128 Padua, Italy
| | - Marialuisa Zilio
- Endocrinology Unit, Department of Medicine, DIMED, University of Padova, Via Ospedale 105, 35128 Padua, Italy
| | - Michelangelo Foti
- Department of Cell Physiology & Metabolism, Centre Médical Universitaire, 1 Rue Michel Servet, 1211 Genèva, Switzerland
| | - Marco Boscaro
- Endocrinology Unit, Department of Medicine, DIMED, University of Padova, Via Ospedale 105, 35128 Padua, Italy
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Chamarthi B, Cincotta AH. Effect of bromocriptine-QR therapy on glycemic control in subjects with type 2 diabetes mellitus whose dysglycemia is inadequately controlled on insulin. Postgrad Med 2017; 129:446-455. [DOI: 10.1080/00325481.2017.1315290] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Bindu Chamarthi
- VeroScience LLC, Tiverton, RI, USA
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
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Chamarthi B, Ezrokhi M, Rutty D, Cincotta AH. Impact of bromocriptine-QR therapy on cardiovascular outcomes in type 2 diabetes mellitus subjects on metformin. Postgrad Med 2016; 128:761-769. [PMID: 27687032 DOI: 10.1080/00325481.2016.1243003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Type 2 diabetes mellitus (T2DM) is associated with a substantially increased risk of cardiovascular disease (CVD). Bromocriptine-QR (B-QR), a quick release sympatholytic dopamine D2 receptor agonist, is a FDA-approved therapy for T2DM which may provide CVD risk reduction. Metformin is considered to be an agent with a potential cardioprotective benefit. This large placebo controlled clinical study assessed the impact of B-QR addition to existing metformin therapy on CVD outcomes in T2DM subjects. METHODS 1791 subjects (1208 B-QR; 583 placebo) on metformin ± another anti-diabetes therapy at baseline derived from the Cycloset Safety Trial, a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were included in this study. The primary CVD endpoint evaluated was treatment impact on CVD event rate, prespecified as a composite of time to first myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina/congestive heart failure. Impact on glycemic control was evaluated as a secondary analysis. RESULTS The composite CVD end point occurred in 16/1208 B-QR treated (1.3%) and 18/583 placebo treated (3.1%) subjects resulting in a 55% CVD hazard risk reduction (intention-to-treat, Cox regression analysis; HR: 0.45 [0.23-0.88], p = 0.028). Kaplan-Meier curves demonstrated a significantly lower cumulative incidence rate of the CVD endpoint in the B-QR treatment group (Log-Rank p = 0.017). In subjects with poor glycemic control (HbA1c ≥ 7.5) at baseline, B-QR therapy relative to placebo resulted in a significant mean %HbA1c reduction of -0.59 at week 12 and -0.51 at week 52 respectively (p < 0.001 for both) and a 10 fold higher percent of subjects achieving HbA1c goal of ≤7% by week 52 (B-QR 30%, placebo 3%; p = 0.003). CONCLUSION These findings suggest that in T2DM subjects on metformin, BQR therapy may represent an effective strategy for reducing CVD risk. Cycloset Safety Trial registration: ClinicalTrials.gov Identifier: NCT00377676.
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Affiliation(s)
- Bindu Chamarthi
- a VeroScience, LLC , Tiverton , RI , USA.,b Division of Endocrinology, Diabetes and Hypertension , Brigham and Women's Hospital , Boston , MA , USA.,c Department of Medicine , Harvard Medical School , Boston , MA , USA
| | | | - Dean Rutty
- d Statistical Operations , Everest Clinical Research Services Inc , Markham , Canada
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