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Wasim R, Ansari TM, Siddiqui MH, Ahsan F, Shamim A, Singh A, Shariq M, Anwar A, Siddiqui AR, Parveen S. Repurposing of Drugs for Cardiometabolic Disorders: An Out and Out Cumulation. Horm Metab Res 2023; 55:7-24. [PMID: 36599357 DOI: 10.1055/a-1971-6965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cardiometabolic disorders (CMD) is a constellation of metabolic predisposing factors for atherosclerosis such as insulin resistance (IR) or diabetes mellitus (DM), systemic hypertension, central obesity, and dyslipidemia. Cardiometabolic diseases (CMDs) continue to be the leading cause of mortality in both developed and developing nations, accounting for over 32% of all fatalities globally each year. Furthermore, dyslipidemia, angina, arrhythmia, heart failure, myocardial infarction (MI), and diabetes mellitus are the major causes of death, accounting for an estimated 19 million deaths in 2012. CVDs will kill more than 23 million individuals each year by 2030. Nonetheless, new drug development (NDD) in CMDs has been increasingly difficult in recent decades due to increased costs and a lower success rate. Drug repositioning in CMDs looks promising in this scenario for launching current medicines for new therapeutic indications. Repositioning is an ancient method that dates back to the 1960s and is mostly based on coincidental findings during medication trials. One significant advantage of repositioning is that the drug's safety profile is well known, lowering the odds of failure owing to undesirable toxic effects. Furthermore, repositioning takes less time and money than NDD. Given these facts, pharmaceutical corporations are becoming more interested in medication repositioning. In this follow-up, we discussed the notion of repositioning and provided some examples of repositioned medications in cardiometabolic disorders.
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Affiliation(s)
| | | | | | - Farogh Ahsan
- Pharmacology, Integral University, Lucknow, India
| | | | - Aditya Singh
- Pharmaceutics, Integral University, Lucknow, India
| | | | - Aamir Anwar
- Pharmacy, Integral University, Lucknow, India
| | | | - Saba Parveen
- Pharmacology, Integral University, Lucknow, India
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2
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Abstract
Severe burn injury is followed by a profound hypermetabolic response that persists up to 2 years after injury. It is mediated by up to 50-fold elevations in plasma catecholamines, cortisol, and glucagon that lead to whole-body catabolism, elevated resting energy expenditures, and multiorgan dysfunction. Modulation of the response by early excision and grafting of burn wounds, thermoregulation, control of infection, early and continuous enteral nutrition, and pharmacologic treatments aimed at mitigating physiologic derangements have markedly decreased morbidity.
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Affiliation(s)
- Felicia N Williams
- Department of Surgery, North Carolina Jaycee Burn Center, University of North Carolina, Chapel Hill, 3007D Burnett Womack Building, CB 7206, Chapel Hill, NC 27599-7206, USA
| | - David N Herndon
- Department of Surgery, Shriners Hospital of Children, University of Texas Medical Branch, 815 Market Street, Galveston, TX 77550, USA.
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Camastra S, Astiarraga B, Tura A, Frascerra S, Ciociaro D, Mari A, Gastaldelli A, Ferrannini E. Effect of exenatide on postprandial glucose fluxes, lipolysis, and ß-cell function in non-diabetic, morbidly obese patients. Diabetes Obes Metab 2017; 19:412-420. [PMID: 27898183 DOI: 10.1111/dom.12836] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/10/2016] [Accepted: 11/25/2016] [Indexed: 01/02/2023]
Abstract
AIMS To investigate the effect of exenatide on glucose disposal, insulin secretion, ß-cell function, lipolysis and hormone concentrations in non-diabetic, morbidly obese subjects under physiological conditions. MATERIALS AND METHODS Patients were assigned to exenatide 10 µg twice daily (EXE, n = 15) or control (CT, n = 15) for 3 months. Patients received a meal test/tracer study (MTT) to measure endogenous glucose production (EGP), rate of oral glucose appearance (RaO), insulin secretion rate (ISR), ß-cell function, hepatic insulin resistance (HIR) and adipose tissue insulin resistance (AT-IR) and insulin sensitivity (IS). RESULTS Post treatment, the EXE group showed a significant reduction in body weight ( P < .001). The postmeal time-course of glucose, insulin and ISR showed a lower peak between 60 and 180 minutes in phase with a reduction in RaO ( P < .01). After an initial similar suppression, EGP resumed at higher rates between 60 and 180 minutes ( P = .02) in EXE vs CT, while total RaO and EGP were similar throughout the MTT. In EXE, the postmeal glucagon, GLP1 and GIP responses were reduced ( P < .05). Fasting and postprandial lipolysis and ß-cell function were unaltered by active treatment. HIR, AT-IR and IS were all improved after exenatide treatment ( P < .05). CONCLUSIONS In morbidly obese non-diabetic subjects, exenatide causes weight loss, decreased postprandial glycaemia and glucagon response without changes in ß-cell function. These effects are consequent upon delayed oral glucose appearance in the circulation. Exenatide treatment is also associated with an improvement in hepatic, adipose tissue and whole-body IS with no influence on postprandial lipolysis.
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Affiliation(s)
- Stefania Camastra
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Brenno Astiarraga
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Andrea Tura
- Institute of Neurosciences, C.N.R., Padua, Italy
| | - Silvia Frascerra
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Andrea Mari
- Institute of Neurosciences, C.N.R., Padua, Italy
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Wright N, Wales J. Assessment and management of severely obese children and adolescents. Arch Dis Child 2016; 101:1161-1167. [PMID: 27312003 DOI: 10.1136/archdischild-2015-309103] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 04/16/2016] [Accepted: 05/23/2016] [Indexed: 01/08/2023]
Abstract
Approximately 3% of children and adolescents in the UK have severe obesity. The incidence of cardiovascular risk factors such as hypertension, hyperinsulinism and hyperlipidaemia approaches 20% in such individuals. Lifestyle intervention programmes and pharmacotherapy are effective in some individuals, but the relapse rate is high. In exceptional cases, bariatric surgery is effective. This review outlines the scale of the problem, highlights those at risk and discusses referral, current services, appropriate screening and therapeutic interventions.
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Affiliation(s)
- Neil Wright
- Sheffield Children's Hospital, Sheffield, UK
| | - Jerry Wales
- Department of Endocrinology & Diabetes, Lady Cilento Children's Hospital, Brisbane, Australia
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Bonaccorso RL, Chepurny OG, Becker-Pauly C, Holz GG, Doyle RP. Enhanced Peptide Stability Against Protease Digestion Induced by Intrinsic Factor Binding of a Vitamin B12 Conjugate of Exendin-4. Mol Pharm 2015; 12:3502-6. [PMID: 26260673 DOI: 10.1021/acs.molpharmaceut.5b00390] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Peptide digestion from proteases is a significant limitation in peptide therapeutic development. It has been hypothesized that the dietary pathway of vitamin B12 (B12) may be exploited in this area, but an open question is whether B12-peptide conjugates bound to the B12 gastric uptake protein intrinsic factor (IF) can provide any stability against proteases. Herein, we describe a new conjugate of B12 with the incretin peptide exendin 4 that demonstrates picomolar agonism of the glugacon-like peptide-1 receptor (GLP1-R). Stability studies reveal that Ex-4 is digested by pancreatic proteases trypsin and chymotrypsin and by the kidney endopeptidase meprin β. Prebinding the B12 conjugate to IF, however, resulted in up to a 4-fold greater activity of the B12-Ex-4 conjugate relative to Ex-4, when the IF-B12-Ex-4 complex was exposed to 22 μg/mL of trypsin, 2.3-fold greater activity when exposed to 1.25 μg/mL of chymotrypsin, and there was no decrease in function at up to 5 μg/mL of meprin β.
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Affiliation(s)
- Ron L Bonaccorso
- Department of Chemistry, Center for Science and Technology, Syracuse University , 111 College Place, Syracuse, New York 13244, United States
| | - Oleg G Chepurny
- Department of Medicine, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States
| | | | - George G Holz
- Department of Medicine, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States.,Department of Pharmacology, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States
| | - Robert P Doyle
- Department of Chemistry, Center for Science and Technology, Syracuse University , 111 College Place, Syracuse, New York 13244, United States.,Department of Medicine, State University of New York, Upstate Medical University , Syracuse, New York 13210, United States
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Wang J, Wang F, Xu J, Ding S, Guo Y. Double-strand adeno-associated virus-mediated exendin-4 expression in salivary glands is efficient in a diabetic rat model. Diabetes Res Clin Pract 2014; 103:466-73. [PMID: 24438876 DOI: 10.1016/j.diabres.2013.12.006] [Citation(s) in RCA: 4] [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: 06/26/2013] [Revised: 09/13/2013] [Accepted: 12/18/2013] [Indexed: 12/19/2022]
Abstract
AIM Exendin-4 (Ex-4) is an agonist of the glucagon-like peptide 1 (GLP-1) receptor, approved for the treatment of type 2 diabetes (T2DM). Several strategies have been tried to develop stable and efficacious Ex-4 expression systems. The purpose of the current study was to determine whether double-stranded adeno-associated virus (dsAAV)-mediated in vivo expression of exendin-4 in salivary glands (SG), improves pathology in the Sprague-Dawley (SD) rat model of diabetes mellitus (DM). METHODS The effects of Ex-4 expression by recombinant dsAAV-NT4-Ex-4 were evaluated in vitro compared with a single-strand (ss) AAV. The dsAAV was delivered into SGs and the blood glucose and insulin levels were assessed in a rat model of DM. RESULTS DsAAV-NT4-Ex-4 virus induces significant exendin-4 expression in vitro. Furthermore, Ex-4 expressed from dsAAV virus in SGs enhances insulins secretion in vivo and significantly controls the onset of hyperglycemia in rat model of DM. CONCLUSIONS Results suggest that sustained secretion of Ex-4 following dsAAV-mediated gene therapy is feasible. SGs appear to be promising targets with potential clinical applicability for the treatment of DM. This represents the example of a successful use of Ex-4 for diabetes therapy, providing support for direct AAV-mediated in vivo as an easy, safe and efficient therapeutic strategy.
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Affiliation(s)
- Junhong Wang
- Department of Endocrine, The Second Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710004, China
| | - Feng Wang
- Department of Nutrition and Food Hygiene, The Fourth Military Medical University, Xi'an 710032, China
| | - Jing Xu
- Department of Endocrine, The Second Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710004, China
| | - Shimei Ding
- Department of Endocrine, The Second Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710004, China
| | - Yonghong Guo
- Department of Infectious Disease, The Second Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710004, China.
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Kubo M, Fukui M, Ito Y, Kitao T, Shirahase H, Hinoi E, Yoneda Y. Insulin Sensitization by a Novel Partial Peroxisome Proliferator-Activated Receptor γ Agonist With Protein Tyrosine Phosphatase 1B Inhibitory Activity in Experimental Osteoporotic Rats. J Pharmacol Sci 2014; 124:276-85. [DOI: 10.1254/jphs.13236fp] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Kim PH, Lee M, Kim SW. Delivery of two-step transcription amplification exendin-4 plasmid system with arginine-grafted bioreducible polymer in type 2 diabetes animal model. J Control Release 2012; 162:9-18. [PMID: 22705459 DOI: 10.1016/j.jconrel.2012.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 05/24/2012] [Accepted: 06/05/2012] [Indexed: 11/18/2022]
Abstract
Exendin-4, glucagon-like peptide 1 (GLP-1) receptor agonist, is an exocrine hormone, which has potent insulinotropic actions similar to GLP-1 such as stimulating insulin biosynthesis, facilitating glucose concentration dependent insulin secretion, slowing gastric emptying, reducing food intake and stimulating β-cell proliferation. Exendin-4, also, has a longer half-life than GLP-1, due to its resistance to degradation by dipeptidyl peptidase-IV (DPP-IV). In spite of its many advantages as a therapeutic agent for diabetes, its clinical application is still restricted. Thus, to improve the activity of exendin-4 in vivo, gene therapy system was developed as an alternative method. An exendin-4 expression system was constructed using the two-step transcription amplification (TSTA) system, which is composed of pβ-Gal4-p65 and pUAS-SP-exendin-4 with combining the advantages of signal peptide (SP) in order to facilitate its secretion in ectopic cells or tissue. Arginine-grafted cyctaminebisacrylamide-diaminohexane polymer (ABP) was used as a gene carrier. Increased expression of exendin-4, glucose dependent insulin secretion in NIT-1 insulinoma cells, and high insulin expression in the presence of DPP-IV were evaluated in vitro after delivery of ABP/TSTA-SP-exendin-4. Blood glucose levels in diabetic mice were decreased dramatically from the third day for experimental period after single intravenous administration with ABP/TSTA-SP-exendin-4. The highest insulinotropic effect of exendin-4 was also observed in the ABP/TSTA/SP-exendin-4-treated mice groups, compared with the others groups from the 3rd day after injection. TSTA exendin-4 expression system with SP and ABP polymer has a potential gene therapy for the treatment of type 2 diabetes.
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Affiliation(s)
- Pyung-Hwan Kim
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA
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9
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Kim PH, Kim SW. Polymer-based delivery of glucagon-like Peptide-1 for the treatment of diabetes. ISRN ENDOCRINOLOGY 2012; 2012:340632. [PMID: 22701182 PMCID: PMC3369441 DOI: 10.5402/2012/340632] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 03/16/2012] [Indexed: 01/19/2023]
Abstract
The incretin hormones, glucagon-like peptide-1 (GLP-1) and its receptor agonist (exendin-4), are well known for glucose homeostasis, insulinotropic effect, and effects on weight loss and food intake. However, due to the rapid degradation of GLP-1 by dipeptidylpeptidase-IV (DPP-IV) enzyme and renal elimination of exendin-4, their clinical applications have been restricted. Although exendin-4 has longer half-life than GLP-1, it still requires frequent injections to maintain efficacy for the treatment of diabetes. In recent decades, various polymeric delivery systems have been developed for the delivery of GLP-1 and exendin-4 genes or peptides for their long-term action and the extra production in ectopic tissues. Herein, we discuss the modification of the expression cassettes and peptides for long-term production and secretion of the native peptides. In addition, the characteristics of nonviral or viral system used for a delivery of a modified GLP-1 or exendin-4 are described. Furthermore, recent efforts to improve the biological half-life of GLP-1 or exendin-4 peptide via chemical conjugation with various smart polymers via chemical conjugation compared with native peptide are discussed.
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Affiliation(s)
- Pyung-Hwan Kim
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Sung Wan Kim
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA
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10
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Abstract
GLP-1 receptors are expressed in the brain, especially in the regions responsible for the regulation of food intake, and intracerebroventricular injection of GLP-1 results in inhibition of food intake. Peripheral administration of GLP-1 dose-dependently enhances satiety and reduces food intake in normal and obese subjects as well as in type 2 diabetic patients. So far, the mechanisms by which GLP-1 exerts its effects are not completely clear. Interactions with neurons in the gastrointestinal tract or possibly direct access to the brain through the blood-brain barrier as observed in rats are possible and discussed in this chapter as well as a novel hypothesis based on the finding that GLP-1 is also expressed in taste cells. Finally, the role of GLP-1 receptor agonists as a possible treatment option in obesity is discussed as well as the role of GLP-1 in the effects of bariatric surgery on adiposity and glucose homeostasis.
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Chakraborti CK. Exenatide: a new promising antidiabetic agent. Indian J Pharm Sci 2011; 72:1-11. [PMID: 20582183 PMCID: PMC2883206 DOI: 10.4103/0250-474x.62228] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 10/26/2009] [Accepted: 12/25/2009] [Indexed: 12/16/2022] Open
Abstract
Exenatide is a unique agent which can effectively control blood glucose levels in type 2 diabetes mellitus without producing dangerous adverse effects. In addition, it can lower body weight which is very essential for the treatment of obese type 2 diabetes mellitus patients. Since it can delay the destruction of islet beta-cells, type 2 diabetes mellitus patients are not rapidly converted to type 1 diabetes mellitus and ultimately appearance of complications of the disease is halted or delayed. Its long-acting-release formula, which would be used once per week, simultaneously retaining all the properties of twice-daily subcutaneous administration, is undergoing clinical trial. This drug is considered as an adjunct to metformin/sulfonylureas/insulin.
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Affiliation(s)
- C K Chakraborti
- Kanak Manjari Institute of Pharmaceutical Sciences, Chhend, Rourkela-769 015, India
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12
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Seetho IW, Jones G, Thomson GA, Fernando DJS. Treating diabetes mellitus in Prader-Willi syndrome with Exenatide. Diabetes Res Clin Pract 2011; 92:e1-2. [PMID: 21227526 DOI: 10.1016/j.diabres.2010.12.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 10/04/2010] [Accepted: 12/06/2010] [Indexed: 11/19/2022]
Abstract
We report the use of Exenatide, a GLP-1 agonist, in the management of diabetes mellitus in a 19 year-old female with Prader-Willi syndrome. The beneficial effects of Exenatide in weight reduction and appetite suppression provide a promising strategy for the treatment of obesity and diabetes mellitus in Prader-Willi syndrome.
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Affiliation(s)
- Ian W Seetho
- Department of Medicine, Nottingham University Hospitals NHS Trust, NG5 1PB, United Kingdom.
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13
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Hornby PJ, Moore BA. The therapeutic potential of targeting the glucagon-like peptide-2 receptor in gastrointestinal disease. Expert Opin Ther Targets 2011; 15:637-46. [DOI: 10.1517/14728222.2011.556620] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Schwartz SS, Kohl BA. Glycemic control and weight reduction without causing hypoglycemia: the case for continued safe aggressive care of patients with type 2 diabetes mellitus and avoidance of therapeutic inertia. Mayo Clin Proc 2010; 85:S15-26. [PMID: 21106867 PMCID: PMC2996166 DOI: 10.4065/mcp.2010.0468] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Diabetes mellitus (DM) is a major and growing concern in the United States, in large part because of an epidemic of obesity in America and its relation to type 2 DM. In affected patients, postprandial glucose may be an early indicator of glucose intolerance or a prediabetes condition, which may be a better predictor of cardiovascular risk than impaired fasting glucose level. Treating patients who have early signs of hyperglycemia, including elevated postprandial glucose level, with intensive glucose control that does not lead to weight gain, and ideally may be associated with weight reduction, may be vital to preventing or reducing later cardiovascular morbidity and mortality. Because hypoglycemia is an important complication of current DM treatments and may cause acute secondary adverse cardiovascular outcomes, not causing hypoglycemia is mandatory. Given that weight loss can significantly lower cardiovascular risk and improve other cardiovascular risk factors in patients with type 2 DM and that medications are available that can result in weight reduction without leading to hypoglycemia, the successful treatment of patients with type 2 DM should be individualized and should address the complete pathophysiologic process. This review is a hypothesis article that presents arguments against general approaches to the treatment of type 2 DM. An algorithm is presented in which the goal for managing patients with type 2 DM is to lower the blood glucose level as much as possible for as long as possible without causing hypoglycemia. In addition, body weight should ideally be improved, reducing cardiovascular risk factors and avoiding therapeutic inertia.
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Affiliation(s)
- Stanley S Schwartz
- Penn Presbyterian Medical Center, Second Floor, Philadelphia Heart Institute, 51 N 39th St, Philadelphia, PA 19104, USA.
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Schwartz SL. Treatment of elderly patients with type 2 diabetes mellitus: A systematic review of the benefits and risks of dipeptidyl peptidase-4 inhibitors. ACTA ACUST UNITED AC 2010; 8:405-18. [DOI: 10.1016/j.amjopharm.2010.10.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2010] [Indexed: 01/05/2023]
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Schwartz A, Ort T, Kajekar R, Wade PR, Hornby PJ. Electrical stimulation of the isolated rat intestine in the presence of nutrient stimulus enhances glucagon-like peptide-1 release. Physiol Meas 2010; 31:1147-59. [PMID: 20664162 DOI: 10.1088/0967-3334/31/9/006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The release of small intestinal hormones by constituents of ingested food, such as fatty acids, is integral to post-prandial responses that reduce food intake. Recent evidence suggests that small intestinal electrical stimulation reduces food intake, although the mechanism of action is debated. To test the hypothesis that intestinal stimulation directly alters hormone release locally we used isolated rat distal ileum and measured glucagon-like peptide-1 (GLP-1) released in the presence or absence of linoleic acid (LA) and electrical field stimulation (EFS). Intact segments were oriented longitudinally between bipolar stimulating electrodes in organ bath chambers containing modified Krebs-Ringers bicarbonate (KRB) buffer including protease inhibitors. Incubation in LA (3 mg ml(-1)) for 45 min increased GLP-1 concentration (21.9 +/- 2.6 pM versus KRB buffer alone 3.6 +/- 0.1 pM). Eleven electrical stimulation conditions were tested. In the presence of LA none of the stimulation conditions inhibited LA-evoked GLP-1 release, whereas two high frequency short pulse widths (14 V, 20 Hz, 5 ms and 14 V, 40 Hz, 5 ms) and one low frequency long pulse width (14 V, 0.4 Hz, 300 ms) EFS conditions enhanced LA-evoked GLP-1 release by >250%. These results are consistent with a local effect of intestinal electrical stimulation to enhance GLP-1 release in response to luminal nutrients in the intestines. Enhancing hormone release could improve the efficacy of intestinal electrical stimulation and provide a potential treatment for obesity and metabolic conditions.
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Affiliation(s)
- Ann Schwartz
- Immunology, Centocor Research & Development, Inc., Radnor, PA 19087, USA
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17
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DeFronzo RA. Current issues in the treatment of type 2 diabetes. Overview of newer agents: where treatment is going. Am J Med 2010; 123:S38-48. [PMID: 20206731 DOI: 10.1016/j.amjmed.2009.12.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Impaired insulin secretion (beta-cell), increased hepatic glucose production (liver), and decreased peripheral (muscle) glucose utilization constitute the traditional primary defects responsible for the development and progression of type 2 diabetes mellitus. beta-Cell failure, ultimately leading to decreased insulin secretion, is now known to occur much earlier in the natural history of type 2 diabetes than originally believed. Additionally, a better understanding of the pathophysiology of type 2 diabetes reveals other etiologic mechanisms beyond the classic triad, now referred to as the ominous octet. In addition to the beta-cell, liver, and muscle, other pathogenic mechanisms include adipocyte insulin resistance (increased lipolysis), reduced incretin secretion/sensitivity (gastrointestinal), increased glucagon secretion (alpha-cell), enhanced glucose reabsorption (kidney), and central nervous system insulin resistance resulting from neurotransmitter dysfunction (brain). Currently, the management of type 2 diabetes focuses on glucose control via lowering of blood glucose (fasting and postprandial) and hemoglobin A(1c). However, the goal of therapy should be to delay disease progression and eventual treatment failure. Treatment should target the known pathogenic disturbances of the disease (i.e., reducing the deterioration of beta-cell function and improving insulin sensitivity). In recent years, treatment strategies have focused on the development of novel therapeutic options that affect many of the defects contributing to type 2 diabetes and that provide durable glucose control through a blunting of disease progression. Optimal management of type 2 diabetes should include early initiation of therapy using multiple drugs, with different mechanisms of action, in combination.
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Affiliation(s)
- Ralph A DeFronzo
- Diabetes Division, University of Texas Health Science Center, San Antonio, Texas 78249-1644, USA.
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18
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Williams FN, Herndon DN, Jeschke MG. The hypermetabolic response to burn injury and interventions to modify this response. Clin Plast Surg 2009; 36:583-96. [PMID: 19793553 PMCID: PMC3776603 DOI: 10.1016/j.cps.2009.05.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Severe burn injury is followed by a profound hypermetabolic response that persists up to 24 months after injury. It is mediated by up to 50-fold elevations in plasma catecholamines, cortisol, and inflammatory cells that lead to whole-body catabolism, elevated resting energy expenditures, and multiorgan dysfunction. All of these metabolic and physiologic derangements prevent full rehabilitation and acclimatization of burn survivors back into society. Modulation of the response by early excision and grafting of burn wounds, thermoregulation, early and continuous enteral feeding with high-protein high-carbohydrate feedings, and pharmacologic treatments have markedly decreased morbidity.
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Affiliation(s)
- Felicia N Williams
- NIH Research Fellow, Department of Surgery, The University of Texas Medical Branch, Galveston, Texas
| | - David N Herndon
- Professor, Department of Surgery, The University of Texas Medical Branch, Galveston, Texas
- Shriners Hospitals for Children, Galveston, Texas
| | - Marc G Jeschke
- Associate Professor, Department of Surgery, The University of Texas Medical Branch, Galveston, Texas
- Shriners Hospitals for Children, Galveston, Texas
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Abu-Hamdah R, Rabiee A, Meneilly GS, Shannon RP, Andersen DK, Elahi D. Clinical review: The extrapancreatic effects of glucagon-like peptide-1 and related peptides. J Clin Endocrinol Metab 2009; 94:1843-52. [PMID: 19336511 PMCID: PMC2690432 DOI: 10.1210/jc.2008-1296] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CONTEXT Glucagon-like peptide-1 (GLP-1) 7-36 amide, an insulinotropic hormone released from the intestinal L cells in response to nutrient ingestion, has been extensively reviewed with respect to beta-cell function. However GLP-1 receptors are abundant in many other tissues. Thus, the function of GLP-1 is not limited to the islet cells, and it has regulatory actions on many other organs. EVIDENCE ACQUISITION A review of published, peer-reviewed medical literature (1987 to September 2008) on the extrapancreatic actions of GLP-1 was performed. EVIDENCE SYNTHESIS The extrapancreatic actions of GLP-1 include inhibition of gastric emptying and gastric acid secretion, thereby fulfilling the definition of GLP-1 as an enterogastrone. Other important extrapancreatic actions of GLP-1 include a regulatory role in hepatic glucose production, the inhibition of pancreatic exocrine secretion, cardioprotective and cardiotropic effects, the regulation of appetite and satiety, and stimulation of afferent sensory nerves. The primary metabolite of GLP-1, GLP-1 (9-36) amide, or GLP-1m, is the truncated product of degradation by dipeptidyl peptidase-4. GLP-1m has insulinomimetic effects on hepatic glucose production and cardiac function. Exendin-4 present in the salivary gland of the reptile, Gila monster (Heloderma suspectum), is a high-affinity agonist for the mammalian GLP-1 receptor. It is resistant to degradation by dipeptidyl peptidase-4, and therefore has a prolonged half-life. CONCLUSION GLP-1 and its metabolite have important extrapancreatic effects particularly with regard to the cardiovascular system and insulinomimetic effects with respect to glucose homeostasis. These effects may be particularly important in the obese state. GLP-1, GLP-1m, and exendin-4 therefore have potential therapeutic roles because of their diffuse extrapancreatic actions.
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Affiliation(s)
- Rania Abu-Hamdah
- Johns Hopkins University School of Medicine, Department of Surgery, Johns Hopkins Bayview Medical Center, Baltimore, Maryland 21224-2780, USA
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Frangioudakis G, Gyte AC, Loxham SJG, Poucher SM. The intravenous glucose tolerance test in cannulated Wistar rats: a robust method for the in vivo assessment of glucose-stimulated insulin secretion. J Pharmacol Toxicol Methods 2008; 57:106-13. [PMID: 18280184 DOI: 10.1016/j.vascn.2007.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2007] [Accepted: 12/21/2007] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Glucose-stimulated insulin secretion (GSIS) is critical in mammalian fuel homeostasis and is diminished early in the evolution of beta-cell dysfunction, ultimately contributing to the development of Type 2 diabetes. We sought to standardise and validate the intravenous glucose tolerance test (IVGTT), a commonly used technique to assess GSIS, in anaesthetised and conscious cannulated male Han Wistar rats. METHODS Male Han Wistar rats were cannulated via the right jugular vein and left carotid artery. Anaesthetised and chronically cannulated conscious models underwent IVGTT using increasing doses of glucose (0.2, 0.5 and 1.0 g glucose/kg LBM) or following pre-treatment with Exendin-4 (EX-4) before receiving a 0.5 g glucose/kg LBM bolus dose. Blood glucose, plasma insulin and plasma C-peptide were measured at time-points throughout the experiments. RESULTS Dose-dependent increases in blood glucose, insulin and C-peptide (where measured) were observed following administration of increasing doses of an intravenous glucose bolus in both the anaesthetised and conscious cannulated rats. The 0.5 g glucose/kg LBM bolus resulted in an intermediate response and was used in the second part of the study. EX-4 pre-treatment in combination with glucose resulted in GSIS potentiation, as assessed by plasma insulin measurement alone (anaesthetised model) or insulin and C-peptide measurements (conscious model). DISCUSSION The IVGTT was standardised in anaesthetised and conscious cannulated male Han Wistar rats by performing a glucose dose response study and validated by examining GSIS potentiation using EX-4. Based on these results, the 0.5 g glucose/kg LBM bolus dose is recommended as the dose to use to assess GSIS in any standardised screening phase of new compounds with the potential to enhance glucose-sensitive pancreatic function. The experimental conditions described in these studies could be transferred to disease models for more detailed assessment of novel compound efficacy.
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Affiliation(s)
- Georgia Frangioudakis
- Cardiovascular and Gastrointestinal Discovery Department, AstraZeneca Pharmaceuticals, Alderley Park, Macclesfield, Cheshire, United Kingdom
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Green JB, Feinglos MN. Exenatide and rimonabant: new treatments that may be useful in the management of diabetes and obesity. Curr Diab Rep 2007; 7:369-75. [PMID: 18173970 DOI: 10.1007/s11892-007-0060-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Diabetes mellitus and obesity have become increasingly prevalent problems worldwide. Unfortunately, with traditionally prescribed glucose-lowering medications most individuals with diagnosed diabetes do not achieve and maintain adequate glycemic control over time; it may be even more challenging to lower blood glucose to an appropriate level without inducing a significant associated weight gain. Exenatide and rimonabant are recently developed agents that have demonstrated benefit in both glucose lowering and reduction of body weight. These medications may well prove to be attractive alternatives or additions to our more established diabetes therapies; however, these drugs have a side-effect profile that may limit their applicability to certain populations.
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Affiliation(s)
- Jennifer B Green
- Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Baker House Room 280, Durham, NC 27710, USA.
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