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Malin SK, Remchak MME, Heiston EM, Battillo DJ, Gow AJ, Shah AM, Liu Z. Intermediate versus morning chronotype has lower vascular insulin sensitivity in adults with obesity. Diabetes Obes Metab 2024; 26:1582-1592. [PMID: 38246697 PMCID: PMC11001524 DOI: 10.1111/dom.15456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/23/2024]
Abstract
AIM Chronotype reflects a circadian rhythmicity that regulates endothelial function. While the morning chronotype (MORN) usually has low cardiovascular disease risk, no study has examined insulin action on endothelial function between chronotypes. We hypothesized intermediate chronotypes (INT) would have lower vascular insulin sensitivity than morning chronotype (MORN). MATERIALS AND METHODS Adults with obesity were classified per Morningness-Eveningness Questionnaire (MEQ) as either MORN (n = 27, 22 female, MEQ = 63.7 ± 4.7, 53.8 ± 6.7 years, 35.3 ± 4.9 kg/m2) or INT (n = 29, 23 female, MEQ = 48.8 ± 6.7, 56.6 ± 9.0 years, 35.7 ± 6.1 kg/m2). A 120 min euglycaemic-hyperinsulinaemic clamp (40 mU/m2/min, 90 mg/dl) was conducted to assess macrovascular insulin sensitivity via brachial artery flow-mediated dilation (%FMD; conduit artery), post-ischaemic flow velocity (resistance arteriole), as well as microvascular insulin sensitivity via contrast-enhanced ultrasound [e.g. microvascular blood volume (perfusion)]. Fasting plasma arginine and citrulline, as well as fasting and clamp-derived plasma endothelin-1 and nitrate/nitrite, were assessed as surrogates of vasoconstriction and nitric oxide-mediated vasodilation. Aerobic fitness (VO2max) and body composition (dual-energy X-ray absorptiometry) were also collected. RESULTS MORN had a higher VO2max compared with INT (p < .01), although there was no difference in fat mass. While fasting FMD was similar between groups, insulin lowered FMD corrected to shear stress and microvascular blood volume in INT compared with MORN after co-varying for VO2max (both p ≤ .02). INT also had a lower fasting nitrate (p = .03) and arginine (p = .07). Higher MEQ correlated with elevated FMD (r = 0.33, p = .03) and lower post-ischaemic flow velocity (r = -0.33, p = .03) as well as shear rate (r = -0.36, p = .02) at 120 min. CONCLUSION When measured during the morning, INT had a lower vascular insulin sensitivity than MORN. Additional work is needed to understand endothelial function differences among chronotypes to optimize cardiovascular disease risk reduction.
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Affiliation(s)
- Steven K. Malin
- Rutgers University, New Brunswick, NJ
- Division of Endocrinology, Metabolism & Nutrition; Rutgers University, New Brunswick, NJ
- New Jersey Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, NJ
- Institute of Translational Medicine and Science, Rutgers University, New Brunswick, NJ
| | | | | | | | | | | | - Zhenqi Liu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA
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Coronary Microvascular Dysfunction in Diabetes Mellitus: Pathogenetic Mechanisms and Potential Therapeutic Options. Biomedicines 2022; 10:biomedicines10092274. [PMID: 36140374 PMCID: PMC9496134 DOI: 10.3390/biomedicines10092274] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Diabetic patients are frequently affected by coronary microvascular dysfunction (CMD), a condition consisting of a combination of altered vasomotion and long-term structural change to coronary arterioles leading to impaired regulation of blood flow in response to changing cardiomyocyte oxygen requirements. The pathogenesis of this microvascular complication is complex and not completely known, involving several alterations among which hyperglycemia and insulin resistance play particularly central roles leading to oxidative stress, inflammatory activation and altered barrier function of endothelium. CMD significantly contributes to cardiac events such as angina or infarction without obstructive coronary artery disease, as well as heart failure, especially the phenotype associated with preserved ejection fraction, which greatly impact cardiovascular (CV) prognosis. To date, no treatments specifically target this vascular damage, but recent experimental studies and some clinical investigations have produced data in favor of potential beneficial effects on coronary micro vessels caused by two classes of glucose-lowering drugs: glucagon-like peptide 1 (GLP-1)-based therapy and inhibitors of sodium-glucose cotransporter-2 (SGLT2). The purpose of this review is to describe pathophysiological mechanisms, clinical manifestations of CMD with particular reference to diabetes, and to summarize the protective effects of antidiabetic drugs on the myocardial microvascular compartment.
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Velagic A, Li JC, Qin CX, Li M, Deo M, Marshall SA, Anderson D, Woodman OL, Horowitz JD, Kemp-Harper BK, Ritchie RH. Cardioprotective Actions of Nitroxyl Donor Angeli's Salt are Preserved in the Diabetic Heart and Vasculature in the Face of Nitric Oxide Resistance. Br J Pharmacol 2022; 179:4117-4135. [PMID: 35365882 PMCID: PMC9540873 DOI: 10.1111/bph.15849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 02/14/2022] [Accepted: 03/09/2022] [Indexed: 11/29/2022] Open
Abstract
Background and Purpose The risk of fatal cardiovascular events is increased in patients with type 2 diabetes mellitus (T2DM). A major contributor to poor prognosis is impaired nitric oxide (NO•) signalling at the level of tissue responsiveness, termed NO• resistance. This study aimed to determine if T2DM promotes NO• resistance in the heart and vasculature and whether tissue responsiveness to nitroxyl (HNO) is affected. Experimental Approach At 8 weeks of age, male Sprague–Dawley rats commenced a high‐fat diet. After 2 weeks, the rats received low‐dose streptozotocin (two intraperitoneal injections, 35 mg·kg−1, over two consecutive days) and continued on the same diet. Twelve weeks later, isolated hearts were Langendorff‐perfused to assess responses to the NO• donor diethylamine NONOate (DEA/NO) and the HNO donor Angeli's salt. Isolated mesenteric arteries were utilised to measure vascular responsiveness to the NO• donors sodium nitroprusside (SNP) and DEA/NO, and the HNO donor Angeli's salt. Key Results Inotropic, lusitropic and coronary vasodilator responses to DEA/NO were impaired in T2DM hearts, whereas responses to Angeli's salt were preserved or enhanced. Vasorelaxation to Angeli's salt was augmented in T2DM mesenteric arteries, which were hyporesponsive to the relaxant effects of SNP and DEA/NO. Conclusion and Implications This is the first evidence that inotropic and lusitropic responses are preserved, and NO• resistance in the coronary and mesenteric vasculature is circumvented, by the HNO donor Angeli's salt in T2DM. These findings highlight the cardiovascular therapeutic potential of HNO donors, especially in emergencies such as acute ischaemia or heart failure.
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Affiliation(s)
- Anida Velagic
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Jasmin Chendi Li
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Cheng Xue Qin
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Mandy Li
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, Australia
| | - Minh Deo
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Sarah A Marshall
- The Ritchie Centre, Department of Obstetrics and Gynaecology, School of Clinical Sciences, Monash University, VIC, Australia
| | - Dovile Anderson
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Owen L Woodman
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - John D Horowitz
- Basil Hetzel Institute, Queen Elizabeth Hospital, University of Adelaide, SA, Australia
| | - Barbara K Kemp-Harper
- Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, Australia
| | - Rebecca H Ritchie
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia.,Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, Australia
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4
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Low glucose metabolizing capacity and not insulin resistance is primary etiology of Type 2 Diabetes Mellitus: A hypothesis. Med Hypotheses 2022. [DOI: 10.1016/j.mehy.2022.110804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Shen X, He S, Wang J, Qian X, Wang H, Zhang B, Chen Y, Li H, Li G. Phenotype of higher post-load insulin response as a predictor of all-cause mortality and cardiovascular mortality in the Chinese non-diabetic population. Diabetol Metab Syndr 2022; 14:19. [PMID: 35090539 PMCID: PMC8796343 DOI: 10.1186/s13098-022-00786-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/06/2022] [Indexed: 11/10/2022] Open
Abstract
AIM This study aimed to assess whether a higher insulin response increased the long-term risk of mortality in a non-diabetic population. METHODS A total of 446 people with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) who participated in the Da Qing Diabetes Study, were stratified into quartiles subgroups according to their baseline insulin area under the curve (AUC) during oral glucose tolerance test, defined as Q1, Q2, Q3 and Q4. The participants were followed from 1986 to 2016 to assess the risk of death in association with the magnitude of post-load insulin response. RESULTS Over 30 years, the rates of all cause death were 9.94, 14.81, 15.02, and 17.58 per 1000 person-years across the four groups respectively. The rate for cardiovascular disease (CVD) death was 5.14, 6.50, 6.80 and 10.47 per 1000 person-years. Compared with Q1, the risk of all-cause death was significantly higher in participants in Q4 (HR = 2.14, 95% CI 1.34-3.42), Q3 (HR = 1.94, 95% CI 1.20-3.14), and Q2 group (HR = 1.70, 95% CI 1.06-2.74). In the Fine-Gray model with non-CVD death as competing risk, the increased insulin AUC were also significantly associated with the CVD death (Q4 vs Q1, HR = 2.04, 95% CI 1.10-3.79). In the fractional polynomial regression analysis, a nonlinear association between insulin AUC and all-cause and CVD death was demonstrated. In addition, insulin AUC was associated with a progressively higher risk of all-cause death and CVD death (fractional power 3, P < 0.001). CONCLUSION A higher post-load insulin response was significantly associated with a long-term increased risk of all-cause and CVD deaths in the Chinese non-diabetic population. It suggests that people featured by this phenotype is a potential important target for further intervention.
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Affiliation(s)
- Xiaoxia Shen
- Center of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences, No. 167 North Lishi Road, Xicheng District, Beijing, 100037, China
| | - Siyao He
- Center of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences, No. 167 North Lishi Road, Xicheng District, Beijing, 100037, China
| | - Jinping Wang
- Department of Cardiology, Da Qing First Hospital, No. 9 Zhongkang Street, Saltu District, Daqing, 163411, Heilongjiang, China
| | - Xin Qian
- Center of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences, No. 167 North Lishi Road, Xicheng District, Beijing, 100037, China
| | - Hui Wang
- Center of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences, No. 167 North Lishi Road, Xicheng District, Beijing, 100037, China
| | - Bo Zhang
- Department of Endocrinology, China-Japan Friendship Hospital, No 2, East Yinghua Road, Chaoyang District, Beijing, 100029, China
| | - Yanyan Chen
- Center of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences, No. 167 North Lishi Road, Xicheng District, Beijing, 100037, China
| | - Hui Li
- Department of Cardiology, Da Qing First Hospital, No. 9 Zhongkang Street, Saltu District, Daqing, 163411, Heilongjiang, China
| | - Guangwei Li
- Center of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences, No. 167 North Lishi Road, Xicheng District, Beijing, 100037, China.
- Department of Endocrinology, China-Japan Friendship Hospital, No 2, East Yinghua Road, Chaoyang District, Beijing, 100029, China.
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Love KM, Barrett EJ, Malin SK, Reusch JEB, Regensteiner JG, Liu Z. Diabetes pathogenesis and management: the endothelium comes of age. J Mol Cell Biol 2021; 13:500-512. [PMID: 33787922 PMCID: PMC8530521 DOI: 10.1093/jmcb/mjab024] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/10/2021] [Accepted: 02/25/2021] [Indexed: 12/03/2022] Open
Abstract
Endothelium, acting as a barrier, protects tissues against factors that provoke insulin resistance and type 2 diabetes and itself responds to the insult of insulin resistance inducers with altered function. Endothelial insulin resistance and vascular dysfunction occur early in the evolution of insulin resistance-related disease, can co-exist with and even contribute to the development of metabolic insulin resistance, and promote vascular complications in those affected. The impact of endothelial insulin resistance and vascular dysfunction varies depending on the blood vessel size and location, resulting in decreased arterial plasticity, increased atherosclerosis and vascular resistance, and decreased tissue perfusion. Women with insulin resistance and diabetes are disproportionately impacted by cardiovascular disease, likely related to differential sex-hormone endothelium effects. Thus, reducing endothelial insulin resistance and improving endothelial function in the conduit arteries may reduce atherosclerotic complications, in the resistance arteries lead to better blood pressure control, and in the microvasculature lead to less microvascular complications and more effective tissue perfusion. Multiple diabetes therapeutic modalities, including medications and exercise training, improve endothelial insulin action and vascular function. This action may delay the onset of type 2 diabetes and/or its complications, making the vascular endothelium an attractive therapeutic target for type 2 diabetes and potentially type 1 diabetes.
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MESH Headings
- Age Factors
- Cardiovascular Diseases/epidemiology
- Cardiovascular Diseases/ethnology
- Cardiovascular Diseases/metabolism
- Cardiovascular Diseases/physiopathology
- Comorbidity
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/epidemiology
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/physiopathology
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/epidemiology
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Exercise
- Female
- Humans
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Insulin Resistance
- Male
- Racial Groups
- Risk Factors
- Sex Factors
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Affiliation(s)
- Kaitlin M Love
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Eugene J Barrett
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Steven K Malin
- Department of Kinesiology and Health, Rutgers University, New Brunswick, NJ, USA
- Division of Endocrinology, Metabolism and Nutrition, Rutgers University, New Brunswick, NJ, USA
- New Jersey Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, NJ, USA
- Institute of Translational Medicine and Research, Rutgers University, New Brunswick, NJ, USA
| | - Jane E B Reusch
- Center for Women’s Health Research, University of Colorado School of Medicine, Aurora, CO, USA
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO, USA
| | - Judith G Regensteiner
- Center for Women’s Health Research, University of Colorado School of Medicine, Aurora, CO, USA
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Zhenqi Liu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
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Sorice GP, Cinti F, Leccisotti L, D'Amario D, Lorusso M, Guzzardi MA, Mezza T, Cocchi C, Capece U, Ferraro PM, Crea F, Giordano A, Iozzo P, Giaccari A. Effect of Dapagliflozin on Myocardial Insulin Sensitivity and Perfusion: Rationale and Design of The DAPAHEART Trial. Diabetes Ther 2021; 12:2101-2113. [PMID: 34037951 PMCID: PMC8266960 DOI: 10.1007/s13300-021-01083-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/12/2021] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Sodium-glucose co-transporter-2 (SGLT-2) inhibitors have been shown to have beneficial effects on various cardiovascular (CV) outcomes in patients with type 2 diabetes (T2D) in primary prevention and in those with a high CV risk profile. However, the mechanism(s) responsible for these CV benefits remain elusive and unexplained. The aim of the DAPAHEART study will be to demonstrate that treatment with SGLT-2 inhibitors is associated with greater myocardial insulin sensitivity in patients with T2D, and to determine whether this improvement can be attributed to a decrease in whole-body (and tissue-specific) insulin resistance and to increased myocardial perfusion and/or glucose uptake. We will also determine whether there is an appreciable degree of improvement in myocardial-wall conditions subtended by affected and non-affected coronary vessels, and if this relates to changes in left ventricular function. METHODS The DAPAHEART trial will be a phase III, single-center, randomized, two-arm, parallel-group, double-blind, placebo-controlled study. A cohort of 52 T2D patients with stable coronary artery disease (without any previous history of myocardial infarction, with or without previous percutaneous coronary intervention), with suboptimal glycemic control (glycated hemoglobin [HbA1c] 7-8.5%) on their current standard of care anti-hyperglycemic regimen, will be randomized in a 1:1 ratio to dapagliflozin or placebo. The primary outcome is to detect changes in myocardial glucose uptake from baseline to 4 weeks after treatment initiation. The main secondary outcome will be changes in myocardial blood flow, as measured by 13N-ammonia positron emission tomography/computed tomography (PET/CT). Other outcomes include cardiac function, glucose uptake in skeletal muscle, adipose tissue, liver, brain and kidney, as assessed by fluorodeoxyglucose (FDG) PET-CT imaging during hyperinsulinemic-euglycemic clamp; pericardial, subcutaneous and visceral fat, and browning as observed on CT images during FDG PET-CT studies; systemic insulin sensitivity, as assessed by hyperinsulinemic-euglycemic clamp, glycemic control, urinary glucose output; and microbiota modification. DISCUSSION SGLT-2 inhibitors, in addition to their insulin-independent plasma glucose-lowering effect, are able to directly (substrate availability, fuel utilization, insulin sensitivity) as well as indirectly (cardiac after-load reduction, decreased risk factors for heart failure) affect myocardial functions. Our study will provide novel insights into how these drugs exert CV protection in a diabetic population. TRIAL REGISTRATION EudraCT No. 2016-003614-27; ClinicalTrials.gov Identifier: NCT03313752.
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Affiliation(s)
- Gian Pio Sorice
- Dipartimento di Scienze Mediche e Chirurgiche, Centro Malattie Endocrine e Metaboliche, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Francesca Cinti
- Dipartimento di Scienze Mediche e Chirurgiche, Centro Malattie Endocrine e Metaboliche, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Lucia Leccisotti
- Dipartimento di Diagnostica Per Immagini, Radioterapia Oncologica ed Ematologia, UOC di Medicina Nucleare, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Domenico D'Amario
- Dipartimento di Scienze Cardiovascolari, UOC di Cardiologia, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Margherita Lorusso
- Dipartimento di Diagnostica Per Immagini, Radioterapia Oncologica ed Ematologia, UOC di Medicina Nucleare, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Maria Angela Guzzardi
- Istituto di Fisiologia Clinica, Consiglio Nazionale Delle Ricerche (CNR), Pisa, Italy
| | - Teresa Mezza
- Dipartimento di Scienze Mediche e Chirurgiche, Centro Malattie Endocrine e Metaboliche, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Camilla Cocchi
- Dipartimento di Scienze Mediche e Chirurgiche, Centro Malattie Endocrine e Metaboliche, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Umberto Capece
- Dipartimento di Scienze Mediche e Chirurgiche, Centro Malattie Endocrine e Metaboliche, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Pietro Manuel Ferraro
- Dipartimento di Scienze Mediche e Chirurgiche, UOC di Nefrologia, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Filippo Crea
- Dipartimento di Scienze Cardiovascolari, UOC di Cardiologia, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Alessandro Giordano
- Dipartimento di Diagnostica Per Immagini, Radioterapia Oncologica ed Ematologia, UOC di Medicina Nucleare, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy
| | - Patricia Iozzo
- Istituto di Fisiologia Clinica, Consiglio Nazionale Delle Ricerche (CNR), Pisa, Italy
| | - Andrea Giaccari
- Dipartimento di Scienze Mediche e Chirurgiche, Centro Malattie Endocrine e Metaboliche, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy.
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Love KM, Liu J, Regensteiner JG, Reusch JE, Liu Z. GLP-1 and insulin regulation of skeletal and cardiac muscle microvascular perfusion in type 2 diabetes. J Diabetes 2020; 12:488-498. [PMID: 32274893 PMCID: PMC8393916 DOI: 10.1111/1753-0407.13045] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/24/2020] [Accepted: 03/31/2020] [Indexed: 12/25/2022] Open
Abstract
Muscle microvasculature critically regulates skeletal and cardiac muscle health and function. It provides endothelial surface area for substrate exchange between the plasma compartment and the muscle interstitium. Insulin fine-tunes muscle microvascular perfusion to regulate its own action in muscle and oxygen and nutrient supplies to muscle. Specifically, insulin increases muscle microvascular perfusion, which results in increased delivery of insulin to the capillaries that bathe the muscle cells and then facilitate its own transendothelial transport to reach the muscle interstitium. In type 2 diabetes, muscle microvascular responses to insulin are blunted and there is capillary rarefaction. Both loss of capillary density and decreased insulin-mediated capillary recruitment contribute to a decreased endothelial surface area available for substrate exchange. Vasculature expresses abundant glucagon-like peptide 1 (GLP-1) receptors. GLP-1, in addition to its well-characterized glycemic actions, improves endothelial function, increases muscle microvascular perfusion, and stimulates angiogenesis. Importantly, these actions are preserved in the insulin resistant states. Thus, treatment of insulin resistant patients with GLP-1 receptor agonists may improve skeletal and cardiac muscle microvascular perfusion and increase muscle capillarization, leading to improved delivery of oxygen, nutrients, and hormones such as insulin to the myocytes. These actions of GLP-1 impact skeletal and cardiac muscle function and systems biology such as functional exercise capacity. Preclinical studies and clinical trials involving the use of GLP-1 receptor agonists have shown salutary cardiovascular effects and improved cardiovascular outcomes in type 2 diabetes mellitus. Future studies should further examine the different roles of GLP-1 in cardiac as well as skeletal muscle function.
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Affiliation(s)
- Kaitlin M. Love
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - Jia Liu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - Judith G. Regensteiner
- Center for Women’s Health Research, University of Colorado School of Medicine, Aurora, Colorado
- Department of Medicine, University of Colorado, Aurora, Colorado
| | - Jane E.B. Reusch
- Center for Women’s Health Research, University of Colorado School of Medicine, Aurora, Colorado
- Department of Medicine, University of Colorado, Aurora, Colorado
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado
| | - Zhenqi Liu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
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9
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Mereweather LJ, Montes Aparicio CN, Heather LC. Positioning Metabolism as a Central Player in the Diabetic Heart. J Lipid Atheroscler 2020; 9:92-109. [PMID: 32821724 PMCID: PMC7379068 DOI: 10.12997/jla.2020.9.1.92] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/28/2019] [Accepted: 12/29/2019] [Indexed: 12/13/2022] Open
Abstract
In type 2 diabetes (T2D), the leading cause of death is cardiovascular complications. One mechanism contributing to cardiac pathogenesis is alterations in metabolism, with the diabetic heart exhibiting increased fatty acid oxidation and reduced glucose utilisation. The processes classically thought to underlie this metabolic shift include the Randle cycle and changes to gene expression. More recently, alternative mechanisms have been proposed, most notably, changes in post-translational modification of mitochondrial proteins in the heart. This increased understanding of how metabolism is altered in the diabetic heart has highlighted new therapeutic targets, with an aim to improve cardiac function in T2D. This review focuses on metabolism in the healthy heart and how this is modified in T2D, providing evidence for the mechanisms underlying this shift. There will be emphasis on the current treatments for the heart in diabetes, alongside efforts for metabocentric pharmacological therapies.
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Affiliation(s)
- Laura J Mereweather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | | | - Lisa C Heather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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10
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Contribution of Impaired Insulin Signaling to the Pathogenesis of Diabetic Cardiomyopathy. Int J Mol Sci 2019; 20:ijms20112833. [PMID: 31212580 PMCID: PMC6600234 DOI: 10.3390/ijms20112833] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/19/2022] Open
Abstract
Diabetic cardiomyopathy (DCM) has emerged as a relevant cause of heart failure among the diabetic population. Defined as a cardiac dysfunction that develops in diabetic patients independently of other major cardiovascular risks factors, such as high blood pressure and coronary artery disease, the underlying cause of DCMremains to be unveiled. Several pathogenic factors, including glucose and lipid toxicity, mitochondrial dysfunction, increased oxidative stress, sustained activation of the renin-angiotensin system (RAS) or altered calcium homeostasis, have been shown to contribute to the structural and functional alterations that characterize diabetic hearts. However, all these pathogenic mechanisms appear to stem from the metabolic inflexibility imposed by insulin resistance or lack of insulin signaling. This results in absolute reliance on fatty acids for the synthesis of ATP and impairment of glucose oxidation. Glucose is then rerouted to other metabolic pathways, with harmful effects on cardiomyocyte function. Here, we discuss the role that impaired cardiac insulin signaling in diabetic or insulin-resistant individuals plays in the onset and progression of DCM.
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Sikder K, Shukla SK, Patel N, Singh H, Rafiq K. High Fat Diet Upregulates Fatty Acid Oxidation and Ketogenesis via Intervention of PPAR-γ. Cell Physiol Biochem 2018; 48:1317-1331. [PMID: 30048968 PMCID: PMC6179152 DOI: 10.1159/000492091] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/25/2018] [Indexed: 01/07/2023] Open
Abstract
Background/Aims: Systemic hyperlipidemia and intracellular lipid accumulation induced by chronic high fat diet (HFD) leads to enhanced fatty acid oxidation (FAO) and ketogenesis. The present study was aimed to determine whether activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) by surplus free fatty acids (FA) in hyperlipidemic condition, has a positive feedback regulation over FAO and ketogenic enzymes controlling lipotoxicity and cardiac apoptosis. Methods: 8 weeks old C57BL/6 wild type (WT) or PPAR-γ−/− mice were challenged with 16 weeks 60% HFD to induce obesity mediated type 2 diabetes mellitus (T2DM) and diabetic cardiomyopathy. Treatment course was followed by echocardiographic measurements, glycemic and lipid profiling, immunoblot, qPCR and immunohistochemistry (IHC) analysis of PPAR-γ and following mitochondrial metabolic enzymes 3-hydroxy-3- methylglutaryl-CoA synthase (HMGCS2), mitochondrial β-hydroxy butyrate dehydrogenase (BDH1) and pyruvate dehydrogenase kinase isoform 4 (PDK4). In vivo model was translated in vitro, with neonatal rat cardiomyocytes (NRCM) treated with PPAR-γ agonist/antagonist and PPAR-γ overexpression adenovirus in presence of palmitic acid (PA). Apoptosis was determined in vivo from left ventricular heart by TUNEL assay and immunoblot analysis. Results: We found exaggerated circulating ketone bodies production and expressions of the related mitochondrial enzymes HMGCS2, BDH1 and PDK4 in HFD-induced diabetic hearts and in PA-treated NRCM. As a mechanistic approach we found HFD mediated activation of PPAR-03B3 is associated with the above-mentioned mitochondrial enzymes. HFD-fed PPAR-γ−/− mice display decreased hyperglycemia, hyperlipidemia associated with increased insulin responsiveness as compared to HFD-fed WT mice PPAR-γ−/−−HFD mice demonstrated a more robust functional recovery after diabetes induction, as well as significantly reduced myocyte apoptosis and improved cardiac function. Conclusions: PPAR-γ has been described previously to regulate lipid metabolism and adipogenesis. The present study suggests for the first time that increased PPAR-γ expression by HFD is responsible for cardiac dysfunction via upregulation of mitochondrial enzymes HMGCS2, BDH1 and PDK4. Targeting PPAR-γ and its downstream mitochondrial enzymes will provide novel strategies in preventing metabolic and myocardial dysfunction in diabetes mellitus.
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Affiliation(s)
- Kunal Sikder
- Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sanket Kumar Shukla
- Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Neel Patel
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Harpreet Singh
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Khadija Rafiq
- Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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Mansor LS, Sousa Fialho MDL, Yea G, Coumans WA, West JA, Kerr M, Carr CA, Luiken JJFP, Glatz JFC, Evans RD, Griffin JL, Tyler DJ, Clarke K, Heather LC. Inhibition of sarcolemmal FAT/CD36 by sulfo-N-succinimidyl oleate rapidly corrects metabolism and restores function in the diabetic heart following hypoxia/reoxygenation. Cardiovasc Res 2018; 113:737-748. [PMID: 28419197 PMCID: PMC5437367 DOI: 10.1093/cvr/cvx045] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 03/23/2017] [Indexed: 11/14/2022] Open
Abstract
Aims The type 2 diabetic heart oxidizes more fat and less glucose, which can impair metabolic flexibility and function. Increased sarcolemmal fatty acid translocase (FAT/CD36) imports more fatty acid into the diabetic myocardium, feeding increased fatty acid oxidation and elevated lipid deposition. Unlike other metabolic modulators that target mitochondrial fatty acid oxidation, we proposed that pharmacologically inhibiting fatty acid uptake, as the primary step in the pathway, would provide an alternative mechanism to rebalance metabolism and prevent lipid accumulation following hypoxic stress. Methods and results Hearts from type 2 diabetic and control male Wistar rats were perfused in normoxia, hypoxia and reoxygenation, with the FAT/CD36 inhibitor sulfo-N-succinimidyl oleate (SSO) infused 4 min before hypoxia. SSO infusion into diabetic hearts decreased the fatty acid oxidation rate by 29% and myocardial triglyceride concentration by 48% compared with untreated diabetic hearts, restoring fatty acid metabolism to control levels following hypoxia-reoxygenation. SSO infusion increased the glycolytic rate by 46% in diabetic hearts during hypoxia, increased pyruvate dehydrogenase activity by 53% and decreased lactate efflux rate by 56% compared with untreated diabetic hearts during reoxygenation. In addition, SSO treatment of diabetic hearts increased intermediates within the second span of the Krebs cycle, namely fumarate, oxaloacetate, and the FAD total pool. The cardiac dysfunction in diabetic hearts following decreased oxygen availability was prevented by SSO-infusion prior to the hypoxic stress. Infusing SSO into diabetic hearts increased rate pressure product by 60% during hypoxia and by 32% following reoxygenation, restoring function to control levels. Conclusions Diabetic hearts have limited metabolic flexibility and cardiac dysfunction when stressed, which can be rapidly rectified by reducing fatty acid uptake with the FAT/CD36 inhibitor, SSO. This novel therapeutic approach not only reduces fat oxidation but also lipotoxicity, by targeting the primary step in the fatty acid metabolism pathway.
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Affiliation(s)
- Latt S Mansor
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Maria da Luz Sousa Fialho
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Georgina Yea
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Will A Coumans
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - James A West
- Department of Biochemistry, University of Cambridge, and MRC Human Nutrition Research, Cambridge, UK
| | - Matthew Kerr
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Carolyn A Carr
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Joost J F P Luiken
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Jan F C Glatz
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Rhys D Evans
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Julian L Griffin
- Department of Biochemistry, University of Cambridge, and MRC Human Nutrition Research, Cambridge, UK
| | - Damian J Tyler
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Lisa C Heather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
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Barrett EJ, Liu Z, Khamaisi M, King GL, Klein R, Klein BEK, Hughes TM, Craft S, Freedman BI, Bowden DW, Vinik AI, Casellini CM. Diabetic Microvascular Disease: An Endocrine Society Scientific Statement. J Clin Endocrinol Metab 2017; 102:4343-4410. [PMID: 29126250 PMCID: PMC5718697 DOI: 10.1210/jc.2017-01922] [Citation(s) in RCA: 295] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 08/29/2017] [Indexed: 01/18/2023]
Abstract
Both type 1 and type 2 diabetes adversely affect the microvasculature in multiple organs. Our understanding of the genesis of this injury and of potential interventions to prevent, limit, or reverse injury/dysfunction is continuously evolving. This statement reviews biochemical/cellular pathways involved in facilitating and abrogating microvascular injury. The statement summarizes the types of injury/dysfunction that occur in the three classical diabetes microvascular target tissues, the eye, the kidney, and the peripheral nervous system; the statement also reviews information on the effects of diabetes and insulin resistance on the microvasculature of skin, brain, adipose tissue, and cardiac and skeletal muscle. Despite extensive and intensive research, it is disappointing that microvascular complications of diabetes continue to compromise the quantity and quality of life for patients with diabetes. Hopefully, by understanding and building on current research findings, we will discover new approaches for prevention and treatment that will be effective for future generations.
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Affiliation(s)
- Eugene J. Barrett
- Division of Endocrinology, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
| | - Zhenqi Liu
- Division of Endocrinology, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
| | - Mogher Khamaisi
- Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215
| | - George L. King
- Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215
| | - Ronald Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Barbara E. K. Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Timothy M. Hughes
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Suzanne Craft
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Barry I. Freedman
- Divisions of Nephrology and Endocrinology, Department of Internal Medicine, Centers for Diabetes Research, and Center for Human Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Donald W. Bowden
- Divisions of Nephrology and Endocrinology, Department of Internal Medicine, Centers for Diabetes Research, and Center for Human Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Aaron I. Vinik
- EVMS Strelitz Diabetes Center, Eastern Virginia Medical Center, Norfolk, Virginia 23510
| | - Carolina M. Casellini
- EVMS Strelitz Diabetes Center, Eastern Virginia Medical Center, Norfolk, Virginia 23510
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Brahma MK, Pepin ME, Wende AR. My Sweetheart Is Broken: Role of Glucose in Diabetic Cardiomyopathy. Diabetes Metab J 2017; 41:1-9. [PMID: 28236380 PMCID: PMC5328690 DOI: 10.4093/dmj.2017.41.1.1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 10/11/2016] [Indexed: 01/09/2023] Open
Abstract
Despite overall reductions in heart disease prevalence, the risk of developing heart failure has remained 2-fold greater among people with diabetes. Growing evidence has supported that fluctuations in glucose level and uptake contribute to cardiovascular disease (CVD) by modifying proteins, DNA, and gene expression. In the case of glucose, clinical studies have shown that increased dietary sugars for healthy individuals or poor glycemic control in diabetic patients further increased CVD risk. Furthermore, even after decades of maintaining tight glycemic control, susceptibility to disease progression can persist following a period of poor glycemic control through a process termed "glycemic memory." In response to chronically elevated glucose levels, a number of studies have identified molecular targets of the glucose-mediated protein posttranslational modification by the addition of an O-linked N-acetylglucosamine to impair contractility, calcium sensitivity, and mitochondrial protein function. Additionally, elevated glucose contributes to dysfunction in coupling glycolysis to glucose oxidation, pentose phosphate pathway, and polyol pathway. Therefore, in the "sweetened" environment associated with hyperglycemia, there are a number of pathways contributing to increased susceptibly to "breaking" the heart of diabetics. In this review we will discuss the unique contribution of glucose to heart disease and recent advances in defining mechanisms of action.
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Affiliation(s)
- Manoja K Brahma
- Division of Molecular and Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mark E Pepin
- Division of Molecular and Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Biomedical Engineering, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Adam R Wende
- Division of Molecular and Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL, USA.
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Mishra PK, Ying W, Nandi SS, Bandyopadhyay GK, Patel KK, Mahata SK. Diabetic Cardiomyopathy: An Immunometabolic Perspective. Front Endocrinol (Lausanne) 2017; 8:72. [PMID: 28439258 PMCID: PMC5384479 DOI: 10.3389/fendo.2017.00072] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/27/2017] [Indexed: 12/12/2022] Open
Abstract
The heart possesses a remarkable inherent capability to adapt itself to a wide array of genetic and extrinsic factors to maintain contractile function. Failure to sustain its compensatory responses results in cardiac dysfunction, leading to cardiomyopathy. Diabetic cardiomyopathy (DCM) is characterized by left ventricular hypertrophy and reduced diastolic function, with or without concurrent systolic dysfunction in the absence of hypertension and coronary artery disease. Changes in substrate metabolism, oxidative stress, endoplasmic reticulum stress, formation of extracellular matrix proteins, and advanced glycation end products constitute the early stage in DCM. These early events are followed by steatosis (accumulation of lipid droplets) in cardiomyocytes, which is followed by apoptosis, changes in immune responses with a consequent increase in fibrosis, remodeling of cardiomyocytes, and the resultant decrease in cardiac function. The heart is an omnivore, metabolically flexible, and consumes the highest amount of ATP in the body. Altered myocardial substrate and energy metabolism initiate the development of DCM. Diabetic hearts shift away from the utilization of glucose, rely almost completely on fatty acids (FAs) as the energy source, and become metabolically inflexible. Oxidation of FAs is metabolically inefficient as it consumes more energy. In addition to metabolic inflexibility and energy inefficiency, the diabetic heart suffers from impaired calcium handling with consequent alteration of relaxation-contraction dynamics leading to diastolic and systolic dysfunction. Sarcoplasmic reticulum (SR) plays a key role in excitation-contraction coupling as Ca2+ is transported into the SR by the SERCA2a (sarcoplasmic/endoplasmic reticulum calcium-ATPase 2a) during cardiac relaxation. Diabetic cardiomyocytes display decreased SERCA2a activity and leaky Ca2+ release channel resulting in reduced SR calcium load. The diabetic heart also suffers from marked downregulation of novel cardioprotective microRNAs (miRNAs) discovered recently. Since immune responses and substrate energy metabolism are critically altered in diabetes, the present review will focus on immunometabolism and miRNAs.
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Affiliation(s)
- Paras K. Mishra
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
- Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE, USA
- *Correspondence: Paras K. Mishra, ; Sushil K. Mahata,
| | - Wei Ying
- Department of Medicine, Metabolic Physiology and Ultrastructural Biology Laboratory, University of California San Diego, La Jolla, CA, USA
| | - Shyam Sundar Nandi
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Gautam K. Bandyopadhyay
- Department of Medicine, Metabolic Physiology and Ultrastructural Biology Laboratory, University of California San Diego, La Jolla, CA, USA
| | - Kaushik K. Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sushil K. Mahata
- Department of Medicine, Metabolic Physiology and Ultrastructural Biology Laboratory, University of California San Diego, La Jolla, CA, USA
- Department of Medicine, Metabolic Physiology and Ultrastructural Biology Laboratory, VA San Diego Healthcare System, San Diego, CA, USA
- *Correspondence: Paras K. Mishra, ; Sushil K. Mahata,
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16
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Bai D, Zhang Y, Shen M, Sun Y, Xia Q, Zhang Y, Liu X, Wang H, Yuan L. Hyperglycemia and hyperlipidemia blunts the Insulin-Inpp5f negative feedback loop in the diabetic heart. Sci Rep 2016; 6:22068. [PMID: 26908121 PMCID: PMC4764951 DOI: 10.1038/srep22068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 02/05/2016] [Indexed: 01/30/2023] Open
Abstract
The leading cause of death in diabetic patients is diabetic cardiomyopathy, in which alteration of Akt signal plays an important role. Inpp5f is recently found to be a negative regulator of Akt signaling, while its expression and function in diabetic heart is largely unknown. In this study, we found that in both the streptozotocin (STZ) and high fat diet (HFD) induced diabetic mouse models, Inpp5f expression was coordinately regulated by insulin, blood glucose and lipid levels. Increased Inpp5f was inversely correlated with the cardiac function. Further studies revealed that Insulin transcriptionally activated Inpp5f in an Sp1 dependent manner, and increased Inpp5f in turn reduced the phosphorylation of Akt, forming a negative feedback loop. The negative feedback plays a protective role under diabetic condition. However, high blood glucose and lipid, which are characteristics of uncontrolled diabetes and type 2 diabetes, increased Inpp5f expression through activation of NF-κB, blunts the protective feedback. Thus, our study has revealed that Inpp5f provides as a negative feedback regulator of insulin signaling and downregulation of Inpp5f in diabetes is cardioprotective. Increased Inpp5f by hyperglycemia and hyperlipidemia is an important mediator of diabetic cardiomyopathy and is a promising therapeutic target for the disease.
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Affiliation(s)
- Danna Bai
- Department of Cardiology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, China.,323 Hospital of PLA, Xi'an 710054, China
| | - Yajun Zhang
- Department of Ultrasound Diagnostics, Tangdu Hospital, the Fourth Military Medical University, Xi'an 710038, China
| | - Mingzhi Shen
- Department of Cardiology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, China.,Department of Cardiology, Hainan Branch of PLA General Hospital, Sanya 572013, China
| | | | - Qing Xia
- 323 Hospital of PLA, Xi'an 710054, China
| | - Yingmei Zhang
- Department of Cardiology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, China
| | - Xuedong Liu
- Department of Neurology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, China
| | - Haichang Wang
- Department of Cardiology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, China
| | - Lijun Yuan
- Department of Ultrasound Diagnostics, Tangdu Hospital, the Fourth Military Medical University, Xi'an 710038, China
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Mansor LS, Mehta K, Aksentijevic D, Carr CA, Lund T, Cole MA, Le Page L, Sousa Fialho MDL, Shattock MJ, Aasum E, Clarke K, Tyler DJ, Heather LC. Increased oxidative metabolism following hypoxia in the type 2 diabetic heart, despite normal hypoxia signalling and metabolic adaptation. J Physiol 2016; 594:307-20. [PMID: 26574233 PMCID: PMC4713751 DOI: 10.1113/jp271242] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 11/10/2015] [Indexed: 01/13/2023] Open
Abstract
KEY POINTS Adaptation to hypoxia makes the heart more oxygen efficient, by metabolising more glucose. In contrast, type 2 diabetes makes the heart metabolise more fatty acids. Diabetes increases the chances of the heart being exposed to hypoxia, but whether the diabetic heart can adapt and respond is unknown. In this study we show that diabetic hearts retain the ability to adapt their metabolism in response to hypoxia, with functional hypoxia signalling pathways. However, the hypoxia-induced changes in metabolism are additive to abnormal baseline metabolism, resulting in hypoxic diabetic hearts metabolising more fat and less glucose than controls. This stops the diabetic heart being able to recover its function when stressed. These results demonstrate that the diabetic heart retains metabolic flexibility to adapt to hypoxia, but is hindered by the baseline effects of the disease. This increases our understanding of how the diabetic heart is affected by hypoxia-associated complications of the disease. ABSTRACT Hypoxia activates the hypoxia-inducible factor (HIF), promoting glycolysis and suppressing mitochondrial respiration. In the type 2 diabetic heart, glycolysis is suppressed whereas fatty acid metabolism is promoted. The diabetic heart experiences chronic hypoxia as a consequence of increased obstructive sleep apnoea and cardiovascular disease. Given the opposing metabolic effects of hypoxia and diabetes, we questioned whether diabetes affects cardiac metabolic adaptation to hypoxia. Control and type 2 diabetic rats were housed for 3 weeks in normoxia or 11% oxygen. Metabolism and function were measured in the isolated perfused heart using radiolabelled substrates. Following chronic hypoxia, both control and diabetic hearts upregulated glycolysis, lactate efflux and glycogen content and decreased fatty acid oxidation rates, with similar activation of HIF signalling pathways. However, hypoxia-induced changes were superimposed on diabetic hearts that were metabolically abnormal in normoxia, resulting in glycolytic rates 30% lower, and fatty acid oxidation 36% higher, in hypoxic diabetic hearts than hypoxic controls. Peroxisome proliferator-activated receptor α target proteins were suppressed by hypoxia, but activated by diabetes. Mitochondrial respiration in diabetic hearts was divergently activated following hypoxia compared with controls. These differences in metabolism were associated with decreased contractile recovery of the hypoxic diabetic heart following an acute hypoxic insult. In conclusion, type 2 diabetic hearts retain metabolic flexibility to adapt to hypoxia, with normal HIF signalling pathways. However, they are more dependent on oxidative metabolism following hypoxia due to abnormal normoxic metabolism, which was associated with a functional deficit in response to stress.
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Affiliation(s)
- Latt S Mansor
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Keshavi Mehta
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Dunja Aksentijevic
- British Heart Foundation Centre of Research Excellence, King's College London, The Rayne Institute, London, UK
| | - Carolyn A Carr
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Trine Lund
- Department of Medical Biology, University of Tromso, Norway
| | - Mark A Cole
- University of Nottingham Medical School, Queens Medical Centre, Nottingham, UK
| | - Lydia Le Page
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | | | - Michael J Shattock
- British Heart Foundation Centre of Research Excellence, King's College London, The Rayne Institute, London, UK
| | - Ellen Aasum
- Department of Medical Biology, University of Tromso, Norway
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Damian J Tyler
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Lisa C Heather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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Holzem KM, Marmerstein JT, Madden EJ, Efimov IR. Diet-induced obesity promotes altered remodeling and exacerbated cardiac hypertrophy following pressure overload. Physiol Rep 2015; 3:3/8/e12489. [PMID: 26290533 PMCID: PMC4562575 DOI: 10.14814/phy2.12489] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Heart failure (HF) is the end stage of cardiovascular disease, in which hypertrophic remodeling no longer meets cardiac output demand. Established animal models of HF have provided insights into disease pathogenesis. However, these models are developed on dissimilar metabolic backgrounds from humans – patients with HF are frequently overweight or obese, whereas animal models of HF are typically lean. Thus, we aimed to develop and investigate model for cardiac hypertrophy and failure that also recapitulates the cardiometabolic state of HF in humans. We subjected mice with established diet-induced obesity (DIO) to cardiac pressure overload provoked by transverse aortic constriction (TAC). Briefly, we fed WT male mice a normal chow or high-fat diet for 10 weeks prior to sham/TAC procedures and until surgical follow-up. We then analyzed cardiac hypertrophy, mechanical function, and electrophysiology at 5–6 weeks after surgery. In DIO mice with TAC, hypertrophy and systolic dysfunction were exacerbated relative to chow TAC animals, which showed minimal remodeling with our moderate constriction intensity. Normalized heart weight was 55.8% greater and fractional shortening was 30.9% less in DIO TAC compared with chow TAC hearts. However, electrophysiologic properties were surprisingly similar between DIO sham and TAC animals. To examine molecular pathways activated by DIO and TAC, we screened prohypertrophic signaling cascades, and the exacerbated remodeling was associated with early activation of the c-Jun-N-terminal kinase (JNK1/2) signaling pathway. Thus, DIO aggravates the progression of hypertrophy and HF caused by pressure overload, which is associated with JNK1/2 signaling, and cardiometabolic state can significantly modify HF pathogenesis.
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Affiliation(s)
- Katherine M Holzem
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Joseph T Marmerstein
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Eli J Madden
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Igor R Efimov
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
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In vivo cardiac glucose metabolism in the high-fat fed mouse: Comparison of euglycemic-hyperinsulinemic clamp derived measures of glucose uptake with a dynamic metabolomic flux profiling approach. Biochem Biophys Res Commun 2015; 463:818-24. [PMID: 26086096 DOI: 10.1016/j.bbrc.2015.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 06/02/2015] [Indexed: 11/23/2022]
Abstract
RATIONALE Cardiac metabolism is thought to be altered in insulin resistance and type 2 diabetes (T2D). Our understanding of the regulation of cardiac substrate metabolism and insulin sensitivity has largely been derived from ex vivo preparations which are not subject to the same metabolic regulation as in the intact heart in vivo. Studies are therefore required to examine in vivo cardiac glucose metabolism under physiologically relevant conditions. OBJECTIVE To determine the temporal pattern of the development of cardiac insulin resistance and to compare with dynamic approaches to interrogate cardiac glucose and intermediary metabolism in vivo. METHODS AND RESULTS Studies were conducted to determine the evolution of cardiac insulin resistance in C57Bl/6 mice fed a high-fat diet (HFD) for between 1 and 16 weeks. Dynamic in vivo cardiac glucose metabolism was determined following oral administration of [U-(13)C] glucose. Hearts were collected after 15 and 60 min and flux profiling was determined by measuring (13)C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates. Cardiac insulin resistance, determined by euglycemic-hyperinsulinemic clamp, was evident after 3 weeks of HFD. Despite the presence of insulin resistance, in vivo cardiac glucose metabolism following oral glucose administration was not compromised in HFD mice. This contrasts our recent findings in skeletal muscle, where TCA cycle activity was reduced in mice fed a HFD. Similar to our report in muscle, glucose derived pyruvate entry into the TCA cycle in the heart was almost exclusively via pyruvate dehydrogenase, with pyruvate carboxylase mediated anaplerosis being negligible after oral glucose administration. CONCLUSIONS Under experimental conditions which closely mimic the postprandial state, the insulin resistant mouse heart retains the ability to stimulate glucose metabolism.
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Nolan CJ, Ruderman NB, Kahn SE, Pedersen O, Prentki M. Insulin resistance as a physiological defense against metabolic stress: implications for the management of subsets of type 2 diabetes. Diabetes 2015; 64:673-86. [PMID: 25713189 PMCID: PMC4338588 DOI: 10.2337/db14-0694] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Stratifying the management of type 2 diabetes (T2D) has to take into account marked variability in patient phenotype due to heterogeneity in its pathophysiology, different stages of the disease process, and multiple other patient factors including comorbidities. The focus here is on the very challenging subgroup of patients with T2D who are overweight or obese with insulin resistance (IR) and the most refractory hyperglycemia due to an inability to change lifestyle to reverse positive energy balance. For this subgroup of patients with T2D, we question the dogma that IR is primarily harmful to the body and should be counteracted at any cost. Instead we propose that IR, particularly in this high-risk subgroup, is a defense mechanism that protects critical tissues of the cardiovascular system from nutrient-induced injury. Overriding IR in an effort to lower plasma glucose levels, particularly with intensive insulin therapy, could therefore be harmful. Treatments that nutrient off-load to lower glucose are more likely to be beneficial. The concepts of "IR as an adaptive defense mechanism" and "insulin-induced metabolic stress" may provide explanation for some of the unexpected outcomes of recent major clinical trials in T2D. Potential molecular mechanisms underlying these concepts; their clinical implications for stratification of T2D management, particularly in overweight and obese patients with difficult glycemic control; and future research requirements are discussed.
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Affiliation(s)
- Christopher J Nolan
- Department of Endocrinology at Canberra Hospital and the Australian National University Medical School, Canberra, Australia
| | - Neil B Ruderman
- Diabetes Research Unit, Boston University Medical Center, Boston, MA
| | - Steven E Kahn
- Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System, and University of Washington, Seattle, WA
| | - Oluf Pedersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marc Prentki
- CRCHUM and Montreal Diabetes Research Center and Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, Quebec, Canada
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Abstract
Cardiomyopathy, the presence of cardiac dysfunction independent of ischemic heart disease and/or hypertension, is becoming a more prominent condition in our diabetic patient population. Unfortunately, we do not yet understand the mechanism(s) responsible for causing diabetic cardiomyopathy. With the recent explosion in the obesity and Type 2 diabetes epidemic, our understanding of dyslipidemia and the adverse effects of lipid surplus on cellular and organ function has grown considerably. Numerous studies now illustrate that excess lipid accumulation may exert direct toxic effects on cellular function, a term coined 'lipotoxicity'. As obesity and Type 2 diabetes are significant risk factors for cardiovascular disease, cardiac lipotoxicity may represent a significant component mediating the diabetic cardiomyopathy phenotype. Therefore, a more complete understanding of how cardiac lipotoxicity is regulated and how different lipid metabolites cause cellular dysfunction may lead to the discovery of novel targets to treat cardiomyopathy in our diabetic patient population.
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Affiliation(s)
- John R Ussher
- Lunenfeld-Tanenbaum, Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada
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22
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Bayeva M, Sawicki KT, Ardehali H. Taking diabetes to heart--deregulation of myocardial lipid metabolism in diabetic cardiomyopathy. J Am Heart Assoc 2013; 2:e000433. [PMID: 24275630 PMCID: PMC3886738 DOI: 10.1161/jaha.113.000433] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Marina Bayeva
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL
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23
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Taegtmeyer H, Beauloye C, Harmancey R, Hue L. Insulin resistance protects the heart from fuel overload in dysregulated metabolic states. Am J Physiol Heart Circ Physiol 2013; 305:H1693-7. [PMID: 24097426 DOI: 10.1152/ajpheart.00854.2012] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Reversing impaired insulin sensitivity has been suggested as treatment for heart failure. However, recent clinical evidence suggests the opposite. Here we present a line of reasoning in support of the hypothesis that insulin resistance protects the heart from the consequences of fuel overload in the dysregulated metabolic state of obesity and diabetes. We discuss pathways of myocardial fuel toxicity, as well as several layers of defense against fuel overload. Our reassessment of the literature suggests that in the heart, insulin-sensitizing agents result in an elimination of some of the defenses, leading to cytotoxic damage. In contrast, a normalization of fuel supply should either prevent or reverse the process. Taken together, we offer a new perspective on insulin resistance of the heart.
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Affiliation(s)
- Heinrich Taegtmeyer
- Division of Cardiology, Department of Internal Medicine, The University of Texas School of Medicine at Houston, Houston, Texas
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24
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Affiliation(s)
- Christopher J Nolan
- ACT Health Diabetes Service and Australian National University Medical School, Canberra, ACT, Australia 2606.
| | - Neil B Ruderman
- Diabetes Research Unit, Boston University Medical Center, Boston, MA, USA
| | - Marc Prentki
- CR-CHUM and Montreal Diabetes Research Center and Departments of Nutrition and Biochemistry, University of Montreal, Montreal, QC, Canada
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25
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Ibrahim HH, Korah TE, Badr EA, Elshafie MK. Serum resistin in acute myocardial infarction patients with and without diabetes mellitus. Egypt Heart J 2012. [DOI: 10.1016/j.ehj.2011.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
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26
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Despa S, Margulies KB, Chen L, Knowlton AA, Havel PJ, Taegtmeyer H, Bers DM, Despa F. Hyperamylinemia contributes to cardiac dysfunction in obesity and diabetes: a study in humans and rats. Circ Res 2012; 110:598-608. [PMID: 22275486 DOI: 10.1161/circresaha.111.258285] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Hyperamylinemia is common in patients with obesity and insulin resistance, coincides with hyperinsulinemia, and results in amyloid deposition. Amylin amyloids are generally considered a pancreatic disorder in type 2 diabetes. However, elevated circulating levels of amylin may also lead to amylin accumulation and proteotoxicity in peripheral organs, including the heart. OBJECTIVE To test whether amylin accumulates in the heart of obese and type 2 diabetic patients and to uncover the effects of amylin accumulation on cardiac morphology and function. METHODS AND RESULTS We compared amylin deposition in failing and nonfailing hearts from lean, obese, and type 2 diabetic humans using immunohistochemistry and Western blots. We found significant accumulation of large amylin oligomers, fibrils, and plaques in failing hearts from obese and diabetic patients but not in normal hearts and failing hearts from lean, nondiabetic humans. Small amylin oligomers were even elevated in nonfailing hearts from overweight/obese patients, suggesting an early state of accumulation. Using a rat model of hyperamylinemia transgenic for human amylin, we observed that amylin oligomers attach to the sarcolemma, leading to myocyte Ca(2+) dysregulation, pathological myocyte remodeling, and diastolic dysfunction, starting from prediabetes. In contrast, prediabetic rats expressing the same level of wild-type rat amylin, a nonamyloidogenic isoform, exhibited normal heart structure and function. CONCLUSIONS Hyperamylinemia promotes amylin deposition in the heart, causing alterations of cardiac myocyte structure and function. We propose that detection and disruption of cardiac amylin buildup may be both a predictor of heart dysfunction and a novel therapeutic strategy in diabetic cardiomyopathy.
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Affiliation(s)
- Sanda Despa
- Department of Pharmacology, University of California-Davis, 451 Health Sciences Drive, Davis, CA 95616, USA.
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27
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Cade WT, Reeds DN, Overton ET, Herrero P, Waggoner AD, Davila-Roman VG, Lassa-Claxton S, Gropler RJ, Soto PF, Krauss MJ, Yarasheski KE, Peterson LR. Effects of human immunodeficiency virus and metabolic complications on myocardial nutrient metabolism, blood flow, and oxygen consumption: a cross-sectional analysis. Cardiovasc Diabetol 2011; 10:111. [PMID: 22151886 PMCID: PMC3258269 DOI: 10.1186/1475-2840-10-111] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 12/08/2011] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND In the general population, peripheral metabolic complications (MC) increase the risk for left ventricular dysfunction. Human immunodeficiency virus infection (HIV) and combination anti-retroviral therapy (cART) are associated with MC, left ventricular dysfunction, and a higher incidence of cardiovascular events than the general population. We examined whether myocardial nutrient metabolism and left ventricular dysfunction are related to one another and worse in HIV infected men treated with cART vs. HIV-negative men with or without MC. METHODS Prospective, cross-sectional study of myocardial glucose and fatty acid metabolism and left ventricular function in HIV+ and HIV-negative men with and without MC. Myocardial glucose utilization (GLUT), and fatty acid oxidation and utilization rates were quantified using 11C-glucose and 11C-palmitate and myocardial positron emission tomography (PET) imaging in four groups of men: 23 HIV+ men with MC+ (HIV+/MC+, 42 ± 6 yrs), 15 HIV+ men without MC (HIV+/MC-, 41 ± 6 yrs), 9 HIV-negative men with MC (HIV-/MC+, 33 ± 5 yrs), and 22 HIV-negative men without MC (HIV-/MC-, 25 ± 6 yrs). Left ventricular function parameters were quantified using echocardiography. RESULTS Myocardial glucose utilization was similar among groups, however when normalized to fasting plasma insulin concentration (GLUT/INS) was lower (p < 0.01) in men with metabolic complications (HIV+: 9.2 ± 6.2 vs. HIV-: 10.4 ± 8.1 nmol/g/min/μU/mL) than men without metabolic complications (HIV+: 45.0 ± 33.3 vs. HIV-: 60.3 ± 53.0 nmol/g/min/μU/mL). Lower GLUT/INS was associated with lower myocardial relaxation velocity during early diastole (r = 0.39, p < 0.001). CONCLUSION Men with metabolic complications, irrespective of HIV infection, had lower basal myocardial glucose utilization rates per unit insulin that were related to left ventricular diastolic impairments, indicating that well-controlled HIV infection is not an independent risk factor for blunted myocardial glucose utilization per unit of insulin. TRIAL REGISTRATION NIH Clinical Trials NCT00656851.
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Affiliation(s)
- W Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, 4444 Forest Park Boulevard, St, Louis, Missouri 63108, USA.
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Bhimaraj A, Tang WHW. Role of oxidative stress in disease progression in Stage B, a pre-cursor of heart failure. Heart Fail Clin 2011; 8:101-11. [PMID: 22108730 DOI: 10.1016/j.hfc.2011.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Oxidative stress represents a persistent imbalance between the production and the compensation of reactive oxygen species. Though predominantly found in advanced heart failure, the most frequent "at-risk" condition has been associated with underlying oxidative stress. It is therefore conceivable that timely detection and early intervention to reduce oxidative stress processes provide an opportunity to prevent disease progression to overt heart failure. This article reviews the current understanding of the current evidence of oxidative stress involvement in the pathophysiology of human heart failure and its potential therapeutic interventions in patients with Stage A and B heart failure.
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Affiliation(s)
- Arvind Bhimaraj
- Methodist DeBakey Cardiology Associates, Smith Tower, 6550 Fannin, Suite 1901, Houston, TX 77030, USA
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29
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McGill JB, Peterson LR, Herrero P, Saeed IM, Recklein C, Coggan AR, DeMoss AJ, Schechtman KB, Dence CS, Gropler RJ. Potentiation of abnormalities in myocardial metabolism with the development of diabetes in women with obesity and insulin resistance. J Nucl Cardiol 2011; 18:421-9; quiz 432-3. [PMID: 21516378 PMCID: PMC3811030 DOI: 10.1007/s12350-011-9362-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 02/16/2011] [Indexed: 01/22/2023]
Abstract
BACKGROUND Because studies in animal models of type-2 diabetes mellitus (DM) show that excessive myocardial fatty acid (FA) metabolism (at the expense of glucose metabolism) cause cardiac dysfunction, we hypothesized that women with DM would have more FA and less glucose myocardial metabolism than normal or even obese (OB) women. RESEARCH DESIGN AND METHODS Women who were lean volunteers (NV) (N = 14; age 35 ± 17 years, body mass index 23 ± 1 kg/m(2)), OB (N = 28;31 ± 6 years, BMI 39 ± 7 kg/m2), and DM (n = 22; 54 ± 11 years, BMI 38 ± 5 kg/m2) were studied. Cardiac positron emission tomography was performed for the determination of myocardial blood flow, oxygen consumption, FA and glucose metabolism. Cardiac work was measured by echocardiography and efficiency by the ratio of work to myocardial oxygen consumption. RESULTS Fractional glucose uptake was comparable between NV and OB but lower in DM (P < .05 versus NV). Myocardial FA utilization and oxidation were both higher in DM compared with NV and OB (P < .0001). Myocardial FA utilization and oxidation had positive correlations with HOMA (R = 0.35, P = .005 and R = 0.40, P = .001, respectively) whereas fractional glucose uptake exhibited an inverse correlation (R = -.31, P = .01). Cardiac work and efficiency were similar among the three groups. CONCLUSIONS In women, the presence of OB and DM compared with OB alone is associated with a greater reliance on myocardial FA metabolism at the expense of glucose metabolism. These perturbations in myocardial metabolism are not associated in a decline left ventricular efficiency or function suggesting that the metabolic perturbations may precede an eventual decline left ventricular function as is seen in animal models of DM.
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Affiliation(s)
- Janet B. McGill
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Linda R. Peterson
- Division of Cardiovascular Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
| | - Pilar Herrero
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
| | - Ibrahim M. Saeed
- Division of Cardiovascular Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Carol Recklein
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Andrew R. Coggan
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
| | - Amanda J. DeMoss
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
| | | | - Carmen S. Dence
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
| | - Robert J. Gropler
- Division of Cardiovascular Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
- Cardiovascular Imaging Laboratory, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO
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30
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Khalaf KI, Taegtmeyer H. Insulin sensitizers and heart failure: an engine flooded with fuel. Curr Hypertens Rep 2011; 12:399-401. [PMID: 20963518 DOI: 10.1007/s11906-010-0158-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Khaled I Khalaf
- Department of Internal Medicine, University of Texas Medical School at Houston, 6431 Fannin, MSB 1.246, Houston, TX 77030, USA.
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31
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Heather LC, Clarke K. Metabolism, hypoxia and the diabetic heart. J Mol Cell Cardiol 2011; 50:598-605. [PMID: 21262230 DOI: 10.1016/j.yjmcc.2011.01.007] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 01/06/2011] [Accepted: 01/11/2011] [Indexed: 12/18/2022]
Abstract
The diabetic heart becomes metabolically remodelled as a consequence of exposure to abnormal circulating substrates and hormones. Fatty acid uptake and metabolism are increased in the type 2 diabetic heart, resulting in accumulation of intracellular lipid intermediates and an increased contribution of fatty acids towards energy generation. Cardiac glucose uptake and oxidation are decreased, predominantly due to increased fatty acid metabolism, which suppresses glucose utilisation via the Randle cycle. These metabolic changes decrease cardiac efficiency and energetics in both humans and animal models of diabetes. Diabetic hearts have decreased recovery following ischemia, indicating a reduced tolerance to oxygen-limited conditions. There is evidence that diabetic hearts have a compromised hypoxia signalling pathway, as hypoxia-inducible factor (HIF) and downstream signalling from HIF are reduced following ischemia. Failure to activate HIF under oxygen-limited conditions results in less angiogenesis, and an inability to upregulate glycolytic ATP generation. Given that glycolysis is already suppressed in the diabetic heart under normoxic conditions, the inability to upregulate glycolysis in response to hypoxia may have deleterious effects on ATP production. Thus, impaired HIF signalling may contribute to metabolic and energetic abnormalities, and impaired collateral vessel development following myocardial infarction in the type 2 diabetic heart.
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Affiliation(s)
- Lisa C Heather
- Cardiac Metabolism Research Group, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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32
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Liu J, Jahn LA, Fowler DE, Barrett EJ, Cao W, Liu Z. Free fatty acids induce insulin resistance in both cardiac and skeletal muscle microvasculature in humans. J Clin Endocrinol Metab 2011; 96:438-46. [PMID: 21047922 PMCID: PMC3048322 DOI: 10.1210/jc.2010-1174] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Insulin recruits microvasculature in both cardiac and skeletal muscle, which increases the endothelial exchange surface area. Plasma concentrations of free fatty acids (FFAs) are elevated in patients with diabetes, which impairs insulin-mediated skeletal muscle microvascular recruitment. OBJECTIVE The objective of the study was to examine whether elevated FFAs likewise cause insulin resistance in cardiac muscle microvasculature. SETTING The study was conducted at the General Clinical Research Center at the University of Virginia. METHODS Twenty-two healthy, young adults were studied twice in random order after an overnight fast. Each subject received a 5-h systemic infusion of either saline or Intralipid/heparin with a 1 mU/min · kg euglycemic insulin clamp superimposed for the last 2 h. Cardiac and forearm skeletal muscle microvascular blood volume (MBV) and flow velocity were measured and microvascular blood flow (MBF) calculated before and at the end of the insulin infusion. RESULTS Insulin significantly increased MBV and MBF in both cardiac (P < 0.0001 for both) and skeletal (P = 0.008 and < 0.03, respectively) muscle. Microvascular flow velocity increased slightly but significantly in the skeletal (P = 0.04) but not in cardiac muscle. Lipid infusion lowered insulin-stimulated whole-body glucose disposal and abolished insulin-mediated increases in MBV and MBF in both cardiac and skeletal muscle. Whole-body insulin sensitivity predicted skeletal but not cardiac muscle microvascular responses to insulin. Insulin even decreased skeletal muscle MBV during lipid infusion in subjects who were moderately sensitive to insulin metabolically. CONCLUSIONS In conclusion, high plasma concentrations of FFAs cause insulin resistance in cardiac as well as skeletal muscle microvasculature in healthy humans. This may contribute to the association of cardiac complications with metabolic insulin resistance in diabetes.
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Affiliation(s)
- Jia Liu
- Division of Endocrinology and Metabolism, Department of Internal Medicine and General Clinical Research Center, University of Virginia Health System, P.O. Box 801410, Charlottesville, Virginia 22908, USA
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Kolaczynski JW. Concept paper: antihyperglycemic therapy and the diabetic heart--do we really know enough? J Diabetes Complications 2011; 25:63-72. [PMID: 19781960 DOI: 10.1016/j.jdiacomp.2009.07.002] [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] [Received: 03/24/2009] [Revised: 06/21/2009] [Accepted: 07/24/2009] [Indexed: 10/20/2022]
Abstract
The purpose of this article is to provide reasons to start looking more critically at the existing glucose-lowering therapies in diabetes, from the point of their effect on cardiac metabolism. The presented arguments begin with the description of major differences between metabolism in myocardium and the skeletal muscle and of examples of myocardial metabolic inflexibility observed in heart failure and Type 2 diabetes. It is proposed that the metabolic inflexibility of diabetic myocardium should be taken into consideration as a factor to explain causes of unexpected cardiovascular mortality observed in the recently published outcome studies such as Action to Control Cardiovascular Risk in Diabetes (ACCORD) and Veterans Affairs Diabetes Feasibility Trial. The same reasoning was applied to challenge the "legacy effect" of the UK Prospective Diabetes Study and Steno-2 trials. A striking paucity of data on the effects of antihyperglycemic therapies on cardiac metabolism is brought to attention in spite of the fact that the technology to study human cardiac metabolism in vivo is available. It is hoped that increased focus on research in this area could contribute to improved cardiovascular safety monitoring of various antihyperglycemic regimens and thereby enhance our ability to save more lives of patients with Type 2 diabetes.
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Affiliation(s)
- Jerzy W Kolaczynski
- Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, UMDNJ—Robert Wood Johnson Medical School, 125 Paterson St, Suite 5100, New Brunswick, NJ 08901, USA.
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Christopher BA, Huang HM, Berthiaume JM, McElfresh TA, Chen X, Croniger CM, Muzic RF, Chandler MP. Myocardial insulin resistance induced by high fat feeding in heart failure is associated with preserved contractile function. Am J Physiol Heart Circ Physiol 2010; 299:H1917-27. [PMID: 20852054 DOI: 10.1152/ajpheart.00687.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous studies have reported that high fat feeding in mild to moderate heart failure (HF) results in the preservation of contractile function. Recent evidence has suggested that preventing the switch from fatty acid to glucose metabolism in HF may ameliorate dysfunction, and insulin resistance is one potential mechanism for regulating substrate utilization. This study was designed to determine whether peripheral and myocardial insulin resistance exists with HF and/or a high-fat diet and whether myocardial insulin signaling was altered accordingly. Rats underwent coronary artery ligation (HF) or sham surgery and were randomized to normal chow (NC; 14% kcal from fat) or a high-fat diet (SAT; 60% kcal from fat) for 8 wk. HF + SAT animals showed preserved systolic (+dP/dt and stroke work) and diastolic (-dP/dt and time constant of relaxation) function compared with HF + NC animals. Glucose tolerance tests revealed peripheral insulin resistance in sham + SAT, HF + NC, and HF + SAT animals compared with sham + NC animals. PET imaging confirmed myocardial insulin resistance only in HF + SAT animals, with an uptake ratio of 2.3 ± 0.3 versus 4.6 ± 0.7, 4.3 ± 0.4, and 4.2 ± 0.6 in sham + NC, sham + SAT, and HF + NC animals, respectively; the myocardial glucose utilization rate was similarly decreased in HF + SAT animals only. Western blot analysis of insulin signaling protein expression was indicative of cardiac insulin resistance in HF + SAT animals. Specifically, alterations in Akt and glycogen synthase kinase-3β protein expression in HF + SAT animals compared with HF + NC animals may be involved in mediating myocardial insulin resistance. In conclusion, HF animals fed a high-saturated fat exhibited preserved myocardial contractile function, peripheral and myocardial insulin resistance, decreased myocardial glucose utilization rates, and alterations in cardiac insulin signaling. These results suggest that myocardial insulin resistance may serve a cardioprotective function with high fat feeding in mild to moderate HF.
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Affiliation(s)
- Bridgette A Christopher
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106-4970, USA
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35
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von Lewinski D, Rainer PP, Gasser R, Huber MS, Khafaga M, Wilhelm B, Haas T, Mächler H, Rössl U, Pieske B. Glucose-transporter-mediated positive inotropic effects in human myocardium of diabetic and nondiabetic patients. Metabolism 2010; 59:1020-8. [PMID: 20045149 DOI: 10.1016/j.metabol.2009.10.025] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Revised: 10/25/2009] [Accepted: 10/26/2009] [Indexed: 11/16/2022]
Abstract
Insulin causes inotropic effects via Ca(2+)-dependent and Ca(2+)-independent pathways. The latter one is potentially glucose dependent. We examined inotropic responses and signal transduction of insulin in human atrial myocardium of diabetic and nondiabetic patients to test for the role of glucose transporters. Experiments were performed in isolated atrial myocardium of 88 patients undergoing cardiac surgery and 28 ventricular muscle samples of explanted hearts. Influence of insulin (0.02 micromol/L) on isometric twitch force was examined with and without blocking glucose transporter (GLUT) 4 translocation (latrunculin), sodium-coupled glucose transporter (SGLT) 1 (phlorizin, T-1095A), or PI3-kinase (wortmannin). Experiments were performed in Tyrode solution containing glucose or pyruvate as energetic substrate. Messenger RNA expression of glucose transporters (GLUT1, GLUT4, SGLT1, SGLT2) was analyzed in atrial and ventricular myocardium of both diabetic and nondiabetic patients. Developed force increases after insulin (to 117.8% +/- 2.4% and 115.8% +/- 1.9%) in trabeculae from patients with and without diabetes. Inotropic effect was reduced after displacing glucose with pyruvate as well as after PI3-kinase inhibition (to 103% +/- 2%) or inhibition of glucose transporters GLUT4 (to 105% +/- 2%) and SGLT1 (phlorizin to 106% +/- 2%, T-1095A to 105% +/- 2%), without differences between the 2 groups. In glucose-free pyruvate-containing solution, only inhibition of PI3-kinase but not blocking glucose transporters resulted in further inhibitory effects. Messenger RNA expression did not show significant differences between patients with or without diabetes. Insulin exerts positive inotropic effects in human atrial myocardium. These effects are mediated via a PI3-kinase-sensitive and a glucose-transport-sensitive pathway. Differences in functional effects or messenger RNA expression of glucose transporters were not detectable between patients with and without diabetes.
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36
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Lopaschuk GD, Ussher JR, Folmes CDL, Jaswal JS, Stanley WC. Myocardial fatty acid metabolism in health and disease. Physiol Rev 2010; 90:207-58. [PMID: 20086077 DOI: 10.1152/physrev.00015.2009] [Citation(s) in RCA: 1449] [Impact Index Per Article: 103.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
There is a constant high demand for energy to sustain the continuous contractile activity of the heart, which is met primarily by the beta-oxidation of long-chain fatty acids. The control of fatty acid beta-oxidation is complex and is aimed at ensuring that the supply and oxidation of the fatty acids is sufficient to meet the energy demands of the heart. The metabolism of fatty acids via beta-oxidation is not regulated in isolation; rather, it occurs in response to alterations in contractile work, the presence of competing substrates (i.e., glucose, lactate, ketones, amino acids), changes in hormonal milieu, and limitations in oxygen supply. Alterations in fatty acid metabolism can contribute to cardiac pathology. For instance, the excessive uptake and beta-oxidation of fatty acids in obesity and diabetes can compromise cardiac function. Furthermore, alterations in fatty acid beta-oxidation both during and after ischemia and in the failing heart can also contribute to cardiac pathology. This paper reviews the regulation of myocardial fatty acid beta-oxidation and how alterations in fatty acid beta-oxidation can contribute to heart disease. The implications of inhibiting fatty acid beta-oxidation as a potential novel therapeutic approach for the treatment of various forms of heart disease are also discussed.
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Affiliation(s)
- Gary D Lopaschuk
- Cardiovascular Research Group, Mazankowski Alberta Heart Institute, University of Alberta, Alberta T6G 2S2, Canada.
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Type 2 diabetes, mitochondrial biology and the heart. J Mol Cell Cardiol 2009; 46:842-9. [PMID: 19217910 DOI: 10.1016/j.yjmcc.2009.02.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 02/05/2009] [Accepted: 02/06/2009] [Indexed: 11/22/2022]
Abstract
Diabetes is recognized as an independent risk factor for cardiovascular morbidity and mortality. This is due, in large part, to premature atherosclerosis, enhanced thrombogenicity and activation of systemic inflammatory programs with resultant vascular dysfunction. More enigmatic mechanisms underpinning diabetes-associated cardiac pathophysiology include the direct metabolic consequences of this disease on the myocardium. Nevertheless, a role for diabetes-associated disruption in cardiac contractile mechanics and in increasing cardiomyocyte susceptibility to ischemic-stress has been implicated independent of vascular pathology. This review will focus broadly on the direct effects of diabetes on the cardiac myocardium with more specific reference to the role of the modulation of cardiomyocyte mitochondrial function in these disease processes. This focus in part, stems from the growing recognition that in some instances mitochondrial dysfunction is central to the development of insulin resistance and diabetes, and in others, diabetes associated disruption in mitochondrial function exacerbates and accentuates the pathophysiology of diabetes.
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Abstract
Cardiovascular disease caused less than 10% of deaths worldwide at the beginning of the 20th century but accounted for nearly 50% toward its end. Obesity has seen a similarly sharp increase in prevalence and is a major contributing factor to the rise in cardiovascular disease incidence. Mechanisms of obesity-induced heart disease are multifaceted and remain largely unknown, but cardiomyocyte programmed cell death, or apoptosis, seems to play a critical role in their development and progression. The heart maintains a delicate balance between cell proliferation and cell death throughout its lifetime. Even a slight increase in the rate of myocyte apoptosis, as seen in various animal models, has devastating consequences for the heart. This article critically reviews studies conducted in animal models of obesity that have expanded our understanding of the mechanisms of cardiomyocyte apoptosis and their role in various obesity-associated cardiovascular diseases.
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Affiliation(s)
- Premal S Trivedi
- Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA
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Raher MJ, Thibault HB, Buys ES, Kuruppu D, Shimizu N, Brownell AL, Blake SL, Rieusset J, Kaneki M, Derumeaux G, Picard MH, Bloch KD, Scherrer-Crosbie M. A short duration of high-fat diet induces insulin resistance and predisposes to adverse left ventricular remodeling after pressure overload. Am J Physiol Heart Circ Physiol 2008; 295:H2495-502. [PMID: 18978196 DOI: 10.1152/ajpheart.00139.2008] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin resistance is an increasingly prevalent condition in humans that frequently clusters with disorders characterized by left ventricular (LV) pressure overload, such as systemic hypertension. To investigate the impact of insulin resistance on LV remodeling and functional response to pressure overload, C57BL6 male mice were fed a high-fat (HFD) or a standard diet (SD) for 9 days and then underwent transverse aortic constriction (TAC). LV size and function were assessed in SD- and HFD-fed mice using serial echocardiography before and 7, 21, and 28 days after TAC. Serial echocardiography was also performed on nonoperated SD- and HFD-fed mice over a period of 6 wk. LV perfusion was assessed before and 7 and 28 days after TAC. Nine days of HFD induced systemic and myocardial insulin resistance (assessed by myocardial 18F-fluorodeoxyglucose uptake), and myocardial perfusion response to acetylcholine was impaired. High-fat feeding for 28 days did not change LV size and function in nonbanded mice; however, TAC induced greater hypertrophy, more marked LV systolic and diastolic dysfunction, and decreased survival in HFD-fed compared with SD-fed mice. Compared with SD-fed mice, myocardial perfusion reserve was decreased 7 days after TAC, and capillary density was decreased 28 days after TAC in HFD-fed mice. A short duration of HFD induces insulin resistance in mice. These metabolic changes are accompanied by increased LV remodeling and dysfunction after TAC, highlighting the impact of insulin resistance in the development of pressure-overload-induced heart failure.
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Affiliation(s)
- Michael J Raher
- Cardiac Ultrasound Laboratory, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA
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Chess DJ, Stanley WC. Role of diet and fuel overabundance in the development and progression of heart failure. Cardiovasc Res 2008; 79:269-78. [PMID: 18343896 DOI: 10.1093/cvr/cvn074] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Under physiological conditions, the human heart derives energy from glucose, fatty acids, and/or lactate depending upon substrate availability, circulating hormone levels, and nutritional status. Circulating free fatty acid and glucose levels often exceed the normal range, as observed with type 2 diabetes, obesity, or physical inactivity. Chronic exposure of the heart to high plasma levels of free fatty acids may cause accumulation of toxic lipid intermediates within cardiomyocytes. Furthermore, suppression of glucose oxidation by increased fatty acid uptake shunts glucose into the oxidative pentose phosphate and hexosamine biosynthetic pathways, both of which yield potentially harmful products. Noxious derivatives of aberrant glucose and fatty acid oxidation can activate signalling cascades leading to myocyte dysfunction or death, processes termed 'glucotoxicity' and 'lipotoxicity'. This review discusses the effects of dietary extremes (e.g. high fat and high carbohydrate consumption) and substrate overabundance in the context of heart failure (HF) development and progression. Emerging data suggest that substrate excess leads to cardiac dysfunction and HF, which may be prevented or slowed by maintaining low body fat and high insulin sensitivity and consuming a diet of low glycaemic load that is high in mono- and polyunsaturated fatty acids.
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Affiliation(s)
- David J Chess
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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Witteles RM, Fowler MB. Insulin-resistant cardiomyopathy clinical evidence, mechanisms, and treatment options. J Am Coll Cardiol 2008; 51:93-102. [PMID: 18191731 DOI: 10.1016/j.jacc.2007.10.021] [Citation(s) in RCA: 264] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 10/04/2007] [Accepted: 10/22/2007] [Indexed: 02/07/2023]
Abstract
Increasing evidence points to insulin resistance as a primary etiologic factor in the development of nonischemic heart failure (HF). The myocardium normally responds to injury by altering substrate metabolism to increase energy efficiency. Insulin resistance prevents this adaptive response and can lead to further injury by contributing to lipotoxicity, sympathetic up-regulation, inflammation, oxidative stress, and fibrosis. Animal models have repeatedly demonstrated the existence of an insulin-resistant cardiomyopathy, one that is characterized by inefficient energy metabolism and is reversible by improving energy use. Clinical studies in humans strongly support the link between insulin resistance and nonischemic HF. Insulin resistance is highly prevalent in the nonischemic HF population, predates the development of HF, independently defines a worse prognosis, and predicts response to antiadrenergic therapy. Potential options for treatment include metabolic-modulating agents and antidiabetic drugs. This article reviews the basic science evidence, animal experiments, and human clinical data supporting the existence of an "insulin-resistant cardiomyopathy" and proposes specific potential therapeutic approaches.
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Affiliation(s)
- Ronald M Witteles
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California 94305, USA.
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42
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Liu Z. Insulin at physiological concentrations increases microvascular perfusion in human myocardium. Am J Physiol Endocrinol Metab 2007; 293:E1250-5. [PMID: 17698984 DOI: 10.1152/ajpendo.00451.2007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vascular endothelium regulates vascular tone and tissue perfusion in response to various physiological and pathological stimuli. Insulin and meal feeding increase microvascular perfusion and thus oxygen, nutrient, and hormone delivery to human skeletal muscle. Meal feeding also increases cardiac microvascular perfusion in healthy humans. To examine whether insulin at physiological concentrations increases microvascular perfusion in human myocardium, we studied 13 healthy, overnight-fasted, lean, young human volunteers by using myocardial contrast echocardiography (MCE) and insulin-clamp techniques. We measured cardiac microvascular blood volume (MBV), microvascular flow velocity (MFV), and microvascular blood flow (MBF) at baseline, 60 min, and 120 min after initiating insulin infusion at 1 mU.kg(-1).min(-1). MBF is the product of MBV and MFV and represents microvascular perfusion. Insulin increased myocardial MBV by 23% at 60 min (P < 0.01) and by 41% at 120 min (P = 0.001) without changing MFV. As a result, insulin-mediated myocardial MBF increased significantly at both 60 min (P < 0.01) and 120 min (P < 0.0005). Insulin also significantly increased brachial artery diameter, flow velocity, and total blood flow at 60 and 120 min (P < 0.05 for all). The changes in cardiac MBV correlated positively with quantitative insulin sensitivity check index (QUICKI) and negatively with body mass index but not with the steady-state glucose-infusion rates or the changes in brachial artery parameters. We conclude that insulin, at physiologically relevant concentrations, increases microvascular perfusion in human heart muscle by increasing cardiac MBV in healthy, insulin-sensitive adults. This insulin-mediated cardiac microvascular perfusion may play an important role in normal human myocardial oxygen and substrate physiology.
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Affiliation(s)
- Zhenqi Liu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA.
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Adachi H, Ohno T, Oguri M, Oshima S, Taniguchi K. Effect of insulin sensitivity on severity of heart failure. Diabetes Res Clin Pract 2007; 77 Suppl 1:S258-62. [PMID: 17467109 DOI: 10.1016/j.diabres.2007.01.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/29/2007] [Indexed: 10/23/2022]
Abstract
Insulin resistance is associated with various cardiac dysfunctions both molecularly and clinically, including cardiac muscle relaxation and blood flow. Although, these dysfunctions result in heart failure, relationship between insulin resistance and severity of heart failure is not well studied yet. Since severity of chronic heart failure can be determined by exercise tolerance, we attempted to assess the insulin resistance in patients with chronic heart failure and evaluated the relationship between insulin sensitivity and exercise tolerance. We examined nine chronic heart failure patients. Insulin sensitivity was determined with euglycemic hyperinsulinemic clamp technique. Exercise tolerance was assessed using cardiopulmonary exercise testing. There was no correlation between body mass index and insulin sensitivity, while between body fat ratio, significant negative correlation was investigated (r=-0.463). Insulin sensitivity was negatively correlated with exercise tolerance (with anaerobic threshold, r=0.548; with peak oxygen uptake, r=0.581). Insulin sensitivity also showed significant positive correlation with cardiac function during exercise (GIR versus peak oxygen pulse: r=0.535). Insulin sensitivity is revealed to have some effects on exercise tolerance and cardiac function in patients with chronic heart failure. Insulin resistance seems to be one of the important targets in managing the chronic heart failure.
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Affiliation(s)
- Hitoshi Adachi
- Gunma Prefectural Cardiovascular Center, 3-12 Kameizumi, Maebashi, Gunma 371-0004, Japan.
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McNulty PH, Tulli MA, Robertson BJ, Lendel V, Harach LA, Scott S, Boehmer JP. Effect of simulated postprandial hyperglycemia on coronary blood flow in cardiac transplant recipients. Am J Physiol Heart Circ Physiol 2007; 293:H103-8. [PMID: 17369474 DOI: 10.1152/ajpheart.00779.2006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Patients with diabetes mellitus exhibit postprandial hyperglycemia, systemic oxidative stress, impaired endothelium-dependent, nitric oxide (NO)-mediated coronary artery dilatation, and an increased incidence of coronary events. Whether hyperglycemia causally mediates these associations is unknown. To test the hypothesis that postprandial hyperglycemia acutely impairs coronary endothelial function in humans, we compared the ability of the endothelium-dependent vasodilator acetylcholine to increase conduit coronary diameter (the macrovascular response) and coronary blood flow velocity (the microvascular response) in 12 cardiac transplant recipients without diabetes before and after blood glucose was raised from 6.7 ± 1.3 mmol/l (121 ± 24 mg/dl) to 17.8 ± 1.5 mmol/l (321 ± 27 mg/dl) for 1 h. Hyperglycemia acutely doubled circulating levels of the oxidation product malondialdehyde, indicating systemic oxidative stress, but did not affect the ability of acetylcholine to dilate conduit coronary segments or accelerate coronary blood flow. We conclude that the oxidative stress associated with a single acute episode of hyperglycemia affects neither acetylcholine-mediated coronary endothelial NO release nor the subsequent bioavailability, metabolism, or action of NO within the coronary circulation of cardiac transplant recipients. These observations imply that the relationship among hyperglycemia, oxidative stress, and coronary endothelial dysfunction is presumably mediated by mechanisms operating over longer periods of time.
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Affiliation(s)
- Patrick H McNulty
- Division of Cardiology, Penn State College of Medicine, Hershey, PA, USA.
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45
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Hafstad AD, Khalid AM, How OJ, Larsen TS, Aasum E. Glucose and insulin improve cardiac efficiency and postischemic functional recovery in perfused hearts from type 2 diabetic (db/db) mice. Am J Physiol Endocrinol Metab 2007; 292:E1288-94. [PMID: 17213470 DOI: 10.1152/ajpendo.00504.2006] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Hearts from type 2 diabetic (db/db) mice demonstrate altered substrate utilization with high rates of fatty acid oxidation, decreased functional recovery following ischemia, and reduced cardiac efficiency. Although db/db mice show overall insulin resistance in vivo, we recently reported that insulin induces a marked shift toward glucose oxidation in isolated perfused db/db hearts. We hypothesize that such a shift in metabolism should improve cardiac efficiency and consequently increase functional recovery following low-flow ischemia. Hearts from db/db and nondiabetic (db/+) mice were perfused with 0.7 mM palmitate plus either 5 mM glucose (G), 5 mM glucose and 300 microU/ml insulin (GI), or 33 mM glucose and 900 microU/ml insulin (HGHI). Substrate oxidation and postischemic recovery were only moderately affected by GI and HGHI in db/+ hearts. In contrast, GI and particularly HGHI markedly increased glucose oxidation and improved postischemic functional recovery in db/db hearts. Cardiac efficiency was significantly improved in db/db, but not in db/+ hearts, in the presence of HGHI. In conclusion, insulin and glucose normalize cardiac metabolism, restore efficiency, and improve postischemic recovery in type 2 diabetic mouse hearts. These findings may in part explain the beneficial effect of glucose-insulin-potassium therapy in diabetic patients with cardiac complications.
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Affiliation(s)
- Anne D Hafstad
- Department of Medical Physiology, Institute of Medical Biology, Faculty of Medicine, University of Tromsø, Tromsø, Norway.
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46
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Ouwens DM, Diamant M. Myocardial insulin action and the contribution of insulin resistance to the pathogenesis of diabetic cardiomyopathy. Arch Physiol Biochem 2007; 113:76-86. [PMID: 17558606 DOI: 10.1080/13813450701422633] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heart disease is the leading cause of death in patients with insulin resistance and type 2 diabetes (DM2). Even in the absence of coronary artery disease and hypertension, functional and structural abnormalities exist in patients with well-controlled and uncomplicated DM2. These derangements are collectively designated by the term diabetic cardiomyopathy (DCM). Changes in myocardial energy metabolism, due to altered substrate supply and utilization, largely underlie the development of DCM. Insulin is an important regulator of myocardial substrate metabolism, but also exerts regulatory effects on intracellular Ca2+ handling and cell survival. The current paper reviews the multiple functional and molecular effects of insulin on the heart, all of which ultimately seem to be cardioprotective both under normal conditions and under ischemia. In particular, the dismal consequences of myocardial insulin resistance contributing to the development of DCM will be discussed.
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Affiliation(s)
- D M Ouwens
- Department of Molecular Cell Biology, Leiden University Medical Centre, Leiden, The Netherlands.
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47
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Abstract
Despite the fact that the heart requires huge amounts of energy to sustain contractile function, it has limited energy reserves and must therefore continually produce large amounts of adenosine triphosphate (ATP) to sustain function. Fatty acids are the primary energy substrate of the adult heart, with more than 60% of the energy normally obtained from the oxidation of fatty acids, the remainder coming from the metabolism of carbohydrates. Alterations in both the rates of ATP production and the type of energy substrate used by the heart can have consequences on contractile function, as well as on its ability to respond to energetic stresses. Switches in myocardial substrate utilization and energy production rates have been shown to occur in various cardiomyopathies, as well as in any subsequent heart failure. Heart failure is characterized by an inefficient pumping of the heart, which fails to meet the energy requirements of the body. A number of cardiomyopathies can lead to heart failure. This paper will review the alterations in energy metabolism that occur in a number cardiomyopathies, including ischemic and diabetic cardiomyopathies, as well as hypertrophic cardiomyopathies resulting from mutations in enzymes involved in energy metabolism, such as 5' adenosine monophosphate-activated protein kinase (AMPK).
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Affiliation(s)
- Maysa Taha
- Cardiovascular Research Group, University of Alberta, Edmonton, Alberta, Canada
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48
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Macín SM, Perna ER, Coronel ML, Kriskovich JO, Bayol PA, Franciosi VA, Riera-Stival JL, González-Arjol B, Badaracco JR. Influencia de la concentración de glucemia en el momento del ingreso en la evolución a largo plazo de los pacientes con síndrome coronario agudo. Rev Esp Cardiol 2006. [DOI: 10.1157/13096598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Søndergaard HM, Bøttcher M, Marie Madsen M, Schmitz O, Hansen SB, Nielsen TT, Bøtker HE. Impact of type 2 diabetes on myocardial insulin sensitivity to glucose uptake and perfusion in patients with coronary artery disease. J Clin Endocrinol Metab 2006; 91:4854-61. [PMID: 16984986 DOI: 10.1210/jc.2006-1416] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND HYPOTHESIS Myocardial insulin resistance (IR) is a feature of coronary artery disease (CAD) with reduced left ventricular ejection fraction (LVEF). Whether type 2 diabetes mellitus (T2DM) with CAD and preserved LVEF induces myocardial IR and whether insulin in these patients acts as a myocardial vasodilator is debated. METHODS We studied 27 CAD patients (LVEF > 50%): 12 with T2DM (CAD+DM), 15 without T2DM (CAD-NoDM). Regional myocardial and skeletal glucose uptake, myocardial and skeletal muscle perfusion were measured with positron emission tomography. Myocardial muscle perfusion was measured at rest and during hyperemia in nonstenotic and stenotic regions with and without acute hyperinsulinemia. RESULTS Myocardial glucose uptake was similar in CAD+DM and CAD-NoDM in both nonstenotic and stenotic regions [0.38 +/- 0.08 and 0.36 +/- 0.11 micromol/g.min; P value nonsignificant (NS)] and (0.35 +/- 0.09 and 0.37 +/- 0.13 micromol/g.min; P = NS). Skeletal glucose uptake was reduced in CAD+DM (0.05 +/- 0.04 vs. 0.10 +/- 0.05 micromol/g.min; P = 0.02), and likewise, whole-body glucose uptake was reduced in CAD+DM (4.0 +/- 2.8 vs. 7.0 +/- 2.4 mg/kg.min; P = 0.01). Insulin did not alter myocardial muscle perfusion at rest or during hyperemia. Insulin increased skeletal muscle perfusion in CAD-NoDM (0.11 +/- 0.03 vs. 0.06 +/- 0.03 ml/g.min; P = 0.02), but not in CAD+DM (0.08 +/- 0.04 and 0.09 +/- 0.05 ml/g.min; P = NS). CONCLUSION Myocardial IR to glucose uptake is not an inherent feature in T2DM patients with preserved LVEF. Acute physiological insulin exposure exerts no coronary vasodilation in CAD patients irrespective of T2DM.
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Affiliation(s)
- Hanne M Søndergaard
- Department of Cardiology B, Aarhus University Hospital (SKS), Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark
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Sharma N, Okere IC, Duda MK, Chess DJ, O'Shea KM, Stanley WC. Potential impact of carbohydrate and fat intake on pathological left ventricular hypertrophy. Cardiovasc Res 2006; 73:257-68. [PMID: 17166490 PMCID: PMC2700717 DOI: 10.1016/j.cardiores.2006.11.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Revised: 11/03/2006] [Accepted: 11/06/2006] [Indexed: 01/11/2023] Open
Abstract
Currently, a high carbohydrate/low fat diet is recommended for patients with hypertension; however, the potentially important role that the composition of dietary fat and carbohydrate plays in hypertension and the development of pathological left ventricular hypertrophy (LVH) has not been well characterized. Recent studies demonstrate that LVH can also be triggered by activation of insulin signaling pathways, altered adipokine levels, or the activity of peroxisome proliferator-activated receptors (PPARs), suggesting that metabolic alterations play a role in the pathophysiology of LVH. Hypertensive patients with high plasma insulin or metabolic syndrome have a greater occurrence of LVH, which could be due to insulin activation of the serine-threonine kinase Akt and its downstream targets in the heart, resulting in cellular hypertrophy. PPARs also activate cardiac gene expression and growth and are stimulated by fatty acids and consumption of a high fat diet. Dietary intake of fats and carbohydrate and the resultant effects of plasma insulin, adipokine, and lipid concentrations may affect cardiomyocyte size and function, particularly in the setting of chronic hypertension. This review discusses potential mechanisms by which dietary carbohydrates and fats ca affect cardiac growth, metabolism, and function, mainly in the context of pressure overload-induced LVH.
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Affiliation(s)
- Naveen Sharma
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
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