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Cheema B, Chokshi A, Orimoloye O, Ardehali H. Intravenous Iron Repletion for Patients With Heart Failure and Iron Deficiency: JACC State-of-the-Art Review. J Am Coll Cardiol 2024; 83:2674-2689. [PMID: 38897678 DOI: 10.1016/j.jacc.2024.03.431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 06/21/2024]
Abstract
Iron deficiency and heart failure frequently co-occur, sparking clinical research into the role of iron repletion in this condition over the last 20 years. Although early nonrandomized studies and subsequent moderate-sized randomized controlled trials showed an improvement in symptoms and functional metrics with the use of intravenous iron, 3 recent larger trials powered to detect a difference in hard cardiovascular outcomes failed to meet their primary endpoints. Additionally, there are potential concerns related to side effects from intravenous iron, both in the short and long term. This review discusses the basics of iron biology and regulation, the diagnostic criteria for iron deficiency and the clinical evidence for intravenous iron in heart failure, safety concerns, and alternative therapies. We also make practical suggestions for the management of patients with iron deficiency and heart failure and outline key areas in need of future research.
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Affiliation(s)
- Baljash Cheema
- Bluhm Cardiovascular Institute, Center for Artificial Intelligence, Northwestern Medicine, Chicago, Illinois, USA; Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
| | - Anuj Chokshi
- McGaw Medical Center, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Olusola Orimoloye
- McGaw Medical Center, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Hossein Ardehali
- Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
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Guo X, Qi Y, Li J, Fan H, Yang L, Wu X, Ni J, Wang H, Wang X. A comprehensive study of the genotoxic and anti-genotoxic effects of homocysteine in HUVECs and mouse bone marrow cells. Food Chem Toxicol 2021; 156:112518. [PMID: 34418477 DOI: 10.1016/j.fct.2021.112518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 01/24/2023]
Abstract
Elevated Homocysteine (Hcy) is associated with increased risk of vascular disease, but whether it induces genotoxicity to vascular endothelial cells remains unknown. Here, we conducted a comprehensive study of the genotoxicity, and unexpected anti-genotoxicity, of Hcy by cytokinesis-blocked micronucleus assay in HUVECs and erythrocyte micronucleus test in mouse bone marrow cells. Our experiments led to several important findings. First, while supraphysiological Hcy (SP-Hcy) exhibited remarkable genotoxicity, physiologically-relevant Hcy (PR-Hcy) reduced the basal genotoxicity. Second, among the metabolites of Hcy, cysteine phenocopied the anti-genotoxicity of PR-Hcy and, methionine, S-adenosylhomocysteine and H2S phenocopied the genotoxicity of SP-Hcy. Third, the genotoxicity of SP-Hcy was mitigated by vitamin B6, Fe2+ and Cu2+, but was exacerbated by N-acetylcysteine. Fourth, under pre-, co- or post-treatment protocol, both SP-Hcy and PR-Hcy attenuated the genotoxicity of cisplatin, mitomycin-C, nocodazole or deoxycholate. Finally, 100 and 250 mg/kg Hcy ameliorated cisplatin-induced genotoxicity in bone marrow cells of CF-1 and Kunming mice. Our results suggest that genotoxicity may be one mechanism through which Hcy confers an increased risk for vascular disease, but more importantly, they challenge the long-standing paradigm that Hcy is always harmful to human health. Our study calls for a more systematic effort in understanding the molecular mechanisms underlying the anti-genotoxicity of Hcy.
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Affiliation(s)
- Xihan Guo
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China; Yunnan Environmental Mutagen Society, Kunming, Yunnan, 650500, China.
| | - Yanmei Qi
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Jianfei Li
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Houhong Fan
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Limei Yang
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Xue Wu
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Juan Ni
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China; Yunnan Environmental Mutagen Society, Kunming, Yunnan, 650500, China
| | - Han Wang
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China; Yunnan Environmental Mutagen Society, Kunming, Yunnan, 650500, China
| | - Xu Wang
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China; Yunnan Environmental Mutagen Society, Kunming, Yunnan, 650500, China.
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Vinchi F. Non-Transferrin-Bound Iron in the Spotlight: Novel Mechanistic Insights into the Vasculotoxic and Atherosclerotic Effect of Iron. Antioxid Redox Signal 2021; 35:387-414. [PMID: 33554718 PMCID: PMC8328045 DOI: 10.1089/ars.2020.8167] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 01/06/2021] [Accepted: 01/25/2021] [Indexed: 12/11/2022]
Abstract
Significance: While atherosclerosis is an almost inevitable consequence of aging, food preferences, lack of exercise, and other aspects of the lifestyle in many countries, the identification of new risk factors is of increasing importance to tackle a disease, which has become a major health burden for billions of people. Iron has long been suspected to promote the development of atherosclerosis, but data have been conflicting, and the contribution of iron is still debated controversially. Recent Advances: Several experimental and clinical studies have been recently published about this longstanding controversial problem, highlighting the critical need to unravel the complexity behind this topic. Critical Issues: The aim of the current review is to provide an overview of the current knowledge about the proatherosclerotic impact of iron, and discuss the emerging role of non-transferrin-bound iron (NTBI) as driver of vasculotoxicity and atherosclerosis. Finally, I will provide detailed mechanistic insights on the cellular processes and molecular pathways underlying iron-exacerbated atherosclerosis. Overall, this review highlights a complex framework where NTBI acts at multiple levels in atherosclerosis by altering the serum and vascular microenvironment in a proatherogenic and proinflammatory manner, affecting the functionality and survival of vascular cells, promoting foam cell formation and inducing angiogenesis, calcification, and plaque destabilization. Future Directions: The use of additional iron markers (e.g., NTBI) may help adequately predict predisposition to cardiovascular disease. Clinical studies are needed in the aging population to address the atherogenic role of iron fluctuations within physiological limits and the therapeutic value of iron restriction approaches. Antioxid. Redox Signal. 35, 387-414.
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Affiliation(s)
- Francesca Vinchi
- Iron Research Program, Lindsley F. Kimball Research Institute (LFKRI), New York Blood Center (NYBC), New York, New York, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA
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Kassianides X, Gordon A, Sturmey R, Bhandari S. The comparative effects of intravenous iron on oxidative stress and inflammation in patients with chronic kidney disease and iron deficiency: a randomized controlled pilot study. Kidney Res Clin Pract 2021; 40:89-98. [PMID: 33745264 PMCID: PMC8041632 DOI: 10.23876/j.krcp.20.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/25/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Concerns exist regarding the pro-oxidant and inflammatory potential of intravenous (IV) iron due to labile plasma iron (LPI) generation. This IRON-CKD trial compared the effects of different IV irons on oxidative stress and inflammation. METHODS In this randomized open-label explorative single-center study in the United Kingdom, non-dialysis-dependent chronic kidney disease (CKD) patients with iron deficiency were randomized (1:1:1:1) to receive a single infusion of 200 mg iron dextran, or 200 mg iron sucrose (IS), or 200 mg or 1,000 mg ferric derisomaltose (FDI) and were followed up for 3 months. The primary outcomes measured were induction of oxidative stress and inflammation. Secondarily, efficacy, vascular function, quality of life, and safety were monitored. RESULTS Forty patients were enrolled. No significant rise in oxidative stress existed, regardless of preparation or dose. There was a significant rise in LPI with 1,000 mg FDI at 2 hours that normalized within a week, not impacting oxidative stress or inflammation. A delayed rise in C-reactive protein was noted with IS. High-dose FDI produced a sustained serum ferritin increase (mean ± standard error of the mean of predose: 69.1 ± 18.4 μg/L, 3 months: 271.0 ± 83.3 μg/L; p = 0.007). Hemoglobin remained stable throughout. No adverse drug reactions were recorded during the study. CONCLUSION A single dose of IV iron in CKD patients does not trigger oxidative stress or inflammation biomarkers. Third-generation IV irons have a reassuring safety profile, and high-dose FDI produced a sustained serum ferritin rise and more efficient iron repletion, with no significant pro-oxidant or inflammatory signals when compared to a lower dose and other IV irons.
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Affiliation(s)
- Xenophon Kassianides
- Academic Renal Research Department, Hull University Teaching Hospitals NHS Trust and Hull York Medical School, Hull Royal Infirmary, Hull, UK
| | - Andrew Gordon
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, UK
| | - Roger Sturmey
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull, UK
| | - Sunil Bhandari
- Academic Renal Research Department, Hull University Teaching Hospitals NHS Trust and Hull York Medical School, Hull Royal Infirmary, Hull, UK
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Nakanishi T, Nanami M, Kuragano T. The pathogenesis of CKD complications; Attack of dysregulated iron and phosphate metabolism. Free Radic Biol Med 2020; 157:55-62. [PMID: 31978539 DOI: 10.1016/j.freeradbiomed.2020.01.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/07/2020] [Accepted: 01/20/2020] [Indexed: 01/17/2023]
Abstract
Chronic kidney disease (CKD) patients have a tremendously higher risk of developing cardiovascular disease (CVD) and infection than the non-CKD population, which could be caused by intertwining actions of hyperphosphatemia and CKD associated misdistribution of iron. CVD is often associated with vascular calcification, which has been attributed to hyperphosphatemia, and could be initiated in mitochondria, inducing apoptosis, and accelerated by reactive oxygen species (ROS). The production of ROS is principally linked to intracellular ferrous iron. For infection, the virulence and pathogenicity of a pathogen is directly related to its capacity to acquire iron for proliferation and to escape or subvert the host's immune response. Iron administration for renal anemia can sometimes be overdosed, which could decrease host immune mechanisms through its direct effect on neutrophils, macrophages and T cell function. Hyperphosphatemia has been demonstrated to be associated with an increased incidence of infection. We hypothesized two possible mechanisms: 1) fibroblast growth factor-23 levels are increased in parallel with serum phosphate levels and directly impair leukocyte recruitment and host defense mechanisms, and 2) circulating non-transferrin-bound iron (NTBI) is increased due to decreased iron binding capacity of the carrier protein transferrin in high-phosphate conditions. From these observations, maintaining an adequate serum range of phosphate levels and minimizing intracellular iron accumulation could attenuate the development of CKD complications.
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Affiliation(s)
- Takeshi Nakanishi
- Department of Nephrology, Sumiyoshigawa Hospital, Japan; Department of Internal Medicine, Division of Kidney and Dialysis, Hyogo College of Medicine, Japan.
| | - Masayoshi Nanami
- Department of Internal Medicine, Division of Kidney and Dialysis, Hyogo College of Medicine, Japan.
| | - Takahiro Kuragano
- Department of Internal Medicine, Division of Kidney and Dialysis, Hyogo College of Medicine, Japan.
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Punj S, Ghafourian K, Ardehali H. Iron deficiency and supplementation in heart failure and chronic kidney disease. Mol Aspects Med 2020; 75:100873. [PMID: 32753256 DOI: 10.1016/j.mam.2020.100873] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/26/2020] [Accepted: 07/02/2020] [Indexed: 12/16/2022]
Abstract
Iron is a key element for normal cellular function and plays a role in many cellular processes including mitochondrial respiration. The role of iron deficiency (ID) in heart failure (HF) has been a subject of debate amid increasing advocacy for intravenous (IV) supplementation. Both the definition and the approach to treatment of ID in HF have been adapted from the experience in patients with chronic kidney disease (CKD). In this review, we highlight the differences in regulatory mechanisms as well as pathophysiology of ID in CKD and HF population both at the systemic and cellular levels. We will review the major clinical trials in HF patients that have shown symptomatic benefit from IV iron supplementation but without effect on clinical outcomes. Intravenous iron loading bypasses the mechanisms that tightly regulate iron uptake and can potentially cause myocardial and endothelial damage by releasing reactive oxygen species. By contrast, newer oral iron preparations do not have similar toxicity concerns and might have a role in heart failure.
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Affiliation(s)
- Shweta Punj
- Department of Medicine, Northwestern University, Chicago, IL, USA
| | | | - Hossein Ardehali
- Department of Medicine, Northwestern University, Chicago, IL, USA; Feinberg Cardiovascular and Renal Research Institute, Northwestern University, Chicago, IL, USA.
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Ghafourian K, Shapiro JS, Goodman L, Ardehali H. Iron and Heart Failure: Diagnosis, Therapies, and Future Directions. JACC Basic Transl Sci 2020; 5:300-313. [PMID: 32215351 PMCID: PMC7091506 DOI: 10.1016/j.jacbts.2019.08.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 12/11/2022]
Abstract
To date, 3 clinical trials have shown symptomatic benefit from the use of intravenous (IV) iron in patients with heart failure (HF) with low serum iron. This has led to recommendations in support of the use of IV iron in this population. However, the systemic and cellular mechanisms of iron homeostasis in cardiomyocyte health and disease are distinct, complex, and poorly understood. Iron metabolism in HF appears dysregulated, but it is still unclear whether the changes are maladaptive and pathologic or compensatory and protective for the cardiomyocytes. The serum markers of iron deficiency in HF do not accurately reflect cellular and mitochondrial iron levels, and the current definition based on the ferritin and transferrin saturation values is broad and inclusive of patients who do not need IV iron. This is particularly relevant in view of the potential risks that are associated with the use of IV iron. Reliable markers of cellular iron status may differentiate subgroups of HF patients who would benefit from cellular and mitochondrial iron chelation rather than IV iron.
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Key Words
- 6MWT, 6-min walk test
- CKD, chronic kidney disease
- DMT1, divalent metal transporter 1 protein
- FCM, ferric carboxymaltose
- FGF, fibroblast growth factor
- Fpn1, ferroportin 1
- Hb, hemoglobin
- I/R, ischemia/reperfusion
- ID, iron deficiency
- IV, intravenous
- LVEF, left ventricular ejection fraction
- NTBI, non–transferrin-bound iron
- NYHA, New York Heart Association
- PGA, Patient Global Assessment
- RCT, randomized clinical trial
- ROS, reactive oxygen species
- TSAT, transferrin saturation
- TfR1, transferrin receptor protein 1
- VO2, peak oxygen uptake
- heart failure
- intravenous iron
- iron chelation
- iron deficiency
- sTfR, soluble transferrin receptor
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Affiliation(s)
| | | | | | - Hossein Ardehali
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University, Chicago, Illinois
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Tymko MM, Tremblay JC, Bailey DM, Green DJ, Ainslie PN. The impact of hypoxaemia on vascular function in lowlanders and high altitude indigenous populations. J Physiol 2019; 597:5759-5776. [PMID: 31677355 DOI: 10.1113/jp277191] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/07/2019] [Indexed: 12/18/2022] Open
Abstract
Exposure to hypoxia elicits widespread physiological responses that are critical for successful acclimatization; however, these responses may induce apparent maladaptive consequences. For example, recent studies conducted in both the laboratory and the field (e.g. at high altitude) have demonstrated that endothelial function is reduced in hypoxia. Herein, we review the several proposed mechanism(s) pertaining to the observed reduction in endothelial function in hypoxia including: (i) changes in blood flow patterns (i.e. shear stress), (ii) increased inflammation and production of reactive oxygen species (i.e. oxidative stress), (iii) heightened sympathetic nerve activity, and (iv) increased red blood cell concentration and mass leading to elevated nitric oxide scavenging. Although some of these mechanism(s) have been examined in lowlanders, less in known about endothelial function in indigenous populations that have chronically adapted to environmental hypoxia for millennia (e.g. the Peruvian, Tibetan and Ethiopian highlanders). There is some evidence indicating that healthy Tibetan and Peruvian (i.e. Andean) highlanders have preserved endothelial function at high altitude, but less is known about the Ethiopian highlanders. However, Andean highlanders suffering from chronic mountain sickness, which is characterized by an excessive production of red blood cells, have markedly reduced endothelial function. This review will provide a framework and mechanistic model for vascular endothelial adaptation to hypoxia in lowlanders and highlanders. Elucidating the pathways responsible for vascular adaption/maladaptation to hypoxia has potential clinical implications for disease featuring low oxygen delivery (e.g. heart failure, pulmonary disease). In addition, a greater understanding of vascular function at high altitude will clinically benefit the global estimated 85 million high altitude residents.
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Affiliation(s)
- Michael M Tymko
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada.,Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Joshua C Tremblay
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth, Australia.,Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada
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Ghafourian K, Chang H, Ardehali H. Intravenous iron therapy in heart failure: a different perspective. Eur J Heart Fail 2019; 21:703-714. [DOI: 10.1002/ejhf.1434] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 01/07/2019] [Indexed: 12/15/2022] Open
Affiliation(s)
- Kambiz Ghafourian
- Feinberg Cardiovascular Research Institute, and Department of Medicine, Feinberg School of MedicineNorthwestern University Chicago IL USA
| | - Hsiang‐Chun Chang
- Feinberg Cardiovascular Research Institute, and Department of Medicine, Feinberg School of MedicineNorthwestern University Chicago IL USA
| | - Hossein Ardehali
- Feinberg Cardiovascular Research Institute, and Department of Medicine, Feinberg School of MedicineNorthwestern University Chicago IL USA
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10
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Jelani QUA, Harchandani B, Cable RG, Guo Y, Zhong H, Hilbert T, Newman JD, Katz SD. Effects of serial phlebotomy on vascular endothelial function: Results of a prospective double-blind randomized study. Cardiovasc Ther 2018; 36:e12470. [PMID: 30341986 DOI: 10.1111/1755-5922.12470] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/11/2018] [Accepted: 10/13/2018] [Indexed: 02/07/2023] Open
Abstract
INTRODUCTION Blood donation has been proposed as a potential therapy to reduce risk of cardiovascular disease, but the effects of phlebotomy on vascular function in human subjects have not been well characterized. AIMS We conducted a prospective randomized double-blind study to determine the effects of serial phlebotomy on vascular endothelial function in the brachial artery. Eighty-four iron-replete, non-anemic subjects were randomly assigned to one of three study treatment groups: (a) four serial phlebotomy procedures each followed by intravenous infusion of placebo normal saline; (b) four serial phlebotomy procedures each followed by intravenous infusion to replete lost iron; and (c) four serial sham phlebotomy procedures each followed by intravenous infusion of placebo normal saline. Assigned phlebotomy procedures were conducted at 56-day intervals. We measured brachial artery reactivity (BAR, %) in response to transient oxidative stress induced by oral methionine with high-resolution duplex ultrasound imaging before and one week after the fourth study phlebotomy. RESULTS Before phlebotomy, oral methionine decreased BAR by -2.04% (95% CI -2.58%, -1.50%), P < 0.001) with no significant difference between groups (P = 0.42). After phlebotomy, the BAR response to oral methionine did not significantly change between groups (P = 0.53). Brachial artery nitroglycerin-mediated dilation did not change in response to phlebotomy. CONCLUSIONS Four serial phlebotomy procedures over six months with or without intravenous iron supplementation did not alter vascular endothelial function in the brachial artery when compared with sham phlebotomy.
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Affiliation(s)
- Qurat-Ul-Ain Jelani
- Department of Medicine, New York University School of Medicine, New York University Langone Medical Center, New York City, New York
| | - Bhisham Harchandani
- Department of Medicine, New York University School of Medicine, New York University Langone Medical Center, New York City, New York
| | | | - Yu Guo
- Department of Population Health, New York University Langone Medical Center, New York City, New York
| | - Hua Zhong
- Department of Population Health, New York University Langone Medical Center, New York City, New York
| | - Timothy Hilbert
- Department of Medicine, New York University School of Medicine, New York University Langone Medical Center, New York City, New York
| | - Jonathan D Newman
- Department of Medicine, New York University School of Medicine, New York University Langone Medical Center, New York City, New York
| | - Stuart D Katz
- Department of Medicine, New York University School of Medicine, New York University Langone Medical Center, New York City, New York
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11
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Agarwal R. Iron deficiency anemia in chronic kidney disease: Uncertainties and cautions. Hemodial Int 2017; 21 Suppl 1:S78-S82. [DOI: 10.1111/hdi.12561] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 03/11/2017] [Indexed: 11/26/2022]
Affiliation(s)
- Rajiv Agarwal
- Department of Medicine; Indiana University School of Medicine and Richard L. Roudebush Veterans Administration Medical Center; Indianapolis Indiana USA
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12
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Agarwal R. What are the Considerations in Balancing Benefits and Risks in Iron Treatment?: Emerging Evidence on the Safety of Intravenous Iron in Chronic Kidney Disease. Semin Dial 2016; 30:22-25. [PMID: 27678472 DOI: 10.1111/sdi.12549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rajiv Agarwal
- Department of Medicine, Indiana University School of Medicine and Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
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13
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Duyuler S, Türker Duyuler P, Batur MK. Impact of Iron and Homocysteine Levels on T Peak-to-End Interval and Tp-e/QT Ratio in Elite Athletes. Ann Noninvasive Electrocardiol 2016; 21:557-565. [PMID: 27019094 DOI: 10.1111/anec.12365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Electrocardiography (ECG) is frequently used in preparticipation evaluation of competitive athletes. Repolarization heterogeneities on ECG is a well-known indicator for malignant ventricular arrhythmias and sudden cardiac death. We aimed to investigate the effect of iron and homocysteine levels on arrhythmogenic indicators, T peak-to-end (Tp-e) interval, and Tp-e/QT ratio in elite athletes. METHODS A total of 72 players (48 football and 24 basketball) with a mean age of 25.4 ± 5.0 years were included to the analysis. Blood biochemistry, homocysteine level, and iron parameters (transferrin saturation and serum iron) were obtained by standard methods. Duration of QRS, QT interval, and Tp-e interval were measured manually on the precordial leads and Tp-e/QT ratio was calculated. RESULTS Baseline demographic and clinical characteristics of the study population were compared in two groups according to the median value of Tp-e/QT = 0.219. Both iron and transferrin saturations were higher in the above median group (P = 0.001 and P = 0.002, respectively), however, homocysteine levels were not statistically different among two groups (P = 0.405). In correlation analysis, both serum iron and transferrin saturation were significantly correlated with Tp-e interval (r = 0.368; P = 0.001 and r = 0.394; P = 0.00, respectively) and Tp-e/QT ratio (r = 0.357; P = 0.002 and r = 0.372; P = 0.001, respectively). Multiple stepwise regression analysis revealed that transferrin saturation was an independent predictor of Tp-e interval and Tp-e/QT ratio (β = 0.325; P = 0.002 and β = 0.372; P = 0.001, respectively). CONCLUSION This study showed an independent relationship between iron status and Tp-e interval and Tp-e/QT ratios of elite sport players which were also not correlated with serum homocysteine levels.
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Affiliation(s)
- Serkan Duyuler
- Department of Cardiology, Acıbadem Ankara Hospital, Ankara, Turkey.
| | - Pınar Türker Duyuler
- Department of Cardiology, Ankara Numune Education and Research Hospital, Ankara, Turkey
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14
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Marques VB, Nascimento TB, Ribeiro RF, Broseghini-Filho GB, Rossi EM, Graceli JB, dos Santos L. Chronic iron overload in rats increases vascular reactivity by increasing oxidative stress and reducing nitric oxide bioavailability. Life Sci 2015; 143:89-97. [PMID: 26523985 DOI: 10.1016/j.lfs.2015.10.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/13/2015] [Accepted: 10/28/2015] [Indexed: 02/07/2023]
Abstract
AIMS Iron overload in animal models and humans increases oxidative stress and induces cardiomyopathy. It has been suggested that the vasculature is also damaged, but the impacts on vascular reactivity and the underlying mechanisms remain poorly understood. In this study, we aimed to identify possible changes in the vascular reactivity of aortas from iron overloaded rats and investigate the underlying mechanisms. MAIN METHODS Rats were treated with 100mg/kg/day iron-dextran, ip, five days a week for four weeks and compared to a saline-injected group. KEY FINDINGS Chronic iron administration increased serum iron and transferrin saturation with significant deposition in the liver. Additionally, iron overload significantly increased the vasoconstrictor response in aortic rings as assessed in vitro, with reduced influence of endothelial denudation or l-NAME incubation on the vascular reactivity. In vitro assay with DAF-2 indicated reduced NO production in the iron overload group. Iron overload-induced vascular hyperactivity was reversed by incubation with tiron, catalase, apocynin, allopurinol and losartan. Moreover, malondialdehyde was elevated in the plasma, and O2(•-) generation and NADPH oxidase subunit (p22phox) expression were increased in the aortas of iron-loaded rats. SIGNIFICANCE Our results demonstrated that chronic iron overload is associated with altered vascular reactivity and the loss of endothelial modulation of the vascular tone. This iron loading-induced endothelial dysfunction and reduced nitric oxide bioavailability may be a result of increased production of reactive oxygen species and local renin-angiotensin system activation.
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Affiliation(s)
| | | | | | | | - Emilly Martinelly Rossi
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES, Brazil
| | | | - Leonardo dos Santos
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES, Brazil.
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15
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A randomized trial of intravenous and oral iron in chronic kidney disease. Kidney Int 2015; 88:905-14. [PMID: 26083656 PMCID: PMC4589436 DOI: 10.1038/ki.2015.163] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 03/31/2015] [Accepted: 04/09/2015] [Indexed: 02/04/2023]
Abstract
Although iron is commonly used to correct iron deficiency anemia (IDA) in chronic kidney disease (CKD) its effect on kidney function is unclear. To assess this, we randomly assigned patients with Stage 3 and 4 CKD and IDA to either open-label oral ferrous sulfate (69 patients to 325 mg three times daily for 8 weeks) or intravenous iron sucrose (67 patients to 200 mg every 2 weeks, total 1 gram). The primary outcome was the between group difference in slope of measured glomerular filtration rate (mGFR) change over two years. The trial was terminated early on the recommendation of an independent Data and Safety Monitoring Board based on little chance of finding differences in mGFR slopes, but a higher risk of serious adverse events in the intravenous iron treatment group. mGFR declined similarly over two years in both treatment groups (oral −3.6 mL/min/1.73m2, intravenous − 4.0 mL/min/1.73m2, between group difference − 0.35 mL/min/1.73m2 (95% confidence interval −2.9 to 2.3). There were 36 serious cardiovascular events among 19 participants assigned to the oral iron treatment group and 55 events among 17 participants of the intravenous iron group (adjusted incidence rate ratio 2.51 (1.56−4.04). Infections resulting in hospitalizations had a significant adjusted incidence rate ratio of 2.12 (1.24−3.64). Thus, among non-dialyzed patients with CKD and IDA, intravenous iron therapy is associated with an increased risk of serious adverse events, including those from cardiovascular causes and infectious diseases.
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16
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Baggott JE, Tamura T. Homocysteine, iron and cardiovascular disease: a hypothesis. Nutrients 2015; 7:1108-18. [PMID: 25668155 PMCID: PMC4344578 DOI: 10.3390/nu7021108] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 01/27/2015] [Indexed: 12/26/2022] Open
Abstract
Elevated circulating total homocysteine (tHcy) concentrations (hyperhomocysteinemia) have been regarded as an independent risk factor for cardiovascular disease (CVD). However, several large clinical trials to correct hyperhomocysteinemia using B-vitamin supplements (particularly folic acid) have largely failed to reduce the risk of CVD. There is no doubt that a large segment of patients with CVD have hyperhomocysteinemia; therefore, it is reasonable to postulate that circulating tHcy concentrations are in part a surrogate marker for another, yet-to-be-identified risk factor(s) for CVD. We found that iron catalyzes the formation of Hcy from methionine, S-adenosylhomocysteine and cystathionine. Based on these findings, we propose that an elevated amount of non-protein-bound iron (free Fe) increases circulating tHcy. Free Fe catalyzes the formation of oxygen free radicals, and oxidized low-density lipoprotein is a well-established risk factor for vascular damage. In this review, we discuss our findings on iron-catalyzed formation of Hcy from thioethers as well as recent findings by other investigators on this issue. Collectively, these support our hypothesis that circulating tHcy is in part a surrogate marker for free Fe, which is one of the independent risk factors for CVD.
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Affiliation(s)
- Joseph E Baggott
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Tsunenobu Tamura
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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17
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Abstract
Anemia and iron deficiency are quite prevalent in patients with heart failure (HF) and may overlap. Both anemia and iron deficiency are associated with worse symptoms and adverse clinical outcomes. In the past few years, there has been an enormous interest in the subject of iron deficiency and its management in patients with HF. In this review, the etiology and relevance of iron deficiency, iron metabolism in the setting of HF, studies on iron supplementation in patients with HF and potential cardiovascular effects of subclinical iron overload are discussed.
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Affiliation(s)
- Natasha P Arora
- Detroit Medical Center, Wayne State University, Detroit, MI, USA
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18
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van Eijk LT, Heemskerk S, van der Pluijm RW, van Wijk SM, Peters WHM, van der Hoeven JG, Kox M, Swinkels DW, Pickkers P. The effect of iron loading and iron chelation on the innate immune response and subclinical organ injury during human endotoxemia: a randomized trial. Haematologica 2013; 99:579-87. [PMID: 24241495 DOI: 10.3324/haematol.2013.088047] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In this double-blind randomized placebo-controlled trial involving 30 healthy male volunteers we investigated the acute effects of iron loading (single dose of 1.25 mg/kg iron sucrose) and iron chelation therapy (single dose of 30 mg/kg deferasirox) on iron parameters, oxidative stress, the innate immune response, and subclinical organ injury during experimental human endotoxemia. The administration of iron sucrose induced a profound increase in plasma malondialdehyde 1 h after administration (433±37% of baseline; P<0.0001), but did not potentiate the endotoxemia-induced increase in malondialdehyde, as was seen 3 h after endotoxin administration in the placebo group (P=0.34) and the iron chelation group (P=0.008). Endotoxemia resulted in an initial increase in serum iron levels and transferrin saturation that was accompanied by an increase in labile plasma iron, especially when transferrin saturation reached levels above 90%. Thereafter, serum iron decreased to 51.6±9.7% of baseline at T=8 h in the placebo group versus 84±15% and 60.4±8.9% of baseline at 24 h in the groups treated with iron sucrose and deferasirox, respectively. No significant differences in the endotoxemia-induced cytokine response (TNF-α, IL-6, IL-10 and IL-1RA), subclinical vascular injury and kidney injury were observed between groups. However, vascular reactivity to noradrenalin was impaired in the 6 subjects in whom labile plasma iron was elevated during endotoxemia as opposed to those in whom no labile plasma iron was detected (P=0.029). In conclusion, a single dose of iron sucrose does not affect the innate immune response in a model of experimental human endotoxemia, but may impair vascular reactivity when labile plasma iron is formed. (Clinicaltrials.gov identifier:01349699).
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Akarsu S, Demir H, Selek S, Oguzoncul F. Iron deficiency anemia and levels of oxidative stress induced by treatment modality. Pediatr Int 2013; 55:289-95. [PMID: 23316876 DOI: 10.1111/ped.12054] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 07/22/2012] [Accepted: 10/09/2012] [Indexed: 01/09/2023]
Abstract
BACKGROUND The effects of iron deficiency anemia (IDA) and its treatment on plasma total antioxidant capacity (TAOC) were investigated. METHODS Sixty patients with IDA and 20 healthy controls were divided into four subgroups: an oral (per os: PO) group (n = 20); an intramuscular (IM) group (n = 20); an intravenous (IV) group (n = 20); and the control group (n = 20). Blood samples were obtained from all patients before treatment, and at 24 h, 7 days, 6 and 13 weeks after initiation of IDA therapy. RESULTS TAOC in the IDA group was low when compared with the control group (P < 0.001). Although TAOC at 24 h in the PO group was not different from the control group, the TAOC in the IM and IV groups was relatively lower (P < 0.001). The TAOC in the PO group at 7 days, and at 6 and 13 weeks was closest to the control group level. The mean TAOC in the IV group at 13 weeks was clearly lower relative to the PO and IM groups. CONCLUSIONS Oxidative stress was minimally induced with oral therapy, while IM and IV therapies induced higher levels of oxidative stress, in increasing order of intensity.
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Affiliation(s)
- Saadet Akarsu
- Division of Hematology, Firat University Faculty of Medicine, Elazig, Turkey.
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20
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Kang P, Liu T, Tian C, Zhou Y, Jia C. Association of total iron binding capacity with coronary artery disease. Clin Chim Acta 2012; 413:1424-9. [DOI: 10.1016/j.cca.2012.05.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/14/2012] [Accepted: 05/14/2012] [Indexed: 11/30/2022]
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Peña-Duque MA, Baños-González MA, Valente-Acosta B, Rodríguez-Lobato LG, Martínez-Ríos MA, Cardoso-Saldaña G, Barragán-García R, Herrera-Alarcón V, Linares-López C, Delgado-Granados H, de la Peña-Díaz A. Homocysteine is related to aortic mineralization in patients with ischemic heart disease. J Atheroscler Thromb 2012; 19:292-7. [PMID: 22240908 DOI: 10.5551/jat.10157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
UNLABELLED Homocysteine is implicated as an early atherosclerotic promoter, which enhances the smooth muscle cell proliferation and produces free radicals that induce cellular damage. These factors must have a role in the progression of atherosclerosis that subsequently leads to vascular mineralization. AIM Identify a correlation between the plasma concentration of total homocysteine and the amount of minerals that accumulate in the aorta of patients with atherosclerosis. METHODS We performed a cross-sectional study in 13 patients with three-vessel coronary artery disease, undergoing coronary artery bypass surgery. Aortic and mammary artery specimens were analyzed using a scanning electron microscope with an energy dispersive X-ray spectrometer. The homocysteine was determined using an immunonephelometry method. RESULTS The amount of minerals in the aorta was greater (300 ± 181.6 particles per 500 µm2 than that in the mammary artery (64 ± 45 particles per 500 µm2 (p < 0.01). The average tHcy was 9.5 ± 2.3 µmol/L. The Spearman's rank correlation coefficient was positive between tHcy, and aortic iron (p < 0.05). CONCLUSIONS Our study demonstrates that the aorta is dramatically affected by mineralization compared to the mammary artery. In addition, a direct correlation was identified between the levels of tHcy and the iron particles in the aortic wall.
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Affiliation(s)
- Marco A Peña-Duque
- Instituto Nacional de Cardiología Ignacio Chávez, Grupo Genética Intervencionista, Departamentos de Biología Molecular, Hemodinámica, Endocrinología, Cirugía, Mexico
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22
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Mariani LH, Berns JS. Do oral iron supplements have any role in dialysis patients? Semin Dial 2011; 24:385-7. [DOI: 10.1111/j.1525-139x.2011.00905.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Treatment of anemia in heart failure: potential risks and benefits of intravenous iron therapy in cardiovascular disease. Cardiol Rev 2011; 18:240-50. [PMID: 20699672 DOI: 10.1097/crd.0b013e3181e71150] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Iron-deficiency anemia is common in patients with heart failure (HF), but the optimum diagnostic tests to detect iron deficiency and the treatment options to replete iron have not been fully characterized. Recent studies in patients with HF indicate that intravenous iron can rapidly replenish iron stores in patients having iron-deficiency anemia, with resultant increased hemoglobin levels and improved functional capacity. Preliminary data from a subgroup analysis also suggest that supplemental intravenous iron therapy can improve functional capacity even in those subjects without anemia. The mechanisms responsible for this observation are not fully characterized, but may be related to beneficial effects of iron supplementation on mitochondrial respiration in skeletal muscle. The long-term safety of using intravenous iron supplementation in HF populations is not known. Iron is a known pro-oxidant factor that can inhibit nitric oxide signaling and irreversibly injury cells. Increased iron stores are associated with vascular endothelial dysfunction and increased risk of coronary heart disease events. Additional clinical trials are needed to more fully characterize the therapeutic potential and safety of intravenous iron in HF patients.
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Friedman J, Cremer M, Jelani QUA, Huang X, Jian J, Shah S, Katz SD. Oral contraceptive use, iron stores and vascular endothelial function in healthy women. Contraception 2011; 84:285-90. [PMID: 21843695 DOI: 10.1016/j.contraception.2011.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 01/12/2011] [Accepted: 01/12/2011] [Indexed: 12/22/2022]
Abstract
BACKGROUND Increased iron stores are associated with greater cardiovascular risk in postmenopausal women. Oral contraceptive pill (OCP) use decreases the volume of menstrual blood loss and increases iron stores, but the link between OCP use, iron stores and cardiovascular risk in premenopausal women has not been characterized. STUDY DESIGN We conducted a cross-sectional study of 23 healthy OCP users to determine the association between type and duration of OCP exposure, iron stores, and vascular endothelial function [flow-mediated dilation (FMD) in the brachial artery]. RESULTS Median duration of OCP use was 45 months. FMD in the brachial artery was significantly associated with progestin type used (estranes/gonanes vs. drospirenone) and duration of OCP use (both p<.05) but not iron stores. In multivariate analysis, progestin type was the only independent predictor of FMD. CONCLUSIONS Use of OCP containing drospirenone was independently associated with greater FMD in the brachial artery and, thus, a potentially more favorable cardiovascular risk profile, when compared with use of OCP containing estranes/gonanes.
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Affiliation(s)
- Julie Friedman
- Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
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25
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Pardo Silva MC, Njajou OT, Alizadeh BZ, Hofman A, Witteman JCM, van Duijn CM, Janssens ACJW. HFE gene mutations increase the risk of coronary heart disease in women. Eur J Epidemiol 2010; 25:643-9. [PMID: 20640879 PMCID: PMC2931632 DOI: 10.1007/s10654-010-9489-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2009] [Accepted: 07/05/2010] [Indexed: 01/14/2023]
Abstract
The purpose of the present study is to examine HFE gene mutations in relation to newly diagnosed (incident) coronary heart disease (CHD). In a population-based follow-up study of 7,983 individuals aged 55 years and older, we compared the risk of incident CHD between HFE carriers and non-carriers, overall and stratified by sex and smoking status. HFE mutations were significantly associated with an increased risk of incident CHD in women but not in men (hazard ratio [HR] for women = 1.7, 95% confidence interval [CI] 1.2–2.4 versus HR for men = 0.9, 95% CI 0.7–1.2). This increased CHD risk associated with HFE mutations in women was statistically significant in never smokers (HR = 1.8, 95% CI 1.1–2.8) and current smokers (HR = 3.1, 95% CI 1.4–7.1), but not in former smokers (HR = 1.3, 95% CI 0.7–2.4). HFE mutations are associated with increased risk of incident CHD in women.
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Affiliation(s)
- M Carolina Pardo Silva
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, The Netherlands
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26
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Kell DB. Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases. BMC Med Genomics 2009; 2:2. [PMID: 19133145 PMCID: PMC2672098 DOI: 10.1186/1755-8794-2-2] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 01/08/2009] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. REVIEW We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here. CONCLUSION Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.
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27
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Pai AB, Conner TA. Oxidative Stress and Inflammation in Chronic Kidney Disease: Role of Intravenous Iron and Vitamin D. J Pharm Pract 2008. [DOI: 10.1177/0897190008316288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cardiovascular disease (CVD) is the leading cause of death among chronic kidney disease patients (CKD). The etiology of CVD in CKD is multifactorial and increasing evidence points to the important contribution of “nontraditional” risk factors including oxidative stress and inflammation. CKD is associated with a chronic imbalance of prooxidant and antioxidant factors that results in a state of chronic inflammation. Intravenous iron supplementation has been shown to induce oxidative stress and has been associated with lipid peroxidation and DNA damage. Conversely, treatment with vitamin D analogs has been associated with improved mortality in hemodialysis patients in 2 recent large cohort studies. These data suggest that vitamin D analogs may exert effects beyond their pharmacologic role in parathyroid hormone suppression. This article addresses the current data regarding the relative contributions of intravenous iron supplementation and vitamin D analog therapy on oxidative stress and inflammation in CKD patients.
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Affiliation(s)
- Amy Barton Pai
- University of New Mexico Health Sciences Center, College of Pharmacy and School of Medicine, Albuquerque, New Mexico,
| | - Todd A. Conner
- University of New Mexico Health Sciences Center, College of Pharmacy and School of Medicine, Albuquerque, New Mexico
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28
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Zheng H, Patel M, Cable R, Young L, Katz SD. Insulin sensitivity, vascular function, and iron stores in voluntary blood donors. Diabetes Care 2007; 30:2685-9. [PMID: 17630263 DOI: 10.2337/dc07-0748] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Reduced iron stores after blood donation are associated with improved vascular function and decreased cardiovascular risk. We sought to determine whether iron-dependent changes in glucose metabolism may contribute to improved vascular function in blood donors. RESEARCH DESIGN AND METHODS We conducted a prospective cross-sectional study in 21 high-frequency blood donors (more than eight donations in the last 2 years) and 21 low-frequency blood donors (one to two donations in the last 2 years) aged 50-75 years. Serum markers of iron stores, whole-body insulin sensitivity index (WBISI) during oral glucose tolerance testing, and flow-mediated dilation in the brachial artery were determined in all subjects. RESULTS Serum ferritin was decreased (median values 23 vs. 36 ng/ml, P < 0.05) and flow-mediated dilation in the brachial artery was increased (median values 5.9 vs. 5.3%, P < 0.05) in high-frequency donors compared with low-frequency donors, respectively, but WBISI (median values 4.8 vs. 4.7) and related measures of glucose tolerance did not differ between groups. Flow-mediated dilation significantly decreased at 1 h after oral glucose loading in both groups, but the decrease in flow-mediated dilation at 1 h did not differ between high- and low-frequency donors. CONCLUSIONS High-frequency blood donation reduced serum ferritin and increased flow-mediated dilation compared with low-frequency donation but did not improve insulin sensitivity or protect the vascular endothelium from the adverse effects of acute hyperglycemia after oral glucose loading. These findings suggest that the mechanisms linking blood donation to improved vascular function are not likely related to changes in glucose metabolism.
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Affiliation(s)
- Haoyi Zheng
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, 135 College St., New Haven, CT 06510, USA
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Bishu K, Agarwal R. Acute injury with intravenous iron and concerns regarding long-term safety. Clin J Am Soc Nephrol 2007; 1 Suppl 1:S19-23. [PMID: 17699372 DOI: 10.2215/cjn.01420406] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Intravenous iron is widely used to maintain adequate iron stores and prevent iron deficiency anemia in patients with chronic kidney disease, yet concerns remain about its long-term safety with respect to oxidative stress, kidney injury, and accelerated atherosclerosis, which are the subjects of this review. Three parenteral iron formulations are available for use in the United States: Iron dextran, iron gluconate, and iron sucrose. Iron dextran, especially the high molecular form, has been linked with anaphylactoid and anaphylactic reactions, and its use has been declining. A portion of intravenous iron preparations is redox-active, labile iron available for direct donation to transferrin. In vitro tests show that commonly available intravenous iron formulations have differing capacities to saturate transferrin directly: Iron gluconate > iron sucrose > iron dextran. Intravenous iron treatment produces oxidative stress, as demonstrated by increases in plasma levels of lipid peroxidation products (malondialdehyde), at a point that is much earlier than the time to peak concentration of catalytically active iron, suggesting a direct effect of iron sucrose on oxidative stress. Furthermore, iron sucrose infusion produces endothelial dysfunction that seems to peak earlier than the serum level of free iron. Intravenous iron sucrose infusion also has been shown to produce acute renal injury and inflammation as demonstrated by increased urinary albumin, enzyme (N-acetyl-beta-glucosaminidase), and cytokine (chemokine monocyte chemoattractant protein-1) excretions. Although the long-term dangers of intravenous iron are unproved, these data call for examination of effects of intravenous iron on the potential for long-term harm in patients with chronic kidney disease.
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MESH Headings
- Acute Kidney Injury/chemically induced
- Acute Kidney Injury/metabolism
- Anemia, Iron-Deficiency/drug therapy
- Anemia, Iron-Deficiency/etiology
- Anemia, Iron-Deficiency/metabolism
- Animals
- Atherosclerosis/chemically induced
- Atherosclerosis/metabolism
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Ferric Compounds/administration & dosage
- Ferric Compounds/adverse effects
- Ferric Compounds/metabolism
- Ferric Oxide, Saccharated
- Glucaric Acid
- Hematinics/administration & dosage
- Hematinics/adverse effects
- Hematinics/metabolism
- Humans
- Inflammation/chemically induced
- Inflammation/metabolism
- Infusions, Intravenous
- Iron-Dextran Complex/administration & dosage
- Iron-Dextran Complex/adverse effects
- Iron-Dextran Complex/metabolism
- Oxidative Stress/drug effects
- Renal Dialysis
- Renal Insufficiency, Chronic/complications
- Renal Insufficiency, Chronic/drug therapy
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/therapy
- Time Factors
- Transferrin/metabolism
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Affiliation(s)
- Kalkidan Bishu
- Department of Medicine, Indiana University School of Medicine, and Richard L. Roudebush VA Medical Center, Indianapolis, Indiana, USA
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30
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Affiliation(s)
- Sundararaman Swaminathan
- Division of Nephrology, University of Arkansas for Medical Sciences, 4301 West Markham St., Slot 501, Little Rock, AR 72205, USA.
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31
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Alvares Delfino VD, de Andrade Vianna AC, Mocelin AJ, Barbosa DS, Mise RA, Matsuo T. Folic acid therapy reduces plasma homocysteine levels and improves plasma antioxidant capacity in hemodialysis patients. Nutrition 2007; 23:242-7. [PMID: 17321110 DOI: 10.1016/j.nut.2007.01.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 01/04/2007] [Accepted: 01/04/2007] [Indexed: 11/19/2022]
Abstract
OBJECTIVE We evaluated the effects of folic acid on homocysteine levels and oxidative stress in 46 stable patients on hemodialysis. METHODS This double-blind, placebo-controlled, randomized trial assessed the effects of 6 mo of 10 mg of folic acid (26 patients) or placebo (20 patients) given three times weekly after each dialysis under nurse supervision on homocysteine levels, total plasma antioxidant capacity, and hydroperoxide plasma levels. RESULTS Folic acid treatment normalized plasma homocysteine levels in most patients, significantly increased total plasma antioxidant capacity levels, but had no significant effect on hydroperoxide levels. Placebo treatment had no statistically significant effect on the three parameters. CONCLUSION The folic acid therapy protocol effectively lowered plasma homocysteine levels and improved the total plasma antioxidant capacity in hemodialysis patients. Further studies are required to assess the usefulness of folic acid for decreasing cardiovascular mortality in patients with chronic kidney disease.
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Baggott JE, Tamura T. Iron-dependent formation of homocysteine from methionine and other thioethers. Eur J Clin Nutr 2007; 61:1359-63. [PMID: 17299471 DOI: 10.1038/sj.ejcn.1602665] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE We tested whether homocysteine is formed from methionine and other thioethers in vitro and in vivo, because methionine can be chemically demethylated to homocysteine. DESIGN In in vitro studies, chemical conversions of thioethers (methionine, S-adenosylhomocysteine and cystathionine) into homocysteine were measured under various aerobic conditions. In humans, oral methionine (0.17 mmol/kg body weight) loading tests with and without an oral iron dose (ferrous sulfate, 13 mumol/kg) were performed. SETTING A university setting in Birmingham, AL, USA. SUBJECTS A total of five healthy adult subjects volunteered. RESULTS The in vitro incubation of methionine, S-adenosylhomocysteine or cystathionine with chelated iron resulted in the formation of homocysteine. These conversions were iron- and pH-dependent (pH optima between 5.0 and 6.0) and it was also chelator-dependent. In humans, oral methionine loading tests resulted in a 45% increase in the area-under-the-curve for plasma total homocysteine concentrations, when iron was given together with methionine. CONCLUSION Our data suggest that iron-dependent chemical formation of homocysteine can occur in vivo, and contribute to the plasma total homocysteine pool, since this formation can occur ceaselessly. We hypothesize that plasma total homocysteine concentrations reflect, in part, non-protein-bound iron in the body.
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Affiliation(s)
- J E Baggott
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Abstract
Recent studies of endothelial function suggest that adverse vascular effects of homocysteine are iron-dependent. Iron sucrose worsens and iron chelation eliminates homocysteine-associated decreases in flow-mediated dialation. There may be no vasculopathic effect of homocysteine without available reactive iron. Iron-dependent amplification of the vascular effects of homocysteine may be one of several mechanisms by which stored iron increases cardiac risk.
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Affiliation(s)
- J L Sullivan
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA.
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