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Nuhu F, Bhandari S. Oxidative Stress and Cardiovascular Complications in Chronic Kidney Disease, the Impact of Anaemia. Pharmaceuticals (Basel) 2018; 11:E103. [PMID: 30314359 PMCID: PMC6316624 DOI: 10.3390/ph11040103] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 09/30/2018] [Accepted: 10/01/2018] [Indexed: 12/17/2022] Open
Abstract
Patients with chronic kidney disease (CKD) have significant cardiovascular morbidity and mortality as a result of risk factors such as left ventricular hypertrophy (LVH), oxidative stress, and inflammation. The presence of anaemia in CKD further increases the risk of LVH and oxidative stress, thereby magnifying the deleterious consequence in uraemic cardiomyopathy (UCM), and aggravating progression to failure and increasing the risk of sudden cardiac death. This short review highlights the specific cardio-renal oxidative stress in CKD and provides an understanding of the pathophysiology and impact of uraemic toxins, inflammation, and anaemia on oxidative stress.
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Affiliation(s)
- Faisal Nuhu
- School of Life Sciences (Biomedical), University of Hull, Cottingham Rd, Hull HU6 7RX, UK.
| | - Sunil Bhandari
- Hull York Medical School & Department of Renal Medicine, Hull and East Yorkshire NHS Hospital Trust, Hull HU3 2JZ, UK.
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Zitt E, Sturm G, Kronenberg F, Neyer U, Knoll F, Lhotta K, Weiss G. Iron supplementation and mortality in incident dialysis patients: an observational study. PLoS One 2014; 9:e114144. [PMID: 25462819 PMCID: PMC4252084 DOI: 10.1371/journal.pone.0114144] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 11/03/2014] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Studies on the association between iron supplementation and mortality in dialysis patients are rare and conflicting. METHODS In our observational single-center cohort study (INVOR study) we prospectively studied 235 incident dialysis patients. Time-dependent Cox proportional hazards models using all measured laboratory values for up to 7.6 years were applied to study the association between iron supplementation and all-cause mortality, cardiovascular and sepsis-related mortality. Furthermore, the time-dependent association of ferritin levels with mortality in patients with normal C-reactive protein (CRP) levels (<0.5 mg/dL) and elevated CRP levels (≧0.5 mg/dL) was evaluated by using non-linear P-splines to allow flexible modeling of the association. RESULTS One hundred and ninety-one (81.3%) patients received intravenous iron, 13 (5.5%) patients oral iron, whereas 31 (13.2%) patients were never supplemented with iron throughout the observation period. Eighty-two (35%) patients died during a median follow-up of 34 months, 38 patients due to cardiovascular events and 21 patients from sepsis. Baseline CRP levels were not different between patients with and without iron supplementation. However, baseline serum ferritin levels were lower in patients receiving iron during follow up (median 93 vs 251 ng/mL, p<0.001). Iron supplementation was associated with a significantly reduced all-cause mortality [HR (95%CI): 0.22 (0.08-0.58); p = 0.002] and a reduced cardiovascular and sepsis-related mortality [HR (95%CI): 0.31 (0.09-1.04); p = 0.06]. Increasing ferritin concentrations in patients with normal CRP were associated with a decreasing mortality, whereas in patients with elevated CRP values ferritin levels>800 ng/mL were linked with increased mortality. CONCLUSIONS Iron supplementation is associated with reduced all-cause mortality in incident dialysis patients. While serum ferritin levels up to 800 ng/mL appear to be safe, higher ferritin levels are associated with increased mortality in the setting of concomitant inflammation.
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Affiliation(s)
- Emanuel Zitt
- Department of Nephrology and Dialysis, Feldkirch Academic Teaching Hospital, Feldkirch, Austria
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
| | - Gisela Sturm
- Department of Dermatology and Venereology, Innsbruck Medical University, Innsbruck, Austria
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Innsbruck Medical University, Innsbruck, Austria
| | - Florian Kronenberg
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Innsbruck Medical University, Innsbruck, Austria
| | - Ulrich Neyer
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
| | - Florian Knoll
- Department of Nephrology and Dialysis, Feldkirch Academic Teaching Hospital, Feldkirch, Austria
| | - Karl Lhotta
- Department of Nephrology and Dialysis, Feldkirch Academic Teaching Hospital, Feldkirch, Austria
- Vorarlberg Institute for Vascular Investigation and Treatment (VIVIT), Feldkirch, Austria
- * E-mail: (KL); (GW)
| | - Günter Weiss
- Department of Internal Medicine VI (Infectious Diseases, Immunology, Rheumatology, Pneumology), Innsbruck Medical University, Innsbruck, Austria
- * E-mail: (KL); (GW)
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Tangri N, Miskulin DC, Zhou J, Bandeen-Roche K, Michels WM, Ephraim PL, McDermott A, Crews DC, Scialla JJ, Sozio SM, Shafi T, Jaar BG, Meyer K, Boulware LE. Effect of intravenous iron use on hospitalizations in patients undergoing hemodialysis: a comparative effectiveness analysis from the DEcIDE-ESRD study. Nephrol Dial Transplant 2014; 30:667-75. [PMID: 25366328 DOI: 10.1093/ndt/gfu349] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Intravenous iron use in hemodialysis patients has greatly increased over the last decade, despite limited studies on the safety of iron. METHODS We studied the association of receipt of intravenous iron with hospitalizations in an incident cohort of hemodialysis patients. We examined 9544 patients from Dialysis Clinic, Inc. (DCI). We ascertained intravenous iron use from DCI electronic medical record and USRDS data files, and hospitalizations through Medicare claims. We examined the association between iron exposure accumulated over 1-, 3- or 6-month time windows and incident hospitalizations in the follow-up period using marginal structural models accounting for time-dependent confounders. We performed sensitivity analyses including recurrent events models for multiple hospitalizations and models for combined outcome of hospitalization and death. RESULTS There were 22 347 hospitalizations during a median follow-up of 23 months. Higher cumulative dose of intravenous iron was not associated with all-cause, cardiovascular or infectious hospitalizations [HR 0.97 (95% CI: 0.77-1.22) for all-cause hospitalizations comparing >2100 mg versus 0-900 mg of iron over 6 months]. Findings were similar in models examining the risk of hospitalizations in 1- and 3-month windows [HR 0.88 (95% CI: 0.79-0.99) and HR 0.88 (95% CI: 0.74-1.03), respectively] or the risk of combined outcome of hospitalization and death in the 6-month window [HR 0.98 (95% CI: 0.78-1.23)]. CONCLUSIONS Higher cumulative dose of intravenous iron may not be associated with increased risk of hospitalizations in hemodialysis patients. While clinical trials are needed, employing higher iron doses to reduce erythropoiesis-stimulating agents does not appear to increase morbidity in routine clinical care.
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Affiliation(s)
- Navdeep Tangri
- Division of Nephrology, Seven Oaks General Hospital, University of Manitoba, Winnipeg Manitoba, Canada
| | - Dana C Miskulin
- Division of Nephrology, Tufts University School of Medicine, Boston, MA, USA
| | - Jing Zhou
- Division of General Internal Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Karen Bandeen-Roche
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Wieneke M Michels
- Division of General Internal Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA Division of Nephrology, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Patti L Ephraim
- Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Aidan McDermott
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Deidra C Crews
- Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Julia J Scialla
- Division of Nephrology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Stephen M Sozio
- Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Tariq Shafi
- Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bernard G Jaar
- Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA Nephrology Center of Maryland, Baltimore, MD, USA
| | - Klemens Meyer
- Division of Nephrology, Tufts University School of Medicine, Boston, MA, USA
| | - L Ebony Boulware
- Division of General Internal Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD, USA Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Comparative short-term safety of bolus versus maintenance iron dosing in hemodialysis patients: a replication study. BMC Nephrol 2014; 15:154. [PMID: 25245951 PMCID: PMC4182851 DOI: 10.1186/1471-2369-15-154] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 09/15/2014] [Indexed: 11/10/2022] Open
Abstract
Background Recent research has reported that patients receiving bolus (frequent large doses to achieve iron repletion) versus maintenance dosing of iron have an increased short-term risk of infection, but a similar risk of cardiovascular events. We sought to determine whether these findings could be replicated using the same methods and a different data source. Methods Clinical data from 6,605 patients of a small U.S. dialysis provider merged with Medicare claims data were examined. Iron dosing patterns (bolus, maintenance, no iron) were identified during 1-month exposure periods and cardiovascular and infection-related outcomes were assessed during 3-month follow-up periods. The effects of bolus versus maintenance dosing were assessed using Cox proportional hazards regression analyses to estimate hazard ratios and semiparametric additive risk models to estimate hazard rate differences, controlling for demographic and clinical characteristics, laboratory values and medications, and comorbidities. Results 48,050 exposure/follow-up periods were examined. 13.9 percent of the exposure periods were bolus dosing, 49.3 percent were maintenance dosing, and the remainder were no iron use. All of the adjusted hazard ratios were >1.00 for the infection-related outcomes, suggesting that bolus dosing increases the risk of these events. The effects were greatest for hospitalized for infection of any major organ system (hazard ratio 1.13 (1.03, 1.24)) and use of intravenous antibiotics (hazard ratio 1.08 (1.02, 1.15). When examining the subgroup of individuals with catheters, the hazard ratios for the infection-related outcomes were generally greater than in the overall sample. There was little association between type of dosing practice and cardiovascular outcomes. Conclusions Results of this study provide further evidence of the association between bolus dosing and increased infection risk, particularly in the subgroup of patients with a catheter, and of the lack of an association between dosing practices and cardiovascular outcomes. Electronic supplementary material The online version of this article (doi:10.1186/1471-2369-15-154) contains supplementary material, which is available to authorized users.
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Costa NA, Kshirsagar AV, Wang L, Detwiler RK, Brookhart MA. Pretransplantation erythropoiesis-stimulating agent hyporesponsiveness is associated with increased kidney allograft failure and mortality. Transplantation 2013; 96:807-13. [PMID: 23982339 DOI: 10.1097/tp.0b013e3182a0f668] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Poor response to erythropoiesis-stimulating agents (ESA) is associated with morbidity and mortality among dialysis patients. It is unclear whether the risk associated with poor ESA response during dialysis extends beyond kidney transplantation. We examined pretransplantation ESA response and its effect on allograft failure and mortality. METHODS The cohort included all adult Medicare recipients from the U.S. Renal Data System who had received a kidney transplant during years 2000 to 2007 and had at least 6 months of hemodialysis immediately before transplantation. ESA hyporesponsiveness was primarily defined as a monthly ESA dose of 75,000 units or higher and hematocrit 33% or less for at least 3 consecutive months in the pretransplantation period. Crude and adjusted Cox proportional hazards models and Kaplan-Meier methods were used to estimate the effect of ESA hyporesponsiveness on allograft failure and all-cause mortality. RESULTS The study group consisted of 36,450 patients; 1004 exhibited hyporesponsiveness. The adjusted hazard ratios (95% confidence interval) for allograft failure and mortality after transplantation were 1.23 (1.10-1.42) and 1.61 (1.43-1.81), respectively, supporting that poor ESA response during hemodialysis is associated with adverse posttransplantation outcomes. CONCLUSIONS ESA hyporesponsiveness may be useful in identifying potential allograft recipients who are at high risk for subsequent morbidity and mortality and may benefit from more intensive pretransplantation and posttransplantation monitoring.
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Affiliation(s)
- Nadiesda A Costa
- 1 Department of Medicine, Division of Nephrology and Hypertension, University of North Carolina, Chapel Hill, NC. 2 Cecil G. Sheps Center for Health Services Research, University of North Carolina, Chapel Hill, NC. 3 Pharmacoepidemiology Program Area, Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC. 4 Address correspondence to: Nadiesda Costa, M.D., M.P.H., Division of Nephrology and Hypertension, Department of Medicine, University of Maryland School of Medicine, 20 South Greene Street, Room N3W143, Baltimore, MD 21201
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Abstract
Intravenous iron is an important component of the treatment of anemia of end-stage renal disease (ESRD), but it is biologically plausible that iron could increase the risk of infection through impairment of neutrophil and T-cell function and promotion of microbial growth. Any such increase in risk would be particularly important because infection is a significant cause of mortality and morbidity in dialysis patients. The overall evidence favors an association between iron and infection in hemodialysis patients, but the optimal iron management strategy to minimize infection risk has yet to be identified. There is a need for further research on this topic, particularly in light of increased utilization of intravenous iron following implementation of the bundled ESRD reimbursement system.
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Affiliation(s)
- Julie H Ishida
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
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Brookhart MA, Freburger JK, Ellis AR, Wang L, Winkelmayer WC, Kshirsagar AV. Infection risk with bolus versus maintenance iron supplementation in hemodialysis patients. J Am Soc Nephrol 2013; 24:1151-8. [PMID: 23787911 DOI: 10.1681/asn.2012121164] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Intravenous iron may promote bacterial growth and impair host defense, but the risk of infection associated with iron supplementation is not well defined. We conducted a retrospective cohort study of hemodialysis patients to compare the safety of bolus dosing, which provides a large amount of iron over a short period of time on an as-needed basis, with maintenance dosing, which provides smaller amounts of iron on a regular schedule to maintain iron repletion. Using clinical data from 117,050 patients of a large US dialysis provider merged with data from Medicare's ESRD program, we estimated the effects of iron dosing patterns during repeated 1-month exposure periods on risks of mortality and infection-related hospitalizations during the subsequent 3 months. Of 776,203 exposure/follow-up pairs, 13% involved bolus dosing, 49% involved maintenance dosing, and 38% did not include exposure to iron. Multivariable additive risk models found that patients receiving bolus versus maintenance iron were at increased risk of infection-related hospitalization (risk difference [RD], 25 additional events/1000 patient-years; 95% confidence interval [CI], 16 to 33) during follow-up. Risks were largest among patients with a catheter (RD, 73 events/1000 patient-years; 95% CI, 48 to 99) and a recent infection (RD, 57 events/1000 patient-years; 95% CI, 19 to 99). We also observed an association between bolus dosing and infection-related mortality. Compared with no iron, maintenance dosing did not associate with increased risks for adverse outcomes. These results suggest that maintenance iron supplementation may result in fewer infections than bolus dosing, particularly among patients with a catheter.
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Affiliation(s)
- M Alan Brookhart
- Department of Epidemiology, University of North Carolina Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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Nagaraju SP, Cohn A, Akbari A, Davis JL, Zimmerman DL. Heme iron polypeptide for the treatment of iron deficiency anemia in non-dialysis chronic kidney disease patients: a randomized controlled trial. BMC Nephrol 2013; 14:64. [PMID: 23514036 PMCID: PMC3606612 DOI: 10.1186/1471-2369-14-64] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 03/13/2013] [Indexed: 11/20/2022] Open
Abstract
Background Anemia secondary to iron deficiency is common in patients with non-dialysis dependent chronic kidney disease (ND-CKD) but it is unclear if oral supplementation is as effective as intravenous (IV) supplementation in re-establishing iron stores. The purpose of this study was to determine if oral Heme Iron Polypeptide (HIP) is as effective as IV iron sucrose in the treatment of iron-deficiency anemia for patients with ND-CKD. Methods Forty ND-CKD patients were randomized; 18 to HIP 11 mg orally 3 times per day and 22 to IV iron sucrose 200 mg monthly for 6 months. Baseline clinical and laboratory data were collected for all patients. The primary and secondary outcomes for the study were hemoglobin (Hgb) concentration and iron indices [ferritin and percentage transferrin saturation (TSAT)] at the end of 6 months respectively. Adverse events were also compared. Results The baseline demographic characteristics and laboratory values were similar for the two groups. After 6 months of treatment, Hb in the HIP group was 117 g/L and 113 g/L in the IV sucrose group (p = 0.37). The TSAT at 6 months was not different between the two groups {p = 0.82}but the serum ferritin was significantly higher in the IV iron sucrose group {85.5 ug/L in HIP and 244 ug/L; p = 0.004}. Overall adverse events were not different between the groups. Conclusion HIP is similar in efficacy to IV iron sucrose in maintaining hemoglobin in ND-CKD patients with no differences in adverse events over 6 months. It is unclear if the greater ferritin values in the IV iron sucrose group are clinically significant. Trial registration ClinicalTrials.gov: NCT00318812
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Affiliation(s)
- Shankar P Nagaraju
- Department of Nephrology, Kasturba Medical College, Manipal, Karnataka,India
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