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Mutsuddi A, Das J, Tashrik S, Ara R, Hawlader MDH. Effect of vitamin and mineral supplementation on nutritional status in children with chronic kidney disease: Protocol for a systematic review and meta-analysis. Medicine (Baltimore) 2022; 101:e31518. [PMID: 36316853 PMCID: PMC9622657 DOI: 10.1097/md.0000000000031518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Persistent kidney illness in children and those on dialysis therapy, risk of vitamin and mineral deficiencies due to abnormal renal metabolism, anorexia, inadequate intake, poor gastrointestinal absorption, drug-nutrient interaction, and dialysis-related losses. Adequate nutritional management is essential to achieve and maintain an optimal nutritional status for the usual pattern of growth, sexual and neurocognitive development, metabolic abnormalities, and ultimately reducing the risk of chronic mortality and morbidity in adulthood. The purpose of this paper is to describe a protocol for a systematic review to assess the effects of vitamin and mineral supplementation in children with chronic renal disease. METHODS This systematic review protocol is developed according to the Preferred Reporting Item for Systematic Review and Meta-Analysis Protocols (PRISMA-P) as well as the Cochrane group guidelines. Comprehensive searching for all possible relevant works of literature- such as PubMed, Google Scholar, MEDLINE, Embase, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), Science-Direct, Scopus, Research-Gate, Clinical Trials for all randomized controlled studies, full paper articles, and articles written in English will be considered. The primary outcome of this review will be measuring any changes (such as changes in body mass, BMI, and overall Z-score) in the nutritional status of the children (age < 18 years) with chronic kidney disease following vitamin and mineral supplementations. This review will help better understand the effects of vitamin and mineral supplementation to improve nutritional status in CKD children and will create a guideline to determine the applicability of these interventions in different feasible settings. CONCLUSION The systematic review protocol has been evaluated and approved by the institutional review board of North South University. Finding will be shared using traditional approaches, including scientific presentations, open-access peer-reviewed platforms. PROSPERO REGISTERED NUMBER CRD42022341339.
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Affiliation(s)
- Archi Mutsuddi
- Department of Public Health, North South University, Dhaka, Bangladesh
- Public Health Professional Development Society (PPDS), Dhaka, Bangladesh
| | - Jyoti Das
- Department of Public Health, North South University, Dhaka, Bangladesh
- Public Health Professional Development Society (PPDS), Dhaka, Bangladesh
| | - Symom Tashrik
- Department of Public Health, North South University, Dhaka, Bangladesh
- Public Health Professional Development Society (PPDS), Dhaka, Bangladesh
| | - Rifat Ara
- Public Health Professional Development Society (PPDS), Dhaka, Bangladesh
- Infectious Disease Division, icddr,b, Dhaka, Bangladesh
- *Correspondence: Rifat Ara, Infectious Disease Division, icddr,b, Dhaka, BangladeshPublic Health Professional Development Society (PPDS), Dhaka, Bangladesh (e-mail: )
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2
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Nieraad H, Pannwitz N, de Bruin N, Geisslinger G, Till U. Hyperhomocysteinemia: Metabolic Role and Animal Studies with a Focus on Cognitive Performance and Decline-A Review. Biomolecules 2021; 11:1546. [PMID: 34680179 PMCID: PMC8533891 DOI: 10.3390/biom11101546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/05/2021] [Accepted: 10/09/2021] [Indexed: 12/18/2022] Open
Abstract
Disturbances in the one-carbon metabolism are often indicated by altered levels of the endogenous amino acid homocysteine (HCys), which is additionally discussed to causally contribute to diverse pathologies. In the first part of the present review, we profoundly and critically discuss the metabolic role and pathomechanisms of HCys, as well as its potential impact on different human disorders. The use of adequate animal models can aid in unravelling the complex pathological processes underlying the role of hyperhomocysteinemia (HHCys). Therefore, in the second part, we systematically searched PubMed/Medline for animal studies regarding HHCys and focused on the potential impact on cognitive performance and decline. The majority of reviewed studies reported a significant effect of HHCys on the investigated behavioral outcomes. Despite of persistent controversial discussions about equivocal findings, especially in clinical studies, the present evaluation of preclinical evidence indicates a causal link between HHCys and cognition-related- especially dementia-like disorders, and points out the further urge for large-scale, well-designed clinical studies in order to elucidate the normalization of HCys levels as a potential preventative or therapeutic approach in human pathologies.
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Affiliation(s)
- Hendrik Nieraad
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (N.P.); (N.d.B.); (G.G.)
| | - Nina Pannwitz
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (N.P.); (N.d.B.); (G.G.)
| | - Natasja de Bruin
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (N.P.); (N.d.B.); (G.G.)
| | - Gerd Geisslinger
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; (N.P.); (N.d.B.); (G.G.)
- Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
| | - Uwe Till
- Former Institute of Pathobiochemistry, Friedrich-Schiller-University Jena, Nonnenplan 2, 07743 Jena, Germany;
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3
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Onyemelukwe OU, Maiha BB. Relationship between plasma homocysteine and blood pressure in hypertensive Northern-Nigerians. Afr Health Sci 2020; 20:324-337. [PMID: 33402920 PMCID: PMC7750072 DOI: 10.4314/ahs.v20i1.38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AIM The study sought to determine whether there is any relationship between plasma homocysteine and blood pressure levels in Nigerians with essential hypertension. METHOD It was a cross-sectional analytical study done on 120 randomly selected hypertensive patients and 120 normal healthy controls seen at the large Conference hall of the Ahmadu Bello University (ABU) Medical Centre, Zaria as well as the ABU Teaching Hospital, Zaria, Northern-Nigeria. Pearson's Correlation and Binary Logistic Regression analysis determined the relationship between homocysteine and hypertension. RESULTS Hyperhomocysteinaemia found in the hypertensive patients (22.8 ± 6.6 µmol/L) differed significantly (p<0.001) from controls (10.9 ± 2.8 µmol/L) with significant (p<0.001), blood pressure difference between both groups. Homocysteine significantly positively correlated with systolic (r = 0.51, p<0.001) and diastolic (r = 0.47, p<0.001) blood pressures in hypertensive subjects. The relation of plasma hcy to hypertension was statistically significant for SBP; OR: 1.08 (95% CI, 1.05-1.11) and DBP; OR: 1.08 (95% CI, 1.03-1.13) in the unadjusted model. When adjusted for confounding variables, hcy was significantly related to SBP; OR: 1.1 (95% CI, 1.04-1.18) but not DBP (p=0.25; OR: 1.06 (95 % CI, 0.96-1.18). The mean plasma folate level was high (115.2 ± 48.0 ng/mL) in the hypertensive subjects. The hyperhomocysteinaemic subjects showed a 2.8 times Odds of developing hypertension. CONCLUSION This study showed higher mean plasma homocysteine levels in hypertensives than controls not accounted for by sub-optimal folate levels. Hyperhomocysteinaemia showed a positive relationship to systolic hypertension after adjusting for confounders.
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Affiliation(s)
- Obiageli Uzoamaka Onyemelukwe
- Department of Medicine, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
- Department of Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria, Nigeria
| | - Bilkisu Bello Maiha
- Department of Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria, Nigeria
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Capelli I, Cianciolo G, Gasperoni L, Zappulo F, Tondolo F, Cappuccilli M, La Manna G. Folic Acid and Vitamin B12 Administration in CKD, Why Not? Nutrients 2019; 11:nu11020383. [PMID: 30781775 PMCID: PMC6413093 DOI: 10.3390/nu11020383] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/09/2019] [Accepted: 02/11/2019] [Indexed: 12/13/2022] Open
Abstract
Patients affected by chronic kidney disease (CKD) or end-stage renal disease (ESRD) experience a huge cardiovascular risk and cardiovascular events represent the leading causes of death. Since traditional risk factors cannot fully explain such increased cardiovascular risk, interest in non-traditional risk factors, such as hyperhomocysteinemia and folic acid and vitamin B12 metabolism impairment, is growing. Although elevated homocysteine blood levels are often seen in patients with CKD and ESRD, whether hyperhomocysteinemia represents a reliable cardiovascular and mortality risk marker or a therapeutic target in this population is still unclear. In addition, folic acid and vitamin B12 could not only be mere cofactors in the homocysteine metabolism; they may have a direct action in determining tissue damage and cardiovascular risk. The purpose of this review was to highlight homocysteine, folic acid and vitamin B12 metabolism impairment in CKD and ESRD and to summarize available evidences on hyperhomocysteinemia, folic acid and vitamin B12 as cardiovascular risk markers, therapeutic target and risk factors for CKD progression.
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Affiliation(s)
- Irene Capelli
- Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, 40138 Bologna, Italy.
| | - Giuseppe Cianciolo
- Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, 40138 Bologna, Italy.
| | - Lorenzo Gasperoni
- Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, 40138 Bologna, Italy.
| | - Fulvia Zappulo
- Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, 40138 Bologna, Italy.
| | - Francesco Tondolo
- Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, 40138 Bologna, Italy.
| | - Maria Cappuccilli
- Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, 40138 Bologna, Italy.
| | - Gaetano La Manna
- Department of Experimental Diagnostic and Specialty Medicine (DIMES), Nephrology, Dialysis and Renal Transplant Unit, S. Orsola Hospital, University of Bologna, 40138 Bologna, Italy.
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5
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Vanholder R, Pletinck A, Schepers E, Glorieux G. Biochemical and Clinical Impact of Organic Uremic Retention Solutes: A Comprehensive Update. Toxins (Basel) 2018; 10:toxins10010033. [PMID: 29316724 PMCID: PMC5793120 DOI: 10.3390/toxins10010033] [Citation(s) in RCA: 191] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/21/2017] [Accepted: 12/23/2017] [Indexed: 02/07/2023] Open
Abstract
In this narrative review, the biological/biochemical impact (toxicity) of a large array of known individual uremic retention solutes and groups of solutes is summarized. We classified these compounds along their physico-chemical characteristics as small water-soluble compounds or groups, protein bound compounds and middle molecules. All but one solute (glomerulopressin) affected at least one mechanism with the potential to contribute to the uremic syndrome. In general, several mechanisms were influenced for each individual solute or group of solutes, with some impacting up to 7 different biological systems of the 11 considered. The inflammatory, cardio-vascular and fibrogenic systems were those most frequently affected and they are one by one major actors in the high morbidity and mortality of CKD but also the mechanisms that have most frequently been studied. A scoring system was built with the intention to classify the reviewed compounds according to the experimental evidence of their toxicity (number of systems affected) and overall experimental and clinical evidence. Among the highest globally scoring solutes were 3 small water-soluble compounds [asymmetric dimethylarginine (ADMA); trimethylamine-N-oxide (TMAO); uric acid], 6 protein bound compounds or groups of protein bound compounds [advanced glycation end products (AGEs); p-cresyl sulfate; indoxyl sulfate; indole acetic acid; the kynurenines; phenyl acetic acid;] and 3 middle molecules [β2-microglobulin; ghrelin; parathyroid hormone). In general, more experimental data were provided for the protein bound molecules but for almost half of them clinical evidence was missing in spite of robust experimental data. The picture emanating is one of a complex disorder, where multiple factors contribute to a multisystem complication profile, so that it seems of not much use to pursue a decrease of concentration of a single compound.
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Affiliation(s)
- Raymond Vanholder
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - Anneleen Pletinck
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - Eva Schepers
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - Griet Glorieux
- Nephrology Section, Department of Internal Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
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6
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Interactions between plasma homocysteine and arterial stiffness in chronic kidney disease in community-dwelling individuals: The Maine-Syracuse Study. J Hum Hypertens 2015; 29:726-31. [PMID: 25787778 DOI: 10.1038/jhh.2015.17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/16/2014] [Accepted: 12/23/2014] [Indexed: 11/08/2022]
Abstract
Plasma homocysteine (tHcy) is associated with kidney disease. However, few, if any, studies have examined homocysteine in relation to arterial stiffness, with stratification by the presence or absence of early-stage chronic kidney disease (CKD). The aim of this study was to examine prospective associations between tHcy and carotid-femoral pulse wave velocity (PWV) in persons with and without early-stage CKD in a sample of community-living individuals free from end-stage renal disease, dialysis, stroke and dementia. We conducted a prospective study with 498 participants of the Maine-Syracuse Longitudinal Study (mean age 61 years). Levels of tHcy were positively related to PWV measured 4-5 years later for participants with early-stage CKD (estimated glomerular filtration rate <60 ml min(-1) per 1.73 m(2)). Statistical adjustment was made for multiple confounders, including demographic factors, PWV-related variables and cardiovascular risk factors (b=4.27, 95% confidence interval: 0.23-8.31, P=0.04). These associations were not observed in persons free from CKD. Plasma tHcy is an important predictor of arterial stiffness, as indexed by PWV, in community-living individuals with modest CKD.
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7
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Abbas S, Raza ST, Ahmed F, Ahmad A, Rizvi S, Mahdi F. Association of genetic polymorphism of PPARγ-2, ACE, MTHFR, FABP-2 and FTO genes in risk prediction of type 2 diabetes mellitus. J Biomed Sci 2013; 20:80. [PMID: 24156506 PMCID: PMC4015124 DOI: 10.1186/1423-0127-20-80] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 10/01/2013] [Indexed: 01/05/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a non-autoimmune, complex, heterogeneous and polygenic metabolic disease condition characterized by persistent elevated blood glucose levels (hyperglycemia). India as said to be the diabetic capital of the world is likely to experience the largest increase in T2DM and a greater number of diabetic individuals in the world by the year 2030. Identification of specific genetic variations in a particular ethnic group has a critical role in understanding the risk of developing T2DM in a much efficient way in future. These genetic variations include numerous types of polymorphisms among which single nucleotide polymorphisms (SNPs) is the most frequent. SNPs are basically located within the regulatory elements of several gene sequences. There are scores of genes interacting with various environmental factors affecting various pathways and sometimes even the whole signalling network that cause diseases like T2DM. This review discusses the biomarkers for early risk prediction of T2DM. Such predictions could be used in order to understand the pathogenesis of T2DM and to better diagnostics, treatment, and eventually prevention.
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Affiliation(s)
- Shania Abbas
- Molecular Biology Lab, Department of Biochemistry, Era’s Lucknow Medical College and Hospital, Lucknow 226003, India
| | - Syed Tasleem Raza
- Molecular Biology Lab, Department of Biochemistry, Era’s Lucknow Medical College and Hospital, Lucknow 226003, India
| | - Faisal Ahmed
- Molecular Biology Lab, Department of Biochemistry, Era’s Lucknow Medical College and Hospital, Lucknow 226003, India
| | - Absar Ahmad
- Molecular Biology Lab, Department of Biochemistry, Era’s Lucknow Medical College and Hospital, Lucknow 226003, India
| | - Saliha Rizvi
- Molecular Biology Lab, Department of Biochemistry, Era’s Lucknow Medical College and Hospital, Lucknow 226003, India
| | - Farzana Mahdi
- Molecular Biology Lab, Department of Biochemistry, Era’s Lucknow Medical College and Hospital, Lucknow 226003, India
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8
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Role of homocysteine in end-stage renal disease. Clin Biochem 2012; 45:1286-94. [PMID: 22683753 DOI: 10.1016/j.clinbiochem.2012.05.031] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 04/26/2012] [Accepted: 05/28/2012] [Indexed: 11/22/2022]
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9
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Raza ST, Abbas S, Ahmed F, Fatima J, Zaidi ZH, Mahdi F. Association of MTHFR and PPARγ2 gene polymorphisms in relation to type 2 diabetes mellitus cases among north Indian population. Gene 2012; 511:375-9. [PMID: 23036708 DOI: 10.1016/j.gene.2012.09.072] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 08/02/2012] [Accepted: 09/12/2012] [Indexed: 12/18/2022]
Abstract
BACKGROUND Type 2 diabetes mellitus is a multifactorial and polygenic disease, which is considered as a major life threatening problem all over the world. There has been a worldwide effort in the identification of susceptibility genes for type 2 diabetes mellitus and its complications. At present, adequate data is not available dealing with MTHFR (rs1801133) and PPARγ2 (rs1801282) gene polymorphisms and its association with type 2 diabetes mellitus cases among north Indian populations. Thus, we conceived the need for further studies to investigate MTHFR and PPARγ2 gene polymorphisms and their susceptibility to type 2 diabetes mellitus in north Indian population. MATERIALS AND METHODS In this study, a total 175 subjects including 87 type 2 diabetes mellitus cases and 88 controls were enrolled. MTHFR and PPARγ2 gene polymorphisms in the cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). RESULTS The MTHFR gene CC, CT, TT genotype frequencies obtained were 40%, 43%, and 17% in type 2 diabetes mellitus cases and 56%, 29%, and 15% in healthy controls respectively. The OR for CC was 0.54 (95%CI 0.29-0.98, P=0.041, χ(2)=4.18, power=0.98), for CT 1.76 (95%CI 0.94-3.30, P=0.07, χ(2)=3.2, power=0.96), and for TT 1.2 (95%CI 0.53-2.70, P=0.66, χ(2)=0.198, power=0.76). The PPARγ2 gene GG CG, CC genotype frequencies obtained were 28%, 41%, and 31% in cases and 40%, 39%, and 21% in healthy controls respectively. OR for GG was 0.58 (95%CI 0.30-1.09, P=0.08, χ(2)=2.9, power=0.96), for CG 1.12 (95%CI 0.61-2.05, P=0.71, χ(2)=0.137, power=0.778), and for CC 1.63 (95%CI 0.82-3.23, P=0.156, χ(2)=2.01, power=0.92). CONCLUSION It might be recommended that MTHFR CC genotype seems to be a good marker for the early identification of population at risk of type 2 diabetes mellitus. While we have detected significant difference in allelic frequencies of PPARγ2 C (Proline) and G (Alanine), but at genotypic level significant difference was not detected in this case-control study. Further study with larger groups may be required to validate the study.
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Affiliation(s)
- Syed Tasleem Raza
- Department of Biochemistry, Era's Lucknow Medical College and Hospital, Lucknow, India 226003.
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Heinz J, Kropf S, Domröse U, Westphal S, Borucki K, Luley C, Neumann KH, Dierkes J. B Vitamins and the Risk of Total Mortality and Cardiovascular Disease in End-Stage Renal Disease. Circulation 2010; 121:1432-8. [DOI: 10.1161/circulationaha.109.904672] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
In observational studies, hyperhomocysteinemia has been found to be a risk factor for total mortality and cardiovascular events in patients with end-stage renal disease. These patients have grossly elevated homocysteine levels that can be lowered by supplementation with folic acid and vitamin B
12
. We conducted a randomized clinical trial with B vitamins to reduce homocysteine levels and therefore cardiovascular events and total mortality.
Methods and Results—
This randomized, double-blind multicenter study was conducted in 33 dialysis centers in north and east Germany between July 2002 and July 2008. We randomly assigned 650 patients with end-stage renal disease who were undergoing hemodialysis to 2 postdialysis treatments: 5 mg folic acid, 50 μg vitamin B
12
, and 20 mg vitamin B
6
(active treatment) or 0.2 mg folic acid, 4 μg vitamin B
12
, and 1.0 mg vitamin B
6
(placebo) given 3 times per week for an average of 2 years. The primary outcome was total mortality; the secondary outcome was fatal and nonfatal cardiovascular events. The primary outcome occurred in 102 patients (31%) receiving the active treatment and in 92 (28%) receiving placebo (hazard ratio, 1.13; 95% confidence interval, 0.85 to 1.50;
P
=0.51). The secondary outcome occurred in 83 patients (25%) receiving the active treatment and in 98 (30%) receiving placebo (hazard ratio, 0.80; 95% confidence interval, 0.60 to 1.07;
P
=0.13).
Conclusions—
Increased intake of folic acid, vitamin B
12
, and vitamin B
6
did not reduce total mortality and had no significant effect on the risk of cardiovascular events in patients with end-stage renal disease.
Clinical Trial Registration—
URL: www.anzctr.org.au. Unique identifier: ACTRN12609000911291. URL: www.cochrane-renal.org. Unique identifier: CRG010600027.
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Affiliation(s)
- Judith Heinz
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
| | - Siegfried Kropf
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
| | - Ute Domröse
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
| | - Sabine Westphal
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
| | - Katrin Borucki
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
| | - Claus Luley
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
| | - Klaus H. Neumann
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
| | - Jutta Dierkes
- From the Institute of Clinical Chemistry (J.H., S.W., K.B., C.L., J.D.), Division of Nephrology (U.D., K.H.N.), and Institute of Biometry and Medical Informatics (S.K.), Magdeburg University Hospital, Magdeburg, Germany
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Leung J, Larive B, Dwyer J, Hibberd P, Jacques P, Rand W. Folic acid supplementation and cardiac and stroke mortality among hemodialysis patients. J Ren Nutr 2010; 20:293-302. [PMID: 20303789 DOI: 10.1053/j.jrn.2010.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE We sought to assess whether the use of folic acid vitamin supplements reduced cardiac and stroke mortality in hemodialysis patients. Further, we examined whether the consumption of folic acid from vitamin supplements >1000 microg compared with the standard 1000 microg, and 1000 microg compared with either a lower dose or no consumption, were associated with reduced cardiac and stroke mortality risk. DESIGN We performed a secondary analysis of data from the Hemodialysis Study, a randomized clinical trial examining dialysis treatment regimens over a 3-year follow-up. PARTICIPANTS Participants included 1846 hemodialysis patients previously participating in the Hemodialysis Study. INTERVENTIONS There were no interventions. MAIN OUTCOME MEASURE Cardiac and stroke mortality were our main outcome measures. RESULTS Based on time-dependent Cox proportional hazard regression models, folic acid consumption from vitamin supplements, above or below the standard 1000-microg dose, was not associated with a decrease or increase in cardiac mortality (P = .53, above vs. standard dose; P = .46, below vs. standard dose). There was also no association between folic acid consumption and mortality from stroke (P = .27, above vs. standard dose; P = .64, below vs. standard dose). CONCLUSION The consumption of higher than the standard 1000-microg prescribed dose of folic acid was not beneficial in reducing cardiac or stroke mortality in hemodialysis patients. Similarly, the consumption of less than the standard dose was not associated with an increase in either cardiac or stroke mortality.
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Affiliation(s)
- June Leung
- Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts 02111, USA.
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12
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Ritch R, Prata TS, de Moraes CGV, Vessani RM, Costa VP, Konstas AGP, Liebmann JM, Schlötzer-Schrehardt U. Association of exfoliation syndrome and central retinal vein occlusion: an ultrastructural analysis. Acta Ophthalmol 2010; 88:91-5. [PMID: 19725816 DOI: 10.1111/j.1755-3768.2009.01578.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE To evaluate prospectively the frequency with which exfoliation syndrome (XFS) occurs in patients with central retinal vein occlusion (CRVO) by clinical examination and ultrastructural examination of conjunctival biopsy specimens. METHODS Prospective observational case series. Thirty-six eyes of 36 consecutive patients with CRVO were investigated for XFS by slit-lamp examination and conjunctival biopsy when XFS was not clinically visible on examination. RESULTS A clinical diagnosis of XFS or a positive biopsy result for exfoliation material (XFM) was present in 22 of the 36 patients (61%; 95% confidence interval 45-75%). Twelve of these 22 patients (54%) had a clinical diagnosis of XFS. Aggregates of XFM were identified ultrastructurally in the biopsy specimens in 10 of 24 patients with no clinical signs of XFS (42%). Patients with and without XFS had similar distribution of age, gender, race and prevalence of systemic disorders. Twelve of the 22 (54%) XFS patients had neither glaucoma nor ocular hypertension prior to the CRVO. CONCLUSION In accordance with previous retrospective and histological studies, this prospective, in vivo study suggests that CRVO is commonly associated with XFS.
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Affiliation(s)
- Robert Ritch
- Department of Ophthalmology, Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York City 10003, USA.
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Chuang FR, Fang JT, Chen JB, Lin CL, Chen HY, Lee CN, Wang PH, Lee CH. Hyperhomocystinemia and the Prevalence of Symptomatic Atherosclerotic Vascular Disease in Taiwanese Chronic Hemodialysis Patients: A Retrospective Study. Ren Fail 2009; 25:765-74. [PMID: 14575285 DOI: 10.1081/jdi-120024292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
AIM Hyperhomocystinemia is now recognized as an independent risk factor for atherosclerotic cardiovascular disease in patients with normal renal function. Hyperhomocystinemia is common in patients with chronic renal failure. This aim of this study was designed to look for associations between hyperhomocystinemia and clinically symptomatic atherosclerotic vascular disease (ASVD) in Taiwanese chronic hemodialysis patients. METHODS Two hundred patients undergoing hemodialysis were enrolled in the study. They had predialysis blood work performed for total homocysteine, serum folate, and vitamin B12 levels. A history of clinically significant ASVD was elicited using information from the patients' questionnaires and verified by careful inpatient and outpatient chart review. RESULTS Mean homocysteine concentration was 29.0 micromol/L overall. A total of 196 patients had hyperhomocystinemia and were enrolled in this study. ASVD was present in 24.5% of patients. The mean homocysteine concentration was 31.9 micromol/L and 28.7 micromol/L in patients with (n = 48) and without (n = 148) ASVD, respectively (P = 0.04). There was association hyperhomocystinemia between chronic hemodialysis patients with ASVD and without ASVD. There were significant differences including age, homocysteine level, vitamin B12 level and glucose intolerance in the two groups (P < 0.05). Plasma homocysteine concentrations showed significant positive correlations with serum folate or vitamin B12 in majority patients. No patient had serum folate or vitamin B12 deficiency. The adjusted odds ratio for atherosclerotic disease was 2.8 (95% CI, 1.109-7.467) for those subjects with a homocysteine level in the highest quartile compared with the lowest 3 quartiles. CONCLUSIONS The prevalence of hyperhomocystinemia is 98% among hemodialysis patients. There is a significant association between hyperhomocystinemia and ASVD in Taiwanese chronic hemodialysis patients. There are also associations between homocysteine levels and serum folate/vitamin B12 levels in the majority of the patients. Clinical trials are needed to determine the optimal therapy of folic acid dose for hyperhomocystinemia in Taiwanese chronic hemodialysis patients in the future.
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Affiliation(s)
- Feng-Rong Chuang
- Division of Nephrology, Chang Gung Memorial Hospital at Chiayi, Chiayi, Taiwan
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Heinz J, Kropf S, Luley C, Dierkes J. Homocysteine as a risk factor for cardiovascular disease in patients treated by dialysis: a meta-analysis. Am J Kidney Dis 2009; 54:478-89. [PMID: 19359080 DOI: 10.1053/j.ajkd.2009.01.266] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 01/21/2009] [Indexed: 11/11/2022]
Abstract
BACKGROUND In the general population, increased homocysteine concentrations are a risk factor for cardiovascular disease and mortality. However, it is not known whether this also applies to patients with end-stage renal disease. STUDY DESIGN Meta-analysis of retrospective (11 studies including 1,506 individuals), prospective observational studies (12 studies including 1,975 individuals), and intervention trials (5 studies including 1,642 dialysis patients). Analyses were carried out separately, according to the study design. SETTING & POPULATION Studies of patients with end-stage renal disease treated by means of hemodialysis or peritoneal dialysis. SELECTION CRITERIA FOR STUDIES Studies investigating the association between total homocysteine level and cardiovascular disease or total mortality or the influence of vitamin supplementation on cardiovascular or mortality risk. INTERVENTION In intervention studies, vitamin preparations with folic acid alone or in combination with other vitamins, such as vitamin B(12) and B(6), were used. OUTCOMES In retrospective studies, cases are patients with cardiovascular diseases. Outcomes for prospective observational and intervention studies are cardiovascular events and total mortality. RESULTS In retrospective studies, there was no significant overall difference in homocysteine concentrations between cases and controls (weighted mean difference in homocysteine, 2.82 micromol/L; 95% confidence interval [CI], -2.22 to 7.86; P = 0.3). The pooled overall risk estimate for prospective observational studies suggests no association between homocysteine level (5-micromol/L increase) and total mortality (hazard ratio [HR], 1.02; 95% CI, 0.93 to 1.12; P = 0.7), but there was an association with cardiovascular events (HR, 1.09; 95% CI, 1.03 to 1.14; P = 0.001). In subgroup analysis of patients not receiving vitamins, an increase in homocysteine level was associated with increased mortality (HR, 1.07; 95% CI, 1.02 to 1.13; P = 0.01). For intervention trials with B vitamins, there was a significant risk reduction for cardiovascular disease (relative risk, 0.73; 95% CI, 0.56 to 0.94; P = 0.02), but no risk reduction for total mortality or the composite end point including total mortality (relative risk, 1.01; 95% CI, 0.88 to 1.15; P = 0.9). LIMITATIONS Many studies are small, which may lead to the observed heterogeneity. Some intervention trials are neither placebo controlled nor randomized. Separate analyses for specific end points and patients treated by means of hemodialysis or peritoneal dialysis were not possible. CONCLUSION Total homocysteine level may be a risk factor for cardiovascular events and total mortality in patients with end-stage renal disease not receiving vitamin supplementation or folic acid food fortification. There may be a potential for reducing cardiovascular disease in this population by folic acid supplementation.
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Affiliation(s)
- Judith Heinz
- Institute of Clinical Chemistry and Pathobiochemistry, University Hospital Magdeburg, Magdeburg, Germany.
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Urquhart BL, Freeman DJ, Cutler MJ, Mainra R, Spence JD, House AA. Mesna for treatment of hyperhomocysteinemia in hemodialysis patients: a placebo-controlled, double-blind, randomized trial. Clin J Am Soc Nephrol 2008; 3:1041-7. [PMID: 18337551 DOI: 10.2215/cjn.04771107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND OBJECTIVES Increased plasma total homocysteine is a graded, independent risk factor for the development of atherosclerosis and thrombosis. More than 90% of patients with end-stage renal disease have hyperhomocysteinemia despite vitamin supplementation. It was shown in previous studies that a single intravenous dose of mesna 5 mg/kg caused a drop in plasma total homocysteine that was significantly lower than predialysis levels 2 d after dosing. It was hypothesized 5 mg/kg intravenous mesna administered thrice weekly, before dialysis, for 8 wk would cause a significant decrease in plasma total homocysteine compared with placebo. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Patients with end-stage renal disease were randomly assigned to receive either intravenous mesna 5 mg/kg or placebo thrice weekly before dialysis. Predialysis plasma total homocysteine concentrations at weeks 4 and 8 were compared between groups by paired t test. RESULTS Mean total homocysteine at 8 wk in the placebo group was 24.9 micromol/L compared with 24.3 micromol/L in the mesna group (n = 22 [11 pairs]; mean difference 0.63). Interim analysis at 4 wk also showed no significant difference between mesna and placebo (n = 32 [16 pairs]; placebo 26.3 micromol/L, mesna 24.5 micromol/L; mean difference 1.88). Multivariable adjustments for baseline characteristics did not alter the analysis. Plasma mesna seemed to reach steady-state concentrations by 4 wk. CONCLUSIONS It is concluded that 5 mg/kg mesna does not lower plasma total homocysteine in hemodialysis patients and that larger dosages may be required.
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Affiliation(s)
- Bradley L Urquhart
- Department of Physiology and Pharmacology, University of Western Ontario, London Health Sciences Centre, London, Ontario, Canada
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16
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Abstract
An increase in the plasma level of Hcy (homocysteine), an intermediate in the catabolism of methionine, has been identified as a risk factor for many diseases including CVD (cardiovascular disease). CVD is the major cause of death in patients with diabetes mellitus. Therefore the study of Hcy metabolism in diabetes mellitus has been a major focus of current research. Studies conducted in our laboratory were able to show that in both Type 1 and Type 2 diabetes with no renal complications, the plasma Hcy levels were lower than in controls. In Type 1 diabetes, increased activities of the trans-sulfuration enzymes were the major cause for the reduction in plasma Hcy. In Type 2 diabetes, BHMT (betaine:homocysteine methyltransferase) was also observed to play a major role in the increased catabolism of Hcy in addition to the trans-sulfuration enzymes. We were also able to demonstrate the direct effect of insulin and the counter-regulatory hormones on the regulation of cystathionine beta-synthase and BHMT, which accounts for the changes in the activities of these two enzymes seen in diabetes mellitus.
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Meert N, Schepers E, De Smet R, Argiles A, Cohen G, Deppisch R, Drüeke T, Massy Z, Spasovski G, Stegmayr B, Zidek W, Jankowski J, Vanholder R. Inconsistency of reported uremic toxin concentrations. Artif Organs 2007; 31:600-11. [PMID: 17651115 DOI: 10.1111/j.1525-1594.2007.00434.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Discrepancies in reported uremic toxin concentrations were evaluated for 78 retention solutes. For this analysis, 378 publications were screened. Up to eight publications per toxin were retained. The highest and the lowest reported concentrations, as well as the median reported concentration were registered. The ratio between the highest and the lowest (H/L) concentrations and, for some solutes, also the ratio between the highest and the median (H/M) concentrations were calculated. The compounds were arbitrarily subdivided into three groups based on their H/L ratio: group A, H/L < 3 (n = 33); group B, 3 < H/L < 8.5 (n = 20); and group C, H/L > 8.5 (n = 25). Solutes of groups A and B showed a low to intermediate scatter, suggesting a homogeneity of reported data. Group C showed a more substantial scatter. For at least 10 compounds of group C, extremely divergent concentrations were registered (H/M > 5.5) using scatter plot analysis. For all solutes of groups A and B, the highest reported concentration could be used as a reference. For some solutes of group C and for the compounds showing a divergent scatter analysis, however, more refined directives should be followed.
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Affiliation(s)
- Natalie Meert
- The Nephrology Section, Department of Internal Medicine, University Hospital, Gent, Belgium
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WINCHESTER JF, AMERLING R, DUBROW A, FEINFELD DA, GRUBER SJ, HARBORD N, KUNTSEVICH V. Dialysis desiderata. Hemodial Int 2007. [DOI: 10.1111/j.1542-4758.2007.00197.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Eloot S, Torremans A, De Smet R, Marescau B, De Deyn PP, Verdonck P, Vanholder R. Complex Compartmental Behavior of Small Water-Soluble Uremic Retention Solutes: Evaluation by Direct Measurements in Plasma and Erythrocytes. Am J Kidney Dis 2007; 50:279-88. [PMID: 17660029 DOI: 10.1053/j.ajkd.2007.05.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 05/18/2007] [Indexed: 11/11/2022]
Abstract
BACKGROUND Although scanty data suggest that large solutes show kinetic behavior different from urea, there are virtually no data comparing the kinetics of urea with those of other small water-soluble uremic compounds, which are believed to behave similarly. STUDY DESIGN Cross-sectional study of kinetics of urea and guanidino compounds in plasma and erythrocyte compartments during a single hemodialysis session. SETTING & PARTICIPANTS Six stable hemodialysis patients on standard low-flux dialysis therapy. PREDICTORS Reduction ratios (RRs) of urea calculated from plasma and erythrocyte concentrations. OUTCOMES RRs for guanidino compounds calculated from measurements of both plasma and erythrocyte concentrations. MEASUREMENTS Blood samples were collected from the dialyzer inlet and outlet at 0, 5, 15, 30, and 120 minutes and at the end of the session. Plasma and erythrocyte concentrations of urea and guanidino compounds (creatinine [CTN], guanidinosuccinic acid [GSA], guanidinoacetic acid [GAA], guanidine [G], and methylguanidine [MG]) were determined. RESULTS Postdialysis plasma RR was higher for GSA (82% +/- 3%) compared with urea (77% +/- 2%; P < 0.01), whereas CTN (69% +/- 4%), GAA (49% +/- 14%), G (55% +/- 7%), and MG (55% +/- 7%) showed smaller RRs (P < 0.01). In erythrocytes, GSA (45% +/- 1%), G (10% +/- 13%), and MG (27% +/- 10%) showed markedly smaller RRs than urea (59% +/- 6%; P < 0.05). Finally, significant differences were found between plasma and erythrocyte RRs for urea, GSA, G, and MG (P < 0.01). LIMITATIONS Discrepancies were found between the biochemical and mathematical approaches. Hence, the erythrocyte compartment does not necessarily conform to the kinetic nonperfused compartment. CONCLUSIONS Our data indicate by means of direct estimations that the compartmental behaviors of guanidino compounds and urea are substantially different. Hence, we should consider that not all changes in concentrations in uremia and dialysis are representatively reflected by urea kinetics, even when considering other small water-soluble substances, such as the guanidino compounds.
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Affiliation(s)
- Sunny Eloot
- Institute for Biomedical Technology, Ghent University, Ghent, Belgium.
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Manrique J, Errasti P, Orbe J, Páramo JA, Rodríguez JA. Folic acid and B vitamins improve hyperhomocysteinemia-induced cardiovascular risk profile in renal transplant recipients. J Thromb Haemost 2007; 5:1072-6. [PMID: 17461937 DOI: 10.1111/j.1538-7836.2007.02506.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Vianna ACA, Mocelin AJ, Matsuo T, Morais-Filho D, Largura A, Delfino VA, Soares AE, Matni AM. Uremic hyperhomocysteinemia: A randomized trial of folate treatment for the prevention of cardiovascular events. Hemodial Int 2007; 11:210-6. [PMID: 17403173 DOI: 10.1111/j.1542-4758.2007.00171.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Homocysteine is a risk factor for atherosclerosis in the general population, and serum homocysteine levels are almost universally elevated in chronic renal failure patients. When such patients are treated with dialysis, cardiovascular disease accounts for more than 50% of their mortality, which, in some proportion, may be pathophysiologically related to the elevated serum homocysteine levels. From April 2003 to March 2005, we conducted a 2-year, double-blind, randomized, placebo-controlled trial of 186 patients with end-stage kidney disease due to any cause, who were older than 18 years and stable on hemodialysis. Patients were assigned to receive either oral folic acid 10 mg 3 times a week immediately after every dialysis session under nurse supervision or an identical-appearing placebo for the entire study. On admission, plasma total homocysteine (tHcy) levels were above 13.9 micromol/L in 96.7% of patients (median 25.0 micromol/L, range 9.3-104.0 micromol/L). In the placebo group, tHcy levels remained elevated at 6, 12, and 24 months, while oral folate significantly decreased tHcy to a median value of 10.5 (2.8-20.3) micromol/L, (p<0.01). During the study, 38 patients (folic acid group 17 vs. placebo group 21; p=0.47) died from cardiovascular disease. Kaplan-Meier life table analysis dealing with the incidence of cardiovascular events, both fatal and nonfatal (myocardial infarction, arrhythmias, angina, heart failure, cerebrovascular accident), showed that 2 years of folic acid treatment and the lowering of the homocysteine blood levels had no effect on cardiovascular events (p=0.41; hazard ratio 1.24, 95% CI 0.74-2.10). However, the carotid artery intima-media wall thickness measured in a blinded fashion decreased from 1.94 +/- 0.59 mm to 1.67 +/- 0.38 mm (p<0.01) after 2 years of folate therapy. In this short-term study of uremic patients, 2 years of folic acid supplementation normalized the tHcy blood levels in 92.3% of patients but did not change the incidence of cardiovascular events compared with the control group. However, ultrasonography of the common carotid arteries performed at entry and 24 months later showed a significant decrease in intima-media thickness with folate supplementation. This suggests that early folate supplementation may benefit patients with chronic renal failure by preventing cardiovascular deterioration.
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Affiliation(s)
- Areuza C A Vianna
- Nephrology Section, Department of Internal Medicine, State University of Londrina, Parana, Brazil
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Sun J, Xu Y, Zhu Y, Lu H. Methylenetetrahydrofolate reductase gene polymorphism, homocysteine and risk of macroangiopathy in Type 2 diabetes mellitus. J Endocrinol Invest 2006; 29:814-20. [PMID: 17114913 DOI: 10.1007/bf03347376] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE A polymorphism in the gene for methylenetetrahydrofolate reductase (MTHFR) has been reported to be associated with hyperhomocysteinemia and risk for atherosclerotic vascular diseases. In this case-control study, we examined the distribution of the MTHFR genotypes in the Chinese population and clarified the relationship between the gene polymorphism for MTHFR and macroangiopathy in Chinese Type 2 diabetes mellitus. METHODS Two hundred and sixteen unrelated patients with Type 2 diabetes mellitus, 112 of whom had macroangiopathy, and 114 healthy control subjects, were recruited. The MTHFR C677T genotype was analyzed by polymerase chain reaction-restriction fragment length polymorphism. Plasma total homocysteine levels were measured using high-performance liquid chromatography (HPLC) with fluorescence detection. RESULTS In 114 healthy control subjects, the frequency of the mutant T allele was 31.1%. The genotype distribution did not differ between control subjects and Type 2 diabetic patients (chi2=3.03, p=0.220). Genotypic analysis revealed that the MTHFR genotype was different between diabetic patients with and without macroangiopathy (chi2=12.42, p=0.002). Type 2 diabetic patients with macroangiopathy displayed a greater prevalence of T allele than Type 2 diabetic patients without macroangiopathy (44.6 vs 29.3%; chi2=10.82, p=0.001). The odds ratio for macroangiopathy in Type 2 diabetic patients in presence of T allele was 1.94 [confidence interval (CI) 95%: 1.31-2.89]. Moreover, plasma homocysteine levels were markedly higher in individuals with TT genotype than those with CC or CT genotype. CONCLUSIONS The C677T mutation of MTHFR gene is common in the Chinese population. MTHFR C677T gene polymorphism associated with a predisposition to increased plasma homocysteine levels could constitute a useful predictive marker for macroangiopathy in Chinese Type 2 diabetic patients.
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Affiliation(s)
- J Sun
- Department of Endocrinology, Zhongnan Hospital, Wuhan University, Wuhan 430071, China.
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Abstract
Uremic toxins with a molecular weight of less than 500 Da are classified as small nitrogenous waste products. They are highly water soluble, relatively homogeneous, and have no protein binding. Other uremic retention toxins differ significantly from the small nitrogenous metabolite class in molecular weight, heterogeneity, protein binding, and hydrophobicity. The European Uremic Toxin Work Group subdivided molecules into two categories: protein-bound solutes and middle molecules. Middle molecules were defined as toxins in the molecular weight range of 500-60,000 Da, which exceeds the molecular weight of 2000 Da defined in the original middle molecule hypothesis. Under this new proposed definition, most of these middle molecules are low molecular weight peptides and proteins (LMWPs). This concise review focuses on LMWPs. The metabolism of LMWPs is described, including molecular weight, physical conformation, and charge. Factors influencing dialytic removal of LMWPs such as membrane characteristics, protein-membrane interactions, and solute removal mechanisms, as well as strategies to enhance clearance of these compounds are discussed.
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Nakajima K. Hyperhomocysteinemia can be ameliorated by dimethylsulfoniopropionate in place of folic acid in mice. J Nutr Sci Vitaminol (Tokyo) 2006; 52:61-5. [PMID: 16637231 DOI: 10.3177/jnsv.52.61] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Acute homocysteinemia mice were prepared by forcibly oral administration of homocysteine (4 mM, 2 mL). The amounts of plasma homocysteine were estimated by a fluorescence method with HPLC. Folic acid (0.6 mM, 2 mL), DMSP, or betaine (20 mM, 2 mL each) was intraperitoneally administrated into the mice suffered from the acute homocysteinemia on the 20th, 40th or 60th min after the oral supplementation of homocysteine, then amounts of plasma homocysteine were determined by the HPLC method 40 min after each addition, respectively. The results indicated that the intraperitoneal addition of folic acid or DMSP in this order of the 40th, 60th and 20th min after the oral supplementation of homocysteine significantly reduce the quantities of plasma homocysteine, but betaine exerted the fairly lesser effects. The amounts of homocysteine without any additive linearly and rapidly appeared to increase up to 60 min, at which those were about 8-12 fold the normal levels of homocysteine, and thereafter decreased in these experiments. Accordingly, folic acid which is known to effectively improve homocysteinemia was proven to be completely replaced by DMSP under the experimental conditions.
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Affiliation(s)
- Kenji Nakajima
- Laboratory of Biochemistry, Faculty of Nutrition, Koshien University, Hyogo, Japan.
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Yi F, Zhang AY, Li N, Muh RW, Fillet M, Renert AF, Li PL. Inhibition of ceramide-redox signaling pathway blocks glomerular injury in hyperhomocysteinemic rats. Kidney Int 2006; 70:88-96. [PMID: 16688115 DOI: 10.1038/sj.ki.5001517] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ceramide-activated NAD(P)H oxidase has been reported to participate in homocysteine (Hcys)-induced abnormal metabolism of the extracellular matrix (ECM) in rat glomerular mesangial cells. However, it remains unknown whether this ceramide-redox signaling pathway contributes to glomerular injury induced by hyperhomocysteinemia (hHcys) in vivo. The present study was designed to address this question, defining the role of ceramide and activated NAD(P)H oxidase in the development of hHcys-induced glomerular injury. Uninephrectomized Sprague-Dawley rats were fed a folate-free diet for 8 weeks to produce hHcys and the de novo ceramide synthesis inhibitor myriocin or the NAD(P)H oxidase inhibitor apocynin was administrated. Rats with folate-free diet significantly increased plasma Hcys levels, renal ceramide levels, and NAD(P)H oxidase activity accompanied by marked glomerular injury. Treatment of rats with myriocin significantly reduced ceramide levels and improved glomerular injury, as shown by decreased urinary albumin excretion and reduced glomerular damage index. ECM components changed towards to normal levels with decreased tissue inhibitor of metalloproteinase-1 and increased matrix metalloproteinase-1 activity. NAD(P)H oxidase activity and Rac GTPase activity were reduced by 69 and 66%, respectively. In rats treated with apocynin, similar beneficial effects in protecting glomeruli from hHcys-induced injury were observed. These results support the view that de novo ceramide production is involved in Hcys-induced NAD(P)H oxidase activity in the kidney of hHcys rats and indicate the important role of ceramide-mediated redox signaling in hHcys-induced glomerular injury in rats.
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Affiliation(s)
- F Yi
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Zoungas S, McGrath BP, Branley P, Kerr PG, Muske C, Wolfe R, Atkins RC, Nicholls K, Fraenkel M, Hutchison BG, Walker R, McNeil JJ. Cardiovascular morbidity and mortality in the Atherosclerosis and Folic Acid Supplementation Trial (ASFAST) in chronic renal failure: a multicenter, randomized, controlled trial. J Am Coll Cardiol 2006; 47:1108-16. [PMID: 16545638 DOI: 10.1016/j.jacc.2005.10.064] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 09/30/2005] [Accepted: 10/03/2005] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The Atherosclerosis and Folic Acid Supplementation Trial (ASFAST) aimed to establish whether high-dose folic acid would slow the progression of atherosclerosis and reduce cardiovascular events in patients with chronic renal failure (CRF). BACKGROUND Hyperhomocysteinemia is a potential contributor to the high rates of cardiovascular morbidity and mortality in patients with CRF. METHODS A total of 315 subjects with CRF, mean age 57 years (range 24 to 79 years) were randomized to 15 mg folic acid daily or placebo and followed for a median of 3.6 years. The primary intima-media thickness (IMT) and clinical end points were: rate of progression of mean maximum carotid IMT and a composite of myocardial infarction (MI), stroke, and cardiovascular death. Secondary end points included all cardiovascular events and change in pulse wave velocity, systemic arterial compliance and augmentation index. Data were analyzed by intention-to-treat. RESULTS Plasma total homocysteine was reduced by 19% in the folic acid group. There was no significant difference between the treatment groups in rate of change of IMT or any measure of artery function. Seventy-seven events occurred in the folic acid group (14.9 per 100 patient-years) as compared with 86 in the placebo group (16.3 per 100 patient-years). The rates of the primary and secondary clinical end points at five years were not significantly different after adjustment for baseline differences between the groups (adjusted hazard ratio for MI, stroke, and cardiovascular death: 0.98 [95% confidence interval: 0.66 to 1.47]; p = 0.94; for all cardiovascular events: 0.95 [95% confidence interval: 0.69 to 1.30]; p = 0.75). CONCLUSIONS High-dose folic acid does not slow atheroma progression or improve cardiovascular morbidity or mortality in patients with CRF.
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Affiliation(s)
- Sophia Zoungas
- Department of Vascular Sciences and Medicine, Centre for Vascular Health, Monash University, Dandenong Hospital, Dandenong, Victoria, Australia
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Czupryniak A, Nowicki M, Chwatko G, Jander A, Bald E. Peritoneal clearance of homocysteine with icodextrin or standard glucose solution exchange. Nephrology (Carlton) 2005; 10:571-5. [PMID: 16354239 DOI: 10.1111/j.1440-1797.2005.00483.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The aim of the study was to assess plasma homocysteine concentration in peritoneal dialysis patients, and to compare the effect of different peritoneal solutions (glucose-based and icodextrin-based) on peritoneal clearance of homocysteine. METHODS The study group comprised 10 chronic peritoneal dialysis patients; the control group comprised 15 healthy, age-matched non-obese subjects with normal renal function. Patients with vitamin B(12) or folate deficiency were excluded. In all subjects, plasma homocysteine and dialysis adequacy parameters were assessed at baseline. The clearance study was carried out with 2.27% glucose and 7.5% icodextrin solutions (12-h dwell time). RESULTS Mean dialysate concentration of homocysteine was similar for both glucose and icodextrin solutions (8.3 +/- 3.2 and 8.4 +/- 1.9 micromol/L, respectively), but homocysteine clearance was significantly higher for icodextrin than glucose solution (1.82 +/- 0.57 vs 1.39 +/- 0.53 mL/min per 1.73 m(2)P = 0.01). Net ultrafiltration after icodextrin solution was also higher than after glucose solution (599 +/- 136 mL vs 134 +/- 337 mL, P < 0.01). A correlation between total plasma level of homocysteine and its peritoneal clearance was found (r = 0.69; P = 0.03). CONCLUSION It appears that peritoneal elimination of homocysteine depends primarily on its plasma concentration. Icodextrin-based solution for peritoneal dialysis seems to be more efficient in homocysteine elimination than a standard glucose-based solution.
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Affiliation(s)
- Aneta Czupryniak
- Department of Nephrology and Dialysis, Polish Mother's Memorial Hospital Research Institute, Lódz, Poland
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Robles NR, Romero J, Gomez Casero L, Escola JM, Ramos JL, Sánchez Casado E. Hyperhomocysteinemia in patients with mild chronic renal failure. Eur J Intern Med 2005; 16:334-8. [PMID: 16137546 DOI: 10.1016/j.ejim.2005.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Accepted: 06/17/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND The aim of this study was to evaluate the prevalence of high plasma levels of homocysteine in patients with mild renal failure. METHODS Forty-six chronic renal failure patients (25 males and 21 females, mean age 55.6+/-14.4 years) were recruited for the study. Mean plasma creatinine was 2.1+/-1.0 mg/dl and mean creatinine clearance was 50.6+/-26.3 ml/min. Patients with severe renal failure were excluded. Patients were compared with a control group with normal renal function (n=35, 22 men and 13 women, mean age 50.0+/-11.5 years). Plasma homocysteine values were measured in both groups at baseline and after an oral overload of methionine. RESULTS Baseline homocysteine levels of patients were higher than those of controls (16.5+/-7.3 vs. 10.4+/-4.2 micromol/l, p<0.0001). Some 34 patients and 4 controls had increased plasma homocysteine levels at baseline. After the oral overload, 4 more patients had abnormally increased homocysteine levels, meaning that 83% of the patients with chronic renal failure had hyperhomocysteinemia. CONCLUSIONS Hyperhomocysteinemia is a very common finding among patients with mild renal failure. The need for vitamin supplementation should be evaluated in the first stage of chronic renal failure.
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Affiliation(s)
- N R Robles
- Sección de Nefrología, Hospital Infanta Cristina, Carretera de Portugal s/n E-06070, Badajoz, Spain.
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Sun J, Xu Y, Xue J, Zhu Y, Lu H. Methylenetetrahydrofolate reductase polymorphism associated with susceptibility to coronary heart disease in Chinese type 2 diabetic patients. Mol Cell Endocrinol 2005; 229:95-101. [PMID: 15607533 DOI: 10.1016/j.mce.2004.09.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Accepted: 09/09/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Epidemiological studies have identified hyperhomocyst(e)inemia as an independent risk factor for atherosclerosis. The C677T variant of the methylenetetrahydrofolate reductase (MTHFR) gene, one of the key enzymes catalyzing remethylation of homocysteine, might play a role in the development of coronary heart disease (CHD). In this study, we examined the distribution of the MTHFR genotypes in the Chinese population and the association between the C677T variant and CHD in Chinese type 2 diabetic patients. METHODS Two hundred and twenty-eight unrelated patients with type 2 diabetes mellitus (126 with coronary heart disease) and 114 healthy control subjects were recruited. The MTHFR genotype was analyzed by PCR followed by HinfI digestion. Plasma total homocysteine levels were measured using high-performance liquid chromatography (HPLC) with fluorescence detection. RESULTS In 114 healthy control subjects, the frequency of the mutant T allele was 38.0%, comparable to that of a Hong Kong (Chinese) population. The genotype distribution did not differ between control subjects and type 2 diabetic patients (chi(2) = 3.67, P > 0.05). Genotypic analysis revealed that type 2 diabetic patients with CHD displayed a greater prevalence of T allele (45.2%) than type 2 diabetic patients without CHD (30.4%) (chi(2) = 8.72, P < 0.005). The odds ratio for CHD in type 2 diabetic patients in presence of T allele was 1.89 (CI 95%, 1.24-2.88). The MTHFR genotype were different between diabetic patients with and without CHD (chi(2) = 11.98, P < 0.005). Moreover, plasma homocysteine levels were markedly higher in individuals with TT genotype than those with CC or CT genotype or CC plus CT genotype. CONCLUSIONS The C677T mutation of MTHFR gene is common in the Chinese population. MTHFR C677T gene polymorphism associated with a predisposition to increased plasma homocysteine levels could constitute a useful predictive marker for CHD in Chinese type 2 diabetic patients.
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Affiliation(s)
- Jiazhong Sun
- Department of Endocrinology, Zhongnan Hospital, Wuhan University, Wuhan 430071, China.
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30
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Durga J, Verhoef P, Bots ML, Schouten E. Homocysteine and carotid intima-media thickness: a critical appraisal of the evidence. Atherosclerosis 2004; 176:1-19. [PMID: 15306169 DOI: 10.1016/j.atherosclerosis.2003.11.022] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2003] [Revised: 10/22/2003] [Accepted: 11/21/2003] [Indexed: 10/26/2022]
Abstract
UNLABELLED This review examines the relationship between hyperhomocysteinemia, a risk factor for vascular disease, and carotid intima-media thickness (CIMT), a valid marker of generalized atherosclerosis and future vascular disease risk. The relationship between two important determinants of hyperhomocysteinemia in the general population-folate status and the 677C --> T methylenetetrahydrofolate reductase (MTHFR) polymorphism-and CIMT is also covered. METHODS We searched literature databases for articles examining homocysteine and CIMT published before September 2003. RESULTS We identified 54 studies. Observational studies generally failed to demonstrate a relationship between homocysteine and CIMT in homocystinuric, uremic, hypercholesterolemic or non-insulin-dependent diabetes mellitus patients or in subjects with insulin insensitivity. Weak associations, but usually only in certain sub-populations were found in vascular disease patients and in population-based studies. B vitamins reduce the progression of CIMT in renal transplant recipients and vascular disease patients as demonstrated by two trials. The majority of studies demonstrated increased CIMT in individuals with the MTHFR 677TT genotype. Folate status showed no relation to CIMT. DISCUSSION In non-patient populations, hyperhomocysteinemia is weakly associated with CIMT. The association of the 677 C--> T MTHFR polymorphism with CIMT further supports this finding. Lastly, folate levels may need to reach a critically low status before an association can be found between folate and CIMT. Larger trials in various population types are needed to determine whether folate alone or in combination with Vitamins B6 and B12 will slow down or even reverse atherosclerotic progression.
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Affiliation(s)
- Jane Durga
- Division of Human Nutrition, Wageningen Centre for Food Sciences, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands.
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Yilmaz H, Agachan B, Ergen A, Karaalib ZE, Isbir T. Methylene tetrahydrofolate reductase C677T mutation and left ventricular hypertrophy in Turkish patients with type II diabetes mellitus. BMB Rep 2004; 37:234-8. [PMID: 15469701 DOI: 10.5483/bmbrep.2004.37.2.234] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study was designed to investigate, in the Turkish population, the association of methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism and left ventricular hypertrophy (LVH) in patients with type II diabetes mellitus. Our study included 249 patients with type II diabetes mellitus (102 men, 147 women) and 214 healthy volunteers as controls (91 men, 123 women). MTHFR C677T genotypes were determined by polymerase chain reaction, restriction fragment length polymorphism techniques. No differences were observed in the distribution of MTHFR genotypes or allele frequencies in the cases versus the controls. The frequency of the MTHFR-mutated allele (T) was 31.7% in the type II diabetes mellitus versus 31.1% of the controls. The homozygous mutation (T/T) in the MTHFR gene was identified in 12% of the type II diabetes mellitus versus 9.3% of the controls. Patients with the TT genotype showed a higher prevalence of LVH when compared to patients with the CC and CT genotypes (p = 0.01). The MTHFR gene C677T mutation may be a possible risk factor for the development of LVH in the type II diabetic patients.
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Affiliation(s)
- Hulya Yilmaz
- Institute of Experimental Medical Research, Department of Molecular Medicine, Istanbul University, Istanbul, Turkey
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Fischbach M, Terzic J, Laugel V, Dheu C, Menouer S, Helms P, Livolsi A. Daily on-line haemodiafiltration: a pilot trial in children. Nephrol Dial Transplant 2004; 19:2360-7. [PMID: 15266034 DOI: 10.1093/ndt/gfh403] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Despite major improvements in paediatric dialysis over the last two decades, cardiovascular outcome is often poor. As France gives priority to kidney transplantation over dialysis, children in chronic haemodialysis are generally pre-adolescents or adolescents with long medical histories and low compliance. In them, the usual weekly schedule of dialysis is often unsuitable. We conducted a study of conversion to daily dialysis, which allowed an enhanced dialysis dose, a gentle ultrafiltration rate and achievement of dry body weight. METHODS In this single-centre, observational, prospective, non-randomized study, five oligoanuric dialysis patients (mean age: 13.8 +/- 3.2 years) were converted from standard on-line haemodiafiltration (S-OL-HDF) (4 h, three times/week) to daily on-line haemodiafiltration (D-OL-HDF) (3 h, six times/week). Patient selection was based on both the presence of uraemic cardiomyopathy (left ventricular hypertrophy and reduced fractional shortening) and their reduced therapeutic compliance. The D-OL-HDF parameters were the same as for the S-OL-HDF. RESULTS Increasing the number of sessions from three to six weekly positively impacted the weekly dialysis dose. On D-OL-HDF, mean arterial blood pressure decreased significantly (from 95 +/- 15 to 82 +/- 13 and 87 +/- 9 mmHg at 6 and 12 months, respectively). Left ventricular hypertrophy decreased and its fractional shortening improved markedly (from 26.6 +/- 17% to 31 +/- 14% and 46.6 +/- 15% at 6 and 12 months, respectively). Pre-dialytic plasma phosphorus also decreased markedly (from 1.87 +/- 0.23 to 1.43 +/- 0.22 and 1.28 +/- 0.29 mmol/l at 6 and 12 months, respectively), as did the calcium-phosphorus product. The post-dialytic recovery time disappeared and so did perception of fatigue. Fasting the day before dialysis to avoid excess weight gain (necessitating longer dialysis) disappeared. Combined with an improved appetite, these changes resulted in higher caloric and protein intake (nPCR), from 1.28 +/- 0.23 to 1.43 +/- 0.24 g/kg at 6 months, and school attendance became regular. The only pre-pubertal child included showed catch-up growth. CONCLUSIONS Increasing dialysis frequency to daily sessions without shortening the durations of sessions excessively allowed us to overcome the "free diet" imposed on these paediatric, very uncompliant patients. This strategy led to a reduction in blood pressure and an improvement of left ventricular size and function, normalization of pre-dialytic plasma phosphorus and improvements in general well-being and dialysis acceptance. Long-term, however, this protocol is only acceptable for the children if associated with the potential of clinical recovery allowing inscription on the kidney transplantation waiting list.
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Affiliation(s)
- Michel Fischbach
- Nephrology Dialysis Transplantation Children's Unit, Hospital de Hautepierre, Avenue Moliere, 67098 Strasbourg, France.
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Goldstein M, Leibovitch I, Yeffimov I, Gavendo S, Sela BA, Loewenstein A. Hyperhomocysteinemia in patients with diabetes mellitus with and without diabetic retinopathy. Eye (Lond) 2004; 18:460-5. [PMID: 15131674 DOI: 10.1038/sj.eye.6700702] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE To evaluate the prevalence of hyperhomocysteinaemia in diabetic patients with no diabetic retinopathy (no DR), with non-proliferative diabetic retinopathy (NPDR) and with proliferative diabetic retinopathy (PDR). RESEARCH DESIGN AND METHODS This prospective, case-control study, included 179 diabetic patients and 156 age-matched controls with no diabetes and no history of ocular disease, who were undergoing routine physical checkups. Plasma homocysteine levels of all study participants were measured using high-performance liquid chromatography (HPLC). Hyperhomocysteinaemia was defined when homocysteine levels were higher than 15 micromol/l. RESULTS The mean plasma homocysteine level was 11.75+-0.24 in the control group,13.46+0.74 in the no DR group, 14.56 + 0.64 in the NPDR group and 15.86 + 1.34 in the PDR group. Mean homocysteine levels were significantly elevated in the NPDR and PDR groups compared to the control group(P = 0.001 and <0.0001, respectively). The prevalence of hyperhomocysteinaemia was also higher in the NPDR and PDR groups compared to the control group (P = 0.032 and 0.011, respectively). No statistically significant difference was found between the no DR and the control group. CONCLUSIONS Our findings suggest that hyperhomocysteinaemia may be associated with diabetic retinopathy and partially explain the increased risk of microvascular angiopathy occurring in these patients.
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Affiliation(s)
- M Goldstein
- Department of Ophthalmology, Tel-Aviv Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
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Genest J, Frohlich J, Steiner G. Effect of fenofibrate-mediated increase in plasma homocysteine on the progression of coronary artery disease in type 2 diabetes mellitus. Am J Cardiol 2004; 93:848-53. [PMID: 15050487 DOI: 10.1016/j.amjcard.2003.12.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2002] [Revised: 12/04/2003] [Accepted: 12/04/2003] [Indexed: 10/26/2022]
Abstract
The Diabetes Atherosclerosis Intervention Study (DAIS) examined the effects of fenofibrate or placebo on the progression of coronary artery disease (CAD) in 418 type 2 diabetic subjects with dyslipidemia. Fenofibrate use was associated with a 6% increase in high-density lipoprotein cholesterol, a 28% decrease in triglycerides, a 5% decrease in low-density lipoprotein cholesterol, and a 55% increase in plasma homocysteine (tHcy). The purpose of the present study was to determine whether this increase in tHcy in the fenofibrate group was associated with CAD progression or with clinical events. The increase in tHcy with fenofibrate (n = 207) was not related to changes in factors known to modulate tHcy levels (serum levels of Vitamin B(12), folate, or renal function). CAD was quantified by angiography at baseline and after a minimum of 3 years of therapy with fenofibrate or placebo. The primary end point was change in mean segment diameter (MSD), minimal lumen diameter, and percent stenosis. Baseline tHcy level was correlated with percent diameter stenosis (r = 0.111, p = 0.028). Baseline, but not end-of-study elevated tHcy levels, decreased the beneficial effect of fenofibrate. Unexpectedly, the final tHcy levels correlated negatively with CAD progression (r = -0.111, p = 0.031) in the overall group. In the fenofibrate group, there was no significant correlation between tHcy and minimal lumen diameter (r = -0.135, p = 0.069), or percent stenosis. An increase in tHcy levels was not correlated with adverse clinical events in the fenofibrate group. This analysis of the the DAIS reveals that the fenofibrate-mediated increase in tHcy levels does not attenuate the beneficial effects of fenofibrate on CAD progression or clinical events.
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Affiliation(s)
- Jacques Genest
- Cardiology Division, McGill University Health Center, Healthy Heart Program, St. Paul's Hospital, Vancouver, British Columbia, Canada.
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Abstract
The uremic syndrome is a mix of clinical features resulting from multiple organ dysfunctions which develop when kidney failure progresses, and is attributed to the retention of solutes, which under normal conditions are excreted by the healthy kidneys into the urine. The most practical classification of uremic solutes is based on their physicochemical characteristics that influence their dialytic removal, in (1) small water soluble compounds, (2) the larger "middle molecules," and (3) the protein bound compounds. Hence, uremic retention is much more complex than originally believed. Among the small water soluble compounds, urea exerts not much toxic activity and is not very representative in its kinetic behavior for many other uremic solutes. Among the middle molecules, many have been recognized to exert biological activity and hence to contribute to the uremic syndrome. Specific dialysis strategies apply large pore membranes to remove those middle molecules and have a beneficial impact on uremic morbidity and mortality. A substantial number of uremic solutes are protein bound. Only recently, a relation between their concentration and clinical status could be demonstrated. Likewise, it was only recently possible to demonstrate more than standard removal with super-flux dialysis membranes. To further improve characterization of uremic solutes and to develop directed therapeutic approaches, further concerted action among various groups of researchers will be needed.
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Affiliation(s)
- Tony Bouré
- University Hospital Ghent, Department of Internal Medicine, Nephrology Division, Ghent, Belgium
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Kasiske B, Cosio FG, Beto J, Bolton K, Chavers BM, Grimm R, Levin A, Masri B, Parekh R, Wanner C, Wheeler DC, Wilson PWF. Clinical practice guidelines for managing dyslipidemias in kidney transplant patients: a report from the Managing Dyslipidemias in Chronic Kidney Disease Work Group of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative. Am J Transplant 2004; 4 Suppl 7:13-53. [PMID: 15027968 DOI: 10.1111/j.1600-6135.2004.0355.x] [Citation(s) in RCA: 217] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The incidence of cardiovascular disease (CVD) is very high in patients with chronic kidney (CKD) disease and in kidney transplant recipients. Indeed, available evidence for these patients suggests that the 10-year cumulative risk of coronary heart disease is at least 20%, or roughly equivalent to the risk seen in patients with previous CVD. Recently, the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (K/DOQI) published guidelines for the diagnosis and treatment of dyslipidemias in patients with CKD, including transplant patients. It was the conclusion of this Work Group that the National Cholesterol Education Program Guidelines are generally applicable to patients with CKD, but that there are significant differences in the approach and treatment of dyslipidemias in patients with CKD compared with the general population. In the present document we present the guidelines generated by this workgroup as they apply to kidney transplant recipients. Evidence from the general population indicates that treatment of dyslipidemias reduces CVD, and evidence in kidney transplant patients suggests that judicious treatment can be safe and effective in improving dyslipidemias. Dyslipidemias are very common in CKD and in transplant patients. However, until recently there have been no adequately powered, randomized, controlled trials examining the effects of dyslipidemia treatment on CVD in patients with CKD. Since completion of the K/DOQI guidelines on dyslipidemia in CKD, the results of the Assessment of Lescol in Renal Transplantation (ALERT) Study have been presented and published. Based on information from randomized trials conducted in the general population and the single study conducted in kidney transplant patients, these guidelines, which are a modified version of the K/DOQI dyslipidemia guidelines, were developed to aid clinicians in the management of dyslipidemias in kidney transplant patients. These guidelines are divided into four sections. The first section (Introduction) provides the rationale for the guidelines, and describes the target population, scope, intended users, and methods. The second section presents guidelines on the assessment of dyslipidemias (guidelines 1-3), while the third section offers guidelines for the treatment of dyslipidemias (guidelines 4-5). The key guideline statements are supported mainly by data from studies in the general population, but there is an urgent need for additional studies in CKD and in transplant patients. Therefore, the last section outlines recommendations for research.
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Austen SK, Coombes JS, Fassett RG. Homocysteine and cardiovascular disease in renal disease. Review Article. Nephrology (Carlton) 2003; 8:285-95. [PMID: 15012699 DOI: 10.1111/j.1440-1797.2003.00210.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Elevated homocysteine (hyperhomocysteinaemia) in renal patients is a major concern for physicians. Although cause and effect between homocysteine and cardiovascular disease (CVD) has not been established in either the general population or renal patients, there is much evidence that this relationship does exist. Purported mechanisms that may explain this effect include increases in endothelial injury, smooth muscle cell proliferation, low-density lipoprotein oxidation and changes in haemostatic balance. Renal patients have a much greater incidence of hyperhomocysteinaemia and this may be explained by decreases in either the renal or extrarenal metabolism of the compound. We conclude that data from long-term placebo-controlled trials are urgently required to determine whether hyperhomocysteinaemia in renal patients is a cause of CVD events and requires therapeutic targeting.
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Affiliation(s)
- Simon K Austen
- School of Human Movement Studies, University of Queensland, St Lucia, Queensland, Australia
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Clark WR, Winchester JF. Middle molecules and small-molecular-weight proteins in ESRD: properties and strategies for their removal. ACTA ACUST UNITED AC 2003; 10:270-8. [PMID: 14681858 DOI: 10.1053/j.arrt.2003.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Molecular weight has traditionally been the parameter most commonly used to classify uremic toxins, with a value of approximately 500 Da frequently used as a demarcation point below which the molecular weights of small nitrogenous waste products fall. This toxin group, the most extensively studied from a clinical perspective, is characterized by a high degree of water solubility and the absence of protein binding. However, uremia is mediated by the retention of a plethora of other compounds having characteristics that differ significantly from those of the previously mentioned group. As opposed to the relative homogeneity of the nitrogenous metabolite class, other uremic toxins collectively are a very heterogeneous group, not only with respect to molecular weight but also other characteristics, such as protein binding and hydrophobicity. A recently proposed classification scheme by the European Uraemic Toxin Work Group subdivides the remainder of molecules into 2 categories: protein-bound solutes and middle molecules. For the latter group, the Work Group proposes a molecular weight range (500-60,000 Da) that incorporates many toxins identified since the original middle molecule hypothesis, for which the upper molecular weight limit was approximately 2,000 Da. In fact, low-molecular-weight peptides and proteins (LMWPs) comprise nearly the entire middle molecule category in the new scheme. The purpose of this article is to provide an overview of the middle molecule class of uremic toxins, with the focus on LMWPs. A brief review of LMWP metabolism under conditions of normal (and in a few cases, abnormal) renal function will be presented. The physical characteristics of several LMWPs will also be presented, including molecular weight, conformation, and charge. Specific LMWPs to be covered will include beta 2-microglobulin, complement proteins (C3a and Factor D), leptin, and proinflammatory cytokines. The article will also include a discussion of the treatment-related factors influencing dialytic removal of middle molecules. Once these factors, which include membrane characteristics, protein-membrane interactions, and solute removal mechanisms, are discussed, an overview of the different therapeutic strategies used to enhance clearance of these compounds is provided.
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Affiliation(s)
- William R Clark
- NxStage Medical, Inc, Indiana University School of Medicine, Indianapolis, USA
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Abstract
Protein-bound uremic retention solutes are molecules with low molecular weight (MW) but should be considered middle or high MW substances. This article describes the best known substances of this group, which include p-cresol, indoxyl sulfate, hippuric acid, 3-carboxy-4-methyl-5-propyl-2-furan-propionic acid (CMPF), and homocysteine. At concentrations encountered during uremia, p-cresol inhibits phagocyte function and decreases leukocyte adhesion to cytokine-stimulated endothelial cells. CMPF has been implicated in anemia and neurologic abnormalities of uremia. CMPF could alter the metabolism of drugs of inhibiting their binding to albumin and their tubular excretion. Indoxyl sulfate administrated to uremic rats increases the rate of progression of renal failure. Hippuric acid inhibits glucose utilization in the muscle, and its serum concentration is correlated with neurologic symptoms of uremia. Homocysteine predisposes uremic patients to cardiovascular disease through impairment of endothelial and smooth muscle cell functions. The removal of protein-bound compounds by conventional hemodialysis is low. Other strategies to decrease their concentrations include increase in dialyze pore size, daily hemodialysis, peritoneal dialysis, reduction of production or acceleration of degradation, and preservation of residual renal function.
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Affiliation(s)
- Philippe Brunet
- EMI 0019, Faculté de Pharmacie, Université de la Méditerraneé, Marseille, France.
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de Gómez Dumm NT, Giammona AM, Touceda LA. Variations in the lipid profile of patients with chronic renal failure treated with pyridoxine. Lipids Health Dis 2003; 2:7. [PMID: 14575530 PMCID: PMC222990 DOI: 10.1186/1476-511x-2-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2003] [Accepted: 09/18/2003] [Indexed: 12/01/2022] Open
Abstract
Background Hyperhomocysteinemia and lipid abnormalities are commonly found in patients with chronic renal failure; both are recognized as risk factors for atherosclerosis. The homocysteine-lowering effect of pyridoxine is controversial. This study was performed to determine the effect of a high dose of pyridoxine (300 mg i.v. three times a week) on plasma and red blood cell lipid profile and plasma homocysteine concentration in twelve chronic renal failure patients on regular hemodialysis. Fasting blood samples were taken at the beginning of the study (basal 1), after 30 and 60 days of treatment and 4 months after withdrawal (basal 2). Results Pyridoxine supplementation induced a significant decrease in total plasma homocysteine level and also a lowering effect in plasma total cholesterol and triglycerides. These biochemical data increased when the samples were taken at basal 2, reaching the levels obtained at the beginning of the experiment. LDL cholesterol increased whereas HDL cholesterol was reduced during the treatment. In erythrocyte membranes vitamin B6 therapy enhanced the cholesterol/phospholipid ratio as well as the fluorescence anisotropy of diphenyl-hexatriene. Conclusions We conclude that high doses of pyridoxine represent an effective strategy to ameliorate both plasma homocysteine levels and lipid profiles in chronic renal failure patients, protecting them from atherosclerosis. Further research using a long-term treatment would be necessary in an attempt to restore the fatty acid pattern and the fluidity of red cell membranes.
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Affiliation(s)
| | | | - Luis A Touceda
- Cátedra de Medicina Interna, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, 1900, La Plata, Argentina. Fax: 54:221 4258988
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Maduell F, Navarro V, Torregrosa E, Rius A, Dicenta F, Cruz MC, Ferrero JA. Change from three times a week on-line hemodiafiltration to short daily on-line hemodiafiltration. Kidney Int 2003; 64:305-13. [PMID: 12787423 DOI: 10.1046/j.1523-1755.2003.00043.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Daily dialysis has shown excellent clinical results because a higher frequency of dialysis is more physiologic. On-line hemodiafiltration (OL-HDF) is a HDF technique that combines diffusion with high convection in which the dialysis fluid itself is used as a reinfusion solution. The aim of this study was to demonstrate the beneficial effect of the more effective dialysis schedule (daily dialysis) with the dialysis modality that offers the highest uremic toxin removal (on-line HDF). METHODS Eight patients, six males and two females, on standard 4 to 5 hours three times a week OL-HDF (S-OL-HDF) were switched to daily OL-HDF (D-OL-HDF) 2 to 21/2 hours six times per week. Dialysis parameters were identical during both periods and only frequency and dialysis time of each session were changed. Tolerance, uremic toxin removal, urea kinetics, biochemical and anemia profiles, blood pressure, and left ventricular hypertrophy were evaluated. RESULTS D-OL-HDF was well accepted and tolerated. The disappearance of postdialysis fatigue was rapidly reported by patients. Patients mantained the same [time average concentration (TAC) and weekly single-pool Kt/V (spKt/V)] throughout the study. However, equivalent renal urea clearance (EKR), standard Kt/V and weekly urea reduction ratio (URR) were increased during D-OL-HDF. Weekly urea, creatinine, osteocalcin, beta2-microglobulin, myoglobin, and prolactin reduction ratios were improved with D-OL-HDF. There was a significant decrease in predialysis plasma levels of urea, creatinine, acid uric, beta2-microglobulin and homocysteine over 6 months. Phosphate binders were reduced and antihypertensive drugs were stopped. A 30% regression of left ventricular mass was observed. CONCLUSION The change from S-OL-HDF to D-OL-HDF was well tolerated. Disappearance of postdialysis fatigue, better dialysis adequacy, a higher removal of middle and large molecules, a reduction of phosphate binders, improvement of status nutritional, and an important reduction of cardiovascular risk factors were observed.
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Vessani RM, Ritch R, Liebmann JM, Jofe M. Plasma homocysteine is elevated in patients with exfoliation syndrome. Am J Ophthalmol 2003; 136:41-6. [PMID: 12834668 DOI: 10.1016/s0002-9394(03)00077-1] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE To compare plasma homocysteine concentrations among patients with exfoliation syndrome, exfoliative glaucoma, normal-tension glaucoma, and normal control subjects without vascular or inflammatory ocular disease or glaucoma. DESIGN Cross-sectional study. METHODS We tested 25 patients with exfoliation syndrome, 50 with exfoliative glaucoma, 25 with normal-tension glaucoma, and 24 control subjects. Fasting plasma homocysteine concentrations were measured by fluorescence polarization immunoassay. Patients using vitamin supplements or medications known to alter serum homocysteine were excluded. RESULTS Homocysteine levels were higher in both exfoliatin groups compared with controls (exfoliation syndrome: P =.003; exfoliative glaucoma: P =.009); levels in normal-tension glaucoma were higher than but not significantly different from those in controls (P =.2). Hyperhomocysteinemia was present in 16 of 25 (64%) exfoliation syndrome patients, 28 of 50 (56%) exfoliative glaucoma patients, 13 of 25 (52%) normal-tension glaucoma patients, and 7 of 24 (29.2%) controls (P =.005). Multiple logistic regression analyses comparing exfoliation syndrome and exfoliative glaucoma patients with controls indicated that elevated plasma homocysteine concentration was a significant risk factor for exfoliation syndrome, in both those patients (odds ratios per 1.0 micromol/l increase in plasma homocysteine concentrations = 1.47; 95% confidence interval [CI] = 1.08-2.0) and in exfoliative glaucoma patients (odds ratio = 1.3; 95% CI = 1.07-1.6). Although exfoliative glaucoma and normal-tension glaucoma patients were not significantly different with respect to hyperhomocysteinemia, logistic regression modeling of exfoliative glaucoma vs normal-tension glaucoma patients showed that an increased homocysteine concentration was a significant risk factor for exfoliation syndrome in the presence of glaucoma (odds ratio per 1.0 micromol/l increase in homocysteine = 1.2, 95% CI = 1.0-1.4). These relationships were not affected by adjustment for potential confounding due to sex, history of hypertension, or other factors. RESULTS Elevated plasma homocysteine, a risk factor for cardiovascular disease, is more common in exfoliation syndrome and exfoliative glaucoma patients than healthy controls. Patients with exfoliation syndrome may benefit from measurement of homocysteine levels.
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Affiliation(s)
- Roberto M Vessani
- Department of Ophthalmology, The New York Eye and Ear Infirmary, New York, New York 10003, USA
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Vanholder R, De Smet R, Glorieux G, Argilés A, Baurmeister U, Brunet P, Clark W, Cohen G, De Deyn PP, Deppisch R, Descamps-Latscha B, Henle T, Jörres A, Lemke HD, Massy ZA, Passlick-Deetjen J, Rodriguez M, Stegmayr B, Stenvinkel P, Tetta C, Wanner C, Zidek W. Review on uremic toxins: classification, concentration, and interindividual variability. Kidney Int 2003; 63:1934-43. [PMID: 12675874 DOI: 10.1046/j.1523-1755.2003.00924.x] [Citation(s) in RCA: 1103] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The choice of the correct concentration of potential uremic toxins for in vitro, ex vivo, and in vivo experiments remains a major area of concern; errors at this level might result in incorrect decisions regarding therpeutic correction of uremia and related clinical complications. METHODS An encyclopedic list of uremic retention solutes was composed, containing their mean normal concentration (CN), their highest mean/median uremic concentration (CU), their highest concentration ever reported in uremia (CMAX), and their molecular weight. A literature search of 857 publications on uremic toxicity resulted in the selection of data reported in 55 publications on 90 compounds, published between 1968 and 2002. RESULTS For all compounds, CU and/or CMAX exceeded CN. Molecular weight was lower than 500 D for 68 compounds; of the remaining 22 middle molecules, 12 exceeded 12,000 D. CU ranged from 32.0 ng/L (methionine-enkephalin) up to 2.3 g/L (urea). CU in the ng/L range was found especially for the middle molecules (10/22; 45.5%), compared with 2/68 (2.9%) for a molecular weight <500 D (P < 0.002). Twenty-five solutes (27.8%) were protein bound. Most of them had a molecular weight <500 D except for leptin and retinol-binding protein. The ratio CU/CN, an index of the concentration range over which toxicity is exerted, exceeded 15 in the case of 20 compounds. The highest values were registered for several guanidines, protein-bound compounds, and middle molecules, to a large extent compounds with known toxicity. A ratio of CMAX/CU <4, pointing to a Gaussian distribution, was found for the majority of the compounds (74/90; 82%). For some compounds, however, this ratio largely exceeded 4 [e.g., for leptin (6.81) or indole-3-acetic acid (10.37)], pointing to other influencing factors than renal function, such as gender, genetic predisposition, proteolytic breakdown, posttranslation modification, general condition, or nutritional status. CONCLUSION Concentrations of retention solutes in uremia vary over a broad range, from nanograms per liter to grams per liter. Low concentrations are found especially for the middle molecules. A substantial number of molecules are protein bound and/or middle molecules, and many of these exert toxicity and are characterized by a high range of toxic over normal concentration (CU/CN ratio). Hence, uremic retention is a complex problem that concerns many more solutes than the current markers of urea and creatinine alone. This list provides a basis for systematic analytic approaches to map the relative importance of the enlisted families of toxins.
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Affiliation(s)
- Raymond Vanholder
- The Nephrology Section, Department of Internal Medicine, University Hospital, Ghent, Belgium.
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Abstract
Cardiovascular mortality is markedly increased in patients with end-stage renal disease (ESRD), particularly those receiving dialysis. Coronary artery disease is the most important cause of death in these patients. As in the general population, older age, male gender, and the postmenopausal state in women are cardiovascular risk factors in patients with ESRD. However, hypertension, diabetes mellitus, and dyslipidemia, known to promote cardiovascular disease in the general population, are particularly likely to do so in patients with ESRD because of their high prevalence in this population. In addition, nontraditional cardiovascular risk factors, such as hyperhomocystinemia, inflammation, elevated calcium x phosphate product, endothelial dysfunction, and oxidant stress, occur frequently in patients with ESRD. Vigorous treatment of modifiable cardiovascular risk factors has reduced cardiovascular risk in patients without ESRD. The extent to which such risk factor modification would alter cardiovascular risk in ESRD remains uncertain.
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Affiliation(s)
- Sarah Prichard
- Nephrology Division, Royal Victoria Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
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REFERENCES. Am J Kidney Dis 2003. [DOI: 10.1016/s0272-6386(03)00125-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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De Smet R, Van Kaer J, Van Vlem B, De Cubber A, Brunet P, Lameire N, Vanholder R. Toxicity of free p-cresol: a prospective and cross-sectional analysis. Clin Chem 2003; 49:470-8. [PMID: 12600960 DOI: 10.1373/49.3.470] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Uremic syndrome is the consequence of the retention of solutes usually cleared by the healthy kidneys. p-Cresol can be considered a prototypic protein-bound uremic toxin. It is conceivable, analogous with drugs, that the non-protein-bound fraction of p-cresol exerts toxicity. This aspect had never been evaluated, nor have the factors influencing the free fraction of p-cresol. METHODS In a transsectional study we evaluated the relationship between prehemodialysis free p-cresol and the ratio of free to total p-cresol (F:T) to clinical and biological factors in 44 chronic renal failure patients. The evolution of free p-cresol was assessed prospectively in 12 patients showing a change in serum albumin of at least 5 g/L over time. Hospitalization days attributable to infection and the free p-cresol concentrations were noted over a 1-year period. The impact of free p-cresol in vitro on leukocyte functional capacity was evaluated by chemiluminescence. RESULTS We observed a correlation between total and free p-cresol (r = 0.84; P <0.001). In the multivariate analyses, free p-cresol and F:T showed a negative correlation with albumin. A shift from normal serum albumin to hypoalbumininemia in 12 patients led to an increase in free p-cresol from 5.9 +/- 3.2 to 8.2 +/- 4.5 micro mol/L (P <0.05; 0.64 +/- 0.35 to 0.89 +/- 0.49 mg/L). Free p-cresol (P <0.05) was higher in the patients hospitalized for infectious disease. In vitro, free p-cresol was higher in a 25 g/L than in a 50 g/L albumin solution (P <0.05). Leukocyte chemiluminescence production was more inhibited in the low albumin (high free p-cresol) solution (28% +/- 6% vs 21% +/- 8%; P <0.05). CONCLUSIONS Hypoalbuminemia and total p-cresol increase the free fraction of p-cresol. Patients hospitalized for infections have higher free p-cresol. In vitro, high free p-cresol has a negative impact on leukocyte chemiluminescence production. These data demonstrate the toxicity of free p-cresol.
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Affiliation(s)
- Rita De Smet
- University Hospital Gent, Department of Internal Medicine, Renal Division, Belgium.
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Lévesque R, Dumont M, Leblanc M. No Association between Hyperhomocysteinemia and Vascular Access Thrombosis in Chronic Hemodialysis. J Vasc Access 2003. [DOI: 10.1177/112972980300400104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PurposeHyperhomocysteinemia, recognized as a risk factor for cardiovascular diseases, has also been related with controversy to vascular access thrombosis in hemodialysis. Our objective was to determine if such an association could be found in our hemodialysis population.MethodsThe survey was conducted in a cohort of 165 chronic hemodialysis patients. Their vascular access history was considered from hemodialysis initiation until November 1999, including the number of vascular accesses created (either native or synthetic fistulae), focussing on vascular access thrombotic events, and excluding primary vascular access dysfunction. Diabetes, hemoglobin, erythropoietin dose, anticoagulation, and methyltetrahydrofolate reductase (MTHFR) status were considered. Serum total homocysteine (tHcy) measures were sampled for all patients in June 1998 and repeated yearly. Patients had not been supplemented routinely with hydrosoluble vitamins until June 1998, after which all received DiaVite® (R&D Laboratories, CA, USA) daily.ResultsMedian survival of native fistulae was significantly longer (81 months, 95%CI 35–127) than for synthetic fistulae (31 months, 95%CI 27–51). Median vascular access survival was reduced for diabetics vs non diabetics (28 vs 57 months) (P<0.05), whereas sex, age and smoking had no impact. No correlation was found between tHcy concentration and the number of vascular access thrombotic events; homozygotes for MTHFR had higher tHcy but no more vascular access thrombotic events. The 38 patients with a mean vascular access survival of less than 12 months (6±3 months) were compared to the 127 patients with a mean vascular access survival of ≥ 12 months (39±25 months) (P<0.05): no difference in their respective tHcy concentrations before and after DiaVite® introduction was found (31±13 and 20±8 vs 34±17 and 22±6 μmol/L), but the first group presented more numerous synthetic fistulae (p<0.0001), lower hemoglobin levels, and higher erythropoietin doses.ConclusionsNo significant association between hyperhomocysteinemia and vascular access thrombosis could be found in our population. DiaVite® introduction allowed a significant reduction in tHcy, but had no impact on vascular access survival, except for a slight but not significant reduction in the prevalence of vascular access thrombotic events during the year on DiaVite®. Potential benefits of approaches to reduce tHcy for vascular access time-life prolongation remain to be demonstrated.
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Affiliation(s)
- R. Lévesque
- Nephrology Department, Campus Notre-Dame, Centre Hospitalier de l'Université de Montréal, Quebec - Canada
| | - M. Dumont
- Biostatistics, University of Montreal, Quebec - Canada
| | - M. Leblanc
- Nephrology Department, Hôpital Maisonneuve-Rosemont Montreal, Quebec - Canada
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Agulló-Ortuño MT, Albaladejo MD, Parra S, Rodríguez-Manotas M, Fenollar M, Ruíz-Espejo F, Tebar J, Martínez P. Plasmatic homocysteine concentration and its relationship with complications associated to diabetes mellitus. Clin Chim Acta 2002; 326:105-12. [PMID: 12417101 DOI: 10.1016/s0009-8981(02)00287-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND METHODS In the search for new factors of cardiovascular risk associated to diabetes mellitus (DM), special attention has been paid in recent years to hyperhomocysteinaemia. Therefore, we have established the concentration of homocysteine (Hcy) and other biochemical parameters in the plasma of a group of 57 type 1 and 32 type 2 diabetic patients and 54 control subjects and studied whether plasmatic homocysteinaemia was related to macroangiopathy, nephropathy, retinopathy and neuropathy. Because of significant differences for plasma Hcy values between men and women in the control group, we distinguished between both groups throughout the study. RESULTS Patients with DM had higher Hcy than control subjects (11.7+/-5.4 vs. 10.1+/-2.4 micromol/l, p<0.05). Fasting hyperhomocysteinaemia was considered as the mean of the plasma Hcy for control subjects+2 SD (14.9 micromol/l in total group, 15.6 micromol/l in males and 13.9 micromol/l in females). In the studied groups with complications, we found significant differences between normohomocysteinaemic type 1 diabetic patients and those considered hyperhomocysteinaemic by us. On the other hand, patients having type 1 DM and complications had higher plasmatic Hcy concentration than those with no complications. CONCLUSIONS We have found a relationship between high Hcy levels and prevalence of macroangiopathy, retinopathy and nephropathy in the type 1 diabetic patients, which was not been observed in the type 2 diabetic patients of our study. As a result, we consider plasmatic Hcy a complication-risk indicator in type 1 DM, and we recommend its use together with already established biochemical parameters in the control of the evolution of the disease.
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Affiliation(s)
- M T Agulló-Ortuño
- Servicio de Análisis Clínicos, Laboratorio de Bioquímica, Hospital Universitario Virgen de la Arrixaca, Ctra Madrid-Cartagena, 30120 El Palmar, Murcia, Spain.
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Huang JW, Yen CJ, Pai MF, Wu KD, Tsai TJ, Hsieh BS. Association between serum aspartate transaminase and homocysteine levels in hemodialysis patients. Am J Kidney Dis 2002; 40:1195-201. [PMID: 12460038 DOI: 10.1053/ajkd.2002.36948b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Hyperhomocysteinemia is a common metabolic abnormality in patients undergoing hemodialysis (HD). An impairment of remethylation of homocysteine (Hcy) is seen in these patients but cannot account completely for hyperhomocysteinemia. Homocysteine is derived from transmethylation of methionine that can be metabolized through transamination pathway alternatively. However, the significance of transamination in the metabolism of Hcy in HD patients is not studied. METHODS A total of 145 patients undergoing HD for more than 3 months were enrolled in the study. Vitamins B were not prescribed routinely to these patients. Among them, 49 patients had positive test results for hepatitis B surface antigen or antihepatitis C virus antibody. Serum Hcy, folic acid, vitamin B12, pyridoxal 5' -phosphate, methionine, and transaminase were measured, and parameters of dialysis adequacy were calculated. Multiple linear regression model was used to analyze the factors determining Hcy levels. RESULTS All patients had higher Hcy levels (40.3 +/- 28.3 micromol/L) than the upper limit of reference range 15 micromole/L. The levels of vitamin B(12) were all higher than 160 pg/mL (118 pmol/L). Only 9 patients had serum folic acid lower than 3 ng/mL (6.8 nmol/L). The predialysis Hcy levels were correlated with age, HD duration, folic acid, vitamin B12, and aspartate transaminase (AST) levels among all patients or the subgroup of hepatitis noncarriers with linear multiple regression analysis. In hepatitis carriers, AST levels were not associated with Hcy. A cutoff value of AST less than 14 U/L predicted a predialysis Hcy level higher than 27 micromol/L in noncarriers, with a sensitivity of 83.9% and a specificity of 50.2%. CONCLUSION In addition to vitamin B12 and folic acid, the serum AST levels correlated inversely with predialytic Hcy levels independently in hepatitis noncarrier HD patients. The results suggest that transamination may play an important role in the development of hyperhomocysteinemia when impaired transmethylation is encountered in uremic patients.
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Affiliation(s)
- Jenq-Wen Huang
- Department of Internal Medicine, National Taiwan University Hospital and Far Eastern Memorial Hospital, Taipei, Taiwan
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