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Stewart G, Jardine AG, Briggs JD. Ischaemic heart disease following renal transplantation. Nephrol Dial Transplant 2000; 15:269-77. [PMID: 10648681 DOI: 10.1093/ndt/15.2.269] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- G Stewart
- Renal Unit and Department of Medicine & Therapeutics, Western Infirmary, Glasgow, UK
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52
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Ducloux D, Motte G, Challier B, Gibey R, Chalopin JM. Serum total homocysteine and cardiovascular disease occurrence in chronic, stable renal transplant recipients: a prospective study. J Am Soc Nephrol 2000; 11:134-137. [PMID: 10616849 DOI: 10.1681/asn.v111134] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Renal transplant recipients have disproportionately high rates of arteriosclerotic outcomes, and recent studies provided controlled evidence that clinically stable renal transplant recipients have an excess prevalence of hyperhomocysteinemia. Few studies suggest that hyperhomocysteinemia may be a cardiovascular risk factor in renal transplant recipients. In the study presented here, the association between atherosclerotic events and homocysteine concentrations was examined in 207 stable renal transplant recipients. The role of hyperhomocysteinemia was analyzed with respect to other known cardiovascular risk factors. The mean follow-up was 21.2 +/- 1.9 mo (range, 14 to 26). Mean total homocysteine (tHcy) was 21.1 +/-9.5 micromol/L and median concentration was 19 micromol/L. Seventy percent of patients (n = 153) were hyperhomocysteinemic (values >15 micromol/L). tHcy correlated negatively with folate concentration (r = -0.3; P < 0.01). tHcy was closely related to creatinine concentration (r = 0.54; P < 0.001). Cardiovascular disease events (CVE) including death were observed in 30 patients (14.5 %; 7.34 events per 1000 person-months of follow-up). Fasting tHcy values were higher in patients who experienced CVE (31.5 +/- 10.3 versus 17.8 +/- 7.5; P < 0.001). Cox regression analysis showed that tHcy was a risk factor for cardiovascular complications (relative risk [RR] 1.06; 95% confidence interval (95% CI), 1.04 to 1.09; P < 0.0001). This corresponds to an increase in RR for CVE of 6% per micromol/L increase in tHcy concentration. Age (RR 1.55; 95% CI, 1.09 to 2.19; P < 0.01) and creatinine concentration (RR 1.34; 95% CI, 1.08 to 1.66; P < 0.01) were also independent predictors for CVE. This study demonstrates that elevated fasting tHcy is an independent risk factor for the development of CVE in chronic stable renal transplant recipients. Randomized, placebo-controlled homocysteine studies of the effect of tHcy lowering on CVE rates are urgently required in this patient population.
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Affiliation(s)
- Didier Ducloux
- Department of Nephrology and Renal Transplantation, Saint Jacques Hospital, Besançon, France
| | - Gérard Motte
- Department of Nephrology and Renal Transplantation, Saint Jacques Hospital, Besançon, France
| | - Bruno Challier
- Department of Medical Information, Saint Jacques Hospital, Besançon, France
| | - Roger Gibey
- Department of Biochemistry, Saint Jacques Hospital, Besançon, France
| | - Jean-Marc Chalopin
- Department of Nephrology and Renal Transplantation, Saint Jacques Hospital, Besançon, France
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Tsai MY. Moderate hyperhomocysteinemia and cardiovascular disease. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2000; 135:16-25. [PMID: 10638690 DOI: 10.1016/s0022-2143(00)70016-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- M Y Tsai
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, USA
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Abstract
This article discusses the metabolism of homocysteine, factors affecting its plasma level, and the evidence for its role in the pathogenesis of vascular disease. The treatment of hyperhomocysteinemia and its possible impact on vascular disease prevention and progression are described also.
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Affiliation(s)
- N Seshadri
- Department of Cardiology, Cleveland Clinic Foundation, Ohio, USA
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55
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Beaulieu AJ, Lapane KL, Gohh RY, Selhub J, Monaco AP, Dworkin L, Rosenberg IH, Bostom AG. Short-term reproducibility of total homocysteine determinations in stable renal transplant recipients. Transplant Proc 1999; 31:2121-3. [PMID: 10455988 DOI: 10.1016/s0041-1345(99)00281-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- A J Beaulieu
- Division of Nephrology, Rhode Island Hospital, USA
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Abstract
Homocysteine is a sulfur-containing amino acid generated through the demethylation of methionine. It is largely catabolized by trans-sulfuration to cysteine, but it may also be remethylated to methionine. Regulation of homocysteine is dependent on nutrient intake, especially folate, vitamins B6 and B12. It is also controlled by individual genetic differences in how vitamins are utilized as cofactors in the reactions controlling homocysteine metabolism. In excess quantities, homocysteine is thought to be thrombophilic and to damage the vascular endothelium. Total plasma homocysteine (tHcy) is now established as a clinical risk factor for coronary artery disease, as well as other arterial and venous occlusive disease in adult populations. These effects are probably related to its role as a teratogen in the pathogenesis of neural tube defects--genetic variants causing hyperhomocysteinemia are associated with both neural tube defects in susceptible pregnancies and with risks for vaso-occlusive disease in later years. Considerable care must be taken in assaying tHcy. Plasma should be separated shortly after collection to avoid artifactual increases due to synthesis by blood cells in vitro. tHcy concentrations must be interpreted in light of the fact that serum albumin, urate, creatinine, and vitamin concentrations may be important analytical covariates. Moreover, concentrations are age- and sex-dependent and are altered by renal function, hormonal status, drug intake, and a variety of other common clinical factors. Why then is homocysteine now of such great clinical and scientific interest? If the homocysteine moiety itself is important in the pathogenesis of vaso-occlusive disease, then simple treatment of hyperhomocysteinemia with vitamins should lead to a significant reduction in disease risk. Such a possibility lies behind the growing momentum to recommend increased supplements of folate and B vitamins to at-risk populations and patient groups today.
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Affiliation(s)
- L J Langman
- Department of Laboratory Medicine and Pathobiology, University of Toronto, ON
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58
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Bostom AG, Gohh RY, Beaulieu AJ, Han H, Jacques PF, Selhub J, Dworkin L, Rosenberg IH. Determinants of fasting plasma total homocysteine levels among chronic stable renal transplant recipients. Transplantation 1999; 68:257-61. [PMID: 10440398 DOI: 10.1097/00007890-199907270-00017] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Although several studies have demonstrated an unadjusted association between folate status and fasting plasma total homocysteine (tHcy) levels among renal transplant recipients, no data confirming the strength or independence of this association have been reported. METHODS We determined fasting plasma folate, B12, and pyridoxal 5'-phosphate (active vitamin B6) levels, along with other potential determinants of plasma tHcy levels (i.e., age, sex, creatinine levels, and Cockcroft-Gault estimated creatinine clearance, current immunosuppressive regimen, and history of clinical cardiovascular disease), among 86 renal transplant recipients. The recipients were > or =6 months after transplantation, lived in the Providence, Rhode Island metropolitan area, and were examined between February and June 1998. RESULTS Stepwise general linear modeling with analysis of covariance revealed that only creatinine level, age, and vitamin status were independent regressors (i.e., P<0.100) of tHcy levels. Moreover, creatinine level alone determined most of the variability in tHcy levels (i.e., R2) accounted for by these independent variables (R2=0.416 for creatinine level alone; total R2=0.575). In contrast, the R2 for folate alone was only 0.046, and even for all three B vitamins combined, the R2 was just 0.088. CONCLUSIONS We conclude that renal function is the overriding independent determinant of fasting tHcy levels among stable renal transplant recipients. In comparison to renal function, vitamin status has a relatively marginal influence on tHcy levels and cyclosporine use has essentially none at all.
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Affiliation(s)
- A G Bostom
- Division of General Internal Medicine, Memorial Hospital of Rhode Island, Providence 02860, USA.
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59
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Vychytil A, Födinger M, Papagiannopoulos M, Wölfl G, Hörl WH, Sunder-Plassmann G. Peritoneal elimination of homocysteine moieties in continuous ambulatory peritoneal dialysis patients. Kidney Int 1999; 55:2054-61. [PMID: 10231471 DOI: 10.1046/j.1523-1755.1999.00437.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The amount of total homocysteine eliminated by peritoneal dialysis and its relationship to peritoneal transport characteristics in continuous ambulatory peritoneal dialysis (CAPD) patients are unknown. METHODS The influence of total homocysteine, folate, and vitamin B12 plasma concentrations, serum albumin levels, age, sex, dialysate to plasma ratio (D/P) creatinine, D/D0 glucose, D/P albumin, dialysate effluent volume, and effluent albumin on the daily peritoneal excretion of total homocysteine was investigated in 39 CAPD patients. The relationship of D/P creatinine to D/P total homocysteine, D/P free homocysteine, and D/P protein-bound homocysteine was analyzed additionally in a subgroup of 25 patients. RESULTS We observed a significant influence of plasma total homocysteine concentrations (P = 0.0001) of the daily dialysate effluent volume (P = 0.0221) and of the D/P creatinine (P = 0.0132) on peritoneal elimination of total homocysteine. The daily peritoneal excretion of total homocysteine was 38.94 +/- 20.82 mumol (5.27 +/- 2.81 mg). There was a positive linear association of the daily total homocysteine elimination with plasma total homocysteine concentrations (P = 0.0001). A significant linear correlation was observed between D/P creatinine and D/P total homocysteine (P = 0.0001), D/P free homocysteine (P = 0.0001), as well as D/P protein-bound homocysteine (P = 0.0001). CONCLUSIONS The peritoneal elimination of total homocysteine primarily depends on the plasma total homocysteine concentration. Elevated total homocysteine plasma levels cannot be reduced efficiently by peritoneal dialysis.
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Affiliation(s)
- A Vychytil
- Klinische Abteilung für Nephrologie und Dialyse, Universitätsklinik für Innere Medizin III, Vienna, Austria
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60
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Affiliation(s)
- A G Bostom
- Memorial Hospital of Rhode Island, Pawtucket 02860, USA.
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61
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Woodside JV, Fogarty DG, Lightbody JH, Loughrey CM, Yarnell JW, Maxwell AP, Young IS. Homocysteine and B-group vitamins in renal transplant patients. Clin Chim Acta 1999; 282:157-66. [PMID: 10340444 DOI: 10.1016/s0009-8981(99)00023-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Increased plasma homocysteine is an independent risk factor for cardiovascular disease. We have investigated homocysteine and B-group vitamin levels in renal transplant patients. Fasting blood was collected from 55 renal transplant recipients with good renal function and 32 age/sex matched control subjects. Total homocysteine was increased in transplant recipients in comparison to controls (10.9+/-1.5 vs. 6.7+/-1.3 micromol/l, P < 0.001). There was no difference in homocysteine between patients receiving cyclosporin (n = 39, homocysteine 11.0+/-1.5 micromol/l) and patients receiving prednisolone + azathioprine (n = 16, 10.8+/-1.6 micromol/l, mean+/-S.D.), although there was a significant correlation between homocysteine and serum cyclosporin concentration in the sub-group of patients receiving that immunosuppressive regimen (r = 0.42, P < 0.05). Levels of B-group vitamins were similar in patients and controls. Plasma homocysteine is increased in renal transplant recipients even in the presence of minor degrees of renal impairment and normal levels of B-group vitamins.
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Affiliation(s)
- J V Woodside
- School of Clinical Medicine, The Queen's University of Belfast, Northern Ireland, UK
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62
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Tsai MY, Welge BG, Hanson NQ, Bignell MK, Vessey J, Schwichtenberg K, Yang F, Bullemer FE, Rasmussen R, Graham KJ. Genetic causes of mild hyperhomocysteinemia in patients with premature occlusive coronary artery diseases. Atherosclerosis 1999; 143:163-70. [PMID: 10208491 DOI: 10.1016/s0021-9150(98)00271-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Elevated plasma homocysteine is increasingly being recognized as a risk factor for coronary artery disease (CAD). Although there is general agreement on the importance of micronutrients and genetic predisposition to elevated plasma homocysteine, the exact influence of the known prevalent mutations in genes which regulate homocysteine metabolism is not clear. We studied 376 cases of individuals with premature CAD with respect to their fasting and post-methionine load (PML) total homocysteine (tHcy) concentrations. We also determined the presence or absence of the T833C and G919A mutations of the cystathionine-beta-synthase (CBS) gene, the C677T mutation of the methylene tetrahydrofolate reductase (MTHFR) gene, and the A2756G transition of the B12 dependent methionine synthase (MS) gene. Our objectives were therefore both to confirm the relationship of plasma homocysteine with premature CAD and to examine the importance of genetic influence on both fasting and PML homocysteine. Approximately 32% of the CAD patients had fasting hyperhomocysteinemia and 16% had PML hyperhomocysteinemia. Of these, 8.5% had both forms of hyperhomocysteinemia (combined hyperhomocysteinemia). The T133C mutation in the CBS gene and the thermolabile C677T mutation in the MTHFR gene seem to play an important role in the subset of individuals with combined hyperhomocysteinemia. The A2756G transition in the MS gene is not associated with elevated plasma tHcy. Many cases (47%) of hyperhomocysteinemia are not associated with micronutrient deficiencies, impaired renal function, and/or currently known genetic mutations. Further work is needed to study whether unknown mutations, particularly those residing in the intronic sequences of the genes involved in homocysteine metabolism, other environmental factors, or interaction of gene, nutrient, and environmental factors may be the cause of currently unexplained cases of mild hyperhomocysteinemia.
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Affiliation(s)
- M Y Tsai
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis 55455, USA.
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63
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Födinger M, Wölfl G, Fischer G, Rasoul-Rockenschaub S, Schmid R, Hörl WH, Sunder-Plassmann G. Effect of MTHFR 677C>T on plasma total homocysteine levels in renal graft recipients. Kidney Int 1999; 55:1072-80. [PMID: 10027946 DOI: 10.1046/j.1523-1755.1999.0550031072.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Hyperhomocysteinemia is an established, independent risk factor for vascular disease morbidity and mortality. The 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism C677T has been shown to result in increased total homocysteine concentrations on the basis of low folate levels caused by a decreased enzyme activity. The effect of this polymorphism on total homocysteine and folate plasma levels in renal transplant patients is unknown. METHODS We screened 636 kidney graft recipients for the presence of the MTHFR C677T gene polymorphism. The major determinants of total homocysteine and folate plasma concentrations of 63 patients, who were identified to be homozygous for this gene polymorphism compared with heterozygotes (N = 63), and patients with wild-type alleles (N = 63), who were matched for sex, age, glomerular filtration rate (GFR), and body mass index, were identified by analysis of covariance. The variables included sex, age, GFR, body mass index, time since transplantation, folate and vitamin B12 levels, the use of azathioprine, and the MTHFR genotype. To investigate the impact of the kidney donor MTHFR genotype on total homocysteine and folate plasma concentrations, a similar model was applied in 111 kidney graft recipients with stable graft function, in whom the kidney donor C677T MTHFR gene polymorphism was determined. RESULTS The allele frequency of the C677T polymorphism in the MTHFR gene was 0.313 in the whole study population [wild-type (CC), 301; heterozygous (CT), 272; and homozygous mutant (TT), 63 patients, respectively] and showed no difference in the patient subgroups with various renal diseases. The MTHFR C677T gene polymorphism significantly influenced total homocysteine and folate plasma concentrations in renal transplant recipients (P = 0.0009 and P = 0.0002, respectively). Furthermore, a significant influence of the GFR (P = 0.0001), folate levels (P = 0.0001), age (P = 0.0001), body mass index (P = 0.0001), gender (P = 0.0005), and vitamin B12 levels (P = 0.004) on total homocysteine concentrations was observed. The donor MTHFR gene polymorphism had no influence on total homocysteine and folate levels. Geometric mean total homocysteine levels in patients homozygous for the mutant MTHFR allele were 18.6 micromol/liter compared with 14.6 micromol/liter and 14.9 micromol/liter in patients heterozygous for the MTHFR gene polymorphism and those with wild-type alleles (P < 0.05 for TT vs. CT and CC). Geometric mean folate levels were lower in CT and TT patients (11.2 and 10.2 nmol/liter) compared with CC patients (13.6 nmol/liter, P < 0.05 vs. CT and TT). CONCLUSIONS This study demonstrates that homozygosity for the C677T polymorphism in the MTHFR gene significantly increases total homocysteine concentrations and lowers folate levels in kidney graft recipients, even in patients with excellent renal function (GFR more than median). These findings have important implications for risk evaluation and vitamin intervention therapy in these patients who carry an increased risk for the development of cardiovascular disease.
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Affiliation(s)
- M Födinger
- Klinisches Institut für Medizinische und Chemische Labordiagnostik, Universität Wien, Vienna, Austria
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van Guldener C, Janssen MJ, de Meer K, Donker AJ, Stehouwer CD. Effect of folic acid and betaine on fasting and postmethionine-loading plasma homocysteine and methionine levels in chronic haemodialysis patients. J Intern Med 1999; 245:175-83. [PMID: 10081520 DOI: 10.1046/j.1365-2796.1999.00430.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To study fasting and postmethionine-loading (increment and decrement) plasma homocysteine levels in end-stage renal disease (ESRD) patients in relation to B-vitamin status and after folic acid treatment without or with betaine. DESIGN Plasma total homocysteine (tHcy) and methionine levels were measured in chronic haemodialysis patients after an overnight fast, and 6 and 24 h after an oral methionine load (0.1 g kg-1). The patients were subsequently randomized to treatment with folic acid 5 mg daily with or without betaine 4 g daily, and the loading test was repeated after 12 weeks. The patients were then re-randomized to treatment with 1 or 5 mg folic acid daily for 40 weeks, after which a third loading test was performed. SETTING Haemodialysis unit of university hospital and centre for haemodialysis. SUBJECTS Twenty-nine consecutive maintenance (> 3 months) haemodialysis patients, not on folic acid supplementation, 26 of whom completed the study. RESULTS At baseline, the mean fasting, the 6 h postload and the 6 h postload increment plasma tHcy levels were increased as compared with those in healthy controls (46.8 +/- 6.9 (SEM), 92.8 +/- 9.1 and 46.0 +/- 4.2 mumol L-1, respectively) and correlated with serum folate (r = -0.42, P = 0.02; r = -0.61, P = 0.001 and r = -0.54, P = 0.003, respectively), but not with vitamin B6 or vitamin B12. At week 12, these variables had all decreased significantly. Betaine did not have additional homocysteine-lowering effects. At week 52, fasting and postload tHcy levels did not differ significantly between patients on 1 or 5 mg folic acid daily. Plasma tHcy half-life and plasma methionine levels after methionine loading were not altered by folic acid treatment. CONCLUSIONS In chronic haemodialysis patients, fasting as well as postmethionine-loading plasma tHcy levels depend on folate status and decrease after folic acid therapy. Increased postload homocysteine levels in these patients therefore do not necessarily indicate an impaired transsulphuration capacity only; alternatively, folate may indirectly influence transsulphuration. The elucidation of the complex pathogenesis of hyperhomocysteinaemia in chronic renal failure requires further investigation.
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Affiliation(s)
- C van Guldener
- Department of Nephrology, Vrije Universiteit, Amsterdam, The Netherlands
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65
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Bostom AG, Gohh RY, Bausserman L, Hakas D, Jacques PF, Selhub J, Dworkin L, Rosenberg IH. Serum cystatin C as a determinant of fasting total homocysteine levels in renal transplant recipients with a normal serum creatinine. J Am Soc Nephrol 1999; 10:164-6. [PMID: 9890323 DOI: 10.1681/asn.v101164] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Serum creatinine, a surrogate for both renal function and homocysteine generation, is an important determinant of fasting plasma total homocysteine levels in stable renal transplant recipients. In this study, it is hypothesized that among stable renal transplant recipients with normal creatinine levels (i.e., < or = 1.5 mg/dl), serum cystatin C, a more sensitive indicator of GFR, would better predict fasting total homocysteine levels compared with serum creatinine. Fasting plasma total homocysteine, folate, vitamin B12, and pyridoxal 5'-phosphate levels, along with serum cystatin C, creatinine, and albumin levels, were determined in 28 consecutive renal transplant recipients (mean age 47 +/- 14 yr; 60.7% men) with stable allograft function, whose serum creatinine was < or = 1.5 mg/dl. General linear modeling with analysis of covariance revealed that serum cystatin C was independently predictive (partial R = 0.494; P = 0.023) of fasting total homocysteine levels after adjustment for age, gender, vitamin status, albumin, and creatinine levels. In contrast, creatinine levels were not predictive of fasting total homocysteine levels in this model (P = 0.110) or an identical model that excluded cystatin C (P = 0.131). Serum cystatin C levels may reflect subtle decreases in renal function that independently predict fasting total homocysteine levels among stable renal transplant recipients with a normal serum creatinine.
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Affiliation(s)
- A G Bostom
- Division of General Internal Medicine, Memorial Hospital of Rhode Island, Providence, USA.
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66
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Cole DEC, Ross HJ, Evrovski J, Langman LJ, Miner SES, Daly PA, Wong PY. Correlation between total homocysteine and cyclosporine concentrations in cardiac transplant recipients. Clin Chem 1998. [DOI: 10.1093/clinchem/44.11.2307] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Increased circulating total homocysteine (tHcy) has been implicated as an independent risk factor for atherosclerotic disease. In cardiac transplant patients, accelerated coronary atherosclerosis is an important cause of late allograft failure; however, studies of tHcy in this at-risk group are limited. We sampled a cohort of 72 subjects 3.95 ± 3.14 (mean ± SD) years after transplantation and found that all had tHcy concentrations above our upper reference limit (15.0 μmol/L). The mean tHcy in the transplant group (25.4 ± 7.1 μmol/L) was significantly greater than in our reference group (9.0 ± 4.3 μmol/L; n = 457; P <0.001). We also examined the effect of age, gender, time since transplant, serum folate and cobalamin, total protein, urate, creatinine, albumin, and trough whole blood cyclosporine concentrations. In a multiple linear regression model, only creatinine (mean 144 ± 52 μmol/L; P = 0.021) and trough cyclosporine concentrations (191 ± 163 μg/L; P = 0.015) were independent positive predictors of tHcy, whereas serum folate (8.35 ± 7.43 nmol/L; P = 0.018) and time since transplant (P = 0.049) were significant negative predictors. We conclude that hyperhomocysteinemia is a common characteristic of cardiac transplant recipients. Our analysis suggests that folate and renal glomerular dysfunction are important contributory factors; however, whole blood cyclosporine concentrations may also predict the degree of hyperhomocysteinemia in this population and therefore influence interpretation of any apparent response to treatment.
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Affiliation(s)
- David EC Cole
- Departments of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Medicine, University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Pediatrics (Genetics), University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Laboratories, The Toronto Hospital, Toronto, Ontario, Canada M5G 2C4
- Departments of Medicine, The Toronto Hospital, Toronto, Ontario, Canada M5G 2C4
| | - Heather J Ross
- Departments of Medicine, University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Medicine, The Toronto Hospital, Toronto, Ontario, Canada M5G 2C4
| | - Jovan Evrovski
- Departments of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1L5
| | - Loralie J Langman
- Departments of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Laboratories, The Toronto Hospital, Toronto, Ontario, Canada M5G 2C4
| | - Steven ES Miner
- Departments of Medicine, University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Medicine, The Toronto Hospital, Toronto, Ontario, Canada M5G 2C4
| | - Paul A Daly
- Departments of Medicine, University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Medicine, The Toronto Hospital, Toronto, Ontario, Canada M5G 2C4
| | - Pui-Yuen Wong
- Departments of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada M5G 1L5
- Departments of Laboratories, The Toronto Hospital, Toronto, Ontario, Canada M5G 2C4
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67
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Kronenberg F. Homocysteine, lipoprotein(a) and fibrinogen: metabolic risk factors for cardiovascular complications of chronic renal disease. Curr Opin Nephrol Hypertens 1998; 7:271-8. [PMID: 9617557 DOI: 10.1097/00041552-199805000-00006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
High plasma concentrations of homocysteine, lipoprotein(a) and fibrinogen are accompanied by an increased risk for cardiovascular complications in the general population. All three parameters are markedly elevated in patients with renal disease, a group with a high prevalence and incidence of cardiovascular complications. This review discusses these parameters in such patients in relation to the occurrence of atherosclerotic complications.
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Affiliation(s)
- F Kronenberg
- Institute of Medical Biology and Human Genetics, University of Innsbruck, Austria.
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68
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Bostom AG, Shemin D, Gohh RY, Verhoef P, Nadeau MR, Bianchi LA, Hopkins-Garcia BJ, Jacques PF, Selhub J, Dworkin L, Rosenberg IH. Lower fasting total plasma homocysteine levels in stable renal transplant recipients versus maintenance dialysis patients. Transplant Proc 1998; 30:160-2. [PMID: 9474989 DOI: 10.1016/s0041-1345(97)01219-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- A G Bostom
- Vitamin Bioavailability Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Boston, Massachusetts, USA
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