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- Held, Claes, 1956-, et al.
(författare)
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Correlations between plasma homocysteine and folate concentrations and carotid atherosclerosis in high-risk individuals : baseline data from the Homocysteine and Atherosclerosis Reduction Trial (HART)
- 2008
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Ingår i: Vascular Medicine. - 1358-863X .- 1477-0377. ; 13:4, s. 245-253
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Tidskriftsartikel (refereegranskat)abstract
- Homocysteine has been proposed as a risk factor for atherosclerosis. The association between plasma total homocysteine (tHcy) concentration and carotid atherosclerosis has not been thoroughly studied in high-risk populations with vascular disease. For this study, carotid atherosclerosis was assessed by measurements of carotid intima-media thickness (IMT) and plaque calcification in 923 patients with vascular disease or diabetes. Associations with tHcy and plasma folate concentrations were examined. The mean and single maximum carotid IMT were 1.27 +/- 0.34 mm and 2.41 +/- 0.83 mm, respectively. The mean segment plaque calcification score was 27.8%. tHcy correlated with mean (r = 0.13; p < 0.001) and single maximum (r = 0.12; p < 0.001) carotid IMT. There was a progressive increase in mean and single maximum carotid IMT across quartiles of tHcy (p < 0.0001 for trend). These associations were no longer significant after adjusting for other CV risk factors. A trend towards an inverse association between plasma folate and mean max carotid IMT was found in both univariate and multivariable analyses. However, the plaque calcification score increased across quartiles of tHcy (p < 0.01) and decreased across quartiles of plasma folate concentrations (p < 0.05) after multiple adjustments. In conclusion, in high-risk individuals, tHcy and low folate concentrations were only weakly associated with carotid IMT. In contrast, we found an independent association with the plaque calcification score, a measure of more advanced atherosclerosis. The effect of tHcy lowering on carotid atherosclerosis and stroke prevention warrants further investigation.
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| 2. |
- Mann, Johannes F. E., et al.
(författare)
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Homocysteine lowering with folic acid and B vitamins in people with chronic kidney disease : results of the renal Hope-2 study
- 2008
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 23:2, s. 645-653
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Elevated plasma homocysteine levels are reported to be associated with higher rates of vascular diseases. Plasma homocysteine increases in chronic kidney disease (CKD) and could contribute to the increased cardiovascular risk in CKD. METHODS: Participants aged 55 years or older with CKD, defined as estimated GFR<60 ml/min and at high cardiovascular risk, were randomly assigned to the combination of folic acid, 2.5 mg, vitamin B6, 50 mg and vitamin B12, 1 mg (n = 307) or placebo (n = 312) daily for 5 years. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction and stroke. RESULTS: Mean baseline plasma homocysteine was 15.9 +/- 7.3 micromol/l in the active treatment group and 15.7 +/- 5.7 micromol/l in placebo group and decreased to 11.9 +/- 3.3 micromol/l (P < 0.001) on active treatment (15.5 +/- 4.5 on placebo). Primary outcome events occurred in 90 participants (29.3%) on active therapy and in 80 (25.6%) on placebo (relative risk, 1.19; 95% confidence interval, 0.88-1.61; P = 0.25). There were no significant treatment benefits on death from cardiovascular causes (1.24; 0.84-1.83), myocardial infarction (1.10; 0.76-1.61) and stroke (1.00; 0.54-1.85). More participants in the active treatment group were hospitalized for heart failure (1.98; 1.21-3.26; P = 0.007) and for unstable angina (1.70; 1.02-2.83; P = 0.04). Incidence of primary outcome increased with decreasing GFR. CONCLUSIONS: Active treatment with B vitamins lowered homocysteine levels in participants with CKD but did not reduce cardiovascular risk.
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| 3. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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