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Background: Hyperhomocysteinaemia is an independent risk factor for atherosclerosis and is thought to induce its effects through causing endothelial dysfunction. We studied the effect of homocysteine-lowering treatment with folic acid plus vitamin B6 on urinary and plasma markers of endothelial function, and on plasma C-reactive protein, a marker of chronic inflammation., Design: We performed a placebo-controlled 2-year trial among 158 healthy siblings of patients with premature atherosclerotic disease to determine the effect of daily folic acid (5 mg) plus vitamin B6 (250 mg) treatment as compared with placebo medication (n = 80) on markers of endothelial function (urinary albumin-to-creatinine ratio and plasma concentrations of soluble E-selectin, soluble vascular cell adhesion molecule-1, von Willebrand factor, tissue-type plasminogen activator and plasminogen activator inhibitor-1) and inflammation (C-reactive protein). Outcome variables were assessed at baseline and after 1 and 2 years of treatment., Results: Fasting homocysteine concentrations ( micromol L-1) at baseline and after treatment were 14.7 +/- 8.2 and 7.4 +/- 1.9 in the vitamin and 14.7 +/- 8.8 and 12.0 +/- 5.4 for the placebo group, respectively. Vitamin treatment was associated with a decreased urinary albumin-to-creatinine ratio at follow up [regression coefficient (beta) -0.20 mg mmol-1 (CI: -0.43-0.03); P = 0.09]. After adjustment for age, sex, baseline concentrations of postmethionine total homocysteine plus the baseline albumin-to-creatinine ratio, the beta was -0.23 mg mmol-1 (CI: -0.43 to -0.02; P = 0.03), which amounts to a decrease of approximately 20%. There was no apparent effect of vitamin treatment on the other markers., Conclusions: Homocysteine-lowering vitamin treatment in healthy siblings of patients with premature atherosclerotic disease is associated with a decreased urinary albumin-to-creatinine ratio, but not with other markers of endothelial dysfunction, or in plasma C-reactive protein. The clinical significance of these findings remains to be determined.

The aim of this study was to determine whether the morphology of the muscular femoral artery in patients with atherosclerosis and hyperhomocysteinemia differs from that of atherosclerotic vessels from patients with normal homocysteine levels. Whole-vessel biopsies of the superficial femoral artery were taken from patients with symptomatic atherosclerotic disease with and without hyperhomocysteinemia and from patients without atherosclerosis from traumatic amputations. The morphology of these specimens was studied qualitatively by light and electron microscopy and quantitatively by light microscopy in combination with a video overlay system. Atherosclerotic lesions in patients with hyperhomocysteinemia were morphologically similar to those in patients with normal homocysteine levels, except for a significantly decreased smooth muscle cell/extracellular matrix ratio of the media in hyperhomocysteinemic patients (P=0.02 versus normohomocysteinemic atherosclerotic group and P=0.001 versus group without a history of cardiovascular disease). Hyperhomocysteinemia is associated with a significant decrease of the smooth muscle cell/extracellular matrix ratio of the media of muscular femoral arteries without significant changes in medial thickness. Further investigations should concentrate on the cause of this newly discovered phenomenon and its impact on vascular compliance.

Background: Mild hyperhomocysteinaemia (HHC) is associated with an increased risk of premature atherothrombotic cerebrovascular disease. We investigated the clinical efficacy with regard to the incidence of cardiovascular events of treatment of mild HHC with vitamin B(6) plus folic acid., Methods: We studied 224 consecutive patients with clinically manifest atherothrombotic cerebrovascular disease with onset before the age of 56. Follow-up was obtained in 203 (90.6%) patients. At baseline, 52 (25.6%) were hyperhomocysteinaemic after methionine loading and started treatment with vitamin B(6) (250 mg) plus folic acid (5 mg); 151 (74.4%) were normohomocysteinaemic (reference group)., Results: During follow-up (median 57 months), 31 (20.5%) of the normo- and 11 (21.2%) of the hyperhomocysteinaemic patients had a new cardiovascular event. The crude incidence rate per person-year for any cardiovascular event was similar in both groups (0.043 [CI, 0.029-0.057] in the normo- vs. 0.045 [CI, 0.021-0. 069] in the hyperhomocysteinaemic group). Multivariate Cox-regression analyses showed that hypertension and cholesterol levels were associated with an increased risk of new cardiovascular events in the total group [relative risk [RR] (yes vs. no), 7.4 (3. 4-16.0) and RR (per 1 mmol/l), 1.9 (CI, 1.4-2.7)]. The adjusted RR for new cardiovascular events in the hyper- as compared to the normohomocysteinaemic patients was 0.96 (CI, 0.48-1.92)., Conclusion: These data are consistent with a protective effect of treatment with vitamin B(6) plus folic acid in patients with premature atherothrombotic cerebrovascular disease and post-methionine HHC.

Background: A high plasma homocysteine concentration is associated with increased risk of atherothrombotic disease. We investigated the effects of homocysteine-lowering treatment (folic acid plus vitamin B6) on markers of subclinical atherosclerosis among healthy siblings of patients with premature atherothrombotic disease., Methods: We did a randomised, placebo-controlled trial among 158 healthy siblings of 167 patients with premature atherothrombotic disease. 80 were assigned placebo and 78 were assigned 5 mg folic acid and 250 mg vitamin B6 daily for 2 years. The primary endpoint was the development or progression of subclinical atherosclerosis as estimated from exercise electrocardiography, the ankle-brachial pressure index, and carotid and femoral ultrasonography., Findings: Ten participants in the treatment group, and 14 in the placebo group dropped out. Vitamin treatment, compared with placebo, was associated with a decrease in fasting homocysteine concentration (from 14.7 to 7.4 micromol/L vs from 14.7 to 12.0 micromol/L), and in postmethionine homocysteine concentration (from 64.9 to 34.9 micromol/L vs from 64.8 to 50.3 micromol/L). It was also associated with a decreased rate of abnormal exercise electrocardiography tests (odds ratio 0.40 [0.17-0.93]; p=0.035). There was no apparent effect of vitamin treatment on ankle-brachial pressure indices (0.87 [0.56-1.33]), or on carotid and peripheral-arterial outcome variables (1.02 [0.26-4.05] and 0.86 [0.47-1.59], respectively)., Interpretation: Homocysteine-lowering treatment with folic acid plus vitamin B6 in healthy siblings of patients with premature atherothrombotic disease is associated with a decreased occurrence of abnormal exercise electrocardiography tests, which is consistent with a decreased risk of atherosclerotic coronary events.