The effect of long-term homocysteine-lowering on carotid intima-media thickness and flow-mediated vasodilation in stroke patients: a randomized controlled trial and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Experimental and epidemiological evidence suggests that homocysteine (tHcy) may be a causal risk factor for atherosclerosis. B-vitamin supplements reduce tHcy and improve endothelial function in short term trials, but the long-term effects of the treatment on vascular structure and function are unknown.</p> <p>Methods</p> <p>We conducted a sub-study of VITATOPS, a randomised, double-blind, placebo-controlled intervention trial designed to test the efficacy of long term B-vitamin supplementation (folic acid 2 mg, vitamin B₆25 mg and vitamin B₁₂0.5 mg) in the prevention of vascular events in patients with a history of stroke. We measured carotid intima-medial thickness (CIMT) and flow-mediated dilation (FMD) at least two years after randomisation in 162 VITATOPS participants. We also conducted a systematic review and meta-analysis of studies designed to test the effect of B-vitamin treatment on CIMT and FMD.</p> <p>Results</p> <p>After a mean treatment period of 3.9 ± 0.9 years, the vitamin-treated group had a significantly lower mean plasma homocysteine concentration than the placebo-treated group (7.9 μmol/L, 95% CI 7.5 to 8.4 versus 11.8 μmol/L, 95% CI 10.9 to 12.8, p < 0.001). Post-treatment CIMT (0.84 ± 0.17 mm vitamins versus 0.83 ± 0.18 mm placebo, p = 0.74) and FMD (median of 4.0%, IQR 0.9 to 7.2 vitamins versus 3.0%, IQR 0.6 to 6.6 placebo, p = 0.48) did not differ significantly between groups. A meta-analysis of published randomised data, including those from the current study, suggested that B-vitamin supplements should reduce CIMT (-0.10 mm, 95% CI -0.20 to -0.01 mm) and increase FMD (1.4%, 95% CI 0.7 to 2.1%). However, the improvement in endothelial function associated with homocysteine-lowering treatment was significant in short-term studies but not in longer trials.</p> <p>Conclusion</p> <p>Although short-term treatment with B-vitamins is associated with increased FMD, long-term homocysteine-lowering did not significantly improve FMD or CIMT in people with a history of stroke.</p> <p>Trial Registration</p> <p>Clinical Trial Registration URL: <url>http://www.actr.org.au/</url></p> <p>Trial Registration number: 12605000005651</p

Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild cognitive impairment (review)

This review investigated whether people with mild cognitive impairment can reduce their risk of developing dementia, or can prevent their memory or other thinking skills from deteriorating further, by taking vitamin or mineral supplements

Guidelines for management of ischaemic stroke and transient ischaemic attack 2008

This article represents the update of the European Stroke Initiative Recommendations for Stroke Management. These guidelines cover both ischaemic stroke and transient ischaemic attacks, which are now considered to be a single entity. The article covers referral and emergency management, Stroke Unit service, diagnostics, primary and secondary prevention, general stroke treatment, specific treatment including acute management, management of complications, and rehabilitation

Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals.

BACKGROUND: Elevated plasma homocysteine is a risk factor for Alzheimer disease, but the relevance of homocysteine lowering to slow the rate of cognitive aging is uncertain. OBJECTIVE: The aim was to assess the effects of treatment with B vitamins compared with placebo, when administered for several years, on composite domains of cognitive function, global cognitive function, and cognitive aging. DESIGN: A meta-analysis was conducted by using data combined from 11 large trials in 22,000 participants. Domain-based z scores (for memory, speed, and executive function and a domain-composite score for global cognitive function) were available before and after treatment (mean duration: 2.3 y) in the 4 cognitive-domain trials (1340 individuals); Mini-Mental State Examination (MMSE)-type tests were available at the end of treatment (mean duration: 5 y) in the 7 global cognition trials (20,431 individuals). RESULTS: The domain-composite and MMSE-type global cognitive function z scores both decreased with age (mean ± SE: -0.054 ± 0.004 and -0.036 ± 0.001/y, respectively). Allocation to B vitamins lowered homocysteine concentrations by 28% in the cognitive-domain trials but had no significant effects on the z score differences from baseline for individual domains or for global cognitive function (z score difference: 0.00; 95% CI: -0.05, 0.06). Likewise, allocation to B vitamins lowered homocysteine by 26% in the global cognition trials but also had no significant effect on end-treatment MMSE-type global cognitive function (z score difference: -0.01; 95% CI: -0.03, 0.02). Overall, the effect of a 25% reduction in homocysteine equated to 0.02 y (95% CI: -0.10, 0.13 y) of cognitive aging per year and excluded reductions of >1 mo per year of treatment. CONCLUSION: Homocysteine lowering by using B vitamins had no significant effect on individual cognitive domains or global cognitive function or on cognitive aging

VITATOPS, the VITAmins TO Prevent Stroke Trial: Rationale and design of a randomised trial of B-vitamin therapy in patients with recent transient ischaemic attack or stroke (NCT00097669) (ISRCTN74743444)

Background Epidemiological studies suggest that raised plasma concentrations of total homocysteine (tHcy) may be a common, causal and treatable risk factor for atherothromboembolic ischaemic stroke, dementia and depression. Although tHcy can be lowered effectively with small doses of folic acid, vitamin B12 and vitamin B6, it is not known whether lowering tHcy, by means of B vitamin therapy, can prevent stroke and other major atherothromboembolic vascular events. Aim To determine whether the addition of B-vitamin supplements (folic acid 2 mg, B6 25 mg, B12 500 μg) to best medical and surgical management will reduce the combined incidence of stroke, myocardial infarction (MI) and vascular death in patients with recent stroke or transient ischaemic attack (TIA) of the brain or eye. Design A prospective, international, multicentre, randomised, double blind, placebo-controlled clinical trial. Setting One hundred and four medical centres in 20 countries on five continents. Subjects Eight thousand (6600 recruited as of 5 January, 2006) patients with recent (7 months) stroke (ischaemic or haemorrhagic) or TIA (brain or eye). Randomisation Randomisation and data collection are performed by means of a central telephone service or secure internet site. Intervention One tablet daily of either placebo or B vitamins (folic acid 2mg, B6 25 mg, B12 500 μg). Primary outcome The composite of stroke, MI or death from any vascular cause, whichever occurs first. Outcome and serious adverse events are adjudicated blinded to treatment allocation. Secondary outcomes TIA, unstable angina, revascularisation procedures, dementia, depression. Statistical power With 8000 patients followed up for a median of 2 years and an annual incidence of the primary outcome of 8% among patients assigned placebo, the study will have at least 80% power to detect a relative reduction of 15% in the incidence of the primary outcome among patients assigned B vitamins (to 6·8%/year), applying a two-tailed level of significance of 5%. Conclusion VITATOPS aims to recruit and follow-up 8000 patients between 1998 and 2008, and provide a reliable estimate of the safety and effectiveness of folic acid, vitamin B12, and vitamin B6 supplementation in reducing recurrent serious vascular events among a wide range of patients with TIA and stroke throughout the world. The VITATOPS Trial Study Grou