Relation of plasma homocyst(e)ine to cerebral infarction and cerebral atherosclerosis

A bibliometric analysis of the 100 most-cited clinical articles in the research of intracranial artery stenosis and intracranial atherosclerosis

Background

Intracranial arterial stenosis (ICAS), caused by intracranial atherosclerosis, is one of the major causes of ischemic stroke. This study identified the top 100 most-cited publications on ICAS through a bibliometric analysis.

Methods

Two independent authors conducted a search in the Web of Science database for clinical articles on ICAS published between 1993 and 2022. The top 100 most-cited articles were then extracted. For each article, the analysis covered the title, author, country of origin/affiliation, journal, total number of citations, number of citations per year, and type of study.

Results

The top 100 most-cited papers in the ICAS were authored by 565 authors from 12 countries and published in 29 journals. In terms of the 5-year trend, the largest number of papers were published between 2003 and 2007 (n = 31). The median number of citations for the 100 papers was 161 (range 109-1,115). The journal with the highest proportion of the 100 most published articles was Stroke, accounting for 41% of articles and 37% of the citations. According to country of origin, the United States of America accounted for the largest number of articles, followed by China, Japan, and South Korea, with these four countries together accounting for 81% of the total number of articles and 88% of the citations. Trends in the past five years included the use of terms such as acute ischemic stroke and mechanical thrombectomy.

Conclusion

The findings of this study provide novel insight into this field and will facilitate future research endeavors.

Hyperhomocysteinemia and Ischemic Stroke: A Potential Dose-Response Association-A Systematic Review and Meta-analysis

Background and Purpose  Previous studies suggest an association between increased homocysteine (Hcy) and risk of ischemic stroke. Yet, it remains unknown whether a dose-response association exists between Hcy levels and risk of ischemic stroke. Methods  Systematic literature searches were performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were studies investigating ischemic stroke risk in an adult population with measured Hcy levels. We computed odds ratios (ORs) for a 5 µmol/L increase in Hcy levels using a random effects meta-analysis. Results  In total, 108 studies met the inclusion criteria of which 22 were rated as high-quality studies, and 20 studies included a dose-response analysis. Hcy levels were analyzed either as a continuous or categorical variable. The majority of the studies found an increased risk of ischemic stroke when comparing the highest-to-lowest Hcy strata. A graded association was observed over the Hcy strata, indicating a dose-response association, with the most apparent effect when Hcy levels exceeded approximately 15 µmol/L. No studies explored a potential nonlinear association between Hcy levels and ischemic stroke. Six studies were included in a meta-analysis, showing an OR of 1.43 (95% confidence interval [CI]: 1.28-1.61) per 5 µmol/L increase in Hcy levels. Conclusion  This review and meta-analysis indicate a dose-response association between Hcy levels and ischemic stroke. An evident increase in effect measures was observed when Hcy levels exceeded 15 µmol/L, indicating a nonlinear association between ischemic stroke and Hcy levels. This nonlinear association warrants further study. This study is registered with clinical trial ( https://www.crd.york.ac.uk/prospero/ ; unique identifier: CRD42019130371).

The Antioxidant Role of One-Carbon Metabolism on Stroke

One-carbon (1C) metabolism is a metabolic network that is centered on folate, a B vitamin; it integrates nutritional signals with biosynthesis, redox homeostasis, and epigenetics. This metabolic pathway also reduces levels of homocysteine, a non-protein amino acid. High levels of homocysteine are linked to increased risk of hypoxic events, such as stroke. Several preclinical studies have suggested that 1C metabolism can impact stroke outcome, but the clinical data are unclear. The objective of this paper was to review preclinical and clinical research to determine whether 1C metabolism has an antioxidant role on stroke. To accomplish the objective, we searched for publications using the following medical subject headings (MeSH) keywords: antioxidants, hypoxia, stroke, homocysteine, one-carbon metabolism, folate, methionine, and dietary supplementation of one-carbon metabolism. Both pre-clinical and clinical studies were retrieved and reviewed. Our review of the literature suggests that deficiencies in 1C play an important role in the onset and outcome of stroke. Dietary supplementation of 1C provides beneficial effects on stroke outcome. For stroke-affected patients or individuals at high risk for stroke, the data suggest that nutritional modifications in addition to other therapies could be incorporated into a treatment plan.

Elevated homocysteine as an independent risk for intracranial atherosclerotic stenosis

To investigate the association of homocysteine concentration with intracranial atherosclerotic stenosis (ICAS), we assessed 933 acute ischemic stroke patients (346 with ICAS, 587 without ICAS) and 798 non-stroke controls (175 with ICAS, 623 without ICAS) with magnetic resonance angiography (MRA). Homocysteine concentration was found to be significantly higher in participants with ICAS than those without ICAS. In logistic regression analyses, homocysteine concentration was significantly associated with ICAS both in patients (OR: 1.04; 95% CI: 1.01–1.08; P=0.008) and controls (OR: 1.10; 95% CI: 1.06–1.15; P<0.001) for 1 μmol/L increment in homocysteine. Compared with the lowest quartile, the second (OR:1.53; 95% CI: 1.01-2.33), third (OR:1.71; 95% CI: 1.14 -2.60) and fourth (OR:2.48; 95%CI: 1.63-3.81) quartiles were independent predictors of ICAS in patients (P for trend<0.001); the third (OR:1.99; 95% CI: 1.18-3.40) and fourth (OR:2.36; 95%CI: 1.38-4.10) quartiles were independent predictors of ICAS in controls (P for trend<0.001). Hence, elevated homocysteine might be an independent risk for ICAS.

Association between homocysteine and multivascular atherosclerosis in stroke-related vascular beds determined by three-dimensional magnetic resonance vessel wall imaging

BACKGROUND

Atherosclerosis in stroke-related vascular beds is the major cause of stroke. Studies demonstrated that multivascular atherosclerosis is prevalent in stroke patients and those with multivascular plaques had higher risk of recurrent stroke.

OBJECTIVES

This study investigated the relationship between homocysteine and multivascular atherosclerosis in stroke-related vascular beds using magnetic resonance imaging.

METHODS

Patients with recent ischemic cerebrovascular symptoms were enrolled and underwent three-dimensional magnetic resonance vessel wall imaging for intracranial arteries, extracranial carotid arteries and aortic arch. Traditional risk factors and homocysteine were measured. Presence of multivascular plaques defined as plaques in at least two stroke-related vascular beds on magnetic resonance imaging was determined. The relationship between homocysteine and characteristics of multivascular plaques was determined.

RESULTS

Of 49 enrolled patients (mean age: 56.3 ± 13.8 years; 35 males), 23 had multivascular plaques. Homocysteine (odds ratio, 1.17; 95% confidence interval, 1.02-1.34; p = 0.022) and age (odds ratio, 1.71; 95% confidence interval, 1.22-2.41; p = 0.002) were significantly associated with presence of multivascular plaques. The adjusted associations remained significant (both p < 0.05). In discriminating presence of multivascular plaques, the area-under-the-curve of age, homocysteine and combination of them was 0.79, 0.70 and 0.87 respectively.

CONCLUSIONS

Homocysteine is independently associated with stroke-related multivascular plaques and combination of age and homocysteine has stronger predictive value.

Small Vessel Cerebrovascular Pathology Identified by Magnetic Resonance Imaging Is Prevalent in Alzheimer's Disease and Mild Cognitive Impairment: A Potential Target for Intervention

BACKGROUND

There is evidence that Alzheimer's disease (AD) has significant cerebrovascular etiopathogenesis. Understanding potentially modifiable risk factors for vascular disease can help design long-term intervention strategies for controlling or preventing cognitive dysfunction attributable to cerebrovascular disease.

OBJECTIVE

To evaluate the presence and severity of markers of cerebrovascular pathology, its relationship to diagnostic categories of dementia, including AD, and association with the metabolic biomarker homocysteine.

METHODS

In a cross-sectional observational study, 340 community-dwelling elders received a clinical evaluation including brain MRI and neuropsychological tests. Dementia and mild cognitive impairment (MCI) were diagnosed by consensus committee. Fasting total plasma homocysteine was measured. Statistical analyses were adjusted for demographics and cerebrovascular risk factors.

RESULTS

Nearly 25% of those diagnosed with AD had small vessel infarcts (SVI). Periventricular white matter hyperintensity (pvWMHI) was prevalent in participants with AD (61%) or MCI (amnesic 61% and non-amnesic 54%, respectively). Participants with SVI and/or pvWMHI also had greater brain atrophy. Homocysteine concentrations were higher in individuals with cerebrovascular findings than in those without. In individuals with cerebrovascular disease, homocysteine was inversely related to executive function (p = 0.022) and directly related to degree of brain atrophy (p = 0.009).

CONCLUSIONS

We demonstrated a significant prevalence of small vessel markers of cerebrovascular pathology in individuals diagnosed with AD, with a significant concurrence between cerebrovascular disease and brain and ventricular atrophy. While current research on AD has focused on amyloid-βpeptide deposition, tau-pathology, and microglial activation and inflammation, greater attention to the cerebrovascular contribution to this neurodegenerative disease presents an additional target for therapeutic prevention and intervention.

Correlation analysis between 25-hydroxyvitamin D3, vitamin B12 and vitamin C and endothelial function of patients with CHD

The aim of the study was to investigate the correlation between levels of 25-hydroxyvitamin D3, vitamin B12 and C and endothelial function of patients with coronary heart disease (CHD). Forty patients with CHD diagnosed in Shanghai Tenth People's Hospital from May 2016 to April 2017 were selected as the observation group. A total of 45 healthy individuals were selected as the control group. The participants included 54 males and 31 females. General information was collected. Peripheral serum biochemical indicators, levels of 25-hydroxyvitamin D3, vitamin B12 and C, homocysteine (Hcy), nitric oxide (NO) and endothelial NOS (eNOS) were measured. Arterial lesions detected by coronary angiography were recorded and indexes of observation and control group were compared for the correlation analysis. A proportion of hypertensive patients and their body mass index (BMI) were significantly higher in the observation than in the control group (P<0.05). Levels of 25-hydroxyvitamin D3, vitamin B12 and C in peripheral blood of observation were significantly lower than those of the control group (P<0.05). Compared with the control group, incidence of single-branch lesion and non-lesion rate were significantly lower, but incidence of double- and triple-branch lesions were significantly higher in observation than in control group (P<0.05). In addition, the level of Hcy in the observation group was higher than that in the control group, but levels of NO and eNOS in observation were significantly lower than those in control group (P<0.05. The correlation analysis revealed that 25-hydroxyvitamin D3 (r=0.792, P<0.01), vitamin B12 (r=0.635, P<0.01) and vitamin C (r=0.703, P<0.01) were negatively correlated with serum NO level. Thus, hypertension, BMI, 25-hydroxyvitamin D3, vitamin B12 and C have independent predictive value for coronary endothelial dysfunction (P<0.05). In conclusion, serum levels of 25-hydroxyvitamin D3, vitamin B12 and C are closely related to vascular endothelial dysfunction in patients with CHD and affect the severity of vascular endothelial dysfunction in patients with CHD.

Evaluation of efficacy and safety of Reteplase and Alteplase in the treatment of hyper-acute cerebral infarction

Objective: The present study aimed to investigate the efficacy and safety of Reteplase (rPA) and Alteplase (rt-PA) in the treatment of hyper-acute cerebral infarction (CI).

Methods: Six hundred and eleven patients with hyper-acute CI selected from September 2014 to September 2016 were assigned into the aspirin, rt-PA, rPA, rt-PA + aspirin, and rPA + aspirin groups based on their willingness. The difference of efficacy in five groups were evaluated with National Institute of Health Stroke Scale (NIHSS), modified rankin scale (mRS), and Barthel Index (BI). Coagulation function, blood lipid, and hemodynamics were analyzed. The safety differences were compared by observing the adverse reactions.

Results: Compared with the rt-PA, rPA, and aspirin groups, NIHSS score, mRS score, the incidence of non- and symptomatic cerebral hemorrhage as well as the rate of adverse reactions were decreased, while BI were increased in the rt-PA + aspirin and rPA + aspirin groups after treatment. Compared with the rt-PA and rPA groups, total cholesterol (TC), triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were lower, whereas the hematocrit, whole blood high shear viscosity, whole blood low shear viscosity, plasma viscosity, erythrocyte electrophoresis time, fibrinogen, erythrocyte sedimentation rate (ESR), K value in blood sedimentation equation, and the comprehensive abnormality degree of blood rheology were higher in the rt-PA + aspirin and rPA + aspirin groups.

Conclusion: The efficacy and safety of rt-PA or rPA combined with aspirin in the treatment of hyper-acute CI were better than those of rPA or rt-PA monotherapy.

A metabolomic study on high-risk stroke patients determines low levels of serum lysine metabolites: a retrospective cohort study

Metabolic alteration at early neurological deterioration during cerebral ischemia.

Brain microangiopathy and macroangiopathy share common risk factors and biomarkers

AIMS

Besides carotid or cardiac embolism, stroke can occur via microangiopathy (small arterial disease [SAD]) and macroangiopathy (intracranial atherosclerotic stroke [ICAS]) of the intracranial vasculature. There have been efforts to identify risk factors specific to microangiopathy and macroangiopathy, including vascular risk factors, and protein and genetic biomarkers. We hypothesized that despite the anatomic and pathophysiological differences between microvessels and macrovessels, microangiopathy and macroangiopathy share common risk factors during disease progression.

METHODS

Among 714 patients with acute infarctions within middle cerebral artery territory, 126 with SAD and 116 with ICAS were included in this study. Subclinical microangiopathy (degree of leukoaraiosis) and macroangiopathy (number of tandem stenosis) was graded in each patient. Inflammatory biomarkers (C-reactive protein, E-selectin, and LpPLA2), endothelial dysfunction (asymmetric dimethylarginine, urinary albumin-to-creatinine ratio, endostatin, and homocysteine), atherogenesis (lipoprotein(a), adiponectin, and resistin), and renal function (creatinine clearance and estimated glomerular filtration rate) were assessed.

RESULTS

Compared with the patients with isolated SAD, those with isolated ICAS were younger, were current smokers, and showed higher apoB levels (p < 0.05 in all cases). However, with the progression of subclinical microangiopathy, asymptomatic macroangiopathy worsened and vice versa. No significant differences in risk factors were observed between advanced SAD and ICAS. Decreased renal function was independently associated with progression of microangiopathy and macroangiopathy. Markers of endothelial dysfunction, but not the other markers, were significantly related to creatinine clearance level.

CONCLUSIONS

Mild to moderate loss of renal function is strongly associated with both intracranial microangiopathy and macroangiopathy. Endothelial dysfunction may be associated with this relationship.

Correlations between homocysteine and grey matter volume in patients with Alzheimer's disease

BACKGROUND

Previous studies have reported that elevated total homocysteine levels are associated with cognitive dysfunction. However, few studies have examined the radiological markers of associated neuropathology in Alzheimer's disease (AD). We hypothesized that elevated levels of homocysteine are associated with cerebral grey matter volume loss. We compared the grey matter in a high homocysteine group and a normal homocysteine group using an optimized voxel-based morphometry.

METHODS

The study included 79 patients with AD who were divided into two groups: a high homocysteine group and a normal homocysteine group. The participants underwent brain magnetic resonance imaging using a standardized protocol and neurocognitive evaluation. Homocysteine tests and other routine laboratory examinations for dementia assessment were carried out in all patients.

RESULTS

There was no significant difference in grey matter volume between the patients with high homocysteine levels and those with normal homocysteine levels. A multiple regression analysis also revealed that the levels of homocysteine were not associated with the grey matter volume in patients with AD. Homocysteine levels were not correlated significantly with Mini-Mental State Examination, Global Deterioration Scale, or Clinical Dementia Rating.

CONCLUSION

Our results showed that elevated homocysteine levels are not associated with reduced cerebral grey matter volume in AD. Larger samples will be needed to assess potential correlations between homocysteine and neuroanatomical pathology in the future.

Serum Levels of High-sensitivity C-Reactive Protein at Admission Are More Strongly Associated with Poststroke Depression in Acute Ischemic Stroke than Homocysteine Levels

Inflammatory processes have fundamental roles in depression. The primary purpose of this study was to assess the serum levels of high-sensitivity C-reactive protein (Hs-CRP) and homocysteine (HCY) at admission to the presence of poststroke depression (PSD). From December 2012 to December 2013, first-ever acute ischemic stroke patients who were admitted to the hospital within the first 24 h after stroke onset were consecutively recruited and followed up for 6 months. Serum levels of Hs-CRP and HCY were tested at admission. Based on the symptoms, diagnoses of depression were made in accordance with DSM-IV criteria for depression at 6 months after stroke. Ninety-five patients (42.0%) showed depression (major + minor) at 6 months after admission, and in 69 patients (30.5%), this depression was classified as major. In the 69 patients with major depression, our results showed significantly higher Hs-CRP and HCY levels at admission than patients without major depression. After adjusting all other possible covariates, Hs-CRP and HCY still were independent predicators of PSD with adjusted OR of 1.332 (95% CI, 1.230-1.452; P < 0.001) and 1.138 (95% CI, 1.072-1.274; P < 0.001), respectively. The area under the receiver operating characteristic curve values of Hs-CRP and HCY were 0.765 (95% CI, 0.701-0.9825) and 0.684 (95% CI, 0.610-0.757) for PSD, respectively. The prognostic accuracy of combined model (HCY and Hs-CRP) was higher compared to those biomarkers alone and other markers. Elevated serum levels of Hs-CRP and HCY at admission were found to be associated with depression 6 months after stroke, suggesting that these alterations might participate in the pathophysiology of depression symptoms in stroke patients.

Discovery of S-adenosyl-L-homocysteine hydrolase inhibitors based on non-adenosine analogs

High throughput screening using Automated Ligand Identification System (ALIS) resulted in the discovery of a new series of S-adenosyl-L-homocysteine hydrolase inhibitors based on non-adenosine analogs. The optimization campaign led to very potent and competitive compound 39 with a Ki value of 1.5 nM. Compound 39 could be a promising lead compound for research to reduce elevated homocysteine levels.

Combination of high-sensitivity C-reactive protein and homocysteine predicts the short-term outcomes of Chinese patients with acute ischemic stroke

BACKGROUND

Ischemic stroke is one of the most common causes of death worldwide. Early and accurate prediction of outcome in acute ischemic stroke (AIS) is important and influences risk-optimized therapeutic strategies. We investigated the changes in high-sensitivity C-reactive protein (Hs-CRP) and homocysteine (HCY) levels, two of the risk factors, during the acute period of AIS and evaluated the relationship between these levels and short-term prognosis.

METHODS

We prospectively studied 189 patients with AIS who were admitted within 24 hours after the onset of symptoms. Serum Hs-CRP, HCY levels, and National Institutes of Health Stroke Scale (NIHSS) were measured at the time of admission. Short-term functional outcome was measured by the modified Rankin scale (mRS), 90 days after admission.

RESULTS

The median serum Hs-CRP and HCY levels were significantly higher in AIS patients as compared to normal controls (P < 0.0001, respectively). High-sensitivity C-reactive protein and HCY were independent prognostic markers of functional outcome and death (adjusted for age and the NIHSS) in patients with AIS. In receiver operating characteristic curve analysis, the prognostic accuracy of the combined model (HCY and Hs-CRP) was higher compared to all measured biomarkers individually and the NIHSS score.

CONCLUSION

High-sensitivity C-reactive protein and HCY are independent predictors of short-term outcome and mortality after AIS. The combined model may provide additional general prognostic information.

Serum level of homocysteine is correlated to carotid artery atherosclerosis in Chinese with ischemic stroke

OBJECTIVES

To investigate the relationship between serum level of homocysteine (Hcy) and carotid artery atheroscleosis (CAA).

METHODS

Both sides of the common carotid artery and internal carotid artery in 126 Chinese patients with ischemic stroke were measured by B-mode ultrasound. The patients were divided into groups: normal, A, B, C and D according to the severity of CAAs. With fasting serum, Hcy as well as folate, vitamin B(12) and lipids were detected. The mean +/- SD age was 64 +/- 13 years (range 39-87 years).

RESULTS

In a logistic regression model, the Hcy concentrations were associated with an elevated risk of CAAs independent of all traditional risk factors, and when CAAs became severer, the serum Hcy was higher. The levels of the normal group and A, B, C, D groups were 13.22 +/- 6.15 micromol/L, 16.29 +/- 9.81 micromol/l, 19.49 +/- 11.16 micromol/l, 27.21 +/- 17.47 micromol/l, and 24.14 +/- 8.64 micromol/l, respectively. Rank test showed a significant difference between normal and other groups (p<0.05). The levels of folate and vitamin B(12) were negatively correlated with the Hcy concentrations. Spearman correlation coefficient were -0.23 and -0.42 (p<0.05).

CONCLUSIONS

Hyperhomocysteinaemia is an independent risk factor of CAAs and the degree of CAAs is highly correlated with the level of Hcy in serum. The causes of hyperhomocysteinemia may be the result from the decrease in folate and vitamin B(12). Clinical trials are now required to evaluate the effect of treatment with these vitamins on the primary and secondary prevention of cerebral vascular diseases.

Ideal cardiovascular health metrics on the prevalence of asymptomatic intracranial artery stenosis: a cross-sectional study

Background and Purpose

Intracranial Artery Stenosis (ICAS) is one of the most common causes of ischemic stroke in Asia. Previous studies have shown the number of ideal cardiovascular health (CVH) metrics was associated with lower risk of stroke. This study aimed to investigate the relationship between ideal CVH metrics and prevalence of ICAS.

Methods

A random sample of 5,412 participants (selected from Kailuan Study as a reference population) aged 40 years or older (40.10% women), free of stroke, transient ischemic attack, and coronary disease, were enrolled in the Asymptomatic Polyvascular Abnormalities Community study from 2010 to 2011. We collected information on the seven CVH metrics (including smoking, body mass index, dietary intake, physical activity, blood pressure, total cholesterol and fasting blood glucose); and assessed ICAS by transcranial Doppler. The relationship between the ideal CVH metrics and prevalence of ICAS was analyzed using the multivariate logistic regression.

Results

After adjusting for age, sex, and other potential confounders, the adjusted odds ratios(95% confidence interval) for ICAS were 0.76(0.58–0.99), 0.55(0.43–0.72), 0.49(0.37–0.65), 0.43(0.31–0.61), and 0.36(0.22–0.62), respectively, for those having 2, 3, 4, 5, and 6–7 ideal CVH metrics compared with those having 0–1 ideal metric(p-trend<0.0001). Similar inverse associations were observed in different age and gender groups (all p-trends<0.05).

Conclusion

We found a clear gradient relationship between the number of ideal CVH metrics and lower prevalence of ICAS in a Chinese population, which supports the importance of ideal health behaviors and factors in the prevention of ICAS.

Biomarkers for stroke

Background

Major stroke clinical trials have failed during the past decades. The failures suggest the presence of heterogeneity among stroke patients. Biomarkers refer to indicators found in the blood, other body fluids or tissues that predicts physiologic or disease states, increased disease risk, or pharmacologic responses to a therapeutic intervention. Stroke biomarkers could be used as a guiding tool for more effective personalized therapy.

Main Contents

Three aspects of stroke biomarkers are explored in detail. First, the possible role of biomarkers in patients with stroke is discussed. Second, the limitations of conventional biomarkers (especially protein biomarkers) in the area of stroke research are presented with the reasons. Lastly, various types of biomarkers including traditional and novel genetic, microvesicle, and metabolomics-associated biomarkers are introduced with their advantages and disadvantages. We especially focus on the importance of comprehensive approaches using a variety of stroke biomarkers.

Conclusion

Although biomarkers are not recommended in practice guidelines for use in the diagnosis or treatment of stroke, many efforts have been made to overcome the limitations of biomarkers. The studies reviewed herein suggest that comprehensive analysis of different types of stroke biomarkers will improve the understanding of individual pathophysiologies and further promote the development of screening tools for of high-risk patients, and predicting models of stroke outcome and rational stroke therapy tailored to the characteristics of each case.

Diagnostic efficacy of total homocysteine and C-reactive protein for ocular ischemic syndrome

BACKGROUND

To assess diagnostic efficacy of plasma total homocysteine (tHcy) and C-reactive protein (CRP) levels for ocular ischemic syndrome (OIS).

METHODS

In all, 87 patients with retinal vein occlusion (RVO), 955 patients with a stenosis of internal carotid artery (ICA) <90% and 159 patients with a stenosis of ICA >90% were included between 2003 and 2009. A total of 43 patients with a stenosis ICA >90% were diagnosed as OIS. Fasting tHcy, CRP, lipid profiles, creatinine were measured, and diagnostic values of hyperhomocysteinemia or elevated CRP for OIS were evaluated.

RESULT

The mean plasma levels of tHcy (18.8 μmol/l) and CRP (1.1 mmol/l) were the highest in patients with OIS among the groups. The prevalences of hyperhomocysteinemia (72%) and elevated CRP (77%) were the highest in OIS among the groups. In patients with stenosis of ICA, the diagnostic sensitivity/specificity for OIS was 70/79% in hyperhomocysteinemia and 73/73% in elevated CRP. The diagnostic sensitivity and specificity for OIS were 53 and 86% in both hyperhomocysteinemia and elevated CRP. The lipid profiles and creatinine levels were similar among the groups.

CONCLUSION

Our results suggest that hyperhomocysteinemia and elevated CRP may be associated with the development of OIS. The measurements of tHcy and CRP in blood may help to assist the diagnosis of OIS in a stenosis of ICA.

A community based study of the relationship between homocysteine and some of the life style factors

Till date no community based data on plasma homocysteine is available in North Eastern Region. Hence, the present study was conducted to analyze and correlate the plasma homocysteine level with some life style factors like diet, alcohol intake, smoking habit and body weight, in a cross-section of population. 12 h fasting samples of 970 apparently healthy, Assamese population of both genders in the age group of 35-86 years, mostly from the urban area of Assam were tested for plasma total homocysteine level over a period of 3 years. Out of 970 volunteers, hyperhomocysteinemia was detected in 533 (55%) individuals with a mean value of 18.41 μmol/l. Of that hyperhomocysteinemia, 89.1% were in the range of moderately high and rest 10.9% were intermediate high. Another finding was that males had a tendency towards greater value (mean = 20.36 μmol/l) than females (mean = 16.37 μmol/l). It was observed that the relationship of homocysteine levels to gender and some of the life style factors were also significant.

[Recurrent ischemic stroke revealing Biermer's disease]

INTRODUCTION

Biermer's disease is an autoimmune disorder characterized by vitamin B12 deficiency. Ischemic stroke is an uncommon complication of Biermer's disease, possibly though hyperhomocysteinemia.

CASE REPORT

A 58-year-old male presented with recurrent ischemic stroke. Extensive investigations were normal, except for a high plasma level of homocysteine in the context of pernicious anemia which was otherwise asymptomatic.

DISCUSSION

Hyperhomocysteinemia is a known marker, and probably a risk factor, for stroke, fostering atherosclerosis and thrombosis. It can be found among individuals suffering from homocysteinuria, but also when there is deficiency of vitamin B12 or folic acid. Vitamin B12 supplementation would reduce homocysteine concentration which in turn would reduce the risk of ischemic stroke.

Epidemiology of intracranial stenosis

Intracranial stenosis is a common etiology for ischemic stroke. Due to limitations of imaging studies, there are limited data on the prevalence of symptomatic and asymptomatic intracranial stenosis. Intracranial stenosis is more prevalent in Asian, Hispanic, and African-American populations. The reported proportion of patients with symptomatic intracranial stenosis among those hospitalized for ischemic cerebral events varies from 1% in non-Hispanic whites to as high as 50% in Asian populations. In population-based studies, the estimated prevalence of symptomatic intracranial disease varies from 1 in 100,000 for whites to 15 in 100,000 in African Americans. A Chinese population-based study reported intracranial stenosis in 7% of the population aged more than 40 years. Autopsy studies have noted intracranial atherosclerotic disease in about 23% of population in the 6th decade and 80% of population in the 9th decade of life. Angiotensin-converting enzyme polymorphisms, plasma endostatin/vascular endothelial growth factor ratio, glutathione S-transferase omega-1 gene polymorphism, and plasma homocysteine levels are non-modifiable risk factors noted to be associated with intracranial stenosis. Hypertension and serum lipid profile are major modifiable risk factors, whereas sickle cell disease is an uncommon risk factor that can be managed to reduce risk. Associations of intracranial atherosclerosis with diabetes mellitus, metabolic syndrome, Alzheimer's disease, aortic plaques, radiotherapy, and meningitis are less well documented.

Intracranial atherosclerotic disease: an update

The consensus conference on intracranial atherosclerosis provides a comprehensive review of the existing literature relevant to the epidemiology, diagnosis, prevention, and treatment of intracranial atherosclerosis, and identifies principles of management and research priorities. Patients who have suffered a stroke or transient ischemic attack attributed to stenosis (50-99%) of a major intracranial artery face a 12 to 14% risk for subsequent stroke during the 2-year period after the initial ischemic event, despite treatment with antithrombotic medications. The annual risk for subsequent stroke may exceed 20% in high-risk groups. In patients with intracranial atherosclerotic disease, short-term and long-term anticoagulation is not superior to antiplatelet treatment. Overall, the subgroup analyses from randomized trials provide evidence about benefit of aggressive atherogenic risk factor management. Intracranial angioplasty with or without stent placement has evolved as a therapeutic option for patients with symptomatic intracranial atherosclerotic disease, particularly those with high-grade stenosis with recurrent ischemic symptoms, medication failure, or both. A multicenter randomized trial is currently under way to compare stent placement with intense medical management for patients with high-grade symptomatic intracranial atherosclerotic disease.

Postgraduate Symposium The MTHFR C677T polymorphism, B-vitamins and blood pressure

High blood pressure (BP) and elevated homocysteine are reported as independent risk factors for CVD and stroke in particular. The main genetic determinant of homocysteine concentrations is homozygosity (TT genotype) for the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene, typically found in approximately 10% of Western populations. The B-vitamins folate, vitamin B12and vitamin B6are the main nutritional determinants of homocysteine, with riboflavin more recently identified as a potent modulator specifically in individuals with the TT genotype. Although observational studies have reported associations between homocysteine and BP, B-vitamin intervention studies have shown little or no BP response despite decreases in homocysteine. Such studies, however, have not considered the MTHFR C677T polymorphism, which has been shown to be associated with BP. It has been shown for the first time that riboflavin is an important determinant of BP specifically in individuals with the TT genotype. Research generally suggests that 24 h ambulatory BP monitoring provides a more accurate measure of BP than casual measurements and its use in future studies may also provide important insights into the relationship between the MTHFR polymorphism and BP. Further research is also required to investigate the association between specific B-vitamins and BP in individuals with different MTHFR genotypes in order to confirm whether any genetic predisposition to hypertension is correctable by B-vitamin intervention. The present review will investigate the evidence linking the MTHFR C677T polymorphism to BP and the potential modulating role of B-vitamins.

Intracranial atherosclerotic disease

Symptomatic intracranial arterial stenosis carries one of the highest rates of recurrent stroke (10%-20% per year) despite antithrombotic therapy. Stroke prevention strategies for intracranial atherosclerotic disease follow the guidelines for secondary stroke prevention that target atherogenic risk factors. These include following standard stroke prevention guidelines of weight loss for overweight patients, moderate physical exercise (at least 30 minutes most days), cessation of cigarette smoking, and a low-fat, low-cholesterol diet. Pharmacologic treatments include antiplatelet agents, statins, blood sugar control for diabetics, and antihypertensive medications. Goals may include low-density lipoprotein cholesterol less than 100 mg/dL (< 70 mg/dL in high-risk patients). The absolute blood pressure reduction target is uncertain, but average long-term reductions of 10/5 mm Hg are recommended. Angioplasty with stent placement for the treatment of symptomatic severe intracranial stenosis (>/= 70%) is currently being evaluated in a phase 3 randomized controlled trial. It is unclear whether angioplasty with stent placement is superior to angioplasty alone for the treatment of intracranial stenosis, so both endovascular methods are currently acceptable. Complication and success rates for intracranial angioplasty and stent placement are highly variable, so the widespread application of this procedure is generally not recommended outside of clinical trials and experienced centers.

The serum high-sensitive C reactive protein and homocysteine levels to evaluate the prognosis of acute ischemic stroke

Ischemic stroke is one of the most common causes of death worldwide and is most often caused by thrombotic processes. We investigated the changes in hsCRP and homocysteine levels, two of these risk factors, during the acute period of ischemic stroke and evaluated the relationship between these levels and the short-term prognosis. HsCRP and homocysteine levels were measured at the 2nd, 5th, and 10th days in forty patients admitted within second of an ischemic stroke. The clinical status of the patients was simultaneously evaluated with the Scandinavian stroke scale. The results were compared with 40 healthy control subjects whose age and sex were matched with the patients. The mean hsCRP levels of the patients were 9.4 ± 7.0 mg/L on the 2nd day, 11.0 ± 7.4 mg/L on the 5th day, and 9.2 ± 7.0 mg/L on the 10th day. The mean hsCRP level of the control subjects was 1.7 ± 2.9 mg/L. The mean hsCRP levels of the patients on the 2nd, 5th, and 10th days were significantly higher than the control subjects (P < .001). The patients' mean homocysteine levels were 40.6 ± 9.6 μmol/L on the 2nd day, 21.7 ± 11.1 μmol/L on the 5th day, and 20.7 ± 9.2 μmol/L on the 10th day. The mean homocysteine level of the control subjects was 11.2 ± 1.1 μmol/L. The homocysteine levels of the patients were higher than the control subjects at all times (P < .01). In conclusion, patients with stroke have a higher circulating serum hsCRP and homocysteine levels. Short-term unfavorable prognosis seems to be associated with elevated serum hsCRP levels in patients with stroke. Although serum homocysteine was found to be higher, homocysteine seems not related to prognosis.

The genetics of cerebrovascular atherosclerosis

Ischemic stroke attributable to atherosclerosis remains a major public health problem. Genetic factors are increasingly recognized as influencing risk for atherosclerosis directly and indirectly. Genetic makeup may influence the development of major vascular risk factors or alter susceptibility of the cerebral vasculature to these risk factors. More recently, newly identified risk factors for atherosclerosis, such as plasma homocysteine and infection, have also been reported to be influenced by important genetic determinants. This article reviews the current nature on genetics of cerebral and precerebral atherosclerosis and seeks to identify areas of promise for future clinical application.

Acute multiple brain infarction in large-artery atherosclerosis is associated with hyperhomocyst(e)inemia

OBJECTIVES

Although hyperhomocyst(e)inemia had been proven to be a potent risk factor for ischemic stroke, it is still controversial which subtype of stroke is associated with hyperhomocyst(e)inemia. The aim of this study was to clarify the association between plasma homocyst(e)ine (Hcy) levels and stroke subtypes according to TOAST classifications based on MRI findings.

METHODS

We prospectively recruited 124 consecutive first-ever ischemic stroke patients hospitalized in Toride Kyodo General Hospital. Each patient underwent brain MRI including diffusion-weighted imaging (DWI) and was evaluated for total plasma Hcy levels in addition to routine laboratory tests.

RESULTS

Of the 93 patients enrolled in this study, 19 were subtyped with large-artery atherosclerosis with acute multiple brain infarction [LA-AMBI(+)], 13 with LA-AMBI(-). Patients with LA-AMBI(+) showed significantly higher plasma Hcy levels than those with LA-AMBI(-). Moreover, for LA-AMBI, the plasma Hcy level was associated with an OR of 1.3 (95% CI 1.06-1.71, P=0.017) per 1 mumol increase in concentration, and 1.4 (95% CI 1.04-1.77, P=0.025) after adjustment for age, sex and serum cholesterol levels.

CONCLUSION

In the subset of patients with LA strokes, those with high Hcy levels are more likely to have AMBI than those without elevated Hcy levels possibly due to plaque instability.

Plasma concentrations of C-reactive protein and total homocysteine in relation to the severity and risk factors for cerebrovascular disease

Higher C-reactive protein (CRP) and plasma homocysteine (tHcy) concentrations have been shown to indicate increased risk of coronary heart disease and cerebrovascular disease (CVD), but the mechanisms by which they increase the risk of atherothrombotic disease are under investigation. This study evaluates the associations of high-sensitivity C-reactive protein (hs-CRP) and tHcy with the risk factors, severity, and outcome on discharge in patients with CVD. hs-CRP, fasting tHcy, and lipid profile were determined in 50 patients with CVD and 20 healthy control subjects. Clinical data, National Institutes of Health stroke scale (NIHSS) on admission and disability Rankin scale on discharge, were recorded. Based on epidemiologic studies, cutoff points of 1.5 mg/L (hs-CRP) and 15mumol/L (tHcy) were used to indicate increased risk. Univariate and multivariate logistic regression analyses were used to relate tHcy with other CVD risk factors, NIHSS on admission and the disability Rankin scale on discharge. Overall, 38% of patients had increased hs-CRP and 26% had elevated tHcy. hs-CRP (P = 0.005) and tHcy (P < 0.0001) concentrations were significantly higher in patients compared with controls, and these differences remained significant after correction for age and sex. tHcy showed significant correlations with hs-CRP (rs = 0.35; P = 0.003) and low-density lipoprotein-cholesterol (LDL-C; rs = 0.49; P = 0.005). Logistic regression analysis with CVD as the dependent variable showed significant association with hs-CRP (P = 0.01) and tHcy (P < 0.0001) after adjustment for potential confounders. hs-CRP showed increased trend with disease severity and significant association with the disability Rankin scale (P = 0.033). These data support 4 main conclusions: (1) Elevation of hs-CRP and tHcy are common in CVD; (2) the significant relationship between tHcy and hs-CRP suggests that the association of tHcy with CVD risk may be dependent on inflammation-related mechanisms; (3) increased hs-CRP and tHcy show that patients with CVD may be at greater risk of subsequent coronary heart disease; and (4) admission hs-CRP could be used as an indicator of prognosis.

Relation between interleukin-6 level and subclinical intracranial large-artery atherosclerosis

BACKGROUND

The levels of systemic inflammatory markers have been shown to predict future cardiovascular events, but whether they are associated with intracranial large-artery atherosclerosis is uncertain. We investigated the relation between the level of inflammatory markers interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) and subclinical intracranial large-artery atherosclerosis in patients with risk factors for atherosclerosis.

METHODS

Magnetic resonance angiography (MRA) was performed in 226 Japanese patients age range, 45-87 years without a history of cerebrovascular disease. Serum IL-6 and hsCRP and conventional risk factors for atherosclerosis were assessed.

RESULTS

Forty-six patients (20.4%) were found by MRA to have one or more intracranial steno-occlusive lesions. Mean IL-6 levels were higher in patients with intracranial large-artery atherosclerosis than in those without. In addition, patients in the highest IL-6 tertile had higher unadjusted odds ratio (OR) for intracranial large-artery atherosclerosis than that of those in the lowest tertile (OR 3.25, 95% CI; 1.42-7.39). These associations were only slightly attenuated upon adjustment for conventional atherosclerotic risk factors and carotid intima-media thickness.

CONCLUSIONS

Increased levels of IL-6 appear to be associated with intracranial large-artery disease, suggesting a role for the inflammatory process in atherosclerosis of intracranial large arteries.

Research on the plasma levels of homocysteine, folate and vitamin B12 and their correlations in nonalcoholic fatty liver disease

AIM: To explore the plasma levels of homocy-steine, folate and vitamin B₁₂ as well as their correlations in nonalcoholic fatty liver disease (NAFLD).

METHODS: B-ultrasound examination was performed on 199 individuals, of which 67 cases were confirmed with NAFLD and 132 cases served as controls. The plasma levels of homocysteine, folate and vitamin B₁₂ were tested and their correlations were analyzed.

RESULTS: The plasma level of homocysteine in NAFLD group was higher than that in normal group (18.64 ± 11.2 µmol/L vs 12.49 ± 6.4 µmol/L, P < 0.01), and an inverse linear correlation existed between the plasma levels of homocysteine and folate (r = -0.381, P < 0.01), either between the plasma levels of homocysteine and vitamin B₁₂ (r = -0.561, P < 0.001).

CONCLUSION: The plasma level of homocysteine is enhanced in NAFLD patients, and hyperhomocysteinemia may be a new risk factor in NAFLD.

Homocysteine reduces cholinesterase activity in rat and human serum

In the present study we investigated the effect of homocysteine administration, the main metabolite accumulating in homocystinuria, on cholinesterase activity in rat and human serum. For the in vivo study, 8-, 15- and 60-day-old rats received one subcutaneous injection of homocysteine (0.3, 0.4 or 0.6 micromol/g of body weight, respectively) or saline (control) and were sacrificed 1h later, when serum was collected in order to determine cholinesterase activity. For the in vitro studies, serum of 8-, 15- and 60-day-old untreated rats or 20-25- and 52-60-day-old human beings (healthy volunteers) were incubated with 10-500 microM homocysteine. Results showed that acute hyperhomocysteinemia (in vivo study) significantly reduced cholinesterase activity in the serum of rats of all ages tested. We also observed that 500 microM homocysteine added to the incubation medium (in vitro study) significantly inhibited cholinesterase activity both in serum of rats and humans. Our findings seem to reinforce the proposed associations of cholinesterase activity with hyperhomocysteinemia.

Serial measurements of plasma homocysteine levels in early and late phases of ischemic stroke

High plasma levels of homocysteine (Hcy) may predispose to ischemic stroke (IS), but results of previous studies have been conflicting. We decided to determine in IS patients whether their Hcy levels are elevated, whether levels vary at different time points following stroke, whether levels are associated with stroke severity, outcome, recurrence, etiology, infarct volume, or risk factors, and whether levels are correlated with hemostatic factors or C-reactive protein values. We measured plasma Hcy levels in 102 consecutive IS patients on admission and at 1 week, 1 month, and 3 months after stroke and once in 102 control subjects. Hemostatic factors were measured in 55 patients. Compared with controls, plasma Hcy levels in patients were significantly lower on admission but not at later time points, with levels increasing by week and remaining at this level for 3 months. Hcy levels showed a positive correlation with age and a negative correlation with Mini-Mental State Examination (MMSE) scores. Plasma Hcy levels inversely correlated with plasminogen activator inhibitor type-1. Decreased Hcy levels on admission may reflect the strength of the acute-phase response rather than a pathogenetic event. The negative correlation between Hcy levels and MMSE scores is more probably age-related than stroke-related.

L’accident ischémique cérébral, une complication rare de la maladie de Biermer

INTRODUCTION

Stroke in a young adult justifies an extensive etiologic workup.

OBSERVATION

We present a 44-year-old women victim of a frontal ischemic stroke. Extensive evaluation was normal, except for high plasma level of homocysteine in the context of pernicious anemia, otherwise asymptomatic.

DISCUSSION

Hyperhomocysteinemia is a known marker, and probably risk factor for stroke, fostering atherosclerosis and thrombosis. It can be found among individuals suffering from homocystinuria, in individuals homozygous for the MHTFR T allele but also when there is deficiency of vitamin B12 or folic acid. Although it is very seldom ascribed, pernicious anemia would be a cause of stroke, possibly though hyperhomocysteinemia.

Plasma homocysteine and folate levels in patients with chronic plaque psoriasis

BACKGROUND

Hyperhomocysteinaemia is a well-known risk factor for cardiovascular diseases. Patients with severe chronic plaque psoriasis have a higher risk of death due to arterial and/or venous thrombosis.

OBJECTIVES

To investigate the relationship among plasma homocysteine and folate levels and severity of chronic plaque psoriasis in a selected cohort of patients with psoriasis without known risk factors for acquired hyperhomocysteinaemia.

METHODS

We performed a case-control study in 40 patients with chronic plaque psoriasis and 30 age- and sex-matched healthy controls. Cases and controls were selected excluding individuals with conditions or diseases associated with acquired hyperhomocysteinaemia, and were also asked to stop alcohol and coffee consumption for 1 week before blood sampling. The plasma levels of homocysteine and folic acid were measured and were correlated with the severity of psoriasis (Psoriasis Area and Severity Index, PASI).

RESULTS

Patients with psoriasis had plasma homocysteine levels higher than controls (mean +/- SD 16.0 +/- 5.6 vs. 10.4 +/- 4.7 micro mol L(-1); P < 0.001). Conversely, folic acid levels were lower in patients with psoriasis compared with controls (mean +/- SD 3.6 +/- 1.7 vs. 6.5 +/- 1.7 nmol L(-1); P < 0.001). Plasma homocysteine levels in patients with psoriasis correlated directly with disease severity (PASI) and inversely with folic acid levels. Plasma folic acid levels were inversely correlated with the PASI. No abnormalities of plasma vitamin B(6) and B(12) were found.

CONCLUSIONS

Patients with psoriasis may have a tendency to hyperhomocysteinaemia, which may predispose to higher cardiovascular risk. Dietary modification of this risk factor appears relevant to the global management of patients with moderate to severe psoriasis.

Hyperhomocysteinemia can be ameliorated by dimethylsulfoniopropionate in place of folic acid in mice

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.

Hyperhomocysteinemia increases damage on brain slices exposed to in vitro model of oxygen and glucose deprivation: prevention by folic acid

In the present study we evaluate the effects of homocysteine on cellular damage using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation), an in vitro model of hypoxic-ischemic events. For chronic treatment, we induced elevated levels of homocysteine in blood (500 microM), comparable to those of human homocystinuria, and in brain (60 nmol/g wet tissue) of young rats by subcutaneous injections of homocysteine (0.3-0.6 micromol/g of body weight), twice a day with 8 h intervals, from the 6 th to the 28 th postpartum day and controls received saline. Rats were sacrificed 1, 3 or 12 h after the last injection. For acute treatment, 29-day-old rats received one single injection of homocysteine (0.6 micromol homocysteine/g body weight) or saline and were sacrificed 1h later. In another set of experiments rats were pretreated with Vitamins E (40 mg/kg) and C (100 mg/kg) or folic acid (5 mg/kg) during 1 week; 12 h after the last administration they received a single injection of homocysteine or saline and were sacrificed 1 h later. Results showed that both chronic (1 h after homocysteine administration) and acute hyperhomocysteinemia increased the cellular damage measured by LDH released to de incubation medium, suggesting an increase of tissue damage caused by OGD. Pretreatment with folic acid completely prevented the damage caused by acute hyperhomocysteinemia, whereas Vitamin E just partially prevented such effect. These findings may be relevant to explain, at least in part, the higher susceptibility of hyperhomocysteinemic patients to be susceptible to ischemic events and point to a possible preventive treatment.

Folic acid pretreatment prevents the reduction of Na+,K+‐ATPase and butyrylcholinesterase activities in rats subjected to acute hyperhomocysteinemia

The main objective of the present study was to evaluate the effect of folic acid pretreatment on parietal cortex Na(+),K(+)-ATPase and serum butyrylcholinesterase activities in rats subjected to acute hyperhomocysteinemia. Animals were pretreated daily with an intraperitoneal injection of folic acid (5 mg/kg) or saline from the 22th to the 28th day of age. Twelve hours after the last injection of folic acid or saline, the rats received a single subcutaneous injection of homocysteine (0.6 micromol/g of weight body) or saline and were killed 1h later. Serum was collected and the brain was quickly removed and parietal cortex dissected. Results showed that acute homocysteine administration significantly decreased the activities of Na(+),K(+)-ATPase and butyrylcholinesterase on parietal cortex and serum, respectively. Furthermore, folic acid pretreatment totally prevented these inhibitory effects. We also evaluated the effect of acute homocysteine administration on some parameters of oxidative stress, namely thiobarbituric acid-reactive substances and total thiol content in parietal cortex of rats. No alteration of these parameters were observed in parietal cortex of homocysteinemic animals, indicating that these oxidative stress parameters were probably not responsible for the reduction of Na(+),K(+)-ATPase and butyrylcholinesterase activities. The presented results confirm previous findings that acute hyperhomocysteinemia produces an inhibition of Na(+),K(+)-ATPase and butyrylcholinesterase activities and that pretreatment with folic acid prevents such effects. Assuming that homocysteine might also reduce the activities of these enzymes in human beings, our results support a new potential therapeutic strategy based on folic acid supplementation to prevent the neurological damage found in hyperhomocysteinemia.

High homocysteine and low B vitamins predict cognitive decline in aging men: the Veterans Affairs Normative Aging Study

BACKGROUND

Elevated homocysteine concentrations may contribute to cognitive impairment. Most elevations in homocysteine result from inadequate folate, vitamin B-12, or vitamin B-6 intake. It is not clear whether the observed associations between homocysteine and cognitive measures are causal or whether they are due to homocysteine, to independent actions of the B vitamins, or to both.

OBJECTIVE

We aimed to assess the individual and independent effects of baseline plasma homocysteine, folate, vitamin B-12, and vitamin B-6 and of dietary B vitamin intakes on 3-y changes in cognitive measures in 321 aging men.

DESIGN

Participants were from the Veterans Affairs Normative Aging Study. Cognitive function was assessed with the Mini-Mental State Examination and on the basis of measures of memory, verbal fluency, and constructional praxis, which were adapted from the revised Wechsler Adult Intelligence Scale and the Consortium to Establish a Registry for Alzheimer's Disease batteries at 2 time points. At baseline, dietary intakes were assessed with a food-frequency questionnaire, and blood was drawn for the measurement of B vitamins and homocysteine.

RESULTS

Over a mean 3-y follow-up, declines in constructional praxis, measured by spatial copying, were significantly associated with plasma homocysteine, folate, and vitamins B-6 and B-12 and with the dietary intake of each vitamin. Folate (plasma and dietary) remained independently protective against a decline in spatial copying score after adjustment for other vitamins and for plasma homocysteine. Dietary folate was also protective against a decline in verbal fluency. A high homocysteine concentration was associated with a decline in recall memory.

CONCLUSIONS

Low B vitamin and high homocysteine concentrations predict cognitive decline. Spatial copying measures appear to be most sensitive to these effects in a general population of aging men.

The central nervous system in animal models of hyperhomocysteinemia

Growing epidemiological evidence of associations between mildly elevated plasma homocysteine with age-related cognitive impairment, neurodegenerative and cerebrovascular disease has stimulated interest in the role of homocysteine in neurological and neuropsychiatric disorders. Homocysteine is an intermediate in the folate, vitamin B12 and B6 dependent pathways of one-carbon and sulfur amino acid metabolism. Impairments of these pathways may cause CNS dysfunction by promoting the intracellular generation of homocysteine, which is postulated to have vasotoxic and neurotoxic properties. It might also inhibit the methylation of myelin basic protein and membrane phospholipids, or disrupt biogenic amine metabolism and many other vital CNS reactions. However, it is unclear which, if any, of these putative mechanisms underlies the epidemiological associations. Genetic mouse models of hyperhomocysteinemia suggest that the primary metabolic disturbances rather than homocysteine per se may be important in determining neurological outcomes. However, severe and early developmental abnormalities in these mice limit their usefulness for understanding the relation of hyperhomocysteinemia to adult CNS disorders. Pharmacologic and dietary studies on homocysteine in rodents have reported heightened neuronal sensitivity to neurotoxic insults, neurochemical abnormalities and cerebrovascular dysfunction. Such studies are consistent with a causal relationship, but they fail to distinguish between effects that might result from a dietary imbalance and those that might be caused by homocysteine per se. Future work should be directed towards refining these models in order to distinguish between the effects of homocysteine and its determinants on neurological and behavioral outcomes that represent different CNS disorders.

Plasma homocysteine level and functional outcome of patients with ischemic stroke

OBJECTIVE

To investigate the possible relationships between total plasma homocysteine level (tHcy) and functional outcome of stroke patients as evaluated by the FIM instrument.

DESIGN

Retrospective chart analysis.

SETTING

Inpatient stroke rehabilitation ward of a university-affiliated referral hospital.

PARTICIPANTS

Consecutive patients (N=113) presenting with acute ischemic stroke. Patients were divided into 2 groups according to their tHcy levels (< or = 15 micromol/L, >15 micromol/L) and into 3 groups according to their FIM scores (low, < or =40; moderate, 41-80; high, >80).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The tHcy level was determined shortly after stroke onset by a high performance liquid chromatography method with fluorescence detection. Functional outcome was measured by the FIM instrument at admission and discharge. The tHcy level and FIM scores were obtained for all patients. Data outcomes were analyzed by t tests, 1-way analysis of variance, Mann-Whitney U, and Fisher exact tests, as well as by the 2 ordered polytomous logistic regression model.

RESULTS

The 2 tHcy groups were similar in demographic, stroke, and comorbidity characteristics, differing only by higher frequency of hypertension in those with a tHcy greater than 15 micromol/L (51.7% vs 80.8%, respectively, P=.01). Compared with patients who had tHcy levels at 15 micromol/L or lower and were discharged from rehabilitation being in the highest FIM score group (>80), higher tHcy levels were not associated with a discharge FIM score of less than 40 (odds ratio [OR]=.77; 95% confidence interval [CI], 0.13-4.65; P=.77) or with a better functional outcome FIM score between 40 and 80 (OR=3.71; 95% CI, 0.73-18.99; P=.11).

CONCLUSIONS

Our findings suggest that determination of tHcy level does not correlate with functional outcome in patients presenting for rehabilitation after acute ischemic stroke.

Preventing a second stroke in the young

In the United States, more than 220,000 adults under the age of 45 have had a stroke. Secondary stroke prevention is critical in this population because of the potential impact of a second stroke on productivity and future quality of life. In addition to conventional stroke risk factors, younger patients have special risk factors inherent to genetic and environmental elements, such as the use of illicit drugs and cardiac abnormalities; in women, risk factors include pregnancy, migraine, and the use of oral contraceptives.