Homocysteine and carotid intima-media thickness: a critical appraisal of the evidence

Cardiovascular Disease-Associated Skin Conditions

According to data from the American Heart Association and the World Health Organization, cardiovascular disease (CVD) is the most frequent cause of premature death. Several inflammatory and non-inflammatory skin diseases have been associated with metabolic syndrome and cardiovascular risk (CVR). Here, we classified these conditions into traditionally CVR-associated and those that have been linked to a lesser degree. Psoriasis and hidradenitis suppurativa are commonly associated with CVD, sharing common inflammatory pathways and a higher prevalence of traditional cardiovascular risk factors. Many other diseases could be associated indirectly – with no common pathogenic features with the atheromatous disease – but share a higher prevalence of standard cardiovascular risk and chronic inflammatory state. This review aims to highlight the associated cardiovascular risk that exists for some dermatologic diseases and sensitize cardiologists, dermatologists, and first care providers to implement risk factor control promptly.

Vitamin B12, folate and homocysteine concentrations during pregnancy and early signs of atherosclerosis at school-age

Background & aims

Suboptimal circulating vitamin B12, folate and homocysteine concentrations during fetal life seem to be associated with cardiometabolic health at school-age. We examined whether fetal exposure to lower circulating vitamin B12 and folate concentrations and higher circulating homocysteine concentrations is also associated with early signs of atherosclerosis at school-age.

Methods

This study among 3826 school-age children and their mothers was embedded in the Generation R Study, a population-based prospective cohort study from early pregnancy onwards. We examined the associations of early-pregnancy and cord blood serum total and active B12 and plasma folate and homocysteine concentrations with common carotid artery intima-media thickness and distensibility in the children aged ten years.

Results

As compared to normal early-pregnancy serum total B12 concentrations (≥145 pmol/L), low serum total B12 concentrations (<145 pmol/L) were associated with higher carotid intima-media thickness in the children at school-age (difference 0.09 standard deviations score (SDS); 95% confidence interval (CI): 0.01, 0.16). As compared to normal early-pregnancy plasma folate concentrations (≥8 nmol/L), low plasma folate concentrations (<8 nmol/L) were associated with lower carotid disten-sibility in the children at school-age (difference −0.16 SDS; 95% CI: −0.28, −0.04). Early-pregnancy circulating total and active B12, folate and homocysteine concentrations measured continuously were not associated with carotid intima-media thickness or carotid distensibility in the children at school-age. One SDS higher plasma homocysteine concentrations measured in cord blood at birth was associated with a −0.05 SDS (95% CI: −0.09, −0.02) lower carotid distensibility at school-age. Cord blood total and active B12 and folate concentrations were not associated with carotid intima-media thickness or carotid distensibility at school-age.

Conclusions

Circulating total B12, folate and homocysteine concentrations during fetal life seem to be associated with markers of subclinical atherosclerosis at school-age. Further studies need to examine the causality and mechanisms underlying these associations.

Associations among amino acid, lipid, and glucose metabolic profiles in childhood obesity

Background

Plasma-free amino acid profiles have been reported to correlate with obesity and glucose metabolism, and have been studied as potentially useful biomarkers of lifestyle-related diseases affecting metabolism in adulthood. However, knowledge of these relationships is lacking in children, despite the growing public health problem posed by childhood obesity.

The aim of this study was to assess whether plasma-free amino acid profiles can serve as useful biomarkers of lifestyle-related diseases in children with obesity.

Methods

This retrospective study used the medical records of 26 patients (15 male, 11 female) aged 9 or 10 years presenting with moderate to severe obesity and hyperlipidemia between April 2015 and March 2017. A degree of obesity of 30% or more was defined as moderate or severe. Amino acid levels were compared between obese children with and without impaired glucose tolerance using a t-test or Mann–Whitney U test. In addition, the influence of factors such as intima media thickness, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, amino acids, and homeostasis model assessment-insulin resistance (HOMA-IR) were analyzed pairwise using Pearson’s correlation or Spearman’s rank correlation.

Results

HOMA-IR was positively correlated with valine, leucine (Leu), isoleucine, phenylalanine, tryptophan, methionine, threonine, lysine, alanine, tyrosine, glutamate (Glu), proline, arginine, ornithine, total free amino acids (all P < 0.01), and aspartate (P = 0.010). Moreover, blood uric acid levels were positively correlated with Leu (P = 0.005) and Glu (P = 0.019), and negatively correlated with serine, glycine, and asparagine (P = 0.007, P = 0.003, and P = 0.013, respectively).

Conclusions

Amino acid profile reflects impaired glucose tolerance and hyperuricemia at an early stage of obesity. It is therefore a useful marker to inform early intervention in children with obesity, as in adults.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1647-8) contains supplementary material, which is available to authorized users.

Homocysteine Level in Children with Classic Congenital Adrenal Hyperplasia: Relationship to Carotid Intimal Wall Thickness and Left Ventricular Function

BACKGROUND/AIMS

Homocysteine is an important and independent risk factor for atherosclerotic diseases. The aim of this study was to evaluate serum levels of homocysteine in children with congenital adrenal hyperplasia (CAH) and their relation to carotid artery intima-media thickness (CA-IMT) and left ventricular (LV) function.

METHODS

This study included 36 children with classic CAH and 36 healthy children. All underwent anthropometric evaluation. Measurement of serum levels of total homocysteine was carried out. The LV mass (LVM) and function were assessed using conventional echocardiography. Duplex ultrasonography was used to measure CA-IMT.

RESULTS

Compared to the controls, the patients had higher homocysteine levels (p = 0.001), a thicker CA-IMT (p = 0.01), a higher LVM index (LVMI) (p = 0.001), and a prolonged mitral deceleration time (DcT) (p = 0.01). Abnormalities were marked in children who were uncontrolled on medical treatment. In multivariate analysis, homocysteine levels were significantly correlated with systolic (OR = 2.2; 95% CI: 1.10-1.18; p = 0.01) and diastolic blood pressures (OR = 2.9; 95% CI: 1.45-2.4; p = 0.01), atherogenic index (OR = 2.6; 95% CI: 1.33-2.89; p = 0.01), HOMA-IR (OR = 1.3; 95% CI: 1.04-1.34; p = 0.001), LVMI (OR = 2.6; 95% CI: 1.1-1.13; p = 0.001), mitral DcT (OR = 2.4; 95% CI: 1.15-2.05; p = 0.01), and CA-IMT (OR = 1.6; 95% CI: 1.16-1.57; p = 0.01).

CONCLUSIONS

Serum total homocysteine was elevated in children with classic CAH, particularly in those with poor control on medical treatment, and it was correlated with CA-IMT, LVMI, and mitral DcT. Measurement of homocysteine in children with CAH may help to identify those at high risk of developing LV dysfunction and subclinical atherosclerosis.

Carotid Artery Atherosclerosis: A Review on Heritability and Genetics

Carotid atherosclerosis (CAS) is associated with increased cardiovascular risk, and therefore, assessing the genetic versus environmental background of CAS traits is of key importance. Carotid intima-media-thickness and plaque characteristics seem to be moderately heritable, with remarkable differences in both heritability and presence or severity of these traits among ethnicities. Although the considerable role of additive genetic effects is obvious, based on the results so far, there is an important emphasis on non-shared environmental factors as well. We aimed to collect and summarize the papers that investigate twin and family studies assessing the phenotypic variance attributable to genetic associations with CAS. Genes in relation to CAS markers were overviewed with a focus on genetic association studies and genome-wide association studies. Although the role of certain genes is confirmed by studies conducted on large populations and meta-analyses, many of them show conflicting results. A great focus should be on future studies elucidating the exact pathomechanism of these genes in CAS in order to imply them as novel therapeutic targets.

Association between hyperhomocysteinemia and metabolic syndrome with early carotid artery atherosclerosis: A cross-sectional study in middle-aged Chinese population

OBJECTIVES

Homocysteine is a modifiable, independent risk factor for cardiovascular disease. The association between hyperhomocysteinemia and metabolic syndrome with the presence of early carotid artery atherosclerosis remains unknown in middle-aged Chinese adults.

METHODS

Chinese adults (n = 1607) of Han ethnicity, age 35 to 65 y, and living in their communities >2 y were surveyed. Hyperhomocysteinemia was defined as homocysteine concentrations >15 µmol/L. Carotid intima-media thickness and carotid plaque were examined by ultrasonography. All participants were classified into four groups by hyperhomocysteinemia and metabolic syndrome status.

RESULTS

Participants with both hyperhomocysteinemia and metabolic syndrome had the highest levels of waist circumference and systolic blood pressure compared with the three other groups. The highest proportion of increased carotid intima-media thickness (61.3%) was in the subgroup of both hyperhomocysteinemia and metabolic syndrome. After adjustments for the covariates, the risk of increased carotid intima-media thickness was only significantly higher in the group with metabolic syndrome but without hyperhomocysteinemia (odds ratio: 1.47; 95% confidence interval, 1.13-1.93) compared with people without hyperhomocysteinemia and metabolic syndrome. Furthermore, statistically significant variances of prevalence of plaque among the four subgroups were not discovered.

CONCLUSIONS

Our study demonstrated that metabolic syndrome had a strong effect on carotid intima-media thickness However, the increased homocysteine levels were not significantly associated with early carotid artery atherosclerosis in middle-aged Chinese people.

Cardiovascular disease in systemic lupus erythematosus: A comprehensive update

Heightened rates of both cardiovascular (CV) events and subclinical atherosclerosis, documented by imaging and vascular function techniques are well established in systemic lupus erythematosus (SLE). While traditional CV factors such as smoking, dyslipidemia, diabetes mellitus (DM), hypertension, central obesity and hyperhomocysteinemia have been reported to be prevalent in lupus patients, they do not fully explain the high rates of ischemic events so far reported, implying that other factors inherent to disease itself could account for the enhanced risk, including disease duration, activity and chronicity, psychosocial factors, medications, genetic variants and altered immunological mechanisms. Though the exact pathogenesis of atherosclerosis in the setting of lupus remains ill defined, an imbalance between endothelial damage and atheroprotection seems to be a central event. Insults leading to endothelial damage in the setting of lupus include oxidized low density lipoprotein (oxLDL), autoantibodies against endothelial cells and phospholipids, type I interferons (IFN) and neutrophil extracellular traps (NETs) directly or through activation of type I IFN pathway. Increased oxidative stress, reduced levels of the normally antioxidant high density lipoprotein (HDL), increased levels of proinflammatory HDL (piHDL) and reduced paraoxonase activity have been related to increased oxLDL levels. On the other hand, impaired atheroprotective mechanisms in lupus include decreased capacity of endothelial repair-partly mediated by type I IFN- and dampened production of atheroprotective autoantibodies. In the present review, traditional and disease related risk factors for CV disease (CVD) in the setting of chronic autoimmune disorders with special focus on SLE will be discussed.

Associations between homocysteine metabolism related SNPs and carotid intima-media thickness: a Chinese sib pair study

Carotid intima-media thickness (CIMT) is a good surrogate for atherosclerosis. Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. We aim to investigate the relationships between homocysteine (Hcy) related biochemical indexes and CIMT, the associations between Hcy related SNPs and CIMT, as well as the potential gene–gene interactions. The present study recruited full siblings (186 eligible families with 424 individuals) with no history of cardiovascular events from a rural area of Beijing. We examined CIMT, intima-media thickness for common carotid artery (CCA-IMT) and carotid bifurcation, tested plasma levels for Hcy, vitamin B6 (VB6), vitamin B12 (VB12) and folic acid (FA), and genotyped 9 SNPs on MTHFR, MTR, MTRR, BHMT, SHMT1, CBS genes. Associations between SNPs and biochemical indexes and CIMT indexes were analyzed using family-based association test analysis. We used multi-level mixed-effects regression model to verify SNP-CIMT associations and to explore the potential gene–gene interactions. VB6, VB12 and FA were negatively correlated with CIMT indexes (p < 0.05). rs2851391 T allele was associated with decreased plasma VB12 levels (p = 0.036). In FABT, CBS rs2851391 was significantly associated with CCA-IMT (p = 0.021) and CIMT (p = 0.019). In multi-level mixed-effects regression model, CBS rs2851391 was positively significantly associated with CCA-IMT (Coef = 0.032, se = 0.009, raw p < 0.001) after Bonferoni correction (corrected α = 0.0056). Gene–gene interactions were found between CBS rs2851391 and BHMT rs10037045 for CCA-IMT (p = 0.011), as well as between CBS rs2851391 and MTR rs1805087 for CCA-IMT (p = 0.007) and CIMT (p = 0.022). Significant associations are found between Hcy metabolism related genetic polymorphisms, biochemical indexes and CIMT indexes. There are complex interactions between genetic polymorphisms for CCA-IMT and CIMT.

Serum homocysteine as a risk factor for carotid intimal thickening in acute stroke: A cross sectional observational study

Introduction:

The present study aimed to analyse if there is a correlation between carotid intima medial thickening (CIMT) and Hcy in stroke patients.

Methodology:

We studied 100 consecutive cases of acute anterior circulation strokes at St. John's Medical College, Bangalore, India. Fasting serum samples for homocysteine were sent within 24 hours of admission and all patients underwent a carotid Doppler scan and carotid intima-medial thickness (CIMT) was estimated on both sides.

Results:

There was significant correlation between serum homocysteine levels and carotid intima-medial thickness (r = 0.409, p = 0.000). Also after controlling for other possible risk factors it was found that elevations in serum homocysteine levels would cause a variation of 60% in the carotid intima-medial thickening.

Conclusion:

Serum Hcy levels correlate well with CIMT and hence may predict atherothrombotic events.

Plasma total homocysteine and carotid intima-media thickness in type 1 diabetes: a prospective study

OBJECTIVE

Plasma total homocysteine (tHcy) has been positively associated with carotid intima-media thickness (IMT) in non-diabetic populations and in a few cross-sectional studies of diabetic patients. We investigated cross-sectional and prospective associations of a single measure of tHcy with common and internal carotid IMT over a 6-year period in type 1 diabetes.

RESEARCH DESIGN AND METHODS

tHcy levels were measured once, in plasma obtained in 1997-1999 from patients (n = 599) in the Epidemiology of Diabetes Interventions and Complications (EDIC) study, the observational follow-up of the Diabetes Control and Complications Trial (DCCT). Common and internal carotid IMT were determined twice, in EDIC "Year 6" (1998-2000) and "Year 12" (2004-2006), using B-mode ultra-sonography.

RESULTS

After adjustment, plasma tHcy [median (interquartile range): 6.2 (5.1, 7.5) μmol/L] was significantly correlated with age, diastolic blood pressure, renal dysfunction, and smoking (all p < 0.05). In an unadjusted model only, increasing quartiles of tHcy correlated with common and internal carotid IMT, again at both EDIC time-points (p < 0.01). However, multivariate logistic regression revealed no significant associations between increasing quartiles of tHcy and the 6-year change in common and internal carotid IMT (highest vs. lowest quintile) when adjusted for conventional risk factors.

CONCLUSIONS

In a type 1 diabetes cohort from the EDIC study, plasma tHcy measured in samples drawn in 1997-1999 was associated with measures of common and internal carotid IMT measured both one and seven years later, but not with IMT progression between the two time-points. The data do not support routine measurement of tHcy in people with Type 1 diabetes.

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.

Palm tocotrienol-rich fraction improves vascular proatherosclerotic changes in hyperhomocysteinemic rats

This study investigated the effects of palm tocotrienol-rich fraction (TRF) on aortic proatherosclerotic changes in rats fed with a high methionine diet. Forty-two male Wistar rats were divided into six groups. The first group was the control (fed with a basal diet). Another five groups were fed with 1% methionine diet for 10 weeks. From week 6 onward, folate (8 mg/kg diet) or palm TRF (30, 60, and 150 mg/kg diets) was added into the diet of the last four rat groups, respectively. The high methionine diet raised the plasma total homocysteine and aortic lipid peroxidation, which were reduced by the palm TRF and folate supplementations. Plasma nitric oxide was reduced in the high methionine group compared to the control (3.72 ± 0.57 versus 6.65 ± 0.53 μmol/L, P < 0.05), which reduction was reversed by the palm TRF (60 and 150 mg/kg) and folate supplementations. The increased aortic vascular cell adhesion molecule-1 expression in the methionine group (2.58 ± 0.29) was significantly reduced by the folate (1.38 ± 0.18) and palm TRF at 150 mg/kg (1.19 ± 0.23). Palm TRF was comparable to folate in reducing high methionine diet-induced plasma hyperhomocysteinemia, aortic oxidative stress, and inflammatory changes in rats.

Role of surrogate markers of atherosclerosis in clinical and subclinical thyroidism

Background. Data on the relationship between homocysteine, plasminogen activator inhibitor 1, hs-CRP, fibrinogen, and carotid intima media thickness (CA-IMT) is plenty but contradicting and the majority of the studies investigated this issue in only specific thyroidism groups. The aim of this paper was to investigate these relations in patients with subclinical and clinical hypo- and hyperthyroidism. Methods. In this cross-sectional study, 16 patients from each thyroidism group and 20 healthy cases were enrolled. Fibrinogen levels and plasminogen activator inhibitor 1 (PAI-1) activity were assessed. CA-IMT was determined by gray-scale high-resolution color Doppler ultrasound. Results. Serum homocysteine levels were higher in hypothyroidic patients compared to the control (P = 0.003). Fibrinogen levels were higher in patients with subclinical hypothyroidism compared to other groups (P < 0.05). There was no difference between groups regarding PAI-1. Whereas total cholesterol, homocysteine, and LDL were correlated with CAIMT, hs-CRP, PAI-1, and fibrinogen were not. In the clinical hypothyroidism group, the correlation of homocysteine with CA-IMT was derived from the correlation between CA-IMT and homocysteine. Conclusions. Homocysteine and fibrinogen levels are higher in patients with clinical and subclinical hypothyroidism, respectively. Homocysteine level is associated with CA-IMTonly in patients with clinical hypothyroidism.

Multiparametric assessment of vascular function and atherosclerosis in patients with autoimmune gastritis: a comparative study

BACKGROUND/AIMS

Patients with autoimmune gastritis might have accelerated atherosclerosis due to autoimmunity and chronic inflammation. Endothelial dysfunction often precedes manifest atherosclerosis. The aim of the present study was to evaluate the risk factors of early atherosclerosis by using several different techniques.

METHODS

A total of 99 patients with autoimmune gastritis were compared to 42 healthy age sex-matched subjects. Patients with a known risk factor for atherosclerosis were excluded. Intima-media thickness of the common carotid artery, pulse wave velocity and flow-mediated dilation of brachial artery were measured. Clinical data and laboratory parameters (serum gastrin, antiparietal cell antibody, anti-Hp IgG, serum vitamin B(12) and lipid profile) were also determined.

RESULTS

Intima-media thickness (mm) of the carotid artery was significantly higher in autoimmune gastritis (0.062 ± 0.031 vs. 0.042 ± 0.007, P < 0.001) than in healthy individuals. Flow-mediated dilation was significantly lower in patients with autoimmune gastritis compared to control group (13.91 ± 6.68% vs. 20.37 ± 7.80%, P = 0.021) and there was a significant increase in pulse wave velocity (m/s) in autoimmune gastritis patients compared to controls (9.25 ± 3.42 vs. 6.40 ± 0.91, P = 0.001). Antiparietal cell antibody positivity (P = 0.05), low vitamin B(12) level (P = 0.05), and age (P = 0.002) were the predictors of high pulse wave velocity (>14 m/s).

CONCLUSION

Patients with autoimmune gastritis may have an increased risk for the development of early atherosclerosis. As early preventive treatment for accelerated atherosclerosis is available, it is important to detect those patients with autoimmune gastritis who would benefit from such treatment.

Treatment of risk factors to prevent stroke

Much of the decline in stroke incidence and mortality for the past several decades in Western countries has been attributed to better treatment of risk factors. Many epidemiological studies and clinical trials confirmed the importance of managing hypertension. Comparative trials of anti-hypertensive drugs or drug classes have not yielded clear results, but blood pressure variability may play an important role beyond the absolute value of blood pressure. Diabetes therapy remains a conundrum. Although diabetes is clearly a risk factor for ischemic stroke, treatment trials targeting different glycemic goals have not indicated that glucose lowering results in stroke prevention. Trials focused on insulin resistance are ongoing and they may be able to help establish the management of diabetes/impaired glucose tolerance. Evidence for treatment of dyslipidemia has contrasted science to diabetes mellitus. Dyslipidemia has not been strongly or consistently linked to ischemic stroke but the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial showed the impact of statin treatment in stroke prevention. The results of clinical trials investigating dabigatran and rivaroxaban clearly indicate alternative strategies to vitamin K antagonists in stroke prevention for persons with atrial fibrillation. Evidence for stroke prevention by life style modification, treating metabolic syndrome, sleep disordered breathing, lipoprotein (a), hyperhomocysteinemia, and coagulation disorders are also discussed.

Are Stroke Biomarkers Seeing Brain Vessels in Patients With Ischemic Stroke?

Background and Purpose—

The significance of asymptomatic coronary artery atherosclerosis burden (CAB) in the interpretation of stroke biomarker results is unknown. We investigated biomarker values to determine if they are related to cerebral atherosclerosis with consideration of CAB.

Methods—

We prospectively recruited patients with noncardioembolic ischemic cerebrovascular disease who had no history of coronary artery disease. Patient-based vascular assessment was conducted using MRA for the cerebral arteries and cardiac CT angiography for the coronary arteries. Biomarkers including the C-reactive protein and homocysteine were measured.

Results—

A total of 178 patients were included in the study. The extracranial carotid stenosis was associated with the highest quartile of C-reactive protein (OR, 2.24; 95% CI, 1.04–4.55), whereas age was the only predictor of the highest quartile of homocysteine (OR, 1.06; 95% CI, 1.02–1.11). However, with consideration of CAB, CAB (≥2 segments with ≥50% stenosis) remained the only independent predictor for the highest quartile of C-reactive protein (OR, 8.69; 95% CI, 2.41–31.30) and homocysteine (OR, 11.44; 95% CI, 2.61–50.11).

Conclusions—

Our data emphasize the importance of CAB in biomarker studies of patients with ischemic stroke.

Intima-media thickness of the common carotid artery is not significantly higher in Crohn's disease patients compared to healthy population

BACKGROUND

Patients with Crohn's disease might have accelerated atherosclerosis due to: chronic systemic inflammation, metabolic changes or prolonged steroid treatment.

AIMS

The aim of this study was to assess the risk of sub-clinical atherosclerosis in Crohn's disease, by measuring the intima-media thickness and peak systolic velocity of the common carotid artery.

METHODS

Fifty Crohn's disease patients aged between 20 and 45 years were compared to 25 controls. Patients with a family history of cardiovascular diseases or a known risk for atherosclerosis were excluded. All participants underwent nutritional assessment. Carotid artery ultrasonography was performed and intima-media thickness and peak systolic velocity were measured, proximal to the common carotid bifurcation. Clinical data and laboratory parameters (hemoglobin, highly sensitive C-reactive protein, and plasma homocysteine) were determined.

RESULTS

No significant differences between the groups were found for intima-media thickness or peak systolic velocity. Multiple regression analysis revealed a positive correlation of intima-media thickness with older age. Peak systolic velocity was negatively associated with age.

CONCLUSIONS

Crohn's disease patients do not have an increased risk for developing early atherosclerosis.

Contribution of dietary intakes of antioxidants to homocysteine-induced low density lipoprotein (LDL) oxidation in atherosclerotic patients

PURPOSE

Elevated circulating oxidized low density lipoprotein (Ox-LDL) levels are associated with increased risk of atherosclerosis, which may be due to high plasma homocysteine (Hcy) and low intakes of antioxidants. We investigated the contribution of dietary intakes of antioxidants to Hcy-induced LDL oxidation in atherosclerotic patients (AP) and controls.

MATERIALS AND METHODS

Male AP (n = 101) who were confirmed by coronary angiography and 91 controls were evaluated by blood biochemistry and dietary intakes. To determine whether homocysteine is an independent risk factor for atherosclerosis, subjects were divided into three groups; low- (<or= 6.9 uM/L), normal- (7 uM-12 uM/L) and high- (>or= 12.1 uM/L) Hcy.

RESULTS

Plasma levels of homocysteine and LDL were higher, but plasma apo A-I in HDL and folate were lower in the AP group. The odds ratio (OR) for the risk of atherosclerosis was 3.002 [95% confidence interval (CI), 1.27-7.09] for patients in the highest tertile with homocysteine >or= 12.1 uM/L. AP having high homocysteine levels had low intakes of vitamin A, beta-carotene and vitamin C. By logistic regression analysis, age, body mass index (BMI), plasma LDL, plasma folate, and low intakes of vitamin A and beta-carotene were found to be risk factors for atherosclerosis in patients with high-Hcy, but dietary B vitamins including folate were not.

CONCLUSION

A high-Hcy level was a risk factor for atherosclerosis in patients with high Ox-LDL levels. High intakes of antioxidants appeared to be a protective factor for atherosclerosis, perhaps exerting a pro-oxidative effect on LDL when combined with high levels of Hcy and LDL. However, more evidence for the benefits of B vitamins as a homocysteine-lowering therapy is needed.

Joint Metabonomic and Instrumental Analysis for the Classification of Migraine Patients with 677-MTHFR Mutations

Migraine is a neurological disorder that correlates with an increased risk of cerebrovascular lesions. Genetic mutations of the MTHFR gene are correlated to migraine and to the increased risk of artery pathologies. Also, migraine patients show altered hematochemical parameters, linked to an impaired platelet aggregation mechanism. Hence, the vascular assessment of migraineurs is of primary importance.Transcranial Doppler sonography (TCD) is used to measure cerebral blood flow velocity (CBFV) and vasomotor reactivity (by an index measured during breath-holding - BHI). Aim of this study was the metabolic profiling of migraine subjects with T/T677-MTHFR and C/T677-MTHFR mutations and its correlation with CBFV and BHI.Metabonomic multidimensional techniques were used to describe and cluster subjects. Fifty women suffering from migraine (age: 18-64; 21 with aura) underwent TCD examination, hematochemical blood analysis, Born test, and genetic tests for MTHFR mutation. Fourteen (7 with aura) had T/T677, 18 (8 with aura) had C/T677, and 18 (6 with aura) had no mutation. The total number of variables was 24.Unsupervised and supervised techniques_showed the correlation between CBFV and BHI with mutation. Discriminant analysis allowed for classifying the subjects with 95.9% sensitivity and 89.0% specificity. Aura was not correlated to mutation or variations of instrumental data.Our study showed that metabonomics could be effectively applied in clinical problems to show the overall correlation structure of complex systems in pathology. Specifically, our results confirmed the importance of TCD in the metabolic profiling and follow-up of migraine patients.

Hyperhomocysteinemia, intima-media thickness and C677T MTHFR gene polymorphism: a correlation study in patients with cognitive impairment

OBJECTIVE

Intima-media thickness (IMT) seems associated with risk of Alzheimer disease (AD). Homocysteine (hcy) is a risk factor for vascular diseases and dementia. This study aimed at investigating the possible relationship among IMT, plasma hcy and C677T methylentetrahydrofolate reductase (MTHFR) polymorphism in relation to cognitive status.

METHODS

Sixty-three patients with cognitive impairment and 64 controls underwent biochemical, neuropsychological and carotid ultrasound assessment.

RESULTS

After age and folate adjustment, plasma hcy correlated with both Mini Mental State Examination (MMSE) score (r=-0.7, p<0.01) and IMT (r=0.7, p<0.01). Among patients with cognitive impairment, carriers of TT677 MTHFR genotype had plasma hcy (p<0.001) and IMT (p<0.01) values higher than non carriers. Furthermore, multiple regression analysis showed that MMSE scores were associated with plasma hcy (beta=-0.3, p=0.01), IMT (beta=-0.3, p=0.01) and TT677 MTHFR genotype (beta=-0.3, p=0.02). Structural equation modelling showed that the relation between hcy levels and MMSE score was partly direct (parameter estimate=-0.6; p=0.01) and partly mediated by IMT values (parameter estimate=-0.4; p=0.03). Finally, IMT resulted associated with hypertension (parameter estimate=0.8; p<0.0001).

CONCLUSION

Our findings suggest that TT677 MTHFR genotype promotes plasma homocysteine increase which in turn may favour intima-media thickening in patients with cognitive impairment. Hcy may promote neuronal damage through multiple mechanisms, including a micro-vascular damage, mediated by IMT increase, and a direct neuro-toxic effect.

Serum total homocysteine, folate, 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype and subclinical atherosclerosis

OBJECTIVE

To determine the relationship of serum total homocysteine (tHcy), serum folate and 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype with ultrasonic arterial wall measurements associated with subclinical atherosclerosis.

STUDY DESIGN

Cross-sectional analysis of 767 participants in an ongoing prospective study. Intima-media thickness (IMT) of the common carotid (IMTcc), IMT of the internal carotid including plaque when present (IMT(max)) and the sum of the thickest plaques present in both carotid and both common femoral bifurcations (total plaque thickness (TPT)) were measured using ultrasound.

RESULTS

People in the upper homocysteine quartile were more likely to have clinical cardiovascular disease (CVD) than those in the lowest three quartiles. They were also more likely to have plaques. The MTHFR 677C-->T genotype was not associated with any of the measures of subclinical atherosclerosis in either men or women but was the most important determinant of total homocysteine levels in men under 60 years of age.

CONCLUSIONS

Increased homocysteine levels but not MTHFR 677C-->T genotype, are associated with subclinical atherosclerosis and the presence of plaques. Our results indicate that measurements of blood levels of homocysteine and folate in people at intermediate risk for atherosclerotic CVD before symptoms occur, might improve risk stratification and facilitate the decision to provide folate/B vitamin intervention in primary prevention.

Correlations between plasma homocysteine and folate concentrations and carotid atherosclerosis in high-risk individuals: baseline data from the Homocysteine and Atherosclerosis Reduction Trial (HART)

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.

Increased homocysteine-induced release of excitatory amino acids in the striatum of spontaneously hypertensive stroke-prone rats

BACKGROUND AND PURPOSE

Increased plasma [homocysteine] is associated with stroke but its direct effects on the brain during a stroke are unknown. Since excitatory amino acids are important in inducing brain damage, we examined the effect of homocysteine on the release of various amino acids in the striatum of spontaneously hypertensive stroke-prone (SHSP) rats before and after a stroke.

METHODS

In vivo microdialysis was carried out in the striatum of anesthetized SHSP rats before and after signs of stroke. Animals were exposed to 20 and 200 muM homocysteine in the microdialysis solution and then the microdialysates were analyzed 30 min later for amino acid content. Brain cryosections were silver-stained to quantify infarcts in the non-ischemic and the damaged tissues in pre-stroke and post-stroke rats.

RESULTS

Both pre-stroke and post-stroke animals had similar levels of all amino acids in the striatum. Homocysteine did not alter amino acid release in rats prior to stroke but induced a significant increase in the release of all amino acids tested in the post-stroke rats. However, the increase was significantly greater with the excitatory amino acids glutamate and aspartate, and with tyrosine in post-stroke animals as compared to those in pre-stroke, normal animals. The mean pixel density of the gray matter of post-stroke animals was significantly decreased following homocysteine treatment indicating the presence of neurological damage.

CONCLUSIONS

Homocysteine-induced neurological damage in post-infarct SHSP rats was associated with a hypersecretion of excitatory amino acids. Patients with hyperhomocysteinemia may be at risk for augmented brain damage from an ischemic infarct due to a selective activation of neuronal excitatory amino acids.

Decreased cardiovagal regulation in exfoliation syndrome

PURPOSE

To investigate the parasympathetic cardiovascular regulation, baroreflex sensitivity (BRS), and pulse wave velocity (PWV) in exfoliation syndrome (XFS).

METHODS

Heart rate variability indices [standard deviation of all RR intervals (SDNN); the mean of absolute successive differences (RMSSD); the percentage of intervals differing by >50 ms from the preceding interval (pNN50); low frequency power, and high frequency power], as well as BRS and PWV, were determined on 27 consecutive white XFS patients and 20 white control subjects under standard circumstances, with controlled breath rate of 0.25 Hz. The paired t test, the Mann-Whitney U test, and the Fisher exact test were used for comparisons.

RESULTS

There was no significant difference between the XFS and control groups in sex distribution, age, heart rate, blood pressure, body mass index, systemic diseases, or medication. But in XFS patients, SDNN (mean+/-SD, 24+/-7.3 vs. 49+/-16.5 ms), RMSSD (17+/-7.3 vs. 45+/-29.1 ms), pNN50 (1.6%+/-2.5% vs. 17.7%+/-25.9%), high frequency (112+/-109 vs. 479+/-554 ms), and BRS (4.64+/-2.12 vs. 9.49+/-4.76 ms/mm Hg for BRS+ and 5.28+/-2.16 vs. 10.29+/-4.62 ms/mm Hg for BRS-) were all significantly lower than in the control group (P<0.01 for each parameter). Low frequency was also reduced in XFS (72+/-55 vs. 253+/-241 ms) (P=0.027). In XFS, PWV was significantly increased compared with the control group (11.6+/-4.1 vs. 9.3+/-2.2 m/s) (P=0.023).

DISCUSSION

Our results suggest a clinically and statistically significant impairment of cardiovagal regulation and impairment of conduit artery function in XFS patients.

Homocysteine, left ventricular dysfunction and coronary artery disease: is there a link?

Experimental and observational studies support a role of plasma homocysteine levels (tHcy) in coronary artery disease (CAD). In the GENICA (Genetic and Environmental factors In Coronary Atherosclerosis) study, we found that high tHcy predicted cardiovascular mortality in hypertensive, but not in normotensive, patients independently of CAD and history of myocardial infarction. Moreover, despite not being associated with the coronary atherosclerotic burden, tHcy was inversely associated with left ventricular (LV) ejection fraction. This inverse relationship between LV systolic function and tHcy, which has been independently confirmed, might explain the association of tHcy with the risk of incident heart failure documented in the Framingham Heart Study. Thus, additional mechanistic investigation taking into consideration the effects of tHcy on LV function is necessary to further explore the potential therapeutic usefulness of tHcy lowering treatment in CAD.

Homocysteine and carotid intima-media thickness in ischemic stroke patients are not correlated

INTRODUCTION

Hyperhomocysteinemia has been linked to cardiovascular morbidity and mortality by numerous authors. Whether this association is causal or not remains uncertain. The aim of the study was to investigate the association of hyperhomocysteinemia with the degree of carotid atherosclerosis in stroke patients.

METHODS

We studied 97 Greek patients in our stroke unit who were hospitalized as a result of ischemic stroke between March 2006 and May 2007. The patients were divided into two groups: the first (52 patients) included stroke patients with serum levels of homocysteine below 15 mumol/L, but in the second group (45 patients) serum homocysteine exceeded this value. We measured carotid intima-media thickness (cIMT) in all patients and correlated it with serum homocysteine.

RESULTS

The mean homocysteine concentration was 11.5 mumol/L in the first group and 21.5 mumol/L in the second group. Carotid IMT was 1.012 mm in the first group, and 1.015 mm in the second group, an insignificant difference. On the contrary, serum folate concentration was 21.3 nmol/L in the first group compared with 16.7 nmol/L in the second group (p < 0.001). VitB12 was 401 pmol/L in the first group and 340 pmol/L in the second group, a statistically significant difference (p < 0.001).

CONCLUSIONS

Serum levels of homocysteine were not correlated with cIMT in ischemic stroke patients. Both folate and vitB12 were decreased in hyperhomocysteinemic ischemic stroke patients.

Measuring subclinical atherosclerosis: is homocysteine relevant?

OBJECTIVES

We systematically reviewed published studies looking at the relationship between total serum homocysteine (tHcy) and subclinical markers of atherosclerosis, such as carotid intimal-medial thickness (C-IMT), coronary artery calcium (CAC) and ankle-brachial index (ABI) in asymptomatic individuals. We analyzed these studies to examine this relationship as well as to guide future avenues of investigation by identifying studies that will help in the inclusion of tHcy levels in current guidelines on atherosclerotic disease management.

BACKGROUND

tHcy has been known to be associated with clinically evident atherosclerotic disease. However, tHcy is not incorporated in current guidelines for diagnosis of subclinical disease in high-risk asymptomatic individuals.

METHODS

We searched online databases (e.g., PUBMED, MEDLINE) for published articles assessing the relationship between tHcy and C-IMT, CAC and ABI. We limited the studies to asymptomatic populations, and excluded any study including symptomatic patients or individuals with a history of coronary, peripheral or cerebrovascular disease.

RESULTS

A systemic review of 19 articles revealed a significant association between elevated levels of tHcy and subclinical markers of atherosclerosis in asymptomatic individuals in most studies. Mean tHcy levels were consistently found to be higher in men compared to women. A total of 12 studies showed a significant association between tHcy and other risk markers of atherosclerosis, even after adjusting for age, sex and conventional risk factors. There were seven studies in unique populations that showed no significant relationship. We also observed that studies lowering baseline tHcy levels did not lead to an improvement in C-IMT, CAC or ABI scores. This might indicate that tHcy has a stronger role as a marker of atherosclerotic disease than as a risk factor for the same.

CONCLUSIONS

Based on our review, we conclude that there is a significant association between the subclinical atherosclerotic process and tHcy, and it shows potential as a cheap marker for risk stratification of asymptomatic patients. However, future studies further elucidating this association and elaborating the exact role of tHcy in the atherosclerotic disease process are required. The results of these studies suggest the incorporation of plasma tHcy levels in future risk reduction protocols for identification of individuals at higher risk of atherosclerotic events, and thus to categorize them for more aggressive treatment with established preventive and therapeutic measures.

Associations of methylenetetrahydrofolate reductase C677T polymorphism with markers of subclinical atherosclerosis: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

To study whether the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism or serum homocysteine concentration is associated with carotid artery intima media thickness (IMT), carotid artery compliance (CAC) or brachial artery flow mediated dilatation (FMD) in a healthy Finnish adult population.

METHODS

Cross-sectional data obtained in 2001 for the Cardiovascular Risk in Young Finns Study were used. Carotid artery IMT, CAC and brachial FMD were measured by ultrasound and serum homocysteine concentrations using a commercial immunoassay kit. We studied 1,440 subjects (aged 24-39 years). Genotyping was performed using the 5' nuclease TaqMan assay.

RESULTS

Homocysteine values differed between genotypes in women and men (ANOVA, p<0.001 for both sex groups): the genotype raised values in the order of CC, CT, TT. There was a significant difference in CAC values between the MTHFR genotypes in men (ANOVA, p = 0.008), and the CC genotype had the lowest values. In multivariate linear regression analysis adjusted for other major coronary risk factors (e.g. age, smoking, body mass index, systolic blood pressure, C-reactive protein), the association remained significant (R (2) = 25.8 %, beta = 0.091; p = 0.02). Homocysteine level was directly associated with CAC in the whole population (R (2) = 18.0 %, beta = 0.012; p = 0.014) and in women (R (2) = 9.3%, beta = 0.02; p = 0.013), but not in men (R (2) = 15.2 %, beta = 0.004; p = 0.444). We found no association between homocysteine level or the MTHFR polymorphism and carotid IMT or brachial artery FMD.

CONCLUSIONS

The findings suggest that the MTHFR polymorphism does not influence IMT or FMD, but that the T allele may have an effect on CAC in men.

Plasma folate concentration and cognitive performance: Rotterdam Scan Study

BACKGROUND

Evidence is increasing for beneficial and independent effects of folate on cognitive function, but the underlying biologic mechanism is as yet unknown.

OBJECTIVE

We examined the independent association of plasma folate concentration with cognitive performance and explored the nature of this association by evaluating brain-imaging markers for cerebrovascular disease and brain cell loss.

DESIGN

In the population-based Rotterdam Scan Study, 1033 nondemented participants aged 60-90 y underwent extensive cognitive testing and brain imaging. We cross-sectionally examined the association between plasma folate concentration and cognitive test performance by multivariate linear regression. To evaluate the role of vascular or other mechanisms in this association, we subsequently studied whether plasma folate was related to the presence of white matter lesions and hippocampal and amygdalar volumes.

RESULTS

After multivariate adjustment, the mean change in test score per 1-SD increase in plasma folate was 0.05 (95% CI: 0.01, 0.09) for global cognitive function, 0.08 (95% CI: 0.04, 0.13) for psychomotor speed, and 0.02 (95% CI: -0.04, 0.07) for memory function. Adjustment for homocysteine concentration only slightly diminished these associations. The odds ratio relating a 1-SD increase in plasma folate to the presence compared with the absence of severe white matter lesions was 0.79 (95% CI: 0.66, 0.94), whereas no relation was seen between folate status and hippocampal or amygdalar volume.

CONCLUSIONS

Higher plasma folate concentrations are associated with better global cognitive function and better performance on tests of psychomotor speed, regardless of homocysteine concentration. These associations may be mediated by vascular mechanisms.

Hyperhomocysteinemia-mediated DNA hypomethylation and its potential epigenetic role in rats

Hyperhomocysteinemia (HHcy), which is an independent risk factor for atherosclerosis, might cause dysregulation of gene expression, but the characteristics and key links involved in its pathogenic mechanisms are still poorly understood. The objective of the present study was to investigate the effect of HHcy on DNA methylation and the underlying mechanism of homocysteine (Hcy)-induced DNA methylation. HHcy was induced in Sprague-Dawley rats after 4 weeks of a low, medium or high methionine diet. The levels of total homocysteine, S-adenosylmethionine (AdoMet) and S-adenosylhomocysteine (AdoHcy) were detected by high-performance liquid chromatography. The expression levels of genes and proteins of S-adenosylhomocysteine hydrolase, DNA methyltransferase and methyl-CpG-binding domain 2 were detected by real-time reverse transcription-polymerase chain reaction and Western blot analysis. A high-throughput quantitative methylation assay using fluorescence-based real-time polymerase chain reaction was employed to determine the levels of DNA methylation. The results indicated that HHcy induced the elevation of AdoHcy concentration, the decline of AdoMet concentration, the ratios of AdoMet/AdoHcy and the RNA and protein expression of S-adenosylhomocysteine hydrolase and methyl-CpG-binding domain 2, as well as an increase of DNA methyltransferase activity. With different methylation-dependent restriction endonucleases, the aberrant demethylation was found to prefer CCGG sequences to CpG islands. Increasing levels of HHcy significantly increased genome hypomethylation in B1 repetitive elements. The impacts of different levels of HHcy showed that the varied detrimental effects of HHcy could be attributed to different concentrations through different mechanisms. In mild and moderate HHcy, the Hcy might primarily influence the epigenetic regulation of gene expression through the interference of transferring methyl-group metabolism. However, at high Hcy concentrations, the impacts might be more injurious through oxidative stress, apoptosis and inflammation.

Augmentation index and carotid intima-media thickness are differently related to age, C-reactive protein and oxidized low-density lipoprotein

OBJECTIVE

Ageing, plasma circulating C-reactive protein (CRP), oxidized low-density lipoprotein (OxLDL) and homocysteine (Hcy) are associated with atherosclerosis. The aim of this study was to evaluate the relationship between age, inflammatory and oxidative stress-related markers with functional and structural changes of the arteries in asymptomatic persons.

METHODS

CRP, OxLDL and Hcy were measured in 175 clinically healthy subjects, aged 40-70 years. Ultrasonography and pulse wave analysis were used to measure carotid intima-media thickness (IMT) and augmentation index (AIx).

RESULTS

OxLDL was correlated with IMT (r = 0.24, P = 0.003), whereas CRP was correlated with AIx (r = 0.21, P = 0.005). No correlation was detected between Hcy and AIx or age-adjusted IMT. There was a significant association between AIx and age <or=50 years (r = 0.33; P = 0.001) and between IMT and age > 50 years (r = 0.40; P = 0.001). In stepwise regression analysis age, weight, white blood cell count, OxLDL, heart rate and timing of the reflected waveform adjusted for height were significantly and independently associated with IMT (R = 0.41; P < 0.001). At the same time, AIx as the dependent variable correlated positively with age, gender, CRP and mean arterial pressure, and negatively with heart rate, weight and height, in stepwise regression analysis (R = 0.63; P < 0.001).

CONCLUSION

The results of the present study showed that CRP, OxLDL, Hcy and age are not similarly related to AIx and IMT in asymptomatic persons. The results suggest that CRP and younger age are related to arterial stiffness, whereas OxLDL and older age become more important determinants of structural changes of the arteries in asymptomatic persons.

Clinical Use of Carotid Intima-Media Thickness: Review of the Literature

Carotid intima-media thickness (CIMT) is a simple and inexpensive tool to assess the cumulative effect of atherosclerotic risk factors and is an independent predictor of future cardiovascular risk. CIMT is commonly used as a surrogate end point in research trials as a marker of atherosclerosis. However, new software programs have made CIMT a clinically practical examination for risk evaluation. CIMT correlates with cardiac risk factors and is an independent predictor of future myocardial infarction and stroke risk. Tests for subclinical atherosclerosis, such as CIMT, will help clinicians to more effectively identify the vulnerable patient who would benefit from aggressive prevention intervention.

Circulating homocysteine and large arterial stiffness and thickness in a population-based sample of middle-aged and elderly men

Elevated plasma homocysteine (tHcy) is considered as a risk factor for cardiovascular events, and has been associated with arterial stiffness and subclinical atherosclerosis in subjects with classical cardiovascular risk factors. The aim of this study is to investigate the association of plasma tHcy with functional and structural changes in the large arteries by measuring aortic pulse-wave velocity (PWV) and carotid artery intima-media thickness (CIMT). In a population-based sample of 376 middle-aged and elderly men, tHcy levels were measured by using fluorescence polarization immunoassay. Aortic stiffness was assessed non-invasively by measuring carotid-femoral PWV with the use of applanation tonometry. CIMT was measured by ultrasonography. We used multivariate linear regression analysis with the log-transformed value of tHcy as the determinant, and aortic PWV and CIMT as outcomes. In the univariate model, PWV increased with increasing tHcy concentration; PWV increased by 2.64 m/s (95% confidence interval (CI) 1.74; 3.54) per unit change in log tHcy. After adjustment for confounders, no statistically significant association remained; PWV increased by 0.42 m/s (95% CI -0.27; 1.11) per unit change in log tHcy. Furthermore, in the univariate model, CIMT increased significantly with increasing tHcy concentration; CIMT increased by 0.19 mm (95% CI 0.11; 0.26) per unit increase log tHcy. This association was attenuated and did not remain significant after additional adjustment for age and cardiovascular confounders (beta=0.06 (95% CI -0.01; 0.13)). The results of this study do not support the presence of an independent relationship between circulating tHcy levels and large artery stiffness and thickness.

Evaluation of cardiovascular risk factors and related clinical markers in healthy young Japanese adults

BACKGROUND

Since atherosclerosis is a slowly progressive process at a young age, effective preventive measures should be taken early in life to prevent future events associated with cardiovascular disease.

METHODS

The study population comprised 132 young Japanese adults (mean age 21.4 years, range 18-31 years). We screened plasma total homocysteine and serum folate levels and evaluated mean carotid intima-media thickness and cardio-ankle vascular index.

RESULTS

Multiple regression analysis after adjustment for age and sex revealed that only folate levels were significantly correlated with plasma total homocysteine levels (beta=-0.37, p=0.028). Carotid intima-media thickness adjusted for age and sex and compared between quintiles of total homocysteine levels was significantly increased in the highest quintile compared with other quintiles. Cardio-ankle vascular index increased with age in both women and men, but no additional determinants were identified in young adults.

CONCLUSION

Serum folate is an independent determinant of plasma total homocysteine levels, and mild hyperhomocysteinemia may represent a risk factor for increased carotid intima-media thickness, even in young adults. Comprehensive health education from the early period of life, including the suggestion of appropriate dietary measures, is important for effective prevention of future atherosclerosis.

Homocysteine, B vitamins, and the incidence of dementia and cognitive impairment: results from the Sacramento Area Latino Study on Aging

BACKGROUND

High concentrations of homocysteine have been linked to a greater risk of Alzheimer disease, dementia, and cognitive decline.

OBJECTIVE

We evaluated the association between homocysteine and 4.5-y combined incidences of dementia and cognitive impairment without dementia (CIND) in a cohort of 1779 Mexican Americans aged 60-101 y.

DESIGN

Homocysteine, red blood cell (RBC) folate, and plasma vitamin B-12 were measured at baseline. New cases of dementia or CIND were ascertained by neuropsychological and clinical examinations and expert adjudication. We used proportional hazards models to estimate the risk of homocysteine-associated dementia or CIND and the influence of RBC folate and plasma vitamin B-12 on that association.

RESULTS

High homocysteine concentrations were associated with a greater risk of dementia or CIND: hazard ratio (HR): 2.39; 95% CI: 1.11, 5.16. Plasma vitamin B-12 modified the association between homocysteine and the outcome. The rates of dementia or CIND associated with homocysteine for those in the lowest and highest tertiles of vitamin B-12, respectively, were significantly higher (HR: 1.61, P = 0.04) and lower (HR: 0.94, P = 0.015) than the risk for those in the middle tertile.

CONCLUSIONS

Homocysteine is an independent risk factor for both dementia and CIND. Higher plasma vitamin B-12 may reduce the risk of homocysteine-associated dementia or CIND.

Carotid intima-media thickness in coronary slow flow: relationship with plasma homocysteine levels

BACKGROUND AND OBJECTIVE

Coronary slow-flow phenomenon is characterized by delayed opacification of coronary vessels in a normal coronary angiogram. Although clinical and pathological features have been previously described, the underlying pathophysiology has not been fully elucidated. Thus, it still remains to be determined whether either microvascular or epicardial diffuse atherosclerotic disease is related to slow flow. In this study, we aimed to determine the carotid artery intima-media thickness, which is a marker of atherosclerosis in patients with coronary slow flow, and its possible relationship with the total homocysteine level.

METHOD

The study population consisted of 88 patients who underwent coronary angiography because of typical and quasi-typical symptoms of angina. Forty-four patients with angiographically proven coronary slow flow and 44 individuals with normal coronary flow pattern with similar risk profiles were enrolled in the study. Coronary flow patterns of the latter were determined by the thrombolysis in myocardial infarction frame count method. Intima-media thickness was measured by recording ultrasonographic images of both the left and the right common carotid artery with a 12-MHz linear array transducer. Plasma homocysteine, folate and B12 levels were measured from blood samples.

RESULTS

Plasma homocysteine levels (mumol/l) and carotid intima-media thickness (mm) of patients with coronary slow flow were found to be significantly higher than that of controls (12.4+/-4.9 vs. 8.5+/-2.8, P=0.0001; 0.75+/-0.08 vs. 0.69+/-0.06, P=0.0001, respectively). The plasma folate level (ng/ml) was lower in coronary slow-flow patients than in controls (13.8+/-4.4 vs. 16.5+/-5.6, P=0.014). The plasma homocysteine level was significantly positively correlated with the mean thrombolysis in myocardial infarction frame count and intima-media thickness of the carotid artery in correlation analysis (r=0.58, P=0.0001; r=0.41, P=0.0001; respectively).

CONCLUSION

Homocysteine levels and carotid intima-media thickness increased but folate levels decreased in patients with coronary slow flow. The present findings allow us to conclude that the possible disturbance in the metabolism of homocysteine in patients with coronary slow flow may have a role in the etiopathogenesis of this phenomenon by causing generalized atherosclerosis.

Association of Homocysteine and Asymmetric Dimethylarginine With Atherosclerosis and Cardiovascular Events in Maintenance Hemodialysis Patients

BACKGROUND

Homocysteine (Hcy) and asymmetric dimethylarginine (ADMA) recently were recognized as potential risk factors for atherosclerosis in the general population, and the metabolism of each of these substances seems to be closely related. This study investigates the association between these substances and whether elevated serum Hcy and ADMA levels are related to high risk for atherosclerosis and cardiovascular events in maintenance hemodialysis (HD) patients.

METHODS

A study was made of 197 HD patients (132 men, 65 women; mean age, 56.9 +/- 8.6 years) for the correlation between plasma total Hcy (tHcy) and ADMA concentrations and the association of these substances with atherosclerotic indices of cervical intima-media thickness, plaque diameter, aortic calcification index, and aortic elongation. Cardiovascular events were followed up for 5 years in these patients.

RESULTS

Mean plasma tHcy (37.3 +/- 25.8 micromol/L) and ADMA (0.77 +/- 0.16 micromol/L) levels were significantly greater in HD patients than in healthy subjects. Plasma tHcy level did not correlate with plasma ADMA level (r = -0.1; P = not significant). Although ADMA level was associated significantly with atherosclerotic indices from a simple regression analysis, this association was less from multiple regression analysis. When patients were classified into 3 groups according to ADMA level, cardiovascular events during 5 years were significantly greater in the group with the highest ADMA levels than in the other groups, confirmed by using a Cox proportional hazard model. However, no association was found between tHcy levels and atherosclerotic indices or cardiovascular events.

CONCLUSION

ADMA level emerged as a potential risk factor for cardiovascular events that might be mediated in part by atherosclerosis in HD patients. Conversely, neither high nor low plasma tHcy levels were associated with atherosclerotic indices and cardiovascular events. This result for our HD patients does not fulfill the terms of traditional epidemiology and paradoxical reverse epidemiology of Hcy.

Lack of the antioxidant glutathione peroxidase-1 does not increase atherosclerosis in C57BL/J6 mice fed a high-fat diet

Oxidative stress is thought to contribute to the initiation and progression of atherosclerosis. As glutathione peroxidase-1 (Gpx1) is an antioxidant enzyme that detoxifies lipid hydroperoxides, we tested the impact of Gpx1 deficiency on atherosclerotic processes and antioxidant enzyme expression in mice fed a high-fat diet (HFD). After 12 weeks of HFD, atherosclerotic lesions at the aortic sinus were of similar size in control and Gpx1-deficient mice. However, after 20 weeks of HFD, lesion size increased further in control but not in Gpx1-deficient mice, even though plasma and aortic wall markers of oxidative damage did not differ between groups. In control mice, the expression of Gpx1 increased and that of Gpx3 decreased at the aortic sinus after 20 weeks of HFD, with no change in the expression of Gpx2, Gpx4, catalase, peroxiredoxin-6, glutaredoxin-1 and -2, or thioredoxin-1 and -2. By comparison, in Gpx1-deficient mice, the expression of antioxidant genes was unaltered except for a decrease in glutaredoxin-1 and an increase in glutaredoxin-2. These changes were associated with increased expression of the proinflammatory marker monocyte chemoattractant protein-1 in control mice but not in Gpx1-deficient mice. In summary, a specific deficiency in Gpx1 was not accompanied by an increase in markers of oxidative damage or increased atherosclerosis in a murine model of HFD-induced atherogenesis.

Increase of carotid artery stiffness and decrease of baroreflex sensitivity in exfoliation syndrome and glaucoma

AIM

To investigate the distensibility of the common carotid artery (CCA), baroreflex sensitivity (BRS) and its relation to plasma homocysteine concentration in exfoliation syndrome or exfoliation glaucoma (XFS/XFG).

METHODS

Homocysteine concentrations were measured in 30 XFS/XFG patients and 18 age matched controls. In 21 patients and 17 controls the end diastolic diameter of the CCA and pulsatile distension were measured and BRS was calculated.

RESULTS

There was no significant difference between the groups in sex distribution, age, heart rate, blood pressure, systemic diseases, or medication. In XFS/XFG patients homocysteine concentration was significantly elevated (unpaired t test, p = 0.023), and CCA stiffness was higher (p<0.05), while strain, cross sectional compliance coefficient, distensibility, and BRS were significantly reduced compared to the controls (Mann-Whitney U test, p< or =0.013 for each parameter). In XFS/XFG patients a positive correlation was found between age and plasma homocysteine level (Pearson's correlation, r = 0.490, p = 0.007), and a negative correlation between age and BRS (Kendall's correlation r = -0.374, p = 0.021), as well as between homocysteine concentration and BRS (Kendall's correlation r = -0.377, p = 0.024). No correlation was seen between these variables in the control group.

CONCLUSIONS

These results suggest a pathological large artery function as well as altered parasympathetic vascular control in XFS/XFG which increases with age and with higher homocysteine concentration.

Homocysteine Lowering with Folic Acid and Vitamin B Supplements

Cardiovascular disease (CVD) is the leading cause of death in older men and women and contributes significantly to morbidity in later life. Folic acid and other vitamin B deficiencies and elevated total plasma homocysteine levels are associated with increased cardiovascular risk in geriatric patients, but recent studies have questioned the importance of these risk factors in older people. Data on the effects of homocysteine-lowering therapy (e.g. folic acid and vitamin B supplements) on surrogate CVD endpoints, such as atherosclerotic progression, endothelial function, inflammation and hypercoagulation, are conflicting. Findings from randomised clinical trials using clinical CVD outcomes show that folic acid and vitamin B supplements may not provide cardiovascular protection. Furthermore, these findings raise questions about whether the combination of folic acid and B vitamins may actually be harmful. Other large randomised clinical trials are underway to help clarify the role of folic acid and vitamin B supplements in CVD prevention in older people. Data to date do not support use of homocysteine-lowering therapies in either middle-aged or older adults.

Homocysteine is not associated with arterial thickness and stiffness in healthy middle-aged French volunteers

BACKGROUND

To study the association between the total plasma homocysteine (tHcy) concentration and the carotid artery intima-medial wall thickness (IMT), pulse wave velocity (PWV) and the presence of arterial plaques in a French population.

METHODS

Cross-sectional analysis of data from 556 male and 559 female middle-aged participants (mean (+/-SD) age 59.6+/-4.7 years) provided by an ongoing intervention trial.

RESULTS

Mean geometric tHcy concentration was higher for men than for women (10.6 vs. 8.5 micromol/L, p<0.001) and was associated in the expected direction with known determinants. The mean IMT was 0.71+/-0.1 mm for men and 0.69+/-0.1 mm for women (p<0.001), the mean PWV was, respectively, 12.0+/-2.8 and 10.9+/-2.2 m/sec (p<0.001), and the percentages of subjects with plaques were, respectively, 40.8% and 22.7% (p<0.001). In men only, the age-adjusted mean IMT and PWV increased with an increasing tHcy concentration: the IMT was 0.71 mm in the first tHcy-quartile and 0.73 mm in the fourth tHcy-quartile (p for linear trend=0.03), the PWV values were, respectively, 11.6 and 12.4 m/sec (p for linear trend=0.01). These associations disappeared after adjustment for conventional cardiovascular disease risk factors.

CONCLUSION

In this population, the tHcy concentration was not associated with measures of arterial thickness and stiffness.