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Plasma Homocysteine Levels (plasma + homocysteine_level)

Distribution by Scientific Domains

Medical Sciences	93%

Distribution within Medical Sciences

Neurology	27%
Dermatology	13%

Selected Abstracts

Effect of Chronic Alcohol Consumption on Total Plasma Homocysteine Level in Rats

ALCOHOLISM, Issue 3 2000
Felix Stickel
Background: Chronic alcoholism in humans is associated with the development of hyperhomocysteinemia, the mechanism of which remains unclear. Among the causes of hyperhomocysteinemia is depletion of folate, vitamin B12, or vitamin B6, Population-based studies indicate that folate is the strongest vitamin determinant of hyperhomocysteinemia and, in most settings, folate supplementation effectively lowers elevated homocysteine levels. However, it is not clear whether folate deficiency is the cause of alcoholrelated hyperhomocysteinemia. Methods: In the present study, 10 male Sprague Dawley® rats were fed ethanol-containing Lieber- DeCarli diets with 13 mg of folic acid per kilogram of diet. This represents a folate intake more than 20 times the basal requirement. Ethanol represented 36% of total energy, which yielded a concentration of 6.2% (vol/vol). The same number of rats were pair-fed with isocaloric control diets that contained an identical level of folate in which ethanol was entirely replaced by maltodextrin. Results: At the end of 4 weeks, alcohol-fed rats did not show any significant reduction in plasma or hepatic folate concentrations, plasma pyridoxal-5,-phosphate concentration, or plasma vitamin B12 concentration. On the other hand, alcohol-fed rats were significantly hyperhomocysteinemic (17.24 ± 4.63 ,mol/liter,p < 0.01) compared to the nonalcohol group (10.73 ± 2.76 ,mol/liter). Alcohol-fed rats also had a significantly lower hepatic S-adenosylmethionine and higher hepatic S-adenosylhomocysteine levels. Conclusions: Chronic alcohol consumption produces hyperhomocysteinemia by a mechanism that is related to interference with one-carbon metabolism, and not through vitamin depletion. [source]

C677T polymorphism of methylenetetrahydrofolate reductase gene affects plasma homocysteine level and is a genetic factor of late-onset Alzheimer's disease

PSYCHOGERIATRICS, Issue 1 2004
Tomoyuki KIDA
Abstract Background:, Elevated plasma homocysteine levels are known as a risk for atherosclerotic vascular disease and venous thrombosis and have been shown as a risk for late-onset Alzheimer's disease (LOAD). Method:, To examine the effect of genetic factors predisposing to elevated plasma homocysteine levels on the occurrence of LOAD, we determined the genotype of a C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene and a variable number tandem repeat (VNTR) spanning exon 13,intron 13 boundary of cystathionine ,-synthase (CBS) gene in patients with LOAD and community-based control subjects. Results:, Logistic regression indicated that the MTHFR-T allele was a risk for LOAD (P < 0.05), independently from apolipoprotein E-,4 (APOE-,4) allele. Kaplan,Meier tests showed that in APOE-,4 non-carriers, individuals with the MTHFR-TT genotype have occurences of LOAD earlier than those with the MTHFR-CC genotype (P < 0.05). Multiple regression analysis indicates that MTHFR-T allele increases plasma homocysteine levels (P = 0.0002), while the number of X chromosomes decreases (P = 0.01). Plasma homocysteine level was not correlated with age, plasma albumin reflecting nutritional condition, and the dose of APOE-,4 allele. The CBS-20 VNTR allele showed the same trend to increase plasma homocysteine level as the MTHFR-T allele, but a risk effect for LOAD was not evident. Conclusion:, A genetic propensity for elevated plasma homocysteine levels, explained by the MTHFR-T allele encoding defective enzymatic function, is involved in the development of LOAD, particularly in APOE-,4 non-carriers, and that homocysteine metabolism could be a preventive target to LOAD in the elderly. [source]

Homocysteine, white matter hyperintensities, and cognition in healthy elderly people

ANNALS OF NEUROLOGY, Issue 2 2003
Carole Dufouil PhD
Hyperhomocysteinemia is associated with an increased risk of vascular disease, and recent results suggest that it also could increase the risk of dementia. We examined the relationship between homocysteine and cognitive decline in 1,241 subjects aged 61 to 73 years, followed up over 4 years. Plasma homocysteine levels were determined in all participants as well as cardiovascular risk factors, apolipoprotein E genotype, plasma levels of folate, and vitamin B12. Cognitive performances were assessed repeatedly by using Mini-Mental State Examination, Trail Making Test, Digit Symbol Substitution Test, and Finger Tapping Test. At 2-year follow-up, 841 subjects underwent cerebral magnetic resonance imaging, and white matter hyperintensities were rated visually. Analyses were adjusted for all cardiovascular risk factors. Cross-sectional analyses showed that higher concentrations of homocysteine were significantly related to poorer performances at all neuropsychological tests. Longitudinal analyses confirmed this finding. The odds of cognitive decline was 2.8-fold (p < 0.05) higher in subjects with homocysteine levels above 15,mol/L compared with those with homocysteine levels below 10,mol/L. In participants who underwent magnetic resonance imaging, the relationship between homocysteine and cognition was unchanged after taking into account white matter hyperintensities suggesting that white matter hyperintensities do not mediate the association between homocysteine and cognition. Ann Neurol 2003;53:000,000 [source]

Plasma homocysteine and folate levels in patients with chronic plaque psoriasis

BRITISH JOURNAL OF DERMATOLOGY, Issue 6 2006
M. Malerba
Summary 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 ,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 B6 and B12 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. [source]

C677T polymorphism of methylenetetrahydrofolate reductase gene affects plasma homocysteine level and is a genetic factor of late-onset Alzheimer's disease

Homozygous thermolabile variant of the methylenetetrahy-drofolate reductase gene: a potential risk factor for hyperhomo-cysteinaemia, CVD, and stroke in childhood

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 4 2001
Mara Prengler
In this study of 118 children (median age 5.1 years; range 6 months to 17 years) with ischaemic stroke or transient ischaemic attack (TIA), 22 children (19%) were homozygous for the thermolabile variant of the methylenetetrahydrofolate reductase allele (t-MTHFR), compared with nine of 78 (12%) of a reference population (p=0.18, OR 1.76, 95% CI 0.76 to 4.04). Of those with cerebrovascular disease (CVD), 17 of 84 were homozygous for the t-MTHFR allele (p=0.13 compared with the reference population (OR 1.95, 95% CI 0.81 to 4.65). There was a significant (p<0.025) increment of plasma total homocysteine concentration in homozygotes for the t-MTHFR allele compared with heterozygotes, negatives for the t-MTHFR allele, and control children with no history of stroke. In four of 12 homozygotes for the t-MTHFR allele, plasma homocysteine levels were raised, compared with three of 38 of those who were negative or heterozygous (p=0.047; OR 5.8, 95% CI 1.1 to 31.2). Homozygotes for the t-MTHFR allele were significantly more likely to have a recurrent event than those who were negative or heterozygous (Cox regression p=0.031, hazard ratio 2.18, 95% CI 1.08 to 4.42). These data suggest that homozygosity for the t-MTHFR allele is associated with raised homocysteine levels in children and is a risk factor for primary and secondary stroke and TIA. [source]

An Assessment of the Potential Value of Elevated Homocysteine in Predicting Alcohol-withdrawal Seizures

EPILEPSIA, Issue 5 2006
Stefan Bleich
Summary:,Purpose: Higher homocysteine levels were found in actively drinking patients with alcohol dependence. Recent studies have shown that high homocysteine levels are associated with alcohol-withdrawal seizures. The aim of the present study was to calculate the best predictive cutoff value of plasma homocysteine levels in actively drinking alcoholics (n = 88) with first-onset alcohol-withdrawal seizures. Methods: The present study included 88 alcohol-dependent patients of whom 18 patients had a first-onset withdrawal seizure. All patients were active drinkers and had an established diagnosis of alcohol dependence, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Sensitivity and specificity were calculated by using every homocysteine plasma level found in the study population as cut-off value. A Bayes theorem was used to calculate positive (PPV) and negative (NPV) predictive values for all cutoff values used. Results: The highest combined sensitivity and specificity was reached at a homocysteine plasma cutoff value of 23.9 ,M. Positive predictive values ranged from 0.23 to 0.745; the maximum was reached at a homocysteine plasma level of 41.7 ,M. Negative predictive values ranged from 0.50 to 0.935, with a maximum at a homocysteine plasma level of 15.8,M. Conclusions: Homocysteine levels above this cutoff value on admission are a useful screening tool to identify actively drinking patients at higher risk of alcohol-withdrawal seizures. This pilot study gives further hints that biologic markers may be helpful to predict patients at risk for first-onset alcohol-withdrawal seizures. [source]

The effects of tobacco smoke on the homocysteine level,a risk factor of atherosclerosis

ADDICTION BIOLOGY, Issue 2 2003
ANDRZEJ SOBCZAK
Homocysteine may promote atherogenesis and thrombogenesis. There is evidence from case,control and cross-sectional cohort studies that there is a positive association between plasma homocysteine levels and coronary artery disease, cerebrovascular disease and peripheral vascular disease. There is also some evidence that certain life-style factors such as cigarette smoking may affect homocysteine levels. In this work is presented a review of recent opinion about the influence of tobacco smoking on homocysteine levels. [source]

Epidemiology of Intracranial Stenosis

JOURNAL OF NEUROIMAGING, Issue S1 2009
M. Fareed K. Suri MD
ABSTRACT 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. [source]

Plasma Homocysteine, Fasting Insulin, and Androgen Patterns among Women with Polycystic Ovaries and Infertility

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 3 2001
Dr. E. Scott Sills
Abstract Objective: To measure plasma homocysteine, androgen, and insulin concentrations in women with normal and polycystic-appearing ovaries in an infertility setting. Methods: Among women referred for infertility evaluation (n = 54), homocysteine, androstenedione, DHEAS, total testosterone, fasting insulin/glucose and methyltetrahydrofolate reductase (MTHFR) polymorphism status (C677T mutation) were studied. Ovaries were examined via transvaginal sonogram by one observer and scored as either normal (n = 18) or polycystic (n = 36). Results: When polycystic ovaries were identified, mean total testosterone was significantly higher than when non-polycystic ovaries were present (p = 0.01), although no measured androgen was outside the normal reference range in either group. Average BMI was higher in the polycystic group, but the difference was not significant (p = 0.10). We observed a trend toward higher mean fasting insulin levels in women with polycystic ovaries, but this increase did not reach statistical significance (p = 0.07). Median plasma homocysteine was identical (7.0 mmol/l) in both populations, and no study subject exceeded the current recommended maximum reference value. Conclusions: In this population, the presence of polycystic ovaries was associated with higher serum androgens (especially total testosterone) although none of the measured androgens were above the normal range. While fasting insulin levels were also higher in this group, median plasma homocysteine levels were similar irrespective of ovarian morphology. Concomitant plasma homocysteine derangements in this population of young, lean patients with polycystic-appearing ovaries seem unlikely. Further studies are needed to clarify the role(s) of homocysteine in human reproductive physiology. [source]

C677T polymorphism of methylenetetrahydrofolate reductase gene affects plasma homocysteine level and is a genetic factor of late-onset Alzheimer's disease

The effect of isotretinoin treatment on plasma homocysteine levels in acne vulgaris

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2010
M. R. Roodsari
Summary Isotretinoin has revolutionized the treatment of acne by improving the cosmetic outcome and decreasing the psychological damage. However, use of isotretinoin is associated with significant side-effects such as mucocutaneous involvement, dyslipidaemia and liver dysfunction, as indicated by increases in liver enzymes. The responsible enzyme for homocysteine metabolism, cystathionine-,-synthase, might also be affected by isotretinoin-induced liver dysfunction, which leads to hyperhomocysteinaemia, an independent risk factor for thrombovascular diseases. The aim of this study was to evaluate homocysteine levels and the responsible vitamins for its metabolism in patients with moderate to severe acne vulgaris on isotretinoin treatment, before and after treatment. We found increased level of homocysteine in patients after 2 months of taking isotretinoin. Our findings suggest that isotretinoin may increase the risk of cardiovascular disorders by causing hyperhomocysteinaemia. [source]

HYPERHOMOCYSTEINAEMIA AND MEMBRANE FLUIDITY OF RED BLOOD CELLS IN NORMOTENSIVE AND HYPERTENSIVE MEN: AN ELECTRON PARAMAGNETIC RESONANCE INVESTIGATION

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 2007
Kazushi Tsuda
SUMMARY 1The purpose of the present study was to assess the possible link between plasma homocysteine and membrane fluidity in normotensive and hypertensive men. 2The membrane fluidity (a reciprocal value of membrane microviscosity) of red blood cells (RBC) was measured using an electron paramagnetic resonance and spin-labelling method. The membrane fluidity of RBC was decreased in hypertensive compared with normotensive men. 3Total plasma homocysteine levels were significantly higher in hypertensive men than normotensive men. In contrast, plasma levels of nitric oxide (NO) metabolites were significantly lower in hypertensive men than in normotensive men. The decreased membrane fluidity of RBC was associated with hyperhomocysteinaemia and reduced plasma levels of NO metabolites. 4The results of the present study suggest that hyperhomocysteinaemia may have a role in modulating the rheological behaviour of RBC and microcirculation in men by, at least in part, reducing NO bioavailability. [source]