Short-term cognition deficits during early alcohol withdrawal are associated with elevated plasma homocysteine levels in patients with alcoholism

Alcohol use disorders and the brain

A diagnosis of alcohol use disorder is associated with a higher risk of dementia, but a dose-response relationship between alcohol intake consumption and cognitive impairment remains unclear. Alcohol is associated with a range of effects on the central nervous system at different doses and acts on a number of receptors. Acute disorders include Wernicke's encephalopathy (WE), traumatic brain injury, blackouts, seizures, stroke and hepatic encephalopathy. The most common manifestations of chronic alcohol consumption are Korsakoff's syndrome (KS) and alcohol-related dementia (ARD). There is limited evidence for benefit from memantine in the treatment of ARD, but stronger evidence for the use of high-dose parenteral thiamine in the progression of neuropsychiatric symptoms for WE. Accumulating evidence exists for pharmacological treatment in the prevention of hepatic encephalopathy. Rehabilitation of people with ARD may take several years, and requires an approach that addresses physical and psychosocial factors.

Homocysteine, Alcoholism, and Its Potential Epigenetic Mechanism

Alcohol is the most socially accepted addictive drug. Alcohol consumption is associated with some health problems such as neurological, cognitive, behavioral deficits, cancer, heart, and liver disease. Mechanisms of alcohol-induced toxicity are presently not yet clear. One of the mechanisms underlying alcohol toxicity has to do with its interaction with amino acid homocysteine (Hcy), which has been linked with brain neurotoxicity. Elevated Hcy impairs with various physiological mechanisms in the body, especially metabolic pathways. Hcy metabolism is predominantly controlled by epigenetic regulation such as DNA methylation, histone modifications, and acetylation. An alteration in these processes leads to epigenetic modification. Therefore, in this review, we summarize the role of Hcy metabolism abnormalities in alcohol-induced toxicity with epigenetic adaptation and their influences on cerebrovascular pathology.

Are Alcohol Anti-relapsing and Alcohol Withdrawal Drugs Useful in Cannabinoid Users?

Cannabinoids are still classified as illegal psychoactive drugs despite their broad and increasingly acknowledged therapeutic potential. These substances are most famous for their wide recreational use, particularly among young adults to either alter the state of consciousness, intensify pleasure induced by other psychoactive substances or as an alternative to the previously abused drugs. It is important to emphasize that cannabinoids are often taken together with a variety of medications intended for the treatment of alcohol use disorder (AUD) or alcohol withdrawal syndrome (AWS). These medications include disulfiram, acamprosate, and naltrexone. In this paper, we summarize recent advances in the knowledge of possible beneficial effects and interactions between cannabinoids and drugs commonly used for treatment of AUD and AWS either comorbid or existing as a separate disorder.

Alcohol and cognition in the elderly: a review

Consumption of large amounts of alcohol is known to have negative effects, but consumption in smaller amounts may be protective. The effect of alcohol may be greater in the elderly than in younger adults, particularly with regard to cognition. However, the drinking pattern that will provide optimal protection against dementia and cognitive decline in the elderly has not been systematically investigated. The present paper is a critical review of research on the effect of alcohol on cognitive function and dementia in the elderly. Studies published from 1971 to 2011 related to alcohol and cognition in the elderly were reviewed using a PubMed search. Alcohol may have both a neurotoxic and neuroprotective effect. Longitudinal and brain imaging studies in the elderly show that excessive alcohol consumption may increase the risk of cognitive dysfunction and dementia, but low to moderate alcohol intake may protect against cognitive decline and dementia and provide cardiovascular benefits. Evidence suggesting that low to moderate alcohol consumption in the elderly protects against cognitive decline and dementia exists; however, because of varying methodology and a lack of standardized definitions, these findings should be interpreted with caution. It is important to conduct more, well-designed studies to identify the alcohol drinking pattern that will optimally protect the elderly against cognitive decline and dementia.

Biological markers for alcohol withdrawal seizures: a retrospective analysis

AIMS

Alcohol withdrawal seizures (AWS) are among the most important possible complications during the detoxification treatment of alcohol-dependent patients. Pharmacological therapy is often used during detoxification, but can cause dangerous side effects [Eur Addict Res 2010;16:179-184]. In separate studies several biological markers have been described as being associated with AWS risk. We investigated the role of homocysteine (HCT), carbohydrate-deficient transferrin (CDT) and prolactin (PRL) as biological markers for the risk of developing AWS.

METHODS

The present study included 189 alcohol-dependent patients of whom 51 had a history of AWS. We investigated the HCT, CDT and PRL levels of all patients and calculated sensitivity and specificity. Bayes' theorem was used to calculate positive (PPV) and negative (NPV) predictive values.

RESULTS

The highest combined sensitivity and specificity for %CDT was reached at a plasma cutoff value of 3.75%. The combination of HCT at a cutoff value of 23.9 μmol/l and %CDT at a cutoff value of 3.75% showed the best predictive values (sensitivity 47.1%, specificity 88.4%, PPV 0.504, NPV 0.870).

CONCLUSION

A combined assessment of HCT and CDT levels can be a useful method to identify patients at a higher risk of AWS, which may lead to a more individualized therapy.

Reduced de novo synthesis of 5-methyltetrahydrofolate and reduced taurine levels in ethanol-treated chick brains

In previous studies, exogenous ethanol (3 mmol EtOH/kg egg) caused a 1.6-fold increase in chick brain homocysteine (HoCys) levels at 11 days of development and the mixture of 3 mmol EtOH/kg egg and 34 micromol folic acid/kg egg attenuated EtOH-induced increases in chick brain HoCys levels. Because HoCys is converted to methionine utilizing the methyl donor, 5-methyltetrahydrofolate (5-methyl THF), we studied whether exogenous ethanol (3 mmol EtOH/kg egg) or the mixture of 3 mmol EtOH/kg egg and 34 micromol 5-methyl THF/kg egg inhibited chick brain 10-formyltetrahydrofolate dehydrogenase (10-FTHF DH; EC 1.5.1.6) activities and brain N5, N10-methylenetetrahydrofolate reductase (MTHFR; EC 1.5.1.20) activities at 11 days of development. Three daily dosages of 3 mmol EtOH/kg egg (E0-2) caused approximately a 7-fold reduction in brain 10-FTHF DH activities and approximately a 1.9-fold reduction in brain MTHFR activities as compared to controls at 11 days of development (p<or=0.05). Because HoCys is also removed by the transsulfuration pathway, which synthesizes taurine, we studied whether exogenous ethanol (3 mmol EtOH/kg egg) or the mixture of 3 mmol EtOH/kg egg and 34 micromol 5-methyl THF/kg egg influenced chick brain taurine levels. In EtOH-treated and EtOH and 5-methyl THF-treated embryos, brain taurine levels decreased by approximately 5.5-fold and 6.2-fold as compared to controls, respectively (p<or=0.05). Exogenous 5-methyl THF failed to attenuate EtOH-induced decreased brain taurine levels at 11 days of development.

Ethanol and cognition: indirect effects, neurotoxicity and neuroprotection: a review

Ethanol affects cognition in a number of ways. Indirect effects include intoxication, withdrawal, brain trauma, central nervous system infection, hypoglycemia, hepatic failure, and Marchiafava-Bignami disease. Nutritional deficiency can cause pellagra and Wernicke-Korsakoff disorder. Additionally, ethanol is a direct neurotoxin and in sufficient dosage can cause lasting dementia. However, ethanol also has neuroprotectant properties and in low-to-moderate dosage reduces the risk of dementia, including Alzheimer type. In fetuses ethanol is teratogenic, and whether there exists a safe dose during pregnancy is uncertain and controversial.

Short-term influence of elevation of plasma homocysteine levels on cognitive function in young healthy adults

BACKGROUND

Acute homocysteine elevation has been shown to have a significant impact on cognitive function in animal models.

OBJECTIVES

Investigation of the short-term impact of elevation of plasma homocysteine levels through a dietary intervention on cognitive abilities of young healthy adults.

PARTICIPANTS

100 healthy medical students of both genders were enrolled in the study.

DESIGN AND MEASUREMENTS

Homocysteine levels and cognitive abilities were measured at 08:30 (before breakfast) and at 15:00 (two hours after lunch and six hours after breakfast). Food intake was restricted to specified comestibles. The cognitive assessment comprised a version of the Short Test for General Intelligence, three subtests of the Syndrome Short Test and the Stroop test.

RESULTS

At 15:00 plasma homocysteine was significantly elevated in 56 participants (P < 0.00001), whilst in 44 it was decreased (P < 0.00001) in comparison to baseline (08:30). The decrease was however of limited clinical significance. The differences in the changes in cognitive performance between the two groups did not attain statistical significance (P > 0.05) and the direction of the changes did not differ between them. Accordingly, the multiple linear regression analysis did not reveal an important influence of homocysteine elevation on cognitive performance variations.

CONCLUSIONS

Significant increase of plasma homocysteine is not associated with a straightforward inhibitory or facilitatory short-term effect on physiological cognitive parameters in young healthy adults.

Exogenous folate ameliorates ethanol-induced brain hyperhomocysteinemia and exogenous ethanol reduces taurine levels in chick embryos

The effects of exogenous ethanol and/or folic acid on endogenous homocysteine (HoCys) and SAM (S-adenosylmethionine)/SAH (S-adenosylhomocysteine) levels in chick brains were studied at 11 days of development. Embryonic EtOH (3.0 mmol/kg egg) exposure caused a 1.6-fold increase in brain HoCys levels and a 9-fold decrease in brain SAM/SAH levels as compared to controls (p<or=0.05). Brain HoCys and SAM/SAH levels returned to control values when injected with a mixture of EtOH and folic acid (3.0 mmol EtOH/kg egg and 34 mumol folic acid/kg egg). The effects of exogenous EtOH on the remethylation pathway, as measured by 10-formyltetrahydrofolate dehydrogenase (10-FTHF DH) activities, and the transsulfuration pathway, as measured by taurine levels, were studied at 18 days of development. A single dosage of EtOH (3.0 mmol/kg egg; E(0)) and two daily dosages of EtOH (E(0-1)) failed to influence brain and hepatic 10-FTHF DH activities when compared to controls. However, three daily dosages of EtOH (E(0-2)) caused approximately a two-fold increase in brain 10-FTHF DH activities and a three-fold increase in hepatic 10-FTHF DH activities as compared to controls (p<or=0.05). Three daily EtOH dosages (E(0-2)) caused reduced taurine levels in both brain and hepatic tissues (p<or=0.05). Meanwhile, a single EtOH dosage (E(0)), two daily EtOH dosages (E(0-1)), and three daily EtOH dosages (E(0-2)), caused reduced hepatic taurine levels as compared to controls (p<or=0.05).

Herp mRNA expression in patients classified according to Lesch's typology

Chronic alcoholism is associated with hyperhomocysteinemia. Herp (homocysteine-induced endoplasmic reticulum [ER] protein) levels are elevated as a response to ER stress prior to mitochondrial dysfunction and cell death. The Lesch classification system has been applied in many studies and has been found useful. This study was undertaken to assess Herp mRNA expression in actively drinking patients with alcoholism who were classified according to Lesch's typology. Herp mRNA expression levels were measured by quantitative PCR in the blood of 76 male alcoholic patients. Patients were classified according to Lesch's typology (type I-IV). With respect to Lesch's typology, a significant difference in Herp mRNA expression regarding the four subtypes could be shown (F[3,72]=2.83, P=.044). In a logistic regression model (dependent variable Herp dichotomized by a median-split; adjusted for age and homocysteine levels) the subtype II differed statistically significant from the others (odds ratio, 5.75; 95% confidence interval, 2.07-15.98; P=.001). Type II alcoholic patients had a statistically significant higher expression of Herp mRNA due to upregulation of the expression of this neuroprotective cell non-chaperone by toxic effects of ethanol. These findings might explain why type II patients do not express severe withdrawal symptomatology (i.e., withdrawal seizures). These findings may be useful in the understanding and treatment considerations of different subtypes of alcohol dependence.

Review. Neurogenetic studies of alcohol addiction

Neurogenetic studies of alcohol dependence have relied substantially on genetic animal models, particularly rodents. Studies of inbred strains, selectively bred lines and mutants bearing genes whose function has been targeted for over or under expression are reviewed. Studies focused on gene expression changes are the most recent contributors to this literature, and some genetic effects may work through epigenetic mechanisms. In a few instances, interesting parallels have been revealed between genetic risk in humans and studies in non-human animal models. Future approaches are likely to be increasingly complex.

The effect of 12-week open-label memantine treatment on cognitive function improvement in patients with alcohol-related dementia

There is compelling evidence that alcohol-induced neurotoxicity is related to glutamate excitotoxicity. It was hypothesized that the low-affinity NMDA receptor antagonist memantine would improve the cognitive function of patients with alcoholic dementia. The aim of this study was to test this hypothesis and to evaluate the effect of memantine on the cognitive improvement of patients with alcohol-related dementia (ARD). The study was designed as a 12-wk open-label study investigating the efficacy of 20 mg memantine, a low-affinity NMDA receptor antagonist, as a treatment for cognitive and behavioural problems in 19 patients with probable ARD according to the criteria for ARD proposed by Oslin and colleagues. The CERAD-K (Consortium to Establish a Registry for Alzheimer's Disease - Korean version) and several clinical assessment scales were completed before and after the 12-wk memantine treatment period. Significant improvements in the mean scores from baseline to final assessment were observed in the Global Deterioration Scale (p<0.05), Brief Psychiatric Rating Scale (p<0.01), Geriatric Quality of Life - Dementia scale (p<0.01) and Neuropsychiatric Inventory (p<0.01) at the end of week 12. The CERAD-K subscales of word list recall (p<0.05), word list recognition (p<0.05), time orientation (p<0.01), drawing an interlocking pentagon (p<0.05), and the total MMSE-K (Mini Mental State Examination - Korean version) scores (p<0.01) of the patients all showed significant improvement following the memantine trial. In this open-label study, patients with ARD treated with 20 mg/d memantine for 12 wk showed improvement on global cognition, quality of life and behavioural symptoms. The result of this study suggests the possible usefulness of memantine for the treatment of ARD. As this was an open-label study, the possibility that participants improved cognitively on their own due to protracted abstinence from alcohol cannot be discounted.

Breath alcohol level and plasma amino acids: a comparison between older and younger chronic alcohol-dependent patients

AIM

The aim of the present study is to examine the distribution of plasma excitatory and inhibitory amino acids, according to the age and current breath alcohol levels (BrAl+/-), of alcohol-dependent patients.

PARTICIPANTS AND METHODS

78 alcohol-dependent patients (mean age=46.2+/-11 years, men/women=54/24) were clinically tested, including the determination of the major excitatory as well as inhibitory amino acids. The independent variables were gender, age and current alcohol consumption measured with the breath alcohol level (BrAl+/-status).

RESULTS

In comparison to BrAl negatives, BrAl positives had higher plasma levels of glutamic acid (P=0.01) and proline (P=0.026), and lower levels of aminobutyric acid (P=0.002), serine (P=0.031) and urea (P=0.01). In the BrAl positives, no age effect was found related to the plasma amino acids. In contrast, the BrAl negatives displayed age-related differences. The older (>or=50 years) BrAl negative patients had higher plasma levels of cystine, tyrosine, citrulline and urea, and lower histidine levels, compared to the younger group (<50 years). In general, differences in plasma levels of certain amino acids were dependent on gender, BrAl status, age and biochemical markers (GGT, MCV) of alcohol abuse.

CONCLUSIONS

Abstaining patients (BrAl-/) display age-related differences in AAs' distribution, while active drinking (BrAl+/) seems to even out those differences, underpinning the hypothesis that drinking mimics changes seen with advanced age.

NGF plasma levels increase due to alcohol intoxication and decrease during withdrawal

Recent studies show that alcohol dependence is associated with alterations in plasma levels of nerve growth factor (NGF). The aim of this study was to further elucidate reported alterations in NGF plasma levels during alcohol intoxication and withdrawal. Therefore, we assessed NGF plasma levels by enzyme-linked immunosorbent assay (ELISA) on admission (day 0) and day 7 of alcohol withdrawal in male alcohol dependent patients (n=75) in comparison to healthy controls (n=44). We found significant higher (U=1005.0, p<0.001) NGF plasma levels in the alcohol-dependent patients. Subgroup analysis showed significant higher (U=-2.934, p=0.003) NGF plasma levels in patients suffering from acute alcohol intoxication (group A) than in early abstinent patients (group B). From day 0 to day 7 of alcohol withdrawal NGF plasma levels decreased significantly in both groups (group A: Z=-3.118, p=0.002, group B: Z=-2.103, p=0.035). Our results suggest that acute alcohol intoxication is associated with an increase in NGF plasma levels, which decrease during alcohol withdrawal. These results suggest that NGF plasma levels increase as part of a regulation mechanism that counteracts alcohol intoxication.

The Worldwide Challenge of the Dementias: A Role for B Vitamins and Homocysteine?

Dementia has reached epidemic proportions, with an estimated 4.6 million new cases worldwide each year. With an aging world population, the prevalence of dementia will increase dramatically in the next few decades. Of the predicted 114 million who will have dementia in 2050, about three-quarters will live in less developed regions. Although strongly age-related, dementia is not an inevitable part of aging but is a true disease, caused by exposure to several genetic and nongenetic risk factors. Prevention will be possible when the nongenetic risk factors have been identified. Apart from age, more than 20 nongenetic risk factors have been postulated, but very few have been established by randomized intervention studies. Elevated blood concentrations of total homocysteine and low-normal concentrations of B vitamins (folate, vitamin B12, and vitamin B6) are candidate risk factors for both Alzheimer's disease and vascular dementia. Seventy-seven cross-sectional studies on more than 34,000 subjects and 33 prospective studies on more than 12,000 subjects have shown associations between cognitive deficit or dementia and homocysteine and/or B vitamins. Biologically plausible mechanisms have been proposed to account for these associations, including atrophy of the cerebral cortex, but a definite causal pathway has yet to be shown. Raised plasma total homocysteine is a strong prognostic marker of future cognitive decline, and is common in world populations. Low-normal concentrations of the B vitamins, the main determinant of homocysteine concentrations, are also common and occur in particularly vulnerable sections of the population, such as infants and elderly. Large-scale randomized trials of homocysteine-lowering vitamins are needed to see if a proportion of dementia in the world can be prevented.

Ethanol-induced increased endogenous homocysteine levels and decreased ratios of SAM/SAH are only partially attenuated by exogenous glycine in developing chick brains

The effects of exogenous ethanol (EtOH) and/or glycine on chick (Gallus gallus) embryo viability, brain apoptosis (caspase-3 activities), and the endogenous levels of brain homocysteine (HoCys), S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and SAM/SAH were studied. Embryonic EtOH exposure caused decreased embryo viability as measured by EtOH-induced reductions in % living embryos at theoretical stage 37, EtOH-induced reductions in embryo masses, and EtOH-induced reductions in brain caspase-3 (Casp-3) activities. Exogenous glycine failed to attenuate EtOH-induced decreased embryo viability and EtOH-induced increased brain Casp-3 activities. Embryonic EtOH exposure caused elevated levels of endogenous HoCys, decreased levels of SAM, increased levels of SAH, and decreased SAM/SAH ratios in embryonic chick brains. While exogenous glycine failed to attenuate EtOH-induced increased HoCys levels, exogenous glycine attenuated EtOH-induced decreased levels of SAM, increased levels of SAH, and decreased SAM/SAH levels in embryonic chick brains.

Apolipoprotein E gene polymorphism and previous alcohol withdrawal seizures

Aim of this study was to investigate the possible association of apolipoprotein E (ApoE) gene polymorphism with a history of alcohol withdrawal seizures. We included 194 patients with alcohol dependence who were divided into patients with (SZ+) and without (SZ-) previous alcohol withdrawal seizures. ApoE genotypes were determined using PCR. For statistical analysis we examined the number of ApoE alleles (ApoE2: n=36; ApoE3: n=311; ApoE4: n=41). A significant positive association with a positive history of withdrawal seizures (SZ+) was found in the ApoE3 allele group (Fisher's exact test: p=0.006) while a significant negative association was observed in the ApoE2 allele group (Fisher's exact test: p=0.029). For the ApoE4 allele group no significant differences were found regarding a history of withdrawal seizures. Our findings suggest an association between the apolipoprotein E3 gene variant and an elevated risk of alcohol withdrawal seizures. These preliminary results must be validated in further studies.

Apolipoprotein E polymorphism, homocysteine serum levels and hippocampal volume in patients with alcoholism: an investigation of a gene-environment interaction

There is growing evidence that disadvantageous influences of the apolipoprotein E4 allele in the central nervous system are modified by environmental and dietary conditions. The present study investigated the gene-environment interaction of apolipoprotein E4 with homocysteine serum levels in patients with alcohol dependence with regard to alcohol-related hippocampal volume loss using volumetric high-resolution magnetic resonance imaging. We included 52 patients with alcohol-dependence. ApoE genotypes, homocysteine serum levels and hippocampal volumes were determined. We found a significant impact of homocysteine (F=13.2; df=1; P<0.001; 1-beta=0.95), not for ApoE4 genotype (F=0.482; df=1; P=0.49; 1-beta=0.05) on hippocampal volume. There was a significant interaction between both factors (ApoE4 x Hcy; F=8.8; df=1; P=0.005; 1-beta=0.80). The ApoE4 allele constitutes a risk factor for hippocampal volume loss in patients with alcohol dependence under the conditions of hyperhomocysteinemia. We suggest that the disadvantageous effects of apolipoprotein E4 on alcohol-related brain volume loss are based on certain gene-environment interactions.

Binding of copper is a mechanism of homocysteine toxicity leading to COX deficiency and apoptosis in primary neurons, PC12 and SHSY-5Y cells

Children with hereditary severe hyperhomocysteinemia present with a variety of neurological impairment, and mild hyperhomocysteinemia has been associated with neurodegeneration in the elderly. The link of hyperhomocysteinemia to neurological dysfunction is unknown. We investigated mitochondrial mechanisms of homocysteine (HCys) neurotoxicity in rat dopaminergic pheochromocytoma cells, human neuroblastoma cells and primary rat cerebellar granule neurons. HCys dose dependently impaired cytochrome c oxidase (COX) activity as well as stability and induced reactive oxygen species and apoptotic cell death. We found that HCys binds the COX cofactor Cu(2+), and Cu(2+) supplementation prior to HCys treatment preserved COX activity and prevented cell death. The Cu(2+) chelating action of HCys and impairement of COX activity represent novel mechanisms of HCys neurotoxicity, which might be preventable by supplementation of Cu(2+).

An assessment of the potential value of elevated homocysteine in predicting alcohol-withdrawal seizures

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 microM. Positive predictive values ranged from 0.23 to 0.745; the maximum was reached at a homocysteine plasma level of 41.7 microM. Negative predictive values ranged from 0.50 to 0.935, with a maximum at a homocysteine plasma level of 15.8 microM.

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.

Epigenetic DNA hypermethylation of the HERP gene promoter induces down-regulation of its mRNA expression in patients with alcohol dependence

BACKGROUND

Elevated plasma homocysteine concentrations can influence genomic and gene-specific DNA methylation in peripheral blood cells. The aim of this study was to investigate in patients with alcohol dependence, who show chronically elevated homocysteine levels, whether DNA methylation pattern within the HERP (homocysteine-induced endoplasmic reticulum protein) promoter region and expression of HERP mRNA is altered.

METHODS

The HERP mRNA expression level was measured by quantitative PCR in the blood of 66 male alcoholic patients and 55 nondrinking healthy controls. Epigenetic genomic DNA methylation status and HERP promoter methylation were measured with a nonradioactive elongation assay.

RESULTS

We observed a significant increase (7.6%) in the HERP promoter DNA methylation in patients with alcohol dependence (t test, t = -2.45, p < 0.02) when compared with healthy controls (80.4%, SD 14.5), which was significantly associated with their elevated homocysteine levels (multiple linear regression, p < 0.007). Furthermore, we found a significantly lower HERP mRNA expression in patients with alcohol dependence (t test, -7.61 DeltaCT; SD 1.87, p < 0.001) when compared with healthy controls (-6.04 DeltaCT; SD 2.41). The lowered HERP mRNA expression in alcoholic patients was best explained by the hypermethylation of the regulatory HERP gene promoter (regression analysis, p = 0.004).

CONCLUSIONS

To our knowledge, this is the first study evaluating HERP mRNA expression and its specific gene promoter methylation in alcoholic patients. As hypermethylation of DNA is an important epigenetic factor in the down-regulation of gene expression, and as HERP has been considered to play an essential role within the intracellular defense system, these findings may be useful in the understanding and treatment of different disease conditions associated with alcohol dependence.

DIFFERENT ALLELE-DISTRIBUTION OF MTHFR 677 C → T AND MTHFR −393 C → A IN PATIENTS CLASSIFIED ACCORDING TO SUBTYPES OF LESCH'S TYPOLOGY

AIMS

The typology by Lesch distinguishes between four subtypes: type 1 (model of allergy), type 2 (model of anxiety or conflict), type 3 (alcohol as an antidepressant), and type 4 (alcohol as adaptation). Taking into account that alcohol dependence is associated with elevated homocysteine levels, this study was undertaken to investigate different MTHFR (methylenetetrahydrofolate reductase) genotypes related to homocysteine metabolism in patients with alcohol dependence who were classified according to Lesch's typology (LT).

SUBJECTS AND METHODS

134 non-abstinent chronic alcoholics (112 males, 22 females; mean age 44.2 (SD 8.9) years) were classified according to LT and divided into four groups: LT 1 (n = 26), LT 2 (n = 65), LT 3 (n = 58), and LT 4 (n = 18). Total plasma homocysteine levels and MTHFR genotypes -393, 677, and 1,793 were determined.

RESULTS

We observed a significantly higher frequency of the thermolabile MTHFR 677 C-->T variant (TT) in patients classified as subtype LT4 when compared with subtypes LT2 and LT3 (P = 0.005). Furthermore, for the MTHFR -393 C --> A-polymorphism, significantly more AC/AA variants were found in subtype LT4 (P = 0.034). No differences in allele-distribution were detected for MTHFR 1793.

CONCLUSION

To our knowledge, this is the first study evaluating MTHFR genotypes in patients who were classified according to LT. Significantly different distributions of MTHFR 677 and -393 variants within Lesch Type 4 as compared with Types 2 and 3 hint at genetic determination of Lesch subtypes.

Cognitive impairment and its association with homocysteine plasma levels in females with eating disorders – findings from the HEaD-study

Higher plasma homocysteine levels have been found in females with anorexia nervosa. Furthermore, elevated homocysteine levels are associated with cognitive decline in dementia and healthy elderly people. Aim of this prospective study was to investigate a possible association between homocysteine serum levels and Clinically well known cognitive deficits in females with eating disorders. We found that moderately elevated plasma homocysteine levels were associated with normal short- and long-term verbal memory while normal plasma homocysteine levels were associated with poorer memory performance in 14 females with anorexia nervosa and 12 females with bulimia nervosa (logistic forward regression Wald chi(2)=8.566, OR=24.75, CI 2.89 - 212.23, P=0.003). These results indicate that under the special circumstances of eating disorders elevated homocysteine levels improve memory signaling possibly by facilitating long-term potentiation.

Apolipoprotein E4 genotype is not associated with short-term cognition deficits during alcohol withdrawal

Aim of this prospective study was to investigate a possible association between the apolipoprotein E4 (ApoE4) genotype and clinically well-known cognition deficits during alcohol withdrawal. We examined 172 patients with alcohol dependence (137 men, 35 women) during withdrawal treatment. The ApoE genotype was determined in all patients using polymerase chain reaction. Cognitive function was assessed applying the c.I.-Test on day 0 (admission) and on day 7 of withdrawal treatment. Using Pearson's chi2 test we found no significant association between the ApoE4 genotype and cognition deficits for both dates (day 0: p=.463; day 7: p=.760). Moreover, multivariate logistic regression analyses revealed no significant association between presence of the ApoE4 allele and cognitive dysfunction. Even though ApoE4 plays an important role in alcoholism-related brain atrophy and cognition deficits in demented as well as in nondemented healthy elderly people, this study provides no evidence for an association with short-term cognition deficits during alcohol withdrawal.