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Carcinogenesis Sep 2017Alcohol is a major risk factor for oesophageal squamous cell carcinoma (OSCC), the most prevalent histological subtype of oesophageal cancer (OC) worldwide. The... (Review)
Review
Alcohol is a major risk factor for oesophageal squamous cell carcinoma (OSCC), the most prevalent histological subtype of oesophageal cancer (OC) worldwide. The metabolism of alcohol is regulated by specific enzymes whose activity and expression is influenced by genetic polymorphisms. We conducted a systematic review of current epidemiological evidence of the relationship between alcohol intake and OC risk, including the role of tobacco smoking and functional polymorphisms of alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases (ALDHs). Potential biological mechanisms underlying oesophageal carcinogenesis are also discussed. Frequency and intensity of alcohol intake have been consistently associated with an increased risk of OSCC in regions with low and high incidence of the disease. The highest risk was reported among tobacco smokers, whereas the association between alcohol and OSCC risk was weak in the absence of tobacco use. The ADH1B, ADH1C and ALDH2 gene polymorphisms influence the risk of OSCC through modulation of acetaldehyde metabolism and propensity to alcohol intake. These functional variants may be suitable proxies of alcohol exposure for use in Mendelian randomization studies if complemented by reported alcohol intake data. Recent epidemiological and experimental studies investigating the role of alcohol consumption in OC development have implicated the microbiome as a new promising avenue for research, which entail novel potential mechanisms of alcohol-related oesophageal carcinogenesis. Microbial communities associated with alcohol consumption might be used as biomarkers to raise the potential of intervening among susceptible individuals.
Topics: Acetaldehyde; Alcohol Dehydrogenase; Alcohol Drinking; Biomarkers, Tumor; Carcinoma, Squamous Cell; Case-Control Studies; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Ethanol; Humans; Microbiota; Polymorphism, Genetic; Risk Factors; Smoking
PubMed: 28645180
DOI: 10.1093/carcin/bgx067 -
Antioxidants (Basel, Switzerland) Jul 2022Alcohol use disorder (AUD) is a highly prevalent, comorbid, and disabling disorder. The underlying mechanism of ethanol neurotoxicity and the involvement of oxidative... (Review)
Review
Alcohol use disorder (AUD) is a highly prevalent, comorbid, and disabling disorder. The underlying mechanism of ethanol neurotoxicity and the involvement of oxidative stress is still not fully elucidated. However, ethanol metabolism has been associated with increased oxidative stress through alcohol dehydrogenase, the microsomal ethanol oxidation system, and catalase metabolic pathways. We searched the PubMed and genome-wide association studies (GWAS) catalog databases to review the literature systematically and summarized the findings focusing on AUD and alcohol abstinence in relation to oxidative stress. In addition, we reviewed the ClinicalTrials.gov resource of the US National Library of Medicine to identify all ongoing and completed clinical trials that include therapeutic interventions based on antioxidants. The retrieved clinical and preclinical studies show that oxidative stress impacts AUD through genetics, alcohol metabolism, inflammation, and neurodegeneration.
PubMed: 35883865
DOI: 10.3390/antiox11071374 -
Mutagenesis May 2012Alcohol drinking is a major risk factor for head and neck cancer (HNC). This risk may be modified by alcohol dehydrogenase (ADH) genes, particularly ADH1B and ADH1C,... (Meta-Analysis)
Meta-Analysis Review
Alcohol drinking is a major risk factor for head and neck cancer (HNC). This risk may be modified by alcohol dehydrogenase (ADH) genes, particularly ADH1B and ADH1C, that oxidise ethanol to its carcinogenic metabolite, acetaldehyde. A meta-analysis was conducted to assess the association between ADH1B and ADH1C and HNC risk. Twenty-nine studies from 28 articles identified from a literature search were included. Summary odds ratios (meta-ORs) were generated using random effect models. A reduced risk for HNC was associated with carrying the ADH1B*2 and ADH1C*1 alleles that confer faster metabolism of ethanol to acetaldehyde [meta-OR ADH1B, 0.50; 95% confidence interval (CI): 0.37-0.68, 13 studies; meta-OR ADH1C, 0.87; 95% CI: 0.76-0.99, 22 studies]. ADH1B*2 and ADH1C*1 alleles appear to be protective for HNC, possibly due to: (i) decreasing the opportunity for oral microflora to produce acetaldehyde locally from a prolonged systemic circulation of ethanol, (ii) preventing ethanol from acting as a solvent for other carcinogens, and (iii) decreasing the amount of ethanol a person consumes since a consequent peak in systemic acetaldehyde could cause discomfort. These results underscore the importance of ADH1B and ADH1C in the association between alcohol consumption and the risk for HNC.
Topics: Alcohol Dehydrogenase; Ethanol; Genetic Association Studies; Genetic Predisposition to Disease; Head and Neck Neoplasms; Humans; Isoenzymes; Risk Factors
PubMed: 22042713
DOI: 10.1093/mutage/ger073 -
Annals of Epidemiology Sep 2023To estimate the burden of alcohol-attributable cancer in East Asian populations accounting for aldehyde dehydrogenase-2 (ALDH2) genotype-specific cancer risk and alcohol... (Meta-Analysis)
Meta-Analysis
PURPOSE
To estimate the burden of alcohol-attributable cancer in East Asian populations accounting for aldehyde dehydrogenase-2 (ALDH2) genotype-specific cancer risk and alcohol exposure.
METHODS
We conducted a systematic review and meta-analysis of eight databases on cancer risk to derive alcohol dose-response curves by ALDH2 genotype. A simulation-based approach using the Global Burden of Disease (GBD) modeling framework was applied to estimate the population attributable fraction, incidence, and disability-adjusted life-years (DALYs) lost to alcohol-attributable cancer.
RESULTS
We included 34 studies (66,655 participants) from China, Japan, and South Korea in the meta-analysis. Alcohol dose-response curves for liver, esophageal, and oral cavity/pharynx cancer showed an increased risk for people with the inactivated ALDH2 genetic polymorphism, resulting in a higher burden of alcohol-attributable cancer compared to GBD estimates. Our methods estimated annual incidence of cancer of 230,177 cases, an underestimate of 69,596 cases compared to GBD estimates. Similarly, total DALYs lost annually were underestimated by 1.20 million.
CONCLUSIONS
The burden of liver, esophageal, and oral cavity/pharynx cancer attributable to alcohol is underestimated in populations with the ALDH2 genetic polymorphism when compared to current estimates.
Topics: Humans; Alcohol Drinking; Asia, Eastern; Ethanol; Esophageal Neoplasms; Polymorphism, Genetic; Pharyngeal Neoplasms; Risk Factors; Aldehyde Dehydrogenase, Mitochondrial
PubMed: 37268241
DOI: 10.1016/j.annepidem.2023.05.013 -
PLoS Medicine Mar 2008Alcohol has been reported to be a common and modifiable risk factor for hypertension. However, observational studies are subject to confounding by other behavioural and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Alcohol has been reported to be a common and modifiable risk factor for hypertension. However, observational studies are subject to confounding by other behavioural and sociodemographic factors, while clinical trials are difficult to implement and have limited follow-up time. Mendelian randomization can provide robust evidence on the nature of this association by use of a common polymorphism in aldehyde dehydrogenase 2 (ALDH2) as a surrogate for measuring alcohol consumption. ALDH2 encodes a major enzyme involved in alcohol metabolism. Individuals homozygous for the null variant (*2*2) experience adverse symptoms when drinking alcohol and consequently drink considerably less alcohol than wild-type homozygotes (*1*1) or heterozygotes. We hypothesise that this polymorphism may influence the risk of hypertension by affecting alcohol drinking behaviour.
METHODS AND FINDINGS
We carried out fixed effect meta-analyses of the ALDH2 genotype with blood pressure (five studies, n = 7,658) and hypertension (three studies, n = 4,219) using studies identified via systematic review. In males, we obtained an overall odds ratio of 2.42 (95% confidence interval [CI] 1.66-3.55, p = 4.8 x 10(-6)) for hypertension comparing *1*1 with *2*2 homozygotes and an odds ratio of 1.72 (95% CI 1.17-2.52, p = 0.006) comparing heterozygotes (surrogate for moderate drinkers) with *2*2 homozygotes. Systolic blood pressure was 7.44 mmHg (95% CI 5.39-9.49, p = 1.1 x 10(-12)) greater among *1*1 than among *2*2 homozygotes, and 4.24 mmHg (95% CI 2.18-6.31, p = 0.00005) greater among heterozygotes than among *2*2 homozygotes.
CONCLUSIONS
These findings support the hypothesis that alcohol intake has a marked effect on blood pressure and the risk of hypertension.
Topics: Alcohol Dehydrogenase; Alcohol Drinking; Blood Pressure; Genetic Predisposition to Disease; Humans; Hypertension; Male
PubMed: 18318597
DOI: 10.1371/journal.pmed.0050052 -
Bulletin of the World Health... May 2015To refine estimates of the burden of alcohol-related oesophageal cancer in Japan. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To refine estimates of the burden of alcohol-related oesophageal cancer in Japan.
METHODS
We searched PubMed for published reviews and original studies on alcohol intake, aldehyde dehydrogenase polymorphisms, and risk for oesophageal cancer in Japan, published before 2014. We conducted random-effects meta-analyses, including subgroup analyses by aldehyde dehydrogenase variants. We estimated deaths and loss of disability-adjusted life years (DALYs) from oesophageal cancer using exposure distributions for alcohol based on age, sex and relative risks per unit of exposure.
FINDINGS
We identified 14 relevant studies. Three cohort studies and four case-control studies had dose-response data. Evidence from cohort studies showed that people who consumed the equivalent of 100 g/day of pure alcohol had an 11.71 fold, (95% confidence interval, CI: 2.67-51.32) risk of oesophageal cancer compared to those who never consumed alcohol. Evidence from case-control studies showed that the increase in risk was 33.11 fold (95% CI: 8.15-134.43) in the population at large. The difference by study design is explained by the 159 fold (95% CI: 27.2-938.2) risk among those with an inactive aldehyde dehydrogenase enzyme variant. Applying these dose-response estimates to the national profile of alcohol intake yielded 5279 oesophageal cancer deaths and 102,988 DALYs lost - almost double the estimates produced by the most recent global burden of disease exercise.
CONCLUSION
Use of global dose-response data results in an underestimate of the burden of disease from oesophageal cancer in Japan. Where possible, national burden of disease studies should use results from the population concerned.
Topics: Alcohol Dehydrogenase; Alcohol Drinking; Esophageal Neoplasms; Ethanol; Humans; Japan; Quality-Adjusted Life Years; Risk Factors
PubMed: 26229204
DOI: 10.2471/BLT.14.142141 -
Clinical Toxicology (Philadelphia, Pa.) Jul 2022Ethylene glycol is metabolized to toxic metabolites that cause acute kidney injury, metabolic acidemia, and death. The treatment of patients with ethylene glycol...
CONTEXT
Ethylene glycol is metabolized to toxic metabolites that cause acute kidney injury, metabolic acidemia, and death. The treatment of patients with ethylene glycol poisoning includes competitively inhibiting alcohol dehydrogenase with ethanol or fomepizole to prevent the formation of toxic metabolites, and extracorporeal treatments such as hemodialysis to remove ethylene glycol and its metabolites. In the absence of significant metabolic acidemia or kidney injury, it is hypothesized that extracorporeal treatments may be obviated without adverse outcomes to the patient if alcohol dehydrogenase inhibitors are used.
OBJECTIVES
The objectives of this study are to: (1) identify indicators predicting ADH inhibitor failure in patients with ethylene glycol poisoning treated with either ethanol or fomepizole for whom extracorporeal treatment was not performed (aside from rescue therapy, see below) (), and (2) validate if the anion gap, shown in a previous study to be the best surrogate for the glycolate concentration, is associated with acute kidney injury and mortality ().
METHODS
We conducted a systematic review to identify all reported patients with ethylene glycol poisoning treated without extracorporeal treatments but with either fomepizole () or ethanol (). Analyses were performed using both one case per patient and all cases (if multiple events were reported for a single patient). Data were compiled regarding poisoning, biochemistry, and outcomes. Treatment failure was defined as mortality, worsening of acid-base status, extracorporeal treatments used as rescue, or a worsening of kidney or neurological function after alcohol dehydrogenase inhibition was initiated. Also, we performed an analysis of previously described anion gap thresholds to determine if they were associated with outcomes such as acute kidney injury and mortality.
RESULTS
Of 115 publications identified, 96 contained case-level data. A total of 180 cases were identified with ethanol monotherapy, and 231 with fomepizole monotherapy. Therapy failure was noted mostly when marked acidemia and/or acute kidney injury were present prior to therapy, although there were cases of failed ethanol monotherapy with minimal acidemia (suggesting that ethanol dosing and/or monitoring may not have been optimal). Ethylene glycol dose and ethylene glycol concentration were predictive of monotherapy failure for ethanol, but not for fomepizole. In the anion gap study (207 cases), death and progression of acute kidney injury were almost nonexistent when the anion gap was less than 24 mmol/L and mostly observed when the anion gap was greater than 28 mmol/L.
CONCLUSION
This review suggests that in patients with minimal metabolic acidemia (anion gap <28 mmol/L), fomepizole monotherapy without extracorporeal treatments is safe and effective regardless of the ethylene glycol concentration. Treatment failures were observed with ethanol monotherapy which may relate to transient subtherapeutic ethanol concentrations or very high ethylene glycol concentrations. The results are limited by the retrospective nature of the case reports and series reviewed in this study and require prospective validation.
Topics: Acidosis; Acute Kidney Injury; Alcohol Dehydrogenase; Antidotes; Ethanol; Ethylene Glycol; Fomepizole; Humans; Poisoning; Renal Dialysis; Retrospective Studies
PubMed: 35311442
DOI: 10.1080/15563650.2022.2049810 -
Japanese Journal of Clinical Oncology May 2011Although alcohol drinking is considered as an important risk factor for esophageal cancer, the magnitude of the association might be varied among geographic areas.... (Meta-Analysis)
Meta-Analysis Review
Although alcohol drinking is considered as an important risk factor for esophageal cancer, the magnitude of the association might be varied among geographic areas. Therefore, we reviewed epidemiologic studies on the association between alcohol drinking and esophageal cancer among the Japanese population. Original data were obtained from MEDLINE, searched using PubMed or from searches of the Ichushi database, complemented with manual searches. Evaluation of associations was based on the strength of evidence ('convincing', 'probable', 'possible' or 'insufficient') and the magnitude of association ('strong', 'moderate', 'weak' or 'no association'), together with biological plausibility as previously evaluated by the International Agency of Research on Cancer. We identified four cohort studies and nine case-control studies. All cohort studies and case-control studies showed strong positive associations between esophageal cancer and alcohol drinking. All cohort studies and six case-control studies showed that alcohol drinking had the dose- or frequency-response relationships with esophageal cancer. In addition, four case-control studies showed that acetaldehyde dehydrogenase Glu504Lys polymorphism had strong effect modification with alcohol drinking. We conclude that there is convincing evidence that alcohol drinking increases the risk of esophageal cancer in the Japanese population.
Topics: Alcohol Drinking; Aldehyde Dehydrogenase; Aldehyde Dehydrogenase, Mitochondrial; Asian People; Case-Control Studies; Cohort Studies; Confounding Factors, Epidemiologic; Esophageal Neoplasms; Female; Gene Frequency; Humans; Japan; Life Style; Male; Polymorphism, Single Nucleotide; Risk Assessment; Risk Factors; Severity of Illness Index; Sex Factors
PubMed: 21430021
DOI: 10.1093/jjco/hyr026 -
Archives of Oral Biology Apr 2024Head and neck cancer (HNC) is a prevalent and complex group of malignancies with increasing incidence globally. Alcohol dehydrogenases (ADHs) play a crucial role in... (Meta-Analysis)
Meta-Analysis Review
Association between alcohol dehydrogenase polymorphisms (rs1229984, rs1573496, rs1154460, and rs284787) and susceptibility to head and neck cancers: A systematic review and meta-analysis.
OBJECTIVE
Head and neck cancer (HNC) is a prevalent and complex group of malignancies with increasing incidence globally. Alcohol dehydrogenases (ADHs) play a crucial role in alcohol metabolism, and their polymorphisms have been linked to HNC risk. This systematic review and meta-analysis aims to evaluate the association between ADH polymorphisms and susceptibility to HNCs, incorporating additional analyses and adding more studies to increase power and accuracy of the results.
DESIGN
Subgroup analysis, meta-regression analysis, and sensitivity analyses were conducted to explore potential differences within the data and assess the stability of pooled odds ratios (ORs). To mitigate the risk of false conclusions from meta-analyses, a trial sequential analysis was performed.
RESULTS
For ADH1B rs1229984, the pooled OR (95 % confidence interval (CI)) was 0.73 (0.65, 0.82), 0.42 (0.35, 0.50), 0.57 (0.44, 0.73), 0.56 (0.50, 0.62), and 0.80 (0.73, 0.88), as well as for ADH7 rs1573496, the pooled OR was 0.72 (0.62, 0.85), 0.36 (0.17, 0.74), 0.76 (0.64, 0.91), 0.80 (0.71, 0.91), and 0.38 (0.18, 0.78) with a p < 0.05 in all allelic, homozygous, heterozygous, recessive, and dominant models, respectively. However, no significant association was found between the ADH7 rs1154460 and rs284787 polymorphisms and the risk of HNC with pooled ORs of 1.11 (p = 0.19) and 1.09 (p = 0.24) for the recessive model, respectively. The ethnicities, tumor subsites, control sources, sample sizes, quality scores, and Hardy-Weinberg equilibrium statuses were confounding factors.
CONCLUSION
The ADH1B rs1229984 and ADH7 rs1573496 polymorphisms are significantly associated with a reduced risk of HNC.
Topics: Humans; Alcohol Dehydrogenase; Polymorphism, Genetic; Head and Neck Neoplasms; Heterozygote; Genetic Predisposition to Disease; Polymorphism, Single Nucleotide
PubMed: 38278126
DOI: 10.1016/j.archoralbio.2024.105898 -
Nutrition Reviews Jul 2023Emerging evidence indicates that variants of alcohol-metabolizing enzymes may influence lipid metabolism. (Meta-Analysis)
Meta-Analysis
CONTEXT
Emerging evidence indicates that variants of alcohol-metabolizing enzymes may influence lipid metabolism.
OBJECTIVE
This study aimed to investigate whether the rs671 and rs1229984 variants affect lipid levels in East Asian individuals.
DATA SOURCES
PubMed, Foreign Medical Journal Service, Embase, Cochrane Library, Scopus, MEDLINE, Web of Science, Web of Knowledge, Wanfang, and Chinese Biomedical Literature databases were searched until December 31, 2021.
DATA EXTRACTION
Meta-analyses of studies that examined the effects of alcohol-metabolizing enzyme variants on lipid levels, as well as the interaction with alcohol intake, were selected. Data extraction was conducted independently by two investigators and confirmed by the third.
DATA ANALYSIS
In total, 86 studies (179 640 individuals) were analyzed. The A allele of rs671 (a functional variant in the ALDH2 gene) was linked to higher levels of low-density lipoprotein cholesterol (LDL-C) and lower levels of triglycerides and high-density lipoprotein cholesterol. In contrast, the A allele of the rs1229984 (a functional variant in the ADH2 gene) was associated only with lower levels of LDL-C. The effects of rs671 and rs1229984 on lipid levels were much stronger in Japanese than in Chinese individuals and in males than in females. Regression analysis indicated that the effects of rs671 on lipid levels were independent of alcohol intake in an integrated East Asian population (ie, Japanese, Chinese, and Korean individuals). Intriguingly, alcohol intake had a statistical influence on lipid levels when the sample analyzed was restricted to Japanese individuals or to males.
CONCLUSIONS
The rs671 and rs1229984 variants of alcohol-metabolizing enzymes have significant effects on lipid levels and may serve as genetic markers for lipid dyslipidemia in East Asian populations. Circulating lipid levels in Japanese individuals and in males were modulated by the interaction between rs671 and alcohol intake.
Topics: Female; Humans; Male; Alcohol Drinking; Aldehyde Dehydrogenase, Mitochondrial; Asian People; Cholesterol, LDL; Polymorphism, Single Nucleotide; Triglycerides
PubMed: 36565468
DOI: 10.1093/nutrit/nuac100