ADH1B, the adipocyte-enriched alcohol dehydrogenase, plays an essential, cell-autonomous role in human adipogenesis.

Alcohol dehydrogenase 1B (ADH1B) is a primate-specific enzyme which, uniquely among the ADH class 1 family, is highly expressed both in adipose tissue and liver. Its expression in adipose tissue is reduced in obesity and increased by insulin stimulation. Interference with ADH1B expression has also been reported to impair adipocyte function. To better understand the role of ADH1B in adipocytes, we used CRISPR/Cas9 to delete ADH1B in human adipose stem cells (ASC). Cells lacking ADH1B failed to differentiate into mature adipocytes manifested by minimal triglyceride accumulation and a marked reduction in expression of established adipocyte markers. As ADH1B is capable of converting retinol to retinoic acid (RA), we conducted rescue experiments. Incubation of ADH1B-deficient preadipocytes with 9-cis-RA, but not with all-transretinol, significantly rescued their ability to accumulate lipids and express markers of adipocyte differentiation. A homozygous missense variant in ADH1B (p.Arg313Cys) was found in a patient with congenital lipodystrophy of unknown cause. This variant significantly impaired the protein's dimerization, enzymatic activity, and its ability to rescue differentiation in ADH1B-deficient ASC. The allele frequency of this variant in the Middle Eastern population suggests that it is unlikely to be a fully penetrant cause of severe lipodystrophy. In conclusion, ADH1B appears to play an unexpected, crucial and cell-autonomous role in human adipocyte differentiation by serving as a necessary source of endogenous retinoic acid.

Effectiveness of genetic feedback on alcohol metabolism to reduce alcohol consumption in young adults: an open-label randomized controlled trial.

BACKGROUND: It is unclear whether brief interventions using the combined classification of alcohol-metabolizing enzymes aldehyde dehydrogenase 2 (ALDH2) and alcohol dehydrogenase 1B (ADH1B) together with behavioral changes in alcohol use can reduce excessive alcohol consumption. This study aimed to examine the effects of a brief intervention based on the screening of ALDH2 and ADH1B gene polymorphisms on alcohol consumption in Japanese young adults. METHODS: In this open-label randomized controlled trial, we enrolled adults aged 20-30 years who had excessive drinking behavior (average amount of alcohol consumed: men, ≥ 4 drinks/per day and women, ≥ 2 drinks/per day; 1 drink = 10 g of pure alcohol equivalent). Participants were randomized into intervention or control group using a simple random number table. The intervention group underwent saliva-based genotyping of alcohol-metabolizing enzymes (ALDH2 and ADH1B), which were classified into five types. A 30-min in-person or online educational counseling was conducted approximately 1 month later based on genotyping test results and their own drinking records. The control group received traditional alcohol education. Average daily alcohol consumption was calculated based on the drinking diary, which was recorded at baseline and at 3 and 6 months of follow-up. The primary endpoint was average daily alcohol consumption, and the secondary endpoints were the alcohol-use disorder identification test for consumption (AUDIT-C) score and behavioral modification stages assessed using a transtheoretical model. RESULTS: Participants were allocated to the intervention (n = 100) and control (n = 96) groups using simple randomization. Overall, 28 (29.2%) participants in the control group and 21 (21.0%) in the intervention group did not complete the follow-up. Average alcohol consumption decreased significantly from baseline to 3 and 6 months in the intervention group but not in the control group. The reduction from baseline alcohol consumption values and AUDIT-C score at 3 months were greater in the intervention group than in the control group (p < 0.001). In addition, the behavioral modification stages were significantly changed by the intervention (p < 0.001). CONCLUSIONS: Genetic testing for alcohol-metabolizing enzymes and health guidance on type-specific excessive drinking may be useful for reducing sustained average alcohol consumption associated with behavioral modification. TRIAL REGISTRATION: R000050379, UMIN000044148, Registered on June 1, 2021.

Risk stratification of synchronous gastric cancers including alcohol-related genetic polymorphisms.

BACKGROUND AND AIM: We previously identified that ever-smoking and severe gastric atrophy in pepsinogen are risk factors for synchronous gastric cancers (SGCs). This study aimed to determine the association of alcohol drinking status or alcohol-related genetic polymorphism with SGCs and also stratify their risk. METHODS: This multi-center prospective cohort study included patients who underwent endoscopic submucosal dissection for the initial early gastric cancers at 22 institutions in Japan. We evaluated the association of alcohol drinking status or alcohol dehydrogenase 1B (ADH1B) and acetaldehyde dehydrogenase 2 (ALDH2) genotypes with SGCs. We then stratified the risk of SGCs by combining prespecified two factors and risk factors identified in this study. RESULTS: Among 802 patients, 130 had SGCs. Both the ADH1B Arg and ALDH2 Lys alleles demonstrated a significant association with SGCs on multivariate analysis (odds ratio, 1.77), although alcohol drinking status showed no association. The rates of SGCs in 0-3 risk factors in the combined evaluation of three risk factors (ever-smoking, severe gastric atrophy in pepsinogen, and both the ADH1B Arg and ALDH2 Lys alleles) were 7.6%, 15.0%, 22.0%, and 32.1%, respectively. The risk significantly increased from 0 to 3 risk factors on multivariate analysis (P for trend <0.001). CONCLUSIONS: Both the ADH1B Arg and ALDH2 Lys alleles were at high risk for SGCs. The risk stratification by these three factors may be a less invasive and promising tool for predicting their risk.

Genetic influences on alcohol flushing in East Asian populations.

BACKGROUND: Although it is known that variation in the aldehyde dehydrogenase 2 (ALDH2) gene family influences the East Asian alcohol flushing response, knowledge about other genetic variants that affect flushing symptoms is limited. METHODS: We performed a genome-wide association study meta-analysis and heritability analysis of alcohol flushing in 15,105 males of East Asian ancestry (Koreans and Chinese) to identify genetic associations with alcohol flushing. We also evaluated whether self-reported flushing can be used as an instrumental variable for alcohol intake. RESULTS: We identified variants in the region of ALDH2 strongly associated with alcohol flushing, replicating previous studies conducted in East Asian populations. Additionally, we identified variants in the alcohol dehydrogenase 1B (ADH1B) gene region associated with alcohol flushing. Several novel variants were identified after adjustment for the lead variants (ALDH2-rs671 and ADH1B-rs1229984), which need to be confirmed in larger studies. The estimated SNP-heritability on the liability scale was 13% (S.E. = 4%) for flushing, but the heritability estimate decreased to 6% (S.E. = 4%) when the effects of the lead variants were controlled for. Genetic instrumentation of higher alcohol intake using these variants recapitulated known associations of alcohol intake with hypertension. Using self-reported alcohol flushing as an instrument gave a similar association pattern of higher alcohol intake and cardiovascular disease-related traits (e.g. stroke). CONCLUSION: This study confirms that ALDH2-rs671 and ADH1B-rs1229984 are associated with alcohol flushing in East Asian populations. Our findings also suggest that self-reported alcohol flushing can be used as an instrumental variable in future studies of alcohol consumption.

Alcohol metabolism genes and risks of site-specific cancers in Chinese adults: An 11-year prospective study.

Two genetic variants that alter alcohol metabolism, ALDH2-rs671 and ADH1B-rs1229984, can modify oesophageal cancer risk associated with alcohol consumption in East Asians, but their associations with other cancers remain uncertain. ALDH2-rs671 G>A and ADH1B-rs1229984 G>A were genotyped in 150 722 adults, enrolled from 10 areas in China during 2004 to 2008. After 11 years' follow-up, 9339 individuals developed cancer. Cox regression was used to estimate hazard ratios (HRs) for site-specific cancers associated with these genotypes, and their potential interactions with alcohol consumption. Overall, the A-allele frequency was 0.21 for ALDH2-rs671 and 0.69 for ADH1B-rs1229984, with A-alleles strongly associated with lower alcohol consumption. Among men, ALDH2-rs671 AA genotype was associated with HR of 0.69 (95% confidence interval: 0.53-0.90) for IARC alcohol-related cancers (n = 1900), compared to GG genotype. For ADH1B-rs1229984, the HRs of AG and AA vs GG genotype were 0.80 (0.69-0.93) and 0.75 (0.64-0.87) for IARC alcohol-related cancers, 0.61 (0.39-0.96) and 0.61 (0.39-0.94) for head and neck cancer (n = 196) and 0.68 (0.53-0.88) and 0.60 (0.46-0.78) for oesophageal cancer (n = 546). There were no significant associations of these genotypes with risks of liver (n = 651), colorectal (n = 556), stomach (n = 725) or lung (n = 1135) cancers. Among male drinkers, the risks associated with higher alcohol consumption were greater among ALDH2-rs671 AG than GG carriers for head and neck, oesophageal and lung cancers (Pinteraction < .02). Among women, only 2% drank alcohol regularly, with no comparable associations observed between genotype and cancer. These findings support the causal effects of alcohol consumption on upper aerodigestive tract cancers, with ALDH2-rs671 AG genotype further exacerbating the risks.

Alcohol dehydrogenase expression patterns in normal prostate, benign prostatic hyperplasia, and prostatic adenocarcinoma in African American and Caucasian men.

BACKGROUND: In situ metabolism of ethanol by alcohol dehydrogenases (ADHs) contributes to oxidative damage of cells and DNA and has been linked to carcinogenesis in numerous epithelial tissues. The goal of this study was to determine expression patterns of ADH1 and ADH7 isozymes in normal, hyperplastic (benign prostatic hyperplasia [BPH]) and neoplastic (prostate cancer [PCa]) prostate. Furthermore, racial differences in ADH expression between African Americans and Caucasians were investigated. METHODS: ADH expression patterns were characterized by density analysis of ADH immunohistochemistry (n = 21) and real-time RT-PCR of total RNAs by laser-capture microdissection (n = 10) and whole tissue formalin-fixed paraffin embedded prostate biopsies (n = 63). RESULTS: ADH protein is found in normal prostate and is primarily associated with glandular epithelium. Transcripts of ADH1B are suppressed in PCa compared to BPH (p = 0.0095). Racial differences in ADH7 transcripts exist between African American and Caucasian men. A total of 57.6% of biopsies from African American prostates have detectable ADH7 messenger RNA (mRNA) transcripts compared to the 13.3% of Caucasian prostate biopsies with detectable transcripts (p = 0.0005). This increased frequency of detection contributes to higher mean ADH7 mRNA transcript levels in African Americans (p = 0.001). CONCLUSIONS: To our knowledge this study is the first to report downregulation of ADH1B in neoplastic prostate at the transcriptional level, suggesting protective regulatory functions. ADH7 transcripts were not detectable in all samples and was found in higher frequency and amount in our African American samples. Racial differences in ADH7 within the prostate is a novel finding and should be investigated further.

Differentiating Types of Self-Reported Alcohol Abstinence.

We contrast three types of abstinence: quit after alcohol associated problems (Q-AP), quit for other reasons (Q-OR), and lifetime abstainer (LTA). We summarized the characteristics of people living with HIV (PLWH), and matched uninfected individuals, by levels of alcohol use and types of abstinence. We then identified factors that differentiate abstinence and determined whether the association with an alcohol biomarker or a genetic polymorphism is improved by differentiating abstinence. Among abstainers, 34% of PLWH and 38% of uninfected were Q-AP; 53% and 53% were Q-OR; and 12% and 10% were LTA. Logistic regression models found smoking, alcohol, cocaine, and hepatitis C increased odds of Q-AP, whereas smoking and marijuana decreased odds of LTA. Differentiating types of abstinence improved association. Q-APs and LTAs can be readily differentiated by an alcohol biomarker and genetic polymorphism. Differentiating type of abstinence may enhance understanding of alcohol health effects.

Telomere shortening in the oral epithelium in relation to alcohol intake, alcohol dehydrogenase (ADH-1B), and acetaldehyde dehydrogenase (ALDH-2) genotypes and clinicopathologic features.

BACKGROUND: Progressive telomere shortening with age or chronic inflammation may lead to genomic instability that characterizes the early stage of carcinogenesis. Certain risk factors, such as drinking alcoholic beverages or smoking, predispose the oral mucosa to squamous cell carcinoma. The ADH1B and ALDH2 genotypes can influence the risk of cancer due to alcohol drinking. In the present study, we analyzed chromosomal instability due to telomere shortening in the oral mucosa in relation to cancer risk factors. DESIGN: Using our quantitative fluorescence in situ hybridization (Q-FISH) technique, we estimated telomere lengths (TL) in the background mucosa from 23 cases of mucosal carcinoma, 12 cases of oral epithelial dysplasia, and 21 non-neoplasia cases. ALDH2 and ADH1B genotypes were determined using DNA extracted from paraffin sections. We analyzed TL in relation to alcohol drinking, smoking, and cancer multiplicity. RESULTS: Telomeres in the backgrounds of dysplasia and mucosal carcinoma were significantly shorter than in controls. In comparison with adult controls, telomeres were significantly (P = .038) shorter in the ADH1B less-active type (ADH1B*1/*1), but not (P = .841) in the ALDH2 inactive type (ALDH2*1/*2 or *2/*2). Cancer multiplicity and smoking had no significant relationship with TL. CONCLUSION: Telomeres in the oral epithelium are shorter in cases of oral dysplasia or mucosal carcinoma than in non-neoplasia. Unlike the esophageal epithelium of alcoholics, they are also shorter in individuals with the less-active rather than the active ADH1B gene. Telomeres in the oral epithelium may be directly affected by alcohol drinking.

The Genetic Relationship Between Alcohol Consumption and Aspects of Problem Drinking in an Ascertained Sample.

BACKGROUND: Genomewide association studies (GWAS) have begun to identify loci related to alcohol consumption, but little is known about whether this genetic propensity overlaps with specific indices of problem drinking in ascertained samples. METHODS: In 6,731 European Americans who had been exposed to alcohol, we examined whether polygenic risk scores (PRS) from a GWAS of weekly alcohol consumption in the UK Biobank predicted variance in 6 alcohol-related phenotypes: alcohol use, maximum drinks within 24 hours (MAXD), total score on the Self-Rating of the Effects of Ethanol Questionnaire (SRE-T), DSM-IV alcohol dependence (DSM4AD), DSM-5 alcohol use disorder symptom counts (DSM5AUDSX), and reduction/cessation of problematic drinking. We also examined the extent to which an single nucleotide polymorphism (rs1229984) in ADH1B, which is strongly associated with both alcohol consumption and dependence, contributed to the polygenic association with these phenotypes and whether PRS interacted with sex, age, or family history of alcoholism to predict alcohol-related outcomes. We performed mixed-effect regression analyses, with family membership and recruitment site included as random effects, as well as survival modeling of age of onset of DSM4AD. RESULTS: PRS for alcohol consumption significantly predicted variance in 5 of the 6 outcomes: alcohol use (Δmarginal R2  = 1.39%, Δ area under the curve [AUC] = 0.011), DSM4AD (Δmarginal R2  = 0.56%; ΔAUC = 0.003), DSM5AUDSX (Δmarginal R2  = 0.49%), MAXD (Δmarginal R2  = 0.31%), and SRE-T (Δmarginal R2  = 0.22%). PRS were also associated with onset of DSM4AD (hazard ratio = 1.11, p = 2.08e-5). The inclusion of rs1229984 attenuated the effects of the alcohol consumption PRS, particularly for DSM4AD and DSM5AUDSX, but the PRS continued to exert an independent effect for all 5 alcohol measures (Δmarginal R2 after controlling for ADH1B = 0.14 to 1.22%). Interactions between PRS and sex, age, or family history were nonsignificant. CONCLUSIONS: Genetic propensity for typical alcohol consumption was associated with alcohol use and was also associated with 4 of the additional 5 outcomes, though the variance explained in this sample was modest. Future GWAS that focus on the multifaceted nature of AUD, which goes beyond consumption, might reveal additional information regarding the polygenic underpinnings of problem drinking.

Aldehyde dehydrogenase 2 polymorphism affects the outcome of methanol poisoning in exposed humans.

As the susceptibility of humans to xenobiotics often depends on genetic factors, we assumed that ADH1B and ALDH2 genetic variants may affect susceptibility to the acute methanol exposure. To evaluate the role of genetic variants of enzymes involved in methanol catabolism in humans, we analysed ADH1B (rs1229984) and ALDH2 (rs441) polymorphisms in 50 adults who survived acute methanol poisoning, 246 individuals with alcoholic liver cirrhosis, and in 545 healthy controls. GG homozygotes of ADH1B were more common among methanol-poisoned patients (98%) and among patients with alcoholic liver cirrhosis (98%) than among healthy controls (90%) (P = 0.08 and < 0.001, respectively). Minor C allele carriers of the ALDH2 were significantly more common among methanol-poisoned persons (46%) than among patients with alcoholic liver cirrhosis or healthy controls (31% in both groups, P < 0.05 and 0.025, respectively); the odds ratios were 1.89 (95% CI 1.02-3.52) and 1.94 (1.08-3.48), respectively. As there was a substantial amount of subjects with alcohol abuse between both groups of patients, ADH1B is unlikely to affect the susceptibility to methanol poisoning. By contrast, the genetic variant of the ALDH2 enzyme seems to specifically affect the susceptibility to methanol in acutely exposed humans and potentially plays a role in the outcome of methanol poisoning.

Association between ALDH2 and ADH1B polymorphisms, alcohol drinking and gastric cancer: a replication and mediation analysis.

BACKGROUND: Aldehyde dehydrogenase 2 (ALDH2; rs671, Glu504Lys) and alcohol dehydrogenase 1B (ADH1B; rs1229984, His47Arg) polymorphisms have a strong impact on carcinogenic acetaldehyde accumulation after alcohol drinking. To date, however, evidence for a significant ALDH2-alcohol drinking interaction and a mediation effect of ALDH2/ADH1B through alcohol drinking on gastric cancer have remained unclear. We conducted two case-control studies to validate the interaction and to estimate the mediation effect on gastric cancer. METHODS: We calculated odds ratios (OR) and 95% confidence intervals (CI) for ALDH2/ADH1B genotypes and alcohol drinking using conditional logistic regression models after adjustment for potential confounding in the HERPACC-2 (697 cases and 1372 controls) and HERPACC-3 studies (678 cases and 678 controls). We also conducted a mediation analysis of the combination of the two studies to assess whether the effects of these polymorphisms operated through alcohol drinking or through other pathways. RESULTS: ALDH2 Lys alleles had a higher risk with increased alcohol consumption compared with ALDH2 Glu/Glu (OR for heavy drinking, 3.57; 95% CI 2.04-6.27; P for trend = 0.007), indicating a significant ALDH2-alcohol drinking interaction (Pinteraction = 0.024). The mediation analysis indicated a significant positive direct effect (OR 1.67; 95% CI 1.38-2.03) and a protective indirect effect (OR 0.84; 95% CI 0.76-0.92) of the ALDH2 Lys alleles with the ALDH2-alcohol drinking interaction. No significant association of ADH1B with gastric cancer was observed. CONCLUSION: The observed ALDH2-alcohol drinking interaction and the direct effect of ALDH2 Lys alleles may suggest the involvement of acetaldehyde in the development of gastric cancer.

Modification of the Associations of Alcohol Intake With Serum Low-Density Lipoprotein Cholesterol and Triglycerides by ALDH2 and ADH1B Polymorphisms in Japanese Men.

BACKGROUND: Although beneficial associations have been reported between moderate alcohol intake and the serum lipid profile, it is unclear whether polymorphisms in alcohol-metabolizing enzymes can modify these associations. Here, we assessed the effects of ADH1B His48Arg (rs1229984), ALDH2 Glu504Lys (rs671), and their combination on these associations. Furthermore, we examined if the findings for ALDH2 could be replicated. METHODS: We categorized 889 male participants in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study into two groups based on presence or absence of minor allele(s) or four groups based on genotype combinations. We performed regression analyses of serum lipid concentrations on alcohol intake, with multivariable adjustment. The replication study was conducted among 2,562 men in the Shizuoka part of the J-MICC Study. RESULTS: The ALDH2 Glu/Lys or Lys/Lys groups showed significant decreases in serum low-density lipoprotein (LDL) cholesterol with increasing alcohol consumption; the coefficient per intake increase of 10 g/day was -2.49 mg/dL (95% confidence interval [CI], -3.85 to -1.13), and a significant interaction with the polymorphism was confirmed (P for interaction = 0.006). This inverse correlation was more evident among the ADH1B His/His + ALDH2 Glu/Lys or Lys/Lys groups (-3.24 mg/dL, 95% CI, -5.03 to -1.45). Serum triglycerides were positively associated with alcohol consumption in the ADH1B His/His group (P for interaction = 0.020). The stronger association between serum LDL cholesterol and alcohol consumption in the ALDH2 Glu/Lys or Lys/Lys groups was replicated. CONCLUSIONS: The ALDH2 Glu504Lys polymorphism can modify the association between alcohol intake and serum LDL cholesterol in Japanese men.

Polymorphisms in ADH1B and ALDH2 genes associated with the increased risk of gastric cancer in West Bengal, India.

BACKGROUND: Gastric cancer (GC) is one of the most frequently diagnosed digestive tract cancers and carries a high risk of mortality. Acetaldehyde (AA), a carcinogenic intermediate of ethanol metabolism contributes to the risk of GC. The accumulation of AA largely depends on the activity of the major metabolic enzymes, alcohol dehydrogenase and aldehyde dehydrogenase encoded by the ADH (ADH1 gene cluster: ADH1A, ADH1B and ADH1C) and ALDH2 genes, respectively. This study aimed to evaluate the association between genetic variants in these genes and GC risk in West Bengal, India. METHODS: We enrolled 105 GC patients (cases), and their corresponding sex, age and ethnicity was matched to 108 normal individuals (controls). Genotyping for ADH1A (rs1230025), ADH1B (rs3811802, rs1229982, rs1229984, rs6413413, rs4147536, rs2066702 and rs17033), ADH1C (rs698) and ALDH2 (rs886205, rs968529, rs16941667 and rs671) was performed using DNA sequencing and RFLP. RESULTS: Genotype and allele frequency analysis of these SNPs revealed that G allele of rs17033 is a risk allele (A vs G: OR = 3.67, 95% CI = 1.54-8.75, p = 0.002) for GC. Significant association was also observed between rs671 and incidence of GC (p = 0.003). Moreover, smokers having the Lys allele of rs671 had a 7-fold increased risk of acquiring the disease (OR = 7.58, 95% CI = 1.34-42.78, p = 0.009). CONCLUSION: In conclusion, rs17033 of ADH1B and rs671 of ALDH2 SNPs were associated with GC risk and smoking habit may further modify the effect of rs671. Conversely, rs4147536 of ADH1B might have a protective role in our study population. Additional studies with a larger patient population are needed to confirm our results.

Validating Harmful Alcohol Use as a Phenotype for Genetic Discovery Using Phosphatidylethanol and a Polymorphism in ADH1B.

BACKGROUND: Although alcohol risk is heritable, few genetic risk variants have been identified. Longitudinal electronic health record (EHR) data offer a largely untapped source of phenotypic information for genetic studies, but EHR-derived phenotypes for harmful alcohol exposure have yet to be validated. Using a variant of known effect, we used EHR data to develop and validate a phenotype for harmful alcohol exposure that can be used to identify unknown genetic variants in large samples. Herein, we consider the validity of 3 approaches using the 3-item Alcohol Use Disorders Identification Test consumption measure (AUDIT-C) as a phenotype for harmful alcohol exposure. METHODS: First, using longitudinal AUDIT-C data from the Veterans Aging Cohort Biomarker Study Cohort (VACS-BC), we compared 3 metrics of AUDIT-C using correlation coefficients: (i) AUDIT-C closest to blood sampling (closest AUDIT-C), (ii) the highest value (highest AUDIT-C), (iii) and longitudinal trajectories generated using joint trajectory modeling (AUDIT-C trajectory). Second, we compared the associations of the 3 AUDIT-C metrics with phosphatidylethanol (PEth), a direct, quantitative biomarker for alcohol in the overall sample using chi-square tests for trend. Last, in the subsample of African Americans (AAs; n = 1,503), we compared the associations of the 3 AUDIT-C metrics with rs2066702 a common missense (Arg369Cys) polymorphism of the ADH1B gene, which encodes an alcohol dehydrogenase isozyme. RESULTS: The sample (n = 1,851, 94.5% male, 65% HIV+, mean age 52 years) had a median of 7 AUDIT-C scores over a median of 6.1 years. Highest AUDIT-C and AUDIT-C trajectory were correlated r = 0.86. The closest AUDIT-C was obtained a median of 2.26 years after the VACS-BC blood draw. Overall and among AAs, all 3 AUDIT-C metrics were associated with PEth (all p < 0.05), but the gradient was steepest with AUDIT-C trajectory. Among AAs (36% with the protective ADH1B allele), the association of rs2066702 with AUDIT-C trajectory and highest AUDIT-C was statistically significant (p < 0.05), and the gradient was steeper for the AUDIT-C trajectory than for the highest AUDIT-C. The closest AUDIT-C was not statistically significantly associated with rs2066702. CONCLUSIONS: EHR data can be used to identify complex phenotypes such as harmful alcohol use. The validity of the phenotype may be enhanced through the use of longitudinal trajectories.

The roles of alcohol dehydrogenase in patients with atrial fibrillation.

BACKGROUND: Alcohol consumption is known to increase the risk of atrial fibrillation (AF). Whether the genotypes of alcohol-metabolizing genes (alcohol dehydrogenase [ADH1B]) are associated with the risk of AF recurrence after catheter ablation remains unclear. METHODS AND RESULTS: The ADH1B genotypes of 281 patients who received catheter ablation for AF were examined. We followed this group of patients to monitor their AF recurrence. Alcohol consumption levels of this cohort were evaluated before and after catheter ablation. There was no difference in the underlying diseases presented by the patients with different ADH1B genotypes. Regardless of the ADH1B genotypes, the amount of alcohol consumption was the only factor associated with left atrial dilatation. The ADH1B*2 alleles (hazard ratio: ADH1B*1/*2 vs *1/*1: 2.64; ADH1B*2/*2 vs *1/*1: 1.80, P = 0.02) and the levels of alcohol consumption were independently associated with AF recurrence in the patients with paroxysmal AF after catheter ablation. ADH1B polymorphisms were not associated with AF recurrence in the patients with nonparoxysmal AF. We also found that the association of increased AF recurrence with alcohol consumption and the ADH1B genotypes cannot be explained by mechanisms of systemic inflammation. CONCLUSIONS: ADH1B*2/*2 genotype and amount of alcohol consumption increase the risk of AF recurrence after catheter ablation.

The allele frequency of ALDH2*Glu504Lys and ADH1B*Arg47His for the Ryukyu islanders and their history of expansion among East Asians.

OBJECTIVES: A cline of frequencies of the derived allele of the ALDH2 gene, which causes a deficiency of an enzyme and "facial flushing" in humans who drink alcohol, has been known among the people of the Japanese archipelago. This cline is conventionally explained by admixture with immigrants from the Asian continent occurring during the Yayoi period. Previous studies lack sufficient data from the peripheral regions of the indigenous Jomon people, and those data the ADH1B gene that is involved in the Class I ADH gene cluster and contains another variant leading to a functional change. METHODS: We focused on the southwestern-most people from the Ryukyu Islands (n = 218) and those from northern Kyushu (n = 21) where the Yayoi immigrants likely arrived. We investigated both the Class I ADH and ALDH2 loci, as well as neutral genetic markers. RESULTS: In the Ryukyu Islands, the frequencies of the ancestral alleles in both loci were always higher than those in mainland Japan, while the frequencies of ADH1B were less than those of the derived allele. A haplotype block was not observed in ALDH2 but was in Class I ADH. DISCUSSION: Our data suggest that the derived allele of ALDH2 came with the Yayoi immigrants from the Asian continent to the Japanese archipelago. However, the derived allele of ADH1B is unlikely to be related to the Yayoi migration. Therefore, we postulate that the expansion of the derived allele of ADHIB in East Asia could be traced back to the last glacial period.

Genetic variations of aldehyde dehydrogenase 2 and alcohol dehydrogenase 1B are associated with the etiology of atrial fibrillation in Japanese.

BACKGROUND: Alcohol consumption and oxidative stress are well-known risk factors for developing atrial fibrillation (AF). Single nucleotide polymorphisms (SNPs) of alcohol dehydrogenase (ADH1B) and aldehyde dehydrogenase 2 (ALDH2) genes encoding enzymes of alcohol and reactive aldehyde metabolism, respectively, are prevalent among East Asians. Here, we examined whether these SNPs were associated with AF in Japanese patients. METHODS AND RESULTS: Five hundred seventy-seven Japanese patients with AF undergoing catheter ablation and 1935 controls at Hiroshima University Hospital were studied. Alcohol consumption habits, medical history, electrocardiogram (EKG), electrophysiology and cardiac echocardiography were reviewed. Patients were also genotyped for ALDH2 (rs671) and ADH1B (rs1229984). A significant linear correlation was found between ALDH2 genotype and mean alcohol intake (P = 1.7 × 10-6). Further, ALDH2 (rs671) was associated with AF (P = 7.6 × 10-4, odds ratio [OR] = 0.6). Frequency of the ALDH2 SNP allele A which limits acetaldehyde metabolism was lower in patients with AF (18.8%) than in controls (23.5%). In contrast, we found that the frequencies of the ADH1B SNP genotypes were similar in patients with AF and in controls. Subset analysis among the 182 patients with lone AF and 914 controls (control II) (<60 years of age and without hypertension), both ALDH2 and ADH1B SNPs were significantly associated with AF (P = 0.013, OR = 0.7; P = 0.0007, OR = 1.4, respectively). The frequency of the dysfunctional allele A of ALDH2 was significantly lower and the dysfunctional allele G of ADH1B was significantly higher in patients with lone AF than in control II (ALDH2 A allele frequency = 0.176 vs 0.235, OR = 1.3, P = 0.013, ADH1B SNP G allele frequency = 0.286 vs 0.220, OR = 1.4, P = 0.0007). CONCLUSIONS: When considering all patients enrolled, the dysfunctional ALDH2 allele was negatively associated with AF. When examining a subset of patients with lone AF, the dysfunctional ALDH2 allele was negatively associated with AF and the slower metabolizing ADH1B allele was positively associated with AF. Hence, prolonged metabolic conversion of alcohol to acetaldehyde may be associated with the occurrence of AF in the Japanese and other East Asian populations.

ALDH2 polymorphism is associated with fasting blood glucose through alcohol consumption in Japanese men.

Associations between alcohol consumption and type 2 diabetes risk are inconsistent in epidemiologic studies. This study investigated the associations of ADH1B and ALDH2 polymorphisms with fasting blood glucose levels, and the impact of the associations of alcohol consumption with fasting blood glucose levels in Japanese individuals. This cross-sectional study included 907 men and 912 women, aged 35-69 years. The subjects were selected from among the Japan Multi-institutional Collaborative Cohort study across six areas of Japan. The ADH1B and ALDH2 polymorphisms were genotyped by Invader Assays. The ALDH2 Glu504Lys genotypes were associated with different levels of fasting blood glucose in men (P = 0.04). Mean fasting glucose level was positively associated with alcohol consumption in men with the ALDH2 504 Lys allele (P trend = 0.02), but not in men with the ALDH2 504Glu/Glu genotype (P trend = 0.45), resulting in no statistically significant interaction (P = 0.38). Alcohol consumption was associated with elevated fasting blood glucose levels compared with non-consumers in men (P trend = 0.002). The ADH1B Arg48His polymorphism was not associated with FBG levels overall or after stratification for alcohol consumption. These findings suggest that the ALDH2 polymorphism is associated with different levels of fasting blood glucose through alcohol consumption in Japanese men. The interaction of ALDH2 polymorphisms in the association between alcohol consumption and fasting blood glucose warrants further investigation.

Comorbid alcohol dependence disorder may be related to aldehyde dehydrogenase 2 (ALDH2) and alcohol dehydrogenase 1B (ADH1B) in bipolar II disorder, but only to ALDH2 in bipolar I disorder, in Han Chinese.

OBJECTIVES: A high prevalence rate of bipolar disorder (BP) comorbid with alcohol dependence (AD) (BP+AD) in Western patients with BP has been reported, but whether this is true for Han Chinese with BP is uncertain. We explored the prevalence of BP+AD in a Han Chinese population with BP, and investigated the effect of alcohol-metabolizing genotypes on bipolar I disorder (BP-I) + AD and bipolar II disorder (BP-II) + AD. METHODS: Healthy controls (HCs) (n = 672) and 18- to 65-year-old patients with BP (BP-I: n = 530; BP-II: n = 788) were recruited. Patients with any other major or minor mental illnesses, neurological disorders, or organic mental disorders were excluded. A polymerase chain reaction and restriction fragment length polymorphism analysis was used to determine genotypes for alcohol dehydrogenase 1B (ADH1B) and aldehyde dehydrogenase 2 (ALDH2), two alcohol-metabolizing enzymes. RESULTS: AD comorbidity rates were 11.7% with BP-I and 17.1% with BP-II. Significantly fewer patients with BP not comorbid with AD (BP-AD) carried the AHD1B*1 allele than did the HCs. Logistic regression analysis showed a main effect of ALDH2*1/*1 only in the BP-I-AD group. In BP+AD patients, logistic regression analysis showed main effects of ALDH2*1/*1 and ADH1B*1/*1 only in the BP-II+AD group. CONCLUSIONS: Having BP-II+AD may be related to ALDH2 and ADH1B, but having BP-I+AD may be related only to ALDH2. We conclude that ALDH2 and ADH1B have different effects in Han Chinese patients with BP-I+AD and BP-II+AD.

Childhood adversity moderates the effect of ADH1B on risk for alcohol-related phenotypes in Jewish Israeli drinkers.

Childhood adversity and genetic variant ADH1B-rs1229984 have each been shown to influence heavy alcohol consumption and disorders. However, little is known about how these factors jointly influence these outcomes. We assessed the main and additive interactive effects of childhood adversity (abuse, neglect and parental divorce) and the ADH1B-rs1229984 on the quantitative phenotypes 'maximum drinks in a day' (Maxdrinks) and DSM-Alcohol Use Disorder (AUD) severity, adjusting for demographic variables, in an Israeli sample of adult household residents (n = 1143) evaluated between 2007 and 2009. Childhood adversity and absence of the protective ADH1B-rs1229984 A allele were associated with greater mean Maxdrinks (mean differences: 1.50; 1.13, respectively) and AUD severity (mean ratios: 0.71; 0.27, respectively). In addition, childhood adversity moderated the ADH1B-rs1229984 effect on Maxdrinks (P < 0.01) and AUD severity (P < 0.05), in that there was a stronger effect of ADH1B-rs1229984 genotype on Maxdrinks and AUD severity among those who had experienced childhood adversity compared with those who had not. ADH1B-rs1229984 impacts alcohol metabolism. Therefore, among those at risk for greater consumption, e.g. those who experienced childhood adversity, ADH1B-rs1229984 appears to have a stronger effect on alcohol consumption and consequently on risk for AUD symptom severity. Evidence for the interaction of genetic vulnerability and early life adversity on alcohol-related phenotypes provides further insight into the complex relationships between genetic and environmental risk factors.