Effects of ADH1B and ALDH2 Genetic Polymorphisms on Alcohol Elimination Rates and Salivary Acetaldehyde Levels in Intoxicated Japanese Alcoholic Men.

BACKGROUND: The genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) are associated with the risk of alcoholism and upper aerodigestive tract cancer in alcoholics. Salivary ethanol (sEtOH) levels are well correlated with blood EtOH levels. METHODS: To study the effects of ADH1B and ALDH2 genotypes on the alcohol elimination rate (AER) and salivary acetaldehyde (sAcH) levels, we measured the sEtOH and sAcH levels twice at a 1-hour intervals in 99 intoxicated Japanese alcoholic men who had stopped drinking for 4 or more hours. RESULTS: The initial sEtOH levels did not differ between the ADH1B*2 group (n = 50) and the ADH1B*1/*1 group (n = 49) (median: 0.617 vs. 0.762 mg/ml). The salivary AER (sAER) increased as the sEtOH levels increased (p < 0.0001). After stratification according to the sEtOH levels (<0.4, 0.4 to 0.99, and ≥1.00 mg/ml), the median sAER of the ADH1B*2 group was 0.075, 0.188, and 0.228 mg/ml/h, respectively, and that of the ADH1B*1/*1 group was 0.037, 0.115, and 0.233 mg/ml/h, respectively. The sAER of the ADH1B*2 group was faster than that of the ADH1B*1/*1 group overall (p = 0.001) and when the sEtOH category was 0.4 to 0.99 mg/ml (p < 0.0001). The ADH1B genotype and the sEtOH levels had an interaction effect on the sAER (p = 0.036). A multiple linear regression analysis with a stepwise procedure selected the ADH1B*2 allele (p = 0.004) and the sEtOH levels (p < 0.0001) as positive predictors of sAER. The sAER did not differ according to the ALDH2 genotype. The sAcH levels were higher than the blood AcH levels reported in alcoholics, probably because of AcH production by oral microorganisms. The sAcH of the ALDH2*1/*2 group (n = 18) was higher than that of the ALDH2*1/*1 group (n = 81) overall (p = 0.0008) and when the corresponding sEtOH category was ≥1.00 mg/ml (median: 3.195 vs. 1.776 µg/ml, p = 0.009). A multiple linear regression analysis selected the ALDH2*1/*2 and the sEtOH levels as positive predictors of the sAcH levels (p < 0.0001). CONCLUSIONS: The enhanced AER in ADH1B*2 carriers and the increased sAcH levels in ALDH2*1/*2 carriers among intoxicated alcoholics provide possible mechanisms explaining how each genetic polymorphism affects the risk of alcoholism and upper aerodigestive tract cancer.

[Verification and Validation on Single Nucleotide Polymorphism Analysis of Alcohol Metabolism-Related Genes ADH1B and ALDH2, Using Dried-Saliva Samples].

We have developed a new method for unprocessed biological specimens as templates directly into the TaqMan assay. Saliva was needed to be put on a water-soluble paper and dried, because foreign substances, such as a filter paper, hinder fluorescence detection through the assay. Genotyping of alcohol metabolism-related genes ADH1B (rs1229984) and ALDH2 (rs671) polymorphisms was, subsequently, performed by TaqMan PCR assay using dried saliva in the present investigation. The optimized technique was tested on 114 samples of alcoholic patients. The PCR-RFLP methods with purified DNA from blood samples were employed for validation of the assay. Upon validation, complete concordance was observed between the two independent results. These results highlight the ability of TaqMan PCR assays using dried saliva on water-soluble paper in genotyping of ADH1B and ALDH2 genes. Our results showed a rapid, simple, reliable, and cost-effective method for SNP genotyping of mutations in ADH1B and ALDH2 genes. This will be very useful for large-scale association studies in various fields. [Original].

Polymorphisms of alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 and the blood and salivary ethanol and acetaldehyde concentrations of Japanese alcoholic men.

BACKGROUND: The effects of genetic polymorphism of aldehyde dehydrogenase-2 (ALDH2) on alcohol metabolism are striking in nonalcoholics, and the effects of genetic polymorphism of alcohol dehydrogenase-1B (ADH1B) are modest at most, whereas genetic polymorphisms of both strongly affect the susceptibility to alcoholism and upper aerodigestive tract (UADT) cancer of drinkers. METHODS: We evaluated associations between ADH1B/ADH1C/ALDH2 genotypes and the blood and salivary ethanol and acetaldehyde levels of 168 Japanese alcoholic men who came to our hospital for the first time in the morning and had been drinking until the day before. RESULTS: The ethanol levels in their blood and saliva were similar, but the acetaldehyde levels in their saliva were much higher than in their blood, probably because of acetaldehyde production by oral bacteria. Blood and salivary ethanol and acetaldehyde levels were both significantly higher in the subjects with the less active ADH1B*1/*1 genotype than in the ADH1B*2 carriers, but none of the levels differed according to ALDH2 genotype. Significant linkage disequilibrium was detected between the ADH1B and ADH1C genotypes, but ADH1C genotype did not affect the blood or salivary ethanol or acetaldehyde levels. High blood acetaldehyde levels were found even in the active ALDH2*1/*1 alcoholics, which were comparable with the levels of the inactive heterozygous ALDH2*1/*2 alcoholics with less active ADH1B*1/*1. The slope of the increase in blood acetaldehyde level as the blood ethanol level increased was significantly steeper in alcoholics with inactive heterozygous ALDH2*1/*2 plus ADH1B*2 allele than with any other genotype combinations, but the slopes of the increase in salivary acetaldehyde level as the salivary ethanol level increased did not differ between the groups of subjects with any combinations of ALDH2 and ADH1B genotypes. CONCLUSIONS: The ADH1B/ALDH2 genotype affected the blood and salivary ethanol and acetaldehyde levels of nonabstinent alcoholics in a different manner from nonalcoholics, and clear effects of ADH1B genotype and less clear effects of ALDH2 were observed in the alcoholics. Alterations in alcohol metabolism as a result of alcoholism may modify the gene effects, and these findings provide some clues in regard to associations between the genotypes and the risks of alcoholism and UADT cancer.

Salivary acetaldehyde concentration according to alcoholic beverage consumed and aldehyde dehydrogenase-2 genotype.

BACKGROUND: Acetaldehyde is suspected of playing a critical role in cancer development in the upper aerodigestive tract (UADT). The high salivary acetaldehyde levels after alcohol drinking are partly due to acetaldehyde production by oral bacteria. Some alcoholic beverages, especially Calvados and shochu, contain very high levels of acetaldehyde. Inactive heterozygous aldehyde dehydrogenase-2 (ALDH2) increases the risk of UADT cancer in drinkers. METHODS: In a randomized cross-over design study, 19 healthy Japanese volunteers ingested 0.6 g ethanol/kg body weight in the form of 13% ethanol Calvados, 13% ethanol shochu, 13% ethanol red wine, and 5% ethanol beer under the fasting conditions at 3-week intervals. We monitored blood and salivary acetaldehyde concentrations immediately after drinking, and 30, 60, 90, 120, and 180 minutes after completion of drinking. RESULTS: The acetaldehyde concentration of each beverage was: Calvados 0.60 mM (1.86 mM in 40% undiluted solution), shochu 0.60 mM (1.16 mM in 25% undiluted solution), red wine 0.25 mM, and beer 0.14 mM. The salivary acetaldehyde concentration immediately after drinking wine was significantly lower than the other beverages, and it was significantly lower immediately after drinking beer than Calvados. The acetaldehyde concentrations 30 to 180 minutes after drinking were unrelated to the beverage type. Throughout the observation period the salivary acetaldehyde concentrations were much higher than the blood acetaldehyde concentrations in all 12 active ALDH2 homozygotes (24 to 53 microM in saliva vs. 2 to 5 microM in blood) and in all 7 inactive ALDH2 heterozygotes (37 to 76 microM in saliva vs. 12 to 25 microM in blood), and they were 13 to 25 microM higher in the ALDH2 heterozygotes than in the ALDH2 homozygotes after adjusting for age, body weight, sex, smoking and drinking habits, and time since the last toothbrushing. The values after subtracting the blood acetaldehyde concentration from the salivary acetaldehyde concentration were also higher in the ALDH2 heterozygotes than in the ALDH2 homozygotes. CONCLUSIONS: There are differences in exposure of the UADT to high salivary acetaldehyde concentrations according to the type of alcoholic beverage and ALDH2 genotype, and the differences partly explain the differences in the cancer susceptibility of the UADT according to alcoholic beverage and ALDH2 genotype.

Homozygous (TG)11 allele in intron 8 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene has a protective role against bicarbonate decrease in pure pancreatic juice among Japanese male alcoholics.

BACKGROUND: Heavy drinkers have a high incidence of chronic pancreatitis (CP), but the mechanism of alcohol-related CP is largely unknown. Exocrine pancreatic insufficiency exists in about 90% of the patients with cystic fibrosis (CF), which results from an abnormal cystic fibrosis transmembrane conductance regulator gene (CFTR). AIM: To investigate in Japanese alcoholics the association between bicarbonate concentration in pure pancreatic juice and one of the polymorphisms of the CFTR gene, the (TG)m Tn tract length in intron 8. METHODS: Fifty-six patients under treatment for alcohol dependence were stimulated by intravenous injection of secretin during endoscopic retrograde cholangiopancreatography to provide pancreatic juice specimens. Individual maximum bicarbonate concentrations (MBC) were compared with (TG)m Tn tract polymorphisms identified by directly sequencing lymphocyte DNA. RESULTS: Among the 41 patients able to provide adequate pancreatic juice specimens, 15 had low MBC and 26 had normal MBC. The frequencies of the six haplotypes identified in these patients were 17.1% (TG)11T7/(TG)llT7, 46.3% (TG)11T7/(TG)12T7, 29.3% (TG)12T7/(TG)12T7, 2.4% (TG)10T9/(TG)11T7, 2.4% (TG)12T5/(TG)11T7, and 2.4% (TG)12T6/(TG)12T7. Among the 92.7% of patients who had the common (TG) miT7/(TG)m2T7 haplotype, all of the 7 with homozygous (TG)11 alleles had normal MBC (p<0.05). CONCLUSION: Alcoholics with homozygous (TG)11 alleles in intron 8 of the CFTR gene appear to be protected against decreased MBC, compared with those who have the (TG)11/(TG)12 and (TG)12/(TG)12 genotypes, suggesting a role for CFTR gene polymorphism in the progression of alcohol-related pancreatic disease.

Contribution of the alcohol dehydrogenase-1B genotype and oral microorganisms to high salivary acetaldehyde concentrations in Japanese alcoholic men.

The less-active homozygous alcohol dehydrogenase-1B (ADH1B*1/*1) and inactive heterozygous aldehyde dehydrogenase-2 (ALDH2*1/*2) increase the risk of upper aerodigestive tract cancer (UADTC) in Japanese alcoholics. We evaluated associations between ADH1B/ALDH2 genotypes and the blood and salivary ethanol/acetaldehyde levels of 80 Japanese alcoholic men in the morning when they first visited our hospital after drinking the day before. Higher levels of ethanol persisted in the blood for longer periods in ADH1B*1/*1 carriers (n = 25) than in ADH1B*2 allele carriers after adjustment for the amount and time of the preceding alcohol consumption and body weight [median (25th-75th %): 20.5 mM (15.5-52.4) vs. below detection level (

Spirits and gastrectomy increase risk for chronic pancreatitis in Japanese male alcoholics.

INTRODUCTION: Most cases of chronic pancreatitis are alcohol-related, but not all alcoholics develop pancreatitis. AIM: To elucidate historical and biologic risk factors for this disease. METHODOLOGY: Alcoholic Japanese men (n = 132) consecutively admitted to the National Alcoholism Center over 24 months, including 54 with chronic pancreatitis (diagnosed by endoscopic retrograde cholangiopancreatography) and 78 without, were surveyed about drinking history, smoking, education, and marital status, and tested for amylase, glycosylated hemoglobin, body mass, alcohol and aldehyde dehydrogenase genotypes, and K-ras gene mutations in pancreatic juice. RESULTS: Higher risk for chronic pancreatitis was associated with drinking spirits rather than lower-alcohol beverages (odds ratio [OR], 2.58; p= 0.01). Daily ethanol consumption by those who drank spirits was greater than that among those who drank lower-alcohol beverages; however, no differences in either daily ethanol consumption or duration of drinking were observed between alcoholics with and without chronic pancreatitis. Postgastrectomy patients were at higher risk for chronic pancreatitis than unoperated comparison subjects (OR, 4.35, P< 0.05). Elevated glycosylated hemoglobin (OR, 4.62, p< 0.01), decreased amylase (OR 4.20, P<0.02), and low body mass (OR 1.89, P<0.1) were more frequent in alcoholics with chronic pancreatitis. K- gene mutations existed in 18.8% of alcoholics with chronic pancreatitis but in only 11.4% of those without the disorder. The frequencies of alcohol and aldehyde dehydrogenase genotypes in alcoholics with and without pancreatitis did not differ significantly. CONCLUSION: Our study strongly suggested that spirits and partial gastrectomy increase the risk for chronic pancreatitis in male alcoholics.