Effects of genetic polymorphisms in alcohol-metabolizing enzymes on alcohol hypersensitivity and alcohol-related health problems in orientals

Effects of genetic variants of ADH1B and ALDH2 and social network on continued alcohol drinking among young adolescents in Taiwan

BACKGROUND

This study aimed (i) to evaluate the effects of genetic variants of ADH1B and ALDH2 and social network position on continued alcohol use in early adolescence, and (ii) to explore possible moderating role of pubertal development on genetic effects.

METHODS

The sample comprised 496 children who ever drank alcohol before the ages of 10-12. Information pertaining to sociodemographic background, pubertal development, parental drinking, alcohol and tobacco use, alcohol-metabolizing genes, and nominated best friends was collected in four waves of assessment. Polymorphisms of ADH1B (rs1229984) and ALDH2 (rs671) were genotyped. The latent class analysis was first used to characterize longitudinal alcohol use pattern, followed by the multinomial logistic regression analyses to assess its association with genes, pubertal development, and social network.

RESULTS

Three distinct classes of alcohol users (i.e. ex-drinkers, sporadic drinkers, and continued drinkers) were derived from alcohol-experienced children. Both alcohol-metabolizing genes appear to have protective effects, yet such relationships were only significant for youngsters in pre-to-early pubertal stage: the adjusted odds ratio (aOR) of ADH1B fast-genotype for sporadic drinkers was 0.46 and that of ALDH2 slow-genotype for both sporadic and continued drinkers was 0.47 and 0.42, respectively. Children having the bridge position in their peer network were more likely to be sporadic drinkers (aOR=4.15) and continued drinkers (aOR=3.16).

CONCLUSIONS

Our results illustrate a potential moderating effect of pubertal development on the protective influence of alcohol-metabolizing genes on subsequent alcohol use among alcohol-experienced children as well as the independent contribution of early life's social network to their alcohol involvement.

Risks of major depressive disorder and anxiety disorders among Thais with alcohol use disorders and illicit drug use: findings from the 2008 Thai National Mental Health survey

Little is known about the risks of mood and anxiety disorders among Asians with alcohol use disorders and the effect of illicit drug use in this population. All participants from the 2008 Thai National Mental Health survey (N=17,140) were assessed for current major depressive disorder, anxiety disorders, and alcohol use disorders by using the Mini International Neuropsychiatric Interview (MINI) and were interviewed for illicit drug use within one year prior to their assessment. Logistic regression modeling was used to determine (a) whether alcohol use disorders were associated with major depressive disorder and anxiety disorders and (b) whether the use of illicit drugs increased these associations. Sex, age, marital status, region, and educational level were found to be significantly associated with major depressive disorder and anxiety disorders and were taken into account in the regression analysis. Compared with the general population, individuals with alcohol use disorders alone had significantly increased risks of major depressive disorder (OR 2.49, 95%CI 1.76-3.53 in men and OR 4.09, 95%CI 2.31-7.26 in women) and anxiety disorders (OR 2.21, 95%CI 1.46-3.36 in men and OR 4.34, 95%CI 2.35-8.03 in women). The risks became higher among individuals with both alcohol use disorders and illicit drug use (OR 3.62, 95% CI 1.64-8.01 in men and OR 11.53, 95%CI 1.32-100.65 in women for major depressive disorder, and OR 3.20, 95%CI 1.36-7.51 in men and OR 13.10, 95%CI 1.48-115.60 in women for anxiety disorders). In conclusion, alcohol use disorders were significantly associated with major depressive disorder and anxiety disorders. Illicit drug use was an important factor in increasing these associations, especially in women. Screening for depression, anxiety, and illicit drug use should be done in individuals with alcohol use disorders.

Association of ALDH2 genotypes with periodontitis progression

The progression of periodontitis may be affected by ALDH2 genotypes with respect to the oxidation of acetaldehyde to acetate, which leads to the accumulation of acetaldehyde in plasma and potential toxic effects. We examined the prospective association of ALDH2 genotypes in terms of alcohol sensitivity between alcohol consumption and periodontal disease progression. In 2003, 224 of 256 (87.5%) individuals examined at baseline (1999) completed probing pocket depth measurements for the evaluation of periodontitis progression. Missing data on self-reported questionnaires and blood samples were excluded; therefore, 183 samples were analyzed. Individuals who consumed > or = 33.0 g/day of alcohol exhibited high periodontal disease progression risk (OR = 3.54). ALDH2 *1/*2 individuals who consumed > or = 33 g/day of alcohol displayed a significant odds ratio (OR = 4.28) of periodontitis progression risk, in contrast to ALDH2 *1/*1 individuals. These results suggested that alcohol consumption as well as alcohol sensitivity may be a risk factor for periodontitis progression.

Association of ALDH(2) genotypes and alcohol consumption with periodontitis

There is little information regarding the association between alcohol consumption and periodontitis risk. We assessed whether alcohol consumption and ALDH(2) genotypes were associated with periodontitis. Subjects' lifestyle was examined by a self-administered questionnaire, and the percentage of pocket depths > or = 3.5 mm was used as a periodontal parameter. ALDH(2) genotypes were determined with the use of a PCR/RFLP method. Multiple logistic analyses showed that alcohol consumption was significantly associated with periodontitis, and its odds ratio was 1.98. There was no significant relationship between periodontal status and ALDH(2) genotypes. However, ALDH(2)*1/*2 subjects who consumed > or = 33 g/day of alcohol had a significantly greater percentage of pocket depths > or = 3.5 mm than those whose daily consumption was lower, while there was no significant difference in periodontal status associated with alcohol consumption in ALDH(2)*1/*1 subjects. Our results suggest that alcohol consumption may be a risk indicator for periodontitis in ALDH(2)*1/*2 subjects who consume larger amounts of alcohol.

Alcohol dehydrogenase-2 and aldehyde dehydrogenase-2 genotypes and male alcohol use disorders in Khon Kaen, north-east Thailand

A case-control study on the relationship between alcohol dehydrogenase-2 (ADH2), aldehyde dehydrogenase-2 (ALDH2) and male probable alcohol use disorders (AUD) was performed in Khon Kaen, north-east Thailand. One hundred and fifty-three paired cases (probable AUD) and controls (non-probable AUD) were sampled from villagers aged 18-65 years using the modified Michigan Alcoholism Screening Test - Thai version, controls being matched for gender, age (+/- 4 years) and village. All of the cases and 86.9% of the controls were current drinkers. The percentage of ADH2*1/1 among cases was 47.1%, being significantly larger than the 29.4% among controls, and yielding a univariate odds ratio (OR) of 2.421* (95% confidence interval (CI) = 1.419-4.132) for developing probable AUD. The ALDH2*1/1 proportion among cases, 92.8%, was comparable to the 92.2% among controls, yielding a univariate OR of 1.100 (95%CI = 0.757-1.599). Multivariate analysis based on a conditional logistic regression model and a hierarchically well-formulated model strategy revealed that: (i) the OR of developing probable AUD due to 1 g increment of daily ethanol drinking was 1.110* among farmers (95%CI = 1.054-1.170); (ii) OR due to 1 g increment of daily ethanol drinking was 1.329* among non-farmers (95%CI = 1.109-1.593); (iii) OR due to either ADH2*1/1 or ALDH2*1/1 was insignificant; and (iv) the daily amount of smoking is independently associated with probable AUD. The present findings suggest that one of the genetic factors that may be related to probable AUD among Thai males living in the north-east is the ADH2 gene.

Genetic polymorphisms of tobacco- and alcohol-related metabolizing enzymes and human esophageal squamous cell carcinoma susceptibility

Many human cancers are caused by synthetic or natural chemical compounds in the environment. Esophageal squamous cell carcinoma has been reported to be epidemiologically associated with tobacco and alcohol consumption. We studied the association between genetic polymorphisms of tobacco- and alcohol-related metabolizing enzymes and esophageal squamous cell carcinoma susceptibility. We examined genetic polymorphisms of the CYPIA1, GSTM1, CYPIIE1, ADH2, and ALDH2 genes in 94 Japanese patients with esophageal squamous cell carcinoma and 70 unrelated healthy Japanese persons. There were no significant differences between healthy controls and patients with esophageal cancer in the polymorphisms of the CYPIA1, GSTM1, and CYPIIE1 genes. On the other hand, there were significant differences in the ADH2 and ALDH2 polymorphisms between healthy controls and esophageal cancer patients. The ADH2(1)/ADH2(1) and ALDH2(1)/ALDH2(2) genotypes were independently and significantly higher in esophageal cancer patients than in healthy controls. Furthermore, persons with the combined genotypes ADH2(1)/ADH2(1) and ALDH2(1)/ALDH2(2) were at extraordinarily high risk for esophageal squamous cell carcinoma, with an odds ratio of 17.9 (p < 0.001). Thus polymorphisms of alcohol-metabolizing enzymes, that is, ADH2 and ALDH2, may be useful for screening patients at high risk for esophageal cancer, which might facilitate clarification of esophageal tumorigenesis and prevention of esophageal cancer.