Integrating biological and behavioral factors in alcohol use risk: the role of ALDH2 status and alcohol expectancies in a sample of Asian Americans

Interaction between the ADH1B*3 allele and drinking motives on alcohol use among Black college students

BACKGROUND

Black young adults have lower rates of alcohol use than other racial groups. Genetic factors may protect against drinking. Specifically, the ADH1B*3 allele is present almost exclusively in Black populations and has been protective against alcohol use and alcohol use disorder. The protective effects of the ADH1B*3 allele, however, may differ as a function of alcohol-promoting cognitions.

OBJECTIVES

The current study examined whether ADH1B*3 moderated relations of drinking motives with alcohol consumption among Black college drinkers.

METHODS

Participants were 241 undergraduate students of self-identified Black race (mean age = 20 years; 66% female) who reported consuming alcohol at least once in the past 30 days.

RESULTS

ADH1B*3 was not significantly associated with drinking motives or drinking behaviors. However, significant, albeit small, interaction effects of ADH1B*3 with drinking motives on drinking behavior were found; the presence of an ADH1B*3 allele protected against greater drinking quantity among students with high social motives (incidence rate ratio [IRR] = 0.95, 95% CI [0.92, 0.99]) and against frequent drinking among students with low coping motives (IRR = 1.06, 95% CI [1.01, 1.11]).

CONCLUSION

These findings represent a novel demonstration of genetic modulation of alcohol-related cognitions within Black college drinkers, although replication is needed. Results represent an initial step toward better characterizing individual differences in associations of drinking motives with drinking behavior, with potential implications for interventions aimed at motivational processes in alcohol use.

Genetic and Environmental Predictors of Alcohol Use in Asian American Young Adults

OBJECTIVE

Among Asian American young adults, variations in alcohol-metabolizing genes (i.e., aldehyde dehydrogenase [ALDH2] and alcohol dehydrogenase [ADH1B]) are protective, whereas Korean ethnicity, family history of alcohol problems (FH), and acculturation represent risk factors for alcohol misuse. This study aims to integrate these genetic and environmental factors in a sample of Asian Americans expressing a wide range of alcohol use behaviors and problems.

METHOD

Participants were 97 Asian American young adults (42% female) recruited as heavy and light drinkers (n = 49 and 48, respectively). Participants completed the Alcohol Use Disorders Identification Test, Timeline Followback, Vancouver Acculturation Index, and Family Tree Questionnaire. All participants provided buccal cell samples for DNA analysis.

RESULTS

Family history-positive (FH+) subjects reported greater alcohol use than family history-negative (FH-) subjects. A FH × ALDH2 interaction was observed such that FH- subjects demonstrated no ALDH2 effect, yet in FH+ subjects, the ALDH2*2 genotype was associated with increased alcohol use. A significant main effect of acculturation was also moderated by FH such that the positive association between acculturation and alcohol use was greater among FH+ subjects and, in particular, among FH+ men.

CONCLUSIONS

Although preliminary, these results suggest that the potential protective effects conferred by ALDH2 and ADH1B are moderated by FH, such that a positive FH appeared to abolish the protective effect of these genes. Further, acculturation was associated with greater alcohol use in FH+ subjects only. If replicated in larger samples, these data suggest that alcohol-metabolism genes may not be protective in the context of high environmental risk.

Differential relationships of family drinking with alcohol expectancy among urban school children

Background

Positive alcohol outcome expectancy has consistently been linked with problematic drinking, but there is little population-based evidence on its role on early stages of drinking in childhood. The present study seeks to understand the extent to which drinking of family members is differentially associated with the endorsement of alcohol expectancy in late childhood.

Methods

A representative sample of 4th and 6th graders (N = 2455) drawn from 28 public schools in an urban region of Taiwan completed a self-administered paper-and-pencil questionnaire. Each student provided information on alcohol expectancy, drinking experiences, and individual and family attributes. Complex survey analyses were performed to evaluate the relationship, with stratification by children's alcohol drinking history.

Results

An estimated 29% of the 4^th graders and 43% of the 6^th graders had initiated alcohol consumption (over 40% of them had drank on three or more occasions). Alcohol drinking-related differences appear in both the endorsement and the correlates of alcohol expectancy. Positive alcohol expectancy was strongly associated with family drinking, particularly the dimension of "enhanced social behaviors"; negative alcohol expectancy was inversely associated with drinking frequency. Among alcohol naïve children, significant connections appear between paternal drinking and three dimensions of positive alcohol expectancy (i.e., enhanced social behaviors:β_wt = 0.15, promoting relaxation or tension reduction:β_wt = 0.18, and global positive transformation:β_wt = 0.22).

Conclusions

Individual tailored strategies that address family influences on alcohol expectancy may be needed in prevention programs targeting drinking behaviors in children.

Evaluating a cognitive model of ALDH2 and drinking behavior

BACKGROUND

Despite evidence for genetic influences on alcohol use and alcohol-related cognitions, genetic factors and endophenotypes are rarely incorporated in cognitive models of drinking behavior. This study evaluated a model of ALDH2 and drinking behavior stipulating cognitive factors and alcohol sensitivity as accounting for genetic influences on drinking outcomes.

METHODS

Participants were Asian-American young adults (n = 171) who completed measures of alcohol cognitions (drinking motives, drinking refusal self-efficacy, and alcohol expectancies), alcohol sensitivity, drinking behavior, and alcohol-related problems as part of a prospective study. Structural equation modeling (SEM) evaluated a model of drinking behavior that stipulated indirect effects of ALDH2 on drinking outcomes through cognitive variables and alcohol sensitivity.

RESULTS

The full model provided an adequate fit to the observed data, with the measurement model explaining 63% of the variance in baseline heavy drinking and 50% of the variance in alcohol-related problems at follow-up. Associations of ALDH2 with cognitive factors and alcohol sensitivity were significant, whereas the association of ALDH2 with drinking was not significant with these factors included in the model. Mediation tests indicated significant indirect effects of ALDH2 through drinking motives, drinking refusal self-efficacy, and alcohol sensitivity.

CONCLUSIONS

Results are consistent with the perspective that genetic influences on drinking behavior can be partly explained by learning mechanisms and implicate cognitive factors as important for characterizing associations of ALDH2 with drinking.

ALDH2, ADH1B and alcohol expectancies: integrating genetic and learning perspectives

The present study evaluated associations of ALDH2 and ADH1B genotypes with alcohol expectancies and drinking behavior in a sample of Asian American young adults. In addition to assessing global alcohol expectancies, the authors developed a measure of physiological expectancies to evaluate an expectancy phenotype specific to the mechanism by which ALDH2 and ADH1B variations presumably influence drinking behavior. Compared with individuals with the ALDH2*1/*1 genotype, those with the ALDH2*2 allele reported greater negative alcohol expectancies, greater expectancies for physiological effects of alcohol and lower rates of alcohol use. ADH1B was not associated with alcohol expectancies or drinking behavior. Hierarchical models showed that demographic factors, ALDH2 genotype, and expectancy variables explained unique variance in drinking outcomes. Mediation tests showed significant indirect effects of ALDH2 on drinking frequency and peak lifetime consumption through expectancies. These results provide support for influences of genetic factors and alcohol sensitivity on alcohol-related learning and suggest the importance of developing biopsychosocial models of drinking behavior in Asian Americans.

Psychosocial, cultural and genetic influences on alcohol use in Asian American youth

OBJECTIVE

Environmental and cultural factors, as well as a genetic variant of the aldehyde dehydrogenase gene (the ALDH2*2 allele) have been identified as correlates of alcohol use among Asian Americans. However, concurrent examination of these variables has been rare. The present study assessed parental alcohol use, acculturation and ALDH2 gene status in relation to lifetime, current and heavy episodic drinking among Chinese and Korean American undergraduates.

METHOD

Participants (N = 428, 51% women; 52% Chinese American, age 18-19 years) were first-year college students in a longitudinal study of substance use initiation and progression. Data were collected via structured interview and self-report, and participants provided a blood sample for genotyping at the ALDH2 locus.

RESULTS

Gender, parental alcohol use and acculturation significantly predicted drinking behavior. However, none of the hypothesized moderating relationships were significant. In contrast with previous studies, ALDH2 gene status was not associated with alcohol use.

CONCLUSIONS

Results indicate that although the variables examined influence alcohol use, moderating effects were not observed in the present sample of Asian American college students. Findings further suggest that the established association of ALDH2 status and drinking behavior in Asians may not be evident in late adolescence. It is possible that ALDH2 status is associated with alcohol consumption only following initiation and increased drinking experience.