Search resultsDeveloping a quantitative measure of alcohol consumption for genomic studies on prospective cohorts
Title
Developing a quantitative measure of alcohol consumption for genomic studies on prospective cohorts
Publication type
Journal Article
Year of Publication
2009
Authors
Journal
Journal of Studies on Alcohol and Drugs
Volume
70
Issue
2
Pagination
157 - 168
Date published
2009
ISBN
19371888 (ISSN)
Keywords
Adult, alcohol consumption, Alcohol Drinking, alcohol intoxication, Alcoholism, article, cannabis smoking, cohort analysis, Cohort Studies, environmental factor, family history, Female, gene mapping, Genetic Predisposition to Disease, genetic risk, genetic variability, Genomics, heritability, human, Humans, male, phenotype, Psychometrics, psychometry, quantitative analysis, Risk Factors, smoking, Twin Studies as Topic, twins, Young Adult
Abstract
Objective: The purpose of this study was to develop a quantitative measure of alcohol consumption for gene-mapping studies. Method: Using a sample of 3,787 young-adult twin women and an independent sample of 489 men and women from a college drinking study, we developed an alcohol-consumption factor score indexed by (1) maximum typical consumption (log-transformed quantity frequency [LQNTFRQ]), (2) maximum drinks in a 24-hours period (LMAXALC), (3) frequency of drinking five or more drinks per day (FIVE), and (4) frequency of drinking to intoxication (INTOX). We tested (1) for factorial and psychometric equivalence across samples and genders; (2) for construct validity and its equivalence, across samples and genders, using measures of tobacco and cannabis use and family history of alcoholism; and (3) to determine the heritability of the alcohol-consumption factor score using a genetic psychometric model. Results: A single-factor model fit well with factor loadings ranging from .60 to .90. With rare exception, we found support for measurement invariance across the two samples and across genders. Measures of nicotine and cannabis use as well as family history of alcoholism were associated, to a similar extent across samples and genders, with the underlying alcohol-consumption factor. Psychometric twin modeling revealed that each of the alcohol-consumption measures (h2 = 34%-47%) and the underlying factor score (h2 = 50%) were heritable, with the remainder of the variance attributable to individual-specific environmental factors. This moderately heritable alcohol-consumption factor also accounted for a majority of the genetic variance in LQNTFRQ, LMAXALC, FIVE, and INTOX. Conclusions: Quantitative measures of alcohol consumption with the favorable attributes of measurement invariance, construct validity, and moderate heritability can greatly enhance future gene-mapping efforts, supplementing information afforded by conventional diagnostic measures of alcohol abuse/dependence.