Differential genetic associations between dimensions of eating disorders and alcohol involvement in late adolescent twins

Baiyu Qi; Laura M Thornton; Courtney E Breiner; Ralf Kuja-Halkola; Jessica H Baker; Paul Lichtenstein; Sebastian Lundström; Arpana Agrawal; Cynthia M Bulik; Melissa A Munn-Chernoff

doi:10.1111/acer.15150

Differential genetic associations between dimensions of eating disorders and alcohol involvement in late adolescent twins

Alcohol Clin Exp Res (Hoboken). 2023 Sep;47(9):1677-1689. doi: 10.1111/acer.15150. Epub 2023 Sep 17.

Authors

Affiliations

¹ Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
² Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
³ Department of Psychology, University at Albany, State University of New York, Albany, New York, USA.
⁴ Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
⁵ Gillberg Neuropsychiatry Centre, University of Gothenburg, Göteborg, Sweden.
⁶ Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, USA.
⁷ Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.

PMID: 38051153
PMCID: PMC10699207 (available on 2024-09-17)
DOI: 10.1111/acer.15150

Abstract

Background: Twin studies have demonstrated shared genetic and environmental effects between eating disorders and alcohol involvement in adults and middle adolescents. However, fewer studies have focused on late adolescents or investigated a wide range of eating disorder dimensions and alcohol involvement subscales in both sexes. We examined genetic and environmental correlations among three eating disorder dimensions and two alcohol involvement subscale scores in late adolescent twins using bivariate twin models.

Methods: Participants were 3568 female and 2526 male same-sex twins aged 18 years old from the Child and Adolescent Twin Study in Sweden. The Eating Disorder Inventory-2 (EDI) assessed the drive for thinness, bulimia, and body dissatisfaction. Alcohol involvement was assessed with the Alcohol Use Disorder Identification Test consumption (AUDIT-C) and problem (AUDIT-P) subscales.

Results: Only phenotypic and twin correlations in female twins met our threshold for twin modeling. The proportion of total variance for each trait accounted for by additive genetic factors ranged from 0.50 to 0.64 in female twins, with the rest explained by nonshared environmental factors and measurement error. Shared environmental factors played a minimal role in the variance of each trait. The strongest genetic correlation (r_a ) emerged between EDI bulimia and AUDIT-P (r_a = 0.46, 95% confidence interval: 0.37, 0.55), indicating that the proportion of genetic variance of one trait that was shared with the other trait was 0.21. Nonshared environmental correlations between eating disorder dimensions and alcohol involvement ranged from 0.03 to 0.13.

Conclusions: We observed distinct patterns of genetic and environmental effects for co-occurring eating disorder dimensions and alcohol involvement in female vs. male twins, supporting sex-specific treatment strategies for late adolescents with comorbid eating disorders and alcohol use disorder. Our findings emphasize the importance of assessing family history of multiple eating disorder dimensions while treating late adolescents with problematic alcohol use, and vice versa, to improve detection and treatment.

Keywords: alcohol use; comorbidity; eating disorders; twin study; young adult.

Abstract

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