Cohort Effects on Tobacco Consumption and its Genetic and Environmental Variance Among Finnish Adults born between 1880-1957

Stephanie Zellers; Hermine H M Maes; Antti Latvala; Jaakko Kaprio

doi:10.1093/ntr/ntae091

Cohort Effects on Tobacco Consumption and its Genetic and Environmental Variance Among Finnish Adults born between 1880-1957

Nicotine Tob Res. 2024 Apr 17:ntae091. doi: 10.1093/ntr/ntae091. Online ahead of print.

Authors

Stephanie Zellers¹, Hermine H M Maes², Antti Latvala³, Jaakko Kaprio¹

Affiliations

¹ Institute for Molecular Medicine Finland, University of Helsinki.
² Virginia Institute for Psychiatric and Behavioral Genetics, Department of Human and Molecular Genetics, Psychiatry and Massey Cancer Center, Virginia Commonwealth University.
³ Institute of Criminology and Legal Policy, University of Helsinki.

PMID: 38630445
DOI: 10.1093/ntr/ntae091

Abstract

Introduction: Population research indicates that smoking behaviors in Finland have varied over time by sex and birth cohort. Smoking behaviors are influenced by genes and the environment; like the behaviors themselves, these underlying influences are not necessarily stable over time and may be modifiable by national drug policy.

Methods: We utilized longitudinal mixed effects models and causal-common-contingent twin models to evaluate sex and cohort effects on tobacco consumption and the underlying genetic and environmental variance components in a birth cohort sample of same-sex twins born in Finland between 1880-1957, assessed in 1975, 1981, 1990, and 2011.

Results: We identified significant main effects of age, sex, and cohort on quantity of cigarette consumption, as well as significant age×cohort and sex×cohort interactions. We also identified sex and cohort effects on the liability to initiate regular smoking and the magnitude of variation underlying quantity of cigarette consumption. That said, heritability and environmental contributions to both traits were not different between the four sex×cohort groups.

Conclusions: Our results indicate sex and cohort effects on the prevalence of smoking and its underlying variation. Our results on changing prevalence mirror existing population-level research in Finnish samples, but we did not identify differences in heritability found in other studies of cohort effects in tobacco use, potentially due to power issues. These results highlight the importance of considering age, cohort, and timing of policy changes when evaluating changes in substance consumption across time.

Implications: This study identifies sex and cohort effects influencing tobacco consumption in a sample of Finnish adult twins born between 1880-1957. Our results are in line with other population level research in Finland and research on cohort effects influencing alcohol use in the same sample. Our results highlight the intertwining effects of age, cohort, sex, and substance policies on substance use.

Keywords: common-causal-contingent model; heritability; social control; social trigger.