Genotype × Environment Interaction in Smoking Behaviors: A Systematic Review

Area of Science:

• Genetics and Behavioral Science
• Public Health Research

Background:

• Growing research interest in gene-environment interaction (G×E) influencing smoking behaviors.
• Lack of a systematic review on G×E in smoking behavior research.

Purpose of the Study:

• To systematically review existing evidence on gene-environment interaction (G×E) contributing to smoking risk.
• To identify methodologies, genes, and environmental factors associated with smoking behaviors in G×E studies.

Main Methods:

• Systematic literature search of electronic databases up to May 2014.
• Identification and comparison of 16 studies focusing on G×E and smoking behaviors.
• Analysis of research design, sample characteristics, measures of smoking and environment, and genes explored.

Main Results:

• 81.2% of reviewed studies reported significant G×E associations with smoking behaviors.
• Considerable heterogeneity in analytic methods, phenotypes, environmental measures, and G×E testing was observed.
• Methodological variations impeded the comparison of findings and evaluation of evidence strength.

Conclusions:

• Methodological heterogeneity in G×E smoking research complicates evidence assessment.
• Recommendations are proposed for environmental variable measurement, effect reporting, covariate treatment, and analysis.
• Further research is needed to elucidate the mechanisms of gene-environment interplay in smoking behaviors.