title: Association of the DBH Polymorphism rs3025343 With Smoking Cessation in a Large Population-Based Sample.
abstract: BACKGROUND
  Genetic variations in DBH-gene and its surroundings have been shown to associate with smoking behavior including smoking cessation in several studies. In this study we replicate and measure the effect size for association between DBH polymorphism rs3025343 and smoking cessation in a large population-based sample while examining environmental factors that could relate to the association.
  
  
  METHODS
  We studied 11 926 adult subjects from four surveys of the National FINRISK Study. The analysis was restricted to either current or former smokers. Logistic and linear regression analyses were conducted to investigate the relationships of the single nucleotide polymorphism (SNP), covariates, smoking cessation, and smoking severity (cotinine, CPD). Gene-environment interactions were tested by likelihood-ratio test.
  
  
  RESULTS
  The association between rs3025343 and smoking cessation (prevalence odds ratio, OR = 1.12, p = .094, 95%CI = 0.98-1.30) was replicated identically with the GWAS study of The Tobacco and Genetics Consortium (OR = 1.12, 95%CI = 1.08-1.18). None of our tested phenotypes significantly influenced the association between rs3025343 and smoking cessation. Overall, marital status, education, depression, alcohol use, self-rated health, and chronic obstructive pulmonary disease (COPD) showed phenotypic associations with smoking cessation, but the association of various phenotypes with smoking cessation did not vary by genotype.
  
  
  CONCLUSIONS
  The current study replicates the effect size for the association between rs3025343 and smoking cessation despite lack of overall significance due to smaller sample size. We could not show environmental influences on the association of rs3025343 with smoking cessation.
  
  
  CONCLUSIONS
  Our study replicates the direction and strength of the association of DBH polymorphism rs3025343 with smoking cessation. We could not detect environmental influences on the strength of the association of rs3025343 with smoking cessation, but the limited power of our analysis needs to be taken into account.
authors.affiliation: Department of Public Health, University of Helsinki, Helsinki, Finland.|Institute for Molecular Medicine FIMM, University of Helsinki, Helsinki, Finland.
authors.forename: Katariina
authors.initials: K
authors.lastname: Hirvonen
authors.affiliation: Department of Public Health, University of Helsinki, Helsinki, Finland.|Institute for Molecular Medicine FIMM, University of Helsinki, Helsinki, Finland.|Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
authors.forename: Tellervo
authors.initials: T
authors.lastname: Korhonen
authors.affiliation: Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Veikko
authors.initials: V
authors.lastname: Salomaa
authors.affiliation: Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Männistö
authors.affiliation: Department of Public Health, University of Helsinki, Helsinki, Finland.|Institute for Molecular Medicine FIMM, University of Helsinki, Helsinki, Finland.|Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
mesh_terms: D000328:Adult; D000368:Aged; D004299:Dopamine beta-Hydroxylase / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012907:Smoking / Q000453:epidemiology / Q000235:genetics; D016540:Smoking Cessation / Q000706:statistics & numerical data*
chemical_list: D004299:Dopamine beta-Hydroxylase