Abstract
Background
The effects and associations of genetic variation, psychological, and environment factors associated with cigarette smoking and nicotine dependence remain largely unknown.
Objective
To determine the influence and association of functional genetic polymorphisms of cytochrome P450 2A6 (CYP2A6), anxiety, and environmental factors on cigarette smoking and nicotine dependence.
Method
A cross-sectional study was conducted at King Chulalongkorn Memorial Hospital, Thailand between October 2014 and June 2015. We recruited 127 Thai adult smokers when they visited for an annual physical check-up. Participants completed questionnaires regarding demographic characteristics, The Fagerstrom Test for Nicotine Dependence, and The Thai Hospital Anxiety and Depression Scale. Blood was collected for CYP2A6 genotyping to determine the enzyme metabolism level/group.
Results
Factors associated with significantly greater cigarette consumption were age and being ultrarapid/ extensive metabolizers (UM/EM). Anxiety and smoking by household family members were significantly associated with the degree of nicotine dependence. We observed associations between severe nicotine dependence and genotype (UM/EM) and age (b = 0.037; P = 0.005), intermediate metabolizers (IM) and age (b = 0.031; P = 0.43), UM/EM and anxiety (b = 0.258; P < 0.001), IM and anxiety (b = 0.285; P < 0.001), UM/EM and household smoking in the family members (b = 1.427; P = 0.003), and IM and smoking by household family members (b = 1.293; P = 0.024).
Conclusions
Information regarding the association between the gene encoding enzyme metabolism, anxiety, and their interactions may be beneficial for selecting treatment choices for smoking cessation for individual genotypic metabolizers.