The association of environmental, individual factors, and dopamine pathway gene variation with smoking cessation

Abstract

This study aimed to examine whether dopamine (DA) pathway gene variation were associated with smoking cessation, and compare the relative importance of infulence factors on smoking cessation. Participants were recruited from 17 villages of Shandong Province, China. Twenty-five single nucleotide polymorphisms in 8 DA pathway genes were genotyped. Weighted gene score of each gene was used to analyze the whole gene effect. Logistic regression was used to calculate odds ratios (OR) of the total gene score for smoking cessation. Dominance analysis was employed to compare the relative importance of individual, heaviness of smoking, psychological and genetic factors on smoking cessation. 415 successful spontaneous smoking quitters served as the cases, and 404 unsuccessful quitters served as the controls. A significant negative association of total DA pathway gene score and smoking cessation was observed (p < 0.001, OR: 0.25, 95% CI 0.16-0.38). Dominance analysis showed that the most important predictor for smoking cessation was heaviness of smoking score (42%), following by individual (40%), genetic (10%) and psychological score (8%). In conclusion, although the DA pathway gene variation was significantly associated with successful smoking cessation, heaviness of smoking and individual factors had bigger effect than genetic factors on smoking cessation.

Smoking Genes: A Case–Control Study of Dopamine Transporter Gene (SLC6A3) and Dopamine Receptor Genes (DRD1, DRD2 and DRD3) Polymorphisms and Smoking Behaviour in a Malay Male Cohort

“…Tobacco smoking is highly addictive because of nicotine. The role of genetics in nicotine addiction supports the known associations of smoking behaviour and cessation with genetic variations [1][2][3][4]. Nicotine continuously exerts "rewarding effects" by increasing the production of dopamine in the nucleus accumbens of the brain and thus alters the mesolimbic dopamine pathway [3,5,6].…”

“…The role of genetics in nicotine addiction supports the known associations of smoking behaviour and cessation with genetic variations [1][2][3][4]. Nicotine continuously exerts "rewarding effects" by increasing the production of dopamine in the nucleus accumbens of the brain and thus alters the mesolimbic dopamine pathway [3,5,6]. Interestingly, nicotine addiction has been significantly associated with polymorphisms in the dopamine receptor or dopamine transporter genes, which play roles in the dopamine pathway [7,8].…”