OBJECTIVEA Meta-analysis was performed to assess the association of defective hepatic cytochrome P450 2A6 (CYP2A6) gene with smoking behaviors.

METHODSAll eligible studies published up to 2014 were searched out from PubMed, China National Knowledge Internet (CNKI), ISI Web of knowledge (ISI), vip citation databases (VIP), Chinese BioMedical Literature (CBM) and Elsevier Science Direct, searching words were "smok*","nicotine dependence","CYP2A6","cytochrome P450 2A6","polymorphism","mut*"and"varia*", while 436 articles were concluded. Meta-analysis was performed using Statal 3.1.

RESULTSA total of ten studies were finally included. We didn't find a significant effect of defective CYP2A6 gene on smoking initiation (fixed effect model (FEM): OR = 0.90, 95%CI: 0.78-1.03, I(2) = 25.8%), smoking persistence (random effect model (REM): OR = 0.85, 95%CI: 0.59-1.23, I(2) = 66.3%) and smoking cessation (REM: OR = 0.89, 95%CI: 0.57-1.40, I(2) = 67.1%). But it showed a significant protective effect of CYP2A6*4 on smoking initiation (FEM: OR = 0.78, 95%CI: 0.61-0.99, I(2) = 28.2%), smoking persistence (FEM: OR = 0.53, 95%CI: 0.36-0.77, I(2) = 41.0%) and smoking cessation (REM: OR = 0.49, 95%CI: 0.31-0.80, I(2) = 0.0%).

CONCLUSIONSThis Meta-analysis suggested that there was not a protective effect of defective CYP2A6 gene against smoking behaviors. But smokers with whole CYP2A6 gene deletion would be less likely to start smoking, less smoking persistence and more likely to quit smoking successful than smokers with wild CYP2A6 gene.

Aryl Hydrocarbon Hydroxylases ; Asian Continental Ancestry Group ; China ; Cytochrome P-450 CYP2A6 ; Gene Deletion ; Humans ; Polymorphism, Genetic ; Protective Factors ; Smoking ; Smoking Cessation ; Tobacco Use Disorder

OBJECTIVETo examine the association between social support and successful smoking cessation outcomes in males from rural areas.

METHODSA community-based case-control study was conducted with 642 adult male cases who appeared to be successful spontaneous smoking quitters as cases, together with other 700 adult males who failed quitting smoking to serve, as controls. Social Support Rating Scale (SSRS) was used to assess the individual social support. Multiple linear method was used to evaluate the relationship between social support and the outcome of successful cessation in smoking.

RESULTSAfter adjusting the potential confounders as age, education, marital status, profession, age of initial smoking and number of pack-years on smoking, the adjusted mean of subjective social support in successful quitters was significant lower than that in the failed ones (P<0.001). The differences of adjusted means between objective social support and its utility were not statistically different in the two groups among the population who recognized that cigarettes should always be provided when people interact with each other (P=0.124; P=0.763). However, the adjusted means of social support and the related three dimensions did not show significant differences in the two groups among the population in disapproval of the above said social norms (P>0.05).

CONCLUSIONData from our research indicated that social support would negatively affect the successful spontaneous cessation of smoking among people under unhealthy smoking culture.

Adult ; Case-Control Studies ; Humans ; Male ; Rural Population ; Smoking ; psychology ; Smoking Cessation ; psychology ; statistics & numerical data ; Smoking Prevention ; Social Support

OBJECTIVETo estimate the mediating effect of smoking abstinence self-efficacy (SASE) on the association between awareness of smoking hazard and successful smoking cessation.

METHODSA community-based case-control study was conducted in 642 smokers who successfully stopped smoking, and 700 smokers who failed in smoking cessation were used as controls. The awareness of smoking hazard was evaluated by total score of 12 items. The SASE was assessed by using Smoking Abstinence Self-Efficacy (ASES-S). The total effect was classified as direct effect and indirect effect through logistic regression analysis based on the KHB method.

RESULTSAfter adjusting the potential confounders, including age, age of smoking initiation, occupation, educational level and marital status, the mediating effect of SASE accounted for 6.03% among the total effect of awareness of smoking hazard in those who successfully stopped smoking while the direct effect accounted for 93.97% among the total effect. In the three specific situation of SASE, the mediating effect of SASE accounted for 6.80% (positive/social situations), 3.08% (negative/affective situations) and 2.32% (habit/addictive situations) among the total effect, respectively.

CONCLUSIONSASE has part mediating effect to influence on the association between the awareness of smoking hazard and successful smoking cessation. Improving smokers' awareness of smoking hazard may not only promote successful smoking cessation directly, but also contribute to quit smoking through improving the score of SASE.

Case-Control Studies ; Health Knowledge, Attitudes, Practice ; Humans ; Self Efficacy ; Smoking ; psychology ; Smoking Cessation ; psychology ; Tobacco Use Disorder

OBJECTIVETo investigate the relationship between smoking abstinence self- efficacy (SASE) and age.

METHODSA cross-sectional questionnaire survey in form of face-to-face interview was performed. The SASE level was assessed by using the Smoking Abstinence Self-Efficacy Scale. Univariate two-degree fractional polynomials (FPs) regression model was used to explore the relationship between SASE and age after adjusting of potential confounders: marital status, occupation and education.

RESULTSThe relationship between SASE and age showed a U-shaped curve with the nadir at 60 years old.

CONCLUSIONThe distribution of SASE is not consistent among age groups; middle aged person has lower level of SASE than both the younger and the elder.

Age Factors ; Cross-Sectional Studies ; Humans ; Middle Aged ; Models, Statistical ; Self Efficacy ; Smoking Cessation ; psychology ; Smoking Prevention ; Surveys and Questionnaires

OBJECTIVETo study the association between reasons for smoking and results related to successful smoking cessation.

METHODSA community-based case-control study was conducted with 642 male adults recognized as successful spontaneous smoking quitters being the subject cases while another 700 male adults who had failed to quit smoking were served as the controls. Russell Reason for Smoking Questionnaire (RRSQ) was used to investigate the reasons for smoking. Dominance logistic regression was performed to determine the relative importance of reasons for starting smoking and the endpoint of successful quit smoking.

RESULTSAfter adjusting the potential confounders of age, age of smoking initiation, marital status, profession, and education, the adjusted means of sedative and stimulation of RRSQ in the successful quitters were significant lower than that in the failed quitters. Results from the dominance logistic regression showed that the first two important factors for smoking cessation were sedative and stimulation of RRSQ, followed by psychological image, automatic, hand-mouth activity, indulgence, and addiction.

CONCLUSIONThis study demonstrated that factors as dependence-addiction showed more important impacts than the social-psychological ones on the endpoint of successful smoking cessation.

Adult ; Behavior, Addictive ; Case-Control Studies ; Humans ; Male ; Smoking ; psychology ; Smoking Cessation ; statistics & numerical data ; Smoking Prevention ; Surveys and Questionnaires