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The aim of this study was to explore the changes in the characteristics of titanium surface and the osteoblast-titanium interactions under cigarette smoke extract (CSE) exposure. In this study, CSE was used to simulate the oral liquid environment around the implant under cigarette smoke exposure. Titanium samples were immersed in CSE to explore the changes in the characteristics of titanium surface. The physical properties of titanium surface were measured, including surface micromorphology, surface elemental composition, roughness, and surface hydrophilicity. MC3T3-E1 cells were cultured on the titanium surface in vitro under different concentrations of CSE exposure, and cell adhesion, cell proliferation, and osteogenic differentiation were observed. The surface micromorphology and elemental composition of titanium surface changed under CSE exposure. No obvious changes were found in the surface roughness and the hydrophilicity of titanium samples. Moreover, the results of in vitro study showed that CSE exposure downregulated the cell spreading, proliferation, and osteogenic differentiation of MC3T3-E1 cells on the titanium surface. It could be speculated that some carbon-containing compounds from CSE adsorbed on the titanium surface and the osteoblast-titanium interactions were influenced under CSE exposure. It is hoped that these results could provide valuable information for further studies on smoking-mediated inhibition of implants osseointegration.

Objective: To explore the interaction between passive smoking and folic acid supplement during pregnancy on children autism spectrum disorder(ASD)behaviors., Methods: Children aged about 3 years were enrolled at kindergarten entrance in Longhua district of Shenzhen in 2014. Self-administered questionnaires were completed by their primary caregivers and the information about children' s age, gender, history of preterm birth and low birth weight, parents' education level, parents' reproductive age and family income were collected. The children ASD behaviors were assessed with Autism Behavior Checklist(ABC). According to the cut point of ABC, the children were divided into normal group with score less than 31, sub-clinical group with score ranging from 31 to 61 and suspect clinical group with score no less than 62. After controlling for potential confounders, multivariate logistic regression analysis was performed to evaluate the main effects and the interaction between passive smoking and folic acid supplement during pregnancy on children ASD behaviors., Results: Maternal passive smoking during pregnancy was significantly associated with children ASD behaviors(sub-clinical group: OR=1.48; suspect clinical group: OR= 2.85), and maternal folic acid supplement during pregnancy was not related to children ASD behaviors(sub-clinical group: OR=1.04; suspect clinical group: OR=0.75). Stratified analysis showed that folic acid supplement during pregnancy was negatively associated with children ASD behaviors(suspect clinical group: OR=0.30)among children without mothers' passive smoking during pregnancy, and that mothers' passive smoking during pregnancy was positively associated with children ASD behaviors(sub-clinical group: OR=1.52; suspect clinical group: OR=4.45)among the children whose mothers had folic acid supplement during pregnancy. Furthermore, an interaction effect on children ASD behaviors was found between passive smoking and folic acid supplement during pregnancy(suspect clinical group: OR=5.30)., Conclusion: Passive smoking and folic acid supplement during pregnancy were related to children ASD behaviors and had an interaction on children ASD behaviors.

Cigarette smoking is an important risk factor for hypertension. However, the effects on hypertension of the interaction between smoking and the genotype of the nicotinic acetylcholine receptor gene are unclear. The purpose of this study is to determine whether the CHRNA3 rs6495308 genotype affects the association between daily cigarette consumption and hypertension. We recruited 947 male smokers in southern China and used a questionnaire administered in face to face interviews to obtain information on their socio-demographic characteristics and smoking behavior. Blood samples were collected to test for CHRNA3 rs6495308 genotype variations. Three blood-pressure measurements were taken for each participant, and the average values recorded. We found that, compared with light smoking (<15 cigarettes per day), heavy smoking (≥15 cigarettes per day) yielded a greater risk of hypertension. We also observed that the interaction between daily cigarette consumption and the CHRNA3 rs6495308 genotype may affect hypertension. Heavy smokers with the homozygous mutant CHRNA3 rs6495308 genotype exhibited a significantly greater risk of hypertension than light smokers with wild-type CHRNA3 rs6495308 genotypes. The positive interaction between heavy smoking and the homozygous mutant CHRNA3 rs6495308 genotype was found to affect the likelihood of hypertension in Chinese male smokers.

Objective: Previous studies have indicated that cigarette smokers are more likely to develop type 2 diabetes and that both smoking and type 2 diabetes are associated with C-reactive protein (CRP). This study examined whether CRP mediates the association between smoking quantity and type 2 diabetes., Methods: Nine hundred and eighty-four current Chinese smokers were selected from a community-based chronic disease survey conducted in Guangzhou and Zhuhai. Type 2 diabetes was defined according to the WHO 1999 criteria. CRP was measured with flow cytometry. Binary logistic regression was performed to assess the mediation., Results: A positive association was observed between smoking quantity and type 2 diabetes (P < 0.05). After controlling for potential confounders, daily cigarette consumption was significantly associated with higher CRP levels. Current smokers with type 2 diabetes had higher CRP levels than smokers without type 2 diabetes. The association between the smoking quantity and type 2 diabetes was mediated by CRP, which accounted for 50.77% of the association., Conclusions: This study provides further evidence that smoking quantity is positively associated with type 2 diabetes and suggests that the association between smoking and type 2 diabetes might be mediated by CRP.

Objectives: Previous studies indicated that cigarette smokers were more likely to develop hypertension, and both smoking and hypertension were associated with inflammation. Whether inflammation mediates the relationship of them is unclear. This study aims to examine whether inflammation mediates the association between smoking and hypertension., Methods: Nine hundred and eighty-four Chinese current smokers from a community-based chronic diseases survey in Guangzhou and Zhuhai were interviewed about sociodemographics, smoking, chronic conditions, and other health-related variables. Hypertension was defined according to 2007 European Society of Hypertension and European Society of Cardiology (ESH-ESC) Practice Guidelines. Inflammatory markers including C-reactive protein (CRP), interleukin (IL)-6, IL-1β, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), and vascular cell adhesion molecule-1 (VCAM-1) were measured by flow cytometry. Logistic regressions were performed to assess the mediation of inflammation on the relationship between smoking quantity and hypertension., Results: We observed a positive association between smoking quantity and hypertension (P<0.05). After controlling for potential confounders, daily cigarette consumption was significantly associated with higher level of CRP and VCAM-1 and lower level of TNF-α among six measured inflammatory markers, and the current smokers with hypertension had significantly higher level of MCP-1 and CRP than those smokers who were normotensive. Furthermore, the association between smoking quantity and hypertension was mediated by CRP, which accounted for 58.59% of the estimated causal effect of smoking on hypertension., Conclusion: We have confirmed previous observations that smoking quantity was positively associated with hypertension, and the results of our study suggested that the association between smoking and hypertension was probably mediated by CRP.

The purpose of this study was to assess whether cytochrome P450 enzyme 2A6 (CYP2A6) genotypes moderate the association between smoking and hypertension. In this study, 954 Chinese male current smokers from a community-based chronic disease screening project in Guangzhou were interviewed with a structured questionnaire about socio-demographic status, smoking and other health-related behaviors. Blood was collected for DNA extraction and CYP2A6 genotyping. Hypertension was defined according to 2007 ESH-ESC Practice Guidelines. A multivariate logistic regression was performed to examine the interaction between smoking quantity and CYP2A6 genotypes on hypertension after adjusting for age, education level and other potential confounders. Multivariate analyses indicated that smoking more than 15 cigarettes per day significantly increased the risk of hypertension (odds ratio (OR)=1.59, 95% confidence interval (CI)=1.21-2.10) compared with smoking 1-15 cigarettes per day, and further suggested that smoking interacted with normal CYP2A6 metabolizer genotype to increase the risk of hypertension. Smokers consuming more than 15 cigarettes per day with normal CYP2A6 metabolizer genotypes had the highest risk of hypertension (OR=2.04, 95% CI=1.11-3.75) compared with those consuming 1-15 cigarettes per day with slower CYP2A6 metabolizer genotypes. These findings demonstrated that smoking quantity was positively associated with hypertension and that CYP2A6 genotypes may moderate this relationship.

Background: Cigarette smoking is an important risk factor for abdominal obesity. However, the degree to which the CYP2A6 genotype moderates the relationship between smoking and abdominal obesity has not been established., Purpose: This study aims to investigate whether or not the relationship between smoking quantity and abdominal obesity is influenced by CYP2A6 genotypes., Methods: Nine hundred fifty-four male current smokers were selected. A venous specimen was collected to test serum cotinine and CYP2A6 genotype, and all smokers were divided into heavy (>15 cigarettes/day) and light smokers (≤15 cigarettes/day)., Results: Heavy smoking increased the risk of abdominal obesity (odds ratio (OR) = 1.57; 95% CI, 1.13-2.19) compared with light smoking. Furthermore, heavy smoking had a positive interactive effect with CYP2A6 poor metabolizer genotype on abdominal obesity (OR = 3.90; 95% CI, 1.25-12.18). Moreover, CYP2A6 poor metabolizer genotypes were associated with slower nicotine metabolism., Conclusions: Heavy smoking may increase the risk of abdominal obesity-particularly in smokers with CYP2A6 poor metabolizer genotypes.

Background: Previous studies in the world reported inconsistent results about the relationship of medical professional education with medical students' smoking behaviors, and no similar research had been published in China., Purpose: This paper aims to explore whether the differences of smoking-related knowledge, attitudes, and behaviors existed between medical and non-medical undergraduate students., Methods: Eight thousand one hundred thirty-eight undergraduate students sampled from a university in Guangzhou were investigated with a self-administered structured questionnaire about their smoking-related knowledge, attitude and behaviors, and other relevant factors. General linear model and multinomial logistic regression were conducted to test the differences in smoking-related knowledge, attitude, and behaviors between medical and non-medical students while controlling for potential confounding variables., Results: There was no difference in smoking-related knowledge scores between medical and non-medical freshmen, but medical sophomores and juniors had higher scores of smoking-related knowledge than their non-medical counterparts. The medical sophomores had higher mean score of attitudes towards smoking than non-medical ones. Before entering university, the difference in the prevalence of experimental and regular smoking between medical and non-medical college students was not significant. After entering university, in contrast, the overall prevalence of regular smoking was significantly higher among male non-medical college students than among male medical students. Stratified by current academic year, this difference was significant only among male sophomores., Conclusions: Medical students have higher smoking-related knowledge, stronger anti-smoking attitude, and lower prevalence of regular smoking than non-medical college students of similar age, which may be associated with medical professional education.

Objective: To explore the interactions between smoking and CYP2A6 genotypes on type 2 diabetes (T2DM) as well as potential pathways for smoking in causing T2DM., Design: Cross-sectional study., Methods: A total of 1344 smokers with complete data from a community-based T2DM survey in Guangzhou and Zhuhai of China from July 2006 to June 2007 were interviewed with a structured questionnaire about socio-demographic status and daily cigarette consumption. Serum glucose, insulin, and cotinine were measured after an overnight fast. Subjects were genotyped for CYP2A6 and classified, according to genotype, into normal, intermediate, slow, or poor nicotine metabolizers based on prior knowledge of CYP2A6 allele associations with nicotine C-oxidation rate. Abdominal obesity was defined as a waist-to-hip ratio ≥0.90 for males or ≥0.85 for females. Type 2 diabetic patients (n=154) were diagnosed according to WHO 1999 criteria. Chi-square tests, multivariate logistic regression models, and a structural equation model were used in this study., Results: Multivariate analysis indicated that, compared with light smoking, heavy smoking significantly increased the risk of T2DM (odds ratio (OR)=1.75, 95% CI=1.01-3.05). There were significant interactions between heavy smoking and slow CYP2A6 (OR=5.12, 95% CI=1.08-24.23) and poor CYP2A6 metabolizer genotypes (OR=8.54, 95% CI=1.28-57.02) on T2DM. Structural equation modeling indicated that CYP2A6 moderation of smoking quantity risk on T2DM was mediated by the effects on serum cotinine, abdominal obesity, insulin resistance, and insulin secretion., Conclusions: Heavy smoking was significantly associated with T2DM, and this association was moderated by CYP2A6 genotype and mediated by serum cotinine, abdominal obesity, insulin resistance, and insulin secretion.

Aims: To investigate the association of CYP2A6 genetic polymorphisms with smoking-related phenotypes in Chinese smokers., Design: Case-only genetic association study., Setting: Southern China., Participants: A total of 1328 Han Chinese smokers who participated in a community-based chronic disease screening project in Guangzhou and Zhuhai from 2006 to 2007., Measurements: All participants answered a structured questionnaire about socio-demographic status and smoking behaviors and informative alleles were genotyped for the cytochrome P450 2A6 (CYP2A6) gene (CYP2A6*4,*5,*7,*9 and *10)., Findings: The frequencies of CYP2A6*4, *5, *7, *9 and *10 alleles were 8.5, 1.2, 6.3, 13.5 and 2.4%, which corresponded to 48.9, 15.4, 24.2 and 11.5% of participants being classified as normal, intermediate, slow and poor metabolizers, respectively. Multivariate analyses in male smokers demonstrated that compared with normal metabolizers, poor metabolizers reported smoking fewer cigarettes per day [adjusted odds ratio (OR) = 0.49; 95% confidence interval (CI): 0.32-0.76], started smoking regularly later in life (adjusted OR = 1.55; 95% CI: 1.06-2.26) and, among former smokers, reported smoking for a shorter duration prior to quitting (adjusted OR = 0.33; 95% CI: 0.12-0.94). However, poor metabolizers were less likely to quit smoking and remain abstinent than normal metabolizers (adjusted OR = 0.54; 95% CI: 0.34-0.86)., Conclusions: Reduced metabolism function of cytochrome P450 2A6 in smokers appears to be associated with fewer cigarettes smoked, later initiation of smoking regularly, shorter smoking duration and lower likelihood of smoking cessation., (© 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.)

Background: Aberrant methylation of promoter DNA and transcriptional repression of specific tumor suppressor genes play an important role in carcinogenesis. Recently, many studies have investigated the association between cigarette smoking and p16(INK4α) gene hypermethylation in lung cancer, but could not reach a unanimous conclusion., Methods and Findings: Nineteen cross-sectional studies on the association between cigarette smoking and p16(INK4α) methylation in surgically resected tumor tissues from non-small cell lung carcinoma (NSCLC) patients were identified in PubMed database until June 2011. For each study, a 2×2 cross-table was extracted. In total, 2,037 smoker and 765 nonsmoker patients were pooled with a fixed-effects model weighting for the inverse of the variance. Overall, the frequency of p16(INK4α) hypermethylation was higher in NSCLC patients with smoking habits than that in non-smoking patients (OR = 2.25, 95% CI = 1.81-2.80). The positive association between cigarette smoking and p16(INK4α) hypermethylation was similar in adenocarcinoma and squamous-cell carcinoma. In the stratified analyses, the association was stronger in Asian patients and in the studies with larger sample sizes., Conclusion: Cigarette smoking is positively correlated to p16(INK4α) gene hypermethylation in NSCLC patients.

Objective: To confirm the effect of cigarette smoking on β-cell function, and further investigate the mediation effect of abdominal obesity., Methods: Participants would include 1440 Chinese smokers who had participated in a community-based chronic disease screening project in Guangzhou and Zhuhai from 2006 to 2007. They were interviewed with structured questionnaire on their socio-demographic status and smoking behaviors. Waist-to-hip ratio (WHR) and fasting serum C-peptide concentration were also measured., Results: After adjustment for the potential confounding factors, when compared with smokers with consumption 1 - 10 cigarettes/day, smokers with consumption of 11 - 20 cigarettes/day (adjusted OR = 1.53, 95%CI: 1.22 - 1.90) or > 20 cigarettes/day (adjusted OR = 1.92, 95%CI: 1.32 - 2.79) had significant higher risks to get C-peptide concentration larger than its median. Furthermore, 37.54% of the effect of cigarette smoking on C-peptide concentration was partially mediated by abdominal obesity., Conclusion: Cigarette smoking might be a risk factor for β-cell dysfunction and abdominal obesity.

Objective: To explore the relationship between psychological stress, fatigue and different smoking behaviors among undergraduate students., Methods: 8138 undergraduate students in grade 1 to 3 were sampled with cluster sampling method from a comprehensive university in Guangzhou, and were studied on their psychological stress, peer and self smoking behaviors, as well as socio-demographic factors with a self-administered questionnaire. Physical and mental fatigue was measured by Chalder fatigue scale. A multinomial logistic regression analysis was performed to explore the association between psychological stress, fatigue and different smoking behaviors with 'non-smokers' defined as control group while 'triers' and 'current smokers' as case group, respectively., Results: There were students trying to smoke or becoming current smokers on university campus. After adjusting the effect of relevant socio-demographic factors and peer smoking behavior, physical fatigue (OR = 1.044, 95% CI: 1.013-1.075) and 'worry about current academic and future work' (OR = 1.020, 95% CI: 1.001-1.040) were the risk factors of trying to smoke among male students, while 'study stress (OR = 1.063,95% CI: 1.012-1.117) was the risk factor for female students when start smoking. 'Personnel relationship and environment stress' (OR = 1.152, 95% CI: 1.012-1.312) were the risk factors for female students' current smoking behavior., Conclusion: Psychological stress and fatigue were moderately associated with smoking behavior among undergraduate students and the impact was different on different gender and smoking behaviors that suggesting that some specific psychological measures should be taken so as to control different smoking behaviors among undergraduate students.

Objective: To explore the determinants of 'signing a agreement for establishing smoke-free homes' among the parents of secondary school students., Methods: 2019 parents were surveyed with self-administered questionnaires on their socio-demographic characteristics, smoking behaviors, attitude toward tobacco control at home and related data of their children. At the same time, parents were asked to sign an agreement for making the 'home as smoking-free'. 'Parents signing the agreement' was defined as dependent variable (0=no, 1=yes), and parent's age, gender, educational level, etc. were defined as independent ones. Multi-variant logistic regression analysis was conducted for identifying the determinants of the parents to sign an agreement for establishing 'smoking-free homes'., Results: Of the 2019 surveyed parents, 1047 (51.86%) had signed the agreement including 49.25% of the fathers and 55.73% of the mothers. The results from multi-variant logistic regression analysis indicated that father's 'signing action' was significantly associated with (a) their intention of carrying out the agreements (OR = 3.37), (b) to teach their children about the consequence between smoking and health (OR = 2.10), (c) knowing tobacco control program at school (OR = 1.38), (d) reading tobacco control material provided by school (OR = 1.38), (e) being current smoker (OR = 0.53) compare to that the mother's 'signing action' was significantly associated to (a) intention to carrying out agreements (OR = 2.36), (b) teaching children not to smoke (OR = 2.22), (c) reading tobacco control material provided by school (OR = 1.57)., Conclusion: Changing parental cognition and attitude toward smoking was beneficial to promote parental participation in tobacco control campaign and to establish 'smoking-free homes'.

Objective: To explore the access to tobacco and exam the predictors of successful tobacco purchase attempts among Chinese minors., Methods: A simulative trial of purchasing cigarettes was participated by 201 sixth grade students to assess the prevalence of illegal cigarette sales to minors in Guangzhou. Methods of Chi-square and unconditional logistic regression were used to identify the significant predictors,with the result of tobacco purchase as the dependent variable and the characteristics of stores, retailers and minors as the independent variables., Results: A total of 165 students succeeded in purchasing cigarettes but 36 failed, and the percentage of successful purchase attempts was 82. 1% . Data from univariate analysis indicated that 9 factors were significantly associated with students' success in purchasing cigarettes. They were age and height of the purchasers, types of stores, seller's gender and age, posting cigarette advertisements,showing warning signs of 'no cigarette selling to minors' ,asking buyer's age,and asking whom you buy the cigarettes for. The results of multivariable analysis showed that only three variables entering the final logistic regression: the age of students, the type of stores, and showing warning signs of 'no cigarette selling to minors'., Conclusion: Chinese minors have easy access to purchasing cigarettes, especially in groceries and small markets. Selling cigarettes by sellers to minors should be monitored and managed in the future.

Objective: To analyze the direct and indirect outcomes of influencing factors on smoking behaviors among adolescents., Methods: Self-administered questionnaires were used to collect smoking-related information from 2021 respondents. Measurement models were built by confirmatory factor analysis and parameters were estimated by ERLS method. The final structural equation model was determined by comprehensive evaluation and necessary modification., Results: Three latent variables were extracted from 10 manifest variables of environment, while only one latent variable was identified from 9 manifest variables of attitudes. The goodness of fit for the structural equation model was satisfactory that all indices had met corresponding requirements. The final model could explain 38.8% of the variance of smoking behaviors. Four factors (smoking environment, smoking restriction from parents and teachers, determination of cigarette refusal and attitudes toward smoking) were directly affecting the smoking behaviors, while another three factors (grade, health knowledge and school environment) had indirect impacts. According to the percentages of their contribution, the risk factors were ranked as follows: smoking environment (45.76%), attitudes toward smoking (19.88%) and grade at school (0.44%). Similarly, the top protective factor were: determination of cigarette refusal (16.61%), followed by smoking restriction from parents and teachers (10.51%), health knowledge (3.89%) and school environment (2.92%)., Conclusions: Heath knowledge had minor effect on smoking in adolescents but could indirectly affect their smoking behaviors through changing their belief. Grade at school had a doubled influence on smoking, but mainly served as a risk factor. Tobacco control measures for adolescents should not only be limited to health education but environment factors as well.

Objective: To explore the influencing factors of smoking behavior transition at different stage of smoking among undergraduate students., Methods: 8138 undergraduate students from grade 1 to 3 were selected using cluster sampling method from an university in Guangzhou with their smoking behaviors and relevant factors studied through a self-administered questionnaire. Beginners, un-regular smokers and regular smokers were defined as "case group", while non-smokers, beginners and un-regular smokers were defined as "control group" accordingly. Three multivariable logistic regressions were separately conducted to explore the influencing factors of behavioral transition at different stage of smoking., Results: Of the 8138 students investigated, the prevalence rates of beginners, un-regular smokers and regular smokers were 19.6%, 2.0% and 1.1%, respectively; while all of the above said three rates increased with grades of the students. Some students might still try to smoke or become regular smoker in the university. In male undergraduate students, determinants for the transition from non-smokers to s mokers were: source of students, father' s educational level, smoking-related knowledge and belief, and smoking habit of the roommates. Risks that influencing the transition from beginners to un-regular smokers were: being non-medical students,smoking-related belief, roommates and classmates who were smokers and transition from un-regular smokers to regular smokers would include father' s educational level and average income of family. In female undergraduate students,influencing factors from non-smokers to beginners were mother's educational level, smoking-related belief, and roommates smokers, while father's educational level, roommates and classmates' smoking habits were significant associated with beginners' change to un-regular smokers., Conclusion: The influencing factors related to the transition of different stage on smoking would be different in undergraduate students,and some specific measures should be taken based on the different stage of smoking.