Genetic correlation between smoking behavior and gastroesophageal reflux disease: insights from integrative multi-omics data.

BACKGROUND: Observational studies have preliminarily revealed an association between smoking and gastroesophageal reflux disease (GERD). However, little is known about the causal relationship and shared genetic architecture between the two. This study aims to explore their common genetic correlations by leveraging genome-wide association studies (GWAS) of smoking behavior-specifically, smoking initiation (SI), never smoking (NS), ever smoking (ES), cigarettes smoked per day (CPD), age of smoking initiation(ASI) and GERD. METHODS: Firstly, we conducted global cross-trait genetic correlation analysis and heritability estimation from summary statistics (HESS) to explore the genetic correlation between smoking behavior and GERD. Then, a joint cross-trait meta-analysis was performed to identify shared "pleiotropic SNPs" between smoking behavior and GERD, followed by co-localization analysis. Additionally, multi-marker analyses using annotation (MAGMA) were employed to explore the degree of enrichment of single nucleotide polymorphism (SNP) heritability in specific tissues, and summary data-based Mendelian randomization (SMR) was further utilized to investigate potential functional genes. Finally, Mendelian randomization (MR) analysis was conducted to explore the causal relationship between the smoking behavior and GERD. RESULTS: Consistent genetic correlations were observed through global and local genetic correlation analyses, wherein SI, ES, and CPD showed significantly positive genetic correlations with GERD, while NS and ASI showed significantly negative correlations. HESS analysis also identified multiple significantly associated loci between them. Furthermore, three novel "pleiotropic SNPs" (rs4382592, rs200968, rs1510719) were identified through cross-trait meta-analysis and co-localization analysis to exist between SI, NS, ES, ASI, and GERD, mapping the genes MED27, HIST1H2BO, MAML3 as new pleiotropic genes between SI, NS, ES, ASI, and GERD. Moreover, both smoking behavior and GERD were found to be co-enriched in multiple brain tissues, with GMPPB, RNF123, and RBM6 identified as potential functional genes co-enriched in Cerebellar Hemisphere, Cerebellum, Cortex/Nucleus accumbens in SI and GERD, and SUOX identified in Caudate nucleus, Cerebellum, Cortex in NS and GERD. Lastly, consistent causal relationships were found through MR analysis, indicating that SI, ES, and CPD increase the risk of GERD, while NS and higher ASI decrease the risk. CONCLUSION: We identified genetic loci associated with smoking behavior and GERD, as well as brain tissue sites of shared enrichment, prioritizing three new pleiotropic genes and four new functional genes. Finally, the causal relationship between smoking behavior and GERD was demonstrated, providing insights for early prevention strategies for GERD.

Understanding e-Cigarette Addictiveness: Triangulation of Focus Group and Netnographic Data.

BACKGROUND: Numerous studies have shown that e-cigarettes are addictive. For example, we previously showed that users of e-cigarette online forums discuss experiences of addiction in a netnographic analysis. However, it is unclear what makes e-cigarettes addictive apart from nicotine. In a focus group analysis, we recently identified 3 unique features of e-cigarettes that users linked to experiences of addiction: the pleasant taste, unobtrusiveness, and unlimited usability of e-cigarettes. OBJECTIVE: This study aimed to validate the previously identified features of e-cigarette addictive potential by triangulating data from the netnographic analysis and focus group discussions. METHODS: Drawing on a netnographic analysis of 3 popular, German-language e-cigarette forums, we studied whether experiences of addiction were linked to specific e-cigarette features. We included 451 threads in the analysis that had been coded for addictive experiences in a previous study by our team. First, we conducted a deductive analysis with preregistered codes to determine whether the features of pleasant taste, unobtrusiveness, and unlimited usability were mentioned in relation to the addictive potential of e-cigarettes in the online forums. Second, an inductive approach was chosen to identify further possible addictive features of e-cigarettes. RESULTS: Our deductive analysis confirmed that the features highlighted in our previous focus group study (pleasant taste, unobtrusiveness, and unlimited usability) were also frequently discussed in online forums in connection to addictive symptoms. In addition, our inductive analysis identified nicotine dosage as a significant feature linked to addiction. Users reported varying their nicotine doses for different reasons, leading to the identification of four distinct user types based on dosing patterns: (1) high doses for intermittent, (2) high doses for constant use, (3) low doses for constant use, and (4) switching between high and low doses depending on the situation. CONCLUSIONS: Our comprehensive analysis of online forum threads revealed that users' experiences of addiction are linked to 4 specific features unique to e-cigarettes: pleasant taste, unobtrusiveness, unlimited usability, and nicotine dosage. Recognizing these addictive features of e-cigarettes is crucial for designing cessation programs and informing public health policies to reduce the addictiveness of e-cigarettes.

Shared Genetic Etiology between Cortical Brain Morphology and Tobacco, Alcohol, and Cannabis Use.

Genome-wide association studies (GWAS) have identified genetic variants associated with brain morphology and substance use behaviors (SUB). However, the genetic overlap between brain structure and SUB has not been well characterized. We leveraged GWAS summary data of 71 brain imaging measures and alcohol, tobacco, and cannabis use to investigate their genetic overlap using linkage disequilibrium score regression. We used genomic structural equation modeling to model a "common SUB genetic factor" and investigated its genetic overlap with brain structure. Furthermore, we estimated SUB polygenic risk scores (PRS) and examined whether they predicted brain imaging traits using the Adolescent Behavior and Cognitive Development (ABCD) study. We identified 8 significant negative genetic correlations, including between (1) alcoholic drinks per week and average cortical thickness, and (2) intracranial volume with age of smoking initiation. We observed 5 positive genetic correlations, including those between (1) insula surface area and lifetime cannabis use, and (2) the common SUB genetic factor and pericalcarine surface area. SUB PRS were associated with brain structure variation in ABCD. Our findings highlight a shared genetic etiology between cortical brain morphology and SUB and suggest that genetic variants associated with SUB may be causally related to brain structure differences.

The association between different types of physical activity and smoking behavior.

BACKGROUND: Smoking is harmful, which has become a major public health burden. Physical activity may be related to smoking. Physical activity is one of the current methods for smoking control and smoking cessation. Different types of physical activity may have different effect on smoking behavior. OBJECTIVE: The purpose of this study was to identify the direction and extent of the impact of different types of physical activity above moderate intensity (including work physical activity, recreational physical activity, commuter physical activity and sedentary behavior) on smoking behavior. MATERIALS AND METHODS: In this study, a total of 2,015 individuals (1,233 males and 782 females, mean age 54.02±17.31 years) was selected from the representative population aged 20 and above in the National Health and Nutrition Survey of the United States from 2017 to 2018. Physical activity was assessed using the Global Physical Activity Questionnaire (GPAQ) ; the tobacco use questionnaire (SMQ) was used to determine whether the sample had smoking behavior at this stage. Binary Logistic regression analysis was performed with various physical activities as independent variables and smoking behavior as dependent variables. All data were analyzed through Statistical Product and Service Solutions (SPSS) 26.0. RESULTS: After adjusted for all confounding variables, physical activity at work was close to significantly associated with smoking behavior (P=0.053), odds ratio (OR) =1.135 (95%Cl: 0.999-1.289). Recreational physical activity was significantly associated with smoking behavior (P < 0.001), OR=0.729 (95%Cl: 0.639-0.832). Commuting physical activity was significantly associated with smoking behavior (P < 0.001), OR=1.214 (95%Cl:1.048-1.405). Sedentary behavior was significantly associated with smoking behavior (P < 0.001), OR=1.363 (95%Cl: 1.154-1.611). CONCLUSIONS: Given that different types of physical activity have different associations with smoking behavior. Therefore, when physical activity is used as a tobacco control measurement, it is necessary to pay attention to the type and environment of physical activity. Recreational physical activities should be appropriately increased, sedentary behavior should be reduced, and smoking prohibit environment should be expanded as far as possible to achieve better clinical intervention effects.

Smokeless and combustible tobacco use among 148,944 South Asian adults: a cross-sectional study of South Asia Biobank.

INTRODUCTION: Tobacco use, in both smoking and smokeless forms, is highly prevalent among South Asian adults. The aims of the study were twofold: (1) describe patterns of SLT and combustible tobacco product use in four South Asian countries stratified by country and sex, and (2) assess the relationships between SLT and smoking intensity, smoking quit attempts, and smoking cessation among South Asian men. METHODS: Data were obtained from South Asia Biobank Study, collected between 2018 and 2022 from 148,944 men and women aged 18 years and above, living in Bangladesh, India, Pakistan, or Sri Lanka. Mixed effects multivariable logistic and linear regression were used to quantify the associations of SLT use with quit attempt, cessation, and intensity. RESULTS: Among the four South Asian countries, Bangladesh has the highest rates of current smoking (39.9% for male, 0.4% for female) and current SLT use (24.7% for male and 23.4% for female). Among male adults, ever SLT use was associated with a higher odds of smoking cessation in Bangladesh (OR, 2.88; 95% CI, 2.65, 3.13), India (OR, 2.02; 95% CI, 1.63, 2.50), and Sri Lanka (OR, 1.36; 95% CI, 1.14, 1.62). Ever SLT use and current SLT use was associated with lower smoking intensity in all countries. CONCLUSIONS: In this large population-based study of South Asian adults, rates of smoking and SLT use vary widely by country and gender. Men who use SLT products are more likely to abstain from smoking compared with those who do not.

Cigarettes smoking and e-cigarettes using among university students: a cross-section survey in Guangzhou, China, 2021.

BACKGROUND: There is an increase in the use of cigarettes and e-cigarettes worldwide, and the similar trends may be observed in young adults. Since 2014, e-cigarettes have become the most commonly used nicotine products among young adults (Sun et al., JAMA Netw Open 4:e2118788, 2021). With the increase in e-cigarette use and the decrease in use of cigarettes and other tobacco products, however, there is limited information about Chinese smokers, e-cigarettes users and trends in cigarettes and e-cigarettes use among university students. Therefore, our objective was to investigate the using status of cigarettes, e-cigarettes and smoking behavior among the students from 7 universities in Guangzhou, China. METHODS: Students at 7 different universities in Guangzhou were investigated online in 2021 through a cross-sectional survey. A total of 10,008 students were recruited and after screening, 9361 participants were adopted in our statistics. Descriptive analysis, Chi-square analysis, and multiple logistic regression analysis were used to explore the smoking status and influencing factors. RESULTS: The average age of the 9361 university students was 22.4 years (SD = 3.6). 58.3% of participants were male. 29.8% of the participants smoked or used e-cigarettes. Among the smokers and users of e-cigarettes, 16.7% were e-cigarettes only users, 35.0% were cigarettes only users, and 48.3% were dual users. Males were more likely to smoke or use e-cigarettes. Medical students, students from prestigious Chinese universities, and students with higher levels of education were less likely. Students with unhealthy lifestyles (e.g., drinking alcohol frequently, playing video games excessively, staying up late frequently) were more likely to smoke or use e-cigarettes. Emotion can have significant impacts on both cigarettes and e-cigarettes dual users when choosing cigarettes or e-cigarettes to use. More than half of dual users said they would choose cigarettes when they were depressed and e-cigarettes when they were happy. CONCLUSION: We identified factors influencing the use of cigarettes and e-cigarettes among university students in Guangzhou, China. Gender, education level background, specialization, lifestyle habits and emotion all influenced the use of cigarettes and e-cigarettes among university students in Guangzhou, China. Male, low education level, from non-prestigious Chinese universities or vocational schools, non-medical specialization, and presence of unhealthy lifestyles were influencing factors for the use of cigarettes and e-cigarettes among university students in Guangzhou and students with these factors were more likely to smoke or use e-cigarettes. Besides, emotions can influence dual users' choice of products. This study provides more information to better understand young people's preferences for cigarettes and e-cigarettes by elucidating the characteristics of cigarettes and e-cigarettes use, as well as related influencing factors, among university students in Guangzhou. Further research involving more variables connected to the use of cigarettes and e-cigarettes will be required in our future study.

Are we equally at risk of changing smoking behavior during a public health crisis? Impact of educational level on smoking from the TEMPO cohort.

BACKGROUND: The COVID-19 pandemic as a public health crisis has led to a significant increase in mental health difficulties. Smoking is strongly associated with mental health conditions, which is why the pandemic might have influenced the otherwise decline in smoking rates. Persons belonging to socioeconomically disadvantaged groups may be particularly affected, both because the pandemic has exacerbated existing social inequalities and because this group was more likely to smoke before the pandemic. We examined smoking prevalence in a French cohort study, focusing on differences between educational attainment. In addition, we examined the association between interpersonal changes in tobacco consumption and educational level from 2018 to 2021. METHODS: Using four assessments of smoking status available from 2009 to 2021, we estimated smoking prevalence over time, stratified by highest educational level in the TEMPO cohort and the difference was tested using chi2 test. We studied the association between interpersonal change in smoking status between 2018 and 2021 and educational attainment among 148 smokers, using multinomial logistic regression. RESULTS: Smoking prevalence was higher among those with low education. The difference between the two groups increased from 2020 to 2021 (4.8-9.4%, p < 0.001). Smokers with high educational level were more likely to decrease their tobacco consumption from 2018 to 2021 compared to low educated smokers (aOR = 2.72 [1.26;5.89]). CONCLUSION: Current findings showed a widening of the social inequality gap in relation to smoking rates, underscoring the increased vulnerability of persons with low educational level to smoking and the likely inadequate focus on social inequalities in relation to tobacco control policies during the pandemic.

The Dunning-Kruger effect: subjective health perceptions on smoking behavior among older Chinese adults.

BACKGROUND: The intrinsic damage and external hazards of smoking are major risk factors for poorer health and are recognized as a global health issue of concern in geriatric health. This study aims to assess the Dunning-Kruger effect through the influence of subjective health perceptions on smoking behavior in older adults. METHODS: This study used data from the 2018 Chinese Longitudinal Healthy Longevity Survey (N = 9,683) provided by the Center for Healthy Aging and Development Studies at Peking University. A binary logistic model was used to examine whether the Dunning-Kruger effect affects smoking behavior in older adults, and a linear probability model was used as a commentary baseline model for logistic regression to prevent measurement bias. In addition, a mediating analysis was used to examine the mechanisms through which the Dunning-Kruger effect occurs. RESULTS: Older adults often overestimated their current health status and underestimated the health risks of smoking, causing the Dunning-Kruger effect to arise from their inadequate self-perceived health (i.e., older adults are more likely to smoke when they have better self-rated health or when hypertension, cardiopathy, stroke, and diabetes have little or no impact on their daily lives). These observations can be explained by the older adults' subjective health perceptions arising from their ingenuous understanding of their health, which indirectly influences their smoking behavior to some extent. CONCLUSION: Older adults' self-perceived health was associated with smoking behavior. Public health institutions should improve older adults' health perceptions so that they objectively understand their own health status.

Risk profiles for smoke behavior in COVID-19: a classification and regression tree analysis approach.

BACKGROUND: COVID-19 pandemic emerged worldwide at the end of 2019, causing a severe global public health threat, and smoking is closely related to COVID-19. Previous studies have reported changes in smoking behavior and influencing factors during the COVID-19 period, but none of them explored the main influencing factor and high-risk populations for smoking behavior during this period. METHODS: We conducted a nationwide survey and obtained 21,916 valid data. Logistic regression was used to examine the relationships between each potential influencing factor (sociodemographic characteristics, perceived social support, depression, anxiety, and self-efficacy) and smoking outcomes. Then, variables related to smoking behavior were included based on the results of the multiple logistic regression, and the classification and regression tree (CART) method was used to determine the high-risk population for increased smoking behavior during COVID-19 and the most profound influencing factors on smoking increase. Finally, we used accuracy to evaluated the performance of the tree. RESULTS: The strongest predictor of smoking behavior during the COVID-19 period is acceptance degree of passive smoking. The subgroup with a high acceptation degree of passive smoking, have no smokers smoked around, and a length of smoking of ≥ 30 years is identified as the highest smoking risk (34%). The accuracy of classification and regression tree is 87%. CONCLUSION: The main influencing factor is acceptance degree of passive smoking. More knowledge about the harm of secondhand smoke should be promoted. For high-risk population who smoke, the "mask protection" effect during the COVID-19 pandemic should be fully utilized to encourage smoking cessation.

Nationwide prevalence and trends in cigarette smoking among adult men with and without disabilities in South Korea between 2009 and 2017.

OBJECTIVES: Current smoking rates for people with and without disabilities vary among countries. This study analyzed smoking behavior over 9 years in adult South Korean men with disabilities, according to disability severity and type, and in those without disabilities. STUDY DESIGN: This was a cross-sectional study. METHODS: This analysis was conducted using national disability registration data and national general health checkup data for 2009-2017. Age-standardized smoking behaviors were analyzed for each year according to the presence, severity, and type of disability. The odds of current smoking were determined by multivariate logistic regression after adjusting for sociodemographic and clinical variables. RESULTS: The age-standardized smoking rate and average number of cigarettes for men with mild disabilities in the younger age group were 1.16 (43.0 vs 36.8%) and 1.05 (16.1 vs 15.3 cigarettes) times higher than in non-disabled men as of 2017. The highest smoking rate was observed in men with physical disabilities in the younger age. In the older age group, the highest smoking rate was that of men with intellectual or psychological disabilities. CONCLUSION: Smoking behaviors remained poorest in men with disabilities, especially those with mild, physical, and intellectual/psychological disabilities. Public health policies should focus on people with disabilities to promote health, prevent secondary conditions, and reduce health disparities by implementing antismoking health policies.

Oral Habits during the Lockdown from the SARS-CoV-2 Pandemic in the Romanian Population.

Background and Objectives: The SARS-CoV-2 pandemic led to changes in population daily patterns. In order to adapt oral health promotion measures for future similar conditions, the main objective of the study was to assess changes in dental hygiene and eating and smoking habits during the government lockdown in Romania. Materials and Methods: The cross-sectional study was conducted immediately after the end of the lockdown and consisted of 800 adult subjects. Data collection was done via an online survey. Participants were divided into two groups: non-medical/dental practitioners (N-M/D group) and medical/dental practitioners (M/D group). Results: An increased use of dental floss from 27% (pre-lockdown) to 30.5% (during lockdown) was identified in the M/D group, while the manual toothbrush usage increased to 64.8% (during lockdown) from 61.7% (pre-lockdown) in the N-MD/group. No significant differences regarding toothbrushing frequency were observed in either group. A change in the number of daily snacks was identified in both groups (3-4 snacks per day: from 11% to 20.2% in the N-M/D group, from 13.1% to 22.2% in the M/D group). The consumption of sweets as a preferred snack was also noticed. A decrease of tobacco consumers was assessed in the lockdown period (from 66.6% to 60.4% in the M/D group, from 68.5% to 61.9% in the N-/M/D group). Conclusions: Oral habits were changed during the pandemic lockdown through the increase in the frequency of the consumption of snacks and sweets and the decrease in frequency of smokers. Only minor changes were observed in oral hygiene.

Impacts of local public smoking bans on smoking behaviors and tobacco smoke exposure.

This paper examines the immediate and long-term effects of public smoking bans on smoking prevalence, smoking regularity, smoking intensity, and secondhand tobacco smoke exposure. We supplement the extensive literature on the effects of various types of tobacco control legislation on smoking behavior in developed countries by studying the provincial smoking bans and more recent national ban of a middle-income country, Argentina. We focus on the difference between full and partial smoking bans, and take advantage of the time and province variation in ban implementation in order to determine the causal effects of each type of ban. We find that full bans reduce national smoking prevalence over time, especially among younger demographic groups, but have no significant impact on intensity of smoking among smokers. Full bans also benefit nonsmokers, as they are associated with a significant reduction in environmental tobacco smoke exposure. Partial bans do not significantly impact smoking prevalence, and are found to increase smoking intensity among individuals who smoke every day. These findings provide support for ratification of full bans by all provinces according to the National Tobacco Control Law of 2011.

Characterizing nicotine exposure among a community sample of non-daily smokers in the United States.

BACKGROUND: Over one-quarter of all smokers in the United States identify as non-daily smokers and this number is projected to rise. Unlike daily smokers who typically maintain consistent levels of nicotine exposure with regular smoking, non-daily smokers have variable patterns of smoking that likely result in high intraindividual variability in nicotine intake. The current study aimed to characterize the weekly intraindividual variability in cotinine and identify smoking-related predictors in nondaily smokers. METHODS: An ecological momentary assessment of 60 non-daily smokers ages 24-57 years was conducted over a consecutive 7-day at-home protocol to log each smoking session, assessments of mood and social activity during smoking, and collection of daily saliva samples in a convenience sample from Pennsylvania, USA. Hierarchical linear regression analyses were conducted to determine the effects of smoking characteristics on total cotinine exposure measured by pharmacokinetic area under the curve and the range, maximum, and minimum cotinine values during the week controlling for demographic variables. RESULTS: The mean daily cotinine level was 119.2 ng/ml (SD = 168.9) with individual values that ranged from nondetectable to 949.6 ng/ml. Menthol predicted increased total cotinine levels (P < 0.05). Shorter time to the first cigarette of the day predicted significantly higher minimum (P < 0.05), maximum (P < 0.05), and total cotinine values (P < 0.05) after controlling for covariates. Negative emotions and social interactions with others were also significantly associated with higher cotinine metrics. There was no significant effect of the nicotine metabolite ratio. CONCLUSIONS: Our findings highlight the variability in nicotine exposure across days among non-daily smokers and point to the role of smoking context in nicotine exposure. The findings suggest the need to develop better assessment methods to determine health and dependence risk and personalized cessation interventions for this heterogeneous and growing group of smokers.

Administration of Exogenous Hormones and the Implications for Cigarette Smoking-Related Behaviors.

PURPOSE OF REVIEW: Preclinical evidence indicates progesterone and estrogen influence drug-taking behaviors, including nicotine/tobacco. However, clinical research on this relationship is less clear. This lack of clarity may be due to measuring naturally occurring endogenous hormones to examine this relationship, which introduces substantial error. Therefore, the goal of this review is to examine the link between the delivery of exogenous hormones and cigarette smoking-related behavior. RECENT FINDINGS: Exogenous progesterone may have favorable effects on cognition, symptomatology, consumption, and smoking cessation. Hormonal replacement therapy does not have a clear relationship with smoking-related behaviors. Oral contraceptive use may have adverse effects on stress response, nicotine metabolism, and symptomatology. Additional research is needed to explore how the administration of exogenous hormones may (a) strengthen research methodology on this topic, (b) enhance our understanding of the role of progesterone/estrogen on smoking-related behaviors, and (c) improve smoking cessation outcomes.

The effect of outdoor smoking ban: Evidence from Korea.

To address exposure to secondhand smoke, which is highly prevalent in Korea, local governments have implemented smoking bans at open public places (parks, bus stops, and school zones) since 2011. Exploiting temporal and spatial variation in the implementation dates of these bans, this study estimates their causal effects on individual smoking behavior. The individual-level longitudinal data from the 2009-2017 Korean Labor and Income Panel Study are linked to the smoking ban legislation information from the National Law Information Center. I find robust evidence that outdoor smoking bans increased the probability of making a quit attempt by 16%. This effect appears immediately after a ban goes into effect and lasts for three or more years. People who spend more time outdoors are more likely to change smoking behavior. I also find heterogeneity in effects across the amount of monetary penalty. Whereas the policy change did not affect the prevalence of smoking overall, higher penalties had stronger impacts on reducing the intensity of smoking and increasing the propensity to try to quit.

Association of smoking behavior among Chinese expectant fathers and smoking abstinence after their partner becomes pregnant: a cross-sectional study.

BACKGROUND: Exposure to secondhand smoke (SHS) during pregnancy can cause pregnancy complications and adverse birth outcomes. About 40% of Chinese expectant fathers are smokers and they rarely attempt to quit smoking. There is a paucity of effective smoking cessation services targeting this population. In this study, we assessed the smoking behavior of Chinese expectant fathers and examined its association with smoking abstinence after their partner became pregnant, which is an essential prerequisite for designing effective smoking cessation interventions. METHODS: We conducted a cross-sectional survey in the obstetrics and gynecology clinic of three tertiary hospitals in China. Expectant fathers who smoked at least one cigarette per day for 1 month within the past 12 months were invited to participate in this study. The participants were asked to complete a structured questionnaire that assessed their smoking behaviors before and after their partner became pregnant. RESULTS: From December 2017 to March 2018, we recruited a total of 466 eligible expectant fathers, among whom 323 (69.3%) were identified as current smokers and 143 (30.7%) were ex-smokers. Using lasso regression, 19 features were selected from among 27 independent variables. The results of the selected multivariable logistic regression model showed that knowledge about the health hazards of smoking among smokers (odds ratio (OR) 1.39; 95% confidence interval (CI) 1.24 to 1.58; p < 0.001), knowledge about the health hazards of SHS to pregnant women (OR 1.46; 95% CI 1.09 to 1.97; p < 0.001), knowledge about harm to the fetus and newborn (OR 1.58; 95% CI 1.25 to 2.03; p < 0.001), and being a first-time expectant father (OR 2.08; 95% CI 1.02 to 3.85; p = 0.046) were significantly positively associated with smoking abstinence among expectant fathers after their partner became pregnant. Significantly negative associations were found for severe dysfunctionality in terms of family support (OR 0.48; 95% CI 0.24 to 0.95; p = 0.036) and smoking only outside the home (OR 0.81; 95% CI 0.26 to 0.98; p < 0.001). CONCLUSIONS: In this study, we identified several factors associated with smoking abstinence among expectant fathers after their partner became pregnant. These findings can guide the development of effective interventions targeting expectant fathers, to help them quit smoking.

Current and former smokers among adolescents aged 12-17 years in Iran: a systematic review and meta-analysis.

BACKGROUND: Smoking, especially among adolescents, is considered a serious public health concern worldwide being associated with increased mortality. The present study was designed as the first systematic review and meta-analysis of the prevalence of current and former smoking behavior among adolescents in Iran. METHODS: Seven international scholarly databases, namely Scopus, Embase, Pubmed/Medline, ISI/Web of Science (WOS), the Cochrane Library, Psyc Info and Cinahl, were extensively searched from January 2000 to September 18, 2019. Google Scholar was also mined. Iranian databases were searched as well (namely, MagIran, Scientific Information Database (SID), and Barakatkns). The DerSimonian-Laird's approach, via the Freeman-Tukey double arcsine method, was used to synthesize the prevalence estimates. RESULTS: The prevalence of current smokers among Iranian adolescents was estimated to be 9% (95% CI: 7 to 10). Stratifying based on gender, the prevalence was 12% among boys (95% CI: 10 to 14) and 6% among girls (95% CI: 5 to 8). The prevalence of former smokers among Iranian adolescents using the random-effect model was computed to be 24% (95% CI: 21 to 27). CONCLUSION: The findings of this study showed that the prevalence of current and former smoking behavior among Iranian adolescents is a relevant public health concern. The country's young population should be given more attention by health policy- and decision-makers and implementation of ad hoc prevention and control policies should be on their agenda.

Are E-cigarette Users a Unique Group of Smokers? Latent Class Analysis of the National Youth Tobacco Survey.

We used data from the 2014 National Youth Tobacco Survey to examine patterns of cigarette smoking behavior and tobacco use. In light of the recent upsurge in e-cigarette use, we modeled current use and future intentions to use vape products along with combustible cigarette smoking and other tobacco products (i.e., cigars, cigarillos, chew, snuff, and dip). Latent class analyses indicated four discrete classes of smokers including a nominally involved class with very modest levels of tobacco product use, a class blending e-cigarette and cigars, a class of youth who predominantly use combustible cigarettes, and a group reporting indiscriminate use of almost all tobacco products excluding chew. Tests of invariance in item response probabilities and latent class proportions showed little variation across race and gender, albeit a new class of combustible cigarette and e-cigarette users emerged when examined by grade. Members of the heavy smoking and tobacco use class were more likely to be male, White, and older. Predictors of class membership included expectancies (perceived benefits of use), perceived harm (risk), media exposure, tobacco dependence, and the desire to quit. Findings are discussed in terms of characterizing risk among already smoking youth and how actionable prevention measures can be incorporated into existing universal and indicated programs that target reducing tobacco use and smoking behaviors.

Response to a commentary on "Food insecurity transitions and smoking behavior among older adults who smoke".

Thank you for the opportunity to respond to the commentary by Kim-Mozeleski and colleagues on "Food insecurity transitions and smoking behavior among older adults who smoke". This study examined the influence of food insecurity transitions on smoking cessation and daily cigarette consumption in 2014 within a sample of older U.S. adults from the Health and Retirement Study (HRS) who indicated that they smoked in 2012. In particular, Kim-Mozeleski and colleagues highlight that findings of Bergmans (2019) contrast with results of a previous publication by Kim-Mozeleski and colleagues. In sum, it is not readily apparent why findings contradict those of Kim-Mozeleski et al. (2018). Moderation or confounding due to macroeconomic factors that influence health and behavior is a possibility. Bergmans (2019) examined associations over a recent 2-year period of U.S. economic growth. In contrast, data from Kim-Mozeleski et al. (2018) spanned 12 years and overlapped the Great Recession. A detailed response to the commentary is provided.

Genome-wide association study in Finnish twins highlights the connection between nicotine addiction and neurotrophin signaling pathway.

The heritability of nicotine dependence based on family studies is substantial. Nevertheless, knowledge of the underlying genetic architecture remains meager. Our aim was to identify novel genetic variants responsible for interindividual differences in smoking behavior. We performed a genome-wide association study on 1715 ever smokers ascertained from the population-based Finnish Twin Cohort enriched for heavy smoking. Data imputation used the 1000 Genomes Phase I reference panel together with a whole genome sequence-based Finnish reference panel. We analyzed three measures of nicotine addiction-smoking quantity, nicotine dependence and nicotine withdrawal. We annotated all genome-wide significant SNPs for their functional potential. First, we detected genome-wide significant association on 16p12 with smoking quantity (P = 8.5 × 10-9 ), near CLEC19A. The lead-SNP stands 22 kb from a binding site for NF-κB transcription factors, which play a role in the neurotrophin signaling pathway. However, the signal was not replicated in an independent Finnish population-based sample, FINRISK (n = 6763). Second, nicotine withdrawal showed association on 2q21 in an intron of TMEM163 (P = 2.1 × 10-9 ), and on 11p15 (P = 6.6 × 10-8 ) in an intron of AP2A2, and P = 4.2 × 10-7 for a missense variant in MUC6, both involved in the neurotrophin signaling pathway). Third, association was detected on 3p22.3 for maximum number of cigarettes smoked per day (P = 3.1 × 10-8 ) near STAC. Associating CLEC19A and TMEM163 SNPs were annotated to influence gene expression or methylation. The neurotrophin signaling pathway has previously been associated with smoking behavior. Our findings further support the role in nicotine addiction.