Secondhand tobacco smoke exposure in homes and vehicles in youth: disparities among racial, and sexual and gender minorities.

Background: Secondhand smoke exposure (SHSe) among youth is a serious public health concern, leading to an increased risk of conditions such as asthma and respiratory infections. However, there is little research on SHSe among vulnerable populations, such as racial and sexual minorities. Understanding the factors associated with youth SHSe in homes and vehicles is crucial to developing better protective policies. Methods: This study utilized 2020 data from the National Youth Tobacco Survey, a representative sample of middle- and high-school students in the US. The primary outcomes were youth SHSe at home and while riding in a vehicle. Multinomial regression models were used to assess factors associated with SHSe. Results: The data included 9,912 students enrolled in grades 6 through 12 in the United States who reported never using any form of tobacco. Non-Hispanic Black students living with someone who does not use any form of tobacco products were significantly more likely to experience moderate [OR = 2.1 (1.1-3.9), p = 0.03] and severe [OR = 5.1 (2.2-11.7), p < 0.001] secondhand smoke exposure (SHSe) in homes compared to their non-Hispanic White counterparts. Heterosexual female students had lower odds of reporting moderate SHSe in the home compared to heterosexual males [OR = 0.7 (0.6-0.99), p = 0.02], whereas bisexual females had two-fold increased odds of severe SHSe in homes [OR = 2.0 (1.2-3.4), p = 0.01]. Conclusion: Significant efforts are needed to develop targeted interventions to reduce SHSe in homes and vehicles, particularly in these vulnerable populations.

Prevalence of Second Hand Smoke Exposure and Measures to Overcome: A Cross Sectional Study among Youth in Urban Hyderabad.

ABSTRACT: In India, the prevalence of secondhand smoke (SHS) exposure is 29.5% in general and 11.2% at home. The youth may expose themselves to SHS without knowing the risk factors and consequences involved. This study is intended to determine the prevalence of SHS exposure and the measures adopted by the youth to avoid exposure. A cross-sectional study was conducted among 338 youth in an urban area in Hyderabad. A modified Global Youth Tobacco Survey questionnaire was used for data collection on SHS exposure and avoidance. The total prevalence of SHS exposure was 35.21%. The mean days of SHS exposure/week were 1.419 (standard deviation -1.806) days. Belonging to the age group 18-21 years, and male gender were significant predictors of SHS exposure. Education of the head of family was a significant predictor of SHS avoidance behavior. Creating awareness among young adults regarding the deleterious effects and preventive strategies of SHS exposure, thereby making them responsible for the health of their family can be a protective long-term strategy.

Secondhand Nicotine Absorption From E-Cigarette Vapor vs Tobacco Smoke in Children.

Importance: With the prevalence of e-cigarette use (vaping) increasing worldwide, there are concerns about children's exposure to secondhand vapor. Objective: To compare nicotine absorption among children who are (1) exposed to secondhand tobacco smoke only or (2) exposed to secondhand vapor only with (3) those exposed to neither. Design, Setting, and Participants: The US Continuous National Health and Nutrition Examination Survey (NHANES) is a repeat cross-sectional survey. Participants are interviewed in their homes and, several days after, visit a mobile examination center to provide biological specimens. This study uses data from a nationally representative sample of US households from 2017 to 2020. Participants were children aged 3 to 11 years with serum cotinine levels incompatible with current firsthand nicotine use (ie, <15 µg/L). The final analysis was conducted on January 9, 2024. Exposures: Reported exposure to secondhand smoke or vapor indoors in the past 7 days (only secondhand smoke, only secondhand vapor, or neither). Covariates included age, sex, ethnicity, family income, body weight, and height. Main Outcomes and Measures: The primary outcome was serum cotinine concentration, an objective biomarker of nicotine absorption. Geometric mean cotinine levels and 95% CIs were calculated using log-normal tobit regression, accounting for the complex survey design and weights. Results: The mean (SD) age of the 1777 children surveyed was 7.4 (2.6) years, 882 (49.6%) were female, and 531 (29.9%) had family incomes below the poverty level. Nicotine absorption, as indexed by serum cotinine level, was highest among children only exposed to secondhand smoke (0.494 µg/L µg/L; 95% CI, 0.386-0.633 µg/L), followed by those exposed only to secondhand vapor (0.081 µg/L; 95% CI, 0.048-0.137 µg/L), equating to 83.6% (95% CI, 71.5%-90.5%; P < .001) lower nicotine absorption. Among children with no reported secondhand exposure, the geometric mean cotinine level was 0.016 µg/L (95% CI, 0.013-0.021 µg/L), or 96.7% (95% CI, 95.6%-97.6%; P < .001) lower than for those with exposure to secondhand smoke. Results were similar after covariate adjustment. Conclusions and Relevance: In this cross-sectional study of US children, nicotine absorption was much lower in children who were exposed to secondhand vapor vs secondhand smoke, but higher than in those exposed to neither. These findings suggest that switching from smoking to vaping indoors may substantially reduce, but not eliminate, children's secondhand exposure to nicotine and other noxious substances.

Effect of peer education on knowledge and frequency of smoking among high school students in disadvantaged districts: A quasi-experimental study.

OBJECTIVE: To evaluate the effectiveness of peer education on changing the knowledge and frequency of smoking of high school students. METHODS: The quasi-experimental study was conducted at the Vocational and Technical Anatolian High School, Turkey, during the 2021-22 academic year, and comprised students of either gender from the 9th to the 11th grade. After baseline assessment, training that blended peer education with the photovoice technique was administered between March 2021 and January 2022. Post-intervention assessment included smoking frequency, cigarette exposure and health literacy. Data was analysed using R version 4.0.5. RESULTS: Of the 465 students available, 395(84.95%) were part of the baseline assessment, while 434(93.3%) took the postintervention assessment. At the baseline, 365(93.8%) participants were males and 24(6.2%) were femaes. The overall median age was 15 years (interquartile range: 15-16 years). Post-training, smoking rate and indoor exposure to cigarette smoke among the students were statistically lower than the baseline values (p<0.05). The mean health literacy score postintervention was significantly higher than the baseline score (p<0.05). CONCLUSIONS: Photovoice combined with peer education seemed beneficial in terms of positive effect on smoking behaviour among youths.

Preventable Deaths Attributable to Second-Hand Smoke in Southeast Asia-Analysis of the Global Burden of Disease Study 2019.

Objectives: In addition to harms caused to individuals who smoke, second-hand smoke (SHS or passive smoke) is an important public health issue. We aim to estimate the extent of preventable deaths due to tobacco and SHS exposure in Southeast Asia. Methods: Data were from the Global Burden of Disease Study 2019. We analysed data from Southeast Asia, including Cambodia, Indonesia, Laos, Malaysia, Maldives, Mauritius, Myanmar, Philippines, Seychelles, Sri Lanka, Thailand, Timor-Leste, and Vietnam. Results: In 2019, there were 728,500 deaths attributable to tobacco in Southeast Asia, with 128,200 deaths attributed to SHS exposure. The leading causes of preventable deaths were ischemic heart disease, stroke, diabetes mellitus, lower respiratory infections, chronic obstructive pulmonary disease, tracheal, bronchus, and lung cancer. Among deaths attributable to tobacco, females had higher proportions of deaths attributable to SHS exposure than males in Southeast Asia. Conclusion: The burden of preventable deaths in a year due to SHS exposure in Southeast Asia is substantial. The implementation and enforcement of smoke-free policies should be prioritized to reduce the disease burden attributed to passive smoking in Southeast Asia.

Global association of secondhand smoke exposure locations and smoking behaviour among adolescents in 99 countries.

AIM: This study classified 99 countries into four income groups and then analysed the impact of secondhand smoke (SHS) exposure at home, in public places and at school, on current cigarette smoking prevalence. METHODS: We utilised data from the WHO Global Youth Tobacco Survey and a meta-analysis was conducted to evaluate the prevalence and weighted odds ratios (wORs) of adolescent smoking behaviour and SHS exposure locations. RESULTS: Both smoking behaviours increased with higher national income levels. Smoking behaviours in high and upper-middle-income countries (HICs and UMICs) exhibited an association with SHS exposure in public places (HIC: wOR, 3.50 [95% CI, 2.85-4.31]; UMIC: wOR, 2.90 [2.60-3.23]) compared to home. Low- and lower-middle-income countries (LICs and LMICs) showed an association with SHS exposure in the home (LIC: wOR, 5.33 [3.59-7.93]; LMIC: wOR, 2.71 [2.33-3.17]) than public places. The association between current cigarette smoking and SHS exposure at home increased with lower income levels, while anticipated future use of any form of tobacco with SHS exposure in public places rose in lower income countries. CONCLUSIONS: Targeted interventions based on income levels are essential, emphasising home strategies in lower income countries and public place efforts in higher income countries.

Sex difference in the associations among secondhand smoke with metabolic syndrome in non-smokers in a large Taiwanese population follow-up study.

Close associations among secondhand smoke (SHS) and metabolic syndrome (MetS) and its components have been demonstrated, however sex differences in these associations remain unclear. We collected 121,364 participants from the Taiwan Biobank, and excluded those with smoking history, the remaining 88,297 participants (male: 18,595; female: 69,702; mean age 50.1 ± 11.0 years) were included. SHS exposure was evaluated based on self-reported questionnaires. SHS was associated with MetS (odds ratio [OR], 1.268, p < 0.001 for males vs. 1.180, p < 0.001 for females), abdominal obesity (OR, 1.234, p < 0.001 for males vs. 1.199, p < 0.001 for females), low high-density lipoprotein cholesterol (OR, 1.183, p = 0.008 for males vs. 1.094, p = 0.011 for females), hyperglycemia (OR, 1.286, p < 0.001 for males vs. 1.234, p < 0.001 for females), but not with hypertriglyceridemia. SHS was associated with high blood pressure (BP) (OR, 1.278, p < 0.001) only in males, but not in females. Furthermore, significant interactions were found between sex x SHS on MetS (p = 0.023), abdominal obesity (p = 0.032), and elevated BP (p < 0.001). Moreover, the participants who were exposed to SHS for ≥1 hour per week were associated with a higher risk (OR = 1.316, p = 0.001 in males vs. OR = 1.220, p < 0.001 in females) of MetS compared to those with no exposure. These results showed an association between SHS and a high OR for MetS in both the males and females. Furthermore, sex differences were identified in the associations between SHS and MetS and its components, and SHS was more closely related to MetS, abdominal obesity, and high BP in males than in females.

Association between lipid profiles and cigarette smoke among adults in the Persian cohort (Shahedieh) study.

OBJECTIVES: Exposure to cigarette smoke introduces a large amount of nicotine into the bloodstream through the lungs. So, smoking can be a risk factor for many diseases. The present study was conducted to investigate the effect of active and passive cigarette smoke on the blood lipid profile and dyslipidemia. METHODS: This cross-sectional study was performed on 5052 individuals who participated in the recruitment phase of the Shahedieh cohort study. A logistic regression model was used to investigate the relationship between smoking exposure status and lipid profiles. RESULTS: The prevalence of abnormal low-density lipoprotein-cholesterol (LDL-C), abnormal HDL-C, abnormal total cholesterol (TC), abnormal triglyceride (TG), and dyslipidemia were 254 (5.00%), 562 (11.10%), 470 (9.30%), 1008 (20.00%), and 1527 (30.20%), respectively. Adjusting for confounders, it was observed that current smokers had higher odds of having abnormal HDL-C [OR (95% CI), 2.90 (2.28-3.69)], abnormal TG [OR (95% CI), 1.71 (1.38-2.13)] and dyslipidemia [OR (95% CI), 1.86 (1.53-2.25)]. Ex-smokers also had greater odds of abnormal HDL-C [OR (95% CI), 1.51 (1.06-2.16)] compared to non-smokers who were not exposed to cigarette smoke. CONCLUSIONS: The findings indicated that current smokers had higher TG and lower HDL. So, necessary measures should be taken to reduce smoking. The findings also showed that the prevalence of abnormal TG and HDL in ex-smokers was lower than in current smokers. Therefore, the existence of incentive policies to quit smoking seems necessary.

Association between secondhand smoke exposure and serum sex hormone concentrations among US female adults: a cross-sectional analysis using data from the National Health and Nutrition Examination Survey, 2013-2016.

OBJECTIVE: To estimate the association between secondhand smoke (SHS) exposure and serum sex hormone concentrations in female adults (never smokers and former smokers). DESIGN: Cross-sectional analysis. SETTING: US National Health and Nutrition Examination Survey, 2013-2016. OUTCOME MEASURES: Serum sex hormone measures included total testosterone (TT) and oestradiol (E2), sex hormone-binding globulin (SHBG), the ratio of TT and E2 and free androgen index (FAI). Isotope dilution-liquid chromatography tandem mass spectrometry was used to measure serum TT and E2. SHBG was measured using immunoassay. The ratio of TT and E2 and FAI were calculated. SHS exposure was defined as serum cotinine concentration of 0.05-10 ng/mL. PARTICIPANTS: A total of 622 female participants aged ≥20 years were included in the analysis. RESULTS: For never smokers, a doubling of serum cotinine concentration was associated with a 2.85% (95% CI 0.29% to 5.47%) increase in TT concentration and a 6.29% (95% CI 0.68% to 12.23%) increase in E2 in fully adjusted models. The never smokers in the highest quartile (Q4) of serum cotinine level exhibited a 10.30% (95% CI 0.78% to 20.72%) increase in TT concentration and a 27.75% (95% CI 5.17% to 55.17%) increase in E2 compared with those in the lowest quartile (Q1). For former smokers, SHBG was reduced by 4.36% (95% CI -8.47% to -0.07%, p for trend=0.049) when the serum cotinine level was doubled, and the SHBG of those in Q4 was reduced by 17.58% (95% CI -31.33% to -1.07%, p for trend=0.018) compared with those in Q1. CONCLUSION: SHS was associated with serum sex hormone concentrations among female adults. In never smokers, SHS was associated with increased levels of TT and E2. In former smokers, SHS was associated with decreased SHBG levels.

Bridging Differences in Cohort Analyses of the Relationship between Secondhand Smoke Exposure during Pregnancy and Birth Weight: The Transportability Framework in the ECHO Program.

BACKGROUND: Estimates for the effects of environmental exposures on health outcomes, including secondhand smoke (SHS) exposure, often present considerable variability across studies. Knowledge of the reasons behind these differences can aid our understanding of effects in specific populations as well as inform practices of combining data from multiple studies. OBJECTIVES: This study aimed to assess the presence of effect modification by measured sociodemographic characteristics on the effect of SHS exposure during pregnancy on birth weights that may drive differences observed across cohorts. We also aimed to quantify the extent to which differences in the cohort mean effects observed across cohorts in the Environmental influences on Child Health Outcomes (ECHO) consortium are due to differing distributions of these characteristics. METHODS: We assessed the presence of effect modification and transportability of effect estimates across five ECHO cohorts in a total of 6,771 mother-offspring dyads. We assessed the presence of effect modification via gradient boosting of regression trees based on the H-statistic. We estimated individual cohort effects using linear models and targeted maximum likelihood estimation (TMLE). We then estimated transported effects from one cohort to each of the remaining cohorts using a robust nonparametric estimation approach relying on TMLE estimators and compared them to the original effect estimates for these cohorts. RESULTS: Observed effect estimates varied across the five cohorts, ranging from significantly lower birth weight associated with exposure [-167.3g; 95% confidence interval (CI): -270.4, -64.1] to higher birth weight with wide CIs, including the null (42.4g; 95% CI: -15.0, 99.8). Transported effect estimates only minimally explained differences in the point estimates for two out of the four cohort pairs. DISCUSSION: Our findings of weak to moderate evidence of effect modification and transportability indicate that unmeasured individual-level and contextual factors and sources of bias may be responsible for differences in the effect estimates observed across ECHO cohorts. https://doi.org/10.1289/EHP13961.

Susceptibility to e-cigarette adoption among tobacco-naïve youths: a cross-sectional study in Shenzhen, China.

Background: The rise in e-cigarette use among youth is a significant global public health issue. It is important to identify those at increased risk and implement effective strategies to reduce e-cigarette popularity among the youth. Objective: This study aims to identify predictors of e-cigarette uptake in youths with no prior tobacco use, considering individual, familial and the broader societal environmental factors. Methods: For this investigation, a group of 2,487 tobacco-free youths was selected from 15 high schools in Shenzhen, China. Susceptibility to e-cigarettes was determined by assessing the possibility of future use and the openness to trying e-cigarettes if presented by friends. Both chi-square tests and logistic regression were applied to identify factors linked to susceptibility to e-cigarette use. Results: Among the respondents, 5.5% (n = 136) were found to be susceptible to e-cigarette use. The analysis revealed factors tied to this risk: perceptions of e-cigarettes, the impact of vaping peers, paternal parenting styles, the extent of social support, exposure to messages both for and against e-cigarettes use, and secondhand smoke (SHS) exposure. Youths who downplayed the addictive nature of e-cigarettes (aOR = 2.01; 95% CI: 1.14-3.55; p = 0.016), those with friends who engaged in vaping (aOR = 3.43-7.64; 95%CI: 2.36-20.42; p < 0.001), those experiencing over-protective or rejective maternal parenting (aOR = 1.68-3.01; 95%CI: 1.11-5.77; p = 0.001-0.014) or rejective paternal parenting (aOR = 3.63; 95%CI: 1.99-6.59; p < 0.001), those aware of e-cigarette advertisements (aOR = 1.82; 95%CI: 1.28-2.60; p = 0.001), and those exposed to SHS at home (aOR = 1.68; 95%CI: 1.17-2.41; p = 0.005) or at public places (aOR = 1.72-1.79; 95%CI: 1.21-2.57; p = 0.002-0.003) were more prone to e-cigarettes. In contrast, youths who believed using e-cigarettes reduces one's attractiveness (aOR = 0.34; 95%CI: 0.16-0.72; p = 0.005) or perceived that vaping made social interactions less enjoyable (aOR = 0.26; 95%CI: 0.12-0.58; p = 0.001), those who benefited from high social support (aOR = 0.30-0.60; 95%CI: 0.17-0.97; p < 0.001), and those who noticed message about e-cigarettes' adverse consequence (aOR = 0.54; 95%CI: 0.38-0.77; p = 0.001) were less likely to be inclined toward e-cigarette use. Conclusion: The propensity of the youth to e-cigarette usage is shaped by a multiple element. An all-encompassing strategy that addresses the individual, familial, and the broader societal aspects is imperative for the effective prevention of e-cigarette initiation among youth.

Association between passive smoking and dental caries status in children: A cross-sectional analytical study.

BACKGROUND: Several risk factors contribute to the development of dental caries in children, including sociodemographic, dietary, oral hygiene-related and other miscellaneous factors. Maternal smoking was highly associated with dental caries when compared to smoking by fathers or other household members. OBJECTIVES: The aim of the study was to determine the prevalence of dental caries and their association with exposure to environmental tobacco smoke (ETS) among 5- to 10-year-old students attending private and government schools. MATERIAL AND METHODS: A cross-sectional analytical study was conducted among schoolchildren. Data was collected from the primary caregivers using a pre-tested form to assess the ETS exposure under 5 domains based on history: antenatal exposure; exposure during the index period; exposure in the school neighborhood; exposure in restaurants/roadside stalls; and exposure in bus stops/railway stations. Dental caries was assessed based on the World Health Organization (WHO) guidelines from 1997. The association was reported using prevalence ratios (PRs) (95% confidence interval (CI)). RESULTS: Data was obtained from 211 schoolchildren attending government (39.8%) and private schools (60.2%). The overall prevalence (95% CI) of dental caries was 49.3% (42.5-56.1%). Among all the risk factors evaluated in the study, exposure to ETS was associated with a significantly increased risk of dental caries. The adjusted prevalence ratio (APR) of ETS exposure varied with the mother's educational status and high sugar exposure, although this was statistically insignificant. CONCLUSIONS: The prevalence of dental caries among schoolchildren aged 5 to 10 years in the city was moderate and similar to the national average. Among the risk factors assessed in the study, antenatal exposure to ETS was found to significantly increase the prevalence of dental caries by 41% after adjusting for other factors. Therefore, it is important to educate parents on the causal role of ETS exposure in dental caries.

Prevalence of Wheezing and Its Association with Environmental Tobacco Smoke Exposure among Rural and Urban Preschool Children in Mpumalanga Province, South Africa.

BACKGROUND: This study aimed to investigate the prevalence of wheezing and its association with environmental tobacco smoke exposure among rural and urban preschool children in Mpumalanga province, South Africa, an area associated with poor air quality. METHODS: In this study, parents/caregivers of preschool children (n = 3145) completed a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Data were analysed using multiple logistic regression models. RESULTS: The overall prevalence of Wheeze Ever was 15.14%, with a higher prevalence in urban preschoolers than rural preschoolers (20.71% vs. 13.30%, p < 0.000). Moreover, the total prevalence of Asthma Ever was 2.34%. The prevalence was greater in urban preschoolers than in rural preschoolers (3.92% vs. 1.81%, p < 0.001). In the final adjusted model, both urban- and rural-area children who lived with one or more people who smoked in the same household (WE: OR 1.44, 95% CI 1.11-1.86) (CW: OR 2.09, 95% CI 1.38-3.16) and (AE: OR 2.49, 95% CI 1.12-5.54) were found to have an increased likelihood of having Wheeze Ever, Current Wheeze, and Asthma Ever as compared to those who lived with non-smokers. CONCLUSIONS: The implementation of smoking limits and prohibition is crucial in areas that are frequented or utilized by children. Hence, it is imperative for healthcare providers to actively champion the rights of those who do not smoke within the society, while also endorsing legislative measures aimed at curtailing the extent of tobacco smoke exposure.

[A study on the dual use of e-cigarettes and cigarettes among adolescents in Shandong Province].

Objective: To understand the current status and its associated factors of dual use of e-cigarettes and cigarettes among adolescents in Shandong Province and explore the reasons for dual use behavior. Methods: A self-administered survey was conducted among 7 999 middle school students who were selected by stratified multi-stage cluster sample method. Data were weighted and analyzed by the SPSS 25.0 complex program. Results: In Shandong Province, the prevalence rates of attempting and current dual use of e-cigarettes and cigarettes among adolescents appeared as 7.7% and 1.3%, respectively. Male, friends smoking, and secondhand smoke exposure in the past 7 days were risk factors for dual use. Compared with cigarette smokers, dual users have no differences in cognition and behavior in quitting smoking (P>0.05). The main reason for dual users to smoke e-cigarettes was curiosity. Conclusions: Dual use of e-cigarettes and cigarettes is common among adolescents in Shandong Province, and its influencing factors are similar to traditional cigarettes. Dual use is not a transitional stage for smoking cessation. Dual users are more likely to continue smoking in the future, which should be paid attention and concern.

Evolution and characteristics of studies estimating attributable mortality to second-hand smoke: a systematic review.

BACKGROUND: Several studies have estimated the impact of second-hand smoke (SHS) exposure on mortality in the population of different countries. This study aimed to identify and describe studies that have estimated the attributable mortality (AM) associated with SHS exposure in the adult population. METHODS: A literature search was conducted in MEDLINE, EMBASE, Cochrane Library and CINAHL databases up to January 2023. Studies that estimated the AM associated with SHS exposure in the adult population and used a prevalence-dependent method were included. The main characteristics of the studies and their results were described. RESULTS: Fifty-three studies were included. Most of them were conducted in North America (n = 13), Europe (n = 14) and China (n = 6) and included lung cancer (n = 46) or ischaemic heart disease (n = 22) as causes of death. There was considerable variety in the population under study regarding the relationship with tobacco: non-smokers (n = 30); never-smokers (n = 9); both non and never-smokers (n = 2); the whole population (n = 1) and not known (n = 11). The age at which AM was estimated also varied between studies, ranging from 15 to 40 years and older. CONCLUSIONS: Studies estimating AM associated with SHS exposure are heterogeneous in terms of the causes of death studied, the age at which mortality is attributed, or the population to which mortality referred: consensus should be reached. Despite their importance, studies assessing AM to SHS are infrequent in low- and middle-income countries.

Secondhand Smoke Exposure and Risk of Dementia in Nonsmokers: A Population-Based Cohort Study.

BACKGROUND: Large population-based prospective studies are necessary to provide clarification on the associations of panoramic secondhand smoking burden, including prenatal and postnatal secondhand smoke (SHS) exposure, with the risk of developing dementia. METHODS: Our study comprised a sample of 353,756 dementia-free individuals from the UK Biobank who were nonsmokers had data on the exposure of maternal smoking as well as SHS exposure in daily life, which was quantified in terms of hours per week (h/week) and whether they lived with household smokers. Multivariable Cox regression models were utilized to analyze the independent and joint associations of maternal smoking and daily life SHS exposure with dementia risk. RESULTS: During a median follow-up of 11.8 years, 4,113 participants developed dementia. Compared with those who lived in the environment without smokers, multivariable-adjusted hazard ratios (HRs) (95% CIs) were 1.11 (1.02, 1.20) and 1.31 (1.13, 1.52) for those who exposed to SHS for >0 but ≤4 h/week and >4 h/week, respectively, and was 1.25 (1.13, 1.39) for those who lived with smokers in the household. A positive history of maternal smoking was associated with a modestly higher risk of dementia (HR = 1.07; 95% CI: 1.01, 1.15). Furthermore, compared with participants with neither history of maternal smoking nor exposure to SHS, a particularly higher risk of dementia was observed among those with both exposures (HR = 1.48; 95% CI: 1.18, 1.86). Additionally, the HR (95% CI) was 1.32 (1.10, 1.59) when comparing participants with a history of maternal smoking who lived with smokers in their households with those who had neither exposures. CONCLUSIONS: Having a history of maternal smoking, longer exposure to SHS, and living with smokers in the household were each associated with an increased risk of developing dementia. Individuals who were simultaneously exposed to maternal smoking and SHS or lived with household smokers had a particularly higher dementia risk.

Tobacco Smoke Exposure in Early Childhood and Later Risk of Inflammatory Bowel Disease: A Scandinavian Birth Cohort Study.

OBJECTIVES: To examine the association between early-life smoking exposure and later risk of inflammatory bowel disease [IBD]. METHODS: We followed 115663 participants from the Norwegian Mother, Father and Child [MoBa] and All Babies in Southeast Sweden [ABIS] cohorts from birth [1997-2009] through 2021. IBD was identified through national patient registers. Validated questionnaire data defined maternal smoking during pregnancy, maternal environmental tobacco smoke [ETS] exposure during pregnancy, and child ETS exposure by ages 12 and 36 months. Cox regression was used to estimate adjusted hazard ratios [aHRs] for sex, maternal age, education level, parental IBD, and origin. Cohort-specific estimates were pooled using a random-effects model. RESULTS: During 1 987 430 person-years of follow-up, 444 participants developed IBD [ABIS, 112; MoBa, 332]. Any vs no maternal smoking during pregnancy yielded a pooled aHR of 1.30 [95% CI = 0.97-1.74] for offspring IBD. Higher level of maternal smoking during pregnancy (compared with no smoking, average ≥6 cigarettes/day: pooled aHR = 1.60 [95% CI = 1.08-2.38]) was associated with offspring IBD, whereas a lower smoking level was not (average 1-5 cigarettes/day: pooled aHR = 1.09 [95% CI = 0.73-1.64]). Child ETS exposure in the first year of life was associated with later IBD (any vs no ETS, pooled aHR = 1.32 [95% CI = 1.03-1.69]). Estimates observed for child ETS exposure by 36 months were similar but not statistically significant. CONCLUSIONS: In this prospective Scandinavian cohort study, children exposed to higher levels of maternal smoking during pregnancy or ETS during the first year of life were at increased risk of later IBD.

The relationship between active/passive smoking and spontaneous preterm birth: Data from a multicenter study.

BACKGROUND: Prematurity is considered to be the leading cause of death in children under 5 years of age, with one child dying every 2 s. Smoking is known to be one of the factors associated with prematurity, with both immediate and late consequences. However, it is difficult to obtain concrete data on the relationship between smoking and spontaneous preterm birth. OBJECTIVE: The aim of this study was to evaluate the influence of active and passive smoking on spontaneous preterm birth. METHODS: This was a multicenter, cross-sectional complementary study that included data on preterm births in 20 maternity hospitals in Brazil between 2011 and 2012. The relationship between smoking category (people who smoke [PWS]; people who smoke indirectly [PWSI]; and people who do not smoke [PWDNS]) and sociodemographic characteristics, birth, and neonatal data was assessed. Statistical analysis was performed using frequencies, percentages, the χ2 test, and stepwise comparisons, with a significance level of 5%. RESULTS: The original study included 5295 pregnant participants and their preterm infants. There were 1491 spontaneous preterm births (SPBs); 1191 preterm rupture of membranes; 1468 therapeutic preterm births; and 1146 term births. The proportion of women who were PWS during pregnancy was 13.5%, and 31.6% were PWSI. Pregnant individuals who smoked and who smoked indirectly had a higher incidence of SPBs (61.2%) compared with PWDNS (48.4%; P < 0.0001); however, multivariate analysis did not confirm causality. CONCLUSIONS: This study did not confirm that smoking during pregnancy increases the risk of SPB. PWSI also did not have an increased incidence of spontaneous preterm birth or adverse neonatal outcomes.

Association Between Secondhand Smoke Exposure and Nonalcoholic Fatty Liver Disease in the General U.S. Adult Nonsmoker Population.

INTRODUCTION: Smoking is a cause of nonalcoholic fatty liver disease (NAFLD), but the dose-response relationship between secondhand smoke exposure (SHS) and NAFLD is unclear. This study sought to determine the relationship between SHS and NAFLD risk among adult nonsmokers in the United States. AIMS AND METHODS: Data from 7412 adult nonsmokers aged ≥20 years who participated in the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016 were used in this study. SHS was defined as a nonsmoker with a serum cotinine concentration of 0.05-10.00 ng/mL. NAFLD was identified using the U.S. fatty liver index (USFLI), hepatic steatosis index (HSI), and fatty liver index (FLI). Weighted multivariable logistic regression and restricted cubic spline models were applied to evaluate the relationship between SHS and NAFLD risk. RESULTS: The participants had a weighted mean age of 49.2 years, and 55.5% were female. SHS was associated with NAFLD (odds ratio [OR] 1.22; 95% confidence interval CI: 1.05 to 1.42), showing a linear dose-response relationship (natural log of cotinine level: OR 1.10, 95% CI: 1.05 to 1.17). Sensitivity analyses using different NAFLD definitions (HSI: OR 1.21, 95% CI: 1.01 to 1.46; FLI: OR 1.26, 95% CI: 1.06 to 1.49), excluding participants taking hepatotoxic drugs, and propensity score-adjusted analysis yielded similar results. The association between SHS and NAFLD was consistent in analyses stratified by age, sex, and race/ethnicity. CONCLUSIONS: Among this nationally representative sample of U.S. adults, SHS had a linear dose-response relationship with the risk of NAFLD, suggesting that measures to lower SHS might lower NAFLD risk. IMPLICATIONS: This study assessed the association between secondhand smoke exposure and the risk of nonalcoholic fatty liver disease (NAFLD) using data from 7412 adult nonsmokers aged 20 years or older who participated in the United States NHANES between 2007 and 2016. Secondhand smoke exposure was measured using serum cotinine levels. Three different noninvasive indexes were used to measure NAFLD. Secondhand smoke exposure was associated with an increased risk of NAFLD, with a linear dose-response relationship. The results of sensitivity analyses and subgroup analyses were consistent.

New Estimates of Smoking-Attributable Mortality in the U.S. From 2020 Through 2035.

INTRODUCTION: The often-cited Centers for Disease Control and Prevention (CDC) estimate of 480,000 annual U.S. smoking-attributable deaths (SADs), including 439,000 first-hand smoke deaths, derives from 2005 to 2009 data. Since then, adult smoking prevalence has decreased by 40%, while the population has grown and the smoking population aged. An updated estimate is presented to determine whether the CDC figure remains accurate or has changed substantially. In addition, the likely annual smoking-related mortality toll is projected through 2035. METHODS: A well-established model of smoking prevalence and health effects is employed to estimate annual SADs among individuals exposed to first-hand smoke in the U.S. for two distinct periods: 2005-2009 and 2020-2035. The estimate for 2005-2009 serves as a benchmark to evaluate the reliability of the model's estimate in comparison to CDC's. The projections for 2020-2035 provide up-to-date figures for SADs, predicting how annual SADs are likely to change in the coming years. Data were collected between 2005 and 2020. The analysis was conducted in 2023. RESULTS: This study's estimate of 420,000 first-hand smoke deaths over 2005-2009 is 95.7% of CDC's estimate during the same period. The model projections indicate that SADs among individuals who currently smoke or formerly smoked have increased modestly since 2005-2009. Beginning in 2020, annual SADs will remain relatively stable at approximately 450,000 before starting to decline around 2030. CONCLUSIONS: These findings suggest that the CDC estimate of the annual mortality burden of smoking remains valid. Despite U.S. population growth and the aging of the smoking population, substantial reductions in smoking will finally produce a steady, if gradual, decline in SADs beginning around 2030.