Cost-effectiveness of lung cancer screening with volume computed tomography in Portugal.

Aim: Lung cancer is the most common cause of cancer death in Portugal. The Dutch-Belgian lung cancer screening (LCS) study (NELSON), the biggest European LCS study, showed a lung cancer mortality reduction in a high-risk population when being screened. In this study, the cost-effectiveness of LCS, based on the NELSON study protocol and outcomes, was evaluated compared with no screening in Portugal. Methods: The present study modified an established decision tree by incorporating a state-transition Markov model to evaluate the health-related advantages and economic implications of low-dose computed tomography (LDCT) LCS from the healthcare standpoint in Portugal. The analysis compared screening versus no screening for a high-risk population aged 50-75 with a smoking history. Various metrics, including clinical outcomes, costs, quality-adjusted life years (QALYs), life-years (LYs) and the incremental cost-effectiveness ratio (ICER), were calculated to measure the impact of LDCT LCS. Furthermore, scenario and sensitivity analyses were executed to assess the robustness of the obtained results. Results: Annual LCS with volume-based LDCT resulted in €558 million additional costs and 86,678 additional QALYs resulting in an ICER of €6440 per QALY for one screening group and a lifetime horizon. In total, 13,217 premature lung cancer deaths could be averted, leading to 1.41 additional QALYs gained per individual diagnosed with lung cancer. Results are robust based on the sensitivity analyses. Conclusion: This study showed that annual LDCT LCS for a high-risk population could be cost-effective in Portugal based on a willingness to pay a threshold of one-time the GDP (€19,290 per QALY gained).

What are the Barriers of Chronic Obstructive Pulmonary Disease (COPD) Patients in Smoking Cessation?

Objectives: Smoking is the major determinant of developing chronic obstructive pulmonary disease (COPD). A substantial proportion of patients with COPD continue smoking although they have significant respiratory symptoms, exacerbation history and comorbidities. We aimed to find the associated factors and clinical features of the patients who maintain smoking. Methods: 200 current smokers and 132 former smokers with a spirometry-confirmed diagnosis of COPD were recruited from the outpatient department. Demographic characteristics, smoking backgrounds, treatment status, comorbidities, exacerbation history of the previous year, pulmonary function tests, blood biochemistry, dyspnea scales, symptom scores, and BECK anxiety scores were all recorded. Results: No age and gender differences were found between current and former smokers. Compared to former smokers, current smokers were less qualified, had more cardiovascular diseases, more frequently exposed to tobacco smoke at home and at work place, more severe pulmonary function impairment, longer duration of COPD, longer time of smoking, earlier age of commencement in smoking, higher scores of BECK anxiety scores (BAI), higher levels of inflammatory markers in blood tests p<0.05. In multivariable analysis, lower values of FEV1%, higher scores of CAT and BAI, higher levels of platelet and CRP were found to decrease the likelihood of smoking cessation p<0.05. Additionally having diabetes, coronary artery disease and hypertension were inversely correlated with quitting smoking p<0.05. Conclusion: COPD is a systemic inflammatory disease. We found over half of the patients with COPD were currently smoking, despite the severity of their airflow limitation, symptoms and even the comorbidities. Furthermore, 2 out of 5 of the current smokers reported having moderate to severe anxiety. Dyspnea and inflammatory markers had negative effects on smoking cessation, and anxiety might be the cause that led these patients to keep smoking.

Diet quality as assessed by the healthy eating index-2020 among different smoking status: an analysis of national health and nutrition examination survey (NHANES) data from 2005 to 2018.

BACKGROUND: Combining smoking with poor eating habits significantly elevates the risk of chronic illnesses and early death. Understanding of how dietary quality shifts post-smoking cessation remains limited. The objective of this study is to examine dietary quality - using Healthy Eating Index (HEI - 2020) and its 13 components, among current, former, and never smokers, and particularly the impact of quitting and the duration of cessation on dietary habits. METHODS: A cross-sectional analysis of 31,569 adults from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 was conducted. Dietary quality was assessed using HEI-2020 scores, which were determined by NIH developed - simple HEI scoring algorithm per person. Smoking status was categorized into current, former, and never smokers, with further subdivisions for current (heavy/light smokers) and former smokers (duration post-cessation). Descriptive analysis and multiple regression models weighted to represent the US population were performed. RESULTS: The current smoking rate was 19.4%, with a higher prevalence in males (22.5%) than females (17.5%). Current smokers reported statistically significantly lower HEI total score than both former and never smokers. Former smokers exhibited HEI scores similar to those of never smokers. The adjusted HEI total scores for current, former, and never smokers were 49.2, 54.0, and 53.3, respectively, with a statistically significant difference (p < 0.001). Moreover, light smokers had better total HEI score than heavy smokers (46.8 vs. 50.8, p < 0.001, respectively), but former and never smokers scored even higher. Quitting smoking immediately improved dietary quality, with former smokers reaching the dietary levels of never smokers within 5-10 years (53.8 vs. 53.3, p > 0.05, respectively). Compared to current smokers, former smokers tended to consume more beneficial foods (e.g., fruits, vegetables, greens and beans, whole grains, proteins, and fatty acids), while also consuming more sodium and less added sugar. CONCLUSIONS: Current smokers, particularly heavy smokers, exhibit poorer dietary habits than former and never smokers. The dietary quality of former smokers aligns with never smokers over time, highlighting the positive impact of smoking cessation on diet. This has implications for reducing chronic disease risks associated with poor diet and smoking.

Psychometric properties of measures for electronic cigarette dependence among former-smoking electronic cigarette users.

BACKGROUND: Measures designed to assess electronic cigarette (ECIG) dependence are largely adapted from those developed for cigarette smoking, and have been evaluated mainly among dual ECIG-cigarette users. The present study evaluated the psychometric properties of four dependence measures among former-smoking ECIG users. METHODS: Respondents (N = 187) were daily ECIG users who had formerly smoked cigarettes regularly. As part of an online survey, they completed four dependence measures: Penn State Electronic Cigarette Dependence Index (PSECDI); E-Cigarette Dependence Scale (EDS-4); Glover Nilsson Behavioral Questionnaire (GNBQ); and Diagnostic and Statistical Manual 5th Edition (DSM-5). RESULTS: Confirmatory factor analysis revealed a single factor structure for all four measures, and fit indices were adequate for all models. Most inter-item correlations (mean r's = 0.21 to 0.45) and all item-total correlations (mean r's = 0.53 to 0.80) were significant for all four measures. Internal consistency was highest for the GNBQ (α = 0.86) followed by the EDS-4 (α = 0.81), PSECDI (α = 0.76), and DSM-5 (α = 0.75). Age of ECIG initiation was correlated negatively with scores on the EDS-4 and DSM-5, while number of ECIG quit attempts was correlated positively with scores on all measures except the GNBQ. Convergent validity was highest for comparisons between the EDS-4 and PSECDI (r = 0.75) though all comparisons were significant (p's < 0.001). CONCLUSIONS: All four measures demonstrated acceptable reliability and validity in this sample of former-smoking ECIG users.

Does misclassification of former tobacco smokers explain the 'smoker's paradox' in the risk of COVID-19? Insights from the Stockholm Public Health Cohort.

BACKGROUND: The association between tobacco smoking and the risk of COVID-19 and its adverse outcomes is controversial, as studies reported contrasting findings. Bias due to misclassification of the exposure in the analyses of current versus non-current smoking could be a possible explanation because former smokers may have higher background risks of the disease due to co-morbidity. The aim of the study was to investigate the extent of this potential bias by separating non-, former, and current smokers when assessing the risk or prognosis of diseases. METHODS: We analysed data from 43,400 participants in the Stockholm Public Health Cohort, Sweden, with information on smoking obtained prior to the pandemic. We estimated the risk of COVID-19, hospital admissions and death for (a) former and current smokers relative to non-smokers, (b) current smokers relative to non-current smokers, that is, including former smokers; adjusting for potential confounders (aRR). RESULTS: The aRR of a COVID-19 diagnosis was elevated for former smokers compared with non-smokers (1.07; 95% confidence interval (CI) =1.00-1.15); including hospital admission with any COVID-19 diagnosis (aRR= 1.23; 95% CI = 1.03-1.48); or with COVID-19 as the main diagnosis (aRR=1.23, 95% CI= 1.01-1.49); and death within 30 days with COVID-19 as the main or a contributory cause (aRR=1.40; 95% CI=1.00-1.95). Current smoking was negatively associated with risk of COVID-19 (aRR=0.79; 95% CI=0.68-0.91). CONCLUSIONS: Separating non-smokers from former smokers when assessing the disease risk or prognosis is essential to avoid bias. However, the negative association between current smoking and the risk of COVID-19 could not be entirely explained by misclassification.

Physical and mental health status of former smokers and non-smokers patients with bipolar disorder.

OBJECTIVES: Up to 70% individuals with bipolar disorder (BD) are lifetime tobacco smokers, a major modifiable risk factor for morbidity. However, quitting smoking is rarely proposed to individuals with BD, mainly because of fear of unfavorable metabolic or psychiatric changes. Evaluating the physical and mental impact of tobacco cessation is primordial. The aim of this study was to characterize the psychiatric and nonpsychiatric correlates of tobacco smoking status (never- vs. current vs. former smokers) in individuals with BD. METHODS: 3860 individuals with ascertained BD recruited in the network of Fondamental expert centers for BD between 2009 and 2020 were categorized into current, former, and never tobacco smokers. We compared the sociodemographic and clinical characteristics assessed by standard instruments (e.g., BD type, current symptoms load, and non-psychiatric morbidity-including anthropometric and biological data) of the three groups using multinomial regression logistic models. Corrections for multiple testing were applied. RESULTS: Current smokers had higher depression, anxiety, and impulsivity levels than former and never-smokers, and also higher risk of comorbid substance use disorders with a gradient from never to former to current smokers-suggesting shared liability. Current smokers were at higher risk to have a metabolic syndrome than never-smokers, although this was only evidenced in cases, who were not using antipsychotics. CONCLUSIONS: Tobacco smoking was associated with high morbidity level. Strikingly, as in the general population, quitting smoking seemed associated with their return to the never-smokers' levels. Our findings strongly highlight the need to spread strategies to treat tobacco addiction in the BD population.

Smokers have increased risk of soft-tissue complications following primary elective TKA.

INTRODUCTION: Smoking has been associated with numerous adverse outcomes following surgical procedures. The purpose of this study was to investigate, whether smoking status at time of surgery influences the outcome of primary TKA. MATERIALS AND METHODS: Six hundred and eighty-one patients who underwent primary TKA between 2003 and 2006 were included in the study. Smoking status was defined as current, former, and never smoker. Complications leading to revisions were assessed until 17 years of follow-up. Functional outcome was evaluated using clinical scores: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analogue Scale (VAS) for pain, Short Form-12 Physical and Mental Component Summaries (SF-12PCS/MCS), and Knee Society Function and Knee Score (KSFS and KSKS). RESULTS: At a mean follow-up of 95 months (± 47 months), 124 complications led to revision surgery. Soft-tissue complications (OR, 2.35 [95% CI 1.08-5.11]; p = 0.032), hematoma formation (OR, 5.37 [95% CI 1.01-28.49]; p = 0.048), and restricted movement (OR, 3.51 [95% CI 1.25-9.84]; p = 0.017) were more likely to occur in current smokers than never smokers. Current smokers were more likely to score higher at KSFS (p < 0.001) and SF-12PCS (p = 0.0197) compared to never smokers. For overall revision, differences were noted. CONCLUSION: Current smoking increases risk of soft-tissue complications and revision after primary TKA, especially due to hematoma and restricted movement. Smoking cessation programs could reduce the risk of revision surgery.

Exposure to diesel exhaust alters the functional metagenomic composition of the airway microbiome in former smokers.

The lung microbiome plays a crucial role in airway homeostasis, yet we know little about the effects of exposures such as air pollution therein. We conducted a controlled human exposure study to assess the impact of diesel exhaust (DE) on the human airway microbiome. Twenty-four participants (former smokers with mild to moderate COPD (N = 9), healthy former smokers (N = 7), and control healthy never smokers (N = 8)) were exposed to DE (300 µg/m3 PM2.5) and filtered air (FA) for 2 h in a randomized order, separated by a 4-week washout. Endobronchial brushing samples were collected 24 h post-exposure and sequenced for the 16S microbiome, which was analyzed using QIIME2 and PICRUSt2 to examine diversity and metabolic functions, respectively. DE exposure altered airway microbiome metabolic functions in spite of statistically stable microbiome diversity. Affected functions included increases in: superpathway of purine deoxyribonucleosides degradation (pathway differential abundance 743.9, CI 95% 201.2 to 1286.6), thiazole biosynthesis I (668.5, CI 95% 139.9 to 1197.06), and L-lysine biosynthesis II (666.5, CI 95% 73.3 to 1257.7). There was an exposure-by-age effect, such that menaquinone biosynthesis superpathways were the most enriched function in the microbiome of participants aged >60, irrespective of smoking or health status. Moreover, exposure-by-phenotype analysis showed metabolic alterations in former smokers after DE exposure. These observations suggest that DE exposure induced substantial changes in the metabolic functions of the airway microbiome despite the absence of diversity changes.

Association of Duration of Smoking Cessation or Cumulative Smoking Amount with Serum hs-CRP Level in Korean Adults: A Nationwide Population-Based Cross-Sectional Study.

This study investigates the association between the duration of smoking cessation or cumulative smoking amount with serum high-sensitivity C-reactive protein (hs-CRP) levels. We assessed the decreasing risk for cardiovascular disease (CVD) and cancer following smoking cessation in Korean adults who were former smokers compared with current smokers. This study used data from the 2016−2018 Korea National Health and Nutrition Examination Survey. A total of 5411 participants were included. The duration of smoking cessation and cumulative smoking amount were classified into cut-offs for 6 and 17 months, and 5 and 20 pack-years, respectively, using tertile values. Elevated serum hs-CRP level was defined as ≥1 mg/L. Multivariate logistic regression analysis was performed. The odds ratio (OR) for elevated serum hs-CRP level was 0.73 times lower in the group whose duration of smoking cessation was 17 months or more than that in the group who were current smokers after adjusting for confounding variables (95% confidence interval (CI): 0.57−0.92; p < 0.01). The OR for elevated serum hs-CRP level was 0.71 and 0.67 times lower in the groups whose cumulative smoking amounts were less than 5 and 5−20 pack-years than that in the group who were current smokers (95% CI: 0.50−0.99 and 0.50−0.92, respectively; both p < 0.05). This study reveals that a duration of smoking cessation of more than 17 months and a cumulative smoking amount of less than 20 pack-years were significantly associated with a decreased risk of elevated serum hs-CRP levels in Korean adults who were former smokers. Therefore, quitting smoking early and a low cumulative smoking amount are a potential preventive strategy for CVD and cancer that can be easily accessible using serum hs-CRP.

Relationships of serum CC16 levels with smoking status and lung function in COPD.

BACKGROUND: The club cell secretory protein (CC16) has anti-inflammatory and antioxidant effects, and low CC16 serum levels have been associated with both risk and progression of COPD, yet the interaction between smoking and CC16 on lung function outcomes remains unknown. METHODS: Utilizing cross-sectional data on United States veterans, CC16 serum concentrations were measured by ELISA and log transformed for analyses. Spirometry was conducted and COPD status was defined by post-bronchodilator FEV1/FVC ratio < 0.7. Smoking measures were self-reported on questionnaire. Multivariable logistic and linear regression were employed to examine associations between CC16 levels and COPD, and lung function with adjustment for covariates. Unadjusted Pearson correlations described relationships between CC16 level and lung function measures, pack-years smoked, and years since smoking cessation. RESULTS: The study population (N = 351) was mostly male, white, with an average age over 60 years. An interaction between CC16 and smoking status on FEV1/FVC ratio was demonstrated among subjects with COPD (N = 245, p = 0.01). There was a positive correlation among former smokers and negative correlation among current or never smokers with COPD. Among former smokers with COPD, CC16 levels were also positively correlated with years since smoking cessation, and inversely related with pack-years smoked. Increasing CC16 levels were associated with lower odds of COPD (ORadj = 0.36, 95% CI 0.22-0.57, Padj < 0.0001). CONCLUSIONS: Smoking status is an important effect modifier of CC16 relationships with lung function. Increasing serum CC16 corresponded to increases in FEV1/FVC ratio in former smokers with COPD versus opposite relationships in current or never smokers. Additional longitudinal studies may be warranted to assess relationship of CC16 with smoking cessation on lung function among subjects with COPD.

Addicted to smoking or addicted to nicotine? A focus group study on perceptions of nicotine and addiction among US adult current smokers, former smokers, non-smokers and dual users of cigarettes and e-cigarettes.

BACKGROUND AND AIMS: In 2017, the US Food and Drug Administration (FDA) proposed to reduce nicotine in cigarettes to minimally or non-addictive levels. This study qualitatively explored perceptions of nicotine and addiction, both independently and in response to messages communicating about nicotine reduction. DESIGN: Qualitative study using focus groups. Participants described their perceptions of nicotine and addiction and their responses to messages about the nicotine reduction. SETTING: Atlanta, GA and San Francisco, CA, USA. Semi-structured focus groups were conducted virtually in Spring 2020. PARTICIPANTS: Exclusive smokers (n = 27), dual users (of cigarettes and electronic cigarettes) (n = 25), former smokers (n = 32) and young adult non-smokers (n = 31). MEASUREMENT: Inductive thematic analysis of transcripts was conducted, and results were compared across smoking status groups. FINDINGS: Participants across all smoking status groups associated nicotine with tobacco products, but consistently misperceived that nicotine caused disease. Perceptions of addiction were largely negative and varied by smoking status. Experienced smokers (exclusive smokers, former smokers and dual users) differentiated tobacco use from other addictions and minimized their own experiences of addiction. Perceptions of addiction across experienced smokers included not only the chemical properties of nicotine, but also the behavioral aspects of tobacco use, including oral fixation, having a smoking routine and response to internal and external cues. In response to messages, many believed that removing the nicotine would not make cigarettes less addictive because of the multi-factorial nature of smoking addiction that includes non-pharmacological cues. CONCLUSIONS: Perceptions of nicotine and addiction among non-smokers, former smokers, exclusive smokers and dual users of cigarettes and e-cigarettes vary based on smoking status, but there is a common tendency to believe that nicotine is addictive, that addiction results from more than just nicotine, and that very low nicotine cigarettes will not necessarily reduce the addictiveness of cigarettes.

Multi-Omics Analysis of the Effects of Smoking on Human Tumors.

Comprehensive studies on cancer patients with different smoking histories, including non-smokers, former smokers, and current smokers, remain elusive. Therefore, we conducted a multi-omics analysis to explore the effect of smoking history on cancer patients. Patients with smoking history were screened from The Cancer Genome Atlas database, and their multi-omics data and clinical information were downloaded. A total of 2,317 patients were included in this study, whereby current smokers presented the worst prognosis, followed by former smokers, while non-smokers showed the best prognosis. More importantly, smoking history was an independent prognosis factor. Patients with different smoking histories exhibited different immune content, and former smokers had the highest immune cells and tumor immune microenvironment. Smokers are under a higher incidence of genomic instability that can be reversed following smoking cessation in some changes. We also noted that smoking reduced the sensitivity of patients to chemotherapeutic drugs, whereas smoking cessation can reverse the situation. Competing endogenous RNA network revealed that mir-193b-3p, mir-301b, mir-205-5p, mir-132-3p, mir-212-3p, mir-1271-5p, and mir-137 may contribute significantly in tobacco-mediated tumor formation. We identified 11 methylation driver genes (including EIF5A2, GBP6, HGD, HS6ST1, ITGA5, NR2F2, PLS1, PPP1R18, PTHLH, SLC6A15, and YEATS2), and methylation modifications of some of these genes have not been reported to be associated with tumors. We constructed a 46-gene model that predicted overall survival with good predictive power. We next drew nomograms of each cancer type. Interestingly, calibration diagrams and concordance indexes are verified that the nomograms were highly accurate for the prognosis of patients. Meanwhile, we found that the 46-gene model has good applicability to the overall survival as well as to disease-specific survival and progression-free intervals. The results of this research provide new and valuable insights for the diagnosis, treatment, and follow-up of cancer patients with different smoking histories.

Smoking and colorectal cancer: A pooled analysis of 10 population-based cohort studies in Japan.

Smoking has been consistently associated with the risk of colorectal cancer (CRC) in Western populations; however, evidence is limited and inconsistent in Asian people. To assess the association of smoking status, smoking intensity and smoking cessation with colorectal risk in the Japanese population, we performed a pooled analysis of 10 population-based cohort studies. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox's proportional hazards model and then pooled using a random-effects model. Among 363 409 participants followed up for 2 666 004 person-years, 9232 incident CRCs were identified. In men, compared with never smokers, ever smokers showed higher risk of CRC. The HRs (95% CI) were 1.19 (1.10-1.29) for CRC, 1.19 (1.09-1.30) for colon cancer, 1.28 (1.13-1.46) for distal colon cancer and 1.21 (1.07-1.36) for rectal cancer. Smoking was associated with risk of CRC in a dose-response manner. In women, compared with never smokers, ever smokers showed increased risk of distal colon cancer (1.47 [1.19-1.82]). There was no evidence of a significant gender difference in the association of smoking and CRC risk. Our results confirm that smoking is associated with an increased risk of CRC, both overall and subsites, in Japanese men and distal colon cancer in Japanese women.

Prevalence and Factors Associated With Attempts to Quit and Smoking Cessation in Malaysia.

Smoking cessation significantly reduces risk of smoking-related diseases and mortality. This study aims to determine the prevalence and factors associated with attempts to quit and smoking cessation among adult current smokers in Malaysia. Data from the National E-Cigarette Survey 2016 were analyzed. Forty nine percent of current smokers had attempted to quit at least once in the past 12 months and 31.4% of the respondents were former smokers. Multivariable analysis revealed that current smokers with low nicotine addiction and aged below 45 years were more likely to attempt to quit smoking. Being married, older age group, and having tertiary education were significantly associated with smoking cessation. Only half of the current smokers ever attempted to quit smoking and only a third of smokers quit. Stronger tobacco control policies are needed in Malaysia to encourage more smokers to quit smoking. Improved access to cessation support for underprivileged smokers is also needed.

The Attentional Bias in Current and Former Smokers.

Attentional bias has been defined as the propensity of a person to allocate selective attention automatically to salient cues (Field and Powell, 2007). In the case of smoking, this bias implies that smokers are implicitly attracted by smoking-related stimuli, which produce behavioral, memory, and emotional effects (Volkow et al., 2006; Giardini et al., 2009). In more detail, scientific evidence pointed out that smoking is strongly supported by attentional bias that activates craving and urgency to smoke a cigarette. However, poor and conflicting data are available regarding the role of this cognitive bias on former smokers. The main aim of this study is to explore the occurrence of the attentional bias on of both current and former smokers, also with the aim to identify associations with behavioral, psychological and cognitive characteristic of participants. We collected data on 245 current, volunteers (male 50.6%; female 49.4%) aged 54.81 (SD = 14.352, range = 18-63), divided in current smokers (98), former smokers (102) and non-smokers (45). A combination of neuropsychology tests (Emotional Smoke Stroop Task and Go/no-Go task), and standardized questionnaires [Behavioral Inhibition System-Behavioral Approach System (BIS-BAS), Fagerström Test for Nicotine Dependence (FTND), Barratt Impulsiveness Scale, Motivational questionnaire] were used to assess the attentional bias, psychological variables, and smoking-related characteristics. Responses at the Emotional Smoke Stroop task revealed that current and former smokers are actually slower than non-smokers are when facing smoking cues, while performances at other Stroop conditions and at the Go/no-Go task are not statistically different. These results confirmed the occurrence of the attentional bias in current smokers, and above all points out that the same effect is present in former smokers. We found only small and selective correlations between attentional bias and psychological variables (e.g., impulsiveness and inhibition). In particular, impulsivity is not directly associated with the AB intensity. Also, smoking characteristics (e.g., years of smoking and dependence level) and the length of the period of abstinence do not seem to modulate implicit cognition of smoking cue. Our data support the idea that the attentional bias may be considered relevant in sustaining smoking and favoring relapse.

Imaging-based clusters in former smokers of the COPD cohort associate with clinical characteristics: the SubPopulations and intermediate outcome measures in COPD study (SPIROMICS).

BACKGROUND: Quantitative computed tomographic (QCT) imaging-based metrics enable to quantify smoking induced disease alterations and to identify imaging-based clusters for current smokers. We aimed to derive clinically meaningful sub-groups of former smokers using dimensional reduction and clustering methods to develop a new way of COPD phenotyping. METHODS: An imaging-based cluster analysis was performed for 406 former smokers with a comprehensive set of imaging metrics including 75 imaging-based metrics. They consisted of structural and functional variables at 10 segmental and 5 lobar locations. The structural variables included lung shape, branching angle, airway-circularity, airway-wall-thickness, airway diameter; the functional variables included regional ventilation, emphysema percentage, functional small airway disease percentage, Jacobian (volume change), anisotropic deformation index (directional preference in volume change), and tissue fractions at inspiration and expiration. RESULTS: We derived four distinct imaging-based clusters as possible phenotypes with the sizes of 100, 80, 141, and 85, respectively. Cluster 1 subjects were asymptomatic and showed relatively normal airway structure and lung function except airway wall thickening and moderate emphysema. Cluster 2 subjects populated with obese females showed an increase of tissue fraction at inspiration, minimal emphysema, and the lowest progression rate of emphysema. Cluster 3 subjects populated with older males showed small airway narrowing and a decreased tissue fraction at expiration, both indicating air-trapping. Cluster 4 subjects populated with lean males were likely to be severe COPD subjects showing the highest progression rate of emphysema. CONCLUSIONS: QCT imaging-based metrics for former smokers allow for the derivation of statistically stable clusters associated with unique clinical characteristics. This approach helps better categorization of COPD sub-populations; suggesting possible quantitative structural and functional phenotypes.

Indicators of cigarette smoking dependence and relapse in former smokers who vape compared with those who do not: findings from the 2016 International Tobacco Control Four Country Smoking and Vaping Survey.

BACKGROUND AND AIMS: It has been proposed that many smokers switch to vaping because their nicotine addiction makes this their only viable route out of smoking. We compared indicators of prior and current cigarette smoking dependence and of relapse in former smokers who were daily users of nicotine vaping products ('vapers') or who were not vaping at the time of survey ('non-vapers'). DESIGN: Cross-sectional survey-based comparison between vaping and non-vaping former smokers, including a weighted logistic regression of vaping status onto predictor variables, adjusting for covariates specified below. SETTING: United States, Canada, Australia and England. PARTICIPANTS: A total of 1070 people aged 18+ years from the 2016 International Tobacco Control (ITC) Four Country Smoking and Vaping Wave 1 Survey who reported having ever been daily smokers but who stopped less than 2 years ago and who were currently vapers or non-vapers. MEASUREMENTS: Dependent variable was current vaping status. Predictor variables were self-reported: (1) smoking within 5 minutes of waking and usual daily cigarette consumption, both assessed retrospectively; (2) current perceived addiction to smoking, urges to smoke and confidence in staying quit. Covariates: country, sample sources, sex, age group, ethnicity, income, education, current nicotine replacement therapy use and time since quitting. FINDINGS: Vapers were more likely than non-vapers to report: (1) having smoked within 5 minutes of waking [34.3 versus 15.9%, adjusted odds ratio (aOR) = 3.74, 95% confidence interval (CI) = 1.99, 7.03), χ2  = 16.92, P < 0.001]; having smoked > 10 cigarettes/day (74.4 versus 47.2%, aOR = 4.39, 95% CI = 2.22, 8.68), χ2  = 18.18, P < 0.001); (2) perceiving themselves to be still very addicted to smoking (41.3 versus 26.2%, aOR = 2.89, 95% CI = 1.58, 5.30, χ2  = 11.87, P < 0.001) and feeling extremely confident about staying quit (62.1 versus 36.6%, aOR = 3.22, 95% CI = 1.86, 5.59, χ2  = 17.36, P < 0.001). Vapers were not more likely to report any urges to smoke than non-vapers (27.7 versus 38.8%, aOR = 0.86, 95% CI = 0.44, 1.65, χ2  = 0.21, P = 0.643). CONCLUSIONS: While former smokers who currently vape nicotine daily report higher levels of cigarette smoking dependence pre- and post-cessation compared with former smokers who are current non-vapers, they report greater confidence in staying quit and similar strength of urges to smoke.

The Effects of Dietary Supplements on Asthma and Lung Cancer Risk in Smokers and Non-Smokers: A Review of the Literature.

Smoking is one of the major global causes of death. Cigarette smoke and secondhand (passive) smoke have been causally related to asthma and lung cancer. Asthma is a potential risk factor for developing lung cancer in both smokers and non-smokers. Prospective studies and randomized control trials (RCTs) of dietary supplements and lung cancer risk in adult smokers and non-smokers have yielded inconsistent results. A few prospective studies have shown that long-term use of high doses of some supplements, such as retinol, ß-carotene, B vitamins, and vitamin E, increase lung cancer risk in current and former smokers. Limited evidence from RCTs suggests that vitamin D supplementation is effective in improving lung function and reducing asthma risk in current/former smokers. The relationship between dietary supplements and lung cancer risk has never before been examined in asthmatic smokers and non-smokers. This short review aims to examine the evidence from existing studies for the effects of dietary supplements on asthma/lung cancer risk and mortality in smokers and non-smokers.

In favour of tobacco control? Former smokers' support for tobacco policies.

BACKGROUND: Tobacco control (TC) in Sweden is being continuously strengthened. AIMS: The study aimed to examine attitudes towards different TC policies among former smokers, the difference between nicotine-free former smokers and those who use nicotine in the form of snus or nicotine replacement therapies (NRTs), and whether different TC strategies tend to become more acceptable over time. METHODS: Respondents are part of a seven-year follow-up of former smokers in Sweden. Initially, 1400 respondents were contacted regarding participation and 705 answered a survey (response rate 50%). The present study used cross-sectional data on attitudes towards different TC policies and respondent's level of support were measured on a 4-point scale. Analyses consist of percentage distribution of level of agreement, in total and between nicotine-free individuals and users of nicotine in the form of snus or NRTs, as well as logistic regressions in order to predict the odds for supporting the different policies. In addition, a percentage distribution of support for different policies introduced during different time-periods is shown. RESULTS: There is an overall support for smoke-free environments. Nicotine users are, however, overall slightly more opposed, especially to policies aiming at denormalising smoking. Public support is important for successful implementation but resistance can pass, and interventions tend to become more acceptable over time. CONCLUSION: While smoke-free indoor environments can be justified by scientific evidence of harm to others, bans against smoking outdoors might be experienced as intrusive. Policies need to rest on scientific arguments and be seen as appropriate actions, underlining the importance of information for successful implementations.