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Tobacco cigarette smoking is associated with disrupted brain network dynamics in resting brain networks including the Salience (SN) and Fronto parietal (FPN). Unified multimodal methods [Resting state connectivity analysis, Diffusion Tensor Imaging (DTI), neurite orientation dispersion and density imaging (NODDI), and cortical thickness analysis] were employed to test the hypothesis that the impact of cigarette smoking on the balance among these networks is due to alterations in white matter connectivity, microstructural architecture, functional connectivity and cortical thickness (CT) and that these metrics define fundamental differences between people who smoke and nonsmokers. Multimodal analyses of previously collected 7 Tesla MRI data via the Human Connectome Project were performed on 22 people who smoke (average number of daily cigarettes was 10 ± 5) and 22 age- and sex-matched nonsmoking controls. First, functional connectivity analysis was used to examine SN-FPN-DMN interactions between people who smoke and nonsmokers. The anatomy of these networks was then assessed using DTI and CT analyses while microstructural architecture of WM was analyzed using the NODDI toolbox. Seed-based connectivity analysis revealed significantly enhanced within network [p = 0.001 FDR corrected] and between network functional coupling of the salience and R-frontoparietal networks in people who smoke [p = 0.004 FDR corrected]. The network connectivity was lateralized to the right hemisphere. Whole brain diffusion analysis revealed no significant differences between people who smoke and nonsmokers in Fractional Anisotropy, Mean diffusivity and in neurite orienting and density. There were also no significant differences in CT in the hubs of these networks. Our results demonstrate that tobacco cigarette smoking is associated with enhanced functional connectivity, but anatomy is largely intact in young adults. Whether this enhanced connectivity is pre-existing, transient or permanent is not known. The observed enhanced connectivity in resting state networks may contribute to the maintenance of smoking frequency.

The health consequences associated with using electronic cigarettes (ECs) are of great public interest because of their potential role in smoking cessation. In 110 participants, including 41 nonusers, 34 people who exclusively use ECs (EC group), and 35 people who smoke tobacco cigarettes (TCs) including 12 dual users (collectively called the TC-D group), the heart rate (HR), blood pressure (BP), and heart rate variability (HRV) were compared at baseline. People in the EC or the TC-D groups were also compared after using a 4th generation EC with or without nicotine, a TC with or without nicotine (TC-D group only), and a straw-control. Baseline HR, BP, and HRV parameters were not different among the EC, the TC-D, and nonuser groups. In people who exclusively use ECs, acute nicotine-EC use increased HR and BP, and produced changes in HRV patterns suggestive of increased cardiac sympathetic influence. In people in the TC-D group, BP increased similarly after acutely smoking a nicotine-TC or a nicotine-EC. However, the increase in HR was significantly greater after smoking a TC compared with the nicotine-EC despite similar acute increases in plasma nicotine. Overall, all exposures containing nicotine significantly increased HR and BP in both cohorts when compared with non-nicotine exposures. Since acute EC use 1) produces an abnormal HRV pattern associated with increased cardiac sympathetic tone in people who chronically use ECs, and 2) similar hemodynamic increases compared with acute TC smoking in people who chronically smoke TCs including dual users, the role of ECs as part of a harm reduction strategy is questioned.NEW & NOTEWORTHY We found that nicotine, not the non-nicotine constituents in tobacco cigarette (TC) or electronic cigarette (EC) emissions, may be the instigator of the acute, potentially adverse, changes in hemodynamics and heart rate variability (HRV) that were recorded several minutes after tobacco product use. Furthermore, acute EC use produced an abnormal HRV pattern associated with increased cardiac risk in people who chronically smoke ECs and produced similar hemodynamic increases compared with acute TC use in people who chronically smoke TCs, including people who are dual users.

BACKGROUND: Little is known about patterns of dual use of tobacco and electronic cigarettes (e-cigarettes), especially regarding the factors that lead people to choose either product in particular situations. Identifying contextual factors that are associated with product use would enhance understanding of the maintenance of dual product use.
METHODS: Individuals who dual use (N = 102) completed ecological momentary assessment surveys via text message regarding the recent use of tobacco and e-cigarettes for 2 weeks. Product legality, availability, craving, the presence of other people who smoke/vape, and social disapproval were assessed. Data were analyzed using hierarchical logistic regression to identify factors associated with the likelihood of tobacco versus e-cigarette use.
RESULTS: Contexts associated with increased likelihood of using tobacco rather than e-cigarettes included being in the presence of other people who smoke (odds ratio [OR] = 3.50, p < .0001) and experiencing elevated tobacco cigarette craving (OR = 3.51, p < .0001). Decreased likelihood of tobacco over e-cigarette use was associated with smoking restrictions (OR = 0.26, p = .003), the presence of other people who vape (OR = 0.38, p < .001), and experiencing elevated e-cigarette craving (OR = 0.23, p < .0001). The legality of e-cigarettes, social disapproval, and the availability of the alternative product were not significantly associated with the use of one product over the other. An individual difference score of relative tobacco (vs. e-cigarette) use pattern did not significantly moderate these effects.
CONCLUSIONS: This study provided essential information regarding behavioral patterns of dual use, which informs our understanding of people who dual use. Contexts such as smoking restrictions, craving, and social context significantly differentiated between the use of tobacco and e-cigarettes. This suggests product-specific motivations for dual use of tobacco and e-cigarettes in people who use both.
CONCLUSIONS: This study assessed the relationship between momentary contextual factors and dual use in a nationally recruited sample of people who dual use. Assessments of dual use in daily life provided novel information regarding patterns of dual use as well as differential use-motivations for each product. This information will be essential to build a theoretical framework of dual use of tobacco and e-cigarettes.

Smoking tobacco cigarettes is a significant (cardiovascular) health risk factor. Although the number of tobacco cigarette users declined over the last decades, shisha smoking and e-cigarette vaping partially compensated for this health benefit. E-cigarettes may create highly addicted dual users (vaping and smoking). E-cigarettes seem not to represent a healthier alternative to tobacco smoking, although they may be less harmful. E-cigarette vaping causes oxidative stress, inflammation, endothelial dysfunction, and associated cardiovascular sequelae. This is primarily due to a significant overlap of toxic compounds in the vapor compared to tobacco smoke and, accordingly, a substantial overlap of pathomechanistic features between vaping and smoking. Whereas the main toxins in vapor are reactive aldehydes such as formaldehyde and acrolein, the toxic mixture in smoke is more complex, comprising particulate matter, reactive gases, transition metals, volatile organic compounds, and N-nitrosamines. However, it seems that both lifestyle drugs impair endothelial function to a quite similar extent, which may be due to the role of oxidative stress as the central pathomechanism to mediate endothelial dysfunction and vascular damage. Finally, the main selling argument for e-cigarette use that they help to quit smoking and get rid of nicotine addiction may be false because it seems that e-cigarettes instead trigger the opposite-younger entrance age and more frequent use. With our review, we summarize the adverse health impact of tobacco cigarettes and e-cigarettes, emphasizing the detrimental effects on endothelial function and cardiovascular health.

Electronic cigarettes are often used for smoking cessation as a harm reduction strategy, but studies comparing risks of electronic cigarettes (ECs) and tobacco cigarettes (TCs) are scarce. Ventricular repolarization in people who smoke TCs is abnormal. Baseline repolarization was compared among nonusers (people who do not use TCs or ECs) and people who use ECs or TCs. The acute effects of ECs and TCs on metrics of ventricular repolarization were then compared in people who chronically smoke. A total of 110 participants (59 female), including 35 people (21 females) in the TC cohort, 34 people (17 females) in the EC cohort, and 41 people (21 females) in the nonuser cohort, were included. None of the primary outcomes, Tpeak-end (Tp-e), Tp-e/QT, and Tp-e/QTc, were different among the three cohorts at supine baseline, even when adjusted for sex. When compared with the control exposure standing after acutely using the EC but not the TC, significantly prolonged all three primary indices of ventricular repolarization in people who smoke TCs. The major new finding in this study is that in people who smoke TCs, using an EC compared with a TC significantly prolongs ventricular repolarization. Furthermore, in our subgroup analysis by sex, this adverse effect on repolarization is found only in male, not female, smokers. In summary, chronic TC smoking is the most prevalent, modifiable risk factor for cardiovascular death, including sudden cardiac death. If used for smoking cessation, ECs should only be used in the short term since they too carry their own risks; this risk appears to be greatest in males compared with females who smoke.NEW & NOTEWORTHY The major new finding in this study is that in people who smoke tobacco cigarettes, using an electronic cigarette but not a tobacco cigarette acutely and significantly prolongs several metrics of ventricular repolarization, including Tpeak-Tend, Tpeak-Tend/QT, and Tpeak-Tend/QTc. Furthermore, in our subgroup analysis by sex, this adverse effect on repolarization is found only in male, not female, smokers.

Adolescents who dual use ENDS with tobacco cigarettes are more likely to have an increased risk of developing dependence. Yet, little is understood about the factors driving dual use among adolescents. The current study sought to reveal the day-to-day socio-temporal contextual and community factors associated with adolescents\' use of electronic nicotine delivery systems (ENDS), and how these factors predict dual use with tobacco cigarettes.
We collected ecological momentary assessments (EMA) from a sample of 50 adolescent past two-week vapers (ages 14-17 years old) over 14 days. Daily EMA data were collected on ENDS and tobacco cigarette use, as well as a range of contextual (i.e., motivations to vape, location of vaping, who with when vaping) and community factors (i.e., exposure to peers vaping, to adults vaping, to ENDS advertising, to ENDS warning messages). Our primary analyses were multilevel regressions, accounting for daily observations nested within individuals (N = 700 observations).
Participants used ENDS exclusively on 44% of days and dual used ENDS and tobacco cigarettes on 8% of the days. Dual use days (versus exclusive ENDS use days) were associated with \"vaping because tobacco use was prohibited\" (OR = 34.65, p < .05). Also, dual use days (versus no use days) were associated with greater exposure to adults vaping (OR = 5.59, p < .05), peers vaping (OR = 7.48, p < .05), and (c) ENDS advertisements or promotions (OR = 2.12, p < .01), whereas exclusive use days (versus no use days) were only associated with greater exposure to peers vaping (OR = 2.58, p < .01).
Results showed that exposure to peers and adults vaping and exposure to ENDS marketing were associated with same day dual use behaviors. And, that adolescents who dual used were motivated to use ENDS because they were easy to conceal. Findings support stricter regulation of ENDS marketing and for smoke-free air laws that include ENDS. In addition, these findings support prioritizing family- and school-based prevention programming that effectively communicates risk associated with ENDS use, including heightened risk of dual use and dependence. Such efforts can reduce the number of adolescents who use ENDS as well as the number who transition to tobacco cigarette use.

BACKGROUND: Electronic cigarettes (e-cigs) as substitute devices for regular tobacco cigarettes (r-cigs) have been increasing in recent times. We investigated neuronal substrates of vaping e-cigs and smoking r-cigs from r-cig smokers.
METHODS: Twenty-two r-cig smokers made two visits following overnight smoking cessation. Functional magnetic resonance imaging (fMRI) data were acquired while participants watched smoking images. Participants were then allowed to smoke either an e-cig or r-cig until satiated and fMRI data were acquired. Their craving levels and performance on the Montreal Imaging Stress Task and a 3-back alphabet/digit recognition task were obtained and analyzed using two-way repeated-measures analysis of variance. Regions-of-interest (ROIs) were identified by comparing the abstained and satiated conditions. Neuronal activation within ROIs was regressed on the craving and behavioral data separately.
RESULTS: Craving was more substantially reduced by smoking r-cigs than by vaping e-cigs. The response time (RT) for the 3-back task was significantly shorter following smoking r-cigs than following vaping e-cigs (interaction: F (1, 17) = 5.3, p = 0.035). Neuronal activations of the right vermis (r = 0.43, p = 0.037, CI = [-0.05, 0.74]), right caudate (r = 0.51, p = 0.015, CI = [0.05, 0.79]), and right superior frontal gyrus (r = -0.70, p = 0.001, CI = [-0.88, -0.34]) were significantly correlated with the RT for the 3-back task only for smoking r-cigs.
CONCLUSIONS: Our findings suggest that insufficient satiety from vaping e-cigs for r-cigs smokers may be insignificant effect on working memory function.

Little is known about e-cigarette use among persons in substance use disorder (SUD) treatment, or their use of e-cigarettes for smoking cessation. Prevalence of e-cigarette use and correlates of e-cigarette use for smoking cessation were examined among clients in SUD treatment. Participants (n = 332) were current cigarette smokers recruited from 20 residential SUD programs in California. We used multivariable logistic regression to identify correlates of using e-cigarettes for quitting smoking. Almost half (45.2%) of the sample had ever used e-cigarettes for smoking cessation, and 34% had used e-cigarettes in the past 30 days. Smokers who had used e-cigarettes for smoking cessation, compared to those who had not, were younger (adjusted odds ratio [AOR] = 0.94, 95% confidence interval [CI] = 0.91, 0.96), had more than a high school education (AOR = 1.69, 95% CI = 1.07, 2.68), sought treatment for both SUD and mental health disorder (AOR = 2.62, 95% CI = 1.38, 5.00), wanted help quitting smoking (AOR = 1.90, 95% CI = 1.03, 3.50) and perceived e-cigarettes as equally harmful (AOR = 3.03, 95% CI = 1.10, 8.33) or less harmful than tobacco cigarettes (AOR = 2.82, 95% CI = 1.02, 7.77). Black/African American and Hispanic/Latino participants were less likely to use e-cigarettes for smoking cessation than participants who identify as White. E-cigarettes were favorably perceived by clients in residential SUD treatment as a quit smoking aid. Treatment programs should consider how to advise clients with respect to the use of e-cigarettes for smoking cessation.

BACKGROUND: This systematic literature review summarizes the impact of smoking on maximal oxygen uptake (maximum [Formula: see text]).
METHODS: Full-text articles were retrieved if the abstract met the assigned criteria. A total of 9 articles were included in the final review based on the inclusion and exclusion criteria. These included articles assessed the effects of tobacco smoking on maximum [Formula: see text] values.
RESULTS: Half of the articles reported a significant difference in maximum [Formula: see text] scores between smokers and nonsmokers, with smokers having a lower maximum [Formula: see text]. The other half of the articles did not identify significant differences between smokers and nonsmokers. One study found a significant difference in maximum [Formula: see text] in only one age group (ie, 20-29 y), but not any of the other age groups.
CONCLUSIONS: More research is needed on the effects of smoking on maximum [Formula: see text] to better understand any relationships or causations.