Browsing by Subject "Smoking"

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    Allopregnanolone during short-term smoking abstinence: associations with depressive symptoms, smoking-related symptomatology and nicotine response
    (2012-11) Allen, Alicia Marie
    Background: Allopregnanolone (ALLO) is a neuroactive steroid metabolized from progesterone and, therefore, varies by menstrual phase in premenopausal women. Previously published literature has shown that risk for relapse to smoking varies by menstrual phase. Further, recent preclinical research indicates that ALLO may protect against drug abuse behaviors. Therefore, this dissertation project aims to characterize ALLO by menstrual phase in women with and without depressive symptoms (Paper #1) and explore the effect of ALLO on smoking-related symptomatology (SRS; Paper #2) and nicotine response (NR; Paper #3) during short-term smoking abstinence. Methods: At screening, participants (n=87) were stratified by depressive symptoms status and, using a controlled cross-over study design, were randomized to testing order (i.e., follicular (F) menstrual phase followed by the luteal (L) phase or vice versa (L-F)). The six-day testing week consisted of two days of ad libitum smoking followed by four days of biochemically verified smoking abstinence. ALLO was measured twice during each testing week: during ad libitum smoking and on the fourth day of smoking abstinence. Participants completed daily forms to assess SRS during the testing week. On the fourth day of smoking abstinence, participants participated in a NR lab session. Growth curve and covariance pattern models, adjusted for menstrual phase and testing order, were used to assess the effect of ALLO on SRS and NR, respectively. Results: In the first paper (n=84), a significant menstrual phase difference was observed in the change in ALLO level during smoking cessation. Specifically, ALLO decreased by 10% in the F phase and increased by 31% in the L phase (p<0.01). There were no significant differences in ALLO levels between the depressive symptoms groups. In the second paper (n=64), the absolute level of ALLO on the day before quit was significantly associated with the following: (1) perceived stress on the day before quit (β=-2.25, p<0.01), (2) the change in perceived stress during smoking abstinence (β=0.79, p<0.01), and (3) premenstrual symptoms of pain and water retention on the day before quit (β=1.09, p<0.01; β=1.08, p<0.01; respectively). The change in ALLO during smoking abstinence was significantly associated with the following: (1) positive and negative affect on the day before quit (β=1.15, p<0.01; β=1.04, p=0.04; respectively), (2) perceived stress on the day before quit (β=-1.77, p=0.01), (3) the change in perceived stress during smoking cessation (β=0.17, p<0.01), and (4) the change in depressive symptoms on the day of quit (β=-1.52, p=0.02). Finally, in the third paper (n=77), ALLO had a significant, positive association with the following variables prior to initiation of nicotine nasal spray: systolic blood pressure (β=0.85, p=0.04), diastolic blood pressure (β=1.19, p<0.01), and subjective levels of physical symptoms (β=0.58, p<0.01), dizziness (β =0.88, p<0.01), jitteriness (β=0.90, p=0.04) and pleasantness (β=2.05, p=0.041). ALLO also had significant associations with changes in cognition from baseline to post nicotine nasal spray use: specifically, discriminability (a measure of attention; β=1.15, p=0.05), and bias (a measure of impulsivity; β=0.12, p=0.02). Conclusion: ALLO varied significantly by menstrual phase and smoking status, and had a significant effect on several measures of SRS and NR. While several of these associations were favorable (i.e., perceived stress on the day before quit and pleasantness on the fourth day of smoking abstinence), some were not (i.e., premenstrual symptoms on the day before quit and increased subjective report of physical symptoms on the fourth day of smoking abstinence). Therefore, it remains unknown whether or not ALLO is a protective factor against drug abuse behaviors. Additional research is needed to explore the role of ALLO directly on smoking cessation outcomes.
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    Atrial fibrillation: relation to the metabolic syndrome, smoking, and development of a clinical risk score.
    (2009-11) Chamberlain, Alanna Marie
    This document provides information on the pathophysiology and epidemiology of atrial fibrillation, along with details on three manuscripts that together form the basis of a doctoral thesis. Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice and poses a great economic burden on the healthcare system. Some well known cardiovascular risk factors, such as smoking and the metabolic syndrome, have not been widely studied in the context of AF. In addition, the majority of studies on AF have used primarily white cohorts from North America and Europe. This dissertation reports the associations of the metabolic syndrome and smoking with incident AF, and provides a 10-year risk prediction score for AF using the Atherosclerosis Risk in Communities (ARIC) study. The ARIC study is a bi-racial cohort of almost 16,000 participants followed since the baseline examination in 1987-1989. The first manuscript describes the association of the metabolic syndrome and the individual components of the metabolic syndrome with risk of incident AF over a mean follow-up of 15.4 years. A 67% increased risk of incident AF was reported for individuals with compared to those without the metabolic syndrome at baseline. Most of the metabolic syndrome components were associated with an increased AF risk, and of the individual components, elevated blood pressure appeared to contribute most to AF risk. In addition, a monotonically increasing risk of AF with increasing number of metabolic syndrome components was observed. In the second manuscript, the associations of smoking status and amount with incident AF in ARIC were examined, and a systematic literature review on prospective cohort studies investigating the effects of smoking on AF incidence was conducted. Current and former smokers exhibited a 98% and 30% increased risk of developing AF compared to never smokers. The risk of incident AF increased with increasing cigarette-years of smoking, and appeared to be somewhat greater among current smokers than former smokers with similar cigarette-years of smoking. However, no consistent association was apparent in previously published studies on smoking and incident AF. A 10-year risk score for AF was developed using risk factors commonly measured in clinical practice for the third manuscript. The risk score had good discrimination and better predicted who would develop AF than the Framingham AF risk score applied to the ARIC cohort. In addition, the Framingham and ARIC coronary heart disease risk scores did not predict the 10-year risk of AF well, highlighting the importance of a separate risk score to predict AF.
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    Cancer-causing agents in new tobacco products
    (University of Minnesota Transdisciplinary Tobacco Use Research Center, 2006-05-10) Stepanov, I.; Jensen, J.; Hatsukami, Dorothy K.; Hecht, S.S.
    To assess whether new, so-called "reduced exposure" tobacco products contain reduced levels of tobacco-specific cancer-causing agents, scientists at the University of Minnesota measured the level of tobacco-specific nitrosamines (TSNAs) in 19 different brands of tobacco products, including several new varieties.
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    Cervical Cancer in Women with HIV in A Setting with High Smoking: Implications for Prevention
    (2021-12) Zhao, Ran
    In China, cervical cancer is recognized as a major public health problem. Human papillomavirus (HPV) infections cause almost all cases of cervical cancer. Tobacco smoking and co-infection with human immunodeficiency virus (HIV) are two independent risk factors for cervical cancer. Women living with HIV (WLWH) have been shown to have higher risks of HPV infection, precancerous lesions, and cervical cancer. Similarly, smoking negatively impacts the immune system and increases the risk of cervical cancer. Routine cervical cancer screening followed by early treatment is effective in reducing the burden of cervical cancer. In 2009, the Chinese government launched a population-based cervical cancer screening program in rural China as the first step towards implementing national population-based cervical cancer screening. Cervical cancer incidence among Chinese WLWH is estimated to be 47.6 per 100,000, compared to 15.5 per 100,000 in the general population. Considering their excess risk of developing cervical cancer, current screening coverage remains low. Moreover, the current cervical cancer screening guidelines for China do not provide separate screening recommendations for WLWH to account for their increased risk. The aims of this dissertation are to provide evidence to support tailored cervical cancer screening programs for WLWH in Guangxi, a region with a high prevalence of HIV in China. Since smoking control is a challenge in China, and more than 70% of adults are exposed to secondhand smoke in a typical week, we specifically consider the additional risk of cervical cancer associated with smoking exposure. In particular, we (1) surveyed WLWH in Guangxi regarding their knowledge about cervical cancer screening and risk factors for cervical cancer, (2) systematically summarized the literature on the effect of smoking exposure on cervical abnormalities among WLWH, and (3) evaluated the benefits and the harms associated with cytology-based cervical cancer screening tailored to WLWH in Guangxi using decision modeling.
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    Characterization of b-nicotyrine-mediated inactivation of cytochrome P450 2A6
    (2013-04) Kramlinger, Valerie Marie
    Nicotine, the primary addictive compound in cigarettes, is metabolized in humans by cytochrome P450 2A enzymes. The hepatic enzyme responsible for the metabolism of nicotine in smokers is P450 2A6. P450 2A13, which shares 94% primary sequence homology with P450 2A6, also catalyzes the metabolism of nicotine and is present in the lung. Loss of P450 2A activity is correlated with modified smoking behavior and addiction. Inhibition of these enzymes decreases nicotine metabolism and may be of benefit in smoking cessation. This thesis investigates tobacco-related molecules that may impact P450 2A function and is presented in three parts. In the first, the potential inhibitory potency of (-)-menthol, (R)-(+)-menthofuran, and -nicotyrine of both P450s 2A6 and 2A13 are investigated. All three compounds inhibit P450 2A6 and 2A13 activity. In addition, menthofuran and b-nicotyrine mediate mechanism-based inactivation of P450 2A6 but not 2A13. Second, the P450 2A6 and P450 2A13-mediated metabolism of b-nicotyrine is studied and three metabolites are identified. b-nicotyrine is readily turned over by both P450 2A6 and P450 2A13 as indicated by the calculated Km (4.4µM and 5.0µM, respectively) and Vmax (21 and 37 pmol product/min/pmol, respectively) values. Also in the second section, b-nicotyrine is shown to be a metabolite of P450 2A6-mediated nicotine metabolism. In the last section, attempts to identify a covalent adduct that would result from menthofuran or b-nicotyrine-mediated inactivation are presented, but these are largely unsuccessful.
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    A comparison of exercise response variables among smokers and non-smokers.
    (2010-10) Bonikowske, Amanda Rachelle
    Heart rate recovery and chronotropic incompetence are two prognostic variables that have been examined as predictors for CAD and all-cause mortality (Cole et al., 1999). Abnormal heart rate recovery is defined as failure of the heart rate to decrease by greater than or equal to twelve beats per minute within the first minute of recovery (Cole, et al., 1999). Chronotropic incompetence is identified as an impaired heart rate response to exercise (Lauer, 2004) and failure to reach 85% of age-predicted heart rate maximum (Lauer et al., 1996). This study examined the effect of an acute bout of exercise on heartrate recovery in smoking and non-smoking men and women (n=32). Participant’s mood and urge to smoke were also examined with two questionnaires before and after. Pearson’s chi-square revealed no significant differences in chronotropic incompetence between the two groups (p=0.833). None of the participants exhibited abnormal heart rate recovery. The within-subjects ANOVA analyzing the Urge to Smoke Questionnaire revealed no significant differences between pre and post exercise urge to smoke among the smoking individuals (n=9; p=0.537). The within-subjects ANOVA revealed no significant differences between pre and post POMS scores among all participants (p=0.517). The findings indicate no effect of smoking status on heart rate recovery or chronotropic response. The findings also indicate no effect of exercise on urge to smoke or mood. Additional studies with larger sample sizes are needed to discover these relationships.
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    Emotion regulation and health behavior: effects of negative affect and emotion regulation strategies on eating and smoking
    (2013-02) Keenan, Nora Kathleen
    Negative affect (NA) and deficits in emotion regulation (ER) are associated with poorer behavioral self-regulation across multiple health domains. Specifically, people who report more NA and have difficulty regulating negative emotions are more likely to engage in emotional eating and eating disordered behavior. Among smokers, NA is associated with higher rates of smoking and more difficulty with cessation. Though ER approaches vary in effectiveness, implementing ER strategies is one promising way of improving self-regulation of eating and other health behaviors. The current research compares the effects of several ER strategies on distress and eating behavior (Study 1), and compares ER skills of smokers versus nonsmokers (Study 2). In Study 1, participants (N = 114) were assigned to one of four ER conditions (suppression, cognitive reappraisal, mindfulness, and a no-instruction control), watched a movie clip to induce NA, and completed a tasting activity. Results showed that, compared to mindfulness or reappraisal, suppression was associated with eating more sweets; furthermore, this effect was stronger for those people naturally tending toward suppression or emotional eating. Study 2 compared ER profiles of daily smokers (N = 99) and nonsmokers from Study 1 (N = 114). Results indicated that, compared to nonsmokers, smokers had significantly poorer ER skills and relied on less effective ER strategies (e.g., suppression). In sum, this research provides a stepping-stone toward improved interventions to facilitate behavioral change processes by linking habitual ER vulnerabilities to health risk behaviors and providing a controlled lab-based test of different ER strategies on health behavior regulation.
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    Environmental tobacco smoke and carcinogen exposure
    (University of Minnesota Transdisciplinary Tobacco Use Research Center, 2005-05-10) University of Minnesota
    To assess the degree of carcinogen exposure among those individuals working or socializing in smoking environments, scientists at the University of Minnesota conducted two studies, which measured the level of carcinogen uptake in nonsmoking casino patrons and in nonsmoking bar and restaurant employees both before and after exposure to environmental tobacco smoke (ETS). Both studies demonstrated that nonsmokers' exposure to ETS causes significant increases in uptake of tobaccospecific carcinogens and toxins.
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    From the silver screen to teens: describing the prevalence of smoking in movies as perceived by teenagers and exploring the underlying mechanism of the association bewteen smoking in movies and adolescent smoking: a longitudinal analysis.
    (2010-08) Choi, Tsz Chun Kelvin
    Smoking in movies has been repeatedly shown to be associated with adolescent smoking. However, previous reports on the association were limited to exposure to top-grossing contemporary movies, and did not assess changes in the exposure over time. These reports were also restricted to exposure during early adolescence (ages 9-15), and focused mainly on initiation of smoking. While they have hypothesized mediators that could potentially explained the association, they did not use a longitudinal study design to assess the abilities of these mediators to explain the association. Using data from the Minnesota Adolescent Community Cohort (n=4735), a prospective observational cohort study with six age cohorts (age cohort 11, 12, 13, 14, 15, and 16), we examined changes in the prevalence of smoking in movies as perceived by teenagers over time. We observed a decline in the perceived prevalence of smoking in movies in all age cohorts, and the decline was steeper in the three older age cohorts than the three younger age cohorts (p<0.05). However, teenagers were still estimated to be exposed to these depictions some of the time at the end of the observation period. We also assessed the effect of changes in the perceived prevalence of smoking in movies on progression of smoking intensity from age 12.5 to 17.9, and found that the perceived prevalence of smoking in movies consistently predicted smoking intensity measured six months later (p<0.05), but only during younger adolescence (exposure from age 13-15.4). In the longitudinal mediation analysis, with data collected when the participants were ages 12-15.9 (n=3112), we found that the perceived prevalence of adult smoking explained an insignificant portion of the association, while the positive expectancies of smoking did not satisfy the criteria for a mediator. Although the amount of smoking in movies has declined, teenagers were still exposed to a moderate amount of these images, which could intensify their smoking behavior, particular when exposed as young adolescents. Further studies are needed to examine other potential mediators to guide the development of interventions to alleviate the negative influence of these images on teenagers.
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    Hope or hazard? What research tells us about "potentially reduced-exposure" tobacco products
    (University of Minnesota Transdisciplinary Tobacco Use Research Center, 2005-04) Hatsukami, Dorothy; Hecht, Stephen
    The goals of this report are to: describe the current state of science regarding potentially reduced-exposure tobacco products (PREPs), comment on whether the marketing claims about PREPs are supported by the current published scientific literature, and outline what we need to know about PREPs in order to assess the claims made about (or the actual harm reduction offered by) these products.
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    "Light" cigarettes and exposure to carcinogens
    (University of Minnesota Transdisciplinary Tobacco Use Research Center, 2005-03-09) University of Minnesota
    To assess whether smoking "light" cigarettes reduces the amount of tobacco-specific carcinogens in the body, scientists at the University of Minnesota measured the level of carcinogen uptake in smokers who were using regular, light, and ultralight cigarettes. No significant differences were observed among smokers of the three different types of cigarettes.
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    Medications to help quit smoking
    (2012-04-09) Bloomberg, Elisabeth
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    No Screening for Lung Cancer
    (2009-05-06) Lackner, Josh
    The most recent assessment of available evidence on lung cancer screening with a sensitive modality (computed tomography) found that we cannot conclude that such screening provides a mortality benefit. The main reason for this, is that there is no available trial that compares CT screening to no screening over an adequate duration of time. Of note, false positive results were very common and tumors found on screening had different characteristics from those found clinically.
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    Psychophysiological and fMRI investigations of tobacco cue reactivity.
    (2010-06) Engelmann, Jeffrey Michael
    Development of new smoking-cessation therapies may be facilitated by identifying the neural basis of smoking-related emotional responses. In this dissertation, the affective consequences of cigarette smoking and abstinence were modeled in rats and humans using a potentiated-startle paradigm. In rats, repeated daily nicotine injections resulted in increased startle amplitude 2 h after nicotine exposure, which is consistent with the emergence of an anxiety-like withdrawal episode. In humans, startle responses to tobacco, pleasant, neutral, and unpleasant cues were measured in nonsmokers, nonabstinent smokers, and smokers who were 24 h into a 48 h abstinence period. Startle amplitude was potentiated during unpleasant cues in nonsmokers and abstinent smokers, but not in nonabstinent smokers, which suggests that smoking a cigarette reduced anxiety. Event-related brain potentials also suggested that abstinent smokers were more emotionally reactive than nonsmokers and nonabstinent smokers to both tobacco cues and unpleasant cues. An additional, functional magnetic resonance imaging study found that that two brain regions, the dorsal striatum and the anterior cingulate cortex, were involved in the expression of abstinent smokers' emotional responses to tobacco and unpleasant cues. These results suggest negative affect may be important in maintaining cigarette smoking and that the potentiated startle paradigm is an ideal model for preclinical and clinical studies of smoking-related emotional responses.
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    Reducing cigarette smoking: Research summary Does it reduce cancer risk?
    (University of Minnesota Transdisciplinary Tobacco Use Research Center, 2004-05-12) University of Minnesota
    To assess whether cutting back on cigarettes reduces the amount of tobacco-specific carcinogens in the body, scientists at the University of Minnesota measured the level of carcinogen uptake in smokers who were reducing their cigarette consumption over 26 weeks. Overall reductions in carcinogen levels were seen, but the levels were modest and were proportionally less than the amount of cigarettes reduced per day.
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    Social diffusion of campaign effects: campaign-generated interpersonal communication as a polarizing mediator of anti-tobacco campaign effects.
    (2009-05) Hwang, Yoori
    Traditionally, campaign effects have been modeled as a result of individuals' direct exposure to campaign messages. A person's indirect exposure to messages through interpersonal conversation about a campaign, however, can be another way that campaign effects occur. Based on the notion of social diffusion of campaign effects, this dissertation research examined the role of campaign conversation in the generation and diffusion of campaign effects. More specifically, this dissertation research tested whether anti-smoking campaign-generated conversation affected individuals’ smoking-related perceptions using the TruthSM campaign data (Study 1) and experiment data (Study 2). Study 1 tested whether campaign conversation, along with individual exposure, can mediate the impact of the TruthSM campaign using secondary analyses of the Legacy Media Tracking Survey (LMTS) data. LMTS is a random digit dialing telephone survey of a nationally representative sample of youth (LMTS II: n =10,357; LMTS III: n = 10,079). Multilevel modeling results of LMTS II data show that both encoded exposure and campaign conversation mediated the relationship between TruthSM campaign availability and smoking beliefs, although the mediating roles of encoded exposure and campaign conversation were not found in LMTS III. The results of LMTS II data also show that campaign conversation widened the difference in smoking beliefs between non-smokers and hardcore smokers, indicating a possibility that campaign conversation can function as a polarizing mediator. Based on the concern of potential backlash effects of conversation among smokers, Study 2 tested whether a smoker’s campaign conversation with another smoker can produce elevated pro-smoking normative perceptions and behavioral intentions using a laboratory experiment (n =72). Results show that smokers’ conversation generated boomerang effects. Although campaign conversation did not affect participants’ injunctive norms, personal descriptive norms, or behavioral intention, it led to elevated pro-smoking societal descriptive norms (i.e., higher smoking prevalence estimates) among participants who had a low number of smoker friends. Altogether, this dissertation research provides general support for the social diffusion process of campaign effects and the important role of campaign conversation in this process. It shows that campaign-generated conversation can generate, amplify, and, sometimes, reduce campaign effects. Theoretical and practical implications for campaign planning and evaluation are discussed.
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    Socioeconomic status and tobacco use behavior in adolescence.
    (2010-08) Mathur, Charu
    INTRODUCTION: Despite the known health problems associated with tobacco use, adolescents continue to initiate and develop regular patterns of tobacco use. Globally adult tobacco consumption is strongly associated with poverty, with those in lower socioeconomic classes using tobacco at higher rates. The association between socioeconomoic status (SES) and tobacco use for youth, however, is much less clear. Understanding the role of SES in initiation and progression of tobacco use among adolescents can improve our ability to design effective interventions targeting adolescent tobacco use behavior. The aim of this dissertation was to examine the impact of SES on tobacco use in youth across different countries, presented in three related manuscripts. METHODS: In the first manuscript, the effect of both individual and community- level SES on smoking outcome was evaluated in the Minnesota Adolescent Community Cohort (MACC) study, a population-based, observational cohort study designed to assess the effects of tobacco control policies and programs on adolescent smoking. Additionally, the cross-level interaction of these two SES measures was examined. The analyses employed a multiple group, multiple cohort growth model. In the second manuscript latent class analysis (LCA) was used to establish classes of tobacco acquisition in the Mobilizing Youth for Tobacco Related Initiatives (MYTRI) study, a large-scale intervention trial in two large cities in India. The third manuscript explored change in tobacco use over time and the moderating effect of SES on change, also in the MYTRI study. Additionally, the distribution of related psychosocial risk factors across schools type was also evaluated. RESULTS: In paper 1, individual-level SES was associated with smoking (low SES was associated with higher adolescent smoking), but community-level SES was not. However, the results for cross-level interaction show that community socioeconomic context affected smoking behavior differentially depending on individual socioeconomic position (i.e., community-level SES had stronger effects on low individual-SES adolescents than on high individual-level SES youth). The results from paper 2 suggest that a 3-latent class and a 4-latent class model were most appropriate for this adolescent population, in private and government schools, respectively. Although, the number of latent classes was the same at both time points, the meaning of these classes differed over time. Finally, in paper 3, the findings about the relationship between SES and tobacco were inconsistent, suggesting a potential change over time in the association of SES and tobacco use. At baseline, low SES was associated with higher prevalence of tobacco use but the relation between SES and tobacco use reversed two years later. These findings were mirrored in the distribution of related psychosocial risk factors. CONCLUSIONS: This dissertation served to examine the relationship between SES and adolescent tobacco use in two different countries/settings. Reducing tobacco initiation and progression in low SES youth that are disproportionately affected is dependent upon effective and sustainable interventions as well as a more comprehensive understanding of the role SES in influencing an adolescent's tobacco use behavior.
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