Innovations in translational sex and gender-sensitive tobacco research

Gender differences in cigarette smoking cessation attempts among adults who smoke and drink alcohol at high levels: Findings from the 2018-2020 International Tobacco Control Four Country Smoking and Vaping Surveys

BACKGROUND

This study examined the association between alcohol consumption and smoking cessation behaviour of adults who smoke in four countries.

METHODS

Data came from 4275 adults (≥18 years) who smoked tobacco ≥ monthly and participated in the 2018 and 2020 International Tobacco Control Four Country Smoking and Vaping Surveys (Australia: n = 720; Canada: n = 1250; US: n = 1011; England: n = 1294). The 2018 Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) survey data coded into three levels ('never/low', 'moderate' or 'heavy' consumption) were analysed using multivariable logistic regression models to predict any smoking cessation attempts and successful cessation by 2020 survey, and whether this differed by gender and country.

RESULTS

Compared to never/low alcohol consumers, only those who drink heavily were less likely to have made a quit smoking attempt (40.4 % vs. 43.8 %; AOR = 0.69, 95 % CI = 0.57-0.83, p < .001). The association differed by gender and country (3-way interaction, p < .001), with females who drink heavily being less likely to attempt to quit smoking in England (AOR = 0.27, 95 % CI = 0.15-0.49, p < .001) and Australia (AOR = 0.38, 95 % CI = 0.19-0.77, p = .008), but for males, those who drink moderately (AOR = 2.18, 95 % CI = 1.17-4.06, p = .014) or heavily (AOR = 2.61, 95 % CI = 1.45-4.68, p = .001) were more likely to make a quit attempt in England only. Alcohol consumption did not predict quit success.

CONCLUSION

Heavy alcohol use among adults who smoke appears to only undermine the likelihood of trying to quit smoking with some variation by gender and country of residence, but not their chances of succeeding if they tried.

The estimated effect of graphic warning labels on smoker's intention to quit in Shanghai, China: a cross-sectional study

BACKGROUND

Tobacco consumption is the leading cause of death worldwide. Overwhelming studies demonstrate graphic warning labels (GWLs) on cigarette packs are effective in eliciting negative response to tobacco smoking, modifying beliefs about tobacco dangers, and increasing reported intention to quit, but the estimated effect of GWLs on smoking cessation intention among smokers is still limited in China. In this study, we aim to understand the smoking intensity, smoking duration and smoking cessation intention among current smokers, and to explore how their smoking cessation intention would be influenced by the GWLs in Shanghai.

METHODS

From January to June 2021, we totally recruited 1104 current smokers in Songjiang district and Fengxian district of Shanghai by multistage sampling design. We used Android pad assisted electronic questionnaire for data collection, and then implemented logistic regression for odds ratio (OR) and 95% confidence interval (CI) calculation to explore how smoking cessation intention would be influenced by the GWLs among current smokers.

RESULTS

One thousand one hundred four current smokers included 914 males (82.79%), with an average age of 43.61 years. 58.06% of current smokers reported smoking cessation intention due to GWLs. Logistic regression indicated a higher percentage of smoking cessation intention due to GWLs was among female smokers [OR = 2.41, 95% CI (1.61-3.59)], smokers with smoking intensity < 20 cigarette/day [OR = 1.92, 95% CI (1.44-2.55)], smokers with tobacco burden < 20% [OR = 1.94, 95% CI (1.35-2.79)], and among smokers had plan to quit in a year [OR = 6.58, 95% CI (4.71-9.18). Smokers with higher individual monthly income had lower percentage of smoking cessation intention (OR were 0.35, 0.46 and 0.41). Meanwhile, among 642 current smokers without plan to quit in a year, approximately 40% of them reported smoking cessation intention due to GWLs.

CONCLUSIONS

Smoking cessation intention due to the assumed GWLs on cigarette packs is high among current smokers in Shanghai, especially in female smokers, smokers with light tobacco burden and mild nicotine dependence. Incorporating smoking intensity as well as smoking burden into the implementation of GWLs as tobacco control measures would discourage smoking in China.

Blunted opioid regulation of the HPA stress response during nicotine withdrawal: therapeutic implications

Endogenous opioids regulate pain, drug reward, and stress responses. We have previously shown reduced hypothalamic-pituitary-adrenal (HPA) responses to psychological stress and to opioid blockade among dependent smokers. In this study, we examined the extent to which biologically confirmed nicotine withdrawal alters endogenous opioid regulation of HPA axis functioning during rest and in response to acute stress. Smokers were randomly assigned to one of two conditions; 24 h withdrawal from all nicotine-containing products (n = 62) or smoking ad libitum (n = 44). A nonsmoking comparison group (n = 43) was also included. Participants (85 males and 64 females) completed two acute stress sessions during which a placebo or 50 mg of naltrexone (opioid antagonist) were administered using a double-blind design. Blood and saliva samples (assayed for cortisol and adrenocorticotropic hormone, i.e. ACTH) and mood measures were obtained during a resting absorption period, after acute stress (public speaking, mental arithmetic, and cold pressor tasks), and during an extended recovery period. Results indicated that opioid blockade (naltrexone) was associated with increased ACTH and cortisol responses to stress, and tobacco withdrawal was associated with blunted hormonal responses. A pattern of sex differences also emerged, with women exhibiting reduced ACTH responses to stress and higher ACTH and plasma cortisol responses to opioid blockade. These results indicated that compared to ad libitum smoking, nicotine withdrawal is associated with blunted opioid modulation of the HPA axis. Sex may modulate these effects. Blunted endogenous opioid regulation may underlie an incentive process that reinforces smoking behavior and may warrant therapeutic attention.

To smoke or not to smoke: Does delay discounting affect the proximal choice to smoke?

BACKGROUND

Delay discounting rate shows robust predictive validity for tobacco use behaviors and is a new therapeutic target in the treatment of tobacco use. Identifying factors that influence relations between delay discounting and the choice to smoke cigarettes is key to the development of effective interventions that target delay discounting to reduce cigarette consumption.

OBJECTIVE

To examine relations between delay discounting, motivational factors, self-efficacy, nicotine dependence level, and the proximal choice to smoke in the context of other commonly rewarding activity choices.

METHODS

In this cross-sectional design, daily smokers (n = 480) from Amazon Mechanical Turk completed a questionnaire that assessed delay discounting rate; motivation, intention, and self-efficacy to quit smoking; nicotine dependence level, and the preference for immediately engaging in multiple commonly rewarding activities. We hypothesized that 1) greater motivation to quit would be associated with lower priority given to smoking; 2) the relation between delay discounting and the priority given to smoking would be mediated by motivation, self-efficacy, and nicotine dependence level.

RESULTS

Greater motivation to quit was significantly associated with a lower priority given to smoking. The relation between delay discounting and the priority given to smoking was marginally mediated by nicotine dependence level (p > .057).

CONCLUSIONS

Motivation to quit influences decision-making by impacting the prioritization of choices. Nicotine dependence is likely to mediate the relation between delay discounting and the choice to smoke. Interventions that target delay discounting to reduce cigarette consumption or prevent relapse need to account for motivation to quit and nicotine dependence level.

Sex Differences in Graphic Warning Label Ratings by Addictions Clients

OBJECTIVES

Research on sex differences in responses to cigarette graphic warning labels (GWLs) has been limited despite tobacco-related, health disparities for women. We examined whether women had stronger responses to certain labels than to others, whether this pattern differed from men's, and whether there were overall sex ratings differences.

METHODS

Smokers (N = 881) in 24, addictions treatment programs rated 3 of 9 Food and Drug Administration-developed labels on credibility, message reactance, quit motivation, and negative emotions. Participants rated one label depicting a woman and/or baby, and 2 depicting tobacco-related disease or male images.

RESULTS

Women's (n = 432) ratings of labels depicting women/babies versus other labels did not differ from men's (n = 449) ratings. Women had higher ratings than men across all labels combined on credibility (p < .001), quit motivation (p = .007), and negative emotions (p < .001). Individual labels were analyzed for sex differences. Women's ratings were higher on credibility for 3 of 9 labels, and on negative emotions for 7 of 9 labels.

CONCLUSIONS

Female smokers in addictions treatment had generally stronger responses to GWLs than men, supporting GWL implementation in the United States to help close the sex gap in smoking cessation.

Sex differences in physiological response to the combination of stress and smoking

Stressful situations are among the most commonly cited smoking triggers. Smoking and stress exposure each individually increase cardiovascular and hypothalamic-pituitary-adrenal measures with larger increases occurring when stress and smoking are combined. In this analysis, sex differences in the physiological response to the combination of stress and smoking are examined. Smokers (36 males; 34 females) completed a laboratory session in which systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), plasma epinephrine (Epi), norepinephrine and cortisol concentrations were measured at rest, while smoking a cigarette, during a speech task occurring immediately after smoking and at several time-points following the stressor. Significant period by sex effects were observed for HR, SBP, DBP and Epi but not for cortisol or norepinephrine concentrations. For SBP (p=0.002), the increase between resting and speech were larger in men than in women, primarily due to a larger increase between smoking and speech occurring in men. A similar pattern was observed for DBP and Epi with a significantly larger Epi increase from smoking to speech observed in men than in women (p=0.016). A different pattern emerged for HR - the total increase was larger in women (p<0.001), due to a larger rest to smoking increase (p<0.001). In most measures therefore, overall increases were greater in men than women, primarily due to larger smoking to speech increases. Additional research is needed to determine the clinical implications of these results as they apply to sex difference in smoking cessation success rates and in the cardiovascular risks of smoking.

Sex disparities in substance abuse research: Evaluating 23 years of structural neuroimaging studies

BACKGROUND

Sex differences in brain structure and clinical course of substance use disorders underscores the need to include women in structural brain imaging studies. The NIH has supported the need for research to address sex differences. We evaluated female enrollment in substance abuse structural brain imaging research and the methods used to study sex differences in substance effects.

METHODS

Structural brain imaging studies published through 2016 (n=230) were evaluated for number of participants by sex and substance use status and methods used to evaluate sex differences. Temporal trends in the numbers of participants by sex and substance use status were analyzed. We evaluated how often sex effects were appropriately analyzed and the proportion of studies that found sex by substance interactions on volumetric measures.

RESULTS

Female enrollment increased over time, but remained significantly lower than male enrollment (p=0.01), with the greatest bias for alcohol and opiate studies. 79% of studies included both sexes; however, 74% did not evaluate sex effects or used an analytic approach that precluded detection of sex by substance use interactions. 85% of studies that stratified by sex reported different substance effects on brain volumes. Only 33% of studies examining two-way interactions found significant interactions, highlighting that many studies were underpowered to detect interactions.

CONCLUSIONS

Although female participation in substance use studies of brain morphometry has increased, sex disparity persists. Studying adequate numbers of both sexes and employing correct analytic approaches is critical for understanding sex differences in brain morphometric changes in substance abuse.

Is the Effect of Anhedonia on Smoking Cessation Greater for Women Versus Men?

INTRODUCTION

Anhedonia has been recognized as a major risk factor for smoking persistence. Potential gender differences in the effect of anhedonia on smoking cessation have not been studied. Using data from a completed clinical trial of maintenance nicotine patch therapy, we hypothesized that gender would moderate the effect of anhedonia on short-term abstinence, such that anhedonic women would be less likely to achieve abstinence.

METHODS

Participants (N = 525; 50% female, 48.2% Black/African American, average age: 46 years) received 21mg/day nicotine patch and four brief behavior counseling sessions over 8 weeks. Participants were classified at baseline using the Snaith-Hamilton Pleasure Scale as anhedonic (scores > 2) or hedonic (scores ≤ 2). Bioverified 7-day point prevalence abstinence was measured at week 8. Using logistic regression analysis, we tested the interaction of anhedonia by gender predicting abstinence, adjusting for age, race, nicotine dependence, and baseline depressive symptomatology.

RESULTS

Seventy participants (13%) were classified as anhedonic. Men were more likely to be anhedonic than women (16.6% vs. 10.2%, p = .03). Contrary to our hypothesis, the interaction of anhedonic status (hedonic vs. anhedonic) by gender was nonsignificant (p = .18). There was a main effect of hedonic capacity, such that anhedonia predicted abstinence, odds ratio = 3.24, 95% confidence interval = 1.39-7.51, p = .006.

CONCLUSION

Both male and female anhedonic smokers were more likely to be abstinent, which contrasts with prior research indicating that anhedonia is a risk factor for difficulty quitting. This unexpected finding may be explained by a possible selective benefit of nicotine patch therapy, which has been observed in some studies to have antidepressant effects.

IMPLICATIONS

This is the first study to examine whether the association between pretreatment anhedonia and smoking cessation differs by gender. For both women and men, anhedonia was associated with a greater likelihood of abstinence after 8 weeks of treatment with 21mg/day nicotine patch and behavior counseling. Our findings indicate that the association between anhedonia and smoking cessation is not as clear as has been assumed and may depend in part on the type of treatment delivered.

Insomnia symptoms as a risk factor for cessation failure following smoking treatment

Insomnia symptoms are associated with smoking, and may interfere with smoking cessation. Specifically, studies have shown that smoking-related sleep problems are associated with long-term smoking relapse, and longer sleep duration is associated with successful smoking cessation. However, it is currently unclear whether pre- or post-quit insomnia symptoms are associated with smoking cessation outcomes. As such, the current study aimed to extend previous findings by using a measure of insomnia symptoms as a predictor of smoking cessation failure by month 3 following smoking cessation treatment. Additionally, we examined whether post-quit insomnia symptoms predicted cessation outcomes. Results indicated that pre-, but not post-quit insomnia, predicted smoking cessation failure by 3 months post-cessation, after covarying for depressive symptoms, anxiety sensitivity, alcohol use disorder severity, treatment condition, and number of cigarettes per day. These findings add to the literature on insomnia symptoms as a risk factor for difficulties with smoking cessation, and suggest it may be a worthy clinical target for smoking populations who are interested in quitting smoking.

Sex Differences in Varenicline Efficacy for Smoking Cessation: A Meta-Analysis

INTRODUCTION

Women have lower rates of quitting than men with both bupropion and nicotine replacement. It is unknown whether varenicline demonstrates differential efficacy for men and women. The purpose of this study was to conduct the first comprehensive meta-analysis of clinical trial data examining sex differences in the efficacy of varenicline for smoking cessation.

METHODS

Searching MEDLINE, EMBASE, and PsychINFO, 17 of 43 clinical trials of varenicline for smoking cessation published through December 31, 2014 were low-bias randomized double-blind placebo-controlled trials. Data (n = 6710 smokers, 34% female, n = 16 studies, 96% of available data) was analyzed with Metafor program in R. Outcome endpoints were 7-day point-prevalence (PP) and continuous-abstinence (CA) at week 12 (end of treatment), week 24 (6-month follow-up), and week 52 (12-month follow-up).

RESULTS

Using placebo, women were less likely than men to quit (PP-12, CA-24; P < .05 for sex). Using varenicline, similar rates of abstinence for men and women were demonstrated for all six outcomes (eg, PP-12 abstinence rates were 53% in both women and men). Varenicline versus placebo outcomes demonstrated that varenicline was more effective for women for short and intermediate outcomes (PP-12, CA-12, CA-24; P < .05 sex × medication interaction). For end-of-treatment PP, varenicline was 46% more effective for women. For continuous abstinence, varenicline was 34% (CA-12) and 31% (CA-24) more effective for women.

CONCLUSIONS

Unlike other smoking cessation medications, varenicline demonstrated greater efficacy among women smokers for short and immediate-term outcomes and equal efficacy for 1-year outcomes. Varenicline may be particularly useful for reducing the sex disparity typically seen in rates of smoking cessation.

IMPLICATIONS

Varenicline is currently the most effective FDA-approved smoking cessation medication and this is the first demonstration that women compared with men have a preferred therapeutic response for a smoking cessation medication when considering short-term outcomes. Importantly, this is also the first demonstration that women have similar rates of quitting to men when considering longer-term, 1-year outcomes.

Has the mist been peered through? Revisiting the building blocks of human health risk assessment for electronic cigarette use

Background

Electronic cigarettes, battery-powered nicotine delivery devices, have been increasingly used in the past decade. However, human health risks associated with E-vapor inhalation have not been fully characterized.

Aims

This critical review aims at revisiting the building blocks of human health risk assessment, summarizing the state of the science, and identifying major knowledge gaps in exposure assessment and toxicity assessment.

Approach

A qualitative research synthesis was conducted based on scientific findings reported to date in peer-reviewed publications and our own preliminary experimental results.

Results

There are a limited number of studies across all lines of evidence on E-vapor exposure and the health impacts of E-vapor inhalation. E-cigarette may be as efficient as traditional cigarettes in nicotine delivery, especially for experienced users, and studies suggest lower emissions of air toxics from E-cigarette vapor and lower second- and third-hand vapor exposures. But some toxic emissions may surpass those of traditional cigarettes, especially under high voltage vaping conditions. Experimentally, E-vapor/E-liquid exposures reduce cell viability and promote pro-inflammatory cytokine release. User vulnerability to concomitant environmental agent exposures, such as viruses and bacteria, may potentially be increased.

Conclusion

While evidence to date suggests that e-cigarettes release fewer toxins and carcinogens and compared to cigarettes, E-vapor is not safe and might adversely affect human immune functions. Major knowledge gaps hinder risk quantification and effective regulation of E-cigarette products including: 1) lack of long-term exposure studies; 2) lack of understanding of biological mechanisms associated with exposure; and 3) lack of integration of exposure and toxicity assessments.,. Better data are needed to inform human health risk assessments and to better understand the public health impact of E-vapor exposures.