Gender differences in the pharmacology of nicotine addiction

Anxiety sensitivity in relation to smoking dependence motives among Latinx persons who smoke

Hispanic/Latinx (hereafter Latinx) persons are an established tobacco disparities population in the United States (US). Past work has suggested that individual differences in anxiety sensitivity, or the fear of arousal-based sensations, is one important cognitive construct for smoking maintenance and relapse among Latinx persons who smoke. However, previous research has not examined if anxiety sensitivity is associated with motivational facets of smoking dependence among this tobacco disparities population. In the current study, anxiety sensitivity was explored in terms of smoking motives for primary, secondary, and overall cigarette dependence. Participants included 336 English-speaking Latinx adults in the US who smoked cigarettes daily (Mage = 35.53, SD = 8.65, 37.3% Female). Results indicated that anxiety sensitivity was statistically significantly and positively related to higher primary and secondary dependence motives and marginally statistically significant to cigarette dependence; findings were evident after adjusting for numerous theoretically relevant variables (e.g., depression). Overall, the current study is the first to document linkages between anxiety sensitivity and numerous motivational bases of tobacco dependence among Latinx persons who smoke from the US.

Subregion specific neuroadaptations in the female rat striatum during acute and protracted withdrawal from nicotine

Epidemiological studies and clinical observations suggest that nicotine, a major contributor of the global burden of disease, acts in a partially sex specific manner. Still, preclinical research has primarily been conducted in males. More research is thus required to define the effects displayed by nicotine on the female brain. To this end, female rats received 15 injections of either nicotine (0.36mg/kg) or saline, over a 3-week period and were then followed for up to 3 months. Behavioral effects of nicotine were assessed using locomotor activity measurements and elevated plus maze, while neurophysiological changes were monitored using ex vivo electrophysiological field potential recordings conducted in subregions of the dorsal and ventral striatum. Behavioral assessments demonstrated a robust sensitization to the locomotor stimulatory properties of nicotine, but monitored behaviors on the elevated plus maze were not affected during acute (24 h) or protracted (3 months) withdrawal. Electrophysiological recordings revealed a selective increase in excitatory neurotransmission in the nucleus accumbens shell and dorsomedial striatum during acute withdrawal. Importantly, accumbal neuroadaptations in nicotine-treated rats correlated with locomotor behavior, supporting a role for the nucleus accumbens in behavioral sensitization. While no sustained neuroadaptations were observed following 3 months withdrawal, there was an overall trend towards reduced inhibitory tone. Together, these findings suggest that nicotine produces selective transformations of striatal brain circuits that may drive specific behaviors associated with nicotine exposure. Furthermore, our observations suggest that sex-specificity should be considered when evaluating long-term effects by nicotine on the brain.

Strengths and Limitations of Web-Based Cessation Support for Individuals Who Smoke, Dual Use, or Vape: Qualitative Interview Study

BACKGROUND

Tobacco use has shifted in recent years, especially with the introduction of e-cigarettes. Despite the current variable and intersecting tobacco product use among tobacco users, most want to quit, which necessitates cessation programs to adapt to these variable trends (vs focusing on combustible cigarettes alone). The use of web-based modalities for cessation support has become quite popular in recent years and has been compounded by the COVID-19 pandemic. Therefore, understanding the current strengths and limitations of existing programs to meet the needs of current various tobacco users is critical for ensuring the saliency of such programs moving forward.

OBJECTIVE

The purpose of this study was to understand the strengths and limitations of web-based cessation support offered through QuitNow to better understand the needs of a variety of end users who smoke, dual use, or vape.

METHODS

Semistructured interviews were conducted with 36 nicotine product users in British Columbia. Using conventional content analysis methods, we inductively derived descriptive categories and themes related to the strengths and limitations of QuitNow for those who smoke, dual use, or vape. We analyzed the data with the support of NVivo (version 12; QSR International) and Excel (Microsoft Corporation).

RESULTS

Participants described several strengths and limitations of QuitNow and provided suggestions for improvement, which fell under 2 broad categories: look and feel and content and features. Shared strengths included the breadth of information and the credible nature of the website. Individuals who smoke were particularly keen about the site having a nonjudgmental feeling. Moreover, compared with individuals who smoke, individuals who dual use and individuals who vape were particularly keen about access to professional quit support (eg, quit coach). Shared limitations included the presence of too much text and the need to create an account. Individuals who dual use and individuals who vape thought that the content was geared toward older adults and indicated that there was a lack of information about vaping and personalized content. Regarding suggestions for improvement, participants stated that the site needed more interaction, intuitive organization, improved interface esthetics, a complementary smartphone app, forum discussion tags, more information for different tobacco user profiles, and user testimonials. Individuals who vape were particularly interested in website user reviews. In addition, individuals who vape were more interested in an intrinsic approach to quitting (eg, mindfulness) compared with extrinsic approaches (eg, material incentives), the latter of which was endorsed by more individuals who dual use and individuals who smoke.

CONCLUSIONS

The findings of this study provide directions for enhancing the saliency of web-based cessation programs for a variety of tobacco use behaviors that hallmark current tobacco use.

Withdrawal from repeated nicotine vapor exposure increases somatic signs of physical dependence, anxiety-like behavior, and brain reward thresholds in adult male rats

Nicotine vapor consumption via electronic nicotine delivery systems has increased over the last decade. While prior work has shed light on the health effects of nicotine vapor inhalation, its unique effects on the brain and behavior have not been thoroughly explored. In this study we assessed markers of withdrawal following 14 days of nicotine vapor exposure. For Experiment 1, 21 adult male rats were exposed to ambient air or 6, 12, or 24 mg/mL nicotine vapor for 14 consecutive days. Following exposure on day 14, rats were injected with the nicotinic receptor antagonist mecamylamine (3.0 mg/mL) and assessed for somatic withdrawal signs and anxiety-like behavior in the elevated plus maze. For Experiment 2, 12 adult male rats were tested for intracranial self-stimulation (ICSS) immediately following exposure to vehicle vapor (50%/50%, vegetable glycerin/propylene glycol) or 24 mg/mL nicotine vapor, for 14 consecutive days. ICSS behavior was assessed for an additional 14 days, following cessation of repeated vapor exposure. Results reveal that rats with repeated nicotine vapor exposure display an increase in behavioral indicators of withdrawal following injection of mecamylamine (precipitated withdrawal). Additionally, increases in ICSS stimulation thresholds, indicative of reduced brain reward sensitivity, persist following cessation of repeated nicotine vapor exposure (spontaneous withdrawal). These data suggest that repeated e-cigarette use leads to nicotine dependence and withdrawal that affects behavior and brain reward function. Further characterization of the health effects of nicotine vapor is necessary to improve treatment strategies for nicotine use disorder and public health policies related to novel nicotine delivery systems.

An Observational Study of 147 Psoriasis Patients: Overweightness and Obesity as a Significant Clinical Factors Correlated with Psoriasis

Background and Objectives: Psoriasis is a common, chronic, and immune-mediated inflammatory skin disease recognized to lead to a wide range of comorbid disorders, mainly obesity. The study aimed to evaluate the problem of overweightness and obesity among psoriasis patients in the context of their prevalence and influence on the disease course. Materials and Methods: The study group encompassed 147 adult patients with plaque psoriasis. Results: The prevalences of overweightness (39.46%) and obesity (37.41%) demonstrated in the study showed the strong predisposition of psoriatic patients for abnormal body mass. The vast majority (77%) of subjects with psoriatic arthritis were overweight or obese. The results of the correlation analysis revealed the significant impacts of overweightness and obesity, as defined by the BMI index, on modifying the severity of psoriasis (as assessed by the PASI with a correlation coefficient of R = 0.23, p = 0.016; and BSA values with a correlation coefficient of R = 0.21, p = 0.023), particularly in contrast to patients with a normal body mass. Conclusions: Overweightness and obesity constitute a major health burden among psoriatic patients, influencing the disease course and severity. Enhanced understanding of the phenomenon may directly translate into improving disease management and overall patient care.

Acute and chronic effects by nicotine on striatal neurotransmission and synaptic plasticity in the female rat brain

Introduction

Tobacco use is in part a gendered activity, yet neurobiological studies outlining the effect by nicotine on the female brain are scarce. The aim of this study was to outline acute and sub-chronic effects by nicotine on the female rat brain, with special emphasis on neurotransmission and synaptic plasticity in the dorsolateral striatum (DLS), a key brain region with respect to the formation of habits.

Methods

In vivo microdialysis and ex vivo electrophysiology were performed in nicotine naïve female Wistar rats, and following sub-chronic nicotine exposure (0.36 mg/kg free base, 15 injections). Locomotor behavior was assessed at the first and last drug-exposure.

Results

Acute exposure to nicotine ex vivo depresses excitatory neurotransmission by reducing the probability of transmitter release. Bath applied nicotine furthermore facilitated long-term synaptic depression induced by high frequency stimulation (HFS-LTD). The cannabinoid 1 receptor (CB1R) agonist WIN55,212-2 produced a robust synaptic depression of evoked potentials, and HFS-LTD was blocked by the CB1R antagonist AM251, suggesting that HFS-LTD in the female rat DLS is endocannabinoid mediated. Sub-chronic exposure to nicotine in vivo produced behavioral sensitization and electrophysiological recordings performed after 2-8 days abstinence revealed a sustained depression of evoked population spike amplitudes in the DLS, with no concomitant change in paired pulse ratio. Rats receiving sub-chronic nicotine exposure further demonstrated an increased neurophysiological responsiveness to nicotine with respect to both dopaminergic- and glutamatergic signaling. However, a tolerance towards the plasticity facilitating property of bath applied nicotine was developed during sub-chronic nicotine exposure in vivo. In addition, the dopamine D2 receptor agonist quinpirole selectively facilitate HFS-LTD in slices from nicotine naïve rats, suggesting that the tolerance may be associated with changes in dopaminergic signaling.

Conclusion

Nicotine produces acute and sustained effects on striatal neurotransmission and synaptic plasticity in the female rat brain, which may contribute to the establishment of persistent nicotine taking habits.

The Evaluation Of Smoking Cessation Treatment Success and Related Factors in Adults Age 65 Years and Older

OBJECTIVES

The aim was to evaluate smoking cessation treatment success and factors associated in older adults.

METHODS

In the retrospective cohort study, the patients' sociodemographic data, smoking history, Fagerström Test for Nicotine Dependence scores (FTND), type of treatments (Pharmacological treatments, behavioral counseling, and/or both) and the number of follow-up sessions in the Smoking Cessation Outpatient Clinic were taken from hospital files of the patients. Treatment success was evaluated as one year of abstinence from smoking.

RESULTS

Participants' reported with 53% classified as high-very high nicotine dependence. Overall, 36% reported abstinence from smoking for one year or more. Treatment success was associated with higher attendance at follow-up sessions. Using pharmacologic treatments and behavioral counseling together was proved to be more effective than behavioral counseling alone.

CONCLUSIONS

One-year smoking cessation was achieved in one-third of older adults attending a smoking cessation clinic. In older adults in this sample low FTND scores, use of combined pharmacologic and behavioral treatment, and attendance at follow up sessions were associated with one year smoking abstinence.

CLINICAL IMPLICATIONS

Older adults should be referred for smoking cessation treatment. Use of combined pharmacological and behavioral counseling is recommended. Efforts to enhance attendance at follow-up sessions should be considered.

Catechol-O-Methyltransferase Effects on Smoking: A Review and Proof of Concept of Sex-Sensitive Effects

Purpose of Review

This article reviews recent research on how catechol-O-methyltransferase (COMT) may impact cigarette smoking behavior, and how effects may be sex-sensitive. Preliminary data are presented on sex-sensitive effects of COMT on response to short-term abstinence in individuals who smoke.

Recent Findings

Although research is mixed, functional variants in the COMT gene have been linked with smoking behavior, cessation outcomes and nicotine abstinence-related symptoms. Our proof-of-concept preliminary data from a human laboratory study of individuals who smoke cigarettes found that those with the high COMT enzyme activity genotype (Val/Val) reported more severe smoking urges and withdrawal symptoms following overnight abstinence than Met carriers. These effects were present in women, but not in men and were abstinent-dependent, in that they dissipated following nicotine administration.

Summary

The preliminary data showing sex-sensitive pharmacogenetic effects may shed light on mechanisms contributing to sex differences in barriers to smoking cessation or potential sex-specific treatment options.

The association between cotinine-measured smoking intensity and sleep quality

INTRODUCTION

METHODS

RESULTS

CONCLUSIONS

The relationship between poor sleep quality measured by Pittsburgh Sleep Quality Index and cigarette smoking according to sex and age

OBJECTIVES

Multiple studies have found that cigarette smokers are more likely to experience sleep disturbances than non-smokers. This study aimed to examine various associations between smoking and sleep quality according to sex and age, which have yet to be sufficiently examined in prior studies.

METHODS

Data analysis was conducted using a nationally representative sample of 224,986 Korean adults who participated in the 2018 Korea Community Health Survey. Sleep quality, as the dependent variable, was measured using the Pittsburgh Sleep Quality Index (PSQI), with PSQI scores indicating either good (≤4 points) or poor (>5 points) sleep quality. Multiple logistic regression analysis was performed considering socio-demographic factors, health behaviors, comorbidities, and psychological factors as covariates.

RESULTS

The overall weighted prevalence of poor sleep quality was 39.4% (95% confidence interval, 39.1 to 39.7). In the multivariate model that excluded psychological factors, poor sleep quality positively correlated to smoking for both sexes and all age groups except for male aged ≥65 years. However, in the full model that included psychological factors, statistically significant odds ratios (approximately 1.5) for poor sleep quality according to smoking status were only observed for female under 65 years of age.

CONCLUSIONS

The relationship between poor sleep quality and smoking status differed according to sex and age. In order to improve the quality of sleep, it is necessary to intervene smoking cessation along with solving psychological problems, especially female in middle age and younger.

Distinct influences of nicotine and sensorimotor stimuli on reducing cravings to smoke and vape among dual users

INTRODUCTION

When considering the clinical efficacy of e-cigarettes for smoking cessation, non-pharmacologic influences, such as conditioned reinforcers (e.g. sensorimotor stimuli), must be considered in addition to nicotine. The present study parsed the influences of nicotine delivery and sensorimotor stimuli (i.e, similarity to smoking) on cravings and other immediate outcomes of e-cigarette use.

METHOD

Participants (N = 127 dual users) completed an experimental ad-lib vaping session in one of 4 conditions: Drug (open label nicotine vs non-nicotine e-cigarettes) crossed with delivery apparatus (normal e-cigarette vs altered sensorimotor apparatus). It was hypothesized that participants who were deprived of the usual vaping stimuli would report less craving reduction via vaping. Nicotine was hypothesized to enhance physiological outcomes.

RESULTS

Moderate effects emerged for nicotine, whereas smaller effects were observed for the sensorimotor manipulation upon both cravings to smoke and cravings to vape. Contrary to the hypothesis, participants who vaped using the altered sensorimotor apparatus reported greater craving reduction compared to those who used normal e-cigarettes. Nicotine delivery also had moderate effects on psychological reward. Main effects were not moderated by gender, withdrawal, or dependence.

CONCLUSIONS

Findings support the role of nicotine in reducing cravings via vaping. They also suggest that sensorimotor similarities to smoking may be less important among experienced vapers or dual users. Indeed, in this sample, the altered sensorimotor apparatus may have reduced craving via distraction or other mechanisms.

Tobacco consumption trends and correlates of successful cessation in Indian females: Findings of Global Adult Tobacco Surveys

BACKGROUND

Female gender is being affected disproportionately by tobacco use. The correlates of tobacco use among women are different from men, which has not been studied in India. To develop gender-sensitive interventions and policies in tobacco control, it's essential to ascertain the factors that affect tobacco consumption and successful cessation among Indian women.

METHODS

This secondary data analysis was done for females respondents aged >15 years using the data generated from the GATS-1 (2009-2010) and GATS-II (2016-2017). The primary dependent variables included interest in quitting smoking/SLT, attempt to quit smoking/SLT, successful quitting. The independent variables were broadly categorized as a community, household, and individual level. Simple descriptive analysis using % age relative change was used to calculate the change in tobacco consumption between two rounds of GATS, whereas; bivariate and multivariable logistic regression were used to calculate the unadjusted and adjusted odds ratio for cessation related variables (GATS-2).

RESULTS

There was a 29.5% relative reduction in the prevalence of tobacco use in round-2 among females. A maximum reduction in the prevalence was observed in the 15-29 years (-51.3%), those not exposed the media advertisements (-19.9%). While unadjusted OR depicted that unmarried women, young age, asked by health workers about tobacco use, and advice given by them increased the interest in quitting smoking, none of them emerged to be significant on a multivariable logistic regression except the advice given by the health care provider. Successful cessation (>6 months) of SLT products is possible in urban areas, with decreased exposure to media advertisements.

CONCLUSION

There is an urgent need for gender-sensitive policies in tobacco control and the integration of these policies with relevant national health programs. This shall help to synergize efforts and obtain better outcomes that would support the overarching goal of tobacco-free India.

The Time Course of Compensatory Puffing With an Electronic Cigarette: Secondary Analysis of Real-World Puffing Data With High and Low Nicotine Concentration Under Fixed and Adjustable Power Settings

INTRODUCTION

In a secondary analysis of our published data demonstrating compensatory vaping behavior (increased puff number, puff duration, and device power) with e-cigarettes refilled with low versus high nicotine concentration e-liquid, here we examine 5-day time course over which compensatory behavior occurs under fixed and adjustable power settings.

AIMS AND METHODS

Nineteen experienced vapers (37.90 ± 10.66 years, eight females) vaped ad libitum for 5 consecutive days under four counterbalanced conditions (ie, 20 days in total): (1) low nicotine (6 mg/mL)/fixed power (4.0 V/10 W); (2) low nicotine/adjustable power; (3) high nicotine (18 mg/mL)/fixed power; (4) high nicotine/adjustable power (at 1.6 Ohm). Puff number, puff duration, and power settings were recorded by the device. For each day, total daily puffing time was calculated by multiplying daily puff number by mean daily puff duration.

RESULTS

A significant day × setting interaction revealed that whilst puffing compensation (daily puffing time) continued to increase over 5 days under fixed power, it remained stable when power settings were adjustable. Separate analysis for puff number and puff duration suggested that the puffing compensatory behavior was largely maintained via longer puff duration.

CONCLUSIONS

Under fixed power conditions (4.0 V/10 W), vapers appear to compensate for poor nicotine delivery by taking longer puffs and this compensatory puffing appears to be maintained over time.

IMPLICATIONS

Studies in smokers suggest that when switching to lower nicotine levels, compensation for poorer nicotine delivery is transient. Our novel findings suggest that vapers show a different pattern of compensation which is influenced by both nicotine strength and device power settings. When power is fixed (4.0 V; 10 W), compensation (via more intensive puffing) appears prolonged, persisting up to 5 days. Under adjustable settings when power is increased, puffing patterns remain stable over time. Implications of such compensatory behaviors for product safety and user satisfaction need further exploration.

Tobacco smoke exposure and sleep: estimating the association of urinary cotinine with sleep quality

INTRODUCTION

A majority of studies on tobacco smoke exposure and sleep quality have relied on self-reported smoking, resulting in potential exposure misclassification and biases related to self-report. The objective of this study was to investigate associations between urinary cotinine, a biological marker of tobacco smoke exposure, and sleep quality measures, including sleep duration, sleep continuity or efficiency, sleep satisfaction and alertness during normal waking hours.

METHODS

Using data on a national sample of 10 806 adults (aged 18-79 years) from the Canadian Health Measures Survey (2007-2013), we performed binary logistic regression analyses to estimate associations between urinary cotinine concentrations and sleep quality measures, while controlling for potential confounders. Additionally, we performed ordinal logistic regression to assess the association between urinary cotinine concentrations and increased number of sleep problems.

RESULTS

Overall, 28.7% of adult Canadian survey respondents had urinary cotinine concentrations above the limit of detection (LOD), nd the prevalence of each sleep problem ranged from 5.5% to 35.6%. Elevated urinary cotinine concentrations (quartile 4 vs. <LOD) were associated with significantly higher odds of short or long sleep duration (OR = 1.41; 95% CI: 1.02-1.95; p-trend = .021), trouble falling or staying asleep (OR = 1.71; 95% CI: 1.28-2.27; p-trend = .003), sleep dissatisfaction (OR = 1.87; 95% CI: 1.21-2.89; p-trend = .011), and increased number of sleep problems (OR = 1.64; 95% CI: 1.19-2.26; p-trend = .001). Stronger associations were observed among females compared to males.

CONCLUSION

Using a biological marker of tobacco smoke exposure, our study contributes to the body of literature of toxic environmental exposures on sleep quality by supporting an association between tobacco smoke exposure and poorer sleep quality. To address the limitations of a cross-sectional study design and to better assess the temporality of tobacco smoke exposure and sleep quality, longitudinal studies are recommended.

Prevalence and behavior regarding cigarette and water pipe smoking among Syrian undergraduates

BACKGROUND

The devastating Syrian crisis has raised concern regarding the social acceptance of smoking especially with water pipe use becoming a growing epidemic. We aim to determine the prevalence of cigarette and water pipe smoking among university students, along with identifying the addictive behavior among university students.

METHODS

A cross-sectional study was conducted at the Syrian Private University during World No-Tobacco Day, in Damascus, Syria during the war crisis. The survey consists of 4 sections: socio-demographic information, Fagerström Test of Nicotine Dependence, attitude towards water pipes, and perspective about smoking. Data were analyzed using the Statistical Package for Sciences version 25.0 (SPSS Inc., United States.).

RESULTS

Of the 622 participants, 429 (69%) were males with a mean age of 21.3 ± 3.1 years. The prevalence of tobacco smoking was 320 (51.4%), 208 (23.8%) for cigarettes, and 112 (18.0%) for water pipe. Smoking was significantly higher among male non-medical university students. The majority were low to moderate dependent when assessed by the Fagerström Test of Nicotine Dependence.

CONCLUSIONS

This study showed a very high prevalence of smoking indicating the need for smoking cessation programs, access to effective quitting treatments, and mass media campaigns to diminish smoking among the youth.

Determining nicotine-related behavior changes in juvenile female rats through long-term maternal nicotine exposure

Nicotine replacement therapy (NRT) has been developed as a drug therapy for smoking cessation and has been considered a safe alternative to smoking during pregnancy. However, the effects of long-term nicotine exposure via NRT on the fetus are still being debated. Here, we determined the effects of long-term maternal nicotine exposure in gestation and lactation on nicotine-related behavior and drug vulnerability in dams and offspring rats. To expose long-term nicotine, on gestation day 14, pregnant rats were implanted with osmotic minipumps releasing nicotine tartrate (6 mg/kg/day, subcutaneously, equivalent to 2 mg nicotine-freebase) for 28 days. The concentration of cotinine in blood was 373.0 ± 109.0 ng/ml in dams and 12.50 ± 1.19 ng/ml in offspring rats. In dams, we found no significant differences in anxiety-like behaviors and various maternal behaviors such as touching, sniffing, pup licking, laying on pups, and retrieval between saline- and nicotine-exposed groups. Adolescent offspring female rats showed no significant differences in anxiety-like behavior and forced alcohol consumption between saline- and nicotine-exposed groups. Nicotine-exposed offspring rats showed more increased nicotine aversion than saline-exposed groups, but the effect was disturbed in the forced alcohol consumption condition on the first day of the nicotine consumption test. Taken together, these results suggest that, in the last gestation and lactation period corresponding to the second and third trimester of human pregnancy, long-term maternal nicotine exposure has a minor effect on dam and female offspring health and does not involve serious pathological changes in rat offspring, despite the presence of nicotine in their blood.

Caudate reactivity to smoking cues is associated with increased responding to monetary reward in nicotine-dependent individuals

Quitting smoking is challenging in part because environmental smoking cues can trigger the desire to smoke. Neurobiological responses to smoking cues are often observed in reward-related brain regions such as the caudate and nucleus accumbens (NAc). While reward plays a well-established role in the formation of cue reactivity, whether general reward responsiveness contributes to individual differences in cue-reactivity among chronic smokers is unclear; establishing such link could provide insight into the mechanisms maintaining cue reactivity. The current study explored this relationship by assessing smoking cue reactivity during functional magnetic imaging followed by an out-of-scanner probabilistic reward task (PRT) in 24 nicotine-dependent smokers (14 women). In addition, owing to sex differences in cue reactivity and reward function, this same relationship was examined as a function of sex. Following recent smoking, greater reward responsiveness on the PRT was associated with enhanced left caudate reactivity to smoking cues. No relationship was found in any other striatal subregion. The positive relationship between reward responsiveness and caudate smoking cue reactivity was significant only in male smokers, fitting with the idea that males and females respond to the reinforcing elements of smoking cues differently. These findings are clinically relevant as they show that, following recent smoking, nicotine-dependent individuals who are more cue reactive are also more likely to be responsive to non-drug rewards, which may be useful for making individualized treatment decisions that involve behavioral reward contingencies.

Altered subcallosal and posterior cingulate cortex-based functional connectivity during smoking cue and mental simulation processing in smokers

BACKGROUND

Long-term cigarette smoking induces sensitization of incentive salience and conditioning of contextual cues which involves brain function alteration across multiple regions. Understanding how nicotine affects hub-based functional connectivities involved in affective and cognitive function can help us determine the treatment strategy for nicotine dependence.

METHOD

Functional MRI was conducted on 30 smokers and 30 non-smokers while mentally simulating neutral and smoking hand movements. Smoking cue and mental simulation processing-related changes in functional connectivity strengths of the subcallosal and posterior cingulate cortex (SCC and PCC) with major brain network nodes were examined.

RESULTS

Compared to non-smokers, smokers showed cue-induced SCC functional connectivities which were enhanced with the intraparietal sulcus and reduced with the medial prefrontal cortex. The PCC activation and functional connectivity enhancements with the anterior insula cortex and rostro-lateral prefrontal cortex was found during smoking mental simulation. The PCC-lateral prefrontal cortex functional connectivity correlated with nicotine dependence severity.

CONCLUSION

The present results demonstrate that smokers can be identified by cue-induced SCC functional connectivity strength decline and increment in the default mode and dorsal attention network nodes. However, nicotine dependence was associated with smoking mental simulation-related PCC-lateral prefrontal cortex functional connectivity strength, suggesting that the development of nicotine dependence may depend on the strength of coupling between the default mode network and the central executive network at the cognitive level.

The influence of gender and oxytocin on stress reactivity, cigarette craving, and smoking in a randomized, placebo-controlled laboratory relapse paradigm

RATIONALE

Female cigarette smokers tend to show greater cessation failure compared with males. Variables that contribute to the maintenance of smoking, including stress and craving, may differentially impact male and female smokers. Novel pharmacotherapies, such as oxytocin, may attenuate stress reactivity and craving in smokers, but work in this area is limited.

OBJECTIVES

This study assessed the influence of gender and oxytocin on stress reactivity, craving, and smoking in a randomized, placebo-controlled laboratory relapse paradigm.

METHODS

Male and female adult cigarette smokers (ages 18-45) were enrolled (women oversampled 2:1) and completed a laboratory session, in which intranasal oxytocin or placebo was administered followed by a laboratory social stress task. The role of gender and oxytocin were assessed on measures of stress reactivity, cigarette craving, latency to smoke in a resistance task, subjective responses to smoking, and ad-libitum smoking.

RESULTS

Participants (N = 144) had a mean age of 31 were 63% female and 56% White. Following stress induction, female smokers evidenced greater subjective stress than males, though males demonstrated greater neuroendocrine reactivity and smoking intensity than females. No gender differences were demonstrated for craving. Oxytocin did not attenuate any aspect of stress reactivity, craving, smoking, or subjective responses to smoking compared with placebo.

CONCLUSIONS

Gender differences in stress reactivity were shown in the hypothesized direction, but oxytocin appeared to exert little impact on subjective or behavioral metrics. Results highlight the complex relationship between gender, stress, and smoking, as well as the implications for oxytocin as a potential pharmacotherapy for smoking cessation.

Clinical Correlates of Smoking Status in Men and Women with Opioid Use Disorder

Background: Smoking is highly prevalent in people with opioid use disorder (OUD) and is a significant contributor to morbidity and mortality in this population. However, little is known about the differences between those with OUD who do and do not smoke cigarettes. Objectives: Our aim was to investigate differences between treatment-seeking adults with OUD who did and did not smoke. Methods: Participants (N = 568; 30% female) completed a battery of self-report questionnaires including measures of current smoking status and number of cigarettes smoked per day as well as measures of clinical characteristics (e.g. craving, anxiety). Results: Of the total sample, 77% were current smokers. Multivariable logistic regression identified heroin use (OR = 2.20, 95% CI = 1.38, 3.53) and younger age (OR = 0.97, 95% CI = 0.95, 0.997) as strong correlates of smoking status; other characteristics were not significant. Older age and opioid craving were associated with more cigarettes smoked per day. Notably, these patterns differed for males and females; opioid craving (B = 0.62, SE_B = 0.24) was associated with the number of cigarettes smoked among men, and anxiety (B = 0.39, SE_B = 0.19) was associated with the number of cigarettes smoked among women. Conclusion: Adults with OUD who used heroin in the past month were more likely to be current smokers. No sex differences were observed in likelihood of smoking; however, the predictors of smoking status and severity differed between men and women.

Comparing the reward value of cigarettes and food during tobacco abstinence and nonabstinence

BACKGROUND

Some addiction theories propose that nicotine dependence is characterized by an imbalance between motivation for cigarettes compared to non-drug rewards. This imbalance may become increasingly polarized during abstinence, which further potentiates smoking. The present study evaluated motivation for cigarettes and food during abstinence and nonabstinence in daily smokers. This study modified a previously validated cue-reactivity procedure to include food as a cue condition, thereby allowing the comparison of cigarettes to food and neutral cues. The Choice Behavior Under Cued Conditions (CBUCC) procedure, in which participants are presented with cues and spend money in order to gain immediate access to that cue, generates multiple variables to evaluate motivational factors and drug use behaviors including reward value, craving, seeking, choice time, and consumption.

METHODS

Fifty daily cigarette smokers underwent two CBUCC sessions under overnight abstinent and nonabstinent conditions.

RESULTS

As an index of reward value, participants spent more money to access cigarettes than food or water and more for food relative to water. Abstinence increased the reward value of cigarettes but did not significantly affect the reward value of food or water. Participants also demonstrated cue-specific craving for cigarettes and food, although overall cigarette craving was greater than food craving.

CONCLUSIONS

This study indicated that motivation was greater for cigarettes than food. Abstinence increased motivation for cigarettes but had little impact on motivation for food. This suggests that heavy smokers do not reallocate motivational resources towards cigarettes during abstinence; rather, motivational processes for food remain constant from nonabstinent to abstinent sessions.

Associations of CYP2A6 Gene Polymorphism with Smoking Status Among Jordanians: Gender-Related Differences

BACKGROUND

Cytochrome P450 2A6 enzyme (CYP2A6), an essential hepatic enzyme involved in the metabolism of drugs, is responsible for a major metabolic pathway of nicotine. Variation in the activity of polymorphic CYP2A6 alleles has been implicated in inter-individual differences in nicotine metabolism.

AIMS

The objective of the current study was to assess the association between the smoking status and the cytochrome P450 2A6 enzyme (CYP2A6) genotype in Jordanians.

METHODS

In the current study, 218 (117 Male and 101 female) healthy unrelated Jordanian volunteers were recruited. CYP2A6*1B, CYP2A6*4 and CYP2A6*9 were determined and correlated with subject smoking status.

RESULTS

*1A/*1A was the most common genetic polymorphism in the overall study population, with no significant frequency differences between smokers and non-smokers. When the population was divided according to gender, only male smokers showed a significant correlation between genotype and smoking status. Considering the CYP2A6*9 genotype, the results showed differences in distribution between smokers and non-smokers, but only women showed a significant association between CYP2A6*9 allele genotype and smoking status.

CONCLUSION

The results of this study show that there is a significant association between CYP2A6*9 genotype and smoking status. They also show that CYP2A6 genotype is significantly influenced by gender.

Sex differences in the effect of acute administration of nicotine on MRS-measured metabolic profile of the rat brain

Women are less able to stop smoking than men. Elucidation of sex differences in the tobacco addiction could facilitate personalized treatment. Specialized brain reward systems are controlling the behavior through reinforcement using specific neuromediators. Using non-invasive magnetic resonance spectroscopy (MRS) to ascertain addiction/harm biomarkers could lead to better management of public health through advancements in regulatory and translational research. Proton MRS was used to monitor changes of specific neurometabolites in hippocampus (HC), nucleus accumbens (NAC), and anterior cingulate cortex (ACC) of rats of both sexes after single intraperitoneal injection of nicotine. At the baseline, male rats showed higher level of GABA, taurine, N-acetyl aspartate, and creatine in HC, and taurine in NAC. Also, there were stronger correlations between neurometabolites in females than in males at the baseline. Nicotine administration changed taurine, GABA, myo-inositol, choline, and N-acetyl aspartate in HC, and taurine in NAC. Significant interactions between time, treatment, and sex were detected for taurine and choline in HC. The number of inter-metabolite correlations increased significantly in ACC and decreased in NAC and HC in females after nicotine administration, while in males it was unchanged. There are distinct sex differences in neurometabolic profiles at the baseline and after acute nicotine administration. Nicotine changes inter-metabolite correlations in females more than in males.

Quitting starts in the brain: a randomized controlled trial of app-based mindfulness shows decreases in neural responses to smoking cues that predict reductions in smoking

Current treatments for smoking yield suboptimal outcomes, partly because of an inability to reduce cue-induced smoking. Mindfulness training (MT) has shown preliminary efficacy for smoking cessation, yet its neurobiological target remains unknown. Our prior work with nonsmokers indicates that MT reduces posterior cingulate cortex (PCC) activity. In individuals who smoke, the PCC, consistently a main hub of the "default mode network," activates in response to smoking cues. In this randomized controlled trial, we tested the effects of app-delivered MT on PCC reactivity to smoking cues and whether individual differences in MT-mediated PCC changes predicted smoking outcomes. Smoking cue-induced PCC reactivity was measured using functional magnetic resonance imaging at baseline and 1 month after receiving smartphone app-based MT (n = 33) vs. an active control (National Cancer Institute's QuitGuide, n = 34). Whether individual differences in treatment-related changes in PCC activity predicted smoking behavior was assessed. The MT group demonstrated a significant correlation between a reduction in PCC reactivity to smoking cues and a decline in cigarette consumption (r = 0.39, p = 0.02). No association was found in the control group (r = 0.08, p = 0.65). No effects of group alone were found in PCC or cigarette reduction. Post hoc analysis revealed this association is sex specific (women, r = 0.49, p = 0.03; men: r = -0.08, p = 0.79). This initial report indicates that MT specifically reduces smoking cue-induced PCC activity in a subject-specific manner, and the reduction in PCC activity predicts a concurrent decline in smoking. These findings link the hypothesized behavioral effects of MT for smoking to neural mechanisms particularly in women. This lays the groundwork for identifying individuals who may benefit from targeted digital therapeutic treatments such as smartphone-based MT, yielding improved clinical outcomes.

Evaluation of Nicotine Pharmacokinetics and Subjective Effects following Use of a Novel Nicotine Delivery System

Introduction

Novel nicotine delivery systems represent an evolving part of the tobacco harm reduction strategy. The pharmacokinetic (PK) profile of nicotine delivered by P3L, a pulmonary nicotine delivery system, and its effects on smoking urges and craving relief in relation to Nicorette inhalator were evaluated.

Methods

This open-label, ascending nicotine levels study was conducted in 16 healthy smokers. Three different nicotine delivery levels, 50, 80, and 150 µg/puff, delivered by the P3L system were evaluated consecutively on different days after the use of the Nicorette inhalator. Venous nicotine PK, subjective effects, and tolerability were assessed.

Results

Geometric least-squares means for maximum plasma nicotine concentration (C_max), generated by the mixed-effect model for exposure comparison, were 9.7, 11.2, and 9.8 ng/mL for the 50, 80, and 150 µg/puff P3L variants, respectively, compared to 6.1 ng/mL after Nicorette inhalator use. Median time from product use start to C_max was 7.0 minutes for all P3L, compared to 30.0 minutes for the Nicorette inhalator. Craving reduction was slightly faster than with the Nicorette inhalator as assessed with the visual analog scale craving score. The mean Questionnaire of Smoking Urges -brief total scores did not differ for both products. P3L was well tolerated.

Conclusions

At all three nicotine levels tested, the inhalation of the nicotine lactate aerosol delivered with the P3L provided plasma nicotine concentrations higher and faster compared to the Nicorette inhalator. The plasma nicotine concentration–time profile supports a pulmonary route of absorption for P3L compared to the oromucosal absorption of the Nicorette inhalator.

Implications

The combination of nicotine and lactic acid with the P3L device shows potential over existing nicotine delivery systems by delivering nicotine with kinetics close to published data on conventional cigarettes and without exogenous carrier substances as used in current electronic nicotine delivery systems. Altogether, the PK profile, subjective effects, and safety profile obtained in this study suggest P3L is an innovative nicotine delivery product that will be acceptable to adult smokers as an alternative to cigarettes.

A Pilot Study of E-Cigarette Naïve Cigarette Smokers and the Effects on Craving After Acute Exposure to E-Cigarettes in the Laboratory

BACKGROUND AND OBJECTIVES

Recent surveys confirm continued increases in the use of electronic-cigarettes (e-cigarettes) in adolescents and adults. Users often state that e-cigarettes reduce tobacco craving and withdrawal symptoms in addition to their smoking. Data from laboratory studies and clinical trials have confirmed these statements, though there are inconsistencies in the outcomes. In this pilot study, we set out to evaluate the effects of e-cigarettes, as compared to the participants' own cigarettes, on baseline craving and smoking severity.

METHODS

Using a within-subjects, placebo-controlled study design, 15 tobacco-dependent, e-cigarette naïve participants sustained abstinence overnight. They completed distinct phases of this protocol during four separate study sessions. Participants were randomized to an e-cigarette device containing one of three doses of nicotine (0, 18, or 36 mg/ml) or their own cigarette. Each study visit was ~3 hours long and separated by at least 7 days. Visits included assessments of craving and smoking severity.

RESULTS

The data showed that after 10 puffs in both the Own cigarette and e-cigarette conditions, breath carbon monoxide levels increased significantly in the former but not the latter. Questionnaire of Smoking Urges and Choices to Smoke scores were not statistically different across groups after two distinct bouts of 10 puffs each. Additionally, E-cigarette Perceptions Questionnaire responses were not significantly different according to dose.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

This experiment provides data demonstrating that e-cigarettes did not reduce craving or smoking severity in e-cigarette naïve users. However, since this was a pilot study, the conclusions that can be drawn are limited. (Am J Addict 2019;28:361-366).

Randomized Trial of Nicotine Inhaler for Pregnant Smokers

Background

Smoking during pregnancy is a serious public health problem in need of better treatments. Nicotine replacement treatment (NRT) (patch or gum) has not been shown in randomized placebo-controlled trials to be efficacious for smoking cessation during pregnancy. However, the nicotine inhaler may have advantages over other NRTs as it replicates some of the sensory effects of smoking.

Objective

The purpose of the study was examine the efficacy and safety of the nicotine inhaler for smoking cessation during pregnancy. We hypothesized that the nicotine inhaler compared to placebo would increase quit rates and reduce smoking during treatment and at the end of pregnancy, result in a higher birth weight and gestational age in the offspring, and reduce the incidence of preterm birth and low birth weight infants.

Study Design

We conducted a randomized, double-blind, placebo-controlled trial of the nicotine inhaler for smoking cessation during pregnancy. Pregnant women who smoked ≥5 cigarettes daily received behavioral counseling and random assignment to a 6-week treatment with nicotine or placebo inhaler, followed by a 6-week taper period. Throughout treatment, we assessed tobacco exposure biomarkers, cessation rates, and adverse events. We also obtained information on birth outcomes. The primary outcome was smoking cessation at 32-34 weeks gestation; secondary outcomes were smoking reduction, birth weight and gestational age, and the incidence of preterm birth or low birth weight infants. We compared treatment groups on these measures using t-tests, Fisher's exact tests, and multivariate linear and logistic regression.

Results

Participants in the placebo (n=67) and nicotine (n=70) groups were comparable on baseline characteristics, though women in the placebo group reported a higher motivation to quit (p=0.016). Biochemically-validated smoking cessation rates were similar with nicotine and placebo (after 6 weeks of treatment: 4% (3/70) vs. 3% (2/67), respectively, p< 0.99, and at 32-34 weeks gestation: 10% (7/70) vs. 18% (12/67), respectively, p=0.220). Cigarettes per day (CPD) decreased over time in both groups (p< 0.001), with the nicotine inhaler group having a greater decrease than the placebo group two (p=0.022) and six weeks after the quit date (p=0.042), but not at 32-34 weeks gestation (p=0.108). Serum cotinine levels, birth weight, gestational age and reductions in carbon monoxide did not differ by group. However, the incidence of preterm delivery was higher in the placebo than the nicotine group: 15% (10/67) vs. 4% (3/67), respectively, p=0.030). The incidence of delivering a low birth weight infant was also higher in the placebo than the nicotine group: 15% (10/67) vs. 6% (4/67), respectively, p=0.035, but not after adjusting for preterm delivery p=0.268.

Conclusions

Although the nicotine inhaler group did not have a higher quit rate during pregnancy than the placebo group, the outcome of preterm delivery occurred less frequently in the nicotine group.

Effects of Nicotine Metabolic Rate on Withdrawal Symptoms and Response to Cigarette Smoking After Abstinence

This study investigated the influence of the rate of nicotine metabolism, as indicated by the nicotine metabolite ratio (NMR), on tobacco dependence. We stratified 136 smokers on the basis of saliva NMR as fast (n = 65) and slow (n = 71) metabolizers. Two "loading cigarettes" were smoked after overnight, and a "reward cigarette" was smoked after 6 hours of daytime, abstinence. Blood nicotine concentrations, expired carbon monoxide, withdrawal/craving, and reward questionnaires were collected before/after smoking and during daytime abstinence. Compared with slow metabolizers, fast metabolizers had a shorter nicotine elimination half-life (P < 0.001), lower plasma nicotine concentrations (P < 0.001), and higher withdrawal/craving scores (P < 0.05) for most times during daytime abstinence, indicating that fast metabolizers are likely smoking more to relieve withdrawal symptoms (negative reinforcement). Reward/satisfaction scores were similar in fast and slow metabolizers, suggesting that faster nicotine metabolism, assessed by NMR, is not associated with greater positive reinforcement. CYP2A6 normal (n = 82) and reduced (n = 42) genotype predicted plasma nicotine concentrations but not withdrawal symptoms.

Sex Differences in Subjective Responses To Moderate Versus Very Low Nicotine Content Cigarettes

Introduction

Men and women may be differentially sensitive to the acute perceptual responses to smoking cigarettes that vary in nicotine content ("dose") but are matched on non-nicotine constituents.

Methods

Dependent adult smokers (43 M, 31 F) took four controlled puffs from Spectrum research cigarettes that were moderate (16-17 mg/g) or very low (0.4 mg/g) in nicotine content, and matched on "tar." To ensure reliable responses, each cigarette was administered singly five times in random order under blind conditions, with one or the other provided every 15 minutes over a 2.5-hour session following overnight abstinence. Subjective perceptions (eg, "satisfying", "how much nicotine") were rated after each cigarette.

Results

Subjective ratings differed due to cigarette nicotine content, as expected, and did so differentially between men and women. The interaction of nicotine content by sex was significant for most rated subjective perceptions of the cigarette, as multivariate analyses showed that differences due to nicotine content were highly significant for men (p < .001) but only marginal for women (p = .08).

Conclusions

Relative to men, women's subjective responses to acute smoking are less sensitive to differences in cigarette nicotine content. To our knowledge, this is the first comparison of sex differences in response to very carefully controlled doses of smoked nicotine per se. Further research should examine possible sex differences in nicotine dosing administered by other smoked and nonsmoked methods, as well as the developmental pattern of these differences during onset and during cessation of dependent smoking.

Implications

Subjective perceptions of smoking cigarettes varying in nicotine contents differ between men and women. These results with research cigarettes are similar to other studies with carefully dosed nicotine administration by other means, supporting the notion that women, relative to men, are less sensitive to pharmacological factors and more sensitive to nonpharmacological factors in acute cigarette smoking. Future studies are warranted to examine sex differences in other responses to controlled nicotine intake via smoking, and via other smoked and nonsmoked methods of administering nicotine doses.

Sex/Gender Differences in Cotinine Levels Among Daily Smokers in the Pennsylvania Adult Smoking Study

BACKGROUND

This study was conducted to determine sex/gender differences in smoke exposure and to quantify the role of potential predictors including puffing behaviors, nicotine dependence, and non-nicotinic factors.

METHODS

The Pennsylvania Adult Smoking Study (PASS) of 332 adult cigarette smokers utilized portable handheld topography devices to capture the smokers' profiles in a naturalistic environment. Sex/gender differences in salivary biomarkers were modeled using ANCOVA to account for measures of dependence (Fagerstrom Test for Nicotine Dependence, nicotine metabolite ratio [3-hydroxycotinine/cotinine]), and nondependence covariates including anthropomorphic factors and stress. The Blinder-Oaxaca method was used to decompose the sex/gender differences in nicotine uptake due to covariates.

RESULTS

Men had significantly higher cotinine levels (313.5 ng/mL vs. 255.8 ng/mL, p < 0.01), cotinine +3-hydroxycotinine levels, (0.0787 mol/L vs. 0.0675 mol/L, p = 0.01), puff volumes (52.95 mL vs. 44.77 mL, p < 0.01), and a lower nicotine metabolite ratio (0.396 vs. 0.475, p = 0.01) than women. The mean Fagerström Test for Nicotine Dependence score did not differ between men and women (p = 0.24). Women had a higher mean Hooked on Tobacco Checklist score than men (7.64 vs. 6.87, p < 0.01). In multivariate analysis, nicotine metabolite levels were not significantly different by sex. Decomposition results show that ten predictors can explain 83% of the sex/gender differences in cotinine uptake. Height was the greatest contributor to these differences, followed by average puff volume. Conclusion and Impact: The higher levels of nicotine metabolites in men, compared to women, can be explained by height, weight, puff volume, and nicotine metabolism.

Genetic Variation of the Mu Opioid Receptor (OPRM1) and Dopamine D2 Receptor (DRD2) is Related to Smoking Differences in Patients with Schizophrenia but not Bipolar Disorder

It is not known why mentally ill persons smoke excessively. Inasmuch as endogenous opioid and dopaminergic systems are involved in smoking reinforcement, it is important to study mu opioid receptor (OPRM1) A118G (rs1799971), dopamine D2 receptor (DRD2) Taq1A (rs1800497) genotypes, and sex differences among patients with schizophrenia or bipolar disorder. Smokers and nonsmokers with schizophrenia (n=177) and bipolar disorder (n=113) were recruited and genotyped. They were classified into three groups: current smoker, former smoker, and never smoker by tobacco smoking status self-report. The number of cigarettes smoked per day was used as the major tobacco smoking parameter. In patients with schizophrenia, tobacco smoking prevalence was greater in males than in females as expected, but women had greater daily cigarette consumption (p<0.01). Subjects with schizophrenia who had the OPRM1 *G genotype smoked more cigarettes per day than the AA allele carriers with schizophrenia (p<0.05). DRD2 Taq1A genotype differences had no effect on the number of cigarettes smoked per day. However, female smokers with schizophrenia who were GG homozygous of the DRD2 receptor smoked more than the *A male smokers with schizophrenia (p<0.05). In bipolar patients, there were no OPRM1 and DRD2 Taq1A genotype differences in smoking status. There also were no sex differences for smoking behavior among the bipolar patients. The results of this study indicate that single nucleotide polymorphism (SNP) of the less functional mu opioid receptor increases tobacco smoking in patients with schizophrenia. Alteration of DRD2 receptor function also increased smoking behavior in females with schizophrenia.

High-fat diet meal patterns during and after continuous nicotine treatment in male rats

Smoking to control body weight is an obstacle to smoking cessation, particularly in western cultures where diets are often rich in calories derived from fat sources. The purpose of this study was to investigate the effects of continuous nicotine administration on meal patterns in rats fed a high-fat diet. Male rats were housed in cages designed to continuously monitor food intake and implanted with minipumps to deliver approximately 1.00 mg/kg/day of nicotine or saline. Meal patterns and body weights were assessed for 2 weeks of treatment and 1 week posttreatment. When compared with controls, rats with continuous nicotine treatment exhibited a decrease in the average meal duration(s) during the first week of treatment and a modest, yet sustained reduction in daily number of meals over the 14-day treatment period. Nicotine-induced decreases in body weight gain were observed throughout the 2 weeks of treatment. No differences in meal patterns or body weight gain were seen for 1 week following cessation of treatment. Results from this study suggest that while continuous nicotine treatment decreases daily food intake, meal durations, meal numbers, and weight gain, cessation of this treatment does not result in significant compensatory increases. Understanding the effects of nicotine on feeding patterns and weight gain may allow for improvements in treatment protocols aimed at addressing the factors that contribute to tobacco use. (PsycINFO Database Record

Adolescent Rats Self-Administer Less Nicotine Than Adults at Low Doses

INTRODUCTION

Although nearly 90% of current smokers initiated tobacco use during adolescence, little is known about reinforcement by nicotine in adolescents. Researchers are currently investigating whether a potential public health policy setting a tobacco product standard with very low nicotine levels would improve public health, and it is essential to understand whether data generated in adults translates to adolescents, particularly as it relates to the threshold dose of nicotine required to support smoking. The present study compared self-administration of low doses of nicotine between adolescent and adult rats.

METHODS

Adolescent (postnatal day [P] 30) and adult (P90) male and female rats were allowed to nosepoke to receive intravenous infusions of nicotine (3-100 μg/kg/infusion) during 16 daily 1-hour sessions.

RESULTS

At 10 μg/kg/infusion nicotine, adolescent rats earned significantly fewer infusions than adults. When responding for 30 μg/kg/infusion nicotine, rats of both ages earned a similar number of infusions; however, there were subtle differences in the distribution of infusions across the 1-hour session. No sex differences were apparent in either age group at any dose.

CONCLUSIONS

These results demonstrate that adolescent rats are less sensitive than adults to the primary reinforcing effects of nicotine. However, at nicotine doses that support self-administration in both age groups, adolescent and adult rats do not differ in acquisition or number of infusions earned. These results suggest that reducing nicotine levels in cigarettes to a level that does not support smoking in adults may be sufficient to reduce the acquisition of smoking in adolescents.

IMPLICATIONS

The results of the present studies demonstrate that adolescent rats are less sensitive than adults to the primary reinforcing effects of nicotine. These results suggest that reducing nicotine levels in cigarettes to a level that does not support smoking in adults will be sufficient to reduce the acquisition of smoking in adolescents.

Does Extended Pre Quit Bupropion Aid in Extinguishing Smoking Behavior?

INTRODUCTION

Understanding the mechanisms by which bupropion promotes smoking cessation may lead to more effective treatment. To the extent that reduced smoking reinforcement is one such mechanism, a longer duration of pre quit bupropion treatment should promote extinction of smoking behavior. We evaluated whether 4 weeks of pre quit bupropion (extended run-in) results in greater pre quit reductions in smoking rate and cotinine and, secondarily, greater short-term abstinence, than standard 1 week of pre quit bupropion (standard run-in).

METHODS

Adult smokers (n = 95; 48 females) were randomized to a standard run-in group (n = 48; 3-week placebo, then 1-week bupropion pre quit) or an extended run-in group (4-week pre quit bupropion; n = 47). Both groups received group behavioral counseling and 7 weeks of post quit bupropion. Smoking rate (and craving, withdrawal, and subjective effects) was collected daily during the pre quit period; biochemical data (cotinine and carbon monoxide) were collected at study visits.

RESULTS

During the pre quit period, the extended run-in group exhibited a greater decrease in smoking rate, compared to the standard run-in group, interaction p = .03. Cigarette craving and salivary cotinine followed a similar pattern, though the latter was evident only among women. Biochemically verified 4-week continuous abstinence rates were higher in the extended run-in group (53%) than the standard run-in group (31%), p = .033.

CONCLUSIONS

The extended use of bupropion prior to a quit attempt reduces smoking behavior during the pre quit period and improved short-term abstinence rates. The data are consistent with an extinction-of-reinforcement model and support further investigation of extended run-in bupropion therapy for smoking cessation.

Commonly used stimulants: Sleep problems, dependence and psychological distress

BACKGROUND

Caffeine and nicotine are commonly used stimulants that enhance alertness and mood. Discontinuation of both stimulants is associated with withdrawal symptoms including sleep and mood disturbances, which may differ in males and females. The present study examines changes in sleep quality, daytime sleepiness and psychological distress associated with use and dependence on caffeine and nicotine.

METHODS

An online survey comprising validated tools to assess sleep quality, excessive daytime sleepiness and psychological distress was completed by 166 participants (74 males, 96 females) with a mean age of 28 years. Participants completed the study in their own time, and were not offered any inducements to participate.

RESULTS

Sleep quality was poorer in those dependent upon caffeine or nicotine, and there were also significant interaction effects with gender whereby females reported poorer sleep despite males reporting higher use of both stimulants. Caffeine dependence was associated with poorer sleep quality, increased daytime dysfunction, and increased levels of night time disturbance, while nicotine dependence was associated with poorer sleep quality and increased use of sleep medication and sleep disturbances. There were strong links between poor sleep and diminished affect, with psychological distress found to co-occur in the context of disturbed sleep.

CONCLUSIONS

Stimulants are widely used to promote vigilance and mood; however, dependence on commonly used drugs including caffeine and nicotine is associated with decrements in sleep quality and increased psychological distress, which may be compounded in female dependent users.

Sex differences in acute relief of abstinence-induced withdrawal and negative affect due to nicotine content in cigarettes

INTRODUCTION

Acute cigarette smoking may relieve withdrawal and negative affect due to tobacco abstinence to a greater extent in women versus men. Yet, the relative contribution of the cigarette's nicotine content to this sex difference is not clear.

METHODS

Non-quitting dependent adult smokers (N = 44; 21 males, 23 females) participated in 2 virtually identical sessions, each after abstaining overnight (CO < 10 ppm) and differing only in the nicotine content of the designated cigarette. While blind to brand markings, they consumed a total of 24 puffs in controlled fashion for 2 hr in each session, either from a nicotine (Quest 1, 0.6 mg) or denicotinized (Quest 3, 0.05 mg) cigarette. Withdrawal symptoms were obtained before and after smoking, and negative affect was assessed after each period of cigarette exposure consisting of 6 puffs every 25 min.

RESULTS

Men and women did not differ in baseline withdrawal and negative affect due to overnight abstinence, but reductions in each symptom were significantly influenced by the interaction of sex × nicotine/denicotinized cigarette (both p < .05). In men, but not in women, each symptom was generally decreased more by the nicotine versus denicotinized cigarette, and the nicotine cigarette reduced each to a greater degree in men versus women.

CONCLUSIONS

Sex differences in relief of abstinence-induced withdrawal and negative affect due to the nicotine content in cigarettes are consistent with prior research indicating that nicotine per se, compared to non-nicotine smoke stimuli, is less rewarding in women versus men.

Behavioral mechanisms underlying nicotine reinforcement

Cigarette smoking is the leading cause of preventable deaths worldwide, and nicotine, the primary psychoactive constituent in tobacco, drives sustained use. The behavioral actions of nicotine are complex and extend well beyond the actions of the drug as a primary reinforcer. Stimuli that are consistently paired with nicotine can, through associative learning, take on reinforcing properties as conditioned stimuli. These conditioned stimuli can then impact the rate and probability of behavior and even function as conditioning reinforcers that maintain behavior in the absence of nicotine. Nicotine can also act as a conditioned stimulus (CS), predicting the delivery of other reinforcers, which may allow nicotine to acquire value as a conditioned reinforcer. These associative effects, establishing non-nicotine stimuli as conditioned stimuli with discriminative stimulus and conditioned reinforcing properties as well as establishing nicotine as a CS, are predicted by basic conditioning principles. However, nicotine can also act non-associatively. Nicotine directly enhances the reinforcing efficacy of other reinforcing stimuli in the environment, an effect that does not require a temporal or predictive relationship between nicotine and either the stimulus or the behavior. Hence, the reinforcing actions of nicotine stem both from the primary reinforcing actions of the drug (and the subsequent associative learning effects) as well as the reinforcement enhancement action of nicotine which is non-associative in nature. Gaining a better understanding of how nicotine impacts behavior will allow for maximally effective tobacco control efforts aimed at reducing the harm associated with tobacco use by reducing and/or treating its addictiveness.

Sex differences in smoking cue reactivity: craving, negative affect, and preference for immediate smoking

BACKGROUND AND OBJECTIVES

Female smokers have greater difficulty quitting, possibly due to increased reactivity to smoking-related cues. This study assessed sex differences in craving, affect, and preference for immediate smoking after cue exposure.

METHODS

Regular smokers (n = 60; 50% female) were exposed to smoking and neutral cues in separate, counterbalanced sessions. Outcomes included changes in craving and affect and preference for immediate smoking following cue exposure.

RESULTS

Findings indicated that women exhibited greater preference for immediate smoking (p = .004), and reported greater cue-induced increases in cigarette craving (p = .046) and negative affect (p = .025).

DISCUSSION AND CONCLUSIONS

These data suggest that women may have greater difficulty inhibiting smoking after cue exposure, possibly as a consequence of greater increases in craving and negative affect.

SCIENTIFIC SIGNIFICANCE AND FUTURE DIRECTIONS

Findings suggest a mechanism that may contribute to greater cessation failure among female smokers.

Nicotine and carcinogen exposure after water pipe smoking in hookah bars

BACKGROUND

Water pipe tobacco smoking is spreading globally and is increasingly becoming popular in the United States, particularly among young people. Although many perceive water pipe smoking to be relatively safe, clinical experimental studies indicate significant exposures to tobacco smoke carcinogens following water pipe use. We investigated biomarkers of nicotine intake and carcinogen exposure from water pipe smoking in the naturalistic setting of hookah bars.

METHODS

Fifty-five experienced water pipe users were studied before and after smoking water pipe in their customary way in a hookah bar. Urine samples were analyzed for nicotine, cotinine, the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and mercapturic acid metabolites of volatile organic compounds (VOC).

RESULTS

We found an average 73-fold increase in nicotine, 4-fold increase in cotinine, 2-fold increase in NNAL, and 14% to 91% increase in VOC mercapturic acid metabolites immediately following water pipe smoking. We saw moderate to high correlations between changes in tobacco-specific biomarkers (nicotine, cotinine, and NNAL) and several mercapturic acid metabolites of VOCs.

CONCLUSION

Water pipe smoking in a hookah bar is associated with significant nicotine intake and carcinogen exposure.

IMPACT

Given the significant intake of nicotine and carcinogens, chronic water pipe use could place users at increased risk of cancer and other chronic diseases. Cancer Epidemiol Biomarkers Prev; 23(6); 1055-66. ©2014 AACR.

Subjective, physiological, and cognitive responses to intravenous nicotine: effects of sex and menstrual cycle phase

Nicotine dependence is a serious public health concern. Optimal treatment of nicotine dependence will require greater understanding of the mechanisms that contribute to the maintenance of smoking behaviors. A growing literature indicates sex and menstrual phase differences in responses to nicotine. The aim of this study was to assess sex and menstrual phase influences on a broad range of measures of nicotine response including subjective drug effects, cognition, physiological responses, and symptoms of withdrawal, craving, and affect. Using a well-established intravenous nicotine paradigm and biochemical confirmation of overnight abstinence and menstrual cycle phase, analyses were performed to compare sex (age 18-50 years; 115 male and 45 female) and menstrual cycle phase (29 follicular and 16 luteal) effects. Females had diminished subjective drug effects of, but greater physiological responses to, nicotine administration. Luteal-phase females showed diminished subjective drug effects and better cognition relative to follicular-phase women. These findings offer candidate mechanisms through which the luteal phase, wherein progesterone is dominant relative to estradiol, may be protective against vulnerability to smoking.

Can tobacco control be transformative? Reducing gender inequity and tobacco use among vulnerable populations

Tobacco use and exposure is unequally distributed across populations and countries and among women and men. These trends and patterns reflect and cause gender and economic inequities along with negative health impacts. Despite a commitment to gender analysis in the preamble to Framework Convention on Tobacco Control there is much yet to be done to fully understand how gender operates in tobacco control. Policies, program and research in tobacco control need to not only integrate gender, but rather operationalize gender with the goal of transforming gender and social inequities in the course of tobacco control initiatives. Gender transformative tobacco control goes beyond gender sensitive efforts and challenges policy and program developers to apply gender theory in designing their initiatives, with the goal of changing negative gender and social norms and improving social, economic, health and social indicators along with tobacco reduction. This paper outlines what is needed to progress tobacco control in enhancing the status of gendered and vulnerable groups, with a view to reducing gender and social inequities due to tobacco use and exposure.

Culturally-specific smoking cessation outreach in a rural community

OBJECTIVE

Tobacco use is the leading preventable cause of death, resulting in 443,000 US deaths per year. Rural adults have higher smoking prevalence and less access to tobacco dependence treatment than their urban counterparts. This study examined exposure to a culturally specific smoking cessation outreach intervention, assessing whether exposure was associated with cessation behaviors.

DESIGN AND SAMPLE

Post-test only quasi-experimental study. Targeted adult smokers (N = 251) living in a rural, economically distressed southeastern US county for at least 6 months.

MEASUREMENTS

Five outreach elements (brochures/pushcards, posters, print and radio advertisements, quilt made by local artisans) based on themes from focus groups with current and former smokers and paired with brief tobacco cessation counseling, and were delivered over 6 months in 2009-2010. Exposure and cessation behavior indicators were collected via cross-sectional random-digit dial survey. The total intervention exposure score was 4.8 (SD = 4.3, range 0-19).

RESULTS

Intervention exposure was associated with having talked to a health care provider about quitting smoking in the past 6 months and planning to quit smoking in the next 6 months.

CONCLUSIONS

Culturally specific outreach materials based on personal narratives are a promising population-based intervention to motivate rural smokers to consider cessation.

The effects of extended pre-quit varenicline treatment on smoking behavior and short-term abstinence: a randomized clinical trial

Preclinical research and learning theory suggest that a longer duration of varenicline treatment prior to the target quit date (TQD) would reduce smoking rates before cessation and improve abstinence outcomes. A double-blind randomized controlled trial tested this hypothesis in 60 smokers randomized to either an Extended run-in group (4 weeks of pre-TQD varenicline) or a Standard run-in group (3 weeks of placebo, 1 week of pre-TQD varenicline); all the participants received 11 weeks of post-TQD varenicline and brief counseling. During the pre-quit run-in, the reduction in smoking rates was greater in the Extended run-in group than in the Standard run-in group (42% vs. 24%, P < 0.01), and this effect was greater in women than in men (57% vs. 26%, P = 0.001). The rate of continuous abstinence during the final 4 weeks of treatment was higher among women in the Extended group compared to women in the Standard run-in group (67% vs. 35%). Although these data suggest that extension of varenicline treatment reduces smoking during the pre-quit period and may further enhance cessation rates, confirmatory evidence is needed from phase III clinical trials.

Electrophysiological evidence of nicotine's distracter-filtering properties in non-smokers

Nicotine-enhanced attentional functions are purported to underlie improvements in behavioral performance in cognitive tasks but it is unclear as to whether these effects involve selective attention or attentional control under conditions of distraction. Behavioral and event-related potential measures were used to examine the effects of nicotine on distractibility in 21 non-smokers who were instructed to ignore task-irrelevant auditory stimuli while they performed a visual discrimination task. In a randomized, double-blind, placebo-controlled cross-over design, nicotine gum (6 mg) shortened overall reaction times but failed to prevent increased response slowing and errors caused by deviant sounds. Relative to placebo, nicotine did not modulate the early pre-attentive detection of deviants as reflected in the mismatch negativity but it attenuated the amplitude of the deviant-elicited P3a, an event-related potential component indexing the involuntary shifting of attention. Nicotine also enhanced attentional re-focusing back on to task-relevant stimuli following distraction as evidenced by an increased amplitude of the re-orienting negativity. These findings and the behavioral-electrophysiological dissociation seen with nicotine are discussed in relation to theories of attention and smoking motivation.

Exploring the impact of gender and reproductive status on outcomes in a randomized clinical trial of naltrexone augmentation of nicotine patch

In a series of exploratory analyses, we examined the roles of gender, reproductive status and negative affect on smoking abstinence in subjects participating in a large (n=385) 6-week randomized clinical trial (RCT) of nicotine patch therapy, with varying doses of oral naltrexone (0mg, 25mg, 50mg, 100mg) treatment. Negative affect was assessed daily during the first post-quit week via telephone interactive voice response (IVR). Weight and adverse events were recorded weekly. In the intent to treat sample, the effects of dose on continuous abstinence were non-significant in the overall model for men and women. In the 295 study completers, there was a significant effect of dose on continuous abstinence in women only (F=8.53, p=0.04). In the 100mg group, 71% of women were continuously abstinent compared to 41% in the placebo group (p<0.05). Women in the active naltrexone groups gained less weight (F=2.91, df=3, p=0.04). Women in the 100mg vs. placebo group were less adherent with medication (F=3.19, p<0.05). These effects were not significant in men. Naltrexone treatment condition (100mg vs. placebo, p=0.02, odds ratio (OR)=0.28), gender (OR=0.55 p=0.09), and IVR ratings of negative affect (OR 1.02, p=0.04) predicted abstinence at Week 1 in study completers. Menstrual cycle status on quit day had a modest affect on abstinence. These data suggest that naltrexone dose, gender, and negative affect play a role in smoking abstinence, particularly in the early stages of treatment. When used in conjunction with nicotine replacement therapy, naltrexone dose may be important in women.

Clinical trials methods for evaluation of potential reduced exposure products

Potential reduced exposure products (PREPs) to tobacco toxicants may have promise in reducing tobacco-related morbidity or mortality or may promote greater harm to individuals or the population. Critical to determining the risks or benefits from these products are valid human clinical trial PREP assessment methods. Such an assessment involves determining the effects of these products on biomarkers of exposure and effect, which serve as proxies for harm, and assessing the potential for consumer uptake and abuse of the product. This article identifies critical methodologic issues associated with PREP assessments, reviews the methods that have been used to assess PREPs, and describes the strengths and limitations of these methods. Additionally, recommendations are provided for clinical trial PREP assessment methods and future research directions in this area based on this review and on the deliberations from a National Cancer Institute sponsored Clinical Trials PREP Methods Workshop.

Alcohol-induced increases in smoking behavior for nicotinized and denicotinized cigarettes in men and women

INTRODUCTION

Alcohol has been shown to increase smoking urges and smoking behavior. However, alcohol's effects on specific components of smoking behavior for nicotine versus non-nicotine factors and potential sex differences in this response have not been investigated.

METHODS

Forty-two young male and female non-dependent, heavy social drinking smokers participated in two double-blind laboratory sessions. They were randomized to either an alcohol (0.8 g/kg; n = 29) or placebo (n = 13) beverage pre-administration group. After beverage consumption, they were assessed for smoking urges and then given the opportunity to smoke cigarettes which were either all nicotinized (0.6 mg/cigarette) or denicotinized (< or =0.05 mg/cigarette) over a 3-h period; smoking behavior was quantified by a smoking topography device. Subjects took standardized puffs of the session's cigarette both before and after beverage administration to provide a reference when making future smoking choices.

RESULTS

Alcohol, compared with placebo beverage, increased both men's and women's smoking urge, as well as subjective ratings of smoking reference puffs for either nicotinized or denicotinized cigarettes. In terms of smoking choice behavior, regardless of cigarette type, alcohol (>placebo) increased men's smoking behavior, including puff count, volume, and duration. In contrast, for women, smoking topography measures did not differ between alcohol and placebo conditions.

DISCUSSION

In summary regardless of nicotine content, in men, alcohol increased smoking urge and behavior, whereas in women, alcohol increased smoking urge but did not increase smoking behavior. These results indicate that the mechanisms underlying co-use of alcohol and tobacco in women may be more complex than in men.