Consideration of sex in clinical trials of transdermal nicotine patch: a systematic review

The impact of the introduction of universal access to free nicotine replacement therapy on the process and outcome of stop smoking services in Ireland

OBJECTIVES

Smoking remains a leading cause of preventable death, disproportionately affecting individuals in lower socio-economic groups. The effectiveness of nicotine replacement therapy (NRT) as a smoking cessation aid is well established; however, cost may act as a barrier to access. The aim of this study was to evaluate the impact of introducing universal NRT access on NRT uptake and smoking cessation.

STUDY DESIGN

Retrospective cohort study.

METHODS

Individuals were followed for twelve weeks following a quit attempt. Changes in NRT use and self-reported quit status were compared between service users before (January 2021-February 2023) and after (March 2023-December 2023) the introduction of fully subsidised NRT.

RESULTS

The total number of participants was 19,717. There was a significant increase in NRT uptake among services users after the introduction of universal NRT access (59 % vs 40 %, p < 0.001) and higher quit rates at four (41 % vs 29 %, p < 0.001) and twelve (29 % vs 20 %, p < 0.001) weeks. NRT was significantly associated with smoking cessation at twelve (aOR 5.41, 95 % CI 4.99-5.86) weeks.

CONCLUSIONS

This study confirms the effectiveness of NRT in a real world context and illustrates the benefits of universal access to this life saving medicine. Overcoming barriers to effective stop smoking care will be key to achieving tobacco endgame, especially for the most disadvantaged population groups. These findings support an urgent call for international policy makers to promote universal access to NRT as a central pillar of tobacco control efforts.

Differential effects of cigarette smoking on cardiovascular disease in females: A narrative review and call to action

OBJECTIVE

Cigarette smoking continues to be a major driver in the incidence and progression of cardiovascular disease (CVD). As females become an increasingly larger fraction of those who smoke it is imperative that the sex-specific effects of smoking be further explored and acted upon.

METHODS

This narrative review describes current evidence on the differential effects of smoking on CVD in females and the need to improve treatment.

RESULTS

Evidence to date suggests that smoking has disproportionately negative effects on the cardiovascular (CV) system in females, especially in those who are younger. Usually, the onset of CVD is later in females than males, but smoking decreases or eliminates this gap. Females are also more likely to develop types of CVD closely tied to smoking, such as ST-elevated myocardial infarctions, with even higher rates among those who are younger. Possible mechanisms for these worse outcomes in females include a complex interplay between nicotine, other products of combusted cigarettes, and hormones. Sex differences also exist in treatment for smoking. In females, Varenicline appears more effective than either Bupropion or nicotine replacement therapy while in males, all three therapies show similar efficacy. Disparities in smoking are also apparent in secondary prevention settings. Females and males are entering secondary prevention with equal rates of smoking, with potentially higher levels of exposure to the byproducts of smoking in females.

CONCLUSIONS

These disproportionately negative outcomes for females who smoke require additional research and these persisting rates of smoking suggest a need for female-specific approaches for treating smoking.

An overview of traditional smoking cessation interventions and E-cigarettes

Many people still struggle with quitting smoking despite available treatment options, making it one of the most significant public health challenges that our society faces. The use of electronic cigarettes (E-cigarettes) has become increasingly popular among people who are seeking to quit smoking. The objective of this review paper is to present a comprehensive analysis of the mechanisms, several types, and impact of E-cigarettes, along with supporting evidence indicating their efficacy in aiding smokers to quit tobacco usage. Additionally, the review discusses recent developments in the treatment of smoking cessation, which include conventional smoking cessation methods. Also, the review discusses the challenges, potential risks, ethical considerations, and controversies surrounding the use of E-cigarettes. The present review presents a comprehensive examination of the existing methods and approaches employed in smoking cessation, including the emerging utilization of E-cigarettes as an effective option in smoking cessation. It explores their efficacy as a valuable instrument in promoting smoking cessation.

Gender, smoking, and tobacco cessation with pharmacological treatment in a cluster randomized clinical trial

INTRODUCTION

Whether men find it easier to quit smoking than women is still controversial. Different studies have reported that the efficacy of pharmacological treatments could be different between men and women. This study conducted a secondary analysis of 'Subsidized pharmacological treatment for smoking cessation by the Spanish public health system' (FTFT-AP study) to evaluate the effectiveness of a drug-funded intervention for smoking cessation by gender.

METHODS

A pragmatic randomized clinical trial by clusters was used. The population included smokers aged ≥18 years, smoking >10 cigarettes per day, randomly assigned to an intervention group receiving regular practice and financed pharmacological treatment, or to a control group receiving only regular practice. The main outcome was continued abstinence at 12 months, self-reported and validated with CO-oximetry. The percentage, with 95% confidence intervals, of continued abstinence was compared between both groups at 12 months post-intervention, by gender and the pharmacological treatment used. Multilevel logistic regression analysis was performed.

RESULTS

A total of 1154 patients from 29 healthcare centers were included. The average age was 46 years (SD=11.78) and 51.7% were men. Overall, the self-reported abstinence at 12 months was 11.1% (62) in women and 15.7% (93) in men (AOR=1.4; 95% CI: 1.0-2.0), and abstinence validated by CO-oximetry was 4.6% (26) and 5.9% (35) in women and men, respectively (OR=1.3; 95% CI: 0.7-2.2). In the group of smokers receiving nicotine replacement treatment, self-reported abstinence was higher in men compared to women (29.5% vs 13.5%, OR=2.7; 95% CI: 1.3-5.8).

CONCLUSIONS

The effectiveness of a drug-financed intervention for smoking cessation was greater in men, who also showed better results in self-reported abstinence with nicotine replacement treatment.

The role of sex hormones in targeting stress-induced tobacco craving, stress-reactivity, and smoking with guanfacine among women who smoke

Women who smoke are particularly vulnerable to tobacco craving, smoking behaviors, and relapse in the context of stress when compared to men who smoke. One factor in this sex difference may be sex hormones, including estradiol and progesterone; however, smoking cessation medication trials often do not explore the impact of sex hormones on drug effects. This secondary analysis of a double-blind, placebo-controlled study explored the impact of levels of actual estradiol and progesterone on guanfacine, a noradrenergic α2a agonist, which attenuates stress-induced smoking behaviors in women. Women who smoke (n = 43) completed a stress induction laboratory paradigm followed by an ad-libitum smoking period. Assessment of tobacco craving, and stress-reactivity (via cortisol response) occurred pre- and post-stress induction. Results indicated that guanfacine attenuated stress-induced tobacco craving (F = 10.94, p = 0.02) and cortisol response (F = 14.23, p < 0.001); however, high levels of estradiol overrode guanfacine's effect on craving (F = 4.00, p = 0.05), cortisol response (F = 14.23, p < 0.001), and smoking during the ad-libitum period (F = 12.23, p = 0.001). Additionally, progesterone proved to be protective against tobacco craving and enhanced guanfacine's medication effect on craving (F = 5.57, p = 0.02). The present study found that sex hormones had a significant impact on medication effects in a smoking cessation trial and thus underscore the importance of examining the role of sex hormones in future medication trials.

Sex effects in predictors of smoking abstinence and neuropsychiatric adverse events in the EAGLES trial

Significance There are sex effects in abstinence outcomes across all smoking cessation medications, but there is limited information regarding sex effects on cessation-related neuropsychiatric adverse events (NPSAEs) or interactions with psychiatric status.

METHODS

Secondary analysis of data from EAGLES of 8144 adults who smoke cigarettes randomized to varenicline, bupropion, nicotine patch or placebo. Design characteristics included region (within/outside US), psychiatric cohort (absent/present), and treatment. Baseline variables included demographics, smoking history, prior use of study treatments, lifetime suicide-related history, and prior psychiatric co-morbidities and medication use. Design characteristics were forced into logistic regressions models, and then interactions among sex, design elements, and baseline characteristics were evaluated for NPSAEs and 6-month cessation outcomes.

RESULTS

Findings demonstrated a significant interaction of sex and race (p < 0.02); Black women were more likely to report NPSAEs than Black men. For cessation outcomes, there were no significant interactions with psychiatric cohort and sex. Women vs men with higher baseline levels of smoking had lower odds of continuous abstinence. Women vs men who used varenicline previously had lower odds of continuous abstinence. For 6-month point prevalence, sex interacted with baseline cigarettes per day (p < 0.01) similar to the interaction for continuous abstinence. Sex interacted with medication (p < 0.03), such that women vs men had relatively greater success at achieving point prevalence abstinence on varenicline.

CONCLUSIONS

Overall, results demonstrated important sex and racial differences in the incidence of NPSAEs, but psychiatric status did not interact with sex on cessation outcomes. Findings did support prior work demonstrating relative increased efficacy of varenicline for women.

Daily adherence to nicotine replacement therapy in low-income smokers: The role of gender, negative mood, motivation, and self-efficacy

BACKGROUND

Low-income smokers may benefit from interventions promoting nicotine replacement therapies (NRTs), particularly for women, as women have worse smoking cessation outcomes than men. Little is known about factors that affect daily NRT adherence, such as negative mood, motivation, and self-efficacy, and whether gender moderates these associations.

METHODS

Secondary analysis of a randomized controlled trial comparing a novel, in session sampling of short-acting combination NRT intervention (In Vivo) to standard care smoking cessation behavioral counseling was performed. Low-income smokers (n = 62; Mage = 47.4; 42 % female; 61 % non-White) completed daily surveys using the Insight™ mHealth platform for 55 consecutive days. Three types of NRT adherence were examined: dose amount of short-acting NRT, nicotine patch wear time, and combination NRT (cNRT) (combined nicotine patch and short-acting NRT).

RESULTS

Generalized multilevel models report same-day negative mood was associated with greater likelihood of nicotine patch adherence in men, but unrelated to women's nicotine patch adherence. Same-day negative mood was associated with greater likelihood of cNRT adherence in men, but less likelihood in women. The relationship between same-day motivation and use of short-acting NRT varied by gender, but simple slope analyses revealed that motivation was unrelated to short-acting NRT use within either group. Same-day self-efficacy was related to an increased likelihood of nicotine patch adherence and cNRT adherence in women but unrelated to men's adherence of either type.

CONCLUSIONS

Future research should focus on gender differences in low-income smokers' same-day negative mood, motivation, and self-efficacy processes on NRT adherence during smoking cessation interventions.

Cocreation of a conversational agent to help patients adhere to their varenicline treatment: A study protocol

Objective

Varenicline is the most efficacious approved smoking cessation medication, making it one of the most cost-effective clinical interventions for reducing tobacco-related morbidity and mortality. Adhering to varenicline is strongly associated with smoking cessation. Healthbots have the potential to help people adhere to their medications by scaling up evidence-based behavioral interventions. In this protocol, we outline how we will follow the UK's Medical Research Council's guidance to codesign a theory-informed, evidence-based, and patient-centered healthbot to help people adhere to varenicline.

Methods

The study will utilize the Discover, Design and Build, and Test framework and will include three phases: (a) a rapid review and interviews with 20 patients and 20 healthcare providers to understand barriers and facilitators to varenicline adherence (Discover phase); (b) Wizard of Oz test to design the healthbot and get a sense of the questions that chatbot has to be able to answer (Design phase); and (c) building, training, and beta-testing the healthbot (Building and Testing phases) where the Nonadoption, Abandonment, Scale-up, Spread, and Sustainability framework will be used to develop the healthbot using the simplest sensible solution, and 20 participants will beta test the healthbot. We will use the Capability, Opportunity, Motivation-Behavior (COM-B) model of behavior change and its associated framework, the Theoretical Domains Framework, to organize the findings.

Conclusions

The present approach will enable us to systematically identify the most appropriate features for the healthbot based on a well-established behavioral theory, the latest scientific evidence, and end users' and healthcare providers' knowledge.

Consideration of sex and gender differences in addiction medication response

Substance use continues to contribute to significant morbidity and mortality in the United States, for both women and men, more so than another other preventable health condition. To reduce the public health burden attributable to substances, the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism have identified that medication development for substance use disorder is a high priority research area. Furthermore, both Institutes have stated that research on sex and gender differences in substance use medication development is a critical area. The purpose of the current narrative review is to highlight how sex and gender have been considered (or not) in medication trials for substance use disorders to clarify and summarize what is known regarding sex and gender differences in efficacy and to provide direction to the field to advance medication development that is consistent with current NIH 'sex as a biological variable' (SABV) policy. To that end, we reviewed major classes of abused substances (nicotine, alcohol, cocaine, cannabis, opioids) demonstrating that, sex and gender have not been well-considered in addiction medication development research. However, when adequate data on sex and gender differences have been evaluated (i.e., in tobacco cessation), clinically significant differences in response have been identified between women and men. Across the other drugs of abuse reviewed, data also suggest sex and gender may be predictive of outcome for some agents, although the relatively low representation of women in clinical research samples limits making definitive conclusions. We recommend the incorporation of sex and gender into clinical care guidelines and improved access to publicly available sex-stratified data from medication development investigations.

Feasibility and acceptability of testing a menstrual-cycle timed smoking cessation intervention for women of reproductive age (Project Phase): Results of a pilot randomized control trial

INTRODUCTION

Menstrual phase influences cigarette smoking-related outcomes. Telephone-based cessation programs (e.g., quitlines) may incorporate the role of the menstrual cycle in an effort to tailor interventions for women.

PURPOSE

The goal of this preliminary randomized clinical trial was to examine the feasibility and acceptability of timing quit date to menstrual phase in women in a quitline setting.

METHODS

We recruited treatment-seeking women with regular menstrual cycles between the ages of 18-40 years. Participants were randomized to the follicular phase (FP; quit date set 6-8 days post onset of menses) or standard of care (SC; no menstrual timing of quit date). All participants received four weeks of nicotine replacement therapy transdermal patch concurrent with six weeks of telephone-based counseling. We explored self-reported and biochemically-verified seven-day point prevalence abstinence at end-of-treatment and three-month follow-up.

RESULTS

Participants (n = 119; FP: n = 58, SC: n = 61) were, on average, 33.4 years old and smoked 13.6 cigarettes/day. The median number of counseling sessions completed was 6 out of 6 available, and 66% of participants completed the intervention. Over 90% of participants reported they would recommend this study to friends/family. Cessation rates did not significantly vary by randomization.

CONCLUSIONS

Results of this preliminary trial indicate that timing quit date to FP is an acceptable and feasible approach to address smoking cessation in women of reproductive age. While we observed similar smoking cessation rates between groups, this preliminary study was not fully powered to determine efficacy. Therefore, the feasibility and acceptability results indicate that a fully-powered efficacy trial is warranted.

Electronic Nicotine Delivery Systems (ENDS) Use and Pregnancy I: ENDS Use Behavior During Pregnancy

PURPOSE OF REVIEW

This review examines Electronic Nicotine Delivery Systems (ENDS) use behavior during pregnancy, including the prevalence of and transitions in use during pregnancy.

RECENT FINDINGS

Twenty-two papers addressed the prevalence of and/or transitions in ENDS use during pregnancy. Findings show a complex landscape of ENDS use. A minority (0.4%-7.0%) of pregnant persons use ENDS; most commonly this occurs in the form of dual use (ENDS and combustible cigarettes (CC); 75%). Many pregnant persons report using ENDS because they perceive them to be a lower-risk alternative and/or potential cessation aide for CC smoking. However, while a subset of those who use ENDS do quit all tobacco product use during pregnancy, only a small proportion switch from exclusive CC smoking to exclusive ENDS use.

SUMMARY

ENDS are a somewhat new addition to the tobacco product landscape. The perception of ENDS as a lower-risk alternative may contribute to ENDS use in pregnancy. There is insufficient evidence to support the notion that ENDS facilities the cessation of tobacco product use during pregnancy.

Sex Differences in the Association of Cigarette Craving With Insula Structure

BACKGROUND

Cigarette craving, which can negatively impact smoking cessation, is reportedly stronger in women than in men when they initiate abstinence from smoking. Identifying approaches to counteract craving in people of different sexes may facilitate the development of personalized treatments for Tobacco Use Disorder, which disproportionately affects women. Because cigarette craving is associated with nicotine dependence and structure of the insula, this study addressed whether a person's sex influences these associations.

METHODS

The research participants (n = 99, 48 women) reported daily cigarette smoking and provided self-reports of nicotine dependence. After overnight abstinence from smoking, they underwent structural magnetic resonance imaging scanning to determine cortical thickness of the left and right anterior circular insular sulcus, and self-rated their cigarette craving before and after their first cigarette of the day.

RESULTS

Women reported stronger craving than men irrespective of smoking condition (i.e., pre- and post-smoking) (P = .048), and smoking reduced craving irrespective of sex (P < .001). A 3-way interaction of sex, smoking condition, and right anterior circular insular sulcus thickness on craving (P = .033) reflected a negative association of cortical thickness with pre-smoking craving in women only (P = .012). No effects of cortical thickness in the left anterior circular insular sulcus were detected. Nicotine dependence was positively associated with craving (P < .001) across groups and sessions, with no sex differences in this association.

CONCLUSIONS

A negative association of right anterior insula thickness with craving in women only suggests that this region may be a relevant therapeutic target for brain-based smoking cessation interventions in women.

A comparison of quit outcomes for men and women in a smoking cessation program offering personalized nicotine replacement therapy and counselling in primary care clinics

INTRODUCTION

Women may have greater difficulty achieving long-term abstinence following a quit attempt compared to men. We sought to determine whether there were differences in treatment characteristics or outcome between female and male primary care patients enrolled in a smoking cessation program providing personalized nicotine replacement therapy (NRT) with counselling support.

METHODS

The sample included 27,601 Ontarians (53% female, 47% male) who enrolled in the Smoking Treatment for Ontario Patients program between 2016 and 2018. Dose, type, and duration of NRT supplied was personalized to need. Thirty-day point prevalence tobacco smoking abstinence was self-reported via online or telephone survey at 6 months post-enrollment.

RESULTS

Both female and male participants received a median of 8 weeks of NRT. Types of NRT received were similar, with 80% of both female and male participants receiving patch and short-acting NRT. Total cumulative dose was somewhat higher for men (1373 mg vs. 1265 mg, p<0.001); but when calculated as dose per day, per cigarette smoked at baseline, dose was slightly higher among women (1.6 mg vs. 1.5 mg, p<0.001). Quit rates at 6 months were lower for women versus men (24% vs. 27%; AOR = 0.84 [95% CI = 0.78-0.90], p<0.001). There were no significant interactions between gender and dose, type or duration of NRT supplied.

CONCLUSIONS

Women were slightly less likely to quit than men, despite receiving similar treatment. There was no evidence that women benefitted more or less from variations in dose, type or duration of NRT supply.

Diversity and inclusion for the All of Us research program: A scoping review

The All of Us Research Program (All of Us) is a national effort to accelerate health research by exploring the relationship between lifestyle, environment, and genetics. It is set to become one of the largest research efforts in U.S. history, aiming to build a national resource of data from at least one million participants. All of Us aims to address the need for more diversity in research and set the stage for that diversity to be leveraged in precision medicine research to come. This paper describes how the program assessed demographic characteristics of participants who have enrolled in other U.S. biomedical research cohorts to better understand which groups are traditionally represented or underrepresented in biomedical research. We 1) reviewed the enrollment characteristics of national cohort studies like All of Us, and 2) surveyed the literature, focusing on key diversity categories essential to the program's enrollment aims. Based on these efforts, All of Us emphasizes enrollment of racial and ethnic minorities, and has formally designated the following additional groups as historically underrepresented: individuals-with inadequate access to medical care; under the age of 18 or over 65; with an annual household income at or below 200% of the federal poverty level; who have a cognitive or physical disability; have less than a high school education or equivalent; are intersex; identify as a sexual or gender minority; or live in rural or non-metropolitan areas. Research accounting for wider demographic variability is critical. Only by ensuring diversity and by addressing the very barriers that limit it, can we position All of Us to better understand and tackle health disparities.

Effectiveness of transdermal nicotine patch in premenopausal female smokers is moderated by within-subject severity of negative affect and physical symptoms

RATIONALE

Nicotine patches may be less effective in female compared with male smokers. However, it is unknown if negative affect and physical symptoms influence transdermal nicotine patch-related effects on smoking behaviors.

METHODS

Eighty-one acutely tobacco-abstinent premenopausal female smokers attended three counter-balanced experimental sessions across the menstrual cycle (early follicular, late follicular, and mid-luteal) and were randomized to patch condition (nicotine [21 mg] vs. placebo [0 mg] transdermal patch). Negative affect and physical symptoms were assessed prior to patch administration. The patch was removed 5 h post-administration, and participants completed a smoking reinstatement task. Multilevel linear models tested associations of patch condition, negative affect and physical symptoms, and their interaction on smoking behavior.

RESULTS

There was a significant patch condition × Negative Affect and Pain symptoms interaction on the number of cigarettes smoked (p < 0.05). When Negative Affect and Pain were lower-than-usual, females administered a nicotine patch smoked significantly fewer cigarettes than females administered a placebo patch (p < .05), but there were no significant patch differences when Negative Affect and Pain were higher-than-usual. There was also a significant patch condition × Negative Affect interaction on time delay. The effects of patch condition on time delay to smoking were greater during sessions in which Negative Affect was higher-than-usual.

CONCLUSIONS

Results suggest that among female smokers transdermal nicotine patch effectiveness may interact with negative affect and pain. Understanding and considering female-specific factors that may impact the efficacy of one of the most commonly used cessation medications is important for improving smoking cessation in female smokers.

One-Year Smoking Trajectories Among Established Adult Smokers With Low Baseline Motivation to Quit

INTRODUCTION

The majority of smokers do not intend to quit in the near term, making unmotivated smokers a key group to target in public health efforts. Although it is often assumed that continuing smokers will have stable rates of smoking over time, limited research has addressed this issue, particularly among smokers not seeking treatment. In the current study, the aims were to (1) characterize the trajectory of naturalistic smoking among unmotivated smokers and (2) examine relationships between naturalistic smoking trajectories and other smoking-related variables.

METHODS

The study sample comprised 579 control-group (ie, untreated) smokers within a parent clinical trial, who completed a total of nine assessments over 1 year.

RESULTS

Trajectory modeling identified four smoking trajectory groups: stable (72%), shallow decreasers (20%), steep decreasers (5%), and increasers (3%). Membership in the decreasing groups was associated with higher motivation to quit, greater history of quit attempts, and higher cigarettes per day. Females were more likely to be in the increasing versus stable group.

CONCLUSIONS

Findings provide needed information on stability and change in cigarette consumption over the course of 1 year among an untreated sample of smokers and identified baseline sociodemographic and smoking-related predictors of smoking trajectory group. Refining understanding of these groups is critical in updating population-based tobacco policy modeling efforts and informing cessation induction efforts that capitalize on naturalistic changes in smoking rate over time.

IMPLICATIONS

In the current study, we found that approximately 25% of smokers who endorsed low quit motivation at baseline reduced their cigarette consumption over the course of a year, while 3% increased their cigarette consumption and the majority of smokers (72%) maintained a stable pattern. Refining understanding of smoking trajectories is critical in updating population-based tobacco policy modeling efforts and informing cessation induction efforts that capitalize on naturalistic changes in smoking rate over time.

Resting-State Functional Connectivity of the Basal Nucleus of Meynert in Cigarette Smokers: Dependence Level and Gender Differences

Introduction

Numerous studies have characterized impaired cerebral functioning in nicotine-addicted individuals. Whereas nicotine interacts with multiple neurotransmitters in cortical and subcortical circuits, it directly targets the cholinergic system, sourced primarily from the basal nucleus of Meynert (BNM). However, no studies have examined how this cholinergic system is influenced by cigarette smoking. Here, we addressed this gap of research.

Methods

Using a dataset from the Functional Connectome Projects, we investigated this issue by contrasting seed-based BNM connectivity of 40 current smokers and 170 age- and gender-matched nonsmokers. We followed our data analytic routines in recent work and examined differences between smokers and nonsmokers in men and women combined as well as separately.

Results

Compared to nonsmokers, female but not male smokers demonstrated greater positive BNM connectivity to the supplementary motor area, bilateral anterior insula, and right superior temporal/supramarginal gyri as well as greater negative connectivity to the posterior cingulate cortex and precuneus. Further, BNM connectivity to the supplementary motor area is negatively correlated to the Fagerström Test for Nicotine Dependence score in male but not female smokers.

Conclusions

Along with a previous report of upregulated nicotinic acetylcholine receptor in male but not female smokers, these new findings highlight functional changes of the cholinergic systems in cigarette smokers. The results suggest sex-specific differences in cholinergic dysregulation and a need for multiple imaging modalities to capture the neural markers of nicotine addiction.

Implications

Nicotine influences cognition via cholinergic projections of the basal forebrain to the cerebral cortex. This study examined changes in resting-state whole-brain functional connectivity of the BNM in cigarette smokers. The new findings elucidate for the first time sex differences in BNM-cerebral connectivity in cigarette smoking.

Sex Differences in Tobacco Use Among Persons Living With HIV/AIDS: A Systematic Review and Meta-Analysis

BACKGROUND

Persons living with HIV/AIDS (PLWH) smoke at higher rates than other adults and experience HIV-related and non-HIV-related adverse smoking consequences. This study conducted a systematic review to synthesize current knowledge about sex differences in smoking behaviors among PLWH.

METHODS

Over 3000 abstracts from MEDLINE were reviewed and 79 publications met all the review inclusion criteria (ie, reported data on smoking behaviors for PLWH by sex). Sufficient data were available to conduct a meta-analysis for one smoking variable: current smoking prevalence.

RESULTS

Across studies (n = 51), the meta-analytic prevalence of current smoking among female PLWH was 36.3% (95% confidence interval [CI]: 28.0% to 45.4%) and male PLWH was 50.3% (95% CI: 44.4% to 56.2%; meta-analytic odds ratio = 1.78, 95% CI: 1.29 to 2.45). When analyses were repeated just on the US studies (n = 23), the prevalence of current smoking was not significantly different for female PLWH (55.1%, 95% CI: 47.6% to 62.5%) compared with male PLWH (55.5%, 95% CI: 48.2% to 62.5%; meta-analytic odds ratio = 1.04, 95% CI: 0.86 to 1.26). Few studies reported data by sex for other smoking variables (eg, quit attempts, noncigarette tobacco product use) and results for many variables were mixed.

DISCUSSION

Unlike the general US population, there was no difference in smoking prevalence for female versus male PLWH (both >50%) indicating that HIV infection status was associated with a greater relative increase in smoking for women than men. More research is needed in all areas of smoking behavior of PLWH to understand similarities and differences by sex to provide the best interventions to reduce the high smoking prevalence for all sexes.

A systematic review of possible serious adverse health effects of nicotine replacement therapy

We conducted a systematic literature review to identify and critically evaluate studies of serious adverse health effects (SAHEs) in humans using nicotine replacement therapy (NRT) products. Serious adverse health effects refer to adverse events, leading to substantial disruption of the ability to conduct normal life functions. Strength of evidence evaluations and conclusions were also determined for the identified SAHEs. We evaluated 34 epidemiological studies and clinical trials, relating NRT use to cancer, reproduction/development, CVD, stroke and/or other SAHEs in patients, and four meta-analyses on effects in healthy populations. The overall evidence suffers from many limitations, the most significant being the short-term exposure (≤12 weeks) and follow-up to NRT product use in most of the studies, the common failure to account for changes in smoking behaviour following NRT use, and the sparse information on SAHEs by type of NRT product used. The only SAHE from NRT exposure we identified was an increase in respiratory congenital abnormalities reported in one study. Limited evidence indicated a lack of effect between NRT exposure and SAHEs for CVD and various reproduction/developmental endpoints. For cancer, stroke and other SAHEs, the evidence was inadequate to demonstrate any association with NRT use. Our conclusions agree with recent statements from authoritative bodies.

How Intravenous Nicotine Administration in Smokers Can Inform Tobacco Regulatory Science

Reducing the negative health effects caused by tobacco products continues to be a public health priority. The Family Smoking Prevention and Tobacco Control Act of 2009 gives the Food Drug Administration authority to pursue several new strategies, including regulating levels of nicotine and other ingredients in tobacco products. A nicotine reduction strategy proposed by Benowitz and Henningfield aims to reduce the nicotine content of tobacco products to an amount below a threshold that supports neither the development nor maintenance of addiction. Many factors must be considered to determine the viability and efficacy of this approach. For example, the policy should be based on precise information on the dose-dependent effects of nicotine on reinforcement and factors that contribute to individual differences in these effects. However, there have been few studies on these topics in humans. Here, we briefly review nicotine pharmacology and reinforcement then present several studies illustrating the application of intravenous (IV) nicotine delivery to study nicotine reinforcement in humans. We discuss how nicotine delivery by IV infusion may be uniquely suited for studying nicotine's dose-dependent effects, and how this can inform tobacco regulatory science to facilitate the development of effective tobacco control policies.

Sex differences in substance use disorders: focus on side effects

Although sex differences in several aspects of substance use disorders (SUDs) have been identified, less is known about the importance of possible sex differences in side effects induced by substances of abuse or by medications used to treat SUDs. In the SUD field, the perception of certain subjective effects are actively sought, while all other manifestations might operationally be considered side effects. This article was aimed at reviewing sex differences in side effects induced by alcohol, nicotine, heroin, marijuana and cocaine and by medications approved for alcohol, nicotine and heroin use disorders. A large body of evidence suggests that women are at higher risk of alcohol-induced injury, liver disease, cardiomyopathy, myopathy, brain damages and mortality. The risk of tobacco-induced coronary heart disease, lung disease and health problems is higher for women than for men. Women also experience greater exposure to side effects induced by heroin, marijuana and cocaine. In addition, women appear to be more vulnerable to the side effects induced by medications used to treat SUDs. Patients with SUDs should be advised that the risk of developing health problems may be higher for women than for men after consumption of the same amount of substances of abuse. Doses of medications for SUD women should be adjusted at least according to body weight. The sex differences observed also indicate an urgent need to recruit adequate numbers of female subjects in pre-clinical and clinical studies to improve our knowledge about SUDs in women.

Effects of intimate partner violence, PTSD, and alcohol use on cigarette smoking in a nationally representative sample

BACKGROUND AND OBJECTIVES

Separate literatures indicate that intimate partner violence (IPV), posttraumatic stress disorder (PTSD), and alcohol use are independently associated with increased risk for cigarette smoking. No previous studies have examined the co-occurrence of these problems on smoking quantity and potential gender-specific relationships. This study will address this gap in the literature.

METHODS

Data from Wave 2 of the National Epidemiologic Study on Alcohol and Related Conditions (NESARC) were examined. Variables were assessed during the past year. Individuals (N = 25,604) who reported being married, dating, or involved in a romantic relationship were included.

RESULTS

Among men, PTSD and alcohol use were associated with more cigarettes smoked per day. Among women, PTSD, alcohol use, and IPV victimization were associated with more cigarettes smoked per day. Women who experienced IPV victimization smoked approximately three additional cigarettes per day.

DISCUSSION AND CONCLUSIONS

IPV victimization, PTSD, and alcohol use were associated with cigarettes smoked among women, while IPV experiences were not associated with smoking risk among men.

SCIENTIFIC SIGNIFICANCE

These findings represent an important contribution to the existing literature in that it elucidates the compounding relationship between a common and complex comorbidity and cigarette smoking. Findings indicate a critical need to implement routine smoking screening and intervention in venues where intimate partner violence is commonly encountered, such as advocacy and substance use treatment settings. (Am J Addict 2016;25:283-290).

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.

Antidepressant-like effects of guanfacine and sex-specific differences in effects on c-fos immunoreactivity and paired-pulse ratio in male and female mice

RATIONALE

The a2A-noradrenergic agonist guanfacine can decreases stress-induced smoking in female, but not male, human smokers. It is not known whether these effects are due to effects on mood regulation and/or result from nicotinic-cholinergic interactions.

OBJECTIVES

The objective of the study was to determine whether there are sex differences in the effect of guanfacine in tests of anxiolytic and antidepressant efficacy in mice at baseline and in a hypercholinergic model of depression induced by the acetylcholinesterase inhibitor physostigmine.

METHODS

The effects of guanfacine were measured in the light/dark box, tail suspension, and the forced swim test in female and male C57BL/6J mice. In parallel, electrophysiological properties were evaluated in the prefrontal cortex, a critical brain region involved in stress responses. c-fos immunoreactivity was measured in other brain regions known to regulate mood.

RESULTS

Despite a baseline sex difference in behavior in the forced swim test (female mice were more immobile), guanfacine had similar, dose-dependent, antidepressant-like effects in mice of both sexes (optimal dose, 0.15 mg/kg). An antidepressant-like effect of guanfacine was also observed following pre-treatment with physostigmine. A sex difference in the paired-pulse ratio in the prefrontal cortex (PFC) (male, 1.4; female, 2.1) was observed at baseline that was normalized by guanfacine. Other brain areas involved in cholinergic control of depression-like behaviors, including the basolateral amygdala and lateral septum, showed sex-specific changes in c-fos expression.

CONCLUSIONS

Guanfacine has a robust antidepressant-like effect and can reverse a depression-like state induced by increased acetylcholine (ACh) signaling. These data suggest that different brain areas are recruited in female and male mice, despite similar behavioral responses to guanfacine.

Targeting the noradrenergic system for gender-sensitive medication development for tobacco dependence

INTRODUCTION

Tobacco use remains the leading cause of morbidity and mortality for both women and men in the United States, and women often experience poorer smoking cessation outcomes than men. Preliminary evidence suggests there are sex differences in medication effectiveness for smoking cessation. However, current medications do not take into account gender-sensitive treatment development and efficacy, underscoring the importance of this underdeveloped area of research.

METHODS

We reviewed preclinical and clinical evidence for gender differences in the inability to quit smoking by examining (a) the effect of increased negative affect and stress reactivity on smoking outcomes in women and (b) smoking for nicotine reinforcement in men. We also reviewed the current literature targeting the noradrenergic system as a novel gender-sensitive treatment strategy for tobacco dependence.

RESULTS

We hypothesize that noradrenergic agents that normalize noradrenergic activity may differentially attenuate stress reactivity in women and nicotine-related reinforcement in men, indicating that targeting the noradrenergic system for smoking cessation may be effective for both genders, with benefits operating through sex-specific mechanisms.

CONCLUSIONS

Converging lines of preclinical and clinical evidence suggest that gender-sensitive approaches to medication development for smoking cessation are a critical next step for addressing low quit rates and exacerbated health risks among women. Evidence reviewed indicates that smoking activates different brain systems modulated by noradrenergic activity in women versus men, and noradrenergic compounds may preferentially target these gender-sensitive systems.