Menstrual cycle phase at quit date predicts smoking status in an NRT treatment trial: a retrospective analysis

Menstrual phase and depressive symptoms differences in physiological response to nicotine following acute smoking abstinence

INTRODUCTION

Accumulating evidence has linked depressive symptoms and sex hormones to risk for relapse; however, the specific mechanisms involved in these associations remain unknown. This randomized crossover study assessed physiological response to nicotine by menstrual phase in female smokers with and without depressive symptoms following acute smoking abstinence.

METHODS

Females, ages 18-40 years with regular menstrual cycles, not on exogenous hormones or psychotropic medications, who reported smoking ≥ 5 cigarettes/day were enrolled. Participants were stratified into 2 groups: no depressive symptoms (NDS; n = 23) and depressive symptoms (DS; n = 24). After 4 days of biochemically verified smoking abstinence, participants completed 2 laboratory sessions in the follicular (F) and luteal (L) phases. Participants used nicotine nasal spray at Time 0, and blood pressure, heart rate, and serum nicotine were measured at Time -1, 5, 10, 20, 30, 45, 60, and 90 min.

RESULTS

Participants (n = 47) were 29.1 ± 6.8 years old and smoked an average of 12.5 ± 5.1 cigarettes/day. The NDS group had more pronounced menstrual phase differences (F > L) in diastolic blood pressure, heart rate, and maximum concentrations of nicotine compared with the DS group (p < .05).

CONCLUSIONS

This study observed an interaction between sex hormones and depressive symptoms such that those without depressive symptoms had a greater menstrual phase difference in the physiological response to nicotine. These data offer additional support for the role of sex hormones in the physiological response to nicotine, which may play a role in menstrual phase effects on smoking cessation.

The impact of sex on brain responses to smoking cues: a perfusion fMRI study

Background

Anecdotal and clinical theories purport that females are more responsive to smoking cues, yet few objective, neurophysiological examinations of these theories have been conducted. The current study examines the impact of sex on brain responses to smoking cues.

Methods

Fifty-one (31 males) cigarette-dependent sated smokers underwent pseudo-continuous arterial spin-labeled perfusion functional magnetic resonance imaging during exposure to visual smoking cues and non-smoking cues. Brain responses to smoking cues relative to non-smoking cues were examined within males and females separately and then compared between males and females. Cigarettes smoked per day was included in analyses as a covariate.

Results

Both males and females showed increased responses to smoking cues compared to non-smoking cues with males exhibiting increased medial orbitofrontal cortex and ventral striatum/ventral pallidum responses, and females showing increased medial orbitofrontal cortex responses. Direct comparisons between male and female brain responses revealed that males showed greater bilateral hippocampal/amygdala activation to smoking cues relative to non-smoking cues.

Conclusions

Males and females exhibit similar responses to smoking cues relative to non-smoking cues in a priori reward-related regions; however, direct comparisons between sexes indicate that smoking cues evoke greater bilateral hippocampal/amygdalar activation among males. Given the current literature on sex differences in smoking cue neural activity is sparse and incomplete, these results contribute to our knowledge of the neurobiological underpinnings of drug cue reactivity.

Gender Differences in Smoking Behaviour and Cessation

This article reviews the literature to compare differential outcomes among men and women after smoking cessation, assess barriers they may face during cessation and provide recommendation to address gender-specific challenges in smoking cessation interventions. There is some evidence that women achieve lower abstinence rates than men after a quit attempt with nicotine replacement therapy, as well as without pharmacotherapy, and several underlying mechanisms were discussed to account for these findings. These include: (a) women have specific genetic variants that affect pharmacokinetics and pharmacodynamics of the medication, (b) hormonal influences increase nicotine metabolism and withdrawal symptoms, (c) women are more responsive to nonpharmacological aspects of smoking than men, (d) women are more vulnerable to depression and negative mood than men, (e) weight concerns are greater barriers for women than for men and (g) women receive less effective social support than men during a quit attempt. Gender-specific counselling that accounts for these factors and addresses the different needs of men and women may be a promising approach to improve long-term abstinence rates. However, more research is required to identify gender-related underlying mechanisms of differential smoking cessation outcomes, develop tailored interventions that account for gender differences and study the implementation and outcomes of gender-responsive treatment approaches.

Novel actions of progesterone: what we know today and what will be the scenario in the future?

Objectives

This article is aimed to review the novel actions of progesterone, which otherwise is considered as a female reproductive hormone. The article focuses on its important physiological actions in males too and gives an overview of its novel perspectives in disorders of central and peripheral nervous system.

Key findings

Progesterone may have a potential benefit in treatment of traumatic brain injury, various neurological disorders and male related diseases like benign prostatic hypertrophy (BPH), prostate cancer and osteoporosis. Norethisterone (NETA), a progesterone derivative, decreases bone mineral loss in male castrated mice suggesting its role in osteoporosis. In the future, progesterone may find use as a male contraceptive too, but still needs confirmatory trials for safety, tolerability and acceptability. Megestrol acetate, a progesterone derivative is preferred in prostatic cancer. Further, it may find utility in nicotine addiction, traumatic brain injury (recently entered Phase III trial) and Alzheimer's disease, diabetic neuropathy and crush injuries. Studies also suggest role of progesterone in stroke, for which further clinical trials are needed. The non genomic actions of progesterone may be in part responsible for these novel actions.

Summary

Although progesterone has shown promising role in various non-hormonal benefits, further clinical studies are needed to prove its usefulness in conditions like stroke, traumatic brain injury, neuropathy and crush injury. In male related illnesses like BPH and prostatic Ca, it may prove a boon in near future. New era of hormonal male contraception may be initiated by use of progesterone along with testosterone.

Gender research in the National Institute on Drug Abuse National Treatment Clinical Trials Network: a summary of findings

BACKGROUND

The National Institute of Drug Abuse's National Drug Abuse Treatment Clinical Trials Network (CTN) was established to foster translation of research into practice in substance abuse treatment settings. The CTN provides a unique opportunity to examine in multi-site, translational clinical trials, the outcomes of treatment interventions targeting vulnerable subgroups of women; the comparative effectiveness of gender-specific protocols to reduce risk behaviors; and gender differences in clinical outcomes.

OBJECTIVES

To review gender-related findings from published CTN clinical trials and related studies from January 2000 to March 2010.

METHODS

CTN studies were selected for review if they focused on treatment outcomes or services for special populations of women with substance use disorders (SUDs) including those with trauma histories, pregnancy, co-occurring eating and other psychiatric disorders, and HIV risk behaviors; or implemented gender-specific protocols. The CTN has randomized 11,500 participants (41% women) across 200 clinics in 24 randomized controlled trials in community settings, of which 4 have been gender-specific.

RESULTS

This article summarizes gender-related findings from CTN clinical trials and related studies, focusing on trauma histories, pregnancy, co-occurring eating and other psychiatric disorders, and HIV risk behaviors.

CONCLUSIONS

These published studies have expanded the evidence base regarding interventions for vulnerable groups of women with SUDs as well as gender-specific interventions to reduce HIV risk behaviors in substance-using men and women. The results also underscore the complexity of accounting for gender in the design of clinical trials and analysis of results.

SCIENTIFIC SIGNIFICANCE

To fully understand the relevance of gender-specific moderators and mediators of outcome, it is essential that future translational studies adopt more sophisticated approaches to understanding and measuring gender-relevant factors and plan sample sizes that are adequate to support more nuanced analytic methods.

Anterior cingulate proton spectroscopy glutamate levels differ as a function of smoking cessation outcome

BACKGROUND

Cigarette smoking is the leading preventable cause of death. Unfortunately, the majority of smokers who attempt to quit smoking relapse within weeks. Abnormal dorsal anterior cingulate cortex (dACC) function may contribute to tobacco smoking relapse vulnerability. Growing evidence suggests that glutamate neurotransmission is involved in mediating nicotine dependence. We hypothesized that prior to a cessation attempt, dACC glutamate levels would be lower in relapse vulnerable smokers.

METHODS

Proton magnetic resonance spectra (MRS) were obtained from dACC and a control region, the parieto-occipital cortex (POC), using two-dimensional J-resolved MRS at 4T and analyzed using LCModel. Nine nicotine-dependent women were scanned prior to making a quit attempt. Subjects then were divided into two groups; those able to maintain subsequent abstinence aided by nicotine replacement therapy (NRT) and those who slipped while on NRT (smoked any part of a cigarette after attaining at least 24h of abstinence).

RESULTS

Slip subjects exhibited significantly reduced dACC MRS glutamate (Glu/Cr) levels (p<0.03) compared to abstinent subjects. This effect was not observed in the POC control region.

CONCLUSIONS

Our preliminary findings suggest that dACC Glu levels as measured with MRS may help identify and/or be a biomarker for relapse vulnerable smokers. Future research following up on these findings may help clarify the role of dACC Glu in smoking dependence that may lead to new treatment strategies.

Dopamine transporter genotype modulation of neural responses to smoking cues: confirmation in a new cohort

Previously we demonstrated profound effects of dopamine transporter (DAT) SLC6A3 genotype on limbic responses to smoking cues (SCs). Probands carrying at least one copy of the 9-repeat allele (9-repeat carriers) had greater neural responses to SCs in the anatomically interconnected rostral ventral striatum/medial orbitofrontal cortex (VS/mOFC), compared with homozygotes for the 10-repeat allele (10/10-repeats). To test the reliability of the initial findings, we examined perfusion functional magnetic resonance images acquired during SC exposure in a new cohort of smokers (N=26) who were genotyped for the SLC6A3 polymorphism. In smokers overall, activity was enhanced in the VS/mOFC (t=3.77). Contrasts between allelic groups revealed that 9-repeat carriers had a greater response to SCs in the VS (t=3.12) and mOFC (t=3.19). In separate groups, 9-repeat carriers showed increased activity in the VS (t=5.47) and mOFC (T=4.96), while no increases were observed in 10-repeats. Subjective reports of craving correlated with increased activity in reward-related structures including the extended amygdala, insula and post-central gyrus, and decreased activity in the dorsolateral prefrontal cortex, and were DAT-genotype dependent (r=0.63-0.96). In secondary analyses, we found that The Fagerström Test for Nicotine Dependence scores correlated with enhanced SC-induced perfusion in 10/10-repeats in the insula, mOFC, medial temporal and superior frontal gyri (r=0.50-0.82), while correlations were absent in 9-repeat carriers. Despite heterogeneity introduced by a host of factors, including variance in other genes involved in smoking behavior, we confirm that DAT genotype predicts the direction and location of neural responses to SCs.

Menstrual cycle phase at quit date and smoking abstinence at 6 weeks in an open label trial of bupropion

BACKGROUND

Quit attempts may have different outcomes based on menstrual cycle phase on quit day. This is the first preliminary study examining whether smoking cessation outcomes vary by menstrual cycle phase of quit date in women receiving a 6-week open trial of sustained release (SR) bupropion.

METHODS

Thirty-three treatment-seeking premenopausal women were studied. Abstinence outcomes were compared for women quitting during the luteal versus follicular phase.

RESULTS

Women receiving bupropion SR whose self-selected quit date occurred in the luteal phase had significantly higher rates of point prevalence abstinence during the final week of a 6-week post-quit treatment period than women quitting in the follicular phase (62.5% versus 29.4%; p<0.05). A similar, but non-significant, pattern of findings was demonstrated for continuous abstinence during the treatment phase and for point prevalence abstinence at 3-month follow-up.

CONCLUSIONS

Women receiving bupropion SR were significantly more likely to be abstinent at treatment completion if quitting occurred during the luteal phase. This is consistent with recent findings of outcome related to cycle phase at quit date in the absence of pharmacotherapy, and differs from findings utilizing nicotine replacement. Results add to emerging data suggesting that smoking cessation interventions with varying mechanisms of action may result in different outcomes for premenopausal women based on gonadal hormones at quit date.

Menstrual cycle effects on perceived exertion and pain during exercise among sedentary women

BACKGROUND

Increasing cardiovascular fitness through exercise participation among sedentary people is important for decreasing all-cause mortality. From an intervention perspective, identifying modifiable factors that maximize the successful initiation of exercise is of utmost importance. For women, cyclic hormonal variations can influence aspects of health and health behaviors, from smoking cessation efficacy to physiological responses to exercise. The purpose of this study was to examine the influence of menstrual cycle phase and hormonal contraceptive (HC) use on subjective response to an initial bout of moderate intensity exercise among previously sedentary women (n = 117).

METHODS

Women completed a treadmill exercise challenge session at 65% of their previously determined maximum oxygen consumption (Vo(2) max) during the early follicular, late follicular, or luteal phase. Participants reported ratings of perceived exertion and pain using Borg's Rating of Perceived Exertion (RPE) and CR10 scales at 10, 20, and 30 minutes during the exercise session.

RESULTS

There was a significant menstrual phase x birth control interaction on change in RPE [F(2, 111) = 3.75, p < 0.05] and change in perceived pain [F(2, 110) = 3.31, p < 0.05]. Women in the early follicular phase who were not using HCs had significantly greater increases in RPE and increases in pain compared with women in the late follicular and luteal phases.

CONCLUSIONS

Our results indicate that the use of HC and cycle phase influence sedentary women's subjective response to exercise. These results have important implications for the timing of exercise interventions aimed at increasing exercise among sedentary women.

Effects of varenicline on smoking cue–triggered neural and craving responses

CONTEXT

Varenicline, an effective smoking cessation medication, functions as an α4β2 nicotinic acetylcholine receptor partial agonist. It indirectly affects the dopaminergic reward system by reducing withdrawal symptoms during abstinence and by decreasing the reinforcement received from nicotine while smoking. We hypothesize that varenicline would have a third mechanism to blunt responses to smoking cues in the reward-related ventral striatum and medial orbitofrontal cortex and would be associated with a reduction in smoking cue–elicited craving.

DESIGN

A laboratory model of conditioned responding and arterial spin-labeled perfusion functional magnetic resonance imaging, a biomarker of regional brain activity, was used to test our hypothesis. Perfusion functional magnetic resonance imaging is quantitative and stable across time, facilitating the measurement of medication-induced neural modifications in the brain in response to a challenge (smoking cue exposure) and in the brain in the resting condition (without provocation). Smokers were imaged during rest and during smoking cue exposure before and after a 3-week randomized placebo-controlled medication regimen. Subjects were nonabstinent to explicitly examine the effects of varenicline on cue reactivity independent of withdrawal.

SETTING

Center for the Study of Addictions, University of Pennsylvania, Philadelphia. Subjects Subjects were nicotine-dependent smokers who responded to advertisements placed on local radio and Listservs to participate in a medication-related research study that specifically stated "this is not a Quit Smoking Study" and "smokers may be contemplating but not currently considering quitting."

RESULTS

Prerandomization smoking cues vs nonsmoking cues activated the ventral striatum and medial orbitofrontal cortex (t = 3.77) and elicited subjective reports of craving (P = .006). Craving reports correlated with increased activity in the posterior cingulate (t = 4.11). Administration of varenicline diminished smoking cue–elicited ventral striatum and medial orbitofrontal cortex responses (t values from –3.75 to –5.63) and reduced self-reported smoking cue–elicited craving, whereas placebo-treated subjects exhibited responses similar to those observed prior to randomization. Varenicline-induced activation of lateral orbitofrontal cortex in the brain at rest (t = 5.63) predicted blunting of smoking cue responses in the medial orbitofrontal cortex (r = –0.74).

CONCLUSIONS

Varenicline's reciprocal actions in the reward-activated medial orbitofrontal cortex and in the reward-evaluating lateral orbitofrontal cortex underlie a diminished smoking cue response, revealing a distinctive new action that likely contributes to its clinical efficacy.

Role of progesterone in nicotine addiction: evidence from initiation to relapse

Nicotine addiction continues to be the main cause of preventable death in developed countries. Women and teen girls appear to be more vulnerable on certain aspects of nicotine addiction compared with men and boys. While the mechanism of gender differences in nicotine addiction is not yet clear, evidence suggests that while estrogen may underlie enhanced vulnerability in females, progesterone may protect females. Thus, progesterone may have therapeutic use for tobacco addiction, especially in female smokers. A greater understanding of the role of progesterone in nicotine addiction is important not only from a treatment standpoint, but also from a prevention standpoint: hormone transition phases, such as those that occur at adolescence, and during pregnancy and following birth, as well as following hormonal manipulation (e.g., using methods of hormonal birth control), may all contribute to changes in vulnerability to nicotine addiction. In this review, we summarize recent evidence from clinical and preclinical studies examining the role of progesterone in nicotine addiction focusing on its role during initiation of use and during later phases of the addiction process as a potential relapse prevention treatment. We conclude with future directions including further examination of progesterone as a potential intervention and treatment of nicotine addiction.

Premenstrual and menstrual symptomatology in young adult Japanese females who smoke tobacco

AIM

The present study examines the correlation between premenstrual and menstrual symptomatology and smoking status in young adult Japanese females.

MATERIAL AND METHODS

A cross-sectional study was conducted to assess premenstrual and menstrual symptomatology using the Moos Menstrual Distress Questionnaire (MDQ). Findings were compared between smokers and nonsmokers. The correlation between symptomatology and smoking status assessed by the Fagerström Test for Nicotine Dependency (FTND) and the Reasons for Smoking Scale (RSS), which identifies smoker's motives, was determined.

RESULTS

Data were obtained from 785 participants, including 71 smokers, 29 quitters and 685 nonsmokers. All smokers consumed 20 or fewer cigarettes per day with the exception of one heavy smoker. Smoking status affected the cycle of menstruation, but did not affect the duration. Smokers demonstrated more severe symptomatology than nonsmokers during the menstrual and premenstrual phases. Among smokers, premenstrual symptomatology was significantly more severe than menstrual symptomatology. Five premenstrual symptom groups (pain, concentration, water retention, behavior change and negative affect) were significantly higher in smokers than in nonsmokers. Overall MDQ scores and those of three subcategories (concentration, behavior change, and negative affect) during the premenstrual phase were significantly correlated with nicotine dependency and smoking motives. Smoking motives were also correlated with the severity of autonomic reaction.

CONCLUSION

Our findings suggest that young adult Japanese females with a light smoking habit have severe premenstrual symptomatology, which was correlated with nicotine dependency and smoking motives.

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.

The role of progestins in the behavioral effects of cocaine and other drugs of abuse: human and animal research

This review summarizes findings from human and animal research investigating the influence of progesterone and its metabolites allopreganolone and pregnanolone (progestins) on the effects of cocaine and other drugs of abuse. Since a majority of these studies have used cocaine, this will be the primary focus; however, the influence of progestins on other drugs of abuse will also be discussed. Collectively, findings from these studies support a role for progestins in (1) attenuating the subjective and physiological effects of cocaine in humans, (2) blocking the reinforcing and other behavioral effects of cocaine in animal models of drug abuse, and (3) influencing behavioral responses to other drugs of abuse such as alcohol and nicotine in animals. Administration of several drugs of abuse in both human and nonhuman animals significantly increased progestin levels, and this is explained in terms of progestins acting as homeostatic regulators that decrease and normalize heightened stress and reward responses which lead to increased drug craving and relapse. The findings discussed here highlight the complexity of progestin-drug interactions, and they suggest a possible use for these agents in understanding the etiology of and developing treatments for drug abuse.

Modeling complex genetic and environmental influences on comorbid bipolar disorder with tobacco use disorder

Background

Comorbidity of psychiatric and substance use disorders represents a significant complication in the clinical course of both disorders. Bipolar Disorder (BD) is a psychiatric disorder characterized by severe mood swings, ranging from mania to depression, and up to a 70% rate of comorbid Tobacco Use Disorder (TUD). We found epidemiological evidence consistent with a common underlying etiology for BD and TUD, as well as evidence of both genetic and environmental influences on BD and TUD. Therefore, we hypothesized a common underlying genetic etiology, interacting with nicotine exposure, influencing susceptibility to both BD and TUD.

Methods

Using meta-analysis, we compared TUD rates for BD patients and the general population. We identified candidate genes showing statistically significant, replicated, evidence of association with both BD and TUD. We assessed commonality among these candidate genes and hypothesized broader, multi-gene network influences on the comorbidity. Using Fisher Exact tests we tested our hypothesized genetic networks for association with the comorbidity, then compared the inferences drawn with those derived from the commonality assessment. Finally, we prioritized candidate SNPs for validation.

Results

We estimate risk for TUD among BD patients at 2.4 times that of the general population. We found three candidate genes associated with both BD and TUD (COMT, SLC6A3, and SLC6A4) and commonality analysis suggests that these genes interact in predisposing psychiatric and substance use disorders. We identified a 69 gene network that influences neurotransmitter signaling and shows significant over-representation of genes associated with BD and TUD, as well as genes differentially expressed with exposure to tobacco smoke. Twenty four of these genes are known drug targets.

Conclusions

This work highlights novel bioinformatics resources and demonstrates the effectiveness of using an integrated bioinformatics approach to improve our understanding of complex disease etiology. We illustrate the development and testing of hypotheses for a comorbidity predisposed by both genetic and environmental influences. Consistent with our hypothesis, the selected network models multiple interacting genetic influences on comorbid BD with TUD, as well as the environmental influence of nicotine. This network nominates candidate genes for validation and drug testing, and we offer a panel of SNPs prioritized for follow-up.

Menstrual cycle and cue reactivity in women smokers

INTRODUCTION

Emerging research suggests potential effects of the menstrual cycle on various aspects of smoking behavior in women, but results to date have been mixed. The present study sought to explore the influence of menstrual cycle phase on reactivity to smoking in vivo and stressful imagery cues in a sample of non-treatment-seeking women smokers.

METHODS

Via a within-subjects design, nicotine-dependent women (N = 37) participated in a series of four cue reactivity sessions, each during a distinct biologically verified phase of the menstrual cycle (early follicular [EF], mid-follicular [MF], mid-luteal [ML], and late luteal [LL]). Subjective (Questionnaire of Smoking Urges-Brief; QSU-B) and physiological (skin conductance and heart rate) measures of craving and reactivity were collected and compared across phases.

RESULTS

Subjective reactive craving (QSU-B) to smoking in vivo cues varied significantly across the menstrual cycle (p = .02) and was higher in both EF and MF phases versus ML and LL phases, but this finding was not sustained when controlling for reactivity to neutral cues. Heart rate reactivity to stressful imagery cues (p = .01) and skin conductance reactivity to smoking in vivo cues (p = .05) varied significantly across the menstrual cycle upon controlling for reactivity to neutral cues, with highest reactivity during the MF phase.

DISCUSSION

Menstrual cycle phase may have an effect on reactivity to smoking-related and stressful cues among women smokers. These findings contribute to an expanding literature, suggesting menstrual cycle effects on smoking behaviors in women.

Patterns of self-selected smoking cessation attempts and relapse by menstrual phase

Clinical studies are emerging which suggest that sex hormones may play a role in quit attempts and relapse. The present study aim is to determine if menstrual phase plays a role on a second self-selected quit attempt and subsequent relapse during a twenty-six week follow-up. Participants (n=138) were 29.7+/-6.5 years old and smoked 16.1+/-4.8 cigarettes per day. Participants were more likely to self-select a second quit date during the Follicular (F) phase (59.4%) than Luteal (L) phase (40.6%, p=0.033) and were also more likely to relapse during the F phase than the L phase (59.7% vs. 40.3%, p=0.043, respectively). Those who self-selected to quit in the L phase experienced a significantly longer time to relapse than those who chose the F phase (median of 3 days vs. 2 days, respectively; Hazard Ratio=1.599, p-value=0.014). This confirms previous work suggesting quit dates in the F phase are associated with worse smoking cessation outcomes. Additional research is needed to investigate how this relationship may vary with the use of pharmacotherapy.

Sex and ovarian hormones influence vulnerability and motivation for nicotine during adolescence in rats

The purpose of this study was to examine sex differences in sensitivity to nicotine's reinforcing effects during adolescence, a hormone transition phase characterized by rapid and marked changes in levels of gonadal hormones. Male and female rats were trained to self-administer nicotine (5 or 10 microg/kg/infusion) under a fixed-ratio 1 schedule beginning on postnatal day 30. Following acquisition, responding was assessed under a progressive-ratio schedule until postnatal day 45 with blood sampling occurring prior to the first 5 sessions in order to determine the relationship between gonadal hormones (i.e., estradiol and progesterone in females and testosterone in males) and responding for nicotine. Under low dose conditions, a greater percentage of females than males acquired nicotine self-administration. Under progressive-ratio testing conditions, although adolescent females and males initially responded at similar levels, by the end of the adolescent testing period, females responded at higher levels than males to obtain nicotine infusions. Levels of responding under the progressive-ratio schedule were negatively associated with progesterone and positively associated with the ratio of estradiol to progesterone. These findings demonstrate an enhanced sensitivity in adolescent females as compared to adolescent males to nicotine's reinforcing effects with evidence implicating circulating hormone levels as modulating this sensitivity.

Altered pattern of sympathetic activity with the ovarian cycle in female smokers

Smoking increases cardiovascular risk in young women and eliminates the protective effect of the premenopausal state. Increased sympathetic nervous system (SNS) activity is associated with increased cardiovascular risk. One potential mechanism by which smoking increases risk is through chronic SNS activation. It has been reported that premenopausal women have high SNS activity during the midluteal (ML) phase, which falls to low levels during the early follicular (EF) phase. We tested the hypothesis that smoking disrupts this fall in SNS activity during the EF phase. We measured blood pressure and muscle sympathetic nerve activity (MSNA) using microneurography in 11 premenopausal female smokers and 11 age-matched nonsmoking controls at two separate times during the ovarian cycle: ML phase (8-10 days after the luteinizing hormone surge) and EF phase (days 1-4 of the menstrual cycle). The change in MSNA from the EF phase to the ML phase was significantly different between the smoking and nonsmoking groups (P = 0.036). Whereas there was a significant decrease in MSNA from the ML phase to the EF phase among nonsmoking controls (22.7 +/- 3.3 vs. 17.9 +/- 2.8 bursts/min, P = 0.012), MSNA remained elevated during the EF phase in smokers (22.5 +/- 3.8 vs. 26.8 +/- 4.0 bursts/min, P = 0.28). Surprisingly, mean arterial pressure (MAP) was significantly lower during the ML phase than in the EF phase in both nonsmokers (P = 0.0080) and smokers (P = 0.0094). We conclude that smoking disrupts the ovarian pattern of SNS activity by preventing the normal fall in MSNA during the EF phase of the ovarian cycle. Such chronic alterations may contribute to the pathogenesis of cardiovascular risk in young smoking females.

Nicotine withdrawal and craving in adolescents: effects of sex and hormonal contraceptive use

While sex differences in the nicotine withdrawal (NW) symptoms and craving (NC) have been extensively described in adult cigarette smokers, few studies have investigated these phenomena in adolescents. We investigated the effect of gender and hormonal contraception (HC) on NW and NC during the first 14 days of cessation in adolescent smokers using data from a randomized, placebo-controlled, double-blind trial of the transdermal nicotine replacement therapy for smoking cessation. Analyses showed similar levels of NW severity in males and females, regardless of HC use. However, significantly higher NC was observed in females compared to males, (2.22+/-0.12 vs. 1.65+/-1.14; p=0.003). Further, females not using HC reported the highest level of NC (2.38+/-0.16) followed by females using HC (2.08+/-0.25) and males (1.71+/-0.16; p=0.007). The current findings suggest that adolescent females experience similar NW severity to males, but have stronger NC. Further, the use of hormonal contraceptives may impact the severity of craving. Addressing these different symptoms in adolescents may be useful in increasing smoking cessation rates in this special population of smokers.