Accelerated metabolism of nicotine and cotinine in pregnant smokers

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.

Understanding pregnant women's adherence-related beliefs about Nicotine Replacement Therapy for smoking cessation: A qualitative study

INTRODUCTION

Reducing smoking during pregnancy is a public health priority. Nicotine replacement therapy (NRT) is offered routinely to pregnant women who smoke in the United Kingdom. However, evidence of treatment efficacy in this population is weak, most likely due to poor adherence. Guided by the Necessity-Concerns Framework, we conducted a qualitative study to better understand pregnant women's perceived needs and concerns regarding NRT use, with consideration of combination NRT.

METHODS

Semi-structured interviews were conducted by telephone with 18 pregnant or recently pregnant women in England and Wales, purposively sampled for different NRT-related experiences. Participants were recruited online via Facebook adverts and through a Stop Smoking Service. A hybrid approach of deductive and inductive thematic coding was used for analysis.

RESULTS

Findings were organized around three themes: 1) the role of motivation to stop smoking; 2) necessity beliefs about using NRT; and 3) concerns about NRT. Some women reported fluctuating motivation for stopping smoking which undermined their NRT use. Others used NRT to cut down the number of cigarettes they smoked. Reasons for low NRT necessity beliefs included a preference for quitting unassisted, low or unrealistic expectations of efficacy, and overconfidence in achieving cessation (necessity testing). Concerns included safety, particularly around increased nicotine exposure with combination NRT, addictiveness, side effects, and capability to use.

CONCLUSION

Pregnant women have multiple necessity beliefs and concerns that influence their use of NRT. Targeting these, alongside increasing and maintaining motivation to quit smoking, will likely help optimize NRT use in pregnancy and improve quit rates.

Anatomical and physiological alterations of pregnancy

The extensive metabolic demands of pregnancy require specific physiological and anatomical changes. These changes affect almost all organ systems, including the cardiovascular, respiratory, renal, gastrointestinal, and hematologic system. The placenta adds another layer of complexity. These changes make it challenging for clinicians to understand presenting signs and symptoms, or to interpret laboratory and radiological tests. Furthermore, these physiological alterations can affect the pharmacokinetics and pharmacodynamics of drugs. Drug safety in lactation is only supported by limited evidence. In addition, the teratogenic effects of medications are often extrapolated from animals, which further adds uncertainties. Unfortunately, pregnant women are only rarely included in clinical drug trials, while doses, regimens, and side effects are often extrapolated from studies conducted in non-pregnant populations. In this comprehensive review, we present the changes occurring in each system with its effects on the pharmacokinetic variables. Understanding these physiological changes throughout normal pregnancy helps clinicians to optimize the health of pregnant women and their fetuses. Furthermore, the information on pregnancy-related physiology is also critical to guide study design in this vulnerable 'orphan' population, and provides a framework to explore pregnancy-related pathophysiology such as pre-eclampsia.

Urinary Cotinine as a Biomarker of Cigarette Smoke Exposure: A Method to Differentiate Among Active, Second-Hand, and Non-Smoker Circumstances

Objective:

To review the literature on the use of urinary cotinine as a biological marker of cigarette smoke exposure.

Methods:

Narrative review of original and review articles on the topic of interest, published in Portuguese or English by June 2018, and selected in the following online databases: PubMed and Virtual Health Library (VHL).

Results:

Urinary cotinine is usually the recommended biomarker to estimate exposure to cigarette smoke, and can be used alone or, preferably, in association with questionnaires. Different analytical techniques can be used to quantify urinary cotinine and are differently performed because of urine sample interfering factors.

Conclusion:

The precise classification of smoking status is essential. It is advisable to use objective measurements regarding smoking habits since self-reported smoking may not always represent the true smoking status of the individual, particularly in groups that are more vulnerable to omitting the information of questionnaries, in addition, it has possible biases of memory. The accurate assessment of smoking is crucial to improve clinical management and counseling for different diseases as well as the establishment of preventive strategies. So, the use of urinary cotinine as a biomarker of cigarette smoke exposure seems to be a suitable assay to distinguish non-smokers from passive and active smokers.

Intensive Behavioural and Pharmacological Treatment for Tobacco Dependence in Pregnant Women with Complex Psychosocial Challenges: A Case Report

Up to 95% of women who use other substances also smoke tobacco during pregnancy. Challenging psychosocial circumstances and other barriers that contribute to high levels of tobacco dependence result in few quitting successfully. This case report describes the treatment of a highly tobacco dependent 34-year-old pregnant woman with a history of recent substance use, mental illness and trauma, enrolled in the Incentives to Quit Tobacco in Pregnancy program. Heavy smoking, both during the day and overnight, was reported. An extensive history of quit attempts, as well as a strong desire to cease tobacco use during pregnancy, was also noted. Treatment utilising extensive behavioural supports, including financial incentives for carbon monoxide verified abstinence and telephone-based counselling, in combination with nicotine replacement therapy (NRT), was offered to assist cessation. Excellent uptake and adherence to all aspects of treatment saw tobacco cessation achieved and maintained for 24 weeks while on the program. NRT used at doses well above those recommended for pregnancy was required to alleviate strong withdrawal symptoms and maintain abstinence. Daily monitoring of carbon monoxide, financial incentives for continued abstinence and regular phone support were critical to maintaining motivation and preventing relapse to smoking. Post-program relapse to smoking did occur, as is common, and highlights the need for longer-term intensive support for pregnant women with complex behavioural and social problems. Given the prevalence of tobacco smoking in such populations, long-term harm reduction treatment models using extensive behavioural support in combination with NRT should be considered for inclusion in current smoking cessation guidelines.

[Physiological and Psychological Data influencing Pregnant Women Smoking Behavior - CNGOF-SFT Expert Report and Guidelines for Smoking Management during Pregnancy]

Nicotine is the main addictive substance in tobacco and its addictive effects mainly involve dopamine. Nicotine is mainly metabolized (C-oxidation) in the liver to cotinine by the cytochrome P450 enzyme system. Nicotine half-life is short being about 2hours. Nicotine metabolism appears to be increased during pregnancy, mainly due to an increased cytochrome activity and maternal cardiac output. Thus, the smoking behavior of the pregnant woman is subsequently modified with an increase in withdrawal syndromes and an increased desire to smoke. These pharmacological elements should be taken into account when prescribing nicotine replacement therapy. Regarding the markers of tobacco intoxication, there is a good correlation between the importance of smoking and the measurement of expired air carbon monoxide. Although there is no evidence of decreased obstetrical complications related to its use, it is simple and non-invasive and therefore may be useful in routine practice. It gives an instantaneous value of tobacco intoxication, and represents a starting point for dialogue and management and can help to highlight the reality of withdrawal. Regarding the evaluation of tobacco addiction, the most commonly used questionnaires are the Fagerström tests (FTCD, HSI…), which are well correlated with cotinine concentration. However, there is insufficient evidence of their usefulness in reducing tobacco consumption during pregnancy to recommend them in current practice. DSM-V diagnostic criteria for addiction should be known as they can also be used to characterize the intensity of this addiction.

General practitioner and obstetrician views on system changes to improve smoking cessation care in pregnancy in Australia: a cross-sectional survey

Introduction

Systemic barriers impacting smoking cessation in pregnant women may include nicotine replacement therapy (NRT) access and training.

Aim

Assess general practitioner (GP) and obstetrician's agreement with system-based changes to improve the management of smoking in pregnancy; compare group responses.

Methods

National cross-sectional survey with two samples: (1) online survey emailed to a random sample of 500 GPs from Royal Australian College of General Practitioners (RACGP); (2) paper survey posted to 5571 GPs and obstetricians from Royal Australia and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). Percentages agreeing that specified changes would improve the management of smoking in pregnancy were calculated. Pairwise comparisons used Kruskal–Wallis tests (RACGP/RANZCOG GPs/obstetricians).

Results

N = 378 participated. Response rates 8.4% (N = 42; online survey) and 6% (N = 335; paper survey), respectively. Total percentages agreeing with system-based changes: 79% training, 64% oral NRT subsidy, 62% Medicare item for smoking cessation, 54% improved access to NRT patches. Within RANZCOG, more GPs (73.1%) agreed that oral NRT should be subsidised (P = 0.001) than obstetricians (53.7%).

Conclusion

GPs and obstetricians agreed that system changes would improve their management of smoking in pregnancy. Oral NRT subsidy was the only pairwise group difference. Subsequently, oral NRT has been subsidised; in time, this may influence prescribing and quit rates.

Pregnancy-Induced Increases in the Nicotine Metabolite Ratio: Examining Changes During Antepartum and Postpartum

INTRODUCTION

Pregnancy-induced increases in nicotine metabolism may contribute to difficulties in quitting smoking during pregnancy. However, the time course of changes in nicotine metabolism during early and late pregnancy is unclear. This study investigated how pregnancy alters the nicotine metabolite ratio (NMR), a common biomarker of nicotine metabolism among nonpregnant smokers.

METHODS

Urinary NMR (trans-3'-hydroxycotinine [3HC]/cotinine [COT]) was assessed using total (free + glucuronide) and free compounds among women (N = 47) from a randomized controlled trial for smoking cessation who self-reported smoking and provided a urine sample during early pregnancy (M ± SD = 12.5 ± 4.5 weeks' gestation), late pregnancy (28.9 ± 2.0 weeks' gestation), and 6 months postpartum (24.7 ± 1.2 weeks since childbirth). Urine samples were analyzed using liquid chromatography-tandem mass spectrometry and NMR were calculated as Total 3HC/Free COT, Free 3HC/Free COT, and Total 3HC/Total COT.

RESULTS

NMR was significantly higher during early and late pregnancy compared to postpartum and significantly increased from early to late pregnancy as measured by Total 3HC/Free COT (0.76, 0.89, 0.60; all p's < .05) and Free 3HC/Free COT (0.68, 0.80, 0.51; all p's < .05). Total 3HC/Total COT did not vary over time (p = .81).

CONCLUSIONS

Total 3HC/Free COT and Free 3HC/Free COT increased in the first trimester and continued to increase throughout pregnancy, suggesting a considerable increase in nicotine metabolism over gestation. Future analyses are needed to interpret the changes in NMR in the context of nicotine pharmacokinetics, as well as its impact on changes in smoking behavior and cessation outcomes.

IMPLICATIONS

We observed that the NMR was significantly higher as early as 12 weeks' gestation and increased further as a function of gestational age. Among nonpregnant smokers, elevated NMR is associated with smoking phenotypes such as smoking more cigarettes per day and poorer response to nicotine patch; therefore, pregnancy-induced increases in the NMR may contribute to smoking during the first trimester of pregnancy and reducing or quitting smoking may become more challenging as the rate of nicotine metabolism accelerates over the course of pregnancy.

High Maternal Circulating Cotinine During Pregnancy is Associated With Persistently Shorter Stature From Birth to Five Years in an Asian Cohort

BACKGROUND

Self-reported maternal active smoking has been associated with reduced offspring birth length and shorter stature in early and late childhood.

OBJECTIVE

To use circulating cotinine as an objective biomarker to investigate the association between smoking and environmental tobacco smoke (ETS) exposure in pregnancy and longitudinal measures of offspring length/height from birth to 60 months.

METHODS

In 969 maternal-offspring dyads from the GUSTO cohort, maternal plasma cotinine at 26-28 weeks' gestation was measured by LC/MS/MS and categorized into four groups: Group 1: cotinine <0.17 ng/mL (the assay's detection limit) and no ETS exposure; Group 2: cotinine <0.17 ng/mL but self-reported ETS; Group 3: cotinine 0.17-13.99 ng/mL (ETS or light smoking); Group 4: cotinine ≥14 ng/mL (active smoking).

RESULTS

Adjusting for infant sex, gestational age at birth, ethnicity, maternal age, education, parity, BMI, and height, Group 4 offspring were shorter at birth [z-score β = -0.42 SD units (SDs) (95% CI = -0.77 to -0.06)] than Group 1 offspring. Group 4 offspring continued to be shorter at older ages, with similar effect sizes at 3 months [-0.57 SDs (-0.95 to -0.20)], 36 months [-0.53 SDs (-0.92 to -0.15)], 48 months [-0.43 SDs (-0.81 to -0.04)], and 60 months [-0.57 SDs (-0.96 to -0.17)]. Associations were particularly marked in boys. No significant differences in stature were observed in Groups 2 or 3 compared with Group 1.

CONCLUSIONS

This Asian longitudinal study associated high prenatal cotinine with persistently shorter stature in offspring from birth and into early childhood, whilst low prenatal cotinine levels and ETS exposure showed no such association.

IMPLICATIONS

Little is known about the long-term effects of prenatal tobacco exposure on offspring stature in Asia where passive smoking is common. This study has used an objective biomarker to reveal that the association of prenatal tobacco exposure with offspring length/height mainly occurs at a high maternal cotinine level of greater than 14 ng/mL in pregnancy, consistent with active smoking, but no significant associations were found with lower cotinine levels, consistent with passive smoking. Encouraging women to quit smoking prior to or during pregnancy may avert the long-term negative impact on their child's height despite appreciable prenatal ETS exposure.

Altered activity of xenobiotic detoxifying enzymes at menopause - A cross-sectional study

Xenobiotic metabolism at menopause is an under-investigated topic, albeit women spend one-third of their life in the postmenopausal period. The present study examined the effect of menopause on the in vivo activities of CYP1A2, CYP2A6, xanthine oxidase (XO) and N-acetyltransferase-2 (NAT2) xenobiotic metabolizing enzymes. Enzyme activity was determined in 152 non-smoking volunteers following oral intake of a single dose of 200 mg caffeine and subsequent determination of caffeine metabolite ratios (CMRs) in a 6-h urine sample as follows: CYP1A2: (AFMU+1U+1X)/17U, CYP2A6: 17U/(17U + 17X), XO: 1U/(1U+1X) and NAT2: AFMU/(AFMU+1U+1X). CMRs among groups were analyzed using one-way ANOVA. Significantly lower CYP1A2 and higher CYP2A6 CMRs were observed in postmenopausal compared to premenopausal women and age-matched men. These changes could be attributed to menopause rather than chronological aging since an age-related effect was not observed in premenopausal women or men of any age group. XO CMRs were higher in postmenopausal women and men>50 compared to premenopausal women and men<50, respectively, suggesting an age-related increase in XO activity. No significant alterations were discerned in NAT2 CMRs, in either slow- or rapid-acetylators, indicating that menopause exerts minimal modulation of xenobiotics metabolized by this enzyme. This study provides evidence that the transition to menopause induces significant alterations in xenobiotic-metabolizing enzymes independent of chronological aging suggesting altered metabolism of pharmaceutical and environmental agents.

Clinical Pharmacokinetic Studies in Pregnant Women and the Relevance of Pharmacometric Tools

BACKGROUND

In clinical pharmacokinetic (PK) studies, pregnant women are significantly underrepresented because of ethical and legal reasons which lead to a paucity of information on potential PK changes in this population. As a consequence, pharmacometric tools became instrumental to explore and quantify the impact of PK changes during pregnancy.

METHODS

We explore and discuss the typical characteristics of population PK and physiologically based pharmacokinetic (PBPK) models with a specific focus on pregnancy and postpartum.

RESULTS

Population PK models enable the analysis of dense, sparse or unbalanced data to explore covariates in order to (partly) explain inter-individual variability (including pregnancy) and to individualize dosing. For population PK models, we subsequently used an illustrative approach with ketorolac data to highlight the relevance of enantiomer specific modeling for racemic drugs during pregnancy, while data on antibiotic prophylaxis (cefazolin) during surgery illustrate the specific characteristics of the fetal compartments in the presence of timeconcentration profiles. For PBPK models, an overview on the current status of reports and papers during pregnancy is followed by a PBPK cefuroxime model to illustrate the added benefit of PBPK in evaluating dosing regimens in pregnant women.

CONCLUSIONS

Pharmacometric tools became very instrumental to improve perinatal pharmacology. However, to reach their full potential, multidisciplinary collaboration and structured efforts are needed to generate more information from already available datasets, to share data and models, and to stimulate cross talk between clinicians and pharmacometricians to generate specific observations (pathophysiology during pregnancy, breastfeeding) needed to further develop the field.

Use of smoking cessation pharmacotherapies during pregnancy is not associated with increased risk of adverse pregnancy outcomes: a population-based cohort study

BACKGROUND

Varenicline, bupropion and nicotine replacement therapy (NRT) are three effective pharmacotherapies for smoking cessation, but data about their safety in pregnancy are limited. We assessed the risk of adverse perinatal outcomes and major congenital anomalies associated with the use of these therapies in pregnancy in Australia.

METHODS

Perinatal data for 1,017,731 deliveries (2004 to 2012) in New South Wales and Western Australia were linked to pharmaceutical dispensing, hospital admission and death records. We identified 97,875 women who smoked during pregnancy; of those, 233, 330 and 1057 were exposed to bupropion, NRT and varenicline in pregnancy, respectively. Propensity scores were used to match exposed women to those who were unexposed to any smoking therapy (1:10 ratio). Propensity scores and gestational age at exposure were used to match varenicline-exposed to NRT-exposed women (1:1 ratio). Time-dependent Cox proportional hazards models estimated hazard ratios (HR) with 95% confidence intervals (95% CI) for any adverse perinatal event (a composite of 10 unfavourable maternal and neonatal outcomes) and any major congenital anomaly.

RESULTS

The risk of any adverse perinatal event was not significantly different between bupropion-exposed and unexposed women (39.2% versus 39.3%, HR 0.93, 95% CI 0.73-1.19) and between NRT-exposed and unexposed women (44.8% vs 46.3%, HR 1.02, 95% CI 0.84-1.23), but it was significantly lower in women exposed to varenicline (36.9% vs 40.1%, HR 0.86, 95% CI 0.77-0.97). Varenicline-exposed infants were less likely than unexposed infants to be born premature (6.5% vs 8.9%, HR 0.72, 95% CI 0.56-0.92), be small for gestational age (11.4% vs 15.4%, HR 0.68, 95% CI 0.56-0.83) and have severe neonatal complications (6.6% vs 8.2%, HR 0.74, 95% CI 0.57-0.96). Among infants exposed to varenicline in the first trimester, 2.9% had a major congenital anomaly (3.5% in unexposed infants, HR 0.91, 95% CI 0.72-1.15). Varenicline-exposed women were less likely than NRT-exposed women to have an adverse perinatal event (38.7% vs 51.4%, HR 0.58, 95% CI 0.33-1.05).

CONCLUSIONS

Pregnancy exposure to smoking cessation pharmacotherapies does not appear to be associated with an increased risk of adverse birth outcomes. Lower risk of adverse birth outcomes in varenicline-exposed pregnancies is inconsistent with recommendations that NRT be used in preference to varenicline.

The Incentives to Quit tobacco in Pregnancy (IQuiP) protocol: piloting a financial incentive-based smoking treatment for women attending substance use in pregnancy antenatal services

INTRODUCTION

While tobacco smoking prevalence is falling in many western societies, it remains elevated among high-priority cohorts. Rates up to 95% have been reported in women whose pregnancy is complicated by other substance use. In this group, the potential for poor pregnancy outcomes and adverse physical and neurobiological fetal development are elevated by tobacco smoking. Unfortunately, few targeted and effective tobacco dependence treatments exist to assist cessation in this population. The study will trial an evidence-based, multicomponent tobacco smoking treatment tailored to pregnant women who use other substances. The intervention comprises financial incentives for biochemically verified abstinence, psychotherapy delivered by drug and alcohol counsellors, and nicotine replacement therapy. It will be piloted at three government-based, primary healthcare facilities in New South Wales (NSW) and Victoria, Australia. The study will assess the feasibility and acceptability of the treatment when integrated into routine antenatal care offered by substance use in pregnancy antenatal services.

METHODS AND ANALYSIS

The study will use a single-arm design with pre-post comparisons. One hundred clients will be recruited from antenatal clinics with a substance use in pregnancy service. Women must be <33 weeks' gestation, ≥16 years old and a current tobacco smoker. The primary outcomes are feasibility, assessed by recruitment and retention and the acceptability of addressing smoking among this population. Secondary outcomes include changes in smoking behaviours, the comparison of adverse maternal outcomes and neonatal characteristics to those of a historical control group, and a cost-consequence analysis of the intervention implementation.

ETHICS AND DISSEMINATION

Protocol approval was granted by Hunter New England Human Research Ethics Committee (Reference 17/04/12/4.05), with additional ethical approval sought from the Aboriginal Health and Medical Research Council of NSW (Reference 1249/17). Findings will be disseminated via academic conferences, peer-reviewed publications and social media.

TRIAL REGISTRATION NUMBER

Australia New Zealand Clinical Trial Registry (Ref: ACTRN12618000576224).

A Validation and Calibration Process for Self-reported Tobacco Use With Participants' Cotinine Levels: An Example From the Building Blocks Trial

INTRODUCTION

Reducing smoking in pregnancy was a primary outcome in our Building Blocks trial of the Family Nurse Partnership. We calibrated maternal reports of smoking using cotinine values derived from urine samples to assess tobacco use. This involves identifying the extent to which an individual accurately reports smoking and requires complete and synchronized data collection over time. However, some urine samples may be missed or collected at a different time from self-report (non-synchronized.

METHODS

We used statistical validation processes to address both non-synchronized and incomplete data. First, we examined consistency in reporting behaviors at baseline and follow-up for participants grouped by extent of non-synchronized time of collection. Second, we used data from complete cases to infer values for mothers with missing urine samples at follow-up. We then used Markov chain transition rate matrix constructed to assess the robustness of such inferences.

RESULTS

Maternal underreporting and overreporting of smoking were consistent across the 870 participants grouped by different levels of noncontemporary data collection (Breslow-Day test: p = .24; chi-square test: p = .69). Using participants' baseline reporting behaviors to infer their follow-ups provided comparable smoking outcomes (4.5 cigarettes/day with SD of 5.5) to the simulated counterparts (4.5 cigarettes/day with SD of 6.0).

CONCLUSION

We have demonstrated consistent reporting behavior over time and minimal impact due to nonaligned follow-up urine sample collection. For studies collecting smoking data, this proposed method provided a pragmatic solution to facilitate the calibration process of self-reported tobacco use and retain adequate power without introducing undue bias.

IMPLICATIONS

Synchronized and completed data collection is essential but very often hard to achieve in smoking related studies. When violated, proper statistical validation process should be followed to minimize the potential bias and loss of power in trial analyses. For this purpose, we provided the Building Block trial as an example to demonstrate how to deal with the non-synchronization and incompleteness issues in data collection.

Prenatal nicotine sex-dependently alters adolescent dopamine system development

Despite persistent public health initiatives, many women continue to smoke during pregnancy. Since maternal smoking has been linked to persisting sex-dependent neurobehavioral deficits in offspring, some consider nicotine to be a safer alternative to tobacco during pregnancy, and the use of electronic nicotine delivery systems is on the rise. We presently show, however, that sustained exposure to low doses of nicotine during fetal development, approximating plasma levels seen clinically with the nicotine patch, produces substantial changes in developing corticostriatal dopamine systems in adolescence. Briefly, pregnant dams were implanted on gestational day 4 with an osmotic minipump that delivered either saline (GS) or nicotine (3 mg/kg/day) (GN) for two weeks. At birth, pups were cross-fostered with treatment naïve dams and were handled daily. Biochemical analyses, signaling assays, and behavioral responses to cocaine were assessed on postnatal day 32, representative of adolescence in the rodent. GN treatment had both sex-dependent and sex-independent effects on prefrontal dopamine systems, altering Catechol-O-methyl transferase (COMT)-dependent dopamine turnover in males and norepinephrine transporter (NET) binding expression in both sexes. GN enhanced cocaine-induced locomotor activity in females, concomitant with GN-induced reductions in striatal dopamine transporter (DAT) binding. GN enhanced ventral striatal D2-like receptor expression and G-protein coupling, while altering the roles of D2 and D3 receptors in cocaine-induced behaviors. These data show that low-dose prenatal nicotine treatment sex-dependently alters corticostriatal dopamine system development, which may underlie clinical deficits seen in adolescents exposed to tobacco or nicotine in utero.

Interventions for pregnant women who use tobacco and other substances: a systematic review protocol

INTRODUCTION

The prevalence of tobacco smoking in pregnancy remains elevated in some disadvantaged populations of women. One group is those who use alcohol and/or other psychoactive substances during pregnancy, with tobacco use prevalence estimates ranging from 71% to 95%. Although effective evidence-based cessation treatments exist, few women with co-occurring substance use problems successfully stop smoking during pregnancy. There is limited information about treatments that specifically target this group and a summary of the available research is required to assist and enhance the development of innovative cessation interventions. This article describes a protocol for a comprehensive review of studies that have trialled behavioural and/or pharmacological tobacco cessation interventions in populations of pregnant women who are nicotine dependent and use alcohol and/or other psychoactive substances.

METHODS AND ANALYSIS

The review will undertake literature searches in MEDLINE, PsycINFO, CINAHL, EMBASE and ProQuest databases, as well as the grey literature. Studies of any design methodology will be included if they describe changes to tobacco smoking behaviours in quantitative terms. No restriction on year of publication or published language will apply. Participants include pregnant women of any age, who smoke tobacco, who are seeking or having treatment, or in post-treatment recovery for the use of psychoactive substances. Interventions are any psychological, behavioural or pharmacological treatments used to treat tobacco use. Outcome measures are any that quantitatively report abstinence or reductions in participant tobacco consumption. Key details and tobacco-related outcomes from included studies will be extracted and tabulated before being narratively synthesised. The systematic review protocol has been developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines.

ETHICS AND DISSEMINATION

Ethics approval is not required. Findings will be disseminated via peer-reviewed literature, conference presentations, media and social media.

PROSPERO REGISTRATION NUMBER

CRD42018108777.

Saliva cotinine concentrations in pregnant women who smoke and use nicotine patches

BACKGROUND AND AIMS

Due to concerns about increased exposure to nicotine, pregnant women using nicotine replacement therapy (NRT) to stop smoking are usually advised to stop using NRT if they relapse to smoking. This study investigated whether this is justified. We compared changes in saliva cotinine from baseline to 2 weeks post-target quit date pregnant smokers who relapsed to smoking and continued to use their patches having been assigned to use nicotine patches or placebo.

DESIGN AND SETTING

Controlled pre-post design stratified by intervention condition from the 'Study of Nicotine Patch in Pregnancy', a randomized, placebo-controlled trial.

PARTICIPANTS

A sample of 268 pregnant women, assigned placebo (n = 122) or nicotine (n = 146) patches, who returned for further supplies of patches and who reported any smoking in the week prior to a visit at 2 weeks after their target quit date.

MEASUREMENTS

Saliva cotinine concentrations were measured at baseline and 2 weeks after participants' target quit dates. Any smoking in the previous week was assessed by self-report, validated by expired air carbon monoxide (CO).

FINDINGS

There was no change in saliva cotinine concentrations between baseline and 2 weeks post-target quit date in saliva cotinine concentration in the nicotine patch group [ratio of geometric means = 0.94, 95% confidence interval (CI) = 0.83 to 1.07; P = 0.37, Bayes factor = 0.15]. However, there was a reduction in reported number of cigarettes smoked/day (mean difference -6, 95% CIs -7 to -5, P < 0.001) and in CO concentrations (mean difference -3.0 parts per million, 95% CIs -4.2 to -1.9, P < 0.001). These changes were not significantly different from changes in the placebo group except for cigarette consumption, which reduced more in the nicotine group (P = 0.046).

CONCLUSIONS

In women trying to stop smoking with the aid of a nicotine patch but having smoked at 2 weeks post-target quit, their nicotine concentration did not change from baseline, but they reported smoking fewer cigarettes and had lower carbon monoxide concentrations.

A Physiologically Based Pharmacokinetic Model for Pregnant Women to Predict the Pharmacokinetics of Drugs Metabolized Via Several Enzymatic Pathways

BACKGROUND

Physiologically based pharmacokinetic modeling is considered a valuable tool for predicting pharmacokinetic changes in pregnancy to subsequently guide in-vivo pharmacokinetic trials in pregnant women. The objective of this study was to extend and verify a previously developed physiologically based pharmacokinetic model for pregnant women for the prediction of pharmacokinetics of drugs metabolized via several cytochrome P450 enzymes.

METHODS

Quantitative information on gestation-specific changes in enzyme activity available in the literature was incorporated in a pregnancy physiologically based pharmacokinetic model and the pharmacokinetics of eight drugs metabolized via one or multiple cytochrome P450 enzymes was predicted. The tested drugs were caffeine, midazolam, nifedipine, metoprolol, ondansetron, granisetron, diazepam, and metronidazole. Pharmacokinetic predictions were evaluated by comparison with in-vivo pharmacokinetic data obtained from the literature.

RESULTS

The pregnancy physiologically based pharmacokinetic model successfully predicted the pharmacokinetics of all tested drugs. The observed pregnancy-induced pharmacokinetic changes were qualitatively and quantitatively reasonably well predicted for all drugs. Ninety-seven percent of the mean plasma concentrations predicted in pregnant women fell within a twofold error range and 63% within a 1.25-fold error range. For all drugs, the predicted area under the concentration-time curve was within a 1.25-fold error range.

CONCLUSION

The presented pregnancy physiologically based pharmacokinetic model can quantitatively predict the pharmacokinetics of drugs that are metabolized via one or multiple cytochrome P450 enzymes by integrating prior knowledge of the pregnancy-related effect on these enzymes. This pregnancy physiologically based pharmacokinetic model may thus be used to identify potential exposure changes in pregnant women a priori and to eventually support informed decision making when clinical trials are designed in this special population.

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.

Tobacco and Pituri Use in Pregnancy: A Protocol for Measuring Maternal and Perinatal Exposure and Outcomes in Central Australian Aboriginal Women

Maternal tobacco smoking is a recognized risk behavior that has adverse impacts onmaternal and fetal health. However, in some populations, the use of smokeless tobacco exceeds theuse of smoked tobacco. In central Australia, Aboriginal populations utilize wild tobacco plants(Nicotiana spp.) as a smokeless product. These plants are known by a variety of names, one of whichis pituri. The plants are masticated and retained in the oral cavity for extended periods of time andtheir use continues throughout pregnancy, birth, and lactation. In contrast to the evidence related tocombusted tobacco use, there is no evidence as to the effects of pituri use in pregnancy. CentralAustralian Aboriginal women who were at least 28 weeks pregnant were stratified into three tobaccoexposure groups: (a) Pituri chewers, (b) smokers, and (c) non-tobacco users. Routine antenatal andbirth information, pre-existing and pregnancy-related maternal characteristics, fetal characteristics,and biological samples were collected and compared. The biological samples were analysed fortobacco and nicotine metabolite concentrations. Samples from the mother included venous blood,urine, hair and colostrum and/or breast milk. From the neonate, this included Day 1 and Day 3 urineand meconium, and from the placenta, arterial and venous cord blood following delivery. This is thefirst study to correlate the pregnancy outcomes of central Australian Aboriginal women with differenttobacco exposures. The findings will provide the foundation for epidemiological data collection inrelated studies. Note to readers: In this article, the term "Aboriginal" was chosen by central Australianwomen to refer to both themselves and the Aboriginal people in their communities. "Indigenous" waschosen to refer to the wider Australian Aboriginal and Torres Strait Islander people.

Improving smoking cessation care in pregnancy at Aboriginal Medical Services: 'ICAN QUIT in Pregnancy' step-wedge cluster randomised study

OBJECTIVES

This study aimed to examine the impact of the 'ICAN QUIT in Pregnancy' intervention on individual health providers (HPs) smoking cessation care (SCC) knowledge, attitudes and practices in general, and specifically regarding nicotine replacement therapy (NRT) prescription.

DESIGN

Step-wedge clustered randomised controlled study. HPs answered a preintervention and 1-6 months postintervention survey.

SETTING

Six Aboriginal Medical Services (AMSs) in three states of Australia.

PARTICIPANTS

All HPs were invited to participate. Of 93 eligible, 50 consented (54%), 45 completed the presurvey (90%) and 20 the post (40%).

INTERVENTION

Included three 1-hour webinar sessions, educational resource package and free oral NRT.

OUTCOMES

HPs knowledge was measured using two composite scores-one from all 24 true/false statements, and one from 12 NRT-specific statements. Self-assessment of 22 attitudes to providing SCC were measured using a five-point Likert scale (Strongly disagree to Strongly agree). Two composite mean scores were calculated-one for 15 general SCC attitudes, and one for 7 NRT-specific attitudes. Self-reported provision of SCC components was measured on a five-point Likert scale (Never to Always). Feasibility outcomes, and data collected on the service and patient level are reported elsewhere.

RESULTS

Mean knowledge composite scores improved from pre to post (78% vs 84% correct, difference 5.95, 95% CI 1.57 to 10.32). Mean NRT-specific knowledge composite score also improved (68% vs 79% correct, difference 9.9, 95% CI 3.66 to 16.14). Mean attitude composite score improved (3.65 (SD 0.4) to 3.87 (SD 0.4), difference 0.23, 95% CI 0.05 to 0.41). Mean NRT-specific attitudes composite score also improved (3.37 (SD 0.6) to 3.64 (SD 0.7), difference 0.36, 95% CI 0.13 to 0.6). Self-reported practices were unchanged, including prescribing NRT.

CONCLUSIONS

A multicomponent culturally sensitive intervention in AMSs was feasible, and might improve HPs provision of SCC to pregnant Aboriginal women. Changes in NRT prescription rates may require additional intensive measures.

TRIAL REGISTRATION NUMBER

ACTRN 12616001603404; Results.

Effectiveness and cost-effectiveness of a tailored text-message programme (MiQuit) for smoking cessation in pregnancy: study protocol for a randomised controlled trial (RCT) and meta-analysis

BACKGROUND

Smoking in pregnancy is a major international public health problem. Self-help support (SHS) increases the likelihood of women stopping smoking in pregnancy and delivering this kind of support by text message could be a cost-effective way to deliver SHS to pregnant women who smoke. SHS delivered by text message helps non-pregnant smokers to stop but the currently available message programmes are not appropriate for use in pregnancy. A randomised controlled trial (RCT) has demonstrated the feasibility and acceptability of using a programme called 'MiQuit' to text SHS support to pregnant women who smoke. Another pilot RCT has shown that it would be feasible to run a larger, multi-centre trial within the UK National Health Service (NHS). The aim of this third RCT is to complete MiQuit's evaluation, demonstrating whether or not this is efficacious for smoking cessation in pregnancy.

METHODS/DESIGN

This is a multi-centre, parallel-group RCT. Pregnant women aged over 16 years, of less than 25 weeks' gestation who smoke one or more daily cigarettes but smoked at least five daily cigarettes before pregnancy and who understand written English and are being identified in 24 English antenatal care hospitals. Participants are randomised to control or intervention groups in a 1:1 ratio stratified by gestation (< 16 weeks versus ≥ 16 weeks). All participants receive a leaflet on stopping smoking during pregnancy; they are also able to access standard NHS smoking cessation support. Intervention group women also receive the 12-week MiQuit programme of tailored, interactive text message, and self-help cessation support. Women are followed up by telephone at 4 weeks after randomisation and 36 weeks' gestation. The RCT will recruit 692 women (346 per group), enabling a 95% confidence interval for the difference in quit rates to be estimated within ± 3%. To determine whether or not MiQuit helps pregnant smokers to stop, intervention group quit rates from this trial will be combined with those from the two earlier trials in a Trial Sequential Analysis (TSA) meta-analysis to derive a pooled efficacy estimate.

DISCUSSION

If effective, MiQuit will be a cheap, cost-effective method to help pregnant women to stop smoking.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03231553 . Registered on 20 July 2017.

Black Light Smokers: How Nicotine Intake and Carcinogen Exposure Differ Across Various Biobehavioral Factors

OBJECTIVE

The study objective was to identify biobehavioral variables associated with greater intake of nicotine and a tobacco carcinogen among Black light smokers who smoke 1 to 10 cigarettes per day (CPD).

METHODS

We analyzed baseline data collected from 426 Black light smokers enrolled in Kick It at Swope III (KIS III), a smoking cessation trial for Black smokers. We examined differences in concentrations of tobacco biomarkers, including urinary total nicotine equivalents (TNE) and total 4-(methylnitrosamino)-1-(3)pyridyl-1-butanonol (NNAL; a human carcinogen), across gender, age, plasma nicotine metabolite ratio (NMR), CPD, and measures of tobacco dependence, including time to first cigarette (TFC), using ANOVA.

RESULTS

Tobacco biomarker levels were significantly higher among those who smoked more CPD (6-10 vs 1-5 CPD) and those with greater reported physical dependence on tobacco. Concurrently, those who smoked 1-5 CPD smoked each cigarette more intensely than those who smoked 6-10 CPD. While we found no gender differences overall, among those who smoked 1-5 CPD, women had higher NNAL levels compared to men. The rate of nicotine metabolism, measured by the nicotine metabolite ratio, was not significantly related to TNE or NNAL levels.

CONCLUSION

Among Black Light smokers, higher cigarette consumption and greater physical dependence-but not rate of nicotine metabolism, menthol use, or socioeconomic status-were associated with greater toxicant exposure and thus a likely increased risk of tobacco-related diseases. The lack of data on light smokers, and specifically on Blacks, make this observation important given the disproportionate burden of lung cancer in this population.

A multicomponent behavioral intervention for smoking cessation during pregnancy: a nonconcurrent multiple-baseline design

Given serious consequences of maternal smoking, we aimed to develop and test a multicomponent behavioral intervention to enhance smoking cessation during pregnancy. In this nonconcurrent, multiple-baseline intervention pilot study, 48 daily smoking pregnant women (mean 13.7 weeks of gestation) were recruited from Buffalo, NY, USA. Upon completion of the repeated baseline smoking monitoring (up to 3 weeks), 30 continuous smokers received a contingent financial incentive-based intervention with three additional components (education and counseling, monitoring and feedback, and family support). After the quit date, participants met with counselors (~1 hr/visit) daily for 2 weeks and twice a week for another 6 weeks. Twenty-one out of 30 participants quit smoking completely (verified by urine cotinine) after receiving the intervention, and the other nine nonquitters decreased smoking substantially. The estimated smoking cessation rate was 70.0% (21/30) at the second week of the intervention, and 63.3% (19/30) at the conclusion of the 8-week intervention assuming the dropouts as smoking. In interrupted time series analysis, the mean daily number of cigarettes smoked among quitters decreased by 6.52, 5.34, and 4.67 among early, delayed, and late intervention groups, respectively. Quitters' mean urine cotinine level maintained stably high before the intervention but decreased rapidly to the nonsmoking range once the intervention was initiated. Most participants (85.7%) reported meeting or exceeding expectations, and 100% would recommend the program to others. This pilot multicomponent intervention was feasible and acceptable to most participants, resulting in a high smoking cessation rate among pregnant smokers who were unlikely to quit spontaneously.

Association of Maternal Cigarette Smoking and Smoking Cessation With Preterm Birth

Importance

Cigarette smoking during pregnancy increases the risk of preterm birth, low birth weight, and infant mortality.

Objective

To assess the probability of preterm birth among expectant mothers who smoked cigarettes before pregnancy and quit smoking at the start or during pregnancy.

Design, Setting, and Participants

This cross-sectional study analyzed information provided on live birth certificates from 2011 through 2017 that were obtained from US states that implemented the 2003 revision of the US live birth certificate. In total, 25 233 503 expectant mothers who delivered live neonates and had known prepregnancy and trimester-specific cigarette smoking frequency were included in the analyses.

Exposures

Cigarette smoking frequency (1-9, 10-19, and ≥20 cigarettes per day) 3 months prior to pregnancy and for each trimester during pregnancy.

Main Outcomes and Measures

Cigarette smoking cessation throughout pregnancy, after the first trimester, after the second trimester, and during the third trimester irrespective of first and second trimester smoking. Probability of preterm birth (<37 weeks' gestation).

Results

Of 25 233 503 expectant mothers who delivered live neonates between 2011 and 2017, the modal age at delivery was 25 to 29 years; 52.9% were non-Hispanic white, 23.6% were Hispanic, and 14.2% were non-Hispanic black women; 22 600 196 mothers did not smoke during the 3 months prior to pregnancy, and 2 633 307 smoked during the 3 months prior to pregnancy. The proportion of prepregnancy smokers who quit throughout pregnancy was 24.3% in 2011 and 24.6% in 2017. The proportion of prepregnancy smokers who quit during the third trimester was 39.5% in 2011 and 39.7% in 2017. High-frequency cigarette smoking often occurred among expectant mothers who smoked during pregnancy (eg, 46.9% of third-trimester smokers smoked ≥10 cigarettes per day in 2017). The probability of preterm birth decreased more the earlier smoking cessation occurred in pregnancy. For example, the probability of preterm birth was 9.8% (95% CI, 9.7%-10.0%) among 25- to 29-year-old, non-Hispanic white, primigravida and primiparous expectant mothers (ie, pregnant for the first time and not yet delivered) who smoked 1 to 9 cigarettes per day prior to pregnancy and maintained this frequency throughout their pregnancy. The probability of preterm birth was 9.0% (95% CI, 8.8%-9.1%) if smoking cessation occurred at the start of the second trimester (an 8.9% relative decrease), and 7.8% (95% CI, 7.7%-8.0%) if cessation occurred at the start of pregnancy (a 20.3% relative decrease).

Conclusions and Relevance

Quitting smoking-and quitting early in pregnancy-was associated with reduced risk of preterm birth even for high-frequency cigarette smokers.

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.

Comparison of nicotine exposure during pregnancy when smoking and abstinent with nicotine replacement therapy: systematic review and meta-analysis

BACKGROUND AND AIMS

Smoking during pregnancy is strongly associated with negative pregnancy and perinatal outcomes. Some guidelines recommend nicotine replacement therapy (NRT) for smoking cessation during pregnancy, but adherence with NRT is generally poor and could be partially explained by nicotine-related safety concerns. We compared pregnant women's cotinine and nicotine exposures from smoking with those when they were abstinent from smoking and using NRT.

DESIGN

Systematic review with meta-analysis and narrative reporting. Twelve studies were included: in most, only one type of NRT was used. Seven were quality-assessed and judge of variable quality.

SETTING

Studies from any setting that reported nicotine or cotinine levels when smoking and later when abstinent and using NRT.

PARTICIPANTS

Pregnant women who smoked and became abstinent but used NRT either in a cessation study or in a study investigating other impacts of NRT.

MEASUREMENTS

We quality-assessed longitudinal cohort studies using a modified version of the Newcastle-Ottawa scale. For meta-analysis, we used mean within-person differences in cotinine or nicotine levels when smoking and at later follow-up when abstinent and using NRT. Where such data were not available, we calculated differences in group mean levels and reported these narratively, indicating where data were not completely longitudinal.

FINDINGS

Of the 12 included studies, four cotinine-measuring studies (n = 83) were combined in a random effects meta-analysis; the pooled estimate for the mean difference (95% confidence intervals) in cotinine levels between when women were smoking and abstinent but using NRT was 75.3 (57.1 to 93.4) ng/ml (I2  = 42.1%, P = 0.11). Of eight narratively-described studies, six reported lower cotinine and/or nicotine levels when abstinent and using NRT; two had mixed findings, with higher levels when abstinent but using NRT reported from at least one assay time-point.

CONCLUSIONS

Pregnant women who use nicotine replacement therapy instead of smoking reduce their nicotine exposure.

Differences in Prenatal Tobacco Exposure Patterns among 13 Race/Ethnic Groups in California

Prenatal tobacco exposure is a significant, preventable cause of childhood morbidity, yet little is known about exposure risks for many race/ethnic subpopulations. We studied active smoking and environmental tobacco smoke (ETS) exposure in a population-based cohort of 13 racially/ethnically diverse pregnant women: white, African American, Hispanic, Native American, including nine Asian/Pacific Islander subgroups: Chinese, Japanese, Korean, Filipino, Cambodian, Vietnamese, Laotian, Samoan, and Asian Indians (N = 3329). Using the major nicotine metabolite, cotinine, as an objective biomarker, we analyzed mid-pregnancy serum from prenatal screening banked in 1999–2002 from Southern California in an effort to understand differences in tobacco exposure patterns by race/ethnicity, as well as provide a baseline for future work to assess secular changes and longer-term health outcomes. Prevalence of active smoking (based on age- and race-specific cotinine cutpoints) was highest among African American, Samoan, Native Americans and whites (6.8–14.1%); and lowest among Filipinos, Chinese, Vietnamese and Asian Indians (0.3–1.0%). ETS exposure among non-smokers was highest among African Americans and Samoans, followed by Cambodians, Native Americans, Vietnamese and Koreans, and lowest among Filipinos, Japanese, whites, and Chinese. At least 75% of women had detectable cotinine. While for most groups, levels of active smoking corresponded with levels of ETS, divergent patterns were also found. For example, smoking prevalence among white women was among the highest, but the group’s ETS exposure was low among non-smokers; while Vietnamese women were unlikely to be active smokers, they experienced relatively high ETS exposure. Knowledge of race/ethnic differences may be useful in assessing disparities in health outcomes and creating successful tobacco interventions.

Nicotine replacement therapy for smoking cessation during pregnancy

Nicotine replacement therapy (NRT) is recommended in current Australian clinical guidelines for pregnant women who are unable to quit smoking unassisted. Clinicians report low levels of prescribing NRT during pregnancy, due to safety concerns and low levels of confidence in their ability to prescribe NRT. Animal models show that nicotine is harmful to the fetus, especially for brain and lung development, but human studies have not found any harmful effects on fetal and pregnancy outcomes. Studies of efficacy and effectiveness in the real world suggest that NRT use during pregnancy increases smoking cessation rates. These rates may be hampered by the fact that studies so far have used an NRT dose that does not adequately account for the higher nicotine metabolism during pregnancy and, therefore, does not adequately treat withdrawal symptoms. Further research is needed to assess the safety and efficacy of higher dosages of NRT in pregnancy, specifically of combination treatment using dual forms of NRT. As NRT is safer than smoking, clinicians need to offer this option to all pregnant women who smoke. A practical guide for initiating and tailoring the dose of NRT in pregnancy is suggested.

Alterations in Xenobiotic-Metabolizing Enzyme Activities across Menstrual Cycle in Healthy Volunteers

The purpose of the study was to determine whether the in vivo activities of drug-metabolizing enzymes CYP1A2 and CYP2A6, xanthine oxidase (XO), and N-acetyltransferase-2 (NAT2) vary across the menstrual cycle. Forty-two healthy women were studied at early follicular phase (EFP: 2nd to 4th days), late follicular phase (LFP: 10th to 12th days), and luteal phase (LP: 19th to 25th days) of a single menstrual cycle, and blood and urine samples were collected at each phase. Spot urine samples obtained 6 hours following 200-mg caffeine administration were used to determine caffeine metabolite ratios (CMRs); blood samples were used to determine CYP1A2*1F (rs762551) and CYP1A2*1C (rs2069514) polymorphisms and the hormonal profile (estradiol, progesterone, and luteinizing and follicle-stimulating hormones) at EFP, LFP, and LP. CMR and hormone variations were analyzed at three levels (EFP, LFP, LP) using one-way repeated-measures analysis of variance. CYP1A2 activity was lower and that of CYP2A6 and NAT2 were higher at LFP compared with EFP and LP. Enzyme alterations were significant in volunteers (n = 21) whose hormonal profiles at EFP, LFP, and LP corresponded to expected levels, but not in volunteers (n = 15) with presumed early or late sampling around LFP. No significant difference was detected in any enzyme activity in presumed anovulatory volunteers (n = 6). The reduction of CYP1A2 activity at LFP was not associated with smoking or CYP1A2*1F polymorphism. XO and NAT2 (fast acetylators) activities remained unaltered. It is suggested that drug-metabolizing enzyme activities are altered across the menstrual cycle. Selection of appropriate sampling periods verified by hormonal assessment and identification of anovulatory cycles are decisive factors in disclosing altered enzyme activity across the menstrual cycle.

Using Phytochemicals to Investigate the Activation of Nicotine Detoxification via Upregulation of CYP2A6 in Animal Models Exposed Tobacco Smoke Condensate by Intratracheal Instillation

This study examined the efficacy of standardized Smilax china L. root extract (SSCR) containing chlorogenic acid on detoxifying nicotine from tobacco smoke condensate (TSC) in vitro and in vivo. Chlorogenic acid is an identified bioactive component in SSCR by ultraperformance liquid chromatography/photodiode array/electrospray ionization/mass spectroscopy (UPLC/PDA/ESI/MS). HepG2 liver cells and A549 lung cells were carried for measuring ROS and antioxidant enzymes. Sprague-Dawley rats were treated with nicotine by intratracheal instillation (ITI). Cell viabilities by pretreatments of 5, 12.5, and 25, 50 μg SSCR/mL ranged from 41 to 76% in HepG2 and 65 to 95% in A549. Pretreatments of SSCR inhibited TSC-mediated production of reactive oxygen species (ROS) by 8 and 10% in HepG2 and A549 cells, respectively. However, the expression of CAT, SOD1, and AOX1 was downregulated by SSCR in the both cells. The highest conversion of cotinine was observed at 50 μg/mL of SSCR after 120 min of incubation. SSCR upregulated CYP2A6 3-fold in A549 cells regardless of TSC cotreatment. When Sprague-Dawley rats were treated with nicotine by ITI or subjected to SSCR administration for 14 days, the levels of cotinine in urine increased in SSCR treatment only. The cellular level of antioxidant capacity at 10 or 100 mg/kg body weight/day of SSCR treatment was 1.89 and 1.86 times higher than those of nicotine-control. Results suggest that the intake of SSCR can detoxify nicotine by elevating nicotine conversion to cotinine and antioxidant capacity.

Variability of urinary concentrations of non-persistent chemicals in pregnant women and school-aged children

BACKGROUND

Exposome studies are challenged by exposure misclassification for non-persistent chemicals, whose temporal variability contributes to bias in dose-response functions.

OBJECTIVES

We evaluated the variability of urinary concentrations of 24 non-persistent chemicals: 10 phthalate metabolites, 7 phenols, 6 organophosphate (OP) pesticide metabolites, and cotinine, between weeks from different pregnancy trimesters in pregnant women, and between days and between seasons in children.

METHODS

154 pregnant women and 152 children from six European countries were enrolled in 2014-2015. Pregnant women provided three urine samples over a day (morning, midday, and night), for one week in the 2nd and 3rd pregnancy trimesters. Children provided two urines a day (morning and night), over two one-week periods, six months apart. We pooled all samples for a given subject that were collected within a week. In children, we also made four daily pools (combining morning and night voids) during the last four days of the first follow-up week. Pools were analyzed for all 24 metabolites of interest. We calculated intraclass-correlation coefficients (ICC) and estimated the number of pools needed to obtain an ICC above 0.80.

RESULTS

All phthalate metabolites and phenols were detected in >90% of pools whereas certain OP pesticide metabolites and cotinine were detected in <43% of pools. We observed fair (ICC = 0.40-0.59) to good (0.60-0.74) between-day reliability of the pools of two samples in children for all chemicals. Reliability was poor (<0.40) to fair between trimesters in pregnant women and between seasons in children. For most chemicals, three daily pools of two urines each (for weekly exposure windows) and four weekly pools of 15-20 urines each would be necessary to obtain an ICC above 0.80.

CONCLUSIONS

This quantification of the variability of biomarker measurements of many non-persistent chemicals during several time windows shows that for many of these compounds a few dozen samples are required to accurately assess exposure over periods encompassing several trimesters or months.

Prevention of perinatal nicotine-induced bone marrow mesenchymal stem cell myofibroblast differentiation by augmenting the lipofibroblast phenotype

Perinatal nicotine exposure drives the differentiation of alveolar lipofibroblasts (LIFs), which are critical for lung injury repair, to myofibroblasts (MYFs), which are the hallmark of chronic lung disease. Bone marrow-derived mesenchymal stem cells (BMSCs) are important players in lung injury repair; however, how these cells are affected with perinatal nicotine exposure and whether these can be preferentially driven to a lipofibroblastic phenotype are not known. We hypothesized that perinatal nicotine exposure would block offspring BMSCs lipogenic differentiation, driving these cells toward a MYF phenotype. Since peroxisome proliferator activated-receptor γ (PPARγ) agonists can prevent nicotine-induced MYF differentiation of LIFs, we further hypothesized that the modulation of PPARγ expression would inhibit nicotine's myogenic effect on BMSCs. Sprague Dawley dams were perinatally administered nicotine (1 mg/kg bodyweight) with or without the potent PPARγ agonist rosiglitazone (RGZ), both administered subcutaneously. At postnatal day 21, BMSCs were isolated and characterized morphologically, molecularly, and functionally for their lipogenic and myogenic potentials. Perinatal nicotine exposure resulted in decreased oil red O staining, triolein uptake, expression of PPARγ, and its downstream target gene adipocyte differentiation-related protein by BMSCs, but enhanced α-smooth muscle actin and fibronectin expression, and activated Wnt signaling, all features indicative of their inhibited lipogenic, but enhanced myogenic potential. Importantly, concomitant treatment with RGZ virtually blocked all of these nicotine-induced morphologic, molecular, and functional changes. Based on these data, we conclude that BMSCs can be directionally induced to differentiate into the lipofibroblastic phenotype, and PPARγ agonists can effectively block perinatal nicotine-induced MYF transdifferentiation, suggesting a possible molecular therapeutic approach to augment BMSC's lung injury/repair potential.

Cigarette consumption and biomarkers of nicotine exposure during pregnancy and postpartum

BACKGROUND AND AIMS

Smokers can regulate their nicotine intake by altering the number of cigarettes smoked per day (CPD) and their smoking intensity. The current study aimed to compare the utility of self-reported CPD, total nicotine equivalents (TNE) and urinary cotinine to estimate nicotine intake during pregnancy.

DESIGN

Longitudinal smoking behavior and biomarker data were collected at early pregnancy, late pregnancy and at postpartum as part of a smoking cessation trial to examine voucher-based incentives for decreasing smoking.

SETTING

Obstetric practices in Burlington, Vermont, United States.

PARTICIPANTS

A subset of participants (n = 47) from the parent trial, recruited between December 2006 and June 2012, who provided a urine sample at each assessment during early pregnancy, late pregnancy and postpartum.

MEASUREMENTS

Smoking was assessed using self-reported CPD, TNE, TNE/CPD and urinary cotinine.

FINDINGS

Pregnant smokers reported smoking 10.4 CPD at early pregnancy, 7.2 CPD at late pregnancy (a 31% reduction at late pregnancy, P = 0.001) and 8.6 CPD at postpartum (a 19% increase from late pregnancy, P = 0.08). TNE exposure was 41% (P = 0.07) and 48% (P = 0.03) lower at early and late pregnancy, respectively, compared to postpartum. TNE/CPD was on average 167% higher at late pregnancy compared to early pregnancy (P = 0.01) and remained high at postpartum, where it was 111% higher compared to early pregnancy (P = 0.007). Uriniary cotinine underestimated nicotine intake by 55% during early pregnancy and by 65% during late pregnancy compared to postpartum (P_interaction  < 0.001); the underestimation was greater in slower (P_interaction  < 0.001) versus faster (P_interaction  = 0.04) nicotine metabolizers.

CONCLUSIONS

Neither cigarettes smoked per day (CPD) nor cotinine provides an accurate estimate of nicotine exposure during pregnancy. CPD underestimates nicotine intake substantially due to under-reporting and/or higher intensity of smoking, while cotinine underestimates nicotine intake markedly due to accelerated nicotine (and cotinine) metabolism during pregnancy.

Pharmaceutical strategies for smoking cessation during pregnancy

Introduction: Tobacco use is the most preventable cause of death worldwide, with over 7 million deaths per year. Smoking during pregnancy causes harm to the mother, fetus, and can result in problems for the infant from childhood into adulthood. Practitioners should ask all expectant mothers about tobacco use. For expectant mothers who smoke or recently quit, practitioners should advice to quit and provide psychosocial interventions. Rates of smoking during pregnancy differ between geographical locations, with estimates of 10.8% in the UK and 7.2% in the US. Practitioners should provide expectant mothers unable to quit smoking with information about the risks and benefits of pharmacotherapy and use a patient-centered approach to determine the use. Although there is no definitive evidence on birth outcomes, nicotine replacement therapy and bupropion are adequate pharmacotherapies to help those unable to quit. Areas covered: Herein, this author looks at the various pharmaceutical strategies to help patients cease smoking and provides expert perspectives on the subject. Expert opinion: Additional research on pharmacotherapy is warranted, especially with varenicline. Practitioners working with pregnant patients should be familiar with the evidence for pharmacotherapy in smoking cessation during pregnancy. This evidence can be difficult to navigate due to conflicting results and limitations with the trials.

Comparing Smoking Topography and Subjective Measures of Usual Brand Cigarettes Between Pregnant and Non-Pregnant Smokers

Introduction

Most pregnant smokers report abruptly reducing their cigarettes per day (CPD) by ~50% after learning of pregnancy and making further smaller reductions over the remainder of their pregnancy. Laboratory and naturalistic studies with non-pregnant smokers have found that these types of reductions often lead to changes in smoking topography (i.e., changes in smoking intensity to maintain a desired blood-nicotine level). If pregnant women smoke more intensely, they may expose themselves and their offspring to similar levels of toxicants despite reporting reductions in CPD.

Methods

Pregnant and non-pregnant female smokers (n = 20 and 89, respectively) participated. At the experimental session, after biochemical confirmation of acute abstinence, participants smoked one usual brand cigarette ad lib through a Borgwaldt CReSS Desktop Smoking Topography device. Carbon monoxide (CO) and measures of nicotine withdrawal, craving, and reinforcement derived from smoking were also collected.

Results

The two groups did not differ on demographic or smoking characteristics at screening, except nicotine metabolism rate, which as expected, was faster in pregnant smokers. Analyses suggest that none of the smoking topography parameters differed between pregnant and non-pregnant smokers, although pregnant smokers had a significantly smaller CO boost. Both groups reported similar levels of relief of withdrawal and craving after smoking, but other subjective effects suggest that pregnant smokers find smoking less reinforcing than non-pregnant smokers.

Conclusions

Pregnant smokers do not smoke cigarettes differently than non-pregnant women, but appear to find smoking comparatively less pleasurable.

Implications

This is the first study to assess smoking topography in pregnant women. Pregnant women appear to be at increased risk for smoking cigarettes with more intensity because of (1) their tendency to make significant abrupt reductions in the number of cigarettes they smoke each day after learning of pregnancy and (2) an increase in nicotine metabolism induced by pregnancy. Despite these changes, the present results suggest that pregnant women do not smoke cigarettes more intensely or in a way that causes more toxicant exposure, perhaps due to a reportedly less pleasurable smoking experience.

Exposure to tobacco smoke and validation of smoking status during pregnancy in the MIREC study

Given that prenatal exposure to tobacco smoke can lead to increased risks of adverse health effects, having valid measures of exposure is important. In a Canadian cohort (n = 2000), maternal and infant biospecimens were analysed for cotinine. Sensitivity and specificity of self-reported active smoking status were estimated. Regression modelling was used to identify potential predictors of maternal and infant plasma cotinine in non-smoking women. During the first trimester, 60.6% of the women reported never smoking, 27.3% were former smokers, 6.1% had quit when they found out they were pregnant, 5.8% were smokers and 42% of the non-smokers reported exposure to secondhand smoke (SHS). Low detection of tobacco biomarkers in meconium limited its ability to identify exposure to SHS. The sensitivity and specificity for self-reported smoking during the 1st trimester were 85.37 and 99.45%, respectively. The lowest sensitivity was found in participants with the highest level of education and income, oldest women and those born outside Canada. Non-smoking women living in an apartment had 1.7 times higher odds of detectable plasma cotinine than those living in a single home after adjusting for other variables. Our results suggest that while self-reports are fairly accurate, they may be less so in populations with higher socio-economic status. This investigation underscores the need to consider the participant socio-economic characteristics and dwelling type when using questionnaires to estimate active and passive tobacco exposure.

Smoking cessation in pregnancy: a continuing challenge in the United States

Despite significant population level declines, smoking during pregnancy remains a major public health issue in the United States (US). Approximately 360,000-500,000 smoke-exposed infants are born yearly, and prenatal smoking remains a leading modifiable cause of poor birth outcomes (e.g. birth < 37 gestational weeks, low birth weight, perinatal mortality). Women who smoke during pregnancy are more likely to be younger and from disadvantaged socioeconomic and racial and ethnic groups, with some US geographic regions reporting increased prenatal smoking rates since 2000. Such disparities in maternal prenatal smoking suggests some pregnant women face unique barriers to cessation. This paper reviews the current state and future direction of smoking cessation in pregnancy in the US. We briefly discuss the etiology of smoking addiction among women, the pathophysiology and effects of tobacco smoke exposure on pregnant women and their offspring, and the emerging issue of electronic nicotine delivery systems. Current population-based and individual smoking cessation interventions are reviewed in the context of pregnancy and barriers to cessation among US women. Finally, we consider interventions that are on the horizon and areas in need of further investigation.

Differential correlations between maternal hair levels of tobacco and alcohol with fetal growth restriction clinical subtypes

Maternal exposure to tobacco and alcohol is a known cause, among others, for fetal growth restriction (FGR). Clinically, FGR can be subclassified into two forms: intrauterine growth restriction (IUGR) and small for gestational age (SGA), based on the severity of the growth retardation, and abnormal uterine artery Doppler or cerebro-placental ratio. This study aimed at investigating any differential correlation between maternal exposures to these toxins with the two clinical forms of FGR. Therefore, a case-control study was conducted in Barcelona, Spain. Sixty-four FGR subjects, who were further subclassified into IUGR (n = 36) and SGA (n = 28), and 89 subjects matched appropriate-for-gestational age (AGA), were included. The levels of nicotine (NIC) and ethyl glucuronide (EtG), biomarkers of tobacco and alcohol exposure, respectively, were assessed in the maternal hair in the third trimester. Our analysis showed 65% of the pregnant women consumed alcohol, 25% smoked, and 19% did both. The odds ratios (ORs) of IUGR were 21 times versus 14 times for being SGA with maternal heavy smoking, while with alcohol consumption the ORs for IUGR were 22 times versus 37 times for the SGA group. The differential correlations between these toxins with the two subtypes of FGR suggest different mechanisms influencing fetal weight. Our alarming data of alcohol consumption during pregnancy should be considered for further confirmation among Spanish women.

[Biomarkers of Smoking - Which Cut-Off Values Should be Used?]

Biomarkers of Smoking - Which Cut-Off Values Should be Used? Abstract. Verification of smoking status by means of biomarkers is important for treatment decisions of patients with smoking-related diseases. Cotinine is currently the best biomarker to document nicotine consumption. A low cost alternative method to determine smoking status is by measurement of carboxyhemoglobin (CO-Hb) in the exhaled breath. The main disadvantage of CO-Hb is the short half-life. The appropriate cut-off value for active nicotine consumption in Switzerland is 50 ng/ml or higher cotinine in the urine or 10 ng/ml and 12 ng/ml in serum and saliva, respectively. CO-Hb levels greater than 2 % indicate smoking with high probability, levels above 3 % with very high probability.

Positive parenting behaviors in women who spontaneously quit smoking during pregnancy: Clues to putative targets for preventive interventions

BACKGROUND

While the majority of pregnant smokers do not respond to intervention, little is known about how a subset of pregnant smokers known as spontaneous quitters achieve sustained biologically-confirmed abstinence through delivery in the absence of intervention. We explore a developmental framework to address this question by viewing spontaneous quitting as an adaptive parenting behavior, facilitated by abilities necessary for sensitive parenting, or responsiveness. Utilizing existing data, we examined responsiveness from parenting assessments in women who exhibited a variety of smoking patterns during pregnancy, including spontaneous quitting.

METHODS

Participants were N = 305 pregnant women assessed for smoking prospectively and biochemically at 16 weeks, 28 weeks, delivery, and 4 weeks postpartum, then reassessed with their children 5 years later with directly-observed home- and lab-based measures of parenting. We used linear regression analysis to compare spontaneous quitters with women who exhibited other prenatal smoking patterns on parenting responsiveness, controlling for potential confounders.

RESULTS

In home-based observations, spontaneous quitters (n = 22) exhibited greater responsiveness with their children relative to intermittent pregnancy smokers [n = 70; β = 0.258, p = .022]; persistent pregnancy smokers [n = 66; β = 0.228, p = .040]; former smokers (quit before pregnancy) [n = 78; β = 266, p = .028]; and never smokers [n = 69; β = 0.312, p = .009]. Hypothesized differences were not observed in lab-based and self-report measures.

CONCLUSIONS

Putative protective characteristics in spontaneous quitters were captured in mother-child interactions at home, but not in lab-based and maternal report measures of responsiveness. Specification of these characteristics using prospective designs that oversample for spontaneous quitters is recommended to enable translation to preventive interventions.

Within-Day, Between-Day, and Between-Week Variability of Urinary Concentrations of Phenol Biomarkers in Pregnant Women

BACKGROUND

Toxicology studies have shown adverse effects of developmental exposure to industrial phenols. Evaluation in humans is challenged by potentially marked within-subject variability of phenol biomarkers in pregnant women, which is poorly characterized.

OBJECTIVES

We aimed to characterize within-day, between-day, and between-week variability of phenol urinary biomarker concentrations during pregnancy.

METHODS

In eight French pregnant women, we collected all urine voids over a 1-wk period (average, 60 samples per week per woman) at three occasions (15±2, 24±2, and 32±1 gestational weeks) in 2012-2013. Aliquots of each day and of the whole week were pooled within-subject. We assayed concentrations of 10 phenols in these pools, and, for two women, in all spot (unpooled) samples collected during a 1-wk period. We characterized variability using intraclass correlation coefficients (ICCs) with spot samples (within-day variability), daily pools (between-day variability), and weekly pools (between-week variability).

RESULTS

For most biomarkers, the within-day variability was high (ICCs between 0.03 and 0.50). The between-day variability, based on samples pooled within each day, was much lower, with ICCs >0.60 except for bisphenol S (0.14, 95% confidence interval [CI]: 0.00, 0.39). The between-week variability differed between compounds, with triclosan and bisphenol S having the lowest ICCs (<0.3) and 2,5-dichlorophenol the highest (ICC >0.9).

CONCLUSION

During pregnancy, phenol biomarkers showed a strong within-day variability, while the variability between days of a given week was more limited. One biospecimen is not enough to efficiently characterize exposure; collecting biospecimens during a single week may be enough to represent well the whole pregnancy exposure for some but not all phenols. https://doi.org/10.1289/EHP1994.

Examining characteristics associated with quitting smoking during pregnancy and relapse postpartum

INTRODUCTION

Smoking during pregnancy is a significant public health concern that can cause adverse health outcomes for both the mother and fetus. Studies have shown only 40% of women quit smoking during pregnancy, with more than half relapsing within 6months, and up to 90% relapsing within one year. This study investigates differences in demographics and smoking-related symptomatology between pregnant smokers and pregnant quitters, as well as factors associated with postpartum relapse.

METHODS

Data on pregnant smokers and pregnant quitters were obtained from two separate parent studies. Data on smoking demographics and smoking-related symptomatology were collected at screening visits.

RESULTS

Compared to pregnant smokers, pregnant quitters had more favorable smoking characteristics (e.g., smoked fewer cigarettes per day, reported higher motivation for abstinence and less dependency). They also had more favorable relationship characteristics (e.g., were more likely to be married, less likely to have a significant other who smokes) and had less reproductive liability (e.g., fewer pregnancies, fewer children). In terms of symptomatology, pregnant quitters reported more positive affect, negative affect, physical symptoms and withdrawal but less craving. Predictors of postpartum relapse included increased maternal age, having a significant other who smokes and an increased likelihood of returning to smoking after pregnancy (self-reported prior to delivery).

CONCLUSIONS

Several demographics and smoking-related symptomatology were significantly different between pregnant quitters and pregnant smokers. In addition, multiple factors predicting postpartum relapse were identified. This information can inform personalized interventions for high risk pregnant smokers and pregnant quitters at risk for postpartum relapse.

Longitudinal Influence of Pregnancy on Nicotine Metabolic Pathways

Nicotine metabolism increases in pregnancy, which may contribute to the difficulties that pregnant women have in quitting smoking. We aimed to determine the extent and timing of changes in nicotine metabolic pathways, including C-oxidation, N-glucuronidation, and the pregnancy-induced influences on the activity of enzymes mediating these pathways (CYP2A6 and UGT2B10, respectively). Current smoking pregnant women (n = 47) provided a urine sample during early pregnancy (12.5 weeks), late pregnancy (28.9 weeks), and 6 months postpartum. Concentrations of urinary nicotine and metabolites were analyzed using liquid chromatography tandem mass spectrometry and compared using general linear repeated measures analyses. Nicotine C-oxidation was 1.07-fold (P = 0.12) and 1.11-fold (P < 0.001) higher at early and late pregnancy, respectively, compared with postpartum. Nicotine N-glucuronidation was 1.33-fold (P = 0.06) and 1.67-fold (P = 0.003) higher at early and late pregnancy, respectively, compared with postpartum. The CYP2A6 phenotype ratio (total 3'-hydroxycotinine/cotinine) was significantly higher at early and late pregnancy compared with postpartum (all P < 0.05) and correlated with nicotine C-oxidation (all P < 0.001), suggesting CYP2A6 activity is induced during pregnancy. The UGT2B10 phenotype ratio (nicotine glucuronide/nicotine) was higher at early and late pregnancy compared with postpartum (P = 0.07 and P < 0.05, respectively) and correlated with a second UGT2B10 phenotype ratio (cotinine glucuronide/cotinine) (all P < 0.001), suggesting UGT2B10 activity is induced during pregnancy. In conclusion, pregnancy-induced increases in nicotine metabolism start by 12 weeks gestation and continue as pregnancy progresses most likely due to induction of CYP2A6 and UGT2B10, resulting in potential reductions in the effectiveness of nicotine replacement therapies and an increase in metabolism of other CYP2A6 and UGT2B10 substrates during pregnancy.

Cigarette smoking is associated with an altered vaginal tract metabolomic profile

Cigarette smoking has been associated with both the diagnosis of bacterial vaginosis (BV) and a vaginal microbiota lacking protective Lactobacillus spp. As the mechanism linking smoking with vaginal microbiota and BV is unclear, we sought to compare the vaginal metabolomes of smokers and non-smokers (17 smokers/19 non-smokers). Metabolomic profiles were determined by gas and liquid chromatography mass spectrometry in a cross-sectional study. Analysis of the 16S rRNA gene populations revealed samples clustered into three community state types (CSTs) ---- CST-I (L. crispatus-dominated), CST-III (L. iners-dominated) or CST-IV (low-Lactobacillus). We identified 607 metabolites, including 12 that differed significantly (q-value < 0.05) between smokers and non-smokers. Nicotine, and the breakdown metabolites cotinine and hydroxycotinine were substantially higher in smokers, as expected. Among women categorized to CST-IV, biogenic amines, including agmatine, cadaverine, putrescine, tryptamine and tyramine were substantially higher in smokers, while dipeptides were lower in smokers. These biogenic amines are known to affect the virulence of infective pathogens and contribute to vaginal malodor. Our data suggest that cigarette smoking is associated with differences in important vaginal metabolites, and women who smoke, and particularly women who are also depauperate for Lactobacillus spp., may have increased susceptibilities to urogenital infections and increased malodor.