Impact of Nicotine Replacement and Electronic Nicotine Delivery Systems on Fetal Brain Development

Tobacco or marijuana use and infertility: a committee opinion

In the United States, approximately 21% of adults report some form of tobacco use, although 18% report marijuana use. Although the negative impact of tobacco use in pregnancy is well documented, the impact of tobacco and marijuana on fertility and reproduction is less clear. This committee opinion reviews the potential deleterious effects of tobacco, nicotine, and marijuana use on conception, ovarian follicular dynamics, sperm parameters, gamete mutations, early pregnancy, and assisted reproductive technology outcomes. It also reviews the current status of tobacco smoking cessation strategies. This document replaces the 2018 American Society for Reproductive Medicine Practice Committee document entitled Smoking and Infertility: a committee opinion (Fertil Steril 2018).

The association between health literacy and e-cigarette use: evidence from Zhejiang, China

Objectives

The worldwide popularity of electronic cigarettes (ECIG) is becoming a public health concern. Compared to conventional cigarettes (CIG), the harm caused by ECIG is more insidious. Studies have shown that lower health literacy (HL) is associated with CIG use; however, the relationship between HL and ECIG use remains controversial. Because ECIG emerged more recently than CIG, there are fewer relevant studies, and the sample populations and evaluation methods of HL in existing studies differ. This study conducted a large-sample survey to examine the relationship between HL and ECIG use.

Methods

As part of the 2022 China Health Literacy Survey, a total of 60,998 valid questionnaires were collected from September to November in 2022 using a stratified multistage probability proportional to the population size sampling frame. Chi-square tests and multinomial logistic regression was used to analyze the relationship between HL and ECIG use. Some demographic variables were included as covariates in the analysis.

Results

The study showed that the average HL score and the HL level of Zhejiang residents in 2022 were 42.8 and 30.8%, respectively. The prevalence of CIG and ECIG was 19.7 and 1.0%, respectively; 19% of participants exclusively used CIG, while only 0.3% of participants used ECIG exclusively; dual users accounted for 0.6%. After adjusting for covariates, adequate HL was associated with lower odds of ECIG-exclusive use (odds ratio [OR] = 0.452, p < 0.001), CIG-exclusive use (OR = 0.833, p < 0.001), and dual use (OR = 0.632, p < 0.001). Young age, male sex, unmarried status, high-income status, and absence of chronic disease were also associated with ECIG use.

Conclusion

HL was a protective factor against both patterns of ECIG use, especially ECIG-exclusive use. Health policymakers and public health practitioners should consider HL as a potential measure for ECIG control.

Modeling disruption of Apis mellifera (honey bee) odorant-binding protein function with high-affinity binders

Chemical toxins pose a great threat to honey bee health because they affect memory and cognition, diminish immunity, and increase susceptibility to infection, resulting in decreased colony performance, reproduction, and survival. Although the behavioral effects of sub-lethal chemical exposure on honey bees have been intensively studied, how xenobiotics affect olfaction, at the molecular level, still needs to be elucidated. In the present work, in silico tools, such as molecular docking, binding free energy calculations, and molecular dynamics simulations are used to predict if environmental chemicals have stronger binding affinities to honey bee antennal odorant-binding protein 14 (OBP14) than the representative floral odors citralva, eugenol, and the fluorescent probe 1-N-phenylnaphthylamine. Based on structural analysis, 21 chemicals from crop pesticides, household appliances, cosmetics, food, public health-related products, and other sources, many of which are pervasive in the hive environment, have higher binding affinities than the floral odors. These results suggest that chemical exposures are likely to interfere with the honey bee's sense of smell and this disruptive mechanism may be responsible for the lower associative learning and memory based on olfaction found in bees exposed to pesticides. Moreover, bees mainly rely on olfactory cues to perceive their environment and orient themselves as well as to discriminate and identify their food, predators, nestmates, and diseased individuals that need to be removed with hygienic behavior. In summary, sub-lethal exposure to environmental toxins can contribute to colony collapse in several ways from the disruption of proper olfaction functioning.

Passive exposure to electronic cigarette aerosol in pregnancy: A case study of a family

BACKGROUND

Passive exposure to the aerosols of electronic cigarettes (e-cigarettes) has been little studied. We assessed this exposure in late pregnancy in a woman and her 3-year-old child, exposed through e-cigarette use by another household member.

METHODS

This prospective longitudinal case study involved a family unit consisting of an e-cigarette user, a pregnant woman who delivered an infant during the study, and the couple's older 3-year-old son. At 31, 36, and 40 weeks of the pregnancy, we measured biomarkers (nicotine metabolites, tobacco-specific nitrosamines, propanediols, glycerol, and metals) in the urine and hair of all three participants and in the saliva of the adults, in cord blood at delivery, and in the breast milk at the postpartum period.

RESULTS

Samples from the e-cigarette user showed quantifiable concentrations of all analytes assessed (maximum urinary cotinine concentration, 4.9 ng/mL). Among samples taken from the mother, nicotine and its metabolites were found mainly in urine and also in saliva and hair, but not in cord blood. During the postpartum period, we found cotinine concentrations of 2.2 ng/mL in the mother's urine and 0.22 ng/mL in breast milk; 1,2-propanediol was generally detected in urine and saliva, but not in cord blood or breast milk. The maximum urinary cotinine concentration in the 3-year-old child was 2.6 ng/mL and propanediols also were detected in his urine. Nitrosamines were not detected in samples taken from the mother or the 3-year-old. Metals found in the refill liquid were detected at low levels in both the mother and the 3-year-old.

CONCLUSIONS

We detected low but not negligible concentrations of e-cigarette-related analytes (including cord blood and breast milk) in an exposed pregnant non-user and in a 3-year-old child also living in the home. Passive exposure to e-cigarette aerosols cannot be disregarded and should be assessed in larger observational studies.

Single-nucleus chromatin accessibility and RNA sequencing reveal impaired brain development in prenatally e-cigarette exposed neonatal rats

Although emerging evidence reveals that vaping alters the function of the central nervous system, the effects of maternal vaping on offspring brain development remain elusive. Using a well-established in utero exposure model, we performed single-nucleus ATAC-seq (snATAC-seq) and RNA sequencing (snRNA-seq) on prenatally e-cigarette-exposed rat brains. We found that maternal vaping distorted neuronal lineage differentiation in the neonatal brain by promoting excitatory neurons and inhibiting lateral ganglionic eminence-derived inhibitory neuronal differentiation. Moreover, maternal vaping disrupted calcium homeostasis, induced microglia cell death, and elevated susceptibility to cerebral ischemic injury in the developing brain of offspring. Our results suggest that the aberrant calcium signaling, diminished microglial population, and impaired microglia-neuron interaction may all contribute to the underlying mechanisms by which prenatal e-cigarette exposure impairs neonatal rat brain development. Our findings raise the concern that maternal vaping may cause adverse long-term brain damage to the offspring.

Alterations of Mitochondrial Network by Cigarette Smoking and E-Cigarette Vaping

Toxins present in cigarette and e-cigarette smoke constitute a significant cause of illnesses and are known to have fatal health impacts. Specific mechanisms by which toxins present in smoke impair cell repair are still being researched and are of prime interest for developing more effective treatments. Current literature suggests toxins present in cigarette smoke and aerosolized e-vapor trigger abnormal intercellular responses, damage mitochondrial function, and consequently disrupt the homeostasis of the organelle's biochemical processes by increasing reactive oxidative species. Increased oxidative stress sets off a cascade of molecular events, disrupting optimal mitochondrial morphology and homeostasis. Furthermore, smoking-induced oxidative stress may also amalgamate with other health factors to contribute to various pathophysiological processes. An increasing number of studies show that toxins may affect mitochondria even through exposure to secondhand or thirdhand smoke. This review assesses the impact of toxins present in tobacco smoke and e-vapor on mitochondrial health, networking, and critical structural processes, including mitochondria fission, fusion, hyper-fusion, fragmentation, and mitophagy. The efforts are focused on discussing current evidence linking toxins present in first, second, and thirdhand smoke to mitochondrial dysfunction.

Association Between Electronic Nicotine Delivery Systems Use and Breastfeeding Duration

Background: Breastfeeding is beneficial for both mothers and infants. Unfortunately, some infants are not breastfed for the recommended duration of time. Previous studies have identified several demographic, socioeconomic, biological, and behavioral factors that impact breastfeeding practices. Studies examining the influence of electronic nicotine delivery systems (ENDS) on breastfeeding practices are currently lacking. Materials and Methods: This population-based, cross-sectional study used data from the 2016-2018 Pregnancy Risk Assessment and Monitoring System (n = 42,827). Chi-squared tests and multivariable logistic regression analyses were performed. Results: The prevalence of prenatal ENDS use was 0.9%. Only 40.8% of women who used ENDS during pregnancy breastfed for at least 3 months compared with 68.5% of women who did not use ENDS during pregnancy. In the multivariable model, the odds of breastfeeding for at least 3 months were significantly lower in women who used ENDS during pregnancy compared with those who did not use ENDS; odds ratio (95% confidence interval) 0.63 (0.44-0.89; p = 0.010). Conclusion: Prenatal exposure to ENDS is negatively associated with breastfeeding duration, independent of potential confounders. This finding suggests that screening for ENDS use during pregnancy can play a vital role in identifying women at-risk for suboptimal breastfeeding and offering ongoing support to improve breastfeeding practices.

Pregnant Smokers' Intention to Switch From Cigarettes to E-Cigarettes: A Reasoned Action Approach

INTRODUCTION

This study used the reasoned action approach (RAA) to examine 1) factors associated with pregnant smokers' intention to switch from cigarettes to e-cigarettes and 2) the influence that intention to switch had on future expectations to resume cigarette use postpartum.

METHODS

U.S. pregnant women (N = 267) who reported past 30-day use of cigarettes completed an online cross-sectional survey between November and December 2019. A 30-item scale measured RAA constructs (intention, instrumental attitudes, experiential attitudes, injunctive norms, descriptive norms, perceived autonomy, and perceived capacity). A confirmatory factor analysis confirmed and structural equation modeling tested the RAA constructs' association with intention to switch and the relationship between intention to switch and future expectations to resume smoking after pregnancy.

RESULTS

The confirmatory factor analysis confirmed the seven-factor measurement model. Structural equation modeling found instrumental attitudes (β = 0.43; p < .001) and descriptive norms (β = 0.53; p < .001) were associated with intention to switch from cigarettes to e-cigarettes. However, there were differences between the constructs' relationships with intention between those who did and did not use e-cigarettes in the past 30 days. Intention to switch was inversely related with future expectations to resume smoking postpartum (β = -0.13; p < .001).

CONCLUSIONS

This study examined multiple facets of behavioral decision-making that may influence pregnant smokers' intention to switch to e-cigarettes during pregnancy. In this sample, pregnant people who believed switching from cigarettes to e-cigarettes was important and that other smokers commonly switched during pregnancy reported greater intention to switch. Novel theories, such as the RAA, may provide an optimal lens to understand pregnant smokers' behavioral decision-making process as they consider switching from cigarettes to e-cigarettes.

Prevalence and Distribution of Electronic Cigarette Use Before and During Pregnancy Among Women in 38 States of the United States

INTRODUCTION

To examine the prevalence and the changing pattern of e-cigarette use from preconception to pregnancy.

AIMS AND METHODS

This is a cross-sectional study using data from the multi-site Pregnancy Risk Assessment Monitoring System in the United States, 2016-2017. All participating mothers with information on e-cigarette use before and during pregnancy were included. Self-reported information about e-cigarette use were assessed using questionnaires. Weighted prevalences of e-cigarette use before and during pregnancy were calculated. Multivariable logistic regressions were used to examine the association between various demographic characteristics and e-cigarette use before or during pregnancy.

RESULTS

This study included 69 508 pregnant women from 38 states in the United States. The weighted prevalence of e-cigarette use before pregnancy and during the last 3 months of pregnancy was 3.6% (95% confidence interval [CI] 3.4%-3.9%) and 1.1% (0.9%-1.2%), respectively. The prevalence varied across states, ranging from 1.3% to 8.3% for e-cigarette use before pregnancy and from 0.1% to 3.4% for e-cigarette use during the last 3 months of pregnancy. Among women who used e-cigarettes before pregnancy, 24.4% (21.7%-27.1%) continued to use e-cigarettes during pregnancy. Among women who used e-cigarettes during pregnancy, 62.3% (56.5%-68.0%) were dual users. In multivariable analyses, cigarette smoking was most strongly associated with e-cigarette use. The adjusted odds ratio comparing smokers with nonsmokers before pregnancy was 11.10 (95% CI 9.34-13.20) for e-cigarette use before pregnancy and 6.72 (95% CI 4.38-10.31) for e-cigarette use during pregnancy.

CONCLUSIONS

Using data from 38 states in the United States, we showed geographical variations in the prevalence of e-cigarette use before and during pregnancy. Among women who used e-cigarettes before pregnancy, a quarter of them continued to use e-cigarettes during pregnancy. Conventional cigarette use is a strong risk factor for e-cigarette use before and during pregnancy. The prevalence of e-cigarette use needs to be monitored continuously.

IMPLICATIONS

This study provides important information to understand the status and changing patterns of e-cigarette use in pregnant women in the United States. Among pregnant women in 38 states in the United States, 3.6% of them used e-cigarettes during the 3 months before pregnancy and 1.1% used them during the last 3 months of pregnancy. The prevalence varied across states. A quarter of women who used e-cigarettes before pregnancy continued to use e-cigarettes during pregnancy. Cigarette smoking is the strongest predictor of e-cigarette use. Future research about health effects of e-cigarette use during pregnancy is in urgent need.

Chronic, Episodic Nicotine Alters Hypoglossal Motor Neuron Function at a Critical Developmental Time Point in Neonatal Rats

Developmental nicotine exposure (DNE), alters brainstem neurons that control breathing, including hypoglossal motor neurons (XIIMNs), which innervate the tongue. Here, we tested the hypothesis that chronic, episodic DNE (eDNE), which mimics nicotine replacement therapies such as e-cigarettes or nicotine gum, alters the function of nicotinic acetylcholine receptors (nAChRs), XIIMN intrinsic properties, and tongue muscle function in vivo similar to what we have observed with a chronic, sustained exposure model. We delivered nicotine to pregnant Sprague Dawley rats through drinking water and studied pups of either sex in two age groups: postnatal day (P)1–P5 and P10–P12, which encompasses a critical period in brain development. At P1–P5, eDNE was associated with delayed recovery of nAChRs from desensitization; however, there were no changes in the magnitude of desensitization, XIIMN intrinsic properties, or tongue muscle function in vivo. By P10–P12, eDNE XIIMNs had lower peak firing frequencies in response to depolarizing current injection, larger delayed rectifier potassium currents, and continued to exhibit delayed nAChR recovery. Moreover, this age group exhibited a blunted and delayed tongue muscle response to nasal occlusion in vivo, indicating that changes to XIIMN intrinsic properties is an important mechanism behind this effect, as it is not produced by altered nAChR function alone. Together, these results show that eDNE alters XIIMNs and tongue muscle function during a critical period in brain development and that the specific effects of chronic nicotine exposure may be pattern dependent.

Identification of newly formed toxic chemicals in E-cigarette aerosols with Orbitrap mass spectrometry and implications on E-cigarette control

The increasing use of electronic nicotine delivery systems (ENDS) is of concern due to multiple emerging adverse health effects. Most analyses of the harmful chemicals of ENDS have targeted metals or carbonyls generated by thermal decomposition of carrier liquids such as propylene glycol. However, new complex compounds not routinely identified and with unknown health consequences could be formed. ENDS aerosol samples were collected by the direct aerosol droplet deposition method. Untargeted analysis was performed using Orbitrap mass spectrometry with high mass accuracy. We identified more than 30 "features" in the aerosol characterized by pairs of the mass-to-charge ratio "m/z" of the compound and the retention time. We identified several compounds containing nicotine and propylene glycol (NIC-PG), whose abundance relative to nicotine increased along with vaping power used. On the basis of the prediction by the Environmental Protection Agency Toxicity Estimation Software Tool, these compounds exert developmental toxicity. In addition, a nitrogen-containing compound, likely tributylamine (a known lung irritant), was identified based on the molecular weight. This compound has not been previously identified in ENDS e-liquids and aerosols. ENDS produce not only small toxic compounds such as aldehydes, but also large complex toxic compounds such as NIC-PG. Predicted development toxicity for NIC-PG is concerning for fetal development in pregnant women who use ENDS, children exposed to secondhand or thirdhand ENDS aerosols, and teenage ENDS users whose brains are still developing. The strong positive association between NIC-PG levels and ENDS power output supports regulating high-powered ENDS.

Gestational Women's Perceptions About the Harms of Cigarette and E-Cigarette Use During Pregnancy

OBJECTIVES

The purpose of this study was to examine differences between perceived harm of cigarette and electronic cigarette (e-cigarette) use while pregnant and differences between healthcare providers' communication about these products during pregnancy.

METHODS

A convenience sample of gestational women (n = 218; ages 18-45) living in the US completed an online survey between May and December 2017. Participants reported perceived likelihood of adverse health outcomes (e.g., low birth weight, sudden infant death syndrome) among infants/children born to mothers who used cigarettes/e-cigarettes. T-tests and two-way ANOVAs examined differences between risk perceptions of using cigarettes/e-cigarettes while pregnant based on pregnancy status (previously pregnant, currently pregnant, future pregnant). Chi-square analyses examined differences between healthcare provider communication about cigarette/e-cigarette use during pregnancy.

RESULTS

Overall, participants believed adverse health outcomes were significantly more likely to be caused by maternal use of cigarettes than e-cigarettes. Participants who planned to be pregnant reported higher endorsement that smoking combustible cigarettes would cause a miscarriage (p < .05) or increased blood pressure (p < .05) for a child than currently pregnant participants. Participants reported healthcare providers asked about (p < .05), advised them not to use (p < .001), and talked to them about health effects of smoking combustible cigarettes while pregnant (p < .001) significantly more than e-cigarettes.

CONCLUSIONS FOR PRACTICE

Healthcare providers working with pregnant women should perform the 5As behavioral intervention method to provide pregnant women with tobacco cessation care. They should also discuss the absolute harm nicotine exposure (via cigarettes or e-cigarettes) can have on fetal health and development.

Early Life Exposure to Nicotine: Postnatal Metabolic, Neurobehavioral and Respiratory Outcomes and the Development of Childhood Cancers

Cigarette smoking during pregnancy is associated with numerous obstetrical, fetal, and developmental complications, as well as an increased risk of adverse health consequences in the adult offspring. Nicotine replacement therapy and electronic nicotine delivery systems (e-cigarettes) have been developed as a pharmacotherapy for smoking cessation and are considered safer alternatives for women to smoke during pregnancy. The safety of nicotine replacement therapy use during pregnancy has been evaluated in a limited number of short-term human trials, but there is currently no information on the long-term effects of developmental nicotine exposure in humans. However, animal studies suggest that nicotine alone may be a key chemical responsible for many of the long-term effects associated with maternal cigarette smoking on the offspring and increases the risk of adverse neurobehavioral outcomes, dysmetabolism, respiratory illness, and cancer. This review will examine the long-term effects of fetal and neonatal nicotine exposure on postnatal health.

Perceptions of nicotine in current and former users of tobacco and tobacco harm reduction products from seven countries

Purpose

Nicotine is widely known as a tobacco constituent and for its use as a tobacco cessation aid. The development of new devices for nicotine delivery in recent years has led to uncertainty among consumers regarding the health risks of nicotine relative to tobacco. The purpose of this study was to discover if current and former consumers of tobacco and tobacco harm reduction (THR) products could distinguish between “nicotine” and “cigarettes” and examined the preceding media dialogue to determine if conflicting messages by the media influence public perceptions.

Design/methodology/approach

A quantitative survey was administered online in Norway (NO), Japan (JP), the United Kingdom (UK) and the United States (US), while face-to-face computer-aided interviews were conducted with randomly selected samples in India (IN), Greece (GR) and South Africa (SA). Participants were between 18 and 69 years of age and either current users of tobacco and THR products or previous users who quit within the past five years. Questions assessed beliefs about harmfulness of nicotine. Nicotine and other products and substances were also independently rated for harmfulness on a scale of 1–10 and subsequently compared. In addition, the authors examined the media dialogue of top media outlets in four countries to assess the potential influence on people’s beliefs.

Findings

A total of 54,267 participants (NO: 1,700, JP: 2,227, UK: 2,250, USA: 2,309, IN: 41,633, GR: 1,801, SA: 2,359) were sampled with the percentage of women participants ranging from 14.8% (IN) to 53.8% (UK). Between 68.3% (men, IN) and 88.7% (men, USA) of current consumers believed nicotine is harmful. Current consumers who agreed with the statement that nicotine is the primary cause of tobacco-related cancer ranged from 43.7% (men, UK) to 78.0% (men, SA). In six countries nicotine was rated nearly as harmful as cigarettes and alcohol, while other substances such as sugar, salt or caffeine, were usually rated as less harmful.

Research limitations/implications

A large proportion of consumers across all surveyed countries view nicotine and cigarettes similarly. Clearer communication on the harmful properties of both by the media is needed to help consumers make informed decisions about products across the continuum of risk. Messaging to consumers, especially via the media, propagates misinformation about the relative harms of tobacco and nicotine through reporting that is often incomplete and biased toward more negative aspects.

Originality/value

This study specifically assessed public perceptions of nicotine as opposed to products containing nicotine, which is the focus of previous studies. Apart from showing that consumers often incorrectly perceive nicotine and cigarettes as similar in terms of harmfulness, the authors highlight the need for more accurate and complete reporting by the media to clarify widespread misunderstandings and mitigate public uncertainty.