Increased Cardiac Sympathetic Activity and Oxidative Stress in Habitual Electronic Cigarette Users: Implications for Cardiovascular Risk

In vitro and in vivo cardiac toxicity of flavored electronic nicotine delivery systems

The usage of flavored electronic nicotine delivery systems (ENDS) is popular, specifically in the teen and young adult age-groups. The possible cardiac toxicity of the flavoring aspect of ENDS is largely unknown. Vaping, a form of electronic nicotine delivery, uses "e-liquid" to generate "e-vapor," an aerosolized mixture of nicotine and/or flavors. We report our investigation into the cardiotoxic effects of flavored e-liquids. E-vapors containing flavoring aldehydes such as vanillin and cinnamaldehyde, as indicated by mass spectrometry, were more toxic in HL-1 cardiomyocytes than fruit-flavored e-vapor. Exposure of human induced pluripotent stem cell-derived cardiomyocytes to cinnamaldehyde or vanillin-flavored e-vapor affected the beating frequency and prolonged the field potential duration of these cells more than fruit-flavored e-vapor. In addition, vanillin aldehyde-flavored e-vapor reduced the human ether-à-go-go-related gene (hERG)-encoded potassium current in transfected human embryonic kidney cells. In mice, inhalation exposure to vanillin aldehyde-flavored e-vapor for 10 wk caused increased sympathetic predominance in heart rate variability measurements. In vivo inducible ventricular tachycardia was significantly longer, and in optical mapping, the magnitude of ventricular action potential duration alternans was significantly larger in the vanillin aldehyde-flavored e-vapor-exposed mice than in controls. We conclude that the widely popular flavored ENDS are not harm free, and they have a potential for cardiac harm. More studies are needed to further assess their cardiac safety profile and long-term health effects.NEW & NOTEWORTHY The use of electronic nicotine delivery systems (ENDS) is not harm free. It is not known whether ENDS negatively affect cardiac electrophysiological function. Our study in cell lines and in mice shows that ENDS can compromise cardiac electrophysiology, leading to action potential instability and inducible ventricular arrhythmias. Further investigations are necessary to assess the long-term cardiac safety profile of ENDS products in humans and to better understand how individual components of ENDS affect cardiac toxicity.

Well-being and harm reduction, the consolidated reality of electronic cigarettes ten years later from this emerging phenomenon: A narrative review

Tobacco use is the greatest threat to public health worldwide, killing more than seven million people annually. This paper, about 10 years after the first review on electronic cigarettes, analyses the evolution that this tool has had in these years. It concludes with comments on the significance of the research and why it constitutes an original contribution. We searched PubMed (National Library of Medicine), and PsycINFO (Ovid) (2006-2020) for studies on e-cigarettes (harms and benefits, e-cigarette use, craving and smoking cessation) and smoking cessation treatment (smoking cessation treatment or varenicline or tobacco cessation or reduction or bupropion or NRT or behavioral treatment or ecigarette) and evidence suggests that they may effective as smoking cessation tool and may be less harmful alternatives to combustible cigarette smoking. Consequently, e-cigarettes could be considered as an applicable instrument for Tobacco Harm Reduction (THR) and smoking cessation.

Effects of Electronic Nicotine Delivery Systems and Cigarettes on Systemic Circulation and Blood-Brain Barrier: Implications for Cognitive Decline

Electronic nicotine delivery systems (often known as e-cigarettes) are a novel tobacco product with growing popularity, particularly among younger demographics. The implications for public health are twofold, as these products may represent a novel source of tobacco-associated disease but may also provide a harm reduction strategy for current tobacco users. There is increasing recognition that e-cigarettes impact vascular function across multiple organ systems. Herein, we provide a comparison of evidence regarding the role of e-cigarettes versus combustible tobacco in vascular disease and implications for blood-brain barrier dysfunction and cognitive decline. Multiple non-nicotinic components of tobacco smoke have been identified in e-cigarette aerosol, and their involvement in vascular disease is discussed. In addition, nicotine and nicotinic signaling may modulate peripheral immune and endothelial cell populations in a highly context-dependent manner. Direct preclinical evidence for electronic nicotine delivery system-associated neurovascular impairment is provided, and a model is proposed in which non-nicotinic elements exert a proinflammatory effect that is functionally antagonized by the presence of nicotine.

Early Cardiovascular Risk in E-cigarette Users: the Potential Role of Metals

PURPOSE OF REVIEW

Electronic cigarettes (e-cigs) are a source of metals. Epidemiologic and experimental evidence support that metals are toxic to the cardiovascular system. Little is known, however, about the role that e-cig metals may play as toxicants for the possible cardiovascular effects of e-cig use. The goal of this narrative review is to summarize the evidence on e-cig use and metal exposure and on e-cig use and cardiovascular toxicity and discuss the research needs.

RECENT FINDINGS

In vitro studies show cytotoxicity and increased oxidative stress in myocardial cells and vascular endothelial cells exposed to e-liquids and e-cig aerosols, with effects partially reversed with antioxidant treatment. There is some evidence that the heating coil plays a role in cell toxicity. Mice exposed to e-cigs for several weeks showed higher levels of oxidative stress, inflammation, platelet activation, and thrombogenesis. Cross-over clinical experiments show e-cig use alters nitric oxide-mediated flow-mediated dilation, endothelial progenitor cells, and arterial stiffness. Cross-sectional evidence from large nationally representative samples in the USA support that e-cig use is associated with self-reported myocardial infarction. Smaller studies found associations of e-cig use with higher oxidized low-density protein and heart variability compared to healthy controls. Numerous studies have measured elevated levels of toxic metals in e-cig aerosols including lead, nickel, chromium, and manganese. Arsenic has been measured in some e-liquids. Several of these metals are well known to be cardiotoxic. Numerous studies show that e-cigs are a source of cardiotoxic metals. Experimental studies (in vitro, in vivo, and clinical studies) show acute toxicity of e-cigs to the vascular system. Studies of long-term toxicity in animals and humans are missing. Longitudinal studies with repeated measures of metal exposure and subclinical cardiovascular outcomes (e.g., coronary artery calcification) could contribute to determine the long-term cardiovascular effects of e-cigs and the potential role of metals in those effects.

Cardiovascular autonomic effects of electronic cigarette use: a systematic review

PURPOSE

Electronic cigarettes (ECs) are the fastest growing tobacco product in the USA, and ECs, like tobacco cigarettes (TCs), have effects on the cardiovascular autonomic nervous system, with clinical implications. The purpose of this review was to collect and synthesize available studies that have investigated the autonomic cardiovascular effects of EC use in humans. Special attention is paid to the acute and chronic effects of ECs, the relative contributions of the nicotine versus non-nicotine constituents in EC emissions and the relative effects of ECs compared to TCs.

METHODS

Using the methodology described in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement, we conducted a literature search of the Ovid PubMed and Embase databases on 6 December 2019 using keywords in titles and abstracts of published literature. Acute (minutes to hours) and chronic (days or longer) changes in heart rate variability (HRV), heart rate (HR) and blood pressure (BP) were used as estimates of cardiovascular autonomic effects.

RESULTS

Nineteen studies were included in this systematic review, all of which used earlier generation EC devices. Acute EC vaping increased HR and BP less than acute TC smoking. Nicotine but not non-nicotine constituents in EC aerosol were responsible for the sympathoexcitatory effects. The results of chronic EC vaping studies were consistent with a chronic sympathoexcitatory effect as estimated by HRV, but this did not translate into chronic increases in HR or BP.

CONCLUSIONS

Electronic cigarettes are sympathoexcitatory. Cardiac sympathoexcitatory effects are less when vaping using the earlier generation ECs than when smoking TCs. Additional studies of the latest pod-like EC devices, which deliver nicotine similarly to a TC, are necessary.

Electronic Cigarette Use and Blood Pressure Endpoints: a Systematic Review

PURPOSE OF REVIEW

E-cigarettes (e-cigs) release toxic chemicals known to increase blood pressure (BP) levels. The effects of e-cigs on BP, however, remain unknown. Studying BP may help characterize potential cardiovascular risks of short- and long-term e-cig use. We summarized published studies on the association of e-cig use with BP endpoints.

RECENT FINDINGS

Thirteen e-cig trials (12 cross-over designs) and 1 observational study evaluated systolic and diastolic blood pressure (SBP and DBP). All trials included at least one e-cig arm with nicotine, 6 a no-nicotine e-cig arm, and 3 a placebo arm. SBP/DBP increased in most nicotine e-cig arms, in some non-nicotine e-cig arms, and in none of the placebo arms. The observational study followed e-cig users and nonsmokers for 3.5 years with inconsistent findings. The use of e-cigs with and without nicotine may result in short-term elevations of both SBP and DBP. Prospective studies that investigate the long-term cardiovascular impact of e-cig use are needed.

Twenty-Four-Hour Cardiovascular Effects of Electronic Cigarettes Compared With Cigarette Smoking in Dual Users

Background

Cardiovascular safety is an important consideration regarding the benefits versus risks of electronic cigarette use (EC) for public health. The single‐use cardiovascular effects of EC have been well studied but may not reflect effects of ad libitum use throughout the day. We aimed to compare the circadian hemodynamic effects as well as 24‐hour biomarkers of oxidative stress, and platelet aggregation and inflammation, with ad libitum cigarette smoking (CS) versus EC versus no tobacco product use.

Methods and Results

Thirty‐six healthy dual CS and EC users participated in a crossover study in a confined research setting. Circadian heart rate, blood pressure and plasma nicotine levels, 24‐hour urinary catecholamines, 8‐isoprostane and 11‐dehydro‐thromboxane B2, and plasma interleukin‐6 and interleukin‐8 were compared in CS, EC, and no nicotine conditions. Over 24 hours, and during daytime, heart rate and blood pressure were higher in CS and EC compared with no tobacco product conditions (P<0.01). Heart rate on average was higher with CS versus EC. Urinary catecholamines, 8‐isoprostane, and 11‐dehydro‐thromboxane B2 were not significantly different, but plasma IL‐6 and IL‐8 were higher with both CS and EC compared with no tobacco product (P<0.01).

Conclusions

CS and EC had similar 24‐hour patterns of hemodynamic effects compared with no tobacco product, with a higher average heart rate with CS versus EC, and similar effects on biomarkers of inflammation. EC may pose some cardiovascular risk, particularly to smokers with underlying cardiovascular disease, but may also provide a harm reduction opportunity for smokers willing to switch entirely to EC.

Registration

URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02470754.

Use of Electronic Cigarettes and Self-Reported Chronic Obstructive Pulmonary Disease Diagnosis in Adults

INTRODUCTION

Electronic cigarette (e-cigarette) use (vaping) has increased in recent years. Chronic obstructive pulmonary disease (COPD) is the third leading cause of death associated with smoking.

AIMS AND METHODS

Based on 2016 and 2017 Behavioral Risk Factor Surveillance System national survey data on 891 242 adult participants who indicated their smoking and vaping status, the cross-sectional association of vaping with self-reported COPD diagnosis was investigated, using univariable and multivariable weighted logistic regression models.

RESULTS

Compared to never users, while dual users showed the highest association with self-reported COPD diagnosis (adjusted odds ratio [aOR] = 4.39; 95% confidence interval [CI] = 3.98 to 4.85), current vapers who were either ex-smokers or never smoked showed significantly higher association with self-reported COPD diagnosis (aOR = 3.24; 95% CI = 2.78 to 3.78 and aOR = 1.47; 95% CI = 1.01 to 2.12, respectively). Current vapers who were ex-smokers showed higher association with self-reported COPD diagnosis than ex-smokers who do not vape (aOR = 1.27; 95% CI = 1.09 to 1.48). Dual users showed higher association with self-reported COPD diagnosis than current smokers who do not vape (aOR = 1.16; 95% CI = 1.05 to 1.27). Ex-smokers showed significantly less association with self-reported COPD diagnosis (aOR = 0.67; 95% CI = 0.64 to 0.71) than current smokers. Current vapers who were either ex-smokers or never smoked had less association with self-reported COPD diagnosis compared to current smokers, with aOR = 0.85 (95% CI = 0.73 to 0.99) and aOR = 0.39 (95% CI = 0.27 to 0.56).

CONCLUSIONS

Vaping is significantly associated with self-reported COPD diagnosis in adults, even among vapers who never smoked. Whether there is a benefit for COPD of switching from smoking to vaping requires study of the long-term effects of vaping.

IMPLICATIONS

With the increase of e-cigarette use in recent years, the health effects of e-cigarettes need to be investigated. While several studies have examined the association of vaping with respiratory symptoms among adolescents, little is known about the association of vaping with susceptibility to COPD among US adults. Using cross-sectional national survey data in adults, our study showed that vaping was significantly associated with self-reported COPD diagnosis. Although our data did not establish the causal relationship between vaping and self-reported COPD diagnosis, this study raises concerns about the observed association between vaping and self-reported COPD diagnosis.

Electronic Cigarette Use and Metabolic Syndrome Development: A Critical Review

The metabolic syndrome is a combination of several metabolic disorders, such as cardiovascular disease, atherosclerosis, and type 2 diabetes. Lifestyle modifications, including quitting smoking, are recommended to reduce the risk of metabolic syndrome and its associated complications. Not much research has been conducted in the field of e-cigarettes and the risk of metabolic syndrome. Furthermore, taking into account the influence of e-cigarettes vaping on the individual components of metabolic syndrome, i.e, abdominal obesity, insulin resistance, dyslipidemia and elevated arterial blood pressure, the results are also ambiguous. This article is a review and summary of existing reports on the impact of e-cigarettes on the development of metabolic syndrome as well as its individual components. A critical review for English language articles published until 30 June 2020 was made, using a PubMed (including MEDLINE), Cochrane, CINAHL Plus, and Web of Science data. The current research indicated that e-cigarettes use does not affect the development of insulin resistance, but could influence the level of glucose and pre-diabetic state development. The lipid of profile an increase in the TG level was reported, while the influence on the level of concentration of total cholesterol, LDL fraction, and HDL fraction differed. In most cases, e-cigarettes use increased the risk of developing abdominal obesity or higher arterial blood pressure. Further research is required to provide more evidence on this topic.

Possible Approaches to Primary Prevention of Cardiovascular Diseases

In recent years there is a positive trend in the development of preventive medicine, in particular, primary prevention of diseases. However, in most cases, patients seek help from a doctor after the manifestation of the disease, and therefore, early identification of risk factors (RF) remains relevant. Conduction of a large number of studies that are aimed at studying modifiable RF associated with the development of cardiovascular diseases (CVD), allowed the experts of the American Heart Association to develop recommendations “Life's Simple 7”, which makes it possible to structure methods of primary prevention of CVD and minimize the risk of their development. In 2019, experts from the American College of Cardiology presented a simplified version of these recommendations, to improve approaches to primary prevention and their effectiveness not only for doctors but also for patients. Thus, by involving the patient in the decision-making process about follow-up treatment, doctors can achieve a high level of compliance, which is essential for improving the prognosis. The “ABCDE” recommendations, in name of which are reflected the first letters of the leading CVD RF, include such paragraphs as RF assessment, the use of antiaggregating therapy, correction of blood pressure, cholesterol levels, smoking elimination, correction of high glucose levels and diabetes treatment, weight loss, assessment of social and economic factors affecting the morbidity in a particular patient. Despite the undoubted benefit of the “ABCDE” recommendations, some problems of primary prevention currently cannot be solved: the inability to accurately assess social and economic RF; the imperfection of the used CVD risk scales. The updated version of the recommendations allows not only to assess the existing RF of the patient, but also to effectively correct them. In addition, the patient himself can read the recommendations, which improves understanding of the primary prevention importance.

Patterns of Circadian Variation in 24-Hour Ambulatory Blood Pressure, Heart Rate, and Sympathetic Tone Correlate with Cardiovascular Disease Risk: A Cluster Analysis

To investigate whether specific time series patterns for blood pressure (BP), heart rate (HR), and sympathetic tone are associated with metabolic factors and the 10-year risk of atherosclerotic cardiovascular disease (ASCVD). A total of 989 patients who underwent simultaneous 24-hour ambulatory BP and Holter electrocardiogram monitoring were enrolled. The patients were categorized into sixteen groups according to their circadian patterns using the consensus clustering analysis method. Metabolic factors, including cholesterol profiles and apolipoprotein, were compared. The 10-year ASCVD risk was estimated based on the Framingham risk model. Overall, 16 significant associations were found between the clinical variables and cluster groups. Age was commonly associated with all clusters in systolic BP (SBP), diastolic BP (DBP), HR, and sympathetic tone. Metabolic indicators, including diabetes, body mass index, total cholesterol, high-density lipoprotein, and apolipoprotein, were associated with the four sympathetic tone clusters. In the crude analysis, the ASCVD risk increased incrementally from clusters 1 to 4 across SBP, DBP, HR, and sympathetic tone. After adjustment for multiple variables, however, only sympathetic tone clusters 3 and 4 showed a significantly high proportion of patients at high risk (≥7.5%) of 10-year ASCVD (odds ratio (OR) = 5.90, 95% confidential interval (CI) = 1.27-27.46, and P value = 0.024 and OR = 15.28, 95% CI = 3.59-65.11, and P value < 0.001, respectively). Time series patterns of BP, HR, and sympathetic tone can serve as an indicator of aging. Circadian variations in sympathetic tone can provide prognostic information about patient metabolic profiles and indicate future ASCVD risk.

Changes in lipid composition associated with electronic cigarette use

Background

Electronic cigarette use is on the rise despite a number of reports linking electronic cigarettes with adverse health outcomes. Recent studies have suggested that alterations in lipid signaling may be one mechanism by which electronic cigarettes contribute to lung pulmonary function. Vitamin E acetate, for example, is synthetic form of Vitamin E transported via lipids, found to be associated with electronic cigarette associated lung injury. Lipids are absolutely critical for normal lung physiology and perturbations in a number of lipid pathways have been associated with respiratory illness. Is it conceivable that electronic cigarette use even in seemingly healthy cohorts are associated with alterations in lipid pathways?

Methods

To investigate quantitative alterations in the plasma lipidome associated with electronic cigarette use in healthy we obtained plasma samples from 119 male and female participants with who were either: (1) chronic tobacco cigarette (TC) smokers (> 12 months of self-reported TC use), (2) chronic Electronic cigarette (EC) users (> 12 months of self-reported EC use), or (3) non-users. We measured quantitative lipid species across different lipid sub-classes from plasma samples using the Sciex Lipidyzer.

Results

We found that male and female tobacco and electronic cigarette users had distinct lipidome signatures across a number of lipid species although the vast majority of lipids were unchanged when compared to non-users. Intriguingly, we found that female but not male electronic cigarette users had lower levels of plasmalogens, critical glycerophospholipids secreted by alveoli and required for normal surfactant function.

Conclusions

In summary, our study does not reveal striking changes associated with electronic cigarette use but we observed sex-specific changes in lipids known to be critical for lung function.

People smoke for nicotine, but lose sexual and reproductive health for tar: a narrative review on the effect of cigarette smoking on male sexuality and reproduction

PURPOSE

To systematically review the impact of smoking habits on cardiovascular (CV) as well as on male sexual and reproductive function and to provide updated evidence on the role of electronic cigarettes (e-Cig) on the same topics.

METHODS

A comprehensive Medline, Embase, and Cochrane search was performed including the following words: smoking, CV system, CV risk, erectile dysfunction (ED), and male fertility. Publications from January 1, 1969 up to February 29, 2020 were included.

RESULTS

Smoking has a tremendous negative impact on CV mortality and morbidity. Current smoking behavior is also negatively associated with erectile dysfunction (ED) and impaired sperm parameters. E-Cig can release significantly lower concentrations of harmful substances when compared to regular combustible cigarettes. Whether or not the latter can result in positive CV, sexual, and fertility outcomes is still under study. Preliminary studies showed that exposure to e-Cig leads to lower vascular damage when compared to the traditional cigarette use. However, data on the long-term effects of e-Cig are lacking. Similarly, preliminary data, obtained in animal models, have suggested a milder effect of e-Cig on erectile function and sperm parameters.

CONCLUSION

Available evidence showed that e-Cig are much less dangerous when compared to the traditional tobacco use. However, it should be recognized that the risk related to e-Cig is still higher when compared to that observed in non-smoking patients. Hence, e-Cig should be considered as a potential tool, in the logic of harm reduction, to reduce the CV, sexual and fertility risk in patients refractory to the fundamental, healthy choice to definitively quit smoking.

Electronic cigarettes cause alteration in cardiac structure and function in diet-induced obese mice

In spite of the widespread use of electronic cigarettes, also known as e-cigarettes, and the proposed adverse cardiac effects of nicotine, the detrimental effects of e-cigarettes on the heart are not well known. This study examines the detrimental effects of e-cigarettes with nicotine at doses that yield circulating nicotine and cotinine in the ranges similar to the levels found in habitual smokers, and a high fat diet (HFD) on cardiac structure and function in a commonly used model of diet-induced obesity (DIO). C57BL/6J mice on an HFD were exposed to e-cigarette in the presence (2.4% nicotine) or absence (0% nicotine) of nicotine and saline aerosol for 12 weeks. Echocardiographic data demonstrated a decrease in left ventricular (LV) fractional shortening, LV ejection fraction, and velocity of circumferential fiber shortening (VCF) in mice treated with e-cigarette (2.4% nicotine) compared to e-cigarette (0% nicotine) or saline exposed mice. Cardiomyocytes (CMs) of mice treated with e-cigarette (2.4% nicotine) exhibited LV abnormalities, including lipid accumulation (ventricular steatosis), myofibrillar derangement and destruction, and mitochondrial hypertrophy, as revealed by transmission electron microscopy. The detrimental effects of e-cigarettes (2.4% nicotine) on cardiac structure and function was accompanied by increased oxidative stress, plasma free fatty acid levels, CM apoptosis, and inactivation of AMP-activated protein kinase and activation of its downstream target, acetyl-CoA-carboxylase. Our results indicate profound adverse effects of e-cigarettes (2.4% nicotine) on the heart in obese mice and raise questions about the safety of the nicotine e-cigarettes use.

Nicotine' actions on energy balance: Friend or foe?

Obesity has reached pandemic proportions and is associated with severe comorbidities, such as type 2 diabetes mellitus, hepatic and cardiovascular diseases, and certain cancer types. However, the therapeutic options to treat obesity are limited. Extensive epidemiological studies have shown a strong relationship between smoking and body weight, with non-smokers weighing more than smokers at any age. Increased body weight after smoking cessation is a major factor that interferes with their attempts to quit smoking. Numerous controlled studies in both humans and rodents have reported that nicotine, the main bioactive component of tobacco, exerts a marked anorectic action. Furthermore, nicotine is also known to modulate energy expenditure, by regulating the thermogenic activity of brown adipose tissue (BAT) and the browning of white adipose tissue (WAT), as well as glucose homeostasis. Many of these actions occur at central level, by controlling the activity of hypothalamic neuropeptide systems such as proopiomelanocortin (POMC), or energy sensors such as AMP-activated protein kinase (AMPK). However, direct impact of nicotine on metabolic tissues, such as BAT, WAT, liver and pancreas has also been described. Here, we review the actions of nicotine on energy balance. The relevance of this interaction is interesting, because considering the restricted efficiency of obesity treatments, a possible complementary approach may focus on compounds with known pharmacokinetic profile and pharmacological actions, such as nicotine or nicotinic acetylcholine receptors signaling.

Elevated Cellular Oxidative Stress in Circulating Immune Cells in Otherwise Healthy Young People Who Use Electronic Cigarettes in a Cross-Sectional Single-Center Study: Implications for Future Cardiovascular Risk

Background

Tobacco cigarettes (TCs) increase oxidative stress and inflammation, both instigators of atherosclerotic cardiac disease. It is unknown if electronic cigarettes (ECs) also increase immune cell oxidative stress. We hypothesized an ordered, “dose‐response” relationship, with tobacco‐product type as “dose” (lowest in nonsmokers, intermediate in EC vapers, and highest in TC smokers), and the “response” being cellular oxidative stress (COS) in immune cell subtypes, in otherwise, healthy young people.

Methods and Results

Using flow cytometry and fluorescent probes, COS was determined in immune cell subtypes in 33 otherwise healthy young people: nonsmokers (n=12), EC vapers (n=12), and TC smokers (n=9). Study groups had similar baseline characteristics, including age, sex, race, and education level. A dose‐response increase in proinflammatory monocytes and lymphocytes, and their COS content among the 3 study groups was found: lowest in nonsmokers, intermediate in EC vapers, and highest in TC smokers. These findings were most striking in CD14_dimCD16⁺ and CD14⁺⁺CD16⁺ proinflammatory monocytes and were reproduced with 2 independent fluorescent probes of COS.

Conclusions

These findings portend the development of premature cardiovascular disease in otherwise healthy young people who chronically vape ECs. On the other hand, that the COS is lower in EC vapers compared with TC smokers warrants additional investigation to determine if switching to ECs may form part of a harm‐reduction strategy.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03823885.

Exposure to e-cigarette advertising, attitudes, and use susceptibility in adolescents who had never used e-cigarettes or cigarettes

Background

Tobacco advertisements have been banned in Hong Kong, but low intensity e-cigarette (EC) advertising can still be found in various media outlets. We investigated the associations between exposure to EC advertising and susceptibility to EC use in adolescents who had never used cigarettes or ECs, with potential mediation by attitudes towards ECs and the tobacco industry.

Methods

The School-based Smoking Survey 2016/17 assessed exposure to EC advertising in the past 30 days, attitudes towards ECs and the tobacco industry, susceptibility to EC use, and other covariates. Generalised linear mixed models and multiple mediation analysis methods were used in data analyses.

Results

Among 7082 students (mean age 14.9 years), 28.8% reported exposure to EC advertising. Exposure was associated with being uncertain about the harm of EC use, being tolerant towards ECs, believing the tobacco industry is respectable, and being susceptible to EC use; the magnitudes of these associations increased with the number of types of advertising exposed (0, 1, and ≥ 2) (all p-values < 0.01). These attitudinal factors were in turn associated with EC use susceptibility (all p-values < 0.001). The perception that tobacco companies make youth smoke was not associated with the advertising exposure or EC use susceptibility. Of the total effects of EC advertising on use susceptibility, only 16.6% were mediated by attitudinal factors: perceived harm (3.1%), attitudes towards ECs (8.2%), and attitudes towards the tobacco industry (4.9%).

Conclusions

Even exposure to low intensity EC advertising was associated with susceptibility to EC use in adolescents who had never used cigarettes or ECs. The association was weakly mediated by tolerant attitudes towards ECs and the tobacco industry. The government should reinforce the regulations on EC advertising to protect adolescent health.

Tobacco Smoke and Endothelial Dysfunction: Role of Aldehydes?

PURPOSE OF REVIEW

Tobacco smoking is the most significant modifiable risk factor in the development of cardiovascular disease (CVD). Exposure to mainstream cigarette smoke (MCS) is associated with CVD through the development of endothelial dysfunction, a condition characterized by an imbalance of vasoactive factors in the vasculature. This dysfunction is thought to be induced in part by aldehydes generated at high levels in MCS.

RECENT FINDINGS

Electronic cigarettes (e-cigs) may also pose CVD risk. Although the health effects of e-cigs are still largely unknown, the presence of aldehydes in e-cig aerosol suggests that e-cigs may induce adverse cardiovascular outcomes similar to those seen with MCS exposure. Herein, we review studies of traditional and emerging tobacco product use, shared harmful and potentially harmful constituents, and measures of biomarkers of harm (endothelial dysfunction) to examine a potential and distinct role of aldehydes in cardiovascular harm associated with cigarette and e-cig use.

Cardiovascular risk of electronic cigarettes: a review of preclinical and clinical studies

Cigarette smoking is the most preventable risk factor related to cardiovascular morbidity and mortality. Tobacco usage has declined in recent years; however, the use of alternative nicotine delivery methods, particularly e-cigarettes, has increased exponentially despite limited data on their short- and long-term safety and efficacy. Due to their unique properties, the impact of e-cigarettes on cardiovascular physiology is not fully known. Here, we summarize both preclinical and clinical data extracted from short- and long-term studies on the cardiovascular effects of e-cigarette use. Current findings support that e-cigarettes are not a harm-free alternative to tobacco smoke. However, the data are primarily derived from acute studies. The impact of chronic e-cigarette exposure is essentially unstudied. To explore the uniqueness of e-cigarettes, we contemplate the cardiovascular effects of individual e-cigarette constituents. Overall, data suggest that exposure to e-cigarettes could be a potential cardiovascular health concern. Further preclinical research and randomized trials are needed to expand basic and clinical investigations before considering e-cigarettes safe alternatives to conventional cigarettes.

Association between electronic cigarette use and metabolic syndrome in the Korean general population: A nationwide population-based study

Objectives

Although smoking is known to have a negative impact in patients with metabolic syndrome (MetS), only a few studies have examined the association between electronic cigarette (e-cig) use and MetS.

Methods

Among 22,948 participants in the 6th Korea National Health and Nutrition Examination Survey, 14,738 (13,459 [91.3%] never, 954 [6.5%] ever, and 325 [2.2%] current e-cig users) were selected. The relationship between e-cig exposure and MetS (based on the National Cholesterol Education Program Adult Treatment Panel [NCEP-ATP] III criteria) was evaluated using a multivariable logistic regression analysis. An unweighted analysis was performed to evaluate this association without a sampling weight. A subgroup analysis was performed among active smokers to compare dual users with never e-cig users.

Results

Among current e-cig users, 85.0% were dual users, 12.7% were former cigarette users, and 2.2% were only e-cig users. After adjustment for covariates, abdominal obesity and hypertriglyceridemia were significantly associated with current e-cig exposure (odds ratio [OR]: 1.88, 95% confidence interval [CI]: 1.41–2.50 and OR: 1.32, 95% CI: 1.00–1.74 respectively [compared with the never e-cig users group]). Compared with never e-cig users, current e-cig users showed an OR of 1.27 (95% CI: 0.96–1.70, P_trend = 0.01) for MetS. In the unweighted analysis, the OR for MetS in current e-cig users was 1.40 (95% CI: 1.08–1.81, P_trend <0.01). Compared with never e-cig users, dual users showed a higher OR for abdominal obesity (OR: 1.71, 95% CI: 1.25–2.34, P_trend <0.001).

Conclusions

Current e-cig exposure was associated with an increased risk of MetS. Dual use of e-cigs and cigarettes was associated with abdominal obesity. Further longitudinal studies and better assessment of e-cig use and type are needed to clarify this relationship.

Biological Toxicity of the Compositions in Electronic-Cigarette on Cardiovascular System

Using electronic cigarette (e-cig) among youth is becoming a critical public health crisis in the USA. However, the biological impacts of the e-cig on multiple organ systems, especially in the cardiovascular system, are largely unknown. Unlike conventional tobacco, e-cig combines various chemical ingredients including nicotine and other add-on non-nicotine chemicals, such as the solvents (propylene glycol and/or vegetable glycerin) and flavoring chemicals, which dramatically increases the diversity of the potential implications. The recent outbreak of e-cig vaping-related tragic deaths in youth and multiple hospitalized patients raised a question on the safety of e-cig use and led to an urgent need for the knowledge of the health risk of the e-cig compositions. Therefore, in the review, we summarized the latest findings from both human and animal studies on the potential cardiovascular toxicological effects of e-cig on the cardiovascular system in terms of the systemic physiological implications and the cellular and molecular mechanisms involved.

Smoking, Vaping, and Tobacco Industry During COVID-19 Pandemic: Twitter Data Analysis

The reports suggesting a beneficial effect of nicotine on coronavirus disease 2019 (COVID-19) severity may encourage smoking. We aimed to analyze tweets on COVID-19 and smoking coming from casual Twitter users and Twitter accounts representing the tobacco industry. We collected tweets on COVID-19 and smoking from January 1 to May 1, 2020, using Twitter application programming interface. We analyzed sentiment, likes, or retweet to followers ratios, and the posts coming from the casual users to find pieces of news that could affect the discourse. Tweets coming from industry were analyzed manually. We analyzed n = 33,890 tweets on COVID-19 and smoking. The sentiment of tweets was negative, hitting a nadir in mid-March, but became less negative in April when preprints suggesting benefits from smoking on COVID-19 were released. Similar trends were observed for the ratios of likes or retweets to followers. We found 58 messages from the tobacco industry concerning COVID-19. Twenty-two (37.9 percent) mentioned the efforts of tobacco companies to support the development of a COVID-19 vaccine. Two tweets included Food and Drug Administration statements that there is no evidence that vaping increases the risk of COVID-19. The occurrence of preprints suggesting benefits of smoking in COVID-19 might increase sentiment and reactions to tweets on tobacco products and the virus. The authors of potentially controversial articles should restrain from the promotion of their results before the completion of the peer-review process. Twitter presents a convenient tool to monitor e-discourse during a health crisis. The research community should monitor the tobacco industry's social media.

Cigarette type or smoking history: Which has a greater impact on the metabolic syndrome and its components?

Few studies have researched the gender-specific effects of electronic nicotine delivery systems on the metabolic syndrome (MetS) and/or its risk factors (central obesity, raised triglycerides, decreased HDL cholesterol, raised blood pressure, raised fasting plasma glucose). Thus, this study investigated the association between smoking behavior (cigarette type, smoking history) and MetS in a nationally representative sample of Korean men and women. Our study employed data for 5,462 cases of MetS and 12,194 controls from the Korea National Health and Nutritional Examination Survey (KNHANES) for the years 2014 to 2017. Logistic regression analysis was employed to determine the association between type of cigarette (non-smoker, ex-smoker, and current smoker-conventional only, current smoker-conventional and electronic) and the prevalence of metabolic syndrome and its risk factors. Smoking history was clinically quantified by pack-year. No association between cigarette type and MetS was found for men. For women, relative to non-smokers, smokers of conventional cigarettes (OR 1.80, 95% CI 1.02-3.18) and both conventional and electronic cigarettes (OR 4.02, 95% CI 1.48-10.93) had increased odds of MetS. While there was no association between smoking history and MetS for women, for men, conventional smoking history was associated with MetS for individuals with a smoking history of > 25 pack-years (> 25 to ≤ 37.5 OR 1.45, 95% CI 1.04-2.02; > 37.5 to ≤ 50 OR 1.53, 95% CI 1.08-2.18; > 50 OR 1.56, 95% CI 1.07-2.27). Sex differences were found in the association between smoking behavior and MetS. Such findings reveal sociodemographic differences that should be considered for interventions regarding conventional and/or e-cigarette users at risk of metabolic complications.

Acute and chronic sympathomimetic effects of e-cigarette and tobacco cigarette smoking: role of nicotine and non-nicotine constituents

Electronic cigarettes (ECs) and tobacco cigarettes (TCs) both release nicotine, a sympathomimetic drug. We hypothesized that baseline heart rate variability (HRV) and hemodynamics would be similar in chronic EC and TC smokers and that after acute EC use, changes in HRV and hemodynamics would be attributable to nicotine, not non-nicotine, constituents in EC aerosol. In 100 smokers, including 58 chronic EC users and 42 TC smokers, baseline HRV and hemodynamics [blood pressure (BP) and heart rate (HR)] were compared. To isolate the acute effects of nicotine vs. non-nicotine constituents in EC aerosol, we compared changes in HRV, BP, and HR in EC users after using an EC with nicotine (ECN), EC without nicotine (EC0), nicotine inhaler (NI), or sham vaping (control). Outcomes were also compared with TC smokers after smoking one TC. Baseline HRV and hemodynamics were not different in chronic EC users and TC smokers. In EC users, BP and HR, but not HRV outcomes, increased only after using the ECN, consistent with a nicotine effect on BP and HR. Similarly, in TC smokers, BP and HR but not HRV outcomes increased after smoking one TC. Despite a similar increase in nicotine, the hemodynamic increases were significantly greater after TC smokers smoked one TC compared with the increases after EC users used the ECN. In conclusion, chronic EC and TC smokers exhibit a similar pattern of baseline HRV. Acute increases in BP and HR in EC users are attributable to nicotine, not non-nicotine, constituents in EC aerosol. The greater acute pressor effects after TC compared with ECN may be attributable to non-nicotine, combusted constituents in TC smoke.NEW & NOTEWORTHY Chronic electronic cigarette (EC) users and tobacco cigarette (TC) smokers exhibit a similar level of sympathetic nerve activity as estimated by heart rate variability. Acute increases in blood pressure (BP) and heart rate in EC users are attribute to nicotine, not non-nicotine, constituents in EC aerosol. Acute TC smoking increased BP significantly more than acute EC use, despite similar increases in plasma nicotine, suggestive of additional adverse vascular effects attributable to combusted, non-nicotine constituents in TC smoke.

Circulating Sestrin Levels Are Increased in Hypertension Patients

Background

Sestrins (Sesns), a group of oxidative stress-related proteins, have been reported to be involved in various cardiovascular diseases, including aortic dissection and chronic heart failure. This study is aimed at investigating the level of circulating Sesn1, Sesn2, and Sesn3 in hypertension patients.

Methods

Plasma levels of Sesn1, Sesn2, and Sesn3 in 400 hypertensive patients and 100 normotensive subjects were detected using enzyme-linked immunosorbent assay (ELISA) kits. The hypertension patients were divided into groups with grade I (n = 140), grade II (n = 180), and grade III (n = 80) hypertension.

Results

Compared with the normotensive subjects, Sesn1, Sesn2, and Sesn3 levels were increased in patients with hypertension, with a gradual increase between the groups with grade I, grade II, and grade III hypertension. Elevated Sesn1, Sesn2, and Sesn3 levels were positively correlated with both the systolic blood pressure (SBP) and diastolic blood pressure (DBP). Moreover, Sesn1, Sesn2, and Sesn3 levels were elevated in patients with dipper hypertension and further increased in patients with nondipper hypertension. In addition, smokers, as well as patients with higher levels of angiotensin II (Ang II) and carotid atherosclerotic plaque (CAP), exhibited increased Sesn1, Sesn2, and Sesn3 levels when compared with patients without these clinical characteristics. Furthermore, plasma levels of Sesn1, Sesn2, and Sesn3 were negatively correlated with the presence of CAP.

Conclusions

Circulating Sesn levels are increased in patients with hypertension and may be a target for the prevention and treatment of clinical hypertension.

Tobacco smoking, related harm and motivation to quit smoking in people with schizophrenia spectrum disorders

This narrative review focuses on the topic of tobacco smoking amongst people with schizophrenia spectrum disorders. We searched PubMed, PsycInfo and Scopus databases for schizophrenia spectrum disorders and smoking and included articles about the epidemiology of tobacco smoking in people with schizophrenia spectrum disorders, examining the relationship between smoking and mental health. This narrative review describes that a higher prevalence, frequency and impact of both high nicotine dependence and its harmful effects in patients with schizophrenia spectrum disorders compared with those in the general population. Despite several existent theories, the reasons for high smoking rates, the high dependence on nicotine and severity of nicotine withdrawal symptoms are not fully understood. The main aim of this paper is to inform mental health personnel and particularly clinical and health psychologists about the impact and role of tobacco smoking for smokers with schizophrenia spectrum disorders.

Electronic Cigarette and Cigarette Social Environments and Ever Use of Each Product: A Prospective Study of Young Adults in Southern California

BACKGROUND

A supportive youth cigarette social environment, for example, friends' approval of use, leads to cigarette use initiation, and cigarette users develop a more supportive social environment. Whether there is a bidirectional relationship of electronic cigarette (e-cigarette) social environment with e-cigarette use has not been studied.

METHODS

Prospective data were collected from 1441 Children's Health Study participants in 2014 (median age = 17.3 years) and at follow-up 1.5 years later. Associations were examined of (1) supportive e-cigarette social environment with subsequent e-cigarette use initiation and (2) baseline e-cigarette use with supportive e-cigarette social environment at follow-up (among those with a nonsupportive baseline social environment).

RESULTS

Participants with three to four friends using e-cigarettes at baseline (vs. no friends) had an odds ratio (OR) of 4.08 of subsequent initiation (95% confidence interval [CI] = 1.96 to 8.49); those with best friends who would have a very friendly (vs. unfriendly) reaction to e-cigarette use had an OR of 2.54 of initiation (95% CI = 1.57 to 4.10); and those with someone in the home using e-cigarettes had an OR of 1.94 of initiation (95% CI = 1.19 to 3.15). Participants who had ever used e-cigarettes at baseline developed a supportive social environment at follow-up (OR of 2.06 of having any friends who used e-cigarettes [95% CI = 1.29 to 3.30] and OR of 2.33 of having friends who were friendly toward use [95% CI = 1.32 to 4.11]). Similar bidirectional associations were observed between ever cigarette use and a supportive cigarette social environment.

CONCLUSIONS

The bidirectional relationship between a supportive e-cigarette social environment and ever use of e-cigarettes was similar to that previously observed between cigarette social environment and cigarette use.

IMPLICATIONS

Disrupting the social acceptability of youth e-cigarette use merits consideration as a strategy for preventing initiation of e-cigarette use, just as the social denormalization of cigarette use has proven to be effective in preventing cigarette initiation.

The Effects of Electronic Nicotine Delivery Systems on Athletes

The rapid rise in popularity of Electronic Nicotine Delivery Systems (ENDS), or vaping, has not eluded the athletic population. Increasing use of youth sports participants, as well as collegiate and professionals, means sports medicine providers and coaches alike should be familiar with the effects of these devices. Current evidence demonstrates an impact on both the cardiovascular and pulmonary systems. These effects appear less significant than smoking tobacco cigarettes, but the extent and longevity of the consequences of ENDS use is unclear. Mechanisms for recovery, such as sleep and injury healing, also are affected. Lastly, the emergence of life-threatening pulmonary disease associated with ENDS use may have devastating effects on an athlete. This article will highlight the recent literature on the impact of ENDS on athletes and athletic performance, as well as the potentially life-threatening consequences of use.

Effects of Electronic Cigarettes on Indoor Air Quality and Health

With the rapid increase in electronic cigarette (e-cig) users worldwide, secondhand exposure to e-cig aerosols has become a serious public health concern. We summarize the evidence on the effects of e-cigs on indoor air quality, chemical compositions of mainstream and secondhand e-cig aerosols, and associated respiratory and cardiovascular effects. The use of e-cigs in indoor environments leads to high levels of fine and ultrafine particles similar to tobacco cigarettes (t-cigs). Concentrations of chemical compounds in e-cig aerosols are generally lower than those in t-cig smoke, but a substantial amount of vaporized propylene glycol, vegetable glycerin, nicotine, and toxic substances, such as aldehydes and heavy metals, has been reported. Exposures to mainstream e-cig aerosols have biologic effects but only limited evidence shows adverse respiratory and cardiovascular effects in humans. Long-term studies are needed to better understand the dosimetry and health effects of exposures to secondhand e-cig aerosols.

Effects of Electronic Cigarettes on Indoor Air Quality and Health

With the rapid increase in electronic cigarette (e-cig) users worldwide, secondhand exposure to e-cig aerosols has become a serious public health concern. We summarize the evidence on the effects of e-cigs on indoor air quality, chemical compositions of mainstream and secondhand e-cig aerosols, and associated respiratory and cardiovascular effects. The use of e-cigs in indoor environments leads to high levels of fine and ultrafine particles similar to tobacco cigarettes (t-cigs). Concentrations of chemical compounds in e-cig aerosols are generally lower than those in t-cig smoke, but a substantial amount of vaporized propylene glycol, vegetable glycerin, nicotine, and toxic substances, such as aldehydes and heavy metals, has been reported. Exposures to mainstream e-cig aerosols have biologic effects but only limited evidence shows adverse respiratory and cardiovascular effects in humans. Long-term studies are needed to better understand the dosimetry and health effects of exposures to secondhand e-cig aerosols.

Neurotoxicity of e-cigarettes

It appears that electronic cigarettes (EC) are a less harmful alternative to conventional cigarette (CC) smoking, as they generate substantially lower levels of harmful carcinogens and other toxic compounds. Thus, switching from CC to EC may be beneficial for smokers. However, recent accounts of EC- or vaping-associated lung injury (EVALI) has raised concerns regarding their adverse health effects. Additionally, the increasing popularity of EC among vulnerable populations, such as adolescents and pregnant women, calls for further EC safety evaluation. In this state-of-the-art review, we provide an update on recent findings regarding the neurological effects induced by EC exposure. Moreover, we discuss possible neurotoxic effects of nicotine and numerous other chemicals which are inherent both to e-liquids and EC aerosols. We conclude that in recognizing pertinent issues associated with EC usage, both government and scientific researchers must address this public health issue with utmost urgency.

Association Between Electronic Cigarette Use and Levels of High-Sensitivity C-Reactive Protein and Uric Acid

The present study investigated whether electronic cigarette use, which is becoming increasingly common, was related to systemic inflammation that may lead to cardiovascular disease, similar to conventional cigarette smoking. The study included 1208 men (19-65 years old) who participated in the 7^th Korean National Health and Nutrition Examination Survey (2016). The participants were categorized as electronic cigarette users, conventional cigarette users, and nonsmokers. Serum high-sensitivity C-reactive protein was used as an inflammatory index, and uric acid level was used as a metabolic indicator. After adjusting for confounding factors, electronic cigarette use was significantly associated with elevated serum high-sensitivity C-reactive protein levels (β = 1.326, P = .002), uric acid levels (β = 0.400, P = .042), and hyperuricemia (uric acid level of >7 mg/mL; odds ratio = 2.67, 95% confidence interval = 1.27-5.58). These findings suggest that electronic cigarette use may be associated with systemic inflammation markers, similar to conventional cigarette use.

A Summary of In Vitro and In Vivo Studies Evaluating the Impact of E-Cigarette Exposure on Living Organisms and the Environment

Worldwide use of electronic cigarettes has been rapidly expanding over recent years, but the long-term effect of e-cigarette vapor exposure on human health and environment is not well established; however, its mechanism of action entails the production of reactive oxygen species and trace metals, and the exacerbation of inflammation, which are associated with potential cytotoxicity and genotoxicity. The present study examines the effects of selected liquid chemicals used in e-cigarettes, such as propylene glycol/vegetable glycerin, nicotine and flavorings, on living organisms; the data collected indicates that exposure to e-cigarette liquid has potentially detrimental effects on cells in vitro, and on animals and humans in vivo. While e-liquid exposure can adversely influence the physiology of living organisms, vaping is recommended as an alternative for tobacco smoking. The study also compares the impact of e-cigarette liquid exposure and traditional cigarette smoke on organisms and the environmental impact. The environmental influence of e-cigarette use is closely connected with the emission of airborne particulate matter, suggesting the possibility of passive smoking. The obtained data provides an insight into the impact of nicotine delivery systems on living organisms and the environment.

Association of Electronic Cigarette Regulations With Electronic Cigarette Use Among Adults in the United States

IMPORTANCE

Millions of Americans use electronic cigarettes (e-cigarettes). A growing number of state and local governments have started to draft and implement laws regarding the sale, marketing, and use of e-cigarettes. The association of US state regulations regarding e-cigarettes with e-cigarette use remains unknown.

OBJECTIVE

To examine the association of US state regulations regarding e-cigarettes with current e-cigarette use among adults in the United States.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included adults aged 18 years or older from the 2016 and 2017 Behavioral Risk Factor Surveillance System, which is a nationwide, telephone-administered survey that collects state-representative data on health-related risk behaviors, chronic health conditions, and use of preventive services. Data analysis was performed from February 1, 2019, to April 31, 2019.

EXPOSURES

United States state laws regulating e-cigarette use, including prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; requiring retailers to purchase a license to sell e-cigarettes; prohibiting self-service displays of e-cigarettes; prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and e-cigarette taxes.

MAIN OUTCOMES AND MEASURES

Current use of e-cigarettes.

RESULTS

Among 894 997 participants aged 18 years or older (503 688 women [51.3%], 679 443 non-Hispanic white [62.6%], 71 730 non-Hispanic black [16.3%], 69 823 Hispanic [11.4%], and 74 001 non-Hispanic other races [9.8%]), 28 907 (weighted prevalence, 4.4%) were currently using e-cigarettes. The age-standardized weighted prevalence of current e-cigarette use varied across US states and territories, from 1.0% in Puerto Rico to 6.2% in Guam. After adjustment for demographic, socioeconomic, and lifestyle factors, including conventional cigarette use, the odds ratios of current e-cigarette use were 0.90 (95% CI, 0.83-0.98) for state laws prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; 0.90 (95% CI, 0.85-0.95) for state laws requiring retailers to purchase a license to sell e-cigarettes; 1.04 (95% CI, 0.99-1.09) for state laws prohibiting self-service displays of e-cigarettes; 0.86 (95% CI, 0.74-0.99) for state laws prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and 0.89 (95% CI, 0.83-0.96) for state laws applying taxes to e-cigarettes.

CONCLUSIONS AND RELEVANCE

These findings suggest that several state regulations regarding e-cigarettes may be associated with reduced e-cigarette use among US adults.

Health Effects Associated With Electronic Cigarette Use: Automated Mining of Online Forums

Background

Our previous infodemiological study was performed by manually mining health-effect data associated with electronic cigarettes (ECs) from online forums. Manual mining is time consuming and limits the number of posts that can be retrieved.

Objective

Our goal in this study was to automatically extract and analyze a large number (>41,000) of online forum posts related to the health effects associated with EC use between 2008 and 2015.

Methods

Data were annotated with medical concepts from the Unified Medical Language System using a modified version of the MetaMap tool. Of over 1.4 million posts, 41,216 were used to analyze symptoms (undiagnosed conditions) and disorders (physician-diagnosed terminology) associated with EC use. For each post, sentiment (positive, negative, and neutral) was also assigned.

Results

Symptom and disorder data were categorized into 12 organ systems or anatomical regions. Most posts on symptoms and disorders contained negative sentiment, and affected systems were similar across all years. Health effects were reported most often in the neurological, mouth and throat, and respiratory systems. The most frequently reported symptoms and disorders were headache (n=939), coughing (n=852), malaise (n=468), asthma (n=916), dehydration (n=803), and pharyngitis (n=565). In addition, users often reported linked symptoms (eg, coughing and headache).

Conclusions

Online forums are a valuable repository of data that can be used to identify positive and negative health effects associated with EC use. By automating extraction of online information, we obtained more data than in our prior study, identified new symptoms and disorders associated with EC use, determined which systems are most frequently adversely affected, identified specific symptoms and disorders most commonly reported, and tracked health effects over 7 years.

Heart Rate Variability for the Prediction of Treatment Response in Major Depressive Disorder

Major depressive disorder (MDD) is one of the disabling diseases in the world-wide, and known to increase cardiac morbidity and mortality. Therefore, previous studies related heart rate variability (HRV) have been conducted to evaluate and diagnose MDD, and to predict treatment outcomes in patient with MDD. We reviewed extensively on the previous peer-reviewed publications associated with this issue, using Pub-Med. In this review article, we introduce the basic concept of HRV and HRV measures, and present several important findings associated with diagnosis and treatment prediction in MDD with using HRV parameters. Furthermore, we discuss the possible underlying mechanism of this phenomenon, and suggest several considerations for the future research.

Protecting Youth From the Risks of Electronic Cigarettes

The rapid increase in e-cigarette use among adolescents and young adults has led to drastic changes in patterns of nicotine consumption worldwide. The use of e-cigarettes, many of which contain high levels of nicotine, is especially harmful in this age group and is associated with increased use of cigarettes and other substances among youth. While the risks of short- and long-term e-cigarette use and secondhand aerosol exposure remain only partially understood, e-cigarettes should not be recommended for smoking cessation for youth in any circumstances given the lack of evidence for effectiveness and potential harmful physical and mental health effects. The perceptions of low e-cigarette risk of adolescents and young adults combined with few market regulations and the appeal of youth-friendly flavors, have created ideal conditions for the e-cigarette industry to thrive and place millions of youth at risk of developing an addiction to nicotine. Policies and regulations aiming to prevent youth-directed marketing and sales of e-cigarette and all nicotine delivery products are needed to protect young people. Public health-led education campaigns and educational curricula are also needed to help inform youth and families about the risks of e-cigarette use. While more research is required to determine the best ways to help youth quit e-cigarette use, adolescent health providers can play a key role in screening and counseling youth about e-cigarette use and should be adequately trained and supported to care for youth with e-cigarette addiction.

Electronic Cigarettes and Cardiovascular Risk: Caution Waiting for Evidence

Electronic cigarettes use is a growing trend in contemporary societies, with the propensity to compete with traditional tobacco smoking. Some preclinical studies demonstrated the toxic and detrimental effects of electronic cigarettes liquid components. Its impact on human health remains unknown and insufficiently studied. While some studies suggest that electronic cigarettes use might be associated with endothelial dysfunction, impaired platelet function and increased risk of adverse clinical events, other studies did not confirm these findings and epidemiological data mostly suggest that the use of electronic cigarettes appears to be safer than that of traditional tobacco cigarettes. This article provides an up-to-date overview of the current state of knowledge regarding electronic cigarettes and their impact on human health, with special emphasis on their effect on cardiovascular diseases.

Bidirectional Associations among Nicotine and Tobacco Smoke, NeuroHIV, and Antiretroviral Therapy

People living with HIV (PLWH) in the antiretroviral therapy (ART) era may lose more life-years to tobacco use than to HIV. Yet, smoking rates are more than twice as high among PLWH than the general population, contributing not just to mortality but to other adverse health outcomes, including neurocognitive deficits (neuroHIV). There is growing evidence that synergy with chronic inflammation and immune dysregulation that persists despite ART may be one mechanism by which tobacco smoking contributes to neuroHIV. This review will summarize the differential effects of nicotine vs tobacco smoking on inflammation in addition to the effects of tobacco smoke components on HIV disease progression. We will also discuss biomarkers of inflammation via neuroimaging as well as biomarkers of nicotine dependence (e.g., nicotine metabolite ratio). Tobacco smoking and nicotine may impact ART drug metabolism and conversely, certain ARTs may impact nicotine metabolism. Thus, we will review these bidirectional relationships and how they may contribute to neuroHIV and other adverse outcomes. We will also discuss the effects of tobacco use on the interaction between peripheral organs (lungs, heart, kidney) and subsequent CNS function in the context of HIV. Lastly, given the dramatic rise in the use of electronic nicotine delivery systems, we will discuss the implications of vaping on these processes. Despite the growing recognition of the importance of addressing tobacco use among PLWH, more research is necessary at both the preclinical and clinical level to disentangle the potentially synergistic effects of tobacco use, nicotine, HIV, cognition and immune dysregulation, as well as identify optimal approaches to reduce tobacco use. Graphical Abstract Proposed model of the relationships among HIV, ART, smoking, inflammation, and neurocognition. Solid lines represent relationships supported by evidence. Dashed lines represent relationships for which there is not enough evidence to make a conclusion. (a) HIV infection produces elevated levels of inflammation even among virally suppressed individuals. (b) HIV is associated with deficits in cognition function. (c) Smoking rates are higher among PLWH, compared to the general population. (d) The nicotine metabolite ratio (NMR) is associated with smoking behavior. (e) HIV and tobacco use are both associated with higher rates of psychiatric comorbidities, such as depression, and elevated levels of chronic stress. These factors may represent other mechanisms linking HIV and tobacco use. (f) The relationship between nicotine, tobacco smoking, and inflammation is complex, but it is well-established that smoking induces inflammation; the evidence for nicotine as anti-inflammatory is supported in some studies, but not others. (g) The relationship between tobacco use and neurocognition may differ for the effects of nicotine (acute nicotine use may have beneficial effects) vs. tobacco smoking (chronic use may impair cognition). (h) Elevated levels of inflammation may be associated with deficits in cognition. (i) PLWH may metabolize nicotine faster than those without HIV; the mechanism is not yet known and the finding needs validation in larger samples. We also hypothesize that if HIV-infection increases nicotine metabolism, then we should observe an attenuation effect once ART is initiated. (j) It is possible that the increase in NMR is due to ART effects on CYP2A6. (k) We hypothesize that faster nicotine metabolism may result in higher levels of inflammation since nicotine has anti-inflammatory properties.

Pro-Oxidative and Proinflammatory Effects After Traveling From Los Angeles to Beijing

Background:

Exposure to air pollution increases cardiovascular morbidity and mortality. Preventing chronic cardiovascular diseases caused by air pollution relies on detecting the early effects of pollutants on the risk of cardiovascular disease development, which is limited by the lack of sensitive biomarkers. We have previously identified promising biomarkers in experimental animals but comparable evidence in humans is lacking.

Methods:

Air pollution is substantially worse in Beijing than in Los Angeles. We collected urine and blood samples from 26 nonsmoking, healthy adult residents of Los Angeles (mean age, 23.8 years; 14 women) before, during, and after spending 10 weeks in Beijing during the summers of 2014 and 2015. We assessed a panel of circulating biomarkers indicative of lipid peroxidation and inflammation. Personal exposure to polycyclic aromatic hydrocarbons (PAHs), a group of combustion-originated air pollutants, was assessed by urinary PAH metabolite levels.

Results:

Urinary concentrations of 4 PAH metabolites were 176% (95% CI, 103% to 276%) to 800% (95% CI, 509% to 1780%) greater in Beijing than in Los Angeles. Concentrations of 6 lipid peroxidation biomarkers were also increased in Beijing, among which 5-, 12-, and 15-hydroxyeicosatetraenoic acid and 9- and 13-hydroxyoctadecadienoic acid levels reached statistical significance (false discovery rate <5%), but not 8-isoprostane (20.8%; 95% CI, −5.0% to 53.6%). The antioxidative activities of paraoxonase (−9.8%; 95% CI, −14.0% to −5.3%) and arylesterase (−14.5%; 95% CI, −22.3% to −5.8%) were lower and proinflammatory C-reactive protein (101%; 95% CI, 3.3% to 291%) and fibrinogen (48.3%; 95% CI, 4.9% to 110%) concentrations were higher in Beijing. Changes in all these biomarkers were reversed, at least partially, after study participants returned to Los Angeles. Changes in most outcomes were associated with urinary PAH metabolites ( P <0.05).

Conclusions:

Traveling from a less-polluted to a more-polluted city induces systemic pro-oxidative and proinflammatory effects. Changes in the levels of 5-, 12-, and 15-hydroxyeicosatetraenoic acid and 9- and 13-hydroxyoctadecadienoic acid as well as paraoxonase and arylesterase activities in the blood, in association with exposures to PAH metabolites, might have important implications in preventive medicine as indicators of increased cardiovascular risk caused by air pollution exposure.

E-cigarettes and Smoking Cessation in Smokers With Chronic Conditions

INTRODUCTION

Many smokers with chronic medical conditions use e-cigarettes. This study assessed the association between e-cigarette use and subsequent smoking-cessation efforts in adult smokers with and without chronic medical conditions.

METHODS

This was a longitudinal cohort study of adult cigarette smokers using Waves 1 and 2 of the Population Assessment of Tobacco and Health Study (2013-2015), analyzed in 2018‒2019. The exposure was the initiation of e-cigarette use by Wave 2. The outcomes at Wave 2 were: (1) past 12-month attempts to quit, (2) cigarette abstinence, (3) ≥50% reduction in cigarette use, and (4) past 12-month use of evidence-based smoking-cessation treatment.

RESULTS

E-cigarette use initiation was associated with increased odds of attempting to quit smoking at Wave 2 among smokers with any chronic medical condition (AOR=1.92, 95% CI=1.42, 2.59) and without chronic medical conditions (AOR=1.81, 95% CI=1.50, 2.18). E-cigarette use initiation was also significantly associated with Wave 2 smoking abstinence in smokers with (AOR=1.95, 95% CI=1.11, 3.43) and without chronic medical conditions (AOR=1.63, 95% CI=1.17, 2.28).

CONCLUSIONS

At a population level, e-cigarette use by smokers with chronic medical conditions is associated with more quitting activity and smoking abstinence. Future studies are needed to assess e-cigarette safety and efficacy to determine whether they may provide an alternative smoking-cessation or harm-reduction strategy for adults with smoking-sensitive disease who cannot achieve these goals with other methods.

Cinnamon-flavored electronic cigarette liquids and aerosols induce oxidative stress in human osteoblast-like MG-63 cells

As noncombustible nicotine delivery devices, electronic cigarettes (e-cigarettes) are the most popular tobacco product among youth. The widespread popularity of e-cigarettes combined with possible health consequences suggest a need to further research health hazards associated with e-cigarette use. Since conventional tobacco use is a risk factor for osteoporosis, this study investigates the impact of nicotine-free, cinnamon-flavored e-cigarette liquid (e-liquid) on bone-forming osteoblasts compared to flavorless e-liquid. Human tumor-derived osteoblast-like MG-63 cells were exposed for 24 h or 48 h to 0.0.4 %, 0.04 %, 0.4 % or 1 % of unvaped e-liquid or 0.0025 %, 0.025 %, 0.25 %, 1 % or 2.5 % of aerosol condensate in addition to a culture medium only control. Changes in cell viability were assessed by MTT assay, and the expression of a key bone protein, collagen type I, was analyzed by immunofluorescence. Production of reactive oxygen species (ROS) was detected by fluorometry to assess oxidative stress. Cell viability decreased in a dose-dependent manner, and ROS production increased, which was most pronounced with cinnamon-flavored e-liquids. There were no detectable changes in collagen type I protein following exposure to any of the aerosol condensates. This study demonstrates osteoblast-like cells are sensitive to both e-liquids and aerosol condensates and suggests the cytotoxicity of cinnamon-flavored e-liquids might be associated with oxidative stress rather than changes in collagen type I protein expression. This in vitro study provides insight into the potential impacts of e-cigarette use on bone cells.

Mechanisms supporting potential use of bone marrow-derived mesenchymal stem cells in psychocardiology

Despite great efforts made in recent years, globally cardiovascular disease (CVD) remains the most common and devastating disease. Pharmacological, interventional and surgical treatments have proved to be only partly satisfactory for the majority of patients. A major underlying cause of poor prognosis is a high comorbidity rate between CVD and mental illness, which calls for the approaches of psychocardiology. As psychiatric disorders and CVD can influence each other bidirectionally, it is necessary to develop novel therapies targeting both systems simultaneously. Therefore, innovative stem cell (SC) therapy has become the most promising treatment strategy in psychocardiology. Bone marrow-derived mesenchymal stem/stromal cells (BM-MSCs), among all different types of SCs, have drawn the most attention due to unique advantages in terms of ethical considerations, low immunogenicity and simplicity of preparation. In this review, we survey recent publications and clinical trials to summarize the knowledge and progress gained so far. Moreover, we discuss the feasibility of the clinical application of BM-MSCs in the area of psychocardiology.