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Trends in Cardiovascular Medicine Aug 2016The cardiovascular safety of nicotine is an important question in the current debate on the benefits vs. risks of electronic cigarettes and related public health policy.... (Review)
Review
The cardiovascular safety of nicotine is an important question in the current debate on the benefits vs. risks of electronic cigarettes and related public health policy. Nicotine exerts pharmacologic effects that could contribute to acute cardiovascular events and accelerated atherogenesis experienced by cigarette smokers. Studies of nicotine medications and smokeless tobacco indicate that the risks of nicotine without tobacco combustion products (cigarette smoke) are low compared to cigarette smoking, but are still of concern in people with cardiovascular disease. Electronic cigarettes deliver nicotine without combustion of tobacco and appear to pose low-cardiovascular risk, at least with short-term use, in healthy users.
Topics: Administration, Inhalation; Animals; Cardiovascular Diseases; Cardiovascular System; Consumer Product Safety; Electronic Nicotine Delivery Systems; Humans; Nicotine; Nicotinic Agonists; Risk Assessment; Risk Factors; Smoking; Smoking Cessation; Smoking Prevention; Time Factors; Vaping
PubMed: 27079891
DOI: 10.1016/j.tcm.2016.03.001 -
The Cochrane Database of Systematic... May 2018Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.
OBJECTIVES
To determine the effectiveness and safety of nicotine replacement therapy (NRT), including gum, transdermal patch, intranasal spray and inhaled and oral preparations, for achieving long-term smoking cessation, compared to placebo or 'no NRT' interventions.
SEARCH METHODS
We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search is July 2017.
SELECTION CRITERIA
Randomized trials in people motivated to quit which compared NRT to placebo or to no treatment. We excluded trials that did not report cessation rates, and those with follow-up of less than six months, except for those in pregnancy (where less than six months, these were excluded from the main analysis). We recorded adverse events from included and excluded studies that compared NRT with placebo. Studies comparing different types, durations, and doses of NRT, and studies comparing NRT to other pharmacotherapies, are covered in separate reviews.
DATA COLLECTION AND ANALYSIS
Screening, data extraction and 'Risk of bias' assessment followed standard Cochrane methods. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.
MAIN RESULTS
We identified 136 studies; 133 with 64,640 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The majority of studies were conducted in adults and had similar numbers of men and women. People enrolled in the studies typically smoked at least 15 cigarettes a day at the start of the studies. We judged the evidence to be of high quality; we judged most studies to be at high or unclear risk of bias but restricting the analysis to only those studies at low risk of bias did not significantly alter the result. The RR of abstinence for any form of NRT relative to control was 1.55 (95% confidence interval (CI) 1.49 to 1.61). The pooled RRs for each type were 1.49 (95% CI 1.40 to 1.60, 56 trials, 22,581 participants) for nicotine gum; 1.64 (95% CI 1.53 to 1.75, 51 trials, 25,754 participants) for nicotine patch; 1.52 (95% CI 1.32 to 1.74, 8 trials, 4439 participants) for oral tablets/lozenges; 1.90 (95% CI 1.36 to 2.67, 4 trials, 976 participants) for nicotine inhalator; and 2.02 (95% CI 1.49 to 2.73, 4 trials, 887 participants) for nicotine nasal spray. The effects were largely independent of the definition of abstinence, the intensity of additional support provided or the setting in which the NRT was offered. A subset of six trials conducted in pregnant women found a statistically significant benefit of NRT on abstinence close to the time of delivery (RR 1.32, 95% CI 1.04 to 1.69; 2129 participants); in the four trials that followed up participants post-partum the result was no longer statistically significant (RR 1.29, 95% CI 0.90 to 1.86; 1675 participants). Adverse events from using NRT were related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. Attempts to quantitatively synthesize the incidence of various adverse effects were hindered by extensive variation in reporting the nature, timing and duration of symptoms. The odds ratio (OR) of chest pains or palpitations for any form of NRT relative to control was 1.88 (95% CI 1.37 to 2.57, 15 included and excluded trials, 11,074 participants). However, chest pains and palpitations were rare in both groups and serious adverse events were extremely rare.
AUTHORS' CONCLUSIONS
There is high-quality evidence that all of the licensed forms of NRT (gum, transdermal patch, nasal spray, inhalator and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50% to 60%, regardless of setting, and further research is very unlikely to change our confidence in the estimate of the effect. The relative effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT. NRT often causes minor irritation of the site through which it is administered, and in rare cases can cause non-ischaemic chest pain and palpitations.
Topics: Administration, Cutaneous; Administration, Inhalation; Chewing Gum; Female; Humans; Male; Nicotine; Nicotinic Agonists; Randomized Controlled Trials as Topic; Smoking Cessation; Smoking Prevention; Tablets; Time Factors; Tobacco Use Cessation Devices
PubMed: 29852054
DOI: 10.1002/14651858.CD000146.pub5 -
Tobacco Control May 2014With the rapid increase in use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes (e-cigarettes), users and non-users are exposed to the... (Review)
Review
OBJECTIVE
With the rapid increase in use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes (e-cigarettes), users and non-users are exposed to the aerosol and product constituents. This is a review of published data on the human health effects of exposure to e-cigarettes and their components.
METHODS
Literature searches were conducted through September 2013 using multiple electronic databases.
RESULTS
Forty-four articles are included in this analysis. E-cigarette aerosols may contain propylene glycol, glycerol, flavourings, other chemicals and, usually, nicotine. Aerosolised propylene glycol and glycerol produce mouth and throat irritation and dry cough. No data on the effects of flavouring inhalation were identified. Data on short-term health effects are limited and there are no adequate data on long-term effects. Aerosol exposure may be associated with respiratory function impairment, and serum cotinine levels are similar to those in traditional cigarette smokers. The high nicotine concentrations of some products increase exposure risks for non-users, particularly children. The dangers of secondhand and thirdhand aerosol exposure have not been thoroughly evaluated.
CONCLUSIONS
Scientific evidence regarding the human health effects of e-cigarettes is limited. While e-cigarette aerosol may contain fewer toxicants than cigarette smoke, studies evaluating whether e-cigarettes are less harmful than cigarettes are inconclusive. Some evidence suggests that e-cigarette use may facilitate smoking cessation, but definitive data are lacking. No e-cigarette has been approved by FDA as a cessation aid. Environmental concerns and issues regarding non-user exposure exist. The health impact of e-cigarettes, for users and the public, cannot be determined with currently available data.
Topics: Aerosols; Cotinine; Electronic Nicotine Delivery Systems; Environmental Exposure; Glycerol; Humans; Nicotine
PubMed: 24732161
DOI: 10.1136/tobaccocontrol-2013-051470 -
The Journal of Physiology Nov 2020E-cigarette aerosols are exceedingly different from conventional tobacco smoke, containing dozens of chemicals not found in cigarette smoke. It is highly likely that... (Review)
Review
E-cigarette aerosols are exceedingly different from conventional tobacco smoke, containing dozens of chemicals not found in cigarette smoke. It is highly likely that chronic use of e-cigarettes will induce pathological changes in both the heart and lungs. Here we review human and animal studies published to date and summarize the cardiopulmonary physiological changes caused by vaping. In terms of cardiac physiology, acute exposure to e-cigarette aerosols in human subjects led to increased blood pressure and heart rate, similar to traditional cigarettes. Chronic exposure to e-cigarette aerosols using animal models caused increased arterial stiffness, vascular endothelial changes, increased angiogenesis, cardiorenal fibrosis and increased atherosclerotic plaque formation. Pulmonary physiology is also affected by e-cigarette aerosol inhalation, with increased airway reactivity, airway obstruction, inflammation and emphysema. Research thus far demonstrates that the heart and lung undergo numerous changes in response to e-cigarette use, and disease development will depend on how those changes combine with both environmental and genetic factors. E-cigarettes have been advertised as a healthy alternative to cigarette smoking, and users are under the impression that vaping of e-cigarettes is harmless, but these claims that e-cigarettes are safer and healthier are not based on evidence. Data from both humans and animal models are consistent in demonstrating that vaping of e-cigarettes causes health effects both similar to and disparate from those of cigarette smoking. Further work is needed to define the long-term cardiopulmonary effects of e-cigarette use in humans.
Topics: Animals; Electronic Nicotine Delivery Systems; Heart; Humans; Lung; Nicotine; Vaping
PubMed: 32975834
DOI: 10.1113/JP279754 -
Tobacco Control Mar 2014Electronic cigarettes, also known as e-cigarettes, are devices designed to imitate regular cigarettes and deliver nicotine via inhalation without combusting tobacco....
SIGNIFICANCE
Electronic cigarettes, also known as e-cigarettes, are devices designed to imitate regular cigarettes and deliver nicotine via inhalation without combusting tobacco. They are purported to deliver nicotine without other toxicants and to be a safer alternative to regular cigarettes. However, little toxicity testing has been performed to evaluate the chemical nature of vapour generated from e-cigarettes. The aim of this study was to screen e-cigarette vapours for content of four groups of potentially toxic and carcinogenic compounds: carbonyls, volatile organic compounds, nitrosamines and heavy metals.
MATERIALS AND METHODS
Vapours were generated from 12 brands of e-cigarettes and the reference product, the medicinal nicotine inhaler, in controlled conditions using a modified smoking machine. The selected toxic compounds were extracted from vapours into a solid or liquid phase and analysed with chromatographic and spectroscopy methods.
RESULTS
We found that the e-cigarette vapours contained some toxic substances. The levels of the toxicants were 9-450 times lower than in cigarette smoke and were, in many cases, comparable with trace amounts found in the reference product.
CONCLUSIONS
Our findings are consistent with the idea that substituting tobacco cigarettes with e-cigarettes may substantially reduce exposure to selected tobacco-specific toxicants. E-cigarettes as a harm reduction strategy among smokers unwilling to quit, warrants further study. (To view this abstract in Polish and German, please see the supplementary files online.).
Topics: Administration, Inhalation; Carcinogens; Drug Delivery Systems; Electronics; Harm Reduction; Humans; Metals, Heavy; Nicotine; Nitrosamines; Noxae; Smoking; Nicotiana; Tobacco Products; Toxicology; Volatile Organic Compounds
PubMed: 23467656
DOI: 10.1136/tobaccocontrol-2012-050859 -
Cardiovascular Toxicology Oct 2019The use of electronic cigarettes has increased exponentially since its introduction onto the global market in 2006. However, short- and long-term health effects remain... (Randomized Controlled Trial)
Randomized Controlled Trial
The use of electronic cigarettes has increased exponentially since its introduction onto the global market in 2006. However, short- and long-term health effects remain largely unknown due to the novelty of this product. The present study examines the acute effects of e-cigarette aerosol inhalation, with and without nicotine, on vascular and pulmonary function in healthy volunteers. Seventeen healthy subjects inhaled electronic cigarette aerosol with and without nicotine on two separate occasions in a double-blinded crossover fashion. Blood pressure, heart rate, and arterial stiffness measured by pulse wave velocity and pulse wave analysis were assessed at baseline, and then at 0 h, 2 h, and 4 h following exposure. Dynamic spirometry and impulse oscillometry were measured following vascular assessments at these time points, as well as at 6 h following exposure. e-Cigarette aerosol with nicotine caused a significant increase in heart rate and arterial stiffness. Furthermore, e-cigarette aerosol-containing nicotine caused a sudden increase in flow resistance as measured by impulse oscillometry, indicating obstruction of the conducting airways. Both aerosols caused an increase in blood pressure. The present study indicates that inhaled e-cigarette aerosol with nicotine has an acute impact on vascular and pulmonary function. Thus, chronic usage may lead to long-term adverse health effects. Further investigation is warranted.
Topics: Administration, Inhalation; Adult; Aerosols; Airway Obstruction; Airway Resistance; Blood Pressure; Cardiovascular System; Cross-Over Studies; Double-Blind Method; Electronic Nicotine Delivery Systems; Female; Healthy Volunteers; Heart Rate; Hemodynamics; Humans; Lung; Male; Nicotine; Nicotinic Agonists; Risk Assessment; Time Factors; Vaping; Vascular Stiffness; Young Adult
PubMed: 30963443
DOI: 10.1007/s12012-019-09516-x -
European Review For Medical and... Jul 2023Smoking cigarettes contributes to lung cancer progression and the development of other respiratory diseases. E-cigs are increasingly being offered to mitigate the... (Review)
Review
Smoking cigarettes contributes to lung cancer progression and the development of other respiratory diseases. E-cigs are increasingly being offered to mitigate the harmful effects of traditional cigarettes and eventually for smoke cessation. Because e-cigs do not burn tobacco, it stands to reason that vaping e-liquid is less harmful than inhaling cigarette smoke. This study critically assessed the underlying biological effects of cigarettes and e-Cigs. We searched PubMed databases to elucidate the fundamental, potentially carcinogenic, molecular pathways and the possible effects of cigarettes and e-cigs products on lung cancer progression. Cigarette smoke leads to chronic obstructive pulmonary disease (COPD), while e-cigs have contributed to lung injury. Cigarette smoke and e-cigs increase proinflammatory cytokine expression in cells and affect protein regulation, leading to an increased lung cancer risk. E-cigs are quickly gaining popularity among consumers. Vaping-related diseases and deaths have attracted attention on a global scale. Excessive nicotine levels in e-liquid have the potential to cause severe toxicity, which can lead to neurological and brain damage and respiratory failure, as well as death. Thus, the toxic effects of e-cigs aerosol exposure are essentially identical to that caused by combustible cigarette smoking.
Topics: Humans; Electronic Nicotine Delivery Systems; Tobacco Products; Lung; Nicotine; Lung Neoplasms
PubMed: 37458647
DOI: 10.26355/eurrev_202307_32990 -
American Journal of Physiology. Heart... Jan 2021Electronic cigarettes (e-cigarettes) are marketed as an alternative to smoking for those who want to decrease the health risks of tobacco. Tobacco cigarettes increase... (Randomized Controlled Trial)
Randomized Controlled Trial
Electronic cigarettes (e-cigarettes) are marketed as an alternative to smoking for those who want to decrease the health risks of tobacco. Tobacco cigarettes increase heart rate (HR) and arterial pressure, while reducing muscle sympathetic nerve activity (MSNA) through sympathetic baroreflex inhibition. The acute effects of e-cigarettes on arterial pressure and MSNA have not been reported: our purpose was to clarify this issue. Using a randomized crossover design, participants inhaled on a JUUL e-cigarette containing nicotine (59 mg/mL) and a similar placebo e-cigarette (0 mg/mL). Experiments were separated by ∼1 mo. We recorded baseline ECG, finger arterial pressure ( = 15), and MSNA ( = 10). Subjects rested for 10 min (BASE) and then inhaled once every 30 s on an e-cigarette that contained nicotine or placebo (VAPE) for 10 min followed by a 10-min recovery (REC). Data were expressed as Δ means ± SE from BASE. Heart rate increased in the nicotine condition during VAPE and returned to BASE values in REC (5.0 ± 1.3 beats/min nicotine vs. 0.1 ± 0.8 beats/min placebo, during VAPE; < 0.01). Mean arterial pressure increased in the nicotine condition during VAPE and remained elevated during REC (6.5 ± 1.6 mmHg nicotine vs. 2.6 ± 1 mmHg placebo, during VAPE and 4.6.0 ± 1.7 mmHg nicotine vs. 1.4 ± 1.4 mmHg placebo, during REC; < 0.05). MSNA decreased from BASE to VAPE and did not restore during REC (-7.1 ± 1.6 bursts/min nicotine vs. 2.6 ± 2 bursts/min placebo, during VAPE and -5.8 ± 1.7 bursts/min nicotine vs. 0.5 ± 1.4 bursts/min placebo, during REC; < 0.05). Our results show that acute e-cigarette usage increases mean arterial pressure leading to a baroreflex-mediated inhibition of MSNA. The JUUL e-cigarette is the most popular e-cigarette in the market. In the present study, inhaling on a JUUL e-cigarette increased mean arterial pressure and heart rate, and decreased muscle sympathetic nerve activity (MSNA). In contrast, inhaling on a placebo e-cigarette without nicotine elicited no sympathomimetic effects. Although previous tobacco cigarette studies have demonstrated increased mean arterial pressure and MSNA inhibition, ours is the first study to report similar responses while inhaling on an e-cigarette. Listen to this article's corresponding podcast at @ https://ajpheart.podbean.com/e/aerosolized-nicotine-and-cardiovascular-control/.
Topics: Administration, Inhalation; Aerosols; Age Factors; Arterial Pressure; Baroreflex; Cardiovascular System; Cross-Over Studies; E-Cigarette Vapor; Electronic Nicotine Delivery Systems; Female; Heart Rate; Humans; Male; Muscle, Skeletal; Nicotine; Nicotinic Agonists; Non-Smokers; Sympathetic Nervous System; Time Factors; Vaping; Young Adult
PubMed: 33164580
DOI: 10.1152/ajpheart.00448.2020 -
Environmental Health and Preventive... Sep 2019Hookah or waterpipe smoking or use is an emerging trend in the US population, especially among the youth. The misperception of hookah being less harmful than cigarettes... (Review)
Review
Hookah or waterpipe smoking or use is an emerging trend in the US population, especially among the youth. The misperception of hookah being less harmful than cigarettes and the availability of different but "appealing" flavors are considered among the main reasons for this trend. Hookah users however are exposed to many of the same toxic compounds/by-products as cigarette users, but at dramatically higher levels, which might lead to more severe negative health effects. In fact, hookah users are at risks of infections, cancers, lung disease, and other medical conditions. Moreover, because of the overlapping toxicant/chemical profile to conventional cigarettes, hookah smoke effects on the cardiovascular system are thought to be comparable to those of conventional cigarettes. A major source of tobacco addiction is nicotine, whose levels in hookah are extremely variable as they depend on the type of tobacco used. Taken together, in this review of literature, we will provide insights on the negative health effects of hookah in general, with a focus on what is known regarding its impact on the cardiovascular system.
Topics: Cardiovascular Diseases; Electronic Nicotine Delivery Systems; Hazardous Substances; Humans; Inhalation Exposure; Nicotine; Smoking Water Pipes; Nicotiana; Tobacco Smoke Pollution; Water Pipe Smoking
PubMed: 31521105
DOI: 10.1186/s12199-019-0811-y -
American Journal of Physiology.... Nov 2018Cigarette smoking is the single most important risk factor for the development of cardiovascular and pulmonary diseases (CVPD). Although cigarette smoking has been in... (Review)
Review
Cigarette smoking is the single most important risk factor for the development of cardiovascular and pulmonary diseases (CVPD). Although cigarette smoking has been in constant decline since the 1950s, the introduction of e-cigarettes or electronic nicotine delivery systems 10 yr ago has attracted former smokers as well as a new generation of consumers. Nicotine is a highly addictive substance, and it is currently unclear whether e-cigarettes are "safer" than regular cigarettes or whether they have the potential to reverse the health benefits, notably on the cardiopulmonary system, acquired with the decline of tobacco smoking. Of great concern, nicotine inhalation devices are becoming popular among young adults and youths, emphasizing the need for awareness and further study of the potential cardiopulmonary risks of nicotine and associated products. This review focuses on the interaction between nicotine and the renin-angiotensin system (RAS), one of the most important regulatory systems on autonomic, cardiovascular, and pulmonary functions in both health and disease. The literature presented in this review strongly suggests that nicotine alters the homeostasis of the RAS by upregulating the detrimental angiotensin-converting enzyme (ACE)/angiotensin (ANG)-II/ANG II type 1 receptor axis and downregulating the compensatory ACE2/ANG-(1-7)/Mas receptor axis, contributing to the development of CVPD.
Topics: Animals; Humans; Nicotine; Peptidyl-Dipeptidase A; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Smoking; Tobacco Products
PubMed: 30088946
DOI: 10.1152/ajpregu.00099.2018