ENDS Respiratory System: Difference between revisions

The study is a double-blind randomized controlled trial. Two hundred and ten smokers were randomized into three groups: nicotine e-cigarette (8 mg/mL nicotine concentration), nicotine-free e-cigarettes (placebo), and control with 1:1:1 ratio. All participants received a 3 months cessation program that included a cognitive-behavioral intervention aimed at supporting people in changing their behavior and improving motivation to quit.

After 6 months about 20% of the entire sample stopped smoking. Participants who used e-cigarettes with nicotine smoked fewer tobacco cigarettes than any other group after 6 months.

The statistical associations between e-cigarette use and respiratory disease are driven by e-cigarette users who are also current or former smokers of combustible tobacco.  

A striking feature of the data is that almost all e-cigarette users were either current or former smokers of combustible tobacco.

Findings suggest that differences in respiratory symptoms between dual and exclusive e-cigarette users appear to be attributable to combustible cigarette smoking, rather than more intense or frequent e-cigarette use across groups.

The present study suggests that EC use may ameliorate objective and subjective COPD outcomes, and that the benefits gained appear to persist long term. EC use for abstinence and smoking reduction may ameliorate some of the harm resulting from tobacco smoking in COPD patients.

Expert opinion: There is growing evidence to support the relative safety of E-Cigarette (EC) emission aerosols for the respiratory tract compared to tobacco smoke. Public Health England estimated, on the basis of a review of 185 studies, that vaping an e-cigarette is likely to be at least 95% less harmful than smoking a regular cigarette. In 2016, the Royal College of Physicians reaffirmed this figure, estimating the risk of long-term inhalation of e-cigarette aerosol to be unlikely to exceed 5% of the risk associated with long-term cigarette smoking. This review article shows that although some potential effects on respiratory cell types can be shown in vitro, and low levels of chronic irritation of the respiratory tract can be anticipated at certain levels of vaping, these effects are much less than those of smoking. The clinical evidence confirms that ECs are unlikely to raise significant health concerns for the respiratory tract under normal conditions of use. Former smokers using and smokers intending to use ECs as a substitute for smoking should receive correct information about residual risks and potential benefits of these products. Promoting further access to ECs may offer an opportunity to reduce or prevent some of the otherwise inevitable burden of respiratory morbidity and mortality caused by tobacco smoking

In an Expert Review in Respiratory Medicine article published about 7 years ago [Caponnetto P, Campagna D, Papale G, et al. The emerging phenomenon of electronic cigarettes. Expert Rev Respir Med. 2012 Feb; 6(1):63–74.., we discussed several important research developments and future avenues for e-cigarette science. In the authors’ view, those expert opinions have been substantiated by the growing body of evidence. We therefore reiterate our prediction that EC use is the most effective method of substituting tobacco cigarettes for those smokers who are unable or unwilling to quit and we are now confident that current vaping products are much less harmful than conventional cigarettes as well as earlier EC designs.

Although ECs are not risk free, they are much less harmful than conventional tobacco smoking. The emerging clinical evidence suggests that ECs are unlikely to raise significant health concerns for the respiratory tract under normal conditions of use, even in smokers with preexisting lung disease. In particular, recent studies in COPD and chronic asthma suggest that substitution of conventional tobacco cigarettes for ECs can ameliorate subjective and objective disease-related outcomes and exacerbation rates as well as improving success in abstaining from smoking long term.  

Here, we assessed the transcriptional response of a primary 3D airway model acutely exposed to e-cigarette aerosol and cigarette (3R4F) smoke.

Based on equivalent or higher nicotine delivery, an acute exposure to e-cigarette aerosol had a reduced impact on gene expression compared to 3R4F smoke exposure in vitro.

While both e-cigarette vapor and conventional cigarette smoke affect surfactant lateral structure, only cigarette smoke disrupts surfactant interfacial properties. The surfactant inhibitory compound in conventional cigarettes is tar, which is a product of burning and is thus absent in e-cigarette vapor.

Conclusion: “These findings suggest that ECs use may aid smokers with COPD reduce their cigarette consumption or remain abstinent, which results in marked improvements in annual exacerbation rate as well as subjective and objective COPD outcomes.”  

Results: “Altogether 941 responses were received. Overall, 29% of responders reported no change in respiratory symptoms, 5% reported worsening, and 66% reported an improvement (95% CI=62.9-69.0).”  

Conclusion: “Smokers invited to switch to electronic cigarettes who completely abstained from smoking showed steady progressive improvements in their exhaled breath measurements and symptom scores. FeNo and eCO normalization is highly supportive of improved respiratory health outcomes and adds to the notion that quitting from tobacco smoking can reverse harm in the lung.”  

Also, given that the propylene glycol in EC aerosols is a potent bactericidal agent, switching from smoking to regular vaping is likely to produce additional lung health benefits.

In conclusion, smokers who quit by switching to regular ECs use can reduce risk and reverse harm from tobacco smoking.  

The e-cig may help smokers with asthma to reduce their cigarette consumption or remain abstinent and hence reduce the burden of smoking-related asthma symptoms. The positive findings observed with e-cigs allows us to advance the hypothesis that these products may be valuable for smoking cessation and/or tobacco harm reduction also in asthma patients who smoke.

By substantially reducing number of cigarettes smoked per day and exposure to their hazardous toxicants, e-cigs may not only improve asthma symptoms and pulmonary function but may also confer an overall health advantage in smokers with asthma [13]. Therefore, e-cig use in asthmatic smokers unable or unwilling to quit should be exploited as a safer alternative approach to harm-reversal (i.e., specific reversal of asthma-related outcomes) and, in general, to harm-reduction (i.e., overall reduction of smoke-related diseases).