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Rapid response to:

Clinical Review State of the Art Review

What are the respiratory effects of e-cigarettes?

BMJ 2019; 366 doi: (Published 30 September 2019) Cite this as: BMJ 2019;366:l5275

Rapid Response:

Re: The impact on respiratory health of e-cigarettes

Dear Editor,

We read with interest the review by Gotts et al. (1) et al. on the respiratory health effects of e-cigarettes.

The Authors claim interesting aspects concerning the potential role in the effects of vaping on the human pulmonary system. However, although the topic is controversial, we have to point out some crucial observations in their review article.

1. For example, the Authors cite the review of Kalkhorn-Glantz et al. (2) highlighting the negative effect of e-cigarettes on smoking cessation but do not consider two other reviews performed by El Dib et al. (3) and Malas et al. (4) that did not reach this conclusion.

2. We appreciate the discussion of in vitro methodology limitations, but many studies have methodological shortcomings. A large number of in vitro studies have been published relating to the cytotoxic effects of vaping products and e-liquids, but the relevance of data obtained from direct e-liquid exposures, instead of aerosol exposures may be questionable as indicated in the literature (5).

3. The Authors have excluded small uncontrolled studies from the analysis. However, case reports studies have been considered (3). Why did the Authors make this choice? Which is the quantitative criterion used to define a series as “small”?

4. The review well underlines the effect of the use of e-cigarettes with other tobacco products including hookah and marijuana. The Centers for Disease Control and Prevention (CDC) assessed that to date, national data suggest that products containing Tetra-Hydro-Cannabinol (THC), particularly those obtained off the street or from other informal sources (e.g., friends, family members, or illicit dealers), are linked to most of the cases and play a major role in the outbreak and that the outbreak was caused by the consumption of some illegal, black market cannabis liquids containing dangerous adulterants (6,7).

5. In conclusion, we think that the question needs to be “what are you vaping” but the upshot is that youth and young adults need better education on the dangers of street drugs and the risks of purchasing black market products.

Malerba Mario, Azzolina Danila

1 Department of Translational Medicine, University of Eastern Piedmont, 84100, Novara, Italy
2 Center of Excellence for the acceleration of HArm Reduction (CoEHAR), University of Catania, Italy;

1. Gotts JE, Jordt S-E, McConnell R, Tarran R. What are the respiratory effects of e-cigarettes? BMJ. 30 September 2019; l5275.
2. El Dib R, Suzumura EA, Akl EA, Gomaa H, Agarwal A, Chang Y, et al. Electronic nicotine delivery systems and/or electronic non-nicotine delivery systems for tobacco smoking cessation or reduction: a systematic review and meta-analysis. BMJ Open. febbraio 2017;7(2):e012680.
3. Kalkhoran S, Glantz SA. E-cigarettes and smoking cessation in real-world and clinical settings: a systematic review and meta-analysis. Lancet Respir Med. February 2016;4(2):116–28.
4. Malas M, van der Tempel J, Schwartz R, Minichiello A, Lightfoot C, Noormohamed A, et al. Electronic Cigarettes for Smoking Cessation: A Systematic Review. Nicotine Tob Res Off J Soc Res Nicotine Tob. 2016;18(10):1926–36.
5. Polosa R, O’Leary R, Tashkin D, Emma R, Caruso M. The effect of e-cigarette aerosol emissions on respiratory health: a narrative review. Expert Rev Respir Med. 2 September 2019;13(9):899–915.

Competing interests: No competing interests

Competing interests: No competing interests

22 November 2019
Mario Malerba
associate professor of respiratory medicine
Danila Azzolina
University of Eastern Piedmont,
Via Solaroli, 17, 28100 Novara, Italy