It’s not the electronic cigarette,it’s the nicotine causing hemodynamic problems: A commentary on the article by Franzen et al.

In a recent issue of Vascular Medicine, Franzen and colleagues report data from a study on the effects of electronic cigarettes (e-cigarettes) and tobacco cigarettes on changes in peripheral and central blood pressures, and parameters of arterial stiffness. ¹ It is important to assess the health impact of e-cigarettes, but results should be interpreted cautiously. A nuanced interpretation of the current study would be that it is not the e-cigarette causing the hemodynamic effects but the nicotine.

Franzen and colleagues used e-cigarettes with an unusual high nicotine concentration of 24 mg/mL in order ‘to illustrate expected effects’. ¹ This is important to bear in mind as the European Tobacco Products Directive, which was implemented in Germany in May 2017 (the country where the study by Franzen et al. was conducted), limits the nicotine concentration in e-cigarettes to a maximum of 20 mg/mL. ² Hence, e-cigarettes with a nicotine concentration above 20 mg/mL are not allowed in European countries (although they are allowed in some other countries, such as the US ³ ). This concentration (20 mg/mL) allows the delivery of nicotine that is comparable to the permitted dose of nicotine derived from a conventional cigarette. ² Nicotine has long been known to have physiological effects on the body, also affecting hemodynamics.^4,5 Hence, the current study seems to confirm previous findings ⁶ that e-cigarettes – at least those with high concentrations of nicotine – can deliver nicotine effectively into the nervous system. Unfortunately, Franzen et al. did not measure nicotine or cotinine levels in their study participants.

The result from the study can easily be misinterpreted. For example, the journal of the influential German Medical Association cited Franzen et al. with the news headline titled ‘E-cigarettes cause elevated blood pressure and heart rate’ and concluded that e-cigarettes may be as harmful as conventional cigarettes. ⁷ This is misleading as the health effects of e-cigarettes are not well established but a current review of Public Health England suggests that vaping e-cigarettes is at least 95% less harmful than smoking cigarettes. ⁸ In Germany, e-cigarettes are mainly used by tobacco smokers to reduce smoking or to quit smoking altogether, and are currently the most frequently used method of quitting tobacco. ⁹ First studies showed that e-cigarettes can indeed help smokers quit tobacco.^10,11 These smokers might be discouraged to use e-cigarettes by the news from the Franzen et al. study and thus potentially miss a prime opportunity to become abstinent from, or at least reduce, tobacco smoking, which is the predominant cause of smoking-related diseases. Furthermore, such headlines might prevent physicians from advising and assisting smoking patients willing to quit, if they wish to assist their quit attempt with an e-cigarette, and thus limit their chances of success.