Reply to: ‘It’s not the electronic cigarette,it’s the nicotine causing hemodynamic problems’ by Kastaun and Kotz

We are very grateful for the commentary by Kastaun and Kotz, ‘It’s not the electronic cigarette, it’s the nicotine causing hemodynamic problems’. ¹ The authors of this commentary are correct in their assertion that the results of our study must be interpreted cautiously and in a nuanced fashion. ²

We have considered the applied and detailed statistical effects of the various test conditions and have found an independent effect of the study arms on peripheral and central hemodynamics as well as on arterial stiffness on which we base our interpretations as well as our conclusions.

Kastaun and Kotz are fully right that the revised European Tobacco Products Directive was implemented in Germany in May 2017. However, our study was planned, approved by the local ethics commission, and completed (i.e., all data collected) before May 2017. Furthermore, as already mentioned in their commentary, there are countries, including the United States, in which such nicotine concentrations are still allowed and used.

We have deliberately avoided giving recommendations regarding the use of e-cigarettes for assisting in smoking cessation because this question or objective was outside the scope of our article. Hence, we point out that further studies, especially long-term studies, are needed to estimate the risk of e-cigarettes. In addition, the current German guideline on smoking cessation does not yet contain any recommendation on the use of e-cigarettes to quit smoking. ³ Results of randomized controlled trials on this topic have not yet been published, which would be completely necessary for assessment in the context of evidence-based medicine.