In Reply We thank Sanchis-Gomar et al for their interest in our work.1 These authors make the interesting, even provocative, suggestion that perhaps the reported differences in sympathetic tone and the susceptibility to oxidative stress are not actually due to an increase in sympathetic tone and oxidative stress in e-cigarette users but rather due to a reduction in these variables in nonusers attributable to greater physical activity.
Middlekauff HR, Araujo JA. Increased Cardiovascular Risk Associated With E-Cigarette Use—Reply. JAMA Cardiol. Published online June 07, 2017. doi:10.1001/jamacardio.2017.1766