Evidence that e-cigs have fast and substantial effects on arteries keeps piling up

Lukasz Antoniewicz and colleagues just published an experimental study in which they had healthy young volunteers take 10 puffs on an e-cigarette over 10 minutes.  There was an immediate increase in the amount of endothelial progenitor cells (EPS) that remained elevated for over 4 hours.  They had returned to baseline levels by 24 hours.
EPC’s are markers of damage to the lining of arteries (called the vascular endothelium).  Damage to the endothelium is linked to immediate increases of the risk of a heart attack in people at risk of heart attacks and also contributes to the long-term development of atherosclerosis (buildup of blockages of arteries in the heart) and peripheral vascular disease (blockage of other arteries).  The reason is that the endothelium is a lining of arteries that protects the underlying muscle and other structures.  When the endothelium is torn, it makes it possible for fat to get into the artery wall and start building up a blockage.
 These effects are comparable in magnitude, but faster than the effects of smoking a cigarette observed by the same group.
These cardiovascular effects are important because they are fast and because cardiovascular and metabolic disease kill more people than cancer, which has been the focus of much of the discussion of the risks of e-cigarettes (see page 677 of the 2014 Surgeon General Report).  These vascular changes i also indirectly affect cancer because they affect the development of blood vessels that tumors need to survive and grow.  Damaged vascular endothelium is also why smoking causes impotence.
The full citation for the paper is Electronic cigarettes increase endothelial progenitor cells in the blood of healthy volunteers. Antoniewicz L, Bosson JA, Kuhl J, Abdel-Halim SM, Kiessling A, Mobarrez F, Lundbäck M.  Atherosclerosis. 2016 Dec;255:179-185. doi: 10.1016/j.atherosclerosis.2016.09.064.