More evidence that e-cigarettes are as bad as cigs in terms of heart disease risk

Mark Olfert and his colleagues recently published “Chronic exposure to electronic cigarette (E-cig) results in impaired cardiovascular function in mice” in Journal of Applied Physiology.  In this study they exposed mice to e-cigarette aerosol for 8 months and found changes in their blood vessels that indicate heightened heart disease risk.  (These results are consistent with short-term studies in humans show that people who use e-cigarettes immediately have compromised functioning of their blood vessels.)   The effects were comparable to those found in mice exposed to cigarette smoke.
 
Interestingly, they did not find effects on lung function, which differs from earlier work.
 
In any event, this paper adds to the strong and consistent case that e-cigarettes use brings substantial cardiovascular risk.  Heart and vascular disease accounts for around half of smoker deaths. 
 
Here is the abstract:
 
Proponents for electronic cigarettes(E-cigs) claim they are a safe alternative to smoking tobacco-based cigarettes,however little is known about the long-term effects of E-cig vapor exposure on vascular function.The purpose of this study was to determine the cardiovascular consequences of chronic E-cig exposure. Female mice (C57Bl/6 background strain)were randomly assigned to chronic daily exposure of E-cig vapor, standard cigarette smoke(using 3R4F-reference-cigarette), or filtered-air(N=15/group). Respective whole-body exposures consisted of 4 x 1-hour exposure blocks, separated by 30-minute intervals of fresh air breaks, resulting in intermittent daily exposure for a total of 4h/day, 5days/week for 8-months. Non-invasive ultrasonography was used to assess cardiac function and aortic stiffness (pulse wave velocity)at 3 times points (before, during, after chronic exposure). Upon completion of the 8-month exposure, ex-vivo wire tension myograph and force transduction measured changes in aortic tension in response to vasoactive inducing compounds. Aortic stiffness increased 2.5- and 2.8-times greater in E-cig and conventional tobacco-cigarettes,respectively, compared to filtered-air exposed control mice(p  
The full citation is Olfert M, et al.   Chronic exposure to electronic cigarette (E-cig) results in impaired cardiovascular function in mice.  J Appl Physiol (1985). 2017 Nov 2:jap.00713.2017. doi: 10.1152/japplphysiol.00713.2017. [Epub ahead of print].  It is available here.