Electronic cigarettes and cardiovascular risk: hype or up in smoke?

Abstract

Smoking damages almost every organ in the human body [2,3]. Smokers have a two to fourfold increased risk for developing coronary artery disease and stroke [2]. There is a 25-fold increased risk of lung cancer [2,3]. In addition numerous respiratory illnesses, congenital malformations, immune dysfunctions and other co-morbidities are seen more frequently in smokers [2,3]. The annual economic costs due to smoking related diseases in the USA are estimated to be between US$289–332.5 billion for the years 2009–2012 [2]. Quitting smoking is extremely difficult for most smokers. Nicotine is highly addictive and cessation is associated with withdrawal symptoms. 85% of people relapse within a week [4]. To cope up with withdrawal symptoms and to obtain relief, various forms of nicotine replacement therapies and coping adjuncts like nicotine gums 1984, nicotine nasal patches 1991, nicotine nasal spray 1996, nicotine inhaler 1998, pharmacotherapy: Zyban (bupropion) 1997, Chantix (varenicline) 2006, electronic cigarettes 2007 and cognitive behavioral therapies have been released in the last 30 years [5]. The potential of targeting the access of nicotine to the brain by developing antibodies and thereby preventing the nicotine reinforcing effects is being studied, however the newest available nicotine replacement therapy is the electronic cigarette [5]. Electronic cigarettes (e-cigarettes) were invented by Hon Lik, a Chinese pharmacist in 2003. An electric ultrasound-emitting element was used to vaporize a pressurized jet of nicotine liquid. E-cigarettes were introduced into the US markets in 2007 and their usage has increased significantly in the recent years [6,7]. In the latest CDC reports, e-cigarette use among youth who never smoked traditional cigarettes increased threefold from 2011–2013. In addition, the intention to smoke traditional cigarettes was twice that in youths who had tried e-cigarettes versus nonusers [8,9]. OpiniOn