Electronic cigarette is proposed as a bridge to smoking cessation. In this study we examine its effects on aortic elasticity, glycocalyx integrity, and exhaled carbon monoxide (CO) concentration and platelet function, both acutely and after 1 month of use.

Two smoker groups matched for age and sex will be assessed:

1. a group of 30 current smokers with no diagnosed cardiovascular disease as the control group for chronic phase
2. a group of 30 current smokers with no diagnosed cardiovascular disease who will be using the electronic cigarette with nicotine for 1 month

In the acute phase all 60 smokers will undergo a "sham" smoking for 7 minutes. Afterwards 30 out of 60 smokers will be randomized to smoke either a normal cigarette or an electronic cigarette with nicotine and after a 60 minute washout period these subjects will be crossed over to the alternate mode of smoking (electronic with nicotine or normal cigarette respectively).

The remaining 30 smokers will be randomized to smoke either a normal cigarette or an electronic cigarette without nicotine and after a 60 minute washout period these subjects will be crossed over to the alternate mode of smoking (electronic without nicotine or normal cigarette respectively.

After the completion of the acute phase all 60 smokers will start the use of an electronic cigarette for one month.

In the acute phase, measurements will be performed at baseline, after sham smoking and after smoking of the normal or electronic cigarette (with or without nicotine). The chronic phase measurements will be performed 1 month after use electronic cigarette with nicotine. Thirty current smokers of similar age and sex will serve as controls and will have measurements at baseline and 1 month after baseline assessment. The nicotine concentration of the electronic cigarette fluid used during both phases will be 12 mg/dL, while the participants will be allowed to use their cigarette of preference in the acute phase. In both phases we will assess a) the aortic pulse wave velocity (PWV) and augmentation index (AIx) by Arteriograph and Complior; b) the perfusion boundary region of the sublingual arterial microvessels using Sideview, Darkfield imaging (Microscan, Glycocheck); c) the exhaled carbon monoxide (CO) level (parts per million -ppm) as a smoking status marker; d) the vital signs; e) an electrocardiogram; and f) plasma levels of C- reactive protein (CRP), transforming growth factor-b (TGF-b), lipoprotein associated phospholipase A2 (LP- LPA2), tumor necrosis factor- α (TNF-α), interleukins 6 and 10 (IL-6 and -10), procollagen propeptide type III (PIIINP), matrix metalloproteinase 2 and 9 (MMP-2 and -9), and macrophage-colony stimulating factor (MCSF), malondialdehyde (MDA) and protein carbonyls (PC) and platelet function tests using the novel Platelet Function Analyzer PFA-100 and the traditional Light Transmission Aggregometry (LTA)

Inclusion Criteria:

• Active conventional cigarette smoker

Exclusion Criteria:

• Health condition adversely affected by smoking, history or presence of cardiovascular disease