Chronic effects of vaping with and without nicotine on arterial stiffness in rats

Abstract

The use of electronic cigarette (E‐cig) devices has increased over the last decade. However, little is known about the cardiovascular effects of vaping over prolonged periods of time.Preliminary data from female Sprague Dawley rats exposed to either air (n=1), nicotine‐free E‐cig vapor without nicotine (E‐cig0, n=3) or E‐cig vapor with 18 mg/ml free‐base nicotine (E‐cig18, n=1) were obtained using 75/25 VG/PG base solution with a 3rd generation tank‐style E‐cig device. Whole body exposure was performed via a dual chamber exposure system (Scireq InExpose) consisting of 20 puffs over 1‐hour each day (1 puff every 3 minutes), 5 days/week, using 5‐sec (55 ml) puffs @17.5 watts. This resulted in an average daily total particulate matter (TPM) concentration of ~120 mg/m3. Total number of particles measured in E‐cig0 and E‐cig18 chambers was 1.09 × 1010 and 2.14 × 1010, with an average daily particle exposure of 6.4 × 105 and 1.18 ×106 particles, respectively. In‐vivo aortic stiffness was assessed under anesthesia using Vevo2100 ultra‐high frequency ultrasound imaging system (VisualSonics) by measuring pulse wave velocity (PWV) in B‐mode and Doppler ultrasound of blood flow signals of the common carotid artery (between the aortic arch and the carotid bifurcation from a single, EKG‐gated, image).Exposure began at 18 weeks (4.2 months) and ended at 40 weeks (9.3 months) of age, resulting in a total exposure period of 22 weeks (5.1 months). Based on the average life expectancy of a rat (24 months) to humans (78 years), 5.1 months of exposure in rat equates ~16.5 years of vaping in humans. Following this exposure in rats, we observed that PWV was 2.94 m/s in the air (control) group, 4.87 m/s in the E‐cig0 group, and 4.45 m/s in the E‐cig18 group. The difference in PWV between air and E‐cig groups was +1.66 m/s (E‐cig0) and +1.51 m/s (E‐cig18). These preliminary data are consistent with previous findings from chronic exposure (up to 8‐months) in mice showing significant increases in PWV with E‐cig18 (+1.14 m/s) and traditional cigarette (+1.28 m/s) exposure (p<0.05).These findings suggest that chronic vaping with or without nicotine will likely illicit similar harmful effects toward arterial stiffness in rats and mice. Given that a +1.0 m/s increase in central PWV is associated with a ~15% greater risk of cardiovascular and all‐cause mortality risk in humans, the clinical implications are that chronic vaping with or without nicotine will increase arterial stiffness and associated mortality. Clinical monitoring of vascular health should be strongly encouraged in all E‐cig users.Support or Funding Information Support: WVU Cancer Institute Philip R Dino Innovative Research Grant (IMO); Transition Grant Support; Office of Research and Graduate Education (IMO), APS STRIDE Fellowship (JO); NIHGMS 5U54GM104942‐03 (PDC)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.