Effects of electronic cigarette E-liquid and device wattage on vascular function

Area of Science:

• Cardiovascular Research
• Toxicology
• Vascular Biology

Background:

• Electronic cigarettes (e-cigs) offer customizable user experiences, including e-liquid composition and wattage.
• Understanding the vascular effects of e-cig aerosol is crucial due to widespread use.

Purpose of the Study:

• To compare vascular outcomes in a conducting artery (thoracic aorta) and a resistance artery (middle cerebral artery, MCA) following exposure to e-cig aerosol.
• To investigate the impact of different e-liquid components (VG vs. PG) and wattage settings on vascular function.

Main Methods:

• Mice (C57Bl/6) were exposed to e-cig aerosol generated from pure vegetable glycerin (VG) or pure propylene glycol (PG).
• Study 1 involved 60-min exposures, while Study 2 examined 5-watt vs. 30-watt settings over 100-min.
• Endothelial-dependent dilation (EDD) was assessed in the thoracic aorta and MCA.

Main Results:

• PG aerosol impaired aortic EDD in Study 1. MCA EDD was impaired by ~50% in both VG and PG groups.
• In Study 2, aortic EDD was unaffected by wattage, but MCA EDD was significantly impaired at both 5-watt (32%) and 30-watt (55%) settings.
• Vascular dysfunction was more pronounced in the MCA compared to the aorta across all exposure conditions.

Conclusions:

• Exposure to e-cig aerosol, regardless of VG/PG composition or wattage, induces vascular dysfunction.
• Resistance arteries, such as the MCA, appear more sensitive to e-cig aerosol-induced vascular impairment than conducting arteries like the aorta.
• These findings suggest potential differential mechanisms of vascular injury based on arterial hierarchy.