Defense Date


Document Type


Degree Name

Doctor of Philosophy



First Advisor

Thomas Eissenberg


Electronic cigarette (ECIG) users can manipulate several device features including liquid nicotine concentration (mg/ml) and heating coil resistance (Ohms). One class of ECIG models, called “sub-Ohm” devices, use coils with a resistance of < 1 Ohms, lower than those observed in conventional ECIGs (e.g., ≥ 1.5 Ohms). Increasing voltage or decreasing coil resistance increases device power. Given that ECIG coil resistance and liquid nicotine concentration have not been manipulated systematically and simultaneously in clinical laboratory studies, the influence of these factors on ECIG acute effects remain unclear. The primary purpose of this study was to examine the influence of coil resistance and liquid nicotine concentration on nicotine delivery, heart rate (HR), subjective effects, puff topography, and liquid consumption.

Thirty-two experienced ECIG users completed four independent laboratory sessions that differed by coil resistance (0.5Ohm or 1.5Ohm ) and liquid nicotine concentration (3 or 8 mg/ml). In each session, participants used a 4.5 V “Kanger SUBOX” loaded with 3.5 ml ECIG liquid in a 10-puff directed and 60-minute ad libitum bout. Nicotine delivery was greatest when using 8 mg+0.5Ohm combination and lowest when using the 3 mg/ml+1.5Ohm combination and HR followed a similar pattern. Abstinence symptom suppression was most pronounced for the 8 mg+0.5Ohm combination and least pronounced for the 3 mg/ml+1.5Ohm combination. Participants provided the highest ratings for pleasantness, satisfaction, and liking of harshness/irritancy and throat hit sensations for the 3 mg+0.5Ohm combination. Overall, use of ECIGs filled with 3 mg/ml nicotine concentration resulted in longer/larger puffs, increased puff frequency, and greater consumption of ECIG liquid. ECIG coil resistance, liquid nicotine concentration, and user puff topography, all of which influence ECIG nicotine delivery, should be considered together when making regulatory decisions aimed at protecting public health.


© Marzena M Hiler

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission