The Influence of Electronic (ECIG) Heater Resistance on ECIG Acute Effects
Condition: Nicotine Dependence
MeSH terms: Tobacco Use Disorder
Study type: Interventional

Summary: 
      The purpose of this study is to measure the individual and combined influence of electronic
      cigarette (ECIG) heating element resistance and liquid nicotine concentration on ECIG acute
      effects. Thirty-two experienced ECIG users will complete four independent laboratory sessions
      that will differ by heater resistance (0.5 ohm or 1.5 ohm) and liquid nicotine concentration
      (3 or 8 mg/ml). Other factors such as voltage, liquid solvent ratio, and liquid flavor will
      be held constant. Plasma nicotine concentration, subjective effects, and puffing behavior
      will be recorded for each condition.
    

Detailed description: 
      Electronic cigarettes (ECIGs) are a popular and rapidly evolving class of products. ECIG
      users can manipulate several device features including liquid nicotine concentration (mg/ml)
      and heating element resistance (ohms). An emerging class of ECIG models includes "sub-Ohm"
      devices that employ low resistance heaters that are often used to achieve high device power.
      Some clinical laboratory data suggest that high power devices deliver nicotine to the user
      effectively, even when paired with a low liquid nicotine concentration. However, given that
      ECIG heater resistance and liquid nicotine concentration have not been manipulated in
      clinical laboratory studies, the influence of these factors on ECIG acute effects remain
      unclear. The purpose of this clinical laboratory study is to measure the influence of heater
      resistance and liquid nicotine concentration on ECIG acute effects. Participants will attend
      the lab for four experimental sessions where they use an ECIG. For each session, the
      participants will be randomly assigned (like the flip of a coin) to receive an ECIG with one
      of two different levels of heating coil resistance (which will determine overall device
      power) and one of two different liquid nicotine concentrations. The four sessions will begin
      at approximately the same time each day, will be separated by at least 48 hours, and will not
      occur more than two times per week. The primary hypotheses are that the low resistance heater
      paired with the 8 mg/ml liquid nicotine concentration, will result in greater nicotine
      delivery and subjective effect profiles, suggestive of higher abuse potential. Results from
      this study will further our understanding of the factors that influence the dependence
      potential of ECIGs and could inform future regulation of these devices.
    

Intervention name(s): ECIG Session
Intervention type(s): Other
Intervention description(s): Participants will complete four sessions using an e-cigarette, including a 10-puff product use bout followed by a 60-minute ad lib bout over an approximately 4-hour period. The study conditions for each session (i.e., heater resistance and nicotine combinations) will be Latin-square ordered.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Basic Science