A Clinical Laboratory Model for Evaluating the Acute Effects of Electronic “Cigarettes”: Nicotine Delivery Profile and Cardiovascular and Subjective Effects

Abstract

Background: Electronic "cigarettes" are marketed to tobacco users as potential reduced exposure products (PREP), albeit with little information regarding electronic cigarette user toxicant exposure and effects. This information may be obtained by adapting clinical laboratory methods used to evaluate other PREPs for smokers.Methods: Thirty-two smokers participated in four independent Latin-square ordered conditions that differed by product: own brand cigarette, "NPRO" electronic cigarettes (NPRO EC; 18 mg cartridge), "Hydro" electronic cigarettes (Hydro EC; 16 mg cartridge), or sham (unlit cigarette). Participants took 10 puffs at two separate times during each session. Plasma nicotine and carbon monoxide (CO) concentration, heart rate, and subjective effects were assessed.Results: Own brand significantly increased plasma nicotine and CO concentration and heart rate within the first five minutes of administration whereas NPRO EC, Hydro EC, and sham smoking did not. Own brand, NPRO EC, and Hydro EC (but not sham) significantly decreased tobacco abstinence symptom ratings and increased product acceptability ratings. The magnitude of symptom suppression and increased acceptability was greater for own brand than for NPRO EC and Hydro EC.Conclusions: Under these acute testing conditions, neither of the electronic cigarettes exposed users to measurable levels of nicotine or CO, although both suppressed nicotine/tobacco abstinence symptom ratings.Impact: This study illustrates how clinical laboratory methods can be used to understand the acute effects of these and other PREPs for tobacco users. The results and methods reported here will likely be relevant to the evaluation and empirically based regulation of electronic cigarettes and similar products. Cancer Epidemiol

Hormonal contraception among electronic cigarette users and cardiovascular risk: a systematic review

“…Of these, 13 articles met inclusion criteria for this review [49][50][51][52][53][54][55][56][57][58][59][60][61]. One article reported on the clinical outcomes of interest (two cases of MI) [49].…”

“…One article reported on the clinical outcomes of interest (two cases of MI) [49]. Eleven articles measured heart rate and BP after EC exposure [50][51][52][53][54][55][56][57][58][59][60]. In 5 of these articles, investigators followed participants for at least 1 week [49,[57][58][59][60], but in 7 articles, authors only reported acute outcomes (changes over b 5 h of exposure) [50][51][52][53][54][55][56].…”

“…We identified seven studies in which investigators observed individuals using ECs in laboratory settings for short time periods (≤ 5 h of observation per session) [50][51][52][53][54][55][56] (Table 2). Participants attended one [50,54] to six [53] sessions.…”

“…Two randomized crossover studies exposed individuals to four [52] or six products [53], with participants randomized to exposure order. In the first study (poor quality), 32 smokers (13 women) used four products (an EC with a cartridge containing 18-mg nicotine/mL e-liquid, an EC with a cartridge containing 16-mg nicotine/mL e-liquid, chosen brand of conventional cigarette and an unlit cigarette) for 10 puffs, then repeated the procedure after an hour with the same product, with heart rate measured every 20 s [52].…”

“…In the first study (poor quality), 32 smokers (13 women) used four products (an EC with a cartridge containing 18-mg nicotine/mL e-liquid, an EC with a cartridge containing 16-mg nicotine/mL e-liquid, chosen brand of conventional cigarette and an unlit cigarette) for 10 puffs, then repeated the procedure after an hour with the same product, with heart rate measured every 20 s [52]. Four sessions were completed (one session per product) with a ≥ 48-h washout period between sessions.…”