The Effects of Changes in Cigarette Menthol Content on Acute Nicotine Pharmacology and Smoking Topography.

INTRODUCTION: Menthol influences the appeal and addictiveness of cigarette smoking, however the data regarding menthol's effects on nicotine pharmacokinetics (PK) and smoking topography are inconsistent. This study investigated the impact of different cigarette menthol levels on nicotine pharmacology and smoking topography in current menthol smokers. AIMS AND METHODS: The study was a double-blind, randomized, four-period, crossover study to investigate the effects of smoking cigarettes with varying menthol content (0, 3, 6, and 12 mg menthol) on nicotine PK, smoking topography, and subjective effects in current menthol smokers. Each experimental session consisted of a prescribed use session, followed by 145 min of no smoking and a 1-h ad libitum smoking session. Serial blood samples were collected; smoking topography was recorded using CReSS Lab topography device. RESULTS: There was no significant effect of menthol on nicotine PK after prescribed smoking of cigarettes with varying menthol contents. During ad libitum smoking, there was significantly smaller total puff volume and puff duration in the 12 mg menthol condition compared to other menthol conditions. Subjective and sensory measures indicated significantly higher overall positive ratings for the 3 mg and 6 mg menthol cigarettes compared to the 0 mg menthol cigarette; the 12 mg menthol cigarette was less liked and harsher than the 3 mg condition. CONCLUSIONS: These findings suggest that menthol, at concentrations reflecting the marketplace (3-6 mg), contributes to positive subjective smoking experiences among menthol smokers, but does not have a significant effect on nicotine PK or smoking topography in an acute laboratory setting. IMPLICATIONS: While our data indicate that varying menthol content does not have a significant impact on nicotine's pharmacological effects under acute exposure conditions, these data highlight the contribution of menthol's flavor and sensory effects to product preference and positive smoking experiences, which facilitate repeated experimentation, progression to regular use, and subsequent dependence.

Divergence in Cigarette Discontinuation Rates by Use of Electronic Nicotine Delivery Systems (ENDS): Longitudinal Findings From the United States PATH Study Waves 1-6.

INTRODUCTION: We compare real-world trends in population-level cigarette discontinuation rates among adults (ages ≥21) who smoked cigarettes, by electronic nicotine delivery systems (ENDS) use. AIMS AND METHODS: U.S nationally representative data from adults in the Population Assessment of Tobacco and Health (PATH) Study (2013/14-2021, Waves 1-6) who smoked cigarettes in the past 30 days (P30D) were analyzed (n = 13 640). The exposure was P30D ENDS use. The outcome was P30D cigarette discontinuation at biennial follow-up. Weighted trend analyses were conducted to test for differences in cigarette discontinuation trends by ENDS use. RESULTS: Between 2013/14 and 2015/16, cigarette discontinuation rates were both 16% for those who used ENDS and for those who did not; between 2018/19 and 2021, rates were ~30% for those who used ENDS and ~20% for those who did not; the time by ENDS use interaction was significant. CONCLUSIONS: The relationship between adults' ENDS use and cigarette discontinuation in the context of an expanded ENDS marketplace, new tobacco regulatory actions, and COVID-19 differs from the relationship in earlier years. IMPLICATIONS: It is important for public health decisions to be informed by research based on the contemporary ENDS marketplace and circumstances.

A Method to Amend Cigarettes With Menthol for Use in Research.

INTRODUCTION: Studies have evaluated the role of menthol cigarettes on various addiction-related outcomes; however, the effect of varying menthol content on these outcomes has not been evaluated. We developed a method to amend non-menthol SPECTRUM Research Cigarettes to contain menthol at four different levels. AIMS AND METHODS: SPECTRUM Research Cigarettes, NRC 600 (0.8 mg nicotine; 10 mg tar), were modified to contain target menthol amounts at 3, 6, and 12 mg/cigarette by injecting 25 µL ethanol/triacetin/menthol solutions of varying concentrations (120 mg menthol/mL, 240 mg/mL, and 480 mg/mL) into four distinct locations in the filter and tobacco rod. Menthol content was tested in triplicate in the whole cigarette and in the tobacco rod and filter at 1, 24, 48, and 72 hours for each target menthol level using an extraction solution of quinoline in methyl-tert-butyl ether and measured using gas chromatography with flame ionization detection. RESULTS: Injections into the filter and tobacco rod (12.5 µL each) yielded equal menthol distribution up to 72 hours. However, total menthol content decreased from an average of 90.3% of the target menthol concentration at 1 hour to 80.7% at 72 hours in cigarettes stored individually in glass tubes at room temperature. Analysis of urinary menthol glucuronide confirmed that amended cigarettes used within 24 hours of injection delivered dose-related menthol levels to participants in a clinical laboratory setting. CONCLUSION: This method can be used to modify cigarettes with a range of reliable menthol levels in both filter and tobacco rod for use in laboratory and clinical research. IMPLICATIONS: This study presents a technique for modifying cigarettes with different levels of menthol that can reliably deliver dose-related menthol levels to participants when smoked in a clinical study. The technique can be used to quickly amend cigarettes to examine the independent effects of varying flavor and additive levels on smoking behavior, nicotine pharmacokinetics, mainstream smoke emissions, and other laboratory or clinical research outcomes.

Correlates of tobacco product initiation among youth and young adults between waves 1-4 of the population assessment of tobacco and Health (PATH) study (2013-2018).

INTRODUCTION: While risk factors for cigarette smoking among youth and young adults are well-documented, less is known about the correlates of initiation of other tobacco products. This study aims to provide estimates and correlates of initiation among U.S. youth and young adults. METHODS: Data on youth aged 12-17 (n = 10,072) and young adults aged 18-24 (N = 5,727) who provided information on cigarettes, electronic nicotine delivery systems (ENDS), cigars, pipe, hookah and smokeless tobacco use in Wave 1 (W1: 2013-2014)-Wave 4 (W4: 2016-2018) of the nationally-representative PATH Study were used to calculate ever use initiation and correlates of initiation by W4. RESULTS: Nearly 6 million youth and 2.5 million young adults used tobacco for the first time between W1-W4. Approximately one quarter of youth and young adult ENDS never users initiated ENDS between W1-W4 of the PATH Study. Among youth, use of other tobacco products, ever substance use, and high externalizing problems were associated with initiation of most products. Among young adults, use of other tobacco products and ever substance use were associated with initiation of most products. In both youth and young adults, Hispanics were more likely to initiate hookah use than their non-Hispanic White counterparts. While male sex was a risk factor for most tobacco product initiation across both age groups, it was not associated with hookah initiation. CONCLUSIONS: Cigarette and non-cigarette products shared many correlates of initiation, although there are noteworthy demographic differences. Findings can help tailor product specific interventions to reach populations at risk during preliminary stages of use.

Nicotine Exposure by Device Type among Adult Electronic Nicotine Delivery System Users in the Population Assessment of Tobacco and Health Study, 2015-2016.

BACKGROUND: Previous studies have examined the characteristics of open and closed system electronic nicotine delivery system (ENDS) users, but population-level information on nicotine exposure among these users has not been available. METHODS: We analyzed nicotine biomarker and survey data from Wave 3 of the Population Assessment of Tobacco and Health (PATH) study collected from October 2015 to October 2016. We identified 277 exclusive ENDS users and 468 dual cigarette and ENDS users and analyzed concentrations of nicotine and its metabolites obtained from urine samples by device type and other characteristics, such as frequency of use and e-liquid flavor. RESULTS: Among exclusive ENDS users, open system users had higher levels of total nicotine exposure (TNE-2) than closed system users [8.8 µmol/g creatinine (95% confidence interval [CI] = 5.3-14.8 µmol/g vs. 2.0 µmol/g (95% CI = 0.7-5.4 µmol/g)]. However, TNE-2 concentrations were similar when open and closed system users were stratified as daily [26.4 µmol/g (95% CI = 20.1-34.7 µmol/g) vs. 27.1 µmol/g (95% CI = 16.4-44.9 µmol/g)] and nondaily [0.5 µmol/g (95% CI = 0.1-1.9 µmol/g) vs. 0.2 µmol/g (95% CI = 0.0-0.7 µmol/g)] ENDS users. Dual users generally had higher nicotine exposure than exclusive users. CONCLUSIONS: Nicotine exposure was observed to be higher among exclusive open system ENDS users compared with closed system users, but levels were similar when users were stratified by frequency of use. IMPACT: These results suggest that exclusive ENDS users with similar use patterns receive comparable levels of nicotine, regardless of whether they use open or closed system devices.