Underreporting of non-study cigarette use by study participants confounds the interpretation of results from ambulatory clinical trial of reduced nicotine cigarettes

BACKGROUND

As part of its comprehensive plan to significantly reduce the harm from tobacco products, the US Food and Drug Administration is establishing a product standard to lower nicotine in conventional cigarettes to make them "minimally addictive or non-addictive". Many clinical studies have investigated the potential impact of such a standard on smoking behavior and exposure to cigarette constituents. These ambulatory studies required participants who smoke to switch to reduced nicotine study cigarettes. In contrast to clinical trials on pharmaceuticals or medical devices, participants had ready access to non-study conventional nicotine cigarettes and high rates of non-study cigarette use were consistently reported. The magnitude of non-compliance, which could impact the interpretation of the study results, was not adequately assessed in these trials.

METHODS

We conducted a secondary analysis of data from a large, randomized trial of reduced nicotine cigarettes with 840 participants to estimate the magnitude of non-compliance, i.e., the average number of non-study cigarettes smoked per day by study participants assigned to reduced nicotine cigarettes. Individual participants' non-study cigarette use was estimated based on his/her urinary total nicotine equivalent level, the nicotine content of the study cigarette assigned and the self-reported number of cigarettes smoked, using a previously published method.

RESULTS

Our analysis showed that (1) there is a large variation in the number of non-study cigarettes smoked by participants within each group (coefficient of variation 90-232%); (2) participants in reduced nicotine cigarette groups underreported their mean number of non-study cigarettes smoked per day by 85-91%; and (3) the biochemical-based estimates indicate no reduction in the mean number of total cigarettes smoked per day for any group assigned to reduced nicotine cigarettes after accounting for non-study cigarettes.

CONCLUSIONS

High levels of non-compliance, in both the rate and magnitude of non-study cigarette use, are common in ambulatory reduced nicotine cigarette trials where participants have access to conventional nicotine non-study cigarettes. The potential impact of high non-compliance on study outcomes should be considered when interpreting the results from such ambulatory studies.

A Randomized, Controlled Study to Assess Changes in Biomarkers of Exposures Among Adults Who Smoke That Switch to Oral Nicotine Pouch Products Relative to Continuing Smoking or Stopping All Tobacco Use

The purpose of this open-label, randomized, controlled, in-clinic, 5-parallel-group study was to assess biomarkers of exposure (BoE) to select harmful and potentially harmful constituents in adults who smoke (N = 144) switching to oral tobacco products (on!® mint nicotine pouches; test products) compared to continuing smoking cigarettes (CS) and completely quitting all tobacco products (NT). Changes in 20 BoE to select harmful and potentially harmful constituents, including 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), were evaluated. Adult smokers smoked their usual brand of cigarettes for 2 days (baseline assessments) and then were randomly assigned to ad libitum use of 2, 4, or 8 mg test products, CS, or NT for 7 days. Analysis of covariance was used to assess the Day 7 BoE levels between each group using test products, CS, and NT. The creatinine-adjusted total urinary NNAL and other 18 of 19 BoE levels (except nicotine equivalents [NEs]) were significantly lower (P < .05) on Day 7, among all test product groups compared to CS. Geometric least-square means were reduced for all biomarkers of exposure, except NEs, in test product groups by approximately 42%-96% compared to the CS group, and reductions were comparable to the NT group. The geometric least-square means for urinary NE between the test product and the CS groups, although not significantly different, the Day 7 mean change relative to the CS group were 49.9%, 65.8%, and 101% for the 2, 4, and 8 mg test product groups, respectively. The substantial reduction in harmful and potentially harmful constituent exposure suggests complete switching from cigarettes to test products may present a harm reduction opportunity for adults who smoke.

A Randomized, Controlled Study to Assess Biomarkers of Exposure in Adult Smokers Switching to Oral Nicotine Products

This open-label, randomized, controlled, in-clinic, 6-parallel-group study evaluated changes in biomarkers of exposure (BoEs) to select harmful and potentially harmful constituents in adult smokers (N = 213) not planning to quit smoking. Adult smokers were randomized to continue smoking (CS), reduce smoking by 50% and dual use oral tobacco-derived nicotine (OTDN) products (VERVE chews/discs), stop smoking and exclusively use discs or chews, or stop using all tobacco products (NT). The primary objective compared 24-hour urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL; a biomarker for the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) in dual and exclusive use of discs and chews to continue smoking and NT on day 7. NNAL levels on day 7 were significantly lower (P < .05) among dual and exclusive users of discs/chews compared to continue smoking; median percent reductions were ≈30% and ≈73%, respectively. NNAL levels were not significantly different between those who used discs/chews and the NT group. Many of the additional secondary biomarkers of exposure were significantly lower in dual users (10/19) and exclusive users of discs/chews (17/19) compared to the continue smoking group. Overall, reductions in secondary biomarkers of exposure were greater in exclusive users than dual users. The 24-hour urinary nicotine equivalents were significantly lower (P < .05) among exclusive users of discs/chews compared to continue smoking. The discs/chews appeared to be well tolerated. These results demonstrate that while switching completely to discs/chews substantially reduces exposure to select harmful and potentially harmful constituents, dual use with 50% reduction in cigarette consumption also reduces exposure. oral tobacco-derived nicotine products like discs/chews may present a harm reduction opportunity for adult smokers, particularly those not intending to quit smoking.

Nicotine pharmacokinetics and subjective responses after using nicotine pouches with different nicotine levels compared to combustible cigarettes and moist smokeless tobacco in adult tobacco users

RATIONALE

Oral tobacco-derived nicotine products include on!® nicotine pouches (NPs) which are tobacco-leaf free and available in multiple flavors and nicotine levels. Switching completely to NPs from cigarettes and moist smokeless tobacco (MST) has the potential to reduce harm for adult tobacco consumers. However, the dependence potential of NPs is not established. Therefore, we characterized the abuse potential of NPs with different nicotine levels compared to cigarettes and MST.

OBJECTIVES

To evaluate nicotine pharmacokinetics (PK) and subjective effects of NPs (ranging from 1.5 to 8 mg nicotine) compared to own brand cigarettes (OBCs) and MST (OBMST).

METHODS

We used a randomized, in-clinic, partial single-blind, 7-way crossover design to assess nicotine PK and subjective effects in dual users of cigarettes and MST.

RESULTS

The mean nicotine Cmax for NPs increased with nicotine level, ranging from 3.5 ng/mL (1.5 mg NP) to 15.4 ng/mL (8 mg NP), compared with 12.2 ng/mL for OBCs and 9.8 ng/mL for OBMST. Nicotine tmax was much longer for all NPs and OBMST (32.5-34.4 min) compared to OBCs (8.5 min). Reductions in urges to smoke after use of the 2 mg, 3.5 mg, and 8 mg NPs were not statistically different (p > 0.05) relative to OBC. Also, NPs resulted in lower ratings of positive subjective effects relative to OBCs and OBMST.

CONCLUSIONS

Overall, based on the study results and literature reported nicotine PK values for cigarettes and MST, the abuse potential of NPs is not likely to be higher than OBCs and OBMST. NPs may be potentially acceptable switching products for users of cigarettes and MST products.

Understanding heterogeneity among individuals who smoke cigarettes and vape: assessment of biomarkers of exposure and potential harm among subpopulations from the PATH Wave 1 Data

Introduction

People who both smoke cigarettes and vape are often considered as a homogenous group even though multiple subgroups may exist. We examined biomarkers of exposure (BOE) and biomarkers of potential harm (BOPH) to differentiate between subgroups of people who smoke and vape based on PATH Study Wave 1 (2013–2014) data.

Methods

We compared people who only smoke cigarettes everyday (Group A, n = 2442) and people who only vape everyday (Group C, n = 169) against people who smoke and vape segmented into subgroups of people who frequently smoke and vape (Group B1, n = 169), frequently smoke and infrequently vape (Group B2, n = 678), frequently vape and infrequently smoke (Group B3, n = 57), and infrequently smoke and vape (Group B4, n = 66). Eighteen BOEs (representing exposure to TSNAs, nicotine, heavy metals, PAHs, and volatile organic compounds) and four BOPHs (representing inflammation and oxidative stress) were compared within the subgroups.

Results

Levels of many BOEs/BOPHs were higher among Group B2 relative to Groups B1, B3, and B4. Compared to Group A, many BOEs were significantly lower in Groups B3 (15/18) and B4 (17/18), and some BOEs were higher among B2 (4/18). Compared to Group C, significantly lower BOEs were observed for Group B4 (2/18).

Conclusions

Overall, the levels of BOEs and BOPHs in people who smoke and vape are associated with frequency of cigarette smoking. Our findings indicate that not all people who smoke and vape are the same, and tobacco product use frequency should be considered when categorizing people who smoke and vape.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12954-022-00673-x.

Characterization of the Abuse Potential in Adult Smokers of a Novel Oral Tobacco Product Relative to Combustible Cigarettes and Nicotine Polacrilex Gum

Novel noncombustible tobacco products offer adult smokers (ASs) alternatives to combustible cigarettes lower on the continuum of risk; however, the abuse potential of such products has not been well studied. The objective of this study was to evaluate the abuse potential of 2 chewable tobacco‐derived nicotine containing products, VERVE Chews Blue Mint (test 1) and Green Mint (test 2), in ASs compared with own‐brand cigarettes (CIGS) and nicotine polacrilex gum (GUM) using subjective measures and nicotine pharmacokinetics. ASs used the test products during a 5‐day at‐home trial prior to completing an in‐clinic 4‐period randomized crossover study. During the study ASs used test products, CIGS, and GUM once on separate days. Responses to Tobacco/Nicotine Withdrawal and Direct Effects of Product questionnaires were documented, and blood samples were collected to assess nicotine pharmacokinetics during each product use. Nicotine pharmacokinetic parameters (C_max and AUC) were statistically significantly lower with use of test products compared with CIGS and statistically significantly higher compared with GUM. No appreciable differences were noted between the 2 flavors for any of the end points measured. Reductions in maximum urge to smoke and maximum responses to the question “Is the Product ‘Pleasant’ Right Now?” for the test products were statistically significantly lower than CIGS but comparable to GUM. Similar results were observed for responses to other items in the 2 questionnaires. The test products, under the conditions of this study, carry lower abuse potential than own‐brand cigarettes and similar to nicotine polacrilex gum.

The human ecology of tornadoes

This paper offers an empirical test of the impact of human ecological patterns and other known correlates on tornado occurrence. It uses the National Severe Storms Forecast Center's information on tornadoes from 1950 through 1990 and employs ecological data from the U.S. Bureau of the Census and the Environmental Protection Agency. The results show that metropolitan and other urban counties have higher odds of tornado occurrence than rural counties, and that the probability of occurrence of tornadoes increases with increases in the number of previous tornadoes. The paper assesses the meaning of this finding for demographers, atmospheric scientists, engineers, and disaster managers.