Impact of flavors and humectants on waterpipe tobacco smoking topography, subjective effects, toxicant exposure and intentions for continued use

Biomarkers of Waterpipe Tobacco Smoke Exposure: A Systematic Review and Meta-Analysis

INTRODUCTION

The prevalence of waterpipe tobacco smoking is increasing globally. Biomarkers of waterpipe tobacco smoke (WTS) exposure are less studied.

AIMS AND METHODS

To identify the types of biomarkers of WTS exposure and estimate changes in biomarker concentrations pre- to post-WTS exposure. PubMed, Embase, Web of Science, CINAHL Plus, PsycINFO, and Cochrane Library were searched for studies up to April 24, 2023. The types of biomarkers were identified. Random-effects models were used to estimate changes in biomarker concentrations pre- to post-WTS exposure.

RESULTS

Seventy-three studies involving 3755 participants exposed to WTS (49% male, mean age: 24.8 years) and 11 types of biomarkers of WTS exposure were identified. The biomarkers included tobacco alkaloids, expired carbon monoxide (eCO), carboxyhemoglobin (COHb), tobacco-specific nitrosamines, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, unmetabolized VOCs, unmetabolized PAHs, furan metabolites, and heterocyclic aromatic amines. Compared with pre-WTS exposure, eCO (breath; mean difference [MD] 27.00 ppm; 95% confidence interval [CI]: 20.91 to 33.08), COHb (blood; MD 4.30%; 95%CI: 2.57 to 6.03), COHb (breath; MD 7.14%; 95%CI: 4.96 to 9.31), nicotine (blood; MD 8.23 ng/mL; 95%CI: 6.27 to 10.19), and cotinine (urine; MD 110.40 ng/mL; 95%CI: 46.26 to 174.54) significantly increased post-WTS exposure.

CONCLUSIONS

Biomarkers of WTS exposure were systematically identified. The similarity between the biomarkers of WTS exposure and those of cigarette smoke and higher concentrations of some biomarkers post-WTS exposure underscore the need for further research on applying biomarkers in surveillance, interventions, and regulations to mitigate the harms of waterpipe tobacco smoking.

IMPLICATIONS

This study provides the first comprehensive overview of biomarkers investigated and available for assessing WTS exposure and their concentration changes in the human body. Researchers can use biomarkers such as eCO, COHb, nicotine, and cotinine to measure the health risks associated with WTS exposure and objectively evaluate the effectiveness of public health interventions aimed at reducing waterpipe tobacco smoking. Public health policymaking can also be informed through increased biomarker concentrations following WTS exposure, to implement regulations and public health education campaigns on limiting or preventing waterpipe tobacco smoking.

Effect of sweet flavouring on the rewarding and reinforcing value of cigarillo use among young adults

INTRODUCTION

Cigarillos dominate the US cigar market, and young adults largely drive use. While young adults prefer flavoured to non-flavoured cigarillos, especially those flavoured to taste like fruit or other sweets, the factors that underlie this preference have received little attention. We sought to determine if key indicators of abuse liability, the rewarding and reinforcing effects, are greater for sweet versus non-flavoured cigarillos.

METHODS

Young adults (18-24 years old) completed three laboratory visits assessing the subjective rewarding value (exposure paradigm), relative reinforcing value (computerised choice task) and absolute reinforcing value (ad libitum cigarillo smoking session) of sweet-flavoured versus non-flavoured cigarillos. General linear regression models were fit with the appropriate family link for each outcome measure.

RESULTS

Young adults rated sweet-flavoured cigarillos as more rewarding (estimated marginal mean (EMM) =4.52, 95% CI 4.00 to 5.03) than the non-flavoured cigarillo (EMM=3.31, 95% CI 2.80 to 3.83; B=1.20, 95% CI 0.80 to 1.60, p<0.001). The reinforcing value of sweet-flavoured cigarillos, measured by break point, was higher relative to non-flavoured cigarillos (6.34 out of 10), especially among young adults with a preference for flavoured cigarillos (B=1.94, 95% CI 0.71 to 3.18, p=0.003). Young adults took 1.9 times the number of puffs (35.75 vs 19.95) from sweet-flavoured cigarillos compared with non-flavoured cigarillos (Rate Ratio =1.94, 95% CI 1.30 to 2.90, p<0.001).

CONCLUSIONS

Sweet flavouring increases the abuse liability of cigarillos among young adults as reflected in greater liking, motivation to use and actual use. Banning sweet flavouring in cigarillos may diminish their use in young adults.Trial registration number CT.gov (NCT05092919).

The sweet spot study-Developing e-liquid product standards for nicotine form and concentration to improve public health: Protocol for a randomized, double-blinded, crossover study

OBJECTIVES

E-cigarettes pose significant risks to youth, but smokers may benefit from switching to e-cigarettes by reducing their exposure to toxicants, which creates a challenge for the Food and Drug Administration (FDA) in regulating e-cigarettes to protect population health. This study aims to develop e-liquid product standards for nicotine form and concentration that reduce the appeal of e-cigarettes to young people while keeping e-cigarettes available as a safer alternative for smokers.

DESIGN AND PARTICIPANTS

A single-visit, double-blinded, randomized crossover design will be used to examine the effects of e-liquids with varying fractions of free-base nicotine (5%, 25%, 45%, 65%, 85%) among a sample of 66 young adult EC users and 66 older adult smokers, across ecologically valid total nicotine concentrations (20 mg or 50 mg/mL).

INTERVENTIONS AND OUTCOMES

A 2-puff session will be conducted to test each of the 10 e-liquids in randomly assigned sequences, followed by a 10-minute washout period and participant ratings on appeal and sensory attributes such as throat hit and harshness, as well as behavioral intentions for continued use. Generalized linear mixed models will be used to determine a free-base nicotine level that has limited or no appeal to young adult e-cigarette users while remaining acceptable to smokers.

CONCLUSIONS

This study will provide the FDA with scientific evidence regarding the effect of product standards that mandate a minimum threshold for the fraction of free-base nicotine.

TRIAL REGISTRATION

The study is registered on clinicaltrials.gov under the identifier NCT05864586.

Parental divorce and smoking dependence in Lebanese adolescents: the mediating effect of mental health problems

BACKGROUND

Lebanon has the highest prevalence estimates among Middle Eastern countries and Arab women regarding cigarette smoking, with 43% of men and 28% of women involved in such trends. Marital disruption is a tremendous source of irritability and discomfort that may hinder a child's healthy development, creating perturbing distress and increasing disobedience that may exacerbate smoking addiction. Additionally, Lebanese adolescents are inflicted by high emotional and economic instability levels, rendering increased susceptibility to distress and propensity to engage in addictive behavior. This study aims to investigate the association between parental divorce and smoking dependence among Lebanese adolescents, along with exploring the potential mediating effect of mental health disorders of such correlation.

METHODS

A total of 1810 adolescents (14 and 17 years) enrolled in this cross-sectional survey-based study (January-May 2019). Linear regressions were conducted to check for variables associated with cigarette and waterpipe dependence. PROCESS v3.4 model 4 was used to check for the mediating effect of mental health disorders between parental divorce and smoking dependence.

RESULTS

Higher suicidal ideation and having divorced parents vs living together were significantly associated with more cigarette and waterpipe dependence. Higher anxiety was significantly associated with more waterpipe dependence. Insomnia and suicidal ideation played a mediating role between parental divorce and cigarette/waterpipe dependence.

CONCLUSION

Our results consolidate the results found in the literature about the association between parental divorce and smoking addiction and the mediating effect of mental health issues. We do not know still in the divorce itself or factors related to it are incriminated in the higher amount of smoking in those adolescents. Those results should be used to inspire parents about the deleterious effect of divorce on their children to lower their risk of smoking addiction. Further longitudinal studies are needed to better understand the complexity of such associations and to see whether the divorce experience by itself or the factors that accompany it are involved in the increased smoking addiction among adolescents.

Internalizing problems are associated with initiation and past 30-Day use of flavored tobacco products

OBJECTIVE

Tobacco use remains disproportionately common among adults with internalizing problems. The rising prevalence of flavored tobacco use among this population may be a contributing factor. Using data from Wave 4 of the Population Assessment of Tobacco and Health Study, this study examined differences across adult ever tobacco users by severity of internalizing problems, in initiation of tobacco use with a flavored product and past 30-day (current) flavored tobacco use (n = 27,425). Severity of internalizing problems was measured using the Global Appraisal of Individual Needs-Short Screener Internalizing Disorder Screener. Tobacco use variables included initiation with or current use of a flavored product, assessed separately for each product. Weighted chi-square tests and multivariable modified Poisson regression models were used to examine the associations between severity of internalizing problems and each outcome.

RESULTS

Controlling for covariates, ever users with severe internalizing problems were more likely to have initiated with flavors for cigarettes (adjusted prevalence ratio [aPR]: 1.16, 95% confidence interval [CI]: 1.09,1.24), cigarillos (aPR: 1.09, 95% CI: 1.03, 1.16), electronic nicotine products (aPR: 1.08, 95% CI: 1.03, 1.13) and smokeless tobacco (aPR: 1.15, 95% CI: 1.04, 1.27), relative to those with low internalizing problems. Ever users with severe internalizing problems were more likely to currently use a flavored tobacco product for cigarettes (aPR: 1.15, 95% CI: 1.07, 1.24) and cigarillos (aPR: 1.15, 95% CI: 1.04, 1.28).

CONCLUSIONS

Flavored tobacco use seems disproportionately common among tobacco users with severe internalizing problems, across a variety of measures.

Markers of oxidative stress and toxicant exposure among young waterpipe smokers in the USA

Waterpipe (aka hookah) tobacco smokers are exposed to toxicants that can lead to oxidative DNA and RNA damage, a precursor to chronic disease formation. This study assessed toxicant exposure and biomarkers of DNA [8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG)] and RNA [8-oxo-7,8-dihydroguanosine (8-oxoGuo)] oxidative damage during smoking of flavored and non-flavored waterpipe tobacco. Thirty waterpipe smokers completed two counterbalanced 2-h lab waterpipe smoking sessions (flavored vs. non-flavored waterpipe tobacco). Urinary concentrations of 8-oxodG and 8-oxoGuo and expired carbon monoxide (eCO) were measured before and after the smoking sessions. A significant increase in the urinary concentrations of 8-oxodG (from 2.12 ± 0.83 to 2.35 ± 0.91 ng/mg creatinine, p = 0.024) and 8-oxoGuo (from 2.96 ± 0.84 to 3.45 ± 0.76 ng/mg creatinine, p = 0.003) were observed after smoking the non-flavored and flavored waterpipe tobacco, respectively. Our results also showed that the mean ± SD of eCO increased significantly after smoking the flavored (from 1.3 ± 1.1 to 20.3 ± 23.6 ppm, p < 0.001) and non-flavored waterpipe tobacco (from 1.8 ± 1.2 to 24.5 ± 26.1 ppm, p < 0.001). There were no significant differences in the means of 8-oxodG (p = 0.576), 8-oxoGuo (p = 0.108), and eCO (p = 0.170) between the flavored and non-flavored tobacco sessions. Smoking non-flavored and flavored waterpipe tobacco leads to oxidative stress and toxicant exposure. Our findings add to the existing evidence about the adverse effects of waterpipe tobacco smoking (WTS) and the need for strong policies to inform and protect young people from the risks of WTS.

Effects of flavourants and humectants on waterpipe tobacco puffing behaviour, biomarkers of exposure and subjective effects among adults with high versus low nicotine dependence

INTRODUCTION

Flavourants and humectants in waterpipe tobacco (WT) increase product appeal. Removal of these constituents, however, is associated with increased intensity of WT puffing, likely due to reduced nicotine delivery efficiency. To clarify the potential public health outcomes of restrictions on flavourants or humectants in WT, we evaluated the effects of these constituents on puffing behaviours, biomarkers of exposure and subjective effects among adults with high versus low WT dependence.

METHODS

N=39 high dependence and N=49 low dependence WT smokers (Lebanese Waterpipe Dependence Scale scores >10 = high dependence) completed four smoking sessions in a cross-over experiment. Conditions were preferred flavour with humectant (+F+H), preferred flavour without humectant (+F-H), unflavoured with humectant (-F+H) and unflavoured without humectant (-F-H). Measures of puff topography, plasma nicotine and expired carbon monoxide (eCO) boost, and subjective effects were assessed.

RESULTS

Level of WT dependence modified the effect of WT condition on average flow rate, average puff volume and eCO boost. Although, overall, participants puffed the +F+H WT least intensely and -F-H WT most intensely, this association was strongest among WT smokers with high dependence. Participants preferred smoking the +F+H WT and achieved the largest plasma nicotine boost in that condition.

DISCUSSION

Findings underscore the complexity of setting product standards related to flavourants and humectants in WT. Future research evaluating whether WT smokers with high dependence would quit or reduce their WT smoking in response to removal of flavourants or humectants from WT is necessary to appreciate the full public health effects of such policies.

Development and Pretesting of Hookah Tobacco Public Education Messages for Young Adults

Young adults’ hookah tobacco use is fueled by misperceptions about risks, appealing flavors, and social use. We developed and pretested public education messages to prevent and reduce hookah tobacco smoking among young adults. We used a two (user status: current hookah user, susceptible never user) by two (risk content: health harms or addiction) by three (message theme: harms/addiction risk alone, harms/addiction risk flavors, or harms/addiction risk social use) design with two messages/condition (n = 12 total messages). Young adults aged 18–30 (N = 713) were randomized to 1 of 12 messages and completed measures assessing message receptivity, attitudes, and negative emotional response. Harms messages were associated with greater receptivity (p < 0.001), positive attitudes (p < 0.001), and negative emotional response (p < 0.001) than addiction messages. Messages with harm or addiction content alone were associated with greater receptivity than social use-themed messages (p = 0.058). Flavor-themed messages did not differ in receptivity from harm or addiction content alone or social use-themed messages. Messages about the health harms of hookah tobacco use resonate more with young adults than addiction risk messages. Social use-themed messages produce the lowest receptivity. These findings can guide population-based approaches to communicate hookah tobacco risks to young adults.