Biomarkers Of Exposure Levels Research Articles

Comparison of biomarkers of exposure among US adult smokers, users of electronic nicotine delivery systems, dual users and nonusers, 2018–2019

The harm caused by cigarette smoking is overwhelmingly due to byproducts of tobacco combustion. Electronic Nicotine Delivery Systems (ENDS) provide nicotine to users without combustion, and may support tobacco harm reduction among cigarette smokers who would not otherwise quit in the near term. Analyses of Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study compared biomarkers of exposure (BOE) levels for nicotine, 3 metals, 2 tobacco-specific nitrosamines and 14 smoking-related volatile organic compounds in 151 exclusive ENDS users, 1341 exclusive cigarette smokers, 115 dual users (cigarettes and ENDS), and 1846 past 30-day nonusers of tobacco, adjusting for demographics. Nicotine exposure in ENDS users and dual users did not significantly differ from smokers. Among ENDS users, 16 of 18 other BOEs were significantly lower than smokers’; 9 BOEs were not significantly different from nonusers. Among dual users smoking < 10 cigarettes/day, 15 of 18 non-nicotine BOEs were significantly lower than smokers’, whereas in dual users smoking ≥ 10 cigarettes per day none of the BOEs significantly differed from smokers’. In this representative sample of US adults, exclusive use of ENDS (vs. cigarette smoking) was associated with much lower exposures to many harmful chemicals associated with smoking-related disease. BOE levels in dual users were directly related to their cigarette consumption. These BOE data provide further evidence that ENDS expose users to substantially lower levels of toxicants than combustible cigarettes, confirming their potential for harm reduction.

Changes in biomarkers of exposure and biomarkers of potential harm after 360 days in smokers who either continue to smoke, switch to a tobacco heating product or quit smoking

The aim of this study was to investigate whether biomarkers of exposure (BoE) and potential harm (BoPH) are modified when smokers either continue to smoke or switch from smoking cigarettes to exclusive use of a tobacco heating product (THP) in an ambulatory setting over the period of a year, and to compare any changes with smokers who quit tobacco use completely and with never smokers’ biomarker levels. Participants in this year-long ambulatory study were healthy smokers with a self-reported low intent to quit assigned either to continue smoking or switch to a THP; a group of smokers with a self-reported high intent to quit who abstained from tobacco use; and a group of never smokers. Various BoE and BoPH related to oxidative stress, cardiovascular and respiratory diseases and cancer were assessed at baseline and up to 360 days. Substantial and sustained reductions in BoE levels were found at 360 days for both participants who switched from smoking to THP use and participants who quit smoking, in many cases the reductions being of a similar order for both groups. The never smoker group typically had lower levels of the measured BoEs than either of these groups, and much lower levels than participants who continued to smoke. Several BoPHs were found to change in a favourable direction (towards never smoker levels) over the year study for participants who completely switched to THP or quit, while BoPHs such as soluble intercellular adhesion molecule-1 were found to change in an unfavourable direction (away from never smoker levels) in participants who continued to smoke. Our findings, alongside chemical and toxicological studies undertaken on the THP used in this study, lead to the conclusion that smokers who would have otherwise continued to smoke and instead switch entirely to the use of this THP, will reduce their exposure to tobacco smoke toxicants and as a consequence are reasonably likely to reduce disease risks compared to those continuing to smoke.

A Systematic Review and Meta-Analysis on Human Biomarkers of Exposure from Heated Tobacco Products Compared to Conventional Cigarettes among Adult Smokers

Introduction: The health effects of Heated Tobacco Products (HTP), which are noncombustible alternatives to Conventional Cigarettes (CC), may be assessed by the measurement of Biomarkers of Exposure (BoE). Methods: This meta-analysis aims to compare the BoE levels between HTP and CC. Systematic computerized search was performed using Pubmed, Google Scholar, and Cochrane database. The studies included randomized controlled trials that evaluated the effectiveness of HTP compared to CC in reducing human BoE. Two reviewers independently appraised each study. Any disparity in assessment was settled by an independent adjudicator. Results: Data from the trials included in this study (N=1,193) showed that there was a significant difference in the levels of BoEs between HTP and CC. The levels of carboxyhemoglobin [-2.0 (95% CI -3.08 to -0.92), Z=3.64, p=0.00001], 4-aminobiphenyl [- 1.67 (95% CI -2.36 to -0.99), Z=4.80, p=0.00001], 3-hydroxypropylmercaptapuric acid [-1.09 (95% CI -1.54 to -0.63), Z=4.70, p= 0.00001], N-nitrosonornicotine [-0.95 (95% CI -1.49 to - 0.41), Z=3.46, p=0.0005], 4-(methylnitrosamino)-1-(3-pyridyl)- 1-butanol [-1.30 (95% CI - 1.72 to -0.89), Z=6.18, p=0.00001], Total Nicotine Equivalents [-0.85 (95% CI -1.36 to -0.34), Z=3.24,p=0.001], Benzo[a]pyrene [-1.70 (95% CI -2.08 to -1.33), Z=8.92, p=0.00001], and Sphenylmercapturic acid [-1.18 (95% CI -1.36 to -0.99), Z=12.36, p= 0.0001] among the participants were significantly reduced in those who used HTP as compared to those who smoked CC. Conclusion: The study showed that the use of HTP could significantly reduce exposure to harmful substances compared to CC using BoEs that are assessed to be most suitable and practical for tobacco product regulation.

A randomized controlled study in healthy participants to explore the exposure continuum when smokers switch to a tobacco heating product or an E-cigarette relative to cessation.

Cigarette smoking is associated with a number of diseases, such as cancer and cardiovascular diseases. Recently, there has been an increase in the use of electronic cigarettes (ECs) and tobacco-heating products (THPs) as an alternative to cigarettes, which may reduce the health burden associated with smoking. However, an exposure continuum when smokers switch to ECs or THPs compared to complete smoking cessation is not well established. 148 healthy smokers were randomized to either continue smoking cigarettes, switch to using the glo THP or a prototype EC, or completely quit any nicotine or tobacco product use for 5 days, after a 2-day baseline period. During this study breath and 24-h urine samples were collected for Biomarker of Exposure (BoE) analysis. After a 5-day switching period BoE levels showed a substantial significant decrease in levels from baseline in the groups using the glo THP, the prototype EC, and having quit all nicotine and tobacco use. On an exposure continuum, smokers who completely quit nicotine had the lowest levels of assessed BoEs, followed by those who switched to the EC and then those who switched to glo THP use. Participants who continued to smoke had the highest levels of BoEs. THP or EC use over a 5-day period resulted in significant reductions in exposure to smoke toxicants, in some cases to levels similar to those for nicotine cessation. These results show that on an exposure continuum, nicotine cessation gives the greatest reduction in exposure to tobacco smoke toxicants, closely followed by the EC and the glo THP. These significant reductions in exposure to toxicants suggest that the glo THP and EC have the potential to be Reduced Risk Products. ISRCTN80651909.

Influence of Machine-Derived Smoke Yields on Biomarker of Exposure (BOE) Levels in Cigarette Smokers*

AbstractIndividual uptake of tobacco smoke constituents by smoking is highly variable in cigarette smokers and cannot be predicted by smoking behaviour variables and machine-derived smoke yields. It is well established that uptake of smoke constituents is best described by a series of bio-markers of exposure (BOEs) such as metabolites of nico-tine, tobacco-specific nitrosamines (TSNAs), polycyclic aromatic hydrocarbons (PAHs), aromatic amines, benzene, 1,3-butadiene, acrolein, hydrogen cyanide, 2,5-dimethyl-furan and other smoke constituents.The purpose of this review is to investigate the relationship between BOE levels and machine-derived smoking yields on the basis of published data. The influence of other smoking behaviour variables, in particular the number of cigarettes smoked per day (CPD) and smoking topography (puffing and inhalation patterns) is also considered, pro-vided suitable data are available.Twenty eight (28) published studies, which report data on machine-derived smoke yields and biomarker concentrations in body fluids of smokers of these products were identified. In total, 33 different BOEs were applied in these studies. Important properties of the BOEs used in the further evaluation were described and discussed. In almost all studies selected, data for CPD were reported. In only a few studies, puffing and inhalation profiles have been determined so that no systematic evaluation of the association between smoking topography and BOE levels was possible. In the studies evaluated, no statistically significant association between daily cigarette consumption (CPD) and smoke yields was observed. This clearly indicates that low machine-derived yields were not com-pensated by increasing the daily cigarette consumption. As expected, positive and statistically significant relationships were found between CPD and BOE levels for most of the biomarkers investigated.Bi- and multivariate linear regressions were calculated for the relationships between BOE levels (dependent variable) and machine-derived yields as well as CPD (independent variables). Whenever possible, results from various studies were combined (this was only possible, when identical biomarkers and yield types were available). Aggregation of the results from all studies independent of BOE and yield type used is feasible on the basis of relative BOE and yield levels. The multivariate linear regression models obtained reveal that both CPD and machine-derived yields are significant predictors of the measured BOE levels. The models predict that, on average, a 50% reduction in CPD or yield are accompanied by a 33 or 15% reduction, respectively, in smoke uptake, as measured by various BOEs. Taken together, the evaluated data from the literature show that lower machine-derived yields lead to a reduced uptake of smoke constituents. The reduction is statistically significant, but substantially lower than the decrease in machine-derived yields. [Beitr. Tabakforsch. Int. 26 (2014) 138-175]

Variability in biomarkers of exposure levels in smokers in a study of smokers switched to reduced toxicant prototype cigarettes

. Variability in biomarker of exposure levels in smokers in a study of smokers switched to reduced toxicant prototype cigarettes. Christopher J. Shepperd1, Alison Eldridge1, Graham Errington1, Oscar M Camacho1, Kevin McAdam1, Ingo Meyer2 and Christopher J. Proctor1* 1British American Tobacco, Group Research & Development, Regents Park Road, Southampton, SO15 8TL, United Kingdom 2Momentum Pharma Services, Hamburg, Germany *Correspondence: christopher_proctor@bat.com