Biomarkers of Exposure and Potential Harm in Two Weeks of Smoking Abstinence: Changes in Biomarkers of Platelet Function, Oxidative Stress, and Inflammation.

: Chronic cigarette smoking is a major risk factor for many serious diseases. While complete cessation of smoking is the best option to reduce harm from smoking, adverse impacts of smoking on health could persist for several years after cessation. Therefore, Biomarkers of Potential Harm (BoPH) are useful in interim evaluations of the beneficial effects of smoking cessation or switching to potentially lower-risk tobacco products. A 14-day smoking abstinence study was conducted under clinical confinement conditions and enrolled 70 subjects into younger (24-34 years, n = 33) and older (35-60 years, n = 37) age cohorts. Biomarkers of Exposure (BoE), which indicate exposure to nicotine and other toxicants, were measured at baseline, 7 and 14 days. Several BoPH including previously identified eicosanoids (leukotriene 4 (LTE4) and 2,3-dinor thromboxane 2 (2,3-d-TXB2) and others were evaluated. Significant declines in BoE, LTE4, 2,3-d-TXB2, neutrophils, WBC and select RBC, and arterial blood gas parameters were observed in both age cohorts at Days 7 and 14 compared to baseline, while other BoPH (e.g., FeNO) showed age-related effects. Rapid and reproducible reductions in LTE4, 2,3-d-TXB2 WBC, and neutrophil counts were consistently detected following smoking abstinence, indicating the value of these markers as useful BoPH.

Inflammatory profile analysis reveals differences in cytokine expression between smokers, moist snuff users, and dual users compared to non-tobacco consumers.

OBJECTIVE AND DESIGN: The aim of this study is to investigate the inflammatory alterations due to the use of smokeless tobacco and dual use of smokeless tobacco and cigarettes, relative to smoking. SUBJECTS: Plasma and saliva samples were collected from healthy smokers (SMK-100 subjects), moist snuff users (MSC-89 subjects), the dual users (DUSMK-49 subjects), and non-tobacco consumers (NTC-99 subjects) from two cross-sectional studies. METHODS: Luminex Human InflammationMAP® 1.0 panel, a multiplex immunoassay. RESULTS: SMK and DUSMK exhibited larger number of alterations in the expression of inflammatory analytes compared to NTC. Eight analytes were significantly elevated (p ≤ .05) within plasma samples of SMK compared to NTC, while one 1 analyte was elevated between the MSC and NTC groups. DUSMK exhibited different levels of 11 analytes, relative to NTC. MSC displayed fewer alterations in inflammatory protein expression compared to smoker groups, and the inflammatory profile of MSC resembles NTC. Five analytes (ICAM-1, VEGF, MMP-9, ferritin and fibrinogen) emerged as potential biomarkers distinguishing tobacco consumers (p < .02). CONCLUSIONS: We identified a set of five proteins as potential biomarkers that can inform of inflammation status due to tobacco usage. Our findings contribute a better understanding of how the use of different tobacco products contributes to inflammation.

A cross-sectional study of biomarkers of exposure and effect in smokers and moist snuff consumers.

BACKGROUND: Cigarette smoking is a major risk factor for several chronic diseases. Epidemiological data indicate the use of smokeless tobacco (ST) is associated with significantly lower risk for smoking-related diseases compared to cigarettes. Several biomarkers of exposure (BioExp) and effect (BioEff) associated with smoking and use of moist snuff (ST) were evaluated. METHODS: A single site, cross-sectional clinical study enrolled three groups of generally healthy male smokers (SMK), moist snuff consumers (MSC), and non-tobacco consumers (NTC), and several BioExp and BioEff were evaluated. RESULTS: Blood and urinary BioExp, including total nicotine equivalents and tobacco-specific nitrosamines, were higher in MSC compared to SMK. Biomarkers of combustion-related toxicants and cadmium were elevated in SMK. Elevated levels of some BioEff associated with oxidative stress (urinary isoprostanes and leukotriene E4), inflammation (white blood cell count), platelet activation (thromboxane metabolites), and lipid metabolism (apolipoprotein B100 and oxidized low-density lipoprotein) were observed in SMK relative to NTC and MSC (all p<0.05). The non-smoking groups (MSC and NTC) showed similar levels of combustion-related BioExp and BioEff. CONCLUSIONS: Higher levels of exposure to nicotine and some N'-nitrosamines may be observed in MSC, and SMK are exposed to higher levels of combustion-related toxicants. Changes in BioEff consistent with some aspects of inflammation, oxidative stress, and altered lipid metabolism were detected in SMK compared to the non-smoking groups. The biomarker data further improve our understanding of pathophysiological changes and the risk continuum associated with various tobacco products, and could be useful components of future assessments of tobacco products.

Switching from usual brand cigarettes to a tobacco-heating cigarette or snus: Part 1. Study design and methodology.

A randomized, multi-center study was conducted to assess potential improvement in health status measures, as well as changes in biomarkers of tobacco exposure and biomarkers of biological effect, in current adult cigarette smokers switched to tobacco-heating cigarettes, snus or ultra-low machine yield tobacco-burning cigarettes (50/group) evaluated over 24 weeks. Study design, conduct and methodology are presented here along with subjects' disposition, characteristics, compliance and safety results. This design and methodology, evaluating generally healthy adult smokers over a relatively short duration, proved feasible. Findings from this randomized study provide generalized knowledge of the risk continuum among various tobacco products (ClinicalTrials.gov Identifier: NCT02061917).

Switching from usual brand cigarettes to a tobacco-heating cigarette or snus: Part 2. Biomarkers of exposure.

A randomized, multi-center study of adult cigarette smokers switched to tobacco-heating cigarettes, snus or ultra-low machine yield tobacco-burning cigarettes (50/group) was conducted, and subjects' experience with the products was followed for 24 weeks. Differences in biomarkers of tobacco exposure between smokers and never smokers at baseline and among groups relative to each other and over time were assessed. Results indicated reduced exposure to many potentially harmful constituents found in cigarette smoke following product switching. Findings support differences in exposure from the use of various tobacco products and are relevant to the understanding of a risk continuum among tobacco products (ClinicalTrials.gov Identifier: NCT02061917).

Switching from usual brand cigarettes to a tobacco-heating cigarette or snus: Part 3. Biomarkers of biological effect.

A randomized, multi-center study of adult cigarette smokers switched to tobacco-heating cigarettes, snus or ultra-low machine yield tobacco-burning cigarettes (50/group) for 24 weeks was conducted. Evaluation of biomarkers of biological effect (e.g. inflammation, lipids, hypercoaguable state) indicated that the majority of consistent and statistically significant improvements over time within each group were observed in markers of inflammation. Consistent and statistically significant differences in pairwise comparisons between product groups were not observed. These findings are relevant to the understanding of biomarkers of biological effect related to cigarette smoking as well as the risk continuum across various tobacco products (ClinicalTrials.gov Identifier: NCT02061917).

Study of cardiovascular disease biomarkers among tobacco consumers, part 2: biomarkers of biological effect.

An age-stratified, cross-sectional study was conducted in the US among healthy adult male cigarette smokers, moist snuff consumers, and non-tobacco consumers to evaluate cardiovascular biomarkers of biological effect (BoBE). Physiological assessments included flow-mediated dilation, ankle-brachial index, carotid intima-media thickness and expired carbon monoxide. Approximately one-half of the measured serum BoBE showed statistically significant differences; IL-12(p70), sICAM-1 and IL-8 were the BoBE that best differentiated among the three groups. A significant difference in ABI was observed between the cigarette smokers and non-tobacco consumer groups. Significant group and age effect differences in select biomarkers were identified.

Study of cardiovascular disease biomarkers among tobacco consumers. Part 3: evaluation and comparison with the US National Health and Nutrition Examination Survey.

Cardiovascular disease (CVD) biomarkers of biological effect (BoBE), including hematologic biomarkers, serum lipid-related biomarkers, other serum BoBE, and one physiological biomarker, were evaluated in adult cigarette smokers (SMK), smokeless tobacco consumers (STC), and non-consumers of tobacco (NTC). Data from adult males and females in the US National Health and Nutrition Examination Survey and a single site, cross-sectional study of healthy US males were analyzed and compared. Within normal clinical reference ranges, statistically significant differences were observed consistently for fibrinogen, C-reactive protein (CRP), hematocrit, mean cell volume, mean cell hemoglobin, hemoglobin, white blood cells, monocytes, lymphocytes, and neutrophils in comparisons between SMK and NTC; for CRP, white blood cells, monocytes, and lymphocytes in comparisons between SMK and STC; and for folate in comparisons with STC and NTC. Results provide evidence for differences in CVD BoBE associated with the use of different tobacco products, and provide evidence of a risk continuum among tobacco products and support for the concept of tobacco harm reduction.

Study of cardiovascular disease biomarkers among tobacco consumers, part 1: biomarkers of exposure.

A study was conducted to evaluate biomarkers of biological effect and physiological assessments related to cardiovascular disease (CVD) among adult male cigarette smokers (SMK), moist snuff consumers (MSC) and non-consumers of tobacco (NTC). Additionally, biomarkers of tobacco and tobacco smoke exposure (BoE) were measured in spot urines and are reported here. Except for the BoE to nicotine and NNK, BoE were generally greater in SMK compared with MSC, and BoE were generally not different in comparisons of MSC and NTC. Results demonstrated that MSC had lower systemic exposures to many harmful and potentially harmful constituents than SMK, which is consistent with epidemiological data that indicate a differential in CVD risk between these groups.

Part two: an unblinded, parallel, randomized study to assess nicotine pharmacokinetics of four Vuse Solo ENDS flavors in smokers.

We report the findings from a randomized, parallel study designed to evaluate nicotine pharmacokinetics (PK) following 10 min of ad libitum use of electronic nicotine delivery system (ENDS) in four flavor variants. Subjects were randomized an investigational product (IP) and blood samples were collected for PK assessments during a test session. Primary endpoints were baseline-adjusted values of maximum plasma nicotine concentration (Cmax) and area under the nicotine concentration-vs-time curve up to 60 min (AUCnic0-60). Baseline-adjusted mean Cmax ranged from 6.53 to 8.21 ng/mL, and mean AUCnic0-60 ranged from 206.87 to 263.52 ng min/mL for all ENDS IPs. Results of geometric mean Cmax and AUCnic0-60 values were within 95% confidence intervals (CI) among the ENDS IP flavor variants tested.

Part three: a randomized study to assess biomarker changes in cigarette smokers switched to Vuse Solo or Abstinence.

Biomarkers of exposure (BoE) can help evaluate exposure to combustion-related, tobacco-specific toxicants after smokers switch from cigarettes to potentially less-harmful products like electronic nicotine delivery systems (ENDS). This paper reports data for one (Vuse Solo Original) of three products evaluated in a randomized, controlled, confinement study of BoE in smokers switched to ENDS. Subjects smoked their usual brand cigarette ad libitum for two days, then were randomized to one of three ENDS for a 7-day ad libitum use period, or to smoking abstinence. Thirteen BoE were assessed at baseline and Day 5, and percent change in mean values for each BoE was calculated. Biomarkers of potential harm (BoPH) linked to oxidative stress, platelet activation, and inflammation were also assessed. Levels decreased among subjects randomized to Vuse Solo versus Abstinence, respectively, for the following BoE: 42-96% versus 52-97% (non-nicotine constituents); 51% versus 55% (blood carboxyhemoglobin); and 29% versus 96% (nicotine exposure). Significant decreases were observed in three BoPH: leukotriene E4, 11-dehydro-thromboxane B2, and 2,3-dinor thromboxane B2 on Day 7 in the Vuse Solo and Abstinence groups. These findings show that ENDS use results in substantially reduced exposure to toxicants compared to smoking, which may lead to reduced biological effects.

Pharmacodynamic and pharmacokinetic assessment of electronic cigarettes, combustible cigarettes, and nicotine gum: implications for abuse liability.

RATIONALE: Electronic cigarettes (ECs) are becoming popular alternatives for smokers, but there has been limited study of their abuse liability. OBJECTIVES: The objective of this study was to evaluate the abuse liability of three Vuse Solo ECs, ranging from 14 to 36 mg in nicotine content, relative to high- and low-abuse liability comparator products (usual brand combustible cigarettes and nicotine gum, respectively) in a group of 45 EC-naïve smokers. METHODS: Enrolled subjects' ratings of subjective effects and nicotine uptake over 6 h were used to measure abuse liability and pharmacokinetics following in-clinic use of each EC. RESULTS: Use of Vuse Solo resulted in subjective measures and nicotine uptake that were between those of combustible cigarettes and nicotine gum, although generally closer to nicotine gum. Compared to combustible cigarettes, use of Vuse Solo resulted in significantly lower scores in measures of product liking, positive effects, and intent to use again. These pharmacodynamic findings were consistent with the pharmacokinetic data, showing that cigarettes produced substantially faster and higher levels of nicotine uptake as compared to Vuse Solo and nicotine gum. Vuse Solo resulted in more rapid initial uptake of nicotine compared to nicotine gum, but peak concentration and long-term extent of uptake were not different or were lower with Vuse. CONCLUSIONS: Collectively, these findings suggest that Vuse Solo likely has an abuse liability that is somewhat greater than nicotine gum but lower than cigarettes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02269514.