Responses to Gradual and Immediate Reduction of Nicotine in Cigarettes in Young Versus Older Adult Smokers.

INTRODUCTION: As the FDA works to determine whether a nicotine reduction policy would benefit public health, one key question is whether to mandate an immediate or gradual reduction in nicotine levels in cigarettes. The aim of this study was to determine whether the effects of gradual versus immediate nicotine reduction on cigarettes per day (CPD), total nicotine equivalents, and subjective responses differed in younger adults versus older adults. METHODS: Using data from a recent randomized trial conducted in the United States (N = 1250) that switched smokers over a 20-week period to very low nicotine content (VLNC) cigarettes either immediately, gradually (via monthly reductions in nicotine content), or not at all (control condition, normal nicotine content research cigarette), we analyzed the moderating effect of age (age 18-24 or 25+). RESULTS: For both age groups, CPD in the immediate condition was significantly lower relative to gradual condition (estimated mean difference of 6.3 CPD in young adults, 5.2 CPD in older adults; p's < .05). Younger and older adults in the immediate and gradual reduction conditions had lower total nicotine equivalents at Week 20 (all p's < .05) than those in the control condition; age group did not moderate this effect. Positive subjective responses to cigarettes were lower among young adults relative to older adults in the immediate condition. CONCLUSIONS: These results indicate that an immediate reduction in nicotine would result in beneficial effects in both young and older adults. Young adults show less positive subjective effects of smoking following switching to VLNC cigarettes relative to older adults. IMPLICATIONS: As researchers work to understand how a potential reduced-nicotine product standard for cigarettes may affect public health, one question is whether nicotine should be reduced immediately or gradually. This study demonstrates that both young and older adults who were switched immediately to the lowest content of nicotine smoked fewer CPD and had lower nicotine intake than those in the gradual condition. Furthermore, young adults appear to show lower positive subjective effects following switching to VLNC cigarettes relative to older adults. This is consistent with previous work demonstrating that young people appear to show lower abuse liability for VLNC cigarettes.

Urinary Cyanoethyl Mercapturic Acid, a Biomarker of the Smoke Toxicant Acrylonitrile, Clearly Distinguishes Smokers From Nonsmokers.

INTRODUCTION: Cyanoethyl mercapturic acid (CEMA) is a urinary metabolite of acrylonitrile, a toxicant found in substantial quantities in cigarette smoke, but not in non-combusted products such as e-cigarettes or smokeless tobacco and rarely in the diet or in the general human environment. Thus, we hypothesized that CEMA is an excellent biomarker of combusted tobacco product use. AIMS AND METHODS: We tested this hypothesis by analyzing CEMA in the urine of 1259 cigarette smokers (urinary cotinine ≥25 ng/mL) and 1191 nonsmokers. The analyses of CEMA and cotinine were performed by validated liquid chromatography-tandem mass spectrometry methods. Logistic regression was fit for log-transformed CEMA to construct the receiver operating characteristic curve. RESULTS: We found that a CEMA cutpoint of 27 pmol/mL urine differentiated cigarette smokers from nonsmokers with sensitivity and specificity greater than 99%. The use of different cotinine cutpoints to define smokers (10-30 ng/mL) had little effect on the results. CONCLUSIONS: CEMA is a highly reliable urinary biomarker to identify users of combusted tobacco products such as cigarettes as opposed to users of non-combusted products, medicinal nicotine, or nonusers of tobacco products. IMPLICATIONS: CEMA can be used to distinguish users of combusted tobacco products from non-combusted products such as e-cigarettes, smokeless tobacco, and medicinal nicotine. Levels of CEMA in the urine of people who use these non-combusted products are extremely low, in contrast to cotinine.

Cigarette Smokers Versus Cousers of Cannabis and Cigarettes: Exposure to Toxicants.

INTRODUCTION: Cannabis and tobacco couse is common and could expose users to higher levels of toxicants. No studies have examined biomarkers of toxicant exposure in cousers of cannabis and cigarettes, compared with cigarette smokers (CS). AIMS AND METHODS: Adult daily CS were recruited from 10 US sites for a study of reduced nicotine cigarettes. In this analysis of baseline data, participants were categorized as either cousers of cannabis and tobacco (cousers; N = 167; urine positive for 11-nor-9-carboxy-Δ 9-tetrahydrocannnabinol and self-reported cannabis use ≥1×/week), or CS (N = 911; negative urine and no self-reported cannabis use). Participants who did not meet either definition (N = 172) were excluded. Self-reported tobacco and cannabis use and tobacco and/or combustion-related biomarkers of exposure were compared between groups. RESULTS: Compared to CS, cousers were younger (couser Mage = 38.96, SD = 13.01; CS Mage = 47.22, SD = 12.72; p < .001) and more likely to be male (cousers = 67.7%, CS = 51.9%, p < .001). There were no group differences in self-reported cigarettes/day, total nicotine equivalents, or breath carbon monoxide, but cousers had greater use of non-cigarette tobacco products. Compared to CS, cousers had higher concentrations of 3-hydroxypropylmercapturic acid, 2-cyanoethylmercapturic acid, S-phenylmercapturic acid, 3-hydroxy-1-methylpropylmercapturic acid (ps < .05), and phenanthrene tetraol (p < .001). No biomarkers were affected by number of cannabis use days/week or days since last cannabis use during baseline (ps > .05). CONCLUSIONS: Cousers had higher concentrations of biomarkers of exposure than CS, but similar number of cigarettes per day and nicotine exposure. Additional studies are needed to determine whether cannabis and/or alternative tobacco products are driving the increased toxicant exposure. IMPLICATIONS: Cousers of cannabis and tobacco appear to be exposed to greater levels of harmful chemicals (ie, volatile organic compounds and polycyclic aromatic hydrocarbons), but similar levels of nicotine as CS. It is unclear if the higher levels of toxicant exposure in cousers are due to cannabis use or the increased use of alternative tobacco products compared with CS. It is important for studies examining biomarkers of exposure among CS to account for cannabis use as it may have a significant impact on outcomes. Additionally, further research is needed examining exposure to harmful chemicals among cannabis users.

Very Low Nicotine Content Cigarettes Disrupt the Feedback Loop of Affective States and Smoking Behavior.

INTRODUCTION: Smoking to reduce negative affect has been identified as a key motivational feature of tobacco use. Our recent work suggests that smoking very low nicotine content (VLNC) cigarettes reduces the relationship between negative affect and smoking behavior over a 6-week period. Here, we sought to extend our findings by evaluating whether a gradual or immediate approach to switching to VLNC cigarettes led to a differential reduction in the relationship between affect and smoking behavior over a longer (20-week) period. AIMS AND METHODS: Participants (n = 1250) were adult smokers from 10 US sites randomized to one of three groups: gradual nicotine reduction (15.5, 11.7, 5.2, 2.4, and 0.4 mg of nicotine per gram of tobacco [mg/g]), immediate nicotine reduction (0.4 mg/g), or standard nicotine content cigarettes (15.5 mg/g; control), for 20 weeks. We examined whether the relationship between affect-both negative and positive-and cigarettes per day differed as a function of reduction group. RESULTS: We found that both negative and positive affect were associated with cigarette consumption in the control group, but not in the gradual or immediate reduction groups across the 20 weeks of exposure. CONCLUSIONS: Our results extend previous findings that switching to VLNC cigarettes disrupts the relationship between affect and cigarette consumption by showing that either gradually or immediately reducing cigarette nicotine content achieves this disruption. These findings provide further evidence that switching to VLNC cigarettes reduces nicotine-related reinforcement of cigarette smoking. IMPLICATIONS: These findings support the notion that switching to very low nicotine content cigarettes reduces the association between affect and smoking behavior, and that either a gradual or immediate nicotine reduction approach achieves this reduction. This provides further evidence that switching to very low nicotine content cigarettes weakens reinforcement mechanisms associated with nicotine dependence.

A Randomized Clinical Trial Examining the Effects of Instructions for Electronic Cigarette Use on Smoking-Related Behaviors and Biomarkers of Exposure.

INTRODUCTION: Electronic cigarettes (e-cigarettes) have the potential to significantly reduce exposure to harmful constituents associated with cigarette smoking when smokers completely substitute cigarettes with e-cigarettes. This study examined patterns of e-cigarette and cigarette use, and extent of toxicant exposure, if smokers were instructed and incentivized to completely switch to e-cigarettes compared to instructions to use the product ad libitum. AIMS AND METHODS: US adult daily smokers (n = 264; 49.2% female; Mage = 47.0), uninterested in quitting smoking immediately, were recruited from Minneapolis, MN, Columbus, OH, and Buffalo, NY. Participants were randomized to 8 weeks of instructions for (1) ad libitum use of e-cigarettes (AD-E), (2) complete substitution of cigarettes with e-cigarettes (CS-E), (3) complete substitution of cigarettes with nicotine gum or lozenge (CS-NRT), or (4) continue smoking of usual brand cigarettes (UB). Participants were incentivized for protocol compliance, including complete switching in the CS-E and CS-NRT groups. Outcome variables were cigarette smoking rate and tobacco-related biomarkers of exposure. RESULTS: Smokers in the CS-E and CS-NRT groups showed lower rates of smoking and lower exposure to carbon monoxide, tobacco carcinogens, and other toxicants than smokers in the AD-E group. In general, no significant differences were observed between CS-E versus CS-NRT or between AD-E versus UB for most biomarkers. Significantly higher 7-day point prevalence smoke-free rates were observed for CS-E versus CS-NRT. CONCLUSIONS: Smokers instructed and incentivized to completely switch to e-cigarettes resulted in lower smoking rates and greater reductions in exposures to harmful chemicals than smokers instructed to use the product ad libitum. IMPLICATIONS: Smokers instructed to completely substitute e-cigarettes for cigarettes displayed significantly lower levels of smoking and biomarkers of exposure to carcinogens and toxicants, compared to smokers instructed to use e-cigarettes ad libitum and similar levels as smokers instructed to completely substitute with nicotine replacement therapies. Furthermore, a higher rate of complete switching was achieved with e-cigarettes versus nicotine replacement therapies. Approaches to maximize complete substitution with e-cigarettes are an important area for future research.

Effects of Very Low Nicotine Content Cigarettes on Smoking Behavior and Biomarkers of Exposure in Menthol and Non-menthol Smokers.

INTRODUCTION: Because 30% of cigarettes sold in the United States are characterized as menthol cigarettes, it is important to understand how menthol preference may affect the impact of a nicotine reduction policy. METHODS: In a recent trial, non-treatment-seeking smokers were randomly assigned to receive very low nicotine cigarettes (VLNC; 0.4 mg nicotine/g tobacco) or normal nicotine cigarettes (NNC; 15.5 mg/g) for 20 weeks. On the basis of preference, participants received menthol or non-menthol cigarettes. We conducted multivariable regression analyses to examine whether menthol preference moderated the effects of nicotine content on cigarettes per day (CPD), breath carbon monoxide (CO), urinary total nicotine equivalents (TNE), urinary 2-cyanoethylmercapturic acid (CEMA), and abstinence. RESULTS: At baseline, menthol smokers (n = 346) reported smoking fewer CPD (14.9 vs. 19.2) and had lower TNE (52.8 vs. 71.6 nmol/mg) and CO (17.7 vs. 20.5 ppm) levels than non-menthol smokers (n = 406; ps < .05). At week 20, significant interactions indicated that menthol smokers had smaller treatment effects than non-menthol smokers for CPD (-6.4 vs. -9.3), TNE (ratio of geometric means, 0.22 vs. 0.10) and CEMA (ratio, 0.56 vs. 0.37; ps < .05), and trended toward a smaller treatment effect for CO (-4.5 vs. -7.3 ppm; p = .06). Odds ratios for abstinence at week 20 were 1.88 (95% confidence interval [CI] = 0.8 to 4.4) for menthol and 9.11 (95% CI = 3.3 to 25.2) for non-menthol VLNC smokers (p = .02) relative to the NNC condition. CONCLUSIONS: Although menthol smokers experienced reductions in smoking, toxicant exposure, and increases in quitting when using VLNC cigarettes, the magnitude of change was smaller than that observed for non-menthol smokers. IMPLICATIONS: Results of this analysis suggest that smokers of menthol cigarettes may respond to a nicotine reduction policy with smaller reductions in smoking rates and toxicant exposure than would smokers of non-menthol cigarettes.

Effect of Immediate vs Gradual Reduction in Nicotine Content of Cigarettes on Biomarkers of Smoke Exposure: A Randomized Clinical Trial.

Importance: The optimal temporal approach for reducing nicotine to minimally or nonaddictive levels in all cigarettes sold in the United States has not been determined. Objectives: To determine the effects of immediate vs gradual reduction in nicotine content to very low levels and as compared with usual nicotine level cigarettes on biomarkers of toxicant exposure. Design, Setting, and Participants: A double-blind, randomized, parallel-design study with 2 weeks of baseline smoking and 20 weeks of intervention was conducted at 10 US sites. A volunteer sample of daily smokers with no intention to quit within 30 days was recruited between July 2014 and September 2016, with the last follow-up completed in March 2017. Interventions: (1) Immediate reduction to 0.4 mg of nicotine per gram of tobacco cigarettes; (2) gradual reduction from 15.5 mg to 0.4 mg of nicotine per gram of tobacco cigarettes with 5 monthly dose changes; or (3) maintenance on 15.5 mg of nicotine per gram of tobacco cigarettes. Main Outcomes and Measures: Between-group differences in 3 co-primary biomarkers of smoke toxicant exposure: breath carbon monoxide (CO), urine 3-hydroxypropylmercapturic acid (3-HPMA, metabolite of acrolein), and urine phenanthrene tetraol (PheT, indicator of polycyclic aromatic hydrocarbons) calculated as area under the concentration-time curve over the 20 weeks of intervention. Results: Among 1250 randomized participants (mean age, 45 years; 549 women [44%]; 958 [77%] completed the trial), significantly lower levels of exposure were observed in the immediate vs gradual reduction group for CO (mean difference, -4.06 parts per million [ppm] [95% CI, -4.89 to -3.23]; P < .0055), 3-HPMA (ratio of geometric means, 0.83 [95% CI, 0.77 to 0.88]; P < .0055), and PheT (ratio of geometric means, 0.88 [95% CI, 0.83 to 0.93]; P < .0055). Significantly lower levels of exposure were observed in the immediate reduction vs control group for CO (mean difference, -3.38 [95% CI, -4.40 to -2.36]; P < .0055), 3-HPMA (ratio of geometric means, 0.81 [95% CI, 0.75 to 0.88]; P < .0055), and PheT (ratio of geometric means, 0.86 [95% CI, 0.81 to 0.92]; P < .0055). No significant differences were observed between the gradual reduction vs control groups for CO (mean difference, 0.68 [95% CI, -0.31 to 1.67]; P = .18), 3-HPMA (ratio of geometric means, 0.98 [95% CI, 0.91 to 1.06]; P = .64), and PheT (ratio of geometric means, 0.98 [95% CI, 0.92 to 1.04]; P = .52). Conclusions and Relevance: Among smokers, immediate reduction of nicotine in cigarettes led to significantly greater decreases in biomarkers of smoke exposure across time compared with gradual reduction or a control group, with no significant differences between gradual reduction and control. Trial Registration: clinicaltrials.gov Identifier: NCT02139930.

Perceived Health Risks of Snus and Medicinal Nicotine Products.

INTRODUCTION: Perceived health risk (PHR) of a tobacco product may influence both uptake and continued use. In this study, we examined PHRs of snus and medicinal nicotine using the PHR scale and the relationship of PHR responses to use of these products in smokers seeking an alternative to smoking. METHODS: Smokers were randomly assigned to snus or to medicinal nicotine for a period of 12 weeks and asked to only use the assigned product. The PHR scale involves rating the extent of perceived risk of a product for different diseases and was given at baseline and weeks 4 and 12 during treatment. Relationships between PHR scale scores and study attrition, compliance with only using the product, and continued use of the product after treatment were determined. RESULTS: Response to the PHR scale showed no significant differences between the snus and medicinal nicotine for perceived risks for lung cancer, emphysema, and bronchitis. However, significant differences were observed for other cancers, heart disease, stroke and risk for addiction, particularly after product use, with higher scores among those assigned to snus. Scores on the PHR scale were not related to any of the trial outcome variables. CONCLUSIONS: Among smokers seeking an alternative to smoking in a clinic setting, PHR of a product changes after product use but may not be related to product use patterns. IMPLICATIONS: PHRs of snus or medicinal nicotine in smokers assigned to these products become more accurate after product use. PHR does not appear to be associated with patterns of product use; rather satisfaction with a product is a better indicator as to whether a smoker is compliant with only using the product or continues to use the product.

Measurement of the Heterocyclic Amines 2-Amino-9H-pyrido[2,3-b]indole and 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in Urine: Effects of Cigarette Smoking.

2-Amino-9H-pyrido[2,3-b]indole (AαC) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) are carcinogenic heterocyclic aromatic amines (HAAs) formed during the combustion of tobacco and during the high-temperature cooking of meats. Human enzymes biotransform AαC and PhIP into reactive metabolites, which can bind to DNA and lead to mutations. We sought to understand the relative contribution of smoking and diet to the exposure of AαC and PhIP, by determining levels of AαC, its ring-oxidized conjugate 2-amino-9H-pyrido[2,3-b]indole-3-yl sulfate (AαC-3-OSO3H), and PhIP in urine of smokers on a free-choice diet before and after a six week tobacco smoking cessation study. AαC and AαC-3-OSO3H were detected in more than 90% of the urine samples of all subjects during the smoking phase. The geometric mean levels of urinary AαC during the smoking and cessation phases were 24.3 pg/mg creatinine and 3.2 pg/mg creatinine, and the geometric mean levels of AαC-3-OSO3H were 47.3 pg/mg creatinine and 3.7 pg/mg creatinine. These decreases in the mean levels of AαC and AαC-3-OSO3H were, respectively, 87% and 92%, after the cessation of tobacco (P < 0.0007). However, PhIP was detected in <10% of the urine samples, and the exposure to PhIP was not correlated to smoking. Epidemiological studies have reported that smoking is a risk factor for cancer of the liver and gastrointestinal tract. It is noteworthy that AαC is a hepatocellular carcinogen and induces aberrant crypt foci, early biomarkers of colon cancer, in rodents. Our urinary biomarker data demonstrate that tobacco smoking is a significant source of AαC exposure. Further studies are warranted to examine the potential role of AαC as a risk factor for hepatocellular and gastrointestinal cancer in smokers.

Reduced nicotine in cigarettes in a marketplace with alternative nicotine systems: randomized clinical trial.

Background: Reducing cigarette addictiveness has the potential to avert millions of yearly tobacco-related deaths worldwide. Substantially reducing nicotine in cigarettes decreases cigarette consumption, but no large clinical trial has determined the effects of reduced-nicotine cigarettes when other nicotine-containing products are available. The aim of this study was to examine the effects of reduced-nicotine cigarettes in the context of the availability of alternative nicotine delivery systems. Methods: In a U.S. six-site, open-label, parallel-arm study, smokers were randomized for twelve weeks to an experimental marketplace containing cigarettes with either 0.4 mg or 15.8 mg nicotine per gram of tobacco; all had access to non-combusted alternative nicotine delivery systems (e.g., e-cigarettes; medicinal nicotine). Group differences in the primary outcomes (cigarettes per day, number of smoke-free days) were examined using linear and negative binomial regression, respectively (Trial Registration: NCT03272685). Findings: Among 438 randomized participants (mean [standard deviation (SD), range] age, 44.5 [11.9, 20-73] years, 225 [51.4%] women, 282 [64.4%] White and 339 [77.4%] trial completers), those in the 0.4 mg vs. 15.8 mg nicotine cigarette condition experienced significantly lower cigarettes per day at the end of intervention (mean [SD], 7.05 [7.88] vs. 12.95 [9.07], adjusted mean difference, -6.21 [95% CI, -7.66 to -4.75], P < 0.0001) and greater smoke-free days during intervention (mean [SD], 18.59 [27.97] vs. 5.06 [13.77], adjusted rate ratio, 4.25 [95% CI, 2.58-6.98], P < 0.0001). Interpretation: A reduced-nicotine cigarette standard in the context of access to other non-combusted nicotine products has the potential to benefit public health. Funding: U.S. NIH/FDA U54DA03165.

Flavored and nonflavored smokeless tobacco products: rate, pattern of use, and effects.

INTRODUCTION: The initiation and maintenance of tobacco use are influenced by several factors, but of equal and often overlooked importance, until recently, is the palatability of the product. Because of the role that flavor may play in the initiation and maintenance of tobacco use, the Food and Drug Administration has decided to ban the use of flavorings, other than menthol, from cigarettes. To date, little attention has been paid to the impact of flavoring in smokeless tobacco (ST) products. METHODS: This study combined the data from 5 previously completed treatment or switching studies to examine the choice of brand flavor in the course of ST use, from initiation to regular use. RESULTS: The analyses revealed that a majority of subjects' first and current choice of product was flavored, specifically mint or wintergreen, and that a significant number of ST users switched to a flavored brand after already initiating ST use with a regular nonflavored product. In this population, however, flavored products did not appear to lead to greater dependence or increased exposure to nicotine or carcinogens. CONCLUSIONS: More treatment seeking ST users began by using mint-flavored product and switched to and were current users of mint-flavored products. It is possible that mint products play a role in the initiation and maintenance of ST use.

Time course of DNA adduct formation in peripheral blood granulocytes and lymphocytes after drinking alcohol.

Alcohol consumption is an established risk factor for cancers of the head and neck, colorectum, liver and female breast. Acetaldehyde, the primary metabolite of ethanol, is suspected to play a major role in alcohol-related carcinogenesis. Acetaldehyde binds to DNA resulting in formation of adducts. DNA adducts are involved in mutagenesis and carcinogenesis. N (2)-Ethylidenedeoxyguanosine (N (2)-ethylidene-dGuo) is the major adduct formed in this reaction. Studies have shown an association between alcohol drinking and levels of this DNA adduct, suggesting its potential use as a biomarker for studying alcohol-related carcinogenesis. However, there are no reports on the kinetics of formation and repair of N (2)-ethylidene-dGuo after alcohol consumption. Therefore, we investigated levels of N (2)-ethylidene-dGuo in DNA from human peripheral blood cells at several time points after consumption of increasing doses of alcohol. Ten healthy non-smokers were recruited and asked to abstain from alcohol consumption except for the study doses. The subjects were given measured doses of alcohol once a week for 3 weeks, targeting increasing blood alcohol levels. Blood was collected at several time points before and after each dose, DNA was isolated from granulocytes and lymphocytes and N (2)-ethylidene-dGuo was quantified as its NaBH(3)CN reduction product N ( 2 )-ethyldeoxyguanosine by liquid chromatography-electrospray ionisation-tandem mass spectrometry. Significant increases in N (2)-ethylidene-dGuo were observed after all doses and in both cell types. However, there was substantial intraindividual variability, indicating that there are other important sources of this adduct in peripheral blood DNA. Further studies are needed to better understand the origins of N (2)-ethylidene-dGuo in blood cells, the exposures it reflects, and thus its potential use as a marker of alcohol's genotoxic effects.

Comparing an immediate cessation versus reduction approach to smokeless tobacco cessation.

INTRODUCTION: Relatively few studies have investigated pharmacological or behavioral treatment of smokeless tobacco (ST) users who do not have immediate quit plans. In this study, we compared a reduction treatment approach with an immediate cessation approach in a population of ST users who reported no immediate plans to quit. METHODS: Subjects randomly assigned to the immediate cessation condition set a quit date soon after enrollment and were offered 2 weeks of nicotine patch therapy to help in their cessation efforts. Subjects assigned to the ST reduction group were provided with their choice of either 4 mg nicotine lozenge or ST brand switching to help them reduce their ST use or levels of nicotine exposure, respectively. Quit date was 6 weeks after the onset of treatment. Follow-up was at 12 weeks and 26 weeks postenrollment and 26 weeks postquit. RESULTS: Both 7-day point prevalence abstinence and prolonged abstinence rates following the quit date were significantly higher in the immediate cessation group versus the reduction group at 12 and 26 weeks (all p values ≤ .04) and for prolonged abstinence at 6 months postquit (p = .002). Significant reductions in ST use among nonquitters were observed for both groups (p < .0001) with no differences between groups. CONCLUSION: Our study demonstrated that immediate cessation with an established quit date resulted in greater cessation success than a gradual reduction approach among ST users who do not have an immediate quit plan but are motivated to quit.

Support for a nicotine reduction policy among participants enrolled in a 20-week trial of very low nicotine content cigarettes.

INTRODUCTION: The Food and Drug Administration is considering a policy to drastically reduce the allowable nicotine content of cigarettes. The current study examined whether the policy implementation approach, i.e., either immediately reducing nicotine content to very low levels or gradually reducing nicotine content over an extended period, influences policy support among people who smoke cigarettes. METHODS: Adults who smoked daily were randomly assigned (double-blind) to an immediate nicotine reduction condition (0.4 mg/g nicotine cigarettes), a gradual nicotine reduction condition (15.5 to 0.4 mg/g), or a control condition (15.5 mg/g) for 20 weeks. Participants were asked if they would "support or oppose a law that reduced the amount of nicotine in cigarettes, to make cigarettes less addictive." Logistic regression analyses assessed if policy support was affected by treatment condition, demographic covariates, interest in quitting, and subjective cigarette effects. RESULTS: At Week 20 (N = 957 completers), 60.4% of participants supported the policy, 17.4% opposed, and 22.2% responded "Don't know." Policy support did not differ by treatment condition. Support was greater among those interested in quitting (OR = 3.37, 95% CI = 2.49, 4.55). Support was lower among males (OR = 0.49, 95% CI = 0.37, 0.67), those with greater dependence scores (OR = 0.92, 95% CI = 0.86, 0.99) and participants aged 18-24 (OR = 0.53, 95% CI = 0.28, 0.99). No other covariates were associated with policy support. CONCLUSIONS: The majority of participants supported a nicotine reduction policy. The implementation approach, immediate or gradual reduction, did not affect policy support. Participants interested in quitting smoking were more likely to support a nicotine reduction policy.

Effects of cessation of cigarette smoking on eicosanoid biomarkers of inflammation and oxidative damage.

The urinary metabolites "prostaglandin E2 metabolite" (PGE-M) and (Z)-7-[1R,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-1-enyl]cyclopentyl]hept-5-enoic acid (8-iso-PGF2α) are biomarkers of inflammation and oxidative damage, respectively, and are elevated in cigarette smokers. Relatively little is known about the effects of smoking cessation on these biomarkers. To investigate this, current cigarette smokers interested in quitting were recruited and invited to participate in a smoking cessation study where varenicline (Chantix) and brief supportive behavioral counseling were offered at each visit after baseline. Subjects returned to the clinic during the 12 week treatment phase for 9 visits post cessation on days 3, 7, 14, 21, 28, 42, 56, 70 and 84. Urine samples were collected at each visit and analyzed by liquid chromatography-tandem mass spectrometry for PGE-M, 8-iso-PGF2α, and cotinine. Cotinine values demonstrated that 15 of 38 subjects quit smoking for the entire 84 day period. Significant decreases in mean levels of PGE-M and 8-iso-PGF2α per milligram creatinine were observed in these subjects, by 44% (p = 0.0014) and 27% (p<0.001), respectively. The results of this study demonstrate that cessation of smoking for 84 days results in modest but significant declines in urinary PGE-M and 8-iso-PGF2α indicating reductions in systemic inflammation and oxidative damage. Given that levels were only modestly decreased, these markers are not specific to tobacco-smoke exposure. The modest declines in these biomarkers should be considered when planning studies with ex-smokers. There is a "hangover" from smoking that lasts at least 3 months.

Quantitation of metabolites of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone after cessation of smokeless tobacco use.

Two major metabolites of the tobacco-specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were previously shown to be highly persistent in human urine after cessation of cigarette smoking. We hypothesized that NNK or its metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), was sequestered in the lung. In this study, we further evaluated this hypothesis by quantifying the NNK metabolites, NNAL and its glucuronides (NNAL-Gluc), in urine and plasma after cessation of smokeless tobacco use, in which NNK is administered p.o. rather than by inhalation. Thirteen male nonsmokers, 11 snuff dippers and 2 tobacco chewers, participated in the study. Urine and plasma were obtained at baseline and at intervals 2-126 days after cessation of smokeless tobacco use. The distribution half-lives t(1/2alpha) (days) of NNAL (1.32 +/- 0.85 versus 3.35 +/- 1.86) and NNAL-Gluc (1.53 +/- 1.22 versus 3.89 +/- 2.43) were significantly shorter in smokeless tobacco users than in smokers. There were no significant differences in the terminal half-lives t(1/2beta) (days) of NNAL (26.3 +/- 16.7 versus 45.2 +/- 26.9) and NNAL-Gluc (26.1 +/- 15.1 versus 39.6 +/- 26.0) in smokeless tobacco users and smokers. Baseline levels as well as renal clearance of the NNK metabolites correlated with number of tins or pouches of smokeless tobacco consumed. Ratios of (S)-NNAL:(R)-NNAL and (S)-NNAL-Gluc:(R)-NNAL-Gluc in urine were significantly (3.1-5.7 times) higher 7 days after cessation than at baseline in both smokeless tobacco users and smokers, indicating stereoselective retention of (S)-NNAL. Collectively, the results of this study suggest that there is a receptor in the human body, possibly in the lung, for (S)-NNAL, the more carcinogenic NNAL enantiomer. These data may have considerable implications for understanding mechanisms of tumor induction by NNK.

Evidence supporting product standards for carcinogens in smokeless tobacco products.

Smokeless tobacco products sold in the United States vary significantly in yields of nicotine and tobacco-specific nitrosamines (TSNA). With the passage of the Family Smoking Prevention and Tobacco Control Act, the Food and Drug Administration now has the authority to establish product standards. However, limited data exist determining the relative roles of pattern of smokeless tobacco use versus constituent levels in the smokeless tobacco product in exposure of users to carcinogens. In this study, smokeless tobacco users of brands varying in nicotine and TSNA content were recruited from three different regions in the U.S. Participants underwent two assessment sessions. During these sessions, demographic and smokeless tobacco use history information along with urine samples to assess biomarkers of exposure and effect were collected. During the time between data collection, smokeless tobacco users recorded the amount and duration of smokeless tobacco use on a daily basis using their diary cards. Results showed that independent of pattern of smokeless tobacco use and nicotine yields, levels of TSNA in smokeless tobacco products played a significant role in carcinogen exposure levels. Product standards for reducing levels of TSNA in smokeless tobacco products are necessary to decrease exposure to these toxicants and potentially to reduce risk for cancer.

Reduced nicotine content cigarettes and nicotine patch.

BACKGROUND: Reduced nicotine content (RNC) cigarettes have led to smoking fewer cigarettes, withdrawal relief, and facilitation of cessation. The aim of this study is to examine the effects RNC cigarettes with and without nicotine patch and patch alone on smoking behavior, toxicant exposure, withdrawal discomfort, and as an exploratory analysis, on long-term abstinence. METHODS: This study involved a randomized, parallel arm design and six weeks of: (i) 0.05-0.09 mg nicotine yield cigarettes (N = 79); (ii) 21 mg nicotine patch (N = 80), or (iii) 0.05-0.09 nicotine yield cigarettes with 21 mg nicotine patch (N = 76); all groups received six weeks of additional behavioral treatment with follow-ups up to six months. RESULTS: Combination approach led to lower rates of smoking assigned cigarettes and hence lower carbon monoxide levels than RNC cigarettes alone. In addition, the combination approach was associated with less withdrawal severity when switching from usual brand to assigned product, and less smoking of usual brand cigarettes during treatment, but not after treatment compared with the other approaches. CONCLUSION: Combining very low nicotine content cigarettes with nicotine patch may improve the acute effects resulting from switching to either of these products alone. IMPACT: These findings may have implications for smoking cessation treatment or a policy measure to reduce nicotine content in cigarettes.

Kinetics of DNA adduct formation in the oral cavity after drinking alcohol.

BACKGROUND: Alcohol consumption is one of the top 10 risks for the worldwide burden of disease and an established cause of head and neck cancer, as well as cancer at other sites. Acetaldehyde, the major metabolite of ethanol, reacts with DNA to produce adducts, which are critical in the carcinogenic process and can serve as biomarkers of exposure and, possibly, of disease risk. Acetaldehyde associated with alcohol consumption is considered "carcinogenic to humans." We have previously developed the technology to quantify acetaldehyde-DNA adducts in human tissues, but there are no studies in the literature defining the formation and removal of acetaldehyde-DNA adducts in people who consumed alcohol. METHODS: We investigated levels of N(2)-ethylidene-dGuo, the major DNA adduct of acetaldehyde, in DNA from human oral cells at several time points after consumption of increasing alcohol doses. Ten healthy nonsmokers were dosed once a week for three weeks. Mouthwash samples were collected before and at several time points after the dose. N(2)-Ethylidene-dGuo was measured as its NaBH(3)CN reduction product N(2)-ethyl-dGuo by liquid chromatography-electrospray-tandem mass spectrometry. RESULTS: N(2)-ethylidene-dGuo levels increased as much as 100-fold from baseline within 4 hours after each dose for all subjects and in a dose-responsive manner (P = 0.001). CONCLUSION: These results show an effect of alcohol on oral cell DNA adduct formation, strongly supporting the key role of acetaldehyde in head and neck cancer caused by alcohol drinking. IMPACT: Our results provide some of the first conclusive evidence linking exposure to a lifestyle carcinogen and kinetics of DNA adduct formation in humans.

Effect of oral snus and medicinal nicotine in smokers on toxicant exposure and withdrawal symptoms: a feasibility study.

BACKGROUND: Smokeless, spitless tobacco products are being introduced and marketed as cigarette substitutes. Data are needed regarding how smokers interested in cessation would use these products, the levels of resultant toxicant exposure, and the feasibility of using these products as aids for tobacco cessation. METHODS: Smokers were randomized to receive Camel Snus (n = 51), Taboka (n = 52), or medicinal nicotine (n = 27) and required to quit smoking for 4 weeks. Measures of toxicant exposure and symptoms of craving and withdrawal were assessed prior to and during product use. RESULTS: Concentrations of exhaled carbon monoxide, urinary cotinine, urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL), and urinary N'-nitrosonornicotine and its glucuronide (total NNN) were significantly (P values <0.05) lower at the end of treatment in each group except for total NNN in those receiving Camel Snus (P = 0.066). A significant group × time effect was observed for total NNAL concentrations (P = 0.002) with the decrease greatest in the medicinal nicotine group and smallest decrease in the Camel Snus group. No significant differences between groups were found in craving and withdrawal symptoms. CONCLUSIONS: Enrolling smokers into a cessation study utilizing newer smokeless tobacco products is feasible. Camel Snus and Taboka use was not found to be superior to medicinal nicotine in reducing withdrawal symptoms but decreases in NNAL were smaller in users of Camel Snus. IMPACT: This study demonstrates the feasibility of conducting a smoking cessation study utilizing these newer tobacco products. An appropriately powered study is needed to assess smoking cessation rates using these newer products compared with established, safer products such as medicinal nicotine.