Longer term exposure to secondhand smoke and health outcomes in COPD: impact of urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol

Association between biomarkers of tobacco smoke exposure and clinical efficacy of ivacaftor in the G551D observational trial (GOAL)

BACKGROUND

Acrolein, an aldehyde in smoke from tobacco products, inhibits CFTR function in vitro. Ivacaftor is an FDA-approved potentiator that improves mutant CFTR function. This human clinical study investigated the relationship between two urinary markers of tobacco smoke exposure - the acrolein metabolite 3-HPMA and the nicotine metabolite NNAL - and sweat chloride response to ivacaftor in the G551D Observational Trial (GOAL).

METHODS

3-HPMA (low: <50th centile; moderate: 50-75th centile; high: >75th centile) and NNAL (detectable/undetectable) in GOAL samples was quantified with LC-MS/MS. Self-report of tobacco smoke exposure (Y/N) served as a subjective measure. Change in sweat chloride from pre- to 6 months post-ivacaftor treatment (ΔSC) was the primary CFTR-dependent readout.

RESULTS

The sample included 151 individuals, mean age 20.7 (SD 11.4) years, range 6-59 years. Smoke exposure prevalence was 15 % per self-reports but 27 % based on detectable NNAL. 3-HPMA was increased in those reporting tobacco smoke exposure (607 vs 354 ng/ml, p = 0.008), with a higher proportion of smoke-exposed in the high- vs low-acrolein group (31 % vs 9 %, p=0.040). Compared to low-acrolein counterparts, high-acrolein participants experienced less decrease in sweat chloride (-35.2 vs -48.2 mmol/L; p = 0.020) and had higher sweat chloride values (50.6 vs 37.6 mmol/L; p = 0.020) 6 months post-ivacaftor. The odds of ivacaftor-mediated potentiation to near normative CFTR function (defined as SC6mo <40 mmol/L) was more than twice as high in the low-acrolein cohort (OR: 2.51, p = 0.026).

CONCLUSIONS

Increased urinary 3-HPMA, an acrolein metabolite of tobacco smoke, is associated with a diminished sweat chloride response to ivacaftor potentiation of CFTR function.

Association between cigarette smoke exposure and urinary bladder cancer in Scottish terriers in a cohort study

Canine urothelial carcinoma (UC) initially responds favorably to treatment, but is ultimately lethal in most cases. Research to identify modifiable risk factors to prevent the cancer is essential. The high breed-associated risk for UC, e.g. 20-fold higher in Scottish terriers, can facilitate this research. The objective was to identify environmental and host factors associated with UC in a cohort of Scottish terriers. Information was obtained through dog owner questionnaires for 120 Scottish terriers ≥ 6 years old participating in a bladder cancer screening study, with comparisons made between dogs that did or did not develop UC during the 3 years of screening. Univariable models were constructed, and variables with P < 0.20 were included when building the multivariable model, and then removed using a backward stepwise procedure. P < 0.05 was considered statistically significant. Urine cotinine concentrations were measured by liquid chromatography-mass spectrometry to further investigate potential cigarette smoke exposure. Biopsy-confirmed UC which was found in 32 of 120 dogs, was significantly associated with the dogs living in a household with cigarette smokers (odds ratio [OR], 6.34; 95 % confidence intervals [CI], 1.16-34.69; P = 0.033), living within a mile of a marsh or wetland (OR, 21.23; 95 % CI, 3.64-123.69; P = 0.001), and history of previous bladder infections (OR, 3.87; 95 % CI, 1.0-14.98; P = 0.050). UC was diagnosed in 18 of 51 dogs (35.3 %) with quantifiable cotinine concentrations, and six of 40 dogs (15.0 %) without quantifiable cotinine concentrations in their urine (P = 0.0165). In conclusion, the main modifiable risk factor for UC in this cohort of dogs was exposure to second-hand tobacco smoke.

CYP2A6 associates with respiratory disease risk and younger age of diagnosis: a phenome-wide association Mendelian Randomization study

CYP2A6, a genetically variable enzyme, inactivates nicotine, activates carcinogens, and metabolizes many pharmaceuticals. Variation in CYP2A6 influences smoking behaviors and tobacco-related disease risk. This phenome-wide association study examined associations between a reconstructed version of our weighted genetic risk score (wGRS) for CYP2A6 activity with diseases in the UK Biobank (N = 395 887). Causal effects of phenotypic CYP2A6 activity (measured as the nicotine metabolite ratio: 3'-hydroxycotinine/cotinine) on the phenome-wide significant (PWS) signals were then estimated in two-sample Mendelian Randomization using the wGRS as the instrument. Time-to-diagnosis age was compared between faster versus slower CYP2A6 metabolizers for the PWS signals in survival analyses. In the total sample, six PWS signals were identified: two lung cancers and four obstructive respiratory diseases PheCodes, where faster CYP2A6 activity was associated with greater disease risk (Ps < 1 × 10-6). A significant CYP2A6-by-smoking status interaction was found (Psinteraction < 0.05); in current smokers, the same six PWS signals were found as identified in the total group, whereas no PWS signals were found in former or never smokers. In the total sample and current smokers, CYP2A6 activity causal estimates on the six PWS signals were significant in Mendelian Randomization (Ps < 5 × 10-5). Additionally, faster CYP2A6 metabolizer status was associated with younger age of disease diagnosis for the six PWS signals (Ps < 5 × 10-4, in current smokers). These findings support a role for faster CYP2A6 activity as a causal risk factor for lung cancers and obstructive respiratory diseases among current smokers, and a younger onset of these diseases. This research utilized the UK Biobank Resource.

High Levels of the Carcinogenic Tobacco-Specific Nitrosamine NNAL and Associated Findings in Children of Smokers: A Case Series

High levels of NNAL, the tobacco smoke exposure (TSE) biomarker of the carcinogen 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), indicate future cancer risk. A prior study of smokers’ children revealed NNAL levels as high as active smokers. Therefore, we conducted a case series to examine the sociodemographics, TSE and clinical patterns, and other TSE biomarker levels in 9 children with extreme NNAL levels of >200 pg/ml to generate hypotheses and explore potential causes and implications. We identified 0 to 4-year-olds who presented to an emergency setting and lived with ⩾1 smoker who were part of a parental tobacco cessation trial (n = 461). Of these children, 52 had urinary NNAL, cotinine, and N-oxides results (n = 52). Nine children (17.3%) had NNAL levels >200 pg/ml, ranging from 206.4 to 1399.0 pg/ml (Median (Mdn) = 489.2 pg/ml; Interquartile Range (IQR) = 222.7-1289.3 pg/ml). The cotinine Mdn (IQR) was 38.5 (10.3-102.2) ng/ml and the N-oxides Mdn (IQR) = 93.8 (24.7-109.6) pg/ml. While all biomarker levels were alarmingly high, these young children would not have been flagged for very high cancer risk based on urinary cotinine levels alone. This underscores the critical role of comprehensive TSE biomarker measurement in capturing different TSE exposure patterns and assessing children’s future risk for cancer and other TSE-related morbidities.

Genetic Factors Associated with COPD Depend on the Ancestral Caucasian/Amerindian Component in the Mexican Population

Genetic variability influences the susceptibility to and severity of complex diseases; there is a lower risk of COPD in Hispanics than in non-Hispanic Caucasians. In this study, we included 830 Mexican-Mestizo subjects; 299 were patients with COPD secondary to tobacco smoking, and 531 were smokers without COPD. We employed a customized genotyping array of single nucleotide polymorphisms (SNPs). The population structure was evaluated by principal component analysis and allele association through a logistic regression model and haplotype identification. In this study, 118 individuals were identified with a high Caucasian component and 712 with a high Amerindian component. Independent of the ancestral contribution, two SNPs were associated with a reduced risk (p ≤ 0.01) of developing COPD in the CYP2A6 (rs4105144) and CYP2B6 (rs10426235) genes; however, a haplotype was associated with an increased risk of COPD (p = 0.007, OR = 2.47) in the CHRNA5-CHRNA3 loci among smokers with a high Caucasian component. In Mexican-Mestizo smokers, there are SNPs in genes that encode proteins responsible for the metabolism of nicotine associated with a lower risk of COPD; individuals with a high Caucasian component harboring a haplotype in the CHRNA5-CHRNA3 loci have a higher risk of suffering from COPD.

Association of secondhand smoke exposure with mental health in men and women: Cross-sectional and prospective analyses using the UK Health and Lifestyle Survey

Objectives:

We examine cross-sectional and prospective associations between objectively measured SHS exposure and mental health using data from the Health and Lifestyle Survey (HALS), a large, UK-wide, general population-based, prospective cohort study with measurements of carbon monoxide or salivary cotinine levels.

Methods:

Mental health was assessed using the 30-item version of the General Health Questionnaire (GHQ). Multivariate logistic regression models adjusting for age, sex, height, body mass index, alcohol intake, social status, and longstanding illness were used to analyze the association between exposure to SHS (exhaled CO and salivary cotinine categories) and psychological distress (≥ 5 GHQ).

Results:

Fully adjusted cross-sectional analysis revealed a positive relationship between exhaled carbon monoxide and psychological distress among smokers (OR 1.36; 95% CI 1.04-1.78) but not among non-smoking adults. In a similar cross-sectional analysis between cotinine level and psychological distress, non-significant associations were found among smokers and non-smokers. Prospective analyses of the cotinine-psychological distress relationship among participants without psychological distress at baseline showed no significant increased risk of psychological distress among both smokers and non-smokers. In a prospective analysis of poor mental health outcome with respect to self-report smoking and SHS status, smokers had an increased risk of psychological distress while SHS and non-smokers did not.

Conclusions:

A non-significant association between objectively measured SHS exposure and poor mental health was found in this study. Our findings show discrepancies with recent studies suggesting the need for additional future research in this growing field of study.

Objective secondhand smoke exposure in chronic obstructive pulmonary disease patients without active smoking: the U.S. National Health and Nutrition Examination Survey (NHANES) 2007-2012

Background

Secondhand smoke (SHS) may be related to worse outcomes in chronic obstructive pulmonary disease (COPD), but the reported SHS prevalence in different studies varied from 27% to 65% and the effects of SHS are still questionable among these patients. The study aims were to estimate the objective SHS prevalence and explore the SHS impact on outcomes among COPD patients without active smoking.

Methods

A cross-sectional design combined with longitudinal death outcome. We selected COPD patients over 40 years old based on the spirometry from National Health and Nutrition Examination Survey (2007–2012), and used the tobacco-specific biomarkers [cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol] to determine exposure statuses (active smoking, SHS exposure, or no smoke exposure). Then we estimated the short-term (past 2–4 days) and medium-term (past 6–12 weeks) SHS prevalence among 334 patients without active smoking. Weighted multiple regressions were performed to assess the associations between medium-term SHS exposure and outcomes (symptoms, health status, medical institution visits, and death).

Results

Among the patients without active smoking, the objective prevalence rates of short-term and medium-term SHS were 66.65% [95% confidence interval (CI), 59.63–73.67%] and 34.91% (95% CI, 28.86%–40.96%), respectively. Medium-term SHS exposure showed a significant effect (odds ratio, 3.57; 95% CI, 1.22–10.40) on more chronic coughing after adjusting for the covariates and indicated a trend of unadjusted increasing death risk (log-rank test, P=0.01).

Conclusions

Among COPD patients without active smoking, both short-term and medium-term SHS exposure are prevalent. Chronic cough may be the most susceptible patient-centred outcome related to medium-term SHS exposure. The crude longitudinal trend of elevated death risk associated with medium-term SHS exposure deserves further study.

Comparison of Urine 4-(Methylnitrosamino)-1-(3)Pyridyl-1-Butanol and Cotinine for Assessment of Active and Passive Smoke Exposure in Urban Adolescents

Background: Many adolescents are exposed to tobacco smoke, from either active smoking (CS) or secondhand smoke (SHS) exposure. Tobacco-specific biomarkers of exposure include cotinine (detects use in past 2-4 days) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL; detects use for a month or longer). NNAL is expected to detect more intermittent tobacco exposure. We compared NNAL and cotinine as biomarkers of exposure to tobacco in urban adolescents and determined the optimal NNAL cutoff point to distinguish CS from SHS exposure.Methods: Surplus urine samples, collected from 466 adolescents attending pediatric well or urgent care visits at Zuckerberg San Francisco General Hospital in 2013 to 2014, were assayed for cotinine and NNAL.Results: Ninety-four percent of adolescents had measurable levels of NNAL compared with 87% for cotinine. The optimal NNAL cutoff point to distinguish CS from SHS was 9.6 pg/mL by latent class or 14.4 pg/mL by receiver-operating characteristic analysis. Cotinine and NNAL were strongly correlated, but the correlation slopes differed for active versus SHS-exposed adolescents. Among nonsmokers, NNAL levels were significantly higher in African American (median, 3.3 pg/mL) compared with other groups (0.9-1.9 pg/mL), suggesting greater exposure to SHS.Conclusions: Urine NNAL screening finds a large majority (94%) of urban adolescents are exposed to tobacco. African Americans are exposed to higher levels of SHS than other ethnic/racial groups.Impact: SHS is associated with significant medical morbidity in adolescents. Routine biochemical screening with NNAL or cotinine detects high prevalence of SHS exposure and should be considered as a tool to reduce SHS exposure in high-risk populations. Cancer Epidemiol Biomarkers Prev; 27(3); 254-61. ©2018 AACR.

The Effects of Air Pollution and Temperature on COPD

Chronic Obstructive Pulmonary Disease (COPD) affects 12-16 million people in the United States and is the third-leading cause of death. In developed countries, smoking is the greatest risk factor for the development of COPD, but other exposures also contribute to the development and progression of the disease. Several studies suggest, though are not definitive, that outdoor air pollution exposure is linked to the prevalence and incidence of COPD. Among individuals with COPD, outdoor air pollutants are associated with loss of lung function and increased respiratory symptoms. In addition, outdoor air pollutants are also associated with COPD exacerbations and mortality. There is much less evidence for the impact of indoor air on COPD, especially in developed countries in residences without biomass exposure. The limited existing data suggests that indoor particulate matter and nitrogen dioxide concentrations are linked to increased respiratory symptoms among patients with COPD. In addition, with the projected increases in temperature and extreme weather events in the context of climate change there has been increased attention to the effects of heat exposure. Extremes of temperature-both heat and cold-have been associated with increased respiratory morbidity in COPD. Some studies also suggest that temperature may modify the effect of pollution exposure and though results are not conclusive, understanding factors that may modify susceptibility to air pollution in patients with COPD is of utmost importance.

Understanding the impact of second-hand smoke exposure on clinical outcomes in participants with COPD in the SPIROMICS cohort

BACKGROUND

Second-hand smoke (SHS) exposure has been linked to the development of and morbidity from lung disease. We sought to advance understanding of the impact of SHS on health-related outcomes in individuals with COPD.

METHODS

Among the participants with COPD in SPIROMICS, recent SHS exposure was quantified as (1) hours of reported exposure in the past week or (2) reported living with a smoker. We performed adjusted regression for SHS with outcomes, testing for interactions with gender, race, smoking and obesity.

RESULTS

Of the 1580 participants with COPD, 20% reported living with a smoker and 27% reported exposure in the past week. Living with a smoker was associated with worse St George's Respiratory Questionnaire score (SGRQ, β 3.10; 95% CI 0.99 to 5.21), COPD Assessment Test score (β 1.43; 95% CI 0.52 to 2.35) and increased risk for severe exacerbations (OR 1.51, 95% CI 1.04 to 2.17). SHS exposure in the past week was associated with worse SGRQ (β 2.52; 95% CI 0.47 to 4.58), nocturnal symptoms (OR 1.58; 95% CI 1.19 to 2.10), wheezing (OR 1.34; 95% CI 1.02 to 1.77), chronic productive cough (OR 1.77; 95% CI 1.33 to 2.35) and difficulty with cough and sputum (Ease of Cough and Sputum scale, β 0.84; 95% CI 0.42 to 1.25). SHS was associated with increased airway wall thickness on CT but not emphysema. Active smokers, obese individuals and individuals with less severe airflow obstruction also had higher susceptibility to SHS for some outcomes.

CONCLUSION

Individuals with COPD, including active smokers, have significant SHS exposure, associated with worse outcomes and airway wall thickness. Active smokers and obese individuals may have worse outcomes associated with SHS.

TRIAL REGISTRATION NUMBER

NCT01969344 (clinicaltrials.gov).

A Comparison of Survey Measures and Biomarkers of Secondhand Tobacco Smoke Exposure among Nonsmokers

OBJECTIVES

Secondhand tobacco smoke (SHS) exposure causes several adverse physical health outcomes. Conceptual differences in survey measures of 'psychosocial' (SHS exposure from smokers in an individual's life) and 'physical' (environments where an individual is exposed to SHS) SHS exposure exist. Few studies have examined the association between psychosocial and physical SHS exposures measures in comparison to biomarkers of SHS exposure.

DESIGN AND SAMPLE

A secondary analysis of cross-sectional data was examined among a convenience sample of 20 adults.

MEASURES

Data included survey items on SHS exposure and hair nicotine and saliva cotinine levels. Spearman analysis was used to assess correlations among variables.

RESULTS

Medium and strong correlations were found among SHS exposure measures with the exception of saliva cotinine levels. Strong correlations were found among and between psychosocial and physical SHS exposure measures. Hair nicotine levels had medium strength associations with only perceived frequency of SHS exposure.

DISCUSSION

As psychosocial measures of exposure were associated with biomarkers, such measures (particularly perceived frequency of SHS exposure) should be added to surveys in addition to physical SHS exposure measures to enhance accuracy of SHS measurement. Future explorations with robust sample sizes should further examine the strength of relationship between psychosocial and physical SHS exposure measures.

Smoking bans linked to lower hospitalizations for heart attacks and lung disease among medicare beneficiaries

Policies limiting exposure to cigarette smoke have been associated with reduced hospitalizations for heart attacks, but little is known about the impact of smoking bans on other health conditions and whether findings from individual communities generalize to other areas. We investigated the association between smoking bans targeting workplaces, restaurants, and bars passed throughout the United States during 1991-2008 and hospital admissions for smoking-related illnesses-acute myocardial infarction and chronic obstructive pulmonary disease-among Medicare beneficiaries age sixty-five or older. Risk-adjusted hospital admission rates for acute myocardial infarction fell 20-21 percent thirty-six months following implementation of new restaurant, bar, and workplace smoking bans. Admission rates for chronic obstructive pulmonary disease fell 11 percent where workplace smoking bans were in place and 15 percent where bar smoking bans were present. By contrast, very little effect was found for hospitalization for gastrointestinal hemorrhage and hip fracture-two conditions largely unrelated to smoking and examined as points of comparison. These findings provide further support for the public health benefits of laws that limit exposure to tobacco smoke.

Biomarkers of tobacco smoke exposure and asthma severity in adults

BACKGROUND

Tobacco biomarkers including serum cotinine and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) have been used in research settings.

PURPOSE

The goal of the study was to examine the association of cotinine and NNAL with asthma outcomes in the U.S. adult population.

METHODS

A cross-sectional design was used, using data from the National Health and Nutrition Examination Survey, 2007-2008, with participants aged >20 years with self-reported asthma (N=456). Past-year asthma exacerbations and emergency room/urgent care visits for asthma were examined. Analyses were conducted in 2013.

RESULTS

Among adult asthmatics, 50.3% reported a past-year asthma attack (61.8% smokers, 46.6% nonsmokers, p=0.029). Among these, 24.7% reported a past-year emergency/urgent visit for asthma (34.7% smokers, 20.1% nonsmokers, p=0.034). Median concentrations of cotinine and creatinine-adjusted NNAL (NNAL/Cr) were significantly higher in those with a past-year asthma attack (0.43 ng/mL and 7.28 pg/mL) than in those without (0.06 ng/mL and 2.26 pg/mL), and highest in those with past-year emergency/urgent visits (0.93 ng/mL and 28.14 pg/mL). Among nonsmokers, increasing levels of log cotinine or log NNAL/Cr, adjusted for demographics, were significantly associated with past-year asthma exacerbation (log cotinine OR=1.46 [95% CI=1.1, 1.92]; log NNAL/Cr OR=1.42 [95% CI=1.07, 1.88]) and past-year emergency/urgent visit (log cotinine OR=1.95 [95% CI=1.32, 2.88]; log NNAL/Cr OR=1.58 [95% CI=1.23, 2.02]). Among smokers, increasing biomarker levels were not significantly associated with either outcome.

CONCLUSIONS

In a population-based cross-sectional analysis, increased cotinine and NNAL were found to be associated with asthma exacerbation and healthcare use in nonsmokers with asthma. If these findings are confirmed in prospective studies, these biomarkers might be candidates for clinical indicators of risk of asthma.

Assessing secondhand smoke using biological markers

Secondhand smoke exposure (SHSe) is a known cause of many adverse health effects in adults and children. Increasingly, SHSe assessment is an element of tobacco control research and implementation worldwide. In spite of decades of development of approaches to assess SHSe, there are still unresolved methodological issues; therefore, a multidisciplinary expert meeting was held to catalogue the approaches to assess SHSe and with the goal of providing a set of uniform methods for future use by investigators and thereby facilitate comparisons of findings across studies. The meeting, held at Johns Hopkins, in Baltimore, Maryland, USA, was supported by the Flight Attendant Medical Research Institute (FAMRI). A series of articles were developed to summarise what is known about self-reported, environmental and biological SHSe measurements. Non-smokers inhale toxicants in SHS, which are mainly products of combustion of organic materials and are not specific to tobacco smoke exposure. Biomarkers specific to SHSe are nicotine and its metabolites (e.g., cotinine), and metabolites of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Cotinine is the preferred blood, saliva and urine biomarker for SHSe. Cotinine and nicotine can also be measured in hair and toenails. NNAL (4-[methylnitrosamino]-1-[3-pyridyl]-1-butanol), a metabolite of NNK, can be determined in the urine of SHS-exposed non-smokers. The selection of a particular biomarker of SHSe and the analytic biological medium depends on the scientific or public health question of interest, study design and setting, subjects, and funding. This manuscript summarises the scientific evidence on the use of biomarkers to measure SHSe, analytical methods, biological matrices and their interpretation.

Environmental monitoring of secondhand smoke exposure

The complex composition of secondhand smoke (SHS) provides a range of constituents that can be measured in environmental samples (air, dust and on surfaces) and therefore used to assess non-smokers' exposure to tobacco smoke. Monitoring SHS exposure (SHSe) in indoor environments provides useful information on the extent and consequences of SHSe, implementing and evaluating tobacco control programmes and behavioural interventions, and estimating overall burden of disease caused by SHSe. The most widely used markers have been vapour-phase nicotine and respirable particulate matter (PM). Numerous other environmental analytes of SHS have been measured in the air including carbon monoxide, 3-ethenylpyridine, polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines, nitrogen oxides, aldehydes and volatile organic compounds, as well as nicotine in dust and on surfaces. The measurement of nicotine in the air has the advantage of reflecting the presence of tobacco smoke. While PM measurements are not as specific, they can be taken continuously, allowing for assessment of exposure and its variation over time. In general, when nicotine and PM are measured in the same setting using a common sampling period, an increase in nicotine concentration of 1 μg/m³ corresponds to an average increase of 10 μg/m³ of PM. This topic assessment presents a comprehensive summary of SHSe monitoring approaches using environmental markers and discusses the strengths and weaknesses of these methods and approaches.

Development of a method for the determination of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in urine of nonsmokers and smokers using liquid chromatography/tandem mass spectrometry

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is an efficient biomarker of tobacco-specific carcinogen 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The ability to monitor biomarker concentrations is very important in understanding potential cancer risk. An analytical method using molecularly imprinted polymer (MIP) column coupled with liquid chromatography/tandem mass spectrometry (LC-MS/MS) for the determination of total NNAL in human urine was developed and validated. The combination of MIP column extraction and LC-MS/MS can provide a high sensitive and relatively simple analytical method. The limit of detection (LOD) was 0.30 pg/ml and analysis time was 6min. The method has been applied to urine samples of 36 nonsmokers and 207 smokers. NNAL was found to be significantly higher in the urine of smokers compared with nonsmokers. Compared with smokers with blended cigarettes, Chinese virginia cigarettes smokers had low urinary NNAL levels. There was a direct association between the 24-h mouth-level exposure of carcinogen NNK from cigarette smoking and the concentration of NNAL in the urine of smokers. However, there was not a positive correlation between urinary total NNAL levels in 24 h and tar. Total urinary NNAL is a valuable biomarker for monitoring exposure to carcinogenic NNK in smokers and in nonsmokers. A prediction model of cigarette smoke NNK and urinary average NNAL levels in 24 h was established (y=2.8987x-245.38, r²=0.9952, n=204).

What are candidate biobehavioral mechanisms underlying the association between secondhand smoke exposure and mental health?

There is a consistent positive and significant association between secondhand smoke exposure and mental health outcomes in the literature. There are potential genetic and behavioral confounders (e.g., psychological stress, maternal depression, and family functioning) were discussed, as well as potential causal neurobiological pathways (e.g., dopamine system). Further neurobiological research to establish causal pathways is needed as well as the integration of positive observational findings into clinical and public health prevention practices.

The case for a worldwide ban on smoking in public places

PURPOSE OF REVIEW

Second-hand smoke (SHS) is a major cause of morbidity and mortality on a global scale. Governments have increasingly sought to mitigate the effects of SHS by introducing legislation that restricts tobacco consumption in public places. There is emerging evidence that such legislation leads to direct and indirect health benefits.

RECENT FINDINGS

Exposure to SHS is now shown to be associated with development of cardiovascular disease, and poorer health outcomes in patients with established chronic obstructive pulmonary disease. Childhood (including in-utero) exposure to SHS has recently been linked with increased risk of cleft palate, demonstrable signs of atherosclerosis, and the development of emphysema and lung cancer in adulthood. Comprehensive bans on smoking in public lead to a reduction in overall exposure to SHS for both adults and children and have also been shown to immediately attenuate the incidence of myocardial infarction and paediatric hospital attendances with acute asthma.

SUMMARY

Banning smoking in public places is an effective tool for reducing tobacco-related morbidity across a multiplicity of diseases. Countries that have not already done so should introduce legislation to enforce effective legislation that prohibits smoking in public places.

Metabolites of a tobacco-specific lung carcinogen in children exposed to secondhand or thirdhand tobacco smoke in their homes

BACKGROUND

People exposed to secondhand tobacco smoke (SHS) inhale the lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) which is metabolized to NNAL and its glucuroniders. These urinary metabolites, termed total NNAL, can be quantified. A related compound, iso-NNAL, has been proposed as a biomarker for exposure to smoke constituent residues on surfaces (thirdhand tobacco smoke). There is limited information in the literature on levels of total NNAL in children exposed to SHS.

METHODS

We recruited 79 parent--child dyads from homes where the enrolled parent was a cigarette smoker and visited their homes. Parents were asked questions, home ambient air quality was evaluated, and children provided urine samples. Urine was analyzed for total NNAL, total cotinine, total nicotine, and iso-NNAL.

RESULTS

Ninety percent of the children had detectable total NNAL in urine; total nicotine and total cotinine were also detected in most samples. There were significant positive relationships between biomarker levels and exposure of children in the home. Levels were highest in homes with no smoking restrictions. African American children had significantly higher levels than other children. iso-NNAL was not detected in any urine sample.

CONCLUSIONS

There was nearly universal exposure of children to the lung carcinogen NNK, due mainly to exposure to SHS from adult smokers in their homes.

IMPACT

Homes with adult smokers should adopt restrictions to protect their children from exposure to a potent lung carcinogen.

Recent contributions of air- and biomarkers to the control of secondhand smoke (SHS): a review

Since the publication of the US Surgeon General Reports in 1996 and 2006 and the report of the California Environmental Protection Agency in 1999, many reports have appeared on the contribution of air and biomarkers to different facets of the secondhand smoke (SHS) issue, which are the targets of this review. These recent studies have allowed earlier epidemiological surveys to be biologically validated, and their plausibility demonstrated, quantified the levels of exposure to SHS before the bans in various environments, showed the deficiencies of mechanical control methods and of partial bans and the frequently correct implementation of the efficient total bans. More stringent regulation remains necessary in the public domain (workplaces, hospitality venues, transport sector, etc.) in many countries. Personal voluntary protection efforts against SHS are also needed in the private domain (homes, private cars). The effects of SHS on the cardiovascular, respiratory and neuropsychic systems, on pregnancy and fertility, on cancers and on SHS genotoxicity are confirmed through experimental human studies and through the relationship between markers and prevalence of disease or of markers of disease risk.

Biomarkers increase detection of active smoking and secondhand smoke exposure in critically ill patients

OBJECTIVES

The association between tobacco smoke exposure and critical illness is not well studied, largely because obtaining an accurate smoking history from critically ill patients is difficult. Biomarkers can provide quantitative data on active and secondhand cigarette smoke exposure. We sought to compare cigarette smoke exposure as measured by biomarkers to exposure by self-report in a cohort of critically ill patients and to determine how well biomarkers of cigarette smoke exposure correlate with each other in this population.

DESIGN, SETTING, AND PATIENTS

Serum and urine cotinine and trans-3'-hydroxycotinine, urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, and hair and nail nicotine levels were measured in 60 subjects enrolled in an observational cohort of critically ill subjects at a tertiary academic medical center in Tennessee. Smoking history was obtained from patients, their surrogates, or the medical chart. Cigarette smoke exposure as measured by biomarkers was compared to exposure by history.

MEASUREMENTS AND MAIN RESULTS

By smoking history, 29 subjects were identified as smokers, 28 were identified as nonsmokers, and 3 were identified as unknown. The combination of serum cotinine and urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol identified 27 of the 28 nonsmokers by history either as active smokers (n = 6, 21%) or as exposed to secondhand smoke (n = 21, 75%). All biomarker levels were strongly correlated with each other (r = .69-.95, p < .0001).

CONCLUSIONS

The combination of serum cotinine and urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol identified considerably more active smokers than did smoking history and detected a high prevalence of secondhand smoke exposure in a critically ill population. These markers will be important for future studies investigating the relationship between active smoking and secondhand smoke exposure and critical illness.

Comparison of urine cotinine and the tobacco-specific nitrosamine metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and their ratio to discriminate active from passive smoking

OBJECTIVES

Cotinine is the most widely used biomarker to distinguish active versus passive smoking. However, there is an overlap in cotinine levels when comparing light or occasional smokers versus heavily exposed passive smokers. 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a tobacco-specific nitrosamine measurable in urine with a much longer half-life than cotinine. The aim of the study was to determine optimal cutoff points to discriminate active versus passive smokers and to compare sensitivity and specificity for the use of cotinine, NNAL, and the ratio of the NNAL/cotinine in urine.

METHODS

Cotinine and NNAL were measured in urine of 373 active smokers and 228 passive smokers.

RESULTS

Geometric mean cotinine levels were 2.03 ng/ml (interquartile interval: 0.43-8.60) and 1,043 ng/ml (658-2,251) and NNAL levels were 5.80 pg/ml (2.28-15.4) and 165 pg/ml (90.8-360) pg/ml in passive and active smokers, respectively. NNAL/cotinine ratio in urine was significantly higher for passive smokers when compared with active smokers (2.85 vs. 0.16, p < .01). The receiver operating characteristics analysis determined optimal cutoff points to discriminate passive versus active smokers: 31.5 ng/ml for cotinine (sensitivity: 97.1% and specificity: 93.9%), 47.3 pg/ml for NNAL (87.4% and 96.5%), and 0.74 x 10⁻³ for NNAL/cotinine ratio (97.3% and 87.3%).

CONCLUSIONS

Both urine cotinine and NNAL are sensitive and specific biomarkers for discriminating the source of tobacco smoke exposure. Cotinine is the best overall discriminator when biomarkers are measured while a person has ongoing exposure to tobacco smoke. NNAL because of its long half-life would be particularly useful when there is a delay between exposure and biomarker measurement. The NNAL/cotinine ratio provides similar sensitivity but poorer specificity at discriminating passive versus active smokers when compared with NNAL alone.

Urine cotinine underestimates exposure to the tobacco-derived lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in passive compared with active smokers

OBJECTIVES

Cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) are widely used biomarkers for tobacco-derived nicotine and the lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), respectively. The discrepancy between cotinine levels in relation to disease risk comparing active versus passive smoking suggests a nonlinear tobacco smoke dose-response and/or that cotinine is not providing an accurate measure of exposure to the toxic constituents of secondhand tobacco smoke.

METHODS

Cotinine and NNAL were measured in the urine of 373 active smokers and 228 passive smokers.

RESULTS

Average cotinine levels were 1,155 (interquartile range, 703-2,715) for active smokers and 1.82 (0.45-7.33) ng/mg creatinine for passive smokers. Average NNAL levels were 183 (103-393) and 5.19 (2.04-11.6) pg/mg creatinine, respectively. NNAL/cotinine ratio in urine was significantly higher for passive smokers when compared with active smokers (2.85 × 10(3) versus 0.16 × 10(3), P < 0.0001).

CONCLUSIONS

Passive smoking is associated with a much higher ratio of NNAL/cotinine in the urine compared with active smoking.

IMPACT

Cotinine measurement leads to an underestimation of exposure to the carcinogen NNK from secondhand smoke when compared with active smoking.

Tobacco smoke exposure in nonsmoking hospitality workers before and after a state smoking ban

Secondhand smoke exposure is estimated to account for 3,000 cancer deaths per year. Although several countries and states in the United States have passed comprehensive smoke-free laws to protect all employees, a significant number of workers are still not protected. The purpose of this study was to determine the effects of passing a comprehensive smoking ban that included bars and restaurants on biomarkers of nicotine and carcinogen exposure. The urines of nonsmoking employees (n = 24) of bars and restaurants that allowed smoking before the smoke-free law were analyzed before and after the law was passed in Minnesota. The results showed significant reductions in both total cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (free plus glucuronidated) after the ban was instituted. These results provide further support for the importance of protecting employees working in all venues.

Elimination kinetics of the tobacco-specific biomarker and lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is tobacco specific and has a longer half-life than other tobacco biomarkers studied thus far. An accurate measurement of the NNAL half-life is important for optimal use to assess exposure to tobacco smoke. We determined the half-life of NNAL in urine in eight daily smokers on a clinical research ward and in five occasional smokers in a real-life environment. Total NNAL in urine was monitored for 14 days in daily smokers after stopping smoking and for up to 60 days in occasional smokers. The average half-life for the terminal phase in the daily smoker group using a two-compartmental body model was 10.3 days (beta phase), and using a noncompartmental model, it was 9.1 days. In the occasional group, these values were 17.6 and 16.0 days, respectively. The alpha-phase half-lives were 14.3 and 27.8 hours for the two groups, respectively. The inter-subject coefficient of variation of the NNAL terminal half-life ranged from 14% to 30%, and the intra-subject coefficient of variation ranged from 3% to 18%. There was very good agreement between the plasma and urinary half-lives in two subjects with plasma analyses: 7.4 versus 7.9 days and 9.2 versus 10.7 days. Mean renal clearance of NNAL was 13 +/- 2.3 mL/min. The terminal half-life of NNAL of 10 to 18 days indicates that this biomarker can be used to detect tobacco smoke exposure for 6 to 12 weeks after cessation of exposure and requires a similar time to assess the steady levels of NNAL after switching from one tobacco product to another.

Secondhand smoke exposure and depressive symptoms

OBJECTIVE

To evaluate the association between secondhand smoke (SHS) exposure and depression. Tobacco smoking and depression are strongly associated, but the possible effects of SHS have not been evaluated.

METHODS

The 2005 to 2006 National Health and Nutrition Examination Survey (NHANES) is a cross-sectional sample of the noninstitutionalized civilian U.S. population. SHS exposure was measured in adults aged > or =20 years by serum cotinine and depressive symptoms by the Patient Health Questionnaire. Zero-inflated Poisson regression analyses were completed with adjustment for survey design and potential confounders.

RESULTS

Serum cotinine-documented SHS exposure was positively associated with depressive symptoms in never-smokers, even after adjustment for age, race/ethnicity, gender, education, alcohol consumption, and medical comorbidities. The association between SHS exposure and depressive symptoms did not vary by gender, nor was there any association between SHS smoke exposure and depressive symptoms in former smokers.

CONCLUSIONS

Findings from the present study suggest that SHS exposure is positively associated with depressive symptoms in never-smokers and highlight the need for further research to establish the mechanisms of association.