Determination of tobacco smoke exposure by plasma cotinine levels in infants and children attending urban public hospital clinics

Factors leading to disparity in lung cancer diagnosis among black/African American communities in the USA: a qualitative study

OBJECTIVE

This study has two objectives: first, to explore the diagnostic experiences of black/African American (BAA) patients with lung cancer to pinpoint pitfalls, suboptimal experiences and instances of discrimination leading to disparities in outcomes compared with patients of other ethnic backgrounds, especially white patients. The second objective is to identify the underlying causes contributing to health disparities in the diagnosis of lung cancer among BAA patients.

METHODS

We employed a phenomenological research approach, guiding in-depth interviews with patients self-identifying as BAA diagnosed with lung cancer, as well as caregivers, healthcare professionals and community advocates knowledgeable about BAA experiences with lung cancer. We performed thematic analysis to identify experiences at patient, primary care and specialist levels. Contributing factors were identified using the National Institute of Minority Health and Health Disparities (NIMHD) health disparity model.

RESULTS

From March to November 2021, we conducted individual interviews with 19 participants, including 9 patients/caregivers and 10 providers/advocates. Participants reported recurring and increased pain before seeking treatment, treatment for non-cancer illnesses, delays in diagnostic tests and referrals, poor communication and bias when dealing with specialists and primary care providers. Factors contributing to suboptimal experiences included reluctance by insurers to cover costs, provider unwillingness to conduct comprehensive testing, provider bias in recommending treatment, high healthcare costs, and lack of healthcare facilities and qualified staff to provide necessary support. However, some participants reported positive experiences due to their insurance, availability of services and having an empowered support structure.

CONCLUSIONS

BAA patients and caregivers encountered suboptimal experiences during their care. The NIMHD model is a useful framework to organise factors contributing to these experiences that may be leading to health disparities. Additional research is needed to fully capture the extent of these experiences and identify ways to improve BAA patient experiences in the lung cancer diagnosis pathway.

Carcinogenic and tobacco smoke-derived particulate matter biomarker uptake and associated healthcare patterns among children

BACKGROUND

The objective was to assess the associations of child tobacco smoke exposure (TSE) biomarkers (urinary cotinine, NNAL, and nicotelline N-oxides) and parent-reported smoking and child TSE patterns with total hospital visits, pediatric emergency department (PED) visits, urgent care (UC), revisits, and hospital admissions among 0-9-year-olds.

METHODS

A convenience sample of PED/UC patients (N = 242) who presented to a large, US children's hospital who had baseline urine samples assayed for the TSE biomarkers of interest were included. Biomarker levels were log-transformed, and linear and Poisson regression models were built.

RESULTS

The geometric means of child cotinine, creatinine-adjusted NNAL, and N-oxide levels were 11.2 ng/ml, 30.9 pg/mg creatinine, and 24.1 pg/ml, respectively. The mean (SD) number of daily cigarettes smoked by parents was 10.2 (6.1) cigarettes. Each one-unit increase in log-NNAL levels was associated with an increase in total UC visits (aRR = 1.68, 95% CI = 1.18-2.39) among 0-9-year-olds, while controlling for the covariates. Each one-unit increase in child log-NNAL/cotinine ratio (×103) values was associated with an increase in total hospital visits (aRR = 1.39, 95% CI = 1.10-1.75) and UC visits (aRR = 1.56, 95% CI = 1.14-2.13) over 6 months.

CONCLUSION

Systematic screening for child TSE should be conducted during all hospital visits. The comprehensive assessment of TSE biomarkers should be considered to objectively measure young children's exposure.

IMPACT

Higher levels of cotinine, a widely used tobacco smoke exposure biomarker, have been associated with higher healthcare utilization patterns among children. Less is known on the associations of carcinogenic and tobacco smoke-derived particulate matter biomarker uptake with child healthcare utilization patterns. This study assessed the associations of several biomarkers with healthcare utilization patterns among pediatric emergency department patients ages 0-9 years who lived with tobacco smokers. Higher urinary NNAL biomarker levels, in individual and ratio form with cotinine, increased children's risk for urgent care visits over 6 months. Higher parent-reported cumulative child tobacco smoke exposure increased children's risk for hospital admissions.

Host, technical, and environmental factors affecting QuantiFERON-TB Gold In-Tube performance in children below 5 years of age

Interferon-gamma release assays performance can be impaired by host-related, technical and environmental factors, but data in young children are limited. We performed a cross-sectional study of children < 5 years-of-age at risk of tuberculosis (TB), using QuantiFERON-TB Gold In-Tube (QFT-GIT) assays. The impact of the following was evaluated: (i) host-related [age; hematological parameters; erythrocyte sedimentation rate (ESR); C-reactive protein (CRP); and tobacco smoke exposure (TSE) based on serum cotinine concentrations], (ii) technical (pre-analytical delay) and (iii) environmental factors (annual season; monthly temperatures). Of 204 children, 35 (17.2%) were diagnosed with latent TB infection or TB disease. QFT-GIT results were indeterminate in 14 (6.9%) patients. In multivariate analysis, younger age and higher ESR were associated with lower positive control responses (beta: 0.247, p = 0.002 and - 0.204, p = 0.007, respectively), and increasing age was associated with lower rates of indeterminate QFT-GIT results [OR (95% CI) 0.948 (0.903-0.996) per month, p = 0.035]. In children with positive QFT-GIT results, average monthly temperatures correlated with antigen responses (r = 0.453, p = 0.020); also, antigen responses were lower in winter than in other seasons (p = 0.027). Serum cotinine concentrations determined in a subgroup of patients (n = 41) indicated TSE in 36 (88%), positive control responses being lower in children with TSE (p = 0.034). In children < 5 years-of-age, young age, elevated ESR, temperature, annual season and TSE can affect the performance of QFT-GIT assays.

Tobacco Retail Outlets, Neighborhood Deprivation and the Risk of Prenatal Smoke Exposure

INTRODUCTION

Smoking and smoke exposure among pregnant women remain persistent public health issues. Recent estimates suggest that approximately one out of four nonsmokers have measurable levels of cotinine, a marker indicating regular exposure to secondhand smoke. Epidemiological research has attempted to pinpoint individual-level and neighborhood-level factors for smoking during pregnancy. However, most of these studies have relied upon self-reported measures of smoking.

AIMS AND METHODS

To more accurately assess smoke exposure resulting from both smoking and secondhand exposure in mothers during pregnancy, we used Bayesian regression models to estimate the association of cotinine levels with tobacco retail outlet (TRO) exposure and a neighborhood deprivation index (NDI) in six counties in North Carolina centered on Durham County.

RESULTS

Results showed a significant positive association between TRO exposure (β = 0.008, 95% credible interval (CI) = [0.003, 0.013]) and log cotinine after adjusting for individual covariates (eg, age, race/ethnicity, education, marital status). TRO exposure was not significant after including the NDI, which was significantly associated with log cotinine (β = 0.143, 95% CI = [0.030, 0.267]). However, in a low cotinine stratum (indicating secondhand smoke exposure), TRO exposure was significantly associated with log cotinine (β = 0.005, 95% CI = [0.001, 0.009]), while in a high cotinine stratum (indicating active smoking), the NDI was significantly associated with log cotinine (β = 0.176, 95% CI = [0.005, 0.372]).

CONCLUSIONS

In summary, our findings add to the evidence that contextual factors are important for active smoking during pregnancy.

IMPLICATIONS

In this study, we found several significant associations that suggest a more nuanced understanding of the potential influence of environmental- and individual-level factors for levels of prenatal smoke exposure. Results suggested a significant positive association between TRO exposure and cotinine levels, after adjusting for the individual factors such as race, education, and marital status. Individually, NDI was similarly positively associated with cotinine levels as well. However, when combining TRO exposure alongside NDI in the same model, TROs were no longer significantly associated with overall cotinine levels.

Neighborhood Deprivation is Associated with Increased Risk of Prenatal Smoke Exposure

Despite years of advisories against the behavior, smoking among pregnant women remains a persistent public health issue in the USA. Recent estimates suggest that 9.4% of women smoke before pregnancy and 7.1% during pregnancy in the USA. Epidemiological research has attempted to pinpoint individual-level and neighborhood-level factors for smoking during pregnancy, including educational attainment, employment status, housing conditions, poverty, and racial demographics. However, most of these studies have relied upon self-reported measures of smoking, which are subject to reporting bias. To more accurately and objectively assess smoke exposure in mothers during pregnancy, we used Bayesian index models to estimate a neighborhood deprivation index (NDI) for block groups in Durham County, North Carolina, and its association with cotinine, a marker of smoke exposure, in pregnant mothers (n = 887 enrolled 2005-2011). Results showed a significant positive association between NDI and log cotinine (beta = 0.20, 95% credible interval = [0.11, 0.29]) after adjusting for individual covariates (e.g., race/ethnicity and education). The two most important variables in the NDI according to the estimated index weights were percent females without a high school degree and percent Black population. At the individual level, Hispanic and other race/ethnicity were associated with lowered cotinine compared with non-Hispanic Whites. Higher education levels were also associated with lowered cotinine. In summary, our findings provide stronger evidence that the socio-geographic variables of educational attainment and neighborhood racial composition are important factors for smoking and secondhand smoke exposure during pregnancy and can be used to target intervention efforts.

Serum cotinine cut-points for secondhand smoke exposure assessment in children under 5 years: A systemic review

Background

Serum cotinine has become the most widely used biomarker of secondhand smoke exposure (SHS) over time in all ages. The aim of this study was to review the serum cotinine cut-points used to classify children under 5 years as exposed to SHS.

Methods

A systematic review performed in the Pubmed (MEDLINE) and EMBASE databases up to April 2021 was conducted using as key words "serum cotinine", “tobacco smoke pollution” (MeSH), "secondhand smoke", "environmental tobacco smoke" and “tobacco smoke exposure”. Papers which assessed SHS exposure among children younger than 5 years old were included. The PRISMA 2020 guidelines were followed. Analysis was pre-registered in PROSPERO (registration number: CRD42021251263).

Results

247 articles were identified and 51 fulfilled inclusion criteria. The selected studies were published between 1985–2020. Most of them included adolescents and adults. Only three assessed postnatal exposure exclusively among children under 5 years. None of the selected studies proposed age-specific cut-points for children < 5 years old. Cut-point values to assess SHS exposure ranged from 0.015 to 100 ng/ml. The most commonly used cut-point was 0.05 ng/ml, derived from the assay limit of detection used by the National Health and Nutrition Examination Survey (NHANES).

Conclusions

No studies have calculated serum cotinine age-specific cut-points to ascertained SHS exposure among children under 5 years old. Children’s age-specific cut-points are warranted for health research and public health purposes aimed at accurately estimating the prevalence of SHS exposure and attributable burden of disease to such exposure, and at reinforcing 100% smoke-free policies worldwide, both in homes, private vehicles and public places.

Secondhand smoke exposure in school children in Malta assessed through urinary biomarkers

School children may be exposed to secondhand smoke (SHS) either at home, in transit or in social gatherings permitting smoking in their presence. Questionnaires about SHS often underestimate prevalence and extent of exposure. A more accurate tool is the use of biomarkers such as cotinine (COT) and trans-3'-hydrocycotinine (3HC) as biomarkers of SHS exposure, alongside 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a reduction product in the body of the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), both potent carcinogens. We measured urinary COT, 3HC and total NNAL using sensitive and specific high-performance LC-MS/MS methods. The limit of quantification (LOQ) for each assay were 0.05 ng/mL, 0.1 ng/mL and 0.25 pg/mL respectively. The aim of this study was to evaluate the exposure to SHS of school children (9-11 years), from five public schools in the island of Malta, from questionnaire information about smoking at home and verify it by urinary biomarker data of COT, 3HC and NNAL. These biomarkers were measurable in 99.4%, 95.4% and 98.3% of the participating children respectively. From the children reporting smoking at home, 11% had a history of asthma and had COT, 3HC and NNAL geometric mean concentrations double compared to the non-asthmatic group. In has been confirmed that non-smokers exposed to SHS and THS have a higher NNAL/COT ratio than the group identified as smokers according to specific and defined COT threshold levels (despite the fact that a priori, the entire study group was composed of non-smokers). The implication of high measured levels of urinary NNAL in children should be of concern given its potency. A main effects multifactor ANOVA model was developed and the children's house and school locations and the smoking frequency were statistically significant to predict the levels of the three metabolites. For 3HC only, the status of the employment of the mother was also an important predictor.

Maternal tobacco smoke exposure is associated with increased DNA methylation at human metastable epialleles in infant cord blood

Metastable epialleles (MEs) are genomic regions that are stochastically methylated prior to germ layer specification and exhibit high interindividual but low intra-individual variability across tissues. ME methylation is vulnerable to environmental stressors, including diet. Tobacco smoke (TS) exposure during pregnancy is associated with adverse impacts on fetal health and maternal micronutrient levels as well as altered methylation. Our objective was to determine if maternal smoke exposure impacts methylation at MEs. Consistent with prior studies, we observed reductions in one-carbon pathway micronutrients with gestational TS exposure, including maternal folate (P = 0.02) and vitamins B6 (P = 0.05) and B12 (P = 0.007). We examined putative MEs BOLA3, PAX8, and ZFYVE28 in cord blood specimens from 85 Newborn Epigenetics STudy participants. Gestational TS exposure was associated with elevated DNA methylation at PAX8 (+5.22% average methylation; 95% CI: 0.33% to 10.10%; P = 0.037). In human conceptal kidney tissues, higher PAX8 transcription was associated with lower methylation (R s = 0.55; P = 0.07), suggesting that the methylation levels established at MEs, and their environmentally induced perturbation, may have meaningful, tissue-specific functional consequences. This may be particularly important because PAX8 is implicated in several cancers, including pediatric kidney cancer. Our data are the first to indicate vulnerability of human ME methylation establishment to TS exposure, with a general trend of increasing levels of methylation at these loci. Further investigation is needed to determine how TS exposure-mediated changes in DNA methylation at MEs, and consequent expression levels, might affect smoking-related disease risk.

Disparities in dental health issues and oral health care visits in US children with tobacco smoke exposure

BACKGROUND

The objective of the authors was to assess the relationships between tobacco smoke exposure (TSE) and dental health and dental care visits among US children.

METHODS

The authors examined 2018-2019 National Survey of Children's Health data on TSE, dental health, and oral health care visits. Children aged 1 through 11 years (N = 32,214) were categorized into TSE groups: no home TSE (did not live with a smoker), thirdhand smoke (THS) exposure (lived with a smoker who did not smoke inside the home), or secondhand smoke (SHS) and THS exposure (lived with a smoker who smoked inside the home). The authors conducted multivariable logistic regression analyses, adjusting for child age, sex, race or ethnicity, prematurity, caregiver education level, family structure, and federal poverty threshold.

RESULTS

Children with home SHS and THS exposure were at increased odds of having frequent or chronic difficulty with 1 or more oral health problem (adjusted odds ratio [AOR], 1.59; 95% CI, 1.07 to 2.35; P = .022) and carious teeth or caries (AOR, 1.74; 95% CI 1.14 to 2.65; P = .010) than those with no TSE. Compared with children aged 1 through 11 years with no TSE, children with SHS and THS exposure were 2.22 times (95% CI, 1.01 to 4.87; P = .048) more likely to have not received needed oral health care but at decreased odds of having had any kind of oral health care visit (AOR, 0.55; 95% CI, 0.32 to 0.95; P = .032), including a preventive oral health care visit (AOR, 0.60; 95% CI, 0.36 to 0.99; P = .047).

CONCLUSIONS

TSE in children is associated with caries and inadequate oral health care visits.

PRACTICAL IMPLICATIONS

The pediatric dental visit is an opportune time to educate caregivers who smoke about dental health to improve their children's teeth condition and increase oral health care visits.

Secondhand tobacco smoke exposure among children under 5 years old: questionnaires versus cotinine biomarkers: a cohort study

OBJECTIVES

Cotinine is the gold standard to estimate prevalence of secondhand tobacco smoke (SHS) exposure, and assay limit of detection (LOD) cut-points are typically used regardless of age. Our aim was to compare the concordance between mother-reported SHS exposure and serum cotinine categorising children as exposed with the assay LOD or age-specific cut-points.

DESIGN

Data from the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort.

SETTING

Hospital or participants' homes.

PARTICIPANTS

389 pregnant women aged 18 years and older, between 13 and 19 weeks of gestation, living in a five-county region of the Cincinnati, Ohio metropolitan area, and with follow-up on their children at birth and ages 12, 24, 36 and 48 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

Children's serum cotinine, mother-reported active smoking and SHS exposure were available at birth and during follow-up visits. We used Cohen's kappa index to assess concordance between maternal self-report and child's serum cotinine concentrations. We estimated optimal age-specific cut-points, their sensitivity-specificity and positive-negative predictive values with receiver operating characteristic curves.

RESULTS

Self-reported exposure and cotinine data were available for 280 women who gave birth to singleton child. When applying the assay LOD (0.015 ng/mL), concordance between maternal report and serum cotinine, without accounting for age, was below 0.23 at all times. When using age-specific cut-points (12 months: 0.11 ng/mL; 24 months: 0.08 ng/mL; 36 months: 0.05 ng/mL and 48 months: 0.04 ng/mL), concordance improved, being low at 12 months (0.39), moderate at 24 and 36 months (0.47 and 0.43) and high at 48 months (0.62).

CONCLUSIONS

Concordance between mother-reported SHS exposure among children under 5 years and serum cotinine improved considerably after applying the cohort-specific and age-specific cut-points. Future studies are necessary to verify these results.

Identifying the Best Questions for Rapid Screening of Secondhand Smoke Exposure Among Children

INTRODUCTION

Many children suffer from secondhand smoke exposure (SHSe), which leads to a variety of negative health consequences. However, there is no consensus on how clinicians can best query parents for possible SHSe among children. We employed a data-driven approach to create an efficient screening tool for clinicians to quickly and correctly identify children at risk for SHSe.

METHODS

Survey data from mothers and biospecimens from children were ascertained from the Neurodevelopment and Improving Children's Health following Environmental Tobacco Smoke Exposure (NICHES) study. Included were mothers and their children whose saliva were assayed for cotinine (n = 351 pairs, mean child age = 5.6 years). Elastic net regression predicting SHSe, as indicated from cotinine concentration, was conducted on available smoking-related questions and cross-validated with 2015-2016 National Health and Nutrition Examination Survey (NHANES) data to select the most predictive items of SHSe among children (n = 1670, mean child age = 8.4 years).

RESULTS

Answering positively to at least one of the two final items ("During the past 30 days, did you smoke cigarettes at all?" and "Has anyone, including yourself, smoked tobacco in your home in the past 7 days?") showed area under the curve = .82, and good specificity (.88) and sensitivity (.74). These results were validated with similar items in the nationally representative NHANES sample, area under the curve = .82, specificity = .78, and sensitivity = .77.

CONCLUSIONS

Our data-driven approach identified and validated two items that may be useful as a screening tool for a speedy and accurate assessment of SHSe among children.

IMPLICATIONS

The current study used a rigorous data-driven approach to identify questions that could reliably predict SHSe among children. Using saliva cotinine concentration levels as a gold standard for determining SHSe, our analysis employing elastic net regression identified two questions that served as good classifier for distinguishing children who might be at risk for SHSe. The two items that we validated in the current study can be readily used by clinicians, such as pediatricians, as part of screening procedures to quickly identify whether children might be at risk for SHSe.

Smoke-Free Home Rules and Association with Child Secondhand Smoke Exposure among Mother-Child Dyad Relationships

Smoke-free home rules restrict smoking in the home, but biomarkers of secondhand smoke exposure are needed to help understand the association between smoke-free homes and child secondhand smoke exposure. Participants (n = 346) were majority Black/African American mother-child dyads from a longitudinal study in North Carolina. Mothers completed questionnaires on household smoking behaviors and rules, and child saliva samples were assayed for secondhand smoke exposure. Regression models used smoke-free home rules to predict child risk for secondhand smoke exposure. Children in households with smoke-free home rules had less salivary cotinine and risk for secondhand smoke exposure. After controlling for smokers in the household, home smoking rules were not a significant predictor of secondhand smoke exposure. Compared to children in households with no smokers, children in households with at least one smoker but a non-smoking mother (OR 5.35, 95% CI: 2.22, 13.17) and households with at least one smoker including a smoking mother (OR 13.73, 95% CI: 6.06, 33.28) had greater risk for secondhand smoke exposure. Results suggest smoke-free home rules are not sufficient to fully protect children from secondhand smoke exposure, especially in homes with smokers. Future research should focus on how household members who smoke can facilitate the prevention of child secondhand smoke exposure.

DNA Methylation in Babies Born to Nonsmoking Mothers Exposed to Secondhand Smoke during Pregnancy: An Epigenome-Wide Association Study

BACKGROUND

Maternal smoking during pregnancy is related to altered DNA methylation in infant umbilical cord blood. The extent to which low levels of smoke exposure among nonsmoking pregnant women relates to offspring DNA methylation is unknown.

OBJECTIVE

This study sought to evaluate relationships between maternal prenatal plasma cotinine levels and DNA methylation in umbilical cord blood in newborns using the Infinium HumanMethylation 450K BeadChip.

METHODS

Participants from the Newborn Epigenetics Study cohort who reported not smoking during pregnancy had verified low levels of cotinine from maternal prenatal plasma (0 ng / mL to < 4  ng / mL ), and offspring epigenetic data from umbilical cord blood were included in this study (n = 79 ). Multivariable linear regression models were fit to the data, controlling for cell proportions, age, race, education, and parity. Estimates represent changes in response to any 1 -ng / mL unit increase in exposure.

RESULTS

Multivariable linear regression models yielded 29,049 CpGs that were differentially methylated in relation to increases in cotinine at a 5% false discovery rate. Top CpGs were within or near genes involved in neuronal functioning (PRKG1, DLGAP2, BSG), carcinogenesis (FHIT, HSPC157) and inflammation (AGER). Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggest cotinine was related to methylation of gene pathways controlling neuronal signaling, metabolic regulation, cell signaling and regulation, and cancer. Further, enhancers associated with transcription start sites were enriched in altered CpGs. Using an independent sample from the same study population (n = 115 ), bisulfite pyrosequencing was performed with infant cord blood DNA for two genes within our top 20 hits (AGER and PRKG1). Results from pyrosequencing replicated epigenome results for PRKG1 (cg17079497, estimate = - 1.09 , standard error  ( SE ) = 0.45 , p = 0.018 ) but not for AGER (cg09199225; estimate = - 0.16 , SE = 0.21 , p = 0.44 ).

DISCUSSION

Secondhand smoke exposure among nonsmoking women may alter DNA methylation in regions involved in development, carcinogenesis, and neuronal functioning. These novel findings suggest that even low levels of smoke exposure during pregnancy may be sufficient to alter DNA methylation in distinct sites of mixed umbilical cord blood leukocytes in pathways that are known to be altered in cord blood from pregnant active smokers. https://doi.org/10.1289/EHP8099.

Subnational exposure to secondhand smoke in Iran from 1990 to 2013: a systematic review

Every year, almost eight million people die from tobacco-related diseases, among which around 1.2 million die from secondhand smoke (SHS) exposure. Generally, it is estimated that SHS constituents generated in the interval between puffs are approximately 3 times more toxic than those produced at the moment of puffing. There is no risk-free level of SHS exposure, and even brief exposure can be harmful to health. The aim of this study was to assess SHS exposure and its trend in the different provinces of Iran from 1990 to 2013. To collect available data on SHS exposure, a systematic review was performed. We searched international and national databases using a combination of Medical Subject Headings (MeSH) and relevant text words in the titles, abstracts, and/or keywords. Also, the data in national surveys were gathered. The frequency of exposure in different provinces as well as age, sex, and rural/urban areas were extracted. Afterwards, modeling was done to estimate SHS exposure from the smoking data. According to our findings, SHS exposure was more prevalent among young people. Moreover, this exposure was greater in rural areas as compared to urban areas. A national study on 13-15-year-old individuals showed the highest exposure occurred outdoors. In addition, a declining trend was observed on SHS exposure over time. It seems that attention to the importance of SHS exposure in researches in Iran dates back to 2001, and gradually, especially in recent years, further studies have been conducted on SHS exposure.

Magnitude and Chronicity of Environmental Smoke Exposure Across Infancy and Early Childhood in a Sample of Low-Income Children

INTRODUCTION

Infants and young children may be at an increased risk for second- and thirdhand exposure to tobacco smoke because of increased respiration rate and exposure to surface residue. However, relatively fewer studies have examined biomarkers of exposure (cotinine) in children under age 4 years. This study examines the magnitude and chronicity of exposure across early childhood among children from low-income families in order to better characterize contextual risk factors associated with exposure.

METHODS

A total of 1292 families were recruited in six nonurban counties of Pennsylvania and North Carolina. Cotinine was assayed from infant saliva at 6, 15, 24, and 48 months of age (N = 1218), and categorized as low (≤0.45 ng/mL), moderate (0.46-12 ng/mL), or high (≥12 ng/mL) at each time point. Categories were highly correlated across time. Latent class analysis was used to summarize patterns of exposure categories across time.

RESULTS

Magnitude of exposure in this sample was high, with approximately 12% of infants registering cotinine values at least 12 ng/mL, consistent with active smoking in adults. Greater exposure was associated with lower income, less education, more residential instability, and more instability in adult occupants in the home, whereas time spent in center-based day care was associated with lower exposure.

CONCLUSIONS

Young children from low-income, nonurban communities appear to bear a higher burden of secondhand smoke exposure than previous studies have reported. Results contribute to understanding populations at greater risk, as well as specific, potentially malleable, environmental factors that may be examined as direct contributors to exposure.

IMPLICATIONS

Results suggest that infants from low-income, nonurban families have higher risk for environmental smoke exposure than data from nationally representative samples. Predictors of exposure offer insights into specific factors that may be targeted for risk reduction efforts, specifically conditions of children's physical space. In addition to considering the increases in risk when an adult smoker lives in a child's home, families should also attend to the possible risk embedded within the home itself, such as residual smoke from previous occupants. For high-risk children, day care appears to mitigate the magnitude of exposure by providing extended time in a smoke-free environment.

Electronic Health Record Classification of Tobacco Smoke Exposure and Cotinine Levels in Hospitalized Pediatric Patients

OBJECTIVES

Documentation of children's tobacco smoke exposure (TSE) in the electronic health record (EHR) can have important implications for clinical care. However, it may not be accurate if it is not based on biochemical assessment, the most reliable method of verifying TSE. Our objectives were to compare the accuracy of EHR classification of TSE with cotinine verification and to explore parent and child variables associated with biochemically verified TSE.

METHODS

Participants were 171 hospitalized pediatric patients (ages 0-17 years; mean age 5.1 [SD 3.7] years) who had EHR documentation of TSE and measured salivary cotinine. Children with cotinine levels >1 ng/mL were classified as having biochemical verification of TSE. Parents reported sociodemographic characteristics, and children's EHRs were abstracted for TSE status, past medical history, and diagnoses. We conducted χ² tests to assess the agreement between EHR classification of TSE status and cotinine levels. Then, we assessed the relationship between sociodemographic and clinical variables and cotinine using crude and adjusted logistic regression models.

RESULTS

Overall, 71% (121 of 171) of EHR classifications were correct on the basis of cotinine levels. Specificity analyses showed that 77% (53 of 69) were correctly identified as exposed to tobacco smoke. Sensitivity analyses showed that 67% (68 of 102) were correctly identified as unexposed. The negative predictive value was 0.61 (53 of 87); 39% (34 of 87) were misclassified as unexposed. The positive predictive value was 0.81 (68 of 84); 19% (16 of 84) were misclassified as exposed.

CONCLUSIONS

Almost 40% of children were misclassified in the EHR as unexposed to tobacco smoke. Biochemical verification should be used as part of universal TSE screening during pediatric hospitalizations.

Gene-Environment Interaction between the IL1RN Variants and Childhood Environmental Tobacco Smoke Exposure in Asthma Risk

(1) Background: Variants of the interleukin-1 receptor antagonist (IL1RN) gene, encoding an anti-inflammatory cytokine, are associated with asthma. Asthma is a chronic inflammatory disease of the airway influenced by interactions between genetic variants and environmental factors. We discovered a gene-environment interaction (GEI) of IL1RN polymorphisms with childhood environmental tobacco smoke (ETS) exposure on asthma susceptibility in an urban adult population. (2) Methods: DNA samples from the NYU/Bellevue Asthma Registry were genotyped for tag SNPs in IL1RN in asthma cases and unrelated healthy controls. Logistic regressions were used to study the GEI between IL1RN variants and childhood ETS exposures on asthma and early onset asthma, respectively, adjusting for population admixture and other covariates. (3) Results: Whereas the rare genotypes of IL1RN SNPs (e.g., GG in SNP rs2234678) were associated with decreased risk for asthma among those without ETS exposure (odds ratio OR = 0.215, p = 0.021), they are associated with increased risk for early onset asthma among those with childhood ETS (OR = 4.467, p = 0.021). (4) Conclusions: We identified a GEI between polymorphisms of IL1RN and childhood ETS exposure in asthma. Analysis of GEI indicated that childhood ETS exposure disrupted the protective effect of some haplotypes/genotypes of IL1RN for asthma and turned them into high-risk polymorphisms for early onset asthma.

Comparison of Liquid Chromatography Mass Spectrometry and Enzyme-Linked Immunosorbent Assay Methods to Measure Salivary Cotinine Levels in Ill Children

Objective: Cotinine is the preferred biomarker to validate levels of tobacco smoke exposure (TSE) in children. Compared to enzyme-linked immunosorbent assay methods (ELISA) for quantifying cotinine in saliva, the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) has higher sensitivity and specificity to measure very low levels of TSE. We sought to compare LC-MS/MS and ELISA measures of cotinine in saliva samples from children overall and the associations of these measures with demographics and TSE patterns. Method: Participants were nonsmoking children (N = 218; age mean (SD) = 6.1 (5.1) years) presenting to a pediatric emergency department. Saliva samples were analyzed for cotinine using both LC-MS/MS and ELISA. Limit of quantitation (LOQ) for LC-MS/MS and ELISA was 0.1 ng/ml and 0.15 ng/ml, respectively. Results: Intraclass correlations (ICC) across methods = 0.884 and was consistent in sex and age subgroups. The geometric mean (GeoM) of LC-MS/MS = 4.1 (range: < LOQ - 382 ng/mL; 3% < LOQ) which was lower (p < 0.0001) than the ELISA GeoM = 5.7 (range: < LOQ - 364 ng/mL; 5% < LOQ). Similar associations of cotinine concentrations with age ( < -0.10, p < 0.0001), demographic characteristics (e.g., income), and number of cigarettes smoked by caregiver ( > 0.07, p < 0.0001) were found regardless of cotinine detection method; however, cotinine associations with sex and race/ethnicity were only found to be significant in models using LC-MS/MS-derived cotinine. Conclusions: Utilizing LC-MS/MS-based cotinine, associations of cotinine with sex and race/ethnicity of child were revealed that were not detectable using ELISA-based cotinine, demonstrating the benefits of utilizing the more sensitive LC-MS/MS assay for cotinine measurement when detecting low levels of TSE in children.

Quantitative biochemical screening for marijuana use and concordance with tobacco use in urban adolescents

BACKGROUND

Assessing the prevalence and level of exposure (dose) of tobacco and marijuana use is important in studies of harm from use of these substances. We used biochemical analysis of urine to quantitatively assess exposure to nicotine and delta 9-tetrahydrocannabinol (THC) in adolescents receiving medical care in a public hospital METHODS: Participants were 686 adolescents between 12 and 21 years old seen at Zuckerberg San Francisco General Hospital between 2012 and 2014. Urine samples were assayed using high sensitivity liquid chromatographic assays for cotinine, a major metabolite of nicotine, and 11-nor-9-carboxy-delta 9-THC (THC-COOH), a major metabolite of THC. A commonly used immunoassay screen for THC-COOH was also performed.

RESULTS

The THC-COOH immunoassay substantially underestimated THC exposure, as measured with the high sensitivity assay. THC use was detected in 25% of participants, with higher prevalence with increasing age and in non-Hispanic blacks. Active tobacco smokers had an 80% prevalence of THC use (odds ratio for cigarette smoking predicting THC use 13.2). Urine cotinine and THC-COOH were significantly correlated (r = 0.60).

CONCLUSIONS

The use of a high sensitivity chromatographic urine assay provides a much more complete picture of adolescent tobacco use compared to a commonly used immunoassay. The immunoassay provides high specificity but moderate sensitivity. We confirm high concordance of tobacco and marijuana use and the high predictive value of cigarette smoking in predicting marijuana use, and provide novel data on the quantitative correlation between level of exposure to nicotine and THC. Quantitative screening of nicotine and THC exposure may enhance our understanding of addiction and harm from single and dual product use.

Determinants of mental health and abuse of psychoactive substances associated with tobacco use. A case-control study

This study aimed to estimate the strength of association among smokers with variables regarding mental health, family functionality, and use of other psychoactive substances. This is a case-control observational study developed from March to November 2016. The study was conducted in a Brazilian Midwest municipality with 646 subjects, of which 323 were cases. In the model, the case group comprised subjects with a certain degree of tobacco dependence. The control group included subjects that were not exposed to tobacco. Concerning tobacco use time, the mean exposure of the case group was 25.65 years. In the multiple logistic regression analysis model the following were positively associated: non-white skin color (p = 0.002); years of study ≤ 8 (p < 0.001); having children (p < 0.001); informal work (p = 0.024); not having a health plan (p < 0.001); high family dysfunction (p = 0.007); AUDIT ≥ 8 (p < 0.001); depression (p < 0.001); having illicit drug in lifetime (p < 0.001); living with other people (p = 0.003) and no religion (p = 0.001). This study reinforces the vulnerability of smokers, associating variables correlated to the field of mental health, and innovates by discussing the influence of family relationships on nicotinic dependence.

Lung cancer health disparities

Compared with all other racial and ethnic groups in the United States, African Americans are disproportionally affected by lung cancer, both in terms of incidence and survival. It is likely that smoking, as the main etiological factor associated with lung cancer, contributes to these disparities, but the precise mechanism is still unclear. This paper seeks to explore the history of lung cancer disparities and review to the literature regarding the various factors that contribute to them.

Long-term exposure to extremely low-dose of nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) induce non-malignant breast epithelial cell transformation through activation of the a9-nicotinic acetylcholine receptor-mediated signaling pathway

Breast cancer (BC) is the most common cancer affecting women worldwide and has been associated with active tobacco smoking. Low levels of nicotine (Nic) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), have been detected in cases of second-hand smoke (SHS). However, the correlation between SHS and BC risk remains controversial. In this study, we investigated whether the physiological SHS achievable dose of Nic and tobacco specific nitrosamine, NNK act together to induce breast carcinogenesis using an in vitro breast cell carcinogenesis model. Immortalized non-tumorigenic breast epithelial cell line, HBL-100 used for a time-course assay, was exposed to very low levels of either Nic or NNK, or both. The time-course assay consisted of 23 cycles of nitrosamines treatment. In each cycle, HBL-100 cells were exposed to 1pM of Nic and/or 100 femtM of NNK for 48 hours. Cells were passaged every 3 days and harvested after 10, 15, and 23 cycles. Our results demonstrated that the tumorigenicity of HBL-100, defined by soft agar colony forming, proliferation, migration and invasion abilities, was enhanced by co-exposure to physiologically SHS achievable doses of Nic and NNK. In addition, α9-nAChR signaling activation, which plays an important role in cellular proliferation and cell survival, was also observed. Importantly, an increase in stemness properties including the prevalence of CD44+/CD24- cells, increase Nanog expression and mammosphere-forming ability were also observed. Our results indicate that chronic and long term exposure to environmental tobacco smoke, may induce breast cell carcinogenesis even at extremely low doses.

Secondhand smoke exposure and asthma outcomes among African-American and Latino children with asthma

BACKGROUND

Secondhand smoke (SHS) exposures have been linked to asthma-related outcomes but quantitative dose-responses using biomarkers of exposure have not been widely reported.

OBJECTIVES

Assess dose-response relationships between plasma cotinine-determined SHS exposure and asthma outcomes in minority children, a vulnerable population exposed to higher levels of SHS and under-represented in the literature.

METHODS

We performed analyses in 1172 Latino and African-American children with asthma from the mainland USA and Puerto Rico. We used logistic regression to assess relationships of cotinine levels ≥0.05 ng/mL with asthma exacerbations (defined as asthma-related hospitalisations, emergency room visits or oral steroid prescription) in the previous year and asthma control. The shape of dose-response relationships was assessed using a continuous exposure variable in generalised additive logistic models with penalised splines.

RESULTS

The OR for experiencing asthma exacerbations in the previous year for cotinine levels ≥0.05 ng/mL, compared with <0.05 ng/mL, was 1.40 (95% CI 1.03 to 1.89), while the OR for poor asthma control was 1.53 (95% CI 1.12 to 2.13). Analyses for dose-response relationships indicated increasing odds of asthma outcomes related with increasing exposure, even at cotinine levels associated with light SHS exposures.

CONCLUSIONS

Exposure to SHS was associated with higher odds of asthma exacerbations and having poorly controlled asthma with an increasing dose-response even at low levels of exposure. Our results support the conclusion that there are no safe levels of SHS exposures.

Self-reported prenatal tobacco smoke exposure, AXL gene-body methylation, and childhood asthma phenotypes

BACKGROUND

Epigenetic modifications, including DNA methylation, act as one potential mechanism underlying the detrimental effects associated with prenatal tobacco smoke (PTS) exposure. Methylation in a gene called AXL was previously reported to differ in response to PTS.

METHODS

We investigated the association between PTS and epigenetic changes in AXL and how this was related to childhood asthma phenotypes. We tested the association between PTS and DNA methylation at multiple CpG loci of AXL at birth using Pyrosequencing in two separate study populations, the Children's Health Study (CHS, n = 799) and the Newborn Epigenetic Study (NEST, n = 592). Plasma cotinine concentration was used to validate findings with self-reported smoking status. The inter-relationships among AXL mRNA and miR-199a1 expression, PTS, and AXL methylation were examined. Lastly, we evaluated the joint effects of AXL methylation and PTS on the risk of asthma and related symptoms at age 10 years old.

RESULTS

PTS was associated with higher methylation level in the AXL gene body in both CHS and NEST subjects. In the pooled analysis, exposed subjects had a 0.51% higher methylation level in this region compared to unexposed subjects (95% CI 0.29, 0.74; p < 0.0001). PTS was also associated with 21.2% lower expression of miR-199a1 (95% CI - 37.9, - 0.1; p = 0.05), a microRNA known to regulate AXL expression. Furthermore, the combination of higher AXL methylation and PTS exposure at birth increased the risk of recent episodes of bronchitic symptoms in childhood.

CONCLUSIONS

PTS was associated with methylation level of AXL and the combination altered the risk of childhood bronchitic symptoms.

Self-Reported Environmental Tobacco Smoke Exposure and Avoidance Compared with Cotinine Confirmed Tobacco Smoke Exposure among Pregnant Women and Their Infants

BACKGROUND

Exposure to environmental tobacco smoke (ETS) presents substantial health risks for pregnant women and newborn infants. Measurements of ETS include invasive and expensive biochemical tests, as well as less invasive and lower-cost, self-reported exposure and avoidance measures. Better understanding of self-report measures will help to select ETS assessments for evaluation.

METHODS

This analysis was conducted within the context of a tailored video intervention to reduce tobacco smoking and ETS exposure during pregnancy and after delivery in the control group sample of 147 nonsmoking women. Measurements of salivary cotinine concentration, self-reported ETS exposure, and avoidance behaviors were captured at 32 weeks’ gestation and 6 months postpartum.

RESULTS

Salivary cotinine concentration was significantly related to ETS avoidance among pregnant nonsmokers at 32 weeks’ gestation, but not ETS exposure. At 6 months postpartum, both the reported ETS exposure of the infant and maternal avoidance behaviors to reduce her infant’s exposure were associated with the infant’s salivary cotinine concentration. At 32 weeks’ gestation and 6 months postpartum, avoidance behaviors decreased as exposure increased.

DISCUSSION

This study suggests that for nonsmoking women during pregnancy, reports of tobacco smoke avoidance are more valid than reports of exposure. After delivery, self-reported ETS exposure or avoidance are associated with each other and the biochemical measurement of salivary cotinine. These results provide researchers and clinicians with evidence to support the inclusion of avoidance behaviors in the selection of ETS measures.

Examining the Validity of Self-reported Primary and Secondary Exposure to Cigarette Smoke in Adolescent Girls: The Utility of Salivary Cotinine as a Biomarker

BACKGROUND

Studies of cigarette use and exposure often rely on either self-report or cotinine assay. In adolescence it is not clear how well assays and self-report correspond, or what effect estrogen exposure has on cotinine.

OBJECTIVES

This study sought to identify optimal cut-points for salivary cotinine thresholds for girls with primary, secondary, and no smoke exposure, and whether menarche and hormone contraceptive use are important for interpreting salivary cotinine.

METHODS

This longitudinal prospective study recruited 262 healthy adolescent girls who participated in three annual interviews across 24 months. Salivary cotinine assays and self-report of primary and secondary smoke exposure, menarcheal status, and hormone contraceptive use were collected.

RESULTS

No adolescents reported primary smoke exposure without secondary exposure. Optimal cut-points for distinguishing primary smoke exposure from secondary-only and no smoke exposure were 1.05 and 3.01 ng/ml, respectively based on receiver operator curves (ROC); no reliable cut-point for secondary-only versus no smoke exposure was identified. The ideal salivary cotinine cut-point to distinguish primary smoke exposure varied by hormone contraceptive use and was 2.14 ng/ml for those using progesterone contraceptives, higher than that of girls using estrogen contraceptives and those not using hormone contraceptives.

CONCLUSIONS

This study is the first to examine variance in salivary cotinine cut-points based on hormone exposure for adolescent girls, with findings indicating that hormone contraceptive use in particular may be a key consideration when identifying adolescent smoking. The use of previously recommended salivary cotinine cut-points of 3.85 ng/ml or higher may overestimate nonsmokers.

A Cluster Randomised Controlled Trial of a Brief Child Health Nurse Intervention to Reduce Infant Secondhand Smoke Exposure

Background Exposure to secondhand smoke (SHS) is a significant contributor to ill health in children. A study was undertaken to determine the effectiveness of two brief multi-strategic child health nurse delivered interventions in: decreasing the prevalence of infants exposed to SHS; decreasing the prevalence of smoking amongst parent/carers of infants and increasing the prevalence of household smoking bans. Methods This study was a 3 arm, cluster randomised controlled trial. Clusters were 39 community based well child health clinics in one local area health service. Clinics were stratified according to annual number of client appointments and then randomly assigned in a 1:1:1 ratio, (Intervention 1: Intervention 2: Control), with 13 clinics in each cluster. Parents/carers of infants in the intervention groups received a brief multi-strategic intervention from child health nurses during clinic consultations. Treatment condition 1 included computer delivered risk assessment and feedback and nurse brief advice. Treatment condition 2 included all elements of Treatment condition 1 with the addition of biochemical feedback of infant SHS exposure. Results When compared to the Control group at 12 months, no significant differences in the prevalence of infant exposure to SHS were detected from baseline to follow-up for Treatment condition 1 (OR 1.16, 95 % CI 0.73-1.85, p = 0.53) or Treatment condition 2 (OR 1.30, 95 % CI 0.88-1.92, p = 0.19) Similarly, no significant differences were detected in the proportion of parent/carers who reported that they were smokers (T1:OR 0.95, 95 % CI 0.78-1.15, p = 0.58 and T2:OR 0.97, 95 % CI 0.80-1.18, p = 0.77), or in the proportion of households reported to have a complete smoking ban (T1:OR 1.21, 95 % CI 0.89-1.64, p = 0.23 and T2:OR 1.06, 95 % CI 0.79-1.43, p = 0.68). Conclusions Further research is required to identify effective interventions that can be consistently provided by child health nurses if the potential of such settings to contribute to reductions in child SHS exposure is to be realised.

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.

Impact of Smoking Ban on Passive Smoke Exposure in Pregnant Non-Smokers in the Southeastern United States

Prenatal passive smoke exposure raises risk for negative birth outcomes. Legislation regulating public smoking has been shown to impact exposure levels, though fewer studies involving pregnant women have been conducted within the U.S. where bans are inconsistent across regions. This study examined the effect of a ban enacted in the southeastern U.S. on pregnant women's cotinine levels. Additional analyses compared self-reported exposure to cotinine and identified characteristics associated with passive exposure. Pregnant women (N = 851) were recruited prospectively between 2005 and 2011 in North Carolina. Sociodemographic and health data were collected via surveys; maternal blood samples were assayed for cotinine. Among non-active smokers who provided self-report data regarding passive exposure (N = 503), 20% were inconsistent with corresponding cotinine. Among all non-smokers (N = 668), being unmarried, African American, and less educated were each associated with greater passive exposure. Controlling for covariates, mean cotinine was higher prior to the ban compared to after, F(1, 640) = 24.65, p < 0.001. Results suggest that banning smoking in public spaces may reduce passive smoke exposure for non-smoking pregnant women. These data are some of the first to examine the impact of legislation on passive smoke exposure in pregnant women within the U.S. using a biomarker and can inform policy in regions lacking comprehensive smoke-free legislation.

Urine Cotinine Screening Detects Nearly Ubiquitous Tobacco Smoke Exposure in Urban Adolescents

INTRODUCTION

Routine biochemical assessment of tobacco smoke exposure could lead to more effective interventions to reduce or prevent secondhand smoke (SHS)-related disease in adolescents. Our aim was to determine using urine cotinine (major nicotine metabolite) measurement the prevalence of tobacco smoke exposure among adolescents receiving outpatient care at an urban public hospital.

METHODS

Surplus urine was collected in 466 adolescents attending pediatric or urgent care clinics at Zuckerberg San Francisco General Hospital, serving families with lower levels of income and education, in 2013-2014. The majority were Hispanic or African American. Urine cotinine cut points of 0.05 to 0.25 ng/ml, 0.25 to 30 ng/ml, and 30 ng/ml were used to classify subjects as light SHS or thirdhand smoke exposed, SHS or light/intermittent active users, and active tobacco users, respectively.

RESULTS

Among subjects 87% were exposed, including 12% active smoking, 46% SHS and 30% lightly exposed. The SHS exposed group adjusted geometric mean cotinine values were significantly higher in African Americans (1.48 ng/ml) compared to other groups (0.56-1.13 ng/ml).

CONCLUSIONS

In a city with a low smoking prevalence (12%), a large majority (87%) of adolescents seen in a public hospital clinic are exposed to tobacco. This is much higher than reported in national epidemiological studies of adolescents, which used a plasma biomarker. Since SHS is associated with significant respiratory diseases and parents and adolescents underreport exposure to SHS, routine biochemical screening should be considered as a tool to reduce SHS exposure. The clinical significance of light exposure needs to be investigated.

IMPLICATIONS

Urine biomarker screening found that a large majority (87%) of adolescents treated in an urban public hospital are exposed to tobacco. Since SHS is associated with significant respiratory diseases and parents and adolescents underreport exposure to SHS, routine biochemical screening should be considered as a tool to reduce SHS exposure.

Trends in exposure to second hand smoke at home among children and nonsmoker adolescents

Data from National Health and Nutrition Examination Survey (NHANES) for the years 1999-2012 were used to evaluate trends in exposure to second hand smoke (SHS) at home among children aged 3-11 years and nonsmoker adolescents aged 12-19 years. A total of 12,815 children and 10,269 adolescents were included in the analyses. Serum cotinine was used as a biomarker for exposure to SHS at home. Regression models with log10 transformed values of serum cotinine as dependent variables and age, race/ethnicity, NHANES survey year, and family poverty income ratio as a surrogate measure of socioeconomic status were used in models for those with and without exposure to SHS at home. In addition, for those with exposure to SHS at home, number of smokers smoking inside home and number of cigarettes smoked at home every day were also used as independent variables. There was a biennial increase of 1.05 ng/L in adjusted serum cotinine levels for children with exposure to SHS at home over the period of 1999-2012. Serum cotinine levels among nonsmoker adolescents with exposure to SHS at home did not change over time. When there was no exposure to SHS at home, there was a statistically significant downward trend for serum cotinine levels for both children and nonsmoker adolescents. Serum cotinine levels attributable to SHS exposure increased with age among nonsmoker adolescents (p≤0.02) but decreased with age among children (p<0.01). For a unit decrease in family poverty income ratio, SHS exposure as measured by serum cotinine levels (Table 6) increased by 1.18 ng/L among children and by 1.30 ng/L among nonsmoker adolescents. In general, observed serum cotinine levels associated with SHS exposure at home were higher for children than they were for nonsmoker adolescents.

Relationship between caregivers' smoking at home and urinary levels of cotinine in children

Objective: To assess the impact of different smoking behaviors of caregivers on environmental tobacco smoke (ETS) exposure in children aged 5–6 years in Changsha, China. Methods: We conducted a cross-sectional, random digit-dial telephone survey of caregivers (n = 543) between August and October 2013. Caregivers’ smoking behaviors were collected by a questionnaire. Exposure assessment was based upon determination of urinary cotinine levels in children employing gas chromatography–triple quadrupole mass spectrometry (GC-MS/MS). Results: In children not living with a smoker, children living with one smoker, and children living with more than one smoker at home, median urinary cotinine concentrations (ng/mL) were 0.72, 2.97, and 4.46, respectively. For children living with one smoker, median urinary cotinine levels of children exposed to ETS were associated with caregiver smoking behaviors, i.e., if a caregiver consumed more cigarettes (>20 compared with ≤10; 7.73 versus 2.29 ng/mL, respectively). Conclusions: The magnitude of ETS exposure in children is correlated with the smoking behaviors of the caregiver. Counseling for smoking cessation and educational interventions are needed urgently for smoking caregivers to increase their awareness about ETS exposure and to encourage smoking cessation at home or to take precautions to protect children’s health.

Intake of toxic and carcinogenic volatile organic compounds from secondhand smoke in motor vehicles

BACKGROUND

Volatile organic compounds (VOC) from tobacco smoke are associated with cancer, cardiovascular, and respiratory diseases. The objective of this study was to characterize the exposure of nonsmokers to VOCs from secondhand smoke (SHS) in vehicles using mercapturic acid metabolites.

METHODS

Fourteen nonsmokers were individually exposed in the backseat to one hour of SHS from a smoker seated in the driver's seat who smoked three cigarettes at 20-minute intervals in a stationary car with windows opened by 10 cm. Baseline and 0- to 8-hour postexposure mercapturic acid metabolites of nine VOCs were measured in urine. Air-to-urine VOC ratios were estimated on the basis of respirable particulate matter (PM2.5) or air nicotine concentration, and lifetime excess risk (LER) of cancer death from exposure to acrylonitrile, benzene, and 1,3-butadiene was estimated for adults.

RESULTS

The greatest increase in 0- to 8-hour postexposure concentrations of mercapturic acids from baseline was MHBMA-3 (parent, 1,3-butadiene; 2.1-fold), then CNEMA (acrylonitrile; 1.7-fold), PMA (benzene; 1.6-fold), MMA (methylating agents; 1.6-fold), and HEMA (ethylene oxide; 1.3-fold). The LER of cancer death from exposure to acrylonitrile, benzene, and 1,3-butadiene in SHS for 5 hours a week ranged from 15.5 × 10(-6) to 28.1 × 10(-6) for adults, using air nicotine and PM2.5 to predict air VOC exposure, respectively.

CONCLUSION

Nonsmokers have significant intake of multiple VOCs from breathing SHS in cars, corresponding to health risks that exceed the acceptable level.

IMPACT

Smoking in cars may be associated with increased risks of cancer, respiratory, and cardiovascular diseases among nonsmokers.

Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis

This guideline is a revision of the clinical practice guideline, "Diagnosis and Management of Bronchiolitis," published by the American Academy of Pediatrics in 2006. The guideline applies to children from 1 through 23 months of age. Other exclusions are noted. Each key action statement indicates level of evidence, benefit-harm relationship, and level of recommendation. Key action statements are as follows:

Cotinine in children admitted for asthma and readmission

OBJECTIVE

To explore the relationship between tobacco smoke exposure (reported versus biomarker) and rates of readmission for children hospitalized for asthma.

METHODS

We enrolled a prospective cohort of 774 children aged 1 to 16 years admitted for asthma or bronchodilator-responsive wheezing. The primary outcome was at least 1 asthma- or wheeze-related readmission within 1 year. Caregivers reported any tobacco exposure at home, in a secondary residence, or in the car. We measured serum and saliva cotinine levels with mass spectrometry. We used logistic regression to evaluate associations between tobacco exposure and readmissions.

RESULTS

A total of 619 children had complete tobacco exposure data; 57% were African American and 76% had Medicaid. Seventeen percent of children were readmitted within 1 year. Tobacco exposure rates were 35.1%, 56.1%, and 79.6% by report, serum, and saliva measures, respectively. Caregiver report of any tobacco exposure was not associated with readmission (adjusted odds ratio: 1.18; 95% confidence interval: 0.79-1.89), but having detectable serum or salivary cotinine was associated with increased odds of readmission (adjusted odds ratio [95% confidence interval]: 1.59 [1.02-2.48] and 2.35 [1.22-4.55], respectively). Among children whose caregivers reported no tobacco exposure, 39.1% had detectable serum cotinine and 69.9% had detectable salivary cotinine. Of the children with reported exposure, 87.6% had detectable serum cotinine and 97.7% had detectable salivary cotinine.

CONCLUSIONS

Detectable serum and salivary cotinine levels were common among children admitted for asthma and were associated with readmission, whereas caregiver report of tobacco exposure was not.

Towards estimating the burden of disease attributable to second-hand smoke exposure in Polish children

OBJECTIVES

To estimate the burden of disease attributable to second-hand smoke (SHS) exposure in Polish children in terms of the number of deaths and disability adjusted life years (DALYs) due to lower respiratory infections (LRI), otitis media (OM), asthma, low birth weight (LBW) and sudden infant death syndrome (SIDS).

MATERIALS AND METHODS

Estimates of SHS exposure in children and in pregnant women as well as information concerning maternal smoking were derived from a national survey, the Global Youth Tobacco Survey, and the Global Adult Tobacco Survey in Poland. Mortality data (LRI, OM, asthma, and SIDS), the number of cases (LBW), and population data were obtained from national statistics (year 2010), and DALYs came from the WHO (year 2004). The burden of disease due to SHS was calculated by multiplying the total burden of a specific health outcome (deaths or DALYs) by a population attributable fraction.

RESULTS

Using two estimates of SHS exposure in children: 48% and 60%, at least 12 and 14 deaths from LRI in children aged up to 2 years were attributed to SHS, for the two exposure scenarios, respectively. The highest burden of DALYs was for asthma in children aged up to 15 years: 2412, and 2970 DALYs, for the two exposure scenarios, respectively. For LRI, 419 and 500 DALYs, and for OM, 61 and 77 DALYs were attributed to SHS, for the two exposure scenarios, respectively. Between 13% and 27% of SIDS cases and between 3% and 16% of the cases of LBW at term were attributed to SHS exposure.

CONCLUSIONS

This study provides a conservative estimate of the public health impact of SHS exposure on Polish children. Lack of comprehensive, up to date health data concerning children, as well as lack of measures that would best reflect actual SHS exposure are major limitations of the study, likely to underestimate the burden of disease.

Evidence of high rates of undiagnosed asthma in central Ohio elementary schoolchildren

BACKGROUND

In Ohio, 14.5% of 5- to 9-year-olds and 17.3% of 10- to 17-year-olds have asthma. Moreover, there is concern that these numbers may underestimate the true disease burden. We sought to evaluate variability in asthma rates and respiratory symptoms among central Ohio fourth graders as a means to assess potential undiagnosed and undertreated asthma and its determinants.

METHODS

We recruited 13 central Ohio elementary schools representing a broad range of nonurban settings and surveyed fourth graders to estimate school-level physician-diagnosed asthma (PDA), respiratory morbidity, and home exposures to smoking and pets. We used generalized linear mixed models with random intercept for school to examine relationships among exposures, respiratory symptoms, and PDA.

RESULTS

Across the 13 schools, 94% of students participated in the survey, and the estimated asthma prevalence rate was 10.2% (N = 101 of 987). An additional 41% reported not having PDA but then went on to report symptoms consistent with asthma potentially suggestive of undiagnosed asthma. Of students with PDA, 21% reported symptoms suggestive of poorly controlled asthma. High levels of secondhand smoke (SHS) exposure were associated both with PDA (p = .05) and with respiratory symptoms (p < .0001). Students who owned a cat or a bird were more likely to report respiratory symptoms (p = .02 and p = .04, respectively).

CONCLUSIONS

We provide evidence that the already high childhood asthma public health burden in central Ohio may be underreported. Schools may be an ideal location to conduct screenings and implement environmental interventions oriented toward SHS and household pets that will yield respiratory morbidity benefits.

Biomarker evidence of tobacco smoke exposure in children participating in lead screening

OBJECTIVES

We assessed tobacco smoke exposure (TSE), defined according to detection of cotinine, in dried blood spots collected from children for lead screening.

METHODS

Dried blood spots collected from a national sample of 1541 Black and White children and submitted to a commercial laboratory for lead analysis were analyzed for cotinine. We used an anonymous administrative data set including information on children's characteristics to conduct univariate and multivariate analyses.

RESULTS

Cotinine was detected in 61% of dried blood spots; 17% of samples had cotinine levels above 3 nanograms per gram. Median cotinine levels were significantly higher among Black than White children (0.66 ng/g vs 0.30 ng/g) and among Medicaid recipients (0.94 ng/g vs < 0.3 ng/g). In multivariate analyses, significant increases in cotinine levels were associated with Black (vs White) race, older age, Medicaid coverage, higher state smoking rate, and higher average winter temperature. Detectable cotinine levels were significantly associated with higher lead levels.

CONCLUSIONS

TSE is highly prevalent among children undergoing lead screening, and exposure levels are greater among Black children and children on Medicaid. TSE may contribute to lead exposure. Concurrent lead screening and biological screening for TSE may be a feasible approach to increasing childhood TSE detection.

Cotinine and trans 3'-hydroxycotinine in dried blood spots as biomarkers of tobacco exposure and nicotine metabolism

Tobacco use is the major preventable cause of premature death in the United States. Second-hand smoke (SHS) exposure also contributes to a number of premature deaths as well as other negative health outcomes. An accurate assessment of tobacco smoke exposure is critical to understanding these disease processes. The plasma concentration of cotinine, the primary metabolite of nicotine, is widely accepted as a quantitative measure of tobacco and SHS exposure. However, it is not always feasible to collect plasma. Dried blood spots (DBS), which are collected routinely from newborns and often from young children for lead screening, provide an alternative sampling method. We have developed a quantitative high throughput liquid chromatography tandem mass spectrometry method for the analysis of cotinine in DBS. The limit of quantitation was 0.3 ng/g (~ 0.2 ng/ml plasma). Cotinine levels in DBS from 83 smokers and 99 non-smokers exposed to SHS were determined. Plasma cotinine concentrations in these subjects ranged from <0.02 to 443 ng/ml. Cotinine was detected in DBS from 157 subjects, and the correlation between cotinine in plasma and DBS was excellent, 0.992 (P<0.001). We also determined the ratio of trans 3'-hydroxycotinine to cotinine, a measure of nicotine metabolism, in DBS from smokers. This ratio in DBS was well correlated with the ratio in plasma, 0.94 (P<0.001). In a small study, we confirmed the feasibility of using extant DBS collected for lead screening to assess SHS exposure in children.

Association of maternal smoking with child cotinine levels

INTRODUCTION

Our aim was to understand the strength of association between parental smoking and child environmental tobacco smoke (ETS) exposure in order to inform the development of future tobacco control policies. ETS was measured using child cotinine levels below the active smoking threshold.

METHODS

Participants were drawn from the Avon Longitudinal Study of Parents and Children and included 3,128 participants at age 7 years and 1,868 participants at age 15 years. The primary outcome was cotinine levels of nonsmoking children, to investigate the relationship between maternal smoking and child cotinine levels. The secondary outcome was cotinine levels of all individuals to investigate the relationship between child smoking and child cotinine levels. Maternal and child smoking behavior was assessed by self-report questionnaire. We adjusted for several sociodemographic variables.

RESULTS

We found an association between maternal smoking and child cotinine at age 7 years (mean cotinine = 1.16ng/ml serum, ratio of geometric means = 3.94, 95% CI = 2.86-5.42) and at age 15 years (mean cotinine = 0.94ng/ml serum, ratio of geometric means = 5.26, 95% CI = 3.06-9.03), after adjustment for potential confounders.

CONCLUSIONS

The magnitude of this association for children whose mothers were heavy smokers was comparable with the quantity of half the levels of cotinine observed among children who were irregular (i.e., nonweekly) active smokers, and it was greater than five times higher than that seen in nonsmoking children whose mothers didn't smoke. This provides further evidence for the importance of public health interventions to reduce smoking exposure in the home.

Race, gender, and nicotine metabolism in adolescent smokers

INTRODUCTION

Differences in the rate of nicotine metabolism between genders and different races have been hypothesized to contribute to disparities in smoking rate, susceptibility to addiction, and ability to quit smoking. The purpose of this study was to determine the effect of race and gender on the rate of nicotine metabolism as indicated by the nicotine metabolite ratio (NMR) in adolescent smokers.

METHODS

One hundred and fifty-nine adolescent smokers aged 13-17 were given 2mg of deuterium-labeled cotinine (cotinine-d4). The NMR was calculated as the ratio of concentrations of deuterium-labeled 3'-hydroxycotinine (ng/ml) to cotinine-d4 (ng/ml) in saliva and is a validated biomarker of the rate of nicotine metabolism.

RESULTS

The sample was 67.3% female and racially mixed. On average, Whites had the fastest rates of metabolism compared with both Blacks/African Americans (p < .01) and Asians (p = .01). The NMR was similar between males and females (p = .70). Among the 19 girls who reported using estrogen-containing contraceptives, there was no significant difference in NMR compared with the 83 girls who did not use contraceptives (p = .24) or the 10 who used progestin-only contraceptives (p = .45).

CONCLUSIONS

Among adolescent smokers, racial variations in rates of nicotine metabolism were similar to those that have been reported in adult smokers. In contrast to findings in adult smokers, the NMR did not vary significantly by gender or self-reported hormone use.

CYP2A6 genotype but not age determines cotinine half-life in infants and children

The formation of cotinine, the main proximate metabolite and a biomarker of nicotine exposure, is mediated primarily by cytochrome P450 (CYP)2A6. Our aim was to determine whether higher cotinine levels in young children exposed to secondhand smoke (SHS) are a result of age-related differences in pharmacokinetics. Forty-nine participants, aged 2-84 months, received oral deuterium-labeled cotinine, with daily urine samples for up to 10 days for cotinine half-life measurement. DNA from saliva was used for CYP2A6 genotyping. The estimate of half-life using a mixed-effect model was 17.9 h (95% confidence interval: 16.5, 19.3), similar to that reported in adults. There was no statistically significant effect of sex, race, age, or weight. Children with normal-activity CYP2A6*1/*1 genotypes had a shorter half-life than those with one or two reduced-activity variant alleles. Our data suggest that higher cotinine levels in SHS-exposed young children as compared with adults are due to greater SHS exposure rather than to different cotinine pharmacokinetics.

Asthma Research for All of the United States

Asthma disproportionally affects different ethnic/racial groups, with Puerto Ricans and African Americans suffering the highest asthma prevalence and morbidity, Mexicans the lowest, and non-Hispanic whites in between. Genome-wide association studies of asthma have found both shared and race/ethnic-specific genetic risks factors for asthma. However, the majority of genetic asthma research is performed in populations of European descent, which limits the benefits of genetic research to European populations. It is important to biomedical and clinical research to include more diverse and underrepresented populations. The rich genetic diversity of all populations can be leveraged to scientific advantage. For example, admixture mapping provides a more powerful approach than traditional genome-wide allelic association studies in discovering genetic associations for complex diseases. By being more inclusive we can achieve a better understanding of the genetics of asthma, address health disparities, and ensure that scientific advances will benefit populations worldwide.