Validation of a five-question survey to assess a child's exposure to environmental tobacco smoke

Predictors of oxylipins in a healthy pediatric population

BACKGROUND

Oxylipins are formed from oxidation of omega-6 (n6) and omega-3 (n3) fatty acids (FAs). Evidence for inflammatory effects comes mostly from adults.

METHODS

Oxylipins from n6 FA (27 n6-oxylipins) and n3 FA (12 n3-oxylipins) were measured through ultra-high-performance liquid chromatography-mass spectrometry (LC-MS/MS) in plasma from 111 children at risk of type 1 diabetes (age 1-17 years) studied longitudinally. Oxylipin precursor FAs (arachidonic acid, linoleic acid, alpha-linolenic acid, docosahexaenoic acid, eicosapentaenoic acid) were measured in red blood cell (RBC) membrane and plasma. Precursor FAs dietary intake was measured through food frequency questionnaire and environmental tobacco smoke (ETS) through questionnaires. Linear mixed models were used to test oxylipins with predictors.

RESULTS

Age associated with 15 n6- and 6 n3-oxylipins; race/ethnicity associated with 3 n6- and 1 n3-oxylipins; sex associated with 2 n6-oxylipins. ETS associated with lipoxin-A4. Oxylipins associated with precursor FAs in plasma more often than RBC. RBC levels and dietary intake of precursor FAs more consistently associated with n3-oxylipins than with n6-oxylipins.

CONCLUSIONS

In healthy children, oxylipin levels change with age. Oxylipins associated with precursor FAs more often in plasma than RBC or diet, suggesting that inflammatory regulation leading to FA release into plasma may also be a determinant of oxylipin generation.

IMPACT

This is the first study to examine predictors of oxylipins in healthy children at risk of type 1 diabetes. In healthy children at risk of type 1 diabetes, many oxylipins change with age, and most oxylipins do not differ by sex or race/ethnicity. Environmental tobacco smoke exposure was associated with the presence of lipoxin A4. Omega-6- and omega-3-related oxylipin levels were consistently associated with their respective precursor fatty acid levels measured in the plasma. Proportionally more omega-3 compared to omega-6 oxylipins were associated with dietary intake and red blood cell membrane levels of the respective precursor fatty acid.

Gluten intake and risk of thyroid peroxidase autoantibodies in the Diabetes Autoimmunity Study In the Young (DAISY)

PURPOSE

Autoimmune diseases co-occur, perhaps due to common risk factors. The age at gluten introduction and gluten intake in early childhood has been associated with the autoimmunity preceding celiac disease (CD) and type-1 diabetes (T1D). We explored their associations with the development of thyroid autoimmunity.

METHODS

DAISY has prospectively followed children at increased risk for T1D and CD since 1993. During follow-up, 107 children developed thyroid autoimmunity, defined as positivity for autoantibodies against thyroid peroxidase on at least two study visits. Age at gluten introduction was ascertained from food history interviews every 3 months until 15 months of age. Gluten intake (g/day) at age 1-2 years was estimated using a food frequency questionnaire.

RESULTS

From multivariable Cox regression, there was no association between the age of gluten introduction nor the amount of gluten intake and development of thyroid autoimmunity. However, females (hazard ratio = 2.19, 95% CI: 1.46, 3.27) and cases of islet autoimmunity (HR = 2.20, 95% CI: 1.39, 3.50) were significantly more likely to develop thyroid autoimmunity, while exposure to environmental tobacco smoke decreased the risk (HR = 0.46, 95% CI: 0.30, 0.71).

CONCLUSIONS

Neither the age of gluten introduction nor the amount of gluten consumed in early childhood is associated with risk of thyroid autoimmunity.

Indoor Air Pollution Sources and Respiratory Symptoms in Bronchopulmonary Dysplasia

OBJECTIVE

To evaluate the impact of exposure to indoor air pollution on respiratory health outcomes (healthcare utilization, symptoms, medication use) in infants and children with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

A total of 244 subjects were included from the Johns Hopkins Bronchopulmonary Dysplasia registry. Parents completed an environmental exposure questionnaire including secondhand smoke and indoor combustion (gas/propane heat, gas or wood stove, gas/wood burning fireplace) exposures in the home. Respiratory symptoms, both acute (healthcare utilization, steroid/antibiotic use) and chronic (cough/wheeze, nocturnal cough, use of beta-agonists, tolerance of physical activity), were also collected.

RESULTS

Three-quarters of the infants were exposed to at least 1 combustible source of air pollution in the home, and this exposure was associated with an increased risk of hospitalization in infants and children on home respiratory support. Only 14% of the study population reported secondhand smoke exposure, but we found that this was associated with chronic respiratory symptoms, including activity limitation and nocturnal cough. Infants on respiratory support also had increased daytime cough and wheezing. Approximately one-third reported having an air purifier in the home, and its presence attenuated the effect of secondhand smoke exposure on reported activity limitation.

CONCLUSIONS

Exposure to combustible sources of indoor air pollution was associated with increased respiratory morbidity in a group of high risk of infants with BPD. Our results support that indoor air pollution is a modifiable risk factor for respiratory health in infants with BPD.

The Relation between Exposure to Environmental Tobacco Smoke and the Quantity of Cotinine in the Urine of School Children in Taif City, Saudi Arabia

Environmental tobacco smoke (ETS) is a major public health problem for all ages. Despite the high prevalence of smoking among the Saudi population, there is limited information about levels of urinary cotinine in Saudi children exposed to SHS. The aim of the study was to assess the exposure of schoolchildren to ETS, and measure their urinary cotinine levels. Multistage cluster sampling was carried out, where schoolchildren from 4 schools were randomly chosen from primary schools in Taif city. A questionnaire including questions on SHS exposure and smoking rules in the residence were sent to students parents/guardians. Urine samples were taken and analyzed for total cotinine using chemiluminescent immunoassay. Of the studied children, 38.4% had a smoking father, 61.8%, 41.2% and 49.3% of them were exposed to ETS indoors, outdoors and both indoors and outdoors respectively. The mean urinary cotinine was significantly higher among children exposed to ETS compared to unexposed children. Urinary cotinine levels in children with both indoor and outdoor exposure was significantly higher compared with its level in children with single exposure. A significant positive correlation was found between urinary cotinine concentrations and the number of cigarette packs smoked by parents, and the number of smokers in the residence. The mean urinary cotinine level was significantly higher in children who reported no smoking rules at the residence.. The study revealed a high exposure of Saudi children to ETS. An antismoking media awareness campaign on the harmful effects of ETS should be carried out, in addition to family counseling programs targeted to parents to protect their children from ETS.

Prenatal tobacco smoke exposure increases hospitalizations for bronchiolitis in infants

Background

Tobacco smoke exposure (TSE) is a worldwide health problem and it is considered a risk factor for pregnant women’s and children’s health, particularly for respiratory morbidity during the first year of life. Few significant birth cohort studies on the effect of prenatal TSE via passive and active maternal smoking on the development of severe bronchiolitis in early childhood have been carried out worldwide.

Methods

From November 2009 to December 2012, newborns born at ≥33 weeks of gestational age (wGA) were recruited in a longitudinal multi-center cohort study in Italy to investigate the effects of prenatal and postnatal TSE, among other risk factors, on bronchiolitis hospitalization and/or death during the first year of life.

Results

Two thousand two hundred ten newborns enrolled at birth were followed-up during their first year of life. Of these, 120 (5.4 %) were hospitalized for bronchiolitis. No enrolled infants died during the study period.

Prenatal passive TSE and maternal active smoking of more than 15 cigarettes/daily are associated to a significant increase of the risk of offspring children hospitalization for bronchiolitis, with an adjHR of 3.5 (CI 1.5–8.1) and of 1.7 (CI 1.1–2.6) respectively.

Conclusions

These results confirm the detrimental effects of passive TSE and active heavy smoke during pregnancy for infants’ respiratory health, since the exposure significantly increases the risk of hospitalization for bronchiolitis in the first year of life.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0312-5) contains supplementary material, which is available to authorized users.

Timing of solid food introduction is associated with urinary F2-isoprostane concentrations in childhood

BACKGROUND

Timing of solid food introduction in infancy has been associated with several chronic diseases. To explore potential mechanisms, we investigated the relationship between timing of solid food introduction and F2-isoprostanes-a marker of oxidative stress.

METHODS

Urinary F2-isoprostanes were assessed in 336 healthy children aged less than 11.5 y with 1,266 clinic visits (mean = 3.8 visits per child) in the Diabetes Autoimmunity Study in the Young. We analyzed the association between F2-isoprostane concentrations and infant diet exposures using linear mixed models adjusted for age, age(2), HLA-DR3/4,DQB1*0302 genotype, first-degree relative with type 1 diabetes, maternal age, maternal education, sex, and exposure to in utero cigarette smoke.

RESULTS

Later solid food introduction was associated with lower F2-isoprostane concentrations in childhood (on average, 0.10 ng/mg per month of age at introduction; estimate: -0.10 (95% confidence interval (CI): -0.18, -0.02) P value = 0.02). Moreover, childhood F2-isoprostane concentrations were, on average, 0.24 ng/mg lower in individuals breastfed at solid food introduction (estimate: -0.24 (95% CI: -0.47, -0.01) P value = 0.04) compared with those who were not. Associations remained significant after limiting analyses to F2-isoprostanes after 2 y of age.

CONCLUSION

Our results suggest a long-term protective effect of later solid food introduction and breastfeeding at solid food introduction against increased F2-isoprostane concentrations throughout childhood.

Impact of passive smoke and/or atopy on adenoid immunoglobulin production in children

The adenoids are exposed to a wide number and variety of microbes, environmental pollutants, and food antigens. Atopy and passive smoke may significantly affect immune responses, mainly in children. The aim of the present study was to investigate whether passive exposure to tobacco smoke and/or atopy could affect immunoglobulin production by adenoidal lymphocytes in a cohort of children presenting with adenoid hypertrophy. A total of 277 children (151 males and 126 females; median age 5.5 years), with adenoidal hypertrophy requiring adenoidectomy and or adeno-tonsillectomy, were consecutively enrolled in the study. Adenoid mononuclear cells were in vitro stimulated with LPS or CpG. When considering both the presence of smoke exposure and atopy, we observed that the CpG-induced decrease in IgA and IgM production was significantly associated with this combination of risk factors. In the T-independent immunoglobulin production assay we found a positive association between the two risk factors and IgA and IgM production. In particular, the presence of both risk factors, showed a significant increase in IgA and IgM production after stimulation. In conclusion, this is the first study that investigated the in vitro adenoidal B cell response after different stimuli in children, also evaluating possible exposure to passive smoke and/or an atopic condition.

Secondhand tobacco smoke exposure in low-income children and its association with asthma

Secondhand tobacco smoke (SHS) is a common indoor environmental exposure that is particularly prevalent in low-income families. It has been found to be associated with asthma in some studies; however, across all relevant studies, results have been conflicting. This study aimed to determine the prevalence of SHS exposure in the home environment in a low-income, minority population and to determine the association of exposure with childhood asthma, wheeze, and oral corticosteroids use. This retrospective study analyzed self-reported data collected as part of the Kansas City Safe and Healthy Homes Partnership to determine prevalence of SHS exposure. A logistic regression model was then used to assess the association between exposure and asthma, oral steroid use, and wheeze. Overall, 40% of children lived with at least one smoker and 15% of children lived with at least one smoker who smoked inside the house. No significant association was found between asthma or oral corticosteroid use and SHS exposure. Children who lived with a smoker had a 1.54 increased odds of wheeze in the past year. A large percentage of low-income children in the Kansas City area continue to suffer the adverse effects of SHS. These data support the need for innovative public policy to protect children from such exposure in their home environment.

Determinants Of Oral corticosteroid Responsiveness in Wheezing Asthmatic Youth (DOORWAY): protocol for a prospective multicentre cohort study of children with acute moderate-to-severe asthma exacerbations

INTRODUCTION

Oral corticosteroids are the cornerstone of acute asthma management in the emergency department. Recent evidence has raised doubts about the efficacy of this treatment in preschool-aged children with viral-induced wheezing and in smoking adults. The aims of the study were to: (1) document the magnitude of response to oral corticosteroids in children presenting to the emergency department with moderate or severe asthma; (2) quantify potential determinants of response to corticosteroids and (3) explore the role of gene polymorphisms associated with the responsiveness to corticosteroids.

METHODS AND ANALYSIS

The design is a prospective cohort study of 1008 children aged 1-17 years meeting a strict definition of asthma and presenting with a clinical score of ≥4 on the validated Pediatric Respiratory Assessment Measure. All children will receive standardised severity-specific treatment with prednisone/prednisolone and cointerventions (salbutamol with/without ipratropium bromide). Determinants, namely viral aetiology, environmental tobacco smoke and single nucleotide polymorphism, will be objectively documented. The primary efficacy endpoint is the failure of emergency department (ED) management within 72 h of the ED visit. Secondary endpoints include other measures of asthma severity and time to recovery within 7 days of the index visit. The study has 80% power for detecting a risk difference of 7.5% associated with each determinant from a baseline risk of 21%, at an α of 0.05.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from all participating institutions. An impaired response to systemic steroids in certain subgroups will challenge the current standard of practice and call for the immediate search for better approaches. A potential host-environment interaction will broaden our understanding of corticosteroid responsiveness in children. Documentation of similar effectiveness of corticosteroids across determinants will provide the needed reassurance regarding current treatment recommendations.

RESULTS

Results will be disseminated at international conferences and manuscripts targeted at emergency physicians, paediatricians, geneticists and respirologists.

TRIAL REGISTRATION NUMBER

This study is registered at Clinicaltrials.gov (NCT02013076).

Secondhand smoke and asthma: what are the effects on healthcare utilization among children?

OBJECTIVE

This study aims to examine the associations between asthma, secondhand smoke exposure and healthcare utilization in a nationally representative sample of children.

METHODS

Data from 5686 children aged 0-11 years were analyzed. Healthcare utilization, asthma diagnosis and demographic information came from the 2001 and 2006 Medical Expenditure Panel Surveys. Secondhand smoke exposure was measured during the 2000 and 2005 National Health Interview Surveys. Multivariable regression models were used to determine the association between secondhand smoke exposure, asthma diagnosis and healthcare utilization (hospitalizations, emergency department visits, outpatient visits and prescription medication use).

RESULTS

Asthma modified the relationship between secondhand smoke exposure and hospitalizations, as exposure more than doubled the odds of hospitalization among children with asthma but had no effect on children without asthma. Secondhand smoke exposure increased the odds by 37% of emergency room visits (P<0.001), but was not associated with outpatient visits or medication use. Children with asthma had a higher odds of utilizing all healthcare services (P<0.001).

CONCLUSIONS

Secondhand smoke exposure was associated with a greater utilization of hospitals and emergency departments, and the effect on hospitalizations was most pronounced among children with asthma. Reducing secondhand smoke exposure would help to reduce the burden on the healthcare system, especially among children with asthma.

Parental smoking patterns and their association with wheezing in children

OBJECTIVE

To investigate parental smoking patterns and their association with wheezing in children.

METHODS

We performed a case-control study that included 105 children between 6 and 23 months of age who were divided into two groups: cases (children with 3 previous episodes of wheezing) and controls (healthy children without wheezing). The children's exposure to cigarette smoking was estimated using a questionnaire completed by the mothers and by the children's urinary cotinine levels.

RESULTS

Based on both the questionnaire results and cotinine levels, exposure to cigarette smoking was higher in the households of cases in which the incidence of maternal smoking was significantly higher than that of paternal smoking. Children in this group were more affected by maternal smoking and by the total number of cigarettes smoked inside the house. Additionally, the questionnaire results indicated that the risk of wheezing was dose dependent. The presence of allergic components, such as atopic dermatitis and siblings with allergic rhinitis and asthma, greatly increased the odds ratio when wheezing was associated with cotinine levels.

CONCLUSION

Children exposed to tobacco smoke have an increased risk of developing wheezing syndrome. This risk increases in association with the number of cigarettes smoked inside the house and the presence of other allergic components in the family.

Secondhand smoke in combination with ambient air pollution exposure is associated with increasedx CpG methylation and decreased expression of IFN-γ in T effector cells and Foxp3 in T regulatory cells in children

BACKGROUND

Secondhand smoke (SHS) and ambient air pollution (AAP) exposures have been associated with increased prevalence and severity of asthma and DNA modifications of immune cells. In the current study, we examined the association between SHS and AAP with DNA methylation and expression of interferon-gamma (IFN-γ) and forkhead box protein 3 (Foxp3) in T cell populations.

METHODS

Subjects 7-18 years old were recruited from Fresno (high AAP; n = 62) and Stanford, CA (low AAP; n = 40) and divided into SHS-exposed (Fresno: n = 31, Stanford: n = 6) and non-SHS-exposed (nSHS; Fresno: n = 31, Stanford: n = 34) groups. T cells purified from peripheral blood were assessed for levels of DNA methylation and expression of IFN-γ (in effector T cells) or Foxp3 (in regulatory T cells).

RESULTS

Analysis showed a significant increase in mean % CpG methylation of IFN-γ and Foxp3 associated with SHS exposure (IFN-γ: FSHS 62.10%, FnSHS 41.29%, p < 0.05; SSHS 46.67%, SnSHS 24.85%, p < 0.05; Foxp3: FSHS 74.60%, FnSHS 54.44%, p < 0.05; SSHS 62.40%, SnSHS 18.41%, p < 0.05) and a significant decrease in mean transcription levels of both genes (IFN-γ: FSHS 0.75, FnSHS 1.52, p < 0.05; SHS 2.25, nSHS 3.53, p < 0.05; Foxp3: FSHS 0.75, FnSHS 3.29, p < 0.05; SSHS 4.8, SnSHS 7.2, p < 0.05). AAP was also associated with hypermethylation (IFN-γ: FSHS vs. SSHS, p < 0.05; FnSHS vs. SnSHS, p < 0.05; Foxp3: FSHS vs. SSHS, p < 0.05; FnSHS vs. SnSHS, p < 0.05) and decreased transcription of both genes (IFN-γ: FSHS vs. SSHS, p < 0.05; FnSHS vs. SnSHS, p < 0.05; Foxp3: FSHS vs. SSHS, p < 0.05; FnSHS vs. SnSHS, p < 0.05). Average methylation between AAP- and SHS-only exposures was not significantly different (IFN-γ: p = 0.15; Foxp3: p = 0.27), nor was Foxp3 expression (p = 0.08); IFN-γ expression was significantly decreased in AAP-only subjects (p < 0.05).

CONCLUSIONS

Exposures to SHS and AAP are associated with significant hypermethylation and decreased expression of IFN-γ in Teffs and Foxp3 in Tregs. Relative contributions of each exposure to DNA modification and asthma pathogenesis warrant further investigation.

Lung function is associated with arterial stiffness in children

Background

In older adults, an independent association exists between impaired lung function and cardiovascular disease. This interaction might be related to the effects of aging and/or smoking. In order to explore possible childhood antecedents to this association, we hypothesized that decreased lung function and vascular stiffness might be related, in early life.

Objective

To determine the relationship between lung function and carotid augmentation index (AIx), a measure of vascular stiffness, in 8-year old children.

Methods

Data on brachial blood pressure, lung function (FEV₁, FVC, FEV₁/FVC, obtained by spirometry) and carotid AIx75 (AIx standardised to an arbitrary heart rate of 75 beats per minute, obtained by applanation tonometry) was available in 249 community-based 8-year old children. These healthy children had been subjects in a randomised controlled trial of two interventions (omega-3 fatty acid supplementation and house-dust mite avoidance) to prevent asthma. Smoking in pregnancy and childhood environmental tobacco smoke (ETS) exposure was prospectively collected by questionnaire. The association between lung function and carotid AIx75 was assessed in multivariate models that included sex, height, smoking status during pregnancy, ETS exposure and randomisation groups (house dust mite avoidance and dietary intervention) as covariates.

Results

In the fully adjusted models, Carotid AIx75 was independently associated with FEV1 (standardised β = −0.17,b = −6.72, partial R² = .02, p = 0.03), FVC (standardised β = −0.29, b = −9.31, partial R² = 0.04, p<0.001) and FEV1/FVC (standardised β = .13, b = 18.4, partial R² = 0.02, p = 0.04).

Conclusion

Lower lung volumes are associated with increased vascular stiffness at an early age. The interaction between lung function and vascular stiffness may thus represent more than just age-related alterations in both the pulmonary and vascular systems.

Interpersonal and temporal variability of urinary cotinine in elderly subjects

Although a single measurement of urinary cotinine is often used for biological monitoring, the validity of this measurement for estimating long-term exposure has not been well evaluated. The purpose of this study was to determine the efficacy of using a single measurement per person to estimate long-term smoking exposure in an elderly population. Analysis was conducted using a cohort of elderly subjects for whom multiple urinary cotinine measurements had been collected over eight weeks. The mixed-effects model of urinary cotinine indicated that interpersonal variability was greater than temporal variability. The efficacy of using single measurements to track the mean long-term exposure of a population is supported by the relatively consistent population averages. The classification of high and low exposure groups using a single measurement or using eight measurements produced similar group distributions. When using cut-off levels of 20 and 100 μg cotinine/g creatinine, 9.3% and 5.6% of individual exposures were misclassified, respectively, when using a single measurement. Urinary cotinine can be a useful biomarker for characterizing exposure to tobacco smoke. Although the incidence of misclassification decreased with an increase in the number of measurements, a single measurement of the urinary cotinine level may accurately represent long-term exposure to tobacco smoke.

Development, design, and conceptual issues of project zero exposure: A program to protect young children from tobacco smoke exposure

BACKGROUND

Tobacco smoke exposure (TSE) is a serious threat to child health. Roughly 40% of children worldwide are exposed to tobacco smoke, and the very young are often "captive smokers" in homes in which others smoke.The goal of this research project is to develop and evaluate an intervention to reduce young child tobacco smoke exposure. The objective of this paper is to document our approach to building the intervention, to describe the planned intervention, and to explore the conceptual issues regarding the intervention and its evaluation.

METHODS/DESIGN

This project is being developed using an iterative approach. We are currently in the middle of Stage 1. In this first stage, Intervention Development, we have already conducted a comprehensive search of the professional literature and internet resources, consulted with experts in the field, and conducted several Design Workshops. The planned intervention consists of parental group support therapy, a website to allow use of an "online/offline" approach, involvement of pediatricians, use of a video simulation game ("Dr. Cruz") to teach parents about child TSE, and personalized biochemical feedback on exposure levels. As part of this stage we will draw on a social marketing approach. We plan to use in-depth interviews and focus groups in order to identify barriers for behavior change, and to test the acceptability of program components.In Stage II, we plan to pilot the planned intervention with 5-10 groups of 10 parents each.In Stage III, we plan to implement and evaluate the intervention using a cluster randomized controlled trial with an estimated 540 participants.

DISCUSSION

The major challenges in this research are twofold: building an effective intervention and measuring the effects of the intervention. Creation of an effective intervention to protect children from TSE is a challenging but sorely needed public health endeavor. We hope that our approach will contribute to building a stronger evidence base for control of child exposure to tobacco smoke.

Maternal cigarette smoking is associated with reduced high-density lipoprotein cholesterol in healthy 8-year-old children

AIMS

Smoking in pregnancy is common. Its effects on lipoprotein levels and arterial structure in childhood are not well characterized. We aimed to determine the effects of maternal smoking in pregnancy on lipoprotein levels and arterial wall thickness in healthy pre-pubertal children.

METHODS AND RESULTS

A community-based longitudinal study with prospective ascertainment of exposure to smoking in pregnancy and environmental tobacco smoke (ETS) since birth and then lipoprotein and arterial measurements at age 8 years. In 616 newborn infants (gestation >36 weeks and birth weight >2.5 kg) data were collected prospectively by questionnaire on smoking in pregnancy and ETS exposure in childhood. At age 8-years, 405 of the children had measurements of lipoproteins, blood pressure (BP) and carotid intima-media thickness. Children born to mothers who smoked in pregnancy had lower HDL cholesterol [1.32 vs. 1.50 mmol/L, 95% confidence interval (CI) for difference -0.28 to -0.08, P = 0.0005], higher triglycerides (1.36 vs. 1.20 mmol/L, 95% CI for ratio 1.01-1.30, P = 0.04) and higher systolic BP (102.1 vs. 99.9 mmHg, 95% CI for difference 0.6-3.8, P = 0.006). After adjustment for maternal passive smoking, post-natal ETS exposure, gender, breast feeding duration, physical inactivity, and adiposity, smoking in pregnancy remained significantly associated with lower HDL cholesterol (difference = -0.22 mmol/L, 95% CI -0.36 to -0.08, P = 0.003) but not with higher systolic BP. Neither smoking in pregnancy nor post-natal ETS exposure was associated with alterations of carotid artery wall thickness.

CONCLUSION

Smoking in pregnancy is independently associated with significantly lower HDL cholesterol in healthy 8-year-old children.

Reduction of secondhand smoke exposure among healthy infants in Iran: randomized controlled trial

INTRODUCTION

The objective of this study was to assess whether counseling both mothers and fathers reduces their infants' exposure to secondhand smoke (SHS).

METHODS

Participants were 130 nonsmoking children aged less than 1 year, exposed to their fathers' or mothers' smoking, and recruited from a health center in southern Tehran. Eligible families were randomly assigned to intervention or control group. Infant urine samples were collected, and parents were interviewed at baseline and at a 3-month follow-up in each of the 2 groups. Mothers of the intervention group were provided 3 counseling sessions, one of which was face to face and 2 of which were by telephone. Fathers were provided 3 counseling sessions by telephone. Parents were also given an educational pamphlet and a sticker depicting a smoke-free home. The control group received usual care. Changes in infant urinary cotinine levels, parental cigarette consumption in the presence of the child, and home- and car-smoking bans were assessed.

RESULTS

The intervention was effective in reducing infant urinary cotinine levels (1-tailed p = .029). There was a greater decrease in the total daily cigarette consumption in the presence of the child in the intervention group compared with the control group, and the differences between the 2 groups were statistically significant (1-tailed p = .03). While the differences between home-smoking bans in the 2 groups were statistically significant (1-tailed p = .049), the differences between car-smoking bans did not reach significance.

CONCLUSION

Counseling similar to that employed in other countries can reduce infant exposure to SHS, suggesting generalizability.

Acceptability of testing children for tobacco-smoke exposure: a national parent survey

BACKGROUND

Tests are available to measure children's exposure to tobacco smoke. One potential barrier to testing children for tobacco-smoke exposure is the belief that parents who smoke would not want their child tested. No previous surveys have assessed whether testing children for exposure to tobacco smoke in the context of their child's primary care visit is acceptable to parents.

OBJECTIVE

To assess whether testing children for tobacco-smoke exposure is acceptable to parents.

DESIGN AND METHODS

We conducted a national random-digit-dial telephone survey of households from September to November 2006. The sample was weighted by race and gender, based on the 2005 US Census, to be representative of the US population.

RESULTS

Of 2070 eligible respondents contacted, 1803 (87.1%) completed the surveys. Among 477 parents in the sample, 60.1% thought that children should be tested for tobacco-smoke exposure at their child's doctor visit. Among the parental smokers sampled, 62.0% thought that children should be tested for tobacco-smoke exposure at the child's doctor visit. In bivariate analysis, lower parental education level, allowing smoking in the home, nonwhite race, and female gender were each associated (P < .05) with wanting the child tested for tobacco-smoke exposure.

CONCLUSIONS

The majority of nonsmoking and smoking parents want their children tested for tobacco-smoke exposure during the child's health care visit.

Passive exposure to smoke results in defective interferon-gamma production by adenoids in children with recurrent respiratory infections

There is evidence that exposure to passive smoke is associated with an increased susceptibility to respiratory infections. Indeed, cigarette smoke extracts may interfere with the immune system, even though the precise mechanism has not been fully understood yet. Recurrent respiratory infections may be sustained by a defective immune response. The aim of the present study was to evaluate whether, in a cohort of children presenting both with recurrent respiratory infections and with a history of exposure to tobacco smoke, these factors were related to a lower local production of interferon-gamma (IFN-gamma) when compared to a similar non-exposed population. The study group included 128 children undergoing adenoidectomy, presenting with more than three respiratory infections per year, independently of exposure to passive smoke at home. The intracellular cytokine profile of lymphocyte subsets in adenoids was evaluated by flow cytometry analysis. Children exposed to tobacco smoke suffered from a significantly greater number of respiratory infections and had a lower percentage of IFN-gamma-producing CD8+ cells in adenoids than non-exposed children, while other T-cell subsets were not affected. The effect of smoke exposure seems to be specific to the IFN-gamma-producing CD8+ cells in adenoids and may contribute to the increased susceptibility to the recurrence of respiratory infections.

Methods for quantification of exposure to cigarette smoking and environmental tobacco smoke: focus on developmental toxicology

Active and passive smoking have been associated with an array of adverse effects on health. The development of valid and accurate scales of measurement for exposures associated with health risks constitutes an active area of research. Tobacco smoke exposure still lacks an ideal method of measurement. A valid estimation of the risks associated with tobacco exposure depends on accurate measurement. However, some groups of people are more reluctant than others to disclose their smoking status and exposure to tobacco. This is particularly true for pregnant women and parents of young children, whose smoking is often regarded as socially unacceptable. For others, recall of tobacco exposure may also prove difficult. Because relying on self-report and the various biases it introduces may lead to inaccurate measures of nicotine exposure, more objective solutions have been suggested. Biomarkers constitute the most commonly used objective method of ascertaining nicotine exposure. Of those available, cotinine has gained supremacy as the biomarker of choice. Traditionally, cotinine has been measured in blood, saliva, and urine. Cotinine collection and analysis from these sources has posed some difficulties, which have motivated the search for a more consistent and reliable source of this biomarker. Hair analysis is a novel, noninvasive technique used to detect the presence of drugs and metabolites in the hair shaft. Because cotinine accumulates in hair during hair growth, it is a unique measure of long-term, cumulative exposure to tobacco smoke. Although hair analysis of cotinine holds great promise, a detailed evaluation of its potential as a biomarker of nicotine exposure, is needed. No studies have been published that address this issue. Because the levels of cotinine in the body are dependent on nicotine metabolism, which in turn is affected by factors such as age and pregnancy, the characterization of hair cotinine should be population specific. This review aims at defining the sensitivity, specificity, and clinical utilization of different methods used to estimate exposure to cigarette smoking and environmental tobacco smoke.

Secondhand tobacco smoke exposure, nicotine dependence, and smoking cessation

OBJECTIVE

To explore the association among the number of sources of secondhand tobacco smoke (SHS) exposure, nicotine dependence (ND), and smoking cessation.

DESIGN

A secondary analysis of cross-sectional data. Responses for the main study were obtained in 2001 from a controlled trial of the Quit and Win Tobacco Free Contest in Kentucky.

SAMPLE

822 current smokers.

MEASUREMENTS

Demographic variables (age, gender, educational status, income, and ethnicity) the number of sources of SHS exposure, smoking frequency, length of abstinence from smoking, age of smoking initiation, smoking cessation attempts, intentions to quit smoking, and ND.

RESULTS

The number of sources of SHS exposure was associated with higher ND and smoking frequency, and related to low intentions and attempts to quit smoking. The number of sources of SHS exposure contributed to 11% of the variance in the final ND model, after accounting for control and potential mediating variables.

CONCLUSIONS

The number of sources of SHS exposure may be an important factor influencing ND and intentions and attempts to quit smoking. Further studies are needed to explore the association between SHS exposure and ND among smokers to guide treatment and policy development.

Active and passive smoking in childhood is related to the development of inflammatory bowel disease

BACKGROUND

The highest prevalence of smoking in the United States is in Kentucky, where smoking typically begins in childhood. The state has many patients who suffer from inflammatory bowel diseases (IBD). The primary aim of this study was to assess whether exposure to active and/or passive tobacco smoke in childhood is related to the likelihood of developing IBD.

METHODS

Recruited into this prospective study were a total of 672 participants (253 patients with Crohn's disease [CD], 177 patients with ulcerative colitis [UC], and 242 controls), all of whom were asked to complete the Behavioral Risk Factor Surveillance Survey modified by the addition of 4 questions on childhood passive smoke exposure.

RESULTS

Survey response rate was 84%. CD and UC patients were more likely than controls to begin smoking regularly by ages 10 and 15, respectively, suggesting that becoming a regular smoker at a younger age may be associated with a subsequent diagnosis of IBD. Smoking by age 10 was associated with an earlier age at diagnosis with UC, but not with CD. CD patients were more likely than controls to have prenatal smoke exposure (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.1-2.71) and were more likely to have passive smoke exposure during childhood, with 1 or both parents or other household members being smokers (OR, 2.04; 95% CI, 1.28-3.31).

CONCLUSIONS

Passive and active smoke exposure in childhood influences the development of IBD. A high incidence of this disease in a state with a high rate of cigarette smoking underscores the profound role of environmental factors in the etiology of these illnesses.

Perinatal and early childhood risk factors associated with rheumatoid factor positivity in a healthy paediatric population

OBJECTIVE

To examine perinatal and childhood risk factors for the presence of rheumatoid factor in healthy children.

METHODS

The Diabetes Autoimmunity Study in the Young (DAISY) is a longitudinal study of children at increased risk of type 1 diabetes, based on possession of human leucocyte antigen (HLA)-DR4 and DR3 alleles or a family history of diabetes. 651 children who participated in DAISY, with an average age of 6.4 (range 1-15) years, were tested for the presence of rheumatoid factor in their most recent serum sample. 23 children were positive for rheumatoid factor. Exposure data were collected prospectively by interview. HLA-DR4 alleles were identified using polymerase chain reaction-based Class II genotyping.

RESULTS

While exploring risk factors for rheumatoid factor positivity in a multivariate model, several important interaction terms involving HLA-DR4 status suggested the need to evaluate risk factors in HLA-DR4-positive and HLA-DR4-negative children separately. In HLA-DR4-negative children, rheumatoid factor-positive infants were less likely to have been breast fed for >3 months (odds ratio (OR) 0.18; 95% confidence interval (CI) 0.04 to 0.99), more likely to have been exposed to non-parental tobacco smoke (OR 5.38; 95% CI 0.93 to 31.27) and more likely to be a race/ethnicity other than non-Hispanic white (OR 6.94; 95% CI 1.10 to 43.88) compared with rheumatoid factor-negative children, after adjusting for age, sex and maternal education. In HLA-DR4-positive children, there were no significantly associated risk factors for rheumatoid factor positivity.

CONCLUSIONS

Risk factors for rheumatoid factor positivity in children vary by HLA-DR4 genotype. In HLA-DR4-negative children, breast feeding may decrease the risk, and environmental tobacco smoke may increase the risk, of autoimmunity.

Deficiency of INFgamma producing cells in adenoids of children exposed to passive smoke

Exposure to passive smoke is a very common event associated with increased susceptibility to respiratory tract infections. Many related adverse effects result from the ability of cigarette smoke extracts to interfere with the immune system, but the mechanism is not yet completely understood. The aim of the present study is to evaluate the intracellular cytokine profile in adenoids and peripheral blood cells of children exposed to passive smoke. Children undergoing adenoidectomy exposed or not exposed to passive smoke were studied. The intracellular cytokine profile of lymphocyte subsets in adenoids and in peripheral blood were evaluated by flow cytometry analysis. Children exposed to tobacco smoke showed a significantly lower percentage of INF-gamma producing CD4+ and CD8+ cells in adenoids. Moreover a significant correlation was observed between the quantity of exposure and reduction in Th1 (CD4+INFgamma+ and CD8+INFgamma+) cells in adenoids. This reduction may be a contributing factor in the increasing susceptibility to respiratory tract infection in children exposed to tobacco smoke.

Measuring exposure to environmental tobacco smoke (ETS): a developing country's perspective

AIMS

To assess exposure to ETS among nonsmokers in the community and examine the relation between various subjective and objective measures of exposure to ETS in a developing country's setting.

METHODS

An interviewer-administered population-based survey of adults 18-65 years residing in Aleppo, Syria. From a total number of 2038 participants, a sub-sample of 419 nonsmokers (27.2% men, 72.8% women, mean age 34 years) underwent subjective and objective assessment of exposure to ETS (saliva cotinine, breath CO, self-reported measures of exposure combined into ETS exposure scale).

RESULTS

Overall, 97.6% of adults nonsmokers assessed in this study, 72.9% of whom were women, have detectable saliva cotinine levels (mean +/- SD 1.7 +/- 1.5 ng/ml). Correlation between self-reported exposure measures and saliva cotinine was moderate with the strongest observed for number of cigarette smokers in the house, average number of cigarettes smoked daily in the house, house policy regarding smoking, and total ETS score (r 0.3-0.4). These same variables were among the best predictors of saliva cotinine according to stepwise linear regression analysis, but their individual relevance differed between men and women reflecting underlying differences in gender-based behavior-mobility patterns. Generally, subjective measures could explain 22% of the variability in cotinine levels in men and 19% in women.

CONCLUSIONS

Exposure to ETS is universal among adult nonsmokers in Syria. Saliva cotinine correlated moderately with self-reported measures, whereby selected subjective measures can be as informative as composite scores incorporating multiple measures. Even in this environment of omnipresence of smoking, household restrictions seem to offer protection against ETS exposure.

Perianal Crohn disease: predictors of need for permanent diversion

OBJECTIVE

Fissures, fistulas, abscesses, and anal canal stenosis are manifestations of perianal Crohn disease (CD). There are no known predictors of which patients will fail sphincter-sparing surgical therapy and ultimately require fecal diversion.

METHODS

Of 356 consecutive patients with CD, 24% (86) had perianal CD (age range, 14-83 years), and women were slightly more frequently affected. Clinical variables were examined for factors predictive of the need for permanent fecal diversion.

RESULTS

CD associated with perianal CD was limited to the small bowel and/or ileocolic area in 23% of patients; the remainder had colorectal CD. Eighty-six patients underwent 344 operations. Forty-two patients (49%) ultimately required permanent diversion; among them were 21 of 32 patients (66%) with anal stricture and 12 of 20 women (60%) with rectovaginal fistula. Univariate analyses of clinical variables were performed with respect to need for permanent fecal diversion. Significant univariate predictors were the presence of colonic CD (P = 0.0045, odds ratio [OR] 5.4), avoidance of ileocolic resection (P = 0.0147, OR 0.4), and the presence of an anal stricture (P = 0.0165, OR 3.0). In multivariate logistic regression, the presence of colonic disease and anal canal stricture were predictors of permanent diversion. The OR associated with the risk of permanent diversion in the presence of colonic disease and in the absence of anal stricture was 10 (P = 0.0345). In the presence of both colonic disease and anal canal stenosis, the OR associated with permanent stoma was 33 (P = 0.0023).

CONCLUSIONS

The management of perianal CD continues to be challenging. Roughly half of patients required permanent fecal diversion, which was even more frequently true for patients with colonic CD and anal stenosis. Recognizing these tendencies will assist both patients and surgeons in planning optimal treatment.

Assessment of Sources of Second-Hand Smoke Exposure in a Putatively Unexposed Population

The authors sought to determine levels of urinary cotinine and its association with collateral exposure to second-hand smoke in public health workers. Urinary cotinine was measured twice at 1-wk intervals in 28 public health workers or their spouses. Information on sources of second-hand smoke exposure and a dietary history were obtained from each participant. Geometric mean and median cotinine levels were 2.74 and 2.33 ng/mL, respectively. Only 6 instances of second-hand smoke exposure were reported from a combined 204 days of potential exposure, and these did not correspond to higher cotinine values. There was no association between consumption of foods containing nicotine and log-transformed urine cotinine levels (p = .80). The authors' analysis indicates dietary sources of nicotine are not important, even for persons with very low urinary cotinine levels. Further study is needed to determine sources of variation in urinary cotinine among largely unexposed populations.

Environmental tobacco smoke exposure in children: parental perception of smokiness at home and other factors associated with urinary cotinine in preschool children

Parental smoking behavior at home and sociodemographic variables may influence exposure to environmental tobacco smoke (ETS) in children. A sample of 115 preschool children aged 3-6 years was enrolled in this study. ETS exposure was evaluated through a questionnaire about parents' smoking behavior and determinations of urinary cotinine -- a biomarker of exposure -- in children. Bivariate and multiple regression analyses were used to evaluate the association between the smoking behavior of each parent at home, sociodemographic factors and cotinine levels in children. The parental perception of smokiness in the home was significantly associated with urinary cotinine in children (r-partial coefficient=0.324; P<0.002). The father's education, mother's smoking status, and day of the week when urine was sampled (Tuesday) were also independently associated with levels of cotinine. These four variables explained 26.4% of the variance in the cotinine levels of children. In designing educational programs to reduce passive smoking among children, it is necessary to take into account those factors related with cotinine levels in children. Our results support the influence of the mothers' smoking status, the fathers' educational level, and the day of the week of sampling on cotinine in children. The perception of parents (smokers and nonsmokers) about the smokiness in the home could also be a useful indicator of the cotinine in children exposed to environmental tobacco smoke in the household.

Decrease in the prevalence of environmental tobacco smoke exposure in the home during the 1990s in families with children

OBJECTIVES

This study explored correlates with and changes in the prevalence of environmental tobacco smoke (ETS) exposure of children in the home.

METHODS

We used multiple logistic regression to explore ETS exposures as reported in the 1992 and 2000 National Health Interview Survey.

RESULTS

ETS exposure in homes with children declined from 35.6% to 25.1% (P <.001) between 1992 and 2000, whereas smoking prevalence declined 26.5% to 23.3%. Home ETS exposures were more prevalent among non-Hispanic Whites than among African Americans (adjusted odds ratio [AOR] = 0.702; 95% confidence interval [CI] = 0.614, 0.802), Asian Americans (AOR = 0.534; 95% CI = 0.378, 0.754), and Hispanics (AOR = 0.388; 95% CI = 0.294, 0.389). Exposures declined across all groups, with greater gains in higher education and income groups.

CONCLUSIONS

Home ETS exposure declined sharply between 1992 and 2000, more than would be predicted by the decline in adult smoking prevalence.

Urinary F2-isoprostanes in young healthy children at risk for type 1 diabetes mellitus

Oxidative stress has been linked to many diseases, but little information exists on biomarkers of oxidative stress in healthy children. The purpose of this study was to describe factors that correlate with urinary F2-isoprostanes, an indicator of oxidative stress, and to establish normal concentrations of F2-isoprostanes in children at risk to develop type 1 diabetes mellitus. Creatinine-adjusted urinary F2-isoprostanes were assessed in 342 Denver children under the age of 7 years, from whom we had collected data during 769 clinic visits from August 1997 through January 2001 (mean 2.3 visits per child). Children were identified by newborn screening for HLA-markers, of varying degrees of prediction, for the development of type 1 diabetes. Plasma antioxidants and carotenoids, age at clinic visit, vitamin supplement use, exposure to environmental tobacco smoke, gender, and race were evaluated as correlates to the degree of oxidative stress, using mixed models for longitudinal data. F2-isoprostane levels were highest in infancy and decreased nonlinearly until 7 years. Female gender, HLA-DR3/4 genotype, higher plasma gamma-tocopherol:total lipids ratio, and lower alpha-carotene:total lipids ratio correlated with higher F2-isoprostane levels. Normal values in this healthy population can be used as the basis for future studies of disease mechanisms involving oxidative stress.