Health effects of passive smoking. 6. Parental smoking and childhood asthma: longitudinal and case-control studies

Parental smoking and respiratory outcomes in young childhood cancer survivors

BACKGROUND

Passive exposure to cigarette smoke has negative effects on respiratory health. Childhood cancer survivors (CCS) are at increased risk for respiratory disease due to treatment regimens that may harm the respiratory system. The objective of this study was to assess the prevalence of parental smoking among CCS and investigate its association with respiratory outcomes.

PROCEDURE

As part of the Swiss Childhood Cancer Survivor Study, between 2007 and 2022, we sent questionnaires to parents of children aged ≤16 years who had survived ≥5 years after a cancer diagnosis. Parents reported on their children's respiratory outcomes including recurrent upper respiratory tract infections (otitis media and sinusitis), asthma, and lower respiratory symptoms (chronic cough persisting >3 months, current and exercise wheeze), and on parental smoking. We used multivariable logistic regression to investigate associations between parental smoking and respiratory outcomes.

RESULTS

Our study included 1037 CCS (response rate 66%). Median age at study was 12 years (interquartile range 10-14 years). Eighteen percent of mothers and 23% of fathers reported current smoking. CCS exposed to smoking mothers were more likely to have recurrent upper respiratory tract infections (OR 2.1; 95%CI 1.1-3.7) and lower respiratory symptoms (OR 2.0; 95%CI 1.1-3.7). We found no association with paternal smoking.

CONCLUSIONS

A substantial proportion of CCS in Switzerland have parents who smoke. Exposure to maternal smoking was associated with higher prevalence of upper and lower respiratory problems. Healthcare providers can support families by addressing caregiver smoking behaviors and providing referrals to smoking cessation programs.

Secondhand Smoke Exposure and Its Impact on Pediatric Lung Function, Aerobic Fitness, and Body Mass: Evidence from a Cross-Sectional Study

BACKGROUND

Several studies have documented the detrimental impacts of secondhand smoke (SHS) exposure to a range of pediatric respiratory conditions, including asthma, bronchitis, and reduced lung function. The aim of the study was to investigate the influence of SHS exposure on lung function, physical fitness, and body mass index (BMI) in children aged 10 to 14 years.

METHODS

This cross-sectional study included children aged 10 to 14 years at the Elementary School "Trilj" in Trilj, Croatia. Data on SHS exposure were collected using a questionnaire. Antropometric and spirometry measurements were performed. Physical fitness was assessed using the shuttle run (BEEP) test.

RESULTS

This study included 157 children, 89 (56.69%) boys and 68 (43.31%) girls. Children exposed to every day SHS in households had significantly lower values of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, peak expiratory flow (PEF) (p < 0.001) and higher z-score BMI levels (p = 0.018) in comparison to unexposed children. Logistic regression showed that children unexposed to SHS had higher odds for better results in the BEEP test (OR 62.45, 95% CI 21.26-179.24, p < 0.001). Children with poorer physical fitness, expressed by lower BEEP score levels, had significantly lower FVC, FEV1, FEV1/FVC, and PEF (p < 0.001).

CONCLUSIONS

Every day SHS exposure in children was associated with poorer lung function, higher BMI, and poorer physical fitness.

Risk and protective factors of asthma and mental health condition multimorbidity in a national sample of Canadian children

BACKGROUND

The coexistence of childhood asthma and mental health (MH) conditions can impact management and health outcomes but we need to better understand the etiology of multimorbidity. We investigated the association between childhood asthma and MH conditions as well as the determinants of their coexistence.

METHODS

We used data from the Canadian Health Survey of Children and Youth 2019 (3-17 years; n = 47,871), a cross-sectional, nationally representative Statistics Canada dataset. Our primary outcome was condition status (no asthma or MH condition; asthma only; MH condition only; both asthma, and a MH condition (AMHM)). Predictors of condition status were assessed using multiple multinomial logistic regression. Sensitivity analyses considered individual MH conditions.

RESULTS

MH condition prevalence was almost two-fold higher among those with asthma than those without asthma (21.1% vs. 11.6%, respectively). There were increased risks of each condition category associated with having allergies, other chronic conditions, and family members smoking in the home while there were protective associations with each condition status category for being female and born outside of Canada. Four additional variables were associated with AMHM and MH condition presence with one additional variable associated with both AMHM and asthma. In sensitivity analyses, the associations tended to be similar for most characteristics, although there was some variability.

CONCLUSION

There are common risk factors of asthma and MH conditions along with their multimorbidity with a tendency for MH risk factors to be associated with multimorbidity. MH condition presence is common and important to assess among children with asthma.

Breastfeeding Versus Bottle Feeding and Risk of Bronchial Asthma in Children in Tabuk Area, Saudi Arabia: A Cross-Sectional Study

Introduction Asthma is a common chronic airway disorder, particularly among children in Saudi Arabia, with an increasing global prevalence. Limited epidemiological studies in the region indicate variable asthma rates, potentially influenced by factors such as modernization and environmental changes. Given the potential health benefits of breastfeeding, it is critical to investigate the relationship between type of feeding, and asthma risk. This study aims to assess the relationship between breastfeeding and bottle-feeding practices and the risk of developing asthma, as well as to evaluate how breastfeeding practices influence the severity of asthma among children in Tabuk, Saudi Arabia.  Methods A cross-sectional study was conducted among children with bronchial asthma at King Salman Armed Forces Hospital in Tabuk City, Saudi Arabia. The study took place from June to August 2023 using convenient sampling. Data were collected through a validated, structured web-based questionnaire distributed to the parents of children with bronchial asthma. The analysis was performed using SPSS (IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp). Results The study comprised 103 participants, of whom 66 (64.1%) were breastfed. There was no significant association between the severity of asthma and breastfeeding practices, including the initiation time, duration, or the age at which formula milk was introduced, as well as the combination of breastfeeding with bottle feeding. However, paternal smoking was significantly associated with asthma (p = 0.003), with 78.5% of children with smoking fathers affected compared to 50% of those without smoking fathers. In the multivariate analysis, having a father employed in the health sector (p = 0.040) and a maternal age over 35 years (p = 0.026) were significantly associated with an increased risk of asthma. Other factors, such as the child's age, gender, birth order, monthly income, parental education, family size, type of accommodation, and maternal diet during pregnancy, did not demonstrate significant associations with asthma. Conclusion Our study underscores the significant role of paternal smoking and specific parental sociodemographic factors, such as having a father employed in the health sector and maternal age over 35 years, in influencing the risk of childhood asthma. While breastfeeding practices, including duration and method, were not significantly associated with asthma severity, understanding these key risk factors can aid in developing targeted interventions for asthma prevention and management.

Mother's smoking habits affects IL10 methylation but not asthma in Ecuadorian children

There is no evidence evaluating the IL10 epigenetic upregulation among mestizo children in a high-altitude Andean city in Latin America.

OBJECTIVE

To identify polymorphisms and methylation profiles in the IL10 gene associated with asthma in children aged 5 to 11.

METHODS

A case-control study was conducted with asthmatic and non-asthmatic children aged 5 to 11 years in Cuenca-Ecuador. Data on allergic diseases and risk factors were collected through a questionnaire for parents. Atopy was measured by skin prick test (SPT) to relevant aeroallergens. Three IL10 single nucleotide polymorphisms were evaluated in all participants, and methylation analysis was performed in 54 participants. Association between risk factors, allergic diseases and genetic factors were estimated using multivariate logistic regression.

RESULTS

The results of polymorphisms showed no differences between cases and controls when comparing the SNPs rs3024495, rs3024496, rs1800896 allelic and genotypic frequencies. In the methylation analysis, no differences in the IL10 methylation profile were found between cases and controls; however, the multivariate analysis showed an association between the mother's smoking habits and the IL10 methylation profile.

CONCLUSION

Smoking habit could be essential as an environmental exposure factor in regulating gene expression in children with asthma.

Status of home-based secondhand smoke exposure among children and its association with health risks in Japan

Objectives

In Japan, secondhand smoke (SHS) exposure in children has changed with increased heated tobacco products (HTPs) and electronic cigarettes (e-cigs) use. We clarified the status of home-based SHS exposure among children, including HTPs and e-cigs, as well as maternal perceptions on SHS avoidance and examined its association with health risks.

Methods

This cross-sectional questionnaire-survey-based study included 379 mothers who were raising children aged < 5 years.

Results

We found that 31.1 % of the children had home-based SHS exposure, with widespread HTP and e-cig use among smoking mothers and family members (74.2 % and 67.0 %, respectively). Significantly (p < 0.05), HTP and cigarettes were used in the kitchen and gardens/balconies, and maternal perceptions of child SHS-exposure avoidance were lower among smokers than non-smokers. Non-smoking mothers also had low perceptions of smoking on balconies and having immediate post-smoking contact with their children (27.6 % and 27.9 %, respectively). Most non-smoking mothers (76.4 %) reported that they do not encourage family members to quit smoking. The structural equation model showed that the presence of smoking at home and low maternal perceptions was correlated with SHS-related child health risks, including respiratory diseases, otitis media, and dental caries.

Conclusions

HTP and e-cig use in the household has been rapidly increasing even among mothers and family members, and the presence of smokers at home and low maternal perceptions may be associated with child health risks. Increasing the maternal awareness of the child health risks of home-based SHS, including HTPs and e-cigs, along with continued smoking-cessation support involving mothers and families, is indispensable.

Spatial proximity to wildfires as a proxy for measuring PM2.5: A novel method for estimating exposures in rural settings

Background

Climate change impacts humans and society both directly and indirectly. Alaska, for example, is warming twice as fast as the global mean, and researchers are starting to grapple with the varied and inter-connected ways in which climate change affects the people there. With the number of wildfires increasing in Alaska as a result of climate change, the number of asthma cases has increased, driven by exposure to small particulate matter. However, it is not clear how far away smoke from wildfires can affect health. In this study, we hope to establish a relationship between proximity to wildfires and asthma in locations where direct PM2.5 measurement is not easily accomplished.

Methods

In this study, we examined whether proximity to wildfire exposure is associated with regional counts of adults with asthma, calculated using Behavioral Risk Factor Surveillance System (BRFSS) survey data and US Census data. We assigned "hotspots" around population centers with a range of various distances to wildfires in Alaska.

Results

We found that wildfires are associated with asthma prevalence, and the association is strongest within 25 miles of fires.

Conclusions

This study highlights the fact that proximity to wildfires has potential as a simple proxy for actual measured wildfire smoke, which has important implications for wildfire management agencies and for policy makers who must address health issues associated with wildfires, especially in rural areas.

Preconception origins of asthma, allergies and lung function: The influence of previous generations on the respiratory health of our children

Emerging research suggests that exposures occurring years before conception are important determinants of the health of future offspring and subsequent generations. Environmental exposures of both the father and mother, or exposure to disease processes such as obesity or infections, may influence germline cells and thereby cause a cascade of health outcomes in multiple subsequent generations. There is now increasing evidence that respiratory health is influenced by parental exposures that occur long before conception. The strongest evidence relates adolescent tobacco smoking and overweight in future fathers to increased asthma and lower lung function in their offspring, supported by evidence on parental preconception occupational exposures and air pollution. Although this literature is still sparse, the epidemiological analyses reveal strong effects that are consistent across studies with different designs and methodologies. The results are strengthened by mechanistic research from animal models and (scarce) human studies that have identified molecular mechanisms that can explain the epidemiological findings, suggesting transfer of epigenetic signals through germline cells, with susceptibility windows in utero (both male and female line) and prepuberty (male line). The concept that our lifestyles and behaviours may influence the health of our future children represents a new paradigm. This raises concerns for future health in decades to come with respect to harmful exposures but may also open for radical rethinking of preventive strategies that may improve health in multiple generations, reverse the imprint of our parents and forefathers, and underpin strategies that can break the vicious circle of propagation of health inequalities across generations.

Association between Environmental Exposures and Asthma among Children in King Williams Town, South Africa

The study aimed to assess the association between environmental exposure and asthma among children between 3 and 12 years old in King Williams Town, South Africa. A quantitative case-control study was conducted at Grey Hospital to assess the association between environmental exposure and asthma among children who reside in King Williams Town. Of the total 566 study participants, 50.5% (286) had asthma while 49.5% did not. Socio-demographic factors associated with asthma in children were being within the age group 9-12 years (OR 1.74, CI 95% 1.09-2.78) and India ethnicity (OR 0.20, CI 95% 0.08-0.48). Factors associated with asthma were weight within 25-35 kg (OR 1.64, CI 95% 1.11-2.42) and BMI within 15-20 (OR 4.80, CI 95% 2.80-8.22). Environmental risk factors associated with asthma were indoor exposure to tobacco smoke from mothers of the participants (OR 5.45, CI 95% 3.08-9.65) and from fathers (OR 4.37; CI 95% 2.77-6.90). Abstaining from eating seafood appeared to be protective from developing asthma (OR 0.01; CI 95% 0.00-0.05). The study found no significant association between outdoor environmental exposures and childhood asthma. The age of participant, weight, BMI, exposure to environmental tobacco smoke (ETS), and eating seafood had significant correlations with childhood asthma. Strengthening the evaluation of children healthcare and encouraging smoking cessation among parents could reduce exposure to environmental asthma triggers among children.

The role of gene-ambient air pollution interactions in paediatric asthma

Globally, asthma prevention and treatment remain a challenge. Ambient air pollution (AAP) is an environmental risk factor of special interest in asthma research. AAP is poorly defined and has been subdivided either by the origin of the air pollution or by the specific bioactive compounds. The link between AAP exposure and asthma exacerbations is well established and has been extensively reviewed. In this narrative review, we discuss the specific genetic variants that have been associated with increased AAP sensitivity and impact in paediatric asthma. We highlight the relative importance of variants associated with genes with a role in oxidant defences and the nuclear factor-κB pathway supporting a potential central role for these pathways in AAP sensitivity.

Mannose-binding lectin 2 gene polymorphisms and predisposition to allergic bronchial asthma in a western Romanian children population: an observational study

OBJECTIVES

To analyse: (1) the associations between different mannose-binding lectin 2 (MBL2) genotypes and susceptibility to bronchial asthma (BA) in Romanian children; and (2) the correlations between several patient sociodemographic variables and MBL2 polymorphisms.

METHODS

This prospective observational case-control study included paediatric patients with symptomatic BA and healthy controls. Participants were genotyped for two MBL2 single-nucleotide polymorphisms (SNPs): exon 1 codon 54 A/B variant rs1800450, and -550 promoter H/L variant rs11003125 (GenBank accession). Associations between MBL2 genotypes and susceptibility to BA were determined by calculated odds ratios, and Kendall Tau's correlations were used to investigate the associations between sociodemographic variables and SNPs.

RESULTS

Among 59 patients with BA and 65 healthy controls, associations between MBL2 polymorphisms and susceptibility to BA were not found to be statistically significant. Statistically significant weak positive correlations were found between age at diagnosis and A/B genotype, and between the smoking status of biologically male and female parents. A statistically significant weak inverse association was found between male parent smoking status and family history of BA.

CONCLUSION

These results may help guide future research into paediatric BA in Romania and Eastern Europe. Due to study limitations, the results require validation in future large-scale studies.

Are Phthalate Exposure Related to Oxidative Stress in Children and Adolescents with Asthma? A Cumulative Risk Assessment Approach

Childhood asthma has become one of the most common chronic diseases in children and adolescents. However, few case–control studies investigating the relationship between phthalate exposure and asthma in children and adolescents have been conducted, especially in Asia. Therefore, we assessed the potential associations between phthalate exposure and asthma among children and adolescents in Taiwan. Because various demographic and environmental variables may influence the incidence and prognosis of asthma, we performed a case–control study with propensity score matching. Out of 615 Childhood Environment and Allergic Diseases Study participants, we conditionally matched 41 children with clinically diagnosed asthma with 111 controls. We then analyzed 11 phthalate metabolites by using liquid chromatography with tandem mass spectrometry. Compared with the control group, the median urinary phthalate levels for most phthalate metabolites in the case group were slightly increased, including monomethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, monoethylhexyl phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate, and mono-(2-carboxymethylhexyl) phthalate. Hence, our results suggest that phthalate exposure may be associated with the development of asthma. In addition, prenatal environmental factors, such as active or passive smoking during pregnancy, may increase the risk of asthma.

Global, regional, and national prevalence of asthma in 2019: a systematic analysis and modelling study

Background

Asthma has a significant impact on people of all ages, particularly children. A lack of universally accepted case definition and confirmatory tests and a poor understanding of major risks interfere with a global response. We aimed to provide global estimates of asthma prevalence and cases in 2019 across four main epidemiological case definitions - current wheezing, ever wheezing, current asthma, and ever asthma. We further investigated major associated factors to determine regional and national distributions of prevalence and cases for current wheezing and ever asthma.

Methods

We identified relevant population-based studies published between January 1, 1990, and December 31, 2019. Using a multilevel multivariable mixed-effects meta-regression model, we assessed the age- and sex-adjusted associations of asthma with study-level variables, including year, setting, region and socio-demographic index (SDI). Using a random-effects meta-analysis, we then identified risk factors for current wheezing and asthma. From a "risk factor-based model", which included current smoking, and biomass exposure for current wheezing, and rural setting, current smoking, biomass exposure, and SDI for ever asthma, we estimated case numbers and prevalence across regions and 201 countries and territories in 2019.

Results

220 population-based studies conducted in 88 countries were retained. In 2019, the global prevalence estimates of asthma in people aged 5-69 years by various definitions, namely current wheezing, ever wheezing, current asthma, and ever asthma were 11.5% (95% confidence interval (CI) = 9.1-14.3), 17.9% (95% CI = 14.2-22.3), 5.4% (95% CI = 3.2-9.0) and 9.8% (95% CI = 7.8-12.2), respectively. These translated to 754.6 million (95% CI = 599. 7-943.4), 1181.3 million (95% CI = 938.0-1,471.0), 357.4 million (95% CI = 213.0-590.8), 645.2 million (95% CI = 513.1-806.2) cases, respectively. The overall prevalence of current wheezing among people aged 5-69 years was the highest in the African Region at 13.2% (95% CI = 10.5-16.5), and the lowest in the Americas Region at 10.0% (95% CI = 8.0-12.5). For ever asthma, the estimated prevalence in those aged 5-69 years was also the highest in the African Region at 11.3% (95% CI = 9.0-14.1), but the lowest in South-East Asia Region (8.8, 95% CI = 7.0-11.0).

Conclusions

Although varying approaches to case identification in different settings make epidemiological estimates of asthma very difficult, this analysis reaffirms asthma as a common global respiratory condition before the COVID-19 pandemic in 2019, with higher prevalence than previously reported in many world settings.

Phthalate Exposure and Oxidative/Nitrosative Stress in Childhood Asthma: A Nested Case-Control Study with Propensity Score Matching

Whether low-dose phthalate exposure triggers asthma among children, and its underlying mechanisms, remain debatable. Here, we evaluated the individual and mixed effects of low-dose phthalate exposure on children with asthma and five (oxidative/nitrosative stress/lipid peroxidation) mechanistic biomarkers—8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO₂Gua), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), 8-isoprostaglandin F2α (8-isoPF2α), and malondialdehyde (MDA)—using a propensity score-matched case-control study (case vs. control = 41 vs. 111). The median monobenzyl phthalate (MBzP) concentrations in the case group were significantly higher than those in the control group (3.94 vs. 2.52 ng/mL, p = 0.02), indicating that dust could be an important source. After adjustment for confounders, the associations of high monomethyl phthalate (MMP) (75th percentile) with 8-NO₂Gua (adjusted odds ratio (aOR): 2.66, 95% confidence interval (CI): 1.03–6.92) and 8-isoPF2α (aOR: 4.04, 95% CI: 1.51–10.8) and the associations of mono-iso-butyl phthalate (MiBP) with 8-isoPF2α (aOR: 2.96, 95% CI: 1.13–7.79) were observed. Weighted quantile sum regression revealed that MBzP contributed more than half of the association (56.8%), followed by MiBP (26.6%) and mono-iso-nonyl phthalate (MiNP) (8.77%). Our findings supported the adjuvant effect of phthalates in enhancing the immune system response.

Trajectories of asthma symptom presenting as wheezing and their associations with family environmental factors among children in Australia: evidence from a national birth cohort study

OBJECTIVES

Asthma is one of the greatest health burdens, yet contributors to asthma symptom trajectories are understudied in Australian children. We aimed to assess the trajectories of asthma symptom and their associations with several family environmental factors during the childhood period in Australia.

DESIGN

Secondary analysis from a cross-sequential cohort study.

SETTING

Nationwide representative data from the 'Longitudinal Study of Australian Children (LSAC)'.

PARTICIPANTS

Participants from the LSAC birth cohort.

OUTCOME MEASURES

Asthma symptom trajectory groups.

METHODS

Asthma symptom presenting as wheezing, family environmental factors and sociodemographic data (2004-2018) were obtained from the LSAC. Group-based trajectory modelling was applied to identify asthma symptom trajectories and multivariable logistic regression models were used to assess the associations between these and environmental factors.

RESULTS

Of 5107 children in the LSAC cohort, 3846 were included in our final analysis. We identified three distinct asthma symptom trajectories from age 0/1 year to 14/15 years: 'low/no' (69%), 'transient high' (17%) and 'persistent high' (14%). Compared with the 'low/no' group, children exposed to 'moderate and declining' (relative risk ratio (RRR): 2.22, 95% CI 1.94 to 2.54; RRR: 1.26, 95% CI 1.08 to 1.46) and 'high and persistent' prevalence of maternal smoking (RRR: 1.41, 95% CI 1.23 to 1.60; RRR: 1.26, 95% CI 1.10 to 1.44) were at increased risk of being classified into the 'transient high' and 'persistent high' trajectories of asthma symptom. Persistently bad external dwelling conditions (RRR: 1.27, 95% CI 1.07 to 1.51) were associated with 'transient high' trajectory while 'moderate and increasing' conditions of cluttered homes (RRR: 1.37, 95% CI 1.20 to 1.56) were associated with 'persistent high' trajectory of asthma symptom. Exposure to tobacco smoke inside the house also increased the risk of being in the 'persistent high' trajectory group (RRR: 1.30, 95% CI 1.12 to 1.50).

CONCLUSION

Poor home environment increased the risk of asthma symptom during childhood. Improving home environment and reducing exposure to tobacco smoke may facilitate a favourable asthma symptom trajectory during childhood.

Thunderstorms, Pollen, and Severe Asthma in a Midwestern, USA, Urban Environment, 2007-2018

BACKGROUND

Previous research has shown an association between individual thunderstorm events in the presence of high pollen, commonly called thunderstorm asthma, and acute severe asthma events, but little work has studied risk over long periods of time, using detailed measurements of storms and pollen.

METHODS

We estimated change in risk of asthma-related emergency room visits related to thunderstorm asthma events in the Minneapolis-St. Paul metropolitan area over the years 2007-2018. We defined thunderstorm asthma events as daily occurrence of two or more lightning strikes during high pollen periods interpolating weather and pollen monitor data and modeling lightning counts. We acquired daily counts of asthma-related emergency department visits from the Minnesota Hospital Association and used a quasi-Poisson time-series regression to estimate overall relative risk of emergency department visits during thunderstorm asthma events.

RESULTS

We observed a 1.047 times higher risk (95% CI:1.012,1.083) of asthma-related emergency department visits on the day of thunderstorm asthma event. Our findings are robust to adjustment for temperature, humidity, wind, precipitation, ozone, PM2.5, day of week, and seasonal variation in asthma cases. Occurrence of lightning alone or pollen alone showed no association with risk of severe asthma. A two-stage analysis combining individual zip code level results shows similar RR and we see no evidence of spatial correlation or spatial heterogeneity of effect.

DISCUSSION

Our results support an association between co-occurrence of lightning and pollen and risk of severe asthma events. Our approach incorporates lightning and pollen data and small-spatial area exposure and outcome counts.

Mmp12 Is Upregulated by in utero Second-Hand Smoke Exposures and Is a Key Factor Contributing to Aggravated Lung Responses in Adult Emphysema, Asthma, and Lung Cancer Mouse Models

Matrix metalloproteinase-12 (Mmp12) is upregulated by cigarette smoke (CS) and plays a critical role in extracellular matrix remodeling, a key mechanism involved in physiological repair processes, and in the pathogenesis of emphysema, asthma, and lung cancer. While cigarette smoking is associated with the development of chronic obstructive pulmonary diseases (COPD) and lung cancer, in utero exposures to CS and second-hand smoke (SHS) are associated with asthma development in the offspring. SHS is an indoor air pollutant that causes known adverse health effects; however, the mechanisms by which in utero SHS exposures predispose to adult lung diseases, including COPD, asthma, and lung cancer, are poorly understood. In this study, we tested the hypothesis that in utero SHS exposure aggravates adult-induced emphysema, asthma, and lung cancer.

Methods: Pregnant BALB/c mice were exposed from gestational days 6–19 to either 3 or 10mg/m³ of SHS or filtered air. At 10, 11, 16, or 17weeks of age, female offspring were treated with either saline for controls, elastase to induce emphysema, house-dust mite (HDM) to initiate asthma, or urethane to promote lung cancer. At sacrifice, specific disease-related lung responses including lung function, inflammation, gene, and protein expression were assessed.

Results: In the elastase-induced emphysema model, in utero SHS-exposed mice had significantly enlarged airspaces and up-regulated expression of Mmp12 (10.3-fold compared to air-elastase controls). In the HDM-induced asthma model, in utero exposures to SHS produced eosinophilic lung inflammation and potentiated Mmp12 gene expression (5.7-fold compared to air-HDM controls). In the lung cancer model, in utero exposures to SHS significantly increased the number of intrapulmonary metastases at 58weeks of age and up-regulated Mmp12 (9.3-fold compared to air-urethane controls). In all lung disease models, Mmp12 upregulation was supported at the protein level.

Conclusion: Our findings revealed that in utero SHS exposures exacerbate lung responses to adult-induced emphysema, asthma, and lung cancer. Our data show that MMP12 is up-regulated at the gene and protein levels in three distinct adult lung disease models following in utero SHS exposures, suggesting that MMP12 is central to in utero SHS-aggravated lung responses.

Prevalence and early-life risk factors of school-age allergic multimorbidity: The EuroPrevall-iFAAM birth cohort

Background

Coexistence of childhood asthma, eczema and allergic rhinitis is higher than can be expected by chance, suggesting a common mechanism. Data on allergic multimorbidity from a pan‐European, population‐based birth cohort study have been lacking. This study compares the prevalence and early‐life risk factors of these diseases in European primary school children.

Methods

In the prospective multicentre observational EuroPrevall‐iFAAM birth cohort study, we used standardized questionnaires on sociodemographics, medical history, parental allergies and lifestyle, and environmental exposures at birth, 12 and 24 months. At primary school age, parents answered ISAAC‐based questions on current asthma, rhinitis and eczema. Allergic multimorbidity was defined as the coexistence of at least two of these.

Results

From 10,563 children recruited at birth in 8 study centres, we included data from 5,572 children (mean age 8.2 years; 51.8% boys). Prevalence estimates were as follows: asthma, 8.1%; allergic rhinitis, 13.3%; and eczema, 12.0%. Allergic multimorbidity was seen in 7.0% of the whole cohort, ranging from 1.2% (Athens, Greece) to 10.9% (Madrid, Spain). Risk factors for allergic multimorbidity, identified with AICc, included family‐allergy‐score, odds ratio (OR) 1.50 (95% CI 1.32–1.70) per standard deviation; early‐life allergy symptoms, OR 2.72 (2.34–3.16) for each symptom; and caesarean birth, OR 1.35 (1.04–1.76). Female gender, OR 0.72 (0.58–0.90); older siblings, OR 0.79 (0.63–0.99); and day care, OR 0.81 (0.63–1.06) were protective factors.

Conclusion

Allergic multimorbidity should be regarded as an important chronic childhood disease in Europe. Some of the associated early‐life factors are modifiable and may be considered for prevention strategies.

Genetics of Asthma and Allergic Diseases

Asthma genes have been identified through a range of approaches, from candidate gene association studies and family-based genome-wide linkage analyses to genome-wide association studies (GWAS). The first GWAS of asthma, reported in 2007, identified multiple markers on chromosome 17q21 as associates of the childhood-onset asthma. This remains the best replicated asthma locus to date. However, notwithstanding undeniable successes, genetic studies have produced relatively heterogeneous results with limited replication, and despite considerable promise, genetics of asthma and allergy has, so far, had limited impact on patient care, our understanding of disease mechanisms, and development of novel therapeutic targets. The paucity of precise replication in genetic studies of asthma is partly explained by the existence of numerous gene-environment interactions. Another important issue which is often overlooked is that of time of the assessment of the primary outcome(s) and the relevant environmental exposures. Most large GWASs use the broadest possible definition of asthma to increase the sample size, but the unwanted consequence of this is increased phenotypic heterogeneity, which dilutes effect sizes. One way of addressing this is to precisely define disease subtypes (e.g. by applying novel mathematical approaches to rich phenotypic data) and use these latent subtypes in genetic studies.

Establishing a patient registry study database of dust mite allergic asthma in children: design, methodology and preliminary exploration

Background

Asthma is a heterogeneous disease with different phenotypes, endotypes and responses to treatment. Dust mite allergic asthma (DMAA) is the most common type in children. Compared with randomized control trials, a patient registry study (PRS) can reflect the real physical condition and clinical diagnosis more comprehensively.

Methods

Children who visited the asthma clinic of the Children’s Hospital of Chongqing Medical University between August 2018 and August 2020, and met the inclusion criteria and also agreed to participate, were enrolled in the registry study. Clinical information, laboratory tests and peripheral blood samples were collected after informed consent was given by guardians.

Results

To date, 208 children have been enrolled in the patient registry database of DMAA. They are mainly male, with >50% having a history of allergic rhinitis, cesarean section, positive family history and passive smoking. Eosinophils and total immunoglobulin E levels were all significantly higher than normal. According to results for the childhood asthma control test (c-ACT) and ratio of forced expiratory volume in 1 s to predicted value after inhaled corticosteroid treatment, the uncontrolled group had higher hemoglobin (Hb) levels than the control group. The group exhibiting abnormal pulmonary function was older, and had longer disease duration, higher fractional exhaled nitric oxide and Hb than the group in which pulmonary function was restored.

Conclusions

We have preliminarily established a registered study database of children with DMAA. By cluster analysis and using blood samples, we can further study the different pathophysiological mechanisms in order to provide more individualized and targeted treatments for all children.

Profile of exposures and lung function in adults with asthma: An exposome approach in the EGEA study

BACKGROUND

Environmental research on multifactorial health outcomes calls for exposome approaches able to assess the joint effect of multiple exposures.

OBJECTIVE

Our aim was to identify profiles of exposure to lifestyle/environmental factors associated with lung function in adults with asthma using a cluster-based approach.

METHODS

We used data from 599 adults of the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA) (mean age 39.0 years, 52% men) who ever had asthma. Exposures to 53 lifestyle/environmental factors were assessed by questionnaires or geographic information systems-based models. A two-step approach was developed: 1) exposome dimension reduction by selecting factors showing association with forced expiratory volume in 1 s (FEV₁) (p < 0.20) in an exposome-wide association study (ExWAS), 2) clustering analysis using the supervised Bayesian Profile Regression (sBPR) to group individuals according to FEV₁ level and to their profile of exposure to a reduced set of uncorrelated exposures (each paired correlation<0.70) identified in step 1.

RESULTS

The ExWAS identified 21 factors showing suggestive association with FEV₁ (none significant when controlling for multiple tests). The sBPR conducted on 15 uncorrelated exposures identified in step 1, revealed 3 clusters composed of 30, 115 and 454 individuals with a mean ± SD FEV₁(%pred) of 79% ± 21, 90% ± 19 and 93% ± 16, respectively. Cluster 1 was composed of individuals with heavy smoking, poor diet, higher outdoor humidity and proximity to traffic, while cluster 2 and 3 included individuals with moderate/low levels of exposure to these factors.

DISCUSSION

This exposome study identified a specific profile of joint lifestyle and environmental factors, associated with a low FEV₁ in adults with asthma. None of the exposures revealed significant association when considered independently.

Factors and mechanisms contributing to the development of preschool wheezing disorders

INTRODUCTION

Half of all children will experience an episode of wheezing by their sixth birthday and acute episodes of wheezing in preschool children account for the majority of all childhood hospital admissions for wheeze. Recurrent preschool wheezing associates with early loss of lung function and a life-long impact on lung health.

AREAS COVERED

We reviewed the literature on PubMed from August 2010-2020 focussing on factors associated with wheeze inception and persistence, paying specific attention to mechanistic studies that have investigated the impact of early life exposures in shaping immune responses in children with underlying susceptibility to wheezing. In particular, the role of early allergen sensitization, respiratory infections, and the impact of the environment on shaping the airway microbiome and resulting immune responses are discussed.

EXPERT OPINION

There is an abundance of associative data showing the role of in utero and postnatal factors influencing wheeze onset and persistence. However, mechanistic and stratified, biomarker-based interventional studies that confirm these associations are now needed if we are to impact the significant healthcare burden resulting from preschool wheezing disorders.

Untargeted Urinary Metabolomics and Children's Exposure to Secondhand Smoke: The Influence of Individual Differences

Children’s exposure to secondhand smoke (SHS) is a severe public health problem. There is still a lack of evidence regarding panoramic changes in children’s urinary metabolites induced by their involuntary exposure to SHS, and few studies have considered individual differences. This study aims to clarify the SHS-induced changes in urinary metabolites in preschool children by using cross-sectional and longitudinal metabolomics analyses. Urinary metabolites were quantified by using untargeted ultra high-performance liquid chromatography-mass spectrometry (UPLC^(c)-MS/MS). Urine cotinine-measured SHS exposure was examined to determine the exposure level. A cross-sectional study including 17 children in a low-exposure group, 17 in a medium-exposure group, and 17 in a high-exposure group was first conducted. Then, a before–after study in the cohort of children was carried out before and two months after smoking-cessation intervention for family smokers. A total of 43 metabolites were discovered to be related to SHS exposure in children in the cross-sectional analysis (false discovery rate (FDR) corrected p < 0.05, variable importance in the projection (VIP) > 1.0). Only three metabolites were confirmed to be positively associated with children’s exposure to SHS (FDR corrected p < 0.05) in a follow-up longitudinal analysis, including kynurenine, tyrosyl-tryptophan, and 1-(3-pyridinyl)-1,4-butanediol, the latter of which belongs to carbonyl compounds, peptides, and pyridines. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that 1-(3-pyridinyl)-1,4-butanediol and kynurenine were significantly enriched in xenobiotic metabolism by cytochrome P450 (p = 0.040) and tryptophan metabolism (p = 0.030), respectively. These findings provide new insights into the pathophysiological mechanism of SHS and indicate the influence of individual differences in SHS-induced changes in urinary metabolites in children.

[Smoking cessation in asthmatic patients and its impact]

INTRODUCTION

The prevalence of smoking in asthmatic patients is similar to, or even higher than in the general population.

OBJECTIVES

This systematic review addresses (1) the effects of smoking on asthma, (2) smoking cessation strategies in asthmatic patients, and (3) the consequences of smoking cessation for people with asthma.

RESULTS

Active or passive smoking can promote the development of asthma. The few studies on smoking cessation in asthma confirm the efficacy of validated smoking cessation strategies in these patients (nicotine replacement therapy, varenicline, bupropion, cognitive and behavioural therapies). Smoking cessation in parents with asthmatic children is essential and is based on the same strategies. Electronic cigarettes may be a useful help to quit smoking in some patients. Smoking cessation is beneficial in asthmatic smokers and associated with (1) a reduction of asthma symptoms, acute exacerbations, bronchial hyperresponsiveness, and bronchial inflammation, (2) decreased use of rescue medications and in doses of inhaled corticosteroids, (3) improved asthma control, quality of life, and lung function.

CONCLUSION

In asthmatic patients, it is essential to assess smoking status and health professionals must assist them to quit smoking.

The association between secondhand smoke and childhood asthma: A systematic review and meta-analysis

BACKGROUND

Secondhand smoke (SHS) exposure can trigger asthma exacerbations in children. Different studies have linked increased asthma symptoms and even deaths in children with SHS, but the risk has not been quantified uniformly across studies. We aimed to investigate the role of SHS exposure as a risk factor of asthma among children.

METHODS

We performed a systematic review in PubMed, Scopus, and Google Scholar from June 1975 to 10 March 2020. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk estimates and confidence intervals of all types of SHS exposure and childhood asthma.

RESULTS

Of the 26 970 studies identified, we included 93 eligible studies (42 cross-sectional, 41 cohort, and 10 case-control) in the meta-analysis. There were significantly positive associations between SHS exposure and doctor-diagnosed asthma (OR = 1.24; 95% confidence interval (CI) = 1.20-1.28), wheezing (OR = 1.27; 95% CI = 1.23-1.32) and asthma-like syndrome (OR = 1.34; 95% CI = 1.34-1.64). The funnel plots of all three outcomes skewed to the right, indicating that the studies generally favor a positive association of the disease with tobacco exposure. Subgroup analysis demonstrated that younger children tended to suffer more from developing doctor-diagnosed asthma, but older children (adolescents) suffered more from wheezing. There was no evidence of significant publication or small study bias using Egger's and Begg's tests.

CONCLUSION

The results show a positive association between prenatal and postnatal secondhand smoking exposure and the occurrence of childhood asthma, asthma-like syndrome, and wheezing. These results lend support to continued efforts to reduce childhood exposure to secondhand smoke.

Asthma in urban Aboriginal children: A cross-sectional study of socio-demographic patterns and associations with pre-natal and current carer smoking

AIM

To describe socio-demographic patterns of asthma prevalence in urban Aboriginal children and quantify associations between asthma prevalence and pre-natal maternal and current carer smoking.

METHODS

Analyses used carer-reported survey data for 1290 urban Aboriginal children aged 2-17 years from the Study of Environment on Aboriginal Resilience and Child Health. Multilevel log-binomial regression was used to estimate asthma prevalence ratios (PRs) for child- and family-level socio-demographic factors, pre-natal maternal smoking and current carer smoking. Smoking-related PRs were compared with general-population estimates derived from meta-analyses of published cross-sectional data.

RESULTS

Overall, 33.9% of children had ever had asthma, and 12.9% had received treatment for asthma in the past month. Prevalence estimates declined with increasing household income and increasing household size (posterior probabilities of decreasing trend >0.98), while children exposed to pre-natal maternal smoking had a higher risk of asthma ever than unexposed children (PR 1.18 (95% credible interval 1.00-1.40)). Recently treated asthma prevalence was not significantly associated with pre-natal maternal (0.98 (0.71-1.41)) or current carer smoking (0.97 (0.68-1.37)); however, there was substantial uncertainty in our PR estimates, and 95% credible intervals contained general-population estimates derived from the meta-analyses (1.37 (1.17-1.65) for pre-natal smoking, 1.28 (1.15-1.44) for current parental or household smoking).

CONCLUSION

Among urban Aboriginal children in the Study of Environment on Aboriginal Resilience and Child Health cohort, asthma prevalence declines as household income and household size increase, while children exposed to pre-natal maternal smoking are at increased risk of ever having asthma. Our results emphasise the importance of reducing smoking in Aboriginal communities, particularly among pregnant women.

Exposure to environmental tobacco smoke and prevalence of asthma among adolescents in a middle eastern country

Background

There is increasing evidence linking environmental tobacco smoke (ETS) exposure at homes to the development of asthma among adolescents. Few studies have addressed this issue in the Middle Eastern countries including Kuwait. Therefore, this cross-sectional study assessed the prevalence of ETS exposure at home, prevalence of asthma and other respiratory conditions and examined the ETS exposure at home and personal tobacco smoking as risk factors for self-reported asthma among high-school students in Kuwait.

Methods

In this cross-sectional study, we enrolled participants from nine high-schools of Hawally Governorate of Kuwait during October 2015. We adapted a previously validated self-administered questionnaire for data collection. Prevalence of self-reported asthma and ETS exposure (≥ 1 smoker at home vs. none) were computed. The association between exposures of interest and self-reported asthma status was examined using a multivariable log-binomial regression model.

Results

Of 800 enrolled participants, 746 (92.2%) consented and completed the questionnaire. The participants with mean (SD) age of 16.8 (0.68) years were predominantly Kuwaiti (74.8%) and female (50.1%). The prevalence of ETS exposure at home and personal current smoking was 54 and 12.4% respectively. Self-reported asthma prevalence was 20.5%. Furthermore, the prevalence of physician-diagnosed asthma, wheezing during the last 12 months and wheezing ‘ever’ was 16.4, 20.1 and 26.2%, respectively. Fitted multivariable log-binomial regression model revealed that compared with the non-asthmatic, participants with self-reported asthma tended to be current smokers (adjusted prevalence ratio (adjusted PR) = 1.82; 95% CI: 1.30–2.56; p = 0.001) or have had ETS exposure at home (adjusted PR = 1.64; 95% CI: 1.21–2.23; p = 0.002).

Conclusions

We recorded a high prevalence of ETS exposure at home, high prevalence of self-reported asthma and identified ETS exposure at home and being a current smoker as strong risk factors for self-reported asthma among adolescents. Voluntary household smoking bans may substantially minimize the ETS exposure among adolescents. Additionally, such restriction may inculcate an antismoking attitude and prevent smoking initiation among adolescents. Such efforts may bring about reduction in ETS exposure and associated asthma risk and other smoking-related morbidities in this and other similar settings.

Maternal smoking during pregnancy affects adult onset of asthma in offspring: a follow up from birth to age 46 years

RATIONALE

Environmental tobacco smoke (ETS) exposure increases asthma risk in children. There is limited knowledge of prenatal ETS for adult-onset asthma.

OBJECTIVES

To determine the association between prenatal ETS and adult onset asthma.

MEASUREMENTS AND MAIN RESULTS

The questionnaire and clinical data of 5200 people, free of physician-diagnosed asthma by 31 years of age, who were included in the Northern Finland Birth Cohort 1966 Study was used. The association of maternal smoking during the last 3 months of pregnancy with onset of physician-diagnosed asthma and with lung function in adult offspring was studied using adjusted multivariate regression analyses. The cumulative incidence of physician-diagnosed asthma between the ages of 31 and 46 years was 5.1% among men and 8.8% among women. Gestational smoke exposure was associated with adult-onset asthma among offspring (adjusted OR 1.54, 95% CI 1.04-2.29), namely among offspring who reported either past non-diagnosed asthma (OR 9.63, 95% CI 2.28-40.67) or past cough with wheeze (3.21, 95% CI 1.71-6.05). A significant association was detected between gestational smoke exposure and the offspring's forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratio at 31 years of age. In offspring with the haplotype rs11702779-AA of RUNX1, gestational smoke exposure was associated with adult-onset asthma (5.53, 95% CI 2.11-14.52, adjusted p-value for interaction 0.10).

CONCLUSION

Maternal smoking during pregnancy is associated with the cumulative incidence of asthma in offspring between the ages of 31 and 46 years. The association was accentuated in offspring who at age 31, reported having past respiratory problems and/or who had haplotype rs11702779-AA. A reduction in FEV₁/FVC ratio was also observed at age 31 years in offspring with gestational smoke exposure. These results could reflect the early vulnerability of offspring's airways to ETS and its putative long-term effects.

Phenotypes of wheezing and asthma in preschool children

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the identified phenotypes of preschool wheezing.

RECENT FINDINGS

Early life wheezing patterns have been described in multiple populations, with several commonalities found between cohorts. Early life environmental exposures have been found to be differentially associated with preschool wheezing phenotypes and their future trajectories. These include allergen and microbe exposure, environmental tobacco smoke exposure, and maternal stress and depression. Elevated IgE in early life may also influence future asthma risk.

SUMMARY

Preschool wheezing phenotypes are heterogeneous and complex, with trajectories that are related to factors including environmental exposures. More research is needed to characterize these relationships, hopefully leading to targeted prevention strategies.

Why Do Intrauterine Exposure to Air Pollution and Cigarette Smoke Increase the Risk of Asthma?

The prevalence of childhood asthma is increasing worldwide and increased in utero exposure to environmental toxicants may play a major role. As current asthma treatments are not curative, understanding the mechanisms underlying the etiology of asthma will allow better preventative strategies to be developed. This review focuses on the current understanding of how in utero exposure to environmental factors increases the risk of developing asthma in children. Epidemiological studies show that maternal smoking and particulate matter exposure during pregnancy are prominent risk factors for the development of childhood asthma. We discuss the changes in the developing fetus due to reduced oxygen and nutrient delivery affected by intrauterine environmental change. This leads to fetal underdevelopment and abnormal lung structure. Concurrently an altered immune response and aberrant epithelial and mesenchymal cellular function occur possibly due to epigenetic reprograming. The sequelae of these early life events are airway remodeling, airway hyperresponsiveness, and inflammation, the hallmark features of asthma. In summary, exposure to inhaled oxidants such as cigarette smoking or particulate matter increases the risk of childhood asthma and involves multiple mechanisms including impaired fetal lung development (structural changes), endocrine disorders, abnormal immune responses, and epigenetic modifications. These make it challenging to reduce the risk of asthma, but knowledge of the mechanisms can still help to develop personalized medicines.

Asthma and elevation of anti-citrullinated protein antibodies prior to the onset of rheumatoid arthritis

BACKGROUND

Anti-citrullinated protein antibodies (ACPA) are central to rheumatoid arthritis (RA) pathogenesis and may develop at inflamed mucosa. We investigated whether asthma, a disease of airway mucosal inflammation, was associated with elevated ACPA before RA diagnosis.

METHODS

We performed a nested case-control study among women in two prospective cohorts, the Nurses' Health Study (NHS; 1976-2014) and NHSII (1989-2015). Blood was obtained on a subset (NHS: 1989-1990; NHSII: 1996-1999). Cases met 1987 ACR or 2010 ACR/EULAR RA criteria by medical record review and were classified as seropositive (ACPA+ or rheumatoid factor positivity) or seronegative by clinical laboratory testing at diagnosis. We identified RA cases with blood drawn before the date of RA diagnosis (index date), matching each to three controls by age, cohort, year, time from blood draw to index date, and menopause. Pre-RA ACPA elevation for cases was defined as >99th percentile of the control distribution on a research assay composed of autoantibodies targeting citrullinated protein epitopes or positivity on the second-generation commercial assay for cyclic citrullinated peptide. Asthma status and covariates were obtained through biennial questionnaires before blood draw. Conditional logistic regression estimated ORs and 95%CIs for RA by pre-RA ACPA and clinical serostatus, adjusted for matching factors, smoking pack-years, passive smoking, and body mass index (BMI).

RESULTS

We identified 284 incident RA cases and 849 matched controls; mean age at the index date was 61.2 years (SD 10.1). Blood was drawn 9.7 years (mean; SD 5.8) before the index date. We identified 96 (33.8%) RA cases with elevated pre-RA ACPA. At blood draw, 17.7% of pre-RA ACPA+ cases and 6.3% of matched controls (p = 0.0008) reported clinician-diagnosed asthma. After adjusting for matching factors, smoking pack-years, passive smoking, and BMI, asthma was significantly associated with pre-RA ACPA+ RA (OR 3.57, 95%CI 1.58,8.04). Asthma was not associated with overall RA (OR 1.45, 95%CI 0.91,2.31), but was significantly associated with seropositive RA (OR 1.79, 95%CI 1.01,3.18).

CONCLUSIONS

Asthma was strongly associated with ACPA elevation in blood drawn prior to RA diagnosis, independent of smoking. Chronic mucosal airway inflammation may contribute to ACPA development and RA pathogenesis.

Childhood Respiratory Risk Factor Profiles and Middle-Age Lung Function: A Prospective Cohort Study from the First to Sixth Decade

RATIONALE

Childhood risk factors for long-term lung health often coexist and their specific patterns may affect subsequent lung function differently.

OBJECTIVES

To identify childhood risk factor profiles and their influence on lung function and chronic obstructive pulmonary disease (COPD) in middle age, and potential pathways.

METHODS

Profiles of 11 childhood respiratory risk factors, documented at age 7, were identified in 8,352 participants from the Tasmanian Longitudinal Health Study using latent class analysis. We investigated associations between risk profiles and post-bronchodilator lung function and COPD at age 53, mediation by childhood lung function and adult asthma, and interaction with personal smoking.

RESULTS

Six risk profiles were identified: 1) unexposed or least exposed (49%); 2) parental smoking (21.5%); 3) allergy (10%); 4) frequent asthma, bronchitis (8.7%); 5) infrequent asthma, bronchitis (8.3%); and 6) frequent asthma, bronchitis, allergy (2.6%). Profile 6 was most strongly associated with lower forced expiratory volume in 1 second (FEV₁) (-261; 95% confidence interval, -373 to -148 ml); lower FEV₁/forced vital capacity (FVC) (-3.4; -4.8 to -1.9%) and increased COPD risk (odds ratio, 4.9; 2.1 to 11.0) at age 53. The effect of profile 6 on COPD was largely mediated by adult active asthma (62.5%) and reduced childhood lung function (26.5%). Profiles 2 and 4 had smaller adverse effects than profile 6. Notably, the effects of profiles 2 and 6 were synergistically stronger for smokers.

CONCLUSIONS

Profiles of childhood respiratory risk factors predict middle-age lung function levels and COPD risk. Specifically, children with frequent asthma attacks and allergies, especially if they also become adult smokers, are the most vulnerable group. Targeting active asthma in adulthood (i.e., a dominant mediator) and smoking (i.e., an effect modifier) may block causal pathways and lessen the effect of such established early-life exposures.

[Vulnerability of women to tobacco: The broncho-pulmonary consequences (asthma, COPD)]

Smoking remains common, with an exposure that begins early during pregnancy. It induces epigenetic changes, with a trans-generational transmission. Smoking increases the risk of uncontrolled asthma during childhood and adult life. Asthma is also associated with increased risk of a decline of lung function and chronic obstructive pulmonary disease (COPD). Women are more at risk of developing early and severe COPD. The mechanisms are currently poorly known.

Asthma and Chronic Rhinosinusitis: Diagnosis and Medical Management

Asthma is a prevalent inflammatory condition of the lower airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchial hyperresponsiveness (BHR). Symptomatically, these patients may demonstrate wheezing, breathlessness, chest tightness, and coughing. This disease is a substantial burden to a growing population worldwide that currently exceeds 300 million individuals. This is a condition that is frequently encountered, but often overlooked in the field of otolaryngology. In asthma, comorbid conditions are routinely present and contribute to respiratory symptoms, decreased quality of life, and poorer asthma control. It is associated with otolaryngic diseases of the upper airways including allergic rhinitis (AR) and chronic rhinosinusitis (CRS). These conditions have been linked epidemiologically and pathophysiologically. Presently, they are considered in the context of the unified airway theory, which describes the upper and lower airways as a single functional unit. Thus, it is important for otolaryngologists to understand asthma and its complex relationships to comorbid diseases, in order to provide comprehensive care to these patients. In this article, we review key elements necessary for understanding the evaluation and management of asthma and its interrelatedness to CRS.

Indoor cannabis smoke and children's health

Cannabis use is increasing and cannabis is typically consumed by smoking. This study explored how indoor secondhand cannabis smoke (SCS) was associated with child health. As part of a larger trial, air particle monitors were placed in 298 homes of families with at least one cigarette smoker and one child under 14 years old in San Diego County, California. Assessment included past 7-day indoor cigarette and cannabis use, the youngest child's exposure to cigarette smoke, and 5 smoke-related past-year child health outcomes: emergency department use for coughing/difficulty breathing; physician diagnosis of ear infection, bronchitis/bronchiolitis, asthma, or eczema/atopic dermatitis. An ordinal measure of adverse health outcomes (0, 1, or ≥2) was regressed on reported indoor cannabis smoking—the main measure of exposure (yes/no). Of 221 parents/guardians asked about cannabis use, 192 (86.9%) provided all required data, and 29 (15.1%) reported indoor cannabis smoking; reports were supported by air particle data. Homes without indoor smoking had lower average 7-day particle concentrations (1968 particles/0.01ft³) than homes with cannabis smoking only (3131 particles/0.01ft³), cigarette smoking only (3095 particles/0.01ft³), or both cigarette and cannabis smoking (6006 particles/0.01ft³). Odds of reporting a greater number of adverse health outcomes were 1.83 (95% CI = 0.89–3.80, p = 0.10) times higher for children of families with indoor cannabis smoking vs families without cannabis smoking, after controlling for exposure to cigarette smoke and other covariates. Our results do not indicate a statistically significant association. However, the magnitude of the (non-significant) association between indoor cannabis smoking and adverse health outcomes warrants more studies.

•

Indoor cannabis smoking raises particle levels and risk of child particle exposure.

•

Smoking cannabis in-home may adversely impact child health.

•

This adverse impact may occur in homes with or without indoor cigarette smoking.

•

Health effects of secondhand cannabis smoke exposure need to be further explored.

Exposure to second-hand smoke among secondary school-going adolescents: Findings from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) study

Background:

Exposure to second-hand smoke (SHS) is one of the main causes of morbidity and it has been proven to be associated with an increased likelihood of smoking initiation among adolescents. Nonetheless, evidence on SHS exposure among Malaysian adolescents is scarce. Therefore, this article aims to demonstrate the magnitude and factors associated with SHS exposure among school-going adolescents in selected secondary schools in Peninsular Malaysia.

Methods:

Data were derived from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) study conducted in 2013. A total of 2599 adolescent were recruited into the study using a two-stage proportionate-to-size sampling method. Data were obtained from self-administered questionnaires. Descriptive analysis and multivariable logistic regression were performed to determine the risk factors/predictors associated with SHS.

Results:

More than half of the respondents had been exposed to SHS during the last one week (56.4%), and SHS exposure was significantly higher among respondents who smoked (94.0% vs. 49.9%, p <0.001). Multivariable analysis revealed that the likelihood of exposure to SHS was higher among those who smoked (adjusted odds ratio (aOR) 12.90, 95% confidence interval (CI): 8.01–20.4), had at least one parent/guardian who smoked (aOR 5.49, 95% CI: 4.41–6.94) and adolescents of Malay descent (aOR 2.10, 95% CI: 1.68–2.63).

Conclusion:

Our findings suggested that the effectiveness of anti-smoking measures implemented in recent years to protect adolescents from the health risks of passive smoking were less evident. Therefore, educational and awareness programmes that emphasize the negative health impacts of SHS exposure on Malaysian adolescents, particularly when among smoking adults, should be intensified to help in preventing adoption of smoking behaviours among adolescents.

Second-hand smoke exposure in adulthood and lower respiratory health during 20 year follow up in the European Community Respiratory Health Survey

BACKGROUND

Early life exposure to tobacco smoke has been extensively studied but the role of second-hand smoke (SHS) for new-onset respiratory symptoms and lung function decline in adulthood has not been widely investigated in longitudinal studies. Our aim is to investigate the associations of exposure to SHS in adults with respiratory symptoms, respiratory conditions and lung function over 20 years.

METHODS

We used information from 3011 adults from 26 centres in 12 countries who participated in the European Community Respiratory Health Surveys I-III and were never or former smokers at all three surveys. Associations of SHS exposure with respiratory health (asthma symptom score, asthma, chronic bronchitis, COPD) were analysed using generalised linear mixed-effects models adjusted for confounding factors (including sex, age, smoking status, socioeconomic status and allergic sensitisation). Linear mixed-effects models with additional adjustment for height were used to assess the relationships between SHS exposure and lung function levels and decline.

RESULTS

Reported exposure to SHS decreased in all 26 study centres over time. The prevalence of SHS exposure was 38.7% at baseline (1990-1994) and 7.1% after the 20-year follow-up (2008-2011). On average 2.4% of the study participants were not exposed at the first, but were exposed at the third examination. An increase in SHS exposure over time was associated with doctor-diagnosed asthma (odds ratio (OR): 2.7; 95% confidence interval (95%-CI): 1.2-5.9), chronic bronchitis (OR: 4.8; 95%-CI: 1.6-15.0), asthma symptom score (count ratio (CR): 1.9; 95%-CI: 1.2-2.9) and dyspnoea (OR: 2.7; 95%-CI: 1.1-6.7) compared to never exposed to SHS. Associations between increase in SHS exposure and incidence of COPD (OR: 2.0; 95%-CI: 0.6-6.0) or lung function (β: - 49 ml; 95%-CI: -132, 35 for FEV1 and β: - 62 ml; 95%-CI: -165, 40 for FVC) were not apparent.

CONCLUSION

Exposure to second-hand smoke may lead to respiratory symptoms, but this is not accompanied by lung function changes.

Birth weight for gestational age and the risk of asthma in childhood and adolescence: a retrospective cohort study

OBJECTIVE

To examine the association between birth weight for gestational age and asthma in childhood and adolescence while controlling for potential confounders and considering smoking as an effect modifier.

METHODS

A retrospective cohort of all singleton term births in Nova Scotia, Canada, between 1989 and 1993 was identified in the provincial perinatal database and followed through 2014 by linking with administrative health data. The outcome, asthma, was defined as having one hospitalisation or two physician visits with an International Classification of Diseases code for asthma in a 2-year period. Birth weight was categorised as small (SGA), large (LGA) or appropriate (AGA) for gestational age. Multivariable-adjusted Cox proportional hazards models were used to examine the association between the birth weight for gestational age and asthma and to test for effect modification by maternal smoking in pregnancy.

RESULTS

Of the 40 724 cohort children, 10.5% and 11.7% were born SGA and LGA, respectively, and the risk of developing asthma to age 18 years was 30.2%. The adjusted HRs for SGA and LGA (relative to AGA) and asthma were 1.07 (95% CI 1.02 to 1.14) and 0.96 (95% CI 0.91 to 1.02), respectively. Relative to AGA children born to non-smoking mothers, SGA children were not at increased risk of asthma (HR 1.02), whereas both AGA and SGA children born to smoking mothers were at significantly increased risk (HR 1.14 and 1.29, respectively).

CONCLUSIONS

Our findings suggest that SGA in term infants is not associated with asthma in childhood in the absence of smoking in pregnancy.

Is preterm birth associated with asthma among children from birth to 17 years old? -A study based on 2011-2012 US National Survey of Children's Health

BACKGROUND

Preterm birth can interrupt lung development in utero and is associated with early life factors, which adversely affects the developing respiratory system. Studies on preterm birth and asthma risk are comparatively sparse and the results are not consistent.

METHODS

Multivariate analyses were performed on a cross-sectional data from the National Survey of Children's Health (NSCH) collected in 2011 to 2012. The NSCH was a nationally representative telephone survey sponsored by the Maternal and Child Health Bureau and conducted by the National Center for Health Statistics. A cross-sectional analysis using data from the US on 90,721 children was conducted to examine the relationship between preterm birth and asthma risk.

RESULTS

A total of 90,721 children under 17 years were included and 12% of the children were reported as preterm birth. The prevalence of diagnosed asthma was 15%, with a male to female ratio of 1.26:1. Children who were born preterm were 1.64 times (95% confidence interval: 1.45-1.84) more likely to develop asthma compared with those who were born term after controlling for confounders. Similarly, children who were low birth weight were 1.43 times (95% confidence interval: 1.25-1.63) more likely for asthma, and the odds ratio increased to 1.77 for those both preborn and low birth weight. Child's gender, race/ethnicity, age, family structure, family income levels, and household smoking were significantly associated with the odds of reported asthma.

CONCLUSIONS

Preterm birth was associated with increased risk of asthma among US children, supporting the notion that preterm birth may play a critical role in asthma development.

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.

Provider Counseling About Secondhand Smoke Exposure for Urban Children With Persistent or Poorly Controlled Asthma

Urban children continue to be exposed to secondhand smoke (SHS), and this is particularly concerning for children with asthma. The objective of this study is to describe SHS exposure among urban children with asthma and assess SHS counseling delivered at primary care visits. We interviewed caregivers of 318 children (2-12 years) with persistent asthma at the time of a health care visit and reviewed medical records. We found that one third (32%) of children lived with a caregiver who smoked and that 15% lived with other smokers. Children whose caregivers smoked had the lowest prevalence of home smoking bans compared with homes with other smokers and no smokers (65% vs. 72% vs. 95%, respectively). Overall, 67% of caregivers received some SHS counseling. Providers most often counseled caregiver smokers; counseling occurred less frequently for caregivers in homes with other or no smokers. Further efforts to improve provider SHS counseling for all children with asthma are needed.

The Association Between Female Smoking and Childhood Asthma Prevalence-A Study Based on Aggregative Data

Aims: Socioeconomic and environmental factors influence childhood asthma prevalence across the world. In-depth epidemiological research is necessary to determine the association between asthma prevalence and socio-environmental conditions, and to develop public health strategies to protect the asthmatic children against the environmental precipitators. Our research was based on aggregative data and sought to compare the asthma prevalence between children of two different age-groups across the world and to identify the association among the key socio-environmental conditions with increased childhood asthma prevalence.

Method: We included forty countries with available data on various socio-environmental conditions (2014–2015). Childhood asthma prevalence of two different age groups (6–7 and 13–14 years) were obtained from global asthma report 2014. Because of significant diversities, the selected countries were divided into two groups based on human developmental index (HDI), a well-recognized parameter to estimate the overall socioeconomic status of a country. Robust linear regression was conducted using childhood asthma prevalence as the dependent variable and female smoking prevalence, tertiary school enrollment (TSE), PM₁₀ (particulate matter ≤10 μm in diameter) and gross domestic product (GDP) as predictors.

Results: Asthma prevalence was not different between two age groups. Among all predictors, only female smoking prevalence (reflecting maternal smoking) was associated with asthma prevalence in the countries with lower socio-economic conditions (HDI), but not in the higher HDI group. The results were unchanged even after randomization.

Conclusions: Childhood asthma prevalence did not change significantly with age. Female smoking may have a positive correlation with childhood asthma prevalence in lower HDI countries.

Tobacco smoke exposure is an independent predictor of vitamin D deficiency in US children

IMPORTANCE

The role of tobacco-smoke exposure on serum vitamin D concentration in US pediatric population is not known. We hypothesized that tobacco smoke exposure would increase the prevalence of vitamin D deficiency in US children.

METHODS

Representative national data were accessed from the National Health and Nutrition Examination Survey (NHANES) 2009-2010 databank on 2,263 subjects of ages 3 to 17 years. Subjects were categorized into two groups based on their age: children, if <10 years; and youth if 10 to 17 years. Descriptive and multiple logistic regression analyses were conducted to determine the effect of serum cotinine-verified tobacco smoke exposure on vitamin D status after controlling for key sociodemographic confounders. Vitamin D deficiency was defined as 25(OH)D <20 ng/mL, insufficiency as 25(OH)D of 20-29.9 ng/mL, and sufficiency as 25(OH)D of ≥30 ng/mL. Tobacco smoke exposure status was defined by serum cotinine concentration as follows: unexposed and non-smoking (<0.05 ng/mL) and exposed (passive and active smokers combined) (≥0.05ng/mL). Specifically, passive and active smoking were defined as cotinine of 0.05-10 ng/mL, and ≥10ng/mL respectively.

RESULTS

The prevalence of second-hand smoke exposure was 42.0% (95%CI, 36.7%-47.5%); while the prevalence of active smoking among teenagers was 9.0% (95%CI, 6.2%-12.5%). Vitamin D deficiency occurred at a frequency of 15.1% in children unexposed to tobacco smoke, 20.9% in children exposed to passive tobacco smoke, and 18.0% among actively smoking youth (p<0.001). Tobacco smoke exposure independently predicted vitamin D deficiency after controlling for age, sex, race, BMI, maternal education, and family socio-economic status (OR:1.50; 95%CI, 1.14-1.85, p = 0.002).

CONCLUSIONS

This analysis of a nationwide database reports that tobacco smoke exposure is an independent predictor of vitamin D deficiency in US children.

Correlation between Domestic Cigarette Smoke Exposure and Respiratory Complaints, Hospitalization and School Absence due to Respiratory Complains in the Indonesian Elementary School-Aged Children

Background:

Over 43 million Indonesian children who are exposed to cigarette smoke are at risk of having health hazard and morbidities.

Aims:

The aim of this study is to identify the correlation between cigarette smoke exposure and respiratory complaints, hospitalization, as well as school absence due to respiratory complaints in elementary school-aged Indonesian children.

Materials and Methods:

A cross-sectional study was conducted in nonsmoking elementary school-aged children. Participants were categorized into the exposed and unexposed groups based on the report of their parents. Questionnaire-retrieved data were analyzed to identify the correlation between cigarette smoke exposure and respiratory complaints, hospitalization, as well as school absence due to respiratory complaints in elementary school-aged children.

Results:

A total of 128 study participants of nonsmoking children aged 6–12 years (mean 9.8 ± standard deviation 1.6 years) were categorized into 64 children exposed and 64 children unexposed to domestic cigarette smoking. There was a significant correlation between smoking exposure and cough episodes as well as upper respiratory infection in children within the past 12 months. A cough episode of ≥3 times/year was found more prevalent in exposed children compared to the unexposed children (26.6% vs. 9.4%; P < 0.05). Cough ≥3 times/year was found in 50% of children exposed to cigarette smoke of a smoker with a smoking habit of >10 cigarettes/day. There was a correlation between cigarette smoke exposure and hospitalization frequency of ≥1 time(s)/year due to respiratory complaints in children (P < 0.05).

Conclusion:

Cigarette smoke exposure is correlated with complaints of cough, upper respiratory tract infection, and hospitalization due to respiratory complaints in children.

Vegetation diversity protects against childhood asthma: results from a large New Zealand birth cohort

We assessed the association between the natural environment and asthma in 49,956 New Zealand children born in 1998 and followed up until 2016 using routinely collected data. Children who lived in greener areas, as measured by the normalized difference vegetation index, were less likely to be asthmatic: a 1 s.d. increase in normalized difference vegetation index was associated with a 6.0% (95% CI 1.9-9.9%) lower risk of asthma. Vegetation diversity was also protective: a 1 s.d. increase in the number of natural land-cover types in a child's residential meshblock was associated with a 6.7% (95% CI 1.5-11.5%) lower risk. However, not all land-cover types were protective. A 1 s.d. increase in the area covered by gorse (Ulex europaeus) or exotic conifers, both non-native, low-biodiversity land-cover types, was associated with a 3.2% (95% CI 0.0-6.0%) and 4.2% (95% CI 0.9-7.5%) increased risk of asthma, respectively. The results suggest that exposure to greenness and vegetation diversity may be protective of asthma.

Children Deserve Smoke Free World

Tobacco smoke, active or passive exposure was the major cause of preventable morbidity and mortality in the world during twentieth century and will continue to be the same in the twenty-first century also if the current trends continue. Both active and passive smoking are having significance in relation to child health. Exposure starts antenatally from placenta to the fetus and later phases through passive exposure to experimental and regular smoking and ultimately addiction and habitual smoking. Evidences are in favour of causal relationship with intrauterine growth restriction, sudden infant death syndrome, decreased pulmonary function, increased risk for respiratory tract infection, otitis media, wheeze, asthma, neurobehavioral disorders, cleft palate and triggering pathogenesis of fetal and childhood onset of adult diseases, especially pulmonary and cardio vascular diseases. All these facts stress the importance of behavioral changes in the population as well as stringent public health measures and legislation for ensuring smoke free work places, public places and households for children. M POWER- Package by WHO is a novel global initiative taking us closer to the target of achieving tobacco free environment for children in the near future.

Lung Development and Aging

The onset of chronic obstructive pulmonary disease (COPD) can arise either from failure to attain the normal spirometric plateau or from an accelerated decline in lung function. Despite reports from numerous big cohorts, no single adult life factor, including smoking, accounts for this accelerated decline. By contrast, five childhood risk factors (maternal and paternal asthma, maternal smoking, childhood asthma and respiratory infections) are strongly associated with an accelerated rate of lung function decline and COPD. Among adverse effects on lung development are transgenerational (grandmaternal smoking), antenatal (exposure to tobacco and pollution), and early childhood (exposure to tobacco and pollution including pesticides) factors. Antenatal adverse events can operate by causing structural changes in the developing lung, causing low birth weight and prematurity and altered immunological responses. Also important are mode of delivery, early microbiological exposures, and multiple early atopic sensitizations. Early bronchial hyperresponsiveness, before any evidence of airway inflammation, is associated with adverse respiratory outcomes. Overlapping cohort studies established that spirometry tracks from the preschool years to late middle age, and those with COPD in the sixth decade already had the worst spirometry at age 10 years. Alveolar development is now believed to continue throughout somatic growth and is adversely impacted by early tobacco smoke exposure. Genetic factors are also important, with genes important in lung development and early wheezing also being implicated in COPD. The inescapable conclusion is that the roots of COPD are in early life, and COPD is a disease of childhood adverse factors interacting with genetic factors.