Decreasing trend in passive tobacco smoke exposure and association with asthma in U.S. children

The Diverging Trend in Exposure to Environmental Tobacco Smoke Among US Children

OBJECTIVE

Environmental tobacco smoke exposure (ETSE) was race/ethnicity-specific, but how the race/ethnicity-specific ETSE has changed over time, diverging or converging, remains unclear. We examined ETSE trends by race/ethnicity in US children aged 3-11 years.

METHODS

We analyzed the data of 9678 children who participated in the biennial National Health and Nutrition Examination Surveys, 1999-2018. ETSE was defined as serum cotinine ≥ 0.05 ng/ml, with ≥ 1 ng/ml as heavy exposure. For trend description, adjusted biennial prevalence ratios (abiPR: the ratio associated with a 2-year increase in time) were estimated by race/ethnicity. The prevalence ratios between races/ethnicities were used to quantify ethnoracial differences in different survey periods. Analyses were performed in 2021.

RESULTS

The overall ETSE prevalence was cut by almost half, from 61.59% (95% confidence interval = 56.55%, 66.62%) in the 1999-2004 survey to 37.61% (33.90%, 41.31%) in 2013-2018, exceeding the national 2020 health target (47.0%). However, the decrease occurred unequally between races/ethnicities. Heavy ETSE declined significantly in white [abiPR = 0.80 (0.74, 0.86)] and Hispanic children [0.83 (0.74, 0.93)], but insignificantly in black children [0.97 (0.92, 1.03)]. Consequently, the adjusted prevalence ratio between black children and white children increased from 0.82 (0.47, 1.44) in 1999-2004 to 2.73 (1.51, 4.92) in 2013-2018 for heavy ETSE. Hispanic children remained at the lowest risk throughout the study period.

CONCLUSION

Overall ETSE prevalence was cut by half between 1999 and 2018. However, due to uneven declines, the gaps between black children and others have expanded in heavy ETSE. Special vigilance is needed in preventive medicine practice with black children.

The impact of exposure to tobacco smoke and e-cigarettes on asthma-related outcomes: Systematic review informing the EAACI guidelines on environmental science for allergic diseases and asthma

To inform the clinical practice guidelines' recommendations developed by the European Academy of Allergy and Clinical Immunology systematic reviews (SR) assessed using GRADE on the impact of environmental tobacco smoke (ETS) and active smoking on the risk of new-onset asthma/recurrent wheezing (RW)/low lung function (LF), and on asthma-related outcomes. Only longitudinal studies were included, almost all on combustion cigarettes, only one assessing e-cigarettes and LF. According to the first SR (67 studies), prenatal ETS increases the risk of RW (moderate certainty evidence) and may increase the risk of new-onset asthma and of low LF (low certainty evidence). Postnatal ETS increases the risk of new-onset asthma and of RW (moderate certainty evidence) and may impact LF (low certainty evidence). Combined in utero and postnatal ETS may increase the risk of new-onset asthma (low certainty evidence) and increases the risk of RW (moderate certainty evidence). According to the second SR (24 studies), ETS increases the risk of severe asthma exacerbations and impairs asthma control and LF (moderate certainty evidence). According to the third SR (25 studies), active smoking increases the risk of severe asthma exacerbations and of suboptimal asthma control (moderate certainty evidence) and may impact asthma-related quality-of-life and LF (low certainty evidence).

Interaction between Serum Cotinine and Magnesium Intake with Childhood Asthma: A Cross-Sectional Study

INTRODUCTION

Serum cotinine and magnesium intake are often associated with childhood asthma. This study evaluated the interaction between serum cotinine and magnesium intake and childhood asthma.

METHODS

This cross-sectional study included 14,159 subjects from the National Health and Nutrition Examination Survey 2005-2018. Serum cotinine levels were classified according to the lower quartile: ≤0.2089 ng/mL as low level and >0.2089 ng/mL as high level. Magnesium intake was categorized as high (>98 mg/1,000 kcal) or low level (≤98 mg/1,000 kcal) based on the upper quartile. Weighted logistic regression analyses were adopted to analyze the association between cotinine, magnesium intake, and childhood asthma. Additionally, the combined effect of cotinine and magnesium intake on childhood asthma risk was examined. The stratified analyses were based on gender, body mass index, and family history of asthma to further examine the relationship between cotinine, magnesium intake, and childhood asthma.

RESULTS

The prevalence of asthma was approximately 17.56%. Compared to low-level cotinine, high-level cotinine was associated with asthma (odds ratio [OR] = 1.25, 95% confidence interval (CI): 1.04-1.50). Low-level magnesium intake was related to asthma compared with high-level magnesium intake (OR = 1.21, 95% CI: 1.04-1.40). Using interaction analysis, we also found that the combined effect of cotinine and magnesium intake was associated with childhood asthma risk, and the interaction between high-level cotinine and low-level magnesium intake was associated with the highest risk of childhood asthma (OR = 1.35, 95% CI: 1.04-1.74). Additionally, this interaction was also found in males, overweight/non-overweight, and those with family history of asthma.

CONCLUSION

There was an interaction between serum cotinine and magnesium intake on childhood asthma. The results suggested that implementing smoking bans in certain settings (e.g., communities, schools) and promoting the consumption of magnesium-rich foods may be effective strategies for preventing childhood asthma.

Tobacco smoke exposure, the lower airways microbiome and outcomes of ventilated children

BACKGROUND

Tobacco smoke exposure increases the risk and severity of lower respiratory tract infections in children, yet the mechanisms remain unclear. We hypothesized that tobacco smoke exposure would modify the lower airway microbiome.

METHODS

Secondary analysis of a multicenter cohort of 362 children between ages 31 days and 18 years mechanically ventilated for >72 h. Tracheal aspirates from 298 patients, collected within 24 h of intubation, were evaluated via 16 S ribosomal RNA sequencing. Smoke exposure was determined by creatinine corrected urine cotinine levels ≥30 µg/g.

RESULTS

Patients had a median age of 16 (IQR 568) months. The most common admission diagnosis was lower respiratory tract infection (53%). Seventy-four (20%) patients were smoke exposed and exhibited decreased richness and Shannon diversity. Smoke exposed children had higher relative abundances of Serratia spp., Moraxella spp., Haemophilus spp., and Staphylococcus aureus. Differences were most notable in patients with bacterial and viral respiratory infections. There were no differences in development of acute respiratory distress syndrome, days of mechanical ventilation, ventilator free days at 28 days, length of stay, or mortality.

CONCLUSION

Among critically ill children requiring prolonged mechanical ventilation, tobacco smoke exposure is associated with decreased richness and Shannon diversity and change in microbial communities.

IMPACT

Tobacco smoke exposure is associated with changes in the lower airways microbiome but is not associated with clinical outcomes among critically ill pediatric patients requiring prolonged mechanical ventilation. This study is among the first to evaluate the impact of tobacco smoke exposure on the lower airway microbiome in children. This research helps elucidate the relationship between tobacco smoke exposure and the lower airway microbiome and may provide a possible mechanism by which tobacco smoke exposure increases the risk for poor outcomes in children.

Trends in adolescent secondhand smoke exposure at home over 15 years in Korea: Inequality by parental education level

INTRODUCTION

Low parental education level and parental smoking are major risk factors for household secondhand smoke (SHS) exposure among adolescents. We investigated the trend in household SHS exposure according to sex, school, and parental education level to determine whether the decline in household SHS exposure over time depends on parental education level.

METHODS

We used cross-sectional Korea Youth Risk Behavior datasets (2006-2020; 806829 subjects were eligible). We applied binary logistic regression to assess household SHS exposure trends and evaluated the interaction between period and parental education level.

RESULTS

Household SHS exposure over 15 years has declined. The difference (0.121) was the smallest for male middle school students with low-educated parents. The slope for the estimated probability of household SHS exposure among students with high-educated parents was steeper than that for those with low-educated parents, except for female high school students (difference=0.141). Students with low-educated parents were at higher risk of household SHS exposure (male middle school students, adjusted odds ratio, AOR=1.52; 95% CI: 1.47-1.56; male high school students, AOR=1.42; 95% CI: 1.38-1.47; female middle school students, AOR=1.62; 95% CI: 1.58-1.67; female high school students, AOR=1.62; 95% CI: 1.57-1.67). The interaction between parental education level and period was significant. We also found a significant interaction between parental education level and parental smoking (other × present interaction, AOR=0.64; 95% CI: 0.60-0.67; low-low × present interaction, AOR=0.89; 95% CI: 0.83-0.95).

CONCLUSIONS

Changes in parental education level over time mainly contributed to changes in adolescents' household SHS exposure. Adolescents with low-educated parents were at higher risk of household SHS exposure, with a slower decline. These gaps must be considered when creating and implementing interventions. Campaigns and community programs to prevent household SHS need to be emphasized among vulnerable adolescents.

Interaction between serum cotinine and body mass index on asthma in the children: a cross-sectional study

Background

The purpose of this study was to explore the interaction between serum cotinine (a marker of environmental tobacco smoke exposure) and body mass index (BMI) on asthma in children.

Methods

This cross-sectional study relied on representative samples of American children included in the National Health and Nutrition Examination Survey in 1999–2018. Multivariate logistic regression analyses were to evaluate the association between serum cotinine level, BMI z-score and asthma. Serum cotinine was dichotomized at 0.0436 ng/mL. Interactions were examined by the estimated joint effect of BMI and serum cotinine levels. We also performed interaction analyses in age and ethnicity subgroups.

Results

Among the 11,504 children aged 3 to 12 years included in the analysis, 15.86% (n = 1852) had childhood asthma, 15.68% (n = 1837) were overweight, and 17.31% (n = 2258) were obese. Compared to low serum cotinine, high serum cotinine was significantly associated with asthma [odds ratio (OR) = 1.190, 95% confidence interval (CI): 1.004–1.410]. Overweight (OR = 1.275, 95%CI: 1.079–1.506) and obesity (OR = 1.636, 95%CI: 1.354–1.977) were significantly associated with asthma compared with normal weight. The adjusted attributable proportion of interaction = 0.206 (95%CI: 0.075–0.337) and the adjusted synergy index = 1.617 (95%CI: 1.126–2.098) indicated that there was a significant synergistic effect of serum cotinine levels and BMI on asthma. In males, females, non-Hispanic White and other Hispanic, there were synergistic interactions between serum cotinine levels and BMI on asthma.

Conclusion

A synergistic interaction between serum cotinine and overweight/obesity on childhood asthma was found. For children with asthma, both intensive weight interventions in overweight or obese children and intensive passive smoking interventions in children exposed to the environment may be important.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03571-0.

Association between Parental Cotinine-verified Smoking Status and Childhood Asthma: a Population-based Nationally Representative Analysis

BACKGROUND

Environmental tobacco smoke exposure due to parents is a modifiable risk factor for childhood asthma, but many studies have evaluated parental smoking using self-reported data. Therefore, we aimed to analyze the relationship between parental cotinine-verified smoking status and asthma in their children.

METHODS

This population-based cross-sectional study used data from the Korean National Health and Nutrition Examination Survey from 2014 to 2017. Participants aged 0 to 18 years with complete self-reported physician-diagnosed childhood asthma and measurement of their parental urinary cotinine levels were included. Parental urinary cotinine-verified smoking status was defined using both urinary cotinine levels and self-report, as active, passive, and non-smoker. Sample weights were applied to all statistical analyses because of a complex, multistage and clustered survey design. Logistic regression model was used to analyze the relationship between childhood asthma and parental smoking.

RESULTS

A total of 5,264 subjects aged < 19 years were included. The prevalence of asthma was 3.4%. The proportions of paternal and maternal urinary cotinine-verified active smokers during the study period were 50.4% and 16.9%, respectively. When parental urinary cotinine level increased, the proportion of parental low household income was increased (P < 0.001). There was no significant association between the parental urinary cotinine-verified smoking group and childhood asthma group. However, the adjusted odds ratios of childhood asthma in the middle and highest tertile of paternal urinary cotinine levels compared with those in lowest tertile were 1.95 (95% confidence interval [CI], 0.98-3.89) and 2.34 (95% CI, 1.21-4.54), respectively.

CONCLUSION

There seems to be a dose-related association between paternal urinary cotinine levels and the risk of childhood asthma. Because of the high rate of paternal smoking, further studies are needed to develop a targeted strategy to reduce parental smoking for childhood asthma.

The burden of asthma in an inner-city area: A historical review 10 years after Isaac

Background

According to the International Study of Asthma and Allergies in Childhood (ISAAC) methodology, in 2003, the prevalence of asthma symptoms in children 6-7 years old and adolescents 13-14 years old was 11.6% and 13.7%, respectively. Since then, the number of asthma cases has increased worldwide. The study was conducted in several districts in northern Mexico City to evaluate the prevalence of asthma in these age groups and examine possible risk factors. The data were compared to the 2003 results from the same area.

Methods

This was a comparative cross-sectional study following the official Global Asthma Network (GAN) methodology. The parents or guardians of participants completed a questionnaire that explored demographics, asthma symptoms, diagnoses, and possible risk factors. Central tendency measurements were determined for statistical analysis and chi-squared distribution for possible risk factors.

Results

A total of 2515 children aged 6-7 years and 3375 adolescents aged 13-14 years participated in the study. Compared to the ISAAC results, we found a greater prevalence of wheezing in both children (at some time in life, 19.2% vs. 27.1%; over the last year, 6.8% vs. 10.6%) and adolescents (at some time in life, 16.9% vs. 19.7%), and for children with an asthma diagnosis (4.5% vs. 5.1%). For both groups, the most common risk factor associated with wheezing was the presence of rhinitis symptoms.

Conclusions

Asthma symptoms are highly prevalent in Mexico City, occurring in almost 20% of adolescents. Compared to a decade ago, there was a 7.9% increase in the prevalence of asthma symptoms in children. Almost half of the children and adolescents presenting with symptoms had experienced more than four episodes per year. However, less than 50% of children and adolescents with asthma symptoms had been diagnosed with this disorder, suggesting under-diagnosis.

United States prevalence of pediatric asthma by environmental tobacco smoke exposure, 2016-2017

OBJECTIVES

We sought to update the prevalence estimates of parent-reported asthma diagnosis by Environmental Tobacco Smoke (ETS) exposure in the United States (US) pediatric population.

METHODS

This cross-sectional study included 71,811 families with children who participated in the 2016-2017 National Survey of Children's Health (NSCH). Weighted asthma prevalence estimates were calculated for ETS-exposed and non-exposed children. Chi-square analysis compared asthma prevalence between the two exposure groups and logistic regression analysis generated adjusted odds ratios (aORs) of asthma diagnosis by ETS exposure by sex, race/ethnicity, and household education and income level.

RESULTS

Asthma prevalence estimates were significantly higher in ETS-exposed vs. non-exposed children (10.7% vs. 7.8%, p < 0.001). Children with a smoker in the house are 30% more likely to have an asthma diagnosis vs. children with no smokers in the house (aOR 1.29, 95% Confidence Interval [CI] 1.09-1.52). Significant predictors for ETS exposure included < high school education and lower family income. Conversely, non-Hispanic black and Hispanic children were less likely to have ETS exposure vs. non-Hispanic white children.

CONCLUSIONS

ETS exposure is a significant risk factor for asthma in the US pediatric population. Smoking cessation initiatives targeting non-Hispanic white parents from lower socioeconomic may improve children's chronic pulmonary health risk.

Trends in Bronchiolitis Hospitalizations in the United States: 2000-2016

OBJECTIVES

To investigate the temporal trend in the national incidence of bronchiolitis hospitalizations, their characteristics, inpatient resource use, and hospital cost from 2000 through 2016.

METHODS

We performed a serial, cross-sectional analysis of nationally representative samples (the 2000, 2003, 2006, 2009, 2012, and 2016 Kids' Inpatient Databases) of children (age <2 years) hospitalized for bronchiolitis. We identified all children hospitalized with bronchiolitis by using International Classification of Diseases, Ninth Revision, Clinical Modification 466.1 and International Classification of Diseases, 10th Revision, Clinical Modification J21. Complex chronic conditions were defined by the pediatric complex chronic conditions classification by using inpatient data. The primary outcomes were the incidence of bronchiolitis hospitalizations, mechanical ventilation use, and hospital direct cost. We examined the trends accounting for sampling weights.

RESULTS

From 2000 to 2016, the incidence of bronchiolitis hospitalization decreased from 17.9 to 13.5 per 1000 person-years in US children (25% decrease; P trend < .001). In contrast, the proportion of bronchiolitis hospitalizations among overall hospitalizations increased from 16% to 18% (P trend < .001). There was an increase in the proportion of children with a complex chronic condition (6%-13%; 117% increase), hospitalization to children's hospital (15%-29%; 93% increase), and mechanical ventilation use (2%-5%; 184% increase; all P trend < .001). Likewise, the hospital cost increased from $449 million to $734 million (63% increase) nationally (with an increase in geometric mean of cost per hospitalization [from $3267 to $4086; 25% increase; P trend < .001] adjusted for inflation) from 2003 to 2016.

CONCLUSIONS

From 2000 through 2016, the incidence of bronchiolitis hospitalizations among US children declined. In contrast, mechanical ventilation use and nationwide hospital direct cost substantially increased.

The increase of asthma prevalence has levelled off and symptoms decreased in adults during 20 years from 1996 to 2016 in Helsinki, Finland

BACKGROUND

Mortality and hospitalization due to asthma have decreased in many European countries, but asthma symptoms still cause a lot of morbidity and costs.

OBJECTIVES

We evaluated prevalence trends of asthma, asthma symptoms and allergic rhinoconjunctivitis in adults aged 20-69 years during a 20-year period from 1996 to 2016 in the city of Helsinki, the capital of Finland.

METHODS

Three cross-sectional postal surveys were conducted in random population samples 10 years apart. In 1996, 2006 and 2016, a total of 6062 (response rate 75.9%), 2449 (61.9%) and 4026 subjects (50.3%) took part, respectively.

RESULTS

In all responders, the prevalence of physician-diagnosed asthma was 6.6% in 1996, 10% in 2006 and 10.9% in 2016. The prevalence increased from 1996 to 2006, but stabilized from 2006 to 2016, both in men and women and in smokers and non-smokers. The prevalence of current asthma (8.5% in 2006 and 8.8% in 2016) and of asthma with rhinoconjunctivitis (7.6% in 2006 and 7.5% in 2016) remained also at the same level. Allergic rhinoconjunctivitis decreased significantly from 2006 (42.7%) to 2016 (39.0%, p = 0.004). Those with physician diagnosed asthma reported significantly less symptoms in 2016 compared to 2006 and 1996, although there was no change in smoking habits or medication use. Young asthmatics (20-29 years) without rhinoconjunctivitis reported least symptoms.

CONCLUSION

Previously observed increase of physician-diagnosed asthma prevalence in adults seems to be levelling off in Helsinki, and patients have fewer symptoms than 20 years ago. In addition, allergic rhinoconjunctivitis is less frequent than 10 years earlier. (247 words).