Effect of active smoking on asthma symptoms, pulmonary function, and BHR in adolescents

Management of difficult-to-treat asthma in adolescence and young adults

The period of adolescence and young adulthood (AYA) has been proposed to extend from 11 to 25 years of age as patients in this age group face similar challenges. AYA is a time of fast and great physiological and psychological growth, in which an individual transitions from a young dependent child to a mature independent adult. Behaviour patterns during adolescence, such as risk taking and desire for privacy, can challenge parents or healthcare professionals' (HCPs') ability to help adolescents to manage their asthma.

Asthma itself tends to remit, become milder or worsen into a severe variant during adolescence. The pre-pubertal male predominance of asthma switches to a female predominance in late teen years. ∼10% of AYA with asthma have “difficult-to-treat asthma (DTA)”, characterised by poor asthma control despite treatment with inhaled corticosteroids (ICS) and other controller medications. DTA management in AYA requires a multidisciplinary team approach and systematic assessment that can address the key questions of objective confirmation of diagnosis, severity assessment, phenotyping, comorbidities, asthma mimickers or other drivers of poor control such as non-adherence to treatment.

A key task for HCPs is to establish the magnitude of the severe asthma componentversusother non-asthma drivers of symptoms (e.g.inducible laryngeal obstruction or breathing pattern disorder). Severe asthma is a subset of DTA and is determined once asthma diagnosis and its severity have been confirmed and adherence to controller (ICS) treatment has been assured. Severe asthma is a heterogeneous disease and appropriate phenotyping is necessary for the management of treatable traits and consideration for biologic therapies.

Finally, an important part of successful management of DTA in the AYA group is the provision of an effective transition of asthma care from paediatric to adult asthma services through setting up a well-designed asthma transition pathway tailored to the individual patient needs.

Issues affecting young people with asthma through the transition period to adult care

Asthma is among the most common medical conditions affecting children and young people, with adolescence a recognised period of increased risk, overrepresented in analyses examining recent increasing asthma mortality rates. Asthma may change significantly during this period and management also occurs in the context of patients seeking increased autonomy and self-governance whilst navigating increasing academic and social demands. A number of disease factors can destabilise asthma during adolescence including: increased rates of anaphylaxis, anxiety, depression, obesity, and, in females, an emerging resistance to corticosteroids and the pro-inflammatory effects of oestrogen. Patient factors such as smoking, vaping, poor symptom recognition, treatment non-adherence and variable engagement with health services contribute to difficult to treat asthma. Significant deficiencies in the current approach to transition have been identified by a recent EAACI task force, and subsequent asthma-specific recommendations, published in 2020 provide an important framework moving forward. As with other chronic conditions, effective transition programmes plan ahead, engage with adolescents and their families to identify the patients' management priorities and the current challenges they are experiencing with treatment. Transition needs may vary significantly across asthma patients and for more complex asthma may include dedicated transition clinics involving multidisciplinary care requiring input including, amongst others, allergy and immunology, psychological medicine, respiratory physicians and scientists and nurse specialists. Across different global regions, barriers to treatment may vary but need to be elicited and an individualised approach taken to optimising asthma care which is sustainable within the local adult healthcare system.

Perimenstrual Asthma in Adolescents: A Shared Condition in Pediatric and Gynecological Endocrinology

Asthma is a frequent medical condition in adolescence. The worsening of the most common symptoms perimenstrually is defined as perimenstrual asthma (PMA). The cause of PMA remains unclear, but a role for hormonal milieu is plausible. Data on PMA in adolescents are limited, and its management is not fully established. We aimed to discuss the PMA phenomenon in young females from pathophysiology to preventive strategies, focusing on the relationship with the hormonal pattern. The fluctuation of estrogens at ovulation and before menstruation and the progesterone secretion during the luteal phase and its subsequent withdrawal seem to be the culprits, because the deterioration of asthma is cyclical during the luteal phase and/or during the first days of the menstrual cycle. Conventional asthma therapies are not always effective for PMA. Preventive strategies may include innovative hormonal contraception. Even a possible beneficial effect of other hormonal treatments, including estrogens, progestogens, and androgens, as well as leukotriene receptor antagonists and explorative approach using microbial-directed therapy, is considered. The underlying mechanisms, through which sex-hormone fluctuations influence asthma symptoms, represent a challenge in the clinical management of such a distressing condition. Further studies focused on young females are mandatory to promote adolescent health.

The Role of Comorbidities in Difficult-to-Control Asthma in Adults and Children

Assessment of asthma comorbidities, conditions that adversely affect the pathobiology of asthma or impair its response to therapies, is a fundamental step in the evaluation and management of patients with difficult-to-treat asthma. Identifying and effectively treating asthma comorbidities, such as obesity, obstructive sleep apnea, and chronic sinusitis with nasal polyps, may improve asthma control and reduce exacerbations. In addition, identifying comorbid T2 inflammatory conditions may help guide optimal selection of biologic therapies. Here, we describe common comorbid conditions found in adult and pediatric difficult-to-control asthma, discuss evidence for the association with asthma morbidity and treatment benefit, and provide information on how and when to assess comorbidities.

Risk factors of asthma in the Asian population: a systematic review and meta-analysis

Background and objective

An increasing trend of asthma prevalence was observed in Asia; however, contributions of environmental and host-related risk factors to the development of this disease remain uncertain. This study aimed to perform a systematic review and meta-analysis for asthma-associated risk factors reported in Asia.

Methods

We systematically searched three public databases (Web of Science, PubMed, and Scopus) in Feb 2021. We only included articles that reported environmental and host-related risk factors associated with asthma in the Asian population. Random-effect meta-analyses were conducted for frequently reported asthma-associated risk factors to provide an overall risk estimate of asthma development.

Results

Of 4030 records obtained from public databases, 289 articles were selected for review. The most frequently reported asthma-associated risk factor was the family history of allergy-related conditions. The random-effect asthma risk estimates (pooled odds ratio, OR) were 4.66 (95% confidence interval (CI): 3.73–5.82) for the family history of asthma, 3.50 (95% CI: 2.62–4.67) for the family history of atopy, 3.57 (95% CI: 3.03–4.22) for the family history of any allergic diseases, 1.96 (95% CI: 1.47–2.61) for the family history of allergic rhinitis, and 2.75 (95% CI: 1.12–6.76) for the family history of atopic dermatitis. For housing-related factors, including the presence of mold, mold spots, mold odor, cockroach, water damage, and incense burning, the random-effect pooled OR ranged from 1.43 to 1.73. Other risk factors with significant pooled OR for asthma development included male gender (1.30, 95% CI: 1.23–1.38), cigarette smoke exposure (1.44, 95% CI: 1.30–1.60), cigarette smoking (1.66, 95% CI: 1.44–1.90), body mass index (BMI)–related parameters (pooled OR ranged from 1.06 to 2.02), various types of air pollution (NO₂, PM10, and O₃; pooled OR ranged from 1.03 to 1.22), and pre- and perinatal factors (low birth weight, preterm birth, and cesarean section; pooled OR ranged from 1.14 to 1.32).

Conclusions

The family history of asthma was the most frequently reported risk factor for asthma development in Asia with the highest risk estimate for asthma development. This suggests a major role of the genetic component in asthma pathogenesis. Further study on asthma genetics is required to improve the current understanding of asthma etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-021-00273-x.

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.

Lung Function Decline after 24 Weeks of Moxa Smoke Exposure in Rats

OBJECTIVE

Moxibustion is a complementary therapy that has been used for thousands of years. Burning moxa produces smoke and inhalable particulates. Recent research has indicated that smoke inhalation is associated with negative lung effects. This study aimed to evaluate the lung function of rats after moxa smoke exposure at different concentrations.

METHODS

Using a randomised block experiment design, 28 male Wistar rats were randomly divided into three moxa smoke groups (opacity) (n=7): low concentration (27.45 mg/m3), medium concentration (168.76 mg/m3), and high concentration (384.67 mg/m3) with a control group. Rats in the moxa smoke groups were exposed in an automatic dynamic exposure device separately with different concentrations for 20 min/d, 6d/week, for 24 weeks. Rats in the control group were exposed in the same space without moxa smoke. Lung function was evaluated by the AniRes 2005 animal pulmonary function analysing system. Statistical Product and Service Solutions 18.0 software was used for data analysis.

RESULTS

In the study, no deaths were found in any group. There was no difference of forced expiratory volume in one second/forced vital capacity percentage (FEV1/FVC%), inspiratory resistance (Ri), and expiratory resistance (Re) among each group after 24 weeks of moxa smoke exposure (P>0.05). Compared with the control group (0.33 ml/cmH20), dynamic compliance (Cdyn) was reduced in the medium (0.29 ml/cmH20) and high (0.25 ml/cmH20) concentration groups (P<0.05); however, Cdyn in the low concentration group (0.29 ml/cmH20) was not significantly affected.

CONCLUSION

Moxa smoke exposure at low concentrations did not affect the rat's lung function. Moxa smoke of medium and high concentrations destroyed the lung function represented by decreased Cdyn. However, moxa smoke of low concentrations (27.45 mg/m3) is much higher than the concentration in a regular moxibustion clinic (3.54 mg/m3). Moxa smoke at higher concentrations might destroy the lung function. The safety evaluation of moxa smoke requires further research.

Tobacco smoke exposure in early life and adolescence in relation to lung function

Maternal smoking during pregnancy is associated with impaired lung function among young children, but less is known about long-term effects and the impact of adolescents' own smoking. We investigated the influence of maternal smoking during pregnancy, secondhand smoke exposure and adolescent smoking on lung function at age 16 years.

The BAMSE (Barn/Child, Allergy, Milieu, Stockholm, Epidemiology) birth cohort collected information on participants' tobacco smoke exposure through repeated questionnaires, and measured saliva cotinine concentrations at age 16 years. Participants performed spirometry and impulse oscillometry (IOS) at age 16 years (n=2295).

Exposure to maternal smoking during pregnancy was associated with reduced forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratio of −1.1% (95% CI −2.0 to −0.2%). IOS demonstrated greater resistance at 5–20 Hz (R_5–20) in participants exposed to maternal smoking during pregnancy. Adolescents who smoked had reduced FEV₁/FVC ratios of −0.9% (95% CI −1.8 to −0.1%) and increased resistance of 6.5 Pa·L^–1·s (95% CI 0.7 to 12.2 Pa·L^–1·s) in R_5–20. Comparable associations for FEV₁/FVC ratio were observed for cotinine concentrations, using ≥12 ng·mL⁻¹ as a cut-off for adolescent smoking.

Maternal smoking during pregnancy was associated with lower FEV₁/FVC ratios and increased airway resistance. In addition, adolescent smoking appears to be associated with reduced FEV₁/FVC ratios and increased peripheral airway resistance.

Maternal smoking in utero and teenage smoking are associated with indices of airway obstruction at age 16 yearshttp://ow.ly/NwF030jFS2W

The Association between Tobacco Smoke and Serum Immunoglobulin E Levels in Korean Adults

Objective Smoking is common in patients with allergic diseases. The aim of this study was to evaluate the cross-sectional association between the current smoking status and total and specific Immunoglobulin E (IgE) levels in Korean adults. Methods Data were obtained from the 2010 Korean National Health and Nutrition Examination Survey, a national cross-sectional study. We analyzed the data of subjects whose smoking status and serum IgE levels were of acceptable quality. Results A total of 1,963 subjects (1,118 never smokers, 340 ex-smokers, and 505 current smokers) were included. The total IgE levels and specific IgE levels to house dust mite Dermatophagoides farinae (Df), cockroach, and dog allergens in never smokers were significantly (p<0.0001) lower than in ex-smokers or current smokers. After adjusting for other variables, current smokers independently had significantly higher levels of total IgE and cockroach-specific IgE than ex-smokers or never smokers. The proportions of subjects with total IgE ≥150 kU/L and specific IgE ≥0.35 kU/L to Df-specific IgE were significantly (p value for trend <0.05) increased in ex-smokers and current smokers. The total IgE levels and IgE levels specific to Df, cockroaches, and dogs significantly (p value for trend <0.05) and proportionally increased with increasing numbers of cigarettes smoked daily. Conclusion Smoking was associated with elevated total IgE levels and IgE levels specific to Df, cockroach, and dog allergens in a cumulative, dose-dependent manner. Furthermore, current smoking status was an independent risk factor for elevated total IgE levels and IgE levels specific to cockroach allergen.

Prevalence of self-reported smoking experimentation in adolescents with asthma or allergic rhinitis

Objective:

To determine the prevalence of smoking experimentation among adolescents with asthma or allergic rhinitis.

Methods:

This was a cross-sectional study involving adolescent students (13-14 years of age) in the city of Belo Horizonte, Brazil. The participants completed the Centers for Disease Control and Prevention and International Study of Asthma and Allergies in Childhood questionnaires, both of which have been validated for use in Brazil. We calculated the prevalence of smoking experimentation in the sample as a whole, among the students with asthma symptoms, and among the students with allergic rhinitis symptoms, as well as in subgroups according to gender and age at smoking experimentation.

Results:

The sample comprised 3,325 adolescent students. No statistically significant differences were found regarding gender or age. In the sample as a whole, the prevalence of smoking experimentation was 9.6%. The mean age for smoking experimentation for the first time was 11.1 years of age (range, 5-14 years). Among the adolescents with asthma symptoms and among those with allergic rhinitis symptoms, the prevalence of self-reported smoking experimentation was 13.5% and 10.6%, respectively.

Conclusions:

The proportion of adolescents with symptoms of asthma or allergic rhinitis who reported smoking experimentation is a cause for concern, because there is strong evidence that active smoking is a risk factor for the occurrence and increased severity of allergic diseases.

Asthma in adolescence: Is there any news?

Asthma is a chronic disease that has a significant impact quality of life, which is particularly important in adolescence. We will discuss aspects of epidemiology, the clinical spectrum, diagnostics, and management of asthma in adolescence. In particular, we will highlight the psychological implications of having asthma during this developmental period. Data published in the past 10 years, since we last reviewed the subject, will be the main focus of this paper. The care of the teenager with asthma should take into account the rapid physical, emotional, cognitive, and social changes that occur during normal adolescence. The diagnostic process may be more difficult since teenagers tend to deny their illness. Thus, both under-diagnosis and under-assessment of asthma severity may lead to under-treatment and potentially avoidable morbidity and even mortality. Conversely, teenagers may be often misdiagnosed as having asthma or their asthma severity may be overestimated leading to inappropriate and sometimes excessive treatment. Educational programs, environmental avoidance measures, proper use of medications along with a skilled approach, and a caring attitude of health providers are all very important for successful management. Pediatr Pulmonol. 2017;52:129-138. © 2016 Wiley Periodicals, Inc.

The Danish National Database for Asthma: establishing clinical quality indicators

Asthma is one of the most common chronic diseases worldwide affecting more than 300 million people. Symptoms are often non-specific and include coughing, wheezing, chest tightness, and shortness of breath. Asthma may be highly variable within the same individual over time. Although asthma results in death only in extreme cases, the disease is associated with significant morbidity, reduced quality of life, increased absenteeism, and large costs for society. Asthma can be diagnosed based on report of characteristic symptoms and/or the use of several different diagnostic tests. However, there is currently no gold standard for making a diagnosis, and some degree of misclassification and inter-observer variation can be expected. This may lead to local and regional differences in the treatment, monitoring, and follow-up of the patients. The Danish National Database for Asthma (DNDA) is slated to be established with the overall aim of collecting data on all patients treated for asthma in Denmark and systematically monitoring the treatment quality and disease management in both primary and secondary care facilities across the country. The DNDA links information from population-based disease registers in Denmark, including the National Patient Register, the National Prescription Registry, and the National Health Insurance Services register, and potentially includes all asthma patients in Denmark. The following quality indicators have been selected to monitor trends: first, conduction of annual asthma control visits, appropriate pharmacological treatment, measurement of lung function, and asthma challenge testing; second, tools used for diagnosis in new cases; and third, annual assessment of smoking status, height, and weight measurements, and the proportion of patients with acute hospital treatment. The DNDA will be launched in 2016 and will initially include patients treated in secondary care facilities in Denmark. In the nearby future, the database aims to include asthma diagnosis codes and clinical data registered by general practitioners and specialised practitioners as well.

Association between high school students' cigarette smoking, asthma and related beliefs: a population-based study

BACKGROUND

Smoking has a detrimental effect on the symptoms and severity of asthma, a common chronic disease among adolescents. The purpose of this study was to examine the association between asthma and smoking among high school students and assess provider-patient communication with asthmatic adolescents regarding smoking and adolescents' beliefs about the harms of smoking.

METHODS

In fall 2014, data from high school students, ages 14-18 years, completing the 2009-2010 Virginia Youth Tobacco Survey (N = 1796) were used in descriptive analyses and multivariable logistic regression models adjusting for model-specific confounders as appropriate.

RESULTS

Overall, an estimated 19 % of high school students in Virginia smoked and 16 % had asthma. Odds of smoking did not differ by asthma status; however, asthmatics had 1.5 times higher odds of being asked if they smoke (95 % CI 1.06-2.13) and being advised not to smoke by a health professional (95 % CI 1.10-2.14) compared to non-asthmatics. Asthmatics who believed second-hand smoke or smoking 1-5 cigarettes/day was not harmful had respectively 4.2 and 2.8 times higher odds of smoking than those who thought each was harmful. Further, asthmatics who thought smoking 1-2 years is safe had 3.4 times higher odds of smoking than those who did not (95 % CI 1.57-10.1).

CONCLUSIONS

While asthmatic adolescents are just as likely to smoke as non-asthmatics, less healthy beliefs about the risks of smoking increase the odds of smoking among asthmatics. Thus, targeted asthma-specific smoking prevention and education to change attitudes and beliefs could be an effective tool for adolescents.

Pulmonary effects of active smoking and secondhand smoke exposure among adolescent students in Juárez, Mexico

BACKGROUND

Youth smoking trends among Latin American countries, including Mexico, are on the rise. Notably, although the high prevalence of smoking in teens has been well documented in the literature, few studies have evaluated the impact of smoking and secondhand smoke (SHS) exposure on their respiratory system.

OBJECTIVE

To investigate the effects of smoking and SHS exposure on the respiratory health and lung function among eighth-grade students in Juárez, Mexico.

METHODS

A cross-sectional study was undertaken on a sample of convenience. The study outcomes centered on evaluating 300 students' lung function by spirometry (forced expiratory volume in 1 second [FEV1], forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC], and forced mid-expiratory flow rate [FEF25%-75%]) and their respiratory health (smoking behavior and SHS exposure) by their self-reported responses to a standardized respiratory questionnaire. The study outcomes were compared among three distinct groups: 1) nonsmokers/nonexposed to SHS; 2) nonsmokers/exposed to SHS; and 3) smokers.

RESULTS

The majority of the study participants were 14 years old (85%), females (54%), who attended eighth grade in a public school setting (56%). Approximately, half reported being of low socioeconomic status (49%) and nonsmokers/exposed to SHS (49%). The lung function parameters of smokers were found to be lower (FEV1 =62.88±10.25; FEV1/FVC =83.50±14.15; and FEF25%-75% =66.35±12.55) than those recorded for the nonsmokers/exposed to SHS (FEV1 =69.41±11.35; FEV1/FVC =88.75±15.75; and FEF25%-75% =78.90±14.65) and significantly reduced when compared to the nonsmokers/nonexposed to SHS (FEV1 =79.14±13.61; FEV1/FVC =94.88±21.88; and FEF25%-75% =87.36±17.02) (P<0.001). Similarly, respiratory complaints were more prevalent among smokers and those exposed to SHS when compared to nonsmokers/nonexposed to SHS.

CONCLUSION

Our findings suggest that initiation of cigarette smoking and, to a lesser extent, exposure to SHS in adolescence leads to increased respiratory symptoms and reduction of pulmonary function test values. Public health initiatives that aim to prevent smoking initiation, assist in cessation, and lessen SHS exposure of adolescents need to be school-based and employed as early as middle school.

Adolescents' smoking experiences, family structure, parental smoking and socio-economic status in Ciudad Juárez, Mexico

BACKGROUND

Cigarette smoking is the leading cause of preventable death worldwide. Tobacco use and secondhand-tobacco smoke (SHS) exposure are classified as a pediatric disease. In Mexico, the prevalence of smoking has decreased among adults but paradoxically increased among adolescents, particularly among young females. This study was designed to determine the association between adolescents' smoking experiences (smoking behaviors and second hand smoke [SHS] exposure), family structure, parental smoking and socio-economic status (SES) in Ciudad Juárez, Mexico.

METHODS

This is a cross-sectional, population-based study. Data was collected from sixth-grade students (N = 506) attending school in Ciudad Juárez, Mexico. Descriptive analyses were conducted. The relationship between key outcome variables (adolescents smoking and SHS exposure) and independent variables (family structure, parental smoking, and SES level) were examined. Adjusted odds ratios were calculated. Multiple logistic regression analysis was performed while controlling for possible confounders (i.e. gender and age).

RESULTS

The overall prevalence of ever/lifetime smoking and SHS exposure at home was 29.6 and 41.1 %, respectively. Results of the logistic regression analysis show that being a member of a non-intact family [(OR = 2.20; 95 % CI = 1.21-3.90) and (OR = 2.45; 95 % CI = 1.19-4.10) respectively], having parents who smoke [(OR = 4.41; 95 % CI = 2.15-5.46) and (OR = 4.95; 95 % CI = 2.25-7.12) respectively], and living in low SES setting [(OR = 1.73; 95 % CI = 1.43-3.30) and (OR = 1.99; 95 % CI = 1.16-4.00) respectively] are significantly associated with ever smoking and SHS exposure at home among sixth grade students.

CONCLUSIONS

The findings of our study show that tobacco use and SHS exposure are strongly associated with adolescents living in low SES, non-intact households that have parents that smoke. To be effective, tobacco strategies specifically tailored for this particularly vulnerable group of adolescents would require a comprehensive, multi-faceted approach centered on prevention, cessation and protection.

Modification of additive effect between vitamins and ETS on childhood asthma risk according to GSTP1 polymorphism: a cross -sectional study

Background

Asthma is characterized by airway inflammation, and bronchial airways are particularly susceptible to oxidant-induced tissue damage.

Objective

To investigate the effect of dietary antioxidant intake and environmental tobacco smoke (ETS) on the risk of childhood asthma according to genotypes susceptible to airway diseases.

Methods

This cross-sectional study included 1124 elementary school children aged 7–12 years old. Asthma symptoms and smoking history were measured using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Intake of vitamin A (including retinol and β-carotene), C, and E was measured by a semi-quantitative food frequency questionnaire (FFQ). GSTP1 polymorphisms were genotyped from peripheral blood samples.

Results

ETS was significantly associated with presence of asthma symptoms (adjusted odds ratio [aOR], 2.48; 95 % confidence interval [CI], 1.29–4.76) and diagnosis (aOR, 1.91; 95 % CI, 1.19–3.06). Dietary antioxidant intake was not associated with asthma symptoms, although ETS plus low vitamin A intake showed a significant positive association with asthma diagnosis (aOR, 2.23; 95 % CI, 1.10–4.54). Children with AA at nucleotide 1695 in GSTP1 who had been exposed to ETS and a low vitamin A intake have an increased risk of asthma diagnosis (aOR, 4.44; 95 % CI,1.58–12.52) compared with children who had not been exposed to the two risk factors. However, ETS exposure and low vitamin A intake did not significantly increase odds of asthma diagnosis in children with AG or GG genotypes.

Conclusion

Low vitamin A intake and ETS exposure may increase oxidative stress and thereby risk for childhood asthma. These relationships may be modified by gene susceptibility alleles of GSTP1.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0093-0) contains supplementary material, which is available to authorized users.

Risk and protective factors for the development of childhood asthma

Childhood asthma prevalence worldwide has been increasing markedly over several decades. Various theories have been proposed to account for this alarming trend. The disease has a broad spectrum of potential determinants ranging from genetics to lifestyle and environmental factors. Epidemiological observations have demonstrated that several important lifestyle and environmental factors including obesity, urban living, dietary patterns such as food low in antioxidants and fast food, non-breastfeeding, gut flora imbalance, cigarette smoking, air pollution, and viral infection are associated with asthma exacerbations in children. However, only environmental tobacco smoke has been associated with the development of asthma. Despite epidemiological studies indicating that many other factors are probably associated with the development of asthma, the relationships are not considered causal due to the inadequate evidence and inconsistent results from recent studies. This may highlight that sufficient data and exact mechanisms of causality are still in need of further study.

The diversity of young adult wheeze: a cluster analysis in a longitudinal birth cohort

BACKGROUND

Cluster analyses have enhanced understanding of the heterogeneity of both paediatric and adult wheezing. However, while adolescence represents an important transitional phase, the nature of young adult wheeze has yet to be clearly characterised.

OBJECTIVES

To use cluster analysis to define, for the first time, clinically relevant young adult wheeze clusters in a longitudinal birth cohort.

METHODS

K-means cluster analysis was undertaken among 309 currently wheezing subjects at 18 years in the Isle of Wight birth cohort (N = 1456). Thirteen disease-characterising clustering variables at 18 years were used. Resulting clusters were then further characterised by severity indices plus potential risk factors for wheeze development throughout the 1st 18 years of life.

RESULTS

Six wheeze clusters were identified. Cluster 1 (12.3%) male-early-childhood-onset-atopic-wheeze-with-normal-lung-function had male predominance, normal spirometry, low bronchodilator reversibility (BDR), intermediate bronchial hyper-responsiveness (BHR), high atopy prevalence and more admissions. Cluster 2 (24.2%) early-childhood-onset-wheeze-with-intermediate-lung-function had no specific sex association, intermediate spirometry, BDR, BHR, more significant BTS step therapy and admissions. Cluster 3 (9.7%) female-early-childhood-onset-atopic-wheeze-with-impaired-lung-function showed female predominance, high allergic disease comorbidity, more severe BDR and BHR, greatest airflow obstruction, high smoking prevalence, higher symptom severity and admissions. Cluster 4 (19.4%) female-undiagnosed-wheezers had adolescent-onset non-atopic wheeze, low BDR and BHR, impaired but non-obstructed spirometry, high symptom frequency and highest smoking prevalence. Cluster 5 (24.6%) female-late-childhood-onset-wheeze-with-normal-lung-function showed no specific atopy association, normal spirometry, low BDR, BHR and symptom severity. Cluster 6 (9.7%) male-late-childhood-onset-atopic-wheeze-with-impaired-lung-function had high atopy and rhinitis prevalence, increased BDR and BHR, moderately impaired spirometry, high symptom severity and higher BTS step therapy.

CONCLUSIONS AND CLINICAL RELEVANCE

Young adult wheeze is diverse and can be classified into distinct clusters. More severe clusters merit attention and are associated with childhood onset, atopy, impaired lung function and in some, smoking. Smoking-associated undiagnosed wheezers also merit recognition. Better understanding of young adult wheeze could facilitate better later adult respiratory health.

Risk factors for non-atopic asthma/wheeze in children and adolescents: a systematic review

Background

The study of non-atopic asthma/wheeze in children separately from atopic asthma is relatively recent. Studies have focused on single risk factors and had inconsistent findings.

Objective

To review evidence on factors associated with non-atopic asthma/wheeze in children and adolescents.

Methods

A review of studies of risk factors for non-atopic asthma/wheeze which had a non-asthmatic comparison group, and assessed atopy by skin-prick test or allergen-specific IgE.

Results

Studies of non-atopic asthma/wheeze used a wide diversity of definitions of asthma/wheeze, comparison groups and methods to assess atopy. Among 30 risk factors evaluated in the 43 studies only 3 (family history of asthma/rhinitis/eczema, dampness/mold in the household, and lower respiratory tract infections in childhood) showed consistent associations with non-atopic asthma/wheeze. No or limited period of breastfeeding was less consistently associated with non-atopic asthma/wheeze. The few studies examining the effects of overweight/obesity and psychological/social factors showed consistent associations. We used a novel graphical presentation of different risk factors for non-atopic asthma/wheeze, allowing a more complete perception of the complex pattern of effects.

Conclusions

More research using standardized methodology is needed on the causes of non-atopic asthma.

The adolescent with asthma

The adolescent with asthma experiences a period of physical and psychosocial changes that affect their health and well-being. Overall, adolescents with asthma are at increased risk for asthma morbidity and death. Increased rates of depression and anxiety, for the adolescent and their caregivers, can lead to non-adherence to their medical regimens, poor symptom control, and poor treatment outcomes. Contextual factors, such as race, ethnicity, and living situation, affect the prevalence, morbidity, and mortality for the adolescent with asthma. These factors also affect the transition process for adolescents entering adult medical care. An overview is presented of how the adolescent with asthma differs and how healthcare providers can promote effective asthma management and better asthma control.

Effect of GSTM2-5 polymorphisms in relation to tobacco smoke exposures on lung function growth: a birth cohort study

Background

Genetic variation within GSTM2-5 genes may interfere with detoxification of environmental compounds, thereby having a detrimental effect on lung function following exposures such as tobacco smoke. We aim to investigate the influence of variants and associated methylation in the GSTM gene cluster with changes in lung function growth during adolescence.

Methods

Growth in forced expiratory volume (FEV₁), forced vital capacity (FVC), and change in FEV₁/FVC ratio measures were obtained from children in the Isle of Wight birth cohort at ages 10 and 18. Illumina GoldenGate assays were used to genotype 10 tagging polymorphisms from GSTM2 (rs574344 and rs12024479), GSTM3 (rs1537236, rs7483, and rs10735234), GSTM4 (rs668413, rs560018, and rs506008), and GSTM5 (rs929166 and rs11807) genes. Diplotypes were generated in the software Phase 3.0.2. DNA methylation was measured in over 450,000 CpG sites using the Infinium HumanMethylation450 BeadChip (Illumina 450K) in a subsample of 245 18-year olds from the Isle of Wight birth cohort. Gender, age, in utero smoke exposure, secondhand smoke exposure (SHS), and current smoking status were assessed via questionnaire; smoke exposures were validated with urine cotinine. We used linear mixed models to estimate the effect of GSTM diplotypes on lung function across time and examine interactions with tobacco smoke.

Results

1,121 (77%) out of 1,456 children had information on lung function at ages 10 or 18. After adjustment for false discovery rate, one diplotype in GSTM3 had a detrimental effect on changes in FEV₁ (p=0.03), and another diplotype in GSTM3 reduced FVC (p=0.02) over time. No significant interactions with smoking were identified. SHS significantly modified the relationship between diplotypes and methylation levels in one GSTM2 CpG site; however, this site did not predict lung function outcomes at age 18. Joint effects of GSTM loci and CpG sites located within these loci on adolescent lung growth were detected.

Conclusions

Diplotypes within GSTM2-5 genes are associated with lung function growth across adolescence, but do not appear to modify the effect of tobacco smoke exposures on adolescent lung growth. Interactions between DNA methylation and diplotypes should be taken into account to gain further understanding on lung function in adolescence.

Dose-response association between smoking and atopic eczema: results from a large cross-sectional study in adolescents

BACKGROUND

Tobacco smoking and exposure to environmental tobacco smoke (ETS) are known risk factors for asthma, but their association with atopic eczema is unclear.

OBJECTIVE

To investigate the association of smoking and exposure to ETS with prevalence of atopic eczema in a national sample of 13- to 14-year-olds in Israel.

METHODS

Cross-sectional study within the framework of the International Study on Asthma and Allergies in Childhood.

RESULTS

Complete data were available for 10,298 schoolchildren. Atopic eczema as well as asthma and allergic rhinitis were significantly more prevalent in smokers than nonsmokers. Multiple regression analysis revealed a dose-response association between smoking and atopic eczema compared to not smoking: occasional smokers, odds ratio (OR) = 1.6 (95% confidence interval (CI) = 1.2-2.3); daily smokers, OR = 2.2 (95% CI = 1.4-3.6). Exposure to ETS at home was significantly associated with asthma (OR = 1.25; 95% CI = 1.1-1.5) but not atopic eczema.

CONCLUSIONS

The dose-response association between active smoking and atopic eczema in adolescents is a novel observation which deserves further consideration.

The effect of oral contraceptives on current wheezing in young women

BACKGROUND

Emerging evidence suggests that sex steroid hormones may influence respiratory symptoms. The existing literature about the role of oral contraceptive pill (OCP) on respiratory disease is scarce and conflicting especially during the adolescent period. In this study, we aimed to investigate the effect of OCPs on current wheezing among adolescents and young adults.

METHODS

A questionnaire was administered face-to-face to adolescents and young women by a physician. The questionnaire included ISAAC survey-comprised questions on ever wheezing, current wheezing, allergic diseases, smoking history (active or passive), and family history of allergic diseases and questions on OCP usage status. The effect of OCPs on wheezing was evaluated by logistic regression analysis.

RESULTS

A total of 487 subjects aged between 11.3 and 25.6years participated in the study and 196 (40.2%) reported that they had used OCPs. 7.4% of the participants had physician-diagnosed asthma and 10.3% of them were active smokers. It was detected that OCPs were associated with increased risk for current wheezing (odds ratio, 2.36; 95% CI, 1.25-4.47 adjusted for asthma and current smoker) and this risk was related with the usage during the past year.

CONCLUSION

Young women taking oral contraceptives had a higher rate of current wheezing, suggesting that sex steroids may be of importance for respiratory health.

US prevalence and trends in tobacco smoke exposure among children and adolescents with asthma

OBJECTIVE

To examine exposure to tobacco smoke products (TSPs), environmental tobacco smoke (ETS), and in-home smoke among youth with asthma in the United States.

METHODS

Nationally representative, cross-sectional data from 2250 youth aged 4 to 19 years with current asthma in the 1988-1994, 1999-2004, and 2005-2010 National Health and Nutrition Examination Survey (NHANES) were analyzed. Outcomes were use of TSPs (serum cotinine level >10 ng/mL or self-reported recent use of cigarettes, cigars, or pipes) and, among non-TSP users, ETS exposure (serum cotinine ≥0.05 ng/mL) and in-home smoke exposure (reported). Multiple logistic regression analyses assessed the associations between the outcomes and age, gender, race/ethnicity, and family income.

RESULTS

Among adolescents (aged 12-19 years) with asthma in 2005-2010, 17.3% reported TSP use. Among youth (aged 4-19 years) with asthma who did not use TSPs, 53.2% were exposed to ETS and 17.6% had in-home smoke exposure. Among low-income youth, 70.1% and 28.1% had exposure to ETS and in-home smoke, respectively. After controlling for sociodemographic factors, higher prevalence of exposure to ETS and in-home smoke persisted among low-income youth. Between 1988-1994 and 2005-2010, there was a decline in ETS and in-home smoke exposure (both P < .001).

CONCLUSIONS

ETS exposure among youth with asthma declined between 1988-1994 and 2005-2010, but a majority remained exposed in 2005-2010, with higher exposure among low-income youth. More than 1 in 6 youth with asthma in 2005-2010 were exposed to in-home smoke and a similar portion of adolescents used TSPs.

Prevalence of anxiety and depressive symptoms in adolescents with asthma: a meta-analysis and meta-regression

It remains unclear whether anxiety and depressive symptoms are more prevalent in adolescents with asthma when compared with healthy individuals. This meta-analysis aimed to evaluate the difference in the aggregate prevalence of depressive and anxiety symptoms between adolescents with asthma and healthy controls and to explore the underlying moderators that potentially explain the heterogeneity of the effect size. A meta-analysis of published work was performed using the random effects model. The differences in aggregate prevalence of depressive and anxiety symptoms between adolescents with asthma and healthy controls were determined. Meta-regression and subgroup analysis were performed to identify factors that may contribute to heterogeneity. A total of eight studies were eligible for analysis. The aggregate prevalence of depressive and anxiety symptoms was significantly higher among 3546 adolescents with asthma than that of 24,884 controls (depression, 0.27; 95% CI, 0.18.6-0.39 vs. 0.13; 95% CI, 0.09-0.19; anxiety, 0.33; 95% CI, 0.19-0.52 vs. 0.21; 95% CI, 0.12-0.33). The risk of developing depression and anxiety is significantly higher among adolescents with asthma when compared with controls (depression: pooled odds ratio, 2.09; 95% CI, 1.65-2.64; p < 0.001; anxiety: pooled odds ratio, 1.83; 95% CI, 1.63-2.07; p < 0.001). Meta-regression revealed that the proportions of Caucasian (p = 0.008) and smokers (p < 0.001) were significant moderators which explained the significant heterogeneity when comparing the risk of developing depressive symptoms among adolescent asthma patients vs. controls while age, gender, and severity of asthma were not significant. Family doctors, pediatricians, and healthcare providers should formulate strategies to detect depressive and anxiety symptoms in adolescents with asthma and offer psychological interventions to reduce the burden of psychiatric comorbidity.

Early impact of smoking on lung function, health, and well-being in adolescents

BACKGROUND

Smoking is the single most important risk factor for the development of chronic obstructive pulmonary disease, and more than 80% of adult smokers started smoking before the age of 20. The aim of our study was to evaluate the early impact of smoking on lung function, health, and well-being in adolescents.

METHODS

Twenty-four non-smokers (10 male, 14 female, mean age 17.6 years) and 24 smokers (mean of 3.5 pack-years; 15 male, 9 female, mean age 17.8 years) were compared in terms of lung function, bronchial hyperreactivity (BHR), levels of exhaled carbon monoxide (eCO), exhaled nitric oxide (eNO), and blood counts. A questionnaire containing items from the ISAAC study was used to detect differences in health and well-being.

RESULTS

There were no significant differences in lung function values between non-smokers and smokers (VC 95% vs. 103%, FEV(1) 106% vs. 116%, FEV(1) %/VC MAX 94.6% vs. 95.2%), whereas BHR significantly differed (P < 0.05). Furthermore, significant differences were found for eCO, eNO, Hb, leukocytes, and neutrophils. Health and well-being in terms of sleep and physical activity were significantly worse in smokers.

CONCLUSION

Our results suggest an early impact of smoking on health after as few as 3.5 pack-years. Early signs of smoking are an increase in BHR, changes in blood count and a decrease of eNO even before changes in lung function become apparent.

Predictors of substance use among black urban adolescents with asthma: a longitudinal assessment

The physical and psychological consequences of asthma, a chronic respiratory disease disproportionately affecting black urban adolescents, may be amplified by substance use, yet studies have not assessed rates or predictors of substance use in this at-risk population. Therefore, this study examined rates of substance use and mental health/ asthma-related predictors of use among 110 black urban adolescents with asthma. Participants completed study questionnaires at baseline and 11 to 14 months post baseline. The mean age of the sample was 15.8 (SD +/- 1.85), 66 (60%) were female, and 82 (74%) of the participants had intermittent/mild persistent asthma. At follow-up, 37 (34%) participants endorsed using at least 1 substance in the past 30 days, including cannabis (n = 18 [16%]), cigarettes (n = 13 [12%]), and/or alcohol (n = 23 [21%]). The substance use variables were dichotomized for analyses (1 = use, 0 = nonuse). Logistic regression results indicated that older age (odds ratio [OR], 1.83; p < .05) was significantly associated with cigarette use and had a marginally significant (p = .06) association with cannabis use at follow-up. Increased anxiety symptoms were significantly associated with alcohol use (OR, 1.12; p < .05) and cannabis use (OR, 0.90; p < .05) at follow-up. Targeting adolescents earlier, those with anxiety difficulties, and those who report early substance initiation may improve prevention/intervention efforts for substance use reduction in this population. Asthma-related factors were not significantly associated with substance use. Future studies should assess the relationship between other asthma-related variables, as well as social and community factors, and substance use among black adolescents with asthma.

Modifying effect of suicidal ideation on the relationship between asthma and cigarette use behaviors among Korean adolescents

Objectives

Although cigarette smoking is known to be related to the exacerbation of asthma symptoms, several studies have indicated that the prevalence of cigarette smoking among asthmatic adolescents is similar to or even higher than that among non-asthmatic adolescents. The aim of this study was to evaluate the relationship between asthma and cigarette use behaviors and whether or not the presence of suicidal ideation modifies this relationship among Korean adolescents.

Methods

We analyzed data from the 2008 Korea Youth Risk Behavior Web-based Survey, which included a nationally representative sample of middle and high school students. Multiple logistic regression models were used to calculate odd ratios and 95% confidence intervals of cigarette use behaviors among current asthmatics, former asthmatics, and non-asthmatics, after adjusting for gender, grade, school records, socioeconomic status, current alcohol use, and suicidal ideation.

Results

Of 75 238 study participants, 3.5% were current asthmatics and 4.5% were former asthmatics. Compared with non-asthmatics, asthmatics were more likely to report current cigarette use, frequent and heavy cigarette use, and cigarette use before 13 years of age. There were statistically significant interactions between asthma and suicidal ideation in cigarette use behaviors.

Conclusions

This study demonstrated that asthmatic adolescents are more likely than non-asthmatic adolescents to engage in cigarette use behaviors and the presence of suicidal ideation is an effect modifier of the relationship between asthma and cigarette use behaviors. Particular attention should be paid to the awareness of health risks of cigarette smoking and mental health problems among asthmatic adolescents.

Smoking and nonsmoking asthma: differences in clinical outcome and pathogenesis

Cigarette smoking in asthma is frequently present and is associated with worsening of symptoms, accelerated lung-function decline, a higher frequency of hospital admissions, a higher degree of asthma severity, poorer asthma control and reduced responsiveness to corticosteroids. Furthermore, it is associated with reduced numbers of eosinophils and higher numbers of mast cells in the submucosa of the airway wall. Airway remodeling is increased as evidenced by increased epithelial thickness and goblet cell hyperplasia in smoking asthmatics. The pathogenesis responsible for smoking-induced changes in airway inflammation and remodeling in asthma is complex and largely unknown. The underlying mechanism of reduced corticosteroid responsiveness is also unknown. This article discusses differences between smoking and nonsmoking asthmatics regarding the clinical expression of asthma, lung function, response to corticosteroids, airway inflammation and remodeling processes. Possible pathogenetic mechanisms that may explain the links between cigarette smoking and changes in the clinical expression of asthma will be discussed, as well as the beneficial effects of smoking cessation.

Acoustic rhinometry, spirometry and nitric oxide in relation to airway allergy and smoking habits in an adolescent cohort

OBJECTIVE

This study aimed to analyze upper and lower airway function and the impact of smoking habits in a cohort of allergic and healthy adolescents. The influence of smoking habits on the outcomes of rhinitis and asthma is well documented, but only few reports are available showing smoke related upper airway impairment by rhinometric measurements, and none with focus on early changes in adolescents.

METHODS

A cohort followed from infancy was re-examined at the age of 18 years concerning allergy development. Acoustic rhinometry (VOL2), spirometry (FEV(1)) and measurements of nitric oxide levels from the upper (nNO) and lower airways (eNO) were performed before and after physical exercise, and smoking habits were registered.

RESULTS

Active smoking habits were reported by 4/21 subjects suffering from allergic rhinitis, by 1/4 from probable allergic rhinitis, by 0/3 subjects with atopic dermatitis and by 2/10 healthy controls. Smoking habits were reported as daily by 2 and occasional by 5 of the 7 active smokers. VOL2 did not increase in smokers after exercise as in non-smokers, resulting in a post-exercise group difference (7.3±1.1cm(3) vs. 8.8±1.5cm(3); p=0.02), and FEV(1) values were lower in smokers compared to non-smokers (89±7% vs. 98±8%; p=0.02). The nNO and eNO levels were, however, only slightly reduced in smokers. Airway allergy was discerned only in subjects with current allergen exposure by increased eNO levels compared to healthy controls (41±44ppb vs. 13±5ppb). The levels of VOL2, nNO and FEV(1) did not differentiate allergic subjects from healthy controls.

CONCLUSIONS

Low levels of tobacco smoke exposure resulted in reduced airway functions in this adolescent cohort. Acoustic rhinometry and spirometry were found to be more sensitive methods compared to nitric oxide measurements in early detection of airway impairment related to smoke exposure. A possible difference in airway vulnerability between allergic and healthy subjects due to smoke exposure remains to be evaluated in larger study groups.