An observational analysis on the influence of parental allergic rhinitis, asthma and smoking on exhaled nitric oxide in offspring.

BACKGROUND: Parental allergic diseases and smoking influence respiratory disease in the offspring but it is not known whether they influence fractional exhaled nitric oxide (FeNO) in the offspring. We investigated whether parental allergic diseases, parental smoking and FeNO levels in parents were associated with FeNO levels in their offspring. METHODS: We studied 609 offspring aged 16-47 years from the Respiratory Health in Northern Europe, Spain and Australia generation (RHINESSA) study with parental information from the Respiratory Health in Northern Europe (RHINE) III study and the European Community Respiratory Health Survey (ECRHS) III. Linear regression models were used to assess the association between offspring FeNO and parental FeNO, allergic rhinitis, asthma and smoking, while adjusting for potential confounding factors. RESULTS: Parental allergic rhinitis was significantly associated with higher FeNO in the offspring, both on the paternal and maternal side (percent change: 20.3 % [95%CI 5.0-37.7], p = 0.008, and 13.8 % [0.4-28.9], p = 0.043, respectively). Parental allergic rhinitis with asthma in any parent was also significantly associated with higher offspring FeNO (16.2 % [0.9-33.9], p = 0.037). However, parental asthma alone and smoking were not associated with offspring FeNO. Parental FeNO was not associated with offspring FeNO after full adjustments for offspring and parental factors. CONCLUSIONS: Parental allergic rhinitis but not parental asthma was associated with higher levels of FeNO in offspring. These findings suggest that parental allergic rhinitis status should be considered when interpreting FeNO levels in offspring beyond childhood.

Disease burden, comorbidities and antecedents of chronic cough phenotypes in Australian adults.

BACKGROUND AND OBJECTIVES: While adult chronic cough has high burden, its phenotypes, particularly those without aetiologically related underlying conditions, are understudied. We investigated the prevalence, lung function and comorbidities of adult chronic cough phenotypes. METHODS: Data from 3608 participants aged 53 years from the Tasmanian Longitudinal Health Study (TAHS) were included. Chronic cough was defined as cough on most days for >3 months in a year. Chronic cough was classified into "explained cough" if there were any one of four major cough-associated conditions (asthma, COPD, gastroesophageal reflux disease or rhinosinusitis) or "unexplained cough" if none were present. Adjusted regression analyses investigated associations between these chronic cough phenotypes, lung function and non-respiratory comorbidities at 53 years. RESULTS: The prevalence of chronic cough was 10% (95%CI 9.1,11.0%) with 46.4% being "unexplained". Participants with unexplained chronic cough had lower FEV1/FVC (coefficient: -1.2% [95%CI:-2,3, -0.1]) and increased odds of comorbidities including obesity (OR=1.6 [95%CI: 1.2, 2.3]), depression (OR=1.4 [95%CI: 1.0, 2.1]), hypertension (OR=1.7 [95%CI: 1.2, 2.4]) and angina, heart attack or myocardial infarction to a lesser extent, compared to those without chronic cough. Participants with explained chronic cough also had lower lung function than both those with unexplained chronic cough and those without chronic cough. CONCLUSIONS: Chronic cough is prevalent in middle-age and a high proportion is unexplained. Unexplained cough contributes to poor lung function and increased comorbidities. Given unexplained chronic cough is not a symptom of major underlying respiratory conditions it should be targeted for better understanding in both clinical settings and research.

Outdoor pollen is a trigger of child and adolescent asthma emergency department presentations: A systematic review and meta-analysis.

BACKGROUND: In the context of increased asthma exacerbations associated with climatic changes such as thunderstorm asthma, interest in establishing the link between pollen exposure and asthma hospital admissions has intensified. Here, we systematically reviewed and performed a meta-analysis of studies on pollen and emergency department (ED) attendance. METHODS: A search for studies with appropriate search strategy in MEDLINE, EMBASE, Web of Science and CINAHL was conducted. Each study was assessed for quality and risk of bias. The available evidence was summarized both qualitatively and meta-analysed using random-effects models when moderate heterogeneity was observed. RESULTS: Fourteen studies were included. The pollen taxa investigated differed between studies, allowing meta-analysis only of the effect of grass pollen. A statistically significant increase in the percentage change in the mean number of asthma ED presentations (MPC) (pooled results from 3 studies) was observed for an increase in 10 grass pollen grains per cubic metre of exposure 1.88% (95% CI = 0.94%, 2.82%). Time series studies showed positive correlations between pollen concentrations and ED presentations. Age-stratified studies found strongest associations in children aged 5-17 years old. CONCLUSION: Exposure to ambient grass pollen is an important trigger for childhood asthma exacerbations requiring ED attendance. As pollen exposure is increasingly a problem especially in relation to thunderstorm asthma, studies with uniform measures of pollen and similar analytical methods are necessary to fully understand its impact on human health.

Association of breast milk fatty acids with allergic disease outcomes-A systematic review.

INTRODUCTION: Dietary polyunsaturated fatty acids (PUFAs) have immunoregulatory properties. Breast milk is rich in PUFA, and it has been hypothesized that these PUFAs may be important in the aetiology of allergic diseases. Despite a growing body of evidence, the associations between breast milk PUFA and allergic disease have not previously been systematically reviewed. METHODS: The search was performed in PubMed and EMBASE databases using breastfeeding, fatty acid and allergic disease terms. Two authors were involved in selecting papers for review according to the inclusion criteria and extracting information on study characteristics and measures of association. Only studies that reported numeric associations between concentration of breast milk fatty acids and allergic disease outcomes were included. RESULTS: A total of 18 papers met the inclusion criteria, reporting results from 15 study populations. The majority were cohort studies (n=11), with data from only two case-control and two cross-sectional studies. Sample size varied between 30 and 352 participants, and follow-up time of the cohorts varied between 3 months and 14 years. Nine studies reported on eczema, seven reported on sensitization, and only five reported on asthma/wheeze. There was heterogeneity among studies in terms of presenting the association between PUFA and allergy; therefore, estimates could not be pooled. Only a few studies observed associations between n-3 and n-6 PUFAs and allergic disease, and the magnitude of this effect varied greatly. CONCLUSIONS: There is insufficient evidence to suggest that colostrum or breast milk polyunsaturated fatty acids influence the risk of childhood allergic diseases.

Menopause, lung function and obstructive lung disease outcomes: a systematic review.

BACKGROUND: The menopausal transition may have significant consequences for respiratory health, risk of chronic respiratory disease and management strategies. OBJECTIVE: To systematically summarize the literature regarding the impact of menopause status on respiratory health outcomes. METHODS: PubMed was searched systematically to identify population-based studies investigating the associations between menopause status and respiratory outcomes including asthma, chronic obstructive pulmonary disease (COPD), respiratory symptoms and lung function. RESULTS: Ten publications were identified for full review. Evidence on menopause and asthma was conflicting, while studies on COPD were scarce. The findings generally support an association between menopause and clinically significant reductions in lung function in a non-obstructive pattern. However, the effects of menopause are clouded by aging, menopausal hormone therapy use, and increased risk of metabolic syndrome during this period. CONCLUSIONS: As the global burden associated with respiratory conditions continues to rise, the need to understand the associations between menopause and respiratory health is essential to identify potentially modifiable risk factors for respiratory disease in adult women. More studies are needed to clarify the impact of menopause on obstructive lung disease.

Atopy in people aged 40 years and over: Relation to airflow limitation.

BACKGROUND: Previous studies have reached conflicting conclusions about the role of atopy as a risk factor for COPD. In part, this is attributable to variation in the definitions of airflow limitation and the treatment of people with asthma. OBJECTIVE: To establish whether there is any independent association between atopy and post-bronchodilator airflow limitation in the general population aged 40 years and over. METHODS: A cross-sectional survey was conducted in a general population sample of 2415 people aged 40 years and over in Australia. A history of ever being diagnosed with asthma was elicited by questionnaire. Atopy was defined as any skin prick test weal to common aeroallergens ≥4 mm. Airflow limitation was defined as post-bronchodilator spirometric (FEV1 /FVC) ratio

Residential greenness and allergic respiratory diseases in children and adolescents - A systematic review and meta-analysis.

BACKGROUND: The aetiology of allergic respiratory disease in children is not yet fully understood. Environmental factors are believed to play a major part. The amount of green vegetation surrounding the home (residential greenness) has been recently identified as a potentially important exposure OBJECTIVES: Our goal was to provide a systematic review and quantitative summary of the evidence regarding the relationship between residential greenness and allergic respiratory diseases in children. METHODS: Peer-reviewed literature published prior to 1 March 2017 was systematically searched using nine electronic databases. Meta-analyses were conducted if at least three studies published risk estimates for the same outcome and exposure measures. RESULTS: We included 11 articles across broad outcomes of asthma and allergic rhinitis. Reported effects were inconsistent with varying measures to define residential greenness. Only limited meta-analysis could be conducted, with the pooled odds ratios for asthma (OR 1.01 95%CI 0.93, 1.09; I2 68.1%) and allergic rhinitis (OR 0.99 95%CI 0.87, 1.12; I2 72.9%) being significantly heterogeneous. CONCLUSIONS: Inconsistencies between the studies were too large to accurately assess the association between residential greenness and allergic respiratory disease. A standardised global measure of greenness which accounts for seasonal variation at a specific relevant buffer size is needed to create a more cohesive body of evidence and for future examination of the effect of residential greenness on allergic respiratory diseases.

Breast milk polyunsaturated fatty acids: associations with adolescent allergic disease and lung function.

BACKGROUND: It has been hypothesized that n-3 PUFA in breast milk may assist immune and lung development. There are very limited data on possible long-term effects on allergic disease and lung function. The aim was to investigate associations of n-3 and n-6 PUFA levels in colostrum and breast milk with allergic disease and lung function at ages 12 and 18 years. METHODS: Polyunsaturated fatty acids were measured in 194 colostrum samples and in 118 three-month expressed breast milk samples from mothers of children enrolled in the Melbourne Atopy Cohort (MACS) Study, a high-risk birth cohort study. Associations with allergic diseases, skin prick tests and lung function assessed at 12 and 18 years were estimated using multivariable regression. RESULTS: Higher levels of n-3 but not n-6 PUFAs in colostrum were associated with a trend towards increased odds of allergic diseases, with strong associations observed for allergic rhinitis at 12 (OR = 5.69[95% CI: 1.83,17.60] per weight%) and 18 years (4.43[1.46,13.39]) and eczema at 18 years (9.89[1.44, 68.49]). Higher levels of colostrum n-3 PUFAs were associated with reduced sensitization (3.37[1.18, 9.6]), mean FEV1 (-166 ml [-332, -1]) and FEV1 /FVC ratio (-4.6%, [-8.1, -1.1]) at 12 years. CONCLUSION: Higher levels of colostrum n-3 PUFAs were associated with increased risks of allergic rhinitis and eczema up to 18 years, and sensitization and reduced lung function at 12 years. As residual confounding may have caused these associations, they should be replicated, but these results could indicate that strategies that increase maternal n-3 PUFA intake may not aid in allergic disease prevention.

Integrating smoking cessation into routine care in hospitals--a randomized controlled trial.

AIMS: To evaluate the effectiveness of a pharmacist-led multi-component smoking cessation programme (GIVE UP FOR GOOD) compared with usual care in hospitalized smokers. DESIGN: Randomized, assessor-blinded, parallel-group trial. SETTING: Three tertiary public hospitals in Australia. PARTICIPANTS: A total of 600 adult in-patient smokers [mean ± standard deviation (SD), age 51 ± 14 years; 64% male] available for 12 months follow-up. INTERVENTIONS: Multi-component hospital pharmacist-led behavioural counselling and/or pharmacotherapy provided during hospital stay, on discharge and 1 month post-discharge, with further support involving community health professionals (n = 300). Usual care comprised routine care provided by hospitals (n = 300). MEASUREMENTS: Two primary end-points were tested using intention-to-treat analysis: carbon monoxide (CO)-validated 1-month sustained abstinence at 6-month follow-up and verified 6-month sustained abstinence at 12-month follow-up. Smoking status and pharmacotherapy usage were assessed at baseline, discharge, 1, 6 and 12 months. FINDINGS: Sustained abstinence rates for intervention and control groups were not significantly different at both 6 months [11.6% (34 of 294) versus 12.6% (37 of 294); odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.55-1.50] and 12 months [11.6% (34 of 292) versus 11.2% (33 of 294); OR = 1.04, 95% CI = 0.63-1.73]. Secondary end-points, self-reported continuous abstinence at 6 and 12 months, also agreed with the primary end-points. Use of pharmacotherapy was higher in the intervention group, both during hospital stay [52.3% (157 of 300) versus 42.7% (128 of 300); P = 0.016] and after discharge [59.6% (174 of 292) versus 43.5% (128 of 294); P < 0.001]. CONCLUSIONS: A pharmacist-led multi-component smoking cessation intervention provided during hospital stay did not improve sustained abstinence rates at either 6 or 12 months compared with routine hospital care.

Population-wide preventive interventions for reducing the burden of chronic respiratory disease.

Chronic obstructive pulmonary disease and asthma impose a substantial burden of disease. This narrative review focuses on potential population-wide interventions that are likely to have an impact on these diseases. The developmental origins of adult disease commence in utero, with maternal nutrition being of particular interest. However, to date, trials of maternal allergen avoidance, dietary supplementation or probiotics have not shown consistent protective effects against asthma. Poor indoor air quality, especially from biomass fuels as well as second-hand tobacco smoke, is a well-recognised risk factor for chronic respiratory diseases. This can be modified by cleaner fuels, cooking stoves or heaters, and improved ventilation. Although allergens are a risk factor for childhood asthma, the results of interventions to reduce exposures have been disappointing. Traffic-related air pollution is associated with an increased incidence of asthma in children. Primary prevention of the adverse effects of air pollution has focused on the development of ambient air quality guidelines, but enforcement remains a challenge in many countries. Occupational asthma may be induced by sensitisers or irritants in the workplace. Prevention involves eliminating the agent or reducing exposure as far as possible, which is more effective than respiratory protective equipment. Smoking cessation remains a key proven preventive strategy for chronic respiratory diseases. There is now an international framework for tobacco control, and recent innovations include plain packaging of tobacco. Chronic respiratory diseases can be substantially prevented by the above population-wide interventions.

The influence of childhood traffic-related air pollution exposure on asthma, allergy and sensitization: a systematic review and a meta-analysis of birth cohort studies.

The impact of early childhood traffic-related air pollution (TRAP) exposure on development of asthma and allergies remains unclear. Birth cohort studies are the best available study design to answer this question, but the evidence from such studies has not been synthesized to date. We conducted a systematic review and meta-analyses of published birth cohort studies to understand the association between early childhood TRAP exposure, and subsequent asthma, allergies and sensitization. Increased longitudinal childhood exposure to PM2.5 and black carbon was associated with increasing risk of subsequent asthma in childhood (PM2.5 : OR 1.14, 95%CI 1.00 to 1.30 per 2 µg/m(3) and black carbon: OR 1.20, 95%CI 1.05 to 1.38 per 1 × 10(-5) m(-1) ). Also, early childhood exposure to TRAP was associated with development of asthma across childhood up to 12 years of age. The magnitude of these associations increased with age, and the pattern was prominent for PM2.5 . Increasing exposure to PM2.5 was associated with sensitization to both aero- and food allergens. There was some evidence that TRAP was associated with eczema and hay fever. In summary, exposure to TRAP was related to asthma and allergic diseases. However, the substantial variability across studies warrants long-term birth cohort studies with regular repeated follow-ups to confirm these findings.

Atopic dermatitis and the atopic march revisited.

Atopic dermatitis (AD) has become a significant public health problem because of increasing prevalence, together with increasing evidence that it may progress to other allergic phenotypes. While it is now acknowledged that AD commonly precedes other allergic diseases, a link termed 'the atopic march', debate continues as to whether this represents a causal relationship. An alternative hypothesis is that this association may be related to confounding by familial factors or phenotypes that comanifest, such as early-life wheeze and sensitization. However, there is increasing evidence from longitudinal studies suggesting that the association between AD and other allergies is independent of confounding by comanifest allergic phenotypes. The hypotheses on plausible biological mechanisms for the atopic march focus on defective skin barrier function and overexpression of inflammatory mediators released by the skin affected by AD (including thymic stromal lymphopoietin). Both human and animal studies have provided evidence supporting these potential biological mechanisms. Evidence from prevention trials is now critical to establishing a causal nature of the atopic march. An emerging area of research is investigation into environmental modifiers of the atopic march. Such information will assist in identifying secondary prevention strategies to arrest the atopic march. Despite much research into the aetiology of allergies, little progress has been made in identifying effective strategies to reduce the burden of allergic conditions. In this context, the atopic march remains a promising area of investigation.

Exhaled breath condensate in pediatric asthma: promising new advance or pouring cold water on a lot of hot air? a systematic review.

BACKGROUND: Exhaled breath condensate (EBC) analysis is a simple non-invasive technique that allows repeated collection of breath samples with a minimum of inconvenience for the subject. These breath samples can potentially indicate lung disease activity and given the ease of collection, EBC is becoming a useful research tool in the study of respiratory diseases. It has the potential to be used in both population-based studies and in the context of pediatric asthma it may prove useful in diagnosis and monitoring. METHODS: A systematic review was conducted to identify studies of EBC markers in childhood asthma. RESULTS: Most of the studies were cross-sectional in design, and the results suggest that simple chemical entities such as hydrogen ions (as pH), hydrogen peroxide, and oxides of nitrogen are associated with pediatric allergic asthma and exacerbations. In addition, more complex molecules including leukotrienes, prostaglandins, and cytokines such as the interleukins IL-4 and IL-5 are also elevated in the breath of those with asthma. CONCLUSION: EBC has the potential to aid diagnosis, and to evaluate the inflammatory status of asthmatic children. Future studies may be able to refine further how best to collect EBC samples, to interpret them, and the technique has the potential to allow repeated sampling which will allow studies of natural history, pathogenesis and response to treatment to be undertaken.

Persistent pollen exposure during infancy is associated with increased risk of subsequent childhood asthma and hayfever.

BACKGROUND: Few studies have focused on pollen exposure and asthma in children. None have examined associations between persistent exposure to pollen in infancy and aeroallergen sensitisation and asthma in childhood. OBJECTIVES: To examine the association between higher ambient levels of pollen in the first 3-6 months of life and risk of eczema, sensitization to food and aeroallergens at 2 years and asthma or hayfever at age 6-7 years combined. METHODS: Using a birth cohort of 620 infants with a family history of allergic disease born between 1990 and 1994, we examined risk of eczema or allergic sensitization (SPT > 3 mm to at least one of cow's milk, egg white, peanut, house dust-mite, rye grass, and cat dander) by age 2 and asthma or hayfever at age 6-7. Daily ambient levels of pollen were measured during this period. RESULTS: Cumulative exposure to pollen concentrations up to 6 months was associated with aeroallergen sensitization with the highest risk occurring at 3 months (aOR = 1.34, 95% CI 1.06-1.72). Cumulative exposure to pollen up to 3 months was also associated with hayfever (aOR = 1.14, 95% CI 1.009-1.29) and between 4 and 6 months exposure with asthma only (aOR=1.35, 95% CI 1.07-1.72). CONCLUSION: Persistent pollen exposure in infancy appears to increase the risk of asthma and hayfever in children. These results support the hypothesis that there is a critical window of opportunity in early development which may be important for modification of allergic outcomes.

Pets at birth do not increase allergic disease in at-risk children.

BACKGROUND: The literature is contradictory concerning pet exposure and risk of allergic disease in childhood especially among those with a family history of allergy. OBJECTIVE: To investigate the relationship between cat and dog exposure at birth and allergic outcomes over the first 12 years in a birth cohort selected for familial allergy. METHODS: A prospective birth cohort of 620 infants with a family history of allergic diseases was recruited. Data on pet keeping, family demographics and cord blood samples were collected at birth. Information on childhood wheeze, eczema and hay fever was collected 18 times in the first 2 years, at 7 years and at 12 years. Skin prick tests were conducted at 2, 7 and 12 years, and in parents. Regression analyses were used to investigate the relevant associations while adjusting for potential confounders. RESULTS: Exposure to cats or dogs at birth showed a moderate reduction in risk of wheeze (aOR = 0.76; 95% CI 0.53, 1.09) and hay fever (aOR = 0.71; 0.49, 1.02) after 7 years of age. Protective effects were stronger in children of non-sensitized fathers (aOR wheeze 0.55; 0.31, 0.98; aOR hay fever 0.33; 0.15, 0.77 on exposure to cats alone, or cats or dogs at birth). Pet keeping was not related to cord blood IgE or sensitization from 2 to 12 years. CONCLUSIONS AND CLINICAL RELEVANCE: Pets at birth either decreased or had no effect on allergic disease up to age 12. We found no evidence that exposure to cats or dogs at birth increases the risk of allergic disease in high-risk children.

The role of seasonal grass pollen on childhood asthma emergency department presentations.

BACKGROUND: Few studies have focused on the role of grass pollen on asthma emergency department (ED) presentations among children. None have examined whether a dose-response effect exists between grass pollen levels and these asthma exacerbations. OBJECTIVES: To examine the association between increasing ambient levels of grass pollen and asthma ED presentations in children. To determine whether these associations are seen only after a thunderstorm, or whether grass pollen levels have a consistent influence on childhood asthma ED visits during the season. METHODS: A short time series ecological study was conducted for asthma presentations to ED among children in Melbourne, Victoria, and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine dose-response associations between daily grass pollen levels and mean daily ED attendance for asthma. RESULTS: A smoothed plot suggested a dose-response association. As ambient grass pollen increased to about 19 grains/m(3) , the same day risk of childhood ED presentations also increased linearly (P < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, P < 0.001). CONCLUSION: This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and levels of ambient grass pollen below 20 grains/m(3) , independent of any impact of thunderstorm-associated asthma. These findings have important implications for patient care, such as asthma management programs that notify the general public regarding periods of high grass pollen exposure, as well as defining the timing of initiation of pollen immunotherapy.