Chronic Bronchitis in Children and Adults: Definitions, Pathophysiology, Prevalence, Risk Factors, and Consequences

The complex nature of chronic bronchitis (CB) and changing definitions have contributed to challenges in understanding its aetiology and burden. In children, CB is characterised by persistent airway inflammation often linked to bacterial infections and is therefore termed "protracted bacterial bronchitis" (PBB). Longitudinal studies suggest that CB in childhood persists into adulthood in a subgroup. It can also be associated with future chronic respiratory diseases including asthma, bronchiectasis, and chronic obstructive pulmonary disease (COPD). Adult CB is traditionally associated with smoking, occupational exposures, and lower socioeconomic status. The interplay between risk factors, childhood CB, adult CB, and other chronic respiratory diseases is intricate, requiring comprehensive longitudinal studies for a clearer understanding of the natural history of CB across the lifespan. Such longitudinal studies have been scarce to date given the logistic challenges of maintaining them over time. In this review, we summarise current evidence on the evolution of the definitions, pathophysiology, risk factors, and consequences of childhood and adulthood chronic bronchitis.

Association between physical activity over a 10-year period and current insomnia symptoms, sleep duration and daytime sleepiness: a European population-based study

OBJECTIVES

To explore the relationship between physical activity over a 10-year period and current symptoms of insomnia, daytime sleepiness and estimated sleep duration in adults aged 39-67.

DESIGN

Population-based, multicentre cohort study.

SETTING

21 centres in nine European countries.

METHODS

Included were 4339 participants in the third follow-up to the European Community Respiratory Health Survey (ECRHS III), who answered questions on physical activity at baseline (ECRHS II) and questions on physical activity, insomnia symptoms, sleep duration and daytime sleepiness at 10-year follow-up (ECRHS III). Participants who reported that they exercised with a frequency of at least two or more times a week, for 1 hour/week or more, were classified as being physically active. Changes in activity status were categorised into four groups: persistently non-active; became inactive; became active; and persistently active.

MAIN OUTCOME MEASURES

Insomnia, sleep time and daytime sleepiness in relation to physical activity.

RESULTS

Altogether, 37% of participants were persistently non-active, 25% were persistently active, 20% became inactive and 18% became active from baseline to follow-up. Participants who were persistently active were less likely to report difficulties initiating sleep (OR 0.60, 95% CI 0.45-0.78), a short sleep duration of ≤6 hours/night (OR 0.71, 95% CI 0.59-0.85) and a long sleep of ≥9 hours/night (OR 0.53, 95% CI 0.33-0.84) than persistently non-active subjects after adjusting for age, sex, body mass index, smoking history and study centre. Daytime sleepiness and difficulties maintaining sleep were not related to physical activity status.

CONCLUSION

Physically active people have a lower risk of some insomnia symptoms and extreme sleep durations, both long and short.

Comprehensive analysis of environmental exposure to hazardous trace elements and lung function: a national cross-sectional study

BACKGROUND

There is growing interest in the joint effects of hazardous trace elements (HTEs) on lung function deficits, but the data are limited. This is a critical research gap given increased global industrialisation.

METHODS

A national cross-sectional study including spirometry was performed among 2112 adults across 11 provinces in China between 2020 and 2021. A total of 27 HTEs were quantified from urine samples. Generalised linear models and quantile-based g-computation were used to explore the individual and joint effects of urinary HTEs on lung function, respectively.

RESULTS

Overall, there were negative associations between forced expiratory volume in 1 s (FEV1) and urinary arsenic (As) (z-score coefficient, -0.150; 95% CI, -0.262 to -0.038 per 1 ln-unit increase), barium (Ba) (-0.148, 95% CI: -0.258 to -0.039), cadmium (Cd) (-0.132, 95% CI: -0.236 to -0.028), thallium (Tl) (-0.137, 95% CI: -0.257 to -0.018), strontium (Sr) (-0.147, 95% CI: -0.273 to -0.022) and lead (Pb) (-0.121, 95% CI: -0.219 to -0.023). Similar results were observed for forced vital capacity (FVC) with urinary As, Ba and Pb and FEV1/FVC with titanium (Ti), As, Sr, Cd, Tl and Pb. We found borderline associations between the ln-quartile of joint HTEs and decreased FEV1 (-20 mL, 95% CI: -48 to +8) and FVC (-14 mL, 95% CI: -49 to+2). Ba and Ti were assigned the largest negative weights for FEV1 and FVC within the model, respectively.

CONCLUSION

Our study investigating a wide range of HTEs in a highly polluted setting suggests that higher urinary HTE concentrations are associated with lower lung function, especially for emerging Ti and Ba, which need to be monitored or regulated to improve lung health.

Association of novel adult cough subclasses with clinical characteristics and lung function across six decades of life in a prospective, community-based cohort in Australia: an analysis of the Tasmanian Longitudinal Health Study (TAHS)

BACKGROUND

Cough is a common yet heterogeneous condition. Little is known about the characteristics and course of cough in general populations. We aimed to investigate cough subclasses, their characteristics from childhood across six decades of life, and potential treatable traits in a community-based cohort.

METHODS

For our analysis of the Tasmanian Longitudinal Health Study (TAHS), a prospective, community-based cohort study that began on Feb 23, 1968, and has so far followed up participants in Tasmania, Australia, at intervals of 10 years from a mean age of 7 years to a mean age of 53 years, we used data collected as part of the TAHS to distinguish cough subclasses among current coughers at age 53 years. For this analysis, participants who answered Yes to at least one cough-related question via self-report questionnaire were defined as current coughers and included in a latent class analysis of cough symptoms; participants who answered No to all nine cough-related questions were defined as non-coughers and excluded from this analysis. Two groups of longitudinal features were assessed from age 7 years to age 53 years: previously established longitudinal trajectories of FEV1, forced vital capacity [FVC], FEV1/FVC ratio, asthma, and allergies-identified via group-based trajectory analysis or latent class analysis-and symptoms at different timepoints, including asthma, current productive cough, ever chronic productive cough, current smoking, and second-hand smoking.

FINDINGS

Of 8583 participants included at baseline in the TAHS, 6128 (71·4%) were traced and invited to participate in a follow-up between Sept 3, 2012, and Nov 8, 2016; 3609 (58·9%) of these 6128 returned the cough questionnaire. The mean age of participants in this analysis was 53 years (SD 1·0). 2213 (61·3%) of 3609 participants were defined as current coughers and 1396 (38·7%) were categorised as non-coughers and excluded from the latent class analysis. 1148 (51·9%) of 2213 participants in this analysis were female and 1065 (48·1%) were male. Six distinct cough subclasses were identified: 206 (9·3%) of 2213 participants had minimal cough, 1189 (53·7%) had cough with colds only, 305 (13·8%) had cough with allergies, 213 (9·6%) had intermittent productive cough, 147 (6·6%) had chronic dry cough, and 153 (6·9%) had chronic productive cough. Compared with people with minimal cough, and in contrast to other cough subclasses, people in the chronic productive cough and intermittent productive cough subclasses had worse lung function trajectories (FEV1 persistent low trajectory 2·9%, 6·4%, and 16·1%; p=0·0011, p<0·0001; FEV1/FVC early low-rapid decline trajectory 2·9%, 12·1%, and 13·0%; p=0·012, p=0·0007) and a higher prevalence of cough (age 53 years 0·0%, 32·4% [26·1-38·7], and 50·3% [42·5-58·2]) and asthma (age 53 years 6·3% [3·7-10·6], 26·9% [21·3-33·3], and 41·7% [24·1-49·7]) from age 7 years to age 53 years.

INTERPRETATION

We identified potential treatable traits for six cough subclasses (eg, asthma, allergies, and active and passive smoking for productive cough). The required management of productive cough in primary care (eg, routine spirometry) might differ from that of dry cough if our findings are supported by other studies. Future population-based studies could apply our framework to address the heterogeneity and complexity of cough in the community.

FUNDING

The National Health and Medical Research Council of Australia, The University of Melbourne, Clifford Craig Medical Research Trust of Tasmania, Victorian Asthma Foundation, Queensland Asthma Foundation, Tasmanian Asthma Foundation, The Royal Hobart Hospital Research Foundation, the Helen MacPherson Smith Trust, GlaxoSmithKline, and the China Scholarship Council.

Can We Use Lung Function Thresholds and Respiratory Symptoms to Identify Pre-COPD? A Prospective, Population-based Cohort Study

RATIONALE

The term 'pre-COPD' refers to individuals at high-risk of developing Chronic Obstructive Pulmonary Disease (COPD) who do not meet conventional spirometric criteria for airflow obstruction. New approaches to identifying these individuals are needed, particularly in younger populations.

OBJECTIVE

To determine whether lung function thresholds and respiratory symptoms can be used to identify individuals at-risk of developing COPD.

METHODS

The Tasmanian Longitudinal Health Study is a population-based cohort first studied in 1968 (age 7). Respiratory symptoms, pre- and post-bronchodilator (BD) spirometry, diffusing capacity and static lung volumes were measured on a subgroup at age 45, and incidence of COPD was assessed at age 53. For each lung function measure, z-scores were calculated using Global Lung Initiative references. The optimal threshold for best discrimination of COPD incidence was determined by the unweighted Youden Index.

MEASUREMENTS AND MAIN RESULTS

Among 801 participants who did not have COPD at age 45, the optimal threshold for COPD incidence by age 53 was pre-BD FEV1/FVC z-score < -1.264, corresponding to the lowest 10th percentile. Those below this threshold had 36-fold increased risk of developing COPD over an eight-year follow-up period (RR 35.8, 95%CI 8.88 to 144), corresponding to a risk difference of +16.4% (95%CI 3.7-67.4). The sensitivity was 88% and specificity 87%. Positive and negative likelihood ratios were 6.79 and 0.14, respectively. Respiratory symptoms, post-BD spirometry, diffusing capacity and static lung volumes did not improve on the classification achieved by pre-BD FEV1/FVC alone.

CONCLUSION

Our findings support the inclusion of pre-BD spirometry in the physiological definition of pre-COPD and indicate that pre-BD FEV1/FVC at the 10th percentile accurately identifies individuals at high-risk of developing COPD in community-based settings.

Cough in Children and Adults: Diagnosis, Assessment and Management (CICADA). Summary of an updated position statement on chronic cough in Australia

INTRODUCTION

Cough is the most common symptom leading to medical consultation. Chronic cough results in significant health care costs, impairs quality of life, and may indicate the presence of a serious underlying condition. Here, we present a summary of an updated position statement on cough management in the clinical consultation.

MAIN RECOMMENDATIONS

Assessment of children and adults requires a focused history of chronic cough to identify any red flag cough pointers that may indicate an underlying disease. Further assessment with examination should include a chest x-ray and spirometry (when age > 6 years). Separate paediatric and adult diagnostic management algorithms should be followed. Management of the underlying condition(s) should follow specific disease guidelines, as well as address adverse environmental exposures and patient/carer concerns. First Nations adults and children should be considered a high risk group. The full statement from the Thoracic Society of Australia and New Zealand and Lung Foundation Australia for managing chronic cough is available at https://lungfoundation.com.au/resources/cicada-full-position-statement.

CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT

Algorithms for assessment and diagnosis of adult and paediatric chronic cough are recommended. High quality evidence supports the use of child-specific chronic cough management algorithms to improve clinical outcomes, but none exist in adults. Red flags that indicate serious underlying conditions requiring investigation or referral should be identified. Early and effective treatment of chronic wet/productive cough in children is critical. Culturally specific strategies for facilitating the management of chronic cough in First Nations populations should be adopted. If the chronic cough does not resolve or is unexplained, the patient should be referred to a respiratory specialist or cough clinic.

Associations of early life and childhood risk factors with obstructive sleep apnoea in middle-age

BACKGROUND AND OBJECTIVE

Early-life risk factors for obstructive sleep apnoea (OSA) are poorly described, yet this knowledge may be critical to inform preventive strategies. We conducted the first study to investigate the association between early-life risk factors and OSA in middle-aged adults.

METHODS

Data were from population-based Tasmanian Longitudinal Health Study cohort (n = 3550) followed from 1st to 6th decades of life. Potentially relevant childhood exposures were available from a parent-completed survey at age 7-years, along with previously characterized risk factor profiles. Information on the primary outcome, probable OSA (based on a STOP-Bang questionnaire cut-off ≥5), were collected when participants were 53 years old. Associations were examined using logistic regression adjusting for potential confounders. Analyses were repeated using the Berlin questionnaire.

RESULTS

Maternal asthma (OR = 1.5; 95% CI 1.1-2.0), maternal smoking (OR = 1.2; 1.05, 1.5), childhood pleurisy/pneumonia (OR = 1.3; 1.04, 1.7) and frequent bronchitis (OR = 1.2; 1.01, 1.5) were associated with probable OSA. The risk-factor profiles of 'parental smoking' and 'frequent asthma and bronchitis' were also associated with probable OSA (OR = 1.3; 1.01, 1.6 and OR = 1.3; 1.01-1.9, respectively). Similar associations were found for Berlin questionnaire-defined OSA.

CONCLUSIONS

We found novel temporal associations of maternal asthma, parental smoking and frequent lower respiratory tract infections before the age of 7 years with adult OSA. While determination of their pathophysiological and any causal pathways require further research, these may be useful to flag the risk of OSA within clinical practice and create awareness and vigilance among at-risk groups.

The longitudinal association between physical activity, strength and fitness, and lung function: A UK Biobank cohort study

BACKGROUND

While physical activity is hypothesized to slow lung-function decline, the evidence is limited at a population level. This study investigated the longitudinal association between physical activity and related measures (grip strength, cardiovascular fitness) and lung function decline.

METHODS

20,111 UK Biobank cohort participants with lung function measures at baseline (2006-2010) and follow-up (2012-2014) were included. Physical activity (International Physical Activity Questionnaire: low, moderate, high categories), grip strength (dynamometer) and cardiovascular fitness (subsample, submaximal stationary bicycle) data were collected. Linear regression was utilized to assess the effect on follow-up FEV1, FVC, FEV1/FVC ratio (as decline in ml/yr and as z-scores) adjusting for baseline lung function and confounders.

RESULTS

After 6.3 years mean follow-up, the decline in mean FEV1 and FVC was 30 ml/year and 38 ml/year respectively (n = 20,111). Consistent low physical activity (across baseline and follow-up) was associated with accelerated decline in FEV1 z-score (-0.119, 95 % Confidence Interval (CI) -0.168, -0.071, n = 16,900) and FVC z-score (-0.133, 95%CI -0.178, -0.088, n = 16,832). Accelerated decline in FEV1 z-scores was observed with decreasing baseline grip strength (-0.029, -95%CI -0.034, -0.024, n = 19,903), and with less strong evidence, decreasing fitness (-0.024, 95%CI -0.070, 0.022, n = 3048).

CONCLUSION

This is the largest ever study to date to identify that lower physical activity, grip strength, and potentially cardiovascular fitness over time is associated with accelerated lung function decline. Although the effect sizes appear modest, such changes at population levels can have a substantial overall impact. This study provides evidence for adding 'lung health benefits' to the current physical activity guidelines.

Longitudinal risk factors for obstructive sleep apnea: A systematic review

Despite substantial disease burden, existing evidence on the risk factors for obstructive sleep apnea (OSA) have been derived primarily from cross-sectional studies without determining temporality. Therefore, we aimed to systematically synthesize the literature on longitudinal risk factors for sleep study-assessed OSA and questionnaire-assessed probable OSA from cohort studies in the general adult population settings. We systematically searched Embase and Medline (on OVID) databases. Eleven studies met the inclusion criteria. Meta-analyses were not conducted due to methodological heterogeneity of exposure and outcome measurements. There was consistent evidence that weight gain was associated with incident (n = 2) and greater severity (n = 2) of OSA. One study each observed an association of higher baseline body-mass index, male sex, asthma, a specific genetic polymorphism in rs12415421, and insulin resistance/hyperglycemia, with incident OSA. Long-term exposure to ambient air pollution (NO2, n = 1) was associated with OSA, and menopausal transitions (n = 1) with higher apnea-hypopnea index. There were no eligible studies on long-term smoking or alcohol use. In conclusion, approximately 10% increase in weight, especially in males, might alert clinicians to consider potential or worsening OSA. Large, well-designed longitudinal studies are needed to consolidate knowledge on other associations with OSA development, especially on potentially modifiable risk factors.

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.

Longitudinal Asthma Phenotypes from Childhood to Middle-Age: A Population-based Cohort Study

Rationale: Asthma is a heterogeneous condition, and longitudinal phenotyping may provide new insights into the origins and outcomes of the disease. Objectives: We aimed to characterize the longitudinal phenotypes of asthma between the first and sixth decades of life in a population-based cohort study. Methods: Respiratory questionnaires were collected at seven time points in the TAHS (Tasmanian Longitudinal Health Study) when participants were aged 7, 13, 18, 32, 43, 50, and 53 years. Current-asthma and ever-asthma status was determined at each time point, and group-based trajectory modeling was used to characterize distinct longitudinal phenotypes. Linear and logistic regression models were fitted to investigate associations of the longitudinal phenotypes with childhood factors and adult outcomes. Measurements and Main Results: Of 8,583 original participants, 1,506 had reported ever asthma. Five longitudinal asthma phenotypes were identified: early-onset adolescent-remitting (40%), early-onset adult-remitting (11%), early-onset persistent (9%), late-onset remitting (13%), and late-onset persistent (27%). All phenotypes were associated with chronic obstructive pulmonary disease at age 53 years, except for late-onset remitting asthma (odds ratios: early-onset adolescent-remitting, 2.00 [95% confidence interval (CI), 1.13-3.56]; early-onset adult-remitting, 3.61 [95% CI, 1.30-10.02]; early-onset persistent, 8.73 [95% CI, 4.10-18.55]; and late-onset persistent, 6.69 [95% CI, 3.81-11.73]). Late-onset persistent asthma was associated with the greatest comorbidity at age 53 years, with increased risk of mental health disorders and cardiovascular risk factors. Conclusions: Five longitudinal asthma phenotypes were identified between the first and sixth decades of life, including two novel remitting phenotypes. We found differential effects of these phenotypes on risk of chronic obstructive pulmonary disease and nonrespiratory comorbidities in middle age.

The effect of early childhood respiratory infections and pneumonia on lifelong lung function: a systematic review

Early childhood respiratory infections, including pneumonia, are an important global public health issue, with more than 40 million annual cases resulting in approximately 650 000 deaths. A growing number of published studies have examined the effects of early childhood lower respiratory tract infections (LRTIs) or pneumonia on lung function, particularly as part of large early-life exposure studies. To our knowledge, there is no published systematic review of these data. We searched PubMed, Embase, and Web of Science for studies published between database inception and May 12, 2022. Case-control, cohort, and cross-sectional studies were included if they reported forced expiratory volume in 1 s (FEV1) or forced vital capacity (FVC) values of participants older than 5 years. Article titles and abstracts were screened in Rayyan before retrieval, assessment, and data extraction of the full text. Primary outcome measures were differences in mean FEV1 or FVC values between exposed groups (ie, children aged ≤5 years with LRTIs) and non-exposed groups. This study is registered with PROSPERO, CRD42021265295. Database searches yielded 3070 articles, and 14 studies were included in this systematic review, providing a total of 23 276 participants, including 9969 children and 13 307 adults. Eight of 14 articles reported significant reductions in FEV1 values, and six of 12 studies reported reductions in FVC values in children and adults with a history of early childhood LRTIs or pneumonia, compared with unexposed controls (p<0·05). Most studies reporting reductions in lung function described deficits consistent with a restrictive spirometry pattern. Only two of 14 studies reported data from low-income and middle-income countries or disadvantaged populations in middle-income and high-income countries, and there were scarce data available on the effect of LRTI severity and recurrence on lung function. LRTIs in early childhood could be associated with a restrictive spirometry pattern in later childhood and adulthood. Data are needed from low-income and middle-income nations, and from disadvantaged populations in middle-income and high-income countries in which early childhood respiratory infection burden is disproportionately high. Data are also needed on the effect of LRTI severity and recurrence on future lung function.

Life course BMI trajectories from childhood to mid-adulthood are differentially associated with anxiety and depression outcomes in middle age

BACKGROUND/OBJECTIVE

Obesity is a risk factor for multimorbidity, including depression and possibly anxiety. However, it is currently unclear how patterns of change in BMI over the life course differentially influence the magnitude in risk of depression and anxiety in mid-adulthood. We aimed to examine associations between BMI trajectories from childhood to adulthood and the risk of depression and anxiety in middle age.

METHODS

In the Tasmanian Longitudinal Health Study (n = 2416), five distinct BMI trajectories were previously defined from age 5 to 45 years using group-based modelling. At age 53, current depression and anxiety were assessed using the Patient Health Questionnaire and the Generalized Anxiety Disorder scale, respectively. Logistic regression models adjusted for potential confounders estimated associations between BMI trajectories and these outcomes.

RESULTS

Those belonging to the child average-increasing (OR = 2.24; 95%CI: 1.24, 4.06) and persistently high (OR = 2.64; 1.26, 5.52) trajectories were more likely to have depression in middle age, compared to the persistently average trajectory. However, the odds of experiencing greater severity of depressive symptoms was highest in the child average-increasing group (OR = 2.36; 1.59, 3.49). Despite finding no evidence of association between BMI trajectories and current anxiety, we observed less severe symptoms in the child high-decreasing trajectory (OR = 0.68; 0.51, 0.91).

CONCLUSION

We found an increased risk of depression in middle age among individuals with a persistently high BMI from childhood to mid-adulthood and individuals with an average BMI in childhood which then increased consistently throughout adulthood. Encouragingly, resolving childhood adiposity by adulthood was associated with lesser anxiety symptoms. Taken together, these findings highlight the need to target mental health screening and treatment towards high-risk BMI trajectory groups and the importance of early interventions to prevent and resolve excess weight.

Biomarkers of asthma relapse and lung function decline in adults with spontaneous asthma remission: A population-based cohort study

BACKGROUND

The extent to which biomarkers of asthma activity persist in spontaneous asthma remission and whether such markers are associated with future respiratory outcomes remained unclear. We investigated the association between sub-clinical inflammation in adults with spontaneous asthma remission and future asthma relapse and lung function decline.

METHODS

The Tasmanian Longitudinal Health Study is a population-based cohort (n = 8583). Biomarkers of systemic inflammation were measured on participants at age 45, and latent profile analysis was used to identify cytokine profiles. Bronchial hyperresponsiveness (BHR) and nitric oxide products in exhaled breath condensate (EBC NOx) were measured at age 50. Participants with spontaneous asthma remission at ages 45 (n = 466) and 50 (n = 318) were re-evaluated at age 53, and associations between baseline inflammatory biomarkers and subsequent asthma relapse and lung function decline were assessed.

RESULTS

We identified three cytokine profiles in adults with spontaneous asthma remission: average (34%), Th2-high (42%) and Th2-low (24%). Compared to the average profile, a Th2-high profile was associated with accelerated decline in post-BD FEV1 /FVC (MD -0.18% predicted per-year; 95% CI -0.33, -0.02), while a Th2-low profile was associated with accelerated decline in both post-BD FEV1 (-0.41%; -0.75, -0.06) and post-BD FVC (-0.31%; -0.62, 0.01). BHR and high TNF-α during spontaneous remission were associated with an increased risk of asthma relapse. In contrast, we found no evidence of association between EBC NOx and either asthma relapse or lung function decline.

CONCLUSION

BHR and serum inflammatory cytokines have prognostic value in adults with spontaneous asthma remission. At-risk individuals with BHR, Th2-high or Th2-low cytokine profiles may benefit from closer monitoring and on-going follow-up.

Lifetime spirometry patterns of obstruction and restriction, and their risk factors and outcomes: a prospective cohort study

BACKGROUND

Interest in lifetime lung function trajectories has increased in the context of emerging evidence that chronic obstructive pulmonary disease (COPD) can arise from multiple disadvantaged lung function pathways, including those that stem from poor lung function in childhood. To our knowledge, no previous study has investigated both obstructive and restrictive lifetime patterns concurrently, while accounting for potential overlaps between them. We aimed to investigate lifetime trajectories of the FEV₁/forced vital capacity (FVC) ratio, FVC, and their combinations, relate these combined trajectory groups to static lung volume and gas transfer measurements, and investigate both risk factors for and consequences of these combined trajectory groups.

METHODS

Using z scores from spirometry measured at ages 7, 13, 18, 45, 50, and 53 years in the Tasmanian Longitudinal Health Study (n=2422), we identified six FEV₁/FVC ratio trajectories and five FVC trajectories via group-based trajectory modelling. Based on whether trajectories of the FEV₁/FVC ratio and FVC were low (ie, low from childhood or adulthood) or normal, four patterns of lifetime spirometry obstruction or restriction were identified and compared against static lung volumes and gas transfer. Childhood and adulthood characteristics and morbidities of these patterns were investigated.

FINDINGS

The prevalence of the four lifetime spirometry patterns was as follows: low FEV₁/FVC ratio only, labelled as obstructive-only, 25·8%; low FVC only, labelled as restrictive-only, 10·5%; both low FEV₁/FVC ratio and low FVC, labelled as mixed, 3·5%; and neither low FEV₁/FVC ratio nor low FVC, labelled as reference, 60·2%. The prevalence of COPD at age 53 years was highest in the mixed pattern (31 [37%] of 84 individuals) followed by the obstructive-only pattern (135 [22%] of 626 individuals). Individuals with the mixed pattern also had the highest prevalence of parental asthma, childhood respiratory illnesses, adult asthma, and depression. Individuals with the restrictive-only pattern had lower total lung capacity and residual volume, and had the highest prevalence of childhood underweight, adult obesity, diabetes, cardiovascular conditions, hypertension, and obstructive sleep apnoea.

INTERPRETATION

To our knowledge, this is the first study to characterise lifetime phenotypes of obstruction and restriction simultaneously using objective data-driven techniques and unique life course spirometry measures of FEV₁/FVC ratio and FVC from childhood to middle age. Mixed and obstructive-only patterns indicate those who might benefit from early COPD interventions. Those with the restrictive-only pattern had evidence of true lung restriction and were at increased risk of multimorbidity by middle age.

FUNDING

National Health and Medical Research Council of Australia, The University of Melbourne, Clifford Craig Medical Research Trust of Tasmania, The Victorian, Queensland & Tasmanian Asthma Foundations, The Royal Hobart Hospital, Helen MacPherson Smith Trust, and GlaxoSmithKline.

Epidemiology of eczema in South-Eastern Australia

BACKGROUND/OBJECTIVES

Eczema is a common chronic debilitating skin condition in childhood. Data on the epidemiology and natural history of eczema across the life course are lacking. This analysis aimed to describe these epidemiological features in Australian children and adults.

METHODS

Data collected on eczema from four Australian cohort studies were analysed: namely HealthNuts, Melbourne Atopic Cohort Study (MACS), Tasmanian Longitudinal Health Study (TAHS) and the Australian arm of the European Community Respiratory Health Survey (ECRHS).

RESULTS

Among children aged under 6 years, 28.8%-35.6% have ever-had eczema, and 16.7%-26.6% had 'current eczema'. Among those aged 6-12 years, 14.6%-24.7% had 'current eczema' with 12.0%-18.5% of those at ages of 6 and 10 years classified as having moderate-to-severe eczema according to the Scoring of Atopic Dermatitis (SCORAD) index. In adults, the prevalence of 'eczema ever' ranged between 13.8% and 48.4%. The 12-month period prevalence of eczema was 15.1% at age 18, while current eczema was 8.5% at an average age of 51, and 8.8% at an average age 53 years. Eczema was more common among young boys, but this difference became non-significant for older children and early adolescents. In contrast, eczema was more common for adult women than men.

CONCLUSIONS

Eczema is common both in children and adults. The proportion of severe eczema in children was substantial.

Early life respiratory infections and pre-adult asthma: could there be an interaction and differential misclassification?

We read the manuscript by van Meelet al. [1] with interest as they have investigated the relationship between early-life infection and both later asthma and lower lung function in school-aged children of the general population, to address an internationally recognised research gap. Using primary data from 150 090 children from 38 participating pregnancy and birth cohorts across Europe, mainly from the EU Child Cohort Network [2], the authors grouped several different types of upper (URTIs) and lower respiratory tract infections (LRTIs) separately as binary exposures and then meta-analysed the individual participant data. Specifically in reference to school-aged asthma, table 3 summarised the positive associations for early-life respiratory infection, which were highest for LRTIs within the stratum of participants without early-life wheezing (i.e. statistically significant 2.1- to 2.7-fold increases in the odds), followed by LRTIs with early-life wheezing (i.e. significant 1.4- to 1.9-fold increases in the odds), URTIs without early-life wheezing (i.e. significant 1.1- to 1.2-fold increases in the odds), and URTIs with early-life wheezing (i.e. generally non-significant 1.0- to 1.2-fold increases in the odds).

Further analyses to clarify the clinical and public health messages for early-life upper respiratory tract infections are suggested to better inform parents and the healthcare professionals who look after these children in the general communityhttps://bit.ly/3xAWxz0

Childhood 'bronchitis' and respiratory outcomes in middle-age: a prospective cohort study from age 7 to 53 years

Background

Chronic bronchitis in childhood is associated with a diagnosis of asthma and/or bronchiectasis a few years later, however, consequences into middle-age are unknown.

Objective

To investigate the relationship between childhood bronchitis and respiratory-related health outcomes in middle-age.

Design

Cohort study from age 7 to 53 years.

Setting

General population of European descent from Tasmania, Australia.

Participants

3202 participants of the age 53-year follow-up (mean age 53, range 51–55) of the Tasmanian Longitudinal Health Study cohort who were born in 1961 and first investigated at age 7 were included in our analysis.

Statistical methods

Multivariable linear and logistic regression. The association between parent reported childhood bronchitis up to age 7 and age 53-year lung conditions (n=3202) and lung function (n=2379) were investigated.

Results

Among 3202 participants, 47.5% had one or more episodes of childhood bronchitis, classified according to severity based on the number of episodes and duration as: ‘non-recurrent bronchitis’ (28.1%); ‘recurrent non-protracted bronchitis’ (18.1%) and ‘recurrent-protracted bronchitis’ (1.3%). Age 53 prevalence of doctor-diagnosed asthma and pneumonia (p-trend <0.001) and chronic bronchitis (p-trend=0.07) increased in accordance with childhood bronchitis severities. At age 53, ‘recurrent-protracted bronchitis’ (the most severe subgroup in childhood) was associated with doctor-diagnosed current asthma (OR 4.54, 95% CI 2.31 to 8.91) doctor-diagnosed pneumonia (OR=2.18 (95% CI 1.00 to 4.74)) and, paradoxically, increased transfer factor for carbon monoxide (z-score +0.51 SD (0.15–0.88)), when compared with no childhood bronchitis.

Conclusion

In this cohort born in 1961, one or more episodes of childhood bronchitis was a frequent occurrence. ‘Recurrent-protracted bronchitis’, while uncommon, was especially linked to multiple respiratory outcomes almost five decades later, including asthma, pneumonia and raised lung gas transfer. These findings provide insights into the natural history of childhood ‘bronchitis’ into middle-age.

Children With Food Allergy Are at Risk of Lower Lung Function on High-Pollen Days

BACKGROUND

Grass pollen exposure is a risk factor for childhood asthma hospital attendances. However, its short-term influence on lung function, especially among those with other allergic conditions, has been less well-studied.

OBJECTIVE

To investigate this association in a population-based sample of children.

METHODS

Within the HealthNuts cohort, 641 children performed spirometry during the grass pollen season. Grass pollen concentration was considered on the day of testing (lag 0), up to 3 days before (lag 1-lag 3), and cumulatively (lag 0-3). We used linear regression to assess the relevant associations and examined potential interactions with current asthma, hay fever or eczema, and food allergy.

RESULTS

Associations were observed only in children with allergic disease (P value for interaction ≤ 0.1). In children with food allergy, grass pollen concentration was associated with a lower ratio of forced expiratory volume in 1 second to forced vital capacity (FEV₁/FVC) and lower mid-forced expiratory flows (FEF_25%-75%) at all lags (eg, at lag 2, FEV₁/FVC z-score = -0.50 [95% CI -0.80 to -0.20] and FEF_25%--75% z-score = -0.40 [-0.60 to -0.04] per 20 grains/m³ pollen increase), and increased bronchodilator responsiveness (BDR) at lag 2 and lag 3 (eg, at lag 2, BDR = (31 [95% CI -0.005 to 62] mL). In children with current asthma, increasing grass pollen concentration was associated with lower FEF_25%-75% and increased BDR, whereas children with current hay fever or eczema had increased BDR only.

CONCLUSIONS

A proactive approach needs to be enforced to manage susceptible children, especially those with food allergy, before high-grass pollen days.

Establishing subclasses of childhood eczema, their risk factors and prognosis

Background

The heterogeneity of development and progression of eczema suggests multiple underlying subclasses for which aetiology and prognosis may vary. A better understanding may provide a comprehensive overview of eczema development and progression in childhood. Thus, we aimed to determine longitudinal eczema subclasses based on assessments and identify their associations with risk factors and allergic outcomes.

Methods

A total of 619 participants with a family history of allergic disease were assessed at 24 time‐points from birth to 12 years. At each time, eczema was defined as the report of current rash treated with topical steroid‐based preparations. Longitudinal latent class analysis was used to determine eczema subclasses. Subsequent analyses using regression models assessed the associations between eczema subclasses and potential risk factors and allergic outcomes at 18‐ and 25‐year follow‐ups (eczema, allergic rhinitis, asthma and allergic sensitization).

Results

We identified five eczema subclasses ‘early‐onset persistent’, ‘early‐onset resolving’, ‘mid‐onset persistent’, ‘mid‐onset resolving’ and ‘minimal eczema’. Filaggrin null mutations were associated with the early‐onset persistent (OR = 2.58 [1.09–6.08]) and mid‐onset persistent class (OR = 2.58 [1.32–5.06]). Compared with ‘minimal eczema’, participants from early‐onset persistent class had higher odds of eczema (OR = 11.8 [5.20–26.6]) and allergic rhinitis (OR = 3.13 [1.43–6.85]) at 18 and at 25 years eczema (OR = 9.37 [3.17–27.65]), allergic rhinitis (OR = 3.26 [1.07–9.93]) and asthma (OR = 2.91 [1.14–7.43]). Likewise, mid‐onset persistent class had higher odds of eczema (OR = 2.59 [1.31–5.14]), allergic rhinitis (OR = 1.70 [1.00–2.89]) and asthma (OR = 2.00 [1.10–3.63]) at 18 and at 25 years eczema (OR = 6.75 [3.11–14–65]), allergic rhinitis (OR = 2.74 [1.28–5.88]) and asthma (OR = 2.50 [1.25–5.00]). Allergic and food sensitization in early life was more common in those in the persistent eczema subclasses.

Conclusion

We identified five distinct eczema subclasses. These classes were differentially associated with risk factors, suggesting differences in aetiology, and also with the development of allergic outcomes, highlighting their potential to identify high‐risk groups for close monitoring and intervention.

Impact of lifetime body mass index trajectories on the incidence and persistence of adult asthma

BACKGROUND

High body mass index trajectories from childhood to adulthood are associated with development of some chronic diseases, but whether such trajectories influence adult asthma has not been investigated to date. Therefore, we investigated associations between body mass index trajectories from childhood to middle age (5-43 years) and incidence, persistence, and relapse of asthma from ages 43 to 53 years.

METHODS

In the Tasmanian Longitudinal Health Study (n= 4194), weight and height were recorded at 8-time points between 5 and 43 years. body mass index trajectories were developed using group-based trajectory modelling. Associations between body mass index trajectories and asthma incidence, persistence, and relapse from 43 to 53 years; bronchial hyper-responsiveness at 50 years; and bronchodilator responsiveness at 53 years were modelled using multiple logistic and linear regression.

RESULTS

Five distinct body mass index trajectories were identified: average, low, high, child high-decreasing, and child average-increasing. Compared to the average trajectory, child average-increasing and high trajectories were associated with increased risk of incident asthma (OR=2.6; 95%CI 1.1, 6.6 and OR=4.4; 1.7, 11.4, respectively) and bronchial hyper-responsiveness in middle age (OR= 2.9; 1.1, 7.5 and OR= 3.5;1.1, 11.4, respectively). No associations were observed for asthma persistence or relapse.

CONCLUSION

Participants with child average-increasing and high body mass index trajectories from childhood to middle age were at higher risk of incident adult asthma. Thus, encouraging individuals to maintain normal body mass index over the life course may help reduce the burden of adult asthma.

Parental preconception BMI trajectories from childhood to adolescence and asthma in the future offspring

BACKGROUND

Recent evidence suggests that parental exposures before conception can increase the risk of asthma in offspring.

OBJECTIVE

We investigated the association between parental preconception Body Mass Index (BMI) trajectories from childhood to adolescence and subsequent risk of asthma in their offspring.

METHODS

Using group-based trajectory modeling from the Tasmanian Longitudinal Health Study (TAHS), we identified BMI trajectories for index participants (parents) when aged 4 to 15 years. Multinomial regression models adjusted for potential confounders were utilized to estimate the association between these early-life parental BMI trajectories and asthma phenotypes in their subsequent offspring.

RESULTS

The main analysis included 1822 parents and 4208 offspring. Four BMI trajectories from age 4 to 15 years were identified as the best fitting model: "low" (8.8%); "normal" (44.1%); "above normal" (40.2%); and "high" (7.0%). Associations were observed between father's "high" BMI trajectory and risk of asthma in offspring before the age of 10 years (RRR=1.70, 95%CI 0.98, 2.93) and also asthma ever (RRR=1.72, 95%CI 1.00, 2.97), especially allergic asthma ever (RRR=2.05, 95%CI 1.12, 3.72). These associations were not mediated by offspring birth weight. No associations were observed for maternal BMI trajectories and offspring asthma phenotypes.

CONCLUSION

This cohort study over six decades of life and across two generations suggests that the "high BMI" trajectory in fathers, well before conception, increased the risk of asthma in their offspring.

Ten-year prediction model for post-bronchodilator airflow obstruction and early detection of COPD: development and validation in two middle-aged population-based cohorts

Background

Classifying individuals at high chronic obstructive pulmonary disease (COPD)-risk creates opportunities for early COPD detection and active intervention.

Objective

To develop and validate a statistical model to predict 10-year probabilities of COPD defined by post-bronchodilator airflow obstruction (post-BD-AO; forced expiratory volume in 1 s/forced vital capacity<5th percentile).

Setting

General Caucasian populations from Australia and Europe, 10 and 27 centres, respectively.

Participants

For the development cohort, questionnaire data on respiratory symptoms, smoking, asthma, occupation and participant sex were from the Tasmanian Longitudinal Health Study (TAHS) participants at age 41–45 years (n=5729) who did not have self-reported COPD/emphysema at baseline but had post-BD spirometry and smoking status at age 51–55 years (n=2407). The validation cohort comprised participants from the European Community Respiratory Health Survey (ECRHS) II and III (n=5970), restricted to those of age 40–49 and 50–59 with complete questionnaire and spirometry/smoking data, respectively (n=1407).

Statistical method

Risk-prediction models were developed using randomForest then externally validated.

Results

Area under the receiver operating characteristic curve (AUC_ROC) of the final model was 80.8% (95% CI 80.0% to 81.6%), sensitivity 80.3% (77.7% to 82.9%), specificity 69.1% (68.7% to 69.5%), positive predictive value (PPV) 11.1% (10.3% to 11.9%) and negative predictive value (NPV) 98.7% (98.5% to 98.9%). The external validation was fair (AUC_ROC 75.6%), with the PPV increasing to 17.9% and NPV still 97.5% for adults aged 40–49 years with ≥1 respiratory symptom. To illustrate the model output using hypothetical case scenarios, a 43-year-old female unskilled worker who smoked 20 cigarettes/day for 30 years had a 27% predicted probability for post-BD-AO at age 53 if she continued to smoke. The predicted risk was 42% if she had coexistent active asthma, but only 4.5% if she had quit after age 43.

Conclusion

This novel and validated risk-prediction model could identify adults aged in their 40s at high 10-year COPD-risk in the general population with potential to facilitate active monitoring/intervention in predicted ‘COPD cases’ at a much earlier age.

Risk factors for chronic cough in adults: A systematic review and meta-analysis

Despite the challenges of diagnosing and managing adult patients with chronic cough, a systematic synthesis of evidence on aetiological risk factor is lacking. We systematically searched PubMed and EMBASE to synthesize the current evidence for longitudinal associations between a wide range of risk factors and chronic cough in the general adult population, following the meta-analysis of observational studies in epidemiology (MOOSE) guidelines. The Newcastle-Ottawa scale was used to assess the quality of the included studies. Fixed-effect meta-analysis was conducted where appropriate. Of 26 eligible articles, 16 domains of risk factors were assessed. There was consistent evidence that asthma (pooled adjusted OR [aOR] = 3.01; 95% CI: 2.33-3.70; I²  = 0%; number of articles [N] = 3) and low education levels/socioeconomic status (SES) (pooled aOR = 1.46; 95% CI: 1.20-1.72; I²  = 0%; N = 3) were associated with an increased risk of chronic cough after adjusting for smoking and other confounders. While continuous smoking was associated with chronic cough (aOR = 1.81; 95% CI: 1.36-2.26; I²  = 57%; N = 3), there was too little evidence to draw conclusions for occupational exposures, outdoor air pollution, early-life exposures, diet, snoring and other chronic conditions, including obesity, chronic obstructive pulmonary disease, gastro-oesophageal reflux disease and chronic pain. Asthma, persistent smoking and lower education/SES were associated with an increased risk of chronic cough. Longitudinal associations between other factors frequently mentioned empirically (i.e., occupational exposures, air pollution and chronic respiratory conditions) need further investigation, ideally with objective and standardized measurement.

Childhood lung function as a determinant of menopause-dependent lung function decline

RATIONALE

The naturally occurring age-dependent decline in lung function accelerates after menopause, likely due to the change of the endocrine balance. Although increasing evidence shows suboptimal lung health in early life can increase adult  susceptibility to insults, the potential effect of poor childhood lung function on menopause-dependent lung function decline has not yet been investigated.

OBJECTIVES

To study whether menopause-dependent lung function decline, assessed as forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), is determined by childhood lung function.

METHODS

The Tasmanian Longitudinal Health Study, a cohort born in 1961, underwent spirometry at age seven.  At ages 45 and 50 serum samples, spirometry and questionnaire data were collected (N = 506). We measured follicle stimulating and luteinizing hormones to determine menopausal status using latent profile analysis. The menopause-dependent lung function decline was investigated using linear mixed models, adjusted for anthropometrics, occupational level, smoking, asthma, asthma medication and study year, for the whole study population and stratified by tertiles of childhood lung function.

MEASUREMENTS AND MAIN RESULTS

The overall menopause-dependent lung function decline was 19.3 mL/y (95%CI 2.2 to 36.3) for FVC and 9.1 mL/y (-2.8 to 21.0) for FEV1. This was most pronounced (pinteraction=0.03) among women within the lowest tertile of childhood lung function [FVC 22.2 mL/y (1.1 to 43.4); FEV1 13.9 mL/y (-1.5 to 29.4)].

CONCLUSIONS

Lung function declines especially rapidly in postmenopausal women who had poor low lung function in childhood. This provides novel insights into respiratory health during reproductive aging and emphasizes the need for holistic public health strategies covering the whole lifespan.

Lung function trajectory and biomarkers in the Tasmanian Longitudinal Health Study

Background and objective

Different lung function trajectories through life can lead to COPD in adulthood. This study investigated whether circulating levels of biomarkers can differentiate those with accelerated (AD) from normal decline (ND) trajectories.

Methods

The Tasmanian Longitudinal Health Study (TAHS) is a general population study that measured spirometry and followed up participants from ages 7 to 53 years. Based on their forced expiratory volume in 1 s (FEV₁) trajectories from age 7 to 53 years, this analysis included those with COPD at age 53 years (60 with AD and 94 with ND) and controls (n=720) defined as never-smokers with an average FEV₁ trajectory. Circulating levels of selected biomarkers determined at 53 and 45 years of age were compared between trajectories.

Results

Results showed that CC16 levels (an anti-inflammatory protein) were lower and C-reactive protein (CRP) (a pro-inflammatory marker) higher in the AD than in the ND trajectory. Higher CC16 levels were associated with a decreased risk of belonging to the AD trajectory (OR=0.79 (0.63-0.98) per unit increase) relative to ND trajectory. Higher CRP levels were associated with an increased risk of belonging to the AD trajectory (OR=1.07, 95% CI: 1.00-1.13, per unit increase). Levels of CC16 (area under the curve (AUC)=0.69, 95% CI: 0.56-0.81, p=0.002), CRP (AUC=0.63, 95% CI: 0.53-0.72, p=0.01) and the combination of both (AUC=0.72, 95% CI: 0.60-0.83, p<0.001) were able to discriminate between the AD and ND trajectories. Other quantified biomarkers (interleukin (IL)-4, IL-5, IL-6, IL-10 and tumour necrosis factor-α (TNF-α)) were not significantly different between AD, ND and controls.

Conclusions

Circulating levels of CRP and CC16 measured in late adulthood identify different lung function trajectories (AD versus ND) leading to COPD at age 53 years.

Predictors of lung function trajectories in population-based studies: A systematic review

Despite the growing body of evidence on lung function trajectories over the life course and their risk factors, the literature has not been systematically synthesized. Publications related to lung function trajectories were identified from PubMed, EMBASE and CINAHL databases. Two authors independently identified publications for inclusion according to predefined selection criteria. Studies that modelled lung function trajectories and reported associated exposures were included. Meta-analyses could not be conducted due to heterogeneity in the exposures and methods used to model lung function trajectories. Nine publications were eligible for inclusion of which four used group-based trajectory modelling to model lung function trajectories, while five used latent profile analysis. Studies with repeated lung function measurements over the life course identified more trajectories than others. Only one study spanning from childhood to middle age reported catch-up trajectory. The following childhood risk factors for subnormal lung function trajectories were observed in at least across two studies: low birth weight, early wheezing, asthma, allergic sensitization, eczema, allergic rhinitis, lower respiratory tract infections, family history of asthma and second-hand smoke exposure. Adult active asthma and personal cigarette smoking were observed to be associated with accelerated decline lung trajectories. Our review identified 10 risk factors associated with the growth, catch-up, reduced plateau and decline trajectories of lung function. Intervention directed at childhood asthma and infections, and tobacco smoke exposure at all ages would help promote lung health and prevent subnormal lung function trajectories.

Association of demographic, career, and lifestyle factors with resilience and association of resilience with mental health outcomes in veterinarians in Canada

OBJECTIVE

To investigate the association of demographic, career, and lifestyle factors with resilience and the association of resilience with mental health outcomes in Canadian veterinarians.

SAMPLE

1,130 veterinarians in clinical practice across Canada.

PROCEDURES

An online questionnaire was used to collect participant data and included 5 validated psychometric scales to evaluate resilience (through the Connor-Davidson Resilience Scale [CD-RISC]), perceived stress (through the Perceived Stress Scale), emotional distress (through the Hospital Anxiety and Depression Scale), burnout (through the Maslach Burnout Inventory), and secondary traumatic stress (through the Professional Quality of Life Scale). A multivariable linear regression model was used to investigate associations between CD-RISC scores and demographic, career, and lifestyle characteristics. Univariable linear regression models were used to assess the relationship between resilience scores and other mental health outcomes.

RESULTS

The strongest positive association was between CD-RISC score and overall health. The level of satisfaction with support from friends and workplace resources had positive associations with the CD-RISC score. The presence of mental illness had the strongest negative association with the CD-RISC score. Being married, working in a small animal practice, or having an associate role were negatively associated with the CD-RISC score. The CD-RISC score had negative associations with scores for perceived stress, anxiety, depression, burnout, and secondary traumatic stress.

CONCLUSIONS AND CLINICAL RELEVANCE

Models provided evidence for the role of resilience in protecting against negative mental health outcomes in veterinarians. Both personal and workplace factors were associated with resilience, presenting opportunities for intervention at each of these levels.

Is short-term exposure to grass pollen adversely associated with lung function and airway inflammation in the community?

BACKGROUND

The association between grass pollen exposure and early markers of asthma exacerbations such as lung function changes and increase in airway inflammation is limited. We investigated the associations between short-term grass pollen exposure and lung function and airway inflammation in a community-based sample, and whether any such associations were modified by current asthma, current hay fever, pollen sensitization, age, and other environmental factors.

METHODS

Cross-sectional and short-term analyses of data from the Melbourne Atopy Cohort Study (MACS) participants (n = 936). Lung function was assessed using spirometry. Airway inflammation was assessed by fractional exhaled nitric oxide (FeNO) and exhaled breath condensate pH and nitrogen oxides (NOx). Daily pollen counts were collected using a volumetric spore trap. The associations were examined by linear regression.

RESULTS

Higher ambient levels of grass pollen 2 days before (lag 2) were associated with lower mid-forced expiratory flow (FEF_25%-75% ) and FEV₁ /FVC ratio (Coef. [95% CI] = -119 [-226, -11] mL/s and -1.0 [-3.0, -0.03] %, respectively) and also 3 days before (lag 3). Increased levels of grass pollen a day before (lag 1) were associated with increased FeNO (4.35 [-0.1, 8.7] ppb) and also at lag 2. Adverse associations between pollen and multiple outcomes were greater in adults with current asthma, hay fever, and pollen sensitization.

CONCLUSION

Grass pollen exposure was associated with eosinophilic airway inflammation 1-2 days after exposure and airway obstruction 2-3 days after exposure. Adults and individuals with asthma, hay fever, and pollen sensitization may be at higher risk.

Does the use of inhaled corticosteroids in asthma benefit lung function in the long-term? A systematic review and meta-analysis

While asthma is known to be associated with an increased risk of progressive lung function impairments and fixed airflow obstruction, there is ongoing debate on whether inhaled corticosteroids (ICS) modify these long-term risks. Searches were performed of the PubMed, Embase and CENTRAL databases up to 22 July 2019 for studies with follow-up ≥1 year that investigated the effects of maintenance ICS on changes in lung function in asthma.Inclusion criteria were met by 13 randomised controlled trials (RCTs) (n=11 678) and 11 observational studies (n=3720). Median (interquartile range) follow-up was 1.0 (1-4) and 8.4 (3-28) years, respectively. In the RCTs, predominantly in individuals with mild asthma, ICS use was associated with improved pre-bronchodilator (BD) forced expiratory volume in 1 s (FEV1) across all age groups (2.22% predicted (95% CI 1.32-3.12), n=8332), with similar estimates of strength in association for children and adults. Improvements in post-BD FEV1 were observed in adults (1.54% (0.87-2.21), n=3970), but not in children (0.20% (-0.49-0.90), n=3924) (subgroup difference, p=0.006). Estimates were similar between smokers and nonsmokers. There were no RCT data on incidence of fixed airflow obstruction. In the observational studies, ICS use was associated with improved pre-BD FEV1 in children and adults. There were limited observational data for post-BD outcomes.In patients with mild asthma, maintenance ICS are associated with modest, age-dependent improvements in long-term lung function, representing an added benefit to the broader clinical actions of ICS in asthma. There is currently insufficient evidence to determine whether treatment reduces incidence of fixed airflow obstruction in later life.

Greenness may improve lung health in low-moderate but not high air pollution areas: Seven Northeastern Cities' study

INTRODUCTION

There is growing interest in the impact of greenness exposure on airway diseases, but the impact of greenness on lung function in children is limited. We aimed to investigate the associations between greenness surrounding schools and lung function in children and whether these associations are modified by air pollution exposure.

METHODS

Between 2012 and 2013, a cross-sectional survey and spirometry were performed among 6740 school children. Lung function patterns were determined as obstructive forced expiratory volume 1 s/forced vital capacity (FEV₁/FVC <0.8) or restrictive (FEV₁/FVC ≥0.8 but FVC <80% of predicted). School greenness was defined by Normalized difference vegetation index (NDVI) and soil-adjusted vegetation index. Nitrogen dioxide, sulphur dioxide and particular matter concentrations were assessed using a spatiotemporal model and national monitoring data. Two-level generalised linear models were used to investigate associations and interactions.

RESULTS

Overall, an IQR in NDVI within 500 m was associated with higher FEV₁ (+57 mL 95% CI 44 to 70) and FVC (+58 mL 95% CI 43 to 73). NDVI was similarly associated with 25% reduced odds of spirometric restriction (OR: 0.75, 95% CI 0.65 to 0.86). However, among children exposed to the highest compared with the lowest quartile of particulate matter, increasing NDVI was paradoxically associated with lower -40 mL FVC (95% CI -47 to -33, p interaction <0.05).

DISCUSSION

Our findings suggest that, in this study population, greening urban areas may promote lung health in low-moderate pollution areas but not in high air pollution areas. If the findings are replicated in other moderate-to-high pollution settings, this highlights a need to have a flexible green policy.

Outdoor pollen-related changes in lung function and markers of airway inflammation: A systematic review and meta-analysis

BACKGROUND

Experimental challenge studies have shown that pollen can have early and delayed effects on the lungs and airways. Here, we qualitatively and quantitatively synthesize the evidence of outdoor pollen exposure on various lung function and airway inflammation markers in community-based studies.

METHODS

Four online databases were searched: Medline, Web of Science, CINAHL and Google Scholar. The search strategy included terms relating to both exposure and outcomes. Inclusion criteria were human-based studies published in English that were representative of the community. Additionally, we only considered cross-sectional or short-term longitudinal studies which investigated pollen exposure by levels or season. Study quality assessment was performed using the Newcastle-Ottawa scale. Meta-analysis was conducted using random-effects models.

RESULTS

We included 27 of 6551 studies identified from the search. Qualitative synthesis indicated associations between pollen exposure and predominantly type-2 inflammation in both the upper and lower airways, but little evidence for lung function changes. People with ever asthma and/or seasonal allergic rhinitis (SAR) were at higher risk of such airway inflammation. Meta-analysis confirmed a positive relationship between pollen season, eosinophilia and eosinophil cationic protein (ECP) in people with ever SAR but the results between studies were highly variable. Heterogeneity was reduced after further subgrouping by age, and the forest plots indicated that eosinophilic airway inflammation to outdoor pollen exposure increased with age.

CONCLUSION

Among people with ever asthma and ever SAR, exposure to increased ambient pollen triggers type-2 upper and lower airway inflammation rather than a non-specific or innate inflammation. These findings can lead to the formulation of specific pollen immunotherapy for susceptible individuals. Future research should be directed towards investigating lagged associations and effect modifications using larger and more generalized populations.

SYSTEMATIC REVIEW REGISTRATION

CRD42020146981 (PROSPERO).

Bronchodilator reversibility as a diagnostic test for adult asthma: findings from the population-based Tasmanian Longitudinal Health Study

Bronchodilator reversibility (BDR) is often used as a diagnostic test for adult asthma. However, there has been limited assessment of its diagnostic utility. We aimed to determine the discriminatory accuracy of common BDR cut-offs in the context of current asthma and asthma–COPD overlap (ACO) in a middle-aged community sample.

The Tasmanian Longitudinal Health Study is a population-based cohort first studied in 1968 (n=8583). In 2012, participants completed respiratory questionnaires and spirometry (n=3609; mean age 53 years). Receiver operating characteristic (ROC) curves were fitted for current asthma and ACO using continuous BDR measurements. Diagnostic parameters were calculated for different categorical cut-offs.

Area under the ROC curve (AUC) was highest when BDR was expressed as change in forced expiratory volume in 1 s (FEV₁) as a percentage of initial FEV₁, as compared with predicted FEV₁. The corresponding AUC was 59% (95% CI 54–64%) for current asthma and 87% (95% CI 81–93%) for ACO. Of the categorical cut-offs examined, the European Respiratory Society/American Thoracic Society threshold (≥12% from baseline and ≥200 mL) was assessed as providing the best balance between positive and negative likelihood ratios (LR+ and LR−, respectively), with corresponding sensitivities and specificities of 9% and 97%, respectively, for current asthma (LR+ 3.26, LR− 0.93), and 47% and 97%, respectively, for ACO (LR+ 16.05, LR− 0.55).

With a threshold of ≥12% and ≥200 mL from baseline, a positive BDR test provided a clinically meaningful change in the post-test probability of disease, whereas a negative test did not. BDR was more useful as a diagnostic test in those with co-existent post-bronchodilator airflow obstruction (ACO).

Using the commonly adopted threshold, a positive BDR test provides a meaningful change in post-test probability of adult asthma, whereas a negative test does not. Discriminatory accuracy is much greater in those with coexistent post-BD airflow obstruction.https://bit.ly/3gPvlm8

Exposure to household air pollution over 10 years is related to asthma and lung function decline

INTRODUCTION

We investigated if long-term household air pollution (HAP) is associated with asthma and lung function decline in middle-aged adults, and whether these associations were modified by glutathione S-transferase (GST) gene variants, ventilation and atopy.

MATERIALS AND METHODS

Prospective data on HAP (heating, cooking, mould and smoking) and asthma were collected in the Tasmanian Longitudinal Health Study (TAHS) at mean ages 43 and 53 years (n=3314). Subsamples had data on lung function (n=897) and GST gene polymorphisms (n=928). Latent class analysis was used to characterise longitudinal patterns of exposure. Regression models assessed associations and interactions.

RESULTS

We identified seven longitudinal HAP profiles. Of these, three were associated with persistent asthma, greater lung function decline and % reversibility by age 53 years compared with the "Least exposed" reference profile for those who used reverse-cycle air conditioning, electric cooking and no smoking. The "All gas" (OR 2.64, 95% CI 1.22-5.70), "Wood heating/smoking" (OR 2.71, 95% CI 1.21-6.05) and "Wood heating/gas cooking" (OR 2.60, 95% CI 1.11-6.11) profiles were associated with persistent asthma, as well as greater lung function decline and % reversibility. Participants with the GSTP1 Ile/Ile genotype were at a higher risk of asthma or greater lung function decline when exposed compared with other genotypes. Exhaust fan use and opening windows frequently may reduce the adverse effects of HAP produced by combustion heating and cooking on current asthma, presumably through increasing ventilation.

CONCLUSIONS

Exposures to wood heating, gas cooking and heating, and tobacco smoke over 10 years increased the risks of persistent asthma, lung function decline and % reversibility, with evidence of interaction by GST genes and ventilation.

Corrigendum: The Complex Relationship Between Veterinarian Mental Health and Client Satisfaction

[This corrects the article DOI: 10.3389/fvets.2020.00092.].

Trajectories of asthma and allergies from 7 years to 53 years and associations with lung function and extrapulmonary comorbidity profiles: a prospective cohort study

BACKGROUND

Longitudinal trajectories of asthma and allergies from childhood to adulthood might be differentially associated with lung function and chronic obstructive pulmonary disease (COPD), but associations with extrapulmonary comorbidities have not been well investigated. We aimed to assess these trajectories and examine their associations with lung function outcomes and profiles of comorbidities.

METHODS

In this prospective cohort study, data for asthma and related allergic conditions (ie, eczema, hay fever, and food allergy) were prospectively collected from the Tasmanian Longitudinal Health Study for participants aged 7-53 years originally recruited in Tasmania, Australia. All surviving individuals in the database with contact details were invited in the most recent follow-up (mean age 53 years). There were no exclusion criteria. With use of latent class analysis, we identified longitudinal trajectories of asthma and allergic conditions from 7-53 years, and profiles of self-reported extrapulmonary conditions recorded at 53 years. The associations between asthma and allergy trajectories and morbidity profiles and lung function at 53 years were investigated with regression models.

FINDINGS

Between Sept 3, 2012, and Nov 8, 2016, of 6128 individuals invited, 3609 (58·9%) individuals were enrolled. We identified five asthma and allergy trajectories: minimal and least asthma and allergies (n= 1767 [49·0%]); late-onset hay fever, no asthma (n=1065 [29·5%]); early-onset remitted asthma and allergies (n=236 [6·5%]); late-onset asthma and allergies (n=317 [8·8%]); and early-onset persistent asthma and allergies (n=224 [6·2%]); and four profiles of extrapulmonary morbidities: minimal or least disease (n=2206 [61·1%]); dominant mental health disorders (n=861 [23·9%]); dominant cardiovascular diseases or risks (n=424 [11·7%]); and multiple disorders (n=117 [3·2%]). The late-onset asthma and allergies trajectory was predominantly associated with the multiple disorders profile (relative risk ratio 3·3 [95% CI 1·9-5·9]), whereas the other asthma and allergy trajectories were associated only with the dominant mental health disorders profile. Both spirometrically defined and clinical COPD were most strongly associated with the early-onset persistent asthma and allergies trajectory (odds ratio [OR] 5·3 [95% CI 3·2-8·6]) and also with the late-onset asthma and allergies trajectory (OR 3·8 [2·4-6·1]).

INTERPRETATION

Distinct longitudinal trajectories of asthma and allergic disease from childhood to 53 years are associated with different profiles of extrapulmonary comorbidities and varying risk of COPD. These findings can inform a personalised approach in clinical guidelines and management focusing on treatable traits. Comorbidity profiles are a new target for early identification and intervention.

FUNDING

National Health and Medical Research Council of Australia, EU's Horizon 2020, The University of Melbourne, Clifford Craig Medical Research Trust of Tasmania, The Victorian, Queensland & Tasmanian Asthma Foundations, The Royal Hobart Hospital, Helen MacPherson Smith Trust, and GlaxoSmithKline.

Respiratory surveillance for coal mine dust and artificial stone exposed workers in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand

Coal mine lung dust disease (CMDLD) and artificial stone (AS) silicosis are preventable diseases which have occurred in serious outbreaks in Australia recently. This has prompted a TSANZ review of Australia's approach to respiratory periodic health surveillance. While regulating respirable dust exposure remains the foundation of primary and secondary prevention, identification of workers with early disease assists with control of further exposure, and with the aims of preserving lung function and decreasing respiratory morbidity in those affected. Prompt detection of an abnormality also allows for ongoing respiratory specialist clinical management. This review outlines a medical framework for improvements in respiratory surveillance to detect CMDLD and AS silicosis in Australia. This includes appropriate referral, improved data collection and interpretation, enhanced surveillance, the establishment of a nationwide Occupational Lung Disease Registry and an independent advisory group. These measures are designed to improve health outcomes for workers in the coal mining, AS and other dust-exposed and mining industries.

Work-related asthma: A position paper from the Thoracic Society of Australia and New Zealand and the National Asthma Council Australia

Work-related asthma (WRA) is one of the most common occupational respiratory conditions, and includes asthma specifically caused by occupational exposures (OA) and asthma that is worsened by conditions at work (WEA). WRA should be considered in all adults with asthma, but especially those with new-onset or difficult to control asthma. Improvement in asthma symptoms when away from work is suggestive of WRA. Clinical history alone is insufficient to diagnose WRA; therefore, objective investigations are required to confirm the presence of asthma and the association of asthma with work activities. Management of WRA requires pharmacotherapy similar to that of non-WRA, however, also needs to take into account control of the causative workplace exposure. Ongoing exposure will likely lead to decline in lung function and worsening asthma control. WRA is a preventable condition but this does rely on increased awareness of WRA and thorough identification and control of all potential occupational respiratory hazards.

The association between traffic-related air pollution and obstructive sleep apnea: A systematic review

Recent evidence suggests that air pollution exposure may be a contributing risk factor for obstructive sleep apnea (OSA), however, current evidence is conflicting. This systematic review aims to determine the association between air pollution and OSA in the general population, and examine for potential effect modification by seasonality, temperature and humidity. Five full-text articles were included in the review out of 905 articles found by systematically searching PubMed, Embase and Scopus databases. The included studies were limited to OSA in adults that were conducted in middle to high-income countries. The results highlight heterogeneity in the diagnostic criteria for OSA and method used to assess air pollution exposure. There is some evidence to support a relationship between air pollution exposure and OSA. However, the duration of exposure to different air pollutants including particulate matter (PM_2.5 and PM₁₀) and nitric oxides (NO₂) in relation to OSA varied across different seasons, temperatures, and countries. This variability of the pollutants across studies warrants a more robust study design using time-series analysis with multiple follow-ups to strengthen the evidence for this relationship before considering its implications.

Are symptoms of insomnia related to respiratory symptoms? Cross-sectional results from 10 European countries and Australia

OBJECTIVES

To compare the prevalence of different insomnia subtypes among middle-aged adults from Europe and Australia and to explore the cross-sectional relationship between insomnia subtypes, respiratory symptoms and lung function.

DESIGN

Cross-sectional population-based, multicentre cohort study.

SETTING

23 centres in 10 European countries and Australia.

METHODS

We included 5800 participants in the third follow-up of the European Community Respiratory Health Survey III (ECRHS III) who answered three questions on insomnia symptoms: difficulties falling asleep (initial insomnia), waking up often during the night (middle insomnia) and waking up early in the morning and not being able to fall back asleep (late insomnia). They also answered questions on smoking, general health and chronic diseases and had the following lung function measurements: forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and the FEV₁/FVC ratio. Changes in lung function since ECRHS I about 20 years earlier were also analysed.

MAIN OUTCOME MEASURES

Prevalence of insomnia subtypes and relationship to respiratory symptoms and function.

RESULTS

Overall, middle insomnia (31.2%) was the most common subtype followed by late insomnia (14.2%) and initial insomnia (11.2%). The highest reported prevalence of middle insomnia was found in Iceland (37.2%) and the lowest in Australia (22.7%), while the prevalence of initial and late insomnia was highest in Spain (16.0% and 19.7%, respectively) and lowest in Denmark (4.6% and 9.2%, respectively). All subtypes of insomnia were associated with significantly higher reported prevalence of respiratory symptoms. Only isolated initial insomnia was associated with lower FEV₁, whereas no association was found between insomnia and low FEV₁/FVC ratio or decline in lung function.

CONCLUSION

There is considerable geographical variation in the prevalence of insomnia symptoms. Middle insomnia is most common especially in Iceland. Initial and late insomnia are most common in Spain. All insomnia subtypes are associated with respiratory symptoms, and initial insomnia is also associated with lower FEV₁.