Epidemiology of asthma in children and adults

Asthma is a globally significant non-communicable disease with major public health consequences for both children and adults, including high morbidity, and mortality in severe cases. We have summarized the evidence on asthma trends, environmental determinants, and long-term impacts while comparing these epidemiological features across childhood asthma and adult asthma. While asthma incidence and prevalence are higher in children, morbidity, and mortality are higher in adults. Childhood asthma is more common in boys while adult asthma is more common in women, and the reversal of this sex difference in prevalence occurs around puberty suggesting sex hormones may play a role in the etiology of asthma. The global epidemic of asthma that has been observed in both children and adults is still continuing, especially in low to middle income countries, although it has subsided in some developed countries. As a heterogeneous disease, distinct asthma phenotypes, and endotypes need to be adequately characterized to develop more accurate and meaningful definitions for use in research and clinical settings. This may be facilitated by new clustering techniques such as latent class analysis, and computational phenotyping methods are being developed to retrieve information from electronic health records using natural language processing (NLP) algorithms to assist in the early diagnosis of asthma. While some important environmental determinants that trigger asthma are well-established, more work is needed to define the role of environmental exposures in the development of asthma in both children and adults. There is increasing evidence that investigation into possible gene-by-environment and environment-by-environment interactions may help to better uncover the determinants of asthma. Therefore, there is an urgent need to further investigate the interrelationship between environmental and genetic determinants to identify high risk groups and key modifiable exposures. For children, asthma may impair airway development and reduce maximally attained lung function, and these lung function deficits may persist into adulthood without additional progressive loss. Adult asthma may accelerate lung function decline and increase the risk of fixed airflow obstruction, with the effect of early onset asthma being greater than late onset asthma. Therefore, in managing asthma, our focus going forward should be firmly on improving not only short-term symptoms, but also the long-term respiratory and other health outcomes

Symptoms and lung function decline in a middle-aged cohort of males and females in Australia

BACKGROUND: The European Community Respiratory Health Survey is a major international study designed to assess lung health in adults. This Australian follow-up investigated changes in symptoms between sexes and the roles of asthma, smoking, age, sex, height, and change in body mass index (ΔBMI) on lung function decline (LFD), which is a major risk factor for chronic obstructive pulmonary disease (COPD). METHODS: LFD was measured as the rate of decline over time in FEV1 (mL/year) (ΔFEV1) and FVC (ΔFVC) between 1993 and 2013. Multiple linear regression was used to estimate associations between risk factors and LFD, separately for males and females. Multiple logistic regression was used to assess sex differences and changes in respiratory symptoms over time. RESULTS: In Melbourne, 318 subjects (53.8% females) participated. The prevalence of most respiratory symptoms had either remained relatively stable over 20 years or decreased (significantly so for wheeze). The exception was shortness of breath after activity, which had increased. Among the 262 subjects who completed spirometry, current smoking declined from 20.2% to 7.3%. Overall mean (± standard deviation) FEV1 declined by 23.1 (±17.1) and FVC by 22.9 (±20.2) mL/year. Predictors of ΔFEV1 in males were age, maternal smoking, and baseline FEV1; and in females they were age, ΔBMI, baseline FEV1, and pack-years in current smokers. Decline in FVC was predicted by baseline FVC, age, and ΔBMI in both sexes; however, baseline FVC predicted steeper decline in females than males. CONCLUSION: Most respiratory symptoms remained stable or decreased over time in both sexes. Age, baseline lung function, and change in BMI were associated with the rate of decline in both sexes. However, obesity and personal smoking appear to put females at higher risk of LFD than males. Health promotion campaigns should particularly target females to prevent COPD

Description et évaluation d'un réseau d'épidémiosurveillance des pathologies porcines mis en place dans un district du Nord Vietnam

Background and objective: Early menarche is increasing in prevalence worldwide, prompting clinical andpublic health interest on its links with pulmonary function. We aimed to investigate the relationship betweenearly menarche and lung function in middle age.Methods: The population-based Tasmanian LongitudinalHealth Study (born 1961; n = 8583), was initiated in 1968.The 5th Decade follow-up data (mean age: 45 years)included age at menarche and complex lung function testing. The 6th Decade follow-up (age: 53 years) repeated spirometry and gas transfer factor. Multiple linear regressionand mediation analyses were performed to determine theassociation between age at menarche and adult lung function and investigate biological pathways, including the proportion mediated by adult-attained height.Results: Girls reporting an early menarche (Conclusion:Early menarche was associated withreduced adult lung function. This is the first study toinvestigate post-BD outcomes and quantify the partialrole of adult height in this association

Skin prick test predictive values for the outcome of cashew challenges in children

Background: Cashew is a common cause of tree nut allergy in children. To date there have been few studies of diagnostic tests for cashew allergy, and positive predictive values (PPVs) for cashew as well as other tree nuts are largely extrapolated from studies of peanut allergy. How relevant these cutoffs are for cashew has not been formally explored. Objective: We aimed to establish skin prick test (SPT) wheal sizes that correlated to 95% PPV for a positive food challenge for cashew. Methods: We included all cashew oral food challenges (OFCs) conducted as part of the HealthNuts (n = 108; age, 4-6 years) and SchoolNuts (n = 37; age, 10-14 years) studies, both recruited from the community (population cohort). A second cohort of all cashew OFCs conducted at the Royal Children's Hospital (RCH) allergy center (n = 343) (2011-2016) and a private allergy clinic based at RCH (n = 43) was included via electronic medical record review (clinic cohort). The 95% PPV for cashew SPT was calculated for both cohorts. Results: Among the population cohort (n = 145), 62% of cashew OFCs were positive compared with 20% of the clinic cohort (n = 386). The SPT cutoff for 95% PPV derived from the population cohort was 10 mm (95% confidence interval [CI], 7.5-12.0). For the clinic cohort, the 95% PPV was 14 mm (95% CI, 9.5-unknown). An SPT wheal size of 8 mm had a PPV of 89% (95% CI, 79-95) in the population cohort and 62% (95% CI, 45-78) in the clinic cohort. Conclusion: A higher SPT wheal size may be more appropriate than the commonly used 8 mm cutoff to guide clinical decisions around when to perform OFC for cashew

The impact of child and adolescent health on adult respiratory health: the evidence, gaps and priorities

Chronic respiratory diseases impart a huge global disease burden. Many cases of adult chronic respiratory disorders are recognised to originate early in life during critical phases of lung growth and development. We therefore reviewed the longitudinal evolution of common childhood respiratory diseases across the lifespan. We included studies relating childhood respiratory health (preterm birth, asthma, low lung function or bronchiectasis) to respiratory health in adolescents and adults, including COPD. The negative impact of preterm birth (with or without bronchopulmonary dysplasia) on future respiratory health has now been quantified, with many having increasing deviation of lung function from the norm over their life course. While previous studies report children with asthma frequently “outgrow their disease” by adolescence or early adulthood, recent data describe asthma trajectories that include relapse, early-onset adult-remitting, and early-onset persistent childhood asthma. Evidence is emerging in adults of the negative impact of chronic productive cough, breathlessness and lower lung function on future respiratory and cardiovascular health and all-cause mortality. In addition, we found that in general, childhood respiratory health and adverse lung function trajectories are inextricably linked to adult respiratory health and cardiovascular events, as well as cardiovascular and all-cause mortality. Thus, we highlight the importance of pulmonary assessments in high-risk groups during childhood (e.g. preterm birth, parental smokers, early life hospitalisation for acute lower respiratory infections). Our review emphasises the importance of childhood respiratory health and the need for interventions to reduce or manage disease burden, which require a whole-of-society approach across the life course

Protein levels, air pollution and vitamin D deficiency: links with allergy

This study provides novel insights into mechanisms of traffic-related air pollution-induced allergy by down-regulation via complement regulators (CFI, PROS1 and PLG) and its interaction with vitamin D deficiency via the complement inhibitor PLG https://bit.ly/3x0jYOw

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 (AUCROC) 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 (AUCROC 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.Jennifer L Perret, Don Vicendese, Koen Simons, Debbie L Jarvis, Adrian J Lowe, Caroline J Lodge ... et al

Lung-function trajectories: relevance and implementation in clinical practice

Lung development starts in utero and continues during childhood through to adolescence, reaching its peak in early adulthood. This growth is followed by gradual decline due to physiological lung ageing. Lung -function development can be altered by several host and environmental factors during the life course. As a result, a range of lung -function trajectories exist in the population. Below average trajectories are associated with respiratory, cardiovascular, metabolic, and mental health comorbidities, as well as with premature death. This Review presents progressive research into lung -function trajectories and assists the implementation of this knowledge in clinical practice as an innovative approach to detect poor lung health early, monitor respiratory disease progression, and promote lung health. Specifically, we propose that, similar to paediatric height and weight charts used globally to monitor children&#039;s growth, lung -function charts could be used for both children and adults to monitor lung health status across the life course. To achieve this proposal, we introduce our free online Lung Function Tracker tool. Finally, we discuss challenges and opportunities for effective implementation of the trajectory concept at population level and outline an agenda for crucial research needed to support such implementation

An update on molecular cat allergens: Fel d 1 and what else? Chapter 1: Fel d 1, the major cat allergen

Background: Cats are the major source of indoor inhalant allergens after house dust mites. The global incidence of cat allergies is rising sharply, posing a major public health problem. Ten cat allergens have been identified. The major allergen responsible for symptoms is Fel d 1, a secretoglobin and not a lipocalin, making the cat a special case among mammals. Main body: Given its clinical predominance, it is essential to have a good knowledge of this allergenic fraction, including its basic structure, to understand the new exciting diagnostic and therapeutic applications currently in development. The recent arrival of the component-resolved diagnosis, which uses molecular allergens, represents a unique opportunity to improve our understanding of the disease. Recombinant Fel d 1 is now available for in vitro diagnosis by the anti-Fel d 1 specific IgE assay. The first part of the review will seek to describe the recent advances related to Fel d 1 in terms of positive diagnosis and assessment of disease severity. In daily practice, anti-Fel d 1 IgE tend to replace those directed against the overall extract but is this attitude justified? We will look at the most recent arguments to try to answer this question. In parallel, a second revolution is taking place thanks to molecular engineering, which has allowed the development of various forms of recombinant Fel d 1 and which seeks to modify the immunomodulatory properties of the molecule and thus the clinical history of the disease via various modalities of anti-Fel d 1-specific immunotherapy. We will endeavor to give a clear and practical overview of all these trends