Approaches to Asthma Diagnosis in Children and Adults

Physical comorbidity is associated with overnight hospitalization in U.S. adults with asthma: an assessment of the 2005-2018 National Health and Nutrition Examination Surveys

OBJECTIVE

Identifying the effects of comorbidity on healthcare utilization is critical for understanding the benefits of improved comorbidity management. Asthma is a common respiratory condition, associated with gastrointestinal, metabolic, psychiatric, and other respiratory conditions. Adults with asthma represent a key population in understanding comorbidity and its consequences. The objective was to explore the relationship between comorbidity and overnight hospitalizations in U.S. adults with asthma.

STUDY DESIGN AND METHODS

A cross-sectional sample of 3,887 subjects aged 20-79 was aggregated from seven cycles (2005-2018) of the National Health and Nutrition Examination Survey (NHANES). The survey design was created using the full seven cycles, then a subpopulation was used for the analysis. Design-based modified Poisson regression with robust standard errors compared the prevalence of overnight hospitalizations in subjects with and without comorbidities. Comorbidity was defined as the presence of one or more additional chronic conditions.

RESULTS

Over half (61.6%) of patients with asthma reported having comorbidities. The overnight hospitalization prevalence was higher in those with comorbidities (21.6%) than those without (7.4%). The adjusted prevalence ratio of overnight hospitalizations in those with comorbidities vs. those without was 2.02 (95% CI: 1.54-2.66). Conclusions from sensitivity analyses remained the same.

CONCLUSIONS

Comorbidity in U.S. adult asthma patients is associated with increased overnight hospitalizations. Study results concur with examinations of other healthcare utilization outcomes, revealing how comorbidity influences healthcare utilization patterns in patients with asthma. The reduction of overnight hospitalizations should be a targeted goal when developing and evaluating interventions to manage comorbidities in patients with asthma.

Diagnosing new-onset asthma in a paediatric clinical trial setting in school-age children

Asthma is a common chronic disease in children. It is a dynamic condition-symptoms change over time, and the outcome of diagnostic tests can vary. Consequently, evaluating the onset of asthma at a single point in time, perhaps when patients are asymptomatic with limited impairment of the lung function, may result in false diagnostic conclusions. The absence of consistent gold-standard diagnostic criteria in children challenges the ability of any study to ascertain an effect of treatment on asthma prevention. A comprehensive review of the diagnostic criteria used for new-onset asthma in school-age children was conducted based on existing recommendations from published clinical guidance, alongside evidence from paediatric asthma prevention trials. Findings from the review were used to propose suggestions for diagnosing new-onset asthma in future asthma prevention trials. Despite an overall lack of consensus in the published clinical guidance, there are similarities between the various recommendations for diagnosing asthma in children, which typically involve assessing the variable symptoms and supplementing the medical history with objective measures of lung function. For future paediatric asthma prevention trials, we suggest that paediatric clinical trials should use a new-onset asthma definition that incorporates the concepts of "possible", "probable" and "confirmed" asthma. "Possible" asthma would capture self-reported features of chronic symptoms and symptom relief with β2-agonist bronchodilator (suggesting reversibility). "Probable" asthma would include symptom chronicity, self-reported symptom relief with β2-agonist bronchodilator, and objective features of asthma (reversibility or bronchial hyper-responsiveness). A "confirmed" diagnosis would be made only if there is a positive response to controller therapy. These suggestions aim to improve the diagnosis of new-onset childhood asthma in clinical trials, which will be useful in the design and conduct of future paediatric asthma prevention trials.

The Exploitation of the Glycosylation Pattern in Asthma: How We Alter Ancestral Pathways to Develop New Treatments

Asthma has reached epidemic levels, yet progress in developing specific therapies is slow. One of the main reasons for this is the fact that asthma is an umbrella term for various distinct subsets. Due to its high heterogeneity, it is difficult to establish biomarkers for each subset of asthma and to propose endotype-specific treatments. This review focuses on protein glycosylation as a process activated in asthma and ways to utilize it to develop novel biomarkers and treatments. We discuss known and relevant glycoproteins whose functions control disease development. The key role of glycoproteins in processes integral to asthma, such as inflammation, tissue remodeling, and repair, justifies our interest and research in the field of glycobiology. Altering the glycosylation states of proteins contributing to asthma can change the pathological processes that we previously failed to inhibit. Special emphasis is placed on chitotriosidase 1 (CHIT1), an enzyme capable of modifying LacNAc- and LacdiNAc-containing glycans. The expression and activity of CHIT1 are induced in human diseased lungs, and its pathological role has been demonstrated by both genetic and pharmacological approaches. We propose that studying the glycosylation pattern and enzymes involved in glycosylation in asthma can help in patient stratification and in developing personalized treatment.

Early life exposure to pollens and increased risks of childhood asthma: a prospective cohort study in Ontario children

Asthma is a disease characterised by wheeze, cough and shortness of breath, and constitutes the most prevalent chronic disease among children [1]. Various phenotypes have been specifically identified in the paediatric population, and include early transient wheeze, current wheeze/asthma, and mild or moderate asthma [2]. Lifestyle behaviours, genetics, maternal and paternal factors, and environment exposures have been identified as risk factors in the multifactorial aetiology of childhood asthma [3].

Increased exposure to tree canopy around the place of residence at birth prevented the risk of childhood asthma development, but this protective effect can be reduced when exposure to weed and tree pollen increases https://bit.ly/3Tboabo

Within-breath oscillometry for identifying exercise-induced bronchoconstriction in pediatric patients reporting symptoms with exercise

Background

Evaluating oscillometry parameters separately for the inspiratory and expiratory breath phases and their within-breath differences can help to identify exercise-induced bronchoconstriction (EIB) in pediatric outpatients disclosing exercise-induced symptoms (EIS).

Aims

To assess the response in impedance parameters following an exercise challenge in patients reporting EIS.

Methods

Sixty-eight patients reporting EIS (34 asthmatics and 34 suspected of asthma, age mean = 10.8 years, range = 6.0-16.0) underwent an incremental treadmill exercise test. Spirometry was performed at baseline and 1, 5-, 10-, 15-, and 20-min post exercise. Oscillometry was performed at baseline and at 3- and 18-min post exercise. Bronchodilator response to 200 µg albuterol was then assessed. EIB was defined as a forced expiratory volume in 1 s (FEV1) fall ≥10% from baseline. Expiratory and inspiratory resistance (Rrs) and reactance (Xrs), their z-score (Ducharme et al. 2022), and their mean within-breath differences (ΔRrs = Rrsexp-Rrsinsp, ΔXrs = Xrsexp-Xrsinsp) were calculated. Receiver operating characteristic (ROC) curves and their areas (AUCs) were used to evaluate impedance parameters' performances in classifying EIB.

Results

Asthmatic patients developed EIB more frequently than those suspected of asthma [18/34 (52.9%) vs. 2/34 (5.9%), p < 0.001]. In the 20 subjects with EIB, Rrsinsp, Rrsexp, Xrsinsp, and Xrsexp peaked early (3'), and remained steady except for Xrsinsp, which recovered faster afterward. ΔXrs widened 18 min following the exercise and reversed sharply after bronchodilation (BD) (-1.81 ± 1.60 vs. -0.52 ± 0.80 cmH2O × s/L, p < 0.001). Cutoffs for EIB leading to the highest AUCs were a rise of 0.41 in z-score Rrsinsp (Se: 90.0%, Sp: 66.7%), and a fall of -0.64 in z-score Xrsinsp (Se: 90.0%, Sp: 75.0%). Accepting as having "positive" postexercise oscillometry changes those subjects who had both z-scores beyond respective cutoffs, sensitivity for EIB was 90.0% (18/20) and specificity, 83.3% (40/48).

Conclusion

Oscillometry parameters and their within-breath differences changed markedly in pediatric patients presenting EIB and were restored after the bronchodilator. Strong agreement between z-scores of inspiratory oscillometry parameters and spirometry supports their clinical utility, though larger studies are required to validate these findings in a broader population.

Phenotypic characteristics, healthcare use, and treatment in children with night cough compared with children with wheeze

OBJECTIVES

Population-based studies of children with dry night cough alone compared with those who also wheeze are few and inconclusive. We compared how children with dry night cough differ from those who wheeze.

METHODS

LuftiBus in the school is a population-based study of schoolchildren conducted between 2013 and 2016 in Zurich, Switzerland. We divided children into four mutually exclusive groups based on reported dry night cough (henceforth referred as "cough") and wheeze and compared parent-reported symptoms, comorbidities, exposures, FeNO, spirometry, and healthcare use and treatment.

RESULTS

Among 3457 schoolchildren aged 6-17 years, 294 (9%) reported "cough," 181 (5%) reported "wheeze," 100 (3%) reported "wheeze and cough," and 2882 (83%) were "asymptomatic." Adjusting for confounders in a multinomial regression, children with "cough" reported more frequent colds, rhinitis, and snoring than "asymptomatic" children; children with "wheeze" or "wheeze and cough" more often reported hay fever, eczema, and parental histories of asthma. FeNO and spirometry were similar among "asymptomatic" and children with "cough," while children with "wheeze" or "wheeze and cough" had higher FeNO and evidence of bronchial obstruction. Children with "cough" used healthcare less often than those with "wheeze," and they attended mainly primary care. Twenty-two children (7% of those with "cough") reported a physician diagnosis of asthma and used inhalers. These had similar characteristics as children with wheeze.

CONCLUSION

Our representative population-based study confirms that children with dry night cough without wheeze clearly differed from those with wheeze. This suggests asthma is unlikely, and they should be investigated for alternative aetiologies, particularly upper airway disease.

Clinical standards for the diagnosis and management of asthma in low- and middle-income countries

BACKGROUND: The aim of these clinical standards is to aid the diagnosis and management of asthma in low-resource settings in low- and middle-income countries (LMICs).METHODS: A panel of 52 experts in the field of asthma in LMICs participated in a two-stage Delphi process to establish and reach a consensus on the clinical standards.RESULTS: Eighteen clinical standards were defined: Standard 1, Every individual with symptoms and signs compatible with asthma should undergo a clinical assessment; Standard 2, In individuals (>6 years) with a clinical assessment supportive of a diagnosis of asthma, a hand-held spirometry measurement should be used to confirm variable expiratory airflow limitation by demonstrating an acute response to a bronchodilator; Standard 3, Pre- and post-bronchodilator spirometry should be performed in individuals (>6 years) to support diagnosis before treatment is commenced if there is diagnostic uncertainty; Standard 4, Individuals with an acute exacerbation of asthma and clinical signs of hypoxaemia or increased work of breathing should be given supplementary oxygen to maintain saturation at 94-98%; Standard 5, Inhaled short-acting beta-2 agonists (SABAs) should be used as an emergency reliever in individuals with asthma via an appropriate spacer device for metered-dose inhalers; Standard 6, Short-course oral corticosteroids should be administered in appropriate doses to individuals having moderate to severe acute asthma exacerbations (minimum 3-5 days); Standard 7, Individuals having a severe asthma exacerbation should receive emergency care, including oxygen therapy, systemic corticosteroids, inhaled bronchodilators (e.g., salbutamol with or without ipratropium bromide) and a single dose of intravenous magnesium sulphate should be considered; Standard 8, All individuals with asthma should receive education about asthma and a personalised action plan; Standard 9, Inhaled medications (excluding dry-powder devices) should be administered via an appropriate spacer device in both adults and children. Children aged 0-3 years will require the spacer to be coupled to a face mask; Standard 10, Children aged <5 years with asthma should receive a SABA as-needed at step 1 and an inhaled corticosteroid (ICS) to cover periods of wheezing due to respiratory viral infections, and SABA as-needed and daily ICS from step 2 upwards; Standard 11, Children aged 6-11 years with asthma should receive an ICS taken whenever an inhaled SABA is used; Standard 12, All adolescents aged 12-18 years and adults with asthma should receive a combination inhaler (ICS and rapid onset of action long-acting beta-agonist [LABA] such as budesonide-formoterol), where available, to be used either as-needed (for mild asthma) or as both maintenance and reliever therapy, for moderate to severe asthma; Standard 13, Inhaled SABA alone for the management of patients aged >12 years is not recommended as it is associated with increased risk of morbidity and mortality. It should only be used where there is no access to ICS.The following standards (14-18) are for settings where there is no access to inhaled medicines. Standard 14, Patients without access to corticosteroids should be provided with a single short course of emergency oral prednisolone; Standard 15, Oral SABA for symptomatic relief should be used only if no inhaled SABA is available. Adjust to the individual's lowest beneficial dose to minimise adverse effects; Standard 16, Oral leukotriene receptor antagonists (LTRA) can be used as a preventive medication and is preferable to the use of long-term oral systemic corticosteroids; Standard 17, In exceptional circumstances, when there is a high risk of mortality from exacerbations, low-dose oral prednisolone daily or on alternate days may be considered on a case-by-case basis; Standard 18. Oral theophylline should be restricted for use in situations where it is the only bronchodilator treatment option available.CONCLUSION: These first consensus-based clinical standards for asthma management in LMICs are intended to help clinicians provide the most effective care for people in resource-limited settings.

Diagnostic value of IL-6 for patients with asthma: a meta-analysis

BACKGROUND

IL-6 is a pleotropic cytokine that acts as a pro-inflammatory mediator and acute-phase response inducer, but has also been reported to possess anti-inflammatory properties. The objective of this study was to assess the validity of serum IL-6 test for diagnosis of asthma.

METHODS

A literature search was conducted using PubMed, Embase, and Cochrane library from January 2007 to March 2021 to identify relevant studies. Eleven studies were included in this analysis, involving 1977 patients with asthma and 1591 healthy non-asthmatic controls. The meta-analysis was performed using Review Manager 5.3 software and Stata 16.0. Random effect model or fixed effect model (FEM) was used to estimate the standardized mean differences (SMDs) with 95% confidence intervals (CIs).

RESULTS

The meta-analysis results revealed that the serum IL-6 levels were higher in asthmatic patients than healthy non-asthmatic controls (SMD 1.31, 95% CI 0.82-1.81, P < 0.00001). IL-6 levels are significantly elevated in pediatric patients with asthma (SMD 1.58, 95% CI 0.75-2.41, P = 0.0002) and mildly elevated in adult patients with asthma (SMD 1.08, 95% CI 0.27-1.90, P = 0.009). In addition, a subgroup analysis of asthma disease status showed that IL-6 levels were increased in stable (SMD 0.69, 95% CI 0.28-1.09, P = 0.009) and exacerbation asthma (SMD 2.15, 95% CI 1.79-2.52, P < 0.00001) patients.

CONCLUSION

The results of this meta-analysis suggest that serum IL-6 levels were significantly elevated in asthmatic patients as compared to normal population. IL-6 levels can be used as an auxiliary indicator to distinguish individuals with asthma from healthy non-asthmatic controls.

Utility of biomarkers in the diagnosis and monitoring of asthmatic children

Asthma imposes a heavy morbidity burden during childhood; it affects over 10% of children in Europe and North America and it is estimated to exceed 400 million people worldwide by the year 2025. In clinical practice, diagnosis of asthma in children is mostly based on clinical criteria; nevertheless, assessment of both physiological and pathological processes through biomarkers, support asthma diagnosis, aid monitoring, and further lead to better treatment outcomes and reduced morbidity. Recently, identification and validation of biomarkers in pediatric asthma has emerged as a top priority across leading experts, researchers, and clinicians. Moreover, the implementation of non-invasive biomarkers for the assessment and monitoring of paediatric patients with asthma, has been prioritized; however, only a proportion of them are currently included in the clinical practise. Although, the use of non-invasive biomarkers is highly supported in recent asthma guidelines for documenting diagnosis and supporting monitoring of asthmatic patients, data on the Pediatric population are limited. In the present report, the Pediatric Asthma Committee of the World Allergy Organization (WAO), aims to summarize and discuss available data for the implementation of non-invasive biomarkers in the diagnosis and monitoring in children with asthma. Information on the most studied biomarkers, including spirometry, oscillometry, markers of allergic sensitization, fractional exhaled nitric oxide, and the most recent exhaled breath markers and "omic" approaches, will be reviewed. Practical limitations and considerations based on both experts' opinion and critical review of the literature, on the utility of all "well-known" and newly introduced non-invasive biomarkers will be presented. A critical commentary on biomarkers' use in diagnosing and monitoring asthma during the COVID-19 pandemic, cost and availability of biomarkers in different settings and in developing countries, the differences on the biomarkers use between Primary Practitioners, Pediatricians, and Specialists and their role on the longitudinal aspect of asthma is provided.

The external validation of the asthma prediction tool in the French ELFE cohort

BACKGROUND

Existing predictive scores for early identification of children at high risk of developing asthma include invasive procedures, and hence have limited utility in a primary care setting. The Leicestershire respiratory cohort (LRC) has developed a noninvasive asthma prediction tool (APT) for children with promising results. We aimed to perform its external validation in the French general population Étude Longitudinale Française depuis l'Enfance (ELFE) cohort.

METHODS

Predictive scores were determined at Age 1 and the primary outcome of asthma was defined as parental reporting of "asthma ever or "wheezing in the past 12 months" at Age 5. Logistic regression was used to calculate the odds ratio (OR) and performance measures, and discriminative performance was reported using the receiver operating curve and area under curve (AUC). Calibration was assessed using Hosmer-Lemeshow goodness-of-fit test and visualized with a calibration plot. Overall performance was determined using Brier scores.

RESULTS

Of the 10,689 children analyzed: 84.9% were at low, 13.1% medium, and 2% at high risk of developing asthma at Age 5. Children in the medium-risk category were three times more likely to develop asthma (OR = 3.3, 95% confidence interval [CI] = 2.97-3.78) whereas 13 times more likely in the high-risk category (OR = 13.8, 95% CI = 10.2-18.8). The tool's AUC was comparable: LRC 0.74 versus ELFE 0.68; as were the Brier scores LRC 0.16 versus ELFE 0.14. The tool's performance was robust to changes in inclusion criteria and outcome definitions.

CONCLUSIONS AND RELEVANCE

Results of the present study and previous validation studies performed in high-risk populations provide a comprehensive measure of the effectiveness of the APT, providing encouragement for its application by general practitioners.

Cohort profile: the ECHO prenatal and early childhood pathways to health consortium (ECHO-PATHWAYS)

PURPOSE

Exposures early in life, beginning in utero, have long-term impacts on mental and physical health. The ECHO prenatal and early childhood pathways to health consortium (ECHO-PATHWAYS) was established to examine the independent and combined impact of pregnancy and childhood chemical exposures and psychosocial stressors on child neurodevelopment and airway health, as well as the placental mechanisms underlying these associations.

PARTICIPANTS

The ECHO-PATHWAYS consortium harmonises extant data from 2684 mother-child dyads in three pregnancy cohort studies (CANDLE [Conditions Affecting Neurocognitive Development and Learning in Early Childhood], TIDES [The Infant Development and Environment Study] and GAPPS [Global Alliance to Prevent Prematurity and Stillbirth]) and collects prospective data under a unified protocol. Study participants are socioeconomically diverse and include a large proportion of Black families (38% Black and 51% White), often under-represented in research. Children are currently 5-15 years old. New data collection includes multimodal assessments of primary outcomes (airway health and neurodevelopment) and exposures (air pollution, phthalates and psychosocial stress) as well as rich covariate characterisation. ECHO-PATHWAYS is compiling extant and new biospecimens in a central biorepository and generating the largest placental transcriptomics data set to date (N=1083).

FINDINGS TO DATE

Early analyses demonstrate adverse associations of prenatal exposure to air pollution, phthalates and maternal stress with early childhood airway outcomes and neurodevelopment. Placental transcriptomics work suggests that phthalate exposure alters placental gene expression, pointing to mechanistic pathways for the developmental toxicity of phthalates. We also observe associations between prenatal maternal stress and placental corticotropin releasing hormone, a marker of hormonal activation during pregnancy relevant for child health. Other publications describe novel methods for examining exposure mixtures and the development of a national spatiotemporal model of ambient outdoor air pollution.

FUTURE PLANS

The first wave of data from the unified protocol (child age 8-9) is nearly complete. Future work will leverage these data to examine the combined impact of early life social and chemical exposures on middle childhood health outcomes and underlying placental mechanisms.

The Prevalence of Bronchodilator Responsiveness "Asthma" Among Adult Indigenous Australians Referred for Lung Function Testing in the Top End Northern Territory of Australia

Background

Among Indigenous Australians, studies examining the clinical significance of airway bronchodilator responsiveness (BDR) are limited. In this retrospective study, we examined the nature of underlying lung disease in adult Indigenous patients with BDR referred for lung function testing (LFT) in the Top End Health Service region of the Northern Territory of Australia.

Methods

Presence or absence of BDR as per usual (FVC or FEV₁ change pre to post ≥12% and ≥0.2L) and updated (2021 ">10% predicted) ATS/ERS criteria among Indigenous and non-Indigenous Australians was determined. The radiological findings in the Indigenous study participants with and without BDR were next assessed for the presence of underlying chronic airway/lung disease.

Results

We found that 123/742 (17%) Indigenous and 578/4579 (13%) non-Indigenous patients had a significant BDR. Indigenous patients with BDR were younger (mean difference 7 years), with a greater proportion of females (52 vs 32%), underweight (15 vs 4%) and current smokers (52 vs 25%). Indigenous patients with BDR displayed lower LFT values, and a higher proportion exhibited FVC BDR compared to non-Indigenous (34 vs 20%). Almost half (46%) of Indigenous patients with BDR had evidence of COPD and/or bronchiectasis on radiology. Adjusting for the presence of radiologic or spirometric evidence of COPD, the presence of BDR was similar between Indigenous and non-Indigenous patients (5-8 vs 7-11%), irrespective of which BDR criteria was used.

Conclusion

BDR was higher overall among Indigenous in comparison to non-Indigenous patients; however, a significant proportion of Indigenous patients demonstrating BDR had evidence of underlying COPD/bronchiectasis. This study highlights that although presence of BDR among Indigenous people may indicate asthma, it may also be observed among patients with COPD/bronchiectasis or could represent asthma/COPD/bronchiectasis overlap. Hence, a combination of clinical history, LFT and radiology should be considered for precise diagnosis of lung disease in this population.

Challenges in the diagnosis of asthma in children, what are the solutions? A scoping review of 3 countries in sub Saharan Africa

Background

Asthma is the commonest chronic respiratory tract disease in children. In low-income countries, challenges exist in asthma diagnosis. In surveys done in children, the prevalence of ‘asthma’ defined by symptoms is high compared to ‘doctor diagnosed asthma’. The questions answered by this review are (i) What challenges have been experienced in the diagnosis of asthma in children? (ii) What solutions will address these challenges?

Methods

The Arksey and O’Malley’s framework for scoping reviews was used for the study methodology, while the PRISMA-ScR checklist guided the reporting process. Electronic databases: PubMed Central, EMBASE and Google Scholar were searched. Primary quantitative and qualitative studies and reviews from 2010 to 2021, from Nigeria, South Africa and Uganda written in English or translated to English, which answered the study questions were included. The author, title, country, study type, methods, purpose, findings and references were captured onto a predefined data collection table. The ‘Preview, Question, Read, Summarise’ system was used and a narrative report was used to summarise the findings.

Results

A total of 28 studies were included. The causes of under-diagnosis of asthma include lack of community knowledge and perception of asthma, poor accessibility to health care, strained health systems, lack of diagnostic tests including spirometry, low levels of knowledge among health-care workers and lack of or non-implementation of asthma guidelines. Strategies to improve asthma diagnosis will include community and school based education programmes, revision of asthma diagnostic terms, guideline development and implementation and health systems strengthening.

Conclusion

This scoping review provides research evidence for policy makers and health-workers involved in the care of asthmatic children on challenges faced in asthma diagnosis and strategies to improve asthma diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02170-y.

Reference values for respiratory sinusoidal oscillometry in children aged 3 to 17 years

BACKGROUND

New oscillometry devices allowing quantification of respiratory function using tidal breathing are commercially available, but reference equations are lacking for the multiethnic Canadian pediatric population.

METHODS

We conducted a prospective cross-sectional study of healthy children carefully selected for absence of asthma, atopy, tobacco smoke, obesity, prematurity, and recent respiratory infection. Triplicate measures were obtained of respiratory system resistance (Rrs) and reactance (Xrs), area under the reactance curve (AX) and resonant frequency (Fres) on four signals, whose testing order was randomized: two signals on the Resmon Pro Full (8 Hz and 5-11-19 Hz) and two signals on the tremoflo C-100 (5-37 Hz and 7-41 Hz). Feasibility was defined as the ability to obtain valid reproducible results. Prediction equations and 95% confidence intervals were derived for whole- and within-breath Rrs and Xrs and for AX and Fres, using linear regression or Generalized Additive Models for Location, Scale and Shape.

RESULTS

Of 306 children randomized, valid and reproducible results on ≥1 signal were obtained in 299 (98%) multiethnic (69% Caucasians: 8% Black: 23% Others) children aged 3-17 years, 91-189 cm tall. Standing height was the strongest predictor with no significant effect of sex, age, body mass index or ethnicity. Significant within-patient differences were observed between Resmon Pro and tremoflo C-100 measurements, justifying the derivation of device-specific reference equations.

CONCLUSION

Valid reproducible oscillometry measurements are highly feasible in children aged 3 years and older. Device-specific reference equations, valid for our multiethnic population, are derived.

Asthma and the Missing Heritability Problem: Necessity for Multiomics Approaches in Determining Accurate Risk Profiles

Asthma is ranked among the most common chronic conditions and has become a significant public health issue due to the recent and rapid increase in its prevalence. Investigations into the underlying genetic factors predict a heritable component for its incidence, estimated between 35% and 90% of causation. Despite the application of large-scale genome-wide association studies (GWAS) and admixture mapping approaches, the proportion of variants identified accounts for less than 15% of the observed heritability of the disease. The discrepancy between the predicted heritable component of disease and the proportion of heritability mapped to the currently identified susceptibility loci has been termed the ‘missing heritability problem.’ Here, we examine recent studies involving both the analysis of genetically encoded features that contribute to asthma and also the role of non-encoded heritable characteristics, including epigenetic, environmental, and developmental aspects of disease. The importance of vertical maternal microbiome transfer and the influence of maternal immune factors on fetal conditioning in the inheritance of disease are also discussed. In order to highlight the broad array of biological inputs that contribute to the sum of heritable risk factors associated with allergic disease incidence that, together, contribute to the induction of a pro-atopic state. Currently, there is a need to develop in-depth models of asthma risk factors to overcome the limitations encountered in the interpretation of GWAS results in isolation, which have resulted in the missing heritability problem. Hence, multiomics analyses need to be established considering genetic, epigenetic, and functional data to create a true systems biology-based approach for analyzing the regulatory pathways that underlie the inheritance of asthma and to develop accurate risk profiles for disease.

The role of respiratory syncytial virus- and rhinovirus-induced bronchiolitis in recurrent wheeze and asthma-A systematic review and meta-analysis

INTRODUCTION

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis. RSV-induced bronchiolitis has been associated with preschool wheeze and asthma in cohort studies where the comparison groups consist of healthy infants. However, recent studies identify rhinovirus (RV)-induced bronchiolitis as a potentially stronger risk factor for recurrent wheeze and asthma.

AIM

This systematic review and meta-analysis aimed to compare the associations of RSV- and RV-induced bronchiolitis with the development of preschool wheeze and childhood asthma.

METHODS

We performed a systematic search of the published literature in five databases by using a MeSH term-based algorithm. Cohort studies that enrolled infants with bronchiolitis were included. The primary outcomes were recurrent wheeze and asthma diagnosis. Wald risk ratios and odds ratios (ORs) were estimated, along with their 95% confidence intervals (CIs). Individual and summary ORs were visualized with forest plots.

RESULTS

There were 38 studies included in the meta-analysis. Meta-analysis of eight studies that had data on the association between infant bronchiolitis and recurrent wheeze showed that the RV-bronchiolitis group were more likely to develop recurrent wheeze than the RSV-bronchiolitis group (OR 4.11; 95% CI 2.24-7.56). Similarly, meta-analysis of the nine studies that had data on asthma development showed that the RV-bronchiolitis group were more likely to develop asthma (OR 2.72; 95% CI 1.48-4.99).

CONCLUSION

This is the first meta-analysis that directly compares between-virus differences in the magnitude of virus-recurrent wheeze and virus-childhood asthma outcomes. RV-induced bronchiolitis was more strongly associated with the risk of developing wheeze and childhood asthma.

Can oscillometry be a substitute to spirometry in the indigent?

The practical difficulties of using spirometry in a 3-year-old girl are highlighted, especially during the COVID-19 era. Oscillometry, a tidal breath-based technique, has shown promising future to reliably assess lung functions in the vulnerable cohort. A simple algorithmic approach has been provided till reference values can be established with multicenter studies.

Predictors of the Development of Protracted Bacterial Bronchitis following Presentation to Healthcare for an Acute Respiratory Illness with Cough: Analysis of Three Cohort Studies

We describe the prevalence and risk factors for protracted bacterial bronchitis (PBB) following healthcare presentation for an acute cough illness in children. Data from three studies of the development of chronic cough (CC) in children were combined. PBB was defined as a wet cough of at least 4-weeks duration with no identified specific cause of cough that resolved following 2–4 weeks of appropriate antibiotics. Anterior nasal swabs were tested for 17 viruses and bacteria by polymerase chain reaction. The study included 903 children. Childcare attendance (adjusted relative risk (aRR) = 2.32, 95% CI 1.48–3.63), prior history of chronic cough (aRR = 2.63, 95% CI 1.72–4.01) and age <2-years (<12-months: aRR = 4.31, 95% CI 1.42–13.10; 12-<24 months: aRR = 2.00, 95% CI 1.35–2.96) increased risk of PBB. Baseline diagnoses of asthma/reactive airways disease (aRR = 0.30, 95% CI 0.26–0.35) or bronchiolitis (aRR = 0.15, 95% CI 0.06–0.38) decreased risk. M. catarrhalis was the most common organism (52.4%) identified in all children (PBB = 72.1%; no PBB = 50.2%, p < 0.001). We provide the first data on risks for PBB in children following acute illness and a hypothesis for studies to further investigate the relationship with wheeze-related illnesses. Clinicians and parents/guardians should be aware of these risks and seek early review if a wet cough lasting more than 4-weeks develops the post-acute illness.

Spirometry reference equations for children from a Middle Eastern population

BACKGROUND

Spirometry is a clinically useful test that can be used to assess lung function among children. Different equations had been formulated to determine the spirometric reference values depending on several individual characteristics. However, the widely used equations do not produce perfect suitability for Middle Eastern children.

OBJECTIVES

This study aims to formulate Middle Eastern-specific equations that may be applicable for other populations in the region.

METHODS

The spirometric data were collected from Jordanian children between the ages of 6 and 17 years. The collected data were used to formulate customised reference equations for Middle Eastern children using generalised additive models for location, scale and shape. The newly formulated equation results were compared with Global Lung Initiative 2012 (GLI-2012) equations predicted values.

RESULTS

Spirometric values for 1576 healthy participants (870 males) were used to formulate the new equations. The assessment of z-scores produced by the present study equations and GLI-2012 indicated that the new equations were more suitable than GLI-2012 for Middle Eastern children. In-depth analysis of the results indicated that the suitability of GLI-2012 equations varied between different age points.

CONCLUSION

This study formulated new spirometric reference equations for Middle Eastern children that can improve the diagnosis and management of different respiratory conditions.

Diagnostic possibility of the combination of exhaled nitric oxide and blood eosinophil count for eosinophilic asthma

BACKGROUND

Tests to identify reversible airflow limitation are important in asthma diagnosis, but they are time-consuming and it may be difficult for patients to cooperate. We aimed to evaluate whether the combination of fractional exhaled nitric oxide (FeNO) and blood eosinophil (B-Eos) can be used to distinguish some asthma patients who could avoid objective tests.

METHODS

We conducted a retrospective cohort study on 7463 suspected asthma cases between January 2014 and December 2019 in Chongqing, China, and identified 2349 patients with complete FeNO, B-Eos count, and spirometry data. Asthma was diagnosed by clinicians by the criteria of recurrent respiratory symptoms and a positive bronchial-provocation or bronchodilation test (BPT, BPD). We evaluated the diagnostic accuracy of FeNO or B-Eos alone or both in combination for asthma using receiver operating characteristic (ROC) curve analysis.

RESULTS

In this study, 824 patients were diagnosed with asthma. When FeNO and B-Eos counts were used in combination, the area under the ROC curve (AUC) for diagnosing asthma increased slightly (0.768 vs. 0.745 [FeNO] or 0.728 [B-Eos]; both P < 0.001). The odds ratio for having asthma increased progressively with a gradual increase in FeNO or B-Eos count (both P < 0.001; assessed using the Cochran-Armitage trend test). Further analysis of in-series combinations of different threshold values for these biomarkers indicated that moderately elevated biomarker levels (FeNO > 40 ppb and B-Eos > 300 cells/μl) support a diagnosis of asthma because diagnostic specificity was > 95% and the positive likelihood ratio (PLR) was > 10. This conclusion was verified when selecting the 2017-2019 data as the internal validation dataset.

CONCLUSION

FeNO or B-Eos count alone is insufficient to accurately diagnose asthma. Patients with moderately elevated biomarkers (FeNO > 40 ppb and B-Eos > 300 cells/μl) could be diagnosed with asthma and avoid objective tests when such tests are not feasible.

Spirometric Response to Bronchodilator and Eucapnic Voluntary Hyperpnea in Adults With Asthma

BACKGROUND

The spirometric response to fast-acting bronchodilator is used clinically to diagnose asthma and in clinical research to verify its presence. However, bronchodilator responsiveness does not correlate with airway hyper-responsiveness measured with the direct-acting stimulus of methacholine, demonstrating that bronchodilator responsiveness is a problematic method for diagnosing asthma. The relationship between bronchodilator responsiveness and airway hyper-responsiveness assessed with indirect-acting stimuli is not known.

METHODS

Retrospectively, the spirometric responses to inhaled bronchodilator and a eucapnic voluntary hyperpnea challenge (EVH) were compared in 39 non-smoking adult subjects with asthma (26 male, 13 female; mean ± SD age 26.9 ± 7.8 y; mean ± SD body mass index 26.3 ± 4.7 kg/m2). All subjects met one or both of 2 criteria: ≥ 12% and 200 mL increase in FEV1 after inhaled bronchodilator, and ≥ 10% decrease in FEV1 after an EVH challenge.

RESULTS

Overall, FEV1 increased by 9.9 ± 7.9% after bronchodilator (3.93 ± 0.97 to 4.28 ± 0.91 L, P < .001) and decreased by 23.9 ± 15.0% after the EVH challenge (3.89 ± 0.89 to 2.96 ± 0.88 L, P < .001). However, the change in FEV1 after bronchodilator did not correlate with the change after EVH challenge (r = 0.062, P = .71). Significant bronchodilator responsiveness predicted a positive response to EVH challenge in 9 of 33 subjects (sensitivity 27%). Following EVH, the change in FEV1 strongly correlated with the change in FVC (FEV1 percent change vs FVC percent change, r = 0.831, P < .001; FEV1 ΔL vs FVC ΔL, r = 0.799, P < .001).

CONCLUSIONS

These results extend previous findings that demonstrate a lack of association between bronchodilator responsiveness and methacholine responsiveness. Given the poor concordance between the spirometric response to fast-acting bronchodilator and the EVH challenge, these findings suggest that the airway response to inhaled β2-agonist must be interpreted with caution and in the context of its determinants and limitations.

A Current Perspective of Allergic Asthma: From Mechanisms to Management

Asthma is a result of heterogenous, complex gene-environment interactions with variable clinical phenotypes, inflammation, and remodeling. It affects more than 330 million of people worldwide throughout their educational and working lives, while exacerbations put a heavy cost/burden on productivity. Childhood asthma is characterized by a predominance of allergic sensitization and multimorbidity, while in adults polysensitization has been positively associated with asthma occurrence. Despite significant improvements in recent decades, asthma management remains challenging. Recently, a group of specialists suggested that the term "asthma" should be preferably used as a descriptive term for symptoms. Moreover, type 2 inflammation has emerged as a pivotal disease mechanism including overlapping endotypes of specific IgE production, while type 2-low asthma includes several disease endotypes. Optimal asthma control requires both appropriate pharmacological interventions, tailored to each patient, as well as trigger avoidance measures. Regular monitoring for maintenance of symptom control, preservation of lung function, and detection of treatment-related adverse effects are warranted. Allergen-specific immunotherapy and the advent of new targeted therapies for patients with difficult to control asthma offer diverse treatment options. The current review summarizes up-to-date knowledge on epidemiology, definitions, diagnosis, and current therapeutic strategies.

A Narrative Review of Occupational Air Pollution and Respiratory Health in Farmworkers

The agricultural crop sector in the United States depends on migrant, seasonal, and immigrant farmworkers. As an ethnic minority group in the U.S. with little access to health care and a high level of poverty, farmworkers face a combination of adverse living and workplace conditions, such as exposure to high levels of air pollution, that can place them at a higher risk for adverse health outcomes including respiratory infections. This narrative review summarizes peer-reviewed original epidemiology research articles (2000-2020) focused on respirable dust exposures in the workplace and respiratory illnesses among farmworkers. We found studies (n = 12) that assessed both air pollution and respiratory illnesses in farmworkers. Results showed that various air pollutants and respiratory illnesses have been assessed using appropriate methods (e.g., personal filter samplers and spirometry) and a consistent pattern of increased respiratory illness in relation to agricultural dust exposure. There were several gaps in the literature; most notably, no study coupled occupational air exposure and respiratory infection among migrant, seasonal and immigrant farmworkers in the United States. This review provides an important update to the literature regarding recent epidemiological findings on the links between occupational air pollution exposures and respiratory health among vulnerable farmworker populations.

Impulse oscillometry and free-running tests for diagnosing asthma and monitoring lung function in young children

BACKGROUND

Separating individuals with viral-induced wheezing from those with asthma is challenging, and there are no guidelines for children under 6 years of age. Impulse oscillometry, however, is feasible in 4-year-old children.

OBJECTIVE

To explore the use of impulse oscillometry in diagnosing and monitoring asthma in young children and evaluating treatment response to inhaled corticosteroid (ICS).

METHODS

A total of 42 children (median age 5.3 years, range 4.0-7.9 years) with physician-diagnosed asthma and lability in oscillometry were followed for 6 months after initiation of ICS treatment. All children performed the 6-minute free-running test and impulse oscillometry at 3 time points. After the baseline, they attended a second visit when they had achieved good asthma control and a third visit approximately 60 days after the second visit. A positive ICS response was defined as having greater than 19 points in asthma control test and no hyperreactivity on the third visit.

RESULTS

In total, 38 of 42 children responded to ICS treatment. Exercise-induced increases of resistance at 5 Hz decreased after ICS treatment (61% vs 18% vs 13.5%, P < .001), and running distance during the 6-minute test was lengthened (800 m vs 850 m vs 850 m, P = .001). Significant improvements in childhood asthma control scores occurred between the baseline and subsequent visits (21 vs 24 vs 24, P < .001) and acute physicians' visits for respiratory symptoms (1, (0-6) vs 0, (0-2), P = .001). Similar profiles were observed in children without aeroallergen sensitization and among those under 5 years of age.

CONCLUSION

Impulse oscillometry is a useful tool in diagnosing asthma and monitoring lung function in young children.

Asthma phenotypes and endotypes in childhood

Asthma is a very heterogeneous disease and since early childhood many classifications have been proposed according to phenotype and endotype. The phenotype includes the clinical features of asthma such as age of onset, triggers, comorbidities, response to treatment and evolution over time. The endotype is more difficult to define, includes the underlying immunopathological mechanisms of the disease and requires reliable biomarkers. A deep knowledge of phenotype and endotype of the patient may guide a tailored therapeutic approach. In this review the main phenotypes and endotypes of asthma acknowledged in children will be discussed.

The applicability of the global lung initiative equations and other regional equations on a sample of healthy Middle Eastern adolescents

BACKGROUND

The Global Lung Initiative 2012 (GLI-2012) spirometry equations are multi-ethnic equations that cover all ages between 3 and 95. However, there is a need to evaluate the suitability of these equations to a sample of Middle Eastern adolescents prior to being applied in clinical practice. The aim of this study is to evaluate the suitability of GLI-2012 equations and two regional equations to a sample of Jordanian adolescents.

METHODS

Spirometric measures were collected from 1036 healthy 14 to 17-year-old Jordanian children. z-scores, predicted values, percent predicted values, and frequency of measures below lower limit of normal (LLN) were calculated for each adolescent using the studied equations.

RESULTS

The means of z-scores produced by GLI-2012 equations for Caucasians in forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC% and mid forced expiratory flow (FEF25-75) for boys were 0.12, -0.06, 0.34 and 0.09, respectively, while for girls they were -0.09, -0.16, 0.19 and -0.05, respectively. The mean of z-scores produced by GLI-2012 Other or Mixed equations in FEV1, FVC, FEV1/FVC% and FEF25-75 for boys were 0.74, 072, 021 and 0.33, respectively, and for girls were 0.53, 0.56,0.02 and 0.2, respectively. The frequency of measures below LLN as produced by GLI 2012 for Caucasians were significantly different from the expected 5% in FEV1 and FEF25-75 in boys only, whereas Other or Mixed produced frequencies significantly different from the expected 5% in most of the parameters.

CONCLUSION

Spirometry reference equations formulated for Jordanian adolescents may improve the diagnosis and treatment of asthma in Jordan.

Assessment of airway reversibility in asthmatic children using forced oscillation technique - A single-center experience from North India

Background:

Lung function testing is recommended for the management of asthma. Due to certain limitations of conventional spirometry in vulnerable patients, forced oscillation technique (FOT) has been studied with promising results. As there is a paucity of data from developing world, we planned to conduct this study in children using FOT. To assess airway reversibility after inhaled salbutamol in asymptomatic children with suspected asthma.

Settings:

This study was conducted at pediatric asthma clinic of a tertiary care referral hospital in North India.

Design:

This was a prospective interventional study over 1-year period.

Subjects and Methods:

Asymptomatic children between 2 and 18 years of age, with history suggestive of asthma, were eligible for participation. Baseline and postbronchodilator pulmonary functions were assessed using FOT. Airway resistance and reactance were monitored at various frequencies. SPSS version 17 was used for statistical analysis.

Results:

Among the 345 enrolled children, baseline mean ± standard deviation total airway resistance (R₅), central airway resistance (R₁₉), peripheral airway resistance (R₅–R₁₉), reactance (X₅), and resonant frequency (Fres) were 6.85 ± 2.60, 5.23 ± 1.93, 1.6 ± 1.16, and − 2.54 ± 1.36 cmH₂O/L/s and 17.28 ± 3.06 Hz. The median (interquartile range) percentage change after inhaled salbutamol was 19.9 (11.40, 29.12), 22.86 (6.88, 38.76), 14.08 (3.40, 22.62), 39.20 (8.20, 62.39), and 15.79 (8.33, 27.27) in respective parameters. All changes were statistically significant. The studied respiratory variables were in maximum negative correlation with height, followed by body mass index.

Conclusions:

FOT is a simple technique for monitoring lung functions in children during asthma management.

Serum ECP as a diagnostic marker for asthma in children less than 5 years: A systematic review and meta-analysis

BACKGROUND

Currently, there are no clear-cut clinical or laboratory parameters to diagnose asthma in young children. Spirometry or the lung function tests cannot be reliably measured in children less than 5 years. The purpose of this study is to evaluate the efficacy of serum eosinophilic cationic protein (sECP) in diagnosing asthma among children less than 5 years of age.

METHODS

A systematic review was performed in PubMed, EMBASE, and Web of Science databases to identify studies investigating the role of sECP in diagnosing childhood asthma. The quality of each study was assessed using quality assessment of diagnostic accuracy studies 2 scale. A meta-analysis was conducted using the RevMan 5.3 application.

RESULTS

A total of eight studies meeting the eligibility criteria were included in the systematic review and five studies in the meta-analysis. There was a degree of clinical heterogeneity between studies primarily related to the definition of asthma and the time of assessment of sECP levels. Pooled sensitivity was 0.79 (95% confidence interval [CI]: 0.66-0.88), pooled specificity was 0.79 (95% CI: 0.54-0.92), and the pooled diagnostic odds ratio was 14.73 (95% CI: 3.58-60.58).

CONCLUSION

Overall, this review found insufficient evidence to support the role of sECP levels in diagnosing early childhood asthma.

Developments allergy in 2019 through the eyes of Clinical and Experimental Allergy, Part II clinical allergy

In the second of two linked articles, we describe the development in clinical as described by Clinical & Experimental Allergy and other journals in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered. In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered.

Assessing the nature of asthma in African epidemiological studies: a scoping review protocol

BACKGROUND

Asthma is one of the most common chronic respiratory conditions in the world and is increasing in prevalence, particularly in Africa and other low-income countries. The disproportionately high numbers of premature deaths and severe or uncontrolled cases in many African countries are indicative of their inability to cope with a costly disease like asthma. Progress has, however, been made in understanding the complex and heterogeneous nature of the disease. The objective of this study will be to summarise the epidemiological literature on the nature of asthma in African countries.

METHODS

We registered a study protocol for a scoping review. The review was designed following the Arksey and O'Malley framework. We will search PubMed/MEDLINE, African Journals Online (AJOL) and relevant grey literature (e.g. Google Scholar, EBSCOhost) from January 1990 onwards. Only primary epidemiological studies of asthma (e.g. frequency, disease mechanisms, associated risk factors and comorbidities) written in English and conducted in Africa will be included. Two reviewers will independently screen all citations, full-text articles and abstract data. Potential conflicts will be resolved through discussion. Findings will be reported using narrative synthesis and tabulation of the summaries.

DISCUSSION

This scoping review will capture the state of the current epidemiological literature on asthma in African countries. Results will be published in a peer-reviewed journal. We anticipate this review will identify gaps and make recommendations for future areas of study.

SCOPING REVIEW REGISTRATION

Open Science Framework http://osf.io/n2p87/.

Identification of continuous immunoglobulin G epitopes of Dermatophagoides farinae allergens by peptide microarray immunoassay

Dermatophagoides farinae, as a common house dust mite species, is one of the main sources of allergens in the world. At present, Dermatophagoides farinae is found to contain more than 30 groups of allergens. These allergens are used for allergen-specific immunotherapy (AIT) of allergic diseases. During the AIT process, immunoglobulin G (IgG) antibodies can block immunoglobulin E (IgE) antibody-induced allergic reactions in the human body. One of the mechanisms may be that IgG and IgE competitively bind to the same allergic protein, so it is necessary to explore the binding sites (epitopes) of IgG antibodies to allergens. In this study, peptide arrays were constructed to react with the serums from patients with allergic asthma to find the IgG epitopes of several allergens including major allergens (Der f 1, 2) and mid-tier allergens (Der f 4, 5, and 7), and then verified by enzyme-linked immunosorbent assay (ELISA) test. Relevant epitopic sequences were located on the tertiary structure of individual allergens, as reconstructed by homology modeling. One IgG epitope of Der f 1 (90-106aa, NVPSELDLRSLRTVTPI), five IgG epitopes of Der f 4 (61-77aa, ERYQPVSYDIHTRSGDE; 193-209aa, FRSDASTHQWPDDLRSI; 226-242aa, HPFIYHETIYYGGNGIN; 271-287aa, LRWLRNFGTEWGLVPSG; 352-368aa, NDWVGPPTDQHGNILSV), and one IgG epitope of Der f 5 (84-101aa, RYNVEIALKSNEILERDL) were identified. IgG epitopes of Der f 2, 7 were not found. There are overlaps between the IgG and IgE epitopes of Der f 1, 4, and 5. These findings not only reflect the practicality of peptide array and ELISA test in the allergen IgG epitope identification, but also provide more information for further understanding of the human immunological changes during AIT and the molecular mechanisms of IgG blocking IgE activity.

Maternal Gestational Diabetes and Type 2 Diabetes During Pregnancy and Risk of Childhood Asthma in Offspring

OBJECTIVE

To examine maternal preexisting type 2 diabetes (T2D) and gestational diabetes mellitus (GDM) on risk of childhood asthma.

STUDY DESIGN

This retrospective birth cohort study included 97 554 singletons born in 2007-2011 within hospitals from a single integrated healthcare system. Children were prospectively followed from age 5 until December 31, 2017, using electronic medical records. Relative risks of childhood asthma associated with maternal diabetes in utero were estimated by hazard ratios using Cox regression adjusting for potential confounders.

RESULTS

There were 3119 children (3.2%) who were exposed to preexisting T2D and 9836 (10.1%) to GDM. Among mothers with GDM, 3380 (34.4%) were dispensed antidiabetic medication during pregnancy. During a median of 7.6 years (IQR, 6.3-9.0 years) after birth, 15 125 children (15.5%) were diagnosed with asthma after age 5. Maternal diabetes interacted with maternal asthma history to affect child's asthma risk (P = .05). Among children without maternal asthma (n = 89 487), the adjusted hazard ratios for childhood asthma were 1.21 (95% CI, 1.08-1.36; P < .001) for exposure to T2D, 1.12 (95% CI, 1.01-1.25; P = .04) for GDM requiring antidiabetic medications, and 1.01 (95% CI, 0.93-1.10; P = .82) for GDM not requiring medications compared with no diabetes during pregnancy. The corresponding hazard ratios were 1.53 (95% CI, 1.19-1.96; P < .001), 1.11 (95% CI, 0.65-1.46; P = .44), and 0.84 (95% CI, 0.66-1.08; P = .17) among children without maternal asthma (n = 8067). Gestational age at GDM diagnosis was not associated with childhood asthma (P = .27).

CONCLUSIONS

The risk of childhood asthma was predominately observed for exposure to preexisting T2D, small for GDM requiring medication, and not increased for GDM not requiring medication during pregnancy, compared with no diabetes during pregnancy.