Risk Of Subsequent Asthma Research Articles

Assisted reproductive techniques and subsequent risk of asthma and allergic rhinitis in offspring: a nationwide birth cohort study in South Korea.

The relationship between assisted reproductive techniques (ART) and the risk of asthma and allergic rhinitis (AR) is controversial. Thus, we aimed to investigate the relationship between ART and the risk of asthma and AR in a nationwide, large-scale birth cohort. This study utilized the National Health Insurance Service data in South Korea to conduct a nationwide, large-scale, population-based birth cohort. We included all infants born between 2017 and 2018. AR, asthma, food allergies, and atopic dermatitis were defined using the International Classification of Diseases tenth edition codes. Asthma was classified as allergic or non-allergic based on accompanying allergic diseases (AR, food allergy, or atopic dermatitis). Using 1:10 propensity score matching, we compared infants conceived through ART with those conceived naturally (non-ART). After matching, logistic regression was used to compare the hazard ratio for asthma and AR between the two groups. We included 543,178 infants [male infants, 280,194 (51.38%)]. After matching, 8,925 and 74,229 infants were selected for the ART and non-ART groups, respectively. The ART group showed a decreased risk of asthma in the offspring [adjusted hazard ratio (aHR), 0.45; 95% confidence interval (CI), 0.41-0.48]. Similarly, for AR, being conceived by ART was associated with a decreased risk of AR (aHR, 0.25; 95% CI, 0.12-0.37). ART offspring showed a decreased risk of asthma and AR in offspring compared to that observed in non-ART offspring. Our study offers important insights for clinicians, researchers, and parents regarding the health outcomes of ART-conceived infants and enhances our understanding of ART's impact on respiratory health.

Periconceptional maternal diet quality and offspring wheeze trajectories: Japan Environment and Children's Study.

The role of prenatal diet on childhood wheezing and subsequent risk of asthma is inconclusive, which may be partly due to the heterogeneity in wheezing phenotypes. We aimed to identify wheeze trajectories in early childhood and to examine their associations with periconceptional maternal diet quality. Data from 70,530 mother-child pairs of liveborn singletons from the Japan Environment and Children's Study were analysed. Wheezing was reported by caregivers using a modified International Study of Asthma and Allergies in Childhood questionnaire yearly from 1 to 4 years of age, from which trajectories were derived using group-based trajectory modelling. Maternal diet in the year preceding the first trimester of pregnancy was assessed using a validated food frequency questionnaire; overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Bayesian inference of multinomial logistic regression models was performed to examine the association between maternal diet quality and wheeze trajectory in early childhood. We identified four wheeze trajectories: 'never/infrequent' (69.1%; reference group), 'early-childhood onset' (6.2%), 'transient early' (16.5%) and 'persistent' (8.2%). After adjustment for confounders, a higher quartile of maternal balanced diet score was associated with a lower risk of belonging to the 'transient early' and 'persistent' wheeze trajectories compared with the 'never/infrequent' wheeze trajectory by 10% of both. Maternal balanced diet score was not associated with belonging to the 'early-childhood onset' wheeze trajectory. Improving maternal diet quality prior to conception may reduce certain wheeze phenotypes in early childhood.

Proton-pump inhibitors are associated with an increased risk of asthma: A nationwide nested case-control study.

Background: Proton-pump inhibitors (PPI) are among the most widely used drugs worldwide. However, the association between PPI use and the risk of asthma remains unclear. Objective: To investigate the association between PPI use and subsequent asthma risk. Methods: We included participants from the Taiwan National Health Insurance Research Database between 1999 and 2013. Patients who used PPIs and experienced new-onset asthma (n = 20,344) were assigned to the case cohort and matched in a 1:1 ratio with controls who did not subsequently develop asthma. PPI use was defined as > 30 cumulative defined daily doses (cDDD); non-PPI use was defined as ≤ 30 cDDDs. The Charlson Comorbidity Index (CCI) score was used for clinical prognosis and comorbidity adjustment. Multivariate Cox regression models were used for the calculation of adjusted odds ratios (OR). Results: There was a significant and dose-dependent association between PPI use and the risk of developing asthma. The adjusted ORs were 1.24 (95% confidence interval [CI], 1.15-1.33), 1.39 (95% CI, 1.28-1.50), and 1.61 (95% CI, 1.43-1.81) for the male subject with 31-120 cDDDs, 120-365 cDDDs, and >365 cDDDs, respectively, compared with PPI nonusers. Men were at higher risk of developing asthma with longer PPI use compared with women. Stratified analyses based on the PPI type showed that exposure to lansoprazole, pantoprazole, omeprazole, and esomeprazole was associated with subsequent asthma risk. Conclusion: Extended use of PPIs was found to be linked to an increased risk of asthma development. This association remained consistent across different age groups, sexes, demographic factors, indications for PPI use, CCI scores, and other atopic diseases. However, further prospective studies are required to elucidate the causal mechanisms involved.

High Insulin in Early Childhood Is Associated With Subsequent Asthma Risk Independent of Body Mass Index

High Insulin in Early Childhood Is Associated With Subsequent Asthma Risk Independent of Body Mass Index

The maternal prenatal and offspring early-life gut microbiome of childhood asthma phenotypes.

The infant fecal microbiome is known to impact subsequent asthma risk, but the environmental exposures impacting this association, the role of the maternal microbiome, and how the microbiome impacts different childhood asthma phenotypes are unknown. Our objective was to identify associations between features of the prenatal and early-life fecal microbiomes and child asthma phenotypes. We analyzed fecal 16 s rRNA microbiome profiling and fecal metabolomic profiling from stool samples collected from mothers during the third trimester of pregnancy (n=120) and offspring at ages 3-6months (n=265), 1 (n=436) and 3 years (n=506) in a total of 657 mother-child pairs participating in the Vitamin D Antenatal Asthma Reduction Trial. We used clinical data from birth to age 6 years to characterize subjects with asthma as having early, transient or active asthma phenotypes. In addition to identifying specific genera that were robustly associated with asthma phenotypes in multiple covariate-adjusted models, we clustered subjects by their longitudinal microbiome composition and sought associations between fecal metabolites and relevant microbiome and clinical features. Seven maternal and two infant fecal microbial taxa were robustly associated with at least one asthma phenotype, and a longitudinal gut microenvironment profile was associated with early asthma (Fisher exact test p=.03). Though mode of delivery was not directly associated with asthma, we found substantial evidence for a pathway whereby cesarean section reduces fecal Bacteroides and microbial sphingolipids, increasing susceptibility to early asthma. Overall, our results suggest that the early-life, including prenatal, fecal microbiome modifies risk of asthma, especially asthma with onset by age 3 years.

Association between early viral lower respiratory tract infections and subsequent asthma development.

BACKGROUNDThe association between hospitalization for human respiratory syncytial virus (HRSV) bronchiolitis in early childhood and subsequent asthma is well established. The long-term prognosis for non-bronchiolitis lower respiratory tract infections (LRTI) caused by viruses different from HRSV and rhinovirus, on the other hand, has received less interest.AIMTo investigate the relationship between infant LRTI and later asthma and examine the influence of confounding factors.METHODSThe PubMed and Global Index Medicus bibliographic databases were used to search for articles published up to October 2021 for this systematic review. We included cohort studies comparing the incidence of asthma between patients with and without LRTI at ≤ 2 years regardless of the virus responsible. The meta-analysis was performed using the random effects model. Sources of heterogeneity were assessed by stratified analyses.RESULTSThis review included 15 articles (18 unique studies) that met the inclusion criteria. LRTIs at ≤ 2 years were associated with an increased risk of subsequent asthma up to 20 years [odds ratio (OR) = 5.0, 95%CI: 3.3-7.5], with doctor-diagnosed asthma (OR = 5.3, 95%CI: 3.3-8.6), current asthma (OR = 5.4, 95%CI: 2.7-10.6), and current medication for asthma (OR = 1.2, 95%CI: 0.7-3.9). Our overall estimates were not affected by publication bias (P = 0.671), but there was significant heterogeneity [I2 = 58.8% (30.6-75.5)]. Compared to studies with hospitalized controls without LRTI, those with ambulatory controls had a significantly higher strength of association between LRTIs and subsequent asthma. The strength of the association between LRTIs and later asthma varied significantly by country and age at the time of the interview. The sensitivity analyses including only studies with similar proportions of confounding factors (gender, age at LRTI development, age at interview, gestational age, birth weight, weight, height, smoking exposure, crowding, family history of atopy, and family history of asthma) between cases and controls did not alter the overall estimates.CONCLUSIONRegardless of the causative virus and confounding factors, viral LRTIs in children < 2 years are associated with an increased risk of developing a subsequent asthma. Parents and pediatricians should be informed of this risk.

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

Recent evidence suggests that parental exposures before conception can increase the risk of asthma in offspring. We investigated the association between parents' preconception body mass index (BMI) trajectories from childhood to adolescence and subsequent risk of asthma in their offspring. Using group-based trajectory modeling from the Tasmanian Longitudinal Health Study, we identified BMI trajectories for index participants (parents) when aged 4 years to 15 years. Multinomial regression models adjusted for potential confounders were utilized to estimate the association between these early-life parents' BMI trajectories and asthma phenotypes in their subsequent offspring. The main analysis included 1822 parents and 4208 offspring. Four BMI trajectories from age 4 years 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 (relative risk ratio [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. This cohort study over 6 decades of life and across 2 generations suggests that the high BMI trajectory in fathers, well before conception, increased the risk of asthma in their offspring.

High Insulin in Early Childhood Is Associated with Subsequent Asthma Risk Independent of Body Mass Index

Asthma and obesity are major, interconnected public health challenges that usually have their origins in childhood, and for which the relationship is strengthened among those with insulin resistance. To determine whether high insulin in early life confers increased longitudinal risk for asthma independent of body mass index. The study used data from the Tucson Children's Respiratory Study (TCRS) and the Avon Longitudinal Study of Parents and Children (ALSPAC). Nonfasting insulin was measured in TCRS participants at age 6 years and fasting insulin in ALSPAC participants at age 8 years. Physician-diagnosed active asthma was determined at baseline and at subsequent assessments up to age 36 years in TCRS and 17 years in ALSPAC. In TCRS, high insulin (upper quartile) at age 6 years was associated with increased odds of having active asthma from ages 8 to 36 years compared with low insulin (odds ratio,1.98; 95% CI, 1.28-3.05; P= .002). Similarly, in ALSPAC, high insulin was associated with a significantly higher risk of active asthma from ages 11 to 17 years compared with low insulin (odds ratio, 1.59; 95% CI, 1.12-2.27; P= .009). These findings were independent of baseline body mass index in both cohorts, and were not related to other demographic and asthma risk factors nor other tested markers of systemic inflammation and metabolic syndrome. In 2 separate birth cohorts, higher blood insulin level in early childhood was associated with increased risk of active asthma through adolescence and adulthood, independent of body mass index. High insulin indicates a novel mechanism for asthma development, which may be a target for intervention.

Time-Varying Association Between Severe Respiratory Syncytial Virus Infections and Subsequent Severe Asthma and Wheeze and Influences of Age at the Infection

Early-life severe respiratory syncytial virus (RSV) infection has been associated with subsequent risk of asthma and recurrent wheeze. However, changes in the association over time and the interaction effect of the age at first RSV infection are less well understood. We aimed to assess the time-varying association between RSV and subsequent asthma and wheeze admission and explore how the association was affected by the age at RSV infection. We retrospectively followed up a cohort of 23 365 children for a median of 6.9 years using Scottish health databases. Children who were born between 2001 and 2013 and had RSV-associated respiratory tract infection (RTI) admissions under 2 years were in the exposed group; those with unintentional accident admissions under 2 years comprised the control group. The Cox proportional-hazards model was used to report adjusted hazard ratios (HRs) of RSV admissions on subsequent asthma and wheeze admissions. We did subgroup analyses by follow-up years. We also explored how this association was affected by the age at first RSV admission. The association was strongest in the first 2 years of follow-up and decreased over time. The association persisted for 6 years in children whose first RSV-RTI admission occurred at 6-23 months of age, with an adjusted HR of 3.9 (95% confidence interval [CI], 3.1-4.9) for the first 2 years, 2.3 (95% CI, 1.6-3.2) for 2 to <4 years, and 1.9 (95% CI, 1.2-2.9) for 4 to <6 years of follow-up. In contrast, the association was only significant for the first 2 years after first RSV-RTI admissions occurring at 0-5 months. We found a more persistent association for subsequent asthma and wheeze in children whose first severe RSV infection occurred at 6-23 months compared to those whose first severe RSV infection occurred at 0-6 months. This provides new evidence for further assessment of the association and RSV intervention programs.

Phenotypes of atopic dermatitis and the risk for subsequent asthma: A systematic review and meta-analysis

Various atopic dermatitis (AD) phenotypes showed an enormously heterogenic risk for subsequent asthma development. We aimed to investigate the association between AD phenotypes and the risk for progression to asthma. We searched PubMed, Embase, and Web of Science databases for relevant publications. Pooled relative risks (RR) with 95% CI were calculated using the CMA-3.0 software. This study has been registered with PROSPERO (CRD42019129273). We analyzed 39 publications with 458,810 participants. The RR for asthma in AD was 2.16 (95% CI, 1.88-2.48). The risk in persistent AD (RR, 3.36; 95% CI, 2.83-3.99) was higher than in transient AD (RR, 1.52; 95% CI, 1.34-1.73), and the risk in severe AD (RR, 2.40; 95% CI, 1.96-2.94) was higher than in mild AD (RR, 1.82; 95% CI, 1.03-3.23) or moderate AD (RR, 1.51; 95% CI, 1.30-1.75). The risk for asthma in early-onset AD was slightly higher than in late-onset AD and higher in boys than in girls. The AD and asthma definitions differed across the included studies. Patients with persistent or severe AD were at a higher risk for developing asthma. These findings further elucidate the atopic march and identify target populations for asthma prevention.

Toll-interacting protein polymorphisms in viral bronchiolitis outcomes.

Toll-interacting protein is a key factor in regulating innate immunity responses via gatekeeping Toll-like receptors. Genetic variance in innate immunity has been linked with susceptibility to infections. Children with viral bronchiolitis in infancy are at increased risk of later asthma. The aim was to evaluate the role of toll-interacting protein gene point mutations in severity of bronchiolitis and subsequent risk of asthma. Infants less than 6 months old were recruited during hospitalization due to bronchiolitis. In all, 166 children were prospectively followed up to age of 1.5, 6, and 11years. Clinical data on viral etiology and severity markers, and further post-bronchiolitis asthma and lung function outcomes were compared with genetic differences in two single-nucleotide point mutations rs116938768 and rs5743854 in the toll-interacting protein gene. Toll-interacting protein rs116938768 or rs5743854 did not show significant associations with severity markers or viral etiology of bronchiolitis. Follow-up data on current asthma or lung function at 6 or 11years of age after bronchiolitis were not associated with the investigated mutations. Toll-interacting protein gene point mutations in rs116938768 or rs5743854 were not involved with the clinical course of viral bronchiolitis in early infancy, and did not predict post-bronchiolitis asthma or lung function reduction by the age of 11years.

The correlation between neonatal vitamin D levels and the risk of childhood asthma attacks.

BackgroundTo explore the correlation between neonatal vitamin D levels and the risk of asthma in children aged 3–9 years.MethodsA total of 1,534 subjects were selected, and clinical and laboratory test data of all subjects were collected at birth, including 25-hydroxyvitamin D3 [25(OH)D3] levels, gender, season of birth, birth weight; whether delivery was premature, cesarean section, or primipara; and parental details including maternal age, ethnicity, level of education, history of smoking, and history of maternal or paternal asthma. The level of 25(OH)D3 was used as a continuous variable to analyze its correlation with the risk of asthma using the Cox proportional regression model. In addition, subjects were divided into four groups according to their 25(OH)D3 quartiles, and the first quantile group was used as a reference to analyze the risk of asthma in the other groups. Further subgroup analysis was conducted according to the patients’ gender and birth season.ResultsAmong the 1,534 subjects included, there were 107 cases in the asthma-affected group and 1,427 cases in the normal control group. Compared with the control group, the level of 25(OH)D3 in the asthma group was significantly lower (P=0.03), the mother’s education level was lower (P=0.002), but the preterm birth rate, cesarean section rate, and parental asthma prevalence rate were significantly higher (all P<0.05). When the neonatal 25(OH)D3 was divided into quartiles to perform a categorical variable analysis, we found that compared with the first quantile (Q1, 0.0–25.1 mmol/L), the risk of asthma in Q4 was reduced by 50% (HR=0.50, 95% CI: 0.38-0.76). The second quantile group (Q2) and the third quantile group (Q3) showed no significant difference in the risk of disease compared with Q1 but showed a trend of decreasing risk as the quantile group increased (the trend P values were both <0.05). This correlation was still valid when a stratified analysis was made based on gender and birth season.ConclusionsThere is a significant correlation between a reduced vitamin D level in newborns and the subsequent risk of asthma in children aged 3–9 years. Moreover, the level of vitamin D is an independent risk factor for childhood asthma.

Predictive prevalence of asthma in children with allergic rhinosinusitis

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Asthma is one of the most common chronic diseases of childhood. In India - prevalence is 10% to 15% in 5-11 year old children according to the World Health Organization (WHO) statistics. Many of these children go on to develop asthma but the ability to predict school-age asthma based on early life characteristics is currently limited. Early identification of these children at risk will help in reducing respiratory complications later in life. Asthma predictive index (API) - one of the first rule-based predictive models for early identification of children at high risk of subsequent asthma was described by Castro-Rodríguez et al based on the Tucson children’s respiratory study. Objectives of the study were to predict the prevalence of subsequent development of asthma in children with allergic rhinosinusitis using modified asthma predictive index (mAPI).&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This cross-sectional observational study was done in 100 children of age ≤3 years of either gender who visited department of ENT, Saveetha Medical College. Demographic details and the mAPI questionnaire filled by the parent were obtained. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Thirteen percent of the children had positive mAPI score, of which 14% (n=8) were male and 12% (n=5) were female children. Majority of them 77% had positive major criteria and 23% of them had positive minor criteria. Our study shows that 13% of these children who were included in the study will most likely develop asthma in their childhood and adult years.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; A positive mAPI substantially increases probability of future asthma. mAPI’s high predictive ability after a positive test can have clinical value for identifying children at risk of asthma. This study may help clinicians better to identify these at-risk children.&lt;/p&gt;

Phenotypes of Atopic Dermatitis and Risk of Subsequent Asthma: A Systematic Review and Meta-Analysis

Phenotypes of Atopic Dermatitis and Risk of Subsequent Asthma: A Systematic Review and Meta-Analysis

Effect of Intrauterine Smoke Exposure on microRNA-15a Expression in Human Lung Development and Subsequent Asthma Risk.

Background: In utero smoke (IUS) exposure is associated with asthma susceptibility. Objective: We sought to test the hypothesis that changes in miRNA expression by IUS exposure during human lung development is associated with asthma susceptibility. Methods: Gene expression was profiled from 53 IUS unexposed and 51 IUS exposed human fetal lung tissues. We tested for the differential expression of miRNAs across post-conception age and by IUS using linear models with covariate adjustment. We tested the IUS-associated miRNAs for association with their gene expression targets using pair-wise inverse correlation. Using our mouse model, we investigated the persistence of the IUS-associated miRNA signature using RT-PCR from the lungs of mouse pups with and without IUS at postnatal day 14. MiRNAs were then tested for association with asthma and exacerbations using whole blood gene expression profiles from Asthma BRIDGE. Results: Five miRNAs were differentially expressed across post-conception age (adjusted p < 0.0002) including two that were differentially expressed by IUS exposure in human fetal lung (p < 0.05). MiR-15a was differentially expressed by post-conception age (p = 0.00002), IUS exposure in human fetal lung (p = 0.005), and in the post-natal mouse lung (p = 0.01). MiR-15a was also associated with the in utero expression of GSDMB (adjusted p = 0.0002), a known childhood asthma gene and with asthma exacerbations (p = 0.0009) in Asthma BRIDGE. Thus, miR-15a is expressed during human lung development, is impacted by IUS exposure, regulates the intrauterine expression of asthma genes, and is associated with asthma severity. Conclusions: These results provide evidence for the role of miR-15a in the fetal origin of asthma.

The Prevalence and Persistence of Atopic Dermatitis in Urban US Children

C McKenzie, JI Silverberg. Ann Allergy Asthma Immunol . 2019;123(2):173–178.e1 To examine the association of atopic dermatitis (AD) prevalence and persistence and the relationship between AD persistence and development of asthma. The authors analyzed data from the Fragile Families and Child Wellbeing Study, a prospective cohort study on 4898 women and their children in 20 large US cities. Baseline in person interviews were conducted at the child’s birth with follow-up telephone or household interviews at 1, 3, 5, 9 and 15 years of age. History of AD in past …

Association Between Early-Childhood Antibiotic Exposure and Subsequent Asthma in the US Medicaid Population

E Fishma, G Crawfor, A DeVries. Ann Allergy Asthma Immunol. 2019;123(2):186–192.e9 To evaluate the association between antibiotic exposure in the first 2 years of life and incidence of asthma later in childhood among children insured by Medicaid. Children with continuous medical and pharmacy coverage from birth to 2.5 years of age whose claims were linked to their mothers’ claims. Children were excluded if they had complex chronic medical conditions, a diagnosis of asthma, a diagnosis of bronchiolitis, or another respiratory condition in the first 2.5 years of life. Medical and pharmacy claims from 13 …

The Fungal Microbiome and Asthma.

Asthma is a group of inflammatory conditions that compromises the airways of a continuously increasing number of people around the globe. Its complex etiology comprises both genetic and environmental aspects, with the intestinal and lung microbiomes emerging as newly implicated factors that can drive and aggravate asthma. Longitudinal infant cohort studies combined with mechanistic studies in animal models have identified microbial signatures causally associated with subsequent asthma risk. The recent inclusion of fungi in human microbiome surveys has revealed that microbiome signatures associated with asthma risk are not limited to bacteria, and that fungi are also implicated in asthma development in susceptible individuals. In this review, we examine the unique properties of human-associated and environmental fungi, which confer them the ability to influence immune development and allergic responses. The important contribution of fungi to asthma development and exacerbations prompts for their inclusion in current and future asthma studies in humans and animal models.

Impact of Prematurity and Severe Viral Bronchiolitis on Asthma Development at 6-9 Years.

BackgroundPremature birth is associated with increased susceptibility for viral infections and chronic airway morbidity. Preterm children, even moderate and late, may be at risk for short- and long-term respiratory morbidities.ObjectiveOur main goal was to compare the burden of two conditions, severe bronchiolitis and prematurity (early and moderate-late), on asthma development at 6–9 years.Patients and MethodsA retrospective cohort of all preterm (<37weeks gestational age) and full-term children hospitalized for bronchiolitis, with current age between 6 and 9 years, was created. A second cohort was made up of preterm children, without admission for bronchiolitis, randomly chosen from the hospital premature births database. Prevalence and risk factors for asthma were analysed. Parents completed the International Study of Asthma and Allergies in Childhood (ISAAC) Questionnaire for asthma symptoms for children 6–7 years. Lung function and aeroallergen sensitization were evaluated.ResultsOf the 480 selected children, 399 could be contacted and agreed to participate: 133 preterm and 114 full-term cases with admission for bronchiolitis and 146 preterm control children without admission for bronchiolitis. The frequency of current asthma at 6–9 years was higher in preterm cases (27%) compared with full-term-cases (15%) and preterm controls (14%) (p=0.04). Among hospitalized-bronchiolitis children, prematurity (p=0.04), rhinovirus infection (p=0.03), viral coinfection (p=0.04) and paternal asthma (p=0.003) were risk factors for asthma at 6–9 years. Among premature children, with and without bronchiolitis admission, the risk factors for asthma at 6–9 years were admission for bronchiolitis (p=0.03) and aeroallergen sensitisation (p=0.01). Moderate and late preterm children without admission for bronchiolitis showed similar prevalence of current asthma than full-term ones, previously admitted for bronchiolitis.ConclusionPreterm birth is an important early life risk factor for asthma in childhood. The addition of other risk factors, such as severe bronchiolitis, especially by rhinovirus or viral coinfections, are associated with even higher risk for subsequent asthma.

Familial Coaggregation of Asthma and Type 1 Diabetes in Children

The association between atopic and autoimmune disease, particularly asthma and type 1 diabetes, has been debated. Further understanding of the underlying factors associated with the comorbidity in children is warranted. To assess the bidirectional association between asthma and type 1 diabetes and examine the possibility of a shared risk for the diseases by studying their pattern of familial coaggregation. A birth cohort study of children born from January 1, 2001, and followed up until December 31, 2015, was performed. Population data were obtained from multiple national Swedish registers. A total of 1 347 901 singleton children, live-born in Sweden between January 1, 2001, and December 31, 2013, were identified, and children with incomplete data were excluded. The remaining 1 284 748 children were linked to their biological full siblings, maternal and paternal half-siblings, cousins, and half-cousins. Data analysis was conducted from April 1, 2019, to January 17, 2020. Cases of asthma and type 1 diabetes were defined using a combination of diagnoses and medication prescriptions found in the registers. In the cohort of 1 284 748 children, 660 738 children (51.4%) were boys; 121 809 children (9.5%) had asthma, 3812 children (0.3%) had type 1 diabetes, and 494 children had both asthma and type 1 diabetes, representing 0.4% of all asthma or 13% of all type 1 diabetes. Mean (SD) age at diagnosis was 3.0 (2.8) years for children with asthma, and 5.9 (3.3) years for those with type 1 diabetes. Asthma and type 1 diabetes were associated within individuals (odds ratio, 1.15; 95% CI, 1.05-1.27). Children with asthma had an increased risk of subsequent type 1 diabetes (hazard ratio, 1.16; 95% CI, 1.06-1.27); however, subsequent asthma risk did not differ substantially among children with type 1 diabetes (hazard ratio, 0.92; 95% CI, 0.75-1.12). Siblings of individuals with asthma were at an increased risk of type 1 diabetes (odds ratio, 1.27; 95% CI, 1.13-1.42) and vice versa. The results remained positive after controlling for the direct association of one disease with the other. This study appears to provide evidence for co-occurrence, importance of sequential appearance, and coaggregation of asthma and type 1 diabetes in children and their siblings. The findings may suggest shared familial factors contributing to the associations. Knowledge of the nature of the association could be of importance in future clinical practice.