Validity of asthma diagnoses and patterns of anti-asthmatic drug use in a cohort of 2053 Danish children

Does having siblings really protect against childhood atopic diseases? A total population and within-family analysis

The association between having older siblings and decreased risk for atopic symptoms is well-established. This has been interpreted as evidence for the microbiota hypothesis, i.e. that increased early-childhood microbial exposure caused by siblings protects from immune hypersensitivities. However, possible confounders of the association have received little attention. We used register data on Finnish cohorts born in 1995-2004 (N = 559,077) to assess medication purchases for atopic diseases: antihistamines, eczema medication, asthma medication and Epinephrine. We modelled the probability of atopic medication purchases at ages 0-15 by birth order controlling for important observed confounders and all unobserved genetic and environmental characteristics shared by siblings in a within-family fixed effects model. We further studied medication purchases among first-borns according to the age difference with younger siblings to assess whether having younger siblings in early childhood is beneficial. Having older siblings was associated with a lower probability of atopic medication purchases. Compared to first-borns, the probability was 10-20% lower among second-borns, 20-40% lower among third-borns, and 30-70% lower among subsequent children, depending on medication type. Confounding accounted for up to 75% of these differences, particularly for asthma and eczema medication, but significant differences by birth order remained across all medication types. Among first-borns, a smaller age difference with younger siblings was related to a lower likelihood of atopic medication use. Our results, based on designs that account for unobserved confounding, show that exposure to siblings in early childhood, protects from atopic diseases, and thus strongly support the microbiota hypothesis.

Increased risk of osteoarthritis in patients with atopic disease

OBJECTIVES

To determine the incidence of osteoarthrits (OA) in patients with atopic disease compared with matched non-exposed patients.

METHODS

We conducted a retrospective cohort study with propensity score matching using claims data from Optum's de-identified Clinformatics Data Mart (CDM) (January 2003 to June 2019) and electronic health record data from the Stanford Research Repository (STARR) (January 2010 to December 2020). We included adult patients without pre-existing OA or inflammatory arthritis who were exposed to atopic disease or who were non-exposed. The primary outcome was the development of incident OA.

RESULTS

In Optum CDM, we identified 117 346 exposed patients with asthma or atopic dermatitis (mean age 52 years; 60% female) and 1 247 196 non-exposed patients (mean age 50 years; 48% female). After propensity score matching (n=1 09 899 per group), OA incidence was higher in patients with asthma or atopic dermatitis (26.9 per 1000 person-years) compared with non-exposed patients (19.1 per 1000 person-years), with an adjusted odds ratio (aOR) of 1.58 (95% CI 1.55 to 1.62) for developing OA. This effect was even more pronounced in patients with both asthma and atopic dermatitis compared with non-exposed patients (aOR=2.15; 95% CI 1.93 to 2.39) and in patients with asthma compared with patients with chronic obstructive pulmonary disease (aOR=1.83; 95% CI 1.73 to 1.95). We replicated our results in an independent dataset (STARR), which provided the added richness of body mass index data. The aOR of developing OA in patients with asthma or atopic dermatitis versus non-exposed patients in STARR was 1.42 (95% CI 1.36 to 1.48).

CONCLUSIONS

This study demonstrates an increased incidence of OA in patients with atopic disease. Future interventional studies may consider targeting allergic pathways for the prevention or treatment of OA.

Asthma Is Associated With Pregnancy Loss and Recurrent Pregnancy Loss: A Nationwide Cohort Study

BACKGROUND

Women with asthma appear to have an increased risk of pregnancy loss (PL). The impact of asthma on recurrent pregnancy loss (RPL), defined as 3 consecutive losses, is, however, unknown.

OBJECTIVE

The aim of this study was to investigate whether having asthma before or during the fertile age is associated with PL and RPL.

METHODS

Based on Danish national health registers, we identified all women aged 6 to 45 years with at least 2 filled prescriptions of an antiasthma drug during the period 1977 to 2019. Women with asthma were compared with women without asthma. Pregnancy outcomes were retrieved for both groups from national health registers. Logistic regression with adjustment for the year of birth and educational level provided odds ratios (ORs) for the number of PLs. Subgroup analyses were conducted for early-onset (age 6-15 years), adult-onset (age 16-39 years), and late-onset (age 40-45 years) asthma. Lastly, we compared uncontrolled asthma (defined as ≥ 400 doses of a short-acting beta-2 agonist in a year) to controlled asthma (defined as < 400 doses of a short-acting beta-2 agonist in a year).

RESULTS

In a population of 1,309,786 women, we identified 128,553 women with asthma and 1,297,233 women without asthma. Compared with nonasthmatic women, women with asthma had ORs for 1, 2, and 3 or more PLs of 1.05 (95% CI 1.03-1.07), 1.09 (95% CI 1.05-1.13), and 1.18 (95% CI1.11-1.24), respectively, and for RPL of 1.19 (95% CI 1.12-1.27). In women with early-onset asthma, the OR of 3 or more PLs was 1.47 (95% CI 1.24-1.72). For women classified as having uncontrolled asthma compared with controlled asthma, we found a significant OR of 1.60 (95% CI 1.16-2.16) for 3 or more PLs.

CONCLUSIONS

We found a significant positive association between asthma and number of PLs and RPLs. Early-onset asthma and uncontrolled asthma were more strongly associated with PL than adult-onset and late-onset asthma and controlled asthma.

Postoperative epilepsy and survival in glioma patients: a nationwide population-based cohort study from 2009 to 2018

PURPOSE

Postoperative epilepsy is common in glioma patients and has been suggested to indicate disease progression, yet knowledge of its role as a prognostic factor is limited. This study investigates the association between postoperative epilepsy and survival amongst patients with gliomas.

METHODS

We included 3763 patients with histopathologically diagnosed grade II, III, and IV gliomas from 2009 to 2018 according to the Danish Neuro-Oncology Registry. Information on epilepsy diagnosis was redeemed from the Danish National Patient Registry, the National Prescription Registry and the Danish Neuro-Oncology Registry. We used Cox proportional hazards models with 95% confidence intervals (CIs) to examine hazard ratios (HRs) for the association between postoperative epilepsy and risk of death. We examined the role of the timing of epilepsy in three different samples: Firstly, in all glioma patients with postoperative epilepsy; secondly, in patients with postoperative de novo epilepsy; thirdly, exclusively in a homogeneous sub-group of grade IV patients with postoperative de novo epilepsy.

RESULTS

Glioma patients with postoperative epilepsy had an increased risk of death, regardless of prior epilepsy status (HR = 4.03; CI 2.69-6.03). A similar increase in the risk of death was also seen in patients with postoperative de novo epilepsy (HR = 2.08; CI 1.26-3.44) and in the sub-group of grade IV patients with postoperative de novo epilepsy (HR = 1.83; CI 1.05-3.21).

CONCLUSIONS

Postoperative epilepsy may negatively impact survival after glioma diagnosis, regardless of preoperative epilepsy status. Postoperative epilepsy may be an expression of a more invasive growth pattern of the gliomas following primary tumor treatment.

Association of Treated and Untreated Gastroesophageal Reflux Disease in the First Year of Life with the Subsequent Development of Asthma

Introduction: Gastroesophageal reflux disease (GERD) as well as its treatment with acid-suppressive medications have been considered possible risk factors for the development of asthma, but few studies have disentangled the role of GERD with that of its treatment. The present study aimed at estimating the association of treated and untreated GERD in the first year of life with the risk of asthma. Methods: Retrospective cohort study including all children born between 2004 and 2015 registered in Pedianet, an Italian primary care database. We analyzed the association of children exposed to GERD (both treated and untreated) in the first year of life with the risk of developing clinically assessed asthma (clinical asthma) after 3 years. Secondary outcomes included asthma identified by anti-asthmatic medications (treated asthma) and wheezing after 3 years. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated comparing children with and without GERD, stratifying by treatment with acid-suppressive medications. Results: Out of 86,381 children, 1652 (1.9%) were affected by GERD in the first year of life, of which 871 (53%) were treated with acid-suppressive medications. Compared with controls, children with GERD were at increased risk of clinical asthma (HR: 1.40, 95% CI 1.15–1.70). Risks were similar between treated and untreated GERD (p = 0.41). Comparable results were found for treated asthma, but no risk increase was seen for wheezing. Discussion: Early-life GERD was associated with subsequent childhood asthma. Similar risks among children with treated and untreated GERD suggest that acid-suppressive medications are unlikely to play a major role in the development asthma.

Air pollution and family related determinants of asthma onset and persistent wheezing in children: nationwide case-control study

OBJECTIVE

To identify risk factors (air pollution and family related) for the onset of asthma and persistent wheezing in children.

DESIGN

Nationwide case-control study.

SETTING

Denmark.

PARTICIPANTS

All Danish children born from 1997 to 2014 and followed for asthma onset and persistent wheezing from age 1 year to 15 years.

MAIN OUTCOME MEASURE

Onset of asthma and persistent wheezing.

RESULTS

A higher incidence of asthma was found in children of parents with asthma (adjusted hazard ratio 2.29 (95% confidence interval 2.22 to 2.35) and mothers who smoked during pregnancy (1.20, 1.18 to 1.22), whereas a lower incidence was found in children of parents with high educational attainment (0.72, 0.69 to 0.75) and high incomes (0.85, 0.81 to 0.89). Exposure to particulate matter ≤2.5 µm (PM_2.5) and ≤10 µm (PM₁₀) and nitrate was associated with an increased risk of asthma and persistent wheezing, with hazard ratios per 5 µg/m³ increase in pollutant concentrations 1.05 (1.03 to 1.07) for PM_2.5, 1.04 (1.02 to 1.06) for PM₁₀, and 1.04 (1.03 to 1.04) for nitrogen dioxide. Only the positive association of PM_2.5 with asthma and persistent wheezing remained robust across the different models and in sensitivity analyses.

CONCLUSIONS

The findings of this study suggest that children exposed to higher levels of PM_2.5 are more likely to develop asthma and persistent wheezing than children who are not exposed. Other risk factors associated with these outcomes were parental asthma, parental education, and maternal smoking during pregnancy.

Risk of Prevalent Asthma among Children Affected by Inflammatory Bowel Disease: A Population-Based Birth Cohort Study

Literature on the risk of asthma among children with inflammatory bowel disease (IBD) is limited and has reported discording results. To the best of our knowledge, no previous study has evaluated the association between asthma and childhood onset IBD, focusing on pediatric IBD with onset between 10 and 17 years, early-onset IBD (EO-IBD) between 0 and 9 years, and very early-onset IBD (VEO-IBD) between 0 and 5 years, all conditions characterized by different clinical progressions. A nested matched case-control design on a longitudinal cohort of 213,515 newborns was adopted. Conditional binomial regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) of asthma among children with IBD compared with controls. We found 162 children with IBD and 1620 controls. Overall, childhood onset IBD was associated with increased risks of being affected by asthma (OR: 1.49 95% CI 1.05–2.12), although a significant risk was only present among males (OR: 1.60 95% CI 1.02–2.51). Children with Crohn’s disease and ulcerative colitis had similarly increased risks, although they failed to attain statistical significance. Risks of asthma based on age at IBD onset were inversely related to age, with the lowest non-significant risks for pediatric IBD and EO-IBD, while children affected by VEO-IBD had the highest risk of asthma (OR: 2.75 95% CI 1.26–6.02). Our study suggests the presence of a higher prevalence of asthma among both male children with IBD and children with VEO-IBD. It could be advisable to pay greater attention to possible respiratory symptoms among these categories at higher risk.