Early preschool wheeze trajectories are predominantly non-allergic with distinct biologic and microbiome traits.

Background: Disentangling preschool wheezing heterogeneity in terms of clinical traits, temporal patterns, and collective healthcare burden is critical for precise and effective interventions.

Objective: We aimed to collectively define contributions and distinct characteristics of respiratory phenotypes based on longitudinal wheeze and atopic sensitization patterns in the first 5 years of life.

Methods: Group-based trajectory analysis was performed in the CHILD Cohort study to identify distinct wheeze and allergic sensitization trajectories.

Associations of dietary patterns and obesity development in school-aged children: results from the CHILD Cohort Study.

Objective: We aimed to understand data-driven dietary patterns in Canadian preschoolers and their impact on obesity development among male and female individuals.

Methods: In the prospective, population-based Canadian pregnancy cohort, the CHILD Cohort Study (N = 2219), dietary intake was assessed at age 3 years using a previously developed 112-item food frequency questionnaire. At age 5 years, we measured height, weight, and waist circumference and calculated BMI and waist circumference z scores.

Determining the interplay of prenatal parental BMI in shaping child BMI trajectories: the CHILD Cohort Study.

Background: Obesity is a major public health concern affecting millions of people globally. Early identification of individuals susceptible to obesity is crucial for reducing the burden of obesity. Obesity is often defined based on body-mass-index (BMI), and tracking BMI trajectories from early childhood offers a valuable tool for risk stratification.

Positional therapy for the treatment of positional obstructive sleep apnea in children: A randomized controlled crossover trial.

Background: Obstructive sleep apnea (OSA) is prevalent in children, but many children remain untreated. Up to one half of children with OSA have positional OSA, a phenotype characterized by the predominance of airway obstruction while supine. Positional devices that prevent sleeping supine may be beneficial for positional OSA.

Exploring the potential mediating role of systemic antibiotics in the association between early-life lower respiratory tract infections and asthma at age 5 in the CHILD study.

Objective: Lower respiratory tract infections (LRTIs) in early life are one of the strongest risk factors for childhood asthma and are often treated with systemic antibiotics (IV or oral). We aimed to explore the association between early-life LRTIs and systemic antibiotics on asthma development and the potential mediating role of antibiotics in this relationship.

Methods: Data were collected as part of the longitudinal, general Canadian population CHILD Study.

The impact of sleep restriction on cerebrovascular reactivity and cognitive outcomes in healthy adolescents: A pilot crossover trial.

Background: The underlying mechanism for the association between sleep restriction (SR) and unfavorable cognitive outcomes in children and adolescents remains unclear. This study aimed to understand the effect of 5-night experimental SR on magnetic resonance imaging (MRI) measurements of cerebrovascular reactivity (CVR) and cognitive function in adolescents.

Methods: This randomized crossover study compared two sleep conditions, SR and Control Sleep (CS) in a home setting.

Are the Reference Values for the Provocative Concentration of Methacholine Appropriate for Children?

Preliminary data in a randomly selected pediatric cohort study in 8-year-olds suggested a rate of positivity to a methacholine challenge test that was unexpectedly high, roughly 30%. The current recommendation for a negative methacholine test is a 20% decrease in the forced expiratory volume in one second at a dose greater than 400 μg. This was derived from studies in adults using the obsolete English Wright nebulizer.

Antibiotics taken within the first year of life are linked to infant gut microbiome disruption and elevated atopic dermatitis risk.

Background: Atopic dermatitis (AD) is the most common chronic inflammatory skin disease in both pediatric and adult populations. The development of AD has been linked to antibiotic usage, which causes perturbation of the microbiome and has been associated with abnormal immune system function. However, imbalances in the gut microbiome itself associated with antibiotic usage have been inconsistently linked to AD.

Divergent maturational patterns of the infant bacterial and fungal gut microbiome in the first year of life are associated with inter-kingdom community dynamics and infant nutrition.

Background: The gut microbiome undergoes primary ecological succession over the course of early life before achieving ecosystem stability around 3 years of age. These maturational patterns have been well-characterized for bacteria, but limited descriptions exist for other microbiota members, such as fungi. Further, our current understanding of the prevalence of different patterns of bacterial and fungal microbiome maturation and how inter-kingdom dynamics influence early-life microbiome establishment is limited.

Cohort profile: investigating SARS-CoV-2 infection and the health and psychosocial impact of the COVID-19 pandemic in the Canadian CHILD Cohort.

The coronavirus disease 2019 (COVID-19) pandemic has affected all Canadian families, with some impacted differently than others. Our study aims to: (1) determine the prevalence and transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among Canadian families, (2) identify predictors of infection susceptibility and severity of SARS-CoV-2, and (3) identify health and psychosocial impacts of the COVID-19 pandemic. This study builds upon the CHILD Cohort Study, an ongoing multi-ethnic general population prospective cohort consisting of 3,454 Canadian families with children born in Vancouver, Edmonton, Manitoba, and Toronto between 2009 and 2012.

Maturational patterns of the infant gut mycobiome are associated with early-life body mass index.

Unlike the bacterial microbiome, the role of early-life gut fungi in host metabolism and childhood obesity development remains poorly characterized. To address this, we investigate the relationship between the gut mycobiome of 100 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study and body mass index Z scores (BMIz) in the first 5 years of life. An increase in fungal richness during the first year of life is linked to parental and infant BMI.

Development of a Symptom-Based Tool for Screening of Children at High Risk of Preschool Asthma.

Importance: Despite advances in asthma therapeutics, the burden remains highest in preschool children; therefore, it is critical to identify primary care tools that distinguish preschool children at high risk for burdensome disease for further evaluation. Current asthma prediction tools, such as the modified Asthma Predictive Index (mAPI), require invasive tests, limiting their applicability in primary care and low-resource settings.

Objective: To develop and evaluate the use of a symptom-based screening tool to detect children at high risk of asthma, persistent wheeze symptoms, and health care burden.

Longitudinal body mass index trajectories at preschool age: children with rapid growth have differential composition of the gut microbiota in the first year of life.

Background/objective: The steep rise in childhood obesity has emerged as a worldwide public health problem. The first 4 years of life are a critical window where long-term developmental patterns of body mass index (BMI) are established and a critical period for microbiota maturation. Understanding how the early-life microbiota relate to preschool growth may be useful for identifying preventive interventions for childhood obesity.

Factors Affecting Cuff Extrusion of Tunneled Hemodialysis Catheters.

Purpose: To identify patient and procedural factors associated with extrusion of the Dacron cuff from the subcutaneous tunnel of tunneled hemodialysis catheters (THDCs).

Materials And Methods: Single center 5-year retrospective analysis of 625 catheters in 293 adult patients. Patient data included age, gender, body mass index (BMI), and common comorbidities.

Adenotonsillectomy, bronchoscopy and bronchoalveolar lavage in the management of preschool children with severe asthma: pilot study.

Purpose: This is a pilot study that describes the feasibility and clinical course of a cohort of preschool children with severe asthma undergoing a combined adenotonillectomy (TA), bronchoscopy (B), and bronchoalveolar lavage (BAL) procedure.

Methods: A retrospective cohort study of preschool patients with severe asthma who underwent a combined TA-B-BAL procedure between 2012 and 2019. Subjects were treated at a tertiary care asthma clinic and had a diagnosis of preschool asthma according to the Canadian Thoracic Society Guidelines.

Reduced peanut sensitization with maternal peanut consumption and early peanut introduction while breastfeeding.

New guidelines for peanut allergy prevention in high-risk infants recommend introducing peanut during infancy but do not address breastfeeding or maternal peanut consumption. We assessed the independent and combined association of these factors with peanut sensitization in the general population CHILD birth cohort (N = 2759 mother-child dyads). Mothers reported peanut consumption during pregnancy, timing of first infant peanut consumption, and length of breastfeeding duration.

Persistent ventilation inhomogeneity after an acute exacerbation in preschool children with recurrent wheezing.

Background: Preschool children with recurrent wheezing suffer high morbidity. It is unclear whether objective measures of asthma control, such as pulmonary function tests (PFTs), provide additional information to the clinical assessment.

Methods: We recruited children between 3 and 6 years old, with a history of recurrent wheezing in the preceding year and treated for acute wheezing exacerbation in the emergency department (ED) into an observational cohort study.