Importance: Maternal overweight, which often results in cesarean delivery, is a strong risk factor for child overweight. Little is known about the joint contribution of birth mode and microbiota in the infant gut to the association between maternal prepregnancy overweight and child overweight.

Objective: To investigate the association of birth mode with microbiota in the infant gut, and whether this mediates the association between maternal and child overweight.

Design, Setting, and ...

BACKGROUND: Studies of the prevalence of asthma among migrating populations may help in identifying environmental risk factors.

METHODS: We analyzed data from Vancouver, Canada, and from Guangzhou, Beijing and Hong Kong, China, collected during phase 3 of the International Study of Asthma and Allergies in Childhood. We subdivided the Vancouver adolescents according to whether they were Chinese immigrants to Canada, Canadian-born Chinese or Canadian-born non-Chinese. We compared the ...

BACKGROUND: Wide variations in the prevalence of asthma, rhinitis and eczema have been reported between regions within Canada and between different countries. The International Study of Asthma and Allergies in Childhood (ISAAC) was developed to provide a standardized tool and methodology to ascertain the prevalence of asthma and allergies in different regions. Comparisons of prevalence rates across geographic regions and at different times may help to identify factors that contribute to ...

BACKGROUND: Low birth weight is associated with lower values for spirometry in adults but it is not known if birth weight influences other measures of pulmonary function. It is also unclear whether postnatal growth affects adult lung function. The associations between birth weight, postnatal growth and adult lung function were assessed in an unselected birth cohort of 1037 children.

METHODS: Birth weight, weight gain between birth and age 3 years, and lung function at age 32 years were ...

BACKGROUND: Although asthma diagnosed by a physician is known to be related to serum IgE levels, it is not known whether there is a relation between the level of IgE and airway hyperresponsiveness to a methacholine challenge. The characteristics of asymptomatic persons that predispose them to airway hyperresponsiveness are also unknown.

METHODS: We studied the relation between the serum total IgE level and airway hyperresponsiveness in the presence or absence of asthma and other atopic ...

Importance: The effect of neonatal and infant feeding practices on childhood obesity is unclear. The gut microbiome is strongly influenced by feeding practices and has been linked to obesity.

Objective: To characterize the association between breastfeeding, microbiota, and risk of overweight during infancy, accounting for the type and timing of supplementary feeding.

Design, Setting, and Participants: In this study of a subset of 1087 infants from the prospective CHILD pregnancy cohort, ...

Background/Objectives:Breastfeeding may protect against excessive weight gain during infancy. However, the breast milk components responsible for this effect are unknown. We examined the variation of three breast milk hormones (adiponectin, leptin and insulin) according to maternal characteristics and determined their association with infant body composition.Subjects/Methods:We studied a representative subset of 430 breastfed infants in the CHILD birth cohort. Breast milk was collected ...

IMPORTANCE: The consumption of artificial sweeteners has increased substantially in recent decades, including among pregnant women. Animal studies suggest that exposure to artificial sweeteners in utero may predispose offspring to develop obesity; however, to our knowledge, this has never been studied in humans.

OBJECTIVE: To determine whether maternal consumption of artificially sweetened beverages during pregnancy is associated with infant body mass index (BMI [calculated as weight in ...

Reasons for the gender differences in prevalence rates for asthma remain unclear. We have examined the relationships between allergen skin-test reactions and diagnoses of hay fever and asthma in New Zealand boys and girls examined at the age of 13 years. Information on current and past wheezing, diagnosed asthma, and hay fever was obtained for 662 subjects (341 boys) of a birth cohort followed longitudinally to the age of 13 years, using a physician-administered questionnaire. Atopic ...

BACKGROUND: Hospitalization rates for asthma vary more than threefold across regions of Ontario. It is not known whether this variation is primarily due to regional differences in the rate of emergency department (ED) visits or hospital admissions.

OBJECTIVE: To determine the variation in ED visit rates for asthma in Ontario, and the relation between ED visit rates and hospitalization rates.

DESIGN, SETTING, AND PATIENTS: We studied patients with an ED disposition diagnosis of asthma in ...

BACKGROUND: Asthma guidelines emphasize both maintaining current control and reducing future risk, but the relationship between these 2 targets is not well understood.

OBJECTIVE: This retrospective analysis of 5 budesonide/formoterol maintenance and reliever therapy (Symbicort SMART Turbuhaler(*)) studies assessed the relationship between asthma control questionnaire (ACQ-5) and Global Initiative for Asthma-defined clinical asthma control and future risk of instability and ...

Airway remodeling may lead to irreversible loss of lung function in asthma. The impact of childhood asthma, airway responsiveness, atopy, and smoking on airway remodeling was investigated in a birth cohort studied longitudinally to age 26. A low postbronchodilator ratio of forced exhaled volume in 1 second (FEV1) to vital capacity (VC) at age 18 or 26 was used as a marker of airway remodeling. "Normal" study members with no history of asthma ever, no wheezing in the last year, and no ...

BACKGROUND: The outcome of childhood asthma in adults has been described in high-risk cohorts, but few population-based studies have reported the risk factors for persistence and relapse.

METHODS: We assessed children born from April 1972 through March 1973 in Dunedin, New Zealand, repeatedly from 9 to 26 years of age with questionnaires, pulmonary-function tests, bronchial-challenge testing, and allergy testing.

RESULTS: By the age of 26 years, 51.4 percent of 613 study members with ...

BACKGROUND: Adjusting medication for uncontrolled asthma involves selecting one of several options from the same or a higher treatment step outlined in asthma guidelines. We examined the relative benefit of introducing budesonide/formoterol (BUD/FORM) maintenance and reliever therapy (Symbicort SMART® Turbuhaler®) in patients previously prescribed treatments from Global Initiative for Asthma (GINA) Steps 2, 3 or 4.

METHODS: This is a post hoc analysis of the results of five large ...

BACKGROUND: Chronic exposure to traffic-related air pollution (TRAP) may contribute to premature mortality, but few studies to date have addressed this topic.

OBJECTIVES: In this study we assessed the association between TRAP and mortality in Toronto, Ontario, Canada.

METHODS: We collected nitrogen dioxide samples over two seasons using duplicate two-sided Ogawa passive diffusion samplers at 143 locations across Toronto. We calibrated land use regressions to predict NO2 exposure on a ...