A peer-reviewed open access journal published by the National Institute of Environmental Health Sciences

To determine the relation between obesity and new-onset asthma among school-age children, the authors examined longitudinal data from 3,792 participants in the Children’s Health Study (Southern California) who were asthma-free at enrollment. New cases of physician-diagnosed asthma, height, weight, lung function, and risk factors for asthma were assessed annually at five school visits between 1993 and 1998. Incidence rates were calculated, and proportional hazards regression models were fitted to estimate the adjusted relative risks of new-onset asthma associated with percentile of body mass index (weight (kg)/height (m)²) and indicators of overweight (>85th body mass index percentile) and obesity (>95th body mass index percentile). The risk of new-onset asthma was higher among children who were overweight (relative risk (RR) = 1.52, 95% confidence interval (CI): 1.14, 2.03) or obese (RR = 1.60, 95% CI: 1.08, 2.36). Boys had an increased risk associated with being overweight (RR = 2.06, 95% 1.33, 3.18) in comparison with girls (RR = 1.25, 95% CI: 0.83, 1.88). The effect of being overweight was greater in nonallergic children (RR = 1.77, 95% CI: 1.26, 2.49) than in allergic children (RR = 1.16, 95% CI: 0.63, 2.15). The authors conclude that being overweight is associated with an increased risk of new-onset asthma in boys and in nonallergic children.

Biologically plausible mechanisms link traffic-related air pollution to metabolic disorders and potentially to obesity. Here we sought to determine whether traffic density and traffic-related air pollution were positively associated with growth in body mass index (BMI = kg/m2) in children aged 5–11 years.

Objective: To address the role of childhood sun exposure on the risk of multiple sclerosis (MS) after controlling for genetic susceptibility, we investigated the association between sun exposure and MS comparing disease-discordant monozygotic (MZ) twins.

Asthma is the most common pediatric chronic disease, estimated to have affected 14% of children globally in 2002-2003.¹ There has been much interest in the effect of outdoor air pollution on asthma risk given its ubiquity and high levels in urban areas, which, compared with rural areas, have higher rates of asthma.² Globally, outdoor air pollution has been recognized as a major public health concern and was estimated to have contributed 6.8% of the annual disability-adjusted life-years lost in 2016.³ Although ambient air pollution exposure has been causally linked to asthma exacerbations in children,⁴ evidence has been limited for a role in asthma development.^2,4 There has been support for a link with close proximity to busy roads,^4-6 but studies of regional pollutants, such as ozone, nitrogen dioxide, and particulate matter (PM), have provided less robust evidence.