A new, large cohort study has confirmed the link between conditions, which was only previously confirmed in adult patients.
Jason E. Lang, MD, MPH
The study, led by Jason E. Lang, MD, MPH, associate professor of pediatrics at Duke University School of Medicine, used data from PEDSnet, a clinical data research network that pools and standardizes electronic health records. The network houses data from 8 large pediatric hospitals and healthcare organizations across the US.
According to the Centers for Disease Control and Prevention (CDC), 18% of children in the US suffer from obesity which, like asthma, disproportionately affects children from low-income families. Heart disease, high blood pressure, and type 2 diabetes are among the health risks associated with obesity.
Lang and his team said that the link between new pediatric asthma cases and obesity has been difficult to define. Some studies report that obesity increases asthma in a subset of patients, while others reported no impact. Of the studies that found positive correlations, the effects of race, sex, atopic status, and timing of obesity was inconsistent.
For this study, researchers included PEDSnet data from January 2009 to December 2015, from 6 institutions: Nemours Children’s Health System, Children’s Hospital of Philadelphia, Seattle Children’s Hospital, Children’s Hospital Colorado, St. Louis Children’s Hospital, and Nationwide Children’s Hospital.
Subjects were aged 2-17 years and were eligible for inclusion if their Body Mass Index (BMI) was at or above the 85th percentile, and no record of asthma diagnosis or wheezing at or before initial visit for study. For each patient that fit the criteria for the obesity risk group, one control subject was randomly selected who was normal weight and identically matched for age at initial visit, sex, race, ethnicity, insurance status, and PEDSnet site.
Asthma incidence was defined at 2 or more asthma diagnoses and 1 or more asthma controller prescriptions. In addition, spirometry was used for more precise confirmation.
Asthma risk was increased among children who were overweight (RR: 1.17; 95% CI: 1.10 - 1.25) and obese (RR: 1.26; 95% CI: 1.18 - 1.34). Children with obesity were also at higher risk for spirometry-confirmed asthma (RR: 1.29; 95% CI: 1.16 - 1.42).
Among the obese children who developed asthma in the study, Lang says he and his colleagues estimated that roughly 25% of these cases are attributable to obesity. Of all the children that developed asthma, obesity was linked to 10% of these cases.
“Our findings would suggest that without obesity in the pediatric US population, of the 6-8 million children that have asthma, between 600,000 and 800,000 of asthma cases would be prevented,” said Lang. “The implications for public health are enormous.”
The risk for obesity-related asthma is expected to be influenced by other factors, such as race/ethnicity, age, sex and co-morbid conditions like atopy.
“We also need to delve into what the causal mechanism or mechanisms are that lead from obesity to asthma,” added Lang.
The study, “Being Overweight or Obese and the Development of Asthma,” was published online in Pediatrics.