According to study results published in Journal of Asthma, there was no association between obesity and severity outcomes in children hospitalized with asthma exacerbations. While there has been speculation regarding an association between childhood asthma and obesity, previous studies have shown inconsistent results. To better understand this relationship, researchers collected data from children hospitalized with asthma exacerbations at an urban tertiary care center and evaluated severity outcome measures.
This 4-year retrospective cohort study included children (between the ages of 4 and 17) hospitalized with a diagnosis of asthma exacerbation. Data such as age, sex, family history of asthma, weight, and use of controller medications were collected. Researchers calculated the body mass index (BMI) for each patient with obesity being defined as more than the 95th percentile as per the US Centers for Disease Control definition. Outcome measures including length of stay, intensive care unit (ICU) admissions, and need for continuous albuterol or intravenous magnesium were evaluated.
A total of 995 patients were included in the study. The average age of the patients was 7.9 years and 17% were identified as obese. Between the 2 groups, there were no differences in sex, family history of asthma, or patient use of controller medication. Unadjusted outcomes demonstrated that patients with obesity were more likely to receive continuous albuterol or magnesium. No differences in length of hospital stay or pediatric ICU (PICU) admissions were found between the 2 groups.
Adjusted outcomes found that there was no difference between patients with obesity and without obesity in PICU admissions (odds ratio [OR], 0.72; 95% CI, 0.43-1.21; P =.22), administration of magnesium (OR, 1.34; 95% CI, 0.95-1.88; P =.09), or length of hospital stay (incidence rate ratio, 0.99; 0.91-1.09; P =.9). However, there was a significant association between obesity and continuous albuterol use (OR, 1.47; 1.02-2.11). Longer lengths of hospitalization were seen in older children, with use of magnesium or continuous albuterol, and in PICU admissions.
Researchers acknowledged limitations in the study, including the lack of standardized guidelines as to when continuous albuterol or magnesium were given; it was at the discretion of the clinician. Auscultation can be more difficult in obese patients because of the increased tissue mass and consequently quieter breath sounds. These patients may have been perceived as “tight” on examination, assumed to need more medical intervention and may have been started on continuous albuterol or magnesium.
Because the study was retrospective, certain confounders such as socioeconomic status were unavailable. Given the link between low economic resources and obesity, it is possible that obesity is a confounder and that socioeconomic status and asthma exacerbations are a causal link. Another limitation to the study was that baseline clinical asthma scores were unavailable to objectively measure exacerbation severity.
Additionally, although the study number was large, patients were limited to 1 institution, and the outcome measures used are possibly institution dependent.
“We find no association between pediatric obesity and many of our severity outcomes we examined including hospital length of stay, ICU admission, or magnesium administration,” the researchers wrote. “There was a positive association between obesity and use of continuous albuterol. The relationship between obesity and asthma remains unclear, and further studies are still needed to clarify this connection.”
Parlar-Chun R, Truong G, Isbell T, Delgado Y, Arca M. Association of obesity with severity outcomes in hospitalized pediatric asthma exacerbations. J Asthma. Published online September 29, 2020. doi:10.1080/02770903.2020.1827422