Body mass index and response to emergency department treatment in adults with severe asthma exacerbations - A prospective cohort study

Background: In acute asthma (AA), overweight/obesity (body mass index [BMI] >= 25 kg/m(2)) have been related to poorer outcomes and higher risk of complications. Methods: We designed a prospective cohort study to determine if overweight/obese adults with severe episodes of AA require longer duration of emergency department (ED) treatment and have higher hospitalization rates compared with underweight/normal asthmatics (BMI < 25 kg/m(2)). All patients received inhaled albuterol (maximum 6 h). Patients were discharged or admitted according to standard accepted criteria. The weight and height of each patient were measured during the ED stay. Results: Four hundred twenty-six patients (mean, 33.4 +/- 11.5 years [+/- SD]; 63% women) with severe exacerbations (FEV1, 28.2 +/- 11.9% of predicted) were enrolled. One hundred sixty-three patients (38.3%) were classified as overweight/obese. Patients with BMI >= 25 kg/m(2) showed significant increases in length of ED stay (2.3 h vs 1.9 h, p = 0.01) and rate of hospitalization (13.7% vs 6.8%, p = 0.02), despite adjustments for other confounding variables. They also presented a higher rate of use of inhaled steroids and theophylline within the past 7 days. At the end of treatment, overweight/obese patients displayed more wheezing. Multivariate analysis demonstrated that BMI >= 25 kg/m(2) resulted unrelated to final change in peak expiratory flow from baseline. By contrast, BMI >= 25 kg/m(2) was related with duration of ED treatment (p = 0.002). Conclusions: Overweight/obese patients were admitted to the hospital more frequently than underweight/normal patients. This may reflect a difference in the perception of dyspnea, or it may reflect an underlying difference in asthma severity between the two groups.