ABSTRACT
E. RAND SUTHERLAND, ELENA GOLEVA, TONYA S. KING, ERIK LEHMAN, ALLEN D. STEVENS, LEISA P. JACKSON, AMANDA R. STREAM, JOHN V. FAHY, and DONALD Y. M. LEUNG FOR THE ASTHMA CLINICAL RESEARCH NETWORK
11.1 INTRODUCTION
Cluster analyses of cross-sectional data from clinical populations have identified phenotypic subsets of patients with asthma, and the assessment of BMI in recent asthma cluster analyses has allowed assessment of the relationship of BMI to clinical features of asthma. Haldar and colleagues reported that obesity was associated with increased symptom expression, reduced eosinophilic airway inflammation, adult age of onset, and female sex, while also being associated with reduced clinical responsiveness to inhaled corticosteroids (ICS) [1]. A separate cluster analysis of patients participating in the NIH Severe Asthma Research Program indicated that elevated body mass index (BMI) was associated with specific clinical features in severe asthma, with the identification of a cluster of patients in
whom elevated BMI was associated with female sex, adult onset asthma, a greater likelihood of complicated asthma treatment regimens, and more frequent health care utilization and need for systemic glucocorticoids (GC) [2]. These two studies have supported the conclusion that asthma phenotype is relatively homogenous in obese patients, with high symptom expression, low atopy and airway eosinophilia, and relative insensitivity to GC, a phenomenon that has been reported by others in both clinical [3]–[5] and in vitro [6] settings.
