Obesity and asthma disease phenotypes

Purpose of review The increasing prevalence of both asthma and obesity is associated with substantial morbidity and healthcare utilization. Herein, we review recent data suggesting that the obese asthmatic may represent a distinct clinical phenotype. Recent findings Obesity is a major risk factor for asthma, and asthma in obese patients appears to be more difficult to control, with decreased responsiveness to controller therapies posing a significant public health issue, as the prevalence of both asthma and obesity continues to rise. Epidemiologic research has defined the association between obesity and asthma, an association in part influenced by physiologic abnormalities attendant to both disorders. Healthcare utilization is also increased in obese asthmatic individuals, with reduced response to asthma controller therapies, a finding likely mediated by specific aspects of systemic and airway inflammation. We end by reviewing the role of comorbid clinical disorders in the association and by highlighting evidence that weight loss is associated with improvement in clinical and physiologic parameters of asthma. Summary Obesity has a significant impact on asthma risk, severity and control. Additional studies are needed to define mechanisms by which airway physiologic and inflammatory phenotypes in asthma are modified by obesity.