%0 Journal Article
%T The Asthma Phenotype in the Obese: Distinct or Otherwise?
%A Sherry Farzan
%J Journal of Allergy
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/602908
%X Asthma is a heterogenous disorder that can be classified into several different phenotypes. Recent cluster analyses have identified an ¡°obese-asthma¡± phenotype which is characterized by late onset, female predominance and lack of atopy. In addition, obesity among early-onset asthmatics clearly exists and heightens the clinical presentation. Observational studies have demonstrated that asthma among the obese has a clinical presentation that is more severe, harder to control, and is not as responsive to standard controller therapies. While weight loss studies have demonstrated improvement in asthma outcomes, further studies need to be performed. The current knowledge of the existence of two obesity-asthma phenotypes (early- versus late-onset asthma) should encourage investigators to study these entities separately since just as they have distinct presentations, their course, response to therapies, and weight loss strategies may be different as well. 1. Introduction Although the clinical definition of asthma, a chronic inflammatory disorder of the airways characterized by bronchial hyperresponsiveness and airway obstruction resulting in respiratory symptoms, is uniform in the over 300 million individuals affected worldwide [1], clinicians diagnosing, treating and managing asthma can unequivocally agree that it is a heterogeneous disease. The clinical spectrum of disease, inflammatory milieu, demographic characteristics, and comorbidities define the asthma phenotype. Phenotype, defined as the set of observable characteristics of an organism that are produced by the interactions of the genotype and the environment, in asthma can be defined based upon a number of factors, including age of onset, atopy, inflammatory infiltrates, severity of disease, response to standard medications as well as a number of other factors. Delving deeper into the pathophysiology of the disease and the resulting endotype of asthma may help to tailor clinician¡¯s management of these diverse presentations of a single disease. The clinician¡¯s experience of such a diversity of asthma presentations has been supported by a plethora of observational and clinical studies as well as a number of recent cluster analyses which use statistical methods to categorize asthmatics based upon clinical and demographic factors. One phenotype which has been suggested in clinical studies and consistently identified in cluster analyses is that of an ¡°asthma-obesity¡± phenotype. With the rising epidemics of both asthma and obesity in the United States, the ¡°asthma-obesity¡± phenotype is attracting more
%U http://www.hindawi.com/journals/ja/2013/602908/