Physiological Mechanisms of Airways Hyperresponsiveness in Obese Asthma.

Am J Respir Cell Mol Biol. 2016 Feb 24;

Authors: Bates JH

Abstract
Obesity affects the incidence and severity of asthma in at least two major phenotypes; an early-onset allergic (EOA) form that is complicated by obesity, and a late-onset non-allergic (LONA) form that occurs only in the setting of obesity. Both groups exhibit airways hyperresponsiveness (AHR) to methacholine challenge, but exhibit differential effects of weight loss. Measurements of lung function in LONA obese asthmatics suggest that this group of individuals may simply be those unlucky enough to have airways that are more compliant than average, and that this leads to AHR at the reduced lung volumes caused by excess adipose tissue around the chest wall. In contrast, the frequent exacerbations in EOA obese asthmatics can potentially be explained by episodic inflammatory thickening of the airway wall synergizing with obesity-induced reductions in lung volume. These testable hypotheses are based on the strong likelihood that LONA and EOS obese asthma are distinct diseases. Both, however, may benefit from targeted therapeutic that impose elevations in lung volume.

PMID: 26909510 [PubMed - as supplied by publisher]