Continuous positive airway pressure for asthma: not a big stretch?

O besity increases the risk of both asthma and obstructive sleep apnoea (OSA). By compromising upper airway anatomy, obesity contributes to compromised pharyngeal mechanics and the development of OSA. The mechanisms for how obesity contributes to the development of asthma are less well understood. The association between obesity and asthma, however, is undeniable and to date over 30 articles have shown a relationship between the two [1, 2]. Obesity has effects on both inflammation and airway mechanics, which may be important in asthma. For example, obesity has been associated with increased inflammatory cytokines and adipokines [3]. The role of leptin, a hormone that decreases appetite and increases metabolism, has been of particular interest in obesity and asthma. Obese subjects have increased levels of leptin, suggesting leptin resistance, at least at the level of hypothalamic appetite regulation. Leptin has been found to be pro-inflammatory and in animal models it may increase airway hyperresponsiveness [4, 5].