Nocturnal gastro-oesophageal reflux, asthma and symptoms of OSA: a longitudinal, general population study.

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field.Nocturnal gastro-oesophageal reflux (nGOR) is associated with asthma and obstructive sleep apnoea (OSA). Our aim was to investigate whether nGOR is a risk factor for onset of asthma and onset of respiratory and OSA symptoms in a prospective population-based study. We invited 2640 subjects from Iceland, Sweden and Belgium for two evaluations over a 9-year interval. They participated in structured interviews, answered questionnaires, and underwent spirometries and methacholine challenge testing. nGOR was defined by reported symptoms. Subjects with persistent nGOR (n=123) had an independent increased risk of new asthma at follow-up (OR 2.3, 95% CI 1.1-4.9). Persistent nGOR was independently related to onset of respiratory symptoms (OR 3.0, 95% CI 1.6-5.6). The risk of developing symptoms of OSA was increased in subjects with new and persistent nGOR (OR 2.2, 95% CI 1.3-1.6, and OR 2.0, 95% CI 1.0-3.7, respectively). No significant association was found between nGOR and lung function or bronchial responsiveness. Persistent symptoms of nGOR contribute to the development of asthma and respiratory symptoms. New onset of OSA symptoms is higher among subjects with symptoms of nGOR. These findings provide evidence that nGOR may play a role in the genesis of respiratory symptoms and diseases.Swedish Heart and Lung foundation Swedish Asthma and Allergy Association Vardal Foundation for Health Care Science and Allergy Research Icelandic Research Council Landspitali University Hospital Fund Research Foundation of Flanders, Belgiu

Upper Airway Mechanics

This review discusses the pathophysiological aspects of sleep-disordered breathing, with focus on upper airway mechanics in obstructive and central sleep apnoea, Cheyne-Stokes respiration and obesity hypoventilation syndrome. These disorders constitute the end points of a spectrum with distinct yet interrelated mechanisms that lead to substantial pathology, i.e. increased upper airway collapsibility, control of breathing instability, increased work of breathing, disturbed ventilatory system mechanics and neurohormonal changes. Concepts are changing. Although sleep apnoea is considered more and more to be an increased loop gain disorder, the central type of apnoea is now considered as an obstructive event, because it causes pharyngeal narrowing, associated with prolonged expiration. Although a unifying concept for the pathogenesis is lacking, it seems that these patients are in a vicious circle. Knowledge of common patterns of sleep-disordered breathing may help to identify these patients and guide therapy